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Maria Teresa Mascellino, Federica Di Timoteo, Massimiliano De Angelis, Alessandra Oliva Department of Public Health and Infectious Diseases, Sapienza University, Rome, Lazio, ItalyCorrespondence: Maria Teresa MascellinoDepartment of Public Health and Infectious Diseases, Sapienza University, Piazzale Aldo Moro 5, Rome, 00185, ItalyTel +39 06 49970880Fax +39 06 49972628Email mariateresa.mascellino@uniroma1.itAbstract: This review takes into consideration the principal vaccines developed against the SARS-CoV-2 in this unprecedented period of Covid-19 pandemic. We evaluated the mechanism of action of each vaccine as well as the efficacy, the safety and the storage temperature. In addition, the problem of the dose units, the vaccinal strategy, the activity of alternative compounds such as the monoclonal antibodies and especially the issue of the virus variants were also described in detail. Four vaccines are currently used in Italy: Pfizer-BioNTech mRNA BNT162b2 (Comirnaty) (USA), Moderna mRNA 1273 (USA), Astra-Zeneca ChAdOx1-S (recombinant) viral vector adenovirus belonging to Oxford (UK) and Pomezia (Italy), Janssen (two recombinant viral vector adenoviruses) belonging to Johnson & Johnson (USA). The efficacy of Pfizer and Moderna for preventing disease or severe disease results 95– 87.5% and 94.5– 100%, respectively. The efficacy of Astra-Zeneca and Janssen is about 70% and 65%, respectively; in the case of Janssen, it depends on the geographical area ranging from 72% to 57%. The problem of the administrated doses (one dose, two doses from the same vaccine or from different vaccines, half dose) is also discussed. The vaccination strategy based on the age group remains the simplest, most transparent and fair criterion. This strategy is also based on accelerating the administration of the vaccines, so that as many subjects as possible can be vaccinated quickly for achieving the “herd immunity”. The monoclonal antibodies appeared to be a valid solution for the treatment of Covid-19 disease. Two antibodies (bamlanivimab and etesevimab) have just been approved by the FDA. They could also be used for the infection by virus variants which represent a big problem due to their higher transmissibility and virulence and to their lower response to the vaccines.Keywords: Covid-19 vaccines, vaccinal strategy, dose units, monoclonal antibodies, virus variants, vaccinal platforms

Maria Teresa Mascellino,1 Barbara Porowska,2 Massimiliano De Angelis,1 Alessandra Oliva1 1Department of Public Health and Infectious Diseases, 2Department of Cardio-Thoracic, Vascular, General Surgery and of Organ Transplants, Policlinico Umberto I, Rome, Italy Abstract: In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp) eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach) is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016) are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently approved in Japan, is also considered to be a promising solution for Hp eradication, even for clarithromycin-resistant strains. Furthermore, there is growing interest in finding new therapeutic strategies, such as the development of vaccines or the use of natural resources, including probiotics, plants, or nutraceuticals. Keywords: eradication, biopsies, rescue

Introduction: Real-life experience with imipenem/cilastatin/relebactam (IMI/REL) for the treatment of KPC-producing Klebsiella pneumoniae complex (KPC-Kp) and difficult-to-treat resistance (DTR) Pseudomonas aeruginosa (DTR-PA) infections is herein described., Methods: Adult patients with KPC-Kp or DTR-PA infections who received ≥48 h of IMI/REL were included. Clinical and microbiological outcomes were retrieved through the medical records. Primary outcome was clinical cure. Secondary outcomes included mortality from infection onset and adverse effects attributable to IMI/REL., Results: We included 10 patients with different infections caused by DTR-PA ( n  = 4), KPC-Kp [ n  = 5, of which 3 ceftazidime/avibactam-resistant (CTV-R KPC-Kp), 2 CTV susceptible (CTV-S KPC-Kp)] or both DTR-PA/KPC-Kp ( n  = 1) successfully treated with IMI/REL: 3 hospital-acquired pneumonia, 1 ventilator-associated pneumonia, 2 skin and soft tissue infections, 1 osteomyelitis, 2 bloodstream infections, 1 complicated urinary tract infection. Clinical cure was achieved in all cases. No patients died and no side effect were reported., Discussion: We reported the preliminary real-life experience on the successful and safe use of IMI/REL for the treatment of KPC-Kp or DTR-PA complicated infections, including pneumonia and bone infections., 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. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Leanza, Mascellino, Volpicelli, Covino, Falletta, Cancelli, Franchi, Carnevalini, Mastroianni and Oliva.)

Brucellosis is a highly contagious zoonotic disease and a major human health problem worldwide. Due to its ways of transmission, direct or indirect contact with infected animals or their contaminated biological products, the disease exhibits strong occupational association with animal handlers comprising a significant population at risk. This study was undertaken to estimate the seroprevalence of brucellosis in animal handlers and to understand the epidemiological and serological aspects of the same. The animal handlers from the state of West Bengal, India were included in this study. It was a prospective and observational cohort study from November 2021 to March 2022. A total of 669 sera samples were collected from animal handlers and tested using various serological tests for Brucella antibodies. All serum samples were tested using the Rose Bengal plate test (RBPT), standard tube agglutination test (STAT), and enzyme-linked immunosorbent assay (ELISA). 106 (15.8%) patients were diagnosed with brucellosis among the total number of patients tested. Most of the patients affected with brucellosis belonged to the age group 51-60 years (23.5%). The seropositivity rate in male animal handlers was higher than female animal handlers in this study. More studies are needed to understand the occupational association of this disease. Awareness programs, safe livestock practices, and prevention of the disease by timely diagnosis must be implemented in order to control human brucellosis., Competing Interests: Conflicts of interest: Maria Teresa Mascellino is an editorial board member for AIMS Microbiology and was not involved in the editorial review or the decision to publish this article. All authors declare that there are no competing interests., (© 2024 the Author(s), licensee AIMS Press.)

