To address concerns about livestock as a source of antimicrobial-resistant bacteria and genes, there have been many recent efforts worldwide to study prescribing practices, optimal antibiotic use, and alternatives to antibiotic use. However, there is empirical evidence supporting the persistence of antimicrobial resistance genes at high densities in cattle pens for at least 2 years after cattle were removed. We describe a mathematical modelling framework to predict and explore the dynamics of antimicrobial-resistant enteric bacteria in food-producing animals and their immediate environments. Using the difference equation based compartmental modelling framework, we algebraically derive a formula for the relative rate of growth of antimicrobial-resistant enteric bacteria in the environment (RAMR). We demonstrate that RAMR > 1 (i.e., growth) of tetracycline-resistant Escherichia coli in feedlot environments can occur under a range of plausible conditions, even in the absence of antimicrobial use in the feedlot cattle. Our model can reproduce data observed under field conditions showing rapid growth of tetracycline-resistant E. coli in the environment despite no antimicrobials being used. Finally, we demonstrate that generic hygiene measures such as scraping pen floors are likely to reduce the density of tetracycline-resistant E. coli in the farm environment considerably, especially in cold climates. Farm environments such as beef cattle feedlots may be conducive to persistence or even growth of antimicrobial resistant bacteria under a wide range of plausible conditions, even in the absence of antimicrobial use. The system may be quite resilient, and even stringent cleaning will likely not be sufficient to eliminate resistant bacteria from the environment in some climates, especially where freeze-thaw cycles are uncommon.

Citrobacter species are increasingly recognised as significant opportunistic pathogens within the Enterobacteriaceae family, capable of causing a variety of infections, including urinary tract infections, sepsis, and neonatal meningitis. Their clinical relevance has been magnified by the rapid emergence of multidrug-resistance, particularly due to the acquisition of extended-spectrum β-lactamases and carbapenemases. Across regions, Citrobacter spp. including C. koseri implicated in severe neonatal central nervous system infection are increasingly recognised in healthcare-associated infections, while rising multidrug-resistance and carbapenemase production add to the global AMR burden. Traditional phenotypic methods often fall short in distinguishing closely related Citrobacter species, necessitating the integration of advanced genotypic techniques such as PCR, MLST, and whole-genome sequencing. This narrative review explores the phenotypic and genotypic characteristics of Citrobacter species, their role in human disease, and the mechanisms underlying their antimicrobial resistance. The review emphasises the importance of precise identification and molecular characterisation in guiding clinical management and informing public health interventions.

Research note: The effect of electron-beam irradiation on microbial load, shelf-life and color of refrigerated chicken tenders.

Consumption of poultry products continues to rise in the United States, highlighting the importance of mitigating foodborne pathogens during poultry processing. Developing new methodologies to improve the detection of pathogens within processing plants is essential to protect food safety. Growing demand for a more representative sample and desire to improve bacterial detection at low levels have led to the evaluation of new sample collection tools. Our objective was to evaluate one such tool, the MicroTally® Mitt, a polymer fabric that has shown improved microbial recovery in beef trim and turkey carcasses, by comparing it to the traditional carcass or parts rinse method for detecting total aerobic microorganisms (rapid aerobic count; RAC), Enterobacteriaceae (EB), Campylobacter, and Salmonella before and after antimicrobial interventions. Additionally, the mitt was tested for its utility in collecting a composite sample (multi-carcass mitt). Three commercial broiler processing establishments were visited twice. Whole carcass samples were collected at hot rehang (n=150) and post-chill (n=150). Wing samples were collected before and after antimicrobial application (n=136 and n=147, respectively). A total of 233 whole carcass rinses (WCRs), 233 single-carcass mitts (SC-mitts), and 117 multi-carcass mitts (MC-mitts) were collected. As expected, recovery was greatest at hot rehang for all microbial counts (RAC, EB, Campylobacter, and Salmonella) and lowest post-chill. Deep serotyping of Salmonella culture-positive samples (n=100) from hot rehang showed multiple serovars were detected in 53% (20/38) WCR, 58% (22/38) single-carcass mitt, and 50% (12/24) of multi-carcass mitt samples. For all microbial counts, the single-carcass mitt had comparable bacterial recovery to rinses in hot rehang samples. Low bacterial recovery following antimicrobial interventions prevented further sample type comparisons at other processing stages but showed processing intervention efficacy.

