scholarly journals Resistance To First-Line Antituberculosis Drugs And Prevalence Of pncA Mutations In Clinical Isolates Of Mycobacterium tuberculosis From Zunyi, Guizhou Province Of China

2019 ◽  
Vol Volume 12 ◽  
pp. 3093-3102 ◽  
Author(s):  
Zhimin Cao ◽  
Yuanbo Lan ◽  
Ling Chen ◽  
Min Xiang ◽  
Zhiyuan Peng ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Isolates ◽  
Guizhou Province ◽  
First Line ◽  
Antituberculosis Drugs

scholarly journals In Vitro Activities of Six Fluoroquinolones against 250 Clinical Isolates of Mycobacterium tuberculosisSusceptible or Resistant to First-Line Antituberculosis Drugs

2000 ◽  
Vol 44 (9) ◽  
pp. 2567-2568 ◽  
Author(s):  
María Jesús Ruiz-Serrano ◽  
Luis Alcalá ◽  
Lucía Martínez ◽  
Marisol Díaz ◽  
Mercedes Marín ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Good Activity ◽  
In Vitro Activity ◽  
First Line ◽  
Antituberculosis Drugs

ABSTRACT Two hundred fifty isolates of Mycobacterium tuberculosis were evaluated for susceptibility to ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, trovafloxacin, and gemifloxacin (SB-265805). Levofloxacin, ciprofloxacin, and grepafloxacin showed the greatest activity (MIC for 90% of strains tested [MIC90] 1 μg/ml), although ofloxacin also showed good activity, with an MIC90 of 2 μg/ml. Trovafloxacin and gemifloxacin showed lower in vitro activity, with MIC90s of 64 and 8 μg/ml, respectively.

scholarly journals Lipoprotein Processing Is Essential for Resistance of Mycobacterium tuberculosis to Malachite Green

2009 ◽  
Vol 53 (9) ◽  
pp. 3799-3802 ◽  
Author(s):  
Niaz Banaei ◽  
Eleanor Z. Kincaid ◽  
S.-Y. Grace Lin ◽  
Edward Desmond ◽  
William R. Jacobs ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Malachite Green ◽  
Cell Envelope ◽  
Sodium Dodecyl ◽  
Signal Peptidase ◽  
Wild Type ◽  
First Line ◽  
Green Is ◽  
Antituberculosis Drugs ◽  
Forming Efficiency

ABSTRACT Malachite green, a synthetic antimicrobial dye, has been used for over 50 years in mycobacterial culture medium to inhibit the growth of contaminants. The molecular basis of mycobacterial resistance to malachite green is unknown, although the presence of malachite green-reducing enzymes in the cell envelope has been suggested. The objective of this study was to investigate the role of lipoproteins in resistance of Mycobacterium tuberculosis to malachite green. The replication of an M. tuberculosis lipoprotein signal peptidase II (lspA) mutant (ΔlspA::lspA mut) on Middlebrook agar with and without 1 mg/liter malachite green was investigated. The lspA mutant was also compared with wild-type M. tuberculosis in the decolorization rate of malachite green and sensitivity to sodium dodecyl sulfate (SDS) detergent and first-line antituberculosis drugs. The lspA mutant has a 104-fold reduction in CFU-forming efficiency on Middlebrook agar with malachite green. Malachite green is decolorized faster in the presence of the lspA mutant than wild-type bacteria. The lspA mutant is hypersensitive to SDS detergent and shows increased sensitivity to first-line antituberculosis drugs. In summary, lipoprotein processing by LspA is essential for resistance of M. tuberculosis to malachite green. A cell wall permeability defect is likely responsible for the hypersensitivity of lspA mutant to malachite green.

scholarly journals Molecular Genetics of para-Aminosalicylic Acid Resistance in Clinical Isolates and Spontaneous Mutants of Mycobacterium tuberculosis

