Transmission of a Klebsiella pneumoniae clone harbouring genes for CTX-M-15-like and SHV-112 enzymes in a neonatal intensive care unit of a Kuwaiti hospital.

The spread of antibiotic-resistant bacteria has become a large problem in most countries including Kuwait. This antibiotic resistance is usually due to the production of extended-spectrum beta-lactamase (ESBL) enzymes such as SHV, TEM and CTX-M. This study reports the emergence and spread of an ESBL-producing Klebsiella pneumoniae clone in a neonatal intensive care unit (NICU) in a Kuwaiti hospital. Eight ESBL-producing K. pneumoniae isolates were from blood cultures of seven neonates, and two were from the fingers of two healthcare workers in a NICU in Al Jahra Hospital, Kuwait. All isolates were obtained in February-March 2006, except for one, which was obtained in August 2005. Identification of the bacteria was based on traditional bacteriological and biochemical tests using the Vitek system. Antibiotic susceptibility was tested by the disc diffusion method using 16 different antibiotics. ESBLs were detected using disc approximation and double-disc synergy methods and confirmed as ESBLs using Etest. PCR and DNA sequencing were performed to determine the genotypes and mutations in the beta-lactamase genes (blaTEM, blaSHV and blaCTX-M). Genetic relatedness was determined by PFGE. All isolates were confirmed to have ESBLs by the Vitek system, disc approximation test, double-disc diffusion test and Etest, being resistant to cefotaxime, ceftazidime, cefepime, gentamicin, tobramycin and ciprofloxacin but susceptible to tetracycline and trimethoprim-sulfamethoxazole. Molecular studies showed the isolates to have TEM-1 beta-lactamase, a CTX-M-15-like ESBL and the newly discovered SHV-112 ESBL. PFGE showed that all isolates had identical banding patterns. The results indicate that a single clone of ESBL-producing K. pneumoniae caused bloodstream infections among babies in a NICU of a Kuwaiti hospital, and may have emerged at least 5 years ago. This clone was also present on the hands of healthcare workers, suggesting that they may have been involved in its transmission. Further studies are recommended to determine whether this clone is also spreading in other Kuwaiti hospitals.

Antibacterial resistance and their genetic location in MRSA isolated in Kuwait hospitals, 1994-2004.

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. CONCLUSION: 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.