Resumen de Intestinal Colonization by Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Infants
Gloria Concepción Huerta García, María Guadalupe Miranda Novales, Rita Díaz Ramos, J. Guillermo Vázquez Rosales, Fortino Solórzano Santos
Background: Members of the Enterobacteriaceae family are common agents of nosocomial infections. Intestinal colonization by these microorganisms represents a major step in the development of systemic infection. Extended-spectrum b-lactamaseproducing bacteria are usually associated with outbreaks, but endemic infections are common in intensive care units. Objective:
To determine the frequency of intestinal colonization with extended-spectrum b-lactamase-producing Enterobacteriaceae in newborns. Patients and Methods: This was a descriptive cohort study. Newborns from two general hospitals (A and B) in Mexico City were included during a five-month period; those with a hospital stay > 7 days were selected. Fecal samples were obtained by rectal swab on day 7 and every week until discharge. Extended-spectrum b-lactamase production was confirmed in enterobacteria by the Etest. Clonal relatedness was established by pulsed-field gel electrophoresis. Results: 102 newborns were included; 63/102 (61.7%) were colonized by extended-spectrum b-lactamase-producing Enterobacteriaceae on day 7, 17/21 (81%) on day 14, and 6/8 (75%) on day 21 of hospitalization. Klebsiella pneumoniae was recovered most frequently (75.4%). A predominant clone (95%) was found in hospital B, and a major clone (75%) in Hospital A. Other extended-spectrum b-lactamase-producing Enterobacteriaceae isolates were Enterobacter spp. (16%) and Escherichia coli (7.6%). Conclusions:
High rates of colonization and horizontal transmission of extended-spectrum b-lactamase-producing Enterobacteriaceae were found in the newborn care units of two general hospitals. Clonal relatedness was identified. Lack of adherence to standard precautions and hand hygiene were determining factors. (REV INVES CLIN. 2015;67:313-7)
