Search Results (495)

Background: Rayeb milk and yogurt provide lasting energy and maintain hydration during fasting. The surge in demand during Ramadan (the holiest month of the year across the Islamic world) increases production to meet consumer needs, potentially compromising strict adherence to safety standards. Data on the prevalence and characterization of Escherichia coli (E. coli) in fermented dairy products during Ramadan, a model of increased batch turnover, remain to be investigated. Objectives: This study aimed to identify the AMR profile and molecularly characterize the AMR and virulence traits of E. coli isolates prevalent in fermented milk products. Methods: A total of 34 E. coli isolates, representing eight distinct serotypes, were recovered from 150 fermented milk samples; rayeb milk (n = 75) and yogurt (n = 75) collected from densely populated towns in the Dakahlia Governorate, Egypt. Results: The most prevalent serotypes were O153:H2, O125:H21, and O119:H6, followed by O111:H2, O26:H11, and O127:H6. The virulence genes stx1 and stx2 were detected in 76.47% of isolates, while eaeA and hlyA were found in O26:H11, O119:H6, and O55:H7 serotypes. In total, 73.53% (25/34) of E. coli isolates were classified as MDR, while 26.47% (9/34) exhibited XDR. Resistance was most prevalent against penicillin, tetracycline, ciprofloxacin, ampicillin, kanamycin, chloramphenicol, and trimethoprim. The kan, dfrA, blaOXA-1, tetA(A), and van(A) AMR genes were positive in 70.59%, 67.65%, 61.76%, 100%, and 47.06% of isolates, respectively. Conclusions: Identified E. coli AMR and virulence panels reflect that production pressure can challenge strict adherence to hygiene control measures and cold-chain maintenance. Subsequently, authorities must enforce proper quality assurance protocols to minimize the risk of food poisoning. Full article

Antimicrobial resistance (AMR) in Escherichia coli (E. coli) from food-producing animals constitutes a substantial public health concern. This study characterized antimicrobial resistance profiles, phylogenetic diversity, virulence-gene distribution, and plasmid-borne extended-spectrum β-lactamase (ESBL) determinants of E. coli isolates recovered from water buffaloes with subclinical mastitis. Among the 54 ESBL-producing E. coli isolates, all were resistant to ampicillin and cefotaxime. High resistance rates were also observed for cephalothin (75.9%), trimethoprim–sulfamethoxazole (74.0%), ceftiofur (70.4%), florfenicol (68.5%), and cefazolin (63.0%). Lower resistance was recorded for colistin sulfate (40.7%), enrofloxacin (33.3%), and gentamicin (25.9%). Phylogenetic analysis of ESBL producers identified phylogroup B1 (42.6%) as predominant, followed by groups A (29.6%) and D (25.9%). Multilocus sequence typing (MLST) revealed that ST50 (20.4%) was the most common sequence type, and serogroup O150 was dominant (70.4%). Virulence genes, such as iss (81.5%), astA (59.3%), and espP (38.9%), were frequently detected among ESBL isolates. ESBL genes were predominantly bla_CTX-M-1 (27.8%) in all isolates, while the narrow-spectrum β-lactamase genes bla_TEM-1 (55.6%) and bla_OXA-10 (14.8%) were also commonly co-detected. Bioinformatic analysis predicted that all ESBL genes were associated with plasmid-derived contigs, with the predicted plasmid size ranging from approximately 32 to 187 kb and belonging to IncFIB, IncFIA, IncI1, IncFIA + I1, and IncFII replicon types. Conjugation frequencies ranged from 4.8 × 10⁻⁷ to 4.1 × 10⁻², and plasmids were predicted to carry additional resistance genes mediating resistance to chloramphenicol (floR), sulfonamides (sul1, sul3), tetracyclines (tet(A) and tet(B)), and trimethoprim (dfrA1, dfrA12). The co-carriage of ESBL genes with additional antimicrobial resistance and virulence determinants suggests the potential role of water buffaloes as reservoirs of clinically relevant resistance traits that may disseminate through horizontal gene transfer. Full article

