scholarly journals Community-based geographical distribution of Mycobacterium ulcerans VNTR-genotypes from the environment and humans in the Nyong valley, Cameroon

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Francis Zeukeng ◽  
Anthony Ablordey ◽  
Solange E. Kakou-Ngazoa ◽  
Stephen Mbigha Ghogomu ◽  
David N’golo Coulibaly ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Tandem Repeats ◽  
Buruli Ulcer ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Community Based ◽  
Human Samples ◽  
Route Of Transmission ◽  
Mode Of Transmission ◽  
Animal Reservoirs

Abstract Background Genotyping is a powerful tool for investigating outbreaks of infectious diseases and it can provide useful information such as identifying the source and route of transmission, and circulating strains involved in the outbreak. Genotyping techniques based on variable number of tandem repeats (VNTR) are instrumental in detecting heterogeneity in Mycobacterium ulcerans (MU) and also for discriminating MU from other mycobacteria species. Here, we describe and map the distribution of MU genotypes in Buruli ulcer (BU) endemic communities of the Nyong valley in Cameroon. We also tested the hypothesis of whether the suspected animal reservoirs of BU that share the human microhabitat are shedding contaminated fecal matters and saliva into their surrounding environments. Methods Environmental samples from suspected MU-risk factors and lesion swabs from human patients were sampled in BU-endemic communities and tested for the presence of MU by qPCR targeting three independent sequences (IS2404, IS2606, KR-B). Positive samples to MU were further genotyped by VNTR with confirmation by sequencing of four loci (MIRU1, Locus 6, ST1, Locus 19). Results MU was detected in environmental samples including water bodies (23%), biofilms (14%), detritus (10%), and in human patients (73%). MU genotypes D, W, and C were found both in environmental and human samples. The micro geo-distribution of MU genotypes from communities showed that genotype D is found both in environmental and human samples, while genotypes W and C are specific to environmental samples and human lesions, respectively. No obvious focal grouping of MU genotypes was observed at the community scale. An additional survey in the human microhabitat suggests that domestic and wild animals do not shed MU in their saliva and feces in sampled communities. Conclusions VNTR typing uncovered different MU genotypes circulating in the endemic communities of the Akonolinga district. A MU environmental genotype was found in patients, yet the mechanism of contamination remains to be investigated; and recovering MU in culture from the environment remains key priority to enable a better understanding of the mode of transmission of BU. We also conclude that excretions from suspected animals are unlikely to be major sources of MU in the Nyong Valley in Cameroon.

scholarly journals Potential Animal Reservoir of Mycobacterium ulcerans: Systematic Review

2018 ◽  
Author(s):  
Avishek Singh ◽  
John McBride ◽  
Brenda Govan ◽  
Mark Pearson
Keyword(s):  
Systematic Review ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Published Data ◽  
Animal Reservoir ◽  
Permanent Disability ◽  
Route Of Transmission ◽  
The World ◽  
Mode Of Transmission ◽  
Animal Reservoirs

Mycobacterium ulcerans is the causative agent of the Buruli ulcer, also known, in Australia, as Daintree ulcer or Bairnsdale ulcer. This destructive skin disease is characterized by extensive and painless necrosis of the skin and soft tissue with the formation of large ulcers, commonly on the leg or arm. To date, 33 countries with tropical, subtropical and temperate climates in Africa, the Americas, Asia and the Western Pacific have reported cases of Buruli Ulcer. The disease is rarely fatal, although it may lead to permanent disability and/ or disfigurement if not treated appropriately or in time. It is the third most common mycobacterial infection in the world after tuberculosis and leprosy. The precise mode of transmission of M. ulcerans is yet to be elucidated. Nevertheless, it is possible that the mode of transmission varies with different geographical areas and epidemiological settings. The knowledge about the possible route of transmission and potential animal reservoir of M. ulcerans is poorly understood and still remains patchy. We conducted a systematic review with selected key words on PubMed and INFORMIT databases to aggregate available published data on animal reservoirs of M. ulcerans. After certain inclusion and exclusion criteria, a total of 17 studies were included in the review. A variety of animals, e.g rodents, shrews, possums (ringtail and brush tail), horses, dogs, alpacas, koalas and Indian flap-shelled turtles have been recorded as being infected with M. ulcerans around the world. The majority of studies included in this review identified animal reservoirs, either aquatic or terrestrial, as predisposing for the emergence and reemergence of M. ulcerans infection. Taken together, the selected studies in this systematic review and discussed so far, it is clear that exotic wildlife, aquatic animals and native mammals play a significant role as reservoirs for M. ulcerans.

