scholarly journals Investigation of skin microbiota reveals Mycobacterium ulcerans-Aspergillus sp. trans-kingdom communication

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Hammoudi ◽  
C. Cassagne ◽  
M. Million ◽  
S. Ranque ◽  
O. Kabore ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Buruli Ulcer ◽  
Opportunistic Pathogen ◽  
Fungal Species ◽  
Negative Control ◽  
Mycobacterium Ulcerans ◽  
Skin Microbiota ◽  
Endemic Region ◽  
Aspergillus Sp

AbstractMycobacterium ulcerans secrete a series of non-ribosomal-encoded toxins known as mycolactones that are responsible for causing a disabling ulceration of the skin and subcutaneous tissues named Buruli ulcer. The disease is the sole non-contagion among the three most common mycobacterial diseases in humans. Direct contact with contaminated wetlands is a risk factor for Buruli ulcer, responsible for M. ulcerans skin carriage before transcutaneous inoculation with this opportunistic pathogen. In this study, we analysed the bacterial and fungal skin microbiota in individuals exposed to M. ulcerans in Burkina Faso. We showed that M. ulcerans-specific DNA sequences were detected on the unbreached skin of 6/52 (11.5%) asymptomatic farmers living in Sindou versus 0/52 (0%) of those living in the non-endemic region of Tenkodogo. Then, we cultured the skin microbiota of asymptomatic M. ulcerans carriers and negative control individuals, all living in the region of Sindou. A total of 84 different bacterial and fungal species were isolated, 21 from M. ulcerans-negative skin samples, 31 from M. ulcerans-positive samples and 32 from both. More specifically, Actinobacteria, Aspergillus niger and Aspergillus flavus were significantly associated with M. ulcerans skin carriage. We further observed that in vitro, mycolactones induced spore germination of A. flavus, attracting the fungal network. These unprecedented observations suggest that interactions with fungi may modulate the outcome of M. ulcerans skin carriage, opening new venues to the understanding of Buruli ulcer pathology, prophylaxis and treatment of this still neglected tropical infection.

scholarly journals Investigation of skin microbiota reveals Mycobacterium ulcerans-Aspergillus sp. trans-kingdom communication

2019 ◽  
Author(s):  
N. Hammoudi ◽  
C Cassagne ◽  
M. Million ◽  
S Ranque ◽  
O. Kabore ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Aspergillus Flavus ◽  
Dna Sequences ◽  
Buruli Ulcer ◽  
Opportunistic Pathogen ◽  
Negative Control ◽  
Mycobacterium Ulcerans ◽  
Skin Microbiota ◽  
Endemic Region

ABSTRACTBackgroundMycobacterium ulcerans secrete a series of non-ribosomal-encoded toxins known as mycolactones that are responsible for causing a disabling ulceration of the skin and subcutaneous tissues named Buruli ulcer. The disease is the sole non-contagion among the three most common mycobacterial diseases in humans. Direct contact with contaminated wetlands is a risk factor for Buruli ulcer, responsible for M. ulcerans skin carriage before transcutaneous inoculation with this opportunistic pathogen.Methodology and principal findingsIn this study, we analysed the bacterial and fungal skin microbiota in individuals exposed to M. ulcerans in Burkina Faso. We showed that M. ulcerans-specific DNA sequences were detected on the unbreached skin of 6/52 (11.5%) asymptomatic farmers living in Sindou versus 0/52 (0%) of those living in the non-endemic region of Tenkodogo. Then, we cultured the skin microbiota of asymptomatic M. ulcerans carriers and negative control individuals, all living in the region of Sindou. A total of 84 different bacterial and fungal species were isolated, 21 from M. ulcerans-negative skin samples, 31 from M. ulcerans-positive samples and 32 from both. More specifically, Actinobacteria, Aspergillus niger and Aspergillus flavus were significantly associated with M. ulcerans skin carriage. We further observed that in vitro, mycolactones induced spore germination of A. flavus, attracting the fungal network.ConclusionThese unprecedented observations suggest that interactions with fungi may modulate the outcome of M. ulcerans skin carriage, opening new venues to the understanding of Buruli ulcer pathology, prophylaxis and treatment of this still neglected tropical infection.Author summaryBuruli ulcer is a chronic infectious disease caused by the environmental opportunistic pathogen Mycobacterium ulcerans which secretes an exotoxin responsible for its pathogenicity. The reservoir and sources of M. ulcerans in the environment remain elusive and its mode of transmission is unclear. To acquire M. ulcerans infection, at least two conditions must be met, viable bacteria and a skin lesion as demonstrated by experimental animal models. In this study, we showed that M. ulcerans specific DNA sequences could be detected on the healthy skin of asymptomatic farmers living in one region of Burkina Faso where Buruli ulcer cases had already been reported, but not in Buruli ulcer-free regions, suggesting skin carriage after contacts with environmental sources. We also investigated the skin microbiota of M. ulcerans carriers and found significant associations of some bacteria and fungi with skin carriage of M. ulcerans. These associations may due to the effect of mycolactones on some fungi species. As we showed previously with Mucor circinelloides and here with Aspergillus flavus.

