scholarly journals In silico Assessment of the Genotypic Distribution of Virulence and Antibiotic Resistance Genes in Vibrio cholerae

2017 ◽  
Vol 16 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Nusrat Nahar ◽  
Ridwan Bin Rashid

Vibrio cholerae has long been reported as an important cause of death in developing countries. The study detected the virulence and antibiotic resistance gene of eight V. cholerae isolates through in silico tools. Cholera toxins, ctxA and ctxB were found in six isolates (75%). Seventy-five percent isolates were also found to be positive for zonula occludens toxin, zot which is known to increase the permeability by altering the tight junction of the small intestine. Accessory cholera enterotoxin ace, responsible for fluid accumulation, was detected in four V. cholerae strains. Seven isolates (87.5%) were positive for toxin-coregulated pilus, tcp which helps the bacteria to adhere to gut mucosa. Both ompW and toxR genes were found in 87.5% of the isolates. Twenty-five percent isolates harboured strA, strB, sulII, dfrA1, floR genes and SXT element demonstrating that they were multidrug-resistant (MDG) bacterium. One isolate was found to be positive for tetA gene while no erythromycin resistance gene, ermA and ermB was found. Virulence genes were found in all genotypes indicating that their distribution was not genotypeoriented while genotype 2 harboured no antibiotic resistance genes. This data helps to predict virulence genes associated with cholera and also demonstrates the presence of antibiotic resistance genes. Bacteria acquired the antibiotic resistance gene through natural process which cannot be stopped. So by analyzing the resistance pattern we can choose appropriate antibiotics. In silico study helps us to predict the antibiotic resistant genotypes and can easily identify antibiotic resistant strains which help us to treat cholera infections and reduce the morbidity and mortality rate of the infected individuals.Dhaka Univ. J. Pharm. Sci. 16(1): 77-85, 2017 (June)

2001 ◽  
Vol 45 (11) ◽  
pp. 2991-3000 ◽  
Author(s):  
Bianca Hochhut ◽  
Yasmin Lotfi ◽  
Didier Mazel ◽  
Shah M. Faruque ◽  
Roger Woodgate ◽  
...  

ABSTRACT 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 SXTMO10, 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, SXTET, does not contain the same resistance genes as SXTMO10. 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.


2000 ◽  
Vol 44 (5) ◽  
pp. 1315-1321 ◽  
Author(s):  
Anders Dalsgaard ◽  
Anita Forslund ◽  
Oralak Serichantalergs ◽  
Dorthe Sandvang

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.


2014 ◽  
Vol 19 (3) ◽  
pp. 34-39
Author(s):  
M. V Podshivalova ◽  
Yu. A Kuzyutina ◽  
I. B Zakharova ◽  
Ya. A Lopasteyskaya ◽  
D. V Viktorov

In the paper there is presented a characteristics of antibiotic-resistant strains of Vibrio cholerae, isolated in the Volgograd region during the period of 1980-2000. There were studied cultural and morphological properties of the isolates, their biochemical activity, resistance to antibiotics of different classes, there was performed the detection of virulence genes and sequences of transmissible SXT-element. There was demonstrated the presence of different types of SXT in the content of the genome of the examined strains - SXT MO10 element with cluster of the antibiotic resistance gene sulII-strB-dfr18, SXT ET element carrying the sequences sulII dfrA1, and not having a resistance gene to aminoglycosides strB, and SXT S element with deleted cluster of antibiotic resistance genes.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 230
Author(s):  
Shan Wan ◽  
Min Xia ◽  
Jie Tao ◽  
Yanjun Pang ◽  
Fugen Yu ◽  
...  

In this study, we used a metagenomic approach to analyze microbial communities, antibiotic resistance gene diversity, and human pathogenic bacterium composition in two typical landfills in China. Results showed that the phyla Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in the two landfills, and archaea and fungi were also detected. The genera Methanoculleus, Lysobacter, and Pseudomonas were predominantly present in all samples. sul2, sul1, tetX, and adeF were the four most abundant antibiotic resistance genes. Sixty-nine bacterial pathogens were identified from the two landfills, with Klebsiella pneumoniae, Bordetella pertussis, Pseudomonas aeruginosa, and Bacillus cereus as the major pathogenic microorganisms, indicating the existence of potential environmental risk in landfills. In addition, KEGG pathway analysis indicated the presence of antibiotic resistance genes typically associated with human antibiotic resistance bacterial strains. These results provide insights into the risk of pathogens in landfills, which is important for controlling the potential secondary transmission of pathogens and reducing workers’ health risk during landfill excavation.


