Retail meat is an important source of nutrition, but it may also serve as a reservoir of antimicrobial-resistant Gram-negative bacteria, posing a significant public health concern. This study investigated 123 retail meat samples collected from outlets in Sindh, Pakistan, including locally produced raw ground meat, imported raw ground meat, raw beef burgers, frozen chicken portions, and swabs from the outer surfaces of chicken carcasses, to identify Gram-negative bacteria and assess their antimicrobial susceptibility patterns. Gram-negative bacteria were recovered from all samples. Among the isolates, Escherichia coli was the most prevalent (37.4%), followed by Klebsiella spp. (25.2%), Salmonella spp. (17.9%), Enterobacter spp. (13.8%), Pseudomonas spp. (2.4%), Citrobacter spp. (2.4%), and Aeromonas spp. (0.8%). Identification was based on culture characteristics, Gram staining, biochemical testing, and API 20E confirmation. Antimicrobial susceptibility testing showed high levels of resistance among the isolates, particularly to ampicillin, amoxicillin-clavulanate, cefotaxime, ceftazidime, and ceftriaxone. E. coli, Klebsiella spp., Salmonella spp., and Enterobacter spp. exhibited substantial multidrug resistance, while comparatively lower resistance was observed for cefepime, gentamicin, and piperacillin-tazobactam in some species. Overall, resistance to multiple antimicrobial classes was common, indicating the widespread presence of multidrug-resistant Gram-negative bacteria in retail meat. These findings highlight the potential role of retail meat as a source of antimicrobial-resistant bacteria in the food chain and underscore the need for strengthened surveillance, improved hygiene practices, and antimicrobial stewardship in food animal production. A One Health approach is essential to help limit the spread of antimicrobial resistance across human, animal, and environmental sectors.

Escherichia coli sequence type (ST) 131 is a globally disseminated multidrug-resistant clone that poses a substantial public health threat. This study investigated the prevalence, virulence characteristics, and antimicrobial resistance profiles of ST131 among companion-animal E. coli isolates. A total of 400 E. coli isolates obtained from dogs and cats diagnosed with urinary tract infections at the National Taiwan University Veterinary Hospital between 2011 and 2019 were analyzed. Phylogenetic grouping identified 192 isolates (48.0%) belonging to phylogroup B2, which is strongly associated with ST131. Among these, 26 isolates (13.5%) were confirmed as ST131 by single-nucleotide polymorphism screening and multilocus sequence typing, and 19 isolates were selected for detailed characterization. Virulence gene analysis by multiplex PCR showed that fyuA (100.0%), traT (94.7%), iutA (89.5%), and kpsMT II (84.2%) were the most prevalent genes. Antimicrobial susceptibility testing demonstrated universal susceptibility to meropenem, whereas all isolates were resistant to amoxicillin and ampicillin. Six canine-derived isolates produced extended-spectrum β-lactamases (ESBLs) or AmpC β-lactamases. Among ESBL producers, bla gene groups blaCTX-M-1, blaCTX-M-9, and blaTEM were detected, whereas blaCMY-178 was the only AmpC gene identified. Conjugation experiments demonstrated transferability for most bla genes, except blaTEM-102, blaTEM-12, and blaCTX-M-55. Plasmid replicon typing revealed IncF (100%) and IncB/O (69%) as the predominant plasmid groups. Only two O-antigen types, O25b and O16, were detected among ST131 isolates, which carried fimH variants fimH22, fimH27, fimH30, or fimH41 subclones. These findings demonstrate the circulation of virulent and multidrug-resistant ST131 strains in companion animals in Taiwan, highlighting their potential relevance within a One Health context.

Community-acquired pneumonia (CAP) causes high pediatric mortality especially in sub-Saharan Africa. In a secondary analysis of samples from the PediCAP trial (ISRCTN63115131), we tracked gastrointestinal resistome and microbiota dynamics of 149 children (<6 years) from South Africa, Zambia, Zimbabwe and Uganda presenting with severe CAP. Patients received initial WHO-standard IV therapy before being randomized to continue IV therapy or step-down to oral amoxicillin or co-amoxiclav for different total treatment durations. Samples were obtained after starting IV antibiotics, at discharge, and at four weeks follow-up. Microbiota dynamics were strongly associated with age and country of origin with specific bacterial genera unique to each country. Oral step-down to either antibiotic regimen or duration did not show any differential effects on the gastrointestinal microbiota and resistome dynamics compared to continuous IV therapy. The data of this secondary analysis complement the primary PediCAP trial analysis, supporting earlier hospital discharge for paediatric CAP patients.

In this study, magnetic iron oxide (Fe2O4) nanoparticles with an inverse spinel structure were synthesized via the co-precipitation method under both thermal and hydrothermal conditions using Fe (II) and Fe (III) chlorides as precursors. The effects of parameters such as temperature and solvent type were investigated. Sodium hydroxide, were used as alkaline agents to adjust the pH during synthesis. To prevent nanoparticle agglomeration and improve size distribution, surface modification was performed using vinyl triethoxy silane (VTES). The morphology and structure of the synthesized nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. Fourier transform infrared spectroscopy confirmed the functional groups, while magnetic properties were analyzed by vibrating sample magnetometry. Subsequently, radical polymerization of glycidyl methacrylate (GMA) and 2-(dimethylamino) ethyl methacrylate (DMAEMA) was carried out on the modified Fe2O4 surface to form a magnetic polymer nanocomposite. The obtained nanocomposite was employed for amoxicillin drug loading under various drug-to-carrier ratios. The results indicate that the synthesized GMA/DMAEMA magnetic nanocomposites possess excellent drug-loading capability, appropriate magnetic response, and promising potential for application as an efficient targeted drug delivery system. The results of invitro release demonstrate that Poly(DMAEMA-GMA)-VTES-coated Fe2O4 nanoparticles exhibit a biphasic release profile with an initial burst followed by sustained, diffusion-controlled amoxicillin release, highlighting their suitability for prolonged drug delivery.