virulence in isoniazid-resistant clinical isolates of mycobacterium tuberculosis from south india
نویسندگان
چکیده
isoniazid, is the only antituberculous drug for which the relation between lack of virulence and acquisition of resistance was associated. inh-resistant mutants were shown to contain defective katg gene. classical studies showed that inh-resistant south indian isolates have lower virulence in guinea pigs and higher susceptibility to h2o2. it is of interest to assess the virulence in south indian clinical mutants of katg (catalase-peroxidase enzyme) associated with inh resistance. five inh-resistant clinical isolates were selected on the basis of mutation in katg gene. mutant isolates were used for infecting macrophage cell line (thp-1) and for the assessment of enzyme activity. in comparison to control h37rv, ser315thr mutant exhibits similar virulence and reduction (4% and 17%) in catalase (c) and peroxidase (p) activity. for the mutants, ser315iso and ser315arg, the virulent nature was slightly reduced with 3% and 2%, and significant reduction was observed in the c (50%; 47%) and p (36%; 43%) activity respectively. ser315asn indicates 4% reduction in virulence with significant reduction in c (56%) and p (64%) activity. asn138ser mutant displayed low-level virulence, cp activity showed 47% and 56% reduction. the results indicate that similar level of virulence in all the mutants except asn138ser which showed relatively low-level whereas a significant decrease in c and p activity was observed in all mutants except ser315thr. the study suggests despite the fact that all mutants do not compromise survival or virulence yet provides inh resistance.
منابع مشابه
Virulence in isoniazid-resistant clinical isolates of Mycobacterium tuberculosis from south India
Isoniazid, is the only antituberculous drug for which the relation between lack of virulence and acquisition of resistance was associated. INH-resistant mutants were shown to contain defective katG gene. Classical studies showed that INH-resistant south Indian isolates have lower virulence in guinea pigs and higher susceptibility to H2O2. It is of interest to assess the virulence in south India...
متن کاملVirulence in isoniazid-resistant clinical isolates of Mycobacterium tuberculosis from south India
متن کامل
Detection of Isoniazid-Resistant Clinical isolates of Mycobacterium tuberculosis from India using Ser315Thr marker by Comparison of molecular methods
In this study, Substitution at codon Ser315 of katG gene, a reliable marker for isoniazid (INH) resistance was analyzed and compared by three molecular methods such as DNA sequencing, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and PCR-single strand conformation polymorphism (PCR-SSCP) in 105 phenotypically resistant isolates obtained from various parts of Ind...
متن کاملIMPORTANCE OF CATALASE ENZYME IN VIRULENCE OF ISONIAZID RESISTANT ST RAINS OF MYCOBACTERIUM TUBERCULOSIS IN GUINEAPIGS
In this study, twenty-five strains of Mycobacterium tuberculosis resistant to isoniazid (INH) were isolated from patients with tuberculosis (TB). Nine strains (36%) were found to be virulent in guinea-pigs [root index virulence (RIV» 1 ]. The remaining sixteen strains (64%) were non-virulent (RIV <1). Of the nine strains resistant to INH as well as virulent to guinea-pigs, eight of them wer...
متن کاملInvestigation of Ser315 Substitutions within katG Gene in Isoniazid-Resistant Clinical Isolates of Mycobacterium tuberculosis from South India
Mutation at codon 315 of katG gene is the major cause for isoniazid (INH) resistance in Mycobacterium tuberculosis (M. tuberculosis). Substitution at codon 315 of katG gene was analyzed in 85 phenotypically resistant isolates collected from various parts of southern India by direct sequencing method. The obtained results were interpreted in the context of minimum inhibitory concentration (MIC) ...
متن کاملdetection of isoniazid-resistant clinical isolates of mycobacterium tuberculosis from india using ser315thr marker by comparison of molecular methods
in this study, substitution at codon ser315 of katg gene, a reliable marker for isoniazid (inh) resistance was analyzed and compared by three molecular methods such as dna sequencing, polymerase chain reaction restriction fragment length polymorphism (pcr-rflp) and pcr-single strand conformation polymorphism (pcr-sscp) in 105 phenotypically resistant isolates obtained from various parts of indi...
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عنوان ژورنال:
international journal of molecular and clinical microbiologyجلد ۱، شماره ۲، صفحات ۸۷-۹۶
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