Wastewater treatment plants represent a primary source of environmental dissemination of multidrug-resistant (MDR) bacteria, underscoring the urgent need for in-depth investigation of these organisms. While the resistome of MDR bacteria has been extensively studied, there remains a critical gap in understanding the role of plasmid-borne genes encoding adaptive metabolic functions. We isolated two MDR strains from municipal wastewater, Klebsiella sp. KOS9 and Pseudomonas veronii Yu15, both exhibiting resistance to antibiotics, including ampicillin, cefazolin, kanamycin, streptomycin, erythromycin, chloramphenicol, tetracycline, and ciprofloxacin. The plasmids of these strains harbored genes encoding aliphatic amidases, as well as antibiotic resistance genes (ARGs) and enzymes involved in glycogen and dTDP-L-rhamnose biosynthesis, which may contribute to virulence. In Klebsiella sp. KOS9 a single acetamidase operon, was found on the megaplasmid, along with copper and silver resistance genes. P. veronii Yu15 harbored an operon containing the acetamidase and formamidase genes on the chromosome, as well as a phylogenetically distant acetamidase operon on the conjugative megaplasmid. Both strains exhibit acetamidase activity and P. veronii Yu15 was able to utilize acetamide and formamide as sole nitrogen sources. The occurrence of ARGs and adaptive accessory genes on plasmids likely enhances the competitiveness and environmental flexibility of these MDR bacteria. Full article

This study presents an exploratory reinforcement learning (RL)-based simulation framework for examining antimicrobial resistance (AMR) dynamics under repeated exposure to a non-antibiotic stressor, using copper as a simplified model compound. The objective is not to provide mechanistic or predictive insight into microbial evolution, but to evaluate how alternative sequential decision-making strategies perform within a constrained and transparent simulation environment. Three agent strategies were compared: random action selection, a rule-based heuristic, and a tabular Q-learning agent. Simulations were conducted over fixed 40-cycle episodes in which agents adjusted copper exposure in response to evolving resistance-related state variables. Across experimental runs, the Q-learning agent exhibited lower cumulative resistance burden, measured by area under the curve (AUC) of minimum inhibitory concentration (MIC) trajectories for chloramphenicol and polymyxin B, while maintaining lower cumulative copper exposure relative to baseline strategies. The rule-based agent demonstrated intermediate performance, whereas the random agent showed greater variability and less stable trajectories. These findings reflect differences in simulated control behavior within a simplified stochastic system. Overall, this work introduces an interpretable reinforcement learning simulation tool intended to support comparative evaluation of adaptive versus static strategies in antimicrobial pressure management under limited observability. Full article

A pathogenic bacterium strain, LBK2, was isolated from giant spiny frog (Quasipaa spinosa) tadpoles infected with perforation disease in this study. Pathogenic strain LBK2, a Gram-negative bacterium with a certain degree of infectivity, was demonstrated to cause anorexia, lethargy, epidermal necrosis, and abdominal perforation in tadpoles in artificial infection experiments. The identification results of 16S rDNA gene sequencing showed that pathogenic strain LBK2 was identified as Pseudomonas sp. Virulence gene identification displayed that strain LBK2 carried three virulence genes: aer, epr, and fla. Finally, the antibiotic susceptibility testing of 11 antibiotics suggested that strain LBK2 was highly sensitive to nine antibiotics, including chloramphenicol, enrofloxacin, and rifampicin, but was resistant to erythromycin, sulfamethoxazole/trimethoprim, and low-concentration trichloroisocyanuric acid. This study determined the pathogenicity of Pseudomonas sp. to giant spiny frog tadpoles based on histopathological analysis and virulence factor carriage, and the drug susceptibility testing further provided a scientific basis for the selection of drugs in the prevention and treatment of abdominal perforation disease in giant spiny frog tadpoles. Full article

