SciELO - Scientific Electronic Library Online

vol.36 número5Translocaciones crípticas de cromosomas acrocéntricos en muestras de tejido de aborto aneuploideLinfoma no Hodgkin primario de sistema nervioso central en un paciente pediátrico sin inmunodeficiencia relacionada índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados




Links relacionados

  • No hay artículos similaresSimilares en SciELO


Acta pediátrica de México

versión On-line ISSN 2395-8235versión impresa ISSN 0186-2391


FLORES-PEREZ, Angélica et al. Sulfhydryl variable-5 extended spectrum β-lactamase in nosocomial enteric bacteria causing sepsis in mexican children. Acta pediatr. Méx [online]. 2015, vol.36, n.5, pp.383-388. ISSN 2395-8235.


Enteric bacteria causing nosocomial infections are often resistant to third-generation cephalosporins due to the production of extended-spectrum β-lactamases (ESBLs).


To describe and characterize the ESBLs pattern present in Klebsiella pneumoniae and Serratia marcescens strains, isolated as causative of nosocomial sepsis in pediatric patients at Instituto Nacional de Pediatría (National Institute of Pediatrics).

Material and methods:

We analyzed 94 strains of K. pneumoniae and 7 of S. marcescens isolated from clinical specimens from 2002-2005, causative of sepsis in a children's hospital. We evaluated antibiotic susceptibility and detection of ESBL phenotypes by disk diffusion methods; ceftazidime-resistant isolates were further characterized by pulsed field gel electrophoresis (PFGE); and ESBLs were phenotypically and genotypically characterized by isoelectric focusing, polymerase chain reaction (PCR) and sequencing. We also assed for presence of conjuga-tive plasmids bearing the ESBL gene.


51/94 (54%) of K. pneumoniae isolates, and 5/7 (71%) of S. marcescens isolates were resistant to ceftazidime; all carried a blaSHV5 gene. All K. pneumoniae isolates had a distinct PFGE profile, yet all carried a -48-Kb plasmid, that was conjugatively transferable to an Escherichia coli receptor, which expressed the resistance phenotype. On the other hand, all S. marcescens isolates had a similar PFGE profile, were unable to transfer the ceftazidime-resistance phenotype, and were isolated from the same ward in a short time-span suggesting an outbreak.


The overall prevalence of ESBL-producing enteric bacteria in this hospital is high but similar to other Latin American reports. The sulfhydryl variable-5 (SHV-5) ESBL gene appears to reside in a highly mobile plasmid, capable of spreading among different K. pneumoniae clones and perhaps even to S. marcescens.

Palabras llave : SHV-5; extended-spectrum beta-lactamase; Klebsiella pneumoniae; Serratia marcescens.

        · texto en Inglés     · Inglés ( pdf )