ESBL-producing Atlantibacter hermannii harboring a plasmid encoding IS26 up and down stream of blaCTX-M-27 ,blaLAP-2, and qnrS1 isolated from an edible river Anabas testudineus fish.

Extended-spectrum ß-lactamase-producing Atlantibacter hermannii was isolated from an edible river fish, Anabas testudineus, which was sold in a market located in Vietnam. The genome sequence was obtained by using next-generation sequencing, which involved Oxford Nanopore and Illumina technologies. The 92 kb plasmid encodes the gene blaCTX-M-27.

Prevalence of Staphylococcus argenteus among food handlers, kitchen utensils, and food samples in Japan.

Staphylococcus argenteus has received increased attention from an aspect of food safety since several food poisoning outbreaks caused by the bacterium were reported in Japan. However, S. argenteus prevalence among food handlers and utensils has not yet been investigated. In this study, we investigated S. argenteus prevalence among a collection of coagulase-positive staphylococci (CPS) that were isolated during food sanitary inspections in Japan. Out of a total of 191 CPS isolates, 14 were identified as S. argenteus. One was isolated from shelled shrimp, nine were isolated from food handlers' hand swabs, and four were isolated from kitchen utensils. Whole-genome sequencing revealed that transmission of S. argenteus from human hands to utensils was possible. Though all 14 isolates were negative for the pvl and tst-1 genes, 6 harbored the seb gene. Only 21.4% of S. argenteus isolates were resistant to antibiotics, while 62.1% of the S. aureus isolates from the same sources were confirmed to be resistant. To the best of our knowledge, this is the first report to demonstrate possible transmission of S. argenteus from food handlers to utensils in food-processing environments.

IncA/C plasmid encoding blaCTX-M-55 in non-O1 Vibrio cholerae isolates from the edible river fish Mastacembelus sp.

Extended-spectrum ß-lactamase-producing non-O1 Vibrio cholerae was isolated from edible Mastacembelus sp. in Vietnam. The genome sequence was sequenced using DNBSEQ-G400 and MinION Mk1b. A plasmid of approximately 183-kb encoding blaCTX-M-55 and blaTEM-1 was detected.

Detection of chromosome-mediated blaNDM-1-carrying Aeromonas spp. in the intestinal contents of fresh water river fish in Ho Chi Minh City, Vietnam.

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. blaNDM-1 was detected in seven strains. Extended-spectrum ß-lactamase and AmpC ß-lactamase-related genes were detected in 28 strains, including blaCTX-M-55, blaCTX-M-15, blaCTX-M-1, and blaDHA,blaFOX, and blaMOX. The blaNDM-1 detected in the seven Aeromonas spp. strains were found chromosomally. This finding suggests that the blaNDM 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.

IncHI2 Plasmid Encoding blaCTX-M-55 and mcr-1.1 in Salmonella enterica SE20-C72-2 and Escherichia coli EC20-C72-1 Isolates from the Edible River Fish Anabas testudineus.

Salmonella enterica SE20-C72-2 and Escherichia coli EC20-C72-1 were isolated from the edible fish Anabas testudineus in Vietnam. The chromosomes and plasmids from both strains were sequenced using Oxford Nanopore and Illumina sequencing. Plasmids approximately 250 kbp long, encoding blaCTX-M-55 and mcr-1.1, were detected in both strains.

ESBL-producing Vibrio vulnificus and V. alginolyticus harbour a plasmid encoding ISEc9 upstream of blaCTX-M-55 and qnrS2 isolated from imported seafood.

In recent years, trade liberalisation has led to the spread of antibiotic-resistant bacteria (ARB) in food products. Because ARB has reportedly been found in imported foods, the spread of plasmid-mediated ARB through food products is a concern. Here, we report the complete genome sequences of ESBL-producing Vibrio vulnificus and V. alginolyticus strains harbouring a plasmid isolated from imported seafood. First, V. vulnificus and V. alginolyticus were isolated from purchased frozen and thawed Litopenaeus vannamei shrimp, and genome extraction and sequencing were performed. Hybrid genome assemblies were performed using Unicycler and annotated using DFAST. Then genome analysis was performed using BRIG. Plasmid comparisons showed that the plasmids carried by both Vibrios are remarkably similar and encode the same antibiotic-resistance genes. The 270-310 kb region specific to both Vibrios were isolated in this study and encodes the antibiotic-resistance genes blaCTX-M and qnr. Furthermore, the mobile genetic factors ISEc9, ISVch4, and ISVpa4 are located upstream and downstream of these genes. This is the first report of ESBL-producing V. vulnificus and V. alginolyticus harbouring a common plasmid encoding ISEc9 upstream of blaCTX-M-55 and qnrS2 isolated from imported seafood.

