Effect of sputum quality and role of Xpert MTB/ RIF assay for detection of smear-negative pulmonary tuberculosis in same-day diagnosis strategy in Addis Ababa, Ethiopia.

Background: There is limited information on the performance of the Xpert MTB/RIF test for diagnosis of smear-negative pulmonary tuberculosis (SNPT) and rifampicin resistance (RR) in the same-day diagnosis approach. The effects of sputum quality and other factors affecting the Xpert performance are also under-investigated.

Objective: This study aimed to determine the performance of the Xpert MTB/RIF test for detection of SNPT and RR in the same-day diagnosis strategy and the effect of sputum quality and other factors on its performance.

Genotypic and phenotypic drug-resistance detection and prevalence of heteroresistance in patients with isoniazid- and multidrug-resistant tuberculosis in Ethiopia.

Objective: To assess the agreement between genotypic and phenotypic methods for detecting drug resistance, and examine the prevalence of heteroresistance among isoniazid (INH)- and multidrug/rifampicin-resistant (MDR/RR) TB.

Method: In total, 127 () isolates, including 65 MDR/RR and 62 INH resistant, were used. First-line drug susceptibility testing (DST) was performed using the LJ method to determine the percentage of resistant bacteria.

PDL1 expression on monocytes is associated with plasma cytokines in Tuberculosis and HIV.

Introduction: PDL1 and its interaction with PD1 is implicated in immune dysfunction in TB and HIV. The expression of PDL1 on multiple subsets of monocytes as well as their associations with cytokines and microbial products have not been well studied.

Method: HIV (TB-HIV+), TB (TB+HIV-) and TB/HIV co-infected (TB+HIV+) patients as well as apparently healthy controls (TB-HIV-) were recruited.

Does Xpert® MTB/RIF assay give rifampicin resistance results without identified mutation? Review of cases from Addis Ababa, Ethiopia.

Background: Xpert® MTB/RIF assay is currently used in Ethiopia for the rapid diagnosis of Mycobacterium tuberculosis (MTB) and mutations that confer Rifampicin resistance. Rifampicin resistance is determined based on any mutation in the 81 bp of rpoB gene using five overlapping probes represented as Probe A (codons 507-511), Probe B (codons 512-518), Probe C (codons 518-523), Probe D (codons 523-529) and Probe E (codons 529-533). In this review, we assessed the frequency of missed probe types for Rifampicin Resistance results.

Effect of 1.5% sodium hydroxide final concentration on recovery rate of Mycobacterial Species and decontamination of other Bacterial and Fungal contaminants on sputum.

Background: Digestion and decontamination of non-sterile clinical specimens such as sputum are an essential step in the isolation of mycobacteria. Masking of mycobacteria in Mycobacterial growth indicator tube (MGIT) 960 liquid culture system by fungi and bacteria other than mycobacteria is a major problem.

Objective: To assess the effect of 1.