Molecular Characterization of Community-Associated Methicillin-Resistant Staphylococcus aureus in Iranian Burn Patients

Abstract

Background & Objective:Methicillin-resistant Staphylococcus aureus (MRSA) is reported as one of the important bacterial causes of burn wound infections. This study was carried out to investigate molecular characterization of community-associated MRSA (CA-MRSA) isolated from Iranian burn patients. Methods:A total of 31 isolates of S. aureus were collected from the Motahari Burns Hospital (Tehran, Iran) in 2016. All isolates were collected from outpatients and inpatients within 48 hours of admission. The mecA, pvl, tsst-1, hla-α, and psmα genes detecting, SCCmec, agr and PFGE typing were done.Results:A total of 13 (41.9%) isolates were cefoxitin-resistant and mecA-positive, which were considered as MRSA. The SCCmec typing MRSA strains revealed type II in 1 (7.7%), type III in 9 (69.2%), and other types in 3 isolates (23.7%) cases. The agr typing of all 31 isolates showed that 14 (45.2%), 1 (3.2%), 6 (19.4%), and 10 (32.3%) strains belonged to agr groups 1, 3, 4, and unknown type, respectively. The pvl, tsst-1, hla-α, and psmα genes were positive in 3 (9.7%), 4 (12.9%), 21 (67.7%), and 31 (100%) isolates, respectively. Considering the cut-off values of ≥50%, 3 groups of related isolates (cluster A1, B1, and C1) in PFGE study were observed.Conclusion:The MRSA strains of this study were initially isolated as Community-associated S. aureus (CA-MRSA); however molecular characterization showed that a significant proportion of them had hospital-associated MRSA (HA-MRSA) features. Therefore, it is likely that the HA-MRSA strains are spread among the community.

Molecular Characterization of Staphylococcus aureus Obtained from Blood Cultures of Paediatric Patients Treated in a Tertiary Care Hospital in Mexico

“…[53][54][55][56] The frequency of pvl in MRSA varies from 9-30%; in Iran (9.7%), South Africa (14%), the US (26%), and China (30%). [50][51][52]55 In the current study, we found the pvl gene in four isolates (1.6%), all with SCCmec-IV. In 2016, the first MRSA SCCmec-IV isolate with pvl was detected.…”

“…In some regions of the world, there has been a decrease in cassettes I, II and III, historically associated with HA infections, and an increase in cassettes IV and V (associated with CA infections). This exchange has been widely described in the U.S., 50 Iran 51 and South Africa. 52 …”

“…It is important to monitor the change in the distribution of SCCmec elements because in other countries, in particular the US, MRSA SCCmec-IV isolates reach 28%, China 61%, South Africa 48% and Japan 52.3%. [50][51][52][53]55 PVL is For personal use only.…”

Clonal diversity and genomic characterization of Panton-valentine Leukocidin (PVL)-positive Staphylococcus aureus in Tehran, Iran

“…All S. aureus strains in this study were screened for MRSA according to resistance to cefoxitin (30 μg) using the Kirby-Bauer disk diffusion method ([ 33 ]). The identity of MRSA strains was confirmed by detection of mec A using PCR method ([ 33 ]). A multiplex PCR-based method was also carried out for SCC mec typing as previously described [ 32 ].…”

Prevalence of SEA and SEB enterotoxin producing methicillin-resistant staphylococcus aureus strains among primary school children in Sari, Iran

“…This gene encodes an alternative penicillin-binding protein, PBP2a that has a low affinity for binding β-lactam antibiotics 3,7 . Community-acquired MRSA (CA-MRSA) normally expresses lower levels of antibiotic resistance compared to hospitalacquired MRSA (HA-MRSA) 8,9 . Over the past few years, the prevalence of nosocomial infections caused by this strain has significantly increased.…”