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In Norway, paratuberculosis has been frequently diagnosed in goats, while cattle have been almost free of the infection. This difference in prevalence between goats and cattle has led to speculations about the existence of a Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolate that is non-pathogenic for cattle. There is little information available on genotypic variation of M. a. paratuberculosis isolated from animals in Norway. In the present study, genotypic information on 51 isolates from goats and four isolates from cattle in Norway was obtained by use of IS900 restriction fragment length polymorphism (RFLP) analysis. All isolates from cattle and 84% of the isolates from goats had the same RFLP pattern (B-C1). Five RFLP patterns not previously detected were found. No genotypic variation that could explain a difference in host origin was found between the isolates from cattle and the majority of the Norwegian goat isolates. This lack of difference indicates that the most common M. a. paratuberculosis isolates in Norway may infect both cattle and goats.

The Norwegian surveillance and control programme for paratuberculosis revealed 8 seroreactors in a single dairy cattle herd that had no clinical signs of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) infection. Paratuberculosis had been a clinical problem in goats several years previously in this herd. All 45 cattle were culled and a thorough investigation of the infection status was conducted by the use of interferon-γ (IFN-γ) immunoassay, measurement of antibodies, and pathological and bacteriological examination. In the IFN-γ immunoassay, 9 animals gave positive results, and 13 were weakly positive, while 19 animals were negative. In the serological test,10 animals showed positive reactions, and 5 were doubtful, while 30 animals gave negative reactions. There appeared to be a weak trend toward younger animals having raised IFN-γ and older animals having raised serological tests. Histopathological lesions compatible with paratuberculosis were diagnosed in 4 animals aged between 4 and 9 years. Three of these animals had positive serological reaction and one animal gave also positive results in the IFN-γ immunoassay. Infection was confirmed by isolation of M. a. paratuberculosis from 2 of these 4 animals. One single bacterial isolate examined by restriction fragment length polymorphism (RFLP) had the same profile, B-C1, as a strain that had been isolated from a goat at the same farm several years previously. Despite many animals being positive in one or both of the immunological tests, indicative of a heavily infected herd, none of the animals showed clinical signs and only one cow was shown to be shedding bacteria. A cross-reaction with other mycobacteria might have caused some of the immunoreactions in these animals. It is also possible that the Norwegian red cattle breed is resistant to clinical infection with M. a. paratuberculosis.

Abstract 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.

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. [ABSTRACT FROM AUTHOR]

In Norway, paratuberculosis has been frequently diagnosed in goats, while cattle have been almost free of the infection. This difference in prevalence between goats and cattle has led to speculations about the existence of a Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolate that is non-pathogenic for cattle. There is little information available on genotypic variation of M. a. paratuberculosis isolated from animals in Norway. In the present study, genotypic information on 51 isolates from goats and four isolates from cattle in Norway was obtained by use of IS900 restriction fragment length polymorphism (RFLP) analysis. All isolates from cattle and 84% of the isolates from goats had the same RFLP pattern (B-C1). Five RFLP patterns not previously detected were found. No genotypic variation that could explain a difference in host origin was found between the isolates from cattle and the majority of the Norwegian goat isolates. This lack of difference indicates that the most common M. a. paratuberculosis isolates in Norway may infect both cattle and goats. [ABSTRACT FROM AUTHOR]

Abstract 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.

Abstract 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.

Abstract Background Mycobacterium avium subsp. avium (Maa) and Mycobacterium avium subsp. hominissuis (Mah) are opportunistic pathogens that may infect several species, including humans and pigs. Mah is however more frequently isolated from pigs than Maa, and it is unclear if this is due to difference in virulence or in exposure to the two organisms. Clinical isolates of each subspecies were administered perorally to ten domestic pigs, respectively. The animals were sacrificed at six and 12 weeks after inoculation. At necropsy, macroscopic lesions were recorded, and tissue samples were collected for mycobacterial culture, IS1245 real time PCR and histopathological examination. Culturing was also performed on faecal samples collected at necropsy. Results Macroscopic and histopathological lesions were detected in pigs infected with each subspecies, and bacterial growth and histopathological changes were demonstrated, also in samples from organs without gross pathological lesions. Six weeks after inoculation, live Mah was detected in faeces, as opposed to Maa. The presence of live mycobacteria was also more pronounced in Mah infected tonsils. In comparison, the Maa isolate appeared to have a higher ability of intracellular replication in porcine macrophages compared to the Mah isolate. Conclusions The study shows that both subspecies were able to infect pigs. Additionally, the more extensive shedding of Mah might cause pig-to-pig transmission and contribute to the higher incidence of infection caused by this subspecies.

