Progressive rise of Mycobacterium tuberculosis resistance to rifampicin and streptomycin in Riyadh, Saudi Arabia

OBJECTIVE: The aim of this study was to investigate, for the first time, the factors associated with resistance to antituberculous drugs in Saudi Arabia, and to follow the long-term trends in drug resistance. METHODOLOGY: A retrospective study of patients with positive Mycobacterium tuberculosis recorded at the Riyadh Tuberculosis Center in 1990 was undertaken. The resistance figures from the same centre for the period July 1996 to June 1997 were reviewed for comparison. RESULTS: Resistance was significantly higher in those previously treated (71%) than in those who denied previous treatment (34%). There was a trend towards association of resistance with cavitatory, multilobar, and acid fast bacilli-positive cases. Nationality (Saudis, Yemenis, others) had no significant effect on resistance. The Riyadh Region now has the same high prevalence of rifampicin resistance as previously reported in the Western Region of the Kingdom. The figures on resistance for the years 1986-88, 1990, and 1996-97 were: isoniazid 19.5/13.8/11.1%, rifampicin 10/20.7/24.6%, streptomycin 5/22/27.4%, ethambutol 3.7/3.9/1.8%, respectively. The reduction in isoniazid and ethambutol resistance coincided with a rise in resistance to rifampicin and streptomycin. We speculate that this resulted from the fact that isoniazid and ethambutol are restricted only to the treatment of tuberculosis and cannot, by law, be dispensed by general practitioners or private pharmacies. Rifampicin and streptomycin, however, are widely used for brucellosis; an endemic disease in Saudi Arabia where up to 12 weeks of rifampicin therapy is recommended. CONCLUSIONS: There has been a significant increase in rifampicin and streptomycin resistance in Saudi Arabia over the last 10 years. Possible causes include poor compliance and wide use of these two drugs for non-tuberculosis conditions. These findings could jeopardize the benefits of the directly observed therapy short course policy which is being implemented in Saudi Arabia. Consideration should be given to prohibiting the routine use of rifampicin for the treatment of brucellosis.     

Drug resistance patterns of Mycobacterium tuberculosis in Riyadh, Saudi Arabia.

OBJECTIVE: To determine the rate and type of anti-tuberculosis drug resistance at King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. DESIGN: Review of microbiology and infection control databases for all patients with culture-positive Mycobacterium tuberculosis between June 1981 and May 2003 at the hospital. BACTEC 460TB radiometry then MGIT 960 were used for both mycobacterial detection and antimicrobial susceptibility testing. RESULTS: A total of 764 M. tuberculosis isolates were obtained from 764 patients. Resistance to first-line agents (isoniazid, rifampicin, ethambutol and streptomycin) was noted in 65 (8.5%). Resistance to isoniazid was the highest, noted in 54 (7.1%); resistance to rifampicin, streptomycin and ethambutol was found in respectively 21 (2.7%), 29 (3.8%) and 12 (1.6%) isolates. Polyresistance was noted in eight (1%) isolates and monoresistance in 38 (5%) isolates. Multidrug-resistant M. tuberculosis was found in 19 (2.5%) isolates. There were 54 primary resistant isolates (7.6%), and 11 (22%) with acquired resistance. The median age of patients with resistant isolates was 38 years compared to 48 years for patients with sensitive isolates (P = 0.002). CONCLUSION: Resistance to first-line anti-tuberculosis agents and multidrug-resistant M. tuberculosis remain relatively low in Saudi Arabia.     

Evaluation of FASTPlaqueTB-RIF for determination of rifampicin resistance in Mycobacterium tuberculosis complex isolates.

SETTING: The Microbiology and Clinical Microbiology Department, Gulhane Military Medical Academy, Ankara, Turkey, a tertiary referral hospital in a region endemic for tuberculosis. OBJECTIVE: To evaluate rifampicin resistance of Mycobacterium tuberculosis complex strains using FASTPlaqueTB-RIF, a rapid and novel bacteriophage-based susceptibility technique. DESIGN: Results of isolates tested with the BACTEC 460 TB system were compared with FASTPlaqueTB-RIF. RESULTS: Susceptibility to rifampicin of M. tuberculosis complex isolates was tested for 88 isolates using FASTPlaqueTB-RIF. Sixty-seven isolates were susceptible and 21 were resistant to rifampicin using the BACTEC 460 TB system. Overall accuracy for FASTPlaqueTB-RIF was 94.3% (95%CI 87.3-97.5) for the detection of rifampicin susceptibility. The sensitivity and specificity of FASTPlaqueTB-RIF were respectively 100.0% (95%CI 84.5-100) and 92.5% (95%CI 83.6-96.7). CONCLUSION: This study demonstrates that FASTPlaqueTB-RlFM is a rapid and inexpensive test which has a good correlation with the BACTEC 460 TB system.     

RPA-LFD技术快速检测结核分枝杆菌利福平耐药性的应用

目的 基于重组酶聚合酶扩增(RPA)技术结合侧向流动试纸条(LFD),建立可快速检测结核分枝杆菌(MTB)利福平耐药的方法,并初步评价其临床应用价值.方法 采用比例法对182株结核分枝杆菌临床分离株进行利福平耐药性检测.建立RPA-LFD技术,检测182株菌株中利福平耐药决定区(RRDR)常见突变位点rpoB 531、...     

细菌噬菌体实验检测结核分枝杆菌利福平耐药:更新的meta分析

目的:我们之前进行过商品化及非商品化噬菌体实验检测耐利福平(RMP)结核(TB)的诊断准确性和操作特点的分析,此文章的目的是基于更多的研究来更新前一次分析。设计及结果:我们运用二元随机效果回归模型和分层综合接受者工作特征曲线(HSROC),对检测实验的准确性进行了系统回顾及Meta分析。评估的实验包括:FASTPlaqueTM、噬菌体荧光素报告(LRP)实验、室内噬菌体扩增实验。利福平检测的敏感性及特异性是主要分析指标。结果:通过更新文献搜索及分析,共有31篇研究(3085个标本)纳入此meta分析中。与室内扩增实验相比(敏感性变异范围为88%～100%,特异性变异范围为84%～100%),商品化试剂盒的指示值变化范围较大(敏感性变异范围为81%～100%,特异性变异范围为73%～100%)。LRP实验诊断的准确性一直很稳定,8项研究中7项敏感性为100%,4项特异性为100%。仅对准确性估计不能获得商品化试剂盒其他重要问题的分析,例如:污染率和不能得到确定结果的比例,直接检测病人标本的利福平耐药率时这2个率分别为3%和36%(平均值为20%)。结论:噬菌体技术需要进一步发展,以获得最多的诊断率并降低技术失误...     

Tuberculosis in Saudi Arabia: epidemiology and incidence of Mycobacterium tuberculosis and other mycobacterial species

The epidemiology of mycobacterial infections was studied in a wide cross-section of the Jeddah population over 2 years (1987-1989). Saudis, non-Saudis and patients from a stable population attending National Guard King Khalid Hospital (NGKKH) were compared. The ratio of Saudi to non-Saudi was 1:2 and males accounted for 65% of the total. The incidence was highest among young adults although the peak varied slightly between Saudi and non-Saudi patients. Extra-pulmonary tuberculosis was also preponderant among young adults, particularly females. Variants of Mycobacterium tuberculosis were investigated for the first time in Saudi Arabia. African and Asian variants were isolated from both Saudi and non-Saudi patients, the former being more numerous. Extra-pulmonary tuberculosis, particularly lymphadenopathy, accounted for a large proportion of mycobacterial infections, 59% at NGKKH. Mycobacterial species other than M. tuberculosis were fully identified and accounted for 9% of the isolates, Mycobacterium fortuitum and Mycobacterium chelonei being the two most prevalent.     