Objectives: Little is known regarding outcomes and optimal therapeutic regimens of infections caused by Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) resistant to ceftazidime/avibactam (CZA) and susceptible to meropenem (MEM). Although susceptible to MEM in vitro, the possibility of developing MEM resistance overtime is a concern. We describe the clinical characteristics of patients with colonization/infection due to KPC variants with a focus on the in vitro activity of fosfomycin (FOS)-containing combinations., Methods: Patients with colonization/infection due to a KPC variant were included. Fosfomycin susceptibility was performed by agar dilution method. Synergistic activity of FOS-based combinations was evaluated by gradient strip-agar diffusion method. The emergence of in vitro MEM resistance was also tested., Results: Eleven patients were included: eight with infection [four with ventilator-associated pneumonia and four with bloodstream infections] and three with colonization. Previous therapy with CZA was administered to all patients (with a mean cumulative duration of 23 days). All subjects with infection received meropenem, in monotherapy (n = 4) or with amikacin (n = 2) or fosfomycin (n = 2), and achieved clinical cure. A new CZA-susceptible and MEM-resistant KPC-Kp strain was subsequently isolated in three patients (27.3%). Meropenem/vaborbactam (MVB) showed high in vitro activity, while FOS+MEM combination was synergistic in 40% of cases. In vitro resistance to MEM was observed with maintenance of CZA resistance., Conclusions: Detection of KPC variants may occur within the same patient, especially if CZA has been previously administered. Although clinical success has been obtained with carbapenems, the emergence of MEM resistance is a concern. Fosfomycin plus meropenem is synergistic and may be a valuable combination option for KPC variants, while MVB may be considered in monotherapy. The detection of KPC variants in an endemic setting for KPC-Kp represents a worryingly emerging condition. The optimal therapeutic approach is still unknown and the development of meropenem resistance is of concern, which may lead to therapeutic failure in clinical practice. In these cases, the addition of fosfomycin to meropenem, or a more potent antibiotic, such as meropenem/vaborbactam, may be valuable therapeutic options., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Nosocomial infections by multidrug-resistant (MDR) bacteria are among the main causes of morbidity and death in patients hospitalized in intensive care units (ICUs) worldwide. Antibiotic resistance has become a major concern for treating the patients with nosocomial infections. The aim of this study was to describe the antibiotic resistance patterns of pathogens causing infections in adult and pediatric patients in the ICUs of a tertiary care hospital in Kolkata, India. A cross-sectional, retrospective study was conducted from January 2022 to October 2022 on a total of 139 adult and 146 pediatric patients. Depending on clinical symptoms of the patients, samples were collected and subjected to antibiotic sensitivity testing. The culture and sensitivity pattern of clinical isolates from blood, urine, sputum, endotracheal tube (ET) aspirate, and central line catheter insertion site swabs were analyzed. A total of 695 and 556 specimens were obtained from adult and pediatric ICU, respectively. Culture positivity rate among adults and pediatric patients were 37% and 40%, respectively. The most commonly isolated organisms were Gram-negative Enterobacterales and non-fermenters. Most of the bacterial isolates showed very high resistance against multiple antibiotics. Escherichia coli from adult and pediatricpatients were found to be resistant to second generation cephalosporins (95% and 96%, respectively), beta-lactams (95% and 63%, respectively), fluoroquinolones (95% and 81%, respectively), and cotrimoxazole (85% and 78%, respectively). Klebsiella spp. from adult patients were found to be resistant to aminoglycosides (75%), second generation cephalosporins (100%), beta-lactams (94%), fluoroquinolones (92%), carbapenems (88%), and cotrimoxazole (83%). Proteus spp., Acinetobacter baumannii , and Pseudomonas spp. werefound to be resistant to multiple antibiotics. Enterococcus spp. from ICUs showed more than 90% resistance against ampicillin and more than 75% resistance against fluoroquinolones. MDR bacterial infections are increasing in both adult and pediatric ICUs, leading to significant therapeutic challenges. A frequent study of antimicrobial resistance patterns is imperative for antibiotic stewardshipin combatting the deadly effect of the MDR bacteria in critically ill patients.

Enteric fever, a potentially fatal multisystem disease that is caused by Salmonella enterica serovar Typhi and Paratyphi, poses a significant risk in low- and middle-income countries. A retrospective study to understand the prevalence and evolving patterns of antibiotic resistance in Salmonella Typhi and Paratyphi was undertaken from June 2017 to June 2022. A total of 4051 blood samples were collected from patients attending inpatient and outpatient departments of the School of Tropical Medicine (Kolkata, India) hospital. Blood samples were cultured, and culture positive samples were further processed for identification using conventional and automated systems. Antibiotic susceptibility test was performed using both the Kirby-Bauer disc diffusion method and VITEK2 (bioMerieux). Forty-five (1.1%) Salmonella species were isolated among the number of total ( n = 4051) samples that were tested. Out of the 45 Salmonella isolates, 35 were Salmonella Typhi (77.77%) and 10 were Salmonella Paratyphi A (22.23%). We found pronounced fluoroquinolone resistance of 100% in the recent years (2019-2022) in both of the S . Typhi and S . Paratyphi A isolates. We found that 1 Salmonella Typhi and 2 Salmonella Paratyphi A isolates were resistant against multiple antibiotics (cefixime, ceftriaxone, ciprofloxacin and nalidixic acid), and 1 multidrug-resistant (MDR) Salmonella Paratyphi A isolate was found in a recent study year (2020) and it showed resistance against different classes of antibiotics (cephalosporins, fluoroquinolones and carbapenems). There was no resistance that was detected to the 3 rd generation cephalosporins in the final years of the study. The emergence of Salmonella isolates that are resistant to multiple antibiotics poses a serious health problem. The antimicrobial resistance patterns that were detected in the study thus warrant further studies to understand the antibiotic susceptibility and resistance pattern of Salmonella against the major classes of antibiotics., Competing Interests: The authors declare no conflict of interest.

