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The role of wildlife, including birds, in antimicrobial resistance is nowadays a speculative topic for the scientific community as they could be spreaders/sources of antimicrobial resistance genes. In this respect, we aimed to investigate the antimicrobial susceptibility of 100 commensal Escherichia coli strains, isolated from wild birds from an Umbrian rescue centre and admitted to the Veterinary Teaching Hospital of Perugia (Central Italy) mainly for traumatic injuries. The possible presence of Salmonella spp. and ESBL-producing E. coli was also estimated. The highest prevalence of resistance was observed for ampicillin (85%) and amoxicillin/clavulanic acid (47%), probably due to their extensive use in human and veterinary medicine. Seventeen out of the one hundred E. coli isolates (17%) displayed a multidrug-resistance profile, including the beta-lactam category, with the most common resistance patterns to three or four classes of antibiotics. Resistance to ciprofloxacin, cefotaxime and ceftazidime exhibited values of 18%, 17% and 15%, respectively. Eight out of the hundred E. coli isolates (8%) were ESBL and seven showed multidrug resistance profiles. Salmonella spp. was not isolated. Resistance to third-generation cephalosporins, also detected in long-distance migratory birds, suggests the need for monitoring studies to define the role of wild birds in antimicrobial resistance circuits.

As a result of public health concerns regarding antimicrobial resistance in animal-based food products, conventional poultry companies have turned to 'raised without antibiotics' (ABF) and organic farming systems. In this work, we evaluated the influence of rearing systems on antimicrobial susceptibility in E. coli and extended-spectrum β-lactamase (ESLB) E. coli diffusion in conventional (C), organic (O) and antibiotic free (ABF) chicken samples collected from cloacal swabs and skin samples in slaughterhouse. The E. coli isolates from conventional (135), antibiotic-free (131) and organic (140) samples were submitted to the Kirby-Bauer method and ESBL E. coli were analyzed by the microdilution test. Conventional samples showed the highest number of strains resistant to ampicillin (89.6%; p < 0.01), cefotaxime (43.7%; p < 0.01), nalidixic acid (57.8%; p < 0.01), ciprofloxacin (44.4%; p < 0.001), and trimethoprim/sulfamethoxazole (62.2%; p < 0.01), with patterns of multi-resistance to three (35.1%) and to four antimicrobials (31.3%), whereas most of the E. coli isolated from antibiotic-free and organic chicken samples revealed a co-resistance pattern (29.2% and 39%, respectively). The highest number of ESBL E. coli was observed in conventional, in both cloacal and skin samples and the lowest in organic ( p < 0.001). Our results are consistent with the effect of conventional farming practices on E. coli antimicrobial resistance and ESBL E. coli number, due to the use of antimicrobials and close contact with litter for most of the production cycle.

This study investigated the effects of a short-term administration of bovine colostrum (BC) in a TNBS model of induced colitis. Colitis was induced by TNBS treatment after seven days of BC (BC group, n = 12) or saline (control group, n = 12) administration in mice. Clinical signs, histopathological characteristics, expression levels of Toll-like receptor 4 (TLR4), pro- and anti-inflammatory cytokines, and microbial composition were assessed. BC was well tolerated and did not induce any histological damage or clinical symptoms. After TNBS treatment, the BC group showed a reduction in body weight (BW) loss compared to Control ( p < 0.05). Moreover, expression levels of TLR4 ( p < 0.01), Interleukin-1β (IL-1β; p < 0.001), Interleukin-8 (IL-8; p < 0.001), and Interleukin-10 (IL-10; p < 0.001) were lower in mice administered with BC. Finally, Escherichia coli were higher ( p < 0.05), while Enterococci ( p < 0.001), Lactobacillus spp. ( p < 0.001), and Bifidobacterium spp. ( p < 0.05) were lower in Control than BC group. This study confirms that pre-treatment with BC modulates the expression of genes and the count of microbes involved in the etiopathogenesis of colitis.