title: Nosocomial bacteremia and urinary tract infections caused by extended-spectrum beta -lactamase-producing Klebsiella pneumoniae with plasmids carrying both SHV-5 and TLA-1 genes.
abstract: We describe the prevalence and molecular characteristics of extended-spectrum beta -lactamase (ESBL)-producing Klebsiella pneumoniae causing nosocomial bacteremia and urinary tract infections in a Mexican general hospital. We analyzed 82 episodes of bacteremia (approximately 60% of episodes) and urinary tract infection (approximately 40% of episodes) due to K. pneumoniae during a 23-month surveillance period. The neonatal intensive care unit accounted for 49% of all episodes. All strains were imipenem susceptible; 62.2% of the strains were resistant to ceftazidime, cefotaxime, and aztreonam; 69.5% were resistant to amikacin; 58.5% were resistant to gentamicin; and 7.3% were resistant to ciprofloxacin. All strains were associated with 28 pulsed-field gel electrophoresis patterns, and dissemination of 2 ceftazidime-resistant clones produced 44% of the cases. The ESBL phenotype in these clones was transferred by identical or highly related megaplasmids. The ESBL activity corresponded to SHV-5 and TLA-1. Cross-transmission of 2 ceftazidime-resistant clones and the horizontal spread of identical or highly related megaplasmids explain the high prevalence of ESBL phenotype in these infections.
authors.affiliation: Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Hospital General de Mexico, Mexico City, Mexico.
authors.forename: Dolores
authors.initials: D
authors.lastname: Alcantar-Curiel
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Tinoco
authors.forename: Catalina
authors.initials: C
authors.lastname: Gayosso
authors.forename: Angeles
authors.initials: A
authors.lastname: Carlos
authors.forename: Carlos
authors.initials: C
authors.lastname: Daza
authors.forename: Maria C
authors.initials: MC
authors.lastname: Perez-Prado
authors.forename: Lorena
authors.initials: L
authors.lastname: Salcido
authors.forename: Jose I
authors.initials: JI
authors.lastname: Santos
authors.forename: Celia M
authors.initials: CM
authors.lastname: Alpuche-Aranda
mesh_terms: D016470:Bacteremia / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D014552:Urinary Tract Infections / Q000382:microbiology*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001618:beta-Lactamases