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Microorganisms May 2024and are extensively utilized to investigate fungal pathogenic mechanisms and to develop biological control agents. Notwithstanding, notable distinctions exist in their...
and are extensively utilized to investigate fungal pathogenic mechanisms and to develop biological control agents. Notwithstanding, notable distinctions exist in their pathogenicity against the same host insect. This study aimed to elucidate the pathogenic differences between and by examining the impact of various ratios of strain AJS91881 and strain SXBN200920 on fifth instar larvae of , focusing on early infection stages and intestinal microbial community structure. The lethal time 50 (LT) for was significantly lower than that for , indicating greater efficacy. Survival analyses in mixed groups (ratios of 1:9, 1:1, and 9:1 to ) consistently demonstrated higher virulence of . Intestinal microbial diversity analysis revealed a significant increase in and in larvae infected with , whereas was notably higher in those infected with Additionally, significant shifts in microbial genera abundances were observed across all mixed infection groups. KEGG pathway enrichment analysis indicated that and employ distinct pathogenic strategies during early infection stages. tests confirmed the superior growth and stress resistance of compared to but the antifungal ability of was better than that of In conclusion, our findings provide preliminary insights into the differential pathogenic behaviors of and during the early infection stages in larvae, enhancing our understanding of their mechanisms and informing biological pest control strategies in agriculture and forestry.
PubMed: 38930511
DOI: 10.3390/microorganisms12061129 -
International Journal of Molecular... Jun 2024and , bacterial degraders of the herbicide glyphosate, were found to induce phosphonatase (phosphonoacetaldehyde hydrolase, EC 3.11.1.1) when grown on minimal media...
and , bacterial degraders of the herbicide glyphosate, were found to induce phosphonatase (phosphonoacetaldehyde hydrolase, EC 3.11.1.1) when grown on minimal media with glyphosate as the sole source of phosphorus. The phosphonatases of the strains were purified to an electrophoretically homogeneous state and characterized. The enzymes differed in their kinetic characteristics and some other parameters from the previously described phosphonatases. The phosphonatase of was first revealed to separate into two stable forms, which had similar kinetic characteristics but interacted differently with affinity and ion-exchange resins. The genomes of the investigated bacteria were sequenced. The phosphonatase genes were identified, and their context was determined: the bacteria were shown to have gene clusters, which, besides the phosphonatase operon, included genes for LysR-type transcription activator (substrate sensor) and putative iron-containing oxygenase PhnHD homologous to monooxygenases PhnY and TmpB of marine organophosphonate degraders. Genes of 2-aminoethylphosphonate aminotransferase (PhnW, EC 2.6.1.37) were absent in the achromobacterial phosphonatase operons; instead, we revealed the presence of genes encoding the putative flavin oxidase HpnW. In silico simulation showed 1-hydroxy-2-aminoethylphosphonate to be the most likely substrate of the new monooxygenase, and a number of glycine derivatives structurally similar to glyphosate to be substrates of flavin oxidase.
Topics: Glyphosate; Glycine; Achromobacter; Operon; Soil Microbiology; Bacterial Proteins; Herbicides; Multigene Family; Kinetics; Gene Expression Regulation, Bacterial
PubMed: 38928116
DOI: 10.3390/ijms25126409 -
The ISME Journal Jun 2024Soil microbial flora constitutes a highly diverse and complex microbiome on Earth, often challenging to cultivation, with unclear metabolic mechanisms in situ. Here, we...
Soil microbial flora constitutes a highly diverse and complex microbiome on Earth, often challenging to cultivation, with unclear metabolic mechanisms in situ. Here, we present a pioneering concept for the in situ construction of functional microbial consortia (FMCs) and introduce an innovative method for creating FMCs by utilising phenanthrene as a model compound to elucidate their in situ biodegradation mechanisms. Our methodology involves single-cell identification, sorting, and culture of functional microorganisms, resulting in the formation of a precise in situ FMC. Through RACS-SIP, we identified and isolated phenanthrene-degrading bacterial cells from Achromobacter sp. and Pseudomonas sp., achieving precise and controllable in situ consortia based on genome-guided cultivation. Our in situ FMC outperformed conventionally designed functional flora when tested in real soil, indicating its superior phenanthrene degradation capacity. We revealed that microorganisms with high degradation efficiency isolated through conventional methods may exhibit pollutant tolerance but lack actual degradation ability in natural environments. This finding highlights the potential to construct FMCs based on thorough elucidation of in situ functional degraders, thereby achieving sustained and efficient pollutant degradation. Single-cell sequencing linked degraders with their genes and metabolic pathways, providing insights regarding the construction of in situ FMCs. The consortium in situ comprising microorganisms with diverse phenanthrene metabolic pathways might offer distinct advantages for enhancing phenanthrene degradation efficiency, such as the division of labour and cooperation or communication among microbial species. Our approach underscores the importance of in situ, single-cell precision identification, isolation, and cultivation for comprehensive bacterial functional analysis and resource exploration, which can extend to investigate MFCs in archaea and fungi, clarifying FMC construction methods for element recycling and pollutant transformation in complex real-world ecosystems.
