暂无摘要。

OBJECTIVE: Ocular bacterial infections are important causes of morbidity and vision loss. Early antimicrobial therapy is necessary to save vision, but their efficacy is increasingly compromised by antimicrobial resistance (AMR). We assessed the etiology of ocular bacterial infections seen at Massachusetts Eye and Ear and investigated the molecular epidemiology and AMR profiles of contemporary isolates.
METHODS: Laboratory investigation.
METHODS: We used a combination of phenotypic tests and genome sequencing to identify the predominant lineages of leading ocular pathogens and their AMR profiles.
RESULTS: A total of 1601 isolates were collected from 2014 to 2021, with Staphylococcus aureus (n = 621), coagulase-negative staphylococci (CoNS) (n = 234), Pseudomonas aeruginosa (n = 213), Enterobacteriaceae (n = 167), and Streptococcus pneumoniae (n = 95) being the most common. Resistance was high among staphylococci, with methicillin resistance (MR) detected in 28% of S aureus and 39.8% of CoNS isolates. Multidrug resistance (MDR) was frequent among MR staphylococci (MRSA 60%, MRCoNS 76.1%). The population of S aureus isolates consisted mainly of 2 clonal complexes (CCs): CC8 (26.1%) and CC5 (24.1%). CC5 strains carried a variety of AMR markers, resulting in high levels of resistance to first-line therapies. Similarly, the population of ocular Staphylococcus epidermidis was homogenous with most belonging to CC2 (85%), which were commonly MDR (48%). Conversely, ocular S pneumoniae, P aeruginosa, and Enterobacteriaceae were often susceptible to first-line therapies and grouped into highly diverse genetic populations.
CONCLUSIONS: Our data showed that ocular bacterial infections in our patient population are disproportionately caused by strains that are resistant to clinically relevant antibiotics and are associated with major epidemic genotypes with both community and hospital associations.

Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region.
PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I2 index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations.
Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I2 > 90%).
The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.

The molecular ecology of Staphylococcus aureus, Staphylococcus pseudintermedius and their methicillin-resistant strains in healthy dogs and cats could serve as good models to understand the concept of bacterial zoonosis due to animal companionship. This study aims to provide insights into pooled prevalence, genetic lineages, virulence and antimicrobial resistance (AMR) among healthy dogs and cats. Original research and brief communication articles published from 2001 to 2021 that reported the nasal detection of S. aureus and S. pseudintermedius in healthy dogs and cats in the community, homes and outside veterinary clinics were examined and analysed. Forty-nine studies were eligible and included in this systematic review. The pooled prevalence of nasal carriage of S. aureus/methicillin-resistant S. aureus (MRSA) in healthy dogs and cats were 10.9% (95% CI: 10.1-11.9)/2.8% (95% CI: 2.4-3.2) and 3.2% (95% CI: 1.9-4.8)/0.5% (95% CI: 0.0-1.1), respectively. Conversely, the pooled prevalence of S. pseudintermedius/methicillin-resistant S. pseudintermedius (MRSP) in healthy dogs and cats were 18.3% (95% CI: 17.1-19.7)/3.1% (95% CI: 2.5-3.7) and 1.3% (95% CI: 0.6-2.4)/1.2% (95% CI: 0.6-2.3), respectively. Although highly diverse genetic lineages of S. aureus were detected in healthy dogs and cats, MSSA-CC1/CC5/CC22/CC45/CC121/CC398 and MRSA-CC5/CC93/CC22/CC30 were mostly reported in dogs; and MSSA-CC5/CC8/CC15/CC48 and MRSA-CC22/CC30/CC80 in cats. Of note, MSSA-CC398 isolates (spa-types t034 and t5883) were detected in dogs. Genetic lineages often associated with MSSP/MRSP were ST20/ST71, highlighting the frequent detection of the epidemic European MRSP-ST71 clone in dogs. S. aureus isolates carrying the luk-S/F-PV, tst, eta, etb and etd genes were seldomly detected in dogs, and luk-S/F-PV was the unique virulence factor reported in isolates of cats. S. pseudintermedius isolates harbouring the luk-S/F-I, seint and expA genes were frequently found, especially in dogs. High and diverse rates of AMR were noted, especially among MRSA/MRSP isolates. There is a need for additional studies on the molecular characterization of isolates from countries with under-studied nasal staphylococci isolates.

Staphylococcus aureus is a common gram-positive human pathogen involved in both community-acquired and nosocomial infections ranging from localised superficial lesions to food poisoning and fatal systemic infections owing to its impressive array of virulence factors responsible for attaching, colonising, invading, and avoiding host immune system. The discovery of antibiotics effectively checked the once deadly infections. However, resistance started soon after their discovery and the first methicillin-resistant strain of staphylococcus aureus was reported in the early 1960s. The most important attribute of methicillin-resistant staphylococcus aureus is its acquisition of mecA gene coding for penicillin-binding protein-2a that blocks inhibitory action on peptidoglycan cross-linking. Methicillin-resistant staphylococcus aureus presents a serious global healthcare concern being responsible for prolonged hospital stays and increased mortality. The precise information of virulence factors and resistant traits of methicillin-resistant staphylococcus aureus and their interplay in a community is key to minimize the intermixing of resistant and susceptible pathogens in the community.

