Methicillin-resistant Staphylococci Research Articles

Presence of Methicillin-Resistant Staphylococci and Carbapenemase-Positive Acinetobacter Isolates on Surfaces in German Dog Daycare Facilities and Correlation with Cleaning Practices.

Many bacteria, including methicillin-resistant staphylococci and opportunistic pathogens such as Acinetobacter (A.) species, in particular members of the A. calcoaceticus-A. baumannii (Acb) complex, are known to survive in environmental settings. This increases the risk of bacterial spreading and transmission to animals and humans, especially in institutions with a high animal population density. This study aimed to identify the presence of multidrug-resistant (MDR) staphylococci and Acinetobacter species in dog daycare facilities (DDFs). The surfaces of 16 DDFs were sampled and information about cleaning practices was obtained. After microbial identification, the detected isolates were investigated by multiplex PCR for antimicrobial resistance genes. In 200 location samples, 38 staphylococci and 109 Acinetobacter spp. isolates were identified. Methicillin-resistant genes were confirmed in 18 staphylococci isolates from four DDFs, including Staphylococcus (S.) equorum, S. saprophyticus, S. cohnii, S. lentus, and S. haemolyticus. Eight A. radioresistens isolates comprising the blaOXA-23 carbapenemase gene and seventeen isolates belonging to the Acb complex were also isolated. This is the first investigation for MDR pathogens in DDFs, a close human-animal interaction environment. Though the role of DDFs in the transmission and spreading of MDR bacteria is not known, the findings should contribute to the public awareness and underscore the necessity of adequate cleaning protocols.

Detection and genetic characterization of multidrug-resistant staphylococci isolated from public areas in an international airport

The environmental realm has been acknowledged as a pivotal arena for the emergence and propagation of antimicrobial resistance. To further explore insight into antimicrobial resistance dynamics beyond clinical and veterinary settings, we embarked on an environmental surveillance initiative targeting the prevalence of antibiotic-resistant bacteria within the bustling confines of an international airport in Japan. Our findings illuminate a high prevalence of methicillin-resistant staphylococci (46.3%) on frequently contacted surfaces in the public domain. Notably, Staphylococcus haemolyticus and S. epidermidis emerged as the preeminent carriers of the mecA gene. Intriguingly, we encountered a virulent strain of livestock-associated MRSA harboring a PVL-positive ST1232 clone, CC398 lineage. Further scrutiny unveiled a repertoire of resistance mechanisms, the methicillin-resistant isolates exhibited two or more resistance genes conferring resistance against different types of antibiotics, including beta-lactams, macrolides, lincosamides, aminoglycosides, chloramphenicol, and fosfomycin. Revealing multidrug-resistant CoNS and a LA-MRSA across various surfaces in urban public areas unearths a looming public health hazard. Thus, implementation of molecular surveillance is imperative, augmenting our capacity for early detection and mitigation of the insidious spread and potential transfer of antibiotic resistance genes and virulence factors amidst urban settings, notably within pivotal nodes such as airports.

Emergence of resistance to last-resort antimicrobials in bacteremia patients: A multicenter analysis of bloodstream pathogens in Korea.

This study retrospectively reviewed the microbiological and clinical characteristics of patients diagnosed with bacteremia. Results from the first positive blood cultures were consecutively collected from July 2022 to June 2023 at a public secondary hospital, a university-affiliated tertiary hospital, and a university-affiliated secondary hospital in the Seoul metropolitan area. Antibiotic spectrum coverage (ASC) scores were calculated on the day the blood culture was performed (B0) and on two days after the blood culture results were reported (R+2). A total of 3,397 isolates were collected from 3,094 patients. Among these, 949 isolates obtained from 893 patients were classified as multidrug-resistant organisms (MDRO), including 170 imipenem-resistant gram-negative bacteria, 714 methicillin-resistant staphylococci, and 65 vancomycin-resistant enterococci. Interestingly, 13 and 42 gram-positive isolates were resistant to linezolid and quinupristin/dalfopristin, respectively. Moreover, 44 and 181 gram-negative isolates were resistant to amikacin and tigecycline, respectively. The proportion of ASC scores corresponding to broad or extremely broad-spectrum coverage was not significantly different between MDRO and non-MDRO groups at B0 (p = 0.0925). However, it increased in the MDRO group at R+2 (p <0.001). This study found that resistance to last-resort antimicrobials is emerging. Therefore, developing and incorporating molecular diagnostics using a wide range of resistance targets may facilitate rapid, tailored antimicrobial treatments.

