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Bacterial resistance, a global public health concern prioritized by the World Health Organization, is particularly alarming in Staphylococcus aureus and Escherichia coli. Urgently addressing this, the search for new antibiotics has turned to plant essential oils. Our study focused essential oils derived from Colombian plants Croton killipianus, Croton smithianus, Croton leptostachyus, Croton hondensis, and Croton gossypiifolius. We performed antimicrobial susceptibility tests targeting Staphylococcus aureus, methicillin-resistant Staphylococus aureus, sensitive Escherichia coli, and ampicillin- and streptomycin-resistant Escherichia coli. Simultaneosly, citotoxic assays and chemical analysis were carried out. The essential oil derived from C. hondensis demonstrated superior inhibitory efficacy, effectively targeting methicillin-resistant S. aureus, susceptible S. aureus, and both sensitive and ampicillin- and streptomycin-resistant strains of E. coli. Furthermore, it exhibited notable potential for protective activity in Chinese hamster ovary cells. C. killipianus manifested inhibitory effects against MRSA and susceptible S. aureus, whereas C. smithianus specifically affected susceptible strains of S. aureus. Chemical analysis of the essential oils revealed rich content in phenolic compounds, flavonoids, tannins, and steroids. Gas-coupled mass spectrometry identified key compounds like γ-muurolene, α-humulene, (E)-caryophyllene, α-copaene, curcumene, and (E)-nerolidol. These findings underscore C. hondensis, C. killipianus, and C. smithianus as potential natural sources for antibacterial agent development. [ABSTRACT FROM AUTHOR]

Background/Objectives: Biofilm-associated infections, particularly those involving Candida auris and Staphylococcus aureus, pose significant challenges in clinical settings due to their resilience and resistance to conventional treatments. This study aimed to synthesize novel triazole derivatives containing a piperazine ring via click chemistry and evaluate their efficacy in disrupting biofilms formed by these pathogens. Methods: Triazole derivatives were synthesized using click chemistry techniques. The antimicrobial activity of the compounds was tested against planktonic cells of C. auris and S. aureus in single and dual-species culture conditions. Biofilm disruption efficacy was assessed, alongside the evaluation of physicochemical properties, oral bioavailability potential, and toxicity profiles. Results: The compound T3 demonstrated potent antimicrobial activity against planktonic cells of C. auris and S. aureus in both single and dual-species cultures. T3 exhibited significant efficacy in reducing microbial viability within biofilms formed by these pathogens. Physicochemical analyses revealed favorable solubility and permeability profiles, supporting its potential for oral bioavailability. Toxicity assessments showed a non-toxic profile, highlighting a promising safety margin for further development. Conclusions: This study underscores the anti-biofilm properties of novel triazole-piperazine derivatives, particularly T3, against single and dual-species biofilms of C. auris and S. aureus. These findings position T3 as a promising candidate for developing therapies targeting polymicrobial infections and provide a foundation for future research into alternative strategies for combating biofilm-associated infections. [ABSTRACT FROM AUTHOR]

Purpose: To explore antimicrobial resistance profiles and mupA gene characterization of Staphylococcus epidermidis recovered from facial skin of healthy females in Shanghai, China. Patients and Methods: In this study, we collected facial skin samples from 107 healthy females in Shanghai, China, and S. epidermidis isolation was performed. The minimal inhibitory concentrations of 10 antibiotics were determined for the S. epidermidis isolates using the agar dilution method. High-level mupirocin-resistant isolates were subjected to whole-genome sequencing and bioinformatics analysis. A total of 94 un-duplicated S. epidermidis isolates were obtained from 107 facial skin samples. Results: Antimicrobial susceptibility tests revealed that 23.4% of the 94 S. epidermidis isolates were resistant to oxacillin and positive for the mecA gene, which could be cauterized as methicillin-resistant S. epidermidis (MRSE). Resistance rates for erythromycin, clindamycin, tetracycline, ciprofloxacin, and gentamicin were 8.5%, 11.7%, 10.6%, 12.8%, and 1.1%, respectively. For mupirocin, the rates of low- and high-level resistance were 3.2% (3/94) and 11.7% (11/94), respectively. Resistance to vancomycin or linezolid was not observed. High-level mupirocin resistance in facial skin isolates is mediated by mupA. WGS and SNP-based phylogenetic analyses revealed diverse phylogenies among the 11 mupA-positive S. epidermidis isolates. Additionally, various resistance and virulence genes were identified in mupA-positive isolates. A new hybrid plasmid carrying mupA genes was found in two S. epidermidis isolates. Conclusion: We observed a considerable level of antimicrobial resistance to several antibiotics and the prevalence of abundant and diverse resistance and virulence genes in the facial skin-origin S. epidermidis isolates. This may pose a potential risk for both public health and S. epidermidis infection. [ABSTRACT FROM AUTHOR]

Background: Due to rising antibiotic-resistant microorganisms, there is a pressing need to screen approved drugs for repurposing and to develop new antibiotics for controlling infections. Current in vitro and ex vivo models have mostly been unsuccessful in establishing in vivo relevance. In this study, we developed a stringent ex vivo-burned porcine skin model with high in vivo relevance to screen topical antimicrobials. Methods: A 3 cm-diameter thermal injury was created on non-sterilized porcine skin using a pressure-monitored and temperature-controlled burn device. Commensals were determined pre- and post-burn. The burn wound was inoculated with a target pathogen, and efficacies of Silvadene, Flammacerium, Sulfamylon, and Mupirocin were determined. The in vivo relevance of this platform was evaluated by comparing the ex vivo treatment effects to available in vivo treatment outcomes (from our laboratory and published reports) against selective burn pathogens. Results: Approximately 1% of the commensals survived the skin burn, and these commensals in the burn wounds affected the treatment outcomes in the ex vivo screening platform. When tested against six pathogens, both Silvadene and Flammacerium treatment exhibited ~1–3 log reduction in viable counts. Sulfamylon and Mupirocin exhibited higher efficacy than both Silvadene and Flammacerium against Pseudomonas and Staphylococcus, respectively. The ex vivo treatment outcomes of Silvadene and Flammacerium against Pseudomonas were highly comparable to the outcomes of the in vivo (rats). Conclusions: The ex vivo model developed in our lab is a stringent and effective platform for antimicrobial activity screening. The outcome obtained from this ex vivo model is highly relevant to in vivo. [ABSTRACT FROM AUTHOR]

Background: This study aimed to develop and evaluate an antibacterial cream emulsion containing mupirocin using Cocamidopropyl betaine (CAPB) as an emulsifier. Mupirocin, a topical antibiotic effective against Staphylococcus aureus (including methicillin-resistant strains), was formulated into a cream to enhance its topical delivery. Materials and Methods: Mupirocin cream emulsion formulations were developed with varying concentrations of CAPB, PEG-400, and glycerol monostearate. The cream formulations were mainly evaluated for in vitro diffusion tests, antibacterial activity tests, and stability studies. Result and Discussion: CAPB produced a stable cream emulsion formulation (F7) at 30% concentration and 2% PEG-400. The formulation (F7) exhibited sustained drug release over 3.5 hours in the diffusion test. The formulation F7 showed a higher zone of inhibition, 32.16±2.2 mm, than the marketed mupirocin cream, 29.56±1.35 mm, for the Staphylococcus aureus strain. The prepared cream formulation F7 was found stable over 90 days at different temperature conditions (8±2°C, 25±2°C and 40±2°C). Conclusion: The study concludes that CAPB effectively enhances mupirocin cream solubility and antibacterial properties, making it a promising option for treating bacterial skin infections.

Abstract Severe cutaneous injuries may not heal spontaneously and may necessitate the use of supplementary therapeutic methods. Electrospun nanofibers possess high porosity and specific surface area, which provide the necessary microenvironment for wound healing. Here in, the nanofibers of Soluplus-soy protein isolate (Sol-SPI) containing mupirocin (Mp) were fabricated via electrospinning for wound treatment. The fabricated nanofibers exhibited water absorption capacities of about 300.83 ± 29.72% and water vapor permeability values of about 821.8 ± 49.12 g/m2 day. The Sol/SPI/Mp nanofibers showed an in vitro degradability of 33.73 ± 3.55% after 5 days. The ultimate tensile strength, elastic modulus, and elongation of the Sol/SPI/Mp nanofibers were measured as 3.61 ± 0.29 MPa, 39.15 ± 5.08 MPa, and 59.11 ± 1.94%, respectively. Additionally, 85.90 ± 6.02% of Mp loaded in the nanofibers was released in 5 days in vitro, and by applying the Mp-loaded nanofibers, 93.06 ± 5.40% and 90.40 ± 5.66% of S. aureus and E. coli bacteria were killed, respectively. Human keratinocyte cells (HaCat) demonstrated notable biocompatibility with the prepared nanofibers. Furthermore, compare to other groups, Sol-SPI-Mp nanofibers caused the fastest re-epithelialization and wound healing in a rat model. The findings of this study present a novel nanofiber-based wound dressing that accelerates the healing of severe skin wounds with the risk of infection.

Jing Sun,1 Tracy Lu,1 Yan Dang,1 Zigang Xu,2 Ying Liu2 1Medical & Scientific Affairs, Haleon (Formerly GSK Consumer Healthcare), Shanghai, People’s Republic of China; 2Department of Dermatology, Beijing Children’s Hospital, Capital Medical University, National Key Discipline of Pediatrics, Key Laboratory of Major Diseases in Children, Ministry of Education, National Center for Children‘s Health, Beijing, People’s Republic of ChinaCorrespondence: Ying Liu, Department of Dermatology, Beijing Children’s Hospital, Capital Medical University, National Key Discipline of Pediatrics, Key Laboratory of Major Diseases in Children, Ministry of Education, National Center for Children’s Health, Beijing, People’s Republic of China, Email ying_lemon@aliyun.comAbstract: Mupirocin, an antibiotic produced by Pseudomonas fluorescens, is mainly used for the topical treatment of various skin and soft tissue infections caused by Staphylococcus (including methicillin-resistant Staphylococcus aureus) and Streptococcus around the world for decades. Nevertheless, the clinical application scope of mupirocin varies in different countries due to differences in their medical policies, prescription types, and drug resistance. According to the experience of Chinese doctors in the past few years, mupirocin presented low drug resistance rates, and could be used as a treatment option for various primary infections and secondary infections, with antibacterial effects in a broad application. In this review, we summarized the experience of mupirocin used in the Chinese population and discussed its clinical value to provide novel insights and inspiration for physicians.Keywords: experience, mupirocin, skin diseases, infectious

Backgrounds: The aim of the current study was to develop a distinctive nanolipid formulation, namely, nanostructured lipid carrier (NLC), which would deliver an antibacterial medication such as mupirocin (MP). Additionally, cinnamon essential oil (CEO), which is reported to exhibit antibacterial activity, was utilized in the development process in an attempt to improve the influence of MP. Methods: As a consequence, different MP–NLC formulations were developed using the central composite design (CCD) approach. One optimized formula was selected and incorporated within the pre-formulated gel matrix, providing the MP–NLC-gel formula for efficient topical application. MP–NLC-gel was assessed for its physical characteristics to check its suitability for topical application and evaluated for its in vitro drug release over 6 h. Furthermore, it studied the formulation for its stability at different conditions; 25°C ± 2°C and at 4°C ± 3°C for 6 months. Finally, the formulation was examined for its antibacterial performance against gram-positive and -negative bacteria. Results: The developed topical NLC-gel formulation demonstrated pH 5.8, viscosity 14,510 cP, and spreadability 58.1 mm, which were seemed to be satisfactory properties for successful topical application. The drug was released successfully for over 6 h with 52.9%. Additionally, it was stable in both storage conditions for 6 months since it displayed non-significant variations in its evaluated characteristics compared to those of fresh preparation. Ultimately, the developed gel formulation could inhibit the growth of different bacterial strains, especially gram-negative strains. Conclusion: To sum up, these findings would demonstrate the efficiency of NLC prepared with CEO and incorporating MP to be a promising antibacterial lipid nanocarrier. [ABSTRACT FROM AUTHOR]

