Metronidazole

1986 ◽  
Vol 7 (10) ◽  
pp. 514-518 ◽  
Author(s):  
Mark Eggleston

Metronidazole was introduced to the market in 1959 as the only effective therapy for Trichomonas vaginalis. A nitroimidazole derivative, its success in the therapy of parasitic infections, including Entamoeba histolytica and Giardia lamblia, has been well documented. Metronidazole's activity against anaerobic bacteria was first described in 1962 by Shinn, and by Davies and associates in 1964. In both reports, metronidazole effectively treated patients with Vincent's angina (necrotizing ulcerative gingivitis). Metronidazole's excellent activity against anaerobes has been substantiated by numerous articles. It has the best bactericidal activity of all drugs active against anaerobic bacteria.

2020 ◽  
Vol 27 ◽  
Author(s):  
Antonio Moreno-Herrera ◽  
Sandra Cortez-Maya ◽  
Virgilio Bocanegra-Garcia ◽  
Bimal Krishna Banik ◽  
Gildardo Rivera

: Infections caused by Trypanosoma brucei, Trypanosoma cruzi, Leishmania spp., Entamoeba histolytica, Giardia lamblia, Plasmodium spp., and Trichomonas vaginalis, are part of a large list of human parasitic diseases. Together, they cause more than 500 million infections per year. These protozoa parasites affect both low- and high-income countries and their pharmacological treatment is limited. Therefore, new and more effective drugs in preclinical development could improve overall therapy for parasitic infections even when their mechanisms of action are unknown. In this review, a number of heterocyclic compounds (diamidine, guanidine, quinoline, benzimidazole, thiazole, diazanaphthalene, and their derivatives) reported as antiprotozoal agents are discussed as options for developing new pharmacological treatments for parasitic diseases.


Author(s):  
Jon E. Rosenblatt ◽  
Bobbi S. Pritt

This chapter covers protozoa, helminths, and arthropods. 1. Protozoa are single-celled, microscopic eukaryotic organisms like amebae and Giardia. Helminths are parasitic worms including nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). Arthropods, like ticks and mites, are generally considered parasites. Specific organisms reviewed include Giardia lamblia, Cyclospora cayetanensis, Blastocystis hominis, Entamoeba histolytica, Plasmodium falciparum, Babesia microti, and Toxoplasma gondii. Diagnosis and treatment of different types of infection are also reviewed.


Author(s):  
Joel H. Elizondo-Luévano ◽  
Oscar A. Pérez-Narváez ◽  
Eduardo Sánchez-García ◽  
Rocío Castro-Ríos ◽  
Magda E. Hernández-García ◽  
...  

Background: Parasitic infections represent one of the main public health problems in humans according to the WHO. Therefore, the need has arisen to find new treatments that can be used as an alternative cure to parasitosis. We aimed to investigate the in-vitro effects of the methanolic extract of Kalanchoe daigremontiana as well as its main component, quercetin against Entamoeba histolytica and Trichomonas vaginalis. Methods: For this purpose, the in-vitro activity of the methanol extract of K. daigremontiana also its main component, quercetin, against trophozoites of E. histolytica and T. vaginalis was evaluated, using the microassay technique. Furthermore, the antioxidant activity was determined. Finally, the cytotoxic and cytoprotective capacity was determined using the hemolysis technique. Results: The IC50 indicated that quercetin significantly (P < 0.05) inhibited the growth rate of the trophozoite stage of E. histolytica and T. vaginalis in comparison to the methanolic extract of K. daigremontiana (KalL). Also, quercetin significantly (P < 0.05) was a better antioxidant as compared with the positive control. In the evaluation of cytotoxicity effects, it could be observed that KalL as compared with quercetin exhibited more cytotoxicity against human erythrocytes. Quercetin significantly (P < 0.001) exhibited better cytoprotective activity compared to KalL. Conclusion: Both K. daigremontiana methanolic extract and quercetin alone demonstrated high antiparasitic activity against E. histolytica and T. vaginalis. However, the in-vivo efficacy of K. daigremontiana and quercetin also requires to be evaluated using an animal model.


2008 ◽  
Vol 53 (2) ◽  
pp. 458-464 ◽  
Author(s):  
Dibyarupa Pal ◽  
Sulagna Banerjee ◽  
Jike Cui ◽  
Aaron Schwartz ◽  
Sudip K. Ghosh ◽  
...  