Aim: The aim of the study was to evaluate the in vitro activity of N-acetylcysteine (NAC), alone or in combination with beta-lactams, against carbapenem-resistant Klebsiella pneumoniae (CR-Kp) and Acinetobacter baumannii (CR-Ab)., Methods: The antibacterial activity of each compound was tested by broth microdilution and the synergism was evaluated by the checkerboard method. Killing studies of NAC alone and in combination with beta-lactams were performed. Bacterial morphological changes were investigated with scanning electron microscopy (SEM)., Results: Overall, 30 strains were included (15 CR-Kp and 15 CR-Ab). The NAC Minimal Inhibitory Concentrations (MIC)50/90 were 5/5 and 2.5/5 mg/mL for CR-Kp and CR-Ab, respectively. For both microorganisms, NAC, in addition to beta-lactams (meropenem for CR-Kp, meropenem and ampicillin/sulbactam for CR-Ab, respectively), was able to enhance their activity. The killing studies showed a rapid and concentration-dependent activity of NAC alone; the addition of NAC to meropenem or ampicillin/sulbactam at subinhibitory concentrations induced a fast and lasting bactericidal activity that persisted over time. The SEM analyses showed evident morphological alterations of the bacterial cells following incubation with NAC, alone and in combination with meropenem., Conclusions: NAC demonstrated a high in vitro activity against CR-Kp and CR-Ab and was able to enhance beta-lactams' susceptibility in the tested strains. The preliminary data on the SEM analyses confirmed the in vitro results.

Implant-associated infections are characterized by microbial biofilm formation on implant surface, which renders the microbiological diagnosis challenging and requires, in the majority of cases, a complete device removal along with a prolonged antimicrobial therapy. Traditional cultures have shown unsatisfactory sensitivity and a significant advance in the field has been represented by both the application of the sonication technique for the detachment of live bacteria from biofilm and the implementation of metabolic and molecular assays. However, despite the recent progresses in the microbiological diagnosis have considerably reduced the rate of culture-negative infections, still their reported incidence is not negligible. Overall, several culture- and non-culture based methods have been developed for diagnosis optimization, which mostly relies on pre-operative and intra-operative (i.e., removed implants and surrounding tissues) samples. This review outlines the principal culture- and non-culture based methods for the diagnosis of the causative agents of implant-associated infections and gives an overview on their application in the clinical practice. Furthermore, advantages and disadvantages of each method are described., 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 © 2021 Oliva, Miele, Al Ismail, Di Timoteo, De Angelis, Rosa, Cutone, Venditti, Mascellino, Valenti and Mastroianni.)

Introduction: There is the need of a simple but highly reliable score system for stratifying the risk of mortality and Intensive Care Unit (ICU) transfer in patients with SARS-CoV-2 pneumonia at the Emergency Room., Purpose: In this study, the ability of CURB-65, extended CURB-65, PSI and CALL scores and C-Reactive Protein (CRP) to predict intra-hospital mortality and ICU admission in patients with SARS-CoV-2 pneumonia were evaluated., Methods: During March-May 2020, a retrospective, single-center study including all consecutive adult patients with diagnosis of SARS-CoV-2 pneumonia was conducted. Clinical, laboratory and radiological data as well as CURB-65, expanded CURB-65, PSI and CALL scores were calculated based on data recorded at hospital admission., Results: Overall, 224 patients with documented SARS-CoV-2 pneumonia were included in the study. As for intrahospital mortality (24/224, 11%), PSI performed better than all the other tested scores, which showed lower AUC values (AUC=0.890 for PSI versus AUC=0.885, AUC=0.858 and AUC=0.743 for expanded CURB-65, CURB-65 and CALL scores, respectively). Of note, the addition of hypoalbuminemia to the CURB-65 score increased the prediction value of intra-hospital mortality (AUC=0.905). All the tested scores were less predictive for the need of ICU transfer (26/224, 12%), with the best AUC for extended CURB-65 score (AUC= 0.708)., Conclusion: The addition of albumin level to the easy-to-calculate CURB-65 score at hospital admission is able to improve the quality of prediction of intra-hospital mortality in patients with SARS-CoV-2 pneumonia., Competing Interests: Competing interests The authors declare no financial and non-financial competing interests., (Copyright © 2016 - 2021 InfezMed.)

Microbial translocation (MT) and intestinal damage (ID) are poorly explored in COVID-19. Aims were to assess whether alteration of gut permeability and cell integrity characterize COVID-19 patients, whether it is more pronounced in severe infections and whether it influences the development of subsequent bloodstream infection (BSI). Furthermore, we looked at the potential predictive role of TM and ID markers on Intensive Care Unit (ICU) admission and in-hospital mortality. Over March-July 2020, 45 COVID-19 patients were enrolled. Markers of MT [LPB (Lipopolysacharide Binding Protein) and EndoCab IgM] and ID [I-FABP (Intestinal Fatty Acid Binding Protein)] were evaluated at COVID-19 diagnosis and after 7 days. As a control group, age- and gender-matched healthy donors (HDs) enrolled during the same study period were included. Median age was 66 (56-71) years. Twenty-one (46.6%) were admitted to ICU and mortality was 22% (10/45). Compared to HD, a high degree of MT and ID was observed. ICU patients had higher levels of MT, but not of ID, than non-ICU ones. Likewise, patients with BSI had lower EndoCab IgM than non-BSI. Interestingly, patients with high degree of MT and low ID were likely to be admitted to ICU (AUC 0.822). Patients with COVID-19 exhibited high level of MT, especially subjects admitted to ICU. COVID-19 is associated with gut permeability., 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 © 2021 Oliva, Miele, Di Timoteo, De Angelis, Mauro, Aronica, Al Ismail, Ceccarelli, Pinacchio, d’Ettorre, Mascellino and Mastroianni.)

