Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda

<p>Abstract</p> <p>Background</p> <p>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 <it>mycobacteria</it>. AccuProbe culture identification kits for the <it>Mycobacterium tuberculosis </it>complex, <it>M. avium </it>complex and <it>M. avium </it>were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) <it>1311 </it>and IS<it>1245 </it>Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates.</p> <p>Results</p> <p>Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as <it>M. bovis</it>, 3 as <it>M. avium </it>subsp.<it>hominissuis</it>, 1 as <it>M. intracellulare</it>, 1 as a mixed culture of <it>M. bovis </it>and <it>M. avium sp</it>. and 1 as <it>M. avium sp</it>. and unidentified <it>mycobacteria</it>. Eleven other <it>mycobacteria </it>outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from <it>M. bovis </it>isolates. Two of the three <it>M. avium </it>subsp.<it>hominissuis </it>isolates showed similar patterns on the IS<it>1311 </it>RFLP but all were different on the IS<it>1245 </it>RFLP.</p> <p>Conclusion</p> <p>The isolation of <it>M. bovis </it>confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental <it>mycobacteria </it>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.</p

Factors associated with pastoral community knowledge and occurrence of mycobacterial infections in human-animal interface areas of Nakasongola and Mubende districts, Uganda

<p>Abstract</p> <p>Background</p> <p>Nontuberculous mycobacteria (NTM) are emerging opportunistic pathogens whose role in human and animal disease is increasingly being recognized. Major concerns are their role as opportunistic pathogens in HIV/AIDS infections. The role of open natural water sources as source and livestock/wildlife as reservoirs of infections to man are well documented. This presents a health challenge to the pastoral systems in Africa that rely mostly on open natural water sources to meet livestock and human needs. Recent study in the pastoral areas of Uganda showed infections with same genotypes of NTM in pastoralists and their livestock. The aim of this study was to determine the environmental, animal husbandry and socio-demographic factors associated with occurrence and the pastoral community knowledge of mycobacterial infections at the human-environment-livestock/wildlife interface (HELI) areas in pastoral ecosystems of Uganda.</p> <p>Methods</p> <p>Two hundred and fifty three (253) individuals were subjected to a questionnaire survey across the study districts of Nakasongola and Mubende. Data were analyzed using descriptive statistics and multivariable logistic regression analysis.</p> <p>Results</p> <p>Humans sharing of the water sources with wild animals from the forest compared to savannah ecosystem (OR = 3.3), the tribe of herding pastoral community (OR = 7.9), number of rooms present in household (3-5 vs. 1-2 rooms) (OR = 3.3) were the socio-demographic factors that influenced the level of knowledge on mycobacterial infections among the pastoral communities. Tribe (OR = 6.4), use of spring vs. stream water for domestic use (OR = 4.5), presence of sediments in household water receptacle (OR = 2.32), non separation of water containers for drinking and domestic use (OR = 2.46), sharing of drinking water sources with wild animals (OR = 2.1), duration of involvement of >5 yrs in cattle keeping (OR = 3.7) and distance of household to animal night shelters (>20 meters) (OR = 3.8) were significant socio-demographic factors associated with the risk of occurrence of mycobacterioses among the pastoral communities in Uganda.</p> <p>Conclusion</p> <p>The socio-demographic, environmental and household related factors influence the risk of occurrence as well as pastoralists' knowledge of mycobacterial infections in the pastoral households at the human-environment-livestock/wildlife pastoral interface areas of Uganda.</p

Isolation of non-tuberculous mycobacteria from pastoral ecosystems of Uganda: Public Health significance

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Method</p> <p>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.</p> <p>Results</p> <p>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, <it>M. fortuitum-peregrinum </it>complex, <it>M. avium </it>complex, <it>M. gordonae</it>, and <it>M. nonchromogenicum </it>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.</p> <p>Conclusions</p> <p>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.</p

Effect of feed supplements on weight gain and carcass characteristics of intact male Mubende goats fed elephant grass (Pennisetum purpureum) ad libitum in Uganda

