Detection of Chronobacter sakazakii and other Enteropathogenic Bacteria from Selected Brands of Commercial Powdered Foods in Nigeria

Aim: Food borne infections continue to debilitate human populations. Powdered Infant foods, cereal based, and malt based foods have been less investigated for the presence of Chronobacter sakazakii and other enteropathogenic bacteria as agents of diarrhea and Necrotizing enterocolitis in neonates and infants. This study was aimed at detecting the presence of multidrug resistant strains of Chronobacter sakazakii and other enteropathogenic bacteria from three brands of commercial powdered foods in Nigeria.

Methods: A total number of 45 samples comprising 15 units each, of NAN 2, Horlicks and Custard powder were purchased randomly from different retail outlets in Lagos, Ekiti and Ondo states Nigeria. The method of the US Food and Drug Administration was adopted in the bacteriological analysis of the samples, and susceptibility of the detected bacteria to 16 antibiotics was determined using the standard methods of CLSI on Mueller-Hinton Agar.

Results: A total number of 57 bacteria species were isolated from all the 45 powdered food samples. Twenty (20) isolates from the PIF were predominantly C. sakazakii 9/20 (45%), S. enterica 4/20 (20%), E. aerogenes 1/20 (5%), S. rubidae 1/20 (5%), K. oxytoca 2/20 (10%), K. pneumoniae 1/20 (5%) and Erw. ananas2/20 (10%). Eight (8) isolates were obtained from malt-based Horlicks, comprising C. sakazakii 3/8 (37.5%), B. licheniformis 2/8 (25%) and Erw. ananas 3/8 (37.5%).Twenty nine (29) isolates were detected in the cereal-based custard, comprising C. sakazakii 11/29 (38%), Erw. ananas 8/29 (27.6%), B. licheniformis 5/29 (17.2%), and S. enterica 2/29 (6.9%), while Erw. persicinus, E. aerogenes and B. cereus were 1/29 (3.4%) respectively. Of all the 57 bacteria isolates, 8 (14%) were Gram positives while 49 (86%) were Gram negatives. All the Gram negative bacteria from the PIF were resistant to Ampicillin but susceptible to Gentamycin and Nalidixic acid, while all the isolates from Horlicks and custard powder were resistant to Ampicillin, Nalidixic acid, Nitrofurantoin and Streptomycin.

Conclusion: Multidrug resistant Chronobacter sakazakii, and other enteropathogenic bacteria are prevalent in commercial cereal based food (custard powder), malt based foods (Horlicks) as well as Powdered Infant Milk Formula (NAN2) in Nigeria.