Comparative proteomic analysis of metronidazole-sensitive and resistant Trichomonas vaginalis suggests a novel mode of metronidazole action and resistance.

The microaerophilic parasite Trichomonas vaginalis occurs worldwide and causes inflammation of the urogenital tract, especially in women. With 156 million infections annually, trichomoniasis is the most prevalent non-viral sexually transmitted disease. Trichomoniasis is treated with 5-nitroimidazoles, especially metronidazole, which are prodrugs that have to be reduced at their nitro group to be activated.

Evaluating the amoeba thioredoxin reductase selenoprotein as potential drug target for treatment of Acanthamoeba infections.

The genus Acanthamoeba comprises facultative pathogens, causing Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). In both diseases, treatment options are limited, and drug development is challenging. This study aimed to investigate the role of the large thioredoxin reductase selenoprotein of Acanthamoeba (AcTrxR-L) as a potential drug target assessing the effects of the thioredoxin reductase inhibitors auranofin, TRi-1, and TRi-2 on AcTrxR-L activity and on the viability of Acanthamoeba trophozoites.

Proteomics-Based RT-qPCR and Functional Analysis of 18 Genes in Metronidazole Resistance of .

Previously, we reported that metronidazole MICs are not dependent on the expression levels of genes in strains and we compared the proteomes of metronidazole-resistant laboratory strains to those of their susceptible parent strains. Here, we used RT-qPCR to correlate the expression levels of 18 candidate genes in a panel of selected, clinical gene-positive and -negative strains to their metronidazole MICs. Metronidazole MICs were correlated with the expression of certain tested genes.

A Comparison of Bottom-Up Proteomic Sample Preparation Methods for the Human Parasite .

Bottom-up proteomic approaches depend on the efficient digestion of proteins into peptides for mass spectrometric analysis. Sample preparation strategies, based on magnetic beads, filter-aided systems, or in-solution digests, are commonly used for proteomic analysis. Time-intensive methods like filter-aided sample preparation (FASP) have led to the development of new, more time-efficient filter-based strategies like suspension trappings (S-Traps) or magnetic bead-based strategies like SP3.

The effects of identical nim gene-insertion sequence combinations on the expression of the nim genes and metronidazole resistance in Bacteroides fragilis strains.

In this study we examined whether the same nim gene-insertion sequence (IS) element combinations give rise to the same expression levels as they harbor shared IS element-borne promoters. From our quantitative analysis, we found that the expressions of the nimB and nimE genes with their cognate IS elements were similar, but the metronidazole resistance of these strains were more diverse.

Proteomic analysis of metronidazole resistance in the human facultative pathogen .

The anaerobic gut bacteria and opportunistic pathogen can cause life-threatening infections when leaving its niche and reaching body sites outside of the gut. The antimicrobial metronidazole is a mainstay in the treatment of anaerobic infections and also highly effective against spp. Although resistance rates have remained low in general, metronidazole resistance does occur in .

Initial expression levels of nimA are decisive for protection against metronidazole in Bacteroides fragilis.

Objectives: In the genus Bacteroides, the nim genes are resistance determinants for metronidazole, a nitroimidazole drug widely used against anaerobic pathogens. The Nim proteins are considered to act as nitroreductases. However, data from several studies suggest that the expression levels of Nim do not increase with increasing resistance which is conflicting with this notion.

Modulation of Iron Import and Metronidazole Resistance in Harboring a Gene.

is a commensal of the human gut but can also cause severe infections when reaching other body sites, especially after surgery or intestinal trauma. is an anaerobe innately susceptible to metronidazole, a 5-nitroimidazole drug that is prescribed against the majority of infections caused by anaerobic bacteria. In most of the cases, metronidazole treatment is effective but a fraction of .

Transcriptional changes of proteins of the thioredoxin and glutathione systems in Acanthamoeba spp. under oxidative stress - an RNA approach.

The thioredoxin (Trx) and the glutathione (GSH) systems represent important antioxidant systems in cells and in particular thioredoxin reductase (TrxR) has been shown to constitute a promising drug target in parasites. For the facultative protozoal pathogen Acanthamoeba, it was demonstrated that a bacterial TrxR as well as a TrxR, characteristic of higher eukaryotes, mammals and humans is expressed on the protein level. However, only bacterial TrxR is strongly induced by oxidative stress in Acanthamoeba castellanii.

Haemin deprivation renders Bacteroides fragilis hypersusceptible to metronidazole and cancels high-level metronidazole resistance.

Background: Infections with Bacteroides fragilis are routinely treated with metronidazole, a 5-nitroimidazole antibiotic that is active against most anaerobic microorganisms. Metronidazole has remained a reliable treatment option, but resistance does occur, including in B. fragilis.

Characterization of the components of the thioredoxin system in Bacteroides fragilis and evaluation of its activity during oxidative stress.

Objectives: Bacteroides fragilis has a pronounced ability to survive prolonged exposure to atmospheric oxygen. The major objective of this study was to biochemically characterize the components of the thioredoxin system in B. fragilis.

Antimicrobial effect of auranofin against Acanthamoeba spp.

Acanthamoebae are opportunistic pathogens that cause serious infections, including Acanthamoeba keratitis, a sight-threatening disease affecting mainly contact lens wearers, and granulomatous amoebic encephalitis, an infection of the central nervous system that occurs mostly in immunocompromised individuals. Although these infections are rare, they are a challenge for healthcare providers. In the last decade, the search for and implementation of novel treatment approaches against these parasites and the infections they cause have intensified, but current options are still unsatisfactory.

