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In the present study, a total of 120 milk samples (50 clinical and 70 subclinical mastitis cases) collected from buffaloes located at different localities at El-Behera Governorate, Egypt were examined phenotypically and genotypically for the presence of S. aureus and coagulase-negative staphylococci. Results showed that 42 S. aureus and 20 coagulase-negative Staphylococcus species isolates were recovered from the examined 120 milk samples. A total of 40 S. aureus and coagulase-negative staphylococci were further identified based on the amplification of 16S rRNA, coa, clfA, and nuc encoding genes. Results revealed that all S. aureus isolated from clinical and subclinical cases were found to harbor 16S rRNA, coa, clfA, and nuc encoding genes. Resistance against 12 antibiotics was determined using disc diffusion methods. All the tested S. aureus and coagulase-negative staphylococcal isolates exhibited resistance to amoxicillin, ampicillin, cefotaxime, ciprofloxacin, cloxacillin, oxacillin, lincomycin, penicillin, and trimethoprim/sulphamethoxazole. Constitutive production of mecA and blaZ encoding resistance against penicillin and cloxacillin was reported in 70% and 20% of S. aureus and 80 % and 30% of the coagulase-negative staphylococcal isolated from clinical and subclinical mastitis, respectively. In contrast, all isolates found to harbor the specific amplicon of the sul1 gene. The amplicon of aac(6”)-aph(2”) encoding resistance gene was observed in only 6 S. aureus isolates. The specific amplicon of norA gene was detected in 4 S. aureus and 2 coagulase-negative staphylococcal isolates recovered from clinical mastitis. To conclude, the emergence of multi-drug resistant S. aureus and coagulase-negative staphylococci as a cause of mastitisin dairy farms is of public health concern requires further investigations. [ABSTRACT FROM AUTHOR]

A grand total of 75 random samples of meat products were collected from different local supermarkets classified into 25 samples each of minced meat, beef burger and luncheon, these products were subjected to organoleptic evaluation, determination of APC, Enterobacteriaceae, Staphylococcus aureus counts and incidence and serologically identification of E.coli count as well as isolation of salmonellae isolates. as well as isolation of salmonellae. Results revealed that minced meat contained the higher mean values of APC (CFU g) (3.3× 105±1.6× 105 ), The obtained results revealed that minced meat contained the higher, while the lower one was reported in Luncheon (2.3× 10³±8.6 × 10² ), E.coli count in beef burger products revered higher incidence (20%). While the lower incidence (12%) was in minced meat. in addition, the incidence of isolated E.coli serotypes from minced meat was ( 16% ), while the incidence of beef burger and luncheon were (12%) of each. Furthermore total staphylococcus count was higher in minced meat (0. 2x10²± 0. 13x10² ) and lower in luncheon (<10² ), beef burger had higher values of Enterobacteriaceae count (7.12x10²±2.5x10² ), while lower value in minced meat (4.27x10³± 1.2x10³ ). Higher incidence of Salmonellae in the examined meat product samples have been showed in minced meat (24%). While lower incidence (12%) was in luncheon and beef burger . Regarding Salmonellae Haifa not recorded in minced meat but was isolated from beef burger and luncheon (4%) of each. Higher appearance of salmonellae Enteritidis in minced meat (8%) and not isolated from luncheon, while of salmonella Ttyphimurium was 16% in minced meat, 4% in beef burger and 8% in luncheon . Higher pH value (5.9±0.086) was reported in luncheon, while Higher TVN and TBA value were 24.69±2.045 and 0.70±0.070 in luncheon and minced meat, respectively. The public health importance of isolated strain were discussed. [ABSTRACT FROM AUTHOR]

Coagulase-negative staphylococci (CoNS) have been recovered from different ecological niches, however, little is known about the genetic relatedness of these isolates. In this study, we used whole genome sequencing to compare mecA positive (mecA+) Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus hominis isolates recovered from hand-touched surfaces from general public settings in East and West London with data of isolates deposited to European Nucleotide Archive (ENA) by other research groups. These included isolates associated with hospital settings (including those recovered from patients), healthy humans, livestock, pets, plants and natural, and other public environments. Using core and accessory phylogenetic analyses we were able to identify that the mecA+ S. epidermidis and S. haemolyticus isolates recovered from general public settings were genetically related to isolates recovered from the bloodstream, urinary tract and eye infections. S. epidermidis isolates recovered in our study were also shown to be genetically related to isolates previously recovered from livestock/livestock housing, whereas S. haemolyticus isolates were genetically related to isolates recovered from a dog and kefir (fermented cow milk drink). MecA+S. hominis isolates were not genetically related to any isolates recovered from clinical samples but were genetically related to isolates recovered from mosquitoes, air samples (residential areas) and kefir. All three species showed to have genetic relatedness to isolates recovered from healthy humans. These results show that CoNS isolates in this study share genetic similarities with those of different lineages and that mecA+ S. epidermidis and S. haemolyticus isolates found in general public settings in this study may pose a risk to public health.

Background: Coagulase-negative staphylococci (CoNS) are part of the normal skin flora. Although CoNS are generally considered as low pathogenic microorganisms, they can cause serious infections, particularly in the context of foreign body material. Case report: Here we present two cases of concomitant infectious endocarditis and spondylodiscitis; one caused by S. epidermidis, the other by S. haemolyticus. Additionally, we reviewed the literature for previously reported cases of concomitant endocarditis and spondylodiscitis due to CoNS. Conclusion: In patients with back pain and a cardiac device in situ, CoNS should be considered as causative pathogens for possible endocarditis and/or spondylodiscitis, and should not be regarded as contamination.

Background: The use of antibiotics in dentistry is associated with the emergence and spread of antibiotic-resistant microorganisms, including commensal staphylococci. Methods: A total of 367 oral samples were collected, from which staphylococci were isolated and identified by using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). The antibiotic susceptibility of the isolates was determined and molecular characteristics for methicillin-resistant staphylococci was performed. Results: A total of 103 coagulase-negative staphylococci (CoNS), among them S. warneri, S. haemolyticus, S. saprophyticus, S. pasteuri, S. epidermidis, S. hominis, S. xylosus, S. equorum, S. kloosii, S. succinus, S. cohnii, and S. simulans, were confirmed by MALDI-TOF. Resistance to most tested antibiotics was statistically higher in CoNS than in S. aureus isolates (P-value < 0.05). CoNS isolates showed high resistance to penicillin (S. saprophyticus 88.9%), erythromycin (S. haemolyticus 84.6%), fusidic acid (S. saprophyticus 77.8%), co-trimoxazole (S. epidermidis 71.4%), gentamicin (S. warneri 63.8%), and tetracycline (S. saprophyticus 55.6%). Multidrug resistance was largely observed, especially among S. haemolyticus and S. saprophyticus species. Methicillin-resistance in S. haemolyticus (38.5%), S. saprophyticus (22.2%) and S. aureus (13.5%) was associated with the presence of the mecA gene and SCCmec type IV or V. Conclusion: Coagulase-negative staphylococci, especially S. haemolyticus and S. saprophyticus, seem to be a reservoir of methicillin resistance and multidrug resistance in the oral cavity.

Staphylococcus spp. remain the leading biofilm-forming agents causing orthopedic implant-associated infections (OIAI). This is a descriptive study of phenotypic and genomic features identified in clinical isolates of S. aureus and coagulase-negative Staphylococcus (CoNS) recovered from OIAIs patients that progressed to treatment failure. Ten isolates were identified by matrix-time-of-flight laser-assisted desorption mass spectrometry (MALDI-TOF-MS) and tested for antibiotic susceptibility and biofilm formation. Genotypic characteristics, including, MLST (Multi Locus Sequence Typing), SCCmec typing, virulence and resistance genes were assessed by whole-genome sequencing (WGS). All S. aureus harbored mecA, blaZ, and multiple resistance genes for aminoglycosides and quinolones. All MRSA were strong biofilm producers harboring the complete icaADBC and icaR operon. Seven CoNS isolates comprising five species (S. epidermidis, S. haemolyticus, S. sciuri, S. capitis and S. lugdunensis) were analyzed, with mecA gene detected in five isolates. S. haemolitycus (isolate 95), and S. lugdunensis were unable to form biofilm and did not harbor the complete icaADBCR operon. High variability of adhesion genes was detected, with atl, ebp, icaADBC operon, and IS256 being the most common. In conclusion, MRSA and CoNS isolates carrying genes for biofilm production, and resistance to β-lactam and aminoglycosides are associated with treatment failure in OIAIs.

