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This study investigated the existence of sulfonamides and colistin resistance genes among extended‐spectrum beta‐lactamase (ESBL)‐producing Escherichia coli recovered from fish gut in Vietnam and evaluated the susceptibility patterns of the ESBL‐producing E. coli to relevant antimicrobials. A total of 88 ESBL‐producing E. coli isolates were analysed for the presence of the ESBLs, sul (1, 2, 3) and mcr (1–3) genes by PCR. Antimicrobial resistance phenotypes of isolates were determined by disc diffusion. Results showed that: (i) A high prevalence of 94·3% of sulfonamide resistance was observed in 88 isolates. Moreover, the existence of 2·3% of ESBL‐producing E. coli harbouring mcr‐1 gene were detected; (ii) The phylogenetic types A and B1 were most frequent, and the blaCTX‐M group1 and blaTEM genes encoding ESBL were detected in 47·7% of the isolates; (iii) ESBL‐producing E. coli harbouring mcr‐1 gene exhibited resistance to 11 antibiotics. The existence of mcr‐1 and sul1,2,3 genes and the extremely high level of multiple drug resistance in all ESBL‐producing E. coli isolates obtained from sampled fish in Vietnam is a major concern. Therefore, it is imperative to monitor ESBL‐producing E. coli in the river waters of Vietnam. Significance and Impact of the Study: Although extended‐spectrum beta‐lactamase (ESBL)‐producing Escherichia coli have been thoroughly investigated in Vietnamese society, distribution of ESBL‐producing E. coli in fisheries has not been. This is the first study reporting ESBL‐producing E. coli isolates harbouring sul and mcr‐1 genes from fish gut in the Mekong delta, Vietnam. The existence of ESBL, sulfonamide and colistin resistance genes and high levels of multiple drug resistance in resistant E. coli isolates obtained from fish gut in this region is a major concern. [ABSTRACT FROM AUTHOR]

Extended-spectrum, β-lactamase-producing Escherichia coli (ESBL-E) harboring the bla -encoding plasmid (ESBL-E55) has been reported to be associated with urinary tract infection (UTI). The aims of this study were to clarify the prevalence of ESBL-E55 in pork meats and workers from the same wholesale market, as well as patients with UTI from a nearby hospital in Vietnam; we also investigated the plasmids encoding bla . Sequencing analysis showed that 66.6% of the ESBL-E isolated from pork meats contained bla , whereas the gene was present in 25.0% of workers and 12.5% of patients with UTI. Plasmid analysis showed that several sizes of plasmid encoded bla in ESBL-E55 isolated from pork meats, whereas ESBL-E55 isolated from workers and patients with UTI contained only 104-139 kbp of bla -encoding plasmids. This indicates that the 104-139 kbp sizes of bla -encoding plasmids were commonly disseminated in pork meats, wholesale market workers, and patients with UTI. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained a mistake. The legends of Tables 2 and 3, Fig. 1 are incorrect. The corrected legends are given below, [ABSTRACT FROM AUTHOR]

The spread of antibiotic-resistant bacteria is a global problem that should be addressed through the perspective of the "one health" concept. The purpose of this study was to determine the contamination rate of antibiotic-resistant Aeromonas spp. in fresh water river fish purchased from a fish market in Vietnam. We then defined the pattern of antibiotic resistance to assess antibiotic-resistant contamination. Antibiotic-resistant Aeromonas spp. were detected in the intestinal contents of 32 of 80 fish. bla NDM-1 was detected in seven strains. Extended-spectrum β-lactamase and AmpC β-lactamase-related genes were detected in 28 strains, including bla CTX-M-55 , bla CTX-M-15 , bla CTX-M-1 , and bla DHA, bla FOX, and bla MOX . The bla NDM-1 detected in the seven Aeromonas spp. strains were found chromosomally. This finding suggests that the bla NDM gene is stable in the natural environment and may spread widely into animals and humans via Aeromonas spp. with a transposon. Our results suggest the importance of continuing to monitor carbapenemase genes in Aeromonas spp. to evaluate the possibility that they may spread in other Enterobacterales, and to elucidate the mechanism of spread., 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 © 2023 Elsevier Ltd. All rights reserved.)