Twenty intact male Mubende goats were randomly divided into five groups of four goats each. Each group was randomly assigned one of the treatments resulting into a complete randomised design. All the animals were individually fed elephant grass (E), used as basal diet, ad libitum. Treatments were isonitrogenous amount (10 g N/d) of banana peels (BP), maize bran (MB), cottonseed cake (CSC) and fresh Leucaena leaves (LL) offered as supplements. Water and mineral blocks were offered ad libitum. At the end of the feeding trials (186 days), the goats were sacrificed for carcass analysis and the various body parts and organs were measured. Final live weights did not differ significantly between treatment groups (P>0.05) although goats fed on CSC were heavier than the rest. Empty body and dressed carcass weights differed significantly (P0.01); however, weights of skin, pluck and feet differed significantly (P<0.01). Various carcass components were highly correlated with live weight across all diets suggesting that all the diets did not severely alter the allometry of growth

Screening of extracts of Zanthoxylum chalybeum and Warburgia ugandensis for activity against measles virus (Swartz and Edmonston strains) in vitro

A large proportion of the population in Uganda still relies on the use of plant extracts for treatment of various ailments. This study tested the claimed efficacy of some plants in the treatment of measles. In vitro antiviral assays were performed on extracts of two medicinal plants (Warburgia ugandensis and Zanthoxylum chalybeum) using measles virus (Edmonston and Swartz strains) as the test organisms. The assays performed were the neutralisation tests and the plaque reduction assays. Of the two plants Z. chalybeum had demonstrable in vitro antiviral activity in the seed extracts (titer reduction factor [TRF]: 100, for the ethanolic extract). The in vitro antiviral activity of the seed extracts was demonstrated to be due to compound 27–135D (TRF=1000), which was characterized by 1H-NMR spectroscopy as the alkaloid skimmianine. Skimmianine had minimal toxicity to VERO cell lines. The petroleum ether extracts and the ethanolic extracts of Warburgia ugandensis had no inhibitory effect on cytopathic effect (CPE) formation, especially at the maximal non-toxic dose (MNTD). The extracts of W. ugandensis were highy toxic to VERO cell lines. The TRF values for the stem bark extracts of W. ugandensis were: water extract, 10; ethanolic extract, 1; fraction 27–163D, 100., which were regarded to be too low. Seed extracts of Z.chalybeum therefore probably cure measles due to the antiviral effect of skimmianine. It is not clear how extracts of W. ugandensis produce a beneficial response in measles disease, if at all

Serosurvey of Brucella abortus in cattle and goats in central and southern Uganda

A serological survey was undertaken from April 1990 to February 1993, to determine the exposure experience to Brucella abortus in cattle and goats in central and southern Uganda. Three serological tests, the standard tube agglutination test (SAT); rose bengal plate test (RBPT) and the milk ring test (MRT) were used. Samples in cluded blond from slaughter cattle (1,055) and goats (271), both from public abattoirs, as well as live cattle (676) from farms. Milk samples were collected from individual cows (208) on the various farms and from several milk collecting centres (364). For cattle, 14.7% (n=1,731) sera were positive by the RBPT and 12.5% (n=1,731) by SAT. The seropositivity for brucellosis as revealed by testing milk from individual dairy cows was 9.6% (n=208) as opposed to 38.5% (n=364) from milk collecting centres which included milk from local cows. From goats,8.9% (n=271) were positive by RBPT and 7% (n=271) by SAT. The prevalence was higher on farms with indigenous, 16.15% (n=291 ), than on farms with exotic breeds of cattle, 7.51% (n=303); and this was attributed to the better sanitary and husbandry methods in farms with exotic breeds. This has been the first comprehensive survey combining detection of antibodies in both serum and milk in cattle in Uganda and the most extensive in the Central and Southern regions of the country in particular. It has revealed a high prevalence of Brucella abortus infection among these food animals in the two regions, pointing tu both the potential for economic importance as well as the public health risk of this disease. Thus, there is need for instituting control measures.Key words: Serosurvey, Brucella arbortus. cattle, goat

Antibacterial and antifungal activities of extracts of Zanthoxylum chalybeum and Warburgia ugandensis, Ugandan medicinal plants

