Isolation and biofilm characterization of Klebsiella spp. and pathogenic E. coli in raw milk and unpasteurized dairy products in Egypt; antibiogram of Klebsiella spp.

Nazmy, Hagar; Awad, Dina; Soliman, Enas

doi:10.21608/bvmj.2024.327526.1880

Isolation and biofilm characterization of Klebsiella spp. and pathogenic E. coli in raw milk and unpasteurized dairy products in Egypt; antibiogram of Klebsiella spp.

Document Type : Original Article

Authors

¹ Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Benha University, Egypt

² Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Benha University, Egypt.

10.21608/bvmj.2024.327526.1880

Abstract

There has been growing interest in traditional popular dairy products in Egypt especially at rural areas like white, acid-coagulated soft cheeses (Karish cheese) and soured cream, but they are highly susceptible to microbial contamination, including Enterobacteriaceae which poses a health risk to consumers. This study aimed to isolate and identify Klebsiella spp. and E. coli from raw milk, karish and soured cream, assess their antibiotic sensitivity, and investigate their biofilm-forming capabilities. About 154 dairy samples, including raw buffalo and cow milk, karish cheese, and soured cream, were collected from various locations in Egypt. Both Klebsiella spp. and E. coli using spread plate methods on MacConkey and EMB agar respectively were isolated and identified by morphological analysis via Gram staining and biochemical tests, followed by molecular identification through PCR targeting the gapA gene and pehX. Antibiotic sensitivity was assessed using the disc diffusion method, and biofilm production was evaluated using crystal violet staining and Congo red agar plating. Our results revealed that Klebsiella species were positive in 3 samples (1.94%), including K. oxytoca and K. ozaenae, and 19 isolates identified as pathogenic E. coli, indicating a prevalence of 12.33%. Antibiotic sensitivity testing showed high resistance in Klebsiella isolates to several antibiotics, including ceftazidime and amoxycillin/clavulanic acid. Biofilm production was evaluated, with most isolates showing weak to moderate biofilm formation, indicating varying degrees of adherence and pathogenicity. This study highlights the public health risks of antibiotic-resistant Klebsiella spp. and E. coli in raw milk and unpasteurized dairy products in Egypt.

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