The aim of this study was to characterize methicillin-resistant coagulase-negative staphylococci (MRCoNS) isolates from the healthy staff of a university veterinary hospital in order to assess their importance as a reservoir of antimicrobial resistance and to determine their population structure and evolution. The study duration was over two years (2020–2021), 94 individuals were analyzed in duplicate, and 78 strains were obtained. The overall prevalence of methicillin-resistant strains detected throughout the study was 61.7%, with point prevalence values of 53.2% in 2020 and 31.5% in 2021. A total of 19.1% of the individuals analyzed were carriers throughout the study. The most frequently identified MRCoNs were Staphylococcus epidermidis (92.3%) and S. warneri (3.8%). A total of 75.6% of the isolates obtained showed the development of multi-resistance, preferentially against erythromycin, gentamicin, and tetracycline, and to a lesser extent against fusidic acid, norfloxacin, and clindamycin; these antimicrobials are frequently used in the veterinary field. Although most of the S. epidermidis isolates obtained showed wide genetic variability and low dispersion, which are characteristic of community-associated isolates, a small number of strains spread between individuals in close physical proximity and were maintained over time, forming stable clones. These clones generally maintained the same type of staphylococcal cassette chromosome mec (SCCmec) and had a similar antimicrobial resistance pattern.

Several different species of animals host staphylococci as normal microbiota. These animals can be a source of staphylococci zoonotic infections. People with routine or occupational exposure to infected/colonized animals are at risk of a potential transmission. Therefore, we aimed to investigate the presence of S. aureus and other staphylococci in camels used for recreational purposes as well as their antimicrobial resistance, virulence factors and genetic lineages. A total of 172 samples were collected from 86 healthy camels (nose and mouth) from different farms located in the Canary Islands, Spain. Antimicrobial susceptibility testing was performed against 14 antimicrobial agents. The presence of virulence genes was studied by PCR. Multilocus sequence typing, spa typing and agr typing were performed in all S. aureus isolates. From the 86 camels tested, 42 staphylococci were isolated, of which there were 11 S. aureus, 13 S. lentus, 12 S. sciuri, 3 S. xylosus, S. epidermidis, S. hominis and S. chromogenes. Staphylococci isolates were resistant to penicillin, ciprofloxacin, clindamycin and fusidic acid. All S. aureus isolates harbored the hla, hlb and hld virulence genes. S. aureus isolates were ascribed to three sequence types (STs) and three spa types. All S. aureus isolates belonged to agr type III. Camels from Gran Canaria used in recreational purposes have a moderate prevalence of S. aureus and other coagulase-negative staphylococci. Nevertheless, S. aureus isolates are susceptible to almost all antibiotics tested.

Coagulase-negative staphylococci (CoNS) have been recovered from different ecological niches, however, little is known about the genetic relatedness of these isolates. In this study, we used whole genome sequencing to compare mecA positive (mecA +) Staphylococcus epidermidis , Staphylococcus haemolyticus and Staphylococcus hominis isolates recovered from hand-touched surfaces from general public settings in East and West London with data of isolates deposited to European Nucleotide Archive (ENA) by other research groups. These included isolates associated with hospital settings (including those recovered from patients), healthy humans, livestock, pets, plants and natural, and other public environments. Using core and accessory phylogenetic analyses we were able to identify that the mecA+ S. epidermidis and S. haemolyticus isolates recovered from general public settings were genetically related to isolates recovered from the bloodstream, urinary tract and eye infections. S. epidermidis isolates recovered in our study were also shown to be genetically related to isolates previously recovered from livestock/livestock housing, whereas S. haemolyticus isolates were genetically related to isolates recovered from a dog and kefir (fermented cow milk drink). MecA + S. hominis isolates were not genetically related to any isolates recovered from clinical samples but were genetically related to isolates recovered from mosquitoes, air samples (residential areas) and kefir. All three species showed to have genetic relatedness to isolates recovered from healthy humans. These results show that CoNS isolates in this study share genetic similarities with those of different lineages and that mecA+ S. epidermidis and S. haemolyticus isolates found in general public settings in this study may pose a risk to public health. [ABSTRACT FROM AUTHOR]

Background: With the wide use of florfenicol to prevent and treat the bacterial infection of domestic animals, the emergence of the florfenicol resistance bacteria is increasingly serious. It is very important to elucidate the molecular mechanism of the bacteria's resistance to florfenicol. Methods: The minimum inhibitory concentration (MIC) levels were determined by the agar dilution method, and polymerase chain reaction was conducted to analyze the distribution of florfenicol resistance genes in 39 CoNS strains isolated from poultry and livestock animals and seafood. The whole genome sequence of one multidrug resistant strain, Staphylococcus lentus H29, was characterized, and comparative genomics analysis of the resistance gene-related sequences was also performed. Results: As a result, the isolates from the animals showed a higher resistance rate (23/28, 82.1%) and much higher MIC levels to florfenicol than those from seafood. Twenty-seven animal isolates carried 37 florfenicol resistance genes (including 26 fexA, 6 cfr and 5 fexB genes) with one carrying a cfr gene, 16 each harboring a fexA gene, 5 with both a fexA gene and a fexB gene and the other 5 with both a fexA gene and a cfr gene. On the other hand, all 11 isolates from seafood were sensitive to florfenicol, and only 3 carried a fexA gene each. The whole genome sequence of S. lentus H29 was composed of a chromosome and two plasmids (pH29-46, pH29-26) and harbored 11 resistance genes, including 6 genes [cfr, fexA, ant(6)-Ia, aacA-aphD, mecA and mph(C)] encoded on the chromosome, 4 genes [cfr, fexA, aacA-aphD and tcaA] on pH29-46 and 1 gene (fosD) on pH29-26. We found that the S. lentus H29 genome carried two identical copies of the gene arrays of radC-tnpABC-hp-fexA (5671 bp) and IS256-cfr (2690 bp), of which one copy of the two gene arrays was encoded on plasmid pH29-46, while the other was encoded on the chromosome. Conclusions: The current study revealed the wide distribution of florfenicol resistance genes (cfr, fexA and fexB) in animal bacteria, and to the best of our knowledge, this is the first report that one S. lentus strain carried two identical copies of florfenicol resistance-related gene arrays. [ABSTRACT FROM AUTHOR]

Phage therapy might be a useful approach for the treatment of nosocomial infections; however, only few lytic phages suitable for this application are available for the opportunistic pathogen, Staphylococcus epidermidis. In the current study, we developed an efficient method to isolate bacteriophages present within the human skin microbiome, by using niche-specific S. epidermidis as the host for phage propagation. Staphylococcus epidermidis was identified on the forehead of 92% of human subjects tested. These isolates were then used to propagate phages present in the same skin sample. Plaques were observable on bacterial lawns in 46% of the cases where S. epidermidis was isolated. A total of eight phage genomes were genetically characterized, including the previously described phage 456. A total of six phage sequences were unique, and spanned each of the major staphylococcal phage families; Siphoviridae (n = 3), Podoviridae (n = 1) and Myoviridae (n = 2). One of the myoviruses (vB SepM BE06) was identified on the skin of three different humans. Comparative analysis identified novel genes including a putative N-acetylmuramoyl-L-alanine amidase gene. The host-range of each unique phage was characterized using a panel of diverse staphylococcal strains (n = 78). None of the newly isolated phages infected more than 52% of the S. epidermidis strains tested (n = 44), and non-S. epidermidis strains where rarely infected, highlighting the narrow host-range of the phages. One of the phages (vB SepM BE04) was capable of killing staphylococcal cells within biofilms formed on polyurethane catheters. Uncovering a richer diversity of available phages will likely improve our understanding of S. epidermidis-phage interactions, which will be important for future therapy. [ABSTRACT FROM AUTHOR]

Background: The main pathogen for neonatal nosocomial infections is coagulase-negative staphylococci (CoNS), particularly in very low-birth-weight and premature newborns. The current study is aimed to assess the outcomes of preterm infants with CoNS infection via a retrospective analysis, to determine the correlation between the clinical profile and mortality and morbidity, and to determine the factors associated with poor outcomes. Materials and Methods: This retrospective case–control study was conducted in the Children's and Women's Health Centre of King Fahad Medical City neonatal intensive care unit in Saudi Arabia. The study period was from January 2013 to December 2019. Results: There were 1333 controls and 137 cases of CoNS infection. There was a significant association between total parenteral nutrition use, surgical insertion of a central line, inotrope use, and spontaneous intestinal perforation and CoNS infection. There was a significant association between umbilical vein catheter (UVC) and peripherally inserted central catheter (PICC) line use and CoNS infection. The use of a UVC or PICC line significantly impacted. The presence of patent ductus arteriosus also significantly impacted. Conclusions: There was a significant association between UVC and PICC line use and outcome. The presence of patent ductus arteriosus or a perforated bowel and the need for inotrope use in CoNS infection was associated with poor outcomes. Mortality, retinopathy of prematurity, and necrotizing enterocolitis requiring surgery were more common in infants with CoNS infections. [ABSTRACT FROM AUTHOR]

