scholarly journals Genetic diversity and antibiotic resistance of clinical and environmental Vibrio cholerae suggests that many serogroups are reservoirs of resistance

2004 ◽  
Vol 132 (5) ◽  
pp. 985-992 ◽  
Author(s):  
L. C. CAMPOS ◽  
V. ZAHNER ◽  
K. E. S. AVELAR ◽  
R. M. ALVES ◽  
D. S. G. PEREIRA ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Pcr Analysis ◽  
Enzyme Electrophoresis ◽  
South American ◽  
Antibiotic Resistance Profile ◽  
Class 1 ◽  
Pandemic Strains ◽  
Close Genetic Relationship

Vibrio cholerae is an important human pathogen and the cause of cholera. Since genetic variation and antibiotic resistance of strains have implications for effective treatment of the disease, we examined the genetic diversity and antibiotic resistance profile in 92 clinical strains (serogroup O1) and 56 environmental strains (O1 antigen, 42 strains; non-O1 antigen, 14 strains) isolated in Brazil between 1991 and 1999. Clinical and environmental O1 strains showed greater drug resistance compared to environmental non-O1 strains. Nearly all clinical O1 strains were resistant to one or more antibiotics while half of the environmental O1 and non-O1 strains were resistant to one or more antibiotics. No plasmids or class 1 integrons were detected in the strains by PCR analysis. Multilocus enzyme electrophoresis analysis (MLEE) suggests most of the O1 strains belong to a single (South American) clone that is related but different to seventh-pandemic strains isolated from other parts of the world. Our results show that there is a close genetic relationship between clinical and environmental O1 strains and that many serogroups and the environment can be a reservoir for antibiotic resistance.

Antibiotic resistance profile of Salmonella enterica isolated from exotic and indigenous leafy green vegetables in Accra, Ghana

2021 ◽  
Author(s):  
Jinru Chen ◽  
Joycelyn Quansah
Keyword(s):  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Gene Cassette ◽  
Nucleotide Sequencing ◽  
Dilution Method ◽  
Class 1 Integron ◽  
Antibiotic Resistant ◽  
Resistance Profile ◽  
Antibiotic Resistance Profile ◽  
Class 1

Fresh produce-borne enteric bacterial pathogens with resistance to antibiotics have posed serious challenges to food safety and public health worldwide.  This study examined the antibiotic resistance profile of Salmonella enterica (n=33), previously isolated from exotic and indigenous leafy green vegetable samples (n=328) collected from 50 vegetable farms in 12 farming areas and 37 vegetable sellers in 4 market centers in Accra, Ghana during the period of March 2016 to March 2017, and determined the distribution of integrons among antibiotic-resistant isolates.  The susceptibility of the Salmonella isolates to 12 antibiotics was assayed using the standard disc diffusion assay.  The minimum inhibitory concentrations (MICs) of the five most resisted antibiotics were determined using the twofold macro dilution method.  PCR assay was used to detect the presence of integrons in Salmonella cells, and PCR product with amplified integron gene cassette was purified and sequenced using the Sanger sequencing technology.  The Salmonella isolates used in the study resisted at least one tested antibiotic, and multi-drug resistant (MDR) isolates were 30.3% (10/33).  Most isolates (81.8%) were resistant to sulfisoxazole.  The MICs of tetracycline, cefoxitin, streptomycin, ampicillin, and sulfisoxazole were 16, 32, 64, 64, and > 1,024 µg/ml, respectively.  A total of five different patterns of MDR were observed among the Salmonella isolates, and the common MDR patterns were AAuFox (30.3%) and AAuFoxSSu (18.1%).  One out of the 33 (3.0%) Salmonella isolates tested positive for class 1 integron with a gene cassette of about 800 bp.  Nucleotide sequencing revealed the class 1 integron carried a single gene dfrA7 .  Future studies are needed to confirm whether the consumption of contaminated leafy green vegetables is a route of acquiring antibiotic-resistant Salmonella by consumers in Accra, Ghana.

Antibiotic Resistance Conferred by a Conjugative Plasmid and a Class I Integron in Vibrio cholerae O1 El Tor Strains Isolated in Albania and Italy

1999 ◽  
Vol 43 (3) ◽  
pp. 693-696 ◽  
Author(s):  
Vincenzo Falbo ◽  
Alessandra Carattoli ◽  
Fabio Tosini ◽  
Cristina Pezzella ◽  
Anna Maria Dionisi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Molecular Basis ◽  
Gene Cassette ◽  
Multidrug Resistant ◽  
Conjugative Plasmid ◽  
Class 1 Integron ◽  
Class 1 ◽  
Vibrio Cholerae O1 ◽  
El Tor

