-
Molecules (Basel, Switzerland) Jun 2024The discovery and investigation of new natural compounds with antimicrobial activity are new potential strategies to reduce the spread of antimicrobial resistance. The...
The discovery and investigation of new natural compounds with antimicrobial activity are new potential strategies to reduce the spread of antimicrobial resistance. The presented study reveals, for the first time, the promising antibacterial potential of two fractions from mucus with an MW < 20 kDa and an MW > 20 kDa against five bacterial pathogens- 1085, 1897, 8691, 3915, and 8754. Using de novo sequencing, 16 novel peptides with potential antibacterial activity were identified in a fraction with an MW < 20 kDa. Some bioactive compounds in a mucus fraction with an MW > 20 kDa were determined via a proteomic analysis on 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and bioinformatics. High homology with proteins and glycoproteins was found, with potential antibacterial activity in mucus proteins named aspernin, hemocyanins, H-lectins, and L-amino acid oxidase-like protein, as well as mucins (mucin-5AC, mucin-5B, mucin-2, and mucin-17). We hypothesize that the synergy between the bioactive components determined in the composition of the fraction > 20 kDa are responsible for the high antibacterial activity against the tested pathogens in concentrations between 32 and 128 µg/mL, which is comparable to vancomycin, but without cytotoxic effects on model eukaryotic cells of . Additionally, a positive effect, by reducing the levels of intracellular oxidative damage and increasing antioxidant capacity, on cells was found for both mucus extract fractions of . These findings may serve as a basis for further studies to develop a new antibacterial agent preventing the development of antibiotic resistance.
Topics: Anti-Bacterial Agents; Mucus; Microbial Sensitivity Tests; Peptides; Enterococcus faecalis; Enterococcus faecium; Bacillus cereus; Animals; Propionibacterium acnes; Salmonella enterica
PubMed: 38930951
DOI: 10.3390/molecules29122886 -
Molecules (Basel, Switzerland) Jun 2024Fluconazole (2-(2,4-difluorophenyl)-1,3-bis(1-1,2,4-triazol-1-yl)propan-2-ol), which was patented in 1981 and introduced for commercial use in 1988, is a widely utilized... (Review)
Review
Fluconazole (2-(2,4-difluorophenyl)-1,3-bis(1-1,2,4-triazol-1-yl)propan-2-ol), which was patented in 1981 and introduced for commercial use in 1988, is a widely utilized antifungal drug whose mechanism of action involves inhibition of the activity of 14-α lanosterol demethylase. Its safety and effectiveness have established it as one of the most frequently employed antifungal agents. Resistance to azole antifungal drugs is becoming more common. It may be related to a mutation of the gene encoding the enzyme. To address this issue, molecules with modifications in three main regions of fluconazole, namely the hydroxyl group, the aromatic ring, and the 1,2,4-triazole rings, have been synthesized in an attempt to create more potent antifungal drugs. These modifications aim at enhancing the effectiveness against microorganisms and improving pharmacokinetic parameters and safety profiles of the synthesized compounds. The present review explores the synthesis of fluconazole derivatives, accompanied by insights into the results of biological studies evaluating the therapeutic effects of these compounds.
Topics: Fluconazole; Antifungal Agents; Humans; Structure-Activity Relationship; Microbial Sensitivity Tests; Animals; Drug Resistance, Fungal; Molecular Structure
PubMed: 38930921
DOI: 10.3390/molecules29122855 -
Molecules (Basel, Switzerland) Jun 2024The aim of this study was to obtain new halolactones with a gem-dimethyl group in the cyclohexane ring (at the C-3 or C-5 carbon) and a methyl group in the lactone ring...
The aim of this study was to obtain new halolactones with a gem-dimethyl group in the cyclohexane ring (at the C-3 or C-5 carbon) and a methyl group in the lactone ring and then subject them to biotransformations using filamentous fungi. Halolactones in the form of mixtures of two diasteroisomers were subjected to screening biotransformations, which showed that only compounds with a gem-dimethyl group located at the C-5 carbon were transformed. Strains from the genus carried out hydrolytic dehalogenation, while strains from the genus carried out hydroxylation of the C-7 carbon. Both substrates and biotransformation products were then tested for antimicrobial activity against multidrug-resistant strains of both bacteria and yeast-like fungi. The highest antifungal activity against and strains was obtained for compound , while antimicrobial activity against MRSA was obtained for compound .
Topics: Lactones; Anti-Bacterial Agents; Biotransformation; Microbial Sensitivity Tests; Fusarium; Antifungal Agents; Absidia; Molecular Structure; Candida albicans; Methicillin-Resistant Staphylococcus aureus
PubMed: 38930886
DOI: 10.3390/molecules29122820 -
Microorganisms Jun 2024Waste Water Treatment Plants (WWTP) aim to reduce contamination in effluent water; however, studies indicate antimicrobial resistance genes (ARGs) persist...
Metagenomic Investigation of the Short-Term Temporal and Spatial Dynamics of the Bacterial Microbiome and the Resistome Downstream of a Wastewater Treatment Plant in the Iskar River in Bulgaria.