scholarly journals Development and Application of Two Multiplex Real-Time PCR Assays for the Detection of Mycobacterium ulcerans in Clinical and Environmental Samples

2007 ◽  
Vol 73 (15) ◽  
pp. 4733-4740 ◽  
Author(s):  
Janet A. M. Fyfe ◽  
Caroline J. Lavender ◽  
Paul D. R. Johnson ◽  
Maria Globan ◽  
Aina Sievers ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Polyketide Synthase ◽  
Variable Number Tandem Repeat ◽  
Buruli Ulcer ◽  
Turnaround Time ◽  
Positive Control ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Taqman Assay ◽  
Vntr Locus

ABSTRACT Mycobacterium ulcerans is a slow-growing environmental bacterium that causes a severe skin disease known as Buruli ulcer. PCR has become a reliable and rapid method for the diagnosis of M. ulcerans infection in humans and has been used for the detection of M. ulcerans in the environment. This paper describes the development of a TaqMan assay targeting IS2404 multiplexed with an internal positive control to monitor inhibition with a detection limit of less than 1 genome equivalent of DNA. The assay improves the turnaround time for diagnosis and replaces conventional gel-based PCR as the routine method for laboratory confirmation of M. ulcerans infection in Victoria, Australia. Following analysis of 415 clinical specimens, the new test demonstrated 100% sensitivity and specificity compared with culture. Another multiplex TaqMan assay targeting IS2606 and the ketoreductase-B domain of the M. ulcerans mycolactone polyketide synthase genes was designed to augment the specificity of the IS2404 PCR for the analysis of a variety of environmental samples. Assaying for these three targets enabled the detection of M. ulcerans DNA in soil, sediment, and mosquito extracts collected from an area of endemicity for Buruli ulcer in Victoria with a high degree of confidence. Final confirmation was obtained by the detection and sequencing of variable-number tandem repeat (VNTR) locus 9, which matched the VNTR locus 9 sequence obtained from the clinical isolates in this region. This suite of new methods is enabling rapid progress in the understanding of the ecology of this important human pathogen.

scholarly journals First Molecular Characterisation of Clinical Strains of Mycobacterium ulcerans in Togo (West Africa)

2019 ◽  
pp. 1-14
Author(s):  
Menssah Teko ◽  
Mounerou Salou ◽  
Solange E. Kakou Ngazoa ◽  
Issaka Maman ◽  
Kodjovi Agbodeka ◽  
...  
Keyword(s):  
West Africa ◽  
Tandem Repeats ◽  
Buruli Ulcer ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Clinical Samples ◽  
Molecular Technique ◽  
Endemic Region ◽  
Typing Method ◽  
Genetic Strains

Background: Buruli ulcer is the third most common mycobacterial disease worldwide. Cases most occur in 30 countries but severe cases occur in West Africa countries such as Benin, Cote d’Ivoire and Togo mainly in rural regions. Early diagnosis may prevent severe disability. The molecular technique seems the best solution and new Mycobacterial Interspersed Repetitive Units (MIRU) and variable number tandem repeats (VNTR) typing method are themost reproducible in this regard. They propose geographical, inter and intraspecies differentiation and can be used as a diagnosis tool. Objective: The objective of this study was to investigate the molecular diversity by using MIRUVNTR typing in clinical samples of BU patients in Togo. Study Design: 64 DNA extracts from clinical samples were collected from BU patients in the two principal endemics districts in Togo (Yoto and Zio) with three less endemic districts (Bas Mono, Lacs and Vo). First, IS2404 and KR real-time PCR plus IS2606 conventional PCR were performed. In a second step, the strains were analysed by PCR typing for five specific and sensitive markers MIRU1, VNTR6, ST1, VNTR19 and VNTR9. Results and Conclusion: 71.11% were positive for IS2404, 3.13% were positives for PCR-KR and 31.11% for IS 2606. By MIRU-VNTR typing, 48.86% positive result was found for MIRU1 and 25.00%, 20.31%, 18.75% and 14.06% for VNTR6, ST1, VNTR19 and VNTR9 respectively. One of the samples was negative for all genotyping markers. Two different genetic profiles were identified by MIRU1, ST1 and VNTR loci by gel-analysed of the amplified products. The VNTR profile B (3,1,1,2) corresponding of 3 copies MIRU1, 1 copy VNTR6, 1 copy ST-1 and two copies of VNTR19 was detected in 15.63% of samples and the VNTR profile A (1,1,1,2) corresponding of 1 copy MIRU1, 1 copy VNTR6, 1 copy ST-1 and 2 copies of VNTR19 was detected in 3.13% of samples and confirms the West African genotype (3,1,1) in Togo. Different genetic strains of Mycobacterium ulcerans (M. ulcerans) were co-circulated in the same endemic region in the country. This study has described first the circulating of different genetic strains of M. ulcerans in Togo.