Abstract Background A high proportion of pigs imported to Serbia from a Lithuanian breeding herd reacted positively against avian and/or bovine tuberculin. The pigs were euthanized and lesions characteristic for mycobacterial infection were detected. An investigation of potential mycobacteriosis in the pigs imported to Serbia and the possible source of infection in the Lithuanian herd were therefore initialised. Results Formalin fixed, paraffin embedded lymph nodes from tuberculin positive animals were examined by real-time PCR for IS1245 and IS6110. IS1245 was detected in 55% and IS6110 in 11% of the samples. Seven of the ten IS6110 positive samples were positive for IS1245. Eleven lymph nodes from 10 pigs and 15 environmental samples were collected from the Lithuanian breeding herd and cultured for mycobacteria. M. avium subsp. hominissuis was detected in all lymph nodes and from eight samples of peat and sawdust. Isolates with identical and related IS1245- and IS1311 RFLP profiles were detected from swine and peat. Conclusions This study demonstrated cross reactions between avian and bovine tuberculin in pigs. Real-time PCR indicated infection with M. avium in the Serbian pigs. However, as a small proportion of the lymph nodes were positive for IS6110, infection with bacteria in the M. tuberculosis complex could not be ruled out. Analyses confirmed the presence of M. avium subsp. hominissuis in porcine and environmental samples from the Lithuanian breeding herd. The results indicate peat as a source of M. avium subsp. hominissuis infection in these pigs, and that the pigs imported to Serbia were infected with M. avium subsp. hominissuis.

Abstract Background In Gram-negative bacteria, the most commonly studied quorum sensing signals are the N-acylhomoserine lactones (AHLs). In Salmonella, AHLs are recognized by SdiA, which is believed to be a sensor of AHLs produced by other bacteria, since Salmonella does not produce AHLs itself. It has been speculated that AHLs produced by the gastrointestinal flora may influence the regulation of virulence traits in Salmonella. The aim of the present work was to study the effect of AHLs on epithelial cell invasion by Salmonella in vitro. Methods Invasion by Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium) strain and its isogenc sdiA mutant was studied using a conventional gentamycin invasion assay with HEp-2 cells at 37°C. Gene expression was studied using a semi-quantitative PCR. Results The S. Typhimurium strain, but not its isogenic sdiA mutant, displayed increased in vitro invasion after addition of both N-hexanoyl-DL-homoserine lactone (C6-AHL) and N-octanoyl-DL-homoserine lactone (C8-AHL). Increased expression of two of the genes in the SdiA regulon (rck and srgE) was observed in the wild type strain, but not in the sdiA mutant. Conclusions The results from the present study show that S. Typhimurium can respond to two different AHL quorum sensing signals (C6-AHL and C8-AHL) with increased cell invasion at 37°C in vitro, and that this response most likely is sdiA mediated. These results indicate that if AHLs are present in the intestinal environment, they may increase the invasiveness of Salmonella.

Abstract 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.

Abstract Background Bovine Tuberculosis (BTB) is a widespread and endemic disease of cattle in Ethiopia. Information relating to genotypic characteristics of Mycobacterium bovis strains affecting the cattle population in Ethiopia is limited. We carried out molecular characterization of M. bovis strains isolated from BTB infected cattle using the spoligotyping technique. The relationship between distribution of spoligotypes and recorded variables was also investigated. A new approach that can numerically reflect the degree of genetic polymorphism in a M. bovis population was also developed. The study was conducted from July 2006 to January 2007 in cattle slaughtered at five representative abattoirs in Ethiopia. Results Forty-five M. bovis isolates were obtained from 406 pathologic tissue specimens collected from 337 carcasses with lesions compatible with BTB. Twelve spoligotypes were identified from 34 distinct strains; with SB1176 as a dominant spoligotype (41.2% of the isolates) followed by SB0133 (14.7%). Comparison of spoligotypes with an M. bovis global database http://www.mbovis.org revealed six new spoligotypes which were subsequently registered in the database with international identification codes of SB1517, SB1518, SB1519, SB1520, SB1521 and SB1522. The majority of strains were obtained from cattle slaughtered at Addis Ababa abattoir. On the basis of the Spoligotype Evolutionary Index, SEI (a numeric expression approach to make standardized comparison of spoligotype evolution), M. bovis isolates from Ethiopia were relatively more heterogeneous (SEI = 3.2) compared to isolates from other countries. This might be attributed to extensive livestock movement linked to trading or seasonal migration, high degree of livestock mingling, and also diversities of the country's agricultural and livestock ecosystems, in addition to lack of disease control measures that led to high infection prevalence. Multiple spoligotype infection was recorded in nine (50%) of infected carcasses and this may indicate the prevailing high degree of super infection. Conclusions This study provided molecular evidence for the widespread distribution of M. bovis in the cattle population in Ethiopia. It also demonstrated a relatively high degree of genetic polymorphism of the isolates. Further molecular investigation of M. bovis strains in humans and other domestic animals is recommended in order to elucidate the zoonotic importance as well as reservoirs and pattern of transmission among various hosts.