Increased incidence of methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis in the skin and nasal carriage among healthcare workers and inanimate hospital surfaces after the COVID-19 pandemic.

Healthcare workers in hospitals are exposed to infectious diseases that occur in the hospital making them a source of infection for the patients. It is interfaced as cross-contamination agents for MRSA and MR-CoNS, and preventive measures need to be adapted accordingly. The study aimed to assess Methicillin-Resistant Staphylococcus (MRS) on the skin and nasal cavities of healthcare workers (HCWs) and identifying isolates to the species level. Swab samples were cultured on mannitol salt agar (MSA) to obtain MRS and determine their ability to produce coagulase. Their susceptibility to antibiotics were determined by agar screening and disk diffusion methods and further identification was done at the species level. The highest percentage of methicillin resistant coagulase positive Staphylococci (MRCoPS) was reported among skins of male HCWs, (71.4%) were identified as MRSA. The highest levels of methicillin resistant coagulase negative Staphylococci (MRCoNS) were mainly detected in both nasal cavities, (75%) were identified as MRSE. MRSA was reported from doctors (p-value 0.033), whereas the highest incidence of MRSE was obtained from the nurses (p-value 0.048). This study highlighted that incidence of MRSA was mainly detected in doctors and MRCoNS in both nasal cavities. The highest percentage of MRCoNS was recovered from the patients' room followed by the reception table. Moreover, vancomycin is suggested to be highly effective in managing and controlling S. aureus, MRSA- and MRSE related infections.

Evaluation of a nucleic acid amplification system, GENECUBE, for rapid detection of staphylococcal nuc and mecA in blood culture samples

ObjectiveThis study determined whether the GENECUBE rapid nucleic acid amplification test could directly detect nuc and mecA genes in clinical blood culture samples of Staphylococcus and various other pathogens. MethodsBetween September 2020 and December 2021, 537 blood culture samples from 192 patients with suspected bacteremia were tested using conventional assays (MicroScan WalkAway96 or VITEK 2 systems) and GENECUBE nuc and mecA assays. Isolates from samples with discrepant results between the conventional and GENECUBE assays were further evaluated using MALDI-TOF mass spectrometry, disk diffusion testing using cefoxitin, broth microdilution testing using oxacillin, and sequencing for mecA. Bacterial solutions containing a mixture of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) were prepared to evaluate the limit of detection (LOD) of mecA. ResultsUsing conventional assays as the reference, the sensitivity, specificity, and positive and negative predictive values (95 % confidence interval) of GENECUBE were 100 % (96.8–100 %), 100 % (99.1–100 %), 100 % (96.8–100 %), and 100 % (99.1–100 %), respectively, for nuc detection and 100 % (96.1–100 %), 98.9 % (97.4–99.6 %), 94.9 % (88.5–98.3 %), and 100 % (99.2–100 %), respectively, for mecA detection. Sequencing analysis of five samples identified as methicillin-sensitive staphylococci using conventional assays and methicillin-resistant staphylococci using GENECUBE revealed the presence of methicillin-resistant isolates in all samples. The estimated LOD of mecA was 104 colony-forming units (CFU)/mL of MRSE with GENECUBE, compared with 105 CFU/mL with conventional assays. ConclusionThe GENECUBE assay accurately detected mecA in positive blood culture samples and had higher sensitivity than conventional assays.

Impact of Methicillin-Resistant Staphylococcus aureus Nasal Polymerase Chain Reaction Screening Tests on Duration of Vancomycin Therapy for Skin and Soft Tissue Infections.

Background: Recent literature demonstrated a 24-hour reduction in vancomycin duration of therapy (DOT) for skin and soft tissue infections (SSTIs) with a negative methicillin-resistant staphylococcus aureus (MRSA) nasal screening versus a positive nasal screening. Objective of this study was to investigate vancomycin DOT in patients with SSTIs who received MRSA nasal polymerase chain reaction (PCR) screening versus those who did not receive MRSA nasal PCR screening. Methods: A retrospective, multi-center, cohort study was completed in admitted adult patients on vancomycin for SSTI from 01/01/2020 to 09/30/2022. Hospital policy permits any clinician to order a MRSA nasal PCR screening test for various indications, including SSTIs, pneumonia and sepsis. Results: One-hundred-fifty-one patients were included, of which 71 had MRSA nasal PCR screening tests obtained, and 80 did not. The median vancomycin DOT in patients with MRSA nasal PCR screening tests was 19.9 versus 36.7 hours (P = .014) in patients without screening tests. Conclusion: Patients with SSTIs who receive MRSA nasal PCR screening tests have a shortened vancomycin DOT. These results contribute to current data in support of the efficacy and clinical utility of obtaining MRSA nasal PCR screening tests for SSTIs.