scholarly journals Multilocus VNTR analysis of Mycobacterium ulcerans strains isolated in Côte d’Ivoire

2010 ◽  
Vol 5 (01) ◽  
pp. 059-063 ◽  
Author(s):  
Grossmann Marie-David Coulibaly-N´Golo ◽  
Euloge Ekaza ◽  
Bakary Coulibaly ◽  
N’guetta Aka ◽  
Raymond Kouassi N’Guessan ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Tandem Repeats ◽  
Côte D’Ivoire ◽  
Buruli Ulcer ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Clinical Samples ◽  
Bacterial Strains ◽  
Cote D’Ivoire ◽  
Côte D'ivoire

Introduction: Buruli ulcer, caused by Mycobacterium ulcerans, is endemic in more than 30 countries worldwide, with Côte d'Ivoire being among the most affected countries. Methodology: We used seven variable number of tandem repeats (VNTR) markers and analyzed 114 samples from 11 Ivorian localities consisting of 33 bacterial strains and 81 clinical samples. Complete data sets at loci 1, 6, 9 and 33 were obtained for 18 of these strains (n = 15) and samples (n = 3) collected in each of the localities. Results: All the strains had allelic profile [3113], corresponding to the previously described Atlantic Africa genotype. Conclusion: Sequencing of PCR products at all loci showed no variation in sequence or repeat number, underlining the genetic monomorphism of M. ulcerans in Côte d'Ivoire.

scholarly journals Snapshot fecal survey of domestic animals in rural Ghana forMycobacterium ulcerans

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2065 ◽  
Author(s):  
Nicholas J. Tobias ◽  
Nana Ama Ammisah ◽  
Evans K. Ahortor ◽  
John R. Wallace ◽  
Anthony Ablordey ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Buruli Ulcer ◽  
Domestic Animals ◽  
Mycobacterium Ulcerans ◽  
Animal Reservoir ◽  
Rural Ghana ◽  
Reservoir Species ◽  
Mode Of Transmission ◽  
High Concentrations ◽  
Negative Controls

Identifying the source reservoirs ofMycobacterium ulceransis key to understanding the mode of transmission of this pathogen and controlling the spread of Buruli ulcer (BU). In Australia, the native possum can harborM. ulceransin its gastrointestinal tract and shed high concentrations of the bacteria in its feces. To date, an analogous animal reservoir in Africa has not been identified. Here we tested the hypothesis that common domestic animals in BU endemic villages of Ghana are reservoir species analogous to the Australian possum. Using linear-transects at 10-meter intervals, we performed systematic fecal surveys across four BU endemic villages and one non-endemic village in the Asante Akim North District of Ghana. One hundred and eighty fecal specimens from a single survey event were collected and analyzed by qPCR for theM. ulceransdiagnostic DNA targets IS2404and KR-B. Positive and negative controls performed as expected but all 180 test samples were negative. This structured snapshot survey suggests that common domestic animals living in and around humans do not shedM. ulceransin their feces. We conclude that, unlike the Australian native possum, domestic animals in rural Ghana are unlikely to be major reservoirs ofM. ulcerans.

scholarly journals Mycobacterium ulcerans Population Genomics To Inform on the Spread of Buruli Ulcer across Central Africa

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Koen Vandelannoote ◽  
Delphin Mavinga Phanzu ◽  
Kapay Kibadi ◽  
Miriam Eddyani ◽  
Conor J. Meehan ◽  
...  
Keyword(s):  
Disease Control ◽  
Population Genomics ◽  
Demographic History ◽  
Buruli Ulcer ◽  
Central Africa ◽  
Mycobacterium Ulcerans ◽  
Evolutionary Trajectory ◽  
Content Type ◽  
Mode Of Transmission ◽  
The Impact