Severe cutaneous injuries may not heal spontaneously and may necessitate the use of supplementary therapeutic methods. Electrospun nanofibers possess high porosity and specific surface area, which provide the necessary microenvironment for wound healing. Here in, the nanofibers of Soluplus-soy protein isolate (Sol-SPI) containing mupirocin (Mp) were fabricated via electrospinning for wound treatment. The fabricated nanofibers exhibited water absorption capacities of about 300.83 ± 29.72% and water vapor permeability values of about 821.8 ± 49.12 g/m2 day. The Sol/SPI/Mp nanofibers showed an in vitro degradability of 33.73 ± 3.55% after 5 days. The ultimate tensile strength, elastic modulus, and elongation of the Sol/SPI/Mp nanofibers were measured as 3.61 ± 0.29 MPa, 39.15 ± 5.08 MPa, and 59.11 ± 1.94%, respectively. Additionally, 85.90 ± 6.02% of Mp loaded in the nanofibers was released in 5 days in vitro, and by applying the Mp-loaded nanofibers, 93.06 ± 5.40% and 90.40 ± 5.66% of S. aureus and E. coli bacteria were killed, respectively. Human keratinocyte cells (HaCat) demonstrated notable biocompatibility with the prepared nanofibers. Furthermore, compare to other groups, Sol-SPI-Mp nanofibers caused the fastest re-epithelialization and wound healing in a rat model. The findings of this study present a novel nanofiber-based wound dressing that accelerates the healing of severe skin wounds with the risk of infection. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus is an important pathogen that causes mild to invasive infections in hospitals and the community. Although methicillinsusceptible Staphylococcus aureus (MSSA) isolates continue to cause different infections, there is no data on the genetic backgrounds of the MSSA colonizing or causing infections in Kuwait hospitals. This study aimed to investigate MSSA isolated from patients admitted to Kuwait hospitals for antibiotic resistance and genetic backgrounds to understand their clonal composition. Methods: Consecutive MSSA isolates were collected from single patients during two surveillance periods in 2016 and 2021 in 13 public hospitals. The isolates were characterized using antibiogram, staphylococcal protein A (spa) typing, DNA microarray analysis, and multilocus sequence typing (MLST) using standard protocols. Results: A total of 446 MSSA was cultured from different clinical samples in 2016 (n  =  240) and 2021 (n  =  206). All isolates were susceptible to vancomycin [minimum inhibitory concentration (MIC) ≤  2  mg/L], teicoplanin (MIC ≤2  mg/L), linezolid (MIC ≤4  mg/L), ceftaroline (MIC ≤2  mg/L), rifampicin, and mupirocin but were resistant to erythromycin (21.3%), clindamycin (14.0%), gentamicin (3.8%), kanamycin (10.5%), fusidic acid (27.0%), tetracycline (6.9%), trimethoprim (23.1%), and ciprofloxacin (35.2%). Molecular typing identified 155 spa types, dominated by t127 (15.0%), t084 (5.4%), t3841 (5.4%), t267 (2.4%), t442 (2.2%), t091 (2.2%), t021 (2.2%), and t003 (2.2%); 31 clonal complexes (CCs); and 56 sequence types (STs). The majority of the isolates (n  =  265; 59.4%) belonged to CC1 (20.6%), CC15 (10.9%), CC22 (5.1%), CC30 (7.6%), CC361 (10.1%), and CC398 (4.7%). Discussion: The MSSA isolates belonged to diverse genetic backgrounds dominated by CC1, CC15, CC22, CC30, CC361, and CC398. The distribution of MSSA clones in 2016 and 2021 showed the stability of these clones over time. The study provides the first comprehensive data on the clonal distribution of MSSA in Kuwait hospitals. [ABSTRACT FROM AUTHOR]

Background: Bacterial pathogens such as Staphylococcus aureus colonize body surfaces of part of the human population, which represents a critical risk factor for skin disorders and invasive infections. However, such pathogens do not belong to the human core microbiomes. Beneficial commensal bacteria can often prevent the invasion and persistence of such pathogens by using molecular strategies that are only superficially understood. We recently reported that the commensal bacterium Staphylococcus lugdunensis produces the novel antibiotic lugdunin, which eradicates S. aureus from the nasal microbiomes of hospitalized patients. However, it has remained unclear if S. lugdunensis may affect S. aureus carriage in the general population and which external factors might promote S. lugdunensis carriage to enhance its S. aureus-eliminating capacity. Results: We could cultivate S. lugdunensis from the noses of 6.3% of healthy human volunteers. In addition, S. lugdunensis DNA could be identified in metagenomes of many culture-negative nasal samples indicating that cultivation success depends on a specific bacterial threshold density. Healthy S. lugdunensis carriers had a 5.2-fold lower propensity to be colonized by S. aureus indicating that lugdunin can eliminate S. aureus also in healthy humans. S. lugdunensis-positive microbiomes were dominated by either Staphylococcus epidermidis, Corynebacterium species, or Dolosigranulum pigrum. These and further bacterial commensals, whose abundance was positively associated with S. lugdunensis, promoted S. lugdunensis growth in co-culture. Such mutualistic interactions depended on the production of iron-scavenging siderophores by supportive commensals and on the capacity of S. lugdunensis to import siderophores. EJt4aqYa_PFzdC4ihACHg3 Video Abstract Conclusions: These findings underscore the importance of microbiome homeostasis for eliminating pathogen colonization. Elucidating mechanisms that drive microbiome interactions will become crucial for microbiome-precision editing approaches. [ABSTRACT FROM AUTHOR]

Background: Wound management is an extremely important clinical and societal concern. Research into the delayed healing process is progressing rapidly, as indicated by novel therapy strategies, such as nano-drug therapy, which is not conventional. Mupirocin is a commonly used antibiotic in wound healing. However, various novel delivery methods have been developed to improve patient compliance, reduce bacterial resistance, and boost mupirocin delivery. Therefore, this pilot study was conducted with the aim of evaluating the effectiveness of mupirocin nanomicelles in insulin-based gel in the management of open skin wounds in Iraqi participants. Materials & methods: A randomized case-control, clinical trial pilot study including 40 skin-wounded patients was conducted in a private surgery clinic in Al-Zubair-Basrah, Iraq. The patients were randomly assigned to two treatment groups (20 male & 20 female patients each): mupirocin nanomicelles in insulin-based gel (2%), and mupirocin gel (2%). They were followed for 5 days. The percentage of wound contraction (% Wound Contraction) was measured and the wound areas were photographed. Results: On day 5 of treatment, all cases treated with mupirocin nanomicells in insulin-based gel showed complete healing (% Wound Contraction = 100) without signs of infection, compared to the mupirocin-treated group (% Wound Contraction = 90.8±1.04) with four cases of infections (p = 0.001). The majority of wounds were located in the arms. Conclusion: The findings suggested that mupirocin nanomicells in insulin-based gel could have applications in the future, as it can promote improved acute wound healing in various regions of the body, percentage of wound contraction, and infection-free status. [ABSTRACT FROM AUTHOR]

