Detection of Prototheca zopfii in Raw Milk and Cheese with Special Reference to Their Antibiogram

Abstract

AbstractMilk and cheese contaminated with Prototheca sp. have zoonotic importance and constitute public health significance to the consumers. In this study, a total of 300 random raw milk and cheese samples were collected from Qena city markets, Egypt, to detect Prototheca sp. Fifty‐five of the total 58 isolates of Prototheca were isolated from raw milk and cheese, respectively. The isolates were identified conventionally and microscopically. API system and biochemical tests divided the isolates into four species as follows: P. zopfii, P. blaschkeae, P. stagnora and P. wickerhamii. The most prevalent isolated species was P. zopfii, which was isolated from 12% of buffalo's milk, 16% of cow's milk, 20% of Damietta and 22% of Kareish cheese samples. Polymerase chain reaction assay for P. zopfii confirmation was carried out by amplification of 18S rDNA that classified P. zopfii as genotypes I (28.88%) and II (71.11%). P. zopfii show in vitro resistance to almost all tested types of antimicrobial except for gentamicin and kanamycin. However, nystatin and ketoconazole showed the highest activity among the antifungal.Practical ApplicationsIn this study, high prevalence of Prototheca sp. in the examined raw milk and cheese samples constitutes a public health hazard to consumers. Therefore, sanitary measures during production, storage and processing, as well as sufficient heat treatment, should be recommended. In addition, the present research contributes to increase the knowledge on the diffusion of antibiotic resistance of P. zopfii strains.