Molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates from major hospitals in Riyadh, Saudi Arabia

Abstract

The few studies that have reported the incidence of methicillin-resistant Staphylococcus aureus (MRSA) in Saudi Arabia have indicated that a diverse number of circulating MRSA strains have been detected in several major hospitals. Thus, this study was designed to track the presence of MRSA strains in major hospitals in Riyadh, Saudi Arabia, and perform comparative chromosomal DNA analysis of MRSA strains for epidemiological investigation using pulsed-field gel electrophoresis (PFGE). Correlation of the PFGE types generated with microbiological and clinical data of the isolates was attempted. Screening for decreased susceptibility to vancomycin among the isolates was also done. A dendogram was generated using PFGE macrorestriction fragments and 6 types were identified (M1-M6) with M1 being predominant and widespread. A clear link between PFGE types and some clinical and microbiological data available for the strains was found. For example, M1 was statistically associated with male patients, whereas the unique types were associated with female patients, M2 was associated with isolates from wounds and age group <5 years, and M4 was associated with isolates from patients admitted to intensive care units. M5 was highly correlated with low sensitivity to linezolid. No vancomycin-resistant isolates were detected.

Prevalence of methicillin-resistant Staphylococcus aureus nasal colonization among medical students in Jeddah, Saudi Arabia

“…From the past 20-years, literature did not show any reports on the nasal colonization status of MRSA in medical students in Saudi Arabia, and few reports on healthcare workers. 14 , 22 This study shows that 6.7% of students carry MRSA strains in their nares, providing evidence that these strains are present in KAU Hospital. Although the rate of MRSA carriers among medical students in their clinical years was relatively low, it remains higher than internationally reported surveillances, 17 , 23 - 26 and can be threatening due to the frequent and direct contact with patients.…”

Antibiotic Based Phenotype and Hospital Admission Profile are the Most Likely Predictors of Genotyping Classification of MRSA

“…In studies conducted between 1990 and 2013 in the Middle East, and in particular in Saudi Arabia, MRSA was mainly classified based on either the health care risk factor or the susceptibility pattern phenotypic method [ 32 ]. One study showed a prevalence of PVL of 30% in a sample of 93 MSSA patients [ 33 ].…”

Detection and simultaneous confirmation of Methicillin-Resistant Staphylococcus aureus by an automated Real-Time PCR method with strain differentiation by analysis of DNA melting curve characteristics

“…Typing plays an important role in understanding the epidemiology of MRSA and evaluating the effectiveness of infection control and antimicrobial prescribing measures [11]. Several investigators have demonstrated the superiority of macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) for strain characterisation, when compared with other techniques [10][11][12]. This method provides highly reproducible restriction profiles that typically show distinct, well-resolved fragments representing the entire bacterial chromosome and is considered to be the method of choice for DNA fingerprinting of MRSA and other bacterial pathogens [11,12].…”