Lecturer, Federal University of Technology Owerri Nigeria
My research is focused on microbial resistance to antibiotics, cellular and molecular mechanisms of bacterial pathogenesis, hos-pathogen interaction, identify vaccine candidates and drug targets to cure infectious diseases. We routinely conduct epidemiological surveillance of antibiotic resistant bacteria of public health importance in southeast Nigeria. In conjunction with out foreign collaborators, we apply molecular and genomic epidemiological approaches to better understand the mechanisms of bacterial resistance to antibiotics and how antibiotic resistant determinants persist in an environment where there is no antibiotic use. In addition, we direct out efforts in conducting research aimed at developing strategies for prevention and control of infectious diseases such as tuberculosis
Abstract: Whole genome sequencing (WGS) of Mycobacterium tuberculosis has been used to trace the transmission of M. tuberculosis, the causative agent of tuberculosis (TB). Previously published studies using WGS were conducted in developed countries with a low TB burden. We sought to evaluate the relative usefulness of traditional VNTR and SNP typing methods, WGS and epidemiological investigations to study the recent transmission of M. tuberculosis in a high TB burden country. We conducted epidemiological investigations of 42 TB patients whose M. tuberculosis isolates were classified into three clusters based on variable-number tandem repeat (VNTR) typing. We applied WGS to 32 (76.2%) of the 42 strains and calculated the pairwise genomic distances between strains within each cluster. Eighteen (56.3%) of the 32 strains had genomic differences ≥100 SNPs with every other strain, suggesting that direct transmission did not likely occurred. Ten strains were grouped into four WGS-based clusters with genomic distances ≤5 SNPs within each cluster, and confirmed epidemiological links were identified in two of these clusters. Our results indicate that WGS provides reliable resolution for tracing the transmission of M. tuberculosis in high TB burden settings. The high resolution of WGS is particularly useful to confirm or exclude the possibility of direct transmission events defined by traditional typing methods.
Pub.: 04 Jun '14, Pinned: 15 Oct '17
Abstract: It is generally believed that drug resistance among treated tuberculosis (TB) patients is as a result of acquired drug resistance due to inappropriate treatment. Previous studies have shown that primary drug resistance caused by transmission also plays a role among treated cases. Differentiating the two types of drug resistance will help in developing appropriate strategies for control of drug resistant tuberculosis. In this study, we tested the hypothesis that drug resistance among treated TB patients is mainly caused by primary resistance rather than acquired resistance. Defining resistance profiles by molecular drug susceptibility test, we used Unit Variable Number Tandem Repeats (VNTR) to genotype and Whole Genome Sequencing (WGS) to confirm the accordance of the first and last Mycobacterium tuberculosis isolates from treated pulmonary TB patients in Shanghai from 2009-2015. Among 81 patients with increasing drug resistance, out of 390 patients enrolled, paired isolates from 59.3% (48/81) had different VNTR patterns indicating primary drug resistance. Our results have demonstrated that primary resistance due to exogenous reinfection is the major cause of drug resistance among treated TB patients in Shanghai; thus, strategies aimed at preventing and interrupting transmission are urgently needed to effectively reduce the epidemic of drug resistant tuberculosis.
Pub.: 11 Aug '17, Pinned: 15 Oct '17
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