scholarly journals DAPSONE RESISTANCE IN A Mycobacterium leprae ISOLATE WITH TWO POINT MUTATIONS IN folP GENE FROM A LEPROSY PATIENT

2016 ◽  
Vol 3 (2) ◽  
pp. 108
Author(s):  
Dinar Ardiaty ◽  
Ratna Wahyuni ◽  
Cita Prakoeswa ◽  
Rasyidin Abdullah ◽  
Indropo Agusni ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Point Mutations ◽  
Control Policy ◽  
Control Program ◽  
Skin Lesions ◽  
Double Mutation ◽  
South Sulawesi ◽  
Leprosy Case ◽  
Morphological Index ◽  
Leprosy Control

Drug resistance in leprosy is important for Leprosy Control Program, since the WHO-Multidrug regiment (MDT) has been used for global treatment of leprosy for more than two decades already. A Dapsone resistance case in a Multibacillary (MB) leprosy case is reported. The patient was diagnosed and treated in Tajuddin Chalid Hospital Makassar, South Sulawesi. Previously he was treated in a health center at South Sulawesi and was given a treatment for one year, before referred to the hospital. The leprosy skin lesions are still active with erythematous skin lesions and thickened ear lobe. Bacteriological examination was positive for Acid Fast Bacilli, the Bacterial Index was 3+ and the Morphological Index was 1%. The specimens of M.leprae isolation was sent to the Institute of Tropical Disease Surabaya for drug resistance study. Using the Lp1-2 and Lp3-4 nested primers, PCR test was positive for M.leprae.Sequencing result for folP gene showed a double mutation at codon 53 (ACC / Threonin ) which become (AGG / Arginine). Simultaneous mutation at two nucleotides at one codon has never been reported in Indonesia before and this phenomenon is important for leprosy control policy.

scholarly journals Genomic Variations in Drug Resistant Mycobacterium tuberculosis Strains Collected from Patients with Different Localization of Infection

Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Ekaterina Chernyaeva ◽  
Mikhail Rotkevich ◽  
Ksenia Krasheninnikova ◽  
Alla Lapidus ◽  
Dmitrii E. Polev ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Central Asia ◽  
Phylogenetic Analyses ◽  
Treatment Success ◽  
Point Mutations ◽  
Whole Genome Sequence ◽  
Public Health Importance ◽  
Resistance Patterns

Mycobacterium tuberculosis is a highly studied pathogen due to public health importance. Despite this, problems like early drug resistance, diagnostics and treatment success prediction are still not fully resolved. Here, we analyze the incidence of point mutations widely used for drug resistance detection in laboratory practice and conduct comparative analysis of whole-genome sequence (WGS) for clinical M. tuberculosis strains collected from patients with pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (XPTB) localization. A total of 72 pulmonary and 73 extrapulmonary microbiologically characterized M. tuberculosis isolates were collected from patients from 2007 to 2014 in Russia. Genomic DNA was used for WGS and obtained data allowed identifying major mutations known to be associated with drug resistance to first-line and second-line antituberculous drugs. In some cases previously described mutations were not identified. Using genome-based phylogenetic analysis we identified M. tuberculosis substrains associated with distinctions in the occurrence in PTB vs. XPTB cases. Phylogenetic analyses did reveal M. tuberculosis genetic substrains associated with TB localization. XPTB was associated with Beijing sublineages Central Asia (Beijing CAO), Central Asia Clade A (Beijing A) and 4.8 groups, while PTB localization was associated with group LAM (4.3). Further, the XPTB strain in some cases showed elevated drug resistance patterns relative to PTB isolates. HIV was significantly associated with the development of XPTB in the Beijing B0/W148 group and among unclustered Beijing isolates.

scholarly journals Microevolution within ST11 group Clostridioides difficile isolates through mobile genetic elements based on complete genome sequencing

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Yuan Wu ◽  
Lin Yang ◽  
Wen-Ge Li ◽  
Wen Zhu Zhang ◽  
Zheng Jie Liu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Genes ◽  
Point Mutations ◽  
Evolutionary Process ◽  
Mobile Genetic Elements ◽  
Genetic Elements ◽  
Clostridioides Difficile ◽  
Hospitalized Elderly ◽  
Great Heterogeneity ◽  
High Level

Abstract Background Clade 5 Clostridioides difficile diverges significantly from the other clades and is therefore, attracting increasing attention due its great heterogeneity. In this study, we used third-generation sequencing techniques to sequence the complete whole genomes of three ST11 C. difficile isolates, RT078 and another two new ribotypes (RTs), obtained from three independent hospitalized elderly patients undergoing antibiotics treatment. Mobile genetic elements (MGEs), antibiotic-resistance, drug resistance genes, and virulent-related genes were analyzed and compared within these three isolates. Results Isolates 10,010 and 12,038 carried a distinct deletion in tcdA compared with isolate 21,062. Furthermore, all three isolates had identical deletions and point-mutations in tcdC, which was once thought to be a unique characteristic of RT078. Isolate 21,062 (RT078) had a unique plasmid, different numbers of transposons and genetic organization, and harboring special CRISPR spacers. All three isolates retained high-level sensitivity to 11 drugs and isolate 21,062 (RT078) carried distinct drug-resistance genes and loss of numerous flagellum-related genes. Conclusions We concluded that capillary electrophoresis based PCR-ribotyping is important for confirming RT078. Furthermore, RT078 isolates displayed specific MGEs, indicating an independent evolutionary process. In the further study, we could testify these findings with more RT078 isolates of divergent origins.

scholarly journals Leprosy Control Program in Thailand.

