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PloS One 2020Mycetoma is a chronic, granulomatous infection of subcutaneous tissue, that may involve deep structures and bone. It can be caused by bacteria (actinomycetoma) or fungi...
BACKGROUND
Mycetoma is a chronic, granulomatous infection of subcutaneous tissue, that may involve deep structures and bone. It can be caused by bacteria (actinomycetoma) or fungi (eumycetoma). There is an epidemiological association between mycetoma and the environment, including rainfall, temperature and humidity but there are still many knowledge gaps in the identification of the natural habitat of actinomycetes, their primary reservoir, and their precise geographical distribution. Knowing the potential distribution of this infection and its ecological niche in endemic areas is relevant to determine disease management strategies and etiological agent habitat or reservoirs.
METHODOLOGY/PRINCIPAL FINDINGS
This was an ambispective descriptive study of 31 patients with actinomycetoma. We determined the biophysical characteristics including temperature, precipitation, soil type, vegetation, etiological agents, and mapped actinomycetoma cases in Northeast Mexico. We identified two disease cluster areas. One in Nuevo Leon, with a predominantly kastanozems soil type, with a mean annual temperature of 22°, and a mean annual precipitation of 585.2 mm. Herein, mycetoma cases were produced by Actinomadura pelletieri, Actinomadura madurae, Nocardia brasiliensis, and Nocardia spp. The second cluster was in San Luis Potosí, where lithosols soil type predominates, with a mean annual temperature of 23.5° and a mean annual precipitation of 635.4 mm. In this area, all the cases were caused by N. brasiliensis. A. madurae cases were identified in rendzinas, kastanozems, vertisols, and lithosols soils, and A. pelletieri cases in xerosols, kastanozems, and rendzinas soils. Previous thorn trauma with Acacia or Prosopis plants was referred by 35.4% of subjects. In these states, the presence of thorny plants, such as Acacia spp., Prosopis spp., Senegalia greggi, Vachellia farnesiana and Vachellia rigidula, are common.
CONCLUSIONS/SIGNIFICANCE
Mapping this neglected tropical infection aids in the detection of disease cluster areas, the development of public health strategies for early diagnosis and disease prediction models; this paves the way for more ecological niche etiological agent research.
Topics: Adolescent; Adult; Aged; Climate; Cross-Sectional Studies; Female; Geography, Medical; Humans; Male; Mexico; Middle Aged; Mycetoma; Soft Tissue Infections; Soil; Young Adult
PubMed: 32384126
DOI: 10.1371/journal.pone.0232556 -
International Journal of Molecular and... 2023The increasing global public health concern of antimicrobial resistance (AMR) necessitates exploration of natural antimicrobial agents as potential alternatives. This...
The increasing global public health concern of antimicrobial resistance (AMR) necessitates exploration of natural antimicrobial agents as potential alternatives. This study aimed to investigate antimicrobial activities of Saharan actinomycetes, with specific focus on the strain AC31, that holds promising potential as an alternative to combat AMR. In this context, 32 actinomycetes were isolated from El Atteuf (Ghardaïa), Algeria. Isolates obtained were characterized morphologically and biochemically. Screened isolate was identified by 16S rRNA gene sequencing. Classification of actinomycete isolates was carried out by UPGMA (Unweighted Pair Group Method with Arithmetic Mean). Then, they were screened for their antimicrobial activity by cross-streak method. Identification of 32 isolates revealed 5 genera: (65.63%), (9.38%), (9.38%), (9.38%) and (6.25%). According to the biochemical and physiological characteristics, UPGMA classified the isolates in 4 phenons. A number of 24 (75.00%) isolates were active against Gram-positive bacteria, 21 (65.63%) isolates were effective against Gram-negative bacteria, and 25 (78.13%) isolates inhibited . Screened strain AC31 showed highest antagonistic activity and revealed an inhibition zones of 41, 38, 41, 42, and 44 mm, against (ATCC 6633), (ATCC 8739), (ATCC 13331), (ATCC 6538) and (ATCC 10231), respectively. Phylogenetic identification of the AC 31 isolate using 16S rRNA gene sequence showed similarity of 100% with NBRC 15411. Actinomycete isolates characterized in this study were endowed with antimicrobial activity against various pathogenic microorganisms that could be used efficiently in developing new antimicrobial substances.
PubMed: 37942257
DOI: 10.22088/IJMCM.BUMS.12.1.51 -
PloS One 2020The type I polyketide SF2487/A80577 (herein referred to as tetromadurin) is a polyether tetronate ionophore antibiotic produced by the terrestrial Gram-positive...
