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The widespread use of chemical disinfectants and antibiotics poses a major threat to food safety and human health. However, the mechanisms of co-transmission of antimicrobial resistance genes (ARGs) and biocides and metal resistance genes (BMRGs) of foodborne pathogens in the food chain is still unclear. This study isolated 343 E. coli strains from animal-derived foods in Beijing and incorporated online data of human-derived E. coli strains from NCBI. Our results demonstrated a relatively uniform distribution of strains from various regions in Beijing, indicating a lack of region-specific clustering. Additionally, predominant sequence types varied between food- and human-derived strains, suggesting a preference for different hosts and environments. Phenotypic association analysis showed that the chlorine disinfectants peroxides had a significant positive correlation with tetracyclines. Many more ARGs and BMRGs were enriched in human-associated E. coli compared with those in chicken- and pork-origin. The quaternary ammonium compounds (QACs) resistance gene qacEΔ1 had a strong correlation with aminoglycoside resistance gene aadA5, folate pathway antagonist resistance gene dfrA17, sul1 and macrolide resistance gene mph(A). The correlation results indicated a significant association between the copper resistance gene cluster pco and the silver resistance gene cluster sil. Coexistence of many resistance genes was observed within the qacEΔ1 gene structure, with qacEΔ1-sul1 being the most common combination. Our findings demonstrated that the epidemiological spread of resistance is affected by a combination of heavy metals, disinfectants and antibiotic use, suggesting that the prevention and control strategies of antimicrobial resistance need to be multifaceted and comprehensive., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Vibrio parahaemolyticus is the leading cause of seafood-borne bacterial poisoning in China and is a threat to human health worldwide. The aim of this study was to assess the antibiotic resistance profiles and distribution of heavy metal resistance of V. parahaemolyticus isolates from Penaeus vannamei from freshwater farms, seawater farms, and their corresponding markets in Zhejiang, China and to assess the relationship between multidrug resistance (MDR) and multi-heavy metal resistance (MHMR). Of the 360 P. vannamei samples that we tested, 90 (25.00%) were V. parahaemolyticus positive, but the occurrence of pathogenic isolates carrying the toxin genes tdh (4.44%) and trh (3.33%) was low. None of the tested isolates harbored both the tdh and trh genes. However, antibiotic resistance profiles varied among different sampling locations, levels of resistance to the antibiotics ampicillin (76.67%) and streptomycin (74.44%) were high overall, and MDR isolates were common (40.00% of all isolates). Heavy metal resistance patterns were similar among the different sampling locations. Overall, the majority of V. parahaemolyticus isolates displayed tolerance to Cd2+ (60.00%), and fewer were resistant to Cu2+ (40.00%), Zn2+ (38.89%), Ni2+ (24.44%), Cr3+ (14.44%), and Co2+ (8.89%). In addition, 34.44% (31/90) of isolates tested in this study were found to be MHMR. Using Pearson's correlation analysis, MDR and MHMR were found to be positively correlated (P = 0.004; R = 0.759). The 18 V. parahaemolyticus isolates that were both MDR and MHMR represented 18 sequence types, of which 12 were novel to the PubMLST database, and displayed a high level of genetic diversity, suggesting that dissemination may be affected by mobile genetic elements via horizontal gene transfer. However, a low percentage of class 1 integrons without gene cassettes and no class 2 or 3 integrons were detected in the 18 MDR and MHMR isolates or in the 90 V. parahaemolyticus isolates overall. Thus, we suggest that future research focus on elucidating the mechanisms that lead to a high prevalence of resistance determinants in V. parahaemolyticus. The results of this study provide data that will support aquatic animal health management and food safety risk assessments in the aquaculture industry. [ABSTRACT FROM AUTHOR]

Contaminated water bodies such as rivers provide reservoirs for bacterial resistance. This field study tested the water quality and the bacterial resistance to heavy metals of Qishan River water pollution. Wastewater discharged to environmental surface waters is a major pathway of heavy metals and heavy metal-resistant bacteria. Contaminated water bodies such as rivers provide reservoirs for bacterial resistance. This field study tested the water quality and bacterial resistance to heavy metals of Qishan River water pollution. Guided by our research hypothesis that an overall increase in downstream heavy metal resistance levels was following an increase in human settlements were eight sites sampled along the Qishan River. These were situated upstream and downstream to the confluence of the Qishan River with the Kaoping River. In the laboratory bacterial heavy metal resistance was bio-assayed by disk diffusion and micro-dilution with six widely used heavy metals. The comparison of bacterial resistance was among Qishan River upstream sites (sites 1-6) and downstream sites (sites 7-9). Multi-drug-resistant bacteria and co-resistance against heavy metals and antibacterials appeared at site 8. This research discusses the correlation between environmental factors, and antibacterial and heavy metal resistance. The results provide stakeholders and authorities responsible for environmental pollution with a reference for risk assessment and management of bacterial resistance., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Hans-Uwe Dahms & Chi-Ying Hsieh report financial support was provided by National Science and Technology Council. Hans-Uwe Dahms reports financial support was provided by National Health Research Institutes. Hans-Uwe Dahms reports financial support was provided by Ministry of Education., (Copyright © 2023. Published by Elsevier Ltd.)