A reassessment of the role of oxygen scavenging enzymes in the emergence of metronidazole resistance in trichomonads.

Trichomonads are an order of parasitic protists which infect a wide range of hosts. The human parasite Trichomonas vaginalis and the bovine parasite Tritrichomonas foetus which also infects cats and swine are of considerable medical and veterinary importance, respectively. Since trichomonads are microaerophiles/anaerobes they are susceptible to 5-nitroimidazoles such as metronidazole.

Recent advances in the molecular biology of the protist parasite .

is an anaerobic/microaerophilic protist parasite which causes trichomoniasis, one of the most prevalent sexually transmitted diseases worldwide. . not only is important as a human pathogen but also is of great biological interest because of its peculiar cell biology and metabolism, in earlier times fostering the erroneous notion that this microorganism is at the root of eukaryotic evolution.

Molecular characterization of metronidazole resistant Bacteroides strains from Kuwait.

Eleven metronidazole resistant Bacteroides and one newly classified Phocaeicola dorei strain from Kuwait were investigated for their resistance mechanisms and the emergence of their resistant plasmids. All but one strain harbored nimE genes on differently sized plasmids. Of the 11 nimE genes, 9 were preceded by full copies of the prototype ISBf6 insertion sequence element, one carried a truncated ISBf6 and one was activated by an additional copy of IS612B.

A powerful qPCR-high resolution melting assay with taqman probe in plasmodium species differentiation.

Background: The use of highly sensitive molecular tools in malaria diagnosis is currently largely restricted to research and epidemiological settings, but will ultimately be essential during elimination and potentially eradication. Accurate diagnosis and differentiation down to species levels, including the two Plasmodium ovale species and zoonotic variants of the disease, will be important for the understanding of changing epidemiological patterns of the disease.

Methods: A qPCR-high resolution melting (HRM) method was to detect and differentiate all human Plasmodium species with one forward and one reverse primer set.

An unusual thioredoxin system in the facultative parasite Acanthamoeba castellanii.

The free-living amoeba Acanthamoeba castellanii occurs worldwide in soil and water and feeds on bacteria and other microorganisms. It is, however, also a facultative parasite and can cause serious infections in humans. The annotated genome of A.

Validation of reference genes for the normalization of RT-qPCR gene expression in Acanthamoeba spp.

Acanthamoebae are potentially pathogenic organisms, with a highly unique, yet still insufficiently investigated metabolism. Many open questions can be addressed by gene expression studies, however, for Acanthamoeba reliable standards have not yet been established. In this study, suitable reference genes (RGs) for RT-qPCR in Acanthamoeba were comprehensively evaluated, comparing different Acanthamoeba strains and employing four different algorithms (NormFinder, GeNorm, BestKeeper and RefFinder).

A novel 5-Plex qPCR-HRM assay detecting human diarrheal parasites.

Background: Intestinal parasitic diseases occur worldwide, and their diagnosis poses considerable challenges. spp., (and, arguably, and spp.

Drug resistance in Giardia: Mechanisms and alternative treatments for Giardiasis.

The use of chemotherapeutic drugs is the main resource against clinical giardiasis due to the lack of approved vaccines. Resistance of G. duodenalis to the most used drugs to treat giardiasis, metronidazole and albendazole, is a clinical issue of growing concern and yet unknown impact, respectively.

Metabolomic Profiling of Wildtype and Transgenic Strains by H HR-MAS NMR Spectroscopy.

, a causative agent of persistent diarrhea in humans, domestic animals, and cattle, is usually treated with nitro compounds. Consequently, enzymes involved in anaerobic nitro reduction have been investigated in detail as potential targets. Their role within the normal metabolic context is, however, not understood.

Identification of the NADH-oxidase gene in Trichomonas vaginalis.

The microaerophilic human parasite Trichomonas vaginalis causes infections in the urogenital tract and is one of the most often sexually transmitted pathogens worldwide. Due to its anaerobic metabolism, it has to quickly remove intracellular oxygen in order to avoid deactivation of essential metabolic enzymes such as oxygen-sensitive pyruvate:ferredoxin oxidoreductase (PFOR). Two major enzyme activities which are responsible for the removal, i.

Activity of methylgerambullin from Glycosmis species (Rutaceae) against Entamoeba histolytica and Giardia duodenalis in vitro.

Entamoeba histolytica and Giardia duodenalis are widespread intestinal protozoan parasites which both spread via cysts that have to be ingested to infect a new host. Their environment, the small intestine for G. duodenalis and the colon for E.

Redox Pathways as Drug Targets in Microaerophilic Parasites.

The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia jointly cause hundreds of millions of infections in humans every year. Other microaerophilic parasites such as Tritrichomonas foetus and Spironucleus spp. pose a relevant health problem in veterinary medicine.

A review on metronidazole: an old warhorse in antimicrobial chemotherapy.

The 5-nitroimidazole drug metronidazole has remained the drug of choice in the treatment of anaerobic infections, parasitic as well as bacterial, ever since its development in 1959. In contrast to most other antimicrobials, it has a pleiotropic mode of action and reacts with a large number of molecules. Importantly, metronidazole, which is strictly speaking a prodrug, needs to be reduced at its nitro group in order to become toxic.