Detection of the mcr-1 gene in Enteropathogenic Escherichia coli (EPEC) and Shigatoxigenic E. coli (STEC) strains isolated from broilers

2020 ◽  
Vol 40 (3) ◽  
pp. 165-169
Author(s):  
Hugo P. Lopes ◽  
Gisllany A. Costa ◽  
Ana C.L.Q. Pinto ◽  
Leandro S. Machado ◽  
Nathalie C. Cunha ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Poultry Products ◽  
Drug Of Choice ◽  
Bacteriological Method ◽  
Enteric Infections ◽  
Polymerase Chain

ABSTRACT: Enteropathogenic Escherichia coli (EPEC) and Shigatoxigenic E. coli (STEC) strains are among the major pathotypes found in poultry and their products, which are capable of causing human enteric infections. Colistin has been claimed the drug of choice against diseases caused by multidrug-resistant Gram-negative bacteria (MDRGN) in humans. The mcr-1 gene was the first plasmidial gene that has been described to be responsible for colistin resistance and has also been detected in birds and poultry products. Our study aimed to detect the mcr-1 gene in enteropathogenic strains of E. coli in order to evaluate the resistance to colistin in broilers. The material was obtained from 240 cloacal samples and 60 broiler carcasses. The strains were isolated by the conventional bacteriological method and by the virulence genes, which characterize the enteropathogenic strains and resistance, and the samples were detected by polymerase chain reaction (PCR). Of the 213 isolated strains of E. coli, 57 (26.76%) were characterized as atypical EPEC and 35 (16.43%) as STEC. The mcr-1 gene was found in 3.5% (2/57) of the EPEC strains and 5.7% (2/35) of the STEC strains. In this study, it was possible to confirm that the mcr-1 resistance gene is already circulating in the broiler flocks studied and may be associated with the pathogenic strains.

scholarly journals Molecular Characterization of Plasmid-Mediated Non-O157 Verotoxigenic Escherichia coli Isolated from Infants and Children with Diarrhea

2020 ◽  
Vol 17 (3) ◽  
pp. 0710
Author(s):  
Md Fazlul Karim Khan ◽  
Shah Samiur Rashid
Keyword(s):  
Escherichia Coli ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Plasmid Curing ◽  
Health Issues ◽  
E Coli ◽  
Disk Diffusion Assay ◽  
Microbiological Techniques ◽  
Polymerase Chain

A significant increase in the incidence of non-O157 verotoxigenic Escherichia coli (VTEC) infections have become a serious health issues, and this situation is worsening due to the dissemination of plasmid mediated multidrug-resistant microorganisms worldwide. This study aims to investigate the presence of plasmid-mediated verotoxin gene in non-O157 E. coli. Standard microbiological techniques identified a total of 137 E. coli isolates. The plasmid was detected by Perfectprep Plasmid Mini preparation kit. These isolates were subjected to disk diffusion assay, and plasmid curing with ethidium bromide treatment. The plasmid containing isolates were subjected to a polymerase chain reaction (PCR) for investigating the presence of plasmid mediated verotoxin gene (VT1 and VT2) in non-O157 E. coli. Among the 137 E. coli isolates, 49 isolates were non-O157 E. coli while 29 (59.1%) isolates were verotoxin producing non-O157 serotypes and 26 non-O157 VTEC isolates possessed plasmids. Certain isolates harboured single sized plasmid while others had multiple plasmids with different size varied from 1.8kb to 7.6kb. A plasmid containing all (100%) the isolates was multidrug-resistant. Eight isolates changed their susceptibility patterns while three isolates were found to lose plasmid after post plasmid curing treatment and the rest of the isolates (15) remained constant. Different PCR sets characterized 3 plasmid-mediated verotoxins producing non-O157 E. coli. This current study demonstrated the occurrence of plasmid mediated verotoxin gene in non-O157 E. coli. To the best of our knowledge, this is the first report in the global literature on plasmid-mediated verotoxin gene in non-O157 E. coli. Timely diagnosis and surveillance of VTEC infections should prioritize to stop or slow down the virulence gene for dissemination by plasmid-mediated gene transfer amongst the same bacteria or other species.

scholarly journals Investigation of multidrug-resistant fatal colisepticaemia in weanling pigs