Clinical Evaluation of Blood Culture Identification Gram-Positive Panel on Methicillin Resistant Gene Testing in a Large Metropolitan Teaching Hospital

Abstract Introduction The ePlex blood culture identification (BCID) gram-positive panel is a PCR-based approach used for the detection of common pathogens associated with bloodstream infections and corresponding antibiotic-resistance genes. One of the genes, mecA, is associated with methicillin, penicillin, and other penicillin-like-antibiotic-resistant gram-positive bacteria (GPB). It is unclear whether the BCID panel has predictive utility and accuracy in treating hospital infections due to GPB. This retrospective study attempts to determine the consistency and accuracy of BCID gene testing compared to more traditional susceptibility methods at a large public hospital. Method A search query was performed for all BCID results at one teaching hospital in a large metropolitan area for one year (2022). The query included demographic information, BCID results, culture results, and combined susceptibility data. The results were filtered to include only cases in which the mecA gene was detected. The filtered results were then analyzed to determine if the susceptibility results from the susceptibility platform (VITEK) were consistent with the expected susceptibility of the target gene, specifically for oxacillin and vancomycin. The susceptibility cutoff was set as &amp;gt;0.5 mcg/mL and &amp;lt;1 mcg/mL respectively, the standard threshold used at the institution. Results A total of 1211 culture results were obtained, of which the mecA gene was identified by BCID in 321 cases, along with the following GPB: Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus sp. (not aureus). The corresponding cultures grew the following isolates: S. aureus, S. epidermidis, S. hominis, and S. haemolyticus. Of the 321 BCID results, 75 were identified as S. aureus. The isolates grew methicillin-resistant Staph aureus (MRSA) (69/75) 92%, while the typical S. aureus grew (6/75) in 8% of the isolates. In these cases, we compared susceptibility testing for both isolates as either sensitive or resistant, with a MIC of &amp;gt;0.5 mcg/mL for oxacillin to be designated as resistant, and &amp;lt;1 mcg/mL to be designated as sensitive to vancomycin. Of the 75 specimens, the concordance rate was 97% (73/75) for oxacillin and 100% (75/75) for vancomycin. The average receipt to verification turnaround time (TAT) was 36 hours for BCID results and 121 hours (about 5 days) for culture sensitivity results. Conclusion The results show that oxacillin resistance can be predicted by detecting S. aureus and the mecA gene using the BCID panel. However, the mecA gene can be identified in other GPB such as S. epidermidis, in which it should not be used to infer oxacillin or vancomycin susceptibilities. In the case of mecA and S. aureus detection by BCID, treating the patient as a MRSA infection may be appropriate before the susceptibilities have been performed. This approach can reduce the turnaround time for antimicrobial resistance reporting and improve antimicrobial stewardship efforts.

Microflora of Secretions in a Surgical Hospital of Orthopedics and Traumatology Profile for 2021-2023 (SI “ITO NAMS of Ukraine”)

Summary. Healthcare-associated infections (HAIs), namely, surgical site infections, early postoperative and subsequent in-hospital infections, are the most common undesirable phenomenon in the world. According to statistics, at least one case of HAIs is diagnosed in every 100 hospitalized patients in hospitals of 7 developed and 15 other countries of the world at any given time. The occurrence of such complications during the treatment of a patient in a hospital leads to the need of additional diagnostic tests, additional courses of antibiotics, and unplanned surgical intervention. Worsening of the prognosis of treatment may occur due to the formation of the so-called resistant microflora in such patients, with a real probability of spreading the infection in the hospital. Prevention of HAIs in practice occurs through planned infection control in operating rooms and procedure rooms in clinical departments and qualified timely diagnostic work of certified microbiological laboratories in hospitals. Objective. The objective of the study was to determine the spectrum of microflora of secretions for three years (2021-2023) in orthopedic and trauma patients due to changes in modern injuries received more often because of military aggression and to propose the identified differences as criteria for prescribing antibacterial drugs in complex inpatient treatment. The work shows that over the past three years (2021-2023), the ratio of gram-positive and gram-negative microorganisms in the study material almost did not change and averaged 1.65. The peculiarity of the analyzed period was an increase in the number of methicillin-resistant staphylococci by 1.3 times. The spectrum of gram-negative clinical strains has changed, namely, the number of Kl.pneumoniae clinical strains with a high level of polyresistance has increased by 2.5 times. The obtained data made it possible to identify the spectrum of microflora of secretions in orthopedic and trauma patients with modern infectious complications, which prompts us to make changes in the standards of antibacterial treatment protocols, and to plan the needs for certain antibiotics in hospitals with personalization of their prescription to improve the effectiveness of treatment and reduce the risk of development of antimicrobial resistance.

Performance of the GeneXpert® MRSA/SA SSTI Test in Periprosthetic Joint Infections: Rate of failure, Outcomes and Risk Factors

BackgroundThe GeneXpert® MRSA/SA SSTI test allows early detection of methicillin-resistant staphylococci in intraoperative samples of prosthetic joint infections (PJI) in order to stop early broad-spectrum antibiotics. Questions/Purpose(1) What is the rate of false-negative GeneXpert® MRSA/SA SSTI test results? (2) Does a false-negative GeneXpert® MRSA/SA SSTI test result increase the risk of treatment failure for the patient with a PJI? (3) What are the risk factors of a false-negative result? MethodA retrospective study was carried out to compare all GeneXpert® assays to conventional cultures in prosthetic joint infections from April 1st, 2012 to October 1st, 2016. False-negative (FN) results (absence of methicillin-resistant staphylococci (MRS) with GeneXpert® test, but presence in the culture) were identified. We compared the rate of treatment failure between FN results and other test results and we established the risk factors of having a FN result. ResultsAmong the 612 GeneXpert® results, the rate of FN results was 3.6 % (22/612). We found a significant increase in treatment failures for prosthetic joint infection with a FN result with 14 treatment failures (14/22) compared to 198 treatment failures (198/590) in the other test results (OR, 2.1; 95 % CI, 1.3-3.4, p = 0.0019). Not considering suppressive antibiotics as a treatment failure, we found no significant difference in the rate of treatment failures between the false-negative tests and the other tests (OR, 1.36; 95 % CI, 0.66-2.81, p = 0.41). Tobacco use (OR, 3.8; 95 % CI, 1.4-10.3, p = 0.004), ASA classification (OR, 2,4; 95 % CI, 0.9-6.9, p = 0.064), history of infection in the joint (OR, 3.2; 95 % CI, 1.2-9.6, p = 0.007), chronic infections (OR, 3.2; 95 % CI, 0.8-17.5, p = 0.01) and polymicrobial infections (OR, 3.2; 95 % CI, 1.1-9.2, p < 0.0001) were risk factors for a FN result. ConclusionGeneXpert® tests in prosthetic joint infections showed a low rate of FN results. An increased risk of treatment failures was observed in FN results only when long-term use of suppressive antibiotics was considered as treatment failure. Level of evidenceIII; Diagnostic retrospective case control study.

Genetic identification of methicillin resistant Staphylococcus aureus (MRSA) isolated from diabetic foot ulcers and evaluating the inhibition activity of reuterin against this bacteria.

To genetically diagnose the isolates of methicillin-resistant staphylococcus aureus taken from patients with severe diabetic foot infections, and to test the inhibitory effect of reuterin on the growth of these bacteria. The experimental study was conducted from June to November 2021 at the Diabetes Unit of Al-Faihaa General Hospital, Basrah, Iraq, and comprised 62 foot ulcer swabs from the necrotic lesions of patients with type 2 diabetes. The swabs were cultivated first in brain heart infusion broth media, and then streaked on Mannitol salt agar and staphylococcus chromogeneic agar media for phenotypic and genetic analysis. The genetic identification of bacteria was confirmed by deoxyribonucleic acid extraction, and methicillin-resistant staphylococcus aureus was confirmed by the presence of plasmid mecA gene. The inhibition activity of reuterin towards methicillin-resistant staphylococcus aureus was determined using the minimum inhibitory concentration test. All data was analyzed with SPSS version 23. A total of 62 swabs were taken from the necrotic lesions of type 2 diabetes mellitus (T2DM) patients with diabetic foot ulcers. Of the total isolates, 9(14.5%) gave mauve to purple colour on staphylococcus chromogeneic agar, which was then genetically confirmed as methicillin-resistant staphylococcus aureus. The minimum inhibitory concentration value of these bacteria was 10μl/ml at 16mm inhibition zone diameter. There was no cytotoxicity of reuterin to human red blood cells. Reuterin was found to be a natural antimicrobial substance suitable for use to disinfect diabetic foot wounds from bacterial contamination and infection, especially those caused by methicillin-resistant staphylococcus aureus.