Gut microbiota plays an important role in human health. It may promote carcinogenesis and is related to several diseases of the gastrointestinal tract. This study of microbial dysbiosis in the etiology of colorectal adenoma aimed to investigate the possible causative role of microbiota in the adenoma-carcinoma sequence and its possible preventive role. A systematic, PRISMA-guided review was performed. The PubMed database was searched using "adenoma microbiota" and selecting original articles between January 2010 and May 2020 independently screened. A higher prevalence of Proteobacteria, Fusobacteria, and Bacteroidetes phyla was observed in the fecal luminal and mucosa-associated microbiota of patients with adenoma. However, other studies provided evidence of depletion of Clostridium , Faecalibacterium , Bacteroides and Romboutsia . Results on the relationship between adenoma endoscopic resection and microbiota were inconsistent. In conclusion, none of the analyzed studies developed a predictive model that could differentiate adenoma from non-adenoma patients, and therefore, to prevent cancer progression. The impact of adenoma's endoscopic resection on microbiota was investigated, but the results were inconclusive. Further research in the field is required.

The aim of this study was to evaluate the secondary resistance in Helicobacter pylori (Hp) infected patients who had failed a first-line therapy, and to compare the genotypic tests performed directly on gastric samples with phenotypic tests performed on culture media. The eradication rate of patients treated with bismuth quadruple therapy (BQT) is also evaluated. A total of 80 positive specimens were retrospectively examined. Antibiotic susceptibility testing of Hp strains was performed by E-test, whereas a molecular commercially available method was used for detecting the mutations involved in clarithromycin and levofloxacin resistance. High resistance levels to metronidazole and clarithromycin (61.6% and 35%, respectively) and worrying resistance levels to levofloxacin (15%) were found phenotypically. Multiple resistance to two or three antibiotics was observed as well. The polymorphism A2143G on clarithromycin 23S rRNA gene was found in 34/80 (42.5%) isolates including 10 mixed infections (29%), whereas 28/80 (35%) strains were resistant phenotypically. Levofloxacin resistance corresponded to 30% by PCR and 15% by E-test (statistically significant, p < 0.05). The knowledge of clarithromycin and levofloxacin resistance is crucial to establish an appropriate therapy in different geographical areas. The genetic methods were superior to phenotypic techniques in the absence of live bacteria or for identifying mixed infections that may lead to a resistance underestimation. The BQT eradication rate was effective (90%).

Introduction: Intestinal colonization with multi-drug resistant (MDR) microorganisms is a consequence of antimicrobial-induced gut dysbiosis. Given the effect of probiotics in modulating gut microbiota, the aim of the study was to investigate whether the ingestion of high concentration multi-strain probiotic formulation would change the antibacterial activity of the feces against clinical strains of MDR microorganisms. The corresponding in vitro antibacterial activity was also investigated. Materials/methods: The feces of healthy donors ( n = 6) were analyzed before and after a 7-day dietary supplementation with a multi-strain probiotic formulation and tested against MDR microorganisms of clinical concern (carbapenem-resistant (CR), Klebsiella pneumoniae (CR-Kp), CR- Acinetobacter baumannii (CR-Ab), CR- Pseudomonas aeruginosa (CR-Pa), and methicillin-resistant Staphylococcus aureus (MRSA)). The tested MDR pathogens were cultured with decreasing concentrations of fecal water obtained before and after the treatment period. Furthermore, to corroborate the results obtained from the feces of healthy donors, the in vitro antibacterial activity of probiotic formulation (both whole probiotic (WP) and probiotic surnatant (PS)) against the same collection of MDR microorganisms was evaluated at different incubation times throughout the minimum bactericidal dilution and the corresponding serial silution number. Results: While before probiotic administration, the fecal water samples did not inhibit MDR microorganism growth, after supplementation, a reduced bacterial growth was shown. Accordingly, a noticeable in vitro activity of WP and PS was observed. Conclusions: Although preliminary, these experiments demonstrated that a specific multi-strain probiotic formulation exhibits in vitro antibacterial activity against MDR microorganisms of clinical concern. If confirmed, these results may justify the administration of probiotics as a decolonization strategy against MDR microorganisms.