PubMed: 38913500
DOI: 10.1093/ismejo/wrae115 -
Frontiers in Microbiology 2024Biodegradation was considered a promising and environmentally friendly method for treating environmental pollution caused by diuron. However, the mechanisms of...
Biodegradation was considered a promising and environmentally friendly method for treating environmental pollution caused by diuron. However, the mechanisms of biodegradation of diuron required further research. In this study, the degradation process of diuron by SL-6 was systematically investigated. The results suggested that the antioxidant system of strain SL-6 was activated by adding diuron, thereby alleviating their oxidative stress response. In addition, degradation product analysis showed that diuron in strain SL-6 was mainly degraded by urea bridge cleavage, dehalogenation, deamination, and ring opening, and finally -muconic acid was generated. The combined analysis of metabolomics and transcriptomics revealed the biodegradation and adaptation mechanism of strain SL-6 to diuron. Metabolomics analysis showed that after the strain SL-6 was exposed to diuron, metabolic pathways such as tricarboxylic acid cycle (-muconic acid), glutathione metabolism (oxidized glutathione), and urea cycle (arginine) were reprogrammed in the cells. Furthermore, diuron could induce the production of membrane transport proteins in strain SL-6 cells and overexpress antioxidant enzyme genes, finally ultimately promoting the up-regulation of genes encoding amide hydrolases and dioxygenases, which was revealed by transcriptomics studies. This work enriched the biodegradation mechanism of phenylurea herbicides and provided guidance for the removal of diuron residues in the environment and promoting agriculture sustainable development.
PubMed: 38912345
DOI: 10.3389/fmicb.2024.1403279 -
Folia Microbiologica Jun 2024Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia are considered emerging pathogens classified as a public health problem due to...
Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia are considered emerging pathogens classified as a public health problem due to extensive antimicrobial resistance. Therefore, the discovery of new therapeutic strategies has become crucial. This study aimed to evaluate the antimicrobial activity of gallic acid and methyl gallate against non-fermenting bacteria. The study included five clinical isolates of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia. The minimum inhibitory concentrations of gallic acid and methyl gallate were determined by the broth microdilution method. Growth curves, metabolic activity, and biofilm formation of each bacterial strain in the presence or absence of phenolic compounds were performed. Finally, the therapeutic efficacy of the compounds was evaluated using an in vivo model. Gallic acid and methyl gallate showed antibacterial activity against bacterial strains in a concentration range of 64 to 256 µg/mL, both compounds reduced bacterial growth and metabolic activity of the strains, even at subinhibitory concentrations. Only, methyl gallate exhibited activity to inhibit the formation of bacterial biofilms. Moreover, gallic acid and methyl gallate increased larval survival by up to 60% compared to 30% survival of untreated larvae in a bacterial infection model in Galleria mellonella. Our results highlight the potential of gallic acid and methyl gallate as therapeutic alternatives for infections by emerging non-fermentative bacteria.
PubMed: 38904883
DOI: 10.1007/s12223-024-01182-z -
The Science of the Total Environment Jun 2024The ubiquity and persistence of organophosphate esters (OPEs) and heavy metal (HMs) pose global environmental risks. This study explored tris(2-chloroisopropyl)phosphate...
The ubiquity and persistence of organophosphate esters (OPEs) and heavy metal (HMs) pose global environmental risks. This study explored tris(2-chloroisopropyl)phosphate (TCPP) biomineralization coupled to lead (Pb) biostabilization driven by denitrifying bacteria (DNB). The domesticated DNB achieved synergistic bioremoval of TCPP and Pb in the batch bioreactor (efficiency: 98 %).TCPP mineralized into PO and Cl, and Pb precipitated with PO. The TCPP-degrading/Pb-resistant DNB: Achromobacter, Pseudomonas, Citrobacter, and Stenotrophomonas, dominated the bacterial community, and synergized TCPP biomineralization and Pb biostabilization. Metagenomics and metaproteomics revealed TCPP underwent dechlorination, hydrolysis, the TCA cycle-based dissimilation, and assimilation; Pb was detoxified via bioprecipitation, bacterial membrane biosorption, EPS biocomplexation, and efflux out of cells. TCPP, as an initial donor, along with NO, as the terminal acceptor, formed a respiratory redox as the primary energy metabolism. Both TCPP and Pb can stimulate phosphatase expression, which established the mutual enhancements between their bioconversions by catalyzing TCPP dephosphorylation and facilitating Pb bioprecipitation. TCPP may alleviate the Pb-induced oxidative stress by aiding protein phosphorylation. 80 % of Pb converted into crystalized pyromorphite. These results provide the mechanistic foundations and help develop greener strategies for synergistic bioremediation of OPEs and HMs.