The type I polyketide SF2487/A80577 (herein referred to as tetromadurin) is a polyether tetronate ionophore antibiotic produced by the terrestrial Gram-positive bacterium Actinomadura verrucosospora. Tetromadurin is closely related to the polyether tetronates tetronasin (M139603) and tetronomycin, all of which are characterised by containing a tetronate, cyclohexane, tetrahydropyran, and at least one tetrahydrofuran ring. We have sequenced the genome of Actinomadura verrucosospora to identify the biosynthetic gene cluster responsible for tetromadurin biosynthesis (the mad gene cluster). Based on bioinformatic analysis of the 32 genes present within the cluster a plausible biosynthetic pathway for tetromadurin biosynthesis is proposed. Functional confirmation of the mad gene cluster is obtained by performing in-frame deletions in each of the genes mad10 and mad31, which encode putative cyclase enzymes responsible for cyclohexane and tetrahydropyran formation, respectively. Furthermore, the A. verrucosospora Δmad10 mutant produces a novel tetromadurin metabolite that according to mass spectrometry analysis is analogous to the recently characterised partially cyclised tetronasin intermediate lacking its cyclohexane and tetrahydropyran rings. Our results therefore elucidate the biosynthetic machinery of tetromadurin biosynthesis and lend support for a conserved mechanism of cyclohexane and tetrahydropyran biosynthesis across polyether tetronates.
Topics: Actinobacteria; Actinomadura; Amino Acid Sequence; Anti-Bacterial Agents; Base Sequence; Biosynthetic Pathways; Cloning, Molecular; Ethers; Furans; Macrolides; Multigene Family; Polyketide Synthases; Polyketides; Sequence Alignment
PubMed: 32925967
DOI: 10.1371/journal.pone.0239054 -
Metabolites Aug 2023Actinomycetia are known for their ability to produce a wide range of bioactive secondary metabolites having significant therapeutic importance. This study aimed to...
Actinomycetia are known for their ability to produce a wide range of bioactive secondary metabolites having significant therapeutic importance. This study aimed to explore the potential of actinomycetia as a source of bioactive compounds with antimicrobial properties against multi-drug-resistant (MDR) clinical pathogens. A total of 65 actinomycetia were isolated from two unexplored forest ecosystems, namely the Pobitora Wildlife Sanctuary (PWS) and the Deepor Beel Wildlife Sanctuary (DBWS), located in the Indo-Burma mega-biodiversity hotspots of northeast India, out of which 19 isolates exhibited significant antimicrobial activity. 16S rRNA gene sequencing was used for the identification and phylogenetic analysis of the 19 potent actinomycetia isolates. The results reveal that the most dominant genus among the isolates was (84.21%), followed by rare actinomycetia genera such as , , and . Furthermore, seventeen of the isolates tested positive for at least one antibiotic biosynthetic gene, specifically type II polyketide synthase (PKS-II) and nonribosomal peptide synthetases (NRPSs). These genes are associated with the production of bioactive compounds with antimicrobial properties. Among the isolated strains, three actinomycetia strains, namely sp. PBR1, sp. PBR36, and sp. DBR11, demonstrated the most potent antimicrobial activity against seven test pathogens. This was determined through in vitro antimicrobial bioassays and the minimum inhibitory concentration (MIC) values of ethyl acetate extracts. Gas chromatography-mass spectrometry (GS-MS) and whole-genome sequencing (WGS) of the three strains revealed a diverse group of bioactive compounds and secondary metabolite biosynthetic gene clusters (smBGCs), respectively, indicating their high therapeutic potential. These findings highlight the potential of these microorganisms to serve as a valuable resource for the discovery and development of novel antibiotics and other therapeutics with high therapeutic potential.
PubMed: 37623855
DOI: 10.3390/metabo13080911 -
Microbiology (Reading, England) Feb 2022The Ojo de Liebre Lagoon is a Marine Protected Area that lies within a UNESCO World Heritage Site and is a critical habitat for important migratory species such as the...
The Ojo de Liebre Lagoon is a Marine Protected Area that lies within a UNESCO World Heritage Site and is a critical habitat for important migratory species such as the grey whale and bird species. Unique hypersaline environments, such as the Ojo de Liebre Lagoon, are underexplored in terms of their bacterial and chemical diversity, representing a potential source for new bioactive compounds with pharmacological properties. Actinobacteria are one of the most diverse and prolific taxonomic bacterial groups in terms of marine bioactive compounds. This study aimed to identify the culturable actinobacterial community inhabiting the Lagoon, as well as to test their potential as new sources of anticancer compounds with pharmacological potential. A selective isolation approach focused on spore-forming bacteria from 40 sediment samples generated a culture collection of 64 strains. The 16S rRNA gene analyses identified three phyla in this study, the Actinobacteria, Firmicutes and Proteobacteria, where the phylum Actinobacteria dominated (57%) the microbial community profiles. Within the Actinobacteria, nine different genera were isolated including the , and sp. We observed seasonal differences on actinobacteria recovery. For instance, strains were recovered during the four sampling seasons, while and were only isolated in February 2018, and and were uniquely isolated in June 2018. Ethyl acetate crude extracts derived from actinobacterial cultures were generated and screened for cytotoxic activity against six cancer cell lines. Strains showed promising low percentages of viability on lung (H1299), cervical (SiHa), colon (Caco-2) and liver (HepG2) cancer lines. Molecular networking results suggest many of the metabolites produced by these strains are unknown and they might harbour novel chemistry. Our results showed the Ojo de Liebre Lagoon is a novel source for isolating diverse marine actinobacteria which produce promising bioactive compounds for potential biotechnological use as anticancer agents.
