International Microbiology最新文献

Dermatophyte infections globally account for 20 to 25% of fungal infections. Dermatophytes have begun exhibiting antifungal drug resistance, making it challenging to treat this particular infection. Essential oils could be used as alternative solutions as they have been used for a long period to treat different infections. The research has demonstrated the antifungal efficacy of cinnamon, clove, lemongrass, tea tree, thyme, and garlic essential oils, and the impact of their combinations was assayed against Microsporum canis, Trichophyton tonsurans, T. violaceum, T. verrucosum, and Epidermophyton floccosum. Polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) was used to identify the most prevalent M. canis. The accession number of M. canis was obtained as ON007275. All tested essential oils exhibited antidermatophytic action except garlic. A synergistic effect was attained by cinnamon + clove, cinnamon + lemongrass, clove + lemongrass, clove + tea tree, and thyme + tea tree combinations. Concerning antifungal activity, M. canis was the most susceptible dermatophytic species, except in the case of thyme T. violaceum, which was the most susceptible dermatophytic species. The maximum inhibition was recorded in the cases of cinnamon and cinnamon + lemongrass combination against M. canis. The least minimum inhibitory concentrations were attained by cinnamon and clove against M. canis, cinnamon + clove against M. canis and T. violaceum, and cinnamon + lemongrass against M. canis, T. violaceum, T. verrucosum, and E. floccosum. The least minimum fungicidal concentration showed by cinnamon against M. canis, cinnamon + clove against M. canis and T. violaceum, cinnamon + lemongrass against M. canis, T. violaceum, T. verrucosum, and E. floccosum, and clove + lemongrass against M. canis.

The honeybee (Apis mellifera) is a key pollinator critical to global agriculture, facing threats from various stressors, including the ectoparasitic Varroa mite (Varroa destructor). Previous studies have identified shared bacteria between Varroa mites and honeybees, yet it remains unclear if these bacteria assemble similarly in both species. This study builds on existing knowledge by investigating co-occurrence patterns in the microbiomes of both Varroa mites and honeybees, shedding light on potential interactions. Leveraging 16S rRNA datasets, we conducted co-occurrence network analyses, explored Core Association Networks (CAN) and assess network robustness. Comparative network analyses revealed structural differences between honeybee and mite microbiomes, along with shared core features and microbial motifs. The mite network exhibited lower robustness, suggesting less resistance to taxa extension compared to honeybees. Furthermore, analyses of predicted functional profiling and taxa contribution revealed that common central pathways in the metabolic networks have different taxa contributing to Varroa mites and honeybee microbiomes. The results show that while both microbial systems exhibit functional redundancy, in which different taxa contribute to the functional stability and resilience of the ecosystem, there is evidence for niche specialization resulting in unique contributions to specific pathways in each part of this host-parasite system. The specificity of taxa contribution to key pathways offers targeted approaches to Varroa microbiome management and preserving honeybee microbiome. Our findings provide valuable insights into microbial interactions, aiding farmers and beekeepers in maintaining healthy and resilient bee colonies amid increasing Varroa mite infestations.

The aquaculture sector, vital to global food security, grapples with bacterial pathogens compromising fish health and industry sustainability. This investigation probes mucosal immune responses and gut microbiota dynamics in snakehead (Channa argus) post-Aeromonas infection, a prevalent aquaculture challenge. Employing infection models, we delineated the integral role of immunoglobulin T (IgT) in mucosal immunity and its interaction with gut microbiota. Fish from a local farm, maintained under controlled conditions, were infected with Aeromonas veronii TH0426 and Aeromonas hydrophila TPS. Post-infection, daily monitoring and sample collection at specified intervals were conducted for comprehensive analysis. Histopathology, quantitative PCR, immunofluorescence, and microbiota profiling revealed significant immune and microbial changes, particularly at day 7. Intestinal IgT, IgM, and pIgR gene expression surged, indicative of a robust response. Immunofluorescence microscopy confirmed increased IgT⁺ and pIgR⁺ cell infiltration in the epithelium. Post-infection dysbiosis, with altered bacterial composition, was partially offset by elevated IgT levels. These insights underscore IgT's crucial function in mucosal defense and suggest potential for probiotic and vaccine strategies to enhance aquaculture disease resilience.