Abstract Background Bovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare. The diagnosis of brucellosis is mainly accomplished using serological tests. However, some Brucella spp. have been isolated from clinical cases in the field and kept in culture collection but their biochemical profiles were not documented. We report biochemical profiling and AMOS-PCR characterization of some of these field isolates of Brucella originating from both commercial and smallholder cattle farming sectors of Zimbabwe. Findings Fourteen isolates of Brucella from culture collection were typed using biochemical profiles, agglutination by monospecific antisera, susceptibility to Brucella-specific bacteriophages and by AMOS-PCR that amplifies species- specific IS711. The results of the biochemical profiles for B. abortus biovar 1 (11 isolates) and biovar 2 (2 isolates) were consistent with those of reference strains. A single isolate from a goat originating from a smallholder mixed animal farm was identified as B. melitensis biovar 1. The AMOS-PCR produced DNA products of sizes 498 bp and 731 bp for B. abortus (biovar 1 and 2) and B. melitensis biovar 1, respectively. Conclusion We concluded that the biochemical profiles and AMOS-PCR characterization were consistent with their respective species and biovars. B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe.

Abstract Background Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all over the world including from biofilms in water distribution systems. The aim of this study was to examine isolates of M. avium subsp. avium and M. avium subsp. hominissuis of different origin for biofilm formation and to look for correlations between biofilm formation and RFLP-types, and to standardise the method to test for biofilm formation. In order to determine the best screening method, a panel of 14 isolates of M. avium subsp. avium and M. avium subsp. hominissuis, were tested for their ability to form biofilm in microtiter plates under different conditions. Subsequently, 83 additional isolates from humans, swine and birds were tested for biofilm formation. The isolates were tested for the presence of selected genes involved in the synthesis of glycopeptidolipids (GPLs) in the cell wall of M. avium, which is believed to be important for biofilm formation. Colony morphology and hsp65 sequvar were also determined. Results Nine isolates from swine produced biofilm. There was a significant higher frequency of porcine isolates forming biofilm compared to human isolates. All isolates were previously characterised by IS1311- and IS1245-RFLP typing. The ability to form biofilm did not correlate with the RFLP-type, hsp65 sequevar, colony morphology or the presence of gene sequences related to GPL synthesis. Conclusion The observed differences in biofilm forming abilities between porcine and human isolates raises questions regarding the importance of biofilm formation for infectious potential. The optimised method worked well for screening of multiple isolates.

Abstract Background Since 1994, Brucella strains have been isolated from a wide range of marine mammals. They are currently recognized as two new Brucella species, B. pinnipedialis for the pinniped isolates and B. ceti for the cetacean isolates in agreement with host preference and specific phenotypic and molecular markers. In order to investigate the genetic relationships within the marine mammal Brucella isolates and with reference to terrestrial mammal Brucella isolates, we applied in this study the Multiple Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA) approach. A previously published assay comprising 16 loci (MLVA-16) that has been shown to be highly relevant and efficient for typing and clustering Brucella strains from animal and human origin was used. Results 294 marine mammal Brucella strains collected in European waters from 173 animals and a human isolate from New Zealand presumably from marine origin were investigated by MLVA-16. Marine mammal Brucella isolates were shown to be different from the recognized terrestrial mammal Brucella species and biovars and corresponded to 3 major related groups, one specific of the B. ceti strains, one of the B. pinnipedialis strains and the last composed of the human isolate. In the B. ceti group, 3 subclusters were identified, distinguishing a cluster of dolphin, minke whale and porpoise isolates and two clusters mostly composed of dolphin isolates. These results were in accordance with published analyses using other phenotypic or molecular approaches, or different panels of VNTR loci. The B. pinnipedialis group could be similarly subdivided in 3 subclusters, one composed exclusively of isolates from hooded seals (Cystophora cristata) and the two others comprising other seal species isolates. Conclusion The clustering analysis of a large collection of marine mammal Brucella isolates from European waters significantly strengthens the current view of the population structure of these two species, and their relative position with respect to the rest of the Brucella genus. MLVA-16 is confirmed as being a rapid, highly discriminatory and reproducible method to classify Brucella strains including the marine mammal isolates. The Brucella2009 MLVA-16 genotyping database available at http://mlva.u-psud.fr/ is providing a detailed coverage of all 9 currently recognized Brucella species.

Abstract Background Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has remained a major source of concern to public health officials in Zambia. Previous investigations have used traditional epidemiological methods that are unable to identify the causative agent and from which dynamics of disease dispersion is difficult to discern. The objective of this study was to isolate, characterize and determine the genetic diversity and relatedness of M. bovis from major cattle rearing districts in Zambia by spoligotyping. A total of 695 carcasses were examined and 98 tissues had gross post-mortem lesions compatible with BTB. Results Forty-two out of the ninety-eight suspected tissues examined had culture properties characteristic of mycobacteria from which 31 isolates yielded interpretable spoligotypes. This technique showed good discriminatory power (HGDI = 0.98), revealing 10 different spoligotype patterns. Twenty-seven isolates belonged to one cluster with more than 95% similarity and inside the cluster, one predominant spoligotype was found in 20 (64.5%) of the isolates tested. The highest number of spoligotypes was observed among samples from Namwala district. Spoligotypes from 26 (83.9%) of the isolates belonged to five spoligotypes that have been reported before while the remaining 5 (16.1%) isolates had unique spoligotypes that are being reported for the first time; these have been assigned numbers SB1763 to SB1767. Five of the 6 districts had the predominant spoligotype (SB0120). Conclusion The study has described the dispersion patterns of M. bovis in Zambian cattle for the first time and has identified 5 spoligotype patterns specific to Zambia. The observation of an overlap in the spoligotype pattern SB0120 in 5 of the 6 districts suggests the probability of sharing a common source of infection.

Abstract Background Mycobacterium avium is an environmental mycobacterium that can be divided into the subspecies avium, hominissuis, paratuberculosis and silvaticum. Some M. avium subspecies are opportunistic pathogens for animals and humans. They are ubiquitous in nature and can be isolated from natural sources of water, soil, plants and bedding material. Isolates of M. avium originating from humans (n = 37), pigs (n = 51) and wild birds (n = 10) in Norway were examined by IS1245 and IS1311 RFLP using new and specific probes and for the presence of IS901 and ISMpa1 by PCR. Analysis and generation of a dendrogram were performed with the software BioNumerics. Results IS1311 RFLP provided clear results that were easy to interpret, while IS1245 RFLP generated more complex patterns with a higher discriminatory power. The combination of the two methods gave additional discrimination between isolates. All avian isolates except one were M. avium subsp. avium with two copies of IS1311 and one copy of IS1245, while the isolates of human and porcine origin belonged to M. avium subsp.hominissuis. The isolates from human patients were distributed randomly among the clusters of porcine isolates. There were few identical isolates. However, one isolate from a human patient was identical to a porcine isolate. Regional differences were detected among the porcine isolates, while there was no clustering of human isolates according to type of clinical symptoms or geographical location of the patient's home addresses. Conclusion The results demonstrate that a wide range of M. avium subsp.hominissuis are present in pigs and humans in Norway, and that some of these isolates are very similar. It remains to be determined whether humans are infected from pigs or if they are infected from common environmental sources.

Mycobacterium tuberculosis, the causative agent of tuberculosis in humans, is considered primarily a human pathogen. It has, however, been reported in a wide range of domestic and wild animals, often living in close prolonged contact with humans. Sputum samples in which acid fast bacteria were detected in smears were collected from patients at three health facilities in Namwala district, Zambia. Samples from cattle presenting gross lesions compatible with bovine tuberculosis were collected at a local abattoir in the same district. Isolated mycobacteria were identified and genotyped using classical molecular methods. From a total of 33 isolates of M. tuberculosis detected (30 from humans and 3 from cattle), two cattle isolates shared the same spoligotype and MIRU-VNTR pattern with a human patient. This study has for the first time documented the isolation of M. tuberculosis from cattle in Zambia and provides molecular evidence of an epidemiological link between M. tuberculosis isolates from humans and cattle in Namwala district. A possible spill back of M. tuberculosis to humans cannot be excluded and therefore further studies documenting to what extent M. tuberculosis is shed in cattle milk are needed. This finding further suggests that veterinary public health measures to control human TB, should also take into account the bovine reservoir.

Brucellosis, a worldwide zoonosis, is linked to reproductive problems in primary hosts. A high proportion of Brucella-positive hooded seals (Cystophora cristata) have been detected in the declined Northeast Atlantic stock. High concentrations of polychlorinated biphenyls (PCBs) have also been discovered in top predators in the Arctic, including the hooded seal, PCB 153 being most abundant. The aim of this study was to assess the pathogenicity of Brucella pinnipedialis hooded seal strain in the mouse model and to evaluate the outcome of Brucella spp. infection after exposure of mice to PCB 153. BALB/c mice were infected with B. pinnipedialis hooded seal strain or Brucella suis 1330, and half from each group was exposed to PCB 153 through the diet. B. pinnipedialis showed a reduced pathogenicity in the mouse model as compared to B. suis 1330. Exposure to PCB 153 affected neither the immunological parameters, nor the outcome of the infection. Altogether this indicates that it is unlikely that B. pinnipedialis contribute to the decline of hooded seals in the Northeast Atlantic., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Mycobacterium avium infection is a severe condition in humans, whereas pigs are often subclinically infected. Pig carcasses represent a possible source of human infection. Faecal excretion of M. avium was recently demonstrated in experimentally infected pigs, along with detection of M. avium in apparently normal lymph nodes. The present study investigates faecal excretion in naturally infected herds and the presence of live mycobacteria in lymph nodes. Two pig herds (A and B), with a history of sporadically suspected M. avium infection were sampled. Herd B used peat, as opposed to Herd A. Samples from peat, sawdust, drinking water, faeces and lymph nodes were collected. Identification of mycobacteria was performed by 16S rDNA sequencing and PCR. Mycobacterium avium isolates were analysed by Multi-Locus Variable Number of Tandem repeat Analysis (MLVA). Mycobacterium avium subsp. hominissuis was detected in samples of faeces, peat and lymph nodes from Herd B, often with identical MLVA profiles. Additionally, other non-tuberculous mycobacteria (NTM) were found in the same material. The absence of macroscopic lymph node lesions in the presence of M. avium subsp. hominissuis was frequently demonstrated. In Herd A, only one NTM isolate, which proved not to be M. avium, was found. Faeces might facilitate transmission of M. avium subsp. hominissuis between pigs and maintain the infection pressure in herds. The low incidence of macroscopic lesions together with the massive presence of M. avium subsp. hominissuis in lymph nodes from pigs kept on peat raises questions related to animal husbandry, food safety and human health.

Bovine tuberculosis (BTB) remains a major threat to animal and human health, and obstructs international and inter-regional livestock trade in Ethiopia. Many aspects of epidemiology of BTB and its causative agent, Mycobacterium bovis (M. bovis) are not well known. Aims of the study were to elucidate molecular characteristics of M. bovis strains using MLVA typing method. Further aim was to determine infection pressure associated with occurrence of multiple genotypes in individual infected cattle. Data and samples were collected in the period July 2006-January 2007 in cattle slaughtered at five representative abattoirs across the country. Molecular investigation of the isolates was carried out using multilocus variable-number tandem-repeat analysis (MLVA) of 28 variable numbers of tandem repeat (VNTR) loci, and the results were compared to spoligotyping. This study is believed to contribute to the knowledge of molecular genetics and epidemiology of M. bovis in Ethiopia and elsewhere with similar BTB epidemic situation and livestock production settings. Four-hundred and six tissue samples from 337 carcasses revealing gross pathologic lesions compatible with BTB were collected from five abattoirs. Fifty-eight isolates obtained from cultured samples were subjected to region of difference (RD) analysis and MLVA typing. RD confirmed all isolates as being M. bovis. MLVA revealed a high heterogeneity of M. bovis (19 genotypes) and the discriminatory power of MLVA was higher than for spoligotyping (Hunter-Gaston Diversity Index (HGDI) 0.92 vs. 0.82). Adoption of the nine VNTR loci with ⩾3 alleles provided good differentiation between the isolates. However, differentiation was optimized when MLVA was combined with spoligotyping (HGDI=0.99). MLVA confirmed infections with multiple genotypes in 38.5% (10/26) of individual animals. In conclusion, the usefulness of MLVA for genotyping M. bovis in high prevalence settings was demonstrated. BTB in Ethiopia is caused by heterogeneous populations of M. bovis and individual carcasses were often infected with different genotypes, indicating a high infection pressure perhaps related to the absence of protective immunity conferred by infection., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Mycobacterium avium subsp. avium (Maa) and M. avium subsp. hominissuis (Mah) are environmental mycobacteria and significant opportunistic pathogens. Mycobacterium avium infections in humans and pigs are mainly due to Mah. It is not known whether this is caused by a difference in virulence or difference in exposure to the two subspecies. The aim of the present study was to investigate the ability of the M. avium subspecies to replicate intracellularly and to characterise the gene expression program triggered by infection of human primary macrophages., Results: All isolates were able to invade and persist within human macrophages. However, intracellular replication was only evident in cells infected with the two Maa isolates. Transcriptional responses to the isolates were characterized by upregulation of genes involved in apoptosis, immune- and inflammatory response, signal transduction and NF-kB signaling, cell proliferation and T-cell activation. Although similar pathways and networks were perturbed by the different isolates, the response to the Maa subspecies was exaggerated, and there was evidence of increased activation of type I and II interferon signaling pathways., Conclusion: Mycobacterium avium isolates of different genetic characteristics invaded monocytes and induced different degree of macrophage activation. Isolates of Maa were able to replicate intracellularly suggesting that differences in exposure, uptake or induction of adaptive immunity are more likely explanations for the difference in prevalence between M. avium subspecies.

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.)

Mycobacterium avium subsp. hominissuis is an environmental bacterium causing opportunistic infections in swine, resulting in economic losses. Additionally, the zoonotic aspect of such infections is of concern. In the southeastern region of Norway in 2009 and 2010, an increase in condemnation of pig carcasses with tuberculous lesions was seen at the meat inspection. The use of peat as bedding in the herds was suspected to be a common factor, and a project examining pigs and environmental samples from the herds was initiated. Lesions detected at meat inspection in pigs originating from 15 herds were sampled. Environmental samples including peat from six of the herds and from three peat production facilities were additionally collected. Samples were analysed by culture and isolates genotyped by MLVA analysis. Mycobacterium avium subsp. hominissuis was detected in 35 out of 46 pigs, in 16 out of 20 samples of peat, and in one sample of sawdust. MLVA analysis demonstrated identical isolates from peat and pigs within the same farms. Polyclonal infection was demonstrated by analysis of multiple isolates from the same pig. To conclude, the increase in condemnation of porcine carcasses at slaughter due to mycobacteriosis seemed to be related to untreated peat used as bedding.

Tuberculosis remains a major public health problem in Zambia. While human to human transmission of Mycobacterium tuberculosis is of major importance in driving the tuberculosis epidemic, the impact of Mycobacterium bovis transmission from infected cattle is largely unknown. This cross-sectional study aimed at molecular characterization of M. bovis in humans and cattle. A total of 100 human sputum samples and 67 bovine tissues were collected and analyzed for the presence of mycobacteria. Of 65 human samples that harbored acid fast bacteria (AFB), 55 isolates were obtained of which 34 were identified as M. tuberculosis and 2 as M. bovis. AFB-positive bovine samples (n = 67) yielded 47 mycobacterial isolates among which 25 were identified as M. bovis and no M. tuberculosis was found. Among the M. bovis isolates, spoligotyping revealed a high homogeneity in genotypes circulating in Namwala district. Human and cattle isolates shared identical MIRU-VNTR genotypes, suggesting that transmission between the two hosts may occur. Therefore, this study has documented zoonotic TB in human patients in Namwala district of Zambia. However, further molecular epidemiological studies in the study area are recommended.

Bovine tuberculosis (BTB) is a chronic bacterial disease caused by Mycobacterium bovis. Infections due to M. bovis, which serves as a stable reservoir, can pose serious challenge to control and eradicate in both wildlife and livestock at the interface. This study aimed at isolating and characterizing M. bovis from Kafue lechwe (Kobus leche kafuensis) and black lechwe (Kobus leche smithemani) at the animal/human interface in Zambia. The samples with lesions compatible with BTB collected during the hunting seasons of 2009 and 2010 were cultured for isolation of mycobacteria using Stonebrink with pyruvate (BD Diagnostics, MD, USA) and Middlebrook 7H10 (BD Diagnostics) slants. Isolated mycobacteria were identified using IS6110 polymerase chain reaction and deletion analysis. Molecular characterization of the isolates was performed using spoligotyping and mycobacteria interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) with nine loci. Data was analyzed using BioNumerics software 6.1. Out of the 39 samples, acid fast bacilli were detected in 27 (69.2 %) based on smear microscopy. Seven isolates were found to belong to Mycobacterium tuberculosis complex, and all were identified as M. bovis based on deletion analysis. All seven isolates were identical on spoligotyping as belonging to the SB0120 (SIT 482). MIRU-VNTR differentiated the isolates into five different patterns. This study has confirmed that M. bovis circulates in the Kafue lechwe, and non-tuberculous mycobacteria were detected in the black lechwe in Zambia which represents a wildlife reservoir, with a potential to spillover to cattle and humans. Isolates of M. bovis from lechwe antelopes are much conserved as only one spoligotype was detected. The study has shown that three loci differentiated fairly well. This option is cheap and less laborious, and hence a better option in resource-strained country like Zambia. The study further showed that some of the loci recommended by the European Reference Laboratory are not suitable for typing M. bovis in Zambia.