Waste Water Treatment Plants (WWTP) aim to reduce contamination in effluent water; however, studies indicate antimicrobial resistance genes (ARGs) persist post-treatment, potentially leading to their spread from human populated areas into the environment. This study evaluated the impact of a large WWTP serving 125,000 people on the Iskar River in Bulgaria, by characterizing the spatial and short-term temporal dynamics in bacterial community dynamics and resistance profiles of the surface water. Pairs of samples were collected biweekly on four dates from two different locations, one about 800 m after the WWTP effluents and the other 10 km downstream. Taxonomic classification revealed the dominance of and , notably the genera , , , , and . The taxonomic structure corresponded with both lentic and lotic freshwater habitats, with exhibiting a significant decrease over the study period. Principal Coordinate Analysis revealed statistically significant differences in bacterial community composition between samples collected on different dates. Differential abundance analysis identified notable enrichment of and There were shifts within the enriched or depleted bacterial taxa between early and late sampling dates. High relative abundance of the genes , , , (macrolides); , , , and (tetracyclines); and (sulphonamides); and , (beta-lactams) were detected, with trends of increased presence in the latest sampling dates and in the location closer to the WWTP. Of note, genes conferring resistance to carbapenems OXA-58 and IMP-33-like were identified. Co-occurrence analysis of ARGs and mobile genetic elements on putative plasmids showed few instances, and the estimated human health risk score (0.19) according to MetaCompare2.0 was low. In total, 29 metagenome-assembled genomes were recovered, with only a few harbouring ARGs. This study enhances our understanding of freshwater microbial community dynamics and antibiotic resistance profiles, highlighting the need for continued ARGs monitoring.
PubMed: 38930632
DOI: 10.3390/microorganisms12061250 -
Microorganisms Jun 2024This study evaluates the suitability of three lactic acid bacteria (LAB) strains-, , and -for use as probiotics in apiculture. Given the decline in bee populations due...
This study evaluates the suitability of three lactic acid bacteria (LAB) strains-, , and -for use as probiotics in apiculture. Given the decline in bee populations due to pathogens and environmental stressors, sustainable alternatives to conventional treatments are necessary. This study aimed to assess the potential of these LAB strains in a probiotic formulation for bees through various in vitro tests, including co-culture interactions, biofilm formation, auto-aggregation, antioxidant activity, antimicrobial activity, antibiotic susceptibility, and resistance to high osmotic concentrations. This study aimed to assess both the individual effects of the strains and their combined effects, referred to as the LAB mix. Results indicated no mutual antagonistic activity among the LAB strains, demonstrating their compatibility with multi-strain probiotic formulations. The LAB strains showed significant survival rates under high osmotic stress and simulated gastrointestinal conditions. The LAB mix displayed enhanced biofilm formation, antioxidant activity, and antimicrobial efficacy against different bacterial strains. These findings suggest that a probiotic formulation containing these LAB strains could be used for a probiotic formulation, offering a promising approach to mitigating the negative effects of pathogens. Future research should focus on in vivo studies to validate the efficacy of these probiotic bacteria in improving bee health.
PubMed: 38930631
DOI: 10.3390/microorganisms12061249 -
Microorganisms Jun 2024The metagenomic surveillance of antimicrobial resistance in wastewater has been suggested as a methodological tool to characterize the distribution, status, and trends...
The metagenomic surveillance of antimicrobial resistance in wastewater has been suggested as a methodological tool to characterize the distribution, status, and trends of antibiotic-resistant bacteria. In this study, a cross-sectional collection of samples of hospital-associated raw and treated wastewater were obtained from February to March 2020. Shotgun metagenomic sequencing and bioinformatic analysis were performed to characterize bacterial abundance and antimicrobial resistance gene analysis. The main bacterial phyla found in all the samples were as follows: , , , and . At the species level, bacteria such as relative abundance decreased between raw and treated wastewater, but , , and increased, as did the persistence of in both raw and treated wastewater. A total of 172 different ARGs were detected; , , , , , , , , , , , , , , , , and were found at the highest abundance and persistence. This study demonstrates the ability of bacteria to survive tertiary treatment processes of hospital wastewater, as well as the persistence of clinically important antimicrobial resistance genes that are spreading in the environment.
PubMed: 38930614
DOI: 10.3390/microorganisms12061231 -
Microorganisms Jun 2024is the first reported pathogen within the genus to cause a catheter-related bloodstream infection, which occurred in 2015. In this study, the complete genome assembly...
is the first reported pathogen within the genus to cause a catheter-related bloodstream infection, which occurred in 2015. In this study, the complete genome assembly of was constructed, and the complete genome of FBCC-B549 consists of a single chromosome (3,137,745 bp) without plasmids. The constructed genome of was compared with those of two closely related species within the genus. exhibited a pattern similar to in terms of gene clusters and synteny analysis. Contrary to previous studies, biosynthetic gene cluster (BGC) analysis for predicting secondary metabolites revealed the presence of the LAP biosynthesis pathway in the complete genome of , predicting the potential synthesis of the secondary metabolite plantazolicin. Furthermore, an analysis to investigate the potential pathogenicity of did not reveal any antibiotic resistance genes; however, nine virulence factors were identified in the Virulence Factor Database (VFDB). According to these matching results in the VFDB, despite identifying a few factors involved in biofilm formation, further research is required to determine the actual impact of on pathogenicity. The complete genome of is expected to serve as a valuable resource for future studies on , which currently lack sufficient genomic sequence information.
