-
Applied and Environmental Microbiology Apr 2024Soil protists have been shown to contribute to the structure and function of the rhizosphere in a variety of ways. Protists are key contributors to nutrient cycling...
Soil protists have been shown to contribute to the structure and function of the rhizosphere in a variety of ways. Protists are key contributors to nutrient cycling through the microbial loop, where biomass is digested by protists and otherwise stored nutrients are returned to the environment. Protists have also been shown to feed on plant pathogenic bacteria and alter root microbiomes in ways that may benefit plants. Recently, a mechanism involving bacterial transport, facilitated by protists, has been hypothesized to contribute to the spatial distribution of bacteria in the rhizosphere. Here, we observe the differential abilities of three soil protists: a ciliate ( sp.), a flagellate ( sp.), and a naked amoeba () to transport nitrogen-fixing to infectible root tips. Co-inoculation of protists plus resulted in the movement of bacteria, as measured by the presence of nitrogen-fixing nodules, up to 15 cm farther down the root systems when compared to plants inoculated with alone. Co-inoculation of the ciliate sp., with , resulted in shoot weights that were similar to plants that grew in nitrogen-replete potting mix. sp.-feeding style and motility likely contributed to their success at transporting bacteria through the rhizosphere. We observed that the addition of protists alone without the co-inoculum of resulted in plants with larger shoot weights than control plants. Follow-up experiments showed that protists plus their associated microbiomes were aiding in plant health, likely through means of nutrient cycling.IMPORTANCEProtists represent a significant portion of the rhizosphere microbiome and have been shown to contribute to plant health, yet they are understudied compared to their bacterial and fungal counterparts. This study elucidates their role in the rhizosphere community and suggests a mechanism by which protists can be used to move bacteria along plant roots. We found that the co-inoculation of protists with nitrogen-fixing beneficial bacteria, , resulted in nodules farther down the roots when compared to plants inoculated with S. alone, and shoot weights similar to plants that received nitrogen fertilizer. These data illustrate the ability of protists to transport viable bacteria to uninhabited regions of the root system.
Topics: Plants; Bacteria; Rhizosphere; Soil; Nitrogen; Plant Roots; Soil Microbiology
PubMed: 38534145
DOI: 10.1128/aem.02011-23 -
Expert Opinion on Drug Metabolism &... Mar 2024Carbonic anhydrases (CAs, EC 4.2.1.1) have been established drug targets for decades, with their inhibitors and activators possessing relevant pharmacological activity... (Review)
Review
INTRODUCTION
Carbonic anhydrases (CAs, EC 4.2.1.1) have been established drug targets for decades, with their inhibitors and activators possessing relevant pharmacological activity and applications in various fields. At least 11 sulfonamides/sulfamates are clinically used as diuretics, antiglaucoma, antiepileptic, or antiobesity agents and one derivative, SLC-0111, is in clinical trials as antitumor/antimetastatic agent. The activators were less investigated with no clinically used agent.
AREAS COVERED
Drug interactions between CA inhibitors/activators and various other agents are reviewed in publications from the period March 2020 - January 2024.
EXPERT OPINION
Drug interactions involving these agents revealed several interesting findings. Acetazolamide plus loop diuretics is highy effective in acute decompensated heart failure, whereas ocular diseases such as X-linked retinoschisis and macular edema were treated by acetazolamide plus bevacizumab or topical NSAIDs. Potent anti-infective effects of acetazolamide and other CAIs, alone or in combination with other agents were demonstrated for the management of , vancomycin resistant enterococci, , and infections. Topiramate, in combination with phentermine is incresingly used for the management of obesity, whereas zonisamide plus levodopa is highly effective for Parkinson's disease. Acetazolamide, methazolamide, ethoxzolamide, and SLC-0111 showed synergistic antitumor/antimetastatic action in combination with many other antitumor drugs.
Topics: Humans; Carbonic Anhydrase Inhibitors; Acetazolamide; Sulfonamides; Drug Interactions; Antineoplastic Agents; Structure-Activity Relationship; Phenylurea Compounds
PubMed: 38450431
DOI: 10.1080/17425255.2024.2328152 -
Archives of Microbiology Mar 2024Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly...
Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and Cu catalyzed azide-alkyne cycloaddition. Characterization by H and C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG) and blank micelles (PCL-PEG) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06 µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG and ITZ-PCL-PEG inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus should be investigated further in vivo to determine its clinical potential.