The phyllosphere of bamboo is rich in microorganisms that can disrupt the intestinal microbiota of the giant pandas that consume them, potentially leading to their death. In the present study, the abundance, diversity, biological functions (e.g., KEGG and CAZyme), and antibiotic resistance genes (ARGs) of bacteria and fungi in two bamboo species phyllosphere (Chimonobambusa szechuanensis, CS; Bashania fangiana, BF) in Daxiangling Nature Reserve (an important part of the Giant Panda National Park) were investigated respectively by amplicon sequencing of the whole 16S rRNA and ITS1-ITS2 genes on PacBio Sequel and whole-metagenome shotgun sequencing on Illumina NovaSeq 6000 platform. The results suggested that there were respectively 18 bacterial and 34 fungi biomarkers between the phyllosphere of the two species of bamboo. Beta diversity of bacteria and fungi communities exited between the two bamboos according to the (un)weighted UniFrac distance matrix. Moreover, the functional analysis showed that the largest relative abundance was found in the genes related to metabolism and global and overview maps. Glycoside hydrolases (GHs) and glycosyl transferases (GTs) have a higher abundance in two bamboo phyllospheres. Co-occurrence network modeling suggested that bacteria and fungi communities in CS phyllosphere employed a much more complex metabolic network than that in BF, and the abundance of multidrug, tetracycline, and glycopeptide resistance genes was higher and closely correlated with other ARGs. This study references the basis for protecting bamboo resources foraged by wild giant pandas and predicts the risk of antibiotic resistance in bamboo phyllosphere bacterial and fungal microbiota in the Giant Panda National Park, China.

Storage of meat has always been challenging due to its deterioration caused by oxidative rancidity and microbial activity, especially in trading. The melanin-coated film acts as a potent antioxidant, prevents the oxidation of fatty acids, and neutralizes the reactive oxygen species (ROS) helping to withstand or perpetuate the oxidative stress of meat. This study emphasizes the production of fungal melanin extracted from Curvularia lunata and the preparation of two different melanin film combinations of gelatin/melanin and agar/melanin at 0.1% and 0.5% formulation for rancidity stability of coated pork lard. Interpretations revealed the delayed rancidity in both peroxide and acid values with 5.76% in 0.5% agar-coated melanin up to the 11th day which was supported by arithmetical analysis showing p < 0.05 are statistically significant. Further, upon testing the brine shrimp assay for melanin toxicity, 7% were in a mortal state at 1000 µg/mL concentration, considered zero lethality. This result implies that modified coatings, particularly when trading meats, that include fungal melanin can effectively prevent the oxidation of pork lard.

Background: The incidence of urinary tract infections associated with Candida is increasing in Yemeni public hospitals.

Objectives: The primary objective of this research was to isolate specific Candida species responsible for catheter-associated urinary tract infections (UTIs) and to examine the antifungal sensitivity of these Candida isolates.

Patients and methods: A total of 200 samples were collected from patients with catheters admitted to multiple hospitals of Thamar city (Yemen). There were 50 positive samples with Candida out of 200 samples. We conducted the primary identification process using the established protocols. Before isolation and identification, all yeast isolates underwent sub-culturing on Sabouraud dextrose agar. We employed the standard microbiological procedures such as Gram staining, colonial morphology analysis, lactophenol cotton blue assay, germ tube formation assessment, colony staining on chrom agar Candida medium, and incubation at 37 °C for 48 h. The assessment of cultures was conducted by evaluating their predominant species. All Candida isolates were tested for antifungal susceptibility using the disk diffusion technique, as indicated by the Clinical and Laboratory Standards Institute (CLSI) M44-A document recommendations.

