scholarly journals MOLECULAR DETECTION AND CHARACTERIZATION OF ESCHERICHIA COLI ISOLATED FROM RAW MILK SOLD IN DIFFERENT MARKETS OF BANGLADESH

2017 ◽  
Vol 14 (2) ◽  
pp. 271-275 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
S. K. Seel

     The study was intended for molecular detection of E. coli isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying staining characteristics, cultural properties on different selective media, biochemical tests, catalase and coagulase test, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found positive for E. coli. 15 Escherichia coli isolates were amplified by 16S rRNA gene based PCR. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the E. coli isolates were resistant to amoxycillin (86.67%) and erythromycin (73.33%) but sensitive to azithromycin (53.33%), ciprofloxacin (86.67%), gentamicin (86.67%), norfloxacin (80%) and streptomycin (66.67%).

2017 ◽  
Vol 14 (2) ◽  
pp. 277-282 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
M. T. Rahman

The study was intended for molecular detection of S. aureus isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying cultural properties on different selective media, biochemical tests, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found to be positive for S. aureus. S. aureus specific 16S rRNA gene was amplified from all isolates and identified as S. aureus. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the S. aureus isolates were resistant to amoxicillin (100%), erythromycin (73.33%) and tetracycline (73.33%) but sensitive to azithromycin (93.33%), ciprofloxacin (93.33%), gentamicin (100%), norfloxacin (86.67%) and streptomycin (86.67%).


Author(s):  
Md. Kauser-Ul Alam ◽  
Nazmul Sarwar ◽  
Shireen Akther ◽  
Monsur Ahmad ◽  
Paritosh Kumar Biswas

Background: Quality and microbial safety of milk is demanding day by day as it is considered as a host for pathogenic and spoilage microorganisms. In this study, isolation and molecular characterization of shigatoxigenic O157 and non-O157 Escherichia coli in raw milk marketed in Chittagong, Bangladesh were done on 186 raw milk samples in Bangladesh. Methods: MacConkey agar was initially used to screen for the presence of E. coli and the suspected growth as evidenced by large pink colonies on MacConkey agar. Finally the organism was verified by plating through Eosin Methylene Blue (EMB) agar (a selective medium for E. coli where it produces metallic sheen) and applying standard biochemical tests for E. coli. The presence of virulent genes, Shiga-like toxin (stx1 and stx2), Intimin (eaeA), O157 antigen rfbE and Enterohemorrhagic Escherichia coli (EHEC) Hemolysin (EHEC) hlyA in the contaminating E. coli population was determined by polymerase chain reaction (PCR) run on a thermocycler (Applied Biosystem, 2720 thermal cycler, Singapore). Result: Among the raw milk samples, 33 samples were identified as E.coli positive and among the isolates, 6 (18.18%) were identified as possible EHEC O157 and rest of the isolates (81.82%) were considered as probable non EHEC O157. About, 3.23% (186 samples) EHEC O157 was isolated from raw milk samples. Then all the 33 isolates were taken under PCR assay for the identification of five virulent genes Stx1, Stx2, eaeA, rfbE and hlyA. No virulent genes were found in non- EHEC O157 isolates, but 4 stx2 (66.67%) and 1 hlyA (16.67%) gene were observed in another 4 EHEC O157 isolates out of 6, but one isolates contained the both genes and hence the prevalence of STEC was 2.15% in raw milk. Result indicated poor hygienic standard of raw milk from uncontrolled environments and the increased public health risk of those consuming raw milk from such uncontrolled sources.


2021 ◽  
pp. 2410-2418
Author(s):  
Waleed Younis ◽  
Sabry Hassan ◽  
Hams M. A. Mohamed

Background and Aim: Raw milk is considered an essential source of nutrition during all stages of human life because it offers a valuable supply of protein and minerals. Importantly, milk is considered a good media for the growth and contamination of many pathogenic bacteria, especially food-borne pathogens such as Escherichia coli. Thus, the objective of this study was to characterize E. coli and detect its virulence factors and antibiotic resistance from raw milk samples. Materials and Methods: Raw milk samples (n=100) were collected from different localities in Qena, Egypt, and investigated for the presence of E. coli using different biochemical tests, IMViC tests, serotyping to detect somatic antigen type, and molecularly by polymerase chain reaction (PCR) tests. The presence of different virulence and antimicrobial genes (hly, eae, stx1, stx2, blaTEM, tetA(A), and tetB genes) in E. coli isolates was evaluated using PCR. Results: The results demonstrated that 10 out of 100 milk samples were contaminated with E. coli. Depending on serology, the isolates were classified as O114 (one isolate), O27 (two isolates), O111 (one isolate), O125 (two isolates), and untypeable (five isolates) E. coli. The sequencing of partially amplified 16S rRNA of the untypeable isolates resulted in one isolate, which was initially misidentified as untypeable E. coli but later proved as Enterobacter hormaechei. Moreover, antibacterial susceptibility analysis revealed that nearly all isolates were resistant to more than 3 families of antibiotics, particularly to β-lactams, clindamycin, and rifampin. PCR results demonstrated that all E. coli isolates showed an accurate amplicon for the blaTEM and tetA(A) genes, four isolates harbored eae gene, other four harbored tetB gene, and only one isolate exhibited a positive stx2 gene. Conclusion: Our study explored vital methods for identifying E. coli as a harmful pathogen of raw milk using 16S rRNA sequencing, phylogenetic analysis, and detection of virulence factors and antibiotic-resistant genes.


