Cronobacter spp. (Enterobacter sakazakii)

Abstract

MICROBIAL FACTSHEET SERIES ISSUE NO. 1 | SEPTEMBER 2011 1. What are Cronobacter spp. (Enterobacter sakazakii)? In 2007, E. sakazakii was reclassified as Cronobacter spp. The new genus is composed of 6 species: Cronobacter sakazakii; C. turicensis; C. malonaticus; C. muytjensii and C. dublinensis. A sixth species was indicated as genomospecies I, however, it includes only 2 representative strains at the present time. Cronobacter spp. are synonymous with E. sakazakii and thus this nomenclature is used throughout this factsheet. Cronobacter spp. have been implicated in outbreaks causing meningitis and enteritis, especially in infants. 2. Sources of Cronobacter spp. The natural habitat is not well understood; however, they have been isolated from a diverse range of environments, e.g. processing plants, domestic environments, and foods, e.g. powdered infant formula, fermented bread, cheese. 3. Cronobacter spp. and Powdered Infant Formula Powdered infant formula (PIF) has been implicated as the vehicle of infection in a number of neonatal infections. PIF is not a sterile product (as it is not possible to manufacture sterile powdered infant formula using current technology) and therefore may occasionally contain pathogens. PIF undergoes a pasteurisation step during its manufacturing process and although Cronobacter spp. do not survive pasteurisation, recontamination may occur during subsequent handling and filling, i.e. via: 1) Raw materials and in particular the heat sensitive nutrients, e.g. vitamins, minerals etc., added after pasteurisation 2) The processing environment, i.e. equipment and processing lines Although Cronobacter spp. cannot grow in PIF, they can survive for a long period of time and therefore, pose a potential risk after rehydration if the product is temperature abused.