Browsing by Author "König, B."

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Increased isolation of nontuberculous mycobacteria among TB suspects in Northeastern, Tanzania: public health and diagnostic implications for control programmes
(2016) Hoza, A. S.; Mfinanga, S. G. M.; Rodloff, A. C.; Moser, I; König, B.
Background: Non-tuberculous mycobacteria (NTM) are increasingly reported worldwide associated with human disease. Defining the significance of NTM in settings with endemic tuberculosis (TB) requires the discrimination of NTM from TB in suspect patients. Correct and timely identification of NTM will impact both therapy and epidemiology of TB and TB-like diseases. The present study aimed at determining the frequency and diversity of NTM among TB suspects in northeastern Tanzania. Methods: A cross-sectional study was conducted between November 2012 through January 2013. Seven hundred and forty-four sputum samples were collected from 372 TB suspects. Detection was done by using phenotypic, Geno- Type® Mycobacterium CM/AS kits, 16S rRNA and hsp65 gene sequencing for identification of isolates not identified by Hain kits. Binary regression model was used to analyse the predictors of NTM detection. Results: The prevalence of NTM was 9.7 % of the mycobacterial isolates. Out of 36 patients with confirmed NTM infection, 12 were HIV infected with HIV being a significant predictor of NTM detection (P < 0.001). Co-infection with Mycobacterium tuberculosis (M. tb) was found in five patients. Twenty-eight NTM isolates were identified using Geno- Type® Mycobacterium CM/AS and eight isolates could not be identified. Identified species included M. gordonae and M. interjectum 6 (16.7 %), M. intracelullare 4 (11.1 %), M. avium spp. and M. fortuitum 2 (5.5 %), M. kansasii, M. lentiflavum, M. simiae, M. celatum, M. marinum 1 (2.8 %) each. Of isolates not identified to subspecies level, we identified M. kumamotonense (2), M. intracellulare/kansasii, M. intermedium/triplex, M. acapulcensis/flavescens, M. stomatepiae, M. colombiense and M. terrae complex (1) each using 16S rRNA sequencing. Additionally, hsp65 gene sequencing identified M. kumamotonense, M. scrofulaceum/M. avium, M. avium, M. flavescens/novocastrense, M. kumamotonense/hiberniae, M. lentiflavum, M. colombiense/M. avium and M. kumamotonense/terrae/hiberniae (1) each. Results of the 16S rRNA and hsp65 gene sequencing were concordant in three and discordant in five isolates not identified by GenoType® Mycobacterium CM/AS. Conclusion: NTM infections may play a vital role in causing lung disease and impact management of TB in endemic settings. GenoType® Mycobacterium CM/AS represents a useful tool to identify clinical NTM infections. However, 16S rRNA gene sequencing should be thought for confirmatory diagnosis of the clinical isolates. Due to the complexity and inconsistence of NTM identification, we recommend diagnosis of NTM infections be centralized by strengthening and setting up quality national and regional infrastructure
Isolation, biochemical and molecular identification of Nocardia species among TB suspects in northeastern, Tanzania; a forgotten or neglected threat?
(2017) Hoza, A. S.; Mfinanga, S. G. M.; Moser, I.; König, B.
Background: Pulmonary nocardiosis mimic pulmonary tuberculosis in most clinical and radiological manifestations. In Tanzania, where tuberculosis is one of the major public health threat clinical impact of nocardiosis as the cause of the human disease remains unknown. The objective of the present study was to isolate and identify Nocardia isolates recovered from TB suspects in Northeastern, Tanzania by using biochemical and molecular methods. Methods: The study involved 744 sputum samples collected from 372 TB suspects from four periphery diagnostic centers in Northeastern, Tanzania. Twenty patients were diagnosed as having presumptively Nocardia infections based on microscopic, cultural characteristics and biomèrieux ID 32C Yeast Identification system and confirmed using 16S rRNA and hsp65 gene specific primers for Nocardia species and sequencing. Results: Biochemically, the majority of the isolates were N. asteroides (n = 8/20, 40%), N. brasiliensis (n = 4/20, 20%), N. farcinica (n = 3/20, 15%), N. nova (n = 1/20, 5%). Other aerobic actinomycetales included Streptomyces cyanescens (n = 2/20, 10%), Streptomyces griseus, Actinomadura madurae each (n = 1/20, 5%). Results of 16S rRNA and hsp65 sequencing were concordant in 15/17 (88. 2%) isolates and discordant in 2/17 (11.8%) isolates. Majority of the isolates belonged to N. cyriacigeorgica and N. farcinica, four (23.5%) each. Conclusions: Our findings suggest that Nocardia species may be an important cause of pulmonary nocardiosis that is underdiagnosed or ignored. This underscores needs to consider pulmonary nocardiosis as a differential diagnosis when there is a failure of anti-TB therapy and as a possible cause of human infections.