Results: In this study, the prevalence of Candida species obtained from catheter-associated UTIs was shown to be the highest among individuals aged 51-60 years (28.0%) and the lowest was among those aged 10-20 years (8.0%). Males exhibit higher rates than females, with males accounting for 56.0 and females for 44.0%, respectively. The predominant strain from catheters linked to urinary tract infections was Candida albicans. The Candida isolates had the highest susceptibility to itraconazole, with fluconazole and nystatin at sensitivity rates of 64, 60, and 50%, respectively. Amphotericin B and ketoconazole exhibited the most elevated concentrations. The p value of duration of catheterization < 5 was significant (p = 0.01), as well as significant in anti-fungal susceptibility testing of itraconazole, ketoconazole, and nystatin which are (p = 0.03), (p = 0.04), and (p = 0.03) respectively.

Conclusion: Urinary tract infection due to candiduria was more common in patients with indwelling urinary catheter. The catheter-associated urinary tract infection caused by Candida species occurred mainly in old male patients. Candia albicans was the predominant Candida species isolated from urinary tract infection associated with urinary catheter at Thamar city hospitals. This study determined that diabetes and antibiotic use are significant predisposing factors associated with isolation of Candida in specimens submitted by patients at Thamar city hospitals.

Background: Transcriptome data from a plant sample frequently include numerous reads originating from RNA virus genomes that were concurrently isolated during RNA preparation. These high-throughput sequencing reads from the virus can be assembled to form a new sequence for the plant RNA genome.

Methods and results: Here, we identify putative novel mitovirus, grapevine mitovirus 1 (GMV1) through high-throughput sequencing (HTS) of grapevine rootstocks (Vitis spp.), and the identified virus was confirmed using virus-specific primers in RT-PCR assay. The genomic RNA of GMV1 encodes complete open reading frame (ORF) of 2,496 nucleotides (nts) in length. RNA-dependent RNA polymerase (RdRp) encoded by the viral genome contained one RdRp conserved domain. BLASTx analysis of GMV1 genome showed sequence identity of 33.18-56.75% with the existing mitovirus sequences. Phylogenetic analysis based on genome sequences showed that GMV1 clustered in a distinct clade to other mitoviruses.

Conclusion: Grapevine mitovirus 1 represents a newly discovered species within the Unuamitovirus genus of the Mitoviridae family, targeting fungal mitochondria. While the majority of recognized mitoviruses typically lack a functional RdRp as per the plant mitochondrial genetic code, GMV1 encodes a complete RdRp in accordance with both fungal and plant mitochondrial genetic codes.

Metarhizium spp. have emerged as an alternative to chemical pesticides for protecting crops from insect pest. Here, we investigated midgut microbial community and metabolites of Spodoptera litura at three different timepoints after infection with Metarhizium flavoviride. The innate immune system of S. litura was activated with levels of polyphenol oxidase, carboxylesterase, multifunctional oxidase, and glutathione S-transferase activity significantly increasing. Exposure to the fungal pathogen also altered bacterial abundance and diversity in host's midgut, and these changes varied depending on the time elapsed since exposure. We identified more operational taxonomic units in the treated samples as compared to the control samples at all tested time points. A total of 372 metabolites were identified, and 88, 149, and 142 differentially accumulated metabolites (DAMs) were identified between the treatment and control groups at 3 timepoints after treatment, respectively. Based on the changes of DAMs in response to M. flavoviride infection at different timepoints and significantly enriched KEGG pathways, we speculated that "tyrosine metabolism," "galactose metabolism," "ATP-binding cassette transporters," "neuroactive ligand-receptor interaction," "purine metabolism," "arginine and proline metabolism," "beta-alanine metabolism," "lysosome," and "carbon metabolism" may participate in the metabolic-level defense response. An integrated pathway-level analysis of the 16S-rDNA and metabolomic data illustrated the connections and interdependencies between the metabolic responses of S. litura and the midgut microorganisms to M. flavoviride infection. This work emphasizes the value of integrated analyses of insect-pathogen interactions, provides a framework for future studies of critical microorganisms and metabolic determinants of these interactions, establishes a theoretical basis for the sustainable use of M. flavoviride.

