Epidemiological and molecular characterization of community and hospital acquired Staphylococcus aureus strains prevailing in Shenyang, Northeastern China

Abstract

In order to obtain adequate information for the treatment of methicillin resistant Staphylococcus aureus (MRSA) infections, it is crucial to identify trends in epidemiological and antimicrobial resistance patterns of local S. aureus strains. Community and hospital acquired S. aureus isolates (n=202) were characterized using staphylococcal cassette chromosome mec (SCCmec) typing, pulse field gel electrophoresis (PFGE) analysis, spa typing and minimal inhibitory concentration (MIC) determination. The prevalence of the Panton-Valentine leukocidine (pvl) and several antibiotic resistance genes among the isolates were also detected by PCR. All of the S. aureus isolates were susceptible to vancomycin, daptomycin and linezolid. Three hospital isolates were resistant to teicoplanin while 14 showed intermediate resistance to teicoplanin. The resistance patterns of community-acquired MRSA (CA-MRSA) isolates to other antimicrobials were similar to those of hospital-acquired MRSA (HA-MRSA) isolates except for clindamycin and gentamicin. There was excellent correlation between phenotypes and genotypes in the determination of S. aureus resistance to erythromycin, gentamicin, and tetracycline. The SCCmec type II and SCCmec type IV were the predominant types detected in hospital and community isolates, respectively. The most frequently encountered spa types were t002 and t030 both in HA- and CA-MRSA isolates. Pulsotype A was the most predominant pulsotype identified among the isolates tested, followed by pulsotype B. Seventy-two hospital isolates (19 HA-MRSA and 53 HA-MSSA) and 10 CA-MRSA were positive for the pvl gene. This study shows that the combination of susceptibility testing and various molecular methods has provided useful information on the antibiotic resistance and molecular diversity of S. aureus in a specific region of China. The high proportion of pvl positive MSSA and MRSA isolates observed in this study indicates that adequate measures are needed to curtail the spread of those MRSA and MSSA clones prevailing both in hospital and the community.

Prevalence of inducible clindamycin resistance in methicillin-resistant Staphylococcus aureus: the first study in Jordan

“…High prevalence of ermA was documented previously in HA-MRSA [19]. In addition, presence of ermA on the transposon Tn554 within SCCmec (staphylococcal cassette chromosome mec) I, II, and III, and absence on SCCmec IV explains the low prevalence of this gene in CA-MRSA [20].…”

Relationship between Antibiotic Resistance Patterns and Coagulase in Clinical Isolates of Staphylococcus aureus in Nowshahr and Chalous

“…Several antibioticresistant genes were examined. All the samples were sensitive to vancomycin and daptomycin, 98.1% resistant to penicillin, and 9.3 resistant to chloramphenicol [12].…”

“…Free coagulase binds with coagulase-reacting factor (CRF) in plasma and creates a complex, staphylothrombin [9][10][11]. Dawnson et al Conducted a descriptive study in China on specific molecular and epidemiological characteristics of S. aureus in patients in Xinyang, China [12]. The Coa gene, coding for the coagulase enzyme, can be used for DNA-based diagnosis of S. aureus.…”

Phenotypic and Genotypic Determination of Antibiotic Resistances of Some Clinical Staphylococcus aureus Isolates

“…Başka bir çalışmada eritromisine dirençli, fakat PCR ile tespit edilen bir eritromisin direnç genine sahip olmayan izolat belirlenmiştir. Araştırmacılar bu duruma zaman zaman kaybolan küçük plazmidlerdeki genlerin konumunun neden olduğunu belirtmişlerdir [20] . Fenotipik eritromisin duyarlılığı ve erm genleri arasında uyumsuzluk bulan bir çalışmada bu uyumsuzluğun, genlerin kodlama veya promotor bölgesindeki bir mutasyona bağlı olabileceği ifade edilmiştir [21] .…”

“…Bizim çalışmamızın aksine birçok çalışma raporunda en sık genetik belirleyici olarak ermA geni tespit edilmiştir [4,10,[12][13][14][15][16][17][18][19][20][21][22] .…”