Although the spread of plasmid-mediated antibiotic-resistant bacteria is a public health concern, food contamination with plasmid-mediated antibiotic-resistant Escherichia coli in Vietnam has not been well investigated. This study aimed to describe the prevalence of colistin-resistant, carbapenem-resistant, and endemic bla CTX-M in extended-spectrum β-lactamase (ESBL) producing E. coli isolates. Colistin and carbapenem-resistant ESBL-producing E. coli were isolated from chickens in Vietnam and Japan. Colistin-resistant and AmpC/ESBL-producing E. coli (52% and 93%, respectively) were detected in chickens from Vietnam, in comparison to 52.7%, AmpC/ESBL-producing E. coli found in chicken from Japan. Carbapenem-resistant E. coli has not been isolated in Vietnam and Japan. Genotyping revealed that colistin-resistant E. coli harboured mcr-1, and most of the AmpC/ESBL-related genes were bla CTX-M-55 and bla CTX-M-65 together with bla TEM in Vietnamese chickens and bla CMY-2 in Japanese chickens. Multi-drug resistance analysis showed that ESBL-producing E. coli isolates had greater resistance to quinolones, streptomycin, and chloramphenicol than colistin-resistant E. coli isolates from Vietnam, suggesting the selection of multiple antibiotic resistance genes in ESBL-producing E. coli. In conclusion, colistin-resistant E. coli was detected in approximately half of the chicken samples, the majority of which harboured mcr-1. The high prevalence of ESBL-producing E. coli has remained constant in the last 5 years. The predominant bla CTX-M in ESBL-producing E. coli was bla CTX-M-55 or bla CTX-M-65 , with the coexistence of bla TEM in Vietnam. These results can be implemented in monitoring systems to overcome the development of antimicrobial resistance., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The prevalence of food-borne bacteria in developing countries is less well understood than in developed countries. The ISO11290-1 isolation method is commonly used to study Listeria contamination in chicken; however, all isolates are identified as untargeted Bacillus cereus. This study aimed to determine the classification, antibiotic susceptibility, and virulence genes of B. cereus isolated from retail chickens in Vietnam. Bacterial isolation using the ISO11290-1 method yielded 12 strains of B. cereus from seven out of 60 chickens. For determining bacterial diversity, panC and multilocus sequence typing (MLST) analyses were performed. PanC analysis showed that all seven strains belong to the phylogenetic group III, to which the highest risk of foodborne illnesses was associated. MLST analysis showed that most strains contained a ST205 complex; further, all strains were found to be resistant to ampicillin, ciprofloxacin, and tetracycline. Virulence genes were also investigated. ces, a cereulide-related gene, was detected in 50% of the isolated strains, followed by cytK, nheA, and hblA enterotoxins in 41.7%, 16.7%, and 25% of the strains, respectively. In conclusion, B. cereus may be erroneously detected when attempting to detect Listeria in food using the ISO11290-1 method. Further study of the prevalence of B. cereus in Vietnamese food is needed to improve food safety., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: Extended-spectrum β-lactamase/AmpC β-lactamase-producing Escherichia coli (ESBL/AmpC-E. coli) are common in developing countries and travellers represent potential reservoirs for their dissemination. The aim of this study was to quantify cefotaxime (CTX)-resistant E. coli harboured by travellers to Vietnam and to conduct a follow-up study., Methods: In total, 19 travellers and 34 travel events were investigated. After confirming that travellers were not colonised with CTX-resistant E. coli before travel, 15 travellers and 20 travel events were studied to quantify travellers harbouring CTX-resistant E. coli after travel. A stool sample (0.1 g) in 10 mL of PBS was diluted and plated. Selected colonies were identified, genotyped and further verified by pulsed-field gel electrophoresis (PFGE)., Results: After travel, travellers harboured an average of 3.6 × 10 7 CFU/g faeces of CTX-resistant E. coli, which continued to be detected for an average of 14 weeks. In the follow-up study, travellers from two travel events had ESBL-E. coli for 12 months. Multiplex PCR showed bla CTX-M-55 and bla CTX-M-27 , with replicon types FIA and F, and FIB and F, respectively. PFGE showed that two travellers harboured a single clonal ESBL-E. coli strain for 12 months. By PFGE, the follow-up study showed that a single type of ESBL/AmpC-E. coli was only detected in individuals living in Japan. Moreover, the same clonal ESBL-E. coli isolate was detected in a group that travelled to Ho Chi Minh City., Conclusion: ESBL/AmpC-E. coli colonised the gut of travellers to Vietnam with CTX-resistant E. coli (>10 7 CFU/g faeces) lasting for 14 weeks., (Copyright © 2019 International Society for Antimicrobial Chemotherapy. Published by Elsevier Ltd. All rights reserved.)