Carbapenem-Resistant Citrobacter freundii and Escherichia coli Harboring a Common IncC-Type Plasmid Encoding IS26 Upstream of blaNDM-1, sul1, aph(3')-VI, and qacE Isolated from Edible Mastacembelidae Fish.

Carbapenem-resistant Citrobacter freundii CF20-4P-1 and Escherichia coli EC20-4B-2 were isolated from edible Mastacembelidae in Vietnam. We present the draft genome sequences, and the complete plasmid genome sequencing was also performed by hybrid assembly sequencing of Oxford Nanopore and Illumina. The 137-kbp plasmid encoding the assembled blaNDM-1 was detected in both strains.

Frequent contamination of edible freshwater fish with colistin-resistant Escherichia coli harbouring the plasmid-mediated mcr-1 gene.

The threat of antimicrobial resistance is increasing. Microbial food contamination poses a serious public health risk; however, there are only a few studies on the prevalence of colistin-resistant Escherichia coli (COL-E) contamination in freshwater fish. This study aimed to characterise the antibiotic resistance genes and antibiotic susceptibility profiles of COL-E in freshwater fish in Vietnam. In total, 103 fish were collected and 63 COL-E were isolated. COL-E was investigated by genotyping mcr and AmpC/extended-spectrum ß-lactamase (ESBL)-related genes. The results show that COL-E and AmpC/ESBL-producing COL-E were confirmed in 24.3 % and 14.6 % of the fish, respectively. Multiplex PCR for mcr-1-9 showed that all 63 COL-E harboured mcr-1, while mcr-3 was detected in 7.9 % of COL-E. The minimum inhibitory concentration of colistin ranged from 2 to 256 µg/mL. Meanwhile, antibiotic susceptibility results show that all COL-E were resistant to ampicillin, streptomycin, and chloramphenicol.

Genome Sequence of Carbapenemase-Producing Enterobacter cloacae 0102-4P-1 Harboring the IncC-Type Plasmid with a Multidrug Resistance Site Encoding blaNDM-1, Isolated from Commercially Imported Shrimp.

A carbapenem-resistant Enterobacter cloacae 0102-4P-1 strain was isolated from commercially imported shrimp in Japan. Here, we present a draft genome sequence. The complete plasmid sequence was also determined by hybrid assembly sequencing using Oxford Nanopore and Illumina methods. The assembled whole genome and plasmid were 5,164,033 bp and 162,852 bp long, respectively.

Abundance of colistin-resistant Escherichia coli harbouring mcr-1 and extended-spectrum ß-lactamase-producing E. coli co-harbouring blaCTX-M-55 or -65 with blaTEM isolates from chicken meat in Vietnam.

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 blaCTX-M in extended-spectrum ß-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 blaCTX-M-55 and blaCTX-M-65 together with blaTEM in Vietnamese chickens and blaCMY-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 blaCTX-M in ESBL-producing E. coli was blaCTX-M-55 or blaCTX-M-65, with the coexistence of blaTEM in Vietnam. These results can be implemented in monitoring systems to overcome the development of antimicrobial resistance.

Structure-Activity Relationship Studies of Antimicrobial Naphthoquinones Derived from Constituents of Tabebuia avellanedae.

In this study, based on our previous study, derivatives of naphtho[2,3-b]furan-4,9-diones were synthesized and their antimicrobial activities were evaluated. The screening of these naphthoquinones revealed that the fluorine-containing NQ008 compound exhibited potent and broad antimicrobial activities against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacteria, and fungi. The results of the ratio of the minimum bactericidal concentration (MBC) to the minimum inhibitory concentrations (MICs) and time-kill assays suggest that the mode of action of NQ008 is bactericidal. Additionally, the results of a drug resistance study revealed that NQ008 exhibited potent antibacterial activity and may delay the development of bacteria resistance. Furthermore, NQ008 exhibited preliminary antiviral activity against the swine influenza virus and Feline calicivirus.