Topics: Actinobacteria; Biodiversity; Caco-2 Cells; Humans; Phylogeny; RNA, Ribosomal, 16S; Streptomyces
PubMed: 35213299
DOI: 10.1099/mic.0.001144 -
Virology Oct 2021To date, there are no broad-spectrum antivirals available to treat infections with flaviviruses such as dengue (DENV) and Zika virus (ZIKV). In this study, we determine...
To date, there are no broad-spectrum antivirals available to treat infections with flaviviruses such as dengue (DENV) and Zika virus (ZIKV). In this study, we determine the broad antiviral activity of the lantibiotic Labyrinthopeptin A1. We show that Laby A1 inhibits all DENV serotypes and various ZIKV strains with IC around 1 μM. The structurally related Laby A2 also displayed a consistent, but about tenfold lower, antiviral activity. Furthermore, Laby A1 inhibits many viruses from divergent families such as HIV, YFV, RSV and Punta Torovirus. Of interest, Laby A1 does not show activity against non-enveloped viruses. Its antiviral activity is independent of the cell line or the used evaluation method, and can also be observed in MDDC, a physiologically relevant primary cell type. Furthermore, Laby A1 demonstrates low cellular toxicity and has a more favorable SI compared to duramycin, a well-described lantibiotic with broad-spectrum antiviral activity. Time-of-drug addition experiments demonstrate that Laby A1 inhibits infection and entry processes of ZIKV and DENV. We reveal that Laby A1 performs its broad antiviral activity by interacting with a viral factor rather than a cellular factor, and that it has virucidal properties. Finally, using SPR interaction studies we demonstrate that Laby A1 interacts with several phospholipids (i.e. PE and PS) present in the viral envelope. Together with other recent Labyrinthopeptin antiviral publications, this work validates the activity of Laby A1 as broad antiviral entry inhibitor with a unique mechanism of action and demonstrates its potential value as antiviral agent against emerging flaviviruses.
Topics: Animals; Antiviral Agents; Bacteriocins; Cell Survival; Cells, Cultured; Cytokines; Dengue Virus; Dose-Response Relationship, Drug; Humans; Peptides; Phospholipids; Viral Envelope; Virus Internalization; Viruses; Zika Virus
PubMed: 34274562
DOI: 10.1016/j.virol.2021.07.003 -
Plants (Basel, Switzerland) Jan 2023was applied in peat-based soilless cultivation systems containing a mixed substrate (peat:vermiculite:perlite = 2:1:1, //) and irrigated by one-strength or...
was applied in peat-based soilless cultivation systems containing a mixed substrate (peat:vermiculite:perlite = 2:1:1, //) and irrigated by one-strength or four-strength Hoagland's nutrient solution to explore whether it can alleviate inhibition by higher-nutrient solutions (four-strength) and bring benefits to improvements of quality. The results showed that higher-nutrient solutions improved the flavor quality of cucumber fruit; especially, the contents of (E,Z)-2,6-nonadienal and (E)-2-Nonenal were effectively increased, which are the special flavor substances of cucumber. K424 effectively improved growth performance, photosynthetic capacity, vitamin C content, soluble sugars, soluble protein, and total pectin in cucumber under higher nutrition solution conditions. Compared with the higher solution treatment, the bacterial diversity significantly increased, whereas the presence of fungi had no significant difference following the K424 application. Moreover, K424 reduced the relative abundance of and promoted that of the , , , , and genera. Redundancy analysis showed that , , and were positively correlated with the substrate enzyme of sucrase, catalase, and urease. This study provides insight that K424 mitigated the deleterious effects of high levels of nutrition solution on cucumber growth and quality by improving the substrate enzyme, regulating the microbial community structure, and enhancing the photosynthetic capacity.
PubMed: 36679013
DOI: 10.3390/plants12020298 -
Beilstein Journal of Organic Chemistry 2021Three new tetronate-class polyketides, nomimicins B, C, and D, along with nomimicin, hereafter named nomimicin A, were isolated from the culture extract of sp AKA43...
Three new tetronate-class polyketides, nomimicins B, C, and D, along with nomimicin, hereafter named nomimicin A, were isolated from the culture extract of sp AKA43 collected from floating particles in the deep-sea water of Sagami Bay, Japan. The structures of nomimicins B, C, and D were elucidated through the interpretation of NMR and MS analytical data, and the absolute configuration was determined by combination of NOESY/ROESY and ECD analyses. Nomimicins B, C, and D showed antimicrobial activity against Gram-positive bacteria, and , with MIC values in the range of 6.5 to 12.5 μg/mL Nomimicins B and C also displayed cytotoxicity against P388 murine leukemia cells with IC values of 33 and 89 μM, respectively.
PubMed: 34497672
DOI: 10.3762/bjoc.17.141 -
Microorganisms Jan 2023Oilseed rape is sensitive to soil phosphorus deficiencies. In contrast, white lupin is widely used as a model plant because it has efficient phosphorus utilization....
Oilseed rape is sensitive to soil phosphorus deficiencies. In contrast, white lupin is widely used as a model plant because it has efficient phosphorus utilization. Therefore, soil fertility and microbial composition in the rhizospheres of oilseed rapes and root exudate metabolites were compared under monocropping and intercropping systems. The main purpose was to explore whether the phosphorus absorption of rapeseed can be promoted by intercropping with white lupine. In comparison with oilseed rape monoculture (RR), the results showed that the contents of soil-available phosphorus, microbial biomass and phosphorus in the rhizospheres of oilseed rapes in the intercropping system (RL) were all higher than those of RR. Meanwhile, in comparison with RR, not only phosphorus-solubilizing bacteria, such as , and , but also phosphorus-solubilizing fungi, such as , , , were enriched in the rhizospheres of the oilseed rape under the RL system. Moreover, more abundant soil bacterial functions, organic acids and metabolites were also detected in root exudates of the oilseed rapes under the RL system. All of the above results suggest that soil phosphorus availability in the rhizospheres of oilseed rape could be improved by intercropping with white lupin. Additionally, soil phosphorus-solubilizing microorganisms, that are enriched in the rhizospheres of oilseed rapes under RL systems, have an important function in the improvement of phosphorus absorption of rapeseed by intercropping with white lupin.
PubMed: 36838291
DOI: 10.3390/microorganisms11020326 -
The Journal of Antimicrobial... Dec 2022Actinomycetoma is a chronic granulomatous disease affecting skin, subcutaneous tissue, fascia, muscle and bones. With increasing resistance against commonly used...
OBJECTIVES
Actinomycetoma is a chronic granulomatous disease affecting skin, subcutaneous tissue, fascia, muscle and bones. With increasing resistance against commonly used treatment regimens, susceptibility testing is urgently needed.
METHODS
We developed an in vitro susceptibility assay for Actinomadura madurae, one of the common causative agents of actinomycetoma, employing resazurin for endpoint reading. Using this assay, reproducible MICs were determined for the most commonly used antibacterial agents for actinomycetoma treatment. The tested antibacterial agents included trimethoprim/sulfamethoxazole, amikacin, streptomycin, amoxicillin, ceftriaxone, gentamicin, ciprofloxacin, doxycycline, imipenem, linezolid, penicillin G and rifampicin.
RESULTS
Following the clinical breakpoints as stated by CLSI, 100% of the tested strains were susceptible to trimethoprim/sulfamethoxazole (MIC 0.03/0.59-1/19 mg/L), amikacin (MIC 0.0078-0.25 mg/L), doxycycline (MIC <0.25-1 mg/L) and linezolid (MIC <0.25-2 mg/L), 90% to ciprofloxacin (MIC <0.25-2 mg/L), 80% to ceftriaxone (MIC <0.5 to >64 mg/L) and imipenem (MIC <0.25-32 mg/L) and only 20% to amoxicillin (MIC <0.5 to >64 mg/L) and rifampicin (MIC 0.5 to >32 mg/L).
CONCLUSIONS
Determinations of MICs by visual readings of colour changes versus spectrophotometric readings were comparable. This convenient visual reading has the advantage of feasible implementation in endemic settings.
Topics: Humans; Amikacin; Linezolid; Doxycycline; Ceftriaxone; Rifampin; Mycetoma; Anti-Bacterial Agents; Amoxicillin; Trimethoprim, Sulfamethoxazole Drug Combination; Imipenem; Ciprofloxacin; Ifosfamide; Microbial Sensitivity Tests
PubMed: 36315595
DOI: 10.1093/jac/dkac367