title: Antibacterial resistance and their genetic location in MRSA isolated in Kuwait hospitals, 1994-2004.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of serious infections in hospitals and in the community worldwide. In this study, MRSA isolated from patients in Kuwait hospitals were analyzed for resistance trends and the genetic location of their resistance determinants.
  
  
  METHODS
  Between April 1994 and December 2004, 5644 MRSA isolates obtained from different clinical samples were studied for resistance to antibacterial agents according to guidelines from the National Committee for Clinical Laboratory Standards and the British Society for Antimicrobial Chemotherapy. The genetic location of their resistance determinants was determined by curing and transfer experiments.
  
  
  RESULTS
  They were resistant to aminoglycosides, erythromycin, tetracycline, trimethoprim, fusidic acid, ciprofloxacin, chloramphenicol, rifampicin, mupirocin, cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide but susceptible to vancomycin, teicoplanin and linezolid. The proportion of the isolates resistant to erythromycin, ciprofloxacin and fusidic acid increased during the study period. In contrast, the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined. High-level mupirocin resistance increased rapidly from 1996 to 1999 and then declined. They contained plasmids of 1.9, 2.8, 3.0, 4.4, 27 and 38 kilobases. Genetic studies revealed that they carried plasmid-borne resistance to high-level mupirocin resistance (38 kb), chloramphenicol (2.8-4.4 kb), erythromycin (2.8-3.0 kb) and cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide (27 kb) and chromosomal location for methicillin, the aminoglycosides, tetracycline, fusidic acid, ciprofloxacin and trimethoprim resistance. Thus, the 27 kb plasmids had resistance phenotypes similar to plasmids reported in MRSA isolates in South East Asia.
  
  
  CONCLUSIONS
  The prevalence of resistance to erythromycin, ciprofloxacin, high-level mupirocin and fusidic acid increased whereas the proportion of isolates resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim declined during the study period. They contained 27-kb plasmids encoding resistance to cadmium acetate, mercuric chloride, propamidine isethionate and ethidium bromide similar to plasmids isolated in MRSA from South East Asia. Molecular typing of these isolates will clarify their relationship to MRSA from South East Asia.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait. EDET@has.edu.kw
authors.forename: Edet E
authors.initials: EE
authors.lastname: Udo
authors.forename: Noura
authors.initials: N
authors.lastname: Al-Sweih
authors.forename: Eiman
authors.initials: E
authors.lastname: Mokaddas
authors.forename: Molly
authors.initials: M
authors.lastname: Johny
authors.forename: Rita
authors.initials: R
authors.lastname: Dhar
authors.forename: Huda H
authors.initials: HH
authors.lastname: Gomaa
authors.forename: Inaam
authors.initials: I
authors.lastname: Al-Obaid
authors.forename: Vincent O
authors.initials: VO
authors.lastname: Rotimi
mesh_terms: D000085:Acetates / Q000494:pharmacology; D001550:Benzamidines / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004996:Ethidium / Q000494:pharmacology; D005672:Fusidic Acid / Q000494:pharmacology; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D016106:Methicillin Resistance; D010957:Plasmids; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D017334:Teicoplanin / Q000494:pharmacology; D013997:Time Factors; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000085:Acetates; D001550:Benzamidines; D005839:Gentamicins; D002104:Cadmium; D005672:Fusidic Acid; D017334:Teicoplanin; D014640:Vancomycin; C046651:propamidine isethionate; C028031:cadmium acetate; D004996:Ethidium