A systematic review of dalbavancin efficacy as a sequential therapy for infective endocarditis.

Dalbavancin is an antibiotic characterized by an extended half-life and efficacy against methicillin-resistant Staphylococci. Currently, there are only narrative reviews summarizing the evidence about the use of dalbavancin for infective endocarditis (IE), many of which are focused primarily on its use as consolidation therapy. For this reason, we conducted a systematic review to describe the clinical efficacy and the safety of dalbavancin in IE treatment. We searched for available evidence using the MEDLINE (PubMed), Embase, Scopus, Cochrane Library and Web of Science libraries, with no restrictions regarding the publication year. The risk of bias was performed using the Cochrane ROBINS-I tool for the comparative studies and the Newcastle-Ottawa Scale for descriptive studies. Nine studies were included. All of them were observational. Native valve endocarditis was the most common kind of IE found in the studies' populations (128/263, 48.7%), followed by prosthetic valve endocarditis, and cardiovascular implantable electronic device-related endocarditis. Coagulase-negative Staphylococci were the most common pathogens isolated (83/269, 30.1%), followed by S. aureus, Enterococci spp and Streptococci spp. Five out of nine studies documented a clinical failure rate of less than 10%. Dalbavancin showed a favourable safety profile. Dalbavancin appears to be a promising option for the consolidation therapy of IE. However, further studies comparing dalbavancin with standard of care are needed. CRD42023430032.

Prevalence and associated risk factors of staphylococcus aureus and methicillin-resistant staphylococcus aureus isolates obtained from patients seeking treatment in Nakuru county referral and teaching hospital, Kenya

Staphylococcus aureus is a pathogenic bacterium that can evolve rapidly to methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a global health concern that is associated with significant morbidity and mortality. This study was to determine the prevalence and Associated Risk Factors of staphylococcus aureus and MRSA isolates obtained from patients seeking treatment in Nakuru County Referral and Teaching Hospital. A descriptive cross-section study design was used with a laboratory experimental component and it was carried out in Nakuru County Referral and Teaching Hospital, Kenya. A total of 354 laboratory samples were randomly collected from different laboratory samples/sites: blood, urine, wound, nasal swabs, pus, tissue, abscess, sputum, ear swabs, as well as cerebrospinal fluid (CSF) culture, skin swabs and synovial fluid culture over a period of six months. These samples were tested for presence of staphylococcus aureus and MRSA isolates using Culture methods and Antibiotic Sensitivity Tests. The study analyzed 354 participants, with a median age of 35 years. Most participants (56.7%) were from medical wards, 20.4% from outpatient clinics, and 11% from Diabetic Care Centre. Staphylococcus aureus was found in 7.1% of samples, with MRSA present in 2.3%. Other isolated organisms included Coagulase Negative Staphylococci (7.1%), E. coli (6.8%), Proteus spp. (5.1%), and Pseudomonas spp. (5.9%). The prevalence of MRSA among the participants is low.

Genomic portraits of methicillin-resistant staphylococci (MRS) from food fish unveiled the genes associated with staphylococcal food poisoning (SFP), virulence and antimicrobial resistance

BackgroundCharacteristics of non-clinical strains of methicillin-resistant Staphylococcus aureus (MRSA) especially from fishery environment are poorly understood. This research, in addition to comprehensive characterisation, sought to delineate the genetic relatedness between the MRSA strains originating from clinical as well as non-clinical settings. Out of 39 methicillin-resistant staphylococcal isolates from 197 fish samples, 6 (Three each of methicillin-resistant S. haemolyticus (MRSH) and MRSA) with distinct resistance profiles were selected for whole-genome sequencing. Using respective bioinformatics tools, MRSA genomes were comprehensively characterized for resistome, virulomes, molecular epidemiology and phylogenetic analysis. Simultaneously, MRSH genomes were specifically examined to characterize antimicrobial resistance genes (ARGs), owing to the fact that MRSH is often recognized as a reservoir for resistance determinants.ResultsThree MRSA clones identified in this study include ST672-IVd/t13599 (sequence type-SCCmec type/spa type), ST88-V/t2526, and ST672-IVa/t1309. Though, the isolates were phenotypically vancomycin-sensitive, five of the six genomes carried vancomycin resistance genes including the VanT (VanG cluster) or VanY (VanM cluster). Among the three MRSA, only one harbored the gene encoding Panton-Valentine Leukocidin (PVL) toxin, while staphylococcal enterotoxin (SEs) genes such as sea and seb, associated with staphylococcal food poisoning were identified in two other MRSA. Genomes of MRSH carried a composite of type V staphylococcal cassette chromosome mec (SCCmec) elements (5C2 & 5). This finding may be explained by the inversion and recombination events that may facilitate the integration of type V elements to the SCC elements of S. aureus with a methicillin-susceptible phenotype. Phylogenetically, MRSA from a non-clinical setting displayed a considerable relatedness to that from clinical settings.ConclusionThis study highlights the genetic diversity and resistance profiles of MRSA and MRSH, with non-clinical MRSA showing notable relatedness to clinical strains. Future research should explore resistance gene transfer mechanisms and environmental reservoirs to better manage MRSA spread.