Chronic non‐healing wounds pose significant challenges due to an elevated inflammatory response caused in part by bacterial contamination (Physiol Rev. 2019;99:665). These wounds lead to billions being spent in the health care system worldwide (N Engl J Med. 2017;376:2367, Int J Pharm. 2014;463:119). We studied the in‐vitro and in‐vivo antimicrobial effects of a multimodal wound matrix (MWM) against two common wound pathogens, Methicillin‐Resistant Staphylococcus aureus (MRSA USA300) and Pseudomonas aeruginosa ATCC 27312 (PA27312) (Int Wound J. 2019;16:634). The in‐vitro study conducted was a zone of inhibition test with the two microbes at 104 Log CFU/mL inoculated on Tryptic soy agar with 5% sheep blood (TSAII) plates. Treatments used were MWM, Mupirocin (Positive control for MRSA), Silver Sulfadiazine (Positive Control for PA), Petrolatum and Sterile Saline (both serving as Negative Controls). Treatments were allowed to diffuse into the agar for 3 h and then were incubated for 24 h at 37°C. The in‐vivo study utilized a deep dermal porcine wound model (22 × 22 × 3 mm) created on six animals. Three animals were inoculated with MRSA USA300 and the other three with PA27312 with each allowing a 72‐h biofilm formation. After 72 h, baseline wounds were assessed for bacterial concentration and all remaining wounds were treated with either MWM alone, Silver Treatment or Untreated Control. Wounds were assessed on days 4, 8 and 12 after treatment application for microbiological analysis. In‐vitro, MWM exhibited significant inhibition of MRSA USA300 and PA27312 growth when compared to negative controls (p ≤ 0.05). Likewise, in‐vivo, the MWM‐treated wounds exhibited a significant (p ≤ 0.05) bacterial reduction compared to all other treatment groups, especially on days 8 and 12 for both pathogens. MWM demonstrated promise in addressing colonized wounds with biofilms. Additional studies on MWM's benefits and comparisons with existing treatments are warranted to optimize wound care strategies (Adv Wound Care. 2021;10:281). [ABSTRACT FROM AUTHOR]

By combining mechanical treatment of aluminium alloy with subsequent surface modification using micro-arc oxidation (MAO) technology, zinc oxide (ZnO) oxide coatings were prepared, which achieved enhanced hydrophobic properties, excellent antibacterial activity and corrosion resistance. The coatings were oxidised at different MAO discharge intensities using different frequencies. All surfaces were subjected to determination of wettability, corrosion resistance and chemical stability at 1, 7, 14, and 28 days and antibacterial activity of the coatings against the bacterial population of Staphylococcus aureus, Escherichia coli with an evaluation of population inhibition after 24 h. The surfaces mechanically modified by blasting showed a hydrophobic character; their subsequent oxidation by MAO contributed to a significant increase in hydrophobic properties. The sample with the highest Zn content (1.1 wt%), prepared at an MAO source frequency of 222 Hz, i.e. at the most intense plasma discharge, showed the most significant chemical stability in simulated body fluid (SBF) and distilled water and showed the highest antibacterial activity after 24 h. Thus, blasting of aluminium alloy surfaces and their subsequent MAO in alkaline electrolyte allows to obtain oxide coatings with antibacterial, hydrophobic and corrosion-resistant properties with the possibility of their use on surfaces with potential occurrence of harmful bacteria. • Oxide layers on aluminium alloy were prepared in alkaline electrolyte. • Frequencies of 49, 95 and 222 Hz, blasting and MAO technology combination were used. • Mechanically modified layers and MAO coatings achieved hydrophobic properties. • ZnO-doped MAO coatings had antibacterial properties and higher corrosion resistance. [ABSTRACT FROM AUTHOR]

Introduction: Neonatal myiasis is a rare condition, with few reports available on the subject. Surgical management is recommended in some cases. In this study, we present the case of a 7-day-old male neonate with larvae in his scrotum who underwent surgery. Case presentation: A full-term 7-day-old male infant (Aryan race) was referred to a children's hospital. On the sixth day after birth, three 3–4 mm long larvae crawled out from his scrotum, with the number increasing over time. He was given intravenous antibiotics and topical mupirocin to combat secondary infections. The surgical treatment involved two steps: first, the larvae were extracted, and then the infection site was washed with betadine and hydrogen peroxide to help remove any possible remaining larvae. Conclusion: Scrotal myiasis is a rare disease that occurs in infants and requires immediate treatment. Surgical treatment is effective in removing dead or decaying larvae from a deep-seated location and washing the infection site to prevent secondary infection. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is a new update on the resistance profile, Macrolide–Lincosamide–Streptogramin B resistance mechanisms and biofilm formation in the Staphylococcus aureus isolated from health care workers (HCWs) nasal carriage at a children's teaching hospital in Babol (Northern Iran). Results: A total of 143 non-repetitive nasal swab samples were collected from volunteers, where 53.8% (n; 77/143) were HCWs, 33.6% (n; 48/143) medical students, and 12.6% (n; 18/143) resident students. The prevalence of nasal carriers of S. aureus was 22.4% (n; 32/143), among them, 40.6% (n; 13/32) were identified as methicillin-resistant Staphylococcus aureus (MRSA(carriers. Antimicrobial susceptibility testing showed that erythromycin (68.8%, n; 22/32) and ciprofloxacin (15.6%, n; 5/32) had the highest and lowest resistance rate, respectively. The frequency of resistance genes in the strains was as follows; ermC (n; 17/32, 53.1%), ermA (n; 11/32, 34.4%), ermB (n; 6/32, 18.7%), ereA (n; 3/32, 9.4%). Moreover, 50.0% (n; 16/32), 28.1% (n; 9/32) and 21.8% (n; 7/32) of isolates were strongly, weakly and moderately biofilm producer, respectively. Macrolides-lincosamides-streptogramins B (MLSB) antibiotic resistance among S. aureus isolates from HCWs nasal carriage have found significant prevalence rates throughout the globe. It is crucial to remember that the development of biofilms and MLS B antibiotic resistance are both dynamic processes. [ABSTRACT FROM AUTHOR]

Introduction: Staphylococcus aureus is an identified pathogen involved in the recurrence of symptoms in patients with chronic rhinosinusitis with nasal polyps. We investigated the effectiveness of a topical ointment of mupirocin applied in the nasal vestibule in lessening symptom recurrence and improving the efficiency of functional endoscopic sinus surgery. Materials and Methods: Patients with chronic rhinosinusitis, nasal polyps, and a positive nostril culture for Staphylococcus aureus were included in a clinical trial. The right nostril was determined as the intervention group (applying mupirocin ointment) and the left as the control group (applying vitamin A ointment). Lund-Mackay radiological scores and Lund-Kennedy endoscopic scores were examined at the time of diagnosis and six months later. Results: Among 60 patients with chronic rhinosinusitis with nasal polyps, 91.6% were positive for nostril Staphylococcus aureus. Comparing the average of the diagnostic radiological and endoscopic scores with the follow-up values in both groups indicated a significant improvement after surgery (Pvalue= 0.001, 0.001). However, there was no significant difference in the radiological and endoscopic score improvements between the study and control groups (P-value > 0.56, 0.74). Conclusion: Nasal mupirocin administration following endoscopic sinus surgery cannot significantly prevent symptom recurrence in chronic rhinosinusitis with nasal polyps. [ABSTRACT FROM AUTHOR]

