PREVALENCE OF MULTIDRUG-RESISTANT BEIJING FAMILY ISOLATES AMONG RECURRENT TB CASES IN KAZAKHSTAN

Abstract

TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: Kazakhstan is one of 30 countries with high rates of multidrug resistant tuberculosis (MDR-TB) that is characterized by resistance to the most effective first-line anti-TB drugs – isoniazid and rifampicin. In many studies, MDR-TB is associated with Beijing genotype of M. tuberculosis. The purpose of the study is to characterize the genotypes of Kazakhstani M. tuberculosis isolates among recurrent lung TB cases. METHODS: 151 M. tuberculosis clinical isolates were gathered from recurrent lung TB cases in different regions of Kazakhstan. Susceptibility to first-line anti-tuberculosis drugs was detected using absolute concentrations method and BACTEC-MGIT 960 Mycobacteria Growth Indicator Tube. Genotyping of the isolates was done by 15 MIRU-VNTR approach. Phylogenetic tree was built using UPGMA algorithm on MIRU-VNTRplus web application. RESULTS: Drug susceptibility testing showed that 94% (n=141) of isolates among 151 recurrent lung TB cases were drug resistant and 6% (n=10) of isolates were drug-susceptible. Most of drug-resistant M. tuberculosis isolates were MDR (88.7%, 125/141), while poly- and mono-resistant isolates were determined in 8.5% (12/141) and 2.8% (4/141) cases, respectively. According to MIRU-VNTR genotyping results, Beijing family isolates prevailed among all drug resistant groups: MDR – 89.6%, poly-resistant – 83.4% and mono-resistant – 75%. Other M. tuberculosisfamilies such as LAM, URAL, Haarlem, New-1 and Delhi/CAS were identified in 0.8-8.3% cases among all drug-resistant groups. CONCLUSIONS: MDR-TB prevailed among recurrent lung TB cases in Kazakhstan (86%, 130/151), most of MDR isolates (89.6%, 112/125) belonged to Beijing family. Strains of this family are considered a significant risk factor for treatment failure and development of chronic forms of tuberculosis. CLINICAL IMPLICATIONS: It is important to implement genotyping of Beijing family isolates into National TB program for monitoring of MDR-TB in Kazakhstan. DISCLOSURES: No relevant relationships by Ainur Akhmetova, source=Web Response No relevant relationships by Ainur Akilzhanova, source=Web Response No relevant relationships by Ulan Kozhamkulov, source=Web Response