Background/Objectives: The Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM) conducts longitudinal monitoring of antimicrobial resistance (AMR) in indicator bacteria from food-producing animals. For Escherichia coli from healthy pigs, slaughterhouse-based sampling has been conducted for approximately a decade, yielding a substantial accumulation of MIC data. While JVARM reporting has traditionally focused on annual resistance proportions by drug, the availability of long-term data enables investigation of cross-drug relationships, including MIC similarity and co-resistance patterns. This study aimed to (i) identify the co-resistance structure among antimicrobial agents using MIC- and phenotype-based similarity measures and (ii) identify drug resistances most strongly associated with multidrug resistance (MDR). Methods: We analyzed broth microdilution MIC data obtained annually for E. coli isolates from healthy pigs in the JVARM program in Japan between 2012 and 2023. Antimicrobial resistance was classified from MIC results and annual resistance prevalence was calculated for each antimicrobial. For the co-resistance and MDR analyses, isolate-level data were pooled across the full study period. To identify co-resistance structure, we performed hierarchical clustering using (i) correlation-based similarity of MIC profiles and (ii) Jaccard similarity of binary resistance profiles (resistant/susceptible classification). Multidrug resistance (MDR; ≥3 antimicrobial classes) was further modeled using XGBoost with each drug resistance as a predictive feature, and feature contributions were evaluated using gain, permutation importance, and SHAP values. We also examined how SHAP-based attributions varied when the outcome definition was set to ≥1-, ≥2-, or ≥3-class resistance. Results: Within the study period, resistance remained highest for tetracycline and moderate for streptomycin, ampicillin, sulfamethoxazole–trimethoprim, and chloramphenicol, whereas resistance to other agents was low. MIC-based correlation analysis revealed coordinated variation among ampicillin, sulfamethoxazole–trimethoprim, streptomycin, chloramphenicol, and tetracycline. Separately, Jaccard similarity of binary resistance profiles identified two closely positioned co-resistance groupings (Ampicillin/Streptomycin/Tetracycline and chloramphenicol/sulfamethoxazole–trimethoprim). Ampicillin was identified as the medoid in both MIC-based and resistance-profile similarity spaces, with streptomycin also positioned near the center in both structures. In the XGBoost model for MDR (≥3 classes), ampicillin resistance was consistently the highest-contributing feature when evaluated by gain, permutation importance, and SHAP. When we examined how SHAP-based attributions varied across outcome definitions (≥1-, ≥2-, and ≥3-class resistance), feature importance largely followed resistance prevalence at ≥1–≥2 classes (tetracycline highest) but shifted at ≥3 classes to ampicillin as the top feature. Conclusions: Both MIC-based and phenotype-based analyses revealed co-resistance structures. Under the MDR definition used in this study, explainable machine-learning analyses showed that ampicillin resistance emerged as a leading resistance feature associated with MDR. Because these findings are associative rather than causal, further work will be needed to clarify mechanisms. These findings have important implications for antimicrobial resistance control in the Japanese pig sector, indicating that stewardship strategies may need to be tailored according to antimicrobial class and underlying co-resistance structure. Full article

Pasture-based farming systems remain understudied as a source of antibiotic-resistant bacteria and antagonistic yeasts under low-input management. In this study, soil, feed, and freshwater samples from Lithuanian farms were analyzed to characterize resistance phenotypes and inhibitory interactions among cultivable microorganisms. Bacterial and yeast isolates, representing 14 and 9 genera, respectively, were identified using molecular methods. Bacterial isolates recovered under antibiotic-selective conditions exhibited resistance to at least one of four antibiotics (ampicillin, streptomycin, tetracycline, chloramphenicol), with 41% showing multidrug resistance and the highest frequencies observed for ampicillin (59%) and streptomycin (48%). Microbial distribution was habitat-specific, with soil containing the highest diversity of antibiotic-resistant bacteria and feed samples harboring the greatest abundance of yeasts. Functional assays demonstrated consistent antagonistic activity of several Wickerhamomyces anomalus strains against susceptible yeasts and antibiotic-resistant Bacillus spp. These findings highlight the coexistence of resistance and antagonistic traits in pasture-associated microbiota and suggest their potential interaction under controlled conditions. Full article

Antimicrobial resistance in microorganisms associated with fermented foods is increasingly recognized, yet rapid methods to characterize antibiotic response dynamics remain limited. This study evaluates antibiotic susceptibility and physiological response patterns of kombucha-associated acetic acid bacteria and motile Escherichia coli using optical nanomotion detection (ONMD), a label-free technique that quantifies single-cell mechanical activity. Two cellulose-producing species (Komagataeibacter xylinus and K. rhaeticus), one non-cellulose-producing species (K. melaceti), and E. coli were exposed to ampicillin, ciprofloxacin, and chloramphenicol. Minimum inhibitory concentrations (MICs) were determined prior to time-resolved ONMD analysis. Susceptible strains exhibited progressive suppression of confined nanomotion consistent with MIC-defined susceptibility, whereas resistant profiles maintained sustained mechanical activity. Chloramphenicol initially induced persistent or increased nanomotion at 120 min; however, extending the observation to 180 min revealed delayed suppression in susceptible strains, demonstrating that bacteriostatic antibiotics require longer observation windows for accurate ONMD classification. In motile E. coli, ONMD revealed both intracellular nanomotion puncta and swimming trajectories, which were progressively attenuated following antibiotic exposure. These findings demonstrate that ONMD complements conventional susceptibility testing by resolving time-dependent suppression of both translational motility and intracellular nanomechanical activity at the single-cell level. Full article