Chitosan-based biomaterials are being investigated for their unique properties that support skin regeneration and wound healing. This study focused on the preparation and characterization of a mupirocin (Mup)-loaded PEGylated chitosan (CS-PEG) nanoparticulate film (NF) [CBNF]. The CBNF was characterized using FTIR spectroscopy and SEM analysis. The results demonstrated that CBNF was successfully incorporated into the composites, as shown by functional group modification through FTIR analysis. Additionally, the SEM micrograph revealed the deposition of nanoparticles (<200 nm) on the surface of transparent CBNF. The film has higher water absorption (≥1700%) and moderate water retention ability within 6 h. Furthermore, histological findings showed significant development, with re-epithelialization and granulation of tissues after 19 days, indicating the healing efficiency of CNBF. These results suggest that drug-loaded films could be an effective carrier and delivery agent for Mup-like anti-inflammatory drugs. [ABSTRACT FROM AUTHOR]

Purpose: Biofilms significantly contribute to the persistence and antibiotic resistance of Staphylococcus aureus infections. However, the regulatory mechanisms governing biofilm formation of S. aureus remain not fully elucidated. This study aimed to investigate the function of the S. aureus lineage-specific two-component system, desKR, in biofilm regulation and pathogenicity. Methods: Bioinformatic analysis was conducted to assess the prevalence of desKR across various S. aureus lineages and to examine its structural features. The impact of desKR on S. aureus pathogenicity was evaluated using in vivo mouse models, including skin abscess, bloodstream infection, and nasal colonization models. Crystal violet staining and confocal laser scanning microscopy were utilized to examine the impact of desKR on S. aureus biofilm formation. Mechanistic insights into desKR-mediated biofilm regulation were investigated by quantifying polysaccharide intercellular adhesin (PIA) production, extracellular DNA (eDNA) release, autolysis assays, and RT-qPCR. Results: The prevalence of desKR varied among different S. aureus lineages, with notably low carriage rates in ST398 and ST59 lineages. Deletion of desKR in NCTC8325 strain resulted in decreased susceptibility to β-lactam and glycopeptide antibiotics. Although desKR did not significantly affect acute pathogenicity, the ΔdesKR mutant exhibited significantly reduced nasal colonization and biofilm-forming ability. Overexpression of desKR in naturally desKR-lacking strains (ST398 and ST59) enhanced biofilm formation, suggesting a lineage-independent effect. Phenotypic assays further revealed that the ΔdesKR mutant showed reduced PIA production, decreased eDNA release, and lower autolysis rates. RT-qPCR indicated significant downregulation of icaA, icaD, icaB, and icaC genes, along with upregulation of icaR, whereas autolysis-related genes remained unchanged. Conclusion: The desKR two-component system positively regulates S. aureus biofilm formation in a lineage-independent manner, primarily by modulating PIA synthesis via the ica operon. These findings provide new insights into the molecular mechanisms of biofilm formation in S. aureus and highlight desKR as a potential target for therapeutic strategies aimed at combating biofilm-associated infections. [ABSTRACT FROM AUTHOR]

ImportanceUniversal nasal mupirocin plus chlorhexidine gluconate (CHG) bathing in intensive care units (ICUs) prevents methicillin-resistant Staphylococcus aureus (MRSA) infections and all-cause bloodstream infections. Antibiotic resistance to mupirocin has raised questions about whether an antiseptic could be advantageous for ICU decolonization.ObjectiveTo compare the effectiveness of iodophor vs mupirocin for universal ICU nasal decolonization in combination with CHG bathing.Design, setting, and participantsTwo-group noninferiority, pragmatic, cluster-randomized trial conducted in US community hospitals, all of which used mupirocin-CHG for universal decolonization in ICUs at baseline. Adult ICU patients in 137 randomized hospitals during baseline (May 1, 2015-April 30, 2017) and intervention (November 1, 2017-April 30, 2019) were included.InterventionUniversal decolonization involving switching to iodophor-CHG (intervention) or continuing mupirocin-CHG (baseline).Main outcomes and measuresICU-attributable S aureus clinical cultures (primary outcome), MRSA clinical cultures, and all-cause bloodstream infections were evaluated using proportional hazard models to assess differences from baseline to intervention periods between the strategies. Results were also compared with a 2009-2011 trial of mupirocin-CHG vs no decolonization in the same hospital network. The prespecified noninferiority margin for the primary outcome was 10%.ResultsAmong the 801 668 admissions in 233 ICUs, the participants' mean (SD) age was 63.4 (17.2) years, 46.3% were female, and the mean (SD) ICU length of stay was 4.8 (4.7) days. Hazard ratios (HRs) for S aureus clinical isolates in the intervention vs baseline periods were 1.17 for iodophor-CHG (raw rate: 5.0 vs 4.3/1000 ICU-attributable days) and 0.99 for mupirocin-CHG (raw rate: 4.1 vs 4.0/1000 ICU-attributable days) (HR difference in differences significantly lower by 18.4% [95% CI, 10.7%-26.6%] for mupirocin-CHG, P

Allergic contact dermatitis is a rare cause of emergency room visits. However, it can progress to life-threatening conditions such as urticaria and angioedema. In this report, we describe a case that developed severe allergic contact dermatitis around the eye applying an eyelash dye containing p-Phenylenediamine. A 21-year-old female patient was admitted to the emergency department with the complaint of swelling and redness around both eyes. Swelling and redness started 3 days ago with permanent eyelash dye (containing p-Phenylenediamine) application in the beauty center. Clinically, periocular edema and rash was suspected to be an allergic reaction to a substance contained in the eyelash dye. For allergic contact dermatitis, 40 mg methylprednisolone, 45.5 mg pheniramine maleate, IV bolus was administered. The vesicular rash was thought to be a herpes lesion. She was discharged from the emergency department, with an initial dose of 16 mg methyl prednisolone (discontinued by reducing the dose), 500 mg oral valacyclovir twice a day, mupirocin cream on twice a day and oral levocetrizine 5 mg once daily. It was observed that the patient's lesions and redness regressed after 2 weeks. The effects of cosmetic products, which are the agents that come into contact with the skin most often, may differ individually. Agents included in cosmetic products, such as in our case, may cause severe contact dermatitis that requires treatment. Beauticians should also be informed about PPD. Patients who have had allergic reactions due to the use of PPD-containing dyes should use PPD-free cosmetic products. [ABSTRACT FROM AUTHOR]

