Enumeration of bacteria
Serial dilutions from the resulting growth from the nutrient broth
medium were pour-plated on count agar (PCA) and incubated for
24 h at 37°C under aerobic condition. The number of estimated
Colony forming units (CFU) for each sample was then counted.
Samples were inoculated in mannitol salt agar (MSA), sheep blood
agar (BA), and plate count agar (PCA) media for counting total
bacteria and on Sabouraud dextrose agar medium for counting
fungi. Duplicate plates for each media were made for each dilution.
All pure isolated colonies were sub-cultured onto sheep blood agar
plates (for growth of heterotrophic bacteria) and MacConkey agar
plates (for coliforms) for 24 h at 37°C for colony isolation and
morphological identification (Koch, 1984).
Isolation of organisms
Colonies showing a good growth and characters on plates were
picked and streaked on new MSA, BA, and nutrient agar plates. A
rapidly growing, visually distinct colony and a separate, morphologically
unique isolates were selected for further analysis and
purified by repeated plating. A slide coagulase test differentiated
staphylococcal isolates into S. aureus and coagulase-negative
staphylococci (CoNS) were performed (Koch, 1984).