Topics: Humans; Micelles; Itraconazole; Acanthamoeba castellanii; Alkynes; Polymers
PubMed: 38433145
DOI: 10.1007/s00203-024-03854-3 -
Parasitology Research Mar 2024Free-living amoebae (FLA) include amphizoic microorganisms important in public health, widely isolated from air, water, and soil. However, its occurrence in... (Meta-Analysis)
Meta-Analysis
Free-living amoebae (FLA) include amphizoic microorganisms important in public health, widely isolated from air, water, and soil. However, its occurrence in sewage-related environments still needs to be systematically documented. This study summarizes the occurrence of FLA in sewage-related environments through a systematic review with meta-analysis. A total of 1983 scientific article were retrieved from different databases, of which 35 were selected and analyzed using a random effects forest plot model with a 95% confidence interval (IC). The pooled overall prevalence of FLA in sewage across 12 countries was 68.96% (95% IC = 58.5-79.42). Subgroup analysis indicates high prevalence in all environments analyzed, including sewage water from the sewage treatment plant (81.19%), treated sewage water (75.57%), sewage-contaminated water (67.70%), sediment contaminated by sewage (48.91%), and sewage water (47.84%). Prevalence values of Acanthamoeba spp., Hartmanella/Vermamoeba spp., and Naegleria spp. are 47.48%, 28.24%, and 16.69%, respectively. Analyzing the species level, the distribution is as follows: Acanthamoeba palestinensis (88%), A. castellanii (23.74%), A. astronyxis (19.18%), A. polyphaga (13.59%), A. culbertsoni (12.5%), A. stevensoni (8.33%), A. tubiashi (4.35%) and A. hatchetti (1.1%), Naegleria fowleri (28.4%), N. gruberi (25%), N. clarki (8.33%), N. australiensis (4.89%) and N. italica (4.29%), Hartmannella/Vermamoeba exundans (40%) and H.V. vermiform (32.61%). Overall, our findings indicate a high risk associated with sewage-related environments, as the prevalence of FLA, including pathogenic strains, is high, even in treated sewage water. The findings of this study may be valuable both for risk remediation actions against amoebic infections and for future research endeavors.
Topics: Acanthamoeba; Amoeba; Hartmannella; Prevalence; Sewage; Water
PubMed: 38433138
DOI: 10.1007/s00436-024-08164-7 -
Journal of Basic Microbiology Apr 2024Free-living amoebae of the genus Acanthamoeba are infected by various bacteria in nature, and thus bacteria can protect themselves from adverse environmental conditions....
Free-living amoebae of the genus Acanthamoeba are infected by various bacteria in nature, and thus bacteria can protect themselves from adverse environmental conditions. Contrary to this ameba-bacteria relationship whether Acanthamoeba has antibacterial effects on bacteria is the different aspect of the relationship between these microorganisms. In this study, we investigate various Acanthamoeba strains have antibacterial effects on various Staphylococcus strains. Three environmental Acanthamoeba strains, isolated from various aquatic environments in Turkey, and Acanthamoeba castellanii ATCC 50373 standard strains were used in the study. The antistaphylococcal effect of cell-free supernatant (CFS) obtained from these amoebae against 12 different Staphylococcus bacteria was investigated by colony counting method. In addition, the pathogenicity of the tested Acanthamoeba strains was determined using osmotolerance and thermotolerance tests. CFSs obtained from Acanthamoeba were found to have varying degrees of antistaphylococcal effects on various Staphylococcus strains (0%-100%). It was determined that the CFS of the standard Acanthamoeba strain showed 100% inhibitory effect against one clinical methicillin-resistant Staphylococcus aureus strain (M2). Also, CFS of Ugöl strain showed 99.97% inhibitory effect against one clinical methicillin-sensitive Staphylococcus epidermidis strain (L3). It was determined that all Acanthamoeba isolates had no pathogenic potential. According to the results, it has been observed that Acanthamoeba produces antibacterial substance(s) against Staphylococcus bacteria and that the ameba-bacteria relationship may also result in the detriment of the bacteria. Furthermore, the current study indicates that new and natural antimicrobial agents from Acanthamoeba can be used as an alternative to infections caused by Staphylococcus.
Topics: Staphylococcus; Methicillin-Resistant Staphylococcus aureus; Acanthamoeba castellanii; Anti-Infective Agents; Anti-Bacterial Agents; Bacteria
PubMed: 38416601
DOI: 10.1002/jobm.202300551 -
Antimicrobial Agents and Chemotherapy Apr 2024Organic and synthetic chemistry plays a crucial role in drug discovery fields. Moreover, chemical modifications of available molecules to enhance their efficacy,...
