Chickens can acquire bacteria at different stages, and bacterial diversity can occur due to production practices, diet, and environment. The changes in consumer trends have led to increased animal production, and chicken meat is one of the most consumed meats. To ensure high levels of production, antimicrobials have been used in livestock for therapeutic purposes, disease prevention, and growth promotion, contributing to the development of antimicrobial resistance across the resident microbiota. Enterococcus spp. and Escherichia coli are normal inhabitants of the gastrointestinal microbiota of chickens that can develop strains capable of causing a wide range of diseases, i.e., opportunistic pathogens. Enterococcus spp. isolated from broilers have shown resistance to at least seven classes of antibiotics, while E. coli have shown resistance to at least four. Furthermore, some clonal lineages, such as ST16, ST194, and ST195 in Enterococcus spp. and ST117 in E. coli, have been identified in humans and animals. These data suggest that consuming contaminated animal-source food, direct contact with animals, or environmental exposure can lead to the transmission of antimicrobial-resistant bacteria. Therefore, this review focused on Enterococcus spp. and E. coli from the broiler industry to better understand how antibiotic-resistant strains have emerged, which antibiotic-resistant genes are most common, what clonal lineages are shared between broilers and humans, and their impact through a One Health perspective.

Antimicrobial resistance is increasing globally and is now one of the major public health problems. Therefore, there is a need to search for new antimicrobial agents. The food industry generates large amounts of by-products that are rich in bioactive compounds, such as phenolic compounds, which are known to have several health benefits, including antioxidant and antimicrobial properties. Thus, we aimed to characterize the phenolic compounds present in pomegranate, quince, and persimmon by-products, as well as their antioxidant and antimicrobial activities. Phenolic compounds were extracted from pomegranate, quince, and persimmon leaves, seeds, and peels using a mixture of ethanol/water (80/20). The polyphenol profile of the extracts was determined by high-performance liquid chromatography. The antioxidant activity of the extracts was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) methods. Antimicrobial susceptibility was evaluated using the Kirby–Bauer disk diffusion method. In general, leaves showed higher concentrations of phenolics than the peel and seeds of fruits. In total, 23 phenolic compounds were identified and quantified, with sanguiin and apigenin-3-O-galactoside being present in the highest concentrations. Leaf extracts of pomegranate showed higher antioxidant activities than the other components in all methods used. In general, all extracts had a greater antimicrobial activity against Gram-positive bacteria. Persimmon leaf and seed extracts inhibited a greater number of bacteria, both Gram-positive and -negative. The lowest minimum inhibitory concentration (MIC) detected among Gram-positive and -negative bacteria was 10 mg/mL for pomegranate peel and leaf extracts against Staphylococcus aureus and S. pseudintermedius and for pomegranate leaf extract against Escherichia coli. Our results reinforce the need to value food industry by-products that could be used as food preservatives and antibiotic adjuvants against multiresistant bacteria.

Hospital wastewaters often carry multidrug-resistant bacteria and priority pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). Pathogens and antibiotic resistance genes present in wastewaters may reach the natural environment facilitating their spread. Thus, we aimed to isolate MRSA from wastewater of 3 hospitals located in the north of Portugal and to characterize the isolates regarding the antimicrobial resistance and genetic lineages. A total of 96 wastewater samples were collected over six months. The water was filtered, and the filtration membrane was immersed in BHI broth supplemented with 6.5% of NaCl and incubated. The inoculum was streaked in ORSAB agar plates for MRSA isolation. The isolates susceptibility testing was performed against 14 antimicrobial agents. The presence of resistance and virulence genes was accessed by PCR. Molecular typing was performed in all isolates. From the 96 samples, 28 (29.2%) were MRSA-positive. Most isolates had a multidrug-resistant profile and carried the mecA, blaZ, aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, ermA, ermB, ermC, tetL, tetM, dfrA dfrG and cat_pC221 genes. Most of the isolates were ascribed to the immune evasion cluster (IEC) type B. The isolates belonged to ST22-IV, ST8-IV and ST105-II and spa-types t747, t1302, t19963, t6966, t020, t008 and tOur study shows that MRSA can be found over time in hospital wastewater. The wastewater treatment processes can reduce the MRSA load. The great majority of the isolates belonged to ST22 and spa-type t747 which suggests the fitness of these genetic lineages in hospital effluents.

The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6′-aph2′′, and ant4). Our results highlight that wild rabbits are reservoirs or “temporary hosts” of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances.

Background/Objectives: The food industry produces substantial amounts of fruit byproducts, which are often discarded despite their high content of bioactive compounds with potential therapeutic applications. Pyrus communis (pear) residues, which are particularly rich in phenolic compounds, represent a valuable yet underutilized resource. These byproducts have demonstrated significant antioxidant and antibacterial properties, suggesting their potential for medical and pharmaceutical applications. This review aims to provide a comprehensive analysis of the phenolic profile of P. communis byproducts, emphasizing their antioxidant and antibacterial mechanisms and their prospective use in combating oxidative stress and antibacterial resistance. Methods: A comprehensive review of the key phenolic compounds from P. communis residues was conducted using ScienceDirect and Google Scholar databases (from 2014 to 2024). Studies assessing antioxidant and antibacterial activities were reviewed, with a focus on their mechanisms of action against Gram-positive and Gram-negative bacterial pathogens. Results: A minimum of 14 distinct phenolic compounds were identified among P. communis residues. However, chlorogenic acid and catechin were identified as the primary contributors to the antioxidant activity of P. communis residues. Hydroquinone and chlorogenic acid exhibited strong antibacterial effects through membrane disruption, enzyme inhibition, and metabolic interference. Despite this potential, hydroquinone’s cytotoxicity and regulatory concerns limit its direct pharmaceutical application. Conclusions: While P. communis phenolics show promise as natural antibacterial agents, future research should address bioavailability, extraction standardization, and safe formulation strategies. Investigating their synergy with conventional antibiotics and improving stability for cosmetic applications are key steps toward their practical use. In vivo and clinical studies are crucial to validating their therapeutic potential and ensuring regulatory approval.

Sternal bursitis, a common inflammatory condition in poultry, poses significant challenges to both animal welfare and public health. This study aimed to investigate the prevalence, antimicrobial resistance, and genetic characteristics of Staphylococcus aureus isolates associated with sternal bursitis in chickens. Ninety-eight samples were collected from affected chickens, and 24 S. aureus isolates were identified. Antimicrobial susceptibility testing revealed resistance to multiple agents, with a notable prevalence of aminoglycoside resistance genes. Whole genome sequencing elucidated the genetic diversity and virulence profiles of the isolates, highlighting the predominance of clonal complex 5 (CC5) strains. Additionally, biofilm formation assays demonstrated moderate biofilm production capacity among the isolates. These findings underscore the importance of vigilant monitoring and targeted interventions to mitigate the impact of sternal bursitis in poultry production systems.