Dataset Information

Different behavior of myeloperoxