Pattern and characteristics of mutations conferring resistance to second line drugs in Mycobacterium tuberculosis isolates of pulmonary and extrapulmonary TB samples.

BACKGROUND & OBJECTIVES: The purpose of present study is to analyse the distribution and pattern of genetic mutations in PRE-XDR-TB and extensive drug resistant Mycobacterium tuberculosis (XDR-TB) using second-line line probe assay and to compare them with different parameters. METHOD: Sputum, Lymph node aspirate and cold accesses from patients with rifampicin resistant Tuberculosis were subjected to first line and second line Probe Assay (Genotype MTBDRsl by Hain Life Science, Germany) to assess additional drug resistance to fluroquinolones (Levofloxacin & Moxifloxacin) and Aminoglycosides (Amikacin, Ofloxacin and Kanamycin). The genetic mutation pattern was analysed and compared with demographic, clinical and other parameters. RESULTS: The final study population included 123 fluoroquinolone resistant isolates including 14 isolates with additional second line aminoglycosides drug resistance. The most frequent mutation observed among Gyr A drug resistance mutation was D94G (Gyr A MUT3C, 50/123,40%) corresponding to high level resistance to levofloxacin and moxifloxacin. The most frequent wild type mutant among Gyr A gene locus was WT 3 (85/123,69%). The most common mutation among second line aminoglycoside resistant isolates was at eis WT2 (7/14,50%) followed by rrs MUT 2 (4/14,29%). CONCLUSIONS: GyrA MUT3C (Asp94Gly) was the most common mutation in Gyr A gene locus in M. tuberculosis causing high level levofloxacin and moxifloxacin resistance. Patients with Asp94Gly mutation was significantly associated with underweight body mass index (p = 0.026). This study also observed that history of anti-tuberculosis therapy is a risk factor for FQ drug resistance mutations (p < 0.001).

Fluoroquinolone resistance mutations among Mycobacterium tuberculosis and their interconnection with treatment outcome.

Background: Fluoroquinolone (FQ) antibiotics are among the most potent second-line antitubercular drugs these days. The aim of the study was to analyze the frequency and pattern of genetic mutation in preextensive (pre-XDR) and extensively drug-resistant Mycobacterium tuberculosis using second-line line probe assay (LPA) and to compare drug-resistant mutations with different treatment outcomes. Methods: Sputum, lymph node aspirate, and cold accesses from patients with rifampicin-resistant Tuberculosis (TB) were subjected to first-line and second-line LPA (Genotype MTBDRsl by Hain Life Science, Germany) to assess additional drug resistance to fluoroquinolones (levofloxacin and moxifloxacin). Final treatment outcomes as per the National TB Elimination Program were assessed and compared with the mutation profile. Results: One hundred and fifty subjects were observed to have mutations associated with resistance to FQs and constituted the final study population. The most frequent mutation observed among GyrA drug resistance mutation was D94G (Gyr A MUT3C, 44/150, 66%) corresponding to high-level resistance to levofloxacin and moxifloxacin. The same mutation was associated with poor treatment outcome as died or treatment failure (odds ratio 2.50, relative risk 1.67, P = 0.043). The most common hetero-resistance mutation pattern observed in GyrA gene was wild type plus Asp94Gly mutation in 24.6% of isolates. Conclusions: GyrA MUT3C hybridization corresponding to single-point mutation of aspartic acid to glycine at codon 94 constitutes the most common mutation in GyrA gene locus in M. tuberculosis with significant association with treatment outcome as died compared to those with treatment outcome as cured.

Pattern of InhA and KatG mutations in isoniazid monoresistant Mycobacterium tuberculosis isolates.