Abstract Background Nasal carriage of Staphylococcus aureus is a risk factor for surgical site infections (SSI) in orthopaedic surgery. The efficacy of decolonisation for S. aureus on reducing the risk of SSI is uncertain in this speciality. The objective was to evaluate the impact of a nasal screening strategy of S. aureus and targeted decolonisation on the risk of S. aureus SSI. Methods A retrospective pre-post and here-elsewhere study was conducted between January 2014 and June 2020 in 2 adult orthopaedic surgical sites (North and South) of a French university hospital. Decolonisation with Mupirocin and Chlorhexidine was conducted in S. aureus carriers starting February 2017 in the South site (intervention group). Scheduled surgical procedures for hip, knee arthroplasties, and osteosyntheses were included and monitored for one year. The rates of S. aureus SSI in the intervention group were compared to a historical control group (South site) and a North control group. The risk factors for S. aureus SSI were analysed by logistic regression. Results A total of 5,348 surgical procedures was included, 100 SSI of which 30 monomicrobial S. aureus SSI were identified. The preoperative screening result was available for 60% (1,382/2,305) of the intervention group patients. Among these screenings, 25.3% (349/1,382) were positive for S. aureus and the efficacy of the decolonisation was 91.6% (98/107). The rate of S. aureus SSI in the intervention group (0.3%, 7/2,305) was not significantly different from the historical control group (0.5%, 9/1926) but differed significantly from the North control group (1.3%, 14/1,117). After adjustment, the risk factors of S. aureus SSI occurrence were the body mass index (ORaper unit, 1.05; 95%CI, 1.0-1.1), the Charlson comorbidity index (ORaper point, 1.34; 95%CI, 1.0–1.8) and operative time (ORaper minute, 1.01; 95%CI, 1.00–1.02). Having benefited from S. aureus screening/decolonisation was a protective factor (ORa, 0.24; 95%CI, 0.08–0.73). Conclusions Despite the low number of SSI, nasal screening and targeted decolonisation of S. aureus were associated with a reduction in S. aureus SSI.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. The chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here, we studied the antimicrobial activity of two synthetic PPAP-derivatives, the water-insoluble PPAP23 and the water-soluble sodium salt PPAP53. In vitro, both compounds exhibited good activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar effect was also seen with serum albumin. In silico docking studies with PPAP53 revealed that it binds to the F1 pocket of human serum albumin with a binding energy of −7.5 kcal/mol. In an infection model of septic arthritis, PPAP23 decreased the formation of abscesses and S. aureus load in kidneys; in a mouse skin abscess model, topical treatment with PPAP53 reduced S. aureus counts. Both PPAPs were active against anaerobic Gram-positive gut bacteria such as neurotransmitter-producing Clostridium, Enterococcus or Ruminococcus species. Based on these results, we foresee possible applications in the decolonization of pathogens. [ABSTRACT FROM AUTHOR]

Background: Antibiotic resistance is one of the most serious biomedical problems that require new agents to combat bacterial pathogens. Potassium aluminium sulphate (alum) has recently drawn the attention of the scientific community as an efficient, safe and eco-friendly inorganic compound with antimicrobial activity. Methods: Ten samples of bacteria, five types of Eschericha coli (E. coli) and five types of S. aureus were isolated from patients. Eschericha coli isolated from urine sample by sterile container. Staphylococcus aureus (S. aureus) isolated from wound samples by a cotton swab. The samples were cultured on the following media (Mannitol salt agar, eosin methylene blue agar, and blood agar). Well diffusion method used to evaluate the antimicrobial activity. Alum aqueous solution with two concentrations (1% and 2%) was determined as well as amoxicillin, gentamicin, and ceftriaxone. Results: E. coli is sensitive by 50%for both concentrations of alum (1%, 2%), S. aureus is 100% resistant to a concentration of 1% of alum and 50% resistant to a concentration of 2% of alum. Combination of amoxicillin with alum for each concentration (1% and 2%) has no significant effect on the activity of amoxicillin for both E. coli and S. aureus (p= 97 and p= 0.62) respectively. Combination of ceftriaxone with alum for each concentration (1% and 2%) has no significant effect. The combination of gentamicin with alum for each concentration in E. coli has no significant effect. But for S. aureus the mean of gentamicin sensitivity was 39.50± 3.87, the mean is decreased after combination with 1% alum 41.50± 4.35 and 2% alum 40± 5.83 with significant statically differences (p= 0.02). Conclusions: The white alum effect is dose response, and greater concentration will lead to enhanced decrease on bacterial growth. This study suggests more than 1% and 2% concentrations of white alum could be used as antimicrobial agent. The effect of 1% and 2% alum combined with ceftriaxone and amoxicillin shoed no significant differences (p> 0.05). [ABSTRACT FROM AUTHOR]

This study provides a comparative analysis of 243 Methicillin-resistant Staphylococcus aureus (MRSA) isolated strains from Greece and Romania, focusing on their epidemiology and antibiotic resistance patterns. Laboratory procedures included phenotypic and automated identification methods, susceptibility testing, DNA isolation, and PCR for detecting antibiotic resistance genes (MecA, SCCmec). Our study results show significant regional differences. In both regions, males have higher MRSA infection rates than females, but the percentages vary. Greece has a higher incidence of MRSA in younger age groups compared to Romania. The majority of MRSA infections occur in inpatient settings in both countries, highlighting the necessity for enhanced infection control measures. Antibiotic resistance profiles reveal higher resistance to several antibiotics in Greece compared to Romania. A molecular analysis shows a widespread distribution of antibiotic resistance genes among MRSA isolates in Greece. These results highlight the necessity for accomplished preventive strategies and optimized treatment protocols. [ABSTRACT FROM AUTHOR]

In response to the escalating global threat of antimicrobial resistance, our laboratory has established a phagemid packaging system for the generation of CRISPR-Cas13a-antimicrobial capsids targeting methicillin-resistant Staphylococcus aureus (MRSA). However, a significant challenge arose during the packaging process: the unintentional production of wild-type phages alongside the antimicrobial capsids. To address this issue, the phagemid packaging system was optimized by strategically incorporated silent mutations. This approach effectively minimized contamination risks without compromising packaging efficiency. The study identified the indispensable role of phage packaging genes, particularly terL-terS, in efficient phagemid packaging. Additionally, the elimination of homologous sequences between the phagemid and wild-type phage genome was crucial in preventing wild-type phage contamination. The optimized phagemid-LSAB(mosaic) demonstrated sequence-specific killing, efficiently eliminating MRSA strains carrying target antibiotic-resistant genes. While acknowledging the need for further exploration across bacterial species and in vivo validation, this refined phagemid packaging system offers a valuable advancement in the development of CRISPR-Cas13a-based antimicrobials, shedding light on potential solutions in the ongoing battle against bacterial infections. [ABSTRACT FROM AUTHOR]