Background: Clostridioides difficile infection (CDI) might be complicated by the development of nosocomial bloodstream infection (n-BSI). Based on the hypothesis that alteration of the normal gut integrity is present during CDI, we evaluated markers of microbial translocation, inflammation, and intestinal damage in patients with CDI., Methods: Patients with documented CDI were enrolled in the study. For each subject, plasma samples were collected at T0 and T1 (before and after CDI therapy, respectively), and the following markers were evaluated: lipopolysaccharide-binding protein (LPB), EndoCab IgM, interleukin-6, intestinal fatty acid binding protein (I-FABP). Samples from nonhospitalized healthy controls were also included. The study population was divided into BSI+/BSI- and fecal microbiota transplantation (FMT) +/FMT- groups, according to the development of n-BSI and the receipt of FMT, respectively., Results: Overall, 45 subjects were included; 8 (17.7%) developed primary n-BSI. Markers of microbial translocation and intestinal damage significantly decreased between T0 and T1, however, without reaching values similar to controls ( P < .0001). Compared with BSI-, a persistent high level of microbial translocation in the BSI+ group was observed. In the FMT+ group, markers of microbial translocation and inflammation at T1 tended to reach control values., Conclusions: CDI is associated with high levels of microbial translocation, inflammation, and intestinal damage, which are still present at clinical resolution of CDI. The role of residual mucosal perturbation and persistence of intestinal cell damage in the development of n-BSI following CDI, as well as the possible effect of FMT in the restoration of mucosal integrity, should be further investigated., (© The Author(s) 2019. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Purpose: (i) To compare infections caused by carbapenem-susceptible (CS) and carbapenemase producing carbapenem-resistant Enterobacteriaceae (CP-CRE); (ii) to evaluate the clinical effectiveness of the double-carbapenem (DC) regimen in comparison with the best available treatment (BAT) in infections caused by CP-CRE; and (iii) to determine the exact minimal inhibitory concentrations (MICs) of meropenem/ertapenem (MEM/ETP) and the degree of in vitro ETP+MEM synergism in subjects receiving the DC., Methodology: Over a 3-year period (2014-2017), patients with infections due to Enterobacteriaceae were included in a single-center, retrospective, observational study. According to the susceptibility to carbapenems, subjects were divided into CSE and CP-CRE groups. CP-CRE group was further divided into subjects receiving the DC regimen and those treated with other regimens (BAT group). Clinical characteristics and the presence of 5 th -day response and 60-day outcome were evaluated for DC and BAT groups. The determination of MEM and ETP actual MICs and the MEM+ETP synergistic activity were performed on strains obtained from subjects receiving the DC regimen., Results: A total of 128 patients were included in the study: 55/128 (43%) with infections due to CP-CRE and 73/128 (57%) with infections due to CSE. Among CP-CRE (n=55), 21 subjects (39%) were treated with the DC regimen whereas 34 (61%) received BAT. No differences in terms of severity of infection, presence/absence of concomitant bacteremia, type of infection, and resolution of infection were found; in contrast, DC group tended to have a higher rate of sepsis or septic shock at the onset of infection and a higher rate of 5 th -day response. MICs 50/90 were 256/512 and 256/256 μ g/mL for MEM and ETP, respectively. Overall, complete in vitro synergism was found in 6/20 strains (30%)., Conclusion: The DC regimen is a valid and effective therapeutic option in patients with infections due to KPC producing CRE, including those with bacteremic infection and more severe clinical conditions. The clinical effectiveness is maintained even in the presence of extremely high MEM MICs.

Purpose: Herein, an extended investigation of Tea tree oil (TTO) against a number of multi-drug resistant (MDR) microorganisms in liquid and vapor phases is reported., Methods: The activity of TTO was tested against methicillin-sensitive Staphylococcus aureus (MSSA), Escherichia coli , and clinical strains of methicillin-resistant S. aureus (MRSA), extended-spectrum beta lactamases producer carbapenem-sensitive Klebsiella pneumoniae (ESBL-CS-Kp), carbapenem-resistant K. pneumoniae (CR-Kp), Acinetobacter baumannii (CR-Ab), and Pseudomonas aeruginosa (CR-Pa). Minimal inhibitory/bactericidal concentrations (MIC/MBCs) and synergistic activity between TTO and different antimicrobials were determined. In the vapor assay (VP), TTO-impregnated discs were placed on the lid of a petri dish and incubated for 24 h at 37 °C., Results: TTO showed a potent bactericidal activity against all the tested microorganisms. TTO in combination with each reference antimicrobial showed a high level of synergism at sub-inhibitory concentrations, particularly with oxacillin (OXA) against MRSA. The VP assay showed high activity of TTO against CR-Ab., Conclusion: Evaluation of in-vitro activity clearly indicated TTO as a potential effective antimicrobial treatment either alone or in association with known drugs against MDR. Therefore, TTO could represent the basis for a possible role in non-conventional regimens against S. aureus and Gram-negative MDR. TTO in VP might represent a promising option for local therapy of pneumonia caused by CR-Ab.

Forty patients infected by Helicobacter pylori were studied. The treatment was based on the positivity or negativity of cultures (tailored therapy or empiric therapy). The eradication rate was 68% and 82% respectively. Genotypic susceptibility testing proved very useful in case of heteroresistance or mixed infections that represent a real problem possibly leading to a resistance underestimation. Real-time PCR detected the resistant population at a very low concentration not detectable by phenotypic tests. Bismuth quadruple therapy (PPI, bismuth, metronidazole, tetracycline, PBMT) was effective in the Hp eradication rate consistent with a high level of clarithromycin resistance.

Helicobacter pylori ( Hp ) is responsible for one of the most common infections in the world. The prevalence exceeds 50% of the population in developing countries, and approximately one-third of the adults are colonized in North Europe and North America. It is considered a major pathogenic agent of chronic gastritis, peptic ulcer, atrophic gastritis, gastric cancer, and mucosa-associated lymphoid tissue lymphoma (MALT). Hp colonization modifies the composition of gastric microbiota that could drive the development of gastric disorders. Currently, an emerging problem in Hp treatment is represented by the increasing rate of antimicrobial therapy resistance. In this context, the search for adjuvant agents can be very useful to overcome this issue and probiotics administration can represent a valid option. The aim of this review is to describe the gastric microbiota changes during Hp colonization, the mechanisms of action, and a possible role of probiotics in the treatment of this infection.