ABSTRACT Multidrug-resistant Vibrio cholerae O1 El Tor strains isolated during the 1994 outbreak of cholera in Albania and Italy were characterized for the molecular basis of antibiotic resistance. All strains were found to be resistant to tetracycline, streptomycin, spectinomycin, trimethoprim, sulfathiazole, and the vibriostatic compound O/129 (2,4-diamino-6,7-diisopropylteridine). Resistance genes were self-transferable by a conjugative plasmid of about 60 MDa, with the exception of spectinomycin resistance, which was conferred by theaadA1 gene cassette located in the bacterial chromosome within a class 1 integron. The resistance to trimethoprim and O/129 was conferred by the dfrA1 gene, which was present on the plasmid. Although the dfrA1 gene is known to be borne on an integron cassette, class 1, 2, or 3 intI genes were not detected as part of the plasmid DNA from the strains studied.

scholarly journals Allelic Diversity and Population Structure in Vibrio cholerae O139 Bengal Based on Nucleotide Sequence Analysis

2002 ◽  
Vol 184 (5) ◽  
pp. 1304-1313 ◽  
Author(s):  
M. Farfán ◽  
D. Miñana-Galbis ◽  
M. C. Fusté ◽  
J. G. Lorén
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Vibrio Cholerae ◽  
Allelic Diversity ◽  
Nucleotide Sequence Analysis ◽  
Intragenic Recombination ◽  
Enzyme Electrophoresis ◽  
Epidemic Period ◽  
The Matrix ◽  
Clonal Population Structure

ABSTRACT Comparative analysis of gene fragments of six housekeeping loci, distributed around the two chromosomes of Vibrio cholerae, has been carried out for a collection of 29 V. cholerae O139 Bengal strains isolated from India during the first epidemic period (1992 to 1993). A toxigenic O1 ElTor strain from the seventh pandemic and an environmental non-O1/non-O139 strain were also included in this study. All loci studied were polymorphic, with a small number of polymorphic sites in the sequenced fragments. The genetic diversity determined for our O139 population is concordant with a previous multilocus enzyme electrophoresis study in which we analyzed the same V. cholerae O139 strains. In both studies we have found a higher genetic diversity than reported previously in other molecular studies. The results of the present work showed that O139 strains clustered in several lineages of the dendrogram generated from the matrix of allelic mismatches between the different genotypes, a finding which does not support the hypothesis previously reported that the O139 serogroup is a unique clone. The statistical analysis performed in the V. cholerae O139 isolates suggested a clonal population structure. Moreover, the application of the Sawyer's test and split decomposition to detect intragenic recombination in the sequenced gene fragments did not indicate the existence of recombination in our O139 population.

scholarly journals Distribution and Content of Class 1 Integrons in Different Vibrio cholerae O-Serotype Strains Isolated in Thailand

2000 ◽  
Vol 44 (5) ◽  
pp. 1315-1321 ◽  
Author(s):  
Anders Dalsgaard ◽  
Anita Forslund ◽  
Oralak Serichantalergs ◽  
Dorthe Sandvang
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Gene Cassette ◽  
Gene Cassettes ◽  
Class 1 Integrons ◽  
Class 1

ABSTRACT In this study, 176 clinical and environmental Vibrio cholerae strains of different O serotypes isolated in Thailand from 1982 to 1995 were selected and studied for the presence of class 1 integrons, a new group of genetic elements which carry antibiotic resistance genes. Using PCR and DNA sequencing, we found that 44 isolates contained class 1 integrons harboring the aadB,aadA2, blaP1, dfrA1, anddfrA15 gene cassettes, which encode resistance to gentamicin, kanamycin, and tobramycin; streptomycin and spectinomycin; β-lactams; and trimethoprim, respectively. Each cassette array contained only a single antibiotic resistance gene. Although resistance genes in class 1 integrons were found in strains from the same epidemic, as well as in unrelated non-O1, non-O139 strains isolated from children with diarrhea, they were found to encode only some of the antibiotic resistance expressed by the strains. Serotype O139 strains did not contain class 1 integrons. However, the appearance and disappearance of the O139 serotype in the coastal city Samutsakorn in 1992 and 1993 were associated with the emergence of a distinct V. cholerae O1 strain which contained the aadA2resistance gene cassette. A 150-kb self-transmissible plasmid found in three O1 strains isolated in 1982 contained the aadB gene cassette. Surprisingly, several strains harbored two integrons containing different cassettes. Thus, class 1 integrons containing various resistance gene cassettes are distributed among differentV. cholerae O serotypes of mainly clinical origin in Thailand.

scholarly journals Cloning, Nucleotide Sequencing, and Analysis of the AcrAB-TolC Efflux Pump of Enterobacter cloacae and Determination of Its Involvement in Antibiotic Resistance in a Clinical Isolate

2007 ◽  
Vol 51 (9) ◽  
pp. 3247-3253 ◽  
Author(s):  
Astrid Pérez ◽  
Delia Canle ◽  
Cristina Latasa ◽  
Margarita Poza ◽  
Alejandro Beceiro ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Clinical Isolate ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Pcr Analysis ◽  
Nucleotide Sequencing ◽  
Efflux Pump Inhibitor ◽  
Antibiotic Resistance Profile

