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Nanoscale Advances Feb 2024extract (GME) has severe pharmacokinetic deficiencies and is made up of a variety of bioactive components. GME has proven its anti- effectiveness. In this...
extract (GME) has severe pharmacokinetic deficiencies and is made up of a variety of bioactive components. GME has proven its anti- effectiveness. In this investigation, a GME-loaded niosome was developed to increase its potential therapeutic efficacy. A GME-loaded niosome was prepared by encapsulation in a mixture of span60, cholesterol, and chloroform by the thin film hydration method. The vesicle size, zeta potential, percentage of entrapment efficiency, and stability of GME-loaded niosomes were investigated. The values for GME-loaded niosome size and zeta potential were 404.23 ± 4.59 and -32.03 ± 0.95, respectively. The delivery system enhanced the anti- activity, which possessed MIC values of 0.25-4 mg mL. In addition, the niosomal formulation decreased the toxicity of GME by 16 times. GME-loaded niosome must be stored at 4 °C, as the quantity of remaining GME encapsulated is greater at this temperature than at room temperature. SEM revealed the damage to the cell membrane caused by trophozoites and cysts, which led to dead cells. In light of the above, it was found that GME-loaded niosomes had better anti- activity. The study suggested that GME-loaded niosomes could be used as an alternative to 's therapeutic effects.
PubMed: 38419876
DOI: 10.1039/d3na01016c -
Pathogens (Basel, Switzerland) Feb 2024keratitis (AK) is a severe, rare protozoal infection of the cornea. can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens... (Review)
Review
keratitis (AK) is a severe, rare protozoal infection of the cornea. can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.
PubMed: 38392880
DOI: 10.3390/pathogens13020142 -
The Science of the Total Environment Apr 2024Biofilms, constituting over 95 % of the biomass in drinking water distribution systems, form an ecosystem impacting both the aesthetic and microbiological quality of...
Biofilms, constituting over 95 % of the biomass in drinking water distribution systems, form an ecosystem impacting both the aesthetic and microbiological quality of water. This study investigates the microbiome of biofilms within a real-scale drinking water distribution system in eastern Spain, utilizing amplicon-based metagenomics. Forty-one biofilm samples underwent processing and sequencing to analyze both bacterial and eukaryotic microbiomes, with an assessment of active biomass. Genus-level analysis revealed considerable heterogeneity, with Desulfovibrio, Ralstonia, Bradyrhizobium, Methylocystis, and Bacillus identified as predominant genera. Notably, bacteria associated with corrosion processes, including Desulfovibrio, Sulfuricella, Hyphomicrobium, and Methylobacterium, were prevalent. Potentially pathogenic bacteria such as Helicobacter, Pseudomonas, and Legionella were also detected. Among protozoa, Opisthokonta and Archaeplastida were the most abundant groups in biofilm samples, with potential pathogenic eukaryotes (Acanthamoeba, Naegleria, Blastocystis) identified. Interestingly, no direct correlation between microbiota composition and pipe materials was observed. The study suggests that the usual concentration of free chlorine in bulk water proved insufficient to prevent the presence of undesirable bacteria and protozoa in biofilms, which exhibited a high concentration of active biomass.
Topics: Water Quality; Drinking Water; Microbiota; Bacteria; Biofilms; Water Supply; Water Microbiology
PubMed: 38382601
DOI: 10.1016/j.scitotenv.2024.171086 -
Nucleic Acids Research Apr 2024MicroRNAs (miRNAs) are important and ubiquitous regulators of gene expression in both plants and animals. They are thought to have evolved convergently in these lineages...
MicroRNAs (miRNAs) are important and ubiquitous regulators of gene expression in both plants and animals. They are thought to have evolved convergently in these lineages and hypothesized to have played a role in the evolution of multicellularity. In line with this hypothesis, miRNAs have so far only been described in few unicellular eukaryotes. Here, we investigate the presence and evolution of miRNAs in Amoebozoa, focusing on species belonging to Acanthamoeba, Physarum and dictyostelid taxonomic groups, representing a range of unicellular and multicellular lifestyles. miRNAs that adhere to both the stringent plant and animal miRNA criteria were identified in all examined amoebae, expanding the total number of protists harbouring miRNAs from 7 to 15. We found conserved miRNAs between closely related species, but the majority of species feature only unique miRNAs. This shows rapid gain and/or loss of miRNAs in Amoebozoa, further illustrated by a detailed comparison between two evolutionary closely related dictyostelids. Additionally, loss of miRNAs in the Dictyostelium discoideum drnB mutant did not seem to affect multicellular development and, hence, demonstrates that the presence of miRNAs does not appear to be a strict requirement for the transition from uni- to multicellular life.