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: A high proportion of pigs imported to Serbia from a Lithuanian breeding herd reacted positively against avian and/or bovine tuberculin. The pigs were euthanized and lesions characteristic for mycobacterial infection were detected. An investigation of potential mycobacteriosis in the pigs imported to Serbia and the possible source of infection in the Lithuanian herd were therefore initialised., Results: Formalin fixed, paraffin embedded lymph nodes from tuberculin positive animals were examined by real-time PCR for IS1245 and IS6110. IS1245 was detected in 55% and IS6110 in 11% of the samples. Seven of the ten IS6110 positive samples were positive for IS1245. Eleven lymph nodes from 10 pigs and 15 environmental samples were collected from the Lithuanian breeding herd and cultured for mycobacteria. M. avium subsp. hominissuis was detected in all lymph nodes and from eight samples of peat and sawdust. Isolates with identical and related IS1245- and IS1311 RFLP profiles were detected from swine and peat., Conclusions: This study demonstrated cross reactions between avian and bovine tuberculin in pigs. Real-time PCR indicated infection with M. avium in the Serbian pigs. However, as a small proportion of the lymph nodes were positive for IS6110, infection with bacteria in the M. tuberculosis complex could not be ruled out. Analyses confirmed the presence of M. avium subsp. hominissuis in porcine and environmental samples from the Lithuanian breeding herd. The results indicate peat as a source of M. avium subsp. hominissuis infection in these pigs, and that the pigs imported to Serbia were infected with M. avium subsp. hominissuis.

Paratuberculosis was diagnosed in a goat herd that participated in a sanitation program against Mycobacterium avium subsp. paratuberculosis. The aim of this study was to characterise the development of gamma interferon (IFN-γ) and antibody responses as well as the occurrence of faecal shedding. Faecal culture appeared surprisingly sensitive as about 18% and 40% of the goats were positive at 9 and 15-17 months of age, respectively, and shedding was often seen prior to peripheral immune responses. Peripheral IFN-γ responses were not related to protection as clinical and high shedding goats often had high responses. An IFN-γ response usually preceded a humoral response. However, positive antibody titers could sometimes be seen simultaneously with, and even prior to, IFN-γ responses. In conclusion, faecal culture appeared as sensitive as IFN-γ testing. Furthermore, the antibody ELISA and the IFN-γ assay may perform equally well in an infected herd if surveillance is conducted annually., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: In Gram-negative bacteria, the most commonly studied quorum sensing signals are the N-acylhomoserine lactones (AHLs). In Salmonella, AHLs are recognized by SdiA, which is believed to be a sensor of AHLs produced by other bacteria, since Salmonella does not produce AHLs itself. It has been speculated that AHLs produced by the gastrointestinal flora may influence the regulation of virulence traits in Salmonella. The aim of the present work was to study the effect of AHLs on epithelial cell invasion by Salmonella in vitro., Methods: Invasion by Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium) strain and its isogenc sdiA mutant was studied using a conventional gentamycin invasion assay with HEp-2 cells at 37°C. Gene expression was studied using a semi-quantitative PCR., Results: The S. Typhimurium strain, but not its isogenic sdiA mutant, displayed increased in vitro invasion after addition of both N-hexanoyl-DL-homoserine lactone (C6-AHL) and N-octanoyl-DL-homoserine lactone (C8-AHL). Increased expression of two of the genes in the SdiA regulon (rck and srgE) was observed in the wild type strain, but not in the sdiA mutant., Conclusions: The results from the present study show that S. Typhimurium can respond to two different AHL quorum sensing signals (C6-AHL and C8-AHL) with increased cell invasion at 37°C in vitro, and that this response most likely is sdiA mediated. These results indicate that if AHLs are present in the intestinal environment, they may increase the invasiveness of Salmonella.

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.

