Epidemiology of Klebsiella Isolates by Antimicrobial Resistance Gene Analysis

ABSTRACT

One hundred of clinical isolates of Klebsiella spp. from three hospitals were analyzed by phenotypic and genotypic characteristics for epidemiologic investigation. Almost all isolates of Klebsiella spp. showed highly resistance to ampicillin, and carbenicillin and 4.5-7.9% of K. pneumoniae isolates were also resistant to cefotaxime and ceftazidime, and 10-15% to aminoglycoside antibiotics except amikacin. However, all strains were highly susceptible to imipenem, cefotetan, amikacin and ciprofloxacin. All Koxytoca strains were susceptible to antimicrobials tested except Ap, Am and Cb. Twelve strains of K. pneumoniae hybridized with TEM or SHV probe and extended spectrum B-lactamases from 7 strains were TEM type. Eleven conjugative R plasmids and their parental strains were analyzed. Among them, three couples of plasmids showed identical or nearly identical resistance phenotypes of B-lactams and aminoglycosides, molecular weights, and pI values by isoelectric focusing, and hybridized fragment patterns with TEM probe by Southern hybridization, EcoR1 restriction endonuclease fragment patterns. Their parental strains were isolated from sputum, tissue, and ascites of patients and had similar characteristics. These results indicate that the epidemic strains or epidemic plasmids were present in this hospital and antimicrobial resistance anlysis can be used to discriminate clinical isolates of multi-resistant K. pneumoniae.