ISOLATION AND IDENTIFICATION OF BACTERIA AND FUNGI IN HUMAN BREAST MILK, POWEDERED COW MILK AND YOGHURT.

ABSTRACT

This research was carried out to isolate and identify bacteria and fungi present in human breast milk, powdered cow milk and yogurt as well as their hemolysin production and sensitivity to antibiotics. Human breast milk samples were aseptically obtained from lactating mothers, in the University of Benin Teaching Hospital and stored in a sterile universal bottles. These were transported to the laboratory for microbiological analysis. Similarly, one brand each of powdered cow milk and yogurt samples were purchased from Uselu market, in Benin City and taken to the laboratory for microbiological analysis. All samples were serially diluted and cultured using pour plate method on Nutrient agar (NA) for bacterial counts and on Potato dextrose agar (PDA) for fungal counts. The plates were incubated for 24hours at 37c for bacteria growth and 48hours for fungal growth. Bacterial isolates were identified by cultural, morphological and biochemical characteristics. While fungal isolates were identified using visual characteristics. Bacterial isolates were further subjected to antibacterial susceptibility testing using disk diffusion method. The antibiotics used ranged from ciprofloxacin, tetracycline, metronidazole, colistin, gentamicin, cefuroxin, erythromycin and clindamycin. The bacterial counts obtained from these samples ranged from 2.0 ×10³ - 20.5 ×10³ cfu/ml. Similarly, the fungal counts obtained ranged from 1.3 ×10³ - 21.5×10³ cfu/ml. Five bacterial isolates identified were Staphylococcus aureus, Streptococcus sp, Lactobacillus sp, Bacillus sp and Serratia marsences. The fungi identified were Aspergillus flavus and Saccharomyces cerevisiae. The results of the antibacterial susceptibility testing revealed that all bacterial isolates were susceptible to ciprofloxacin (100%) and also displayed resistance to clindamycin, cefuroxin, colistin and tetracycline. These research findings concludes that human breast milk, powdered milk and yogurt contains microorganisms that are of great concern to the public’s health.