In-Plant Validation of Postharvest Water Sanitation Practices to Prevent Cross-Contamination in Michigan Commercial Apple Packinghouses.

ABSTRACT Oecophylla smaragdina (red weaver ant) is traditionally consumed across various regions including Mexico and Africa as a protein and nutrient‐rich food source, as well as for its medicinal properties as recognized by indigenous healers. Like other animals, ants engage in mutualistic associations with microbial symbionts residing within their bodies. These endosymbionts play critical roles in host biology, including nutritional supplementation, digestion, nitrogen recycling, and pathogen defense. Despite their importance, the gut‐specific bacterial communities of ants and their functional contributions particularly in the context of bioactive compound production remain underexplored. In this study, the gut microbiota of O. smaragdina colonies collected from India was investigated using 16S rRNA gene sequencing and biochemical characterization of culturable isolates. Several bacterial genera were identified for the first time in this species, with members of the families Enterobacteriaceae and Staphylococcaceae emerging as the most dominant. Notably, the gut bacterial profile observed in this study diverges from those reported in previous investigations, suggesting unique microbial diversity within O. smaragdina collected from India. Interestingly, some endosymbionts exhibited similarities to human gut microbiota, highlighting the potential complexity and diversity of the ant gut ecosystem. The identification of diverse and unique gut‐associated bacterial taxa in O. smaragdina highlights their potential as promising candidates for future bioprospecting and exploration of microbial metabolites with prospective health benefits.

The field experiment was conducted in 2016–2018 at the Department of Agronomy of the Poznań University of Life Sciences on the fields of the Research and Education Centre in Gorzyń, Złotniki branch. It was a single-factor experiment with six sowing dates of an ultra-early maize variety: A1—12 April, A2—26 April, A3—10 May, A4—24 May, A5—7 June, and A6—21 June. Seeds of the maize variety ‘Pyroxenia’ were used in the experiment. This variety is characterized by extremely early maturity (FAO 130), rapid initial development and elongation growth. Delaying the maize sowing date from A1 to A2 resulted in a 16.5% reduction in starch content in the silage dry matter, and a 14.6% increase in the ADF (Acid Detergent Fiber) fiber fraction. The difference in milk production per hectare between maize sown on date A1 and date A6 was 14,189.51 kg/ha, representing 97.1%. Delaying the maize sowing date led to an increase in the abundance of Clostridium spp. in silages, which are responsible for increased losses of dry matter, including starch. No butyric acid was detected in the silages as a final product of butyric fermentation. The low abundance of bacteria from the family Enterobacteriaceae in the silages indicated that they were well prepared. Silages prepared from maize sown at later dates were characterized by a higher abundance of undesirable mold fungi, which are responsible for dry matter losses, including starch. The coefficient of determination showed that 38.54% of the variation in silage starch content was explained by variation in mold abundance in the silage. According to the Flieg–Zimmer scale, all silages received a very good rating, regardless of maize sowing date.