Introduction: Sonication showed more sensitivity than traditional culture in the diagnosis of device infections. Aims of the study were to assess the role of sonication in the microbiological diagnosis and management of cardiac device infections (CDIs), to evaluate the sensitivity of sonication in patients on antimicrobial therapy at the time of device removal, and to analyze biofilm formation of the isolated strains., Materials and Methods: A total of 90 devices (31 generators and 59 electrodes) collected from 31 patients with infection underwent sonication before culture. Devices were sonicated for 5 min and centrifuged at 3200 rpm for 15 min. Intraoperative traditional cultures were performed in 26 patients. Microorganisms were identified using conventional methods. Staphylococcal strains were tested for slime production., Results: Microbiological diagnosis was achieved in 28 patients (90%). Sonicate fluid was positive in 68/90 (76%) of devices (27/31 [87%] generators and 41/59 [69%] electrodes), whereas intraoperative pocket swabs grew bacteria in 10/26 patients (38%, P = 0.0007). Among leads, 37/59 (62.7%) yielded bacteria even in the absence of vegetation. Coagulase-negative Staphylococci accounted for 83.8% (57/68) of the total; Staphylococcus aureus and Gram-negative bacilli were found in 4.4% (3/68) and 5.8% (4/68), respectively. Biofilm production was present in 15/22 (69%) staphylococcal strains. Overall, patients on therapy ( n = 23) had a microbiological diagnosis in 20/23 (86.9%) and 7/22 (30.4%) through sonication and intraoperative cultures, respectively ( P = 0.0002)., Discussion: Our data showed the high sensitivity of sonication in the diagnosis of CDIs, even in patients under antimicrobial therapy., Conclusion: Sonication represents an essential tool for both diagnosis and management of CDIs., Competing Interests: There are no conflicts of interest.

Objectives and Methods: We evaluated the in vitro activity of different antimicrobial combinations with and without colistin against 39 carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains (colistin + meropenem/doripenem, colistin + tigecycline, colistin + rifampicin, gentamicin + meropenem, gentamicin + tigecycline and the double-carbapenem regimen meropenem + ertapenem) using the chequerboard method. The triple combination colistin + meropenem + tigecycline was also tested. In addition, killing studies were performed for meropenem + ertapenem., Results: Gentamicin-based combinations showed a high level of synergy. Meropenem + ertapenem was synergic in 12/39 (30.7%) of the strains, whereas based on killing studies 1 × MIC meropenem + 1 × MIC ertapenem and 2 × MIC meropenem + 1 × MIC ertapenem combinations were bactericidal and synergic at 24 h [mean area under the bactericidal curve (AUBC) 54.9 ± 26.1 and 44.2 ± 15.3 compared with 1 × MIC meropenem (134.5 ± 40.1) and 2 × MIC meropenem (126.4 ± 5.4), respectively, P  <   0.0001]. When the results were stratified according to meropenem MIC, we found that the degree of synergy significantly increased for isolates with lower meropenem (and not ertapenem) MICs, up to an MIC of 128 mg/L. Among colistin-containing combinations, synergy was observed in 18/39 (46.1%), 33/34 (97%), 24/39 (61.5%) and 17/39 (43.5%) of the strains for colistin + meropenem, colistin + rifampicin, colistin + tigecycline and colistin + doripenem, respectively, including colistin-resistant strains. Colistin + meropenem + tigecycline at subinhibitory concentrations resulted in the absence of growth of 37/39 strains (94.8%)., Conclusions: Our in vitro data suggest that colistin might be a valid therapeutic option against CR-Kp, even in the presence of colistin resistance, whereas the double-carbapenem regimen represents a viable option when colistin is not recommended, especially if the meropenem MIC is ≤ 128 mg/L. Since traditional antimicrobial susceptibility reports are not sufficiently informative for clinicians, synergy testing as well as actual meropenem MIC evaluation should always be performed in the case of CR-Kp infections., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Available therapeutic options against carbapenem-resistant Klebsiella pneumoniae (CR-Kp) are limited because of the high level of resistance to other antimicrobial classes including polymyxins. The double-carbapenem regimen has been recently considered a possible therapeutic strategy. In the present study, we evaluated the in vitro bactericidal and synergistic activity of a double-carbapenem regimen consisting of ertapenem plus high-dose meropenem in a series of patients with healthcare-associated CR-Kp infections in whom the use of colistin was not indicated because of potential nephrotoxicity and/or resistance. In vitro synergy was evaluated using checkerboard and killing studies. A total of 15 patients were included in the study, with sepsis, severe sepsis and septic shock found in two (13.3%), five (33.3%) and one (6.7%) patients, respectively. Overall, the clinical/microbiological response was 12/15 (80%). Synergy was observed in 11/14 (78.6%) isolates using the checkerboard method whereas in killing studies 12/14 (85.7%) and 14/14 (100%) strains were synergistic and bactericidal at 24 h at concentrations of 1 × MIC MEM+1 × MIC ERT and 2 × MEM+1 × MIC ERT, respectively, with a significant decrease of log CFU/mL compared with other combinations (p <0.0001). The double-carbapenem regimen showed clinical and in vitro effectiveness in patients with CR-Kp infections., (Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Transplant recipients are at high risk of infections caused by multidrug resistant microorganisms. Due to the limited therapeutic options, innovative antimicrobial combinations against carbapenem-resistant Enterobacteriaceae causing severe infections are necessary.A 61-year-old woman with a history of congenital solitary kidney underwent renal transplantation. The postoperative course was complicated by nosocomial pneumonia due to Stenotrophomonas maltophilia and pan-sensitive Escherichia coli, successfully treated with antimicrobial therapy. On postoperative day 22, diagnosis of surgical site infection and nosocomial pneumonia with concomitant bacteremia due to a Klebisella pneumoniae carbapenemase-producer E coli was made. The patient was treated with the double-carbapenem regimen (high dose of meropenem plus ertapenem) and a potent synergistic and bactericidal activity of this un-conventional therapeutic strategy was observed in vitro. Despite a microbiological response with prompt negativity of blood cultures, the patient faced a worse outcome because of severe hemorrhagic shock.The double-carbapenem regimen might be considered as a rescue therapy in those subjects, including transplant recipients, in whom previous antimicrobial combinations failed or when colistin use might be discouraged. Performing in vitro synergy testing should be strongly encouraged in cases of infections caused by pan-drug resistant strains, especially in high-risk patients., Competing Interests: The authors have no conflicts of interest to disclose.