PubMed: 38930609
DOI: 10.3390/microorganisms12061227 -
Microorganisms Jun 2024Antibiotics are routinely added to ornamental fish tanks for treating bacterial infection or as a prophylactic measure. However, the overuse or subtherapeutical...
Antibiotics are routinely added to ornamental fish tanks for treating bacterial infection or as a prophylactic measure. However, the overuse or subtherapeutical application of antibiotics could potentially facilitate the selection of antibiotic resistance in bacteria, yet no studies have investigated antibiotic use in the retail ornamental fish sector and its impact on microbial communities. The present study analyzed the concentrations of twenty antibiotics in the carriage water (which also originates from fish tanks in retail shops) collected monthly from ten local ornamental fish shops over a duration of three months. The antibiotic concentrations were correlated with the sequenced microbial community composition, and the risk of resistance selection in bacteria was assessed. Results revealed that the detected concentrations of tetracyclines were the highest among samples, followed by fluoroquinolones and macrolides. The concentrations of oxytetracycline (44.3 to 2,262,064.2 ng L) detected across three months demonstrated a high risk for resistance selection at most of the sampled shops. Zoonotic pathogens (species of , , and ) were positively correlated with the concentrations of oxytetracycline, tetracycline, chlortetracycline, and enrofloxacin. This suggests that antibiotic use in retail shops may increase the likelihood of selecting for zoonotic pathogens. These findings shed light on the potential for ornamental fish retail shops to create a favorable environment for the selection of pathogens with antibiotics, thereby highlighting the urgent need for enhanced antibiotic stewardship within the industry.
PubMed: 38930567
DOI: 10.3390/microorganisms12061184 -
Microorganisms Jun 2024Salt-tolerant aerobic granular sludge(AGS) was successfully cultivated under the dual stress of tetracycline and 2.5% salinity, resulting in an average particle size of...
Salt-tolerant aerobic granular sludge(AGS) was successfully cultivated under the dual stress of tetracycline and 2.5% salinity, resulting in an average particle size of 435.0 ± 0.5 and exhibiting a chemical oxygen demand(COD) removal rate exceeding 80%, as well as excellent sedimentation performance. The analysis of metagenomics technology revealed a significant pattern of succession in the development of AGS. The proportion of , a type of salt-tolerant bacteria, exhibited a gradual increase and reached 38.07% after 42 days, which indicated that an AGS system based on moderate halophilic bacteria was successfully constructed. The expression levels of targeted genes were found to be reduced across the entire AGS process and formation, as evidenced by qPCR analysis. The presence of (7.67 log10 gene copies g in 0 d sludge sample) enabled microbes to horizontally transfer ARGs genes along the AGS formation under the double pressure of TC and 2.5% salinity. These findings will enhance our understanding of ARG profiles and the development in AGS under tetracycline pressure, providing a foundation for guiding the use of AGS to treat hypersaline pharmaceutical wastewater.
PubMed: 38930555
DOI: 10.3390/microorganisms12061173 -
Microorganisms Jun 2024We determined antibiotic susceptibility and employed Oxford Nanopore whole-genome sequencing to explore strain diversity, resistance, and virulence gene carriage among...
We determined antibiotic susceptibility and employed Oxford Nanopore whole-genome sequencing to explore strain diversity, resistance, and virulence gene carriage among methicillin-resistant (MRSA) strains from different infection sites and timepoints in a tertiary Kenyan hospital. Ninety-six nonduplicate clinical isolates recovered between 2010 and 2023, identified and tested for antibiotic susceptibility on the VITEK ID/AST platform, were sequenced. Molecular typing, antibiotic resistance, and virulence determinant screening were performed using the relevant bioinformatics tools. The strains, alongside those from previous studies, were stratified into two periods covering 2010-2017 and 2018-2023 and comparisons were made. Mirroring phenotypic profiles, '″ [aminoglycosides]; (S84L) and (S80Y) [fluoroquinolones]; [anti-folates]; and [tetracycline] resistance determinants dominated the collection. While the proportion of ST239/241-t037-SCCmec III among MRSA reduced from 37.7% to 0% over the investigated period, ST4803-t1476-SCCmec IV and ST152-t355-SCCmec IV were pre-eminent. The prevalence of Panton-Valentine leucocidin (PVL) and arginine catabolic mobile element (ACME) genes was 38% (33/87) and 6.8% (6/87), respectively. We observed the displacement of HA-MRSA ST239/241-t037-SCCmec III with the emergence of ST152-t355-SCCmec IV and a greater clonal heterogeneity. The occurrence of PVL+/ACME+ CA-MRSA in recent years warrants further investigations into their role in the CA-MRSA virulence landscape, in a setting of high PVL prevalence.
PubMed: 38930553
DOI: 10.3390/microorganisms12061171