Milk is a major part of human food and
plays a prominent role in their nutrition. Spoiled milk is
the result of an overgrowth of bacteria that
compromises the quality, flavor, and texture of milk.
This study was carried out to isolate Salmonella and
Shigellaspp from spoilt pasteurized liquid milk. A total
of ten (10) tins of pasteurized liquid milk were used for
the analysis. The tins were opened using sterilized
knives and were not preserved in the refrigerator for 3-
4 days. They were later analysed for the presence of
spoilage microorganisms using Salmonella Shigella
Agar. Out of the 10 samples that were analysed, 7
(70%) samples had Salmonella spp while 5 (50%)
samples had Shigella spp. The antibiotic susceptibility
pattern of the isolates revealed thatfive (5) isolates of
Salmonella spp were sensitive to Ampicillin and Septrin,
while only 4 isolates were sensitive to both Augumentin
and chloramphenicol. Also, 6 isolates were sensitive to
Ofloxacin while all the 7 isolates were sensitive to both
Ciprofloxacin and Trimethoprim. However, all the
isolates were resistant to Cefoxitin and Perfloxacin.
Also, 4 Shigellaisolates were sensitive to Ampicillin
while 5 isolates were sensitive to both Ciprofloxacin and
Septrin. All the isolates were resistant to Pefloxacin,
Augmentin, Ofloxacin, Chloramphenicol,
Trimethoprim and Cefoxitin. This study shows that
poor preservation of the milk samples led to the growth
of the microorganisms which can be detrimental to
human health when consumed. Hence, already
opened/exposed pasteurized liquid milk should be
refrigerated at a temperature of between 0°C to 4°C to
avoid microbial growth. Keeping milk cold is critical to
ensure it stays fresh, lasts longer, and keeps its delicious
taste.
Keywords : Liquid milk, Pasteurized, spoilage, Salmonella spp., Shigella spp