Organic and synthetic chemistry plays a crucial role in drug discovery fields. Moreover, chemical modifications of available molecules to enhance their efficacy, selectivity and safety have been considered as an attractive approach for the development of new bioactive agents. Indoles, a versatile group of natural heterocyclic compounds, have been widely used in pharmaceutical industry due to their broad spectrum of activities including antimicrobial, antitumoral and anti-inflammatory among others. Herein, we report the amoebicidal activity of different indole analogs on Neff. Among the 40 tested derivatives, eight molecules were able to inhibit this protistan parasite. The structure-activity relationship (SAR) analysis of their anti- activity would suggest that a carboxylation of C-3 position and the incorporation of halogen as chlorine/fluorine would enhance their biological profile, presumably by increasing their lipophilicity and therefore their ability to cross the cell membrane. Fluorescence image base system was used to investigate the effect of indole 6o c-6 on the cytoskeleton network and various programmed cell death features. We were able to highlight that the methyl 6-chloro-1H-indole-3-carboxylate could induce program cell death by the mitochondrial dysfunction.
Topics: Amebicides; Acanthamoeba castellanii; Cell Death; Apoptosis; Indoles
PubMed: 38412000
DOI: 10.1128/aac.01651-23 -
Journal of Applied Microbiology Mar 2024The aim of the study was to evaluate the efficiency of mimivirus as a potential therapeutic and prophylactic tool against Acanthamoeba castellanii, the etiological agent...
AIM
The aim of the study was to evaluate the efficiency of mimivirus as a potential therapeutic and prophylactic tool against Acanthamoeba castellanii, the etiological agent of Acanthamoeba keratitis, a progressive corneal infection, that is commonly associated with the use of contact lenses and can lead to blindness if not properly treated.
METHODS AND RESULTS
Mimivirus particles were tested in different multiplicity of infection, along with commercial multipurpose contact lenses' solutions, aiming to assess their ability to prevent encystment and excystment of A. castellanii. Solutions were evaluated for their amoebicidal potential and cytotoxicity in MDCK cells, as well as their effectiveness in preventing A. castellanii damage in Madin-Darby canine kidney (MDCK) cells. Results indicated that mimivirus was able to inhibit the formation of A. castellanii cysts, even in the presence of Neff encystment solution. Mimivirus also showed greater effectiveness in controlling A. castellanii excystment compared to commercial solutions. Additionally, mimivirus solution was more effective in preventing damage caused by A. castellanii, presented greater amoebicidal activity, and were less cytotoxic to MDCK cells than commercial MPS.
CONCLUSIONS
Mimivirus demonstrates a greater ability to inhibit A. castellanii encystment and excystment compared to commercial multipurpose contact lens solutions. Additionally, mimivirus is less toxic to MDCK cells than those commercial solutions. New studies utilizing in vivo models will be crucial for confirming safety and efficacy parameters.
Topics: Animals; Dogs; Giant Viruses; Amebiasis; Biotechnology
PubMed: 38373822
DOI: 10.1093/jambio/lxae044 -
Microbiology Spectrum Mar 2024species are clinically relevant free-living amoebae (FLA) ubiquitously found in soil and water bodies. Metabolically active trophozoites graze on diverse microbes via...
species are clinically relevant free-living amoebae (FLA) ubiquitously found in soil and water bodies. Metabolically active trophozoites graze on diverse microbes via phagocytosis. However, functional studies on Rab GTPases (Rabs), which are critical for controlling vesicle trafficking and maturation, are scarce for this FLA. This knowledge gap can be partly explained by the limited genetic tools available for cell biology. Here, we developed plasmids to generate fusions of strain Neff proteins to the N- or C-termini of mEGFP and mCherry2. Phylogenomic and structural analyses of the 11 Neff Rab7 paralogs found in the RefSeq assembly revealed that eight of them had non-canonical sequences. After correcting the gene annotation for the Rab7A ortholog, we generated a line stably expressing an mEGFP-Rab7A fusion, demonstrating its correct localization to acidified macropinocytic and phagocytic vacuoles using fluorescence microscopy live cell imaging (LCI). Direct labeling of live ESTM1D_MKCAZ16_6a (Sm18) cells with pHrodo Red, a pH-sensitive dye, demonstrated that they reside within acidified, Rab7A-positive vacuoles. We constructed new mini-Tn7 delivery plasmids and tagged Sm18 with constitutively expressed mScarlet-I. Co-culture experiments of Neff trophozoites with Sm18::mTn7TC1_Pc_mScarlet-I, coupled with LCI and microplate reader assays, demonstrated that Sm18 underwent multiple replication rounds before reaching the extracellular medium via non-lytic exocytosis. We conclude that belongs to the class of bacteria that can use amoeba as an intracellular replication niche within a -containing vacuole that interacts extensively with the endocytic pathway.IMPORTANCEDiverse lineages (genotypes) are of increasing clinical concern, mainly causing amoebic keratitis and granulomatous amebic encephalitis among other infections. ranks among the top 10 most prevalent multidrug-resistant opportunistic nosocomial pathogens and is a recurrent member of the microbiome hosted by and other free-living amoebae. However, little is known about the molecular strategies deployed by for an intracellular lifestyle in amoebae and other professional phagocytes such as macrophages, which allow the bacterium to evade the immune system and the action of antibiotics. Our plasmids and easy-to-use microtiter plate co-culture assays should facilitate investigations into the cellular microbiology of interactions with and other opportunistic pathogens, which may ultimately lead to the discovery of new molecular targets and antimicrobial therapies to combat difficult-to-treat infections caused by these ubiquitous microbes.