Background: Nasal carriage of Staphylococcus aureus is a risk factor for surgical site infections (SSI) in orthopaedic surgery. The efficacy of decolonisation for S. aureus on reducing the risk of SSI is uncertain in this speciality. The objective was to evaluate the impact of a nasal screening strategy of S. aureus and targeted decolonisation on the risk of S. aureus SSI. Methods: A retrospective pre-post and here-elsewhere study was conducted between January 2014 and June 2020 in 2 adult orthopaedic surgical sites (North and South) of a French university hospital. Decolonisation with Mupirocin and Chlorhexidine was conducted in S. aureus carriers starting February 2017 in the South site (intervention group). Scheduled surgical procedures for hip, knee arthroplasties, and osteosyntheses were included and monitored for one year. The rates of S. aureus SSI in the intervention group were compared to a historical control group (South site) and a North control group. The risk factors for S. aureus SSI were analysed by logistic regression. Results: A total of 5,348 surgical procedures was included, 100 SSI of which 30 monomicrobial S. aureus SSI were identified. The preoperative screening result was available for 60% (1,382/2,305) of the intervention group patients. Among these screenings, 25.3% (349/1,382) were positive for S. aureus and the efficacy of the decolonisation was 91.6% (98/107). The rate of S. aureus SSI in the intervention group (0.3%, 7/2,305) was not significantly different from the historical control group (0.5%, 9/1926) but differed significantly from the North control group (1.3%, 14/1,117). After adjustment, the risk factors of S. aureus SSI occurrence were the body mass index (ORaper unit, 1.05; 95%CI, 1.0-1.1), the Charlson comorbidity index (ORaper point, 1.34; 95%CI, 1.0–1.8) and operative time (ORaper minute, 1.01; 95%CI, 1.00–1.02). Having benefited from S. aureus screening/decolonisation was a protective factor (ORa, 0.24; 95%CI, 0.08–0.73). Conclusions: Despite the low number of SSI, nasal screening and targeted decolonisation of S. aureus were associated with a reduction in S. aureus SSI. [ABSTRACT FROM AUTHOR]

Background: Infections caused by multidrug-resistant organisms (MDROs) have been increasingly reported from healthcare facilities. The spread of MDROs in hospitals further increases the financial burden on healthcare facility due to prolonged hospital stays and the need for more expensive investigations and treatment. Methicillin Resistant Staphylococcus aureus (MRSA) is known to be widely distributed in the healthcare facilities and accounts for a substantial proportion of the infectious disease burden. Hence, active surveillance for MRSA is carried out to identify colonized patients or Healthcare workers (HCWs) in a facility. This prospective study was conducted to study and compare the carriage of MRSA among doctors, nurses, General Duty Attendants (GDA) and Houseman/ House woman (HM/HW) working in cardiac unit of a tertiary care hospital. Screening was done by collecting swabs from hands and anterior nares. These specimens were processed by standard procedures for the isolation of Staphylococcus aureus and resistance to methicillin was determined using cefoxitin, 30µg disks as per Clinical and Laboratory Standards Institute (CLSI) guidelines. The carriage rate of MRSA was found to be highest among HM/HW (13%) followed by nurses (8%) and GDA (7%). Out of 11 doctors screened, none was found to carry MRSA. A higher percentage carriage in HM/HW can probably be accounted to their close and prolonged contact with infected patients and involvement in activities like emptying urinary bags, floor mopping and other activities of environmental cleaning. Management of MRSA carriers include applying stringent hand hygiene, contact precautions and core strategies including isolating and cohorting patients, increased environmental cleaning, dedicated patient equipment and decolonization. Active surveillance including screening of HCWs can help in decreased risk of spread to their close contacts and further reduction of MRSA prevalence among patients. [ABSTRACT FROM AUTHOR]

A 35-year-old intramural male athlete presented to the athletic training staff with a 4.5- × 2.2-cm itchy, painful, swollen, and infected insidious skin lesion on his right lateral malleolus due to an underlying dermatologic deficiency. Suspecting infection, the patient was referred to his nurse practitioner and was diagnosed with atopic dermatitis caused by a ceramide deficiency. He was placed on cefalexin and mupirocin 2% ointment but returned due to the lesion increasing to 8.5 × 6 cm, although the infection seemed controlled. He was instructed to use Ceravé topical cream, clobetasol propionate 5%, and to consume foods rich in healthy oils (omega-3 fatty acids, olive oil). Unmitigated, this lesion could have resulted in severe infection and tissue damage. Atopic dermatitis is relatively common in the general population, but its appearance in healthy athletes highlights that athletic trainers need to be well versed in not just apparent causes of skin ailments (ie, infection) but also root causes. [ABSTRACT FROM AUTHOR]

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Pseudomonas bacteria are renowned for their remarkable capacity to synthesize antibiotics, namely mupirocin, gluconic acid, pyrrolnitrin, and 2,4-diacetylphloroglucinol (DAPG). While these substances are extensively employed in agricultural biotechnology to safeguard plants against harmful bacteria and fungi, their potential for human medicine and healthcare remains highly promising for common science. However, the challenge of obtaining stable producers that yield higher quantities of these antibiotics continues to be a pertinent concern in modern biotechnology. Although the interest in antibiotics of Pseudomonas bacteria has persisted over the past century, many uncertainties still surround the regulation of the biosynthetic pathways of these compounds. Thus, the present review comprehensively studies the genetic organization and regulation of the biosynthesis of these antibiotics and provides a comprehensive summary of the genetic organization of antibiotic biosynthesis pathways in pseudomonas strains, appealing to both molecular biologists and biotechnologists. In addition, attention is also paid to the application of antibiotics in plant protection. [ABSTRACT FROM AUTHOR]

ZnO nanorod nonwoven fabrics (ZNRN) were developed through hydrothermal synthesis to facilitate the prevention of the transmission of respiratory pathogens. The superhydrophobicity and antibacterial properties of ZNRN were improved through the response surface methodology. The synthesized material exhibited significant water repellency, indicated by a water contact angle of 163.9°, and thus demonstrated antibacterial rates of 91.8% for Escherichia coli (E. coli) and 79.75% for Staphylococcus aureus (S. aureus). This indicated that E. coli with thinner peptidoglycan may be more easily killed than S. aureus. This study identified significant effects of synthesis conditions on the antibacterial effectiveness, with comprehensive multivariate analyses elucidating the underlying correlations. In addition, the ZnO nanorod structure of ZNRN was characterized through SEM and XRD analyses. It endows the properties of superhydrophobicity (thus preventing bacteria from adhering to the ZNRN surface) and antibacterial capacity (thus damaging cells through the puncturing of these nanorods). Consequently, the alignment of two such features is desired to help support the development of personal protective equipment, which assists in avoiding the spread of respiratory infections. [ABSTRACT FROM AUTHOR]