Background: Acinetobacter baumannii has been associated with high morbidity and mortality rates, even in pediatric patients. Therapeutic options are limited, especially when the strain is multidrug resistant., Methods: Clinical and microbiological analyses of 4 cases of systemic infections caused by multi drug resistant A. baumannii treated with colistin/vancomycin combination at a Pediatric Intensive Care Unit were performed in order to explore the potential synergistic activity of colistin plus vancomycin. All the patients were treated with colistin, meropenem and vancomycin., Results: Four severe infections due to MDR A. baumannii were observed. All patients treated with colistin/vancomycin combination had a positive outcome with no infection relapses. Most importantly, no significant adverse events related to the simultaneous administration of COL plus VAN were observed. In our in-vitro experiments, the synergistic effect of the combination COL plus VAN showed an early bactericidal activity even at VAN concentration of 16 mg/L, which reflects the serum trough concentrations obtained in patients., Discussion: An antimicrobial strategy based on the activity of colistin plus vancomycin was in-vitro and in-vivo effective in life-threatening infections caused by multidrug-resistant A. baumannii in a Pediatric Intensive Care Unit, in the absence of adverse effects. Colistin plus vancomycin were highly synergic and bactericidal against carbapenem-resistant, colistin sensitive A. baumannii whereas the addition of meropenem did not enhance the in-vitro activity of colistin plus vancomycin., Conclusions: Our results confirm existing data on the potential synergistic activity of a therapeutic strategy including colistin plus vancomycin and provide important new clinical information for its potential use as a therapeutic option against MDR A. baumannii infections, especially in the pediatric population.

Infections due to carbapenemase-producing Klebsiella pneumoniae represent an emerging threat due to the high mortality rate and lack of valid antimicrobial combinations, especially when the strain is colistin-resistant. We report a case of bloodstream infection due to pandrug-resistant K. pneumoniae treated successfully with an innovative regimen comprising a combination of colistin plus double carbapenem, along with an in vitro analysis showing the synergistic and bactericidal effect., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Migration and HIV infection are known risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage and infection. The aim of the study was to analyze the prevalence of MRSA nasal colonization in a high risk population of HIV-negative migrants and HIV-infected subjects. Secondary aim was to investigate over time MRSA carriage prevalence in HIV-infected subjects., Methods: During the study period (January-June 2008), nasal swabs were collected from 96 HIV-negative migrants and 63 HIV-infected patients. A group of 68 seropositive subjects was additionally screened for MRSA carriage in 2012. Subjects were evaluated for HIV status, previous antibiotic use or hospitalization, soft tissue and skin infections (SSI), nationality and work conditions. The swab specimens were plated and incubated for 24-h under static condition at 37 degrees and then identified as S. aureus by using standard methods., Results: A total of 227 subjects, 131 HIV-infected adults (63 in 2008 and 68 in 2012) and 96 HIV-negative migrants, were analyzed. Overall, 71/227 (31.2%) were S. aureus carriers: 34 out of 131 (25.9%) among HIV infected subjects and 37 out of 96 (38.5%) among migrants. Two MRSA were detected in HIV-infected patients (2.8%). Between 2008 and 2012 there was an increase of MRSA carriage in HIV+ group (p=0.49). No statistically significant differences were found between S. aureus carriers and no-carriers in terms of CD4+ cell count, TMP/SMX prophylaxis, previous antibiotic use or hospitalization, nationality and duration of stay in Italy. Among HIV+ patients there was a higher prevalence of SSI in MSSA carriers compared with no carriers (25% vs 4%, p=0.028). In the migrants group, having a job based on a close human contact was significantly associated with S. aureus colonization (p=0.0038)., Conclusions: Despite of the high prevalence of S. aureus isolation (31.2%), the present study showed the low rate of MRSA carriage in a high risk population. The main factor associated with S. aureus colonization was a close human contact rather than the HIV status and the condition of being migrant.

The sonication technique has been shown to be a promising tool for microbiological diagnosis of device-related infections. We evaluated the usefulness of the sonication method for pathogen detection in 80 explanted cardiac components collected from 40 patients, and the results were compared with those of conventional cultures. Forty subjects undergoing cardiac device removal were studied: 20 had cardiac device infection, and 20 subjects underwent elective generator replacement or revision in the absence of infection. Sonication of explanted devices was more sensitive than traditional culture for microbial detection (67% and 50%, respectively; P = 0.0005). The bacterial count detected in sonication fluid culture was significantly higher than that detected in traditional culture in both infected (P = 0.019) and uninfected (P = 0.029) devices. In the infected patients, sonication fluid culture yielded a significantly higher rate of pathogen detection in explanted electrodes than traditional culture (65% versus 45%; P = 0.02), while no differences were found in the generators. Ten strains were detected only through sonication fluid culture: 6 Staphylococcus epidermidis strains, 1 Staphylococcus hominis strain, 2 Corynebacterium striatum strains, and 1 Brevundimonas sp. Neither the type nor the duration of antimicrobial therapy before device removal had an effect on the diagnostic performance of sonication fluid culture (P = 0.75 and P = 0.56, respectively). In the patients without infection, sonication fluid culture was positive in 8 cases (40%), whereas conventional culture was positive in only 4 (20%). In summary, the sonication technique improves the microbiological diagnosis of explanted cardiac devices.

Lactococcus garvieae is a human opportunistic pathogen with low virulence, but it is a well-known pathogen in aquaculture. A total of 21 human infections have been reported in the literature, mostly endocarditis. Automated methods can wrongly identify this microorganism as Enterococcus spp with a non-standard phenotype, leading to an underestimation of the incidence of this infection. The route of infection could be the ingestion of raw fish, grilled fish or fresh dairy products. We describe the first case of L. garvieae mitral valve endocarditis in Italy, in a patient with mitral valve repair with autologous pericardium, mechanic prosthetic aortic valve and colonic diverticulosis.