Untargeted Phylogenetic Group III of Multi-drug-Resistant Bacillus cereus Isolated Using Fraser Medium from Retail Chickens in Ho Chi Minh City.

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.

Application of gamma radiation for disinfection of fungi in a large volume of historical archives damaged by flood following Typhoon Hagibis 2019, Japan: A case report.

A large volume of historical archives was extensively damaged by flood water, following Typhoon Hagibis in Fukushima, Japan, in October 2019. They were rescued from the stricken area within a week, however, the prolonged exposure of paper documents to water caused severe biodegradation by fungal growth. To disinfect fungi, the paper documents were exposed to gamma radiations emitted by a source of Cobalt 60 by the industrial irradiation service. The wet paper documents were mainly contaminated with hydrophilic and cellulolytic fungi, including Trichoderma, Stachybotrys, and Fusarium; no fungi grew after irradiation. These results indicated that the average absorbed dosage from 13.1 kGy to 16.1 kGy were sufficient to disinfect paper documents heavily contaminated with fungi. In the present study, we demonstrated the successful practical use of irradiation in fungi-damaged paper documents using a commercial gamma-irradiation facility.

Quantification and long-term carriage study of human extended-spectrum/AmpC ß-lactamase-producing Escherichia coli after international travel to Vietnam.

OBJECTIVES: Extended-spectrum ß-lactamase/AmpC ß-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 × 107 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 blaCTX-M-55 and blaCTX-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 (>107 CFU/g faeces) lasting for 14 weeks.

Prevalence Of mcr-1 Among Cefotaxime-Resistant Commensal Escherichia coli In Residents Of Vietnam.

PURPOSE: The dissemination of colistin-resistant bacteria harboring the colistin-resistance gene mcr-1 in developing countries has recently entered the spotlight as an emerging public health threat, which is attributed to the abuse of colistin use in these countries. However, the prevalence of these bacteria in developing countries has not been extensively investigated. Therefore, in the present study, we examined the prevalence of cefotaxime-resistant commensal Escherichia coli harboring mcr-1 among residents of a representative Vietnamese village and assessed the characteristics of these isolates. MATERIALS AND METHODS: The stool samples, one stool sample per resident, of 612 residents were cultured on MacConkey agar with cefotaxime. Resulting E. coli-like colonies were isolated and examined further for the presence of colistin-resistant extended-spectrum ß-lactamase (ESBL)-producing E. coli with mcr-1. Antibiotic susceptibility tests were performed, and clonal relationship among colistin-resistant isolates was assessed. RESULTS: Thirty-one of the 451 cefotaxime-resistant E. coli isolates were resistant to colistin and the majority possessed mcr-1, blaCTX-M , and/or blaTEM , except for two isolates that produced the AmpC ß-lactamase. All mcr-1 ESBL-producing E. coli isolates were multidrug-resistant (5-11 antibiotics). The isolates contained various plasmid replicon types, including the most prevalent types IncHI2 (54.8%), IncFIB (48.4%), and IncN (41.9%). In addition, 83.9% of the mcr-1 ESBL-E. coli isolates possessed a transposon ISApl1-mcr-1 segment. Furthermore, 77.4% of the mcr-1 ESBL-E. coli isolates belonged to phylogenetic group A. Pulsed-field gel electrophoresis analysis indicated limited clonal expansion of a specific strain. CONCLUSION: These results demonstrate the wide dissemination of colistin-resistant ESBL-E. coli harboring mcr-1 among commensal bacteria of rural residents in Vietnam, suggesting possible mobilization of the mcr-1 gene among ESBL-producing microbiota, which is a great public health concern.

The presence of colistin resistance gene mcr-1 and -3 in ESBL producing Escherichia coli isolated from food in Ho Chi Minh City, Vietnam.

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 ß-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.

Foodborne Outbreak of Group G Streptococcal Pharyngitis in a School Dormitory in Osaka, Japan.