Abstract: Vibrio parahaemolyticus is a widespread bacterium in the marine environment and is one of the leading causes of food-derived bacterial poisoning in humans worldwide. The main objective of this study was to determine the prevalence, virulence factors, and antibiotic and heavy metal resistance profiles of V. parahaemolyticus in Pacific mackerel (Pneumatophorus japonicus) from different markets in Zhejiang Province, People's Republic of China. In total, 112 (31.11%) V. parahaemolyticus isolates were identified from 360 Pacific mackerel samples, with an extremely low occurrence of the virulence genes trh (1.79%, 2 of 112) and tdh (0%, 0 of 112). Antibiotic resistance testing revealed that most isolates showed resistance to ampicillin (96.43%, 108 of 112) and streptomycin (90.18%, 101 of 112), whereas all strains were sensitive to kanamycin, florfenicol, cefamandole, and trimethoprim-sulfamethoxazole. Furthermore, 46.43% (52 of 112) of isolates, which had 12 different phenotypes, were classified as multidrug resistant. In addition, the multiple antibiotic resistance index values of isolates were between 0.05 and 0.63, and the maximum multiple antibiotic resistance index was attributed to two isolates that exhibited resistance to 12 antibiotics. Heavy metal resistance patterns were similar among the six different markets. The majority of isolates showed resistance to Cd2+ (78.57%) and Pb2+ (51.79%), and fewer were resistant to Cu2+ (37.50%), Zn2+ (25.00%), Co2+ (9.82%), Ni2+ (6.25%), and Mn2+ (4.46%). No isolates were resistant to Cr3+. In total, 22.32% (25 of 112) of strains were multiheavy metal resistant. Furthermore, multidrug resistance and multiheavy metal resistance were found to be positively correlated in the V. parahaemolyticus strains by using Pearson's correlation analysis (P = 0.008; R = 0.925). This information will contribute to the monitoring of variations in the antibiotic and heavy metal resistance profiles of V. parahaemolyticus strains from seafood and provide insight into the appropriate use of antibiotics and the safe consumption of seafood., (Copyright ©, International Association for Food Protection.)

Vibrio parahaemolyticus is a causative agent of human serious seafood-borne gastroenteritis disease and even death. Shrimps, often eaten raw or undercooked, are an important reservoir of the bacterium. In this study, we isolated and characterized a total of 400 V. parahaemolyticus strains from commonly consumed fresh shrimps (Litopenaeus vannamei, Macrobrachium rosenbergii, Penaeus monodon, and Exopalaemon carinicauda) in Shanghai fish markets, China in 2013-2014. The results revealed an extremely low occurrence of pathogenic V. parahaemolyticus carrying two major toxic genes (tdh and trh, 0.0 and 0.5 %). However, high incidences of antibiotic resistance were observed among the strains against ampicillin (99 %), streptomycin (45.25 %), rifampicin (38.25 %), and spectinomycin (25.50 %). Approximately 24 % of the strains derived from the P. monodon sample displayed multidrug resistant (MDR) phenotypes, followed by 19, 12, and 6 % from the E. carinicauda, L. vannamei, and M. rosenbergii samples, respectively. Moreover, tolerance to heavy metals of Cr(3+) and Zn(2+) was observed in 90 antibiotic resistant strains, the majority of which also displayed resistance to Cu(2+) (93.3 %), Pb(2+) (87.8 %), and Cd(2+)(73.3 %). The pulsed-field gel electrophoresis (PFGE)-based genotyping of these strains revealed a total of 71 distinct pulsotypes, demonstrating a large degree of genomic variation among the isolates. The wide distribution of MDR and heavy-metal resistance isolates in the PFGE clusters suggested the co-existence of a number of resistant determinants in V. parahaemolyticus population in the detected samples. This study provided data in support of aquatic animal health management and food safety risk assessment in aquaculture industry.

Increasing industrialization and use of antimicrobial agents in aquaculture production, have led to heavy metals and multidrug resistant (MDR) pathogens becoming serious problems. These resistances are conferred in two ways: intrinsic and transfer via conjugation, or transformation by the major transmission mediators. Integrative and conjugative elements (ICEs) are one of the major mediators; however, few studies on ICEs of environmental origin have been reported in Asia. Herein, we determined the prevalence, antimicrobial susceptibility, heavy metal resistance and genotypes of 126 strains of Vibrio cholerae isolated from aquatic products and the environment in Shanghai, China. 92.3% of isolates were ICEs-positive from aquaculture water and 89.3% of isolates from shrimp showed MDR. Tracing the V. cholerae genotypes, showed no significant relevance of genotype among the antimicrobial resistance strains bearing the ICEs or not. Thus, in aquaculture, ICEs are not the major transmission mediators of resistance to antibiotics or heavy metals., (Copyright © 2015 Elsevier Ltd. All rights reserved.)