The occurrence, seasonal variation and genetic diversity of Campylobacter spp. in pigeons and crows over a 1-year period were evaluated. Campylobacter spp. were isolated from 166 (34.6 %) out of 480 wild bird faecal samples. The occurrence of Campylobacter spp. in faecal samples was higher among crows (39.2 %) than pigeons (30.0 %), (P < 0.05). Campylobacter jejuni was the most common species detected among wild bird faecal samples (98.2 %). Meanwhile, Campylobacter coli prevalence in wild bird faecal samples was low-6 %. The Simpson's diversity index of C. jejuni flaA RFLP types was lower in pigeons (D = 0.88) compared with C. jejuni isolates detected in crows (D = 0.97). Obtained results revealed that C. jejuni are widely prevalent among crows and pigeons, indicating these wild birds as potential infection sources to humans. Further studies are required to determine crows and pigeons role in zoonotic transmission of Campylobacter.

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The meat industry generates large amounts of by-products, and their mass represents approximately one-third of the live weight of animals. Most by-products are disposed of and not used for processing, although they meet hygiene requirements and are suitable for human consumption or for the processing of food supplements. The aim of this study was to investigate the effect of lyophilization on the nutritional value and retention of functional ingredients in ovine and porcine by-products: liver, kidneys, hearts, and lungs. For this purpose, meat by-products of the third category were selected in X and Y slaughterhouses and divided into two parts: one part was freeze-dried at −80 °C for 72 h, and the other part was left raw. Fatty acid composition was determined by gas chromatography–mass spectrometry (GC-MS), and amino acid analysis was performed by AccQ Tag technology (Waters Corp., Milford, MA, USA) and HPLC. Our study shows that the lyophilization process did not significantly affect protein and fat content. The largest decrease in the amount of proteins was determined in samples of ovine kidneys, at 0.8%, while the difference in protein in ovine liver samples before and after lyophilization was 0.38%. The composition of essential amino acids did not change after lyophilization, except a decrease in Leu and Thr in porcine samples and Leu, Thr, and Met in ovine samples (p < 0.05). The lyophilization process did not significantly affect the polyunsaturated fatty acid content, including the amounts of omega 3 and omega 6 fatty acids. The optimal ratio of omega 6 and 3 fatty acids was determined in samples of lyophilized ovine livers (2.65), and the largest ratio was found in samples of lyophilized porcine hearts (16.67). The study results show that, after lyophilization, meat by-products of the third category (according to Regulation (EC) No. 1069/2009, Categorization, Article 10), especially ovine liver, can be used as a source of amino acids and polyunsaturated fatty acids for functional food processing. The process of lyophilization is also appropriate for preserving meat by-products without losing the nutritional value and beneficial components.

The antimicrobial effect of spice-based marinades against Campylobacter jejuni on inoculated fresh broiler wings was investigated. Experiments were carried out with 1 strain of C. jejuni and 6 marinades. Four experimental marinades were composed for the study and contained spices (thyme, rosemary, basil, marjoram, and so on) and different combination of bioactive compounds. Two marinades were commercial and contained spices (black pepper, sweet red pepper, and so on) and chemical additives (monosodium glutamate, sodium diacetate, calcium lactate), 1 commercial marinade was also enriched with bioactive compounds (linalool, cinnamaldehyde, lactic acid). Total aerobic bacterial count was examined to estimate the possible effect of tested marinades on the shelf-life of marinated broiler wings. Study revealed that thyme-based marinade was the most effective against C. jejuni on broiler wings and reduced the numbers of campylobacters by 1.04 log colony forming unit (CFU)/g (P ≤ 0.05) during storage for 168 h at 4 °C temperature. Moreover, it was more effective against C. jejuni than commercial marinade with 0.47 log CFU/g (P ≤ 0.05) reduction effect. Both experimental and commercial marinades had very similar effect on the total aerobic bacterial count. Although experimental and commercial marinades had different effect on pH of broiler wings, this parameter did not show a major impact on the antimicrobial effect of tested marinades (P ≥ 0.05). Our study shows that experimental natural thyme-based marinade can reduce numbers of C. jejuni more effectively than tested commercial marinades.

Cold smoked salmon products (belly flaps, pieces, fillet, and loin) obtained from the retail market in Lithuania were tested for the presence of L. monocytogenes. It was found that contamination of the cold smoked fish products with Listeria spp. depends on the type of the product. Contamination with listeria in salmon belly flaps was 7.5 times higher than in the loin (P<0.05), 1.8 times higher than in the pieces (P<0.05) and 30 times higher than in the fillet (P<0.05). Microbiological analysis showed that 32.5% (P<0.05) of the fish product samples were infected with L. monocytogenes, while multiplex PCR confirmed 31.25% positive samples (P<0.01). According to the study results, L. monocytogenes strains were divided into two serotypes: 4b (94.6%) and 1/2a (5.4%). High contamination of the products with Listeria spp. showed that cold smoked salmon products, sold in local market, can be a reason of human listeriosis in Lithuania.