Isolation, Identification and Antibiotic Susceptibility of Microorganisms from Pasteurized Milk Samples

Sheefa Tarannum

Abstract: Even though pasteurization is a widely recognized technique for eradicating pathogens, microbial contamination in pasteurized milk continues to pose a major public health issue. The objective of this research was to isolate, identify, and evaluate the antibiotic resistance of microorganisms found in pasteurized milk samples. The present investigation showed a total of 60 bacterial isolates from the milk samples. Escherichia coli was identified as the most prevalent pathogen, accounting for 31.6% of the isolates, followed by Pseudomonas spp. at 21.6%, Klebsiella oxytoca at 15%, and Enterococci spp. at 11.6%. The antibiotic susceptibility tests revealed notable resistance patterns among these pathogens. Escherichia coli exhibited significant resistance to Ampicillin (60%) and Ciprofloxacin (55%), yet demonstrated susceptibility to Amikacin (85%) and Gentamicin (80%). Enterococci spp. showed resistance to Ampicillin (70%) but remained susceptible to Levofloxacin (85%). Klebsiella oxytoca displayed resistance to Ampicillin (65%) while being susceptible to Ceftazidime (85%). Pseudomonas spp. demonstrated resistance to Ciprofloxacin (60%) and Tetracycline (50%), but retained susceptibility to Amikacin (80%).

Keywords: Pasteurization, Susceptibility, contamination, multi-drug-resistant, antibiotic

How to Cite?: Sheefa Tarannum, "Isolation, Identification and Antibiotic Susceptibility of Microorganisms from Pasteurized Milk Samples", Volume 14 Issue 12, December 2025, International Journal of Science and Research (IJSR), Pages: 1656-1663, https://www.ijsr.net/getabstract.php?paperid=SR251220205644, DOI: https://dx.doi.org/10.21275/SR251220205644