2009 ◽  
Vol 53 (5) ◽  
pp. 2100-2109 ◽  
Author(s):  
Vanessa Mathys ◽  
René Wintjens ◽  
Philippe Lefevre ◽  
Julie Bertout ◽  
Amit Singhal ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Acid Resistance ◽  
Clinical Isolates ◽  
Alternative Mechanism ◽  
Aminosalicylic Acid ◽  
Coding Region ◽  
First Line ◽  
Marked Contrast ◽  
Dilution Assay ◽  
Spontaneous Mutants

ABSTRACT The emergence of Mycobacterium tuberculosis resistant to first-line antibiotics has renewed interest in second-line antitubercular agents. Here, we aimed to extend our understanding of the mechanisms underlying para-aminosalicylic acid (PAS) resistance by analysis of six genes of the folate metabolic pathway and biosynthesis of thymine nucleotides (thyA, dfrA, folC, folP1, folP2, and thyX) and three N-acetyltransferase genes [nhoA, aac(1), and aac(2)] among PAS-resistant clinical isolates and spontaneous mutants. Mutations in thyA were identified in only 37% of the clinical isolates and spontaneous mutants. Overall, 24 distinct mutations were identified in the thyA gene and 3 in the dfrA coding region. Based on structural bioinformatics techniques, the altered ThyA proteins were predicted to generate an unfolded or dysfunctional polypeptide. The MIC was determined by Bactec/Alert and dilution assay. Sixty-three percent of the PAS-resistant isolates had no mutations in the nine genes considered in this study, revealing that PAS resistance in M. tuberculosis involves mechanisms or targets other than those pertaining to the biosynthesis of thymine nucleotides. The alternative mechanism(s) or pathway(s) associated with PAS resistance appears to be PAS concentration dependent, in marked contrast to thyA-mutated PAS-resistant isolates.

scholarly journals Susceptibilities of Mycobacterium tuberculosis Complex Isolates to First-line Antituberculosis Drugs at Dokuz Eylül University Hospital

2021 ◽  
Author(s):  
Nazlı Arslan ◽  
Müge Hacer Özkarataş ◽  
Nuran Esen ◽  
Aydan Özkütük
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
University Hospital ◽  
Surveillance Program ◽  
Tuberculosis Complex ◽  
First Line ◽  
Antituberculosis Drugs ◽  
Number Of Patients

Objective: Tuberculosis retains its importance as the only infectious disease in the world that affects 10 million people and causes 1.5 million deaths per se. The major obstacle in the elimination and control of tuberculosis is the emergence and spread of resistant tuberculosis cases. It was aimed to determine the current Mycobacterium tuberculosis complex and its susceptibility to antituberculosis drugs at Dokuz Eylül University Hospital. Method: In our study, the results of all samples sent between January 2013 and November 2019 were examined retrospectively for the presence of M. tuberculosis complex and drug susceptibility results. The samples were cultured in Löwenstein Jensen media and BACTEC MGIT 960 system. Drug susceptibility testing was performed with the BACTEC MGIT 960 SIRE kit in accordance with the recommendations of the manufacturer. Results: In a total of 473 (2.2%) of 21620 specimens M. tuberculosis complex was reproduced. The samples were classified as pulmonary (n:300; 63.4%) and extrapulmonary (n:173; 36.6%), samples. When repeated samples of the same patient, were excluded, positive culture test results were determined in a total of 365 patients. Susceptibility to all primary antituberculosis drugs was shown in 275 of 321 (85.7%) patients, while total rates of resistance to streptomycin, isoniazid, rifampicin and ethambutol were found in respective number of patients as follows: (n:24 (7.5%), 22 (6.8%), (n:7; 2.2%) and (n:2; 0.6%). The rate of MDR was 0.6% in 2 patients. Conclusion: In our hospital, streptomycin is the first-line antituberculosis drug with the highest resistance rate. All susceptibility rates were seen lower than the data reported in Turkey Tuberculosis Control Report and other studies of Turkey. Implementing drug surveillance program plays an important role for maintaining these low rates and for the management of tuberculosis.

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