Drug and Alcohol Rehabilitation: Rapid Identification of Extensively and Extremely Drug Resistant Tuberculosis From Multidrug Resistant Strains; Using PCR-RFLP and PCR-SSCP.

Rapid identification of extensively and extremely drug resistant tuberculosis from multidrug resistant strains; using PCR-RFLP and PCR-SSCP.

Filed under: Drug and Alcohol Rehabilitation

Iran J Microbiol. 2012 Dec; 4(4): 165-70
Tahmasebi P, Farnia P, Sheikholslami F, Velayati A

Resistance in Mycobacterium tuberculosis is caused by mutations in genes encoding drug targets. Investigators have already demonstrated the existence of mutations in codons 88 to 94 in the gyrA gene and also in codons 1400, 1401, and 1483 of rrs gene among extensively and extremely drug resistant tuberculosis (XDR & XXDR-TB) strains. The aim of this study was to identify the XDR and XXDR-TB stains based on their mutational analysis.Susceptibility testing against first and second-line anti-tuberculosis drugs was performed by the proportional method. Based on susceptibility results, samples were later analyzed, using PCR-SSCP and PCR-RFLP for detection of mutation in gyrA and rrs genes.Overall, using proportional method, sixty-three strains (64.9%) were identified as MDR, 8(8.2%) as non-MDR and 26 strains (26.8%) were susceptible. Thirty-one cases (31.9%) were amikacin-resistant and 18 (18.5%) samples were ciprofloxacin-resistant. Using PCR-SSCP and PCR-RFLP, we identified 6(6.2%) and 7(7.2%) resistant strains, respectively. Discrepancy in strains was cross-checked by sequencing. The results showed no mutation in 66.6% and 77.4% of CIP and AMK- resistant strains.Rapid detection of drug-resistant Mycobacterium tuberculosis using molecular techniques could be effective in determining therapeutic regimen and preventing the spread of XDR and MDR TB in the community. We should still keep in mind that a high number of resistant strains may have no mutation in proposed candidate genes.
HubMed – drug


Multi-Locus Sequence Typing (MLST) and Repetitive Extragenic Palindromic Polymerase Chain Reaction (REP-PCR), characterization of shigella spp. over two decades in Tianjin China.

Filed under: Drug and Alcohol Rehabilitation

Int J Mol Epidemiol Genet. 2012; 3(4): 321-32
Cao Y, Wei D, Kamara IL, Chen W

To understand the change of the dominant serogroup of Shigella spp., their antimicrobial resistance over more than two decades in Tianjin, their phylogenetic similarity and to determine their evolutionary biology by using REP-PCR and MLST in order to study their epidemiological character. Multi-locus Sequence Typing was performed to determine their lineage and phylogenetic similarity. REP-PCR typing was used to study the homology of their genomic DNA. The isolated rate of group D Shigella in 2009 and 2010 had obviously increased. Antimicrobial susceptibility test results showed that the resistant rates of the 1981-1983 Shigella flexneri to tetracycline, streptomycin and chloramphenicol varied from 76.47 to 100%, they were all sensitive to other antibiotics. During 2009-2010, the resistance rates of the isolated Shigella flexneri to gentamicin, amikacin, third and fourth Generation Cephalosporins and quinolones had increased. MLST results produced five sequence types and two sequence type complexes. REP-PCR showed DNA band similarities between the 1981-1983 and 2009-2010 strains. The dominant serogroup of Shigella in Tianjin has changed from Shigella flexneri to Shigella sonnei. Increased drug resistance of Shigella flexneri is higher than Shigella sonnei because a great variety of antibiotics has been used. The MLST results showed that the 1981-1983 strains had the same sequence type with some of the 2009-2010 strains. Combination of MLST and REP-PCR produced better discriminatory power than using either method alone.
HubMed – drug


A novel in silico approach to identify potential therapeutic targets in human bacterial pathogens.

Filed under: Drug and Alcohol Rehabilitation

Hugo J. 2011 Dec; 5(1-4): 25-34
Vetrivel U, Subramanian G, Dorairaj S

In recent years, genome-sequencing projects of pathogens and humans have revolutionized microbial drug target identification. Of the several known genomic strategies, subtractive genomics has been successfully utilized for identifying microbial drug targets. The present work demonstrates a novel genomics approach in which codon adaptation index (CAI), a measure used to predict the translational efficiency of a gene based on synonymous codon usage, is coupled with subtractive genomics approach for mining potential drug targets. The strategy adopted is demonstrated using respiratory pathogens, namely, Streptococcus pneumoniae and Haemophilus influenzae as examples. Our approach identified 8 potent target genes (Streptococcus pneumoniae-2, H. influenzae-6), which are functionally significant and also play key role in host-pathogen interactions. This approach facilitates swift identification of potential drug targets, thereby enabling the search for new inhibitors. These results underscore the utility of CAI for enhanced in silico drug target identification. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11568-011-9152-7) contains supplementary material, which is available to authorized users.
HubMed – drug


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