In September 2016, 140 patients with primary symptoms of sore throat and fever were identified in a school dormitory in Osaka, Japan. Epidemiological and laboratory investigations determined that these symptomatic conditions were from a foodborne outbreak of group G streptococcus (GGS), with GGS being isolated from samples from patients, cooks, and foods. The strain of GGS was identified as Streptococcus dysgalactiae subsp. equisimilis of two emm types (stG652.0 and stC36.0). The causative food, a broccoli salad, was contaminated with the two types of S. dysgalactiae subsp. equisimilis, totaling 1.3 × 104 CFU/g. Pulsed-field gel electrophoresis (PFGE) of samples from patients, cooks, and foods produced similar band patterns among samples with the same emm type. This result suggested the possibility of exposure from the contaminated food. The average onset time was 44.9 h and the prevalence rate was 62%. This is the first report to identify the causative food of a foodborne outbreak by Streptococcus dysgalactiae subsp. equisimilis.

Carriage of colistin-resistant, extended-spectrum ß-lactamase-producing Escherichia coli harboring the mcr-1 resistance gene after short-term international travel to Vietnam.

BACKGROUND: Due to increasing colistin usage, the dissemination of the colistin-resistant gene mcr-1 has been increasingly investigated. The aim of this study was to determine whether a traveler on a short-term international trip to a developing country could bring mcr-1 back to their home country. MATERIALS AND METHODS: Thirty-four travel events from Japan to Vietnam encompassing 19 travelers were assessed. A fecal specimen was collected from each traveler before and after each travel event and was inoculated on CHROMagar containing cefotaxime (CTX). Three to seven colonies exhibiting the characteristics of Escherichia coli were collected. Susceptibility to antibiotics and extended-spectrum ß-lactamase (ESBL) production were determined by the disk diffusion method and the double-disk synergy test, respectively. ESBL-encoding genes were genotyped, and phylogenetic groupings were determined by multiplex polymerase chain reaction (PCR). The presence of mcr-1 was also confirmed by PCR and sequencing. RESULTS: A total of 175 ESBL-producing E. coli isolated before and up to 2 weeks after traveling to Vietnam were analyzed. Genotyping of ESBL-producing isolates showed that blaCTX-M-1/blaTEM (27.7%) and blaCTX-M-9 (45.9%) were the most prevalent genotypes, while the most frequently detected phylogenetic group was D (41.9%) followed by B2 (23.0%). In a significant number of travel events, travelers brought ESBL-producing E. coli back to Japan and three events by three travelers carried mcr-1. ESBL-producing E. coli isolates harboring mcr-1 were identified as those carrying both blaCTX-M-14 or blaCTX-M-55 and mcr-1. CONCLUSION: Using Vietnam as an example, we have shown that even a short-term trip to some countries may result in ESBL-producing mcr-1-positive E. coli carriage by international travelers.

Extended-spectrum ß-lactamase-producing Escherichia coli contributes to the survival of cefotaxime-susceptible E. coli under high concentrations of cefotaxime by acquisition of increased AmpC expression.

Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-E) are becoming increasingly widespread in Vietnam. Antibiotics are detected in many Vietnamese foods; however, the effect of ESBL-E and antibiotic consumption on intestinal bacteria has not been studied sufficiently. Here, we investigated the effect of oral administration of ESBL-E (TB19) and cefotaxime on luminescence-emitting cefotaxime-sensitive E. coli (X14). Mice were given water containing TB19 and then received three injections of 1.0 × 108 CFU of X14 harboring a luciferase gene. The mice were administered 100 µg of cefotaxime and luminescent bacteria were monitored over 24 h, following which luminescent bacteria were isolated from mouse feces. Luminescence continued to be detected in mice administered TB19 24 h after cefotaxime ingestion. Fecal analysis revealed two types of luminescent colonies: cefoxitin-resistant E. coli (X14-R) and Pseudomonas aeruginosa. Pulse-field gel electrophoresis confirmed that X14-R was a clonal strain of X14, suggesting that X14 survived using ESBLs originating from TB19 and acquired cefoxitin resistance due to cefotaxime consumption. Moreover, in vitro analysis of X14 indicated that expression of the ampC gene was upregulated by cefotaxime. Overall, ESBL-E and cefotaxime promoted the expansion of cefoxitin-resistant E. coli in the absence of plasmid-mediated gene transfer.