Background Staphylococcus epidermidis is a common cause of nosocomial infections worldwide. This study analyzed the differences in genetic endowment and clonal lineages with pathogenesis and resistance traits of S. epidermidis isolates collected from community and hospital environments (patients and healthcare staff) of the same ecological niche, time period, and geographical location in China.Methodology/Principal FindingsMolecular epidemiology and population analysis showed that nasal colonization rates of S. epidermidis in the community of Shanghai area of China and in healthcare personnel were 44.8% (methicillin-resistant S. epidermidis, MRSE: 17.2%) and 61.3% (MRSE: 30.0%), respectively. 86.7% of clinical isolates were MRSE. Among the strains studied, 44 sequence types (STs) were identified with 91.7% belonging to clonal complex 2 (CC2). Only 40.8% isolates from patients were also found in healthy individuals. MRSE-ST2-SCCmecIII was the predominant clone in clinical isolates, almost resistant to all antibiotics tested. Biofilm-related genes IS256 and icaA were detected in majority of the predominant clinical MRSE-ST2 clone with a 40.5% biofilm-positive rate. No ST2 isolate was found in community setting. We found a high prevalence of arginine catabolic mobile element (ACME) (74.1%). The prevalence of ACME-arc and ACME-opp3 clusters was 71.6% and 32.4%, respectively. Methicillin-sensitive S. epidermidis (MSSE) isolates harbored more ACME (83.3%) than MRSE isolates (67.7%), and there was no association between ACME and SCCmec types. An association was found between low-level ACME presence and invasive infections.Conclusions/SignificanceWe observed a high level of diversity within S. epidermidis in this study, with CC2 as the dominant clonal complex in both community and hospital settings. Only 40.8% of the isolates from patients were also found in healthy individuals. Contrary to that biofilm formation and multiple antibiotic resistance were associated closely with pathogenicity of S. epidermidis, ACME was more likely to be an indicator for colonization rather than a virulence factor.

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Background: Streptococcus agalactiae colonization in pregnant women leads to prenatal and neonatal infections worldwide; thus, early detection is very crucial. Objectives: Development of a rapid detection method for S. agalactiae. Methods: Genomic DNA of cultured S. agalactiae was prepared and loop-mediated isothermal amplification (LAMP) primers were designed based on the cAMP gene in bacteria. The optimum primer set was selected based on the reaction speed and specificity. The reaction result was monitored visually. The sensitivity and specificity of the LAMP method were evaluated and compared with polymerase chain reaction (PCR) method. Results: Using the optimum primer set the reaction can be completed in 40 minutes at 63°C in a water bath. The LAMP assay was 10 -100 times more sensitive than PCR, with a detection limit of 10 CFU/mL of S. agalactiae. Forty vaginal swab were examined by LAMP, and the specificity was 100%. Conclusions: Thus, for S. agalactiae detection, the LAMP method is a valuable diagnostic tool, with easy, rapid, visual, accurate, and sensitive advantages.