scholarly journals Triple oral beta-lactam containing therapy for Buruli ulcer treatment shortening

2018 ◽  
Author(s):  
María Pilar Arenaz Callao ◽  
Rubén González del Río ◽  
Ainhoa Lucía Quintana ◽  
Charles J. Thompson ◽  
Alfonso Mendoza-Losana ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Amoxicillin Clavulanate ◽  
Low Toxicity ◽  
Potential Use ◽  
Ulcer Treatment

ABSTRACTThe potential use of clinically approved beta-lactams for Buruli ulcer (BU) treatment was investigated with representative classes analyzed in vitro for activity against Mycobacterium ulcerans. Beta-lactams tested were effective alone and displayed a strong synergistic profile in combination with antibiotics currently used to treat BU, i.e. rifampicin and clarithromycin; this activity was further potentiated in the presence of the beta-lactamase inhibitor clavulanate. In addition, quadruple combinations of rifampicin, clarithromycin, clavulanate and beta-lactams resulted in multiplicative reductions in their minimal inhibitory concentration (MIC) values. The MIC of amoxicillin against a panel of clinical isolates decreased more than 200-fold within this quadruple combination. Amoxicillin/clavulanate formulations are readily available with clinical pedigree, low toxicity, and orally and pediatric available; thus, supporting its potential inclusion as a new anti-BU drug in current combination therapies.

scholarly journals Experimental pieces of evidence for Mycobacterium ulcerans dormancy

2020 ◽  
Author(s):  
A. Loukil ◽  
R. Lalaoui ◽  
H. Bogreau ◽  
S. Regoui ◽  
M. Drancourt ◽  
...  
Keyword(s):  
Physiological State ◽  
Nile Red ◽  
Buruli Ulcer ◽  
Ambient Air ◽  
Opportunistic Pathogen ◽  
Oxygen Depletion ◽  
Mycobacterium Ulcerans ◽  
Ecological Niches ◽  
Intracellular Lipid ◽  
First Time

ABSTRACTBackgroundWhether Mycobacterium ulcerans, the etiological agent of the neglected Buruli ulcer in numerous tropical countries, would exist in a dormant state as reported for closely related Mycobacterium species, is not established.MethodologySix M. ulcerans strains were exposed to a progressive depletion in oxygen for two months, using a previously described Wayne model of dormancy; and further examined by microscopy using DDD staining, microcalorimetry and subculture in the presence of dead and replicative M. ulcerans as controls.Principal Findings/ConclusionsM. ulcerans CU001 strain died during the progressive oxygen depletion and four of five remaining strains exhibited Nile Red-stained intracellular lipid droplets after DDD staining and a 14-20-day regrowth when exposed to ambient air, diagnosing dormancy. A fifth M. ulcerans 19423 strain stained negative in DDD and slowly regrew in 27 days. Three tested M. ulcerans strains yielded microcalorimetric pattern similar to that of the negative (dead) homologous controls, differing from that of the homologous positive (replicative) controls. The relevance of these experimental observations, suggesting a previously unreported dormancy state of M. ulcerans, needs to be investigated in the natural ecological niches where M. ulcerans thrive and in Buruli ulcer lesions.Author summaryMycobacterium ulcerans is an environmental opportunistic pathogen of mammals and humans, causing a subcutaneous necrotizing infection named Buruli ulcer. Molecular detection of M. ulcerans DNA revealed different ecological niches where M. ulcerans may thrive, but the molecular biology approach does not catch the physiological state of M. ulcerans in these different ecological niches. Thus, the reservoir and the mode of transmission of M. ulcerans remain elusive. Here, we investigated experimental dormancy of M. ulcerans by using a previously described Wayne model of dormancy coupled with microscopy using DDD staining, microcalorimetry and subculture. Our findings demonstrate for the first time that some M. ulcerans strains exhibit a physiological state of dormancy; potentially limiting isolation and culture of M. ulcerans from environmental niches.

scholarly journals First isolation of Mycobacterium ulcerans from Swabs and Fine-Needle-Aspiration Specimens in Togo.

