Vibrio cholerae O1 from Accra, Ghana carrying a class 2 integron and the SXT element.
Ontology highlight
ABSTRACT: Objectives
Vibrio cholerae O1 from a 2006 outbreak in Accra were commonly resistant to multiple antimicrobials and, in particular, to trimethoprim/sulfamethoxazole, drugs commonly used in the treatment of cholera. We sought to determine the genetic basis for trimethoprim/sulfamethoxazole resistance in outbreak isolates.Methods
Twenty-seven isolates from the outbreak were screened by PCR and sequencing for class 1 and 2 integrons and for the SXT element.Results
Twenty-one of the 27 isolates examined, all from the Accra metropolitan area, carried both SXT, an integrated chromosomal element, and a class 2 integron bearing dfrA1, sat and aadA1 cassettes. All these isolates had identical random amplification of polymorphic DNA profiles and two of them also carried a class 1 integron.Conclusions
Most strains characterized carried multiple elements conferring resistance to trimethoprim. This suggests that trimethoprim/sulfamethoxazole should not be used empirically in cholera treatment.
SUBMITTER: Opintan JA
PROVIDER: S-EPMC2566517 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Changes in the drug susceptibility pattern were observed in Vibrio cholerae O1 isolated in the Lao People's Democratic Republic during 1993 to 2000. In this study, 50 V. cholerae O1 strains were selected during this period for studying the presence of class I integron and SXT constin. Twenty-four streptomycin-resistant strains out of 26 isolated before 1997 contained a class I integron harboring the aadA1 gene cassette. Twenty-four strains isolated after 1997 contained an SXT constin (a large conjugative element). Twenty of the strains were resistant to chloramphenicol, tetracycline, streptomycin, and trimethoprim-sulfamethoxazole, while four strains were susceptible to the antibiotic tested. The resistance genes included in the SXT constins were floR, tetA, strAB, and sulII, which encode resistance to chloramphenicol, tetracycline, streptomycin, and sulfamethoxazole, respectively. The antibiotic resistance gene cluster was found to be deleted in the four susceptible strains. SXT(LAOS) did not contain dfrA1 or dfr18, which confer resistance to trimethoprim in SXT(ET) and SXT(MO10), respectively. A hot spot region of SXT(LAOS) was sequenced, and we identified two novel open reading frames showing homology to sO24 (exonuclease) and sO23 (helicase) of the genomic island associated with the multidrug resistance region of Salmonella enterica serovar Typhimurium DT104. Analysis of SXT(LAOS) showed that there is a continuous flux of genes among V. cholerae SXT constins which should be carefully monitored.
| S-EPMC434172 | biostudies-literature
Project description: Not available
| S-EPMC3320466 | biostudies-literature
Project description:SXT-related integrating conjugative elements (ICEs) became prevalent in Asian Vibrio cholerae populations after V. cholerae O139 emerged. Here, we describe an SXT-related ICE, ICEVchMex1, in a Mexican environmental V. cholerae isolate. Identification of ICEVchMex1 represents the first description of an SXT-related ICE in the Western Hemisphere. The significant differences between the SXT and ICEVchMex1 genomes suggest that these ICEs have evolved independently.
| S-EPMC1449008 | biostudies-literature
Project description:BackgroundCholera has been endemic in Ghana since its detection in 1970. It has been shown that long-term survival of the bacteria may be attained in aquatic environments. Consequently, cholera outbreaks may be triggered predominantly in densely populated urban areas. We investigated clinical and environmental isolates of Vibrio cholerae O1 in Accra to determine their virulence genes, antibiotic susceptibility patterns and environmental factors maintaining their persistence in the environment.MethodsWater samples from various sources were analyzed for the presence of V. cholerae O1 using culture methods. Forty clinical isolates from a previous cholera outbreak were included in the study for comparison. Antibiotic susceptibility patterns of the bacteria were determined by disc diffusion. Virulence genes were identified by analyzing genes for ctx, tcpA (tcpAEl Tor tcpACl), zot, ompW, rbfO1 and attRS using PCR. Physicochemical characteristics of water were investigated using standard methods. One-way ANOVA and student t - test were employed to analyze the relationship between physicochemical factors and the occurrence of V. cholerae O1.ResultsEleven V. cholerae O1 strains were successfully isolated from streams, storage tanks and wells during the study period. All isolates were resistant to one or more of the eight antibiotics used. Multidrug resistance was observed in over 97% of the isolates. All isolates had genes for at least one virulence factor. Vibrio cholerae toxin gene was detected in 82.4% of the isolates. Approximately 81.8% of the isolates were positive for tcpAEl Tor gene, but also harbored the tcpAcl gene. Isolates were grouped into thirteen genotypes based on the genes analyzed. High temperature, salinity, total dissolved solids and conductivity was found to significantly correlate positively with isolation of V. cholerae O1. V. cholerae serotype Ogawa biotype El tor is the main biotype circulating in Ghana with the emergence of a hybrid strain.ConclusionsMultidrug resistant V. cholerae O1 with different genotypes and pathogenicity are present in water sources and co-exist with non O1/O139 in the study area.
