Characterization of multidrug-resistant potential pathogens isolated from milk and some dairy products in Egypt.

Objective: This study aimed to explore the incidence and antimicrobial resistance (AMR) of Escherichia coli, Staphylococcus aureus, and Bacillus cereus in raw milk and some Egyptian dairy products, namely Kariesh cheese and rice with milk. Material and Methods: 112 samples (70 raw milk, 30 Kariesh cheese, and 12 rice with milk) were randomly collected from different districts in Cairo and Giza, Egypt. The samples were examined for E. coli, S. aureus, and B. cereus presence. The susceptibility of the obtained isolates was tested against 11 antimicrobials using the disk diffusion method, and further, the presence of AMR genes was examined. Results: The incidences of E. coli, S. aureus, and B. cereus were 69.64%, 12.5%, and 16.7% in the examined samples, respectively. The antibiogram indicated that E. coli isolates (n = 60) were resistant to gentamycin (73.33%), ampicillin (AM, 53.3%), and cefotaxime (CTX, 16.66%). Multidrug-resistant (MDR) E. coli strains (n = 5) were tested for ß-lactams resistance genes. blaTEM was detected in all isolates, and two of them additionally carried blaCTX-M. Staphylococcus aureus isolates (n = 10) were resistant to AM (100%), followed by tetracycline (TE), CTX, and gentamycin (60% each). All MDR S. aureus strains (n = 4) carried blaZ and tetK, and three of them additionally carried aac(6')-aph (2''). Bacillus cereus isolates (n = 30) showed resistance to AM (100%), amoxicillin (20%), and TE (6.66%). bla and tetA genes were detected in all MDR B. cereus isolates (n = 6). Conclusion: Our findings denote the high incidence of potential health hazards in raw milk and some of its products and the existence of AMR bacteria, including MDR strains, which can cause human illnesses that are difficult to treat.

Nutritional, antimicrobial and medicinal properties of Camel's milk: A review.

Camel's milk is an important part of staple diet in several parts of the world, particularly in the arid and semi-arid zones. Camel's milk is rich in health-beneficial substances, such as bioactive peptides, lactoferrin, zinc, and mono and polyunsaturated fatty acids. These substances could help in the treatment of some important human diseases like tuberculosis, asthma, gastrointestinal diseases, and jaundice. Camel's milk composition is more variable compared to cow's milk. The effects of feed, breed, age, and lactation stage on milk composition are more significant in camel. Region and season significantly change the ratio of compounds in camel's milk. Camel's whey protein is not only composed of numerous soluble proteins, but also has indigenous proteases such as chymotrypsin A and cathepsin D. In addition to their high nutritional value, these whey proteins have unique characteristics, including physical, chemical, physiological, functional, and technological features that are useful in the food application. The hydrolysis of camel's milk proteins leads to the formation of bioactive peptides, which affect major organ systems of the body and impart physiological functions to these systems. The camel's milk has antioxidant, antimicrobial, angiotensin-I-converting enzyme (ACE)-inhibitory peptides, antidiabetic as well as anticholesterol activities.

Prevalence and Molecular Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Raw Milk and Raw Milk Cheese in Egypt.