The increasing occurrence of antibiotic residues in poultry meat represents a serious food safety concern associated with antimicrobial resistance and potential risks to human health. This study investigated the effects of electron beam irradiation on antibiotic residues and nutritional quality parameters of poultry meat. All experiments and data collection were carried out in 2025. Fresh poultry samples were irradiated using an ILU-10 pulsed linear electron accelerator at doses of 2, 4, 6, 8, and 10 kGy. Antibiotic residues were determined by HPLC-DAD, amino acid composition was analyzed using HPLC, and fatty acid profiles were evaluated by gas chromatography. Electron beam irradiation produced significant dose-dependent changes in the chemical composition of poultry meat. Total amino acid content decreased progressively with increasing irradiation dose, with reductions of up to 60–73% at 10 kGy depending on tissue type. Branched-chain and essential amino acids showed similar trends. Fatty acid analysis revealed a shift toward higher proportions of saturated fatty acids and a decline in monounsaturated and polyunsaturated fatty acids. The PUFA/SFA ratio decreased from 0.48 in control samples to 0.25 at 10 kGy. Tetracycline residues were not detected in any samples, whereas chloramphenicol residues were present in control meat but were progressively reduced after irradiation and became undetectable at doses ≥ 8 kGy. These results demonstrate that electron beam irradiation can effectively reduce antibiotic residues in poultry meat; however, higher irradiation doses may significantly alter amino acid and lipid composition. Therefore, optimization of irradiation parameters is necessary to balance improvements in food safety with the preservation of nutritional quality for the production of safe and sustainable food products. Optimization of irradiation parameters is therefore necessary to balance food safety benefits with preservation of nutritional quality. Furthermore, this research contributes to the achievement of Sustainable Development Goal (SDG) 2, while the obtained results also support SDG 3 by promoting safer food systems and protecting public health. Full article

Objectives: Multidrug-resistant (MDR) Pseudomonas aeruginosa represents a major clinical challenge, driven in part by resistance–nodulation–division (RND) efflux pumps that reduce intracellular antibiotic concentrations and limit the efficacy of many antibacterial agents, including fluoroquinolones. The aim of this study was to identify and characterize TXA11114 as a small-molecule efflux pump inhibitor (EPI) capable of restoring the activity of the fluoroquinolone levofloxacin against MDR P. aeruginosa. Methods: The antibacterial activity of the TXA11114–levofloxacin combination was evaluated using minimum inhibitory concentration (MIC) assays against panels of clinical isolates. Mechanistic studies included levofloxacin accumulation assays, ethidium bromide accumulation assays, outer-membrane permeability measurements, and whole-genome sequencing of mutants with altered potentiation phenotypes. In vivo efficacy was evaluated in murine thigh and lung infection models, while preliminary safety and drug-like properties were assessed using cytotoxicity assays and in vitro ADME profiling. Results: The TXA11114–levofloxacin combination produced > 1 log₁₀ CFU reductions in bacterial burden in murine thigh and lung infection models, exceeding the activity of levofloxacin monotherapy. TXA11114 markedly potentiated levofloxacin activity, producing substantial reductions in levofloxacin MIC values across multiple MDR clinical isolates, and also enhanced the activity of several additional efflux pump substrates, including β-lactams, tetracyclines, chloramphenicol, and trimethoprim–sulfamethoxazole. Mechanistic experiments demonstrated increased intracellular accumulation of efflux substrates without evidence of nonspecific membrane disruption, and mutations in ompH were associated with altered potentiation phenotypes. Conclusions: The TXA11114–levofloxacin combination produced significantly greater bacterial reductions than levofloxacin monotherapy in murine infection models. Levofloxacin was selected because fluoroquinolone resistance in P. aeruginosa is frequently driven by efflux-mediated mechanisms. While this study focused on levofloxacin potentiation, future work will evaluate additional efflux pump substrates and further define the molecular target of TXA11114. Full article