ABSTRACT Buruli ulcer is a neglected tropical disease of skin and subcutaneous tissue caused by infection with the pathogen Mycobacterium ulcerans. Many critical issues for disease control, such as understanding the mode of transmission and identifying source reservoirs of M. ulcerans, are still largely unknown. Here, we used genomics to reconstruct in detail the evolutionary trajectory and dynamics of M. ulcerans populations at a central African scale and at smaller geographical village scales. Whole-genome sequencing (WGS) data were analyzed from 179 M. ulcerans strains isolated from all Buruli ulcer foci in the Democratic Republic of the Congo, The Republic of Congo, and Angola that have ever yielded positive M. ulcerans cultures. We used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our phylogeographic analysis revealed one almost exclusively predominant sublineage of M. ulcerans that arose in Central Africa and proliferated in its different regions of endemicity during the Age of Discovery. We observed how the best sampled endemic hot spot, the Songololo territory, became an area of endemicity while the region was being colonized by Belgium (1880s). We furthermore identified temporal parallels between the observed past population fluxes of M. ulcerans from the Songololo territory and the timing of health policy changes toward control of the Buruli ulcer epidemic in that region. These findings suggest that an intervention based on detecting and treating human cases in an area of endemicity might be sufficient to break disease transmission chains, irrespective of other reservoirs of the bacterium. IMPORTANCE Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans. The disease is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Currently, the major hurdles facing disease control are incomplete understandings of both the mode of transmission and environmental reservoirs of M. ulcerans. As decades of spasmodic environmental sampling surveys have not brought us much closer to overcoming these hurdles, the Buruli ulcer research community has recently switched to using comparative genomics. The significance of our research is in how we used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our approach shows that it might be possible to use bacterial population genomics to assess the impact of health interventions, providing valuable feedback for managers of disease control programs in areas where health surveillance infrastructure is poor.

scholarly journals Genetic Diversity in Mycobacterium ulcerans Isolates from Ghana Revealed by a Newly Identified Locus Containing a Variable Number of Tandem Repeats

2006 ◽  
Vol 188 (4) ◽  
pp. 1462-1465 ◽  
Author(s):  
Markus Hilty ◽  
Dorothy Yeboah-Manu ◽  
Daniel Boakye ◽  
Ernestina Mensah-Quainoo ◽  
Simona Rondini ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Tandem Repeats ◽  
Polymorphic Locus ◽  
Variable Number ◽  
Mycobacterium Ulcerans ◽  
Apparent Lack ◽  
Variant Genotype ◽  
Typing Methods ◽  
Genotype C ◽  
Clonal Population Structure

ABSTRACT The molecular typing methods used so far for Mycobacterium ulcerans isolates have not been able to identify genetic differences among isolates from Africa. This apparent lack of genetic diversity among M. ulcerans isolates is indicative of a clonal population structure. We analyzed the genetic diversity of 72 African isolates, including 57 strains from Ghana, by variable number of tandem repeat (VNTR) typing based on a newly identified polymorphic locus designated ST1 and the previously described locus MIRU 1. Three different genotypes were found in Ghana, demonstrating for the first time the genetic diversity of M. ulcerans in an African country. While the ST1/MIRU 1 allele combination BD/BAA seems to dominate in Africa, it was only rarely found in isolates from Ghana, where the combination BD/B was dominant and observed in all districts studied. A third variant genotype (C/BAA) was found only in the Amansie-West district. The results indicate that new genetic variants of M. ulcerans emerged and spread within Ghana and support the potential of VNTR-based typing for genotyping of M. ulcerans.

scholarly journals Mycobacterium ulceransin Mosquitoes and March flies captured from endemic areas of Northern Queensland, Australia

2018 ◽  
Author(s):  
Avishek Singh ◽  
William John Hannan McBride ◽  
Brenda Govan ◽  
Mark Pearson ◽  
Scott A. Ritchie
Keyword(s):  
Causative Agent ◽  
Buruli Ulcer ◽  
Mycobacterial Infection ◽  
Blood Feeding ◽  
Mycobacterium Ulcerans ◽  
Mechanical Transmission ◽  
Environmental Reservoir ◽  
Nontuberculous Mycobacterial Infection ◽  
Mode Of Transmission ◽  
Endemic Areas

