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Background: Members of the Mycobacterium avium complex (MAC) cause disease in both human and animals. Their ubiquitous nature makes them both successful microbes and difficult to source track. The precise characterization of MAC species is a fundamental step in epidemiological studies and evaluating of possible reservoirs. This study aimed at identifying and characterizing Mycobacterium avium subsp. hominissuis isolated from human, slaughter cattle and pigs in various parts of the Uganda cattle corridor (UCC) at two temporal points using variable number of tandem repeat (VNTR) analysis., Methods: A total of 46 M. avium isolates; 31 from 997 pigs, 12 from 43 humans biopsies and three from 61 cattle lesions were identified to subspecies level using IS1245 and IS901 PCR, thereafter characterized using VNTR. Twelve loci from two previously described VNTR methods were used and molecular results were analyzed and interpreted using Bionumerics 6.1., Principal Findings: 37 of the isolates were identified as M. avium subsp. hominissuis and four as M. avium subsp. avium, while five could not be differentiated, possibly due to mixed infection. There was distinct clustering that coincides with the temporal and spatial differences of the isolates. The isolates from humans and cattle in the North Eastern parts of the UCC shared identical VNTR genotypes. The panel of loci gave an overall discriminatory power of 0.88. Some loci were absent in several isolates, probably reflecting differences in isolates from Uganda/Africa compared to isolates previously analyzed by these methods in Europe and Asia., Conclusions: The findings indicate a molecular difference between M. avium subsp. hominissuis isolates from pigs in Mubende and cattle and human in the rest of the UCC. Although human and cattle shared VNTR genotypes in the North Eastern parts of the UCC, it is most likely a reflection of a shared environmental source., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Multiple strain tuberculosis (TB) infections are now an acceptable facet of tuberculosis epidemiology. Identification of patients infected with more than one strain gives an insight in disease dynamics at individual and population level. This study therefore aimed at identifying multiple strain infections among TB infected patients. Furthermore, to determine factors associated with multiple strain infections in Mubende district of Uganda. A total of 72 Mycobacterium tuberculosis isolates from patients at Mubende regional referral hospital were characterized using 15 loci MIRU-VNTR, Spoligotyping and deletion analysis. Genotypic and epidemiological data were analyzed using MIRU-VNTR plus, Bionumerics software version 6.1 and an exact logistic regression model respectively. Eight (11.1%) of the 72 patients had mixed TB infections. Five were exclusively pulmonary mixed infections while three had both pulmonary and extra-pulmonary infections (Compartmentalized TB infections). Unlike previous studies that have linked this phenomenon to Beijing strains, multiple strains in this study belonged to T2-Uganda, X2 and T1 lineages. Two of the pulmonary mixed infections were resistant to rifampicin or isoniazid. All except one were HIV positive, newly diagnosed cases and urban residents of Mubende district. The study revealed that one in nine urban dwelling, HIV/TB co-infected patient were infected with more than one M. tuberculosis strains. The molecular findings give indications of a vital component of the disease dynamics that is most likely under looked at clinical level., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background: Tuberculosis (TB) remains a global public health problem whose effects have major impact in developing countries like Uganda. This study aimed at investigating genotypic characteristics and drug resistance profiles of Mycobacterium tuberculosis isolated from suspected TB patients. Furthermore, risk factors and economic burdens that could affect the current control strategies were studied., Methods: TB suspected patients were examined in a cross-sectional study at the Mubende regional referral hospital between February and July 2011. A questionnaire was administered to each patient to obtain information associated with TB prevalence. Isolates of M. tuberculosis recovered during sampling were examined for drug resistance to first line anti-TB drugs using the BACTEC-MGIT960(TM) system. All isolates were further characterized using deletion analysis, spoligotyping and MIRU-VNTR analysis. Data were analyzed using different software; MIRU-VNTR plus, SITVITWEB, BioNumerics and multivariable regression models., Results: M. tuberculosis was isolated from 74 out of 344 patients, 48 of these were co-infected with HIV. Results from the questionnaire showed that previously treated TB, co-infection with HIV, cigarette smoking, and overcrowding were risk factors associated with TB, while high medical related transport bills were identified as an economic burden. Out of the 67 isolates that gave interpretable results, 23 different spoligopatterns were detected, nine of which were novel patterns. T2 with the sub types Uganda-I and Uganda-II was the most predominant lineage detected. Antibiotic resistance was detected in 19% and multidrug resistance was detected in 3% of the isolates., Conclusion: The study detected M. tuberculosis from 21% of examined TB patients, 62% of whom were also HIV positive. There is a heterogeneous pool of genotypes that circulate in this area, with the T2 lineage being the most predominant. High medical related transport bills and drug resistance could undermine the usefulness of the current TB strategic interventions.

