Molecular Identification and Virulence Genes Detection of Cronobacter Spp Isolated from Clinical Cases in Infants Under Two Years in Mosul City, Iraq

Cronobacter spp. are facultative-anaerobic non-spore forming Gram-negative bacteria, that are part of the Enterobacteriaceae family. They are opportunistic organisms that occasionally cause severe infections such as meningitis, necrotizing enterocolitis, and bloodstream infections in newborns and young children. There is a limited amount of information available about the diversity, pathogenicity, and virulence of Cronobacter species isolated from different sources. This study was conducted to isolate and identify Cronobacter spp from different clinical cases in children under two years in Mosul city and determine some virulence genes which are indicators for their pathogenicity. One hundred and fifty clinical specimens (diarrhea, blood and cerebrospinal fluid) were collected and cultured on Enterobacter sakazakii agar (HiCrome) and trypton soy agar. Eight Cronobacter spp were isolated and presumptively identified according to their morphological characteristics on selective media and confirmed by 16S rRNA gene sequencing and direct sequencing of ropB gene. PCR was used to amplify five potential virulence genes (cpa, hly, sip, zpx, and ompA) in order to determine their presence in our strains. The results revealed that all strains exhibited ompA and zpx, however, only four C. sakazakii strains contained cpa and hly genes. The sip gene was found in only two C. malonaticus strains. Lastly, ropB gene were detected in all Cronobacter spp isolated. Identification of Cronobacter from clinical specimens helps in understanding the sources and risks associated with these pathogens. By determining virulence genes, the study provides insights into how these bacteria cause disease which is crucial for developing targeted interventions and treatments. understanding the presence and characteristics of Cronobacter spp. in clinical cases informs diagnostic and treatment strategies, potentially leading to better patient outcomes.