Abstract:
Milk possesses significant nutritional content, making it an ideal medium for bacterial proliferation; hence, it is vulnerable to contamination from diverse sources. This study examines the occurrence and genotyping of pathogenic bacteria (MDR) in milk samples obtained from different local milk vendors in the Mardan District. Total of 60 samples were collected and cultured on Mannitol salt agar (MSA), Eosin Methylene Blue (EMB) and MacConkey Agar(MAC). These isolates were initially identified through biochemical tests like Gram staining, oxidase, coagulase, catalase and triple sugar iron (TSI) tests. The bacterial identification process uncovered several groups, including E. coli, Klebsiella Species, S. aureus and Shigella Species. Among the 60 isolates, 11demonstrated multi-drug resistance, showing resistance to a minimum of three distinct classes of antibiotics. The identification of these isolates, which are resistant to multiple drugs, was achieved by amplifying the 16S rRNA gene. Phylogenetic analysis revealed that five multi-drug-resistant isolates (EC1-MDR, EC2-MDR, EC3-MDR, EC4-MDR and EC5-MDR) were observed E.coli strains, while three isolate (SG1-MDR, SG2-MDR and SG3-MDR) was Shigella Spp. and two species were identified Klebsiella Spp. (KP1-MDR andKP2-MDR). Among all the isolates, Ciprofloxacin and Meropenem consistently showed the highest rates of susceptibility with averages between 84.67% and92%, highlighting their potential as effective treatment options. Conversely, Ceftriaxone, Amoxicillin, and Nalidixic Acid demonstrated moderate susceptibility in specific groups. Conversely, antibiotics such as Penicillin, Chloramphenicol, Ampicillin, and Cefotaxime generally showed high levels of resistance, with averages surpassing 70%, indicating their reduced effectiveness in treatment. The highest levels of resistance were noted with Cefotaxime, Ceftriaxone, Ampicillin, and Penicillin, with average rates surpassing 80%,indicating substantial bacterial resistance. Most antibiotics showed low standard deviations (St dev = 1), suggesting consistent results across trials, except for Ampicillin in Shigella Spp. (St dev = 1.25) and Meropenem in Klebsiella Spp. and S. aureus, which exhibited slight variability. Statistical analysis indicates an inverse correlation between susceptibility and resistance, emphasizing the presence of multi-drug resistance in all isolates. Antibiotics like Ciprofloxacin, Ceftriaxone, and Nalidixic Acid, with susceptibility rates over 50%, were more effective. Conversely, those such as Cefotaxime, Amoxicillin, Penicillin, and Ampicillin, with resistance rates above 90%, showed significant bacterial resistance, potentially limiting their clinical application. The detection of these multi-drug-resistant bacteria in milk samples from local stores highlights the potential public health risks of consuming contaminated dairy products, posing a significant threat to people in the near future.
Page(s):
93-94
DOI:
DOI not available
Published:
Journal: 1st International Conference on "Recent Advances in Green Biotechnology and Climate Resilience", September 15-16, 2025, Volume: 1, Issue: 1, Year: 2025