Molecular epidemiology and characteristic of virulence gene of community-acquired and hospital-acquired methicillin-resistant Staphylococcus aureus isolates in Sun Yat-sen Memorial hospital, Guangzhou, Southern China

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of both hospital and community infections globally. It's important to illuminate the differences between community-acquired MRSA (CA-MRSA) and hospital-acquired MRSA (HA-MRSA), but there have been confusions on the definition, especially for the MRSA isolates identified within 48 h of admission. This study aimed to determine the molecular characteristics and virulence genes profile of CA and HA-MRSA isolates identified less than 48 h after hospital admission in our region. Methods: A total 62 MRSA isolates identified within 48 h after admission and the clinical data were collected. Antimicrobial susceptibility test (AST) of collected isolates were performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI) 2015, and staphylococcal cassette chromosome mec (SCCmec) typing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and virulence gene profiling were performed to explore the molecular diversity. Results: SCCmec III and sequence type (ST) 239 were the most prevalent SCCmec type and ST in both CA and HA-MRSA groups. HA-MRSA group had higher prevalence of SCCmec III (87.2 %) and ST239 (79.5 %) compared with CA-MRSA (60.9 and 43.4 %, both P < 0.001), while the frequency of SCCmec IV (26.0 %) and ST59 (21.7 %) were higher in CA-MRSA than its counterpart (P < 0.001 and P = 0.003). MRSA-ST239-III was the predominant type in this study (61.3 %, 38/62), especially in HA-MRSA group (76.9 %, 30/39). However, CA-MRSA strains exhibited more diversity in genotypes in this study. Meanwhile, CA-MRSA tended to have lower resistant percentage to non-β-lactams antibiotics but more virulence genes carriage, especially the staphylococcal enterotoxins (SE) genes. Notably, seb gene was only detected in CA-MRSA isolates (52.2 %), likely a significant marker for CA-MRSA isolates. Panton-Valentine leukocidin gene (PVL) was highly detected in both groups, while appeared no significantly different between CA-MRSA (47.8 %) and HA-MRSA (43.6 %). Conclusions: Our findings support a difference in the molecular epidemiology and virulence genes profile of CA-MRSA and HA-MRSA. Furthermore, this study indicates a possible transmission from HA-MRSA to CA-MRSA, which may cause the overlap of the definition.

Methicillin-resistant Staphylococcus aureus carriage rate and molecular characterization of the staphylococcal cassette chromosome mec among Syrian refugees in Iraq

“…MRSA rates were lower in males than in females. This is in agreement with studies conducted in Iraq (Assafi et al, 2015) and China (Xie et al, 2016), and in contrast to a study performed in Nepal (Ansari et al, 2016). In addition, the data from the present study revealed that age had no influence on the MRSA nasal colonization rate among local participants and Syrian refugees.…”

“…In addition, the data from the present study revealed that age had no influence on the MRSA nasal colonization rate among local participants and Syrian refugees. Similar results have been reported from studies in China (Lin et al, 2016;Xie et al, 2016) and Nepal (Ansari et al, 2016). Moreover, it was observed that the number of family members showed no association with nasal carriage colonization of MRSA.…”

Characterisation of community-acquired Staphylococcus aureus causing skin and soft tissue infections in a children's hospital in Shanghai, China

“…The prevalence of CA-MRSA SSTIs was reported to be 57% in the US in 2004 [12], but there was no report of such infections in mainland China before 2009. A few studies reported that CA-MRSA accounted for 4.0% of community-acquired S. aureus SSTIs in Beijing (northern China, isolates collected from children between 2008 and 2009), 3.4% in Guangzhou (southern China, 2006-2011, adults and children) and 10.3% in Wuhan (central China, 2011-2013, adults and children) [13][14][15]. Likewise a multicentre study (2009-2011, adults and children) found a low prevalence of CA-MRSA SSTIs ranging from 1.3% in northern China to 6.1% in southwestern China, and 3.8% in a children's hospital in Shanghai [16].…”

Antimicrobial resistance and prevalence of CvfB, SEK and SEQ genes among Staphylococcus aureus isolates from paediatric patients with bloodstream infections

“…Invasive MRSA infection has been identified as an independent risk factor for poor prognosis and is associated with a significant increase in the duration of hospitalization (8,9). Although MRSA-ST239-SCCmec III represents the most common clone in China, others are also in circulation, whose antimicrobial resistance profiles differ (10). Thus, the provision of data concerning antibiotic resistance is important to enable clinicians to choose appropriate treatments.…”