Background: Bovine tuberculosis (TB) caused by Mycobacterium bovis is primarily a disease of ruminants, particularly cattle (Bos primigenius) and buffalo (Syncerus caffer), and is endemic in most developing countries. To date, studies done in Uganda have documented the prevalence of M. bovis in cattle, humans and wild life, in addition to non-tuberculous mycobacteria in pigs. Pigs are increasingly becoming an important component of the livestock sector and share the human ecosystem in rural Uganda. It is therefore of public health interest that they are not a source of human infections. As a follow up to previously published findings on mycobacteria in pigs, this study was aimed at investigating the occurrence and molecular characteristics of M. bovis detected in slaughter pigs in Mubende district, Uganda. One hundred fifty mesenteric lymph nodes with lesions suggestive of mycobacterial infections were collected from approximately one thousand slaughtered pigs in Mubende district over a period of five months. The isolation and identification of M. bovis was done using conventional mycobacteriological methods. Mycobacteria belonging to the Mycobacterium tuberculosis complex (MTC) were identified to species level using deletion analysis. Molecular typing was done using Spoligotyping and MIRU-VNTR analysis. Molecular data were analysed and interpreted using MIRU-VNTR plus, SpolDB4.0 and the Mycobacterium bovis spoligo database., Results: Of the examined animals, one boar and two sows from Madudu Sub County were infected with M. bovis which presented as lesions of a deep yellow colour and a grit-like texture in the mesenteric lymph nodes. This represents 2% (3/150) of the lymph nodes where lesions suggestive of mycobacterial infections were detected. Molecular analysis revealed that the isolates from the infected pigs showed identical MIRU-VNTR profile and spoligotype (SB1469)., Conclusions: This is the first study documenting the occurrence of M. bovis in slaughter pigs in Uganda, revealing that one in fifty slaughter pigs with suspected lesions in mesenteric lymph nodes were infected. Molecular analysis revealed that the isolates were identical, showing a spoligotype previously reported from humans and cattle in the north eastern part of the Uganda cattle corridor. This finding is of public health importance, therefore there is a need for close cooperation between medical and veterinary professionals in designing and implementing control and prevention measures that safeguard the public from this potential source of zoonotic TB in Uganda.

Background: The importance of infections caused by non-tuberculous mycobacteria (NTM) in animals and humans has gained considerable recognition during the past few years. In the developed world, where pig production is extensively practiced, studies on mycobacterial infections and related control strategies have received increasing attention. The infections are reported to be caused by a wide spectrum of NTM. Unfortunately, these infections have been less recognized in sub-Saharan Africa owing to lack of awareness and systematic studies. In this study we aimed at isolating and identifying species of mycobacteria involved in causing infections in slaughter pigs in Mubende district of Uganda. Furthermore we wanted to identify factors associated with infection prevalence in the study area., Methods: A total of 363 lymph nodes were collected and cultured for the presence of mycobacteria. Isolates were identified by 16S rDNA gene sequencing. A questionnaire survey was administered to identify production related factors associated with infection prevalence. Data were assembled and analysed using descriptive statistics and mixed effects logistic regression analysis., Results: Mycobacteria were detected in 39 % (143/363) of the examined lymph nodes, 63 % (59/93) of lymph nodes with gross lesions typical of mycobacteriosis and 31% (84/270) of lymph nodes with no visible lesions. Nineteen per cent of the isolated mycobacteria were identified as Mycobacterium (M) avium, of these 78% and 22% were M. avium sub sp. Hominissuis and avium respectively. Other mycobacterial species included M. senuense (16%), M. terrae (7%) and M. asiaticum (6%). This study found free range systems (OR = 3.0; P = 0.034) and use of water from valley dams (OR = 2.0; P = 0.049) as factors associated with high prevalence of mycobacteria in slaughter pigs., Conclusions: This study demonstrated a high prevalence of NTM infections among slaughter pigs in Mubende district of Uganda. M. avium was the most prevalent of all NTM isolated and identified. Free range system of pig management and valley dam water were the most significant factors associated with NTM prevalence in Mubende district. These findings could be of a major public health concern given that it is in a predominantly pork consuming population with 18% HIV/AIDS prevalence. Therefore, stringent post-mortem inspection at the slaughter houses is of paramount importance to reduce human exposure.

