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Microorganisms Apr 2024This review summarizes the interactions between , the etiologic agent of Chagas disease, its vectors, triatomines, and the diverse intestinal microbiota of triatomines,... (Review)
Review
This review summarizes the interactions between , the etiologic agent of Chagas disease, its vectors, triatomines, and the diverse intestinal microbiota of triatomines, which includes mutualistic symbionts, and highlights open questions. strains show great biological heterogeneity in their development and their interactions. Triatomines differ from other important vectors of diseases in their ontogeny and the enzymes used to digest blood. Many different bacteria colonize the intestinal tract of triatomines, but only Actinomycetales have been identified as mutualistic symbionts. Effects of the vector on are indicated by differences in the ability of to establish in the triatomines and in colonization peculiarities, i.e., proliferation mainly in the posterior midgut and rectum and preferential transformation into infectious metacyclic trypomastigotes in the rectum. In addition, certain forms of develop after feeding and during starvation of triatomines. Negative effects of on the triatomine vectors appear to be particularly evident when the triatomines are stressed and depend on the strain. Effects on the intestinal immunity of the triatomines are induced by ingested blood-stage trypomastigotes of and affect the populations of many non-symbiotic intestinal bacteria, but not all and not the mutualistic symbionts. After the knockdown of antimicrobial peptides, the number of non-symbiotic bacteria increases and the number of decreases. Presumably, in long-term infections, intestinal immunity is suppressed, which supports the growth of specific bacteria, depending on the strain of . These interactions may provide an approach to disrupt transmission.
PubMed: 38792688
DOI: 10.3390/microorganisms12050855 -
Scientific Reports May 2024Pradimicin U is a new dihydrobenzo[a]naphthacenequinone compound found to be active on a screen designed to investigate compounds with antimicrobial activity, produced...
Pradimicin U is a new dihydrobenzo[a]naphthacenequinone compound found to be active on a screen designed to investigate compounds with antimicrobial activity, produced by the actinomycete designated strain FMUSA5-5. The strain was isolated from a bio-fertilizer of Musa spp. collected from Suphanburi province, Thailand. The chemotaxonomic characteristics and 16S rRNA gene analysis revealed that strain FMUSA5-5 is a member of the genus Nonomuraea. Low genome-based taxonomic criteria, average nucleotide identity (ANI) (82.8-88.3%), average amino-acid identity (AAI) (79.4-87.3%), and digital DNA-DNA hybridization (dDDH) (29.5-38.5%) values and several phenotypic differences between strain FMUSA5-5 and its closest type strains of the genus Nonomuraea indicated that strain FMUSA5-5 represents a novel species of the genus Nonomuraea and the name Nonomuraea composti sp. nov. is proposed for the strain. The crude extract from the culture broth of strain FMUSA5-5 displayed promising antimicrobial activity against several pathogens and led to the isolation of a novel secondary metabolite, pradimicin U. Interestingly, this compound displayed a broad spectrum of biological activities such as antimalarial activity against Plasmodium falciparum K1 (IC value = 3.65 µg/mL), anti-Mycobacterium tuberculosis H37Ra (MIC value = 25.0 µg/mL), anti-Alternaria brassicicola BCC 42724 (MIC value = 25.0 µg/mL), anti-Bacillus cereus ATCC 11778 and anti-Staphylococcus aureus ATCC 29213 (MIC values = 6.25 and 1.56 µg/mL, respectively). Moreover, the compound possessed strong anti-human small cell lung cancer (NCI-H187) activity with IC value of 5.69 µg/mL, while cytotoxicity against human breast cancer (MCF-7) and Vero cells was very weak (IC values of 52.49 and 21.84 µg/mL, respectively).
Topics: Humans; Anti-Infective Agents; RNA, Ribosomal, 16S; Microbial Sensitivity Tests; Phylogeny; Actinomycetales; Animals; Thailand; Vero Cells; Musa; Plasmodium falciparum; Chlorocebus aethiops
PubMed: 38740839
DOI: 10.1038/s41598-024-60744-w -
Microbial Genomics May 2024Cutaneous ulcers are common in yaws-endemic areas. Although often attributed to ' subsp. and , quantitative PCR has highlighted a significant proportion of these ulcers...
Using 16s rRNA sequencing to characterize the microbiome of tropical cutaneous ulcer disease: insights into the microbial landscape and implications for diagnosis and treatment.
Cutaneous ulcers are common in yaws-endemic areas. Although often attributed to ' subsp. and , quantitative PCR has highlighted a significant proportion of these ulcers are negative for both pathogens and are considered idiopathic. This is a retrospective analysis utilising existing 16S rRNA sequencing data from two independent yaws studies that took place in Ghana and the Solomon Islands. We characterized bacterial diversity in 38 samples to identify potential causative agents for idiopathic cutaneous ulcers. We identified a diverse bacterial profile, including , , , spp and , consistent with findings from previous cutaneous ulcer microbiome studies. No single bacterial species was universally present across all samples. The most prevalent bacterium, , appeared in 42% of samples, suggesting a multifactorial aetiology for cutaneous ulcers in yaws-endemic areas. This study emphasizes the need for a nuanced understanding of potential causative agents. The findings prompt further exploration into the intricate microbial interactions contributing to idiopathic yaw-like ulcers, guiding future research toward comprehensive diagnostic and therapeutic strategies.
Topics: Humans; RNA, Ribosomal, 16S; Microbiota; Skin Ulcer; Ghana; Male; Yaws; Retrospective Studies; Female; Adult; Bacteria; Melanesia; Middle Aged; Staphylococcus; Streptococcus pyogenes; Arcanobacterium; Campylobacter
PubMed: 38739120
DOI: 10.1099/mgen.0.001234 -
Applied Microbiology and Biotechnology Apr 2024Tobramycin is an essential and extensively used broad-spectrum aminoglycoside antibiotic obtained through alkaline hydrolysis of carbamoyltobramycin, one of the...
Tobramycin is an essential and extensively used broad-spectrum aminoglycoside antibiotic obtained through alkaline hydrolysis of carbamoyltobramycin, one of the fermentation products of Streptoalloteichus tenebrarius. To simplify the composition of fermentation products from industrial strain, the main byproduct apramycin was blocked by gene disruption and constructed a mutant mainly producing carbamoyltobramycin. The generation of antibiotics is significantly affected by the secondary metabolism of actinomycetes which could be controlled by modifying the pathway-specific regulatory proteins within the cluster. Within the tobramycin biosynthesis cluster, a transcriptional regulatory factor TobR belonging to the Lrp/AsnC family was identified. Based on the sequence and structural characteristics, tobR might encode a pathway-specific transcriptional regulatory factor during biosynthesis. Knockout and overexpression strains of tobR were constructed to investigate its role in carbamoyltobramycin production. Results showed that knockout of TobR increased carbamoyltobramycin biosynthesis by 22.35%, whereas its overexpression decreased carbamoyltobramycin production by 10.23%. In vitro electrophoretic mobility shift assay (EMSA) experiments confirmed that TobR interacts with DNA at the adjacent tobO promoter position. Strains overexpressing tobO with ermEp* promoter exhibited 36.36% increase, and tobO with kasOp* promoter exhibited 22.84% increase in carbamoyltobramycin titer. When the overexpressing of tobO and the knockout of tobR were combined, the production of carbamoyltobramycin was further enhanced. In the shake-flask fermentation, the titer reached 3.76 g/L, which was 42.42% higher than that of starting strain. Understanding the role of Lrp/AsnC family transcription regulators would be useful for other antibiotic biosynthesis in other actinomycetes. KEY POINTS: • The transcriptional regulator TobR belonging to the Lrp/AsnC family was identified. • An oxygenase TobO was identified within the tobramycin biosynthesis cluster. • TobO and TobR have significant effects on the synthesis of carbamoyltobramycin.
Topics: Metabolic Engineering; Actinomycetales; Anti-Bacterial Agents; Tobramycin; Actinobacteria
PubMed: 38643456
DOI: 10.1007/s00253-024-13141-2 -
International Journal of Systematic and... Apr 2024The taxonomic position of three actinobacterial strains, BCCO 10_0061, BCCO 10_0798, and BCCO 10_0856, recovered from bare soil in the Sokolov Coal Basin, Czech...
The taxonomic position of three actinobacterial strains, BCCO 10_0061, BCCO 10_0798, and BCCO 10_0856, recovered from bare soil in the Sokolov Coal Basin, Czech Republic, was established using a polyphasic approach. The multilocus sequence analysis based on 100 single-copy genes positioned BCCO 10_0061 in the same cluster as , strain BCCO 10_0798 in the same cluster as , , , and , and strain BCCO 10_0856 clustered together with and . Morphological and chemotaxonomic characteristics of these strains support their assignment to the genus . In all three strains, MK-9(H) accounted for more than 80 % of the isoprenoid quinone. The diagnostic diamino acid in the cell-wall peptidoglycan was -diaminopimelic acid. The whole-cell sugars were rhamnose, ribose, mannose, glucose, and galactose. The major fatty acids (>10 %) were iso-C, anteiso-C, iso-C, and C. The polar lipids were diphosphatidylglycerol, methyl-phosphatidylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol. The genomic DNA G+C content of strains (mol%) was 68.8 for BCCO 10_0061, 69.2 for BCCO 10_0798, and 68.5 for BCCO 10_0856. The combination of digital DNA-DNA hybridization results, average nucleotide identity values and phenotypic characteristics of BCCO 10_0061, BCCO 10_0798, and BCCO 10_0856 distinguishes them from their closely related strains. Bioinformatic analysis of the genome sequences of the strains revealed several biosynthetic gene clusters (BGCs) with identities >50 % to already known clusters, including BGCs for geosmin, coelichelin, ε-poly-l-lysine, and erythromycin-like BGCs. Most of the identified BGCs showed low similarity to known BGCs (<50 %) suggesting their genetic potential for the biosynthesis of novel secondary metabolites. Based on the above results, each strain represents a novel species of the genus , for which we propose the name sp. nov. for BCCO 10_0061 (=DSM 116175), sp. nov. for BCCO 10_0798 (=DSM 116176), and sp. nov. for BCCO 10_0856 (=DSM 116177).
Topics: Phosphatidylethanolamines; Czech Republic; Base Composition; Fatty Acids; Phylogeny; Sequence Analysis, DNA; RNA, Ribosomal, 16S; DNA, Bacterial; Bacterial Typing Techniques; Actinomycetales; Actinobacteria; Bacteria; Coal
PubMed: 38630118
DOI: 10.1099/ijsem.0.006335 -
Frontiers in Microbiology 2024Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide, with its etiology attributed to a complex interplay of genetic, dietary, environmental...
BACKGROUND
Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide, with its etiology attributed to a complex interplay of genetic, dietary, environmental factors, and infections such as . Despite the known risk factors, the role of gut microbiota in the development of gastric cancer remains insufficiently explored. This study aims to elucidate the causal relationship between gut microbiota and gastric cancer using a two-sample Mendelian Randomization (MR) approach.
METHODS
Utilizing genome-wide association study (GWAS) summary data from the MiBioGen consortium and gastric cancer datasets, we selected instrumental variables for MR analysis based on their association with specific microbiota. We employed several MR methods, including inverse variance weighted (IVW), MR-Egger, weighted median, and others, to estimate the causal effects of gut microbiota diversity on the risk of developing gastric cancer.
RESULTS
Our analysis identified significant associations between certain gut microbiota and gastric cancer risk. Specifically, taxa such as (OR = 0.540, 95%CI: 0.354-0.823, = 0.004), (OR = 0.756, 95%CI: 0.613-0.932, = 0.009), (OR = 0.816, 95%CI: 0.666-1.000, < 0.05), (OR = 0.816, 95%CI: 0.666-1.000, < 0.05), (OR = 0.863, 95%CI: 0.746-0.999, = 0.048) were found to have a protective effect against gastric cancer. Conversely, an increased risk of gastric cancer was associated with the abundance of (OR = 1.342, 95%CI: 1.071-1.681, = 0.011), (OR = 1.132, 95%CI: 1.012-1.267, = 0.030), and (OR = 1.207, 95%CI: 1.074-1.355, = 0.002). The findings were robust across various MR methods and were not driven by any single SNP, indicating a genuine causal relationship.
CONCLUSION
Our studies have shown that there is a causal relationship between intestinal flora and gastric cancer at the genetic level. , , , , , and as having a protective role against GC, while , , and were associated with an increased risk.
PubMed: 38628871
DOI: 10.3389/fmicb.2024.1383530 -
Applied and Environmental Microbiology May 2024Dye-decolorizing peroxidases are heme peroxidases with a broad range of substrate specificity. Their physiological function is still largely unknown, but a role in the...
UNLABELLED
Dye-decolorizing peroxidases are heme peroxidases with a broad range of substrate specificity. Their physiological function is still largely unknown, but a role in the depolymerization of plant cell wall polymers has been widely proposed. Here, a new expression system for bacterial dye-decolorizing peroxidases as well as the activity with previously unexplored plant molecules are reported. The dye-decolorizing peroxidase from 75iv2 (DyP2) was heterologously produced in the Gram-positive bacterium TK24 in both intracellular and extracellular forms without external heme supplementation. The enzyme was tested on a series of -glycosides, which are plant secondary metabolites with a phenyl glycosidic linkage. -glycosides are of great interest, both for studying the compounds themselves and as potential models for studying specific lignin-carbohydrate complexes. The primary DyP reaction products of salicin, arbutin, fraxin, naringin, rutin, and gossypin were oxidatively coupled oligomers. A cleavage of the glycone moiety upon radical polymerization was observed when using arbutin, fraxin, rutin, and gossypin as substrates. The amount of released glucose from arbutin and fraxin reached 23% and 3% of the total substrate, respectively. The proposed mechanism suggests a destabilization of the ether linkage due to the localization of the radical in the para position. In addition, DyP2 was tested on complex lignocellulosic materials such as wheat straw, spruce, willow, and purified water-soluble lignin fractions, but no remarkable changes in the carbohydrate profile were observed, despite obvious oxidative activity. The exact action of DyP2 on such lignin-carbohydrate complexes therefore remains elusive.
IMPORTANCE
Peroxidases require correct incorporation of the heme cofactor for activity. Heterologous overproduction of peroxidases often results in an inactive enzyme due to insufficient heme synthesis by the host organism. Therefore, peroxidases are incubated with excess heme during or after purification to reconstitute activity. as a production host can produce fully active peroxidases both intracellularly and extracellularly without the need for heme supplementation. This reduces the number of downstream processing steps and is beneficial for more sustainable production of industrially relevant enzymes. Moreover, this research has extended the scope of dye-decolorizing peroxidase applications by studying naturally relevant plant secondary metabolites and analyzing the formed products. A previously overlooked artifact of radical polymerization leading to the release of the glycosyl moiety was revealed, shedding light on the mechanism of DyP peroxidases. The key aspect is the continuous addition, rather than the more common approach of a single addition, of the cosubstrate, hydrogen peroxide. This continuous addition allows the peroxidase to complete a high number of turnovers without self-oxidation.
Topics: Coloring Agents; Glycosides; Amycolatopsis; Bacterial Proteins; Peroxidases; Peroxidase; Streptomyces lividans; Substrate Specificity
PubMed: 38625022
DOI: 10.1128/aem.00205-24 -
Frontiers in Cellular and Infection... 2024Skin abscess is one of the most common infections of the skin and soft tissues. However, anaerobic bacteria are infrequently identified as the causative agents of this...
Skin abscess is one of the most common infections of the skin and soft tissues. However, anaerobic bacteria are infrequently identified as the causative agents of this particular form of abscess. In this case, a 34-year-old pregnant woman was diagnosed with a skin abscess with the use of ultrasonography. The microbiological analysis results of the purulent fluid revealed the coinfection of and . The patient was first treated empirically with 3 days of cefathiamidine, which resulted in no symptom improvement. Subsequently, a surgical procedure involving incision and draining was performed, with the administration of ceftriaxone. After 7 days of antibiotic intervention, the patient exhibited a satisfactory recovery. Clinicians need to be aware of other types of infections that might be attributed to and , in addition to urinary tract infections.
Topics: Female; Humans; Adult; Abscess; Coinfection; Bacteria, Anaerobic; Actinomycetaceae
PubMed: 38601737
DOI: 10.3389/fcimb.2024.1378197 -
PeerJ 2024Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously...
BACKGROUND
Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity.
METHODS
Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities.
RESULTS
Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: , , , , , , and . This study reports, for the first time of the BHET-degrading properties of the genera and . Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: , , , , and . Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected.
CONCLUSIONS
We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.
Topics: Actinomycetales; Agar; Bacteria; Microbiota; Plastics; Polyesters; Polystyrenes; RNA, Ribosomal, 16S; Sand
PubMed: 38590706
DOI: 10.7717/peerj.17165 -
International Journal of Systematic and... Apr 2024The prokaryotic generic name Downes . 2002 is illegitimate because it is a later homonym of the plant genus Meisner 1840 and the mollusk genus Baker 1941 (Principle 2...
The prokaryotic generic name Downes . 2002 is illegitimate because it is a later homonym of the plant genus Meisner 1840 and the mollusk genus Baker 1941 (Principle 2 and Rule 51b(5) of the International Code of Nomenclature of Prokaryotes). We therefore propose the replacement generic name , with type species comb. nov. The prokaryotic generic name Maszenan . 2000 is illegitimate because it is a later homonym of Popofsky 1913 (Protozoa, Radiolaria) and of Górka 1965 (a fossil dinoflagellate) (Rule 51b(4) of the International Code of Nomenclature of Prokaryotes). We therefore propose the replacement generic name , with type species comb. nov.
Topics: Phylogeny; Sequence Analysis, DNA; RNA, Ribosomal, 16S; DNA, Bacterial; Bacterial Typing Techniques; Base Composition; Fatty Acids; Actinomycetales; Clostridiales
PubMed: 38573081
DOI: 10.1099/ijsem.0.006318