scholarly journals Microbiological Quality Assessment and Identification of Antibiotic Resistant Bacteria at Different Stages of the Milk Supply Chain in Dhaka City of Bangladesh

Author(s):  
Abira Nowar ◽  
Ila Ismail ◽  
Raisa Binte Iqbal ◽  
Sharmin Rumi Alim

Aims: Milk works as an excellent medium for bacterial growth and can turn into a fatal source of food borne diseases when consumed without pasteurization. This study was carried out to examine the microbiological quality of milk from three different points of milk supply chain to investigate whether the dairy stakeholders are maintaining the consumer safety or not. Study Design: A cross sectional study Place and Duration: The study took place at the Food Microbiology lab of Institute of Nutrition and Food Science, University of Dhaka from November 2019 to February 2020. Methodology: A total of 60 samples were studied including raw milk from collection centers, unpackaged pasteurized milk from processing plants and packaged pasteurized milks from retail shops. After carrying out the microbiological analysis the samples were examined for determining the total bacterial count (TBC) and total coliform count (TCC). Antibiotic susceptibility test was done using disk diffusion assay and detection of virulent gene in Salmonella spp. was done by Polymerase Chain Reaction (PCR) using specific invA primer. Results: The results revealed that all raw milk samples were substandard in terms of TBC and TCC and pasteurized milks from processing plants maintained the standard quality. Importantly, packaged pasteurized milk samples from retail shops had high TBC (>4.0× 104 CFU/mL) and TCC (1.2×103 CFU/mL) containing Pseudomonas, Micrococcus, Streptococcus, Salmonella, Proteus, Staphylococcus, Bacillus and E. coli. Bacteria like Salmonella (75%), Proteus (62.5%) and Vibrio (62.5%) possessed high Multiple Antibiotic Resistance (MAR) index and showed resistance towards antibiotics namely Ampicillin, Amoxicillin, Erythromycin and Colistin. Through further molecular analysis we detected invA virulent gene one of the Salmonella isolates which was collected from the pasteurized milk samples of the retail shops. Conclusion: High bacterial load in raw milk and packaged pasteurized milk indicate that the milk we consume is substandard in microbiological quality. Precautionary measurements and careful processing of milk may reduce the prevalence of microbiological contamination in the milk supply chain.

2008 ◽  
Vol 71 (8) ◽  
pp. 1580-1589 ◽  
Author(s):  
DENNIS J. D'AMICO ◽  
ERROL GROVES ◽  
CATHERINE W. DONNELLY

Overall milk quality and prevalence of four target pathogens in raw milk destined for farmstead cheesemaking was examined. Raw milk samples were collected weekly from June to September 2006 from 11 farmstead cheese operations manufacturing raw milk cheese from cow's, goat's, and sheep's milk. Samples were screened for Listeria monocytogenes, Staphylococcus aureus, Salmonella, and Escherichia coli O157:H7 both quantitatively (direct plating) and qualitatively (PCR). Overall, 96.8% of samples had standard plate counts of <100,000 CFU/ml, 42.7% of which were <1,000 CFU/ml. Although no federal standards exist for coliforms in raw milk, 61% of samples tested conformed to pasteurized milk standards under the U.S. Pasteurized Milk Ordinance (PMO) at <10 CFU/ml. All cow and sheep milk samples and 93.8% of goat milk samples were within the limits dictated by the PMO for somatic cell counts. Of the 11 farms, 8 (73%) produced samples that were positive for S. aureus, which was detected in 34.6% (46 of 133) of milk samples. L. monocytogenes was isolated from three milk samples (2.3%), two of which were from the same farm. E. coli O157:H7 was recovered from one sample of goat's milk for an overall incidence of 0.75%. Salmonella was not recovered from any of the 133 samples. The findings of this study suggest that most raw milk intended for farmstead cheesemaking is of high microbiological quality with a low incidence of pathogens. These data will help inform risk assessments associated with the microbiological safety of farmstead cheeses, particularly those manufactured from raw milk.


2019 ◽  
Vol 40 (4) ◽  
pp. 1469
Author(s):  
José Carlos Ribeiro Júnior ◽  
Aline Marangon de Oliveira ◽  
Fernando Godoi Silva ◽  
Lorena Natalino Haber Garcia ◽  
Cátia Maria de Oliveira Lobo ◽  
...  