ABSTRACT Enterobacter cloacae is an emerging clinical pathogen that may be responsible for nosocomial infections. Management of these infections is often difficult, owing to the high frequency of strains that are resistant to disinfectants and antimicrobial agents in the clinical setting. Multidrug efflux pumps, especially those belonging to the resistance-nodulation-division family, play a major role as a mechanism of antimicrobial resistance in gram-negative pathogens. In the present study, we cloned and sequenced the genes encoding an AcrAcB-TolC-like efflux pump from an E. cloacae clinical isolate (isolate EcDC64) showing a broad antibiotic resistance profile. Sequence analysis showed that the acrR, acrA, acrB, and tolC genes encode proteins that display 79.8%, 84%, 88%, and 82% amino acid identities with the respective homologues of Enterobacter aerogenes and are arranged in a similar pattern. Deletion of the acrA gene to yield an AcrA-deficient EcDC64 mutant (EcΔacrA) showed the involvement of AcrAB-TolC in multidrug resistance in E. cloacae. However, experiments with an efflux pump inhibitor suggested that additional efflux systems also play a role in antibiotic resistance. Investigation of several unrelated isolates of E. cloacae by PCR analysis revealed that the AcrAB system is apparently ubiquitous in this species.

scholarly journals Antibiotic Resistance in the ECOR Collection: Integrons and Identification of a Novel aad Gene

2000 ◽  
Vol 44 (6) ◽  
pp. 1568-1574 ◽  
Author(s):  
Didier Mazel ◽  
Broderick Dychinco ◽  
Vera A. Webb ◽  
Julian Davies
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Antimicrobial Agents ◽  
Gene Cassette ◽  
Streptomycin Resistance ◽  
Mercury Resistance ◽  
Class 1 Integron ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT The 72 Escherichia coli strains of the ECOR collection were examined for resistance to 10 different antimicrobial agents including ampicillin, tetracycline, mercury, trimethoprim, and sulfonamides. Eighteen strains were resistant to at least one of the antibiotics tested, and nearly 20% (14 of 72) were resistant to two or more. Several of the resistance determinants were shown to be carried on conjugative elements. The collection was screened for the presence of the three classes of integrons and for the sul1 gene, which is generally associated with class 1 integrons. The four strains found to carry a class 1 integron also had Tn21-encoded mercury resistance. One of the integrons encoded a novel streptomycin resistance gene, aadA7, with an attC site (or 59-base element) nearly identical to the attC site associated with the qacF gene cassette found in In40 (M.-C. Ploy, P. Courvalin, and T. Lambert, Antimicrob. Agents Chemother. 42:2557–2563, 1998). The conservation of associated attCsites among unrelated resistance cassettes is similar to arrangements found in the Vibrio cholerae superintegrons (D. Mazel, B. Dychinco, V. A. Webb, and J. Davies, Science 280:605–608, 1998) and supports the hypothesis that resistance cassettes are picked up from superintegron pools and independently assembled from unrelated genes and related attC sites.

scholarly journals Class 1 Integron-Borne, Multiple-Antibiotic Resistance Encoded by a 150-Kilobase Conjugative Plasmid in Epidemic Vibrio cholerae O1 Strains Isolated in Guinea-Bissau

2000 ◽  
Vol 38 (10) ◽  
pp. 3774-3779 ◽  
Author(s):  
Anders Dalsgaard ◽  
Anita Forslund ◽  
Andreas Petersen ◽  
Derek J. Brown ◽  
Francisco Dias ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistant Strain ◽  
Case Fatality ◽  
Conjugative Plasmid ◽  
Health Concern ◽  
Multiple Antibiotic Resistance ◽  
Class 1 Integron ◽  
Guinea Bissau ◽  
Class 1

In the 1996–1997 cholera epidemic in Guinea-Bissau, surveillance for antimicrobial resistance showed the emergence of a multidrug-resistant strain of Vibrio cholerae O1 during the course of the epidemic. The strain was resistant to ampicillin, erythromycin, tetracycline, furazolidone, aminoglycosides, trimethoprim, and sulfamethoxazole. Concomitant with the emergence of this strain, we observed a resurgence in the number of registered cholera cases as well as an increase in the case fatality rate from 1.0% before the emergence of the multiple-drug-resistant strain to 5.3% after the emergence of the strain. Our study shows that the strain contained a 150-kb conjugative multiple-antibiotic resistance plasmid with class 1 integron-borne gene cassettes encoding resistance to trimethoprim (dhfrXII) and aminoglycosides [ant(3")-1a]). The finding of transferable resistance to almost all of the antibiotics commonly used to treat cholera is of great public health concern. Studies should be carried out to determine to what extent the strain or its resistance genes have been spread to other areas where cholera is endemic.

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