Measles-associated deaths have been reported in infants <9 months during outbreaks. A cohort study was conducted on 210 infants aged 6-8 months to evaluate the immunogenicity and safety of the AIK-C measles vaccine containing 10 4.21 plaque-forming units (PFU)/0.5 mL produced in Vietnam. Paired serum samples were obtained from 196 subjects. Seropositivity was defined as ≥120 mIU/mL. The seroresponse rate was 173/196 (88.27%, 95% confidence interval (CI): 83.77-92.77%) with geometric mean titer (GMT) of 511 mIU/mL (95% CI: 688-880 mIU/mL), and no significant differences were observed by different age groups. Among 196 paired sera, they were categorized into four groups: 122 subjects <14 IU/mL, 28 subjects 14-<60 mIU/mL, 30 subjects 60-<120 mIU/mL, and 16 subjects ≥ 120 mIU/mL. The seroresponse rate was 112/122 (91.8%, 95% CI: 86.94-96.67%) with GMT (597 mIU/mL, 95% CI: 749-1002 mIU/mL) in the <14 mIU/L group. In the 14-<60 mIU/mL group, the seroresponse rate was 18/28 (64.29%) with 184 mIU/L of GMT and was significantly lower (p < 0.01) than that in the <14 mIU/mL group. In the 16 seropositive group, all subjects showed seroconversion (4-fold higher than before) with a higher GMT of 1078 mIU/mL. Local pain and itching at the injection site were observed in 8 subjects (3.8%) within 7 days of the vaccination. Regarding systemic adverse reactions, febrile illness ≥37.5 °C was observed in 14 subjects (6.7%). These results indicate that the AIK-C measles vaccine is effective and safe for infants aged 6-8 months and will contribute to reducing the number of measles-associated deaths in future outbreaks., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Colistin is indicated for the treatment of multidrug-resistant gram-negative bacterial infections. However, the spread of colistin-resistant bacteria harbouring an mcr gene has become a serious concern. This study investigated local foods in Vietnam for contamination with colistin-resistant bacteria. A total of 261 extended-spectrum β-lactamase (ESBL)- and AmpC-producing Escherichia coli isolates from 330 meat and seafood products were analysed for colistin susceptibility and the presence of mcr genes. Approximately, 24% (62/261) of ESBL- or AmpC-producing E. coli isolates showed colistin resistance; 97% (60/62) of colistin-resistant isolates harboured mcr-1, whereas 3% (2/62) harboured mcr-3. As the result of plasmid analysis of two strains, both plasmids harbouring mcr-3 revealed that plasmid replicon type was IncFII. Sequencing analysis indicated that an insertion sequence was present near mcr-3, suggesting that IncFII plasmids harbouring mcr-3 could be transferred to other bacterial species by horizontal transfer of the plasmid or transfer with some insertion sequence. In conclusion, ESBL-producing E. coli and AmpC-producing E. coli have acquired colistin resistance because 24% of such isolates show colistin resistance and 3% of the colistin-resistant strains harbour mcr-3. We reported the present of the mcr-3-carrying ESBL-producing E. coli isolated from pork in Vietnam.

Extended-spectrum, β-lactamase-producing Escherichia coli (ESBL-E) harboring the bla CTX-M-55 -encoding plasmid (ESBL-E55) has been reported to be associated with urinary tract infection (UTI). The aims of this study were to clarify the prevalence of ESBL-E55 in pork meats and workers from the same wholesale market, as well as patients with UTI from a nearby hospital in Vietnam; we also investigated the plasmids encoding bla CTX-M-55 . Sequencing analysis showed that 66.6% of the ESBL-E isolated from pork meats contained bla CTX-M-55 , whereas the gene was present in 25.0% of workers and 12.5% of patients with UTI. Plasmid analysis showed that several sizes of plasmid encoded bla CTX-M-55 in ESBL-E55 isolated from pork meats, whereas ESBL-E55 isolated from workers and patients with UTI contained only 104-139 kbp of bla CTX-M-55 -encoding plasmids. This indicates that the 104-139 kbp sizes of bla CTX-M-55 -encoding plasmids were commonly disseminated in pork meats, wholesale market workers, and patients with UTI.