Topics: Amoebozoa; Dictyostelium; MicroRNAs; Phylogeny; Evolution, Molecular; RNA, Protozoan; Conserved Sequence; RNA Interference
PubMed: 38375870
DOI: 10.1093/nar/gkae109 -
BMC Veterinary Research Feb 2024Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as "free-living". The...
Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020-2022.
Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as "free-living". The majority of amoebae that infect freshwater or marine fish are amphizoic, or free-living forms that may colonize fish under particular circumstances. Symphysodon aequifasciatus, commonly referred to as the discus, is widely recognized as a popular ornamental fish species. The primary objective of the present study was to determine the presence of pathogenic free-living amoebae (FLA) in samples of discus fish. Fish exhibiting clinical signs, sourced from various fish farms, were transferred to the ornamental fish clinic. The skin, gills, and intestinal mucosa of the fish were collected and subjected to culturing on plates containing a 1% non-nutrient agar medium. The detection of FLA was conducted through morphological, histopathological and molecular methods. The construction of the phylogenetic tree for Acanthamoeba genotypes was achieved using the maximum likelihood approach. The molecular sequence analysis revealed that all cultures that tested positive for FLA were T4 genotype of Acanthamoeba and Acanthamoeba sp. The examination of gill samples using histopathological methods demonstrated the presence of lamellar epithelial hyperplasia, significant fusion of secondary lamellae, and infiltration of inflammatory cells. A multitude of cysts, varying in shape from circular to elliptical, were observed within the gills. The occurrence of interlamellar vesicles and amoeboid organisms could be observed within the epithelial tissue of the gills. In the current study, presence of the Acanthamoeba T4 genotype on the skin and gills of discus fish exhibiting signs of illness in freshwater ornamental fish farms was identified. This observation suggests the potential of a transmission of amoebic infection from ornamental fish to humans, thereby highlighting the need for further investigation into this infection among ornamental fish maintained as pets, as well as individuals who interact with them and their environment.
Topics: Humans; Animals; Amoeba; Phylogeny; Iran; Likelihood Functions; Acanthamoeba; Cichlids
PubMed: 38347572
DOI: 10.1186/s12917-024-03902-6 -
Translational Vision Science &... Feb 2024To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients.
PURPOSE
To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients.
METHODS
This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed.
RESULTS
In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013).
CONCLUSIONS
In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D.
TRANSLATIONAL RELEVANCE
This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
Topics: Humans; Acanthamoeba Keratitis; Phylogeny; Retrospective Studies; Genotype; China
PubMed: 38329750
DOI: 10.1167/tvst.13.2.5 -
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 -
Therapeutic Advances in Infectious... 2024Granulomatous amebic encephalitis, caused by the free-living amebae or species, is a rare and deadly infectious syndrome with a current mortality rate of >90%. Much... (Review)
Review
Granulomatous amebic encephalitis, caused by the free-living amebae or species, is a rare and deadly infectious syndrome with a current mortality rate of >90%. Much work remains to define the optimal treatment for these infections. Here, we provide a comprehensive overview of the supporting evidence behind antimicrobials currently recommended by the Centers for Disease Control and Prevention (CDC) with updated statistics on survival rates and medication usage from the CDC Free-Living Ameba Database. We also discuss promising treatments, especially the emerging therapeutic agent nitroxoline, and provide recommendations for the next steps in this area.
PubMed: 38312848
DOI: 10.1177/20499361241228340 -
Allergology International : Official... Jul 2024Atopic conditions are known to be associated with viral and bacterial infections. The purpose of this study was to determine the relationship between the effects of...
BACKGROUND
Atopic conditions are known to be associated with viral and bacterial infections. The purpose of this study was to determine the relationship between the effects of atopic conditions on the severity and recurrence of ocular infections including herpes simplex virus (HSV).
METHODS
This study was performed on 474 consecutive patients with infectious keratitis caused by bacteria, fungus, acanthamoeba, HSV, or varicella-zoster virus. The relationships between the atopic condition and specific infectious pathogens and HSV were determined using real-time PCR.