BackgroundThe Toto Bora trial tested whether a course of azithromycin reduced rates of re-hospitalization or death in the 6 months following hospitalization among Kenyan children. We hypothesized that azithromycin would reduce enteric bacteria and increase carriage of macrolide resistance in the subsequent 3 months.MethodsKenyan children (1-59 months) hospitalized and subsequently discharged for non-traumatic conditions provided fecal samples before and 3 months after randomization to a 5-day course of azithromycin or placebo. Quantitative PCR identified enteropathogens and AMR-conferring genes in fecal samples. Generalized estimating equations assessed the impact of the randomization arm on pathogen and resistance gene detection, accounting for baseline presence and site.ResultsAmong 1,393 baseline stools, 12.4% had at least one bacterial enteropathogen, 94.7% had at least one macrolide-resistance gene, and 92.6% had at least one beta-lactamase-resistance gene identified. At month 3, children randomized to azithromycin had a 6.1% higher likelihood of carrying a macrolide resistance gene compared to placebo (adjusted prevalence ratio [aPR], 1.06; 95% Cl, 1.04–1.08; PcO.OOl). Specifically, azithromycin randomization was associated with a higher relative prevalence of erm(B) (aPR, 1.09 [95% Cl, 1.04-1.15]; P=0.001), erm(C) (aPR, 1.23 [95% Cl, 1.14-1.31]; P<0.001), msr(A) (aPR, 1.14 [95% Cl, 1.04-1.25]; P=0.007), and msr(D) (aPR, 1.07 [95% Cl, 1.03-1.11]; P=0.001). There was no difference in overall bacterial pathogen prevalence (18.9% vs 17.3%) between randomization arms, but a slightly lower proportion of children had Shigella after randomization in the azithromycin arm (3% vs. 5%, aPR, 0.79 [95% Cl, 0.62, 1.01]; P=0.063).InterpretationAzithromycin at hospital discharge was associated with higher carriage of macrolide-resistance-conferring genes in the post-discharge period compared with placebo, without significant declines in enteric pathogen carriage other than modest changes to Shigella. The potential benefits and risks of empiric azithromycin need to be considered, as children are increasingly exposed to this broad-spectrum antibiotic.

Disinfection of poultry processing wastewater using advanced oxidation processes.

Antimicrobial resistance (AMR) is a global health threat that increases the burden of infectious diseases and disproportionately affects communities of low socioeconomic status. Despite the call for community-level AMR data, prospective studies from rural sub-Saharan African communities to inform appropriate targeted interventions remain scarce. Given the role of enteric bacteria in AMR transmission dynamics, there is a need to understand the timing, risk factors, and ecological drivers of gut resistome acquisition and development during infancy. This study aimed to characterize the temporal dynamics of enteric bacterial resistomes during the first 2 years of life and to identify drivers of AMR acquisition and development in a community-based, prospective, observational birth cohort study in a rural South African community. The study aims to enroll 200 newborns and their mothers within 17 days post partum. Data on key exposures and variables include sociodemographics; perinatal and anthropometrics; feeding practices and dietary exposures; illness, medication, and vaccination history; breast milk metabolomic profiles; household socioeconomic status; maternal psychosocial and behavioral factors; hygiene and sanitation practices; and environmental exposures including hydro-meteorological variables, in-house livestock and pets, and drinking water quality. Biological samples include stools from monthly collections and diarrhea episodes for metagenomic analysis and breast milk for metabolomics. Planned analyses include assessing the infant microbiome and resistome structure (diversity, abundance, and composition) across time points and modeling associations between risk factors and AMR outcomes. Additionally, a cross-sectional community survey on knowledge, attitudes, and practices regarding antimicrobial use is conducted to inform knowledge translation through responsive dialogues, thereby developing ethnographically relevant packages for community-level AMR stewardship. Participant identification and enrollment began in August 2023. By October 2025, 167 newborns had been enrolled, with 20 having completed the 24-month follow-up. The characteristics of the enrolled participants are presented in this protocol. This study will offer a unique opportunity to generate longitudinal resistome data from a rural sub-Saharan African setting. The study is expected to contribute knowledge on the microbiome and resistome structure dynamics and trajectories associated with key risk factors of acquisition and development. In addition, co-produced ethnographically tailored educational packages, informed by knowledge, attitudes, and practices and bacterial resistome data, will drive sustainable community-centered AMR awareness interventions.