2019 ◽  
Author(s):  
Tchalare Kondi Makagni ◽  
Maman Issaka ◽  
Piten Ebekalisai ◽  
Disse Kodjo ◽  
Essossimna A. Kadanga ◽  
...  
Keyword(s):  
Fine Needle Aspiration ◽  
Slow Growth ◽  
Buruli Ulcer ◽  
Needle Aspiration ◽  
Mycobacterium Ulcerans ◽  
Clinical Samples ◽  
Direct Examination ◽  
Fine Needle ◽  
Pcr Targeting

Abstract Background Buruli ulcer is a skin disease caused by a mycobacterium called Mycobacterium ulcerans . It is prevalent in more than 33 countries on several continents but West Africa is the most affected. The isolation in culture of the bacteria is difficult because of its slow growth and the facilities required. In Togo, studies have been done on the risk factors for Mycobacterium ulcerans infection and the detection of cases by the Ziehl-Neelsen and PCR technique on clinical and environmental samples, but to date no data of isolates from clinical samples are available. The purpose of this study was to perform an in vitro culture of M. ulcerans from swab and fine needle aspiration samples through the confirmation stages of direct examination and IS2404 -PCR. Method A total of 70 clinical samples from Togo and 10 clinical isolates from Benin are analyzed by the three techniques indicated in the diagnosis, in particular the direct examination of acid-fast bacilli (AFB) using the Ziehl-Neelsen staining, the PCR targeting the IS2404 sequence, and the culture after transport of the samples in a transport medium made of Middlebrook 7H9 medium supplemented with a mixture of PANTA and OADC and decontamination by the modified Petroff method. Results The application of the three techniques of diagnosis for clinical samples yielded 44.28% of positivity rates on direct examination of AFB, 35.71% on culture and 77.14% on qPCR IS2404 with a significantly higher rate for qPCR (0.0001). All samples positive for Ziehl-Neelsen staining and culture were also positive for qPCR. Conclusion : Our results show that the culture, despite it difficulty and the slow growth of the bacteria, can be carried out with recommended tools of the mycobacteria culture and a good method of decontamination of the samples can improve the positivity rates. Its realization will allow the assessment of the in vitro sensitivity to the antibiotics used in the treatment and the discovery of new strains of Mycobacterium ulcerans .

scholarly journals In vitro fungitoxic potential of Lippia gracilis (Schauer) essential oil against phytopathogens

2020 ◽  
pp. 667-674
Author(s):  
Kevison Romulo da Silva França ◽  
Flavia Mota de Figueredo Alves ◽  
Tiago Silva Lima ◽  
Alda Leaby dos Santos Xavier ◽  
Plínio Tércio Medeiros de Azevedo ◽  
...  
Keyword(s):  
Essential Oil ◽  
Mycelial Growth ◽  
Fungal Growth ◽  
Fungal Species ◽  
Phytopathogenic Fungi ◽  
Negative Control ◽  
Growth Speed ◽  
Randomized Design

This study evaluates the in vitro effects of Lippia gracilis essential oil on the mycelial growth of phytopathogenic fungi. Experiments were carried out using a completely randomized design to assess the effects of eight treatments. Five replicates were evaluated for each experimental group. The essential oil was incorporated into the potato dextrose culture medium and poured into Petri dishes. Treatments were comprised of different concentrations of the oil (0.0125, 0.025, 0.05, 0.1, and 0.2%), a negative control (0.0%), and two positive controls (commercial fungicides). The plates were inoculated with fungi including Colletotrichum gloeosporioides, C. musae, C. fructicola, C. asianum, Alternaria alternata, A. brassicicola, Fusarium solani, F. oxysporum f. sp. cubense, and Lasiodiplodia theobromae and were incubated for seven days at 27 ± 2°C. The following variables were measured to verify the differences observed among treatments: percentage of mycelial growth inhibition and index of mycelial growth speed. All concentrations of L. gracilis oil inhibited the mycelial growth of the fungal species evaluated. The complete inhibition was observed between concentrations of 0.0125 and 0.1%. Treatment with oil inhibited fungal growth with similar, or even greater, efficiency than commercial fungicides.. We recommend the development of in vivo tests to verify whether L. gracilis essential oil can protect against fungal disease in live plants.

scholarly journals Whole Genome Comparisons Suggest Random Distribution of Mycobacterium ulcerans Genotypes in a Buruli Ulcer Endemic Region of Ghana

2015 ◽  
Vol 9 (3) ◽  
pp. e0003681 ◽  
Author(s):  
Anthony S. Ablordey ◽  
Koen Vandelannoote ◽  
Isaac A. Frimpong ◽  
Evans K. Ahortor ◽  
Nana Ama Amissah ◽  
...  
Keyword(s):  
Random Distribution ◽  
Buruli Ulcer ◽  
Mycobacterium Ulcerans ◽  
Whole Genome ◽  
Endemic Region ◽  
Genome Comparisons

scholarly journals In Vitro Killing of Mycobacterium ulcerans by Acidified Nitrite

