Evaluating the antagonistic effect of Lactobacillus acidophilus against Shiga toxigenic and non-toxigenic Escherichia coli strains in bioyogurt.

This study was conducted to determine the effect of acidophilus yoghurt (yoghurt fortified with Lactobacillus acidophilus) in comparison to traditional plain yoghurt (St. thermophilus and L. bulgaricus starter cultures) on the survival of three pathogenic Escherichia coli strains; Shiga toxigenic O157 (STx O157), non-toxigenic O157 (Non-STx O157) and Shiga toxigenic non-O157 (STx O145). After six days of refrigerated storage of laboratory-manufactured yoghurt inoculated with the three strains of E. coli separately, all were eliminated in acidophilus yoghurt, while their survival extended in the traditional yoghurt along the storage period (17 d). Reduction percentages of the tested strains in acidophilus yoghurt were 99.93, 99.93 and 99.86%, with log reduction of 3.176, 3.176, and 2.865 cfu/g for Stx O157, Non-Stx O157, and Stx O145 E. coli, respectively, in comparison to 91.67, 93.33 and 93.33%, with log reduction of 1.079, 1.176 and 1.176 cfu/g in traditional yoghurt. Statistical analysis showed a significant effect of acidophilus yoghurt in reducing the count of Stx E. coli O157 (P = 0.001), Non-Stx E. coli O157 (P < 0.01) and Stx E. coli O145 (P < 0.01) compared to the traditional yoghurt. These findings emphasize the potential use of acidophilus yoghurt as a biocontrol alternative method for eliminating pathogenic E. coli, as well as other similar applications in the dairy industry.

Chitosan nanoparticle encapsulation increased the prophylactic efficacy of Lactobacillus plantarum RM1 against AFM1-induced hepatorenal toxicity in rats.

Aflatoxin M1 (AFM1) is a significant contaminant of food, particularly dairy products and can resist various industrial processes. Several probiotic strains like Lactobacillus plantarum are known to reduce aflatoxin availability in synthetic media and some food products. The current work investigated the possible chitosan coating prophylactic efficacy of Lactobacillus plantarum RM1 nanoemulsion (CS-RM1) against AFM1-induced hepatorenal toxicity in rats. Twenty-eight male Wistar rats were divided into four groups (n = 7) as follows: group 1 received normal saline, group 2 received CS-RM1 (1mL contains 6.7 × 1010 CFU), group 3 received AFM1 (60 µg/kg bwt), and group 4 received both CS-RM1(1 mL contains 6.7 × 1010 CFU) and AFM1 (60 µg/kg bwt). All receiving materials were given to rats daily via oral gavage for 28 days. AFM1 caused a significant elevation in serum levels of ALT, AST, ALP, uric acid, urea, and creatinine with marked alterations in protein and lipid profiles. Additionally, AFM1 caused marked pathological changes in the liver and kidneys, such as cellular necrosis, vascular congestion, and interstitial inflammation. AFM1 also increased the MDA levels and decreased several enzymatic and non-enzymatic antioxidants. Liver and kidney sections of the AFM1 group displayed strong caspase-3, TNF-α, and iNOS immunopositivity. Co-treatment of CS-RM1 with AFM1 significantly lowered the investigated toxicological parameter changes and markedly improved the microscopic appearance of liver and kidneys. In conclusion, AFM1 induces hepatorenal oxidative stress damage via ROS overgeneration, which induces mitochondrial caspase-3-dependent apoptosis and inflammation. Furthermore, CS-RM1 can reduce AFM1 toxicity in both the liver and kidneys. The study recommends adding CS-RM1 to milk and milk products for AFM1-elimination.

Management Practices of Bovine Mastitis and Milk Quality on Egyptian Dairies.

Milk production continues to be the main source of income for dairy producers, and mastitis continues to be the major health challenge for dairy cows worldwide. The objective of the current study was to describe the different management practices implemented in Egyptian dairies, which may influence mastitis and improve milk quality. An in-person survey was completed with herd managers and owners of 20 Egyptian dairies selected using a stratified random sample from four of Egypt's milk sheds. The questionnaire included 80 questions that inquired about herd demographics, mastitis status and control, milking practices, and management practices of the study dairies. Statistical analyses included descriptive statistics, multiple factor analysis (MFA), and hierarchical clustering to identify the important principal components and different dairy clusters. Of the surveyed herds, 69.50% had less than 500 lactating cows, with Holstein as the main cow breed. The reported average milk production on the study herds was 31.1 (SE ± 1.10) Kg/cow/day. Housing of lactating, dry, and close-up cows was in open lots. The majority of the dairies milked cows were three times per day (90.63%), the remaining milked cows four (5.00%) or a mix of four and three times per day. Furthermore, herringbone parlor design was the most common parlor design (66.79%) in the study dairies. The most common disinfectants used for both pre- and post-milking teat dip were iodine-based, 90.0% and 95.0%, respectively, while 52.16% of the dairies reported that their milkers wore gloves during milking. The reported mean annual percentage of mastitis was 52.3%, as a percent of the milking herd. The study dairies reported the inspection of udder health through either visual inspection (95.00%), udder hygiene score (86.88%), teat end score (71.88%), and/or using CMT (54.91%). Contagious mastitis pathogens were reported in 45.2% of the study herds. More than 50% of the study herds relied on importing pregnant cows or pregnant heifers as replacements. Multiple factor analysis identified 20 questions and represented 5 components of variability related to mastitis on dairies. The current survey of Egyptian dairies described the herd demographics and different management practices related to mastitis control and prevention. All the study dairies relied on the blanket intramammary antimicrobial drugs at dry off when current research elsewhere has identified selective dry cow therapy as an integral component of antimicrobial stewardship on dairies. Further research is required to identify the association between different management factors and the occurrence of mastitis.

Isolation and characterization of E. coli strains causing intramammary infections from dairy animals and wild birds.

The study was conducted to estimate the prevalence of Escherichia coli (E. coli) in sub-clinically mastitic (SCM) animals, and in wild and migratory birds which may act as reservoir disseminating such pathogen. Farm hygiene, management and milking procedures were listed through a questionnaire. Thirty lactating cows and 15 lactating buffaloes from five small-scale dairy farms were randomly selected and screened for subclinical mastitis (SCM) using California Mastitis Test (CMT) and somatic cell count (SCC). In addition, 80 teat skin swabs, 5 drinking water samples and 38 wild and migratory bird faecal matter were also collected. All samples were processed for E. coli isolation by culturing on Levine's Eosin Methylene Blue (L-EMB) agar, followed by purification and biochemical identification. Positive samples were subjected to molecular identification and serotyping. In addition, the presence of extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing E. coli have been reported by antimicrobial sensitivity testing. Escherichia coli were isolated from 7.7%, 50% and 50% of the positive CMT cows' quarters, cows' composite and buffaloes' composite milk samples, respectively. In addition, 14% of cows' teats, 20% of water samples, 70% of faecal matter from wild bird, and 33.3% of faecal matter from migratory waterfowls were carrying E. coli. Serotyping, antibiotic-resistant pattern and phylogenetic analysis have pointed the bearable implication of milking hygiene and wild birds in disseminating E. coli strains causing intramammary infections.