Coagulase-negative staphylococci (CNS) are among the major causes of subclinical mastitis in dairy ewe flocks. This has a financially significant impact on the ewe dairy sector and consumer health. The determination of the bacterial count, particularly CNS, is critical in terms of the quantity and quality of ovine milk. Thus, the purpose of this study was to quantify the CNS count in the udder surface and raw milk samples of the ewe, in addition, to identify CNS strains (n=8) collected from udder surface and individual raw milk samples by 16S rRNA gene sequencing. A total of 164 samples of udder surface and raw milk originated from four sheep farms were tested. The obtained values were compared between the different farms. Furthermore, values during 2018 and 2019 in the case of Farm I were compared. Significantly higher (p<0.05) average count was observed in udder surface samples taken from Farm I (2.8±1.0 lg CFU/cm2) than that of Farm III samples (2.3±0.6 lg CFU/cm2). In the case of individual raw milk, the higher value was observed in samples derived from Farm III (3.5±0.9 lg CFU/mL), while the obtained value was significantly lower (p<0.05) in samples originated from Farm IV (1.8±0.4 lg CFU/mL). In the bulk tank milk samples, the highest mean value was 5.3±0.4 CFU/mL, and there was no significant (p>0.05) variation between farms. Coagulase-negative staphylococci counts were decreased to a certain extent in both sample types tested during 2019 except for individual raw milk derived from the Tsigai breed. The correlation between the mean CNS counts of udder surface and individual raw milk was very weak (r=0.048). Staphylococcus simulans, Staphylococcus auricularis, and Staphylococcus equorum were identified by molecular sequencing and Staphylococcus simulans were the most frequently identified CNS species. A higher CNS count of bulk tank milk than individual raw milk indicates possible contamination during milking and storage. Therefore, further studies are required to investigate the other sources of bulk tank milk contamination to improve the hygienic quality of milk. [ABSTRACT FROM AUTHOR]

Introduction: Clinical significance of coagulase-negative staphylococci (CoNS) has been gradually acknowledged in both healthcare and clinical research, but approaches for their precise discrimination at the species level remain scarce. The current study aimed to evaluate the association of CoNS with orthopedic infections, where accurate and prompt identification of etiology is crucial for appropriate diagnosis and treatment decision-making., Methods: A 16S rRNA-based quantitative PCR (qPCR) assay was developed for the detection of Staphylococcus genus and two panels of 3-plex qPCR assays for further differentiation of six CoNS species with remarkable clinical significance, including S. epidermidis , S. haemolyticus , S. simulans , S. hominis , S. capitis , and S. caprae . All the assays exhibited excellent analytical performance. ΔCq (quantification cycle) between 16S rRNA and CoNS species-specific targets was established to determine the primary CoNS. These methods were applied to detect CoNS in wound samples from orthopedic patients with and without infection., Results and Discussion: Overall, CoNS were detected in 17.8% (21/118) of patients with clinically suspected infection and in 9.8% (12/123) of patients without any infection symptom ( p  < 0.05). Moreover, the association with infection was found to be bacterial quantity dependent. S. epidermidis was identified as the predominant species, followed by S. simulans , S. haemolyticus , and S. hominis . Male sex, open injury, trauma, and lower extremity were determined as risk factors for CoNS infections. CoNS-positive patients had significantly longer hospitalization duration (20 days (15, 33) versus 13 days (7, 22) for Staphylococcus -negative patients, p  = 0.003), which could be a considerable burden for healthcare and individual patients. Considering the complex characteristics and devastating consequences of orthopedic infections, further expanding the detection scope for CoNS may be pursued to better understand the etiology of orthopedic infections and to improve therapeutic strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Liu, Xia, Cui, Yu, Zhao, Guan, Wang, Wang, Li, Hu and Liu.)

The species- and clone-specific susceptibility of Staphylococcus cells for bacteriophages is governed by the structures and glycosylation patterns of wall teichoic acid (WTA) glycopolymers. The glycosylation-dependent phage-WTA interactions in the opportunistic pathogen Staphylococcus epidermidis and in other coagulase-negative staphylococci (CoNS) have remained unknown. We report a new S. epidermidis WTA glycosyltransferase TagE whose deletion confers resistance to siphoviruses such as ΦE72 but enables binding of otherwise unbound podoviruses. S. epidermidis glycerolphosphate WTA was found to be modified with glucose in a tagE -dependent manner. TagE is encoded together with the enzymes PgcA and GtaB providing uridine diphosphate-activated glucose. ΦE72 transduced several other CoNS species encoding TagE homologs, suggesting that WTA glycosylation via TagE is a frequent trait among CoNS that permits interspecies horizontal gene transfer. Our study unravels a crucial mechanism of phage- Staphylococcus interaction and horizontal gene transfer, and it will help in the design of anti-staphylococcal phage therapies.IMPORTANCEPhages are highly specific for certain bacterial hosts, and some can transduce DNA even across species boundaries. How phages recognize cognate host cells remains incompletely understood. Phages infecting members of the genus Staphylococcus bind to wall teichoic acid (WTA) glycopolymers with highly variable structures and glycosylation patterns. How WTA is glycosylated in the opportunistic pathogen Staphylococcus epidermidis and in other coagulase-negative staphylococci (CoNS) species has remained unknown. We describe that S. epidermidis glycosylates its WTA backbone with glucose, and we identify a cluster of three genes responsible for glucose activation and transfer to WTA. Their inactivation strongly alters phage susceptibility patterns, yielding resistance to siphoviruses but susceptibility to podoviruses. Many different CoNS species with related glycosylation genes can exchange DNA via siphovirus ΦE72, suggesting that glucose-modified WTA is crucial for interspecies horizontal gene transfer. Our finding will help to develop antibacterial phage therapies and unravel routes of genetic exchange., Competing Interests: The authors declare no conflict of interest.

Nitrates and nitrites, which are synthetic additives, are traditionally used as curing agents in meat-based products. These synthetic additives are employed in the preparation of fermented meat foods to improve quality characteristics and microbiological safety, develop distinct flavours and red-colour stability, and counteract lipid oxidation. Nitrites also display significant bacteriostatic and bactericidal action against spoilage microorganisms and foodborne pathogens (such as Clostridium botulinum and Listeria monocytogenes ). However, meat curing is currently under scrutiny because of its links to cardiovascular diseases and colorectal cancer. Based on the current literature, this review provides recent scientific evidence on the potential utilisation of coagulase-negative staphylococci (CNS) as nitrate and nitrite substitutes in meat-based foods. Indeed, CNS are reported to reproduce the characteristic red pigmentation and maintain the typical high-quality traits of cured-meats, thanks to their arginine degradation pathway, thus providing the nitrite-related desirable attributes in cured meat. The alternative strategy, still based on the NOS pathway, consisting of supplementing meat with arginine to release nitric oxide (NO) and obtain a meat characterised by the desired pinkish-red colour, is also reviewed. Exploiting NOS-positive CNS strains seems particularly challenging because of CNS technological adaptation and the oxygen dependency of the NOS reaction; however, this exploitation could represent a turning point in replacing nitrates and nitrites in meat foods., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

We present a first case of Staphylococcus cohnii endocarditis in an 80-year-old patient with a history of valve regurgitation. Endocarditis by this organism has not been reported previously. The patient declined treatment and died a few days later. When present, S. cohnii endocarditis has a poor prognosis as a result of associated comorbidities and the infection itself.

Abstract Hemodialysis requires repeated, reliable access to the systemic circulation; therefore, a well‐functioning vascular access (VA) procedure is crucial for stable hemodialysis. VA infections (VAIs) constitute the most challenging complication and cause considerable morbidity, loss of access, and even death. In this study, we investigated the molecular profiles of different bacterial isolates retrieved from various types of VA grafts. We collected clinical isolates from hemodialysis patients with VAIs in our institution for the period between 2013 and 2018. We identified the bacterial isolates using standard biochemical procedures; we used a polymerase chain reaction for coagulase‐negative staphylococci (CoNS) and Burkholderia cepacia complex (BCC) species identification. The antibiotic resistance and molecular profile were analyzed using the disk diffusion method and multilocus sequence typing, respectively. We studied 150 isolates retrieved from patients with VAI and observed that Staphylococcus aureus was the predominant bacterial species, followed by S. argenteus, BCC, and CoNS. According to multilocus sequence typing data, we identified a wide variety of sequence types (STs) in S. aureus isolates, with ST59, ST45, and ST239 being the predominant types. Burkholderia cepacia with two new ST types, namely ST1723 and ST1724, accounted for most of the BCC infections, along with ST102 B. contaminans, which were mainly isolated from infected tunneled‐cuffed catheters. In summary, the increased incidence of S. argenteus and BCC infections provides insights into their potential clinical effects in VAIs. The various STs identified in different bacterial species indicate the high genetic diversity of bacterial species isolated from VAIs in our institution.