Diagnostic performance of DNA microarray for detecting rifampicin and isoniazid resistance in Mycobacterium tuberculosis

BackgroundWhile rifampicin (RFP) and isoniazid (INH) are the most commonly used first-line antituberculosis drugs, multidrug resistance in Mycobacterium tuberculosis poses a threat to the success of tuberculosis (TB) control programs. Clinical practice guidelines and expert consensuses recommend drug susceptibility testing (DST) before the initiation of antituberculosis treatment. However, traditional DST is time-consuming and has high requirements for laboratory conditions. The recently developed molecular diagnostic techniques, such as DNA microarray, offer new options. We thus investigated the diagnostic value of DNA microarray in detecting RFP + INH-resistant TB, with an attempt to identify simple, efficient, and accurate drug-resistant TB testing methods.MethodsThe clinical features and DST results of patients diagnosed with pulmonary tuberculosis by Bactec MGIT 960 liquid culture system (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) who received DNA microarray analysis in our center from July 2019 to July 2020 were retrospectively analyzed. Level of agreement between liquid culture and DNA microarray technology was assessed by using the Cohen kappa coefficient. With the results of liquid culture as the gold standard, the sensitivity and specificity of the DNA microarray were calculated, and the receiver operating characteristic (ROC) curves were used to assess the diagnostic values of the DNA microarray in detecting RFP + INH-resistant TB.ResultsA total of 825 patients were enrolled. The sensitivity and specificity of DNA microarray were 0.84 and 0.94, respectively, in the detection of RFP resistance, with an area under the curve (AUC) of 0.89 [95% confidence interval (CI): 0.87–0.91)] and a Cohen kappa coefficient of 0.78 (95% CI: 0.72–0.83). For INH resistance, the sensitivity and specificity of the DNA microarray were 0.73 and 0.97, respectively, with an AUC of 0.85 (95% CI: 0.82–0.87) and a Cohen kappa coefficient of 0.75 (95% CI: 0.70–0.80).ConclusionsThe DNA microarray had high specificity and sensitivity in detecting RFP + INH-resistant TB. As a rapid, accurate, and practical technique, it can be routinely performed in clinical laboratories.     

应用基因芯片方法检测结核分枝杆菌利福平和异烟肼的耐药性

目的 应用基因芯片方法检测结核分枝杆菌(Mycobacterium tuberculosis,Mtb)对利福平和异烟肼的耐受性,评价其临床应用价值。方法 应用聚合酶链反应（polymerase chain reaction,PCR）扩增-基因芯片杂交的方法检测经常规药敏实验证实的30株Mtb利福平和异烟肼敏感株和50株耐利福平和异烟肼分离株的rpoB基因及katG和inhA基因突变,同时以PCR-直接测序法为对照。结果 应用PCR-基因芯片与基因测序方法检测30株Mtb利福平敏感株rpoB基因和异烟肼敏感株katG基因和inhA基因均为野生型。50株Mtb利福平耐药株中,PCR-基因芯片与基因测序分析3株rpoB基因均为野生型,41株均为突变型;6株PCR-基因芯片与基因测序结果不一致。50株Mtb异烟肼耐药株中,PCR-基因芯片与基因测序分析16株katG基因和30株inhA基因均为野生型,31株katG基因均为315位密码子突变,7株inhA基因均为15位突变型,其中2株为katG和inhA双重突变;3株katG和13株inhA PCR-基因芯片与基因测序结果不一致。结论 应用PCR-基因芯片方法可快速、有效地检出大多数Mtb耐多药分离株,指导临床用药。     

Standardisation and evaluation of DNA-lanthanide fluorescence spectroscopy for determining rifampicin resistance in Mycobacterium tuberculosis clinical isolates.

SETTING: Tuberculosis Research Centre, Chennai. OBJECTIVE: To rapidly identify multidrug-resistant Mycobacterium tuberculosis using a novel method. DESIGN: A new assay, based on DNA-lanthanide fluorescence, was standardised and evaluated using 93 each of coded rifampicin-resistant and rifampicin-sensitive M. tuberculosis clinical isolates for the correct identification of rifampicin resistance. The results obtained by the new assay were compared with the conventional results. RESULTS AND CONCLUSION: The new assay gave a sensitivity and specificity of 88% and 85%, respectively. It is simple, easy to perform and requires 48 hours for the drug susceptibility results to be available after obtaining the primary culture.     

利福平和利福布汀对结核分枝杆菌交叉耐药率的初步探讨

目的通过对结核分枝杆菌MIC的测定,初步探讨利福平和利福布汀两药间的交叉耐药率。方法利用Alarmar Blue法(Alamar blue susceptibility test,MABA)检测116株结核分枝杆菌临床分离株对利福平和利福布汀的体外MIC。结果 36株利福平敏感株均对利福布汀敏感;80株利福平耐药株中有58株对利福布汀也同时耐药(对利福布汀的MIC>0.5 ug/ml),利福平与利福布汀间的交叉耐药率为72.5%(58/80);同时对利福平和利福布汀耐药的菌株对两种药物的耐药程度呈现正相关。结论利福布汀较利福平有更好的体外抗菌活性。对于利福平耐药而利福布汀敏感的患者仍可选择利福布汀作为联合化疗的有效药物之一。     

Nationwide community survey of tuberculosis epidemiology in Saudi Arabia

In the first nationwide community-based survey of the epidemiology of tuberculosis in Saudi Arabia, 7721 subjects were screened in the 5 provinces (using an equal proportional allocation formula) for 2 parameters: (1) prevalence of positive Mantoux test in non BCG vaccinated subjects; (2) prevalence of bacillary cases on sputum culture.The prevalence of positive Mantoux reaction in children aged 5–14 years was 6% ±1.8; higher in urban areas (10%), and lower in rural areas (2%), thus classifying Saudi Arabia among the middle prevalence countries. These relatively good results (by Third World standards) could reflect the rise of the standard of living and wide availability of free treatment for active cases with a lowered risk of infection in the community. This view is supported by the fact that in our survey, only one subject grew Mycobacterium tuberculosis in the sputum.However, there were foci of high prevalence of Mantoux reaction in the urban communities in the Western province (20% ± 8.7 urban; 1% ± 1.9 rural). The problem may be caused by the fact that the province receives every year over a million pilgrims, some of whom are known to settle illegally and escape the usual screening for tuberculosis imposed on foreign labourers. In conclusion, even in the absence of an enforceable national programme for the eradication of tuberculosis, the economic standard and wide availability of free treatment for active cases has resulted in relatively low rates of prevalence of tuberculin sensitivity in children. The foci of high prevalence in the Western Province require special screening arrangements.     

南京地区近年耐药结核病情况分析

目的通过统计分析我院检验科近十余年来结核菌培养的药敏试验结果,了解本地区结核菌耐药的现状和变化趋势。方法 2002年1月~2014年12月间,经改良罗氏培养阳性的标本共计12515份,采用SPSS17.0软件对药物敏感试验结果进行整理、归纳和统计学分析。结果大多数常用药物的年耐药发生率在一定范围内波动,异烟肼耐药有下降趋势,耐多药的发生率在下降,而左氧氟沙星耐药率在明显上升,从最初10.93%上升至至24.36%,而且单耐左氧氟沙星的病例数也在增多。结论随着国家对结核病管理的加强和规范,结核病的耐药情况有所改善,但仍应加强对抗结核药物使用的管理,减少耐药的发生。     

结核分枝杆菌对异烟肼和利福平的耐药水平与其耐药基因突变的相关性研究

目的 探讨Mtb耐药相关基因katG、inhA、oxyR-ahpC突变与对INH的耐药水平及rpoB突变与对RFP的耐药水平的关系。 方法 采用微孔板Alamar blue显色法分别检测59株耐INH的Mtb临床分离株对INH和30株耐RFP菌株对RFP的最低抑菌浓度（the minimum inhibitory concentration,MIC）,同时用直接测序法检测对INH耐药菌株katG、inhA、oxyR-ahpC和对RFP耐药菌株rpoB的突变情况。 结果 INH MIC为0.2500~1.0000 μg/ml（低水平耐药菌株）和 MIC≥2.0000 μg/ml（高水平耐药菌株）的INH耐药株,inhA启动子突变率前者高于后者［53.8% (7/13),4.3% (2/46)］,katG 315突变率前者低于后者［15.4% (2/13),76.1% (35/46)］,χ²值分别为15.57和13.48,P值均为0.000。RFP MIC为0.5000～16.0000 μg/ml和MIC≥32 0000 μg/ml的RFP耐药株,rpoB 531和526位总突变率前者低于后者［62.5% (5/8),95.5%(21/22)］,P_确切概率＝0.048。 结论 INH耐药菌株inhA启动子突变与INH低水平耐药有关,katG 315突变与INH高水平耐药有关;rpoB 531和526位突变与RFP高水平耐药有关。