Investigation of extended spectrum β-lactamase (ESBL) producing enterobacteriaceae and cronobacter spp. in infant formulas and cereal-based infant formulas

The extended-spectrum-beta-lactamase (ESBL) producing Enterobacteriaceae can have un-anticipated adverse effects such as a delay against or failure of antiotic therapy, resulting in increased risk of infectious morbidity and mortality. The infant formulas and cereal-based infant foods contaminated with Cronobacter spp., and other Enterobacteriacae are a deep threat tothe infant health. The objective of this study was to investigate the presences of Cronobacter spp. and other ESBL producing Enterobacteriacae from a total of 115 specimens (40 infant formula, 60 cereal-based infant formula and 15 milk powder) by phenotypic methods.. After culturing on VRBGA media, oxidase testing was performed. The oxidase negative isolates were initially confirmed on BCP Glucose media for the membership of Enterobacteriaceae, and subsequently identifiedby Vitek® MS. Following that, according to the guidelines by CLSI (2013), the ESBL presumptive isolates were screened by a combination of ceftazidime (CAZ), cefotaxime (CTX), and cefpodoxime (CPD) with/without clavulanic (CLA) acid. Finally, antimicrobial susceptibility testing with MIC determination wwas conducted using Merlin Micronaut-S beta-lactamase VII kit. The readings were analyzed the Sifin Software integrated with a Spectrometer. The results showed that the domestic infant formula samples contained Pantoea agglomerans, while the cereal-based samples included Cronobacter sakazakii, Pantoea) agglomerans, Enterobacter aerogenes, Enterobacter cloacae/asburiae, Klebsiella oxytoca, Leclercia adecarboxylata. The imported infant formulas were free of any bacterial load. The phenotypic screening revealed that the prevelances of ESBL producing enterobacterial was found as 10% in domestic infant formula samples, 10% in the rice flour samples, and 5% inthe semolina samples whereas none of the C. sakazakii isolates were ESBL producer. Keywords: ESBL, Enterobacteriaceae, Cronobacter spp., Infant Food.