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
Folorunso O. Fasina ◽  
Dauda G. Bwala ◽  
Evelyn Madoroba
Keyword(s):  
Escherichia Coli ◽  
South African ◽  
Multidrug Resistant ◽  
Weanling Pigs ◽  
Tissue Samples ◽  
E Coli ◽  
Young Pigs ◽  
Polymerase Chain ◽  
The Impact ◽  
Future Management

Escherichia coli is usually a benign commensal of the gut microflora. However, when E. coli acquires virulence genes it can multiply rapidly and cause disease through colonisation of the intestinal mucosa. Escherichia coli can become a significant pathogen in young pigs. We report an investigation of fatal colisepticaemia in weanling pigs from emerging farms where piglets and weaners were diarrhoeic and the mortality rate ranged between 15% and 70% in each litter. Faecal and tissue samples were processed for histopathology, bacteriology and molecular biology (multiplex and monoplex polymerase chain reaction) and we recovered enteroaggregative multidrug-resistant E. coli producing EAST-1 enterotoxin. An association between poor housing conditions and the observed cases was established and future management programmes were recommended to reduce the impact of such pathogens. Enteroaggregative E. coli is becoming a major problem in the pig industry. It therefore becomes necessary to establish the full impact of E. coli on the South African pig industry and to determine the geographic extent of the problem.

scholarly journals Heterogeneous and Flexible Transmission ofmcr-1in Hospital-AssociatedEscherichia coli

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Yingbo Shen ◽  
Zuowei Wu ◽  
Yang Wang ◽  
Rong Zhang ◽  
Hong-Wei Zhou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Gram Negative Bacteria ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Genes Encoding

ABSTRACTThe recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route ofmcr-1amongEnterobacteriaceaespecies in clinical settings is largely unknown. Here, we present a comprehensive genomic analysis ofEscherichia coliisolates collected in a hospital in Hangzhou, China. We found thatmcr-1-carrying isolates from clinical infections and feces of inpatients and healthy volunteers were genetically diverse and were not closely related phylogenetically, suggesting that clonal expansion is not involved in the spread ofmcr-1. Themcr-1gene was found on either chromosomes or plasmids, but in most of theE. coliisolates,mcr-1was carried on plasmids. The genetic context of the plasmids showed considerable diversity as evidenced by the different functional insertion sequence (IS) elements, toxin-antitoxin (TA) systems, heavy metal resistance determinants, and Rep proteins of broad-host-range plasmids. Additionally, the genomic analysis revealed nosocomial transmission ofmcr-1and the coexistence ofmcr-1with other genes encoding β-lactamases and fluoroquinolone resistance in theE. coliisolates. These findings indicate thatmcr-1is heterogeneously disseminated in both commensal and pathogenic strains ofE. coli, suggest the high flexibility of this gene in its association with diverse genetic backgrounds of the hosts, and provide new insights into the genome epidemiology ofmcr-1among hospital-associatedE. colistrains.IMPORTANCEColistin represents one of the very few available drugs for treating infections caused by extensively multidrug-resistant Gram-negative bacteria. The recently emergentmcr-1colistin resistance gene threatens the clinical utility of colistin and has gained global attention. Howmcr-1spreads in hospital settings remains unknown and was investigated by whole-genome sequencing ofmcr-1-carryingEscherichia coliin this study. The findings revealed extraordinary flexibility ofmcr-1in its spread among genetically diverseE. colihosts and plasmids, nosocomial transmission ofmcr-1-carryingE. coli, and the continuous emergence of novel Inc types of plasmids carryingmcr-1and newmcr-1variants. Additionally,mcr-1was found to be frequently associated with other genes encoding β-lactams and fluoroquinolone resistance. These findings provide important information on the transmission and epidemiology ofmcr-1and are of significant public health importance as the information is expected to facilitate the control of this significant antibiotic resistance threat.

scholarly journals Screening of AmpC-/ESBL-producing Escherichia coli isolates from livestock for STEC/EHEC virulence genes

2021 ◽  
Vol 72 (3) ◽  
pp. 3147
Author(s):  
F PEHLIVANOGLU
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Beta Lactamase ◽  
Chain Reaction ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Polymerase Chain ◽  
Flagellar Antigen

