Isolation and identification of some pathogenic and contaminating bacterial species of milk products in hilla city

The main objective of this study was to identify and classify various pathogenic and contaminating bacterial strains found in milk products, specifically focusing on cheese. A specimen of cheese that was found to be tainted was obtained and, after that, subjected to a sequence of dilution procedures. Subsequently, a portion of these dilutions was inoculated onto various growth media, followed by the implementation of several biochemical assays. Work continued on this project from the date of 22-11-2021/ 22-2-2022. Moreover, the pathogen bacteria species were isolated and identified by cultivating the sample on E. coli, Proteus mirabilis, Klebsiella, Salmonella, and Staph. Aureus medium. Initially, the sample underwent culturing on Eosin Methylene Blue (EMB) and MacConkey agar media to facilitate the identification of Escherichia coli (E. coli) and Klebsiella species. Additionally, Proteus bacteria were isolated and identified through culturing on a blood agar medium. Staphylococcus aureus (staph. aureus) bacteria were diagnosed using the Mannitol Salt agar medium, while Salmonella bacteria were identified on the Selenite-Sulfite agar (S-S-agar) medium. The laboratory tests conducted include the Indole test, Urease test, Simmons citrate test, Catalase test, Oxidase test, Coagulase test, and Fermentation test. Certain isolates exhibited negative results, while others displayed positive outcomes in the biochemical assays. Furthermore, an experiment was undertaken. The study examined the sensitivity of antibacterial agents against various bacterial strains. Results indicated that ciprofloxacin exhibited greater efficacy against Staphylococcus aureus, whereas Gentamycin and Amikacin demonstrated lower effectiveness. Conversely, all antibacterials above displayed equal efficacy against Escherichia coli. Additionally, Pseudomonas bacteria were found to be resistant to all tested antibacterials.