2017 ◽  
Vol 16 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Nusrat Nahar ◽  
Ridwan Bin Rashid

A total of twelve isolates were screened for virulence and antibiotic resistance genes associated with Klebsiella pneumoniae infections. Virulence and antibiotic resistance genes were detected by in silico PCR amplification. Iron uptake protein entB was detected in 66.67% (n=8) of the isolates while no isolate was found to harbour chelating agent irp2. Iron uptake system kfu, involved in purulent tissue infections and capsule formation, was identified in 25% (n=3) of the isolates. Regulator of mucoid phenotype A, rmpA was not found in any of the isolates. The wabG gene, responsible for urinary tract infections was found in seven K. pneumoniae strains. Five uge positive strains might play role in the pathogenicity of K. pneumoniae infections. About 83.33% of the isolates were positive for type 1 fimbriae fimH1 while no type 3 fimbriae mrkD gene was found. Complement reaction blocked by plasmid traT gene was not observed in Klebsiella species while eight isolates harboured outer membrane lipoprotein, ycfM which protects Klebsiella species from antibiotics. Antibiotic resistance genes blaTEM and blaSHV were detected in 33.33% (n=4) and 66.67% (n=8) of the isolates while 25% isolates carried both blaTEM and blaSHV genes. Genotype 1 carried fimH1 and ycfM genes while all the virulence genes studied were present in genotype 2 and 3. The blaSHV gene was detected in all the genotypes while blaTEM gene was found in only genotype 1 and 3. The findings of this study would be helpful to predict virulence gene associated with Klebsiella infections. This data also helps us to choose antibiotics for treating Klebsiella infections. By assessing the genotypic distribution of antibiotic resistance gene, correct antibiotic can be used to treat the infection. This could help reduce emergence of antibiotic resistance since it is known that incorrect choice of antibiotics contributes to antibiotic resistance.Dhaka Univ. J. Pharm. Sci. 16(1): 119-127, 2017 (June)


2012 ◽  
Vol 56 (9) ◽  
pp. 4703-4706 ◽  
Author(s):  
Jennifer L. Cottell ◽  
Mark A. Webber ◽  
Laura J. V. Piddock

ABSTRACTThe treatment of infections caused by antibiotic-resistant bacteria is one of the great challenges faced by clinicians in the 21st century. Antibiotic resistance genes are often transferred between bacteria by mobile genetic vectors called plasmids. It is commonly believed that removal of antibiotic pressure will reduce the numbers of antibiotic-resistant bacteria due to the perception that carriage of resistance imposes a fitness cost on the bacterium. This study investigated the ability of the plasmid pCT, a globally distributed plasmid that carries an extended-spectrum-β-lactamase (ESBL) resistance gene (blaCTX-M-14), to persist and disseminate in the absence of antibiotic pressure. We investigated key attributes in plasmid success, including conjugation frequencies, bacterial-host growth rates, ability to cause infection, and impact on the fitness of host strains. We also determined the contribution of theblaCTX-M-14gene itself to the biology of the plasmid and host bacterium. Carriage of pCT was found to impose no detectable fitness cost on various bacterial hosts. An absence of antibiotic pressure and inactivation of the antibiotic resistance gene also had no effect on plasmid persistence, conjugation frequency, or bacterial-host biology. In conclusion, plasmids such as pCT have evolved to impose little impact on host strains. Therefore, the persistence of antibiotic resistance genes and their vectors is to be expected in the absence of antibiotic selective pressure regardless of antibiotic stewardship. Other means to reduce plasmid stability are needed to prevent the persistence of these vectors and the antibiotic resistance genes they carry.