Molecular characterization of Mycobacterium tuberculosis isolates from Tanga, Tanzania: First insight of MIRU-VNTR and microarray-based spoligotyping in a high burden country
(Elsevier Ltd, 2016-02-13) Hoza, A. S.; Mfinanga, S. G. M.; Moser, I.; König, B.
Molecular typing of Mycobacterium tuberculosis(MTB) has greatly enhanced the understanding of the population structure of MTB isolates and epidemiology of tuberculosis (TB). To characterize prevalent genotypes of MTB, microarrays‑based spoligotyping and mycobacterial interspersed repetitive unit‑variable number of tandem repeats (MIRU‑VNTR) were applied on 80 isolates collected from primary health care facilities in Tanga, North‑eastern Tanzania. A total of 18 distinct spoligotypes were identified. The lineages by order of their predominance were EAI and CAS families (26.25%, 21 isolates each), LAM family and T super‑family (10%, 8 isolates each), MANU family (3.75%, 3 isolates), Beijing family (2.5%, 2 isolates) and S family (1.25%, 1 isolate). Overall, sixteen (20%) strains could not be allocated to any lineage according to the SITVIT_WEB database. The allelic diversity (h) for specific MIRU‑VNTR loci showed a considerable variation ranging from 0.826 of VNTR locus 3192 to 0.141 of VNTR locus 2059. The allelic diversity for 11 loci (VNTR 3192, 2996, 2165, 960, 4052, 424, 4156, 2531, 1644, 802 and 3690) exceeded 0.6, indicating highly discriminatory power. Seven loci (VNTR 2163b, 2401, 1955, 577, 4348, 2687 and 580) showed moderate discrimination (0.3 h 0.6), and three loci (VNTR3007, 154 and 2059) were less polymorphic. The present study suggests that the TB cases in Tanga might be caused by a diverse array of MTB strain families that may be indicative of a cosmopolitan population with frequent migration and travel. Microarray‑based spoligotyping and MIRU‑VNTR could be reliable tools in detecting different MTB genotypes in high burden settings.
The role of nontuberculous mycobacteria in the diagnosis, management and quantifying risks of tuberculosis in Tanga, Tanzania
(Tanzania Journal of Health Research, 2016) Hoza, A. S.; Lupindu, A. M.; Mfinanga, S. G. M.; Moser, I.; König, B.
Background: The role of nontuberculous mycobacteria (NTM) in tuberculosis (TB) diagnosis is well documented in many developing settings. However, this has not been the case in many resource poor settings like Tanzania. This study aimed at understanding the role of NTM in the diagnosis and management of TB in resource poor settings of Tanzania. Methods: A cross-sectional study was conducted in Tanga, Tanzania. Patients with symptoms suggestive of TB self-referred to health care facilities were recruited. Two sputum samples were collected for standard direct smear microscopy. Culture was performed using BacT/Alert 3D system, LöwensteinJensen and Gottsacker slopes. Identification of Mycobacterium tuberculosis and NTM was done by using GenoType®MTBC and GenoType®CM/AS, respectively. Results: A total of 372 patients were involved in the study. Eighty-one (21.8%) patients were diagnosed as having M. tuberculosis by the isolation of the organism from cultures of sputum. Further analysis of culture showed that 8.1% (30/372) were NTM with 7/372 (1.9%) cases of NTM classified as pulmonary tuberculosis (PTB) patients. Ziehl Neelsen stain had a sensitivity of 68.8% and produced 10 false negative results. On the other hand, Fluorescence stain had a sensitivity of 85.7% and gave seven false negative samples when compared with culture results. Weight loss (p = 0.0001), fatigue (p = 0.003), fever (p = 0.038) and night sweats (p = 0.004), young population (18-40 years) (p = 0.0352), males (p = 0.0025) were important risk factors for TB. Four out of 30 NTM diagnosed by culture received first line anti-TB treatment suggesting that a good proportion of patients (4/65, 6.2%) were mistreated as TB patients. Conclusion: Inefficient screening of TB patients in resource poor settings and prevalent increase of NTM may contribute to over diagnosis of TB cases. The need to integrate NTM diagnosis in the routine management of TB is urgently needed for designing effective tuberculosis prevention and control strategies in the country.