巴西圣保罗结核分枝杆菌分离株的过氧化氢酶表达、katG基因及异烟肼最低抑菌浓度

Catalase expression, katG, and MIC of isoniazid for Mycobacterium tuberculosis isolates from São Paulo, Brazil.

作者信息

Ferrazoli L, Palaci M, Telles M A, Ueki S Y, Kritski A, Marques L R, Ferreira O C, Riley L W

机构信息

Setor de Micobacterias, Instituto Adolfo Lutz, São Paulo, Brazil.

出版信息

J Infect Dis. 1995 Jan;171(1):237-40. doi: 10.1093/infdis/171.1.237.

DOI:10.1093/infdis/171.1.237

PMID:7798672

Abstract

The MIC of isoniazid, peroxidase-catalase expression, and the presence of the katG gene for 102 Mycobacterium tuberculosis isolates from patients in São Paulo were compared. Fifty-three isoniazid-resistant and 49 isoniazid-sensitive isolates were analyzed by polymerase chain reaction (PCR) for the presence of katG sequences. All isoniazid-sensitive and 43 (81%) isoniazid-resistant isolates expressed catalase (P = .001). None of isoniazid-sensitive and 4 (7%) of 53 isoniazid-resistant isolates lacked katG sequences. Among 6 isolates with MICs > 50 micrograms/mL, 5 (83%) did not express catalase and 2 lacked katG sequences; only 1 had complete gene deletion shown by Southern blot analysis. These findings indicate a correlation between loss of catalase and isoniazid resistance among highly resistant isolates, but these isolates were a small proportion of resistant clinical M. tuberculosis isolates from São Paulo.

摘要

比较了来自圣保罗患者的102株结核分枝杆菌分离株的异烟肼最低抑菌浓度（MIC）、过氧化物酶-过氧化氢酶表达情况以及katG基因的存在情况。通过聚合酶链反应（PCR）分析了53株异烟肼耐药和49株异烟肼敏感分离株中katG序列的存在情况。所有异烟肼敏感分离株和43株（81%）异烟肼耐药分离株均表达过氧化氢酶（P = 0.001）。53株异烟肼耐药分离株中，异烟肼敏感分离株均无且4株（7%）缺乏katG序列。在最低抑菌浓度>50微克/毫升的6株分离株中，5株（83%）不表达过氧化氢酶，2株缺乏katG序列；经Southern印迹分析，仅1株存在完整基因缺失。这些发现表明，在高耐药分离株中，过氧化氢酶缺失与异烟肼耐药之间存在相关性，但这些分离株在圣保罗耐药临床结核分枝杆菌分离株中所占比例较小。