Clinical sources and prevalence of resistance to antimicrobials of Klebsiella pneumoniae strains in Trinidad

OBJECTIVE: To assess the frequency of Klebsiella pneumoniae (K. pneumoniae) recovery from clinical specimens from hospital and community patients, their antibiotic profile, the extent of extended-spectrum beta lactamase (ESBL) production among such isolates, and the impact on patient management.

METHODS: The study recovered 1,118 K. pneumoniae strains from various clinical specimens from hospital and community patients, from 1995 to 2004, at the Eric Williams Medical Sciences Complex. All 1,118 isolates underwent testing for multi-antibiotic resistance, of which 480 that fulfilled the criteria for possible ESBL production underwent further examination, according to guideline recommendations of the National Committee for Clinical Laboratory Standards.

RESULTS: From 68,537 specimens processed, 62.9% were from hospital patients and 37.1% from community patients. Approximately 21% of the specimens yielded positive bacterial cultures from which, 1118 were K. pneumoniae strains. Ciprofloxacin, imipenem, aztreonam, nalidixic acid and gentamicin showed the greatest efficacy (>95% sensitivity) against isolates from both hospital and community sources. Tetracycline and ampicillin showed almost 100% resistances. The other antibiotics displayed varying degrees of resistance. The prevalence of ESBL production was approximately 8.5% and most ESBL producers (51.2%) were from urine, followed by wounds (22.0%), blood (19.5%), and lower respiratory tract specimens (4.9%). Five K. pneumoniae isolates were resistant to the carbapenem, and imipenem.

CONCLUSION: The study isolated K. pneumoniae from 8% of patients. All K. pneumoniae isolates were resistant to more than 2 antibiotics. The prevalence of ESBL production was 8.5%. Five (12.2%) strains of ESBL producers were resistant to imipenem. Continued infection control measures and prudent use of antibiotic agents are essential in reducing the spread of multi-resistant ESBL producing K. pneumoniae.