The dairy industry strives to produce high quality products with high nutritional value as well as to meet the legal standards for longer shelf life. However, these goals are made unfeasible by the poor quality of raw milk produced in some regions of Brazil. Others Brazilian dairy regions, however, already succeed in producing milk with low microbial counts, such as the municipality of Castro, Paraná state, designated as the ‘Brazilian dairy capital’. In order to evaluate the effect of raw milk quality on microbial counts during the shelf life of pasteurized milk, samples were collected from two dairy regions of Paraná: the northern and Castro region, characterized by milk production with high and low microbiological counts, respectively. Samples were experimentally pasteurized and the total microorganism counts were analyzed for 18 days at 7°C, using the Brazilian standard microbiological count limit for pasteurized milk (8 x 104 CFU/mL) as the end of the shelf life. Low microbiological counts in raw milk (Castro) resulted in significantly lower counts shortly after pasteurization and over the entire shelf life, meeting the pasteurized milk standard for 18 days. The temporal evolution in the counts over 18 days for the milks of high and low microbiological count was similar; however, the disparity between the absolute counts between the regions was significant (p < 0.05). Of the milk samples from northern Paraná, four (44.4%) already had counts higher than that of the legislative limit for pasteurized milk immediately after pasteurization. The others (five) reached the maximum microbiological count limit for pasteurized milk on the 6th day after pasteurization. In contrast, the milk from the Castro region remained below the limit throughout the analysis period. Thus, it can be stated that the microbiological quality of raw milk is directly related to the initial count of microorganisms after pasteurization, and that pasteurized milk produced from raw milk with low microbiological counts complies with the Brazilian legislation for 18 days following thermal processing.


2015 ◽  
Vol 39 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Tasmina Rahman ◽  
Tanzia Akon ◽  
Iftikharun Nessa Sheuli ◽  
Naima Hoque

A total of 300 different milk and yogurt samples were collected from Dhaka city and analyzed for total viable bacterial count (TVBC), total coliform count (TCC) and presence of several pathogens such as Escherichia coli, Salmonella spp., Shigella spp., Vibrio spp. and Listeria monocytogenes. Raw milk samples collected from Moghbazar area showed highest TVBC (4.2 × 106 cfu/ml) and samples from Mohammadpur area showed lowest count (3.5 × 103 cfu/ml). All the pasteurized milk samples showed TVBC of 1.9 × 102 to 2.8 × 103 cfu/ml, and TCC only in one sample Yogurt samples (open) collected from vendor showed TVBC of 9.1 × 103 to 8.2 × 107 cfu/ml, and TCC only in sample collected from Dhanmondi, Dhaka. The packed yogurt samples showed TVBC of 2.2 × 102 to 6.1 × 103 cfu/ml, and TCC only in one sample. All the milk and yogurt samples were found contaminated with E. coli and Shigella-like species. Listeria monocytogenes was not detected in any of the samples studied.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 31-36, 2015


2020 ◽  
Vol 11 (3) ◽  
pp. 3699-3703
Author(s):  
Karthikeyan V ◽  
Gokul Priyan K ◽  
Rajesh Siva ◽  
Gopirajan P V

Milk is a complete food with high nutritional value. Milk is an important culture medium for the growth and reproduction of microorganisms. This study focuses on the samples collected from the different milk distribution areas in MaduranthagamTaluk, South India. Fifty pasteurized milk samples of ten different brands were collected and physicochemical, microbiological analysis were carried out in both raw milk and pasteurized milk samples. The milk samples were subjected to physicochemical analysis such as Fat content, Clearance, Lactometric Reading, Clot on Boiling Test, Solid Non Fat and Acidity were calculated. The milk sample were also subjected to the chemical analysis for the Nitrogen content, crude protein content, Lactose content, ash content were also calculated Methylene blue reduction test has been used to test quality of the milk samples. These findings may be helpful to monitor the quality of the milk products in the market. It can provide an interest in examine the organic and inorganic content in milk. It is reported that all samples added with urea and few samples have sulphate. Raw milk showed inferior quality, processed milk have Low load of bacterial population.


