Molecular Typing of Methicillin By Waseem Shehzad Abbasi U from Pakistan, India and Kuwait Resistant Staphylococcus aureus (MRSA)

Abstract

Methicillin resistant Staphylococcus aureus (MRSA) infections are a worldwide problem and prevalence of MRSA is increasing with a phenomenal rate. MRSA has developed resistance against a number of commonly used antibiotics. A number of diseases are caused by MRSA including fatal diseases like septicemia, endocarditis and staphylococcal pneumonia. In recent years, morbidity and mortality due to MRSA infections has increased. To aid in diagnosis, various methods have been used to identify and classify Staphylococcus aureus. A diverse range of molecular methods has been applied to reach accurate diagnosis in order to contain and control the MRSA U infections successfully. Phenotyping methods such as antibiogram lack accuracy and discriminatory power. Various genotyping methods including, length polymorphism fragment restriction plasmid analysis, multi locus enzyme electrophoresis (MLEE) analysis, (RFLP), pulse field gel electrophoresis (PFGE), variable number tandem repeat (VNTR) analysis, restriction modification (RM) test and multi locus sequence typing (MLST) has been used in various epidemiological studies to investigate outbreaks and pattern of spread of MRSA infections. Present work focuses on molecular typing of MRSA from three countries, Pakistan, India and Kuwait. VNTR- based staphylococcal interspersed repeat units (SIRU) typing along with PFGE, RM typing and MLST was used to analyze MRSA from these three countries. A total of 114 MRSA isolates from Kuwait (n=81), Pakistan (n=22) and India (n=11) were included in the study. MRSA isolates from Pakistan and India showed clonal complex CC8 and CC30 while MRSA isolates from Kuwait belonged to CC1, CC5, CC8, CC22, CC30 and CC45. CC8 was the predominant clonal complex found in these three countries. MLST of these MRSA isolates revealed that sequence type (ST) 239, ST30, and ST113 were found in Pakistani and Indian MRSA. ST239, ST80, ST36, ST22 and ST 133 were found in MRSA from Kuwait. ST239 was the predominant ST in these three countries. SIRU typing resolved 81 MRSA isolates from Kuwait into 49 discrete profiles, 41 SIRU profiles were unique in these MRSA isolates.