1996 ◽  
Vol 65 (2) ◽  
pp. 88-93
Author(s):  
Pradabporn Duangajna
Keyword(s):  
Control Program ◽  
Leprosy Control

scholarly journals Plasmodium falciparum DHODH inhibitor complexes reveal flexible binding site

2014 ◽  
Vol 70 (a1) ◽  
pp. C1793-C1793
Author(s):  
Paul Rowland ◽  
Onkar SINGH ◽  
Leila Ross ◽  
Francisco Gamo ◽  
Maria Lafuente-Monasterio ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Binding Site ◽  
Crystal Structures ◽  
Point Mutations ◽  
Crystal Form ◽  
Drug Binding ◽  
Binding Modes ◽  
Resistance Mutations ◽  
Drug Binding Site

Malaria is a preventable and treatable disease, yet annually there are still hundreds of thousands of malaria-related deaths. The disease is caused by infection with mosquito-borne Plasmodium parasites. With hundreds of millions of cases each year there is a very high potential for drug resistance and this has compromised many existing therapies. One target under investigation is the enzyme dihydroorotate dehydrogenase (DHODH) which catalyses the rate-limiting step of pyrimidine biosynthesis and is an essential enzyme in the malaria parasite. There are currently several Plasmodium-selective DHODH inhibitors under development. To investigate the potential for drug resistance against DHODH inhibitors in vitro resistance selections were carried out using known inhibitors from different structural classes [1]. These studies identified point mutations in the drug binding site which lead to reduced sensitivity to the inhibitors, and in some cases increased sensitivity to a different inhibitor, suggesting a novel combination therapy approach to combat resistance. To help understand the significance of the inhibitor binding site mutations we determined the crystal structures of P. falciparum DHODH in complex with the inhibitors Genz-669178, IDI-6253 and IDI-6273. Co-crystallisation experiments led to a new crystal form in each case. Here we describe the crystal structures, the binding modes of the inhibitors and the great flexibility of the binding site, which is able to adjust to accommodate different inhibitor series. The structural role of the resistance mutations is also discussed.

scholarly journals Early detection of MDR Mycobacterium tuberculosis mutations in Pakistan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ayma Aftab ◽  
Samia Afzal ◽  
Zahida Qamar ◽  
Muhammad Idrees
Keyword(s):  
Early Detection ◽  
Control Program ◽  
Cost Effective ◽  
Treated Group ◽  
Multidrug Resistant ◽  
Control Group ◽  
Double Mutation ◽  
Treatment Regimens ◽  
Mdr Tb ◽  
Save Energy

AbstractThe result of improper treatment has led to the rise of Multidrug-resistant (MDR) strains. This concern still exists in Pakistan. In order to save energy, time and resources an early detection of resistant cases is imperative. Thus, a treated group of 100 isolates and a control group of 56 untreated isolates were studied. PCR and gene sequencing showed mutations at codon 531 and 513 in the rpoB gene. 12% of cases showed a double mutation in the rpoB gene. katG gene showed mutations at codon 315 and 299. 28.6% of the control group cases were positive for MDR whereas 100% of the treated group were positive for MDR. This study explores the significantly increasing ratio of MDR-TB among Pakistani population. This study provides prevalent MDR mutations among Pakistanis and suggests developing such molecular assays that are time and cost effective. Importance: Pakistan is a developing country and has fourth highest incidence rate of MDR-TB. The treatment of MDR-TB is the use of second line drugs that has severe side effects as well as it requires long time span. One of the strategies to control the spread of MDR-TB is to decipher the aberrations at molecular level in order to formulate potent drugs that can treat the patients within short span of time. Determining the mutation profile of MDR in Pakistani populations will open new horizons for the improvement of drug treatment regimens to make it more effective or for the development of novel potent drugs and vaccines to better treat the drug-resistant TB. Moreover, this study will be help in disease control program.

scholarly journals Understanding the Pyrimethamine Drug Resistance Mechanism via Combined Molecular Dynamics and Dynamic Residue Network Analysis

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 904 ◽  
Author(s):  
Arnold Amusengeri ◽  
Rolland Bantar Tata ◽  
Özlem Tastan Bishop
Keyword(s):  
Molecular Dynamics ◽  
Drug Resistance ◽  
Network Analysis ◽  
Binding Free Energy ◽  
Resistance Mechanism ◽  
Point Mutations ◽  
Md Simulations ◽  
Conformational Plasticity ◽  
New Perspective ◽  
The Impact

In this era of precision medicine, insights into the resistance mechanism of drugs are integral for the development of potent therapeutics. Here, we sought to understand the contribution of four point mutations (N51I, C59R, S108N, and I164L) within the active site of the malaria parasite enzyme dihydrofolate reductase (DHFR) towards the resistance of the antimalarial drug pyrimethamine. Homology modeling was used to obtain full-length models of wild type (WT) and mutant DHFR. Molecular docking was employed to dock pyrimethamine onto the generated structures. Subsequent all-atom molecular dynamics (MD) simulations and binding free-energy computations highlighted that pyrimethamine’s stability and affinity inversely relates to the number of mutations within its binding site and, hence, resistance severity. Generally, mutations led to reduced binding affinity to pyrimethamine and increased conformational plasticity of DHFR. Next, dynamic residue network analysis (DRN) was applied to determine the impact of mutations and pyrimethamine binding on communication dispositions of DHFR residues. DRN revealed residues with distinctive communication profiles, distinguishing WT from drug-resistant mutants as well as pyrimethamine-bound from pyrimethamine-free models. Our results provide a new perspective on the understanding of mutation-induced drug resistance.

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