Livestock is an important reservoir of Shiga toxin-producing Escherichia coli and enterohemorrhagic E. coli (STEC/EHEC) strains and acts as a significant source of transmission to humans. In addition to the virulence of STEC/EHEC isolates, antibiotic resistance is also an escalating problem in these bacteria and increases the risk to public health. Therefore, the present study aimed to explore E. coli O157:H7 serotype and STEC/EHEC virulence genes in AmpC- and extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates from cattle, chicken and sheep. A total of 61 confirmed AmpC- or ESBL-producing E. coli isolates were screened for the virulence genes (stx1, stx2, eae, ehxA, espP, katP and saa) and E. coli O157 (rfbO157) and H7 (fliCH7) genes by polymerase chain reaction (PCR). None of the ESBL-producing E. coli was positive for these genes, but six multidrug-resistant AmpC-producing E. coli were positive for the fliCH7 gene only. When considering the function of the H7 flagellar antigen of E. coli, it may be concluded that the development of ESBL/AmpC beta-lactamase production in the E. coli isolates with H7 flagella, which reside in the chicken intestine, may be potentially important for public health regarding both virulence and antimicrobial resistance.

Occurrence of Escherichia coli O157 and Other Verocytotoxin-Producing E. coli in Retail Raw Meats in the Netherlands

1996 ◽  
Vol 59 (12) ◽  
pp. 1267-1272 ◽  
Author(s):  
ANNET E. HEUVELINK ◽  
KAREL WERNARS ◽  
ENNE de BOER
Keyword(s):  
Escherichia Coli ◽  
The Netherlands ◽  
Selective Enrichment ◽  
E Coli ◽  
Enrichment Cultures ◽  
Poultry Products ◽  
Minced Beef ◽  
Test Kit ◽  
Polymerase Chain ◽  
Raw Meats

Raw meats obtained from retail outlets in the Netherlands were examined for the presence of Escherichia coli of serogroup O157 and other verocytotoxin (VT)-producing E. coli (VTEC), in three different surveys. In the first survey O157 VTEC were detected and isolated by selective plating onto sorbitol MacConkey agar following selective enrichment in modified tryptone soy broth with acriflavin. The organisms were isolated from 2 (0.3%) of 770 samples of minced mixed beef and pork, but not detected in samples of raw minced beef (n = 1,000), minced pork (n = 260), or poultry products (n = 300). In the second survey an additional 360 raw meats were examined with the 3M Petrifilm™ Test Kit-HEC, after selective enrichment in modified E. coli broth containing novobiocin. VT-negative E. coli O157 strains were isolated from 22 (6.1%) samples. In the third survey 180 enrichment cultures of the first survey were screened for the presence of VT1 and VT2 genes with a polymerase chain reaction (PCR). Twenty-nine (16.1%) of the 180 enrichment cultures showed a positive PCR: one for the VT1 gene only, 17 for the VT2 gene only, and 11 for both the VT1 and VT2 gene. A total of 46 VTEC strains were isolated from 10 randomly selected PCR-positive samples. Serotyping revealed that 41 of the 46 VTEC isolates belonged to nine different O serogroups; the remaining five were unidentifiable. A number of the serogroups recovered have been associated with human disease.

scholarly journals Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among Klebsiella pneumoniae and Escherichia Coli

2017 ◽  
Vol 11 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Abdulaziz Zorgani ◽  
Hiyam Daw ◽  
Najib Sufya ◽  
Abdullah Bashein ◽  
Omar Elahmer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Gene Encoding ◽  
E Coli ◽  
Infection Control Measures ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
Variant Enzyme

Introduction: Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates. Objective: The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya. Methods: All clinical isolates (76 K. pneumoniae and 75 E. coli) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR). Results: Of the K. pneumoniae and E. coli tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the E. coli isolates were multidrug resistant compared with K. pneumoniae (65.8%). K. pneumoniae ESBL producers were significantly higher (85.5%) compared with (17.3%) E. coli isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of K. pneumoniae, and 4% E. coli isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, blaCMY (n=3), bla MOX (n=1), blaDHA (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: bla CMY and blaEBC (n=1), and blaCMY and blaMOX (n=2). Neither blaFOX nor blaACC was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units. Conclusion: Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.

scholarly journals Experimental infection with enteropathogenic Escherichia coli identified by PCR using enteric-coated capsules in boxer pups

