Analysis of Three Outbreaks Due toKlebsiellaSpecies in a Neonatal Intensive Care Unit

Abstract

AbstractObjective:To investigate the clinical, microbiological, and epidemiologic features of three outbreaks caused byKlebsielladuring 3 years.Setting:Neonatal intensive care unit of a university hospital.Patients:Thirty affected neonates.Methods:Data were collected through chart reviews and conversations with physicians. Screening samples were obtained from the staff, the neonates, and the environment. Antibiogram typing and arbitrarily primed polymerase chain reaction-based fingerprinting were used to type the strains.Results:The first outbreak had 13K. pneumoniaestrains isolated. The second outbreak had 10K. oxytocastrains isolated. The third outbreak had 20K. pneumoniaestrains isolated. More than half of the patients had low birth weights, were premature, and underwent mechanical ventilation and intravenous catheterization. Approximately three-fourths of the patients died. The isolates tested were completely susceptible to meropenem, cefoxitin, and ciprofloxacin and were resistant to cephalothin. More than half of these strains were resistant to many beta-lactam antibiotics, amikacin, and trimethoprim/sul-famethoxazole. Typing procedures yielded 3 antibiotypes and 3 genotypes among the isolates of the first outbreak, 3 antibiotypes with 1 subtype and 2 genotypes with 1 subtype in the second outbreak, and 2 antibiotypes and 2 genotypes in the third outbreak.Conclusions:Klebsiellaoutbreaks mainly affected premature neonates with intravenous catheters, mechanical ventilation, or both. The high mortality rate (76.7%) was notable. Resistance to multiple antibiotics, but mainly to broad-spectrum beta-lactam antibiotics, was observed, particularly inK. pneumoniaeisolates. Molecular typing indicated that the three outbreaks were not related to one other (Infect Control Hosp Epidemiol2003;24:495-500).