Isolation and identification of Cronobacter species from some animal sources

Abstract

Keywords This work was carried out to study the bacteriological importance of Cronobacter sakazakiias a potential foodborne emerging pathogen involved in severe illness and deaths in humans, especially neonates due to consumption of contaminated infant powdered infant formula (PIF) (PIF milk and food). A total of 100 samples [PIF milk (n=55), PIF food (n=15), milk powder (n=15) and milk powder products (n=15) were collected and subjected to bacteriological examination for the presence of Cronobacter. Six samples out of 100 examined (6%) were found positive for Cronobacter spp. The isolation rates were 4% in PIF milk and 1% in PIF food. The identity of the isolated organism was confirmed as Cronobacter spp. by subjecting the bacteriologically positive samples to PCR technique using 16S rRNA species specific primers. Cronobacter specific 16S rRNA was detected respectively in 3/5 and 1/5 of bacteriologically positive PIF milk and PIF food examined. All positive 16S rRNA (n=4) were examined for the presence of C. sakazakii. C. sakazakiiwere confirmed in an isolate from 3 isolates of PIF milk and one of PIF food. The outer membrane protein A (ompA) gene was detected in 2 identified C. sakazakii isolates, while gene encoding for zinc-metaloprotease (zpx) was only identified in 3 C. sakazakii isolates. These results lead to the conclusion that examined milk products could be a potential source of C. Sakazakii, so the retailed powdered milk could have public health significance. Further studies are needed to study control strategies of C. sakazakii.