PubMed: 38901584
DOI: 10.1016/j.scitotenv.2024.173927 -
Annals of Clinical Microbiology and... Jun 2024Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat...
BACKGROUND
Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descriptions of resistance in each taxon. Cefiderocol is a broad-spectrum siderophore cephalosporin increasingly used in the management of Achromobacter infections for which susceptibility data remain scarce. We aimed to describe the susceptibility to cefiderocol of a collection of Achromobacter strains encompassing different species and isolation sources from CF or non-CF (NCF) patients.
METHODS
We studied 230 Achromobacter strains (67 from CF, 163 from NCF patients) identified by nrdA gene-based analysis, with available susceptibility data for piperacillin-tazobactam, meropenem and trimethoprim-sulfamethoxazole. Minimal inhibitory concentrations (MICs) of cefiderocol were determined using the broth microdilution reference method according to EUCAST guidelines.
RESULTS
Strains belonged to 15 species. A. xylosoxidans represented the main species (71.3%). MICs ranged from ≤ 0.015 to 16 mg/L with MIC of ≤ 0.015/0.5 mg/L overall and 0.125/2 mg/L against 27 (11.7%) meropenem-non-susceptible strains. Cefiderocol MICs were not related to CF/NCF origin or species although A. xylosoxidans MICs were statistically lower than those of other species considered as a whole. Considering the EUCAST non-species related breakpoint (2 mg/L), 228 strains (99.1%) were susceptible to cefiderocol. The two cefiderocol-resistant strains (A. xylosoxidans from CF patients) represented 3.7% of meropenem-non-susceptible strains and 12.5% of MDR strains.
CONCLUSIONS
Cefiderocol exhibited excellent in vitro activity against a large collection of accurately identified Achromobacter strains, irrespective of species and origin.
Topics: Microbial Sensitivity Tests; Humans; Achromobacter; Anti-Bacterial Agents; Cephalosporins; Cefiderocol; Cystic Fibrosis; Gram-Negative Bacterial Infections
PubMed: 38886694
DOI: 10.1186/s12941-024-00709-z -
Ecotoxicology and Environmental Safety Jul 2024The anomalies of cadmium (Cd) in karst region pose a severe threat to plant growth and development. In this study, the responses of Rhododendron decorum to Cd stress...
The anomalies of cadmium (Cd) in karst region pose a severe threat to plant growth and development. In this study, the responses of Rhododendron decorum to Cd stress were investigated at physiological, molecular, and endophytic microbial levels, and the potential correlation among these responses was assessed. The Cd stress impeded R. decorum growth and led to an increase in malondialdehyde (MDA) and hydrogen peroxide (HO) levels, as well as enhanced superoxide dismutase (SOD) and catalase (CAT) activities. Meanwhile, Cd stress increased the Cd (up to 80 times compared to the control), sodium (Na), aluminum (Al), and zinc (Zn) contents, while decreased the magnesium (Mg) and manganese (Mn) contents in R. decorum leaves. Transcriptome suggested that Cd significantly regulated the pathways including "protein repair", "hormone-mediated signaling pathway", and "ATP-binding cassette (ABC) transporters". Additionally, q-PCR analysis showed that Cd stress significantly up-regulated the expressions of ABCB19-like and pleiotropic drug resistance, while down-regulated the expressions of indole-3-acetic acid-amido synthetase and cytokinin dehydrogenase. The Cd stress influenced the composition of endophytic microbial communities in R. decorum leaves and enhanced the interspecific bacterial associations. Furthermore, the bacterial genera Achromobacter, Aureimonas and fungal genus Vishniacozyma exhibited a high degree of connectivity with other nodes in networks constructed by the metal element contents, differentially expressed genes (DEGs), and microbial communities, respectively. These findings provide a comprehensive insight into the response of R. decorum to Cd-induced stress, which might facilitate the breeding of the Cd-tolerant R. decorum.