2011 ◽  
Vol 26 (2) ◽  
pp. 144-148
Author(s):  
Eliana Maria Ferreira Gouveia ◽  
Iandara Schettert Silva ◽  
Gerson Nakazato ◽  
Flábio Ribeiro de Araujo ◽  
Marilene Rodrigues Chang
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Experimental Infection ◽  
Control Group ◽  
Enteropathogenic Escherichia Coli ◽  
Enteric Coating ◽  
Coating Solution ◽  
E Coli ◽  
Polymerase Chain ◽  
Enteric Coated

PURPOSE: To verify the possibility of an experimental infection with enteropathogenic Escherichia coli and to confirm by PCR that the symptoms manifested after infection were due to the virulence factors of the studied bacteria. METHODS: Experimental units were 14 healthy pups of Boxer breed, aged 60 days. The animals were divided into three groups. One animal from each litter was included in a control group and the remaining animals were divided into two groups: one inoculated with strain 4083, and another one inoculated with strain SPA14. Gelatinous capsules coated with enteric-coating solution were used for the inoculation of strains. E. coli isolation from feces was performed for all tested animals, and the extracted DNA was subjected to Polymerase Chain Reaction (PCR). RESULTS: All infected animals presented diarrhea and had the gene eae amplified by PCR. CONCLUSION: The efficiency of PCR for the studied strains indicates that this technique can be recommended for the diagnosis of enteropathogenic Escherichia coli as a differential from other pathogens causing diarrhea. It may also be used in the future to verify whether other virulence factors (bfpA gene and EAF plasmid) persist after infection and to assess the pathogenicity of these bacteria.

scholarly journals Hemolysin-Producing Strains among Diarrheagenic Escherichia coli Isolated from Children under 2 Years Old with Diarrheal Disease

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1022
Author(s):  
Anca Mare ◽  
Adrian Man ◽  
Felicia Toma ◽  
Cristina Nicoleta Ciurea ◽  
Răzvan Lucian Coșeriu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Diarrheal Disease ◽  
Multidrug Resistant ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli ◽  
O Antigens ◽  
Hlya Gene ◽  
High Diversity

Even if serotyping based on O antigens is still routinely used by most laboratories for the detection of diarrheagenic Escherichia coli, this method can provide false-positive reactions, due to the high diversity of O antigens. Molecular methods represent a valuable tool that clarifies these situations. In the Bacteriology Laboratory of Mureș County Hospital, between May 2016 and July 2019, 160 diarrheagenic E. coli strains were isolated from children under 2 years old with diarrheic disease. The strains were identified as Shiga toxin-producing E. coli (STEC)/enteropathogenic Escherichia coli (EPEC) via agglutination with polyvalent sera. STEC strains were serotyped using monovalent sera for serogroup O157. Simplex PCR was performed on the strains to determine the presence of the hlyA gene, and, for the positive ones, the hemolytic activity was tested. Antibiotic susceptibility of the identified diarrheagenic E. coli strains was also investigated. STEC strains were the most frequently identified (49.1%), followed by EPEC (40.2%). The hlyA gene was identified in 12 cases, representing 18.2% of the STEC strains. Even if the extended-spectrum β-lactamase (ESBL)-producing strains represented only 10%, a relevant percentage of multidrug-resistant (MDR) strains (24%) was identified.

scholarly journals Addition of L-cysteine to the N- or C-terminus of the all-D-enantiomer [D(KLAKLAK)2] increases antimicrobial activities against multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10176
Author(s):  
Maki K. Ohno ◽  
Teruo Kirikae ◽  
Eisaku Yoshihara ◽  
Fumiko Kirikae ◽  
Isao Ishida
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Cysteine Residue ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
C Terminus