| S-EPMC6341726 | biostudies-literature
Project description:Vibrio cholerae O1 El Tor biotype strains are responsible for three multiyear epidemics of cholera in China during the seventh ongoing pandemic. The presence of the integrative conjugative element SXT is strongly correlated with resistance to nalidixic acid, tetracycline, and trimethoprim-sulfamethoxazole in these strains. Here, we sequenced the conserved genes of the SXT element, including eex, setR, and int, from 59 V. cholerae O1 El Tor strains and extracted and assembled the intact SXT sequences from the 11 genome sequenced strains. These elements had characteristics distinct from those of previously reported integrative conjugative elements (ICEs). They could be clearly divided into two types based on the clustering of conserved genes and gene structures of the elements, showing their possibly independent derivation and evolution. These two types were present before and after 2005, respectively, demonstrating the type substitution that occurred in 2005. Four to six antibiotic-resistant genes were found on the SXT elements, including genes resistant to tetracycline, trimethoprim-sulfamethoxazole, and multiple drugs. In summary, our findings demonstrated the roles of the SXT element in the emergence of multidrug resistance in epidemic O1 El Tor V. cholerae strains in China.
| S-EPMC4783696 | biostudies-literature
Project description:Many recent Asian clinical Vibrio cholerae E1 Tor O1 and O139 isolates are resistant to the antibiotics sulfamethoxazole (Su), trimethoprim (Tm), chloramphenicol (Cm), and streptomycin (Sm). The corresponding resistance genes are located on large conjugative elements (SXT constins) that are integrated into prfC on the V. cholerae chromosome. We determined the DNA sequences of the antibiotic resistance genes in the SXT constin in MO10, an O139 isolate. In SXT(MO10), these genes are clustered within a composite transposon-like structure found near the element's 5' end. The genes conferring resistance to Cm (floR), Su (sulII), and Sm (strA and strB) correspond to previously described genes, whereas the gene conferring resistance to Tm, designated dfr18, is novel. In some other O139 isolates the antibiotic resistance gene cluster was found to be deleted from the SXT-related constin. The El Tor O1 SXT constin, SXT(ET), does not contain the same resistance genes as SXT(MO10). In this constin, the Tm resistance determinant was located nearly 70 kbp away from the other resistance genes and found in a novel type of integron that constitutes a fourth class of resistance integrons. These studies indicate that there is considerable flux in the antibiotic resistance genes found in the SXT family of constins and point to a model for the evolution of these related mobile elements.
| S-EPMC90773 | biostudies-literature
Project description:The resistance profile and its correlation with mobile genetic elements were investigated in 11 Vibrio cholerae O1 and 2 Vibrio parahaemolyticus clinical isolates, as well as in 1 V. cholerae O1 and 1 V. cholerae non-O1 environmental isolate, isolated between 1991 and 1996 in different provinces of Angola. All clinical isolates of V. cholerae O1 were resistant to ampicillin, chloramphenicol, trimethoprim, sulfamethoxazole, and tetracycline. They also contained a large conjugative plasmid (p3iANG) with a set of three class 1 integrons harboring dfrA15, blaP1, and qacH-aadA8 cassettes, which code for resistance to trimethoprim, beta-lactams, quaternary ammonium compounds, and aminoglycosides, clustered in a 19-kb region. Chloramphenicol (cat1), kanamycin (aph), sulfonamide (sul2), and tetracycline (tetG) resistance genes were also carried on the plasmid within the same 19-kb region. A chromosomal integron containing the dfrA15 cassette was also revealed in V. parahaemolyticus strains. SXT integrase genes were present in six V. cholerae isolates but apparently were not associated with known SXT-associated resistance genes. This study indicates that plasmids and integrons contributed mainly to the circulation of multiple-drug resistance determinants in Vibrio strains from Angola.