The chemical reaction of 2-(methylsulfinyl)naphtho[2,3-d]thiazole-4,9-dione (3) using different amines, including benzylamine (4a), morpholine (4b), thiomorpholine (4c), piperidine (4d), and 4-methylpiperazine (4e), produced corresponding new tricyclic naphtho[2,3-d]thiazole–4,9–dione compounds (5a–e) in moderate-to-good yields. The photophysical properties and antimicrobial activities of these compounds (5a–e) were then characterized. Owing to the extended π-conjugated system of naphtho[2,3-d]thiazole–4,9–dione skeleton and substituent effect, 5a–e showed fluorescence both in solution and in the solid state. The introduction of nitrogen-containing heterocycles at position 2 of the thiazole ring on naphtho[2,3-d]thiazole-4,9-dione led to large bathochromic shifts in solution, and 5b–e exhibited orange-red fluorescence with emission maxima of over 600 nm in highly polar solvents. Staphylococcus aureus (S. aureus) is a highly pathogenic bacterium, and infection with its antimicrobial-resistant pathogen methicillin-resistant S. aureus (MRSA) results in serious clinical problems. In this study, we also investigated the antimicrobial activities of 5a–e against S. aureus, MRSA, and S. epidermidis. Compounds 5c with thiomorpholine group and 5e with 4-methylpiperazine group showed potent antimicrobial activity against these bacteria. These results will lead to the development of new fluorescent dyes with antimicrobial activity in the future. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus can colonize and infect a variety of animal species. In dairy herds, it is one of the leading causes of mastitis cases. The objective of this study was to characterize the S. aureus isolates recovered from nasal swabs of 249 healthy cows and 21 breeders of 21 dairy farms located in two provinces of Algeria (Tizi Ouzou and Bouira). Methods: The detection of enterotoxin genes was investigated by multiplex PCRs. Resistance of recovered isolates to 8 antimicrobial agents was determined by disc-diffusion method. The slime production and biofilm formation of S. aureus isolates were assessed using congo-red agar (CRA) and microtiter-plate assay. Molecular characterization of selected isolates was carried out by spa-typing and Multi-Locus-Sequence-Typing (MLST). Results: S. aureus was detected in 30/249 (12%) and 6/13 (28.6%) of nasal swabs in cows and breeders, respectively, and a total of 72 isolates were recovered from positive samples (59 isolates from cows and 13 from breeders). Twenty-six of these isolates (36.1%) harbored genes encoding for staphylococcal enterotoxins, including 17/59 (28.8%) isolates from cows and 9/13 (69.2%) from breeders. Moreover, 49.1% and 92.3% of isolates from cows and breeders, respectively, showed penicillin resistance. All isolates were considered as methicillin-susceptible (MSSA). Forty-five (76.3%) of the isolates from cows were slime producers and 52 (88.1%) of them had the ability to form biofilm in microtiter plates. Evidence of a possible zoonotic transmission was observed in two farms, since S. aureus isolates recovered in these farms from cows and breeders belonged to the same clonal lineage (CC15-ST15-t084 or CC30-ST34-t2228). Conclusions: Although healthy cows in this study did not harbor methicillin-resistant S. aureus isolates, the nares of healthy cows could be a reservoir of enterotoxigenic and biofilm producing isolates which could have implications in human and animal health. [ABSTRACT FROM AUTHOR]

Bacterial RNAP needs to form holoenzyme with σ factors to initiate transcription. While Staphylococcus aureus σA controls housekeeping functions, S. aureus σB regulates virulence, biofilm formation, persistence, cell internalization, membrane transport, and antimicrobial resistance. Besides the sequence difference, the spacers between the −35 element and −10 element of σB regulated promoters are shorter than those of σA regulated promoters. Therefore, how σB recognizes and initiates transcription from target promoters can not be inferred from that of the well studied σ. Here, we report the cryo-EM structures of S. aureus RNAP-promoter open complexes comprising σA and σB, respectively. Structural analyses, in combination with biochemical experiments, reveal the structural basis for the promoter specificity of S. aureus transcription. Although the −10 element of σA regulated promoters is recognized by domain σA2 as single-stranded DNA, the −10 element of σB regulated promoters is co-recognized by domains σB2 and σB3 as double-stranded DNA, accounting for the short spacers of σB regulated promoters. S. aureus RNAP is a validated target of antibiotics, and our structures pave the way for rational drug design targeting S. aureus RNAP. Here, Yuan, Liu, and Xu et al. report cryo-EM structures of Staphylococcus aureus RNAP-promoter open complexes, highlighting distinct interactions of σA and σB with their cognate promoters. [ABSTRACT FROM AUTHOR]

Background: Dermatological infections in dogs are challenging to treat due to antibiotic resistance, which leads to longer recovery time and the need for stronger antibiotics. Aims: This study was undertaken to determine the prevalence of antimicrobial resistance in coagulase-positive staphylococcal isolates from pyoderma infection in dogs. This study also aimed to identify isolates with methicillin-resistance and multidrug resistance. Methods: 73 coagulase-positive staphylococci isolated from varying degrees of canine pyoderma cases. The samples were analyzed for the presence of Staphylococcus spp. using polymerase chain reaction (PCR) and resistance against antibiotics was studied by antimicrobial profile, minimum inhibitory concentration (MIC), and PCR on isolated bacteria. Results: Out of 75 bacterial isolates identified, 73 isolates were confirmed as Staphylococcus species by PCR. A higher percentage of antibiotic resistance was observed against penicillin-G (46.27%), followed by amoxiclav (38.81%), enrofloxacin (32.84%), cefpodoxime, oxytetracycline (28.36% each), levofloxacin (26.86%), and co-trimoxazole (22.39%). 29 (49.15%) S. pseudintermedius, three (50.00%) S. schleiferi subsp. coagulans, and two (100%) S. aureus isolates exhibited multidrug resistance. However, one (1.49%) isolate (S. pseudintermedius) revealed low-level mupirocin resistance in the E-test. Also, 12 (20.34%) methicillin-resistant Staphylococcus pseudintermedius (MRSP), one (16.67%) methicillin-resistant S. schleiferi subsp. coagulans (MRSS) and one (50%) methicillin-resistant S. aureus (MRSA) were reported using PCR. Conclusion: This study helps to understand the increased level and pattern of resistance in coagulase-positive staphylococci isolated from different types of canine pyoderma cases. [ABSTRACT FROM AUTHOR]