Background Antimicrobial peptides have a broad spectrum of antimicrobial activities and are attracting attention as promising next-generation antibiotics against multidrug-resistant (MDR) bacteria. The all-d-enantiomer [D(KLAKLAK)2] has been reported to have antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa, and to be resistant to protein degradation in bacteria because it is composed of D-enantiomer compounds. In this study, we demonstrated that modification of [D(KLAKLAK)2] by the addition of an L-cysteine residue to its N- or C- terminus markedly enhanced its antimicrobial activities against Gram-negative bacteria such as MDR Acinetobacter baumannii, E. coli, and P. aeruginosa. Methods The peptides [D(KLAKLAK)2] (DP), DP to which L-cysteine was added at the N-terminus C-DP, and DP to which L-cysteine was added at the C-terminus DP-C, were synthesized at >95% purity. The minimum inhibitory concentrations of peptides and antibiotics were determined by the broth microdilution method. The synergistic effects of the peptides and the antibiotics against MDR P. aeruginosa were evaluated using the checkerboard dilution method. In order to assess how these peptides affect the survival of human cells, cell viability was determined using a Cell Counting Kit-8. Results C-DP and DP-C enhanced the antimicrobial activities of the peptide against MDR Gram-negative bacteria, including A. baumannii, E. coli, and P. aeruginosa. The antimicrobial activity of DP-C was greater than that of C-DP, with these peptides also having antimicrobial activity against drug-susceptible P. aeruginosa and drug-resistant P. aeruginosa overexpressing the efflux pump components. C-DP and DP-C also showed antimicrobial activity against colistin-resistant E. coli harboring mcr-1, which encodes a lipid A modifying enzyme. DP-C showed synergistic antimicrobial activity against MDR P. aeruginosa when combined with colistin. The LD50 of DP-C against a human cell line HepG2 was six times higher than the MIC of DP-C against MDR P. aeruginosa. The LD50 of DP-C was not altered by incubation with low-dose colistin. Conclusion Attachment of an L-cysteine residue to the N- or C-terminus of [D(KLAKLAK)2] enhanced its antimicrobial activity against A. baumannii, E. coli, and P. aeruginosa. The combination of C-DP or DP-C and colistin had synergistic effects against MDR P. aeruginosa. In addition, DP-C and C-DP showed much stronger antimicrobial activity against MDR A. baumannii and E. coli than against P. aeruginosa.

scholarly journals Prevalence of tet(X4) in Escherichia coli From Duck Farms in Southeast China

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Yu ◽  
Chao-Yue Cui ◽  
Xu Kuang ◽  
Chong Chen ◽  
Min-Ge Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multiple Drug Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Southeast China ◽  
E Coli ◽  
Polymerase Chain ◽  
Human Infections ◽  
Primary Gene

ObjectivesCarbapenems, colistin, and tigecycline are critically important antibiotics in clinics. After the global appearance of blaNDM and mcr mediating the resistance to carbapenems and colistin, respectively, tigecycline becomes the last-resort drug against severe human infections caused by multidrug-resistant bacteria. Recently, a mobile tigecycline resistance gene tet(X4) has been identified in Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii that causes high resistance to tigecycline and other tetracyclines. In this study, the prevalence of tet(X4) in E. coli isolates from duck and goose farms in Southeast China was identified and characterized.MethodsFeces, soil, sewage, and dust samples were collected from duck and goose farms along with the southeast coast provinces of China. Antimicrobial susceptibility testing and polymerase chain reaction screening were performed to investigate the phenotype and genotype of tigecycline resistance. Conjugation, S1 pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing were used to determine the transferability, genetic location, and the genomic characteristics of tet(X4).ResultsIn total, 1,716 samples were collected, and 16 isolates (0.9%) recovered from Guangdong, Shandong, and Jiangsu were positive for tet(X4) gene with tigecycline minimum inhibitory concentrations ≥16 mg/L. Notably, among these tet(X4)-positive E. coil isolates, seven of them were from the environment samples (soil and sewage). PFGE and multilocus sequence typing demonstrated that ST3997 was the most prevalent sequence type (eight isolates, 50%) in Jiangsu province. By conjugation assays, 11 isolates were able to transfer tet(X4) plasmid to E. coli C600 recipient, and these plasmids belonged to IncHI1 and IncX1 detected by sequence analysis. tet(X4) was found adjacent to an insertion sequence ISCR2 downstream and a catD gene upstream for all isolates. In addition, multiple-drug resistance to tigecycline, chlortetracycline, ampicillin, florfenicol, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, and fosfomycin was profiled in most of the tet(X4)-positive isolates.ConclusionThe identification of tet(X4) harboring E. coli strains in duck farms and their surrounding environment enlarges our knowledge of the variety and prevalence of tigecycline resistance. The prevalence of tet(X4) raises concern for the use of tetracyclines in animal farming, and the tet(X4) gene should be listed as primary gene for resistance surveillance.

Sign in / Sign up

Export Citation Format

Share Document