Staphylococcus genus is a Gram-positive coccus normally associated with skin and mucous membranes of warm-blooded animals. It is part of the commensal human microflora, or found in animals, or contaminating surfaces in the community and hospital settings. Staphylococcus aureus is the most pathogenic species belonging to this genus, as it possesses a collection of virulence factors that are expressed solely to evade the immune system. The increase in the misuse of antimicrobial agents predisposed S. aureus to develop antibiotic resistance, including the resistance to methicillin which led to the emergence of Methicillin-Resistant S. aureus (MRSA). MRSA is considered one of the most dangerous nosocomial pathogens causing many hard to treat infections in hospitals and was named as Hospital Associated MRSA (HA-MRSA). Over the past 20-25 years, MRSA was isolated from community settings and thus Community Associated MRSA (CA-MRSA) has emerged. Inside hospitals, MRSA has been isolated from fomites in contact with patients, as well as staff\'s protective and personal items. This review highlights the worldwide prevalence of MRSA on fomites within the contexts of hospital and community settings.

Staphylococcus aureus represents a major human pathogen able to cause a number of infections, especially bloodstream infections (BSI). Clinical use of methicillin has led to the emergence of methicillin-resistant S. aureus (MRSA) and MRSA-BSI have been reported to be associated with high morbidity and mortality. Clinical diagnosis of BSI is based on the results from blood culture that, although considered the gold standard method, is time-consuming. For this reason, rapid diagnostic tests to identify the presence of methicillin-susceptible S. aureus (MSSA) and MRSA isolates directly in blood cultures are being used with increasing frequency to rapidly commence targeted antimicrobial therapy, also in the light of antimicrobial stewardship efforts. Here, we review and report the most common rapid non-molecular and molecular methods currently available to detect the presence of MRSA directly from blood.

Objectives: This study aimed at reviewing the correlation between biofilm formation and antibiotic resistance in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates. Materials and Methods: This review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols. The literature search was conducted in PubMed, Web of Science (ISI), and Scopus databases. Combinations of Mesh terms such as \"biofilms\" OR \"biofilm formation,\" AND \"Drug Resistance\" OR \"Antimicrobial Drug Resistance\" OR \"Antibiotic Resistance\" AND \"Staphylococcus aureus\" OR \"Methicillin-resistant Staphylococcus aureus\" or \"MRSA\" AND \"Methicillin-sensitive Staphylococcus aureus\" OR \"MSSA\" AND \"biofilm-related genes\" AND \"Prevalence\" AND \"Iran\" were searched. Two reviewers independently searched the databases. Analyses were performed in Comprehensive Meta-Analysis software. The random-effects model was used to obtain the combined prevalence with a 95% confidence interval (CI). Results: The combined prevalence of MRSA retrieved from Iranian clinical samples was 48.3% (95% CI: 40.8-55.9). The pooled rate of biofilm formation in MRSA strains was reported as 80.9% (95% CI: 67.8-89.4). Overall, 52.9%, 45.3%, and 22.5% of MRSA isolates were strong, moderate, and weak biofilm producers, respectively. The highest frequency of biofilm-related genes was observed for icaD gene (67.7%) followed by clfA gene with a frequency of 64.7%. Among seven studies that addressed the relationship between biofilm formation and antibiotic resistance, six reported positive associations. Conclusions: Regarding the MRSA strains, they had a significantly higher ability of biofilm formation than MSSA strains; therefore, preventive measures against infections caused by them are required.

BACKGROUND: Coagulase negative Staphylococci (CoNS) are important. The common antibiotics used for the treatment of the infections caused by CoNS are penicillin, oxacillin, ciprofloxacin, clindamycin, erythromycin, gentamicin, and vancomycin. Linezolid is an oxazolidinone group of antibiotic with activity against Gram-positive bacteria. It is used for the treatment of serious infections caused by Gram-positive bacteria resistant to other antibiotics, including streptococci, vancomycin-resistant enterococci (VRE).
OBJECTIVE: This study emphasizes on the judicious use of newer antibiotics to contain the spread of resistance.
METHODS: We are discussing five cases of Linezolid resistant Staphylococcus Haemolyticus which were reported in our laboratory during one year from patients with device related infections and also review of literature is being presented for an update.
RESULTS: In our study, the isolates were resistant to other groups of antimicrobials but susceptible to glycopeptides. All the isolates were methicillin-resistant.
CONCLUSIONS: Linezolid is approved as an alternative drug to be given for catheter-related bloodstream infections. In earlier studies, linezolid-resistant staphylococci have been reported increasingly all over the world. This study is to create awareness amongst clinicians that improper and excessive use of linezolid will make this antibiotic-resistant and thus will be of no help in future, so judicious and relevant use of antibiotics needs to be emphasized.

Published literature on methicillin-resistant Staphylococcus aureus (MRSA) in the Asia-Pacific region was reviewed to document the prevalence of MRSA in the region and to examine the impact of variability in study design on the reported MRSA prevalence data.
This review included studies reporting MRSA prevalence between 2000 and 2016. Studies were excluded if they did not contain complete information on antimicrobial susceptibility testing (AST) methods. Primary outcomes were the proportion of MRSA among S. aureus isolates (resistance proportion) or among individual samples (prevalence).
A total of 229 studies in 19 countries/territories were included in the study. There was substantial heterogeneity in both outcomes (resistance proportion, I2=99.59%; prevalence, I2=99.83%), precluding pooled averages, and meta-regression analyses revealed that these variations were explained by country income status and participant characteristics but not by methodological differences in AST. Also, no significant secular changes in MRSA prevalence or resistance proportions in Asia-Pacific were found.
The resistance proportions and prevalence of MRSA infections in Asia-Pacific are comparable with those reported in other regions with no significant secular changes in the past decade. Country income status and characteristics of the sample population explained more variation in the reported resistance proportions and prevalence of MRSA than methodological differences in AST across locations in the region.