ABSTRACT Infections with Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis, which cause diarrhea, dysentery, and vaginitis, respectively, are each treated with metronidazole. Here we show that Giardia, Entamoeba, and Trichomonas have oxygen-insensitive nitroreductase (ntr) genes which are homologous to those genes that have nonsense mutations in metronidazole-resistant Helicobacter pylori isolates. Entamoeba and Trichomonas also have nim genes which are homologous to those genes expressed in metronidazole-resistant Bacteroides fragilis isolates. Recombinant Giardia, Entamoeba, and Trichomonas nitroreductases used NADH rather than the NADPH used by Helicobacter, and two recombinant Entamoeba nitroreductases increased the metronidazole sensitivity of transformed Escherichia coli strains. Conversely, the recombinant nitroimidazole reductases (NIMs) of Entamoeba and Trichmonas conferred very strong metronidazole resistance to transformed bacteria. The Ehntr1 gene of the genome project HM-1:IMSS strain of Entamoeba histolytica had a nonsense mutation, and the same nonsense mutation was present in 3 of 22 clinical isolates of Entamoeba. While ntr and nim mRNAs were variably expressed by cultured Entamoeba and Trichomonas isolates, there was no relationship to metronidazole sensitivity. We conclude that microaerophilic protists have bacterium-like enzymes capable of activating metronidazole (nitroreductases) and inactivating metronidazole (NIMs). While Entamoeba and Trichomonas displayed some of the changes (nonsense mutations and gene overexpression) associated with metronidazole resistance in bacteria, these changes did not confer metronidazole resistance to the microaerophilic protists examined here.


2019 ◽  
Author(s):  
Araya Gebreyesus Wasihun ◽  
Mekonen Teferi ◽  
Letemichal Negash ◽  
Javier Marugán ◽  
Dejen Yemane ◽  
...  

AbstractBackgroundIntestinal parasitic infections (IPIs) and anaemia are major health problems. This study assessed the prevalence of IPI, anaemia and associated factors among pre-school children in rural areas of the Tigray region, northern Ethiopia.Methodology/Principal FindingA community based cross-sectional study was conducted among 610 pre-school children in rural communities of Northern Ethiopia from June 2017 to August 2017. Stool specimens were examined for the presence of trophozoites, cysts, oocysts, and ova using direct, formal-ethyl acetate concentration, Kato–Katz, and Ziehl-Neelsen techniques. Haemoglobin was measured using a HemoCue spectrometer. Among the 610 pre-school children participated in the study, prevalence of IPIs and anaemia were 58% (95% CI: 54.1–61.9%) and 21·6% (95% CI: 18·5% to 25·1%), respectively. Single, double, and triple parasitic infections were seen in 249 (41%, 95% CI: 37% to 45%), 83 (14%, 95% CI: 11% to 17%), and 22 (3.6%, 95% CI: 2.4% to 5.4%) children, respectively. Of the seven intestinal parasitic organisms recorded from the participants,Entamoeba histolytica/disparwas the most prevalent 220 (36.1%) followed byGiardia lamblia128 (20.1%), andHymenolepis nana102 (16.7%). Mixed infections were common amongG. lamblia, E. histolytica/disparandCryptosporidiumspp. oocyst. Age 48-59 months prevalence ratio (PR = 1·078, P=0·009), child deworming (PR= 1.2; 95% CI=1.00-1.4, p= 0.045), and having two or more children aged under five (PR=0.76, 95% CI= 0.61-0.95, p=0.015) were independent predictors for IPIs. Anaemia was associated with proper disposal of solid waste (PR= 1.5, 95% CI=0.1.1-2.10, p=0.009). Eating raw meat (PR=0.49, 95% CI=0.45-0.54, p=0.000), any maternal education (PR=0.64 95% CI=0.52-0.79, p=0.000), and household water treatment (PR=0.75, 95% CI=0.56-1.0, p=0.044) were associated with lower prevalence of anaemia.ConclusionsMore than half of the children were infected with intestinal parasites and one in five were anaemic. This study has identified a number of potentially modifiable risk factors to address the significant prevalence of IPIs and anaemia in these children. Improvements in sanitation, clean water, hand hygiene, maternal education could address both short and long-term consequences of these conditions in this vulnerable population.Author SummaryIntestinal parasitic infection and anaemia are public health problems in developing counties. Children due to their immature immune systems and frequent exposure to unhygienic environments are at high risk which in turn put them at an increased risk of malnutrition and growth deficits. Similarly, childhood anaemia impairs physical growth, impairs immune function and weakens motor development. The finding of this study reveals more than half of the children were infected.Entamoeba histolytica/dispar, Giardia lambliaandHymenolepis nanawere dominant parasites. Multiple infections was common amongGiardia lamblia, Entamoeba histolytica/disparandCryptosporidiumspp. Oocyst. Children aged 48-59 months were more infected with intestinal parasites. Soli transmitted helminths in this study was low. 21.5% of the children were anaemic and was associated with disposal of solid waste and presence of domestic animals. However, Eating raw meat, maternal education and household water treatment were found preventive of anaemia in the study. It seems worth understanding the prevalence and effects of parasitic infection and anaemia in this vulnerable group to design an appropriate interventions. Finally, if parasite transmission and anaemia is to be significantly prevented control programs such as improving sanitation, clean water, maternal education may be critical in this vulnerable age groups.


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