Prevalent genotypes of meticillin-resistant Staphylococcus aureus: report from Pakistan

Abstract

Meticillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen in Pakistan and is emerging in the community. This is one of the first reports of the prevalent genotypes of MRSA in both hospital and community settings in Pakistan. Isolates collected in 2006-2007 were characterized by PFGE, staphylococcal cassette chromosome mec (SCCmec) typing and multilocus sequence typing (MLST). PFGE identified nine pulsotypes, the majority of isolates belonging to pulsotypes A (n570) and B (n538), which were predominant among hospital-onset MRSA (HO-MRSA) and community-onset MRSA (CO-MRSA) isolates, respectively. Among the HO-MRSA isolates, variants of SCCmec type III were prevalent, whilst SCCmec type IV or variants were predominant in the CO-MRSA isolates. MLST identified two principal sequence types, ST8 and ST239. An association was observed between ST8, PFGE pulsotype B and SCCmec type IV in the CO-MRSA (ST8-MRSA-IV). Similarly, ST239, PFGE pulsotype A and SCCmec type III were associated with HO-MRSA (ST239-MRSA-III). Therefore, the prevalent genotypes circulating in Pakistan at the time of study were ST8-MRSA-IV and ST239-MRSA-III in the community and hospital settings, respectively. A set of HO-MRSA isolates collected in 1997 were characterized by PFGE and SCCmec typing for comparison. The isolates belonged to two PFGE pulsotypes (A, n528; B, n511) and contained just two SCCmec types. These results suggest that an increase in genetic diversity occurred over the period 1997-2007 as a result of either microevolution or the importation of strains from surrounding areas.

Molecular analysis of methicillin-resistant Staphylococcus aureus isolates from four teaching hospitals in Iran: The emergence of Novel MRSA ST- SCCmec clones

“…In previous studies of MRSA and MSSA strains in the cities of Isfahan and Tehran the majority of MRSA isolates belonged to ST239 [25]. The high prevalence of ST239 has been documented from many Asian countries especially India, Pakistan, Vietnam, Thailand, Taiwan, China, Sri Lanka, and Singapore [27]. In accordance with other studies, our MRSA isolates with ST239 belonged to SCCmec types II and III, with similar antibiotic resistance and virulence patterns [22].…”

“…According to MLST genotyping, S. aureus strains have been documented to be highly clonal and the most of the strains belong to a limited number of closely related genotypes. Literature have shown that CC8 (Iberian clone, Brazilian clone, Archaic clone), CC5 (New York/Japanese clone, Pediatric clone) and CC22 (epidemic MRSA-15) belong to epidemic MRSA (EMRSA) clones with global distribution in hospitals [27]. In accordance with our study, CC8-V was found as predominant clone in study conducted in Armenia [8].…”

A Field Guide to Pandemic, Epidemic and Sporadic Clones of Methicillin-Resistant Staphylococcus aureus

“…In Australia, it is a common cause of hospital-acquired infection in the East coast states, and large outbreaks in the 1980s were attributable to this strain [155]. Furthermore, ST239-MRSA-III has also been reported in Argentina [185], Brazil [186]; [187], Chile [185], Egypt (isolates courtesy of M. Kamal El Din, Cairo), India [104], Korea [171], Malaysia [172], Mongolia [168], New Zealand [174], Pakistan [188], Paraguay [42], Russia [189], South Africa [73], Thailand [176] and Uruguay [185]. The reference strain ATCC33592, recovered in a hospital in New York [190], belongs also to ST239-MRSA-III.…”

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal

“…[1][2][3] However, MRSA is not only the problem in hospital but also a serious problem for community due to emergence of the community acquired MRSA. 4 Health care workers(HCWs) colonized with MRSA may carry these virulent hospital strains in their nose and skin and may transmit these organisms to the community creating a more dreadful situation.…”