This article presents the results of a comparative analysis of intestinal microbial composition of various migratory bird species, identifying species features of microbiota formation. Between 2024 and 2025 years 183 samples (droppings and gastrointestinal tract swabs) were collected from 15 bird species in Omsk region and 207 microbial cultures were isolated. The dominance of representatives of the Enterobacteriaceae family was established (62.3%). The species specificity of microbial profiles were revealed: from a balanced community in mallard (equal proportions of Escherichia and Edwardsiella genera) to a specialized one with absolute dominance of Edwardsiella genus in the garganey. The greatest taxonomic diversity was recorded in white-fronted goose: Escherichia (38.1%), Staphylococcus (16.7%), Bacillus (14.3%) and Enterococcus (11.9%). The microbiome of greylag goose was represented by genera Hafnia (66.7%) and Escherichia (33.3%). Species analysis of seagull microbiome showed that Escherichia constituted the basis of the community in all species, but its proportion varied from 38.9% in the steppe gull to 66.7% in the gray gull. The obtained data substantiate the need for a species-specific approach when monitoring the circulation of pathogenic and opportunistic microorganisms and confirm the relevance of research within the framework of the “Unified Health” concept. The studied wild bird species, through their seasonal migrations, connect Omsk region with vast regions of Eurasia and Africa, creating pathways for the transcontinental transfer of potentially dangerous microorganisms. This work has practical significance for the development of regional veterinary and sanitary control programs and the assessment of environmental risks associated with the spread of pathogens through migratory birds.

Acute calculous cholangitis is commonly associated with biliary tract infections and is predominantly caused by enteric bacteria. Increasing antimicrobial resistance, particularly among extended-spectrum β-lactamase (ESBL)-producing Gram-negative organisms, has become a major concern in Southeast Asia, including Vietnam. Updated local microbiological data are essential to guide appropriate empirical antibiotic therapy. This retrospective multicenter study analyzed clinical and microbiological data from patients diagnosed with acute calculous cholangitis. Bacterial culture results were collected from Hanoi Medical University Hospital, Thanh Nhan Hospital, and E Hospital between June 2022 and December 2024. Gram-negative bacteria were predominant (286/366, 78.14%), while Gram-positive bacteria accounted for 80/366 (21.86%). Escherichia coli was the most frequently isolated organism (133/366, 36.34%), of which 77/133 (57.89%) were ESBL producing. Klebsiella spp. accounted for 60/366 (16.39%), with 17/60 (28.33%) ESBL-producing isolates. Enterococcus spp. (n = 80) exhibited high susceptibility to vancomycin (69/80, 86.15%) and complete susceptibility to linezolid (80/80, 100%). This multicenter study highlights evolving pathogen distributions and antimicrobial resistance patterns in acute calculous cholangitis in Vietnam. These findings provide valuable evidence to support the optimization of empirical antibiotic regimens in clinical practice.

The combination of matrine and tannic acid protects chickens against intestinal infection caused by Salmonella Typhimurium.

This study aimed to microbiologically characterize baru nuts, a seed widely consumed in Brazil with growing relevance in the export market. Analyses were conducted for mesophilic and thermophilic aerobic spore-forming bacteria, total mesophilic aerobes, Enterobacteriaceae, Salmonella, Staphylococcus aureus, lactic acid bacteria, molds, and yeasts. Subsequently, Enterobacteriaceae isolates were identified by MALDI-TOF. It was found that in all baru nut samples, counts of S. aureus, lactic acid bacteria, and thermophilic aerobic spore-forming bacteria were below the quantification limits (<2log10CFU/g, <1log10CFU/g, and 1log10spore/g, respectively). All samples had counts above the quantification limits for mesophilic aerobic spore-forming bacteria (>1log10CFU/g) and total mesophilic aerobes (>2log10CFU/g). Enterobacteriaceae counts were below 2.22log10CFU/g, while molds and yeasts reached up to 2.70log10CFU/g. Identification of 17 species from the Enterobacteriaceae family revealed potentially pathogenic microorganisms that serve as important biological markers, including emerging and multidrug-resistant species. Franconibacter pulveris was the most abundant, representing 41.9% of all isolates, followed by Pseudescherichia vulneris and Pantoea septica, each accounting for 10.5%. In addition, Cronobacter sp. (3.8%) and Salmonella sp. (1.0%) were identified-both pathogens commonly associated with nuts and low-water-activity products. The presence of these sanitation-relevant and understudied species highlights the need for ongoing microbiological monitoring and a better understanding of the microbial ecology in food products. PRACTICAL APPLICATIONS: This study provides information on the microorganisms found in baru nuts. These results can help producers improve handling and processing practices, contributing to safer products for consumers and supporting the development of quality standards for this native Brazilian nut.

Comparative genomics and e-pharmacophore search to identify novel therapeutic targets in the druggable genome of MDR Providencia stuartii.