Rice cultivation generates huge amounts of on farm residues especially under mechanical harvesting. Paddy straw being recalcitrant hinders sowing of upcoming rabi crops like wheat and mustard. Non-environmental sustainable practice of on-farm burning of the paddy residues is being popularly followed for quick disposal of the agro-residues and land preparation. However, conservation agriculture involving in situ residue incorporation can be a sustainable option to utilize the residues for improvement of soil biological health. However, low temperature coupled with poor nitrogen status of soil reduces the decomposition rate of residues that may lead to nitrogen immobilization and hindrance in land preparation. In this direction, ecological impact of two approaches viz priming with urea and copiotrophic fungus-based bioformulation (CFB) consisting of Coprinopsis cinerea LA2 and Cyathus stercoreus ITCC3745 was studied for in situ degradation of residues. Succession of bacterial diversity was deciphered through high throughput whole metagenomic sequencing along with studies on dynamics of soil microbial enzymes. Treatments receiving CFB (T1) and urea (T2) when compared with bulk soil (absolute control) showed an increase in richness of the microbial diversity as compared to control straw retained treatment control (T3). The β diversity indices also indicated sufficient group variations among the treatments receiving CFB and urea as compared to only straw retained treatment and bulk soil. Priming of paddy straw with CFB and urea also induced significant rewiring of the bacterial co-occurrence networks. Quantification of soil ligno-cellulolytic activity as well as abundance of carbohydrate active enzymes (CAZy) genes indicated high activities of hydrolytic enzymes in CFB primed straw retention treatment as compared to urea primed straw retention treatment. The genomic insights on effectiveness of copiotrophic fungus bioformulation for in situ degradation of paddy straw will further help in developing strategies for management of crop residues in eco-friendly manner.

The massive emergence of antimicrobial resistance in recent decades has rendered the use of a single-agent strategy ineffective. Consequently, the combination of different therapeutic agents has emerged as a promising new approach. The aim of the present study was to investigate the combined effect of Chlorella vulgaris methanol extract (CVME) and Origanum elongatum essential oil (OEEO) on methicillin-resistant Staphylococcus aureus (MRSA). Thus, the antibacterial activity of OEEO and CVME on Escherichia coli, Staphylococcus aureus, and MRSA was evaluated using the agar well diffusion and broth microdilution methods. The killing activity of CVME and OEEO, individually and in combination, on MRSA ATCC 43300 was tested using the time-kill assay. The synergistic effect was examined by determining the fractional inhibitory concentration index (FICI) using the checkerboard test. The results showed very significant antibacterial activity against all the bacteria tested, for both OEEO and CVME, with minimum inhibitory concentrations (MICs) ranging from 0.125 to 0.25% (v/v) for OEEO and from 3.12 to 6.25 mg mL^-1 for CVME. Minimum bactericidal concentration (MBC) values for OEEO and CVME were in the range 0.125-0.5% (v/v) and 6.25-12.5 mg mL^-1, respectively. The inhibition zones associated with OEEO were distinctly greater than those associated with CVME for all the bacteria examined. When used individually, the time-kill curves of OEEO and CVME revealed a dose-dependent effect on MRSA proliferation. Compared with controls, both agents were able to prolong the latent phase of growth curves and decelerate bacterial growth. The killing effect of OEEO on MRSA was considerably higher than that observed with CVME. OEEO prevented MRSA proliferation at only 1/2 of its MIC, while the CVME did so at 2 times its MIC. The combination of OEEO with CVME demonstrated a synergistic effect against MRSA, with a FIC index value of 0.49. The findings therefore suggest that the combination of C. vulgaris methanol extract and O. elongatum essential oil at very low doses may be promising anti-MRSA candidates. A search of the published literature revealed that, to our knowledge, no studies have yet been carried out on the antibacterial potential of combining essential oils and microalgae extracts in the fight against MRSA.