To determine the risk factors for rectal colonization by extended-spectrum beta-lactamase (ESBL) Klebsiella sp. in 368 newborns admitted consecutively to a neonatal intensive care unit over six months, rectal swabs were cultured on admission and weekly until discharge. Eighty infants (21.7%) had ESBL Klebsiella sp. cultured from their rectal swabs. Eighty controls were selected at random from infants with negative cultures admitted within the 14-day period prior to the detection of ESBL Klebsiella sp. in the cases. Cases had significantly lower birth weight, gestational age, earlier age of admission, longer hospital stay, and higher proportions of congenital malformations, early-onset pneumonia and respiratory distress syndrome compared with controls. Significantly more cases received mechanical ventilation, nasal continuous positive airway pressure support, total parenteral nutrition, umbilical vascular catheterization, arterial line insertion, urinary bladder catheterization, and prior treatment with antibiotics. However, stepwise logistic regression analysis showed that only two independent risk factors were significantly associated with ESBL rectal colonization: duration of hospital stay [adjusted odds ratio (OR): 1.3; 95% confidence intervals (CI): 1.2, 1.4; P<0.0001) and early-onset pneumonia (adjusted OR: 8.3; 95% CI: 1.6, 43.4; P=0.01).
Klebsiella ozaenae is a Gram negative bacillus. It has been described as a colonizer of oral and nasopharyngeal mucosa and is a cause of atrophic rhinitis. Klebsiella ozaenae has seldom been isolated from serious infections. However, several reports have stated that Klebsiella ozaenae may cause invasive infections and even mortality. We report a 55-year-old man with Klebsiella ozaenae infection causing abscesses involving the right eye and left kidney and possibly also in the brain, lungs and prostate. The isolates were sensitive to ceftazidime, ciprofloxacin, chloramphenicol, gentamicin and sulfamethoxazole-trimethoprim but resistant to ampicillin. He responded well to 4 weeks of i.v. ceftazidime and i.v. amoxycillin-clavulanic acid. To our knowledge, such a multiorgan infection has not been reported previously for this organism.