Measles is a killer disease of children in Uganda. The treatment of the disease is mainly directed at the secondary microbial infections. A large proportion of the population in Uganda still relies on the use of herbal remedies, which have been claimed to produce beneficial responses. In this study, the efficacy of Warburgia ugandensis and Zanthoxylum chalybeum against common bacteria and fungi was investigated. Bactericidal and antifungal assays were done using extracts derived from Z. chalybeum and W. ugandensis (agar well diffusion, disc diffusion and colony count assays). All extracts (ethanolic, petroleum ether and aqueous) of Z. chalybeum did not show antimicrobial activity. Phytochemical investigations of Zanthoxylum chalybeum (seed) yielded a pure crystalline alkaloid (27–135D) which was characterized as skimianine based on 1H-NMR spectroscopy and comparison with spectra of authentic samples. Skimmianine did not have antimicrobial activity in this test system. W. ugandensis water extracts elicited antibacterial activity against both Escherischia coli and Staphylococcus aureus in the agar well assay but not in the disc diffusion assay. Warburgia ugandensis water extracts and fraction 27-163D also showed antifungal activity against Candida albicans. Chromatography of extracts of Warburgia ugandensis stem bark afforded compound 49–169K, which was characterized as the sesquiterpine muzigadial (by 1H-NMR spectroscopy), which did not show antibacterial activity but had antifungal activity against C. albicans. Therefore, the claimed efficacy of W. ugandensis could be attributable to antibacterial and antifungal activity of its components. Since Z. chalybeum extracts had neither antifungal nor antibacterial activities, its mode of action is unclear from these results

Bioassay-guided studies on the cytotoxic and in vitro trypanocidal activities of a sesquiterpene (Muzigadial) derived from a Ugandan medicinal plant (Warburgia ugandensis)

Trypanosomiasis is arguably the most important disease of man and his domesticated animals in the tropics. There are few compounds available for its treatment. This has exacerbated the development of drug resistance. There is therefore urgent need to search for newer compounds to treat this important disease. Medicinal plants represent a potential source of the drugs. This paper reports a bioassay-guided study to search for possible biological activity (cytotoxic and trypanocidal) in two Ugandan medicinal plants. The methodology adopted was the so-called ‘ping-pong’ approach, involving phytochemical purification (column chromatography and preparative thin layer chromatography), alongside biological studies (cytotoxicity, antibacterial, trypanocidal and antifungal studies). Phytochemical investigations of Zanthoxylum chalybeum (seed) yielded a pure crystalline compound, 27-135D, which was characterized by 1HNMR as the alkaloid skimmianine. Studies on stem bark yielded three alkaloids 27-165A, 27-173A and 27-173B. All the above pure isolates, and the crude extracts of Z. chalybeum had neither biological activity nor cytotoxicity in the brine shrimp assay. A cytotoxic sesquiterpine, characterized as muzigadial, was isolated from W. ugandensis. It was highly toxic in the brine shrimp assay and also had in vitro trypanocidal activity against IL 3338 as well as IL1180; reference drug-resistant and drug-sensitive trypanosome strains respectively, comparable to diminazene aceturate and Geneticin (G418). Muzigadial also had antifungal activity against Candida albicans. It was concluded that the brine shrimp assay might be a useful predictor of trypanocidal activity of plant extracts and that muzigadial may be potentially valuable in the treatment of drug-resistant trypanosomosis

Designing strategies for integrated control of ticks and tick-borne diseases at the farm level in a mixed crop-livestock system in Uganda

Ticks and tickborne diseases (TTBD) are serious animal health constraints in Uganda and acaricides are the current method of choice for their control. Although widely used, the external-input, single-technology paradigm of chemical control is unsustainable and may inhibit endemic stability. TTBD control could benefit from ecologically-based integrated pest management (IPM), which relies heavily on renewable resources administered in an integrated manner, natural mortality factors and control tactics that disrupt these factors as little as possible. Based on information generated during a preliminary survey, this paper outlines a fiamework for designing IPM strategies for TTBDs

Assessment of financial costs for the control of bovine trypanosomiasis in Mukono county, Uganda

Trypanosomosis is an endemic disease in cattle in Mukono District in south eastern Uganda. A multi-disciplinary project was formulated in order to better understand the infection dynamics, and drug sensitivities, of the trypanosome parasites prevalent in Mukono, and also to assess the economic importance of the disease in this pen-urban dairy production system. This paper describes the occurrence, methods and costs of control of bovine trypanosomosis, and its economic importance in dairy cattle in the pen-urban production system of Mukono County. It is hoped that the information generated from this study will help guide policy formulation on the control of bovine trypanosomosis in Mukono in particular, and Uganda in general