RESULTS
Our findings showed that atopic dermatitis (AD) was significantly associated with the incidence of HSV keratitis (odds ratio (OR), 10.2; P = 0.000). Other associations with AD were observed only with bacteria in an adverse manner. HSV proliferation in the lesions of patients with HSV keratitis whose AD was associated with non-infectious atopic blepharitis were significantly greater by 145-folds (P = 0.000). The presence of asthma or allergic rhinitis also increased the HSV DNA copy numbers. A recurrence of HSV keratitis was observed in 70 patients (43.2 %), and mean time to recurrence was 1647 days. Cox proportional hazard model indicated that the epithelial type of HSV recurrence but not the stromal type was associated with atopic conditions especially with AD. The factors significantly associated with a recurrence was AD associated with non-infectious atopic blepharitis (HR: 6.11, P = 0.000) and asthma (HR: 3.03, P = 0.025).
CONCLUSIONS
Atopic conditions, especially AD with atopic blepharitis, are significantly associated with the development, increased proliferation, and shorter time to a recurrence on HSV keratitis.
Topics: Humans; Female; Male; Recurrence; Adult; Middle Aged; Adolescent; Aged; Dermatitis, Atopic; Keratitis; Young Adult; Keratitis, Herpetic; Child; Simplexvirus; Incidence; Child, Preschool; Aged, 80 and over
PubMed: 38310042
DOI: 10.1016/j.alit.2024.01.008 -
Mikrobiyoloji Bulteni Jan 2024Free-living amoebae belonging to the genus Acanthamoeba are microorganisms that live in air, soil and aquatic environments. In humans, they cause infections such as...
Free-living amoebae belonging to the genus Acanthamoeba are microorganisms that live in air, soil and aquatic environments. In humans, they cause infections such as amoebic keratitis, graulamotous amoebic encephalitis that are difficult to treat and can be fatal. In addition, it is known that they contribute to the replication of bacteria and increase their pathogenicity by being a host for various bacteria. However, information on its inhibitory properties against bacteria and its production of antimicrobial agents is very limited. In this context, in this study, it was aimed to investigate whether cell-free supernatants of Acanthamoeba strains have antibacterial effects against Pseudomonas aeruginosa isolates. Four different Acanthamoeba strains (A10, A13, A14, U.GÖL) isolated from aquatic environments in our country were selected and used in the study, P.aeruginosa isolates (PA2, PA3, PA4, PA5) were selected from clinical strains belonging to patients in our country. Acanthamoeba castellanii ATCC 50373 and P.aeruginosa ATCC 27853 were used as standard strains. P.aeruginosa isolates were grown on nutrient agar at 37 °C and Acanthamoeba strains were grown on E.coli spread non-nutrient agar at 30 °C under aerobic conditions. Pepton yeast extract glucose (PYG) medium supplemented with penicillin and streptomycin was used to obtain axenic cultures of Acanthamoeba strains. After the centrifugation of axenic cultures at 3000 rpm for five minutes, Acanthamoeba-cell-free supernatants were obtained by filtering the supernatant part through a sterile filter with a pore diameter of 0.22 µm. The antibacterial activities of these supernatants against P.aeruginosa isolates were determined using the colony counting method. Analysis of each Acanthamoeba-cell-free supernatants was performed according to the GC-MS method. Acanthamoeba-cell-free supernatants were found to have varying degrees of inhibitory effects (3.9-91.5%) against tested P.aeruginosa isolates. It was determined that the cell-free supernatant of A.castellanii ATCC 50373 strain showed the highest antibacterial effect (91.5%) against PA5 isolate. A14 strain showed similar inhibitory effects (89.4%) against the same Pseudomonas isolate. The average inhibitory effect of most of the Acanthamoeba strains of our country was found to be higher than that of the reference strain A.castellanii ATCC 50492. It is thought that the compounds responsible for the anti-Pseudomonas activity of the tested Acanthamoeba strains may be fructose, phosphoric acid, galactose, N-Acetylphenylalanine and glucopyranose determined as major compounds. This is the first study showing the anti-Pseudomonas activity of microorganisms of the genus Acanthamoeba living in the waters of our country. Acanthamoeba, which is widely found in nature, appears to be a good source for new antimicrobial agents.
Topics: Humans; Pseudomonas aeruginosa; Agar; Pseudomonas; Acanthamoeba castellanii; Anti-Bacterial Agents; Escherichia coli
PubMed: 38263942
DOI: 10.5578/mb.20249950