ABSTRACTBackgroundSpontaneous bacterial peritonitis (SBP) remains a life‐threatening complication in cirrhotic patients with refractory ascites. Evidence for rifaximin (RFX) in SBP prevention and prognosis is lacking in Japan. We investigated the effect of RFX on prognosis and recurrence of SBP and evaluated the prognostic role of oral health within the oral–gut–hepatic axis.MethodsThis single‐center, retrospective study included 142 patients with a first SBP episode. Patients were stratified into an RFX‐treated group and a non‐RFX group. Outcomes included 90‐day survival, SBP recurrence, and cirrhosis‐related complications. Oral health status and acid‐suppressive therapy were also evaluated.ResultsForty‐seven patients received RFX. Ascitic culture positivity was comparable between groups, but RFX‐treated patients had fewer enteric bacteria and more oral flora (p = 0.0033). Ninety‐day survival was significantly higher with RFX (85.1% vs. 60.0%, p = 0.0023). The 12‐month recurrence rate was markedly lower in the RFX‐treated group (10.4% vs. 63.2%; HR 0.19, 95% CI 0.09–0.40). Oral contamination independently predicted overt hepatic encephalopathy (HR 2.56) and variceal rupture (HR 6.72). Denture use was an independent predictor of mortality (HR 2.04, 95% CI 1.23–3.38).ConclusionRifaximin use was associated with higher short‐term survival and lower SBP recurrence in cirrhotic patients with refractory ascites. Oral contamination and denture use were associated with adverse outcomes, providing novel clinical evidence for the oral–gut–hepatic axis. Integration of RFX therapy with oral hygiene interventions may offer a comprehensive strategy to improve prognosis in cirrhosis.

To investigate the bacteriological spectrum and antimicrobial resistance of intraoperative purulent samples from patients with acute appendicitis and provide evidence for empirical therapy. A retrospective study was performed on 110 patients treated between 2021 and 2023. Intraoperative samples were cultured, and susceptibility testing against 20 antibiotics was conducted according to CLSI guidelines. Ninety-eight isolates were obtained. Gram-negative bacteria predominated (91.84%), mainly Escherichia coli (71.43%), Klebsiella pneumoniae (7.14%), and Pseudomonas aeruginosa (6.12%). E. coli showed complete susceptibility to meropenem, imipenem, and amikacin, high susceptibility to piperacillin-tazobactam (97.14%) and cefoxitin (88.57%), but high resistance to amoxicillin (94.29%). K. pneumoniae was universally susceptible to carbapenems, cefoxitin, and amikacin, but resistant to amoxicillin, piperacillin, ticarcillin, cephalothin, and gentamicin. P. aeruginosa was fully susceptible to carbapenems, cefoxitin, amikacin, and piperacillin-tazobactam, but resistant to most first- and second-generation cephalosporins and several aminoglycosides. Gram-negative enteric bacteria, particularly E. coli , are the dominant pathogens in appendiceal infections. Carbapenems and amikacin retain excellent efficacy, whereas amoxicillin and several commonly used antibiotics show poor activity. Piperacillin-tazobactam represents a reasonable first-line empirical choice, while carbapenems should be reserved for severe infections or patients at risk for resistant organisms. These findings highlight the importance of local resistance surveillance to guide institution-specific antibiotic protocols.

