Browsing by Author "Moser, I."

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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.
Nontuberculous mycobacteria infections in Katavi Rukwa ecosystems
(Journal of Agricultural Science and Technology, 2014) Makondo, Z. E.; Kazwala, R. R.; Mwakapuja, R. S.; Malakalinga, J.; Moser, I.; Tanner, M.
A study on nontuberculous mycobacteria (NTM) was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem (KRE). 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opportunistically during professional hunting and game cropping operations in the KRE protected areas. The objective of the study was to generate data on epidemiology of NTM in the wildlife-livestock interface of the KRE. Methods used to identify the NTM were: culture and isolation, polymerase chain reaction, protein heat shock 65 kilodalton (hsp65) and sequencing. Mycobacteria were detected on 25.9% and 11.9% of livestock and wildlife tissue cultures, respectively. The most NTM isolated were M. kansasii (30%), M. gastri (30%), M. fortuitum (1%), M. intracellulare (4%), M. indicus pranii (4%), M. nonchromogenicum (6%) and M. lentiflavum (6%). Other NTM in smaller percentages were M. hibernae, M. engbaekii, M. septicum, M. arupense and M. godii. Due to rise of NTM infection in both human and animals, it is recommended that awareness and laboratory facilities be improved to curb the underreporting especially in TB-endemic countries. For species specific identification, a network of national and regional laboratories is promoted.
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.