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We studied the genetic resistance to Campylobacter coli and Campylobacter jejuni in wild boar using both STR analysis and genome-wide association studies (GWAS). A total of 60 wild boars hunted in Tuscany (Italy) during the 2018/2019 hunting season were analyzed and genotyped. During postmortem operations, fecal swabs, liver samples and kidneys were collected. Two groups of animals were considered for the statistical analysis: 28 Campylobacter positive (22 for C. coli and 6 for C. jejuni) and 32 Campylobacter negative. Regarding STR analysis, 15 markers belonging to a marker panel validated by the International Society of Animal Genetics (ISAG) for swine were used: for each marker, alleles and genotype frequencies between the two groups of animals were compared using the Chi-square test and Fisher's exact tests. To analyze the genetic variability within groups, the following parameters were computed: molecular coancestry coefficients (fij), kinship distance (Dk), inbreeding coefficient (Fi), and genetic similarities (GS). The internal relatedness (IR) was also calculated, and ANOVA was used to verify the relationships between IR and Campylobacter groups. For GWAS, the Geneseek Genomic Profiler Porcine HD (70 k), containing 62,330 SNPs, was used. No differences in the internal relatedness (IR) were observed between the two groups (F = 5.64, P = 0.065) and no significant association between STRs and SNPs and Campylobacter positivity was observed. Although genetic resistance to bacterial diseases is often regulated by multiple genes controlling different processes of the host–pathogen interaction, in our studies no candidate genes that could be directly or indirectly involved in the development of the disease were identified. [ABSTRACT FROM AUTHOR]

Mycobacterium avium paratuberculosis (Map) is a pathogen which causes a chronic progressive granulomatous enteritis known as paratuberculosis or Johne's disease and it primarily affects wild and domestic ruminants. The aim of this research was to examine a flock which consisted of 294 goats and was located in Garfagnana district (Tuscany, Italy) performing ELISA tests, culture and IS900 PCR assay; direct diagnostic methods were carried out not only on bulk tank milk and cheese samples but also on individual milk and tissue specimens collected from nine subjects positive to ELISA tests. Out of 294 animals, 20 goats (6.8%) were positive to ELISA surveys. Bulk tank milk samples were negative to culture and to PCR assay carried out on the DNA extracted directly from them, while, with respect to cheese, Map was detected by culture in 2/12 (16.66%) cheeses ripened for 3-7 days, and by PCR in 2/12 (16.66%) cheeses ripened for 3-7 days and in 3/12 (25%) cheeses ripened for 45 days. Regarding individual milk samples, Map was detected by culture in 2/9 (22.22%) specimens and by PCR in 5/9 (55.55%) samples. Furthermore, Map was isolated from the intestine in 9/9 (100%) animals, from the mesenteric lymph nodes in 8/9 (88.88%) subjects, from the liver in 4/9 (44.44%) goats, from the spleen in 5/9 (55.55%) animals, while Map DNA was found in all the tissue samples analyzed. The results demonstrated the presence of paratuberculosis in a goat flock located in Garfagnana district (Tuscany, Italy). [ABSTRACT FROM AUTHOR]

Currently, donkey milk is receiving an increasing attention from consumers and research community because of its several beneficial aspects, such as a poor allergenic nature and a remarkable antimicrobial compound content. In this study, we evaluated the growth rate of Staphylococcus aureus ATCC 6538, Listeria monocytogenes ATCC 7644TM, Campylobacter jejuni ATCC 33291, and Pseudomonas aeruginosa ATCC 27853 at refrigeration conditions (4 ± 2 °C) in goat milk added with different percentages of donkey milk (1, 2.5, 5, 10% v/ v) along 6 days of storage; furthermore, donkey milk and goat milk samples were employed as controls. Lysozyme content of donkey milk was determined and ranged from 1 mg.mL up to 2 mg.mL. An inhibited growth rate in donkey milk samples was observed during storage for S. aureus, L. monocytogenes, and C. jejuni, with a growth decrease of 0.61 log CFU.mL, 5.55 log CFU.mL, and 1.72 log CFU.mL, respectively. These data confirm the antibacterial activity of donkey milk against Gram-positive and Gram-negative microorganisms; however, microbial growth rates in milk mixtures and goat milk were comparable, with no significant increase in antibacterial activity due to donkey milk addition. Considering a potential employment of donkey milk in dairy products, further studies should be performed in order to detect the optimal balance of milk mixtures in terms of caseins and antimicrobial molecules amounts. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate some probiotic properties of 42 wild Lactobacillus plantarum strains isolated from different Italian foods of animal origin. The strains were first screened for their antibiotic resistance profile (chloramphenicol, erythromycin, gentamicin, and tetracycline), subsequently they were tested for their in vitro resistance to lysozyme (100 mg L), low pH (3.0, 2.5 and 2.0) and bile salts (0.3, 0.5 and 1.0 %). Moreover, agglutination property was studied (adhesion to Saccharomyces cerevisiae cells), as well as the presence of bsh and msa genes. The strains with the best characteristics were subjected to a further trial in order to evaluate their ability to survive to multiple stresses over time (lysozyme, low pH and bile salts) and the effect of these treatments on adhesion to yeast cells. All the strains were susceptible to chloramphenicol, erythromycin and gentamicin, while 6 strains were excluded from further evaluation because of their resistant phenotype against tetracycline. All the strains were able to grow in presence of lysozyme, as well as in MRS broth at pH 3.0. Only 4 strains showed a growth rate lower than 80 % when grown in MRS broth at pH 2.5, while a relevant growth rate decrease was observed after exposure to pH 2.0. Bile salts didn't affect the viability of the L. plantarum cells. Twenty-one strains out of 33 tested strains were able to adhere to S. cerevisiae cells. Presence of both bsh and msa genes was detected in 6 strains. The strains resistant to all the stresses, positive to agglutination with S. cerevisiae and showing bsh and msa genes were selected for further evaluation and subjected to different stress treatments over time. The assessment of growth rates showed that exposure to lysozyme significantly increased low pH resistance in L. plantarum. This increase ranged from 2.35 to 15.57 %. The consequential lysozyme and low pH exposures didn't affect the growth rate values after bile salts treatment, as well as the ability of the strains to adhere to yeast cells wasn't modified by previous treatments (lysozyme, low pH and bile salts). The present work allows to increase knowledge about non starter lactic acid bacteria from Italian food products. The studied L. plantarum strains showed a good potential for their use as probiotic cultures. However, more in vivo tests are necessary to confirm this potentiality. [ABSTRACT FROM AUTHOR]