2004 ◽  
Vol 48 (8) ◽  
pp. 3130-3132 ◽  
Author(s):  
R. Phillips ◽  
S. Kuijper ◽  
N. Benjamin ◽  
M. Wansbrough-Jones ◽  
M. Wilks ◽  
...  
Keyword(s):  
Buruli Ulcer ◽  
Mycobacterium Ulcerans

ABSTRACT Mycobacterium ulcerans, which causes Buruli ulcer, was exposed to acidified nitrite or to acid alone for 10 or 20 min. Killing was rapid, and viable counts were reduced below detectable limits within 10 min of exposure to 40 mM acidified nitrite. M. ulcerans is highly susceptible to acidified nitrite in vitro.

scholarly journals Microbiology of secondary infections in Buruli ulcer lesions; implications for therapeutic interventions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elizabeth Gyamfi ◽  
Charles A Narh ◽  
Charles Quaye ◽  
Adiza Abbass ◽  
Bartholomew Dzudzor ◽  
...  
Keyword(s):  
Secondary Infection ◽  
Buruli Ulcer ◽  
Fungal Species ◽  
Mycobacterium Ulcerans ◽  
Therapeutic Interventions ◽  
Antimicrobial Drugs ◽  
Delayed Wound Healing ◽  
Secondary Infections ◽  
Microbial Infections ◽  
Bacteria And Fungi

Abstract Background Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. M. ulcerans produces mycolactone, an immunosuppressant macrolide toxin, responsible for the characteristic painless nature of the infection. Secondary infection of ulcers before, during and after treatment has been associated with delayed wound healing and resistance to streptomycin and rifampicin. However, not much is known of the bacteria causing these infections as well as antimicrobial drugs for treating the secondary microorganism. This study sought to identify secondary microbial infections in BU lesions and to determine their levels of antibiotic resistance due to the prolonged antibiotic therapy required for Buruli ulcer. Results Swabs from fifty-one suspected BU cases were sampled in the Amansie Central District from St. Peters Hospital (Jacobu) and through an active case surveillance. Forty of the samples were M. ulcerans (BU) positive. Secondary bacteria were identified in all sampled lesions (N = 51). The predominant bacteria identified in both BU and Non-BU groups were Staphylococci spp and Bacilli spp. The most diverse secondary bacteria were detected among BU patients who were not yet on antibiotic treatment. Fungal species identified were Candida spp, Penicillium spp and Trichodema spp. Selected secondary bacteria isolates were all susceptible to clarithromycin and amikacin among both BU and Non-BU patients. Majority, however, had high resistance to streptomycin. Conclusions Microorganisms other than M. ulcerans colonize and proliferate on BU lesions. Secondary microorganisms of BU wounds were mainly Staphylococcus spp, Bacillus spp and Pseudomonas spp. These secondary microorganisms were less predominant in BU patients under treatment compared to those without treatment. The delay in healing that are experienced by some BU patients could be as a result of these bacteria and fungi colonizing and proliferating in BU lesions. Clarithromycin and amikacin are likely suitable drugs for clearance of secondary infection of Buruli ulcer.

scholarly journals Molecular characterization of Mycobacterium ulcerans DNA gyrase and identification of mutations reduced susceptibility against quinolones in vitro

2021 ◽  
Author(s):  
Hyun Kim ◽  
Shigtarou Mori ◽  
Tsuyoshi Kenri ◽  
Yasuhiko Suzuki
Keyword(s):  
Buruli Ulcer ◽  
Dna Gyrase ◽  
Resistance Mechanisms ◽  
Docking Studies ◽  
Mycobacterium Ulcerans ◽  
Amino Acid Residues ◽  
Wild Type Enzyme ◽  
Ulcer Disease

ABSTRACTBuruli ulcer disease is a neglected necrotizing and disabling cutaneous tropical illness caused by Mycobacterium ulcerans (Mul). Fluoroquinolone (FQ), used in the treatment of this disease, has been known to act by inhibiting the enzymatic activities of DNA gyrase; however, the detailed molecular basis of these characteristics and the FQ resistance mechanisms in Mul remains unknown. This study investigated the detailed molecular mechanism of Mul DNA gyrase and the contribution of FQ resistance in vitro using recombinant proteins from the Mul subsp. shinshuense and Agy99 strains with reduced sensitivity to FQs. The IC50 of FQs against Ala91Vla and Asp95Gly mutants of Mul shinshuense and Agy99 GyrA subunits were 3.7- to 42.0-fold higher than those against wild-type enzyme. Similarly, the CC25 was 10- to 210-fold higher than those for the WT enzyme. Furthermore, the interaction between the amino acid residues of WT/mutant Mul DNA gyrase and FQ side chains was assessed via molecular docking studies. This is the first detailed study showing the contribution of Mul DNA GyrA subunit mutations to reduce the susceptibility against FQs.

Sign in / Sign up

Export Citation Format

Share Document