AIMS AND OBJECTIVES: The aim of the study is to detect the pattern of genetic mutation, i.e., Inh A or Kat G or both (Inh A and kat G) in isoniazid (INH) monoresistant mycobacteria and to correlate with the pattern in multidrug-resistant (MDR) isolates. MATERIALS AND METHODS: In this study, a quantitative research approach was used. The research design was descriptive observational study. The study was conducted at the Department of Respiratory Medicine, JLN Medical College, Ajmer, Rajasthan, and Intermediate Referral Laboratory, State TB Demonstration Centre, Ajmer. A total of 298 samples found to have resistant strains of Mycobacterium tuberculosis were enrolled with purposive sampling. RESULTS: The mean age of patients was 40.27 ± 13.82 years. There were 250 (83.9%) males, while 48 (16.1%) were females. One hundred ninety-two (64.4%) were resistant for INH only, while the rest were resistant to both INH as well as rifampicin (MDR-tuberculosis). The most common mutation in INH monoresistance was kat G (125; 65.1%) as compared to inh A (54; 28.1%) and both inh A and kat G (13; 6.7%). Among kat G mutations, the most common gene pattern was the absence of WT (S315T) and the presence of MUT1 (S315T1). CONCLUSION: Knowledge about mutation patterns of different INH resistant strains is important in the present era where there is a provision of separate regimens for INH monoresistant TB. Since these mutations are very closely related to high- or low-degree resistance to INH, the therapeutic regimens cannot be generalized.

A study on pattern of resistance to second line anti tubercular drugs among multi drug resistant tuberculosis patients.

AIMS AND OBJECTIVES: To determine the prevalence and pattern of resistance to second line drugs among multi drug resistant (MDR) tuberculosis patients being treated on category IV regimen. METHODOLOGY: This study was conducted at Department of Respiratory Medicine, J.L.N. Medical College, Ajmer in collaboration with IRL, STDC, Ajmer. Second line anti tubercular drug sensitivity for 398 multi drug resistant tuberculosis patients (between June-2015 and June-2016) was done to find out prevalence and pattern of resistance to second line drugs. Second line drug sensitivity was performed at accredited laboratory, Microbiology department, S.M.S. Medical College, Jaipur. RESULTS: Among these 398 patients, 136 (34.17%) were resistant to fluoroquinolones (Ofloxacin) (Pre XDR); 18 (4.52%) were resistant to one of the aminoglycosides (Inj. Kanamycin, Capreomycin, Amikacin) (Pre XDR); while 22 (5.53%) patients were resistant to fluoroquinolones as well as aminoglycosides (XDR). 148 (37.18%) patients were found sensitive to both the drugs. Samples of 41 (10.3%) patients were contaminated and no growth was seen in 33 (8.29%) patients. CONCLUSION: Nearly half of the multi drug resistant (MDR) tuberculosis patients (44.22%) being treated on category IV regimen also have resistance to either fluoroquinolones or aminoglycosides or both i.e. Pre XDR or XDR. This may result in poor outcome of category IV regimen under RNTCP. There is a strong need for provision of culture sensitivity for all first line drugs and at least two second line drugs viz. Fluoroquinolones and aminoglycosides for all the patients registered as smear positive under RNTCP. There is also a need for development of rapid culture technique for sensitivity to second line drugs.

Intensive behavioral therapy for primary enuresis.

OBJECTIVE: To assess the effect of intensive behavioral therapy on Saudi children with primary enuresis. METHODS: Twenty-six children, aged 6-14-years, presented with complains of bed wetting during a 12-months period from January 2001 through to January 2002, ArAr Central Hospital, Kingdom of Saudi Arabia were studied in an interventional, non-randomized trial without control. After complete verbal autopsy, physical examination and laboratory investigation, they were offered intensive behavioral therapy. They were evaluated for response, regularity, esteem and recurrence of enuresis. RESULTS: Mean age of the study group was 9.6-years (SD = +/- 2.6) and boys were affected almost twice of girls (P<0.05). Family history, social history and school performance did not show any significant (P>0.05) association with enuresis. Sixty point five percent were regular and out of those 27.9% never missed any visits. 91.7% were completely dry out of regular patients. There was 75% success rate in those, who visited 4-8 times while 25% in those, who visited 1-3 times. Ninety-six percent of the parents and 80.7% of the children were fully satisfied with this therapy. Socio-economic status seems to play a significant (P<0.05) role in regularity of follow up and response to behavioral therapy. CONCLUSION: This result shows an excellent response to intensive behavioral therapy in primary enuresis if the follow up is regular.