We examine the Chlamydia trachomatis (Ct) immunopathogenesis on the basis of the complex interaction between host immune response and virulence microorganism factors. Ct infection can be asymptomatic or may produce an inflammation elicited and preserved by reinfections or persistent infections. We discuss the host polymorphisms that, with their anti- or proinflammatory effects, determine the course of the disease. We also took into account the inflammation process following the Chlamydia illness and the role of both CD4 cells producing IFN-γ and CD8 cells with their cytokines production. The crucial role of Ct-hsp60 and the double activity (either damaging or preserving from some kinds of tumors) of anti-Ct-hsp60 antibodies are considered.

Background: Matrix metalloproteinases (MMPs) released by glial cells are important mediators of neuroinflammation and neurologic damage in HIV infection. The use of antiretroviral drugs able to combat the detrimental effect of chronic inflammation and target the exaggerated MMP activity might represent an attractive therapeutic challenge. Recent studies suggest that CCR5 antagonist maraviroc (MVC) exerts immunomodulant and anti-inflammatory activity beyond its anti-HIV properties. We investigated the in vitro effect of MVC on the activity of MMPs in astrocyte and microglia cultures., Methodology/principal Findings: Primary cultures of rat astrocytes and microglia were activated by exposure to phorbol myristate acetate (PMA) or lypopolysaccharide (LPS) and treated in vitro with MVC. Culture supernatants were subjected to gelatin zymography and quantitative determination of MMP-9 and MMP-2 was done by computerized scanning densitometry. MMP-9 levels were significantly elevated in culture supernatants from both LPS- and PMA-activated astrocytes and microglia in comparison to controls. The treatment with MVC significantly inhibited in a dose-dependent manner the levels and expression of MMP-9 in PMA-activated astrocytes (p<0,05) and, to a lesser extent, in PMA-activated microglia. By contrast, levels of MMP-2 did not significantly change, although a tendency to decrease was seen in PMA-activated astrocytes after treatment with MVC. The inhibition of levels and expression of MMP-9 in PMA-activated glial cells did not depend on cytotoxic effects of MVC. No inhibition of MMP-9 and MMP-2 were found in both LPS-activated astrocytes and microglia., Conclusions: The present in vitro study suggests that CCR5 antagonist compounds, through their ability to inhibit MMP-9 expression and levels, might have a great potential for the treatment of HIV-associated neurologic damage.

Corynebacterium striatum is a commensal of human skin and has been recently recognized as an emerging pathogen. A case of nosocomial pacemaker lead endocarditis due to a multidrug-resistant C. striatum strain is described, highlighting the role of sonication as a diagnostic tool in cardiac device infections.

We present a case of Rhodococcus equi primary retroperitoneal abscesses without pulmonary involvement in an immunocompromised patient with severe nephrotic syndrome. No risk factors for exposure to R. equi were present. The infection was successfully treated with long-term combination antibiotic treatment including linezolid and tigecycline., (Copyright 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

In this review, we examine the main virulence determinants in Helicobacter pylori (Hp) strains and the correlation between these and the different diseases following Hp infections. We also discuss the host response to Hp and the implications and advantages of the development of non-invasive pre-endoscopy screening of molecular and serological markers associated with Hp virulence and disease progression putting an emphasis on new screening techniques such as the Luminex--X multi analytes profiling technology and the multiplex PCR.

Glycosphingolipids are essential components of plasma membrane and act as antigens, mediators of cell adhesion, and modulators of signal transduction. Following activation of the Fas receptor, gangliosides are recuited in various intracellular compartments. We have evaluated whether the pro-apoptotic anti-CD95 antibody induces a nuclear localization of GD3 in HUT-78 cells. Our data shows that GD3 translocation from cytosol to nuclei is strongly correlated to concomitant rapid phosphorylation of histone H1 shortly after induction of apoptosis. This work advances the hypothesis that GD3 induces a post-translational modification of histone H1 thus influencing the apoptosis process through transcriptional activation/repression of specific genes.

A study of 371 women (261 asymptomatic and 110 symptomatic subjects with clinical PID) was performed to detect the presence of Chlamydia trachomatis (C.t.) and to correlate the serological markers against this microrganism, such as antibody to chlamydial hsp60 (Ab-Chsp60) and different levels of IgG, IgM and IgA, with epidemiology, pathology, sexual habits, age, diagnostic methods in the groups of women with and without pelvic inflammatory disease (PID). We found a statistically significant difference between the asymptomatic and symptomatic women regarding the presence of C.t. (3.4% versus 20%; p<0.0001). This presence was affected by the age of women (more in the group < or =25 years old), by having sex with new partners mainly if they did not undergo an antibiotic treatment. The association of antibody Chsp60 with the presence of clinical PID was quite striking. We also found a strict correlation between the detection of Ab-Chsp60 and previous chlamydial infection as well as between Ab-Chsp60 and elevated serum chlamydial IgG or IgA levels. Due to these findings, we can say that the use of serological markers for C.t. in clinical practice may be an important tool for an early screening and diagnosis of women at high risk of chlamydial infection.

Little progress has been made in the treatment of African trypanosomiasis over the past decades. L-carnitine has a major role in glycolysis-based energy supply of blood trypanosomes for it stimulates constant ATP production. To investigate whether administration of the isomer D-carnitine could exert a competitive inhibition on the metabolic pathway of the L-form, possibly resulting in parasite replication inhibition, several formulations of this compound were tested on Trypanosoma lewisi and T. brucei rhodesiense in rodent models. High oral dosages of D-cornitine inner salt and proprionyl-D-carnitine were not toxic to animals and induced about 50% parasite growth inhibition in reversible, i.e. competitive, fashion. A putative mechanism could be an interference in pyruvate kinase activity and hence ATP production. Considering both, lack of toxicity and inhibitory activity, D-carnitine may have a role in the treatment of African trypanosomiasis, in association with available trypanocidal drugs.