Coagulase-negative staphylococci (CoNS) are recognized as comprising the main part of human normal microbiota and are rarely associated with severe and intensive infections. However, these organisms can cause a number of infections in humans, especially immunocompromised patients and neonates. Bacterial meningitis, as an important and acute infection in the central nervous system, is still a major global health challenge and a serious infectious disease, causing a high rate of mortality and morbidity. CoNS as causative agents of meningitis are generally related to trauma or direct implantation of foreign bodies and the presence of a cerebrospinal fluid shunt. Numerous epidemiologic and clinical studies have shown that different CoNS isolates such as Staphylococcus capitis, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus epidermidis, Staphylococcus schleiferi, Staphylococcus saprophyticus, Staphylococcus warneri and Staphylococcus haemolyticus are more frequently associated with meningitis. This study attempts to determine the role of CoNS in meningitis and reviews the reported cases of meningitis induced by CoNS from the year 2000 to 2020 in the literature.

ABSTRACT Staphylococcus aureus is a highly significant infection problem in health care centers, particularly after surgery. It has been shown that nearly 80% of S. aureus infections following surgery are the same as those in the anterior nares of patients, suggesting that the anterior nares is the source of the infection strain. This has led to the use of mupirocin ointment being applied nasally to reduce infections; mupirocin resistance is being observed. This study was undertaken to determine whether gel composed of 5% glycerol monolaurate solubilized in a glycol-based, nonaqueous gel (5% GML gel) could be used as an alternative. In our study, 40 healthy human volunteers swabbed their anterior nares for 3 days with the 5% GML gel. Prior to swabbing and 8 to 12 h after swabbing, S. aureus and coagulase-negative staphylococcal CFU per milliliter were determined by plating the swabs on mannitol salt agar. Fourteen of the volunteers had S. aureus in their nares prior to 5% GML gel treatment, most persons with the organisms present in both nares; five had pure cultures of S. aureus. All participants without pure culture of S. aureus were cocolonized with S. aureus and coagulase-negative staphylococci. Five of the S. aureus strains produced the superantigens commonly associated with toxic shock syndrome, though none of the participants became ill. For both S. aureus and coagulase-negative staphylococci, the 5% GML gel treatment resulted in a 3-log-unit reduction in microorganisms. For S. aureus, the reduction persisted for 2 or 3 days. IMPORTANCE In this microflora study, we show that a 5% glycerol monolaurate nonaqueous gel is safe for use in the anterior nares. The gel was effective in reducing Staphylococcus aureus nasally, a highly significant hospital-associated pathogen. The gel may be a useful alternative or additive to mupirocin ointment for nasal use prior to surgery, noting that 80% of hospital-associated S. aureus infections are due to the same organism found in the nose. This gel also kills all enveloped viruses tested and should be considered for studies to reduce infection and transmission of coronaviruses and influenza viruses.

In this paper, we describe a new quantitative method to evaluate and quantify in vitro growth inhibition of mastitis-related bacteria. Colony-forming units of Staphylococcus (S.) aureus (n = 10), Escherichia (E.) coli (n = 10), and Streptococcus (S.) uberis (n = 10) were quantified after their growth on top of layers of trypticase soy agar (TSA) containing six different concentrations (varying from 102 to 107 CFU/mL) of bovine non-aureus staphylococci (NAS), i.e., S. chromogenes (n = 3) and S. simulans (n = 3) isolates. Growth inhibition of the mastitis-related major bacterial pathogens, including E. coli, was confirmed by all NAS, an effect that varied highly among NAS isolates and was not evident from the semiquantitative method with which the new method was compared. By subsequent application of the new method on a larger set of 14 bovine NAS isolates, we observed that S. simulans and NAS originating from teat apices (especially S. epidermidis) required lower concentrations to inhibit both methicillin-sensitive (MSSA) (n = 5) and methicillin-resistant S. aureus (MRSA) isolates (n = 5) originating from milk. Therefore, the new assay is a promising tool to precisely quantify the intra- and inter-species differences in growth inhibition between NAS.

Abstract Background The existence of latent low-virulence anaerobic bacteria in degenerated intervertebral discs (IVDs) remains controversial. In this study, the prevalence of low-virulence anaerobic bacteria in degenerated IVDs was examined, and the correlation between bacterial infection and clinical symptoms was analysed. Methods Eighty patients with disc herniation who underwent discectomy were included in this study. Under a stringent protocol to ensure sterile conditions, 80 disc samples were intraoperatively retrieved and subjected to microbiological culture. Meanwhile, tissue samples from the surrounding muscle and ligaments were harvested and cultured as contamination markers. The severity of IVD degeneration and the prevalence of Modic changes (MCs) were assessed according to preoperative MRI analysis. Results Of the 80 cultured discs, 54 were sterile, and 26 showed the presence of bacteria: Propionibacterium acnes (21 cases) and coagulase-negative staphylococci (5 cases). MRI revealed that the presence of bacteria was significantly associated with MCs (P

Abstract Aim To describe the clinical presentations and management outcomes of Kocuria endophthalmitis and discuss diagnostic dilemmas Design Retrospective interventional comparative case series Intervention Eight unilateral cases with culture-proven Kocuria endophthalmitis from January 2013 to December 2017 underwent vitrectomy/vitreous biopsy and intravitreal antibiotic with or without additional procedures. The undiluted vitreous was subjected to microbiologic evaluation. Main outcome measures The mean age at presentation, etiology, number of interventions, interval between inciting event and presentation, type of intravitreal antibiotic used, and anatomic and functional outcomes were reported. A favorable anatomic outcome was defined as preservation of the globe, absence of hypotony, attached retina, and absence of active inflammation at the last visit. Results In the current series, there were five males and three females. The mean age at presentation was 31 ± 17.44 years (median 30 years). The inciting event was open globe injury in five cases and one case each following cataract surgery, microbial keratitis, and endogenous cause. Visual acuity was ≥ 20/400 in one case at presentation and ≥ 20/400 in three cases at the last visit. The species identified by Vitek 2, included Kocuria kristinae in three, K. rosea in four and K. varians in one. Follow-up period was 8.25 ± 8.24 months (median 6.5). Six cases (75%) had complete resolution of infection and inflammation at the last visit. Anatomic success was achieved in 75%. Conclusions Kocuria is a relatively rare cause of endophthalmitis often misdiagnosed as Staphylococcal endophthalmitis. Clinical presentation can be variable but favorable antibiotic susceptibility and appropriate timely management can result in acceptable visual and anatomic outcomes.

Background and Objective: Due to the emergence and development of antimicrobial resistance in coagulase-negative Staphylococci (CoNS), which is mainly a normal flora of the skin surface and mucous membrane of humans, and the limitation of therapeutic options, this study was aimed to investigate the antibiotic resistance pattern in CoNS strains isolated from clinical specimens. Materials and Methods: In this cross-sectional descriptive study, a total of 44 isolates of coagulase-negative staphylococci were examined from clinical specimens of the patients using standard biochemical methods. Disc diffusion test was utilized to detect resistance to common antibiotics. Multiplex polymerase chain reaction (PCR) was employed to determine the frequency of resistance genes, namely mecA and vanA. Results: The results of disc diffusion test showed that the isolates had the highest resistance rate to erythromycin as 88.64%; while the lowest resistance rate to meropenem was observed 4.55%. A molecular analysis indicated the presence of 18.18% of the mecA gene in the isolates; however no isolates containing vanA gene were observed. Conclusion: Considering the frequency of mecA gene, results of antibiotic resistance pattern among coagulase-negative Staphylococci strains, and lack of any resistance observations to vancomycin by PCR, it is necessary to conduct more precise laboratory methods for the detection of antibiotic resistance to prevent resistance spread in this bacterium

Abstract Objective The antimicrobial resistance of staphylococci rose worldwide. In total, 96 Staphylococcus isolates from food and clinical samples were collected from two provinces in Algeria. The antimicrobial susceptibility testing was performed and resistance-associated genes were detected. Results Fifty-one strains were isolated from food samples and differentiated into 33 Staphylococcus aureus and 18 coagulase-negative staphylococci. Forty-five staphylococci were collected from hospital and community-acquired infection cases. All S. aureus isolated from food were resistant to penicillin and 45.5% were resistant to tetracycline. The resistance rates of 45 clinical Staphylococcus isolates were 86.7%, 48.9%, 37.8% and 20.0% to penicillin, tetracycline, erythromycin and kanamycin, respectively. Nine isolates were confirmed as MRSA from food and clinical isolates. One S. aureus originated from food was confirmed as vancomycin-resistant. Multidrug-resistance was observed among 25.5% and 53.3% of food and clinical staphylococci, respectively. The tetM/K, blaZ, aacA-aphD, ermC and mecA genes were detected in food and clinical isolates. ermA gene was not found. This study provided insight into the status of antimicrobial resistance of staphylococci isolated from food and clinical samples in Algeria. Further investigations and surveillance programmes are mandatory.

