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Molecular Studies on Some Emerging Pathogens in Dairy Products Retailed in Dakahlia Governorate, Egypt
2022
Dalia I. Makkia | Adel H. Mahmoud | Ali A. Bahout | Mohamed A. Bayoumi | Mohamed E. Alnakip
In this study, one hundred and ten samples (25 raw buffalo milk, 25 kareish cheese, 25 small-scale yoghurt, and 35 small-scale ice cream) were collected randomly from local markets, dairy shops, and supermarkets from different localities in Dakahlia Governorate, Egypt during October 2019 to March 2020. The prevalence rates of foodborne pathogens including E. coli, Salmonella spp., and Aeromonas hydrophila (A. hydrophila) were examined. Molecular confirmation and detection of toxin-producing and drug-resistance-related genes were carried out using PCR. E. coli was isolated from the examined raw milk, ice cream, Kareish cheese, and yoghurt at 72%, 25.71%, 40%, and 44%, respectively, while Salmonella spp. was isolated at 36%, 4%, and 24% from the examined raw milk, Kareish cheese, and yoghurt samples, respectively. Aeromonas hydrophila was isolated at 36% from the examined raw milk samples, 8% from Kareish cheese samples, and 76% from the examined yoghurt samples. Twelve out of 98 E. coli isolates, 18 out of 30 Salmonella isolates, and 24 out of 50 A. hydrophila were multidrug-resistant, respectively. The most resistant antibiotics were ceftriaxone and tetracycline. All examined E. coli, Salmonella spp., and A. hydrophila isolates contained blaTEM and TetA(A) resistance genes. 66.7% of the examined E. coli isolates harbored stx1, while stx2 was absent in all examined E. coli isolates. All examined Salmonella spp. isolates contained both stn and avrA virulence genes. All examined A. hydrophila contained the Aerolysin, but just 40% contained the hemolysin virulence genes. Therefore, it is necessary to reduce the excessive usage of antibiotics in dairy farms and to apply strict hygienic measures to inhibit microbial contamination of dairy products intended for human consumption.
اظهر المزيد [+] اقل [-]Virulence Genes of Multi-drug Resistance Pseudomonas species Isolated from Milk and Some Dairy Products
2022
Heba Gamal | Mohamed El-Diasty | Amany Dapgh | Mohammed El-Sherbini | Amira El-Baz | Adel Abdelkhalek
Pseudomonas species is one of the psychotropic bacteria that can survive in low-tempered milk and dairy products besides producing heat-resistant spoilage enzymes. In this study, one hundred and fifty samples of milk and some dairy products were analyzed. The overall prevalence of Pseudomonas spp. was 44.66% (0% pasteurized milk, 16% butter, 20% pasteurized cream, 48.5% Talaga cheese, 50% bulk milk tank, 66.6% raw market milk, and 70% in raw cream). From 67 positive samples, eighty-three isolates were confirmed biochemically as Pseudomonas spp. The most prominent species were P. aeruginosa, then P. fluorescence, P. Fragi, P. psychrophile, P. proteolytica, P. alcaligens, P. lundensis, and P. brenneri by a percent of 38.5%, 37.5%, 10.8%, 6%, 2.4%, 2.4%, 1.2%, and 1.2%, respectively. Fourteen antibiotic discs were selected to measure the antimicrobial susceptibility of 59 isolates of Pseudomonas spp. The higher antimicrobial resistance was against Ampicillin (100%) followed by Colistin (98%), while the antibiotic sensitivity was higher against Imipenem (96.6%) then Meropenem (91.5%). The average MAR index of isolated Pseudomonas spp. was 0.462. Ten isolates of antimicrobial resistance serotypes of P. aeruginosa were O11: E, O8: C, O5: B, O4: F, and O2: B. Molecular identification of P. aeruginosa, P. fluorescence, and P. fragi was carried out using polymerase chain reaction (PCR) to determine their virulence genes (LasB, ExoS, pilB for P. aeruginosa, aprX for P. fluorescence and carA gene for P. fragi). High levels of antimicrobial-resistant (AMR) Pseudomonas spp. threaten public health and cause global concern. The economic and public health impacts were discussed.
اظهر المزيد [+] اقل [-]Prevalence and Characterization of Escherichia coli in Raw Milk and Some Dairy Products at Mansoura City
2022
Amira H.M. Ibrahim | Mohammed E.E. Ali | Marwa F.E. Ahmed | Adel Abdelkhalek
The present study aimed to detect the prevalence and antibiotic sensitivity pattern of Escherichia coli in raw milk and some dairy products (white soft cheese, yoghurt, and Laban rayeb) in Mansoura city, Egypt. A total of 200 samples, obtained equally from raw milk (farm and market milk), white soft cheese (Kareish and Domiati), yoghurt (small scale and large scale), and Laban rayeb (small scale and large scale) were examined for the presence of E. coli by using eosin methylene blue agar (EMB). Suspected E. coli isolates were confirmed by biochemical tests and then selected numbers of E. coli strains were identified serologically. Furthermore, serologically identified strains were subjected to antibiotic sensitivity testing. In total, the prevalence of E. coli recovered from the examined raw milk and dairy products samples was 28% (56/200). The highest prevalence was detected in raw market milk (52%), followed by Kareish cheese (48%) while, the lowest prevalence was obtained in large-scale yoghurt and large-scale Laban rayeb samples (8%). The selected numbers of E. coli strains subjected to serologic examination showed variable somatic and H antigens. About 58.8% of E. coli strains showed multi-antibiotic resistance (MAR) criteria at least to one antimicrobial in three different classes of antibiotics. The highest resistance was obtained from erythromycin (100%) then oxacillin (94%), cefepime (82%), penicillin G (76.5%), and ampicillin (58.5%), nalidixic acid (52.9%) and cefazolin (47.1%). the obtained results show the great hazard proposed to public health, therefore, the application of hygienic measures in all practices concerning dairy industry from farm to fork is not just advice but a necessity to maintain human health.
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