First report of neonatal bacteraemia caused by bla NDM-1 Raoultella ornithinolytica

Abstract

Introduction Raoultella ornitholytica, classified formerly as the genus Klebsiella, is an unusual human pathogen and is a rare cause of infections in neonates. We describe the first case of neonatal bacteraemia caused by blaNDM-1 Raoultella ornitholytica, which has not been reported in children. Case A baby born at 33 weeks was transferred to a tertiary hospital in Durban for ventilation three days after birth. He received penicillin and gentamicin for three days at a district hospital and on admission to the neonatal unit, piperacillin/tazobactam plus amikacin was commenced. A blood culture taken on admission grew R.ornitholytica which was identified using MALDI-TOF (matrix-assisted laser desorption/ionization time of flight mass spectrometry). The Vitek 2 was used for susceptibility testing which demonstrated resistance to most beta-lactams and all aminoglycosides tested. It was susceptible to ciprofloxacin, colistin, tigecycline and cefipime. Ciprofloxacin was commenced when susceptibility Results were available. Detemination of the following carbapenemases was performed; blaKPC, blaNDM, blaVIM, blaIMP, blaGES, and blaOXA-48 and only blaNDM was positive. The patient recovered and was discharged on ciprofloxacin. Discussion The most common infection caused by R. ornitholytica is bacteraemia, mainly in the elderly and those with biliary tract disease. Three cases of R. ornitholytica infections in children have been published; two causing neonatal bacteraemia and one from a broncho-alveolar sample from an infant. However, none of these isolates were resistant to carbapenems. Although Raoultella spp are usually susceptible to most beta-lactams, extendedspectrum beta-lactamase and carbapenemase producers have emerged. A surveillance study in USA first described blaKPC-2 and blaKPC-3 R. planticola and R. ornitholytica. Two cases of R. ornitholytica carrying blaNDM-1 gene have been isolated from soft tissue infections in adults. We describe the first case of blaNDM-1 Raoultella ornitholytica in a neonate - an unusual cause of neonatal bacteraemia with an unexpected susceptibility profile.