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. Aminogly...

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 β-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%), amoxi¬cillin (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.

Subclinical mastitis (SCM) is regarded as not only a problem to dairy producers worldwide but also a threat to human health due to the potential bacterial contamination of milk and dairy products, particularly those made from raw milk. In this study, E. coli were isolated from fourteen (9.3%) SCM milk samples. The isolated E. coli (n=14) were serotyped, their potential pathogenicity and antimicrobial resistances (AMRs) were investigated. Serotyping results showed that the E. coli isolates belonged to the O55:H7 (n=2), O111:H4 (n=2), O127:H6 (n=2), O128:HUN (n=2), O26:HUN (n=1), O44:H18 (n=1), O114:H21 (n=1), O86:HUN (n=1), O124:HUN (n=1) and O127:H7 (n=1) serogroups. Potential pathogenicity was detected in 93% (13/14) of the isolates. In particular, thirteen isolates possessed at least one of the examined virulence genes. Ten isolates (71%) exhibited AMR to at least one of the tested antimicrobials, 4 (40%) of them were- multidrug-resistant and one isolates showed ESBL production. The obtained results indicate that SCM acts as a source for the spread of potentially pathogenic E. coli strains that are resistant to many groups of antibiotics which may constitute a hazard for both public and animal health.

The objective of this study was to evaluate the impact of the antimicrobials nisin and lysozyme to control the growth of spoilage bacteria of pasteurized milk during cold storage. Nisin, lysozyme, and a mixture of them were inoculated into freshly pasteurized milk at 500 IU/ml concentrations each. The acidity, sensory evaluation, and bacteriological quality of the treated pasteurized milk samples were examined at zero time and every 3 days till the samples showed the signs of spoilage, that were checked every day. Obtained results showed that there was a slight increase of the titratable acidity of the control and treated samples during refrigerated storage, but the acidity increase was significantly lower in samples containing lysosomes and/or nisin than the control samples. Nisin and lysozyme at 500 IU/ml concentration possessed inhibitory effect on the total bacterial, aerobic spore-formers, and psychrotrophic bacterial counts and extended the shelf-life of the treated samples. The efficacy of nisin 500 IU/ml combined with lysozyme 500 U/ml was assessed and synergistic activity has been detected, that was expressed in the form of higher inhibitory effect and extending the shelf-life of the samples up to 15 days at cold storage. Moreover, the sensory evaluation showed that nisin and lysozyme does not affect the acceptability of the examined samples. The obtained data indicate that nisin and lysozyme have the potential to enhance the post-process bacteriological safety of pasteurized milk during the storage period and could aid in the elimination of post-process contamination and prolong its shelf-life.

The aim of this work was to study the effect of milk supplementation with lactoferrin on the rheological and sensory properties of yogurt and to evaluate the efficiency of lactoferrin-fortified yogurt in the treatment of iron deficiency anemia (IDA), microcytic hypochromic anemia, in children. For this purpose, yogurt was manufactured from milk fortified with commercial lactoferrin and the yogurt sensory characteristics, pH and concentration of lactic acid of supplemented yogurts, were determined throughout the shelf-life period storage (7 days) at 4°C and compared with a control yogurt. Furthermore, the use of lactoferrin-fortified yogurt in treatment of IDA in comparison to commercial lactoferrin alone (lactoferrin dissolved in water) were assessed with 20 children (2–5 years old) suffering from IDA. Children were divided into two groups (A and B), 10 children each. Group A received lactoferrin-fortified yogurt while, group B received commercial lactoferrin dissolved in water. The blood cells indices, Hb, HCT, MCV, TLC, Platelets, Serum iron, Serum ferritin, TIBC and Transferrin were analyzed before and after treatment for each group. The results showed that manufactured fortified yogurt was firm, with acceptable sensory properties and the Hb and red blood cell indices significantly improved in patients received lactoferrin-fortified yogurt even than patients received lactoferrin only. This study concluded that lactoferrin addition had no significant effect on yogurt manufacture and the yogurt produced from milk fortified with lactoferrin had a vital supportive treatment for the management of IDA in children.