2008 ◽  
Vol 71 (5) ◽  
pp. 1023-1027 ◽  
Author(s):  
R. N. COBBOLD ◽  
M. A. DAVIS ◽  
D. H. RICE ◽  
M. SZYMANSKI ◽  
P. I. TARR ◽  
...  

A survey for Shiga toxigenic Escherichia coli in raw milk and beef was conducted within a defined geographic region of the United States. Prevalence rates based on detection of Shiga toxin gene (stx) were 36% for retail beef, 23% for beef carcasses, and 21% for raw milk samples, which were significantly higher than were Shiga toxigenic E. coli isolation rates of 7.5, 5.8, and 3.2%, respectively. Seasonal prevalence differences were significant for stx positivity among ground beef and milk samples. Distribution of stx subtypes among isolates varied according to sample type, with stx1 predominating in milk, stx2 on carcasses, and the combination of both stx1 and stx2 in beef. Ancillary virulence markers eae and ehx were evident in 23 and 15% of isolates, respectively. Pulsed-field gel electrophoresis demonstrated associations between food isolates and sympatric bovine fecal, and human clinical isolates. These data demonstrate that non-O157 Shiga toxigenic E. coli is present in the food chain in the Pacific Northwest, and its risk to health warrants critical assessment.


Author(s):  
E. Seker ◽  
H. Yardimci

Three hundred rectal faecal samples and 213 raw milk samples obtained from the tanks and containers were examined using standard cultural methods. Escherichia coli O157:H7 was isolated from 11 (3.7 %) of 300 faecal samples and 3 (1.4 %) of 213 raw milk samples. It was determined that 8 (73 %) of E. coli O157:H7 strains isolated from faecal samples originated from water buffaloes younger than 2 years of age and 3 (27 %) from 2-year-old and older water buffaloes. This is the 1st isolation of Escherichia coli O157:H7 from faecal and milk samples of water buffaloes in Turkey.


2019 ◽  
Vol 20 ◽  
Author(s):  
Laryssa F. Ribeiro ◽  
Mayhara M. C. Barbosa ◽  
Fernanda R. Pinto ◽  
Leticia F. Lavezzo ◽  
Gabriel A. M. Rossi ◽  
...  

Abstract This study focused on detecting diarrheagenic Escherichia coli, enteropathogenic E. coli (EPEC), Shiga-toxin-producing E. coli (STEC), enterohemorrhagic E. coli (EHEC or STEC:EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) in raw milk, water, and cattle feces sampled from non-technified dairy farms located in the northeastern São Paulo State, Brazil. Thirty-six water samples were collected at different points, namely, water wells (8 samples), water intended for human consumption (8 samples), water from milking parlor (8 samples), and water intended for animal consumption (7 samples), headwaters (1 sample), rivers (3 samples), and reservoirs (1 sample). Three raw milk samples were taken directly from bulk tanks in each farm, totalizing 24 samples. Feces samples were collected using rectal swabs from 160 bovines (20 animals per farm). E. coli was detected in 128 feces samples (80%), 16 raw milk samples (66.67%), and 20 water samples (55.56%). STEC (26 samples, 16.25%), EPEC (10 samples, 6.25%), STEC: EPEC (5 samples, 3.13%), and STEC: ETEC (1 sample, 0.63%) were the most prevalent strains detected in samples from cattle feces. EPEC, STEC, and STEC: EPEC strains were detected in 4.17% (1 sample), 16.67% (4 samples), and 4.17% (1 sample) of raw milk samples, respectively. STEC strains were detected in water used in the milking parlor, while no EAEC strain was detected. As a conclusion, cattle feces are important contamination sources of pathogenic E. coli in non-technified dairy farms and, consequently, cross-contamination among feces, water, and/or raw milk can occur. The use of quality water and hygienic practices during milking are recommended to avoid contamination since pathogens can be transmitted to humans via raw milk or raw milk cheese ingestion.