This study was aimed at investigating risk factors associated with prevalence of tuberculosis (TB)-like lesions and associated mycobacteria in Ethiopian cattle slaughtered. The study was carried out during 2006-2007 in five selected municipal and export abattoirs. Methods of investigation involved detailed necropsy examination of carcasses and isolation of mycobacteria from pathologic tissue specimens. Factors of animal and environment origin were recorded and examined as explanatory variables in relation to the presence or absence of TB-like lesions and the presence of viable mycobacteria. Multivariable logistic regression analysis was used to identify risk factors associated with prevalence of TB-like lesions and mycobacteria. Out of 3,322 carcasses inspected, 10.2% (95% confidence interval (CI) [9.2-11.3]) and 3.2% (95% CI [2.6-3.8]) were positive, respectively, based on necropsy and bacteriologic examinations. The highest and lowest lesion prevalence was recorded in Adama (24.7%) and Yabello (4.2%), respectively. Multivariable logistic regression analysis identified age, breed, abattoir location, geographic origin and management system as being risk factors for prevalence of TB-like lesions and occurrence of viable mycobacteria in Ethiopian cattle. The study demonstrated mycobacterial infection as important infectious disease of Ethiopian cattle. The reported confirmed cases of the disease in different management and geographic settings in Ethiopia disproved the earlier held opinion of its occurrence as a low sporadic profile. In view of a dietary proclivity of Ethiopian communities (milk and meat are predominantly consumed raw) and lifestyle (close contact of people with animals), the risk of bovine tuberculosis as a public health threat is eminent.

We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2) clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of M. bovis have, in general, four or more copies of the insertion sequence IS6110, in contrast to the majority of M. bovis strains isolated from cattle, which are thought to carry only one or a few copies.

One of the diseases of veterinary and public health importance affecting the Kafue lechwe (Kobus leche kafuensis) on the Kafue flats is brucellosis, for which only scant information is available. During the 2003 (October), 2004 (December), and 2008 (July-December) hunting seasons in the Kafue flats, we conducted a study to determine the seroprevalence of Brucella spp. in the Kafue lechwe and to evaluate serologic tests for detection of Brucella spp. antibodies in lechwe. The Rose Bengal Test (RBT), competitive enzyme-linked immunosorbent assay (cELISA), and fluorescence polarization assay (FPA) were used. A total of 121 Kafue lechwe were hunted for disease investigations in 2003, 2004, and 2008 in the Kafue Flat Game Management Area. Of these, 21.6%, (95% confidence interval [CI]: 14.2-29.1%) had detectable antibodies to Brucella spp. The Kafue lechwe in Lochnivar National Park had higher antibody results than those in Blue Lagoon National Park (odds ratio=3.0; 95% CI: 0.94-9.4). Infection levels were similar in females (21.6%) and males (21.7%). Results were similar among RBT, FPA, cELISA tests, suggesting that these could effectively be used in diagnosing brucellosis in the Kafue lechwe. Our study demonstrates the presence of Brucella infections in the Kafue lechwe in two national parks located in the Kafue flats and further highlights the suitability of serologic assays for testing the Kafue lechwe. Because the Kafue lechwe is the most hunted wildlife species in Zambia, hunters need to be informed of the public health risk of Brucella spp. infection.

Background: Bovine Tuberculosis (BTB) is a widespread and endemic disease of cattle in Ethiopia. Information relating to genotypic characteristics of Mycobacterium bovis strains affecting the cattle population in Ethiopia is limited. We carried out molecular characterization of M. bovis strains isolated from BTB infected cattle using the spoligotyping technique. The relationship between distribution of spoligotypes and recorded variables was also investigated. A new approach that can numerically reflect the degree of genetic polymorphism in a M. bovis population was also developed. The study was conducted from July 2006 to January 2007 in cattle slaughtered at five representative abattoirs in Ethiopia., Results: Forty-five M. bovis isolates were obtained from 406 pathologic tissue specimens collected from 337 carcasses with lesions compatible with BTB. Twelve spoligotypes were identified from 34 distinct strains; with SB1176 as a dominant spoligotype (41.2% of the isolates) followed by SB0133 (14.7%). Comparison of spoligotypes with an M. bovis global database http://www.mbovis.org revealed six new spoligotypes which were subsequently registered in the database with international identification codes of SB1517, SB1518, SB1519, SB1520, SB1521 and SB1522. The majority of strains were obtained from cattle slaughtered at Addis Ababa abattoir. On the basis of the Spoligotype Evolutionary Index, SEI (a numeric expression approach to make standardized comparison of spoligotype evolution), M. bovis isolates from Ethiopia were relatively more heterogeneous (SEI = 3.2) compared to isolates from other countries. This might be attributed to extensive livestock movement linked to trading or seasonal migration, high degree of livestock mingling, and also diversities of the country's agricultural and livestock ecosystems, in addition to lack of disease control measures that led to high infection prevalence. Multiple spoligotype infection was recorded in nine (50%) of infected carcasses and this may indicate the prevailing high degree of super infection., Conclusions: This study provided molecular evidence for the widespread distribution of M. bovis in the cattle population in Ethiopia. It also demonstrated a relatively high degree of genetic polymorphism of the isolates. Further molecular investigation of M. bovis strains in humans and other domestic animals is recommended in order to elucidate the zoonotic importance as well as reservoirs and pattern of transmission among various hosts.