Antimicrobial resistance has increased globally among bacteria within the family Enterobacteriaceae. The present study aimed to identify Enterobacteriaceae species isolated from wild animals in Vietnam, including sika deer, chevrotain, bamboo rat, binturong, otter, palm civet, and wildcat, and to evaluate their antimicrobial susceptibility profiles. A total of 20 samples from wild animals were subjected to biochemical characterization and species identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility was determined by the disc diffusion method according to Clinical and Laboratory Standards Institute guidelines. A total of 42 Enterobacteriaceae isolates were identified, including Escherichia coli (E. coli; 71.4%), Enterobacter asburiae, Enterobacter bugandensis, Enterobacter hormaechei, Escherichia fergusonii, Klebsiella aerogenes, Klebsiella pneumoniae, Klebsiella variicola, and Proteus mirabilis. Most isolates were susceptible to norfloxacin (92.9%) and trimethoprim/sulfamethoxazole (88.1%), and no resistance to imipenem was detected. In contrast, resistance to ampicillin was the most common at 52.4%, followed by ciprofloxacin at 30.9%, cefotaxime at 26.2%, tetracycline at 23.8%, chloramphenicol at 21.4%, and streptomycin at 21.4%. Intermediate susceptibility was observed for doxycycline (9.5%), cefoxitin (9.5%), norfloxacin (7.1%), and gentamicin (4.8%). Among the isolates, 76.7% of E. coli and 91.7% of the remaining Enterobacteriaceae species demonstrated resistance to at least one antimicrobial agent. Seventeen distinct resistance patterns were identified among E. coli, whereas five patterns were observed among other species. Overall, 12 isolates (28.6%) were classified as multidrug-resistant, exhibiting resistance to three or more antimicrobial classes. The present findings indicated that wild animals in Vietnam carried different Enterobacteriaceae species, including multidrug-resistant strains. Consequently, wild animals could serve as a reservoir for antimicrobial-resistant bacteria, emphasizing the need for ongoing surveillance within a One Health approach.

ABSTRACT Bisphenol A (BPA), a widespread endocrine-disrupting chemical and an emerging environmental contaminant, poses significant threats to ecosystems and human health. The present study identifies a bacterial strain affiliated with Enterobacteriaceae family Silvania sp. (GenBank Accession No. PP930832) isolated from industrial effluent, capable of efficiently degrading BPA. High-Performance Liquid Chromatography (HPLC) analysis confirmed the strain’s degradation potential of 62% within 24 h at a concentration of 500 mg/L. Optimization by Design Expert 12.0 resulted in optimum values of pH 9.0, temperature 37.07°C, and inoculum concentration (4% v/v). Mass spectrometric analysis revealed the formation of putative intermediate metabolites during BPA degradation, including ions tentatively assigned to benzoic acid – related aromatic fragments, along with additional low-molecular-weight products indicative of progressive aromatic ring cleavage. The biodegradation pathway is proposed to proceed via enzymatic hydroxylation and oxidation reactions, leading to structural destabilization of BPA and its conversion into benzoic acid as a key intermediate. Subsequent transformations may yield cyclohexa-1,3-diene like intermediates that could potentially enter central metabolic pathway such as the β-ketoadipate and tricarboxylic acid (TCA) pathways. However, complete mineralization to CO₂ and H₂O was not directly verified in this study. These findings underscore the potential applicability of isolated species as an effective biological agent for BPA remediation and highlight its promise for sustainable environmental cleanup strategies.

BackgroundThe role of the gut microbiome and specific enteric bacteria in influencing the development of colorectal cancer (CRC) remains incompletely understood. Recently, it was shown that human CRC-derived strains of Clostridioides difficile were capable of inducing colonic tumorigenesis in a susceptible mouse model. We hypothesized that C. difficile contributes to the pathogenesis of human CRC and would be enriched in CRC tumors compared to paired normal tissues from the same individual.MethodsWe analyzed matched tumor/normal tissue samples from a cohort of 108 individuals presenting to a tertiary care hospital in Kuala Lumpur, Malaysia, for CRC resection between 2013 and 2014. We assessed the prevalence of C. difficile detection using 16S rRNA amplicon sequencing with high-resolution taxonomic assignment as well as culture and PCR.ResultsWe found that detection of C. difficile was prevalent (38% of individuals), but of low abundance (tumor median relative abundance 0.01%, paired normal 0.006% [P = .4]). Detection of C. difficile was more prevalent in individuals with biofilm-positive tumor tissues than biofilm-negative (ie, 81% of C. difficile–positive individuals were biofilm-positive vs 63% of C. difficile–negative individuals [P = .04]). Additionally, in exploratory analyses, we describe patterns of taxonomic and inferred functional pathway differences between C. difficile–positive and C. difficile–negative groups.ConclusionsThese findings suggest that C. difficile is frequently present in low abundance in the tumor microbiome with a potentially significant impact on community composition and function.