The sensitivity of strains of microorganisms isolated from bioptates of atherosclerotic plaques to different antimicrobials was studied. For this study, the samples of atherosclerotic plaques from a group of patients that underwent elective carotid endarterectomy were used. Among 137 strains of coagulase-negative staphylococci 13.1 % of all isolates were methicillin-resistant, but all were sensitive to vancomycin, linezolid and moxifloxacin. Some strains of staphylococci possessed the resistance to erythromycin and tetracycline (16.3 %) and (13.9 %) respectively. The greatest resistance among coagulase-negative staphylococci to chloramphenicol (43.4 %) were identified. The high sensitivity of such bacteria to clindamycin, ciprofloxacin and gentamycin (92.6, 92.0 and 90.5 % respectively) were established. Among 197 isolates of Propionibacterium acnes all strains were highly sensitive to all antibiotics (amoxicillin, amoxicillin-clavulanic acid, benzylpenicillin, imipenem, clindamycin, piperacyllin, piperacyllin/tazobactam, ticarcillin, ticarcillin-clavulanic acid, chloramphenicol amd cefoxitin) which were tested. As exception was a metronidazole resistance to which bacteria are naturally refractory. The data obtained confirm that only small part of coagulase-negative staphylococci possessed the resistance to methicillin (13.1 %), but many among them demonstrated a high level of resistance to chloramphenicol. Between the strains of propionibacteria the acquired resistance to different antibacterials was not revealed.

Elena De Vecchi,1 David A George,2 Carlo L Romanò,3 Fabrizio E Pregliasco,4,5 Roberto Mattina,6 Lorenzo Drago1,4 1Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy; 2Department of Trauma and Orthopaedics, University College London Hospitals, London, UK; 3Centre for Reconstructive Surgery and Osteoarticular Infections, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy; 4Department of Biochemical Sciences for Health, University of Milan, Milan, Italy; 5Health Management Unit, IRCCS Galeazzi Orthopaedic Institute, Milan, Italy; 6Department of Biomedical, Surgical and Dental Science, University of Milan, Milan, Italy Introduction: Coagulase-negative staphylococci (CoNS) are the main pathogens responsible for prosthetic joint infections (PJIs). As normal inhabitants of human skin, it is often difficult to define if they are contaminants, or if they have an active role in initiating infection. This study aims to evaluate differences in CoNS organisms (Staphylococcus hominis, Staphylococcus capitis, Staphylococcus haemolyticus, Staphylococcus warneri) and Staphylococcus aureus in terms of isolation rate and antimicrobial susceptibility from patients who met the International Consensus Meeting (ICM) criteria for PJIs and those who did not. Methods: Staphylococci isolates from January 2014 to December 2015 retrieved from patients undergoing revision joint arthroplasty were classified in accordance with criteria established by the ICM of Philadelphia. Results: As per the consensus classification, 50 CoNS and 39 S. aureus infections were recognized as pathogens, while 16 CoNS and four S. aureus were considered as contaminants. Frequency of isolation of S. aureus was significantly higher in infected patients than in those without infection, while no significant differences were observed among CoNS. Resistance to levofloxacin, erythromycin, gentamicin trimethoprim/sulfamethoxazole, and rifampicin was significantly more frequent in S. haemolyticus than in the other species, as well as resistance to erythromycin and gentamicin in S. hominis. In comparison to S. aureus, CoNS were significantly more resistant to daptomycin and gentamicin and more susceptible to rifampicin.Conclusion: CoNS, other than Staphylococcus epidermidis, are frequently isolated from PJIs, and their infective role and antimicrobial susceptibility need to be assessed on an individual patient basis. S. haemolyticus seems to emerge as responsible for PJI in a large volume of patients, and its role needs to be further investigated, also considering its pattern of resistance. Keywords: periprosthetic joint infections, antibiotics susceptibility, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus capitis, Staphylococcus warneri, Staphylococcus aureus

Aim: Assessment of the status of subclinical mastitis (SCM) in Jamunapari and Barbari goats in Indian organized farms, the involvement of bacterial pathogens and their sensitivity to antibiotics. Materials and Methods: A total of 181 composite milk samples were aseptically collected from the apparently healthy Barbari (n=95) and Jamunapari (n=86) goats. The California mastitis test (CMT) and somatic cell count (SCC) were used to diagnose SCM. The milk samples with CMT scores of 0 and +1 were considered as negative, while the samples with the score of +2 or +3 were taken as positive, and further, the positive samples were used for the bacteriological examination. An antibiotic sensitivity test was performed by disk diffusion method using seven commercially available antibiotic discs. Results: All the samples having CMT score of +2 or +3 demonstrated SCC more than 1 million. Overall, the prevalence of SCM in the goats was assessed as 19.89% (36/181). The prevalence of SCM in Barbari and Jamunapari goats was found as 24.21% (23/95) and 15.12% (13/86), respectively. Out of 11 isolates of Staphylococci, 9 isolates were identified as coagulase-negative Staphylococci (CNS), whereas 2 isolates were found as Staphylococcus aureus. The identified bacterial isolates (n=30) did not show antibiotic resistance. Conclusion: The current investigation showed the considerable prevalence of SCM among Jamunapari and Barbari goats which may have a negative impact on quantity and quality of the milk. CNS was found as the most prevalent cause of SCM in the goats. Negligible antibiotic resistance was found among the identified udder pathogens.

Background: The research scope toward nasal colonization of coagulase-negative staphylococci (CoNS) in animals is largely ignored for many years. Therefore, this study was conducted to investigate the nasal carriage of CoNS among different animals and its public health implication. Materials and Methods: Nasal swabs were gathered from 152 animals (36 cats, 31 dogs, 29 sheep, 32 goats, and 24 cattle). These samples were subjected for isolation and identification of CoNS by conventional bacteriological methods, then molecular confirmation was carried out using Staphylococcus genus-specific 16S rRNA PCR. All CoNS isolates were screened for the presence of antibiotic resistance (mecA and blaZ) and virulence (lukS/F-PV and tsst-1) genes. Moreover, strains carrying resistance and/or virulence genes were identified to species level by 16S rRNA gene sequencing approach. Results: CoNS were identified in 14.5% (22/152) of the examined animals, whereas the prevalence rates among different animals were 27.8%, 3.2%, 8.3%, 10.3%, and 18.8% for cats, dogs, cattle, sheep, and goats, respectively. Of all isolates, two strains (Staphylococcus epidermidis and Staphylococcus warneri) harbored mecA gene, which carried on staphylococcal cassette chromosome mec type I in S. epidermidis and type V in S. warneri, while blaZ gene has been found in one strain (Staphylococcus felis). Importantly, two isolates (S. epidermidis and S. felis) had tsst-1 gene but all of CoNS isolates were negative for Panton-Valentine leukocidin gene. The phylogenetic analysis of the obtained sequences of CoNS of the current study revealed high similarity to those of serious human clinical cases to underscore the public health significance of such isolates. Conclusion: The nasal carriage of antibiotic-resistant and toxigenic CoNS among different animals highlights the potential zoonotic link with great public health implication. [ABSTRACT FROM AUTHOR]