Reports of livestock infections with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) are increasing. Based on interviews conducted over a 6-month period, we found that veterinarians in the Vietnamese province of Thai Binh prefer to prescribe colistin-based drugs (CBD) in chicken farms. We aimed to clarify whether CBD use selects for strains of colistin-resistant ESBL-E. With the cooperation of seven local households, we detected ESBL-E in chickens' feces after treating chickens with CBD. Phylogenetic groupings and the presence of CTX-M/AmpC genes were determined, and the multi-antibiotic susceptibility of isolates was analyzed. Our results showed that ESBL-E presented in seven chickens' feces from two households. Seventy-two percent of ESBL-E isolates harbored CTX-M9 and the phylogenetic group A; the colistin minimum inhibitory concentration (MIC) of all isolated ESBL-E ranged from 0.064 to 1 μg mL -1 . Moreover, ESBL-E isolates were used to experimentally select for colistin resistance, and the effect of commercial CBD on ESBL-E was investigated. The results showed that an ESBL-E strain with a colistin MIC of 4 μg mL -1 was able to grow in media with CBD. Although CBD treatment was effective, in vitro experiments demonstrated that ESBL-E can easily acquire colistin resistance. Therefore, restrictions on colistin use are necessary to prevent the emergence of colistin-resistant bacteria.

Although Vietnamese residents frequently harbor extended-spectrum β-lactamase-producing Escherichia coli (ESBL-E), it is unclear which foods/beverages are risk factors for acquiring these bacteria. The aim of this study was to evaluate the frequency with which edible ice served in restaurants is contaminated with antibiotic-resistant bacteria, and thereby clarify whether this product poses a risk for ESBL-E carriage in humans. Ice from restaurants in Vietnam and Japan was screened for bacteria capable of growing on agar containing cefotaxime (BG-CTX). Of the 119 BG-CTX strains isolated in Vietnam, 40%, 39%, and 12% were identified as Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia, respectively. Meanwhile, of the six such strains isolated in Japan, five were identified as Acinetobacter spp. and one as Pseudomonas spp. More than 10% of the Acinetobacter isolates exhibited cefotaxime, ceftazidime, and sulfa/trimethoprim resistance, while 21% of Pseudomonas and 14% of S. maltophilia isolates exhibited meropenem and sulfa/trimethoprim resistance, respectively. Subsequent multiplex polymerase chain reaction (PCR) analyses detected ESBL-encoding genes in 10% of the BG-CTX. Notably, feces harvested from mice administered water contaminated with BG-CTX contained E. coli harboring the bla CTX-M-9 gene. In conclusion, our findings indicate that consumption of contaminated edible ice is a risk factor for human ESBL-E carriage.

Background: Contamination of food with multiantibiotic-resistant bacteria, particularly extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, is considered a potential source for the wide dissemination of ESBL-producing bacteria in communities. However, little is known about the extent of contamination of food with ESBL-producing bacteria in Vietnam., Objective: This study was conducted to assess the characteristics of ESBL-producing Escherichia coli isolated from retail meats and shrimp in Nha Trang, Vietnam., Materials and Methods: A total of 350 food samples (poultry [n=143], pork [n=147], and shrimp [n=60]) were purchased in July and November 2013 from a local market. ESBL-producing E. coli were isolated, and ESBL genotypes, phylogenetic groups, and antibiotic resistance profiles were determined., Results: The prevalence of ESBL-producing E. coli in retail foods was 40.6%. β-Lactamase-encoding genes of the CTX-M-1 (50.7%), CTX-M-9 (41.5%), TEM (59.9%), and SHV (2.8%) groups were detected singly or in combination. The percentages of single ESBL isolates harboring CTX-M-1 or -9 plus TEM groups were 35.2% and 16.2%, respectively. B1 was the most prevalent phylogroup in ESBL isolates from pork (44.7%), poultry (55.9%), and shrimp (72.7%). B2 was the least prevalent (4.2% and 4.8% for pork and poultry isolates, respectively). The prevalence of multidrug resistance (MDR; resistance to ≥ 3 antimicrobial groups) in ESBL-producing E. coli isolated from food was 85.9%., Discussion and Conclusions: This is the first report of the characteristics of ESBL-producing E. coli in retail foods in a local city in Vietnam. Our findings indicate that retail foods are contaminated with ESBL-producing E. coli, of which many were MDR. Further monitoring and public health efforts targeting food administration are needed to control the spread of ESBL-producing bacteria in communities.