Lubricating oil (LO) is manufactured in various formulations for different applications. The inappropriate disposal of petroleum hydrocarbons can increase soil contamination, promoting deleterious environmental and human health impacts. More specifically, following prolonged exposure, LO contaminants are known to have carcinogenic and neurotoxic effects in humans. Bioremediation provides an effective and attractive strategy to expedite the clean-up processes of LO contaminants. We isolated and identified environmentally adapted strains of Pseudomonas aeruginosa, Pseudomonas putida, and Proteus vulgaris from Houston watershed bayou soils. Interestingly, all three exhibited increased resistance, vis-a-vis surrogate strains, to various antibiotic challenges (of chloramphenicol, tetracycline, kanamycin, penicillin, streptomycin, etc.) and increased biofilm formation ranging from 1.6 to 6.7-fold. In fact, all three environmental strains were significantly better at producing enhanced biofilm formation in the presence of spent LO rather than clean LO as well as outproducing biofilm made by the surrogate strains. Finally, the environmental isolates P. aeruginosa, P. putida, and P. vulgaris demonstrated an enhanced ability to sequester clean (2-, 2.5- and 1.14-fold) and spent (1.4-, 1.5, and 1.2-fold) LO when compared to their commercially acquired surrogate reference strains. Our three environmentally isolated organisms from Houston watershed soils appeared to be environmentally adapted to tolerate LO exposures. In the presence of LOs, all three environmentally isolated strains exhibited enhanced growth, enhanced biofilm production, and improved bioaccumulation of LOs relative to commercial reference strains. Taken together, environmentally adapted organisms can promote the bioremediation of contaminants threatening our environment and, potentially, human health. Full article

Antimicrobial resistance (AMR) emerges and circulates across interconnected human, animal, food, and environmental reservoirs; however, food fermentation systems remain underexplored as indicators of local AMR pressure, even though artisanal dairy fermentations may function as natural sentinels of AMR. In this study, we used an artisanal dairy fermentation chain as a One Health model to investigate whether environmentally exposed lactobacilli can reflect stage-associated shifts in resistance. A total of 1.085 isolates representing 16 Lactobacillus species were recovered from the same artisanal dairy matrix at two fermentation stages: day 5 (“Tyrovolia”; n = 518) and day 30 (“Kopanisti”; n = 567). Susceptibility to 14 antibiotics was evaluated by broth micro-dilution, and L. acidophilus was further screened for selected resistance genes. Overall resistance increased significantly from 69.88% (362/518) at day 5 to 77.25% (438/567) at day 30 (p = 0.0059), while multidrug resistance rose from 37.57% to 60.73% of resistant isolates (p < 0.001). Across the 224 species–antibiotic combinations examined, 129 (57.58%) showed an increased upper MIC limit at day 30, and resistance increased significantly for 9 of the 14 antibiotics tested, with the largest rises observed for metronidazole (RR = 7.67), chloramphenicol (RR = 5.74), quinupristin/dalfopristin (RR = 4.11), vancomycin (RR = 2.78), and trimethoprim (RR = 2.43). In contrast, erythromycin and oxytetracycline resistance declined significantly at the ripened stage. In L. acidophilus, 21 resistance genes were detected in 14/70 day-5 isolates and 19 genes in 13/71 day-30 isolates, but marked genotype–phenotype discordance was observed, including matrix-dependent expression patterns for tetM, ermB, and blaTEM. Collectively, these findings show that environmentally exposed artisanal dairy fermentations can enrich resistance phenotypes and may serve as sensitive sentinels of AMR dynamics at the human–animal–environment interface. Full article