| S-EPMC1489794 | biostudies-literature
Project description:BackgroundIncrease in the number of multidrug resistant pathogens and the accompanied rise in case fatality rates has hampered the treatment of many infectious diseases including cholera. Unraveling the mechanisms responsible for multidrug resistance in the clinical isolates of Vibrio cholerae would help in understanding evolution of these pathogenic bacteria and their epidemic potential. This study was carried out to identify genetic factors responsible for multiple drug resistance in clinical isolates of Vibrio cholerae O1, serotype Ogawa, biotype El Tor isolated from the patients admitted to the Infectious Diseases Hospital, Kolkata, India, in 2009.Methodology/principal findingsOne hundred and nineteen clinical isolates of V. cholerae were analysed for their antibiotic resistance phenotypes. Antibiogram analysis revealed that majority of the isolates showed resistance to co-trimoxazole, nalidixic acid, polymixin B and streptomycin. In PCR, SXT integrase was detected in 117 isolates and its sequence showed 99% identity notably to ICEVchInd5 from Sevagram, India, ICEVchBan5 from Bangladesh and VC1786ICE sequence from Haiti outbreak among others. Antibiotic resistance traits corresponding to SXT element were transferred from the parent Vibrio isolate to the recipient E. coli XL-1 Blue cells during conjugation. Double-mismatch-amplification mutation assay (DMAMA) revealed the presence of Haitian type ctxB allele of genotype 7 in 55 isolates and the classical ctxB allele of genotype 1 in 59 isolates. Analysis of topoisomerase sequences revealed the presence of mutation Ser83 ? Ile in gyrA and Ser85? Leu in parC. This clearly showed the circulation of SXT-containing V. cholerae as causative agent for cholera in Kolkata.ConclusionsThere was predominance of SXT element in these clinical isolates from Kolkata region which also accounted for their antibiotic resistance phenotype typical of this element. DMAMA PCR showed them to be a mixture of isolates with different ctxB alleles like classical, El Tor and Haitian variants.
| S-EPMC3576390 | biostudies-literature
Project description:We investigated the evolution, phylogeny and antimicrobial resistance of Vibrio cholerae O1 isolates (VCO1) from Ghana. Outbreak and environmental sources of VCO1 were characterized, whole-genome sequenced and compared to globally available seventh pandemic (7P) strains of V. cholerae at SNP resolution. Final analyses included 636 isolates. Novel Ghanaian isolates clustered into three distinct clades (clades 1, 2 and 3) in wave 3 of the 7P lineage. The closest relatives of our novel Ghanaian isolates were from Benin, Cameroon, Togo, Niger and Nigeria. All novel Ghanaian isolates were multi-drug resistant. Environmental isolates clustered into clade 2, despite being isolated years later, showing the possibility of persistence and re-emergence of older clades. A lag phase of several years from estimated introduction to reported cases suggests pathogen persistence in the absence of reported cholera cases. These results highlight the importance of deeper surveillance for understanding transmission routes between bordering countries and planning tailored vaccination campaigns in an effort to eradicate cholera.
| S-EPMC8627208 | biostudies-literature
Project description:Vibrio cholerae O1 exists as two major serotypes, Inaba and Ogawa, which are associated with the O antigen of the lipopolysaccharide and are capable of unequal reciprocal interconversion. The 20-kilobase rfb regions encoding O-antigen biosynthesis in strains 569B (Inaba) and O17 (Ogawa) have been cloned in Escherichia coli K-12 and the nucleotide sequences have been determined. Besides several base substitutions and a small deletion in the 569B sequence relative to O17, there is a single nucleotide change resulting in a TGA stop codon within the gene for the 32-kDa RfbT protein. We have demonstrated that rfbT is responsible for serotype conversion (Inaba to Ogawa). The construction of a specific rfbT mutation in the Ogawa strain O17, and the ability of the gene from O17 to complement Inaba strains to Ogawa, confirmed rfbT as the gene required for the Ogawa serotype. By Southern hybridization and sequencing of PCR products of a number of strains, we have shown that the changes observed in one Inaba strain (569B) are not conserved in other Inaba strains. This may explain why some Inaba strains are able to convert to Ogawa whereas others are not. The protein encoded by rfbT has been identified and expressed in E. coli K-12 using a phage T7 expression system. Amino-terminal analysis of partially purified protein has identified the translational start of the protein. Primer extension studies have enabled the 5' end of the mRNA to be defined. It exists as a separate transcript from the rest of the rfb region, and the distinctive G + C content of rfbT suggests that it has been acquired from a non-Vibrio source.
| S-EPMC48702 | biostudies-other