Background: The importance of non-tuberculous mycobacteria (NTM) infections in humans and animals in sub-Saharan Africa at the human-environment-livestock-wildlife interface has recently received increased attention. NTM are environmental opportunistic pathogens of humans and animals. Recent studies in pastoral ecosystems of Uganda detected NTM in humans with cervical lymphadenitis and cattle with lesions compatible with bovine tuberculosis. However, little is known about the source of these mycobacteria in Uganda. The aim of this study was to isolate and identify NTM in the environment of pastoral communities in Uganda, as well as assess the potential risk factors and the public health significance of NTM in these ecosystems., Method: A total of 310 samples (soil, water and faecal from cattle and pigs) were examined for mycobacteria. Isolates were identified by the INNO-Lipa test and by 16S rDNA sequencing. Additionally, a questionnaire survey involving 231 pastoralists was conducted during sample collection. Data were analysed using descriptive statistics followed by a multivariable logistic regression analysis., Results: Forty-eight isolates of NTM were detected; 25.3% of soil samples, 11.8% of water and 9.1% from animal faecal samples contained mycobacteria. Soils around water sources were the most contaminated with NTM (29.8%). Of these samples, M. fortuitum-peregrinum complex, M. avium complex, M. gordonae, and M. nonchromogenicum were the most frequently detected mycobacteria. Drinking untreated compared to treated water (OR = 33), use of valley dam versus stream water for drinking and other domestic use (OR = 20), sharing of water sources with wild primates compared to antelopes (OR = 4.6), sharing of water sources with domestic animals (OR = 5.3), and close contact with cattle or other domestic animals (OR = 13.8) were the most plausible risk factors for humans to come in contact with NTM in the environment., Conclusions: The study detected a wide range of potentially pathogenic NTM from the environment around the pastoral communities in Uganda. Drinking untreated water and living in close contact with cattle or other domestic animals may be risk factors associated with the possibility of humans and animals acquiring NTM infections from these ecosystems.

Mycobacteria from lymph node biopsies of patients with cervical lymphadenitis reporting for tuberculosis treatment in Matany and Moroto Hospitals in the transhumant areas of Karamoja, Uganda were isolated and characterized. The AccuProbe culture identification kits for Mycobacterium tuberculosis complex (MTC), M. avium complex (MAC) and M. avium were used to identify the isolates. Spoligotyping, IS901 PCR and IS1311 and IS1245 restriction fragment length polymorphism (RFLP) were used to characterize the isolates. Of the 43 biopsies, ten M. avium, seven M. tuberculosis, three M. bovis, and two M. intracellulare were isolated. Two isolates could not be identified with AccuProbe and from 19 samples no mycobacteria could be isolated. Three isolates with the Beijing spoligotype were identified from the seven M. tuberculosis isolates. The spoligopatterns of the M. bovis isolates had previously been detected in cattle in Uganda. Isolation of members of the MAC group reflects the complex interaction between the transhumant communities, water sources and their cattle. None of the M. avium isolates harboured IS901, and all showed several bands on IS1311 and IS1245 RFLP, in accordance with M. avium subsp. hominissuis. Composite dendrograms of IS1311 and IS1245 RFLP showed that the isolates were similar and identical patterns were found. The isolation of M. bovis confirms the human infection with zoonotic mycobacteria in areas where consumption of raw milk and meat is routine. Isolation of environmental mycobacteria also confirms their increasing role in human disease and the occupational risk of infection in the transhumant ecosystem in the absence of safe drinking water and environmental contamination.

Background: Bovine tuberculosis is a zoonotic problem in pastoral cattle and communities in Uganda. Tuberculin tests in pastoral cattle had shown a high herd but low animal prevalence, with a high proportion of avian reactors. No work had been done to identify the mycobacterial species involved. The objective of the study was to isolate and characterise Mycobacterial species causing tuberculous lesions in slaughtered animals. Lesioned organs compatible with bovine tuberculosis in slaughtered cattle from pastoral areas in Uganda were collected and cultured to isolate mycobacteria. AccuProbe culture identification kits for the Mycobacterium tuberculosis complex, M. avium complex and M. avium were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) 1311 and IS1245 Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates., Results: Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as M. bovis, 3 as M. avium subsp.hominissuis, 1 as M. intracellulare, 1 as a mixed culture of M. bovis and M. avium sp. and 1 as M. avium sp. and unidentified mycobacteria. Eleven other mycobacteria outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from M. bovis isolates. Two of the three M. avium subsp.hominissuis isolates showed similar patterns on the IS1311 RFLP but all were different on the IS1245 RFLP., Conclusion: The isolation of M. bovis confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental mycobacteria could explain the high avian or non specific tuberculin reactor patterns commonly observed in pastoral cattle and suggests their pathogenic or opportunistic role in the infection of cattle with disseminated bovine tuberculous lesions.