scholarly journals In Silico Analysis of Antibiotic Resistance Genes in the Gut Microflora of Individuals from Diverse Geographies and Age-Groups

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e83823 ◽  
Author(s):  
Tarini Shankar Ghosh ◽  
Sourav Sen Gupta ◽  
Gopinath Balakrish Nair ◽  
Sharmila S. Mande
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)


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Teresa Fasciana ◽  
Bernardina Gentile ◽  
Maria Aquilina ◽  
Andrea Ciammaruconi ◽  
Chiara Mascarella ◽  
...  

Abstract Background Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. Methods 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypes Results MLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico β-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group. Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis. Conclusions Our data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies.


2018 ◽  
Vol 70 (3) ◽  
pp. 581-588
Author(s):  
Tanja Beric ◽  
Marjan Biocanin ◽  
Slavisa Stankovic ◽  
Ivica Dimkic ◽  
Tamara Janakiev ◽  
...  

Identification of 33 Bacillus spp. isolates from different environmental samples collected from the territory of Serbia was performed by sequencing of the 5?-hypervariable section of 16S rRNA gene. Eight species were identified within four phylogenetic groups: B. pumilus, B. megaterium, B. subtilis and B. cereus. Determination of their antibiotic resistance was performed using the minimum inhibitory concentration (MIC) assay. We found that just one isolate was resistant to gentamicin, 9 were resistant to clindamycin and all were resistant to vancomycin. Based on the profile of resistance, the isolates were categorized into 4 categories. In silico analysis of the erythromycin-resistance (erm) gene for clindamycin resistance showed their distribution between related and nonrelated soil and human isolates including different species of Bacillus genera. This finding indicates that Bacillus spp. from the environment could be a source of resistance to clindamycin. The potential for the presence and spread of resistance determinants in the soil and similar ecosystems exists so that monitoring of antibiotic resistance genes in nonpathogenic Bacillus strains from the environment is advised.


2009 ◽  
Vol 53 (6) ◽  
pp. 2492-2498 ◽  
Author(s):  
Laurent Poirel ◽  
Amélie Carrër ◽  
Johann D. Pitout ◽  
Patrice Nordmann

ABSTRACT Antibiotic resistance genes are spread mostly through plasmids, integrons (as a form of gene cassettes), and transposons in gram-negative bacteria. We describe here a novel genetic structure, named the integron mobilization unit (IMU), that has characteristics similar to those of miniature inverted transposable elements (MITEs). Two IMUs (288 bp each) were identified from a carbapenem-resistant Enterobacter cloacae isolate that formed a composite structure encompassing a defective class 1 integron containing the carbapenem resistance gene bla GES-5. This ß-lactamase gene was located on a 7-kb IncQ-type plasmid named pCHE-A, which was sequenced completely. The plasmid pCHE-A was not self conjugative but was mobilizable, and it was successfully transferred from E. cloacae to Pseudomonas aeruginosa. The in silico analysis of the extremities of the IMU elements identified similarities with those of insertion sequence ISSod9 from Shewanella oneidensis MR-1. The mobilization of the IMU composite structure was accomplished by using the transposase activity of ISSod9 that was provided in trans. This is the first identification of MITE-type structures as a source of gene mobilization, implicating here a clinically relevant antibiotic resistance gene.


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)


mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiancheng Zeng ◽  
Xuelin Chi ◽  
Brian T. Ho ◽  
Damee Moon ◽  
Christine Lambert ◽  
...  

ABSTRACT Extensive drug resistance (XDR) is an escalating global problem. Escherichia coli strain Sanji was isolated from an outbreak of pheasant colibacillosis in Fujian province, China, in 2011. This strain has XDR properties, exhibiting sensitivity to carbapenems but no other classes of known antibiotics. Whole-genome sequencing revealed a total of 32 known antibiotic resistance genes, many associated with insertion sequence 26 (IS26) elements. These were found on the Sanji chromosome and 2 of its 6 plasmids, pSJ_255 and pSJ_82. The Sanji chromosome also harbors a type 2 secretion system (T2SS), a type 3 secretion system (T3SS), a type 6 secretion system (T6SS), and several putative prophages. Sanji and other ST167 strains have a previously uncharacterized O-antigen (O89b) that is most closely related to serotype O89 as determined on the basis of analysis of the wzm-wzt genes and in silico serotyping. This O89b-antigen gene cluster was also found in the genomes of a few other pathogenic sequence type 617 (ST617) and ST10 complex strains. A time-scaled phylogeny inferred from comparative single nucleotide variant analysis indicated that development of these O89b-containing lineages emerged about 30 years ago. Comparative sequence analysis revealed that the core genome of Sanji is nearly identical to that of several recently sequenced strains of pathogenic XDR E. coli belonging to the ST167 group. Comparison of the mobile elements among the different ST167 genomes revealed that each genome carries a distinct set of multidrug resistance genes on different types of plasmids, indicating that there are multiple paths toward the emergence of XDR in E. coli. IMPORTANCE E. coli strain Sanji is the first sequenced and analyzed genome of the recently emerged pathogenic XDR strains with sequence type ST167 and novel in silico serotype O89b:H9. Comparison of the genomes of Sanji with other ST167 strains revealed distinct sets of different plasmids, mobile IS elements, and antibiotic resistance genes in each genome, indicating that there exist multiple paths toward achieving XDR. The emergence of these pathogenic ST167 E. coli strains with diverse XDR capabilities highlights the difficulty of preventing or mitigating the development of XDR properties in bacteria and points to the importance of better understanding of the shared underlying virulence mechanisms and physiology of pathogenic bacteria.


2017 ◽  
Vol 20 (1) ◽  
pp. 71-84
Author(s):  
Nusrat Nahar ◽  
Ridwan Bin Rashid ◽  
ANM Hamidul Kabir ◽  
Mohammad Sharifur Rahman

In silico studies of the genes of Staphylococcus spp. might establish some correlations with multiple pathological factors. Sixty isolates of Staphylococcus spp. have been studied here targeting virulence and antibiotic resistance genes through in silico tools. Here, in silico PCR (polymerase chain reaction) amplification detected both virulence and antibiotic resistance genes. Study revealed that most of the isolates harboured either cap5 (40%) or cap8 (31.67%) locus gene. Staphylococcal enterotoxin was detected in 63.33% of the isolates. The sea gene, responsible for food poisoning, was detected in 26.67% of the isolates. The tst positive isolates (5%), responsible for toxic shock syndrome, were present in only genotype 8. No exfoliative toxin was detected. The icaA gene, responsible for intracellular adherence, appeared in 80% of the isolates. Alpha hemolysin gene, hla, was detected in 63.33% of the isolates. Sixty-five percent of the isolates harboured the mecA genes. Both ?-lactamase (blaZ) and erythromycin resistance, ermA genes were available in 38.33% of the isolates. In silico pulsed field gel electrophoresis (PFGE) digestion was able to divide isolates into 23 genotypes. Genotype 8 and 11 harboured tetracycline resistance genes, tetM and tetK. The tetM gene (18.33%) was more prevalent than tetK gene (11.67%). Genotype 1 and 11 were considered more virulent than others. Genotype 11 also carried six antibiotic resistance genes but did not carry the genes msrA, msrB, ermB and ermC. The data generated here might aid in the prediction of the virulence and resistance profile based on genotyping as well as contribute in vaccine development.Bangladesh Pharmaceutical Journal 20(1): 71-84, 2017


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