The goal of this study was to examine antimicrobial resistance and characterize the implicated genes in 222 isolates of Escherichia coli from 187 samples of raw milk and the two most popular cheeses in Egypt. E. coli isolates were tested for susceptibility to 12 antimicrobials by a disk diffusion method. Among the 222 E. coli isolates, 66 (29.7%) were resistant to one or more antimicrobials, and half of these resistant isolates showed a multidrug resistance phenotype (resistance to at least three different drug classes). The resistance traits were observed to tetracycline (27.5%), ampicillin (18.9%), streptomycin (18.5%), sulfamethoxazole-trimethoprim (11.3%), cefotaxime (4.5%), kanamycin (4.1%), ceftazidime (3.6%), chloramphenicol (2.3%), nalidixic acid (1.8%), and ciprofloxacin (1.4%). No resistance to fosfomycin and imipenem was observed. Tetracycline resistance genes tetA, tetB, and tetD were detected in 53 isolates, 9 isolates, and 1 isolate, respectively, but tetC was not detected. Aminoglycoside resistance genes strA, strB, aadA, and aphA1 were detected in 41, 41, 11, and 9 isolates, respectively. Sulfonamide resistance genes sul1, sul2, and sul3 were detected in 7, 25, and 3 isolates, respectively. Of 42 ampicillin-resistant isolates, blaTEM, blaCTX-M, and blaSHV were detected in 40, 9, and 3 isolates, respectively, and 10 (23.8%) ampicillin-resistant isolates were found to produce extended-spectrum ß-lactamase. Each bla gene of extended-spectrum ß-lactamase-producing E. coli was further subtyped to be blaCTX-M-15, blaCTX-M-104, blaTEM-1, and blaSHV-12. The class 1 integron was also detected in 28 resistant isolates, and three different patterns were obtained by PCR-restriction fragment length polymorphism. Sequencing analysis of the variable region revealed that four isolates had dfrA12/orfF/aadA2, two had aadA22, and one had dfrA1/aadA1. These data suggest that antimicrobial-resistant E. coli are widely distributed in the milk production and processing environment in Egypt and may play a role in dissemination of antimicrobial resistance to other pathogenic and commensal bacteria.

Prevalence and pathogenic potential of Escherichia coli isolates from raw milk and raw milk cheese in Egypt.

The objectives of this study were to investigate prevalence and pathogenic potential of Escherichia coli contaminating raw milk and its products in Egypt. Out of 187 dairy products including 72 raw milk samples, 55 Karish cheese and 60 Ras cheese, 222 E. coli isolates including 111, 89 and 22 were obtained from 55 raw milk samples (76.4%), 41 Karish cheese (74.5%), and 13 Ras cheese (21.7%), respectively. Isolated E. coli strains were examined for 24 representative virulence genes present in diarrheagenic E. coli (DEC) and extraintestinal pathogenic E. coli (ExPEC). Among DEC and ExPEC virulence factors, genes for enteropathogenic E. coli (eaeA, bfpA, EAF), enterohemorrhagic E. coli (stx1, stx2, eaeA), enterotoxigenic E. coli (elt, est), enteroinvasive E. coli (invE), enteroaggregative E. coli (Eagg, astA), diffusely adherent E. coli (daaD), ExPEC (cdt-I to cdt-V, cnf1, cnf2, hlyA) and putative adhesins (efa1, iha, ehaA, saa, and lpfAO113) were screened by colony hybridization assay. Out of 222 E. coli strains, 104 (46.8%) isolated from 69 (36.9%) samples carried one or more virulence genes. The most prevalent gene detected was lpfAO113 (40.5%), followed by ehaA (32.4%,), astA (3.15%,), iha (1.80%), hlyA (1.35%), stx1 (0.90%), stx2 (0.90%), eaeA (0.45%), cdt-III (0.45%) and cnf2 (0.45%). Two strains isolated from Karish cheese harbored 5 virulence genes (stx1, stx2, iha, ehaA, lpfAO113). Stx subtype was determined to be stx1 (not stx1c or stx1d) and stx2d. Indeed, expression of hemolysin A, CDT-III, CNF-II, Stx1 and Stx2d was confirmed by blood agar plate, cytotoxicity assay and Western blotting, respectively. Among the 222 E. coli strains, 54 (48.6%), 38 (42.6%) and 12 (54.7%) isolated from raw milk, Karish cheese and Ras cheese were potentially virulent, respectively. O-genotyping indicated that most of the potentially virulent E. coli isolates did not belong to clinically important O serogroups except O75, O91 and O166, which have been associated with human diseases. Phylogenetic grouping revealed that 150 (67.6%), 67 (30.2%) and 5 (2.30%) strains were clustered into A, B1 and D groups, respectively, which are considered to be associated with intestinal infection, indicating that these E. coli strains might have a potential to cause gastroenteritis. To the best of our knowledge, this is the first comprehensive study regarding prevalence and pathogenic potential of E. coli in dairy products in Egypt. Raw milk, Karish cheese and Ras cheese in Egypt are highly contaminated with E. coli including potentially pathogenic strains, which may impose a public health threat.