Prevalence and molecular characterization of multidrug-resistant coagulase negative staphylococci from urban wastewater in Delhi-NCR, India.

Antimicrobial resistance (AMR) is global health concern escalating rapidly in both clinical settings and environment. The effluent from pharmaceuticals and hospitals may contain diverse antibiotics, exerting selective pressure to develop AMR. To study the aquatic prevalence of drug-resistant staphylococci, sampling was done from river Yamuna (3 sites) and wastewater (7 sites) near pharmaceutical industries in Delhi-NCR, India. 59.25% (224/378) were considered presumptive staphylococci while, methicillin resistance was noted in 25% (56/224) isolates. Further, 23 methicillin-resistant coagulase negative staphylococci (MR-CoNS) of 8 different species were identified via 16S rRNA gene sequencing. Multidrug resistance (MDR) was noted in 60.87% (14/23) isolates. PCR based detection of antibiotic resistance genes revealed the number of isolates containing mecA (7/23), blaZ (6/23), msrA (10/23), aac(6')aph (2") (2/23), aph(3')-IIIa (2/23), ant(4')-Ia (1/23), dfrG (4/23), dfrA(drfS1) (3/23), tetK (1/23) and tetM (1/23). The current research highlights the concerning prevalence of MDR-CoNS in aquatic environment in Delhi.

Prevalence and risk factors associated with nasal carriage of methicillin-resistant staphylococci in horses and their caregivers

Antimicrobial resistance is a global threat, and pet-associated strains may pose a risk to human health. Equine veterinarians are at high risk of carrying methicillin-resistant staphylococci (MRS), but specific risk factors remain elusive, and few data are available for other personnel involved in the horse industry. The prevalence, characteristics, and risk factors for nasal carriage of MRS in horses and their caregivers were studied in northwestern Italy. Nasal swabs from 110 asymptomatic horses housed at 21 barns and 34 human caregivers were collected. Data on barns, horses, and personnel were acquired through questionnaires. The samples were incubated in selective media, and the bacterial isolates were identified by mass spectrometry. Risk factors were investigated by Poisson regression. MRS were isolated from 33 horses (30%), 11 humans (32.4%) and 3 environmental samples (14.2%). Most isolates were multidrug resistant (MDRS). The prevalence of MRS and MDRS was greater in racehorses and their personnel than in pleasurable and jumping/dressing horses. MRS carriage in caregivers was associated with an increased prevalence of MRS carriage in horses. The frequency of antimicrobial treatments administered in the barn during the last 12 months was a risk factor for MRS carriage in horses [prevalence ratio (PR) 3.97, 95% CI 1.11, 14.13] and caregivers (PR 2.00, 95% CI 1.05, 3.82), whereas a good ventilation index of the horse tabling environment was a protective factor (PR 0.43, 95% CI 0.20, 0.92). Our data reveal relevant interactions occurring between bacterial communities of horses and humans that share the same environment, suggesting that One Health surveillance programs should be implemented.

Long-term outcomes and risk factors for early bacterial infection after pediatric liver transplantation: a prospective cohort study.