2015 ◽  
Vol 4 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Sourav Kumar Banik ◽  
Kamal Kanta Das ◽  
Md Aftab Uddin

Present study attempted to determine the microbiological quality of raw, pasteurized and UHT (Ultra High Temperature-processed) milk samples collected from different locations in Bangladesh. A total of 46 samples were studied including 22 raw milk samples from the local dairy markets and 24 different brands of pasteurized and ultrahigh temperature (UHT) treated milk manufactured in different beverage industries. The samples were examined for determining the total viable bacterial count (TVBC) and total coliform count (TCC). Results revealed that the raw milk samples were substandard in terms of TVBC and TCC. The range of TVBC and TCC in raw milk samples was 5.2×108 to 1.3×107 cfu/ml and 4.2×104 to 1.0×104 cfu/ml, respectively. On the contrary, the quality of pasteurized and UHT-treated milks was excellent. The TVBC range in pasteurized milk samples was from 1.8×103 to 1.1×102 cfu/ml, slightly lower than that recommended by the Bangladesh Standards and Testing Institution (BSTI). Interestingly sample numbers P-6, P-10 and P-12 of pasteurized milk samples had no growth at all both in terms of TVBC and TCC and none of the UHT processed milk contained any bacteria. So from the consumer point of view, both types of processed milk can be considered safe for consumption within the mentioned expiry date. DOI: http://dx.doi.org/10.3329/sjm.v4i1.22753 Stamford Journal of Microbiology, Vol.4(1) 2014: 5-8


1976 ◽  
Vol 39 (7) ◽  
pp. 490-492 ◽  
Author(s):  
D. A. SCHIEMANN

Pasteurized fluid dairy products (998 samples) and raw milk samples from approximately 1200 producers in Southern Ontario (5574 samples) were examined by the disc assay method, having a sensitivity of 0.0125 unit of penicillin per milliliter of milk, for the presence of inhibitory substances during the period April–August, 1975. One pasteurized milk (0.1%) and 50 raw milk samples (0.9%) contained penicillin. No other antibiotics were detected. Results represent a significant decrease in the incidence of antibiotics in milk compared to reports during the 1950's.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1530
Author(s):  
Amanuel Balemi ◽  
Balako Gumi ◽  
Kebede Amenu ◽  
Sisay Girma ◽  
Muuz Gebru ◽  
...  

A study was carried out from August 2017 to February 2018 on lactating dairy cows, one-humped dromedary camels, and goats to determine mastitis in the Bule Hora and Dugda Dawa districts of in Southern Ethiopia. Milk samples from 564 udder quarters and udder halves from 171 animals consisting of 60 dairy cows, 51 camels, and 60 goats were tested for mastitis. Sixty-four positive udder milk samples were cultured, and bacterial mastitis pathogens were isolated and identified. The antibiotic resistance of bacterial isolates from milk with mastitis was tested against nine antimicrobials commonly used in the study area. Cow- and quarter-level prevalence of mastitis in dairy cows, camels, and goats was 33.3%, 26.3%, and 25% and 17.6%, 14.5%, and 20%, respectively. In cattle, the prevalence was significantly higher in Dugda Dawa than in Bule Hora. Major bacterial isolates were coagulase-negative Staphylococcus species (39.1%), S. aureus (17.2%), S. hyicus (14.1%), and S. intermedius and Escherichia coli (9.4% each). In camels, udder abnormality and mastitis were significantly higher in late lactation than in early lactation. Mastitis tends to increase with parity in camels. E. coli isolates were highly resistant to spectinomycin, vancomycin, and doxycycline, whereas most S. aureus isolates were multidrug-resistant. Most of the rural and periurban communities in this area consume raw milk, which indicates a high risk of infection with multidrug-resistant bacteria. We recommend a community-focused training program to improve community awareness of the need to boil milk and the risk of raw milk consumption.


