Acta bioquímica clínica latinoamericana
Print version ISSN 0325-2957
MAJEED, Zahid et al. Genotypic characterization of prevalent methicillin resistant Staphylococcus aureus in Pakistani community hospitals. Acta bioquím. clín. latinoam. [online]. 2012, vol.46, n.2, pp. 257-270. ISSN 0325-2957.
Protein A gene was used as a genetic marker for the characterization of Pakistani methicillin resistant Staphylococcus aureus (MRSA) isolates. Out of a total of 130 Staphylococcus aureus isolates, 90 were identified as MRSA and of these 90 MRSA, 81 MRSA isolates were characterized by spa typing. All of these isolates were collected from five National Community Hospitals. Two different sets of primers were used to amplify the X-region of Protein A gene in MRSA strains. One set of primers i.e, spa-F/spa-R identified three types of different repeats viz., 7 repeats (spa 2), 8 repeats (spa 3) and 10 repeats (spa 4) and another set of primers i.e. spa-1113F/spa-1514R identified 4 types of different repeats viz., 6 repeats (spa 1), 15 repeats (spa 6), and 17 repeats (spa 7) and 19 repeats (spa 8). Repeat 11 (spa 5) was identified with both sets of primers. Sporadic MRSA types carrying 6, 7, 10, 17 and 19 repeats were less prevalent, while the epidemic MRSA with 8, 11 and 15 repeats were more prevalent and considered to be involved in transmission among the patients within different hospitals. Research work concludes that spa technique is efficient enough to differentiate spa strains carrying variations in general and those slowly transforming from sporadic to epidemic outbreak in particular.
Keywords : Genotyping; Staphylococcus aureus; Protein A; Spa typing; Polymorphism.