Lactic acid bacteria (LAB) in the microbiota play an important role in human and animal health and, when used as probiotics, can contribute to an increased growth performance in livestock management. Animals living in their native habitat can serve as natural sources of microorganisms, so isolation of LAB strains from wild boars could provide the opportunity to develop effective probiotics to improve production in swine industry. In this study, the probiotic potential of 56 LAB isolates, originated from the ileum, colon, caecum and faeces of 5 wild boars, were assessed in vitro in details. Their taxonomic identity at species level and their antibacterial activity against four representative strains of potentially pathogenic bacteria were determined. The ability to tolerate low pH and bile salt, antibiotic susceptibility, bile salt hydrolase activity and lack of hemolysis were tested. Draft genome sequences of ten Limosilactobacillus mucosae and three Leuconostoc suionicum strains were determined. Bioinformatic analysis excluded the presence of any known acquired antibiotic resistance genes. Three genes, encoding mesentericin B105 and two different bacteriocin-IIc class proteins, as well as two genes with possible involvement in mesentericin secretion (mesE) and transport (mesD) were identified in two L. suionicum strains. Lam29 protein, a component of an ABC transporter with proved function as mucin- and epithelial cell-adhesion factor, and a bile salt hydrolase gene were found in all ten L. mucosae genomes. Comprehensive reconsideration of all data helps to select candidate strains to assess their probiotic potential further in animal experiments.

The widespread use of polyvinyl chloride (PVC) and its entry into humans and livestock is of serious concern. In our study, we investigated the impact of PVC treatments on physiological, pathological, hormonal, and microbiota changes in female rabbits. Trend-like alterations in weight were observed in the spleen, liver, and kidney in both low (P1) and high dose (P2) PVC treatment groups. Histopathological examination revealed exfoliation of the intestinal mucosa in the treated groups compared to the control, and microplastic particles were penetrated and embedded in the spleen. Furthermore, both P1 and P2 showed increased 17-beta-estradiol (E2) hormone levels, indicating early sexual maturation. Moreover, the elevated tumor necrosis factor alpha (TNF-α) levels suggest inflammatory reactions associated with PVC treatment. Genus-level analyses of the gut microbiota in group P2 showed several genera with increased or decreased abundance. In conclusion, significant or trend-like correlations were demonstrated between the PVC content of feed and physiological, pathological, and microbiota parameters. To our knowledge, this is the first study to investigate the broad-spectrum effects of PVC microplastic exposure in rabbits. These results highlight the potential health risks associated with PVC microplastic exposure, warranting further investigations in both animals and humans.

This study investigated effects of dietary fumonisins (FBs) on gut and faecal microbiota of weaned pigs. In total, 18 7-week-old male pigs were fed either 0, 15 or 30 mg FBs (FB₁ + FB₂ + FB₃)/kg diet for 21 days. The microbiota was analysed with amplicon sequencing of the 16S rRNA gene V3-V4 regions (Illumina MiSeq). Results showed no treatment effect (p > 0.05) on growth performance, serum reduced glutathione, glutathione peroxidase and malondialdehyde. FBs increased serum aspartate transaminase, gamma glutamyl-transferase and alkaline phosphatase activities. A 30 mg/kg FBs treatment shifted microbial population in the duodenum and ileum to lower levels (compared to control (p < 0.05)) of the families Campylobacteraceae and Clostridiaceae, respectively, as well as the genera Alloprevotella, Campylobacter and Lachnospiraceae Incertae Sedis (duodenum), Turicibacter (jejunum), and Clostridium sensu stricto 1 (ileum). Faecal microbiota had higher levels of the Erysipelotrichaceae and Ruminococcaceae families and Solobacterium, Faecalibacterium, Anaerofilum, Ruminococcus, Subdoligranulum, Pseudobutyrivibrio, Coprococcus and Roseburia genera in the 30 mg/kg FBs compared to control and/or to the 15 mg/kg FBs diets. Lactobacillus was more abundant in the duodenum compared to faeces in all treatment groups (p < 0.01). Overall, the 30 mg/kg FBs diet altered the pig gut microbiota without suppressing animal growth performance.

The aim of this study was metagenomics analyses of acquired antibiotic-resistance genes (ARGs) in the intestinal microbiome of two important food-animal species in Hungary from a One Health perspective. Intestinal content samples were collected from 12 domestic pigs (Sus scrofa) and from a common carp (Cyprinus carpio). Shotgun metagenomic sequencing of DNA purified from the intestinal samples was performed on the Illumina platform. The ResFinder database was applied for detecting acquired ARGs in the assembled metagenomic contigs. Altogether, 59 acquired ARG types were identified, 51 genes from domestic pig and 12 genes from the carp intestinal microbiome. ARG types belonged to the antibiotic classes aminoglycosides (27.1%), tetracyclines (25.4%), β-lactams (16.9%), and others. Of the identified ARGs, tet(E), a bla_OXA-_48-like β-lactamase gene, as well as cphA4, ampS, aadA2, qnrS2, and sul1, were identified only in carp but not in swine samples. Several of the detected acquired ARGs have not yet been described from food animals in Hungary. The tet(Q), tet(W), tet(O), and mef(A) genes detected in the intestinal microbiome of domestic pigs had also been identified from free-living wild boars in Hungary, suggesting a possible relationship between the occurrence of acquired ARGs in domestic and wild animal populations.

The impact of short-term feeding of three distinct diets containing insect meals on the intestinal microbiota of African catfish hybrid (Clarias gariepinus × Heterobranchus longifilis) juveniles was examined. The animals received experimental diets containing 30% insect meals derived from black soldier-fly larvae (BSL) (Hermetia illucens), yellow mealworm (Tenebrio molitor) or blue bottle-fly larvae (Calliphora vicina) for 18 days. The relative abundance of the Bacillaceae, the Planococcaceae and other bacteria significantly increased (p < 0.05) in the intestinal microbiota of the BSL group and also in the pooled group of the three catfish groups that received insect meals. Several strains of the Bacillales cultured from BSL feed had higher (p < 0.05) abundance in the intestinal microbiota of the BSL group compared to those of the control group. Among these Bacillales strains, a single fosB antibiotic resistance gene was identified. In the gut resistomes of both the BSL and the control catfish groups, the tetA(P), tetB(P) and lnu(C) antibiotic-resistance determinants were detected, while fosB was detected only in the BSL group. Overall, the study showed that a short-term shift to diets containing insect meals can induce significant (q < 0.05) changes in the gut microbiota of the African catfish without the development of reduced α-diversity and without the overgrowth of bacteria pathogenic to fish.

P. aeruginosa strain NL201 was cultured from an urban water drain in a populated subway underpass as an environmental isolate for the ST111 global high-risk P. aeruginosa clone. In addition to carrying generally present intrinsic P. aeruginosa antibiotic resistance genes, this serotype O4 isolate also carries a set of additional acquired resistance determinants, including aadA2, bla_OXA-10, sul1, and an aac(6′)-Ib family gene. The NL201 isolate features the bla_PDC-3 allele, which was found to confer significantly higher catalytic efficiency against cefepime and imipenem compared to bla_PDC-1, as well as the potent P. aeruginosa virulence factors exoS, exoT, and algD. Serotype O4 isolates of the ST111 global high-risk P. aeruginosa clone have been reported from clinical samples in Canada and the USA, human stool samples in France, and environmental samples (such as cosmetic, hospital drains, and urban water drain) from various European countries. These observations underscore the effective dissemination of the ST111 global high-risk P. aeruginosa clone between different hosts, environments, and habitats, and they warrant targeted investigations from a One Health perspective on the possible routes of its spread and molecular evolution.