1997 ◽  
Vol 60 (11) ◽  
pp. 1391-1394 ◽  
Author(s):  
JOSEPH A. ODUMERU ◽  
ANN K. TONER ◽  
C. ANNE MUCKLE ◽  
MANSEL W. GRIFFITHS ◽  
JOHN A. LYNCH

Raw and pasteurized milk samples submitted for routine quality analysis were screened for the presence of Bacillus cereus diarrheal enterotoxin (BDE) using the TECRA BDE Visual Immunoassay (VIA) kit. BDE was not detected in 298 raw milk samples tested by the TECRA VIA. B. cereus was isolated from 2 of 298 (0.7%) raw milk samples cultured. Culture supernatants from these isolates were positive for BDE in the TECRA VIA but negative in the Reverse Passive Latex Agglutination (RPLA) test for BDE. Forty-three of 112 (38.4%) pasteurized milk samples incubated at 10°C until their expiry dates were positive for BDE by the TECRA VIA. The same number of samples incubated at 4°C had no detectable levels of enterotoxin. B. cereus in the range of 103 to 106 CFU/ml was isolated from all BDE-positive pasteurized milk samples. BDE was detected in the culture supernatants of all the 43 isolates by TECRA VIA and in 30 of these isolates by RPLA. These results demonstrate that moderate temperature abuse of pasteurized milk may allow the growth of B. cereus and BDE production.


1984 ◽  
Vol 47 (3) ◽  
pp. 206-208 ◽  
Author(s):  
J. J. RYAN ◽  
R. H. GOUGH ◽  
C. H. WHITE

During a 5-month period, 200 raw milk samples were collected from two Louisiana milk plants. Standard Plate Count (SPC), Psychrotrophic Bacteria Count (PBC), and Proteolytic Count (PC) of each sample were initially determined, then monitored daily during a 5-d storage period at 2.2°C. As hypothesized, all bacterial counts increased during the storage period. The magnitude of the increase in bacterial numbers during storage was further investigated by dividing the milk samples into bacteriologically acceptable and unacceptable groups based on SPC or Preliminary Incubation (PI) count. An SPC of 1.0 × 105/ml and PI counts of 1.0 × 105/ml, 1.5 × 105/ml, 2.3 × 105/ml, and 3.0 × 105/ml were used to repeatedly dichotomize the 200 raw milk samples into two groups. Median SPC, PBC, and PC for each acceptable and unacceptable group were then calculated. Dichotomization based on PI counts yielded acceptable sample groups having consistently lower bacterial counts during storage than did the acceptable sample group, which resulted from the dichotomization based on a SPC of 1.0 × 105/ml. The results of this study indicated that the PI count is of considerable value for raw milk quality control.


2015 ◽  
Vol 13 (1) ◽  
pp. 71-78 ◽  
Author(s):  
UT Tasnim ◽  
MT Islam

Milk is such a food which can meet almost all nutritional needs of human lives. Raw or unprocessed milk supports the growth of wide variety of microorganisms. The major interests of this study were examining the microbial quality of raw milk collected from different locations of Jessore city in Bangladesh and determining antibiotic susceptibility pattern of some isolated bacteria. To do so, 12 raw milk samples were collected from different areas of Jessore city. Microbial analysis comprised of enumeration of TVC (total viable count), TCC (total coliform count) and TSC (total staphylococcal count). The highest TVC, TCC and TSC were 1.95x109 CFU/ml, 2.5x107 CFU/ml and 1.02x107 CFU/ml respectively. Prevalent bacterial populations were Klebsiella spp., Enterobacter spp., Shigella spp. Staphylococcus spp., Escherichia coli and Citrobacter spp. In order to observe the antibiotic susceptibility pattern, the antibiotic sensitivity test was performed for some randomly selected isolates of E. coli and Klebsiella spp. More than 90% isolates of Klebsiella spp. were found to be resistant against Erythromycin whereas more than 90% isolates were sensitive against Imipenem. On the other hand, 100% E. coli isolates were observed as resistant against Erythromycin and in case of Trimethopreme 100% isolates were sensitive. Multidrug resistance pattern was also found. These results suggest the necessity of hygienic practices during handling, processing and post-processing of raw milk to improve the microbiological quality and safety of raw milk.DOI: http://dx.doi.org/10.3329/bjvm.v13i1.23723Bangl. J. Vet. Med. (2015). 13 (1): 71-78


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