Topics: Cadmium; Rhododendron; Transcriptome; Microbiota; Plant Leaves; Soil Pollutants; Stress, Physiological; Malondialdehyde; Hydrogen Peroxide
PubMed: 38833983
DOI: 10.1016/j.ecoenv.2024.116536 -
Computers in Biology and Medicine Jul 2024Ovarian cancer (OC) is found to be the third most common gynecologic malignancy over the world, having the highest mortality rate among such tumors. Emerging studies...
BACKGROUND
Ovarian cancer (OC) is found to be the third most common gynecologic malignancy over the world, having the highest mortality rate among such tumors. Emerging studies underscore the presence of microorganisms within tumor tissues, with certain pathogens intricately linked to disease onset and progression. Disruption of the microbiome frequently precipitates disturbances in host metabolic and immune pathways, thereby fostering the development of cancer.
METHODS
In this study, we initiated the investigation by conducting microbial reannotation on the RNA sequencing data derived from ovarian cancer tissues. Subsequently, a comprehensive array of analyses on tissue microbes was executed. These analyses encompassed the assessment of intergroup variations in microbial diversity, differential microbiological analysis, exploration of the association between host gene expression and microbial abundance, as well as an enrichment analysis of functional pathways linked to host genes associated with microbes.
RESULTS
The analysis results revealed that Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were the main components at phylum level in ovarian tissue. Notably, the microbial composition of ovarian cancer tissue significantly diverged from that of normal ovarian tissue e, exhibiting markedly lower alpha diversity and distinct beta diversity. Besides, pathogenic microorganisms Achromobacter xylosoxidans and Enterobacter hormaechei were enriched in cancer tissue. Host genes associated with these pathogens were enriched in key pathways including "JAK-STAT signaling pathway", "Transcriptional misregulation in cancer", and "Th1 and Th2 cell differentiation", suggesting their role in ovarian cancer progression through microbial dysbiosis and immune response interaction.
CONCLUSION
Abundance of pathogenic microorganisms in ovarian cancer tissue could modulate the expression of host genes, consequently impacting cancer-related signaling pathways and fostering cancer progression.
Topics: Humans; Female; Ovarian Neoplasms; Microbiota; Disease Progression
PubMed: 38833797
DOI: 10.1016/j.compbiomed.2024.108641 -
The American Journal of Case Reports Jun 2024BACKGROUND Peritoneal dialysis (PD) serves as a critical renal replacement therapy for individuals with end-stage renal disease (ESRD), leveraging the peritoneum for... (Review)
Review
BACKGROUND Peritoneal dialysis (PD) serves as a critical renal replacement therapy for individuals with end-stage renal disease (ESRD), leveraging the peritoneum for fluid and substance exchange. Despite its effectiveness, PD is marred by complications such as peritonitis, which significantly impacts patient outcomes. The novelty of our report lies in the presentation of a rare case of PD-associated peritonitis caused by 2 unusual pathogens, emphasizing the importance of rigorous infection control measures. CASE REPORT We report on an 80-year-old African-American female patient with ESRD undergoing PD, who was admitted twice within 8 months for non-recurring episodes of peritonitis. These episodes were attributed to the rare pathogens Achromobacter denitrificans/xylosoxidans and Carbapenem-resistant Acinetobacter baumannii. Despite presenting with similar symptoms during each episode, such as abdominal pain and turbid dialysis effluent, the presence of these uncommon bacteria highlights the intricate challenges in managing infections associated with PD. The treatment strategy encompassed targeted antibiotic therapy, determined through susceptibility testing. Notably, the decision to remove the PD catheter followed extensive patient education, ensuring the patient comprehended the rationale behind this approach. This crucial step, along with the subsequent shift to hemodialysis, was pivotal in resolving the infection, illustrating the importance of patient involvement in the management of complex PD-related infections. CONCLUSIONS This case underscores the complexities of managing PD-associated peritonitis, particularly with uncommon and resistant bacteria. It emphasizes the importance of rigorous infection control measures, the need to consider atypical pathogens, and the critical role of patient involvement in treatment decisions. Our insights advocate for a more informed approach to handling such infections, aiming to reduce morbidity and improve patient outcomes. The examination of the literature on recurrent peritonitis and treatment strategies provides key perspectives for navigating these challenging cases effectively.
Topics: Humans; Peritonitis; Female; Aged, 80 and over; Peritoneal Dialysis; Kidney Failure, Chronic; Acinetobacter baumannii; Achromobacter denitrificans; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Acinetobacter Infections; Practice Guidelines as Topic
PubMed: 38831580
DOI: 10.12659/AJCR.943953