Author(s):  
C. G. Ikimi ◽  
F. I. Omeje ◽  
C. K. Anumudu

Meat and meat products are a very important category of food consumed widely to meet the nutritional requirements of humans. Due to the high nutrient and moisture content of meat, they readily support the growth of diverse microorganisms. The consumption of these products, when contaminated by pathogenic microorganisms can pose a risk to health leading to possible food poisoning, with Escherichia coli being the most implicated organism. Thus, this research focused on the isolation of Escherichia coli from raw beef (Bos taurus) retailed in Otuoke market, its biochemical identification, pathogenicity testing and antibiogram. A total of 90 raw beef samples were collected from three retail points (30 samples per point) over 3 months and cultured on Eosin-Methylene Blue (EMB) agar for the elucidation of E. coli. Conventional biochemical tests were performed on isolates to identify E. coli. The isolates were subjected to Congo-red assay to test for pathogenicity and the agar-diffusion assay to test sensitivity to commonly utilized antibiotics. A total of 51 samples (56%) were contaminated with E. coli of which 24 samples (26.6%) had mean aerobic bacteria counts greater than 5.0 Log CFU/gm which is above the European Commission Regulation No. 2073/2005 guideline for fresh beef. All E. coli isolates tested positive to the Congo-red assay, thus indicating their potential pathogenicity. Antimicrobial sensitivity assay indicates the resistance of isolates to Tetracycline (60%), Erythromycin (80%) and Amoxicillin (85%). However, the isolates were sensitive to Nitrofurantoin (90%), Gentamicin (78%) and Ciprofloxacin (82%). The results obtained highlights the high level of contamination by potentially pathogenic E. coli in retailed fresh meats which are highly resistant to some of the commonly used antibiotics. The results obtained from this study is of public health significance as it indicates possible risks of infection to people through the consumption of inadequately cooked meat or the cross-contamination of other food items by the meat products which may lead to outbreaks of food poisoning. 


2007 ◽  
Vol 70 (7) ◽  
pp. 1710-1716 ◽  
Author(s):  
GONÇALO ALMEIDA ◽  
ALEXANDRE FIGUEIREDO ◽  
MARTA RÔLA ◽  
RUI MANUEL BARROS ◽  
PAUL GIBBS ◽  
...  

Seventy raw milk cheeses made in different regions of Portugal, both hard and soft varieties, made with cow's, ewe's, or goat's milk or combinations of these, were sampled within their quoted shelf lives for microbiological safety. On the basis of the presence or numbers of Escherichia coli, E. coli O157, Staphylococcus aureus, Salmonella, and Listeria monocytogenes, cheeses were categorized as satisfactory, acceptable, unsatisfactory, or unacceptable and potentially hazardous. Twenty-two of the 70 cheeses were classified as satisfactory or acceptable. Thirty-seven of the cheeses were considered unsatisfactory because of the presence of E. coli, S. aureus, or both, while 11 of the cheeses were graded as unacceptable and potentially hazardous because of the presence of excessive numbers of S. aureus, E. coli, or L. monocytogenes and the presence of Salmonella in three of these. All cheeses graded as unacceptable and potentially hazardous were soft or semisoft cheeses made with ewe's and goat's milk, with the exception of two hard cheeses made with cow's milk. E. coli O157 was not detected in any of the cheeses. According to the present results, it seems that the presence or counts of pathogenic or indicator organisms in raw milk cheeses cannot be related to the processing conditions, milk type, or region of production.


2017 ◽  
Vol 14 (2) ◽  
pp. 203-208 ◽  
Author(s):  
F. Begum ◽  
M. M. Islam ◽  
M. Sohidullah ◽  
S. M. L. Kabir ◽  
M. Islam ◽  
...  

The present study was designed for the cultural, biochemical characterization and molecular detection of E. coli from apparently healthy and diarrheic goats in and around BAU campus including their antibiogram study. A total of 50 fecal samples were collected among which 13 originated from diarrheic goat and 37 from apparently healthy goats. Out of 50 samples, 35 were found positive for E. coli i.e., overall 70% occurrence. Occurrences of E. coli from diarrheic and apparently healthy goats were 92% and 62% respectively. Occurrences were 60%, 80% and 70% in case of BAU Goat Farm, Veterinary Teaching Hospital and Boyra respectively. On age basis 93%, 54%, 66% and 54% samples originated from 6 months, 7-12 months, 13-18 months and 19 months aged goats were found positive respectively. Occurrences of E. coli on the basis of sex were 78% for male and 62% for female. In case of breed, the occurrences were 69% in Black Bengal and 100% in for Jamunapari. Molecular detection was done by PCR and 13 out of 20 isolates tested gave the bands at the 585 bp specific for E. coli 16S rRNA gene. All the isolates (100%) were found sensitive to ciprofloxacin and norfloxacin; 100% and 35% were intermediately resistant to tetracycline and gentamicin respectively and 25% isolates were resistant to streptomycin. Ciprofloxacin and norfloxacin were found to be the best choice of antibiotics for the treatment of colibacillosis in goats in the study area.


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