Gentamicin resistance among Escherichia coli strains isolated in neonatal sepsis.
Neonatal sepsis is a significant cause of morbidity and mortality among term and preterm infants. Ampicillin and gentamicin are standard empiric therapy for early onset sepsis. Four cases of neonatal sepsis secondary to Escherichia coli (E. coli) found to be gentamicin resistant occurred within a five week period in one neonatal intensive care unit (NICU). To determine whether these cases could be tied to a single vector of transmission, and to more broadly evaluate the incidence of gentamicin resistant strains of E. coli in the neonatal population at our institution compared to other centers, we reviewed the charts of the four neonates (Infants A through D) and their mothers. The E. coli isolates were sent for Pulse Field Gel Electrophoresis (PFGE) to evaluate for genetic similarity between strains. We also reviewed all positive E. coli cultures from one NICU over a two year period. Infants A and B had genetically indistinguishable strains which matched that of urine and placental cultures of Infant B's mother. Infant C had a genetically distinct organism. Infant D, the identical twin of Infant C, did not have typing performed. Review of all cultures positive for E. coli at our institution showed a 12.9 percent incidence of gentamicin-resistance. A review of other studies showed that rates of resistance vary considerably by institution. We conclude that gentamicin-resistant E. coli is a relatively uncommon cause of neonatal sepsis, but should remain a consideration in patients who deteriorate despite initiation of empiric antibiotics.
University of Michigan, Ann Arbor, MI, USA.
J
J
Hasvold
L
L
Bradford
C
C
Nelson
C
C
Harrison
M
M
Attar
T
T
Stillwell
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004200:Diseases in Twins / Q000188:drug therapy; D024881:Drug Resistance, Bacterial; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000635:transmission; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000188:drug therapy*; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy; D018805:Sepsis / Q000188:drug therapy*
D000900:Anti-Bacterial Agents; D005839:Gentamicins
Neonatal sepsis; antibiotic resistance