Liver transplantation (LT) is the most efficient treatment for pediatric patients with end-stage liver diseases, while bacterial infection is the leading reason for post-transplant mortality. The present study is to explore the outcomes and risk factors of early bacterial infection (within 1 months) after pediatric LT. In this prospective cohort study, 1316 pediatric recipients [median (IQR) age: 9.1 (6.3-28.0) months; male: 48.0%; median (IQR) follow-up time: 40.6 (29.1-51.4) months] who received LT from September 2018 to April 2022 were included. Bacterial culture samples such as sputum, abdominal drainage, blood, and so on were collected when recipients were presented with infective symptoms. Kaplan-Meier analysis was applied to estimate the long-term survival rates and logistic regression was used to identify independent risk factors. To explore the role of pretransplant rectal swab culture (RSC) in reducing post-transplant bacterial infection rate, 188 infant LT recipients [median (IQR) age: 6.8 (5.5-8.1) months; male: 50.5%] from May 2022 to September 2023 were included. Log-binomial regression was used to measure the association of pretransplant RSC screening and post-transplant bacterial infection. The 'Expectation Maximization' algorithm was used to impute the missing data. Bacterial infection was the primary cause for early (38.9%) and overall mortality (35.6%) after pediatric LT. Kaplan-Meier analysis revealed inferior 1-year and 5-year survival rates for recipients with post-transplant bacterial infection (92.6 vs. 97.1%, 91.8 vs. 96.4%, respectively; P <0.001). Among all detected bacteria, Staphylococcus spp. (34.3%) and methicillin-resistant coagulase-negative Staphylococci (43.2%) were the dominant species and multidrug resistant organisms, respectively. Multivariable analysis revealed that infant recipients [adjusted odds ratio (aOR) 1.49; 95% CI: 1.01-2.20], male recipients (aOR, 1.43; 95% CI: 1.08-1.89), high graft-to-recipient weight ratio (aOR, 1.64; 95% CI: 1.17-2.30), positive post-transplant RSC (aOR, 1.45; 95% CI: 1.04-2.02) and nasopharyngeal swab culture (aOR 2.46; 95% CI: 1.72-3.52) were independent risk factors for early bacterial infection. Furthermore, RSC screening and antibiotic prophylaxis before transplantation could result in a relatively lower post-transplant infection rate, albeit without statistical significance (adjusted RR, 0.53; 95% CI: 0.25-1.16). In this cohort study, post-transplant bacterial infection resulted in an inferior long-term patient survival rate. The five identified independent risk factors for post-transplant bacterial infection could guide the prophylaxis strategy of post-transplant bacterial infection in the future. Additionally, pretransplant RSC might decrease post-transplant bacterial infection rate.

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis – update from 2017 to 2023

Antimicrobial resistance (AMR) is a critical global health concern. A previous systematic review showed that migrants in Europe are at increased risk of AMR. Since the COVID-19 pandemic there have been rapid changes in patterns of antibiotic use, AMR, and migration. We aimed to present an updated evidence synthesis on the current distribution of AMR among migrants in Europe. We carried out a systematic review and meta-analysis in accordance with PRISMA guidelines (PROSPERO ID: CRD42022343263). We searched databases (MEDLINE, Embase, PubMed and Scopus) from 18 January 2017 until 18 January 2023 to identify primary data from observational studies reporting any laboratory-confirmed AMR among migrants in the European Economic Area (EEA) and European Union-15 (EU-15) countries using over 7 key search terms for migrants and over 70 terms for AMR and countries in Europe. Outcomes were infection with, or colonisation of AMR bacteria. Methodological quality was assessed using Joanna Briggs Institute Critical Appraisal Checklist for Observational Studies. We meta-analysed the pooled-prevalence of infection and/or colonisation of AMR organisms. Among 630 articles, 21 observational studies met the inclusion criteria and were included in this review. The pooled prevalence for any detected AMR was 28.0% (95% CI 18.0%-41.0%, I 2 =100%) compared to a 25.4% seen in the previous review; gram-negative bacteria 31.0% (95% CI 20.0%-44.0%, I 2 =100%), and methicillin-resistant staphylococcus aureus 10.0% (95% CI 5.0%-16.0%, I 2 =99%). Drug-resistant bacteria were more prevalent in community settings in large migrant populations (pooled prevalence: 41.0%, 95% CI 24.0%-60.0%, I 2 =99%) than in hospitals (21.0%, 95% CI 12.0%-32.0%, I 2 =99%). AMR estimates in 'other' migrants were 32.0%, (95% CI 12.0%-57.0%, I 2 =100%) and 28.0% (95% CI 18.0%-38.0%, I 2=100%) in forced migrants. No firm evidence of AMR acquisition with arrival time or length of stay in the host country was found. Studies investigating AMR in migrants are highly heterogenous. However, since the COVID-19 pandemic, migrants may be at higher risk of acquiring resistant bacteria, particularly gram-negative bacteria, within community settings such as refugee camps and detention centres in Europe. Our study highlights the importance of infrastructure and hygiene measures within these settings, to mitigate transmission of resistant pathogens. Policy-makers should screen for AMR in migrants prior to departure from countries of origin, where feasible, and upon arrival to a new country to ensure optimal health screening, infection control and effective treatment. There was no funding source for this study.