The present study aimed to provide a detailed characterization of coagulase-negative staphylococci (CoNS) isolated from cows and buffaloes with mastitis. The study included seventy-five CoNS isolates (60 came from cattle and 15 from buffaloes) originating from 68 individual quarters of 67 dairy cows (53 cattle and 14 buffaloes). The animals belonged to five different small holding dairy herds (n = 140 cows) that show clinical or subclinical mastitis. CoNS isolates were phenotypically characterized using MALDI-TOF-MS and were further genotypically characterized by microarray-based assays. Furthermore, the antimicrobial susceptibility of CoNS strains which carried the mecA gene was examined by broth microdilution. The occurrence of CoNS in the respective five herds was 10.5%, 14.7%, 14.8%, 12.8%, and 9.9%, with an average of 12.4%. Six different CoNS species were identified: S. sciuri (n = 37; 30 from cattle and 7 from buffaloes), S. chromogenes (n = 14; 8 from cattle and 6 from buffaloes), S. haemolyticus (n = 10; nine from cattle and one buffalo), S. xylosus (n = 10; nine from cattle and one buffalo), S. hyicus (n = 2), S. warneri (n = 1), and unidentified CoNS (n = 1). Twenty percent (20%) of CoNS isolates (17.3% of cattle origin) carried at least one antimicrobial resistance gene, while 4% of the isolate including two isolates of S. haemolyticus and one S. warneri of cattle origin carried the mecA gene and were phenotypically identified as methicillin-resistant strains. The genes detected were blaZ (16%), followed by tet(K) (8%), aacA-aphD (4%), aphA3 (2.6%), msr(A) (2.6%), [far1 (2.6%), and fusC (2.6%)], sat (2.6%), and cat (1.3%) conferring resistance to penicillin, tetracycline, gentamicin, neomycin/kanamycin, erythromycin, fusidic acid, streptothricin, and chloramphenicol, respectively. The majority of investigated CoNS strains displayed considerably low prevalence of resistance genes, while resistance to more than three antibiotics was found in S. haemolyticus and S. warneri. Implementing effective preventive measures is, therefore, important for limiting the transmission of CoNS, rather than using antibiotics to control mastitis in bovines. [ABSTRACT FROM AUTHOR]

Study Design: Prospective cohort study.Objective: We aimed to determine the 2-year survival and to identify clinical and microbiological characteristics of patients with native vertebral osteomyelitis (VO) as compared to postoperative VO to find further strategies for improvement of the management of VO.Summary Of Background Data: A relevant subgroup (20%-30%) of patients with VO has a history of spine surgery. Infection in these patients might be clinically different from native VO. However, clinical, microbiological, and outcome characteristics of this disease entity have not been well studied as most trials either excluded these patients or are limited by a small cohort and short observation period.Methods: Between 2008 and 2013, patients who presented at a tertiary care center with symptoms and imaging findings suggestive of VO were reviewed by specialists in infectious diseases, clinical microbiology, and orthopedics to confirm the diagnosis and followed prospectively for a period of 2 years. Statistical analysis for group comparisons, survival analysis, and uni- and multivariable Cox regression models were performed.Results: Thirty percent of the patients with VO (56/189) reported a history of spine surgery in the same segment. Patients with postoperative infection had a lower ASA score (American Society of Anesthesiologists) (P = 0.01) and were less likely to suffer from comorbidities compared to native cases (P = 0.003). Infections caused by coagulase-negative staphylococci (33.3 vs. 6.5%, P < 0.001) and other bacteria of the skin flora (15.2 vs. 0%, P = 0.002) were more prevalent in postoperative patients. Suffering from native VO increased the 2-year mortality risk 3-fold, also when adjusted for the remaining risk factors ASA score and number of comorbidities (hazard ratio 2.916 [95% confidence interval 1.215 -6.999], P = 0.017).Conclusion: Beside clear microbiological differences, the significant better 2-year survival supports the concept of postoperative VO presenting a distinct disease entity. The subtle disease presentation of patients with postoperative VO should not attenuate clinical suspicion of physicians.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background: Methicillin-resistant staphylococci (MRS) are an emerging global problem with serious public health concern. Aims: This study investigated the prevalence and antimicrobial susceptibility of commensal Staphylococcus species isolated from healthy and clinical cats and dogs. Methods: Nasal swab samples were collected from animals and processed using selective and semi-selective mediums. Presumptive isolates were subjected to biochemical testing and analyzed using the Phoenix automated identification and susceptibility testing system. PCRs protocols were used to screen for mecA and pvl genes. Results: In total, 151 pets (103 cats and 48 dogs) were enrolled, of which 14 dogs (29%) and 24 cats (23%) were colonized with various Staphylococcus species mainly originated from healthy animals. A total of 38 staphylococci isolates were collected and distributed between 24 coagulase-negative and 14 coagulase-positive staphylococci. Only 13 staphylococci strains were identified as MRS, out of which only five isolates expressed that the mecA gene exclusively originated from healthy pets. Conclusion: This is the first study reporting the prevalence and colonization status of staphylococci species and MRS strains isolated from cats and dogs in Libya. The study reports important information of medical and clinical importance on antimicrobial and multidrug resistance of different staphylococci strains, particularly the coagulase negative species. [ABSTRACT FROM AUTHOR]

Staphylococci from Sheedal of Northeast India was isolated, identified and characterized. All the isolated staphylococci were found to be coagulase negative. Based on the rpoB gene sequences followed by analysis using NCBI‐BLAST software, seven species of Staphylococcus namely, S. piscifermentans, S. condimenti, S. arlettae, S. sciuri, S. warneri, S. nepalensis and S. hominis were recognized. Phylogenetic analyses revealed three major cluster groups. All the seven Staphylococcus showed their NaCl tolerance from 2 to 8%. No species was able to grow at 55°C. Except S. arlettae and S. sciuri, all the isolated staphylococcal species exhibited growth at pH 4–8. No isolated species was able to ferment mannitol, sucrose and arabinose. All the species exhibited moderate to maximum proteolytic and lipolytic activities. All the seven species were found to be sensitive to the antibiotics, namely, erythromycin, norfloxacin, ampicillin, streptomycin and vancomycin, whereas all were resistant to co‐trimoxazole. Only S. piscifermentans was found antagonist to Salmonella enterica, Escherichia coli and Bacillus subtilis, although the clear zone was minimal. All the staphylococcal species except S. arlettae and S. sciuri exhibited hydrophobicity ranging from 25 to 66%. The observed characteristics of isolated Staphylococci from Sheedal revealed their role in fish fermentation. [ABSTRACT FROM AUTHOR]

One of the major causes of prosthetic joint failure is infection. Recently, coagulase negative Staphylococcus epidermidis has been identified as an emergent, nosocomial pathogen involved in subclinical prosthetic joint infections (PJIs). The diagnosis of PJIs mediated by S. epidermidis is usually complex and difficult due to the absence of acute clinical signs derived from the host immune system response. Therefore, analysis of protein patterns in biofilm-producing S. epidermidis allows for the examination of the molecular basis of biofilm formation. Thus, in the present study, the proteome of a clinical isolate S. epidermidis was analyzed when cultured in its planktonic or sessile form to examine protein expression changes depending on culture conditions. After 24 h of culture, sessile bacteria exhibited increased gene expression for ribosomal activity and for production of proteins related to the initial attachment phase, involved in the capsular polysaccharide/adhesin, surface associated proteins and peptidoglycan biosynthesis. Likewise, planktonic S. epidermidis was able to aggregate after 24 h, synthesizing the accumulation associate protein and cell-wall molecules through the activation of the YycFG and ArlRS, two component regulatory pathways. Prolonged culture under vigorous agitation generated a stressful growing environment triggering aggregation in a biofilm-like matrix as a mechanism to survive harsh conditions. Further studies will be essential to support these findings in order to further delineate the complex mechanisms of biofilm formation of S. epidermidis and they could provide the groundwork for the development of new drugs against biofilm-related infections, as well as the identification of novel biomarkers of subclinical or chronic infections mediated by these emerging, low virulence pathogens. [ABSTRACT FROM AUTHOR]

Possible blood culture (BC) contaminants are generally considered to be skin flora species including coagulase-negative Staphylococci (CNS), Corynebacterium species, Micrococcus species, Bacillus species and Propionibacterium acnes. Prior to October 1, 2016 all possible BC contaminants were fully processed (identification, susceptibility testing) in our laboratory. In order to reduce the laboratory workload from October 1, 2016 a possible contaminant was only processed if it was present in more than one BC pair drawn from the same patient within the same day. The two-year study period was divided in two periods namely period A from January 1, 2016 to September 30, 2016 (first 9 months) and period B from October 1, 2016 to December 31, 2017 (last 15 months). A series of indices (INs) were calculated including among others the Working Rate IN (WR) defined as the total isolates divided to the total number of BCs submitted per month and the CNS Rate (CNSR) defined as the total number of CNS processed divided to the total number of BCs submitted per month. A 23.08% reduction in the CNSR was noted (from 3.51% in period A to 2.70% in period B) whereas the overall WR was reduced from 7.19% in period A to 6.84% in period B. Furthermore, the total number of contaminants processed per month divided to the total number of isolates processed per month was reduced from 54.50% in period A to 42.41% in period B. The reduction in the INs recorded is of great value since it was achieved by the implementation of a simple criterion easily applicable and without any cost. [ABSTRACT FROM AUTHOR]

