Isolation and quantification of microorganisms from some common milk products within Dhaka city, Bangladesh

Abstract

While milk is well known to be a balanced diet with its high nutritional values, conversely milk and milk products may serve as potential substrate for the growth and proliferation of a range of microorganisms which in turn fatally influences mass public health. Current study attempted to examine the likelihood of microbial contamination within some common milk products consumed by the locality of the city of Dhaka, Bangladesh. All samples exhibited the presence of bacterial and fungal contamination within a range of 10 2 -10 4 cfu/mL and 10 2 -10 3 cfu/mL, respectively. Among specific pathogens, Staphylococcus spp. was noticed to be the predominant ones and was recovered from 9 samples out of 20 samples in a range of 10 2 -10 3 cfu/mL. Klebsiella spp. and Vibrio spp. were found within 6 and 9 samples, respectively. Products were also found to be contaminated with Vibrio spp. Study of antibiotic susceptibility test revealed that all the pathogenic bacteria were resistant against most of the commonly used antibiotics of which several isolates showed multi-drug resistant (MDR) trait. Therefore, the presence of pathogenic bacteria with the drug-resistance property in tested milk and milk products overall imparted the necessity of maintaining standardized hygienic handling and processing means for better management of public health.

Microbiological Analysis of Different Flavoured Milk Samples Collected from Various Areas of Dhaka city, Bangladesh

“…Pathogenic bacteria in milk have been a major factor for public health concern since the early days of the dairy industry 4,20,26,27 . As discussed earlier, the health of dairy herd and milking conditions basically determine the presence of microorganisms in milk.…”

“…The use of unclean milking and transport equipment also contribute to the poor hygienic quality 28 . Previously, many experiments were conducted on the bases of milk; very limited experiments have been so far specifically done based on the flavored milk products in Bangladesh 20,26,27,29 . So the present study attempted to determine the bacteriological quality of common flavored milk samples collected from various areas of Dhaka city, Bangladesh.…”

“…Then 1 mL of each sample was taken very carefully by using a micro pipette from the original samples and transferred to 9 ml of normal saline in sterile test tubes. Prior to the estimation of bacterial load, samples were subjected to serial dilutions up to10 -3 (20) .…”

“…For the enumeration of total viable bacterial count (TVBC), an aliquot of 0.1 mL of each dilution was introduced onto the nutrient agar (NA) plates by the spread plate technique 4,20 . The nutrient agar plates were incubated at 37 o C for 24 hours.…”

Microbiological quality analysis of domestic water collected from the slum area’s people in Dhaka city

“…Proliferation of drug-resistant bacteria in hand washing water. In this experiment the Kirby-Bauer disk diffusion test was used to make a decision whether the isolated organisms were susceptible or resistant to a selected pool of antimicrobial agents (23,28). The study showed that, most of the isolates exhibited multidrug resistance (MDR) phenotype (Table 2).…”