European Society of Clinical Microbiology and Infectious Diseases/European Committee on infection control clinical guidelines on pre-operative decolonization and targeted prophylaxis in patients colonized by multidrug-resistant Gram-positive bacteria before surgery

ScopeThe aim of these guidelines is to provide recommendations for decolonization and perioperative antibiotic prophylaxis (PAP) in multidrug-resistant Gram-positive bacteria (MDR-GPB) adult carriers before inpatient surgery. MethodsThese European Society of Clinical Microbiology and Infectious Diseases/European Committee on Infection Control guidelines were developed following a systematic review of published studies targeting methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci, methicillin-resistant coagulase-negative Staphylococci, and pan-drug-resistant-GPB. Critical outcomes were the occurrence of surgical site infections (SSIs) caused by the colonizing MDR-GPB and SSIs-attributable mortality. Important outcomes included the occurrence of SSIs caused by any pathogen, hospital-acquired infections, all-cause mortality, and adverse events associated with the interventions, including resistance development to the agents used and the incidence of Clostridioides difficile infections. The last search of all databases was performed on 1 November 2023. The level of evidence and the strength of each recommendation were defined according to the Grading of Recommendations Assessment, Development, and Evaluation approach. Consensus of a multidisciplinary expert panel was reached for the final list of recommendations. Antimicrobial stewardship considerations were included. RecommendationsThe guideline panel reviewed the impact of decolonization, targeted PAP, and combined interventions (e.g. decolonization and targeted PAP) on the risk of SSIs and other outcomes in MDR-GPB carriers, according to the type of bacteria and type of surgery.We recommend screening for S. aureus before high-risk operations, such as cardiothoracic and orthopaedic surgery. Decolonization with intranasal mupirocin with or without a chlorhexidine bath is recommended in patients colonized with S. aureus before cardiothoracic and orthopaedic surgery and suggested in other surgeries. The addition of vancomycin to standard prophylaxis is suggested for MRSA carriers in cardiothoracic surgery, orthopaedic surgery, and neurosurgery. Combined interventions (e.g. decolonization and targeted prophylaxis) are suggested for MRSA carriers undergoing cardiothoracic and orthopaedic surgery. No recommendation could be made regarding screening, decolonization and targeted prophylaxis for vancomycin-resistant enterococci because of the lack of data. No evidence was retrieved for methicillin-resistant coagulase-negative Staphylococci and pan-drug-resistant-GPB. Careful consideration of the laboratory workload and involvement of antimicrobial stewardship and infection control teams are warranted before implementing screening procedures or performing changes in PAP policy. Future research should focus on novel decolonizing techniques, on the monitoring of resistance to decolonizing agents and PAP regimens, and on standardized combined interventions in high-quality studies.

The crucial relationship between vancomycin minimum inhibitory concentration and therapeutic efficacy against methicillin-resistant coagulase-negative staphylococci

The area under the curve (AUC)/minimum inhibitory concentration (MIC) ratio was used as an indicator of the clinical efficacy of vancomycin. However, the target AUC/MIC has not been set for methicillin-resistant coagulase-negative staphylococci (MR-CNS), and the effectiveness of vancomycin in strains with high MIC is unknown. Therefore, we aimed to investigate the relationship between the vancomycin MIC and therapeutic efficacy in patients with MR-CNS bacteremia. The primary outcome was the difference in treatment failure rate when the MR-CNS vancomycin MIC was 1 or 2 µg/mL. The treatment failure rate did not significantly differ between the two groups (MIC 1 vs. MIC 2: 27.0% vs. 31.0%; p = 0.779). As a result of multivariate analysis, AUC/MIC0–24 h ≤230 was extracted as risk factor for treatment failure, suggesting the importance of a sufficient initial loading dose and early blood concentration monitoring to increase AUC/MIC0–24 h for successful treatment.

Comparative herbal and conventional antimicrobial susceptibility patterns of methicillin-resistant (MR) and methicillin-susceptible (MS) staphylococci of clinical and environmental origin

Comparative herbal and conventional antimicrobial susceptibility patterns of methicillin-resistant (MR) and methicillin-susceptible (MS) staphylococci of clinical and environmental origin