title: High prevalence of class 1 integrons in clinical isolates of methicillin-resistant Staphylococcus aureus from India.
abstract: BACKGROUND
  Class1 integrons are one of the prevalent mechanisms of antibiotic resistance gene transfer in Gram-negative organisms, but their prevalence and role in the spread of antibiotic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) is unexplored. The purpose of this study was to investigate the prevalence of class 1 integrons in clinical isolates of MRSA.
  
  
  METHODS
  Total 143 MRSA isolates obtained from two different cities in India (Pune and Mumbai) were characterized by biochemical tests, and the antibiotic sensitivity was performed using the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of class 1 integrons, sul1/qacE0Δ1 region of class 1 integron and mecA gene among these isolates was determined by polymerase chain reaction (PCR).
  
  
  RESULTS
  All 143 isolates were mecA positive and coagulase-positive. Overall, 71% of the MRSA isolates carried class 1 integrons; 58% (45/77) of the isolates obtained from Mumbai and 85% (56/66) of the isolates from Pune carried class 1 integrons. In all, 39% of these isolates carried sul1/qacEΔ1 region, thus confirming the association of class 1 integrons with antibiotic resistance genes. Along with β-lactam antibiotics the MRSA isolates were resistant to several other antibiotics, with resistance to erythromycin, ciprofloxacin and trimethoprim-sulfamethoxazole being observed in 75%, 66% and 60% of the isolates, respectively.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report of class 1 integrons in MRSA isolates from India. The study provides insights into the prevalence of a novel mechanism adapted by MRSA for the propagation of antibiotic resistance genes.
authors: Microbial Culture Collection, National Center for Cell Science, Ganeshkhind, Pune 411004, India.
authors: N P
authors: NP
authors: Marathe
authors: S S
authors: SS
authors: Nagarkar
authors: A A
authors: AA
authors: Vaishampayan
authors: M H
authors: MH
authors: Rasane
authors: S A
authors: SA
authors: Samant
authors: V
authors: V
authors: Dohe
authors: A
authors: A
authors: Kagal
authors: Y S
authors: YS
authors: Shouche
authors: Department of Microbiology, Abasaheb Garware College, Karve Road, Pune 411004, India.
authors: N
authors: N
authors: Deshpande
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002947:Cities; D004269:DNA, Bacterial / Q000235:genetics; D006801:Humans; D007194:India / Q000453:epidemiology; D032023:Integrons; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial