-
Molecules (Basel, Switzerland) Aug 2023Actinomycetes inhabit both terrestrial and marine ecosystems and are highly proficient in producing a wide range of natural products with diverse biological functions,... (Review)
Review
Actinomycetes inhabit both terrestrial and marine ecosystems and are highly proficient in producing a wide range of natural products with diverse biological functions, including antitumor, immunosuppressive, antimicrobial, and antiviral activities. In this review, we delve into the life cycle, ecology, taxonomy, and classification of actinomycetes, as well as their varied bioactive metabolites recently discovered between 2015 and 2023. Additionally, we explore promising strategies to unveil and investigate new bioactive metabolites, encompassing genome mining, activation of silent genes through signal molecules, and co-cultivation approaches. By presenting this comprehensive and up-to-date review, we hope to offer a potential solution to uncover novel bioactive compounds with essential activities.
Topics: Actinobacteria; Actinomyces; Ecosystem; Anti-Infective Agents; Biological Products
PubMed: 37570885
DOI: 10.3390/molecules28155915 -
Microorganisms Sep 2023species are catalase-positive and coagulase-negative Gram-positive coccoid bacteria that belong to the family Micrococcaceae, order Actinomycetales, and class... (Review)
Review
species are catalase-positive and coagulase-negative Gram-positive coccoid bacteria that belong to the family Micrococcaceae, order Actinomycetales, and class Actinobacteria. Even though they may be relatively rare, they have been increasingly reported as the causes of human infections lately. The present study aims to review all published cases of spp. infections in humans reporting data on epidemiology, microbiology, antimicrobial susceptibility, antimicrobial treatment, and mortality. A narrative review was performed based on a search of Pubmed and Scopus databases in the literature. In total, 73 studies provided data on 102 patients with spp. infections. The mean age of patients was 47 years, and 68.3% were male. The most common types of infection were bacteremia (36.3%), skin and soft tissue infection (18.6%), endophthalmitis (15.7%), infective endocarditis (13.7%), and peritonitis (11.8%), most commonly peritoneal-dialysis-associated. The most frequently isolated species was (46.1%), and antimicrobial resistance was lower for vancomycin (7%) and tetracyclines (6.7%). Vancomycin (47%), cephalosporins (39.6%), and quinolones (36.6%) were the most commonly used antimicrobials. The empirical antimicrobial treatment of spp. infections should include vancomycin as long as antimicrobial susceptibility results are pending. The infection outcome mainly depends on the type of infection and is higher for infective endocarditis. Endophthalmitis is associated with increased rates of low visual acuity after treatment.
PubMed: 37764205
DOI: 10.3390/microorganisms11092362 -
Biotechnology Advances Oct 2023Numerous biotic and abiotic stress in some geographical regions predisposed their agricultural matrix to challenges threatening plant productivity, health, and quality.... (Review)
Review
Numerous biotic and abiotic stress in some geographical regions predisposed their agricultural matrix to challenges threatening plant productivity, health, and quality. In curbing these threats, different customary agrarian principles have been created through research and development, ranging from chemical inputs and genetic modification of crops to the recently trending smart agricultural technology. But the peculiarities associated with these methods have made agriculturists rely on plant rhizospheric microbiome services, particularly bacteria. Several bacterial resources like Proteobacteria, Firmicutes, Acidobacteria, and Actinomycetes (Streptomycetes) are prominent as bioinoculants or the application of their by-products in alleviating biotic/abiotic stress have been extensively studied, with a dearth in the application of rare Actinomycetes metabolites. Rare Actinomycetes are known for their colossal genome, containing well-preserved genes coding for prolific secondary metabolites with many agroactive functionalities that can revolutionize the agricultural industry. Therefore, the imperativeness of this review to express the occurrence and distributions of rare Actinomycetes diversity, plant and soil-associated habitats, successional track in the rhizosphere under diverse stress, and their agroactive metabolite characteristics and functionalities that can remediate the challenges associated with agricultural productivity.
Topics: Actinobacteria; Actinomyces; Bacteria; Rhizosphere; Agriculture; Soil; Soil Microbiology
PubMed: 37356598
DOI: 10.1016/j.biotechadv.2023.108205 -
Cellular and Molecular Gastroenterology... 2024
Topics: Humans; Actinomyces; Actinomycetaceae; Colorectal Neoplasms
PubMed: 38403274
DOI: 10.1016/j.jcmgh.2024.02.009 -
Molecules (Basel, Switzerland) Jun 2023Marine natural products have been recognized as the most promising source of bioactive substances for drug discovery research. This review illustrates the diversity of... (Review)
Review
Marine natural products have been recognized as the most promising source of bioactive substances for drug discovery research. This review illustrates the diversity of culturable actinobacteria associated with marine algae, their bioactivity and metabolites, and approaches to their isolation and determination of their biological properties. Furthermore, actinobacteria associated with marine algae are presented as a new subject for an extensive investigation to find novel and active natural products, which make them a potentially rich and innovative source for new drug development deserving more attention and exploration.
Topics: Actinobacteria; Actinomyces; Biological Products; Drug Discovery; Bacteria
PubMed: 37446800
DOI: 10.3390/molecules28135138 -
Current Opinion in Microbiology Dec 2023Throughout the golden age of antibiotic discovery, Streptomyces have been unsurpassed for their ability to produce bioactive metabolites. Yet, this success has been... (Review)
Review
Throughout the golden age of antibiotic discovery, Streptomyces have been unsurpassed for their ability to produce bioactive metabolites. Yet, this success has been hampered by rediscovery. As we enter a new stage of biodiscovery, omics data and existing scientific repositories can enable informed choices on the biodiversity that may yield novel antibiotics. Here, we focus on the chemical potential of rare actinomycetes, defined as bacteria within the order Actinomycetales, but not belonging to the genus Streptomyces. They are named as such due to their less-frequent isolation under standard laboratory practices, yet there is increasing evidence to suggest these biologically diverse genera harbour considerable biosynthetic and chemical diversity. In this review, we focus on examples of successful isolation and genera that have been the focus of more concentrated biodiscovery efforts, we survey the representation of rare actinomycete taxa, compared with Streptomyces, across natural product data repositories in addition to its biosynthetic potential. This is followed by an overview of clinically useful drugs produced by rare actinomycetes and considerations for future biodiscovery efforts. There is much to learn about these underexplored taxa, and mounting evidence suggests that they are a fruitful avenue for the discovery of novel antimicrobials.
Topics: Actinobacteria; Actinomyces; Anti-Bacterial Agents; Streptomyces; Biodiversity
PubMed: 37804816
DOI: 10.1016/j.mib.2023.102385 -
Frontiers in Microbiology 2023Gut microbiota, particularly , has been previously reported to be associated with kidney stones. However, the conflicting results from both observational and...
BACKGROUND
Gut microbiota, particularly , has been previously reported to be associated with kidney stones. However, the conflicting results from both observational and intervention studies have created substantial uncertainty regarding the contribution of to the formation of kidney stone.
METHODS
We employed a two-sample MR analysis to investigate the causal relationship between gut microbiota and kidney stones using GWASs summary statistics obtained from the MiBioGen and FinnGen consortia. Moreover, we conducted a reserve MR analysis to assess the direction of the causal associations between gut microbiota and kidney stones. The inverse variance weighted (IVW) approach represents the primary method of Mendelian Randomization (MR) analysis.
RESULTS
Our analyses do not yield supportive evidence for a causal link between the genus r (OR = 0.99, 95% CI: 0.90-1.09, = 0.811) and the formation of kidney stones. The order (OR = 0.79, 95% CI: 0.65-0.96, = 0.020), family (OR = 0.79, 95% CI: 0.65-0.96, = 0.019), family (OR = 0.80, 95% CI: 0.67-0.96, = 0.015), genus (OR = 0.81, 95% CI: 0.67-0.98, = 0.030) and genus (OR = 0.86, 95% CI: 0.74-0.99, = 0.040) had protective effects on kidney stones, and the genus (OR = 1.16, 95% CI: 1.01-1.33, = 0.032), genus (OR = 1.38, 95% CI: 1.04-1.84, = 0.028), genus (OR = 1.27, 95% CI: 1.06-1.52, = 0.009) were risk factors for kidney stones. Differential abundance analysis provide no evidence of a association between and kidney stones, and showed genus Subdoligranulum were risk factors for kidney stones. Reverse MR analysis did not indicate any causal association of kidney stones on gut microbiota. No considerable heterogeneity of instrumental variables or horizontal pleiotropy was observed.
CONCLUSION
Our two-sample MR study did not find any causal relationship between genus and kidney stones. The association between gut microbiota and kidney stones does not solely depend on the presence of genus /. A more integrated approach using multiple omics platforms is needed to better understand the pathogenesis of kidney stones in the context of complex gene-environment interactions over time.
PubMed: 37502408
DOI: 10.3389/fmicb.2023.1204311 -
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 -
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 -
PeerJ 2023Climate change may lead to adverse effects on agricultural crops, plant microbiomes have the potential to help hosts counteract these effects. While plant-microbe...
Climate change may lead to adverse effects on agricultural crops, plant microbiomes have the potential to help hosts counteract these effects. While plant-microbe interactions are known to be sensitive to temperature, how warming affects the community composition and functioning of plant microbiomes in most agricultural crops is still unclear. Here, we utilized a 10-year field experiment to investigate the effects of warming on root zone carbon availability, microbial activity and community composition at spatial (root, rhizosphere and bulk soil) and temporal (tillering, jointing and ripening stages of plants) scales in field-grown wheat ( L.). The dissolved organic carbon and microbial activity in the rhizosphere were increased by soil warming and varied considerably across wheat growth stages. Warming exerted stronger effects on the microbial community composition in the root and rhizosphere samples than in the bulk soil. Microbial community composition, particularly the phyla Actinobacteria and Firmicutes, shifted considerably in response to warming. Interestingly, the abundance of a number of known copiotrophic taxa, such as and and genera in increased in the roots and rhizosphere under warming and the increase in these taxa implies that they may play a role in increasing the resilience of plants to warming. Taken together, we demonstrated that soil warming along with root proximity and plant growth status drives changes in the microbial community composition and function in the wheat root zone.
Topics: Triticum; Soil Microbiology; Soil; Microbiota; Bacteria; Crops, Agricultural
PubMed: 37334112
DOI: 10.7717/peerj.15428