2002 ◽  
Vol 184 (15) ◽  
pp. 4259-4269 ◽  
Author(s):  
John W. Beaber ◽  
Bianca Hochhut ◽  
Matthew K. Waldor

ABSTRACT SXT is representative of a family of conjugative-transposon-like mobile genetic elements that encode multiple antibiotic resistance genes. In recent years, SXT-related conjugative, self-transmissible integrating elements have become widespread in Asian Vibrio cholerae. We have determined the 100-kb DNA sequence of SXT. This element appears to be a chimera composed of transposon-associated antibiotic resistance genes linked to a variety of plasmid- and phage-related genes, as well as to many genes from unknown sources. We constructed a nearly comprehensive set of deletions through the use of the one-step chromosomal gene inactivation technique to identify SXT genes involved in conjugative transfer and chromosomal excision. SXT, unlike other conjugative transposons, utilizes a conjugation system related to that encoded by the F plasmid. More than half of the SXT genome, including the composite transposon-like structure that contains its antibiotic resistance genes, was not required for its mobility. Two SXT loci, designated setC and setD, whose predicted amino acid sequences were similar to those of the flagellar regulators FlhC and FlhD, were found to encode regulators that activate the transcription of genes required for SXT excision and transfer. Another locus, designated setR, whose gene product bears similarity to lambdoid phage CI repressors, also appears to regulate SXT gene expression.


2019 ◽  
Author(s):  
Evelyn Loo ◽  
Amanda Zain ◽  
Gaik Chin Yap ◽  
Rikky W Purbojati ◽  
Daniela I Drautz-Moses ◽  
...  

Abstract Background: The rapid spread of multidrug- resistant pathogenic bacteria is a worldwide public health concern. Given the high carriage rate of extended spectrum beta-lactamase (ESBL)- producing Enterobacteriaceae in Asia, we aimed to evaluate community prevalence and dynamics by studying the longitudinal changes in antibiotic resistance gene (ARG) profiles and prevalence of ESBL-producing E coli and K. pneumoniae in the intestinal microbiome of infants participating in the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) study, a longitudinal cohort study of pregnant women and their infants. Methods: We analysed the antibiotic resistance genes profile in the first year of life among 75 infants who had stool samples collected at multiple timepoints using metagenomics. Results: The mean number of ARGs per infant increased with age. The most common ARGs identified confer resistance to aminoglycoside, beta-lactam, macrolide and tetracycline antibiotics; all infants harboured these antibiotic resistance genes at some point in the first year of life. Few ARGs persisted throughout the first year of life. Beta-lactam resistant Escherichia coli and Klebsiella pneumoniae were detected in 4 (5.3%) and 32 (42.7%) of subjects respectively. Conclusion: In this longitudinal cohort study of healthy infants living in a region with high endemic antibacterial resistance, we demonstrate that majority of the infants harboured a number of antibiotic resistance genes in their gut and showed that the infant gut resistome is diverse and dynamic over the first year of life.


2019 ◽  
Vol 71 (2) ◽  
pp. 419-421
Author(s):  
Quentin Le Bastard ◽  
Pajau Vangay ◽  
Eric Batard ◽  
Dan Knights ◽  
Emmanuel Montassier

Abstract Little is known about the effect of human migration on gut microbiome antibiotic resistance gene (ARG) carriage. Using deep shotgun stool metagenomics analysis, we found a rapid increase in gut microbiome ARG richness and abundance in women from 2 independent ethnic groups relocating from Thailand to the United States.


2010 ◽  
Vol 59 (7) ◽  
pp. 804-807 ◽  
Author(s):  
David Skurnik ◽  
Raymond Ruimy ◽  
Derren Ready ◽  
Etienne Ruppe ◽  
Claire Bernède-Bauduin ◽  
...  

The mercury resistance gene merA has often been found together with antibiotic resistance genes in human commensal Escherichia coli. To study this further, we analysed mercury resistance in collections of strains from various populations with different levels of mercury exposure and various levels of antibiotic resistance. The first population lived in France and had no known mercury exposure. The second lived in French Guyana and included a group of Wayampi Amerindians with a known high exposure to mercury. Carriage rates of mercury resistance were assessed by measuring the MIC and by detecting the merA gene. Mercury-resistant E. coli was found significantly more frequently in the populations that had the highest carriage rates of antibiotic-resistant E. coli and in parallel antibiotic resistance was higher in the population living in an environment with a high exposure to mercury, suggesting a possible co-selection. Exposure to mercury might be a specific driving force for the acquisition and maintenance of mobile antibiotic resistance gene carriage in the absence of antibiotic selective pressure.


Sign in / Sign up

Export Citation Format

Share Document