AbstractMycobacterium ulceransis the causative agent of Buruli ulcer (BU). This nontuberculous mycobacterial infection has been reported in over 33 countries worldwide. In Australia, the majority of cases of BU have been recorded in coastal Victoria and the Mossman-Daintree areas of north Queensland. Mosquitoes have been postulated as a vector ofM. ulceransin Victoria, however the specific mode of transmission of this disease is still far from being well understood. In the current study, we trapped and analysed 16,900 (allocated to 845 pools) mosquitoes and 296 March flies from the endemic areas of north Queensland to examine for the presence ofM. ulceransDNA by polymerase chain reaction. Seven of 845 pools of mosquitoes were positive on screening using the IS2404 PCR target but only one pool was positive for presence ofM. ulceransafter confirmatory testing. None of the March fly samples were positive for the presence ofM. ulcerans.M. ulceranswas detected on proboscises of deliberately exposed mosquitoes.Author SummaryThe causative agent of Buruli ulcer is Mycobacterium ulcerans. This destructive skin disease is characterized by extensive and painless necrosis of skin and underlying tissues usually on extremities of body due to production of toxin named mycolactone. The disease is prevalent in Africa and coastal Australia. The exact mode of transmission and potential environmental reservoir for the pathogen still remain obscure. Aquatic and biting insects have been identified as important niche in transmission and maintenance of pathogen in the environment. In this study we screened mosquitoes and march flies captured from endemic areas of northern Queensland for the presence ofM. ulcerans.In addition, we conducted artificial blood feeding experiment to identify the role of mosquitoes in transmission of this pathogen. We found one pool of mosquito out of 845 pools positive forM. ulceransand none of the March fly samples were positive. This could indicate a low burden of the bacteria in the environment coinciding with a comparatively low number of human cases ofM. ulceransinfection seen during the trapping period of the study. Evidence to support mechanical transmission via mosquito proboscises was found.

scholarly journals Isolation of Nontuberculous Mycobacteria from the Environment of Ghanian Communities Where Buruli Ulcer Is Endemic

2016 ◽  
Vol 82 (14) ◽  
pp. 4320-4329 ◽  
Author(s):  
Samuel Yaw Aboagye ◽  
Emelia Danso ◽  
Kobina Assan Ampah ◽  
Zuliehatu Nakobu ◽  
Prince Asare ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Nontuberculous Mycobacteria ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Mycobacterium Fortuitum ◽  
Mycobacterial Species ◽  
Mycobacterium Chelonae ◽  
Content Type ◽  
Rate Of Recovery ◽  
Soil And Water

ABSTRACTThis study aimed to isolate nontuberculous mycobacterial species from environmental samples obtained from some selected communities in Ghana. To optimize decontamination, spiked environmental samples were used to evaluate four decontamination solutions and supplemented media, after which the best decontamination solution and media were used for the actual analysis. The isolates obtained were identified on the basis of specific genetic sequences, including heat shock protein 65, IS2404, IS2606,rpoB, and the ketoreductase gene, as needed. Among the methods evaluated, decontamination with 1 M NaOH followed by 5% oxalic acid gave the highest rate of recovery of mycobacteria (50.0%) and the lowest rate of contamination (15.6%). The cultivation medium that supported the highest rate of recovery of mycobacteria was polymyxin B-amphotericin B-nalidixic acid-trimethoprim-azlocillin–supplemented medium (34.4%), followed by isoniazid-supplemented medium (28.1%). Among the 139 samples cultivated in the main analysis, 58 (41.7%) yielded mycobacterial growth, 70 (50.4%) had no growth, and 11 (7.9%) had all inoculated tubes contaminated. A total of 25 different mycobacterial species were identified. Fifteen species (60%) were slowly growing (e.g.,Mycobacterium ulcerans,Mycobacterium avium,Mycobacterium mantenii, andMycobacterium malmoense), and 10 (40%) were rapidly growing (e.g.,Mycobacterium chelonae,Mycobacterium fortuitum, andMycobacterium abscessus). The occurrence of mycobacterial species in the various environmental samples analyzed was as follows: soil, 16 species (43.2%); vegetation, 14 species (38.0%); water, 3 species (8.0%); moss, 2 species (5.4%); snail, 1 species (2.7%); fungi, 1 species (2.7%). This study is the first to report on the isolation ofM. ulceransand other medically relevant nontuberculous mycobacteria from different environmental sources in Ghana.IMPORTANCEDiseases caused by mycobacterial species other than those that cause tuberculosis and leprosy are increasing. Control is difficult because the current understanding of how the organisms are spread and where they live in the environment is limited, although this information is needed to design preventive measures. Growing these organisms from the environment is also difficult, because the culture medium becomes overgrown with other bacteria that also live in the environment, such as in soil and water. We aimed to improve the methods for growing these organisms from environmental sources, such as soil and water samples, for better understanding of important mycobacterial ecology.

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