Topics: Acanthamoeba castellanii; Stenotrophomonas maltophilia; Vacuoles; Phylogeny; Bacteria
PubMed: 38319117
DOI: 10.1128/spectrum.02988-23 -
Phytomedicine : International Journal... Mar 2024Acanthamoeba is an opportunistic pathogen that can cause human infections such as granulomatous amebic encephalitis and acanthamoeba keratitis. However, no specific drug...
BACKGROUND
Acanthamoeba is an opportunistic pathogen that can cause human infections such as granulomatous amebic encephalitis and acanthamoeba keratitis. However, no specific drug to treat the diseases has been developed. Therefore, the discovery or development of novel drugs for treating Acanthamoeba infections is urgently needed. The anti-protozoan activity of (‒)-epicatechin (EC) has been reported, suggesting it is an attractive anti-protozoal drug candidate. In this study, the amoebicidal activity of EC against A. castellanii was assessed and its mechanism of action was unveiled.
METHODS
The amoebicidal activity of EC against A. castellanii trophozoites and the cytotoxicity of EC in HCE-2 and C6 cells were determined with cell viability assay. The underlying amoebicidal mechanism of EC against A. castellanii was analyzed by the apoptosis/necrosis assay, TUNEL assay, mitochondrial dysfunction assay, caspase-3 assay, and quantitative reverse transcription polymerase chain reaction. The cysticidal activity of EC was also investigated.
RESULTS
EC revealed amoebicidal activity against A. castellanii trophozoites with an IC of 37.01 ± 3.96 µM, but was not cytotoxic to HCE-2 or C6 cells. EC induced apoptotic events such as increases in DNA fragmentation and intracellular reactive oxygen species production in A. castellanii. EC also caused mitochondrial dysfunction in the amoebae, as evidenced by the loss of mitochondrial membrane potential and reductions in ATP production. Caspase-3 activity, autophagosome formation, and the expression levels of autophagy-related genes were also increased in EC-treated amoebae. EC led to the partial death of cysts and the inhibition of excystation.
CONCLUSION
EC revealed promising amoebicidal activity against A. castellanii trophozoites via programmed cell death events. EC could be a candidate drug or supplemental compound for treating Acanthamoeba infections.
Topics: Animals; Humans; Amebicides; Acanthamoeba castellanii; Caspase 3; Catechin; Amebiasis; Trophozoites; Apoptosis; Mitochondrial Diseases; Dieldrin
PubMed: 38306720
DOI: 10.1016/j.phymed.2024.155389 -
Parasitology Research Jan 2024The free living Acanthamoeba spp. are ubiquitous amoebae associated with potentially blinding disease known as Acanthamoeba keratitis (AK) and a fatal central nervous...
The free living Acanthamoeba spp. are ubiquitous amoebae associated with potentially blinding disease known as Acanthamoeba keratitis (AK) and a fatal central nervous system infection granulomatous amoebic encephalitis (GAE). With the inherent ability of cellular differentiation, it can phenotypically transform to a dormant cyst form from an active trophozoite form. Acanthamoeba cysts are highly resistant to therapeutic agents as well as contact lens cleaning solutions. One way to tackle drug resistance against Acanthamoeba is by inhibiting the formation of cysts from trophozoites. The biochemical analysis showed that the major component of Acanthamoeba cyst wall is composed of carbohydrate moieties such as galactose and glucose. The disaccharide of galactose and glucose is lactose. In this study, we analyzed the potential of lactase enzyme to target carbohydrate moieties of cyst walls. Amoebicidal assessment showed that lactase was ineffective against trophozoite of A. castellanii but enhanced amoebicidal effects of chlorhexidine. The lactase enzyme did not show any toxicity against normal human keratinocyte cells (HaCaT) at the tested range. Hence, lactase can be used for further assessment for development of potential therapeutic agents in the management of Acanthamoeba infection as well as formulation of effective contact lens disinfectants.
Topics: Humans; Lactase; Acanthamoeba castellanii; Galactose; Amebiasis; Amebicides; Contact Lens Solutions; Cysts; Genotype; Glucose; Cell Differentiation
PubMed: 38294565
DOI: 10.1007/s00436-024-08131-2