Background/Objectives: The increasing prevalence of antimicrobial-resistant bacteria highlights the need for improved methodologies to evaluate antimicrobial activity beyond conventional minimum inhibitory concentration testing. While resazurin-based assays are widely used for minimum inhibitory concentration determination due to their simplicity and sensitivity, minimum bactericidal concentration assessment still relies on labor-intensive colony-forming unit counting. The objective of this study was to develop and validate a resazurin-based microwell assay capable of determining both the minimum inhibitory concentration and the minimum bactericidal concentration without routine plate counting, thereby simplifying bactericidal evaluation. Methods: A two-step resazurin-based fluorescence assay was designed and performed in microplates. After determining the minimum inhibitory concentration using resazurin as a metabolic indicator, well-showing inhibited bacterial growths were subjected to a regrowth phase by transferring aliquots into fresh antimicrobial-free medium containing resazurin. This additional step allowed discrimination between reversible metabolic inhibition and irreversible bacterial death. The method was evaluated using ciprofloxacin and chloramphenicol against four bacterial species: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Minimum bactericidal concentration values obtained using this assay were compared with those obtained through conventional colony counting on agar plates. Results: Minimum bactericidal concentration values obtained using the two-step fluorescence assay were fully concordant with the conventional colony-forming unit counting method for all tested antibiotics and bacterial species. Conclusions: The proposed two-step resazurin-based microwell assay represents a rapid, reliable, and less labor-intensive alternative for the determination of both the minimum inhibitory concentration and the minimum bactericidal concentration, with potential applications in clinical and industrial microbiology laboratories. Full article

This study evaluated the probiotic, technological, and safety properties of 124 lactic acid bacteria isolated from traditional Beyaz cheese, and the in situ survival of selected strains in fermented milk. Eighteen isolates showing over 80% tolerance in simulated gastric juice (pH 3.0) were subjected to further characterization. On the basis of 16S rRNA gene sequencing, most isolates belong to Lacticaseibacillus paracasei and Lactiplantibacillus plantarum, while Lactobacillus helveticus, Lentilactobacillus kefiri, and Limosilactobacillus fermentum were also identified. L. plantarum EH140 showed the greatest resistance to the simulated gastric environment (pH 2.0), whereas L. paracasei EH131 exhibited the highest bile salt tolerance. L. plantarum EH106 demonstrated strong auto-aggregation, and L. fermentum EH132 displayed notable hydrophobicity. Nine isolates exhibited bile salt hydrolase activity, but none showed γ-hemolysis, gelatinase, or DNase activity. All the isolates were susceptible to ampicillin, erythromycin, clindamycin, and chloramphenicol. Organic acid analysis revealed lactic acid as the major metabolite, followed by acetic acid. Virulence gene screening identified the efaAfs gene only in L. paracasei strains, and no biogenic amine genes were detected. The selected isolates maintained viability above 6 log CFU/mL in milk during storage. Overall, L. plantarum EH106, EH109, EH140, and EH141 were identified as the most promising candidates because of their safety and superior probiotic potential. Full article

The coexistence of antibiotic resistance genes (ARGs), particularly those conferring resistance to last-resort antibiotics, is increasingly present in lesser-studied bacterial species. Tigecycline is currently one of the last important barriers in the treatment of carbapenem-resistant bacterial infections, whose resistance gene, tet(X), is prevalent across multiple bacterial genera, but the coexistence of tet(X3) and tet(X4) in Acinetobacter sp. is rarely observed. Here, we report a strain co-harboring the chromosomal tet(X3) and plasmid-borne tet(X4) isolated from a commercial beef cattle farm in Henan province, China. The strain exhibited resistance to ampicillin, gentamicin, chloramphenicol, sulfamethoxazole, tetracycline, doxycycline, tigecycline, and omadacycline. Based on whole-genome sequencing (WGS), the strain was identified as A. indicus using Average Nucleotide Identity (ANI) and digital DNA–DNA hybridization (dDDH). Chromosomal tet(X3) was identified in the genetic context, ISVsa3-XerD-tet(X3)-res-ISVsa3. The plasmid-located tet(X4) with the genetic context, ISVsa3-abh-tet(X4)-ISVsa3, and 14 additional resistance genes were located in multiple pdif modules. Two different typing methods, the Rep-based strategy (designed for A. baumanii) and MOB-typer, identified the tet(X4)-positive plasmid as GR31 and rep_cluster_1656, respectively. Conjugation assay failed to observe the transfer of the tet(X4)-positive plasmid into recipients, E. coli J53 and Salmonella LGJ2. The co-occurrence of tet(X3) and tet(X4) in Acinetobacter may suggest a risk of rapid dissemination of tigecycline resistance and the hidden presence of numerous undetected bacteria co-carrying high-risk ARGs in the agroecological system, both of which should cause particular concern. Full article