Antibacterial resistance and molecular typing of methicillin-resistant Staphylococcus aureus in a Kuwaiti general hospital.
OBJECTIVE
To investigate antibiotic resistance and genetic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) isolated in a general hospital in Kuwait over a period from 1996 to 1998 and 2001.


METHODS
The isolates were characterized by antibacterial susceptibility testing, coagulase serotyping, coagulase gene polymorphism (coag-RFLP) and pulsed-field gel electrophoresis (PFGE).


RESULTS
The MRSA isolates were highly resistant to gentamicin, kanamycin, ciprofloxacin, tetracycline, fusidic acid and mupirocin. The prevalence of gentamicin, kanamycin, streptomycin, tetracycline and erythromycin resistance remained high (80-96%) throughout the study period, but the prevalence of resistance to ciprofloxacin, fusidic acid and mupirocin steadily increased. The already high mupirocin resistance level increased from 12.5 in 1996, to 85.7% in 2001, and the fusidic acid resistance varied between 70.8 and 85.7%. In contrast, chloramphenicol and trimethoprim resistance declined from 25 and 29% in 1996 to 4.7 and 14.2% in 2001, respectively. The majority (91.5%) of the isolates were coagulase serotype 4. AluI restriction endonuclease analysis of amplified coagulase gene generated four coag-RFLP patterns: 92% of them were coag-RFLP type 1, while types 2, 3 and 4 were 3.5, 4.6 and 1.1% respectively. PFGE differentiated them into seven pulsotypes (PFGE types 1-7). The PFGE type 1 pulsotype constituted 90.2% of the isolates. Isolates with the type A coag-RFLP also had the type1 PFGE pulsotypes.


CONCLUSIONS
The concordant results of PFGE and coag-RFLP demonstrated the presence of a persistent MRSA clone in the hospital during the study period.
Udo
E E
EE
Department of Microbiology, Faculty of Medicine, Kuwait University, Safat 13110. edet@hsc.edu.kw
Al-Sweih
N
N
Mohanakrishnan
S
S
West
P W J
PW
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D017931:DNA Primers; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006769:Hospitals, General; D006801:Humans; D007730:Kuwait; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D017931:DNA Primers