Mobile phones (MPs) have become a tool for the transmission of microorganisms due to lack of personal hygiene and maybe the sharing of the mobile phone by more than one person that which leads it to be a suitable carrier for microbes. This study aimed to draw a bead on the practices of hygiene of MPs among people living in Riyadh, Saudi Arabia, by performing a cross-sectional survey of 204 participants. The response rate of this study was above ~95%. Results showed that 19.6 % of responders clean their MPs once in a day, but the majority (33.8%) never cleaned their MPs. More than a quarter of the respondents (28.4%) use tissue paper to clean MPs. Among the users, ~60% use MPs while eating, 76% realized that their MPs might be resource of transmitting microorganisms. The study was also carried out using standard techniques to identify and count the bacterial contamination using the MPs. A combined number of 75 MPs of the participants in the shopping malls of Riyadh were screened for microorganism identification. From 75 public MPs, 109 bacteria were isolated. Coagulase-negative staphylococci were the predominant organisms isolate (76.1%) and with 1.8% by Staphylococcus aureus. Micrococcus sps. was also found (12.8%). A small number of Kocuria sps. were also isolated (4.6%). These results showed that common peoples’ mobile phones were contaminated with various types of microorganisms. The results provide an evidence base for the development and enhancement of hygienic MPs using practices. [ABSTRACT FROM AUTHOR]

Mastitis is the most economically and productively important disease in the bovine milk production chain. The present work aimed to evaluate the clinical-epidemiological behavior of bovine mastitis in dairy herds of private producers in Villa Clara province. Fifty-five producers, from four municipalities, from ten Credit and Service Cooperatives (CCSs), were included. California Mastitis Test (CMT), somatic cell count (SCC) and bacteriological isolation from milk from individual rooms were performed. Of the 1246 quarters analyzed containing 311 animals, 32.9 % were affected by subclinical mastitis, 0.32 % by clinical mastitis and 1.3 % were atrophied. The main bacteriological isolates of subclinical mastitis corresponded to Staphylococcus aureus, Coagulase-negative Staphylococci and Enterobacteria, with a quarter prevalence of 15.8, 9.3 and 3.7 % respectively, for intramamary infections of 35.5 %. In relation to average values of the SCC obtained in individual cows in the herds (27*103cell/mL), 6.5 % of cows with higher critical values (200*103cell/mL) were obtained. The distribution of the microorganisms by gender showed a higher incidence of Staphylococcus and Enterobacteria (26.9 and 3.7 %, respectively). The index of subclinical mastitis in the municipalities was close to what was considered correct, which was 0.5, managed as an epidemiological indicator of this disease. [ABSTRACT FROM AUTHOR]

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Coagulase-negative staphylococci (CoNS) have engendered substantial interest in recent years as pathogenic causes of infections in both human and veterinary medicine, especially in the immunocompromised, critically ill, long-term hospitalized and in those harboring invasive medical devices such as catheters. They have been implicated in infections such as urinary tract infections, bloodstream infections, and invasive device-related infections, and are responsible for substantial economic losses in livestock production. The advancement of diagnostic techniques has increased our understanding of their molecular mechanisms of pathogenicity, even though distinguishing between innocuousness and pathogenicity is still challenging. The incidence of CoNS varied across the continent in humans and animals (mainly cattle), ranging from 6% to 68% in suspected human infections and from 3% to 61.7% in suspected animal infections, distributed across different geographic locations. Furthermore, there were varying antibiotic resistance patterns observed in CoNS isolates, with high methicillin resistance in some cases, leading to crossresistance against many antibiotics. Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus xylosus were most commonly reported in studies herein reviewed, while the enterotoxin C gene, atl E gene, ica gene, and hemolysin virulence factors were linked with enhanced pathogenicity. Advancement in identification and typing methods, including whole genome sequencing, virulence screening, and the assessment of the immune status of subjects in studies will help to thoroughly assess the true pathogenic potential of isolated CoNS species in developing countries. Careful antibiotic stewardship guidelines should be followed due to the ability of CoNS to develop multidrug resistance. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus epidermidis is a commensal of human skin flora and a frequent causative microorganism in prosthetic joint infections (PJIs). To date, no single marker has been identified to distinguish infecting strains from commensal S. epidermidis populations.Aim: We aimed to find possible genetic markers to distinguish between the two populations.Methods: We analyzed 50 S. epidermidis strains from patients with PJIs, 50 from skin of healthy individuals (commensal strains) and 17 from the surgical field of patients undergoing primary arthroplasty. In these three groups we studied the antimicrobial susceptibility profile, sequence type, biofilm formation, and virulence factors. Strains from the surgical field have not been compared previously with strains from the other two groups.Findings: S. epidermidis strains from PJI patients were significantly more antibiotic resistant than commensal strains and surgical field strains. A wide variety of sequences types was found in commensal and surgical field strains. The predominant sequence type was ST2 and it was only present in PJI strains (44%). Differences in biofilm production did not differ between populations. Virulence genes sdrF and bhp, the complete ica operon, and the insertion sequence IS256 were significantly predominant in PJI strains. In contrast, embp and hld genes and the mobile element ACME were more prevalent in commensal strains. Surgical field strains could be a valid control group to discriminate between infecting and commensal strains.Conclusion: A combination of characteristic features can differentiate between infecting and commensal S. epidermidis strains in PJI, while a single marker cannot. [ABSTRACT FROM AUTHOR]

This review article shows that coagulase-negative staphylococci (CoNS) are widely responsible for laryngological diseases. General characteristics of CoNS infections are shown in the introduction, and the pathogenicity in terms of virulence determinants, biofilm formation and genetic regulation mechanisms of these bacteria is presented in the first part of the paper to better display the virulence potential of staphylococci. The PubMed search keywords were as follows: CoNS and: nares infections, nasal polyps, rhinosinusitis, necrosing sinusitis, periprosthetic joint infection, pharyngitis, osteomyelitis of skull and neck bones, tonsillitis and recurrent tonsillitis. A list of laryngological infections and those related to skull and neck bones was presented with descriptions of the following diseases: rhinosinusitis, necrotizing sinusitis, nasal polyps, nares and nasal skin infections, periprosthetic joint infections, osteomyelitis, pharyngitis, and tonsillitis. Species identification and diagnostic problems challenging for diagnosticians are presented. Concluding remarks regarding the presence of CoNS in humans and their distribution, particularly under the effect of facilitating factors, are mentioned. [ABSTRACT FROM AUTHOR]

Background: Coagulase-negative staphylococci, which belong to the normal microbiota of the skin and mucous membranes, are opportunistic pathogens. sasX, a newly described protein, is thought to play an important role in nasal colonization and methicillin-resistant Staphylococcus aureus virulence, and it may be acquired from coagulase-negative staphylococci by horizontal gene transfer. It has been considered that understanding the function of sasX gene may help clarify the relevance of the different adhesion mechanisms in the pathogenesis of infections associated with biofilm. Aims: To investigate the sasX gene presence, staphylococcal cassette chromosome mec types, and antimicrobial resistance patterns of invasive and noninvasive coagulase-negative staphylococci isolates. Study Design: Cross-sectional study. Methods: The study included a total of 180 coagulase-negative staphylococci strains. Non-invasive isolates (n=91) were obtained from the hands of healthy volunteers who do not work at the hospital (n=30), the nasal vestibule of healthy volunteer hospital workers (n=26), and central venous catheter (n=35). Invasive isolates (n=89) were isolated from peripheral blood cultures of inpatients who do not have catheters. All isolates were identified by conventional microbiological methods, automated systems, and, if needed, with matrix-assisted laser desorption/ionization-time of flight. Staphylococcal cassette chromosome mec typing, sasX and mec gene detection, antibiotic susceptibility, and sasX gene sequence analysis were performed. Results: Peripheral blood, central venous catheter colonization, and nasal vestibule isolates were positive for the sasX gene, whereas hand isolates were negative. sasX gene was present in 17 isolates, and no statistical significance was found between invasive and noninvasive isolates (p=0.173). Sequence analysis of the sasX genes showed high homology to related proteins of Staphylococcus phage SPbeta-like and Staphylococcus epidermidis RP62A. staphylococcal cassette chromosome mec type V was the most prevalent regardless of species. staphylococcal cassette chromosome mec type II was more frequent in invasive isolates and found to be statistically important for invasive and noninvasive S. epidermidis isolates (p=0.029). Staphylococcus haemolyticus isolates had the overall highest resistance rates. Resistance to ciprofloxacin, trimethoprim-sulfamethoxazole, and erythromycin was found to be higher in isolates from catheter and blood culture. Staphylococcus hominis isolates had the highest rate for inducible clindamycin resistance. None of the isolates were resistant to vancomycin, teicoplanin, and linezolid. Conclusion: The sasX gene is detected in 9.44% of the isolates. There is no statistical difference between the sasX-positive and -negative isolates in terms of antibacterial resistance and the presence of sasX and SCCmec types. Further studies about the role of sasX at virulence in coagulase-negative staphylococci, especially from clinical samples such as tracheal aspirate and abscess isolates, and distribution of staphylococcal cassette chromosome mec types are needed. [ABSTRACT FROM AUTHOR]

To identify the molecular characteristics of Gram-positive cocci isolated from blood cultures and clinical outcome among critically ill patients. This retrospective study was conducted in the general intensive care unit of the University General Hospital of Patras, Greece, during a 5-year period (2012–2016). All adult patients with a Gram-positive BSI were included. PCR was applied to identify mecA gene (staphylococci); vanA, vanB, and vanC genes (enterococci). Linezolid-resistant S. epidermidis, MRSA, and VRE were further typed by multilocus sequence typing. Mutations in region V of 23S rDNA and ribosomal protein L4were investigated by PCR and sequencing analysis. The presence of the cfr gene was tested by PCR. In total, 141 Gram-positive BSIs were included. Coagulase-negative staphylococci predominated (n = 69; 65 methicillin-resistant, 23 linezolid-resistant carrying both C2534T and T2504A mutations and belonging to the ST22 clone), followed by enterococci (n = 46; 11 vancomycin-resistant carrying vanA gene, classified into four clones), S. aureus (n = 22; 10 methicillin-resistant, classified into three clones) and streptococci (n = 4). The most common type of infection was catheter-related (66; 46.8%), followed by primary BSI (28; 19.9%). Overall 14-day fatality was 24.8%. Multivariate analysis revealed septic shock as independent predictor of fatality, while appropriate empiric antimicrobial treatment and catheter-related BSI were identified as a predictor of good prognosis. Even though most of Gram-positive cocci were multidrug-resistant, fatality rate was low, associated with catheter-related BSIs. Among CNS, LR isolates represented one-third of BSIs due to the dissemination of ST22 S. epidermidis propagated by utilization of linezolid. [ABSTRACT FROM AUTHOR]

Empirical combination therapy with β-lactams and glycopeptides is recommended for patients with presumed staphylococcal bloodstream infection (BSI). While coagulase-negative staphylococci (CNS) remain susceptible to vancomycin, such isolates have become less susceptible to teicoplanin. The aim of this retrospective study was to evaluate the clinical efficacy of teicoplanin in the treatment of BSI caused by methicillin-resistant CNS according to teicoplanin susceptibility. Inclusion criteria were patients with intravascular-catheter related BSIs caused by methicillin-resistant CNS (positive for two or more specimens); teicoplanin therapy; and at least one of the signs or symptoms caused by BSI. Antimicrobial resistance was defined as minimum inhibitory concentration (MIC) ≥8 μg/mL. The primary efficacy endpoint was clinical success evaluated 2 weeks after the completion of teicoplanin therapy [test of cure (TOC)]. Resistant rate of CNS was 0% for vancomycin and 22.9% for teicoplanin, and geometric mean MICs were 1.31 μg/mL and 3.41 μg/mL, respectively (p < 0.001). The catheter was removed in all patients except one, and high early clinical response at 72 h after starting therapy was obtained irrespective of teicoplanin susceptibility. The clinical success rate at TOC was 60% in patients with BSIs caused by teicoplanin-resistant strains, while 90% in patients with BSIs caused by susceptible strains (p = 0.052). In multivariate analyses, teicoplanin resistance was significant factor for decreased clinical success at TOC (adjusted odds ratio 0.138, 95% confidence interval 0.020–0.961, p = 0.045). Because of the poor clinical efficacy of teicoplanin against teicoplanin-resistant CNS, combination therapy comprising vancomycin and β-lactam antibiotics should be considered in presumed staphylococci BSI. [ABSTRACT FROM AUTHOR]

Our objective was to assess the enterotoxigenic potential of coagulase-negative staphylococci (CNS) isolated from bovine milk in Poland. We analyzed CNS isolates collected from 133 bovine milk batches from dairy farms in the Western Pomerania district during 2 milking seasons. A total of 163 isolates were screened by multiplex/duplex PCR for the presence of 18 of 25 enterotoxin genes identified so far in Staphylococcus aureus. The CNS strains presumed to be potentially enterotoxigenic were identified at the species level based on MALDI-TOF mass spectrometry analysis. Based on the presence of an amplicon matching D, G, or O enterotoxin genes, we initially identified 32 of the 163 CNS isolates tested as potentially enterotoxigenic. However, only 8 of these strains were confirmed as such. All 8 of these CNS strains, identified as Staphylococcus haemolyticus , harbored the seg genes, a prerequisite for enterotoxin G production, but so far not connected with staphylococcal foodborne poisoning cases. None of the CNS bovine milk isolates tested was a potential producer of classical A to E staphylococcal enterotoxins. Results of our surveys revealed a low prevalence of enterotoxigenic CNS among the milk isolates from dairy farms in the Western Pomerania district, Poland, suggesting that they pose only a mild health risk in milk. In our opinion, confirmed formation of nonspecific amplicons leading to false-positive results excludes multiplex/duplex PCR as the sole method for assessing the enterotoxigenic potential of CNS. [ABSTRACT FROM AUTHOR]

The epidemiology of coagulase-negative staphylococcal (CNS) bacteremia among adult ICU patients remains unclear. Decontamination studies among ICU patients provide a unique opportunity to study the impacts of different diagnostic criteria, exposure to various decontamination interventions, and various other factors, on its incidence over three decades. Decontamination studies among ICU patients reporting CNS bacteremia incidence data were obtained mostly from recent systematic reviews. The CNS bacteremia incidence within component (control and intervention) groups of decontamination studies was benchmarked versus studies without intervention (observational groups). The impacts of antibiotic versus chlorhexidine decontamination interventions, control group concurrency, publication year, and diagnostic criteria were examined in meta-regression models. Among non-intervention (observational) studies which did versus did not specify stringent (≥ 2 positive blood cultures) diagnostic criteria, the mean CNS bacteremia incidence per 100 patients (and 95% CI; n) is 1.3 (0.9–2.0; n = 23) versus 3.6 (1.8–6.9; n = 8), respectively, giving an overall benchmark of 1.8 (1.2–2.4; n = 31). Versus the benchmark incidence, the mean incidence is high among concurrent control (5.7; 3.6–9.1%) and intervention (5.2; 3.6–6.9%), but not non-concurrent control (1.0; 0.4–3.9%) groups of 21 antibiotic studies, nor among eleven component groups of chlorhexidine studies. This high incidence remained apparent (p < 0.01) in meta-regression models adjusting for group wide factors such as diagnostic criteria and publication year. The incidence of CNS bacteremia within both intervention and concurrent (but not non-concurrent) control groups of antibiotic-based decontamination studies are unusually high even accounting for variable diagnostic criteria and other factors. [ABSTRACT FROM AUTHOR]

Introduction: Compared to Staphylococcus aureus, coagulase-negative staphylococci (CoNS) are characterized by a lower capacity to cause acute, live-threatened infections. CoNS are, however, of ever increasing importance as pathogens causing infections in immunocompromised patients and after foreign-material implantation. Typically, antibiotics fail to cure foreign body-related infections and removal of the implanted device is inevitable.Areas covered: This review focuses on the emergence of CoNS species, their pathogenic potential in particular due to their ability to form therapy-refractory biofilms on biotic and abiotic surfaces and evasion strategies to resist host response and antibiotic treatment. Their medical significance and proven and novel therapy strategies are discussed.Expert opinion: CoNS contribute significantly to morbidity and socio-economic costs. The anticipated developments in modern medicine, in particular the increasing use of foreign materials and the rising numbers of immunocompromised patients, as well as the changing demographic and hospital-related factors will inevitably contribute to further emergence of CoNS infections. Increasing rates of (multi-)resistant CoNS strains will limit the therapeutic armamentarium and aggravate treatment strategies. Increased research is necessary to understand their role as resistance and virulence gene reservoir and to reduce CoNS infections by the development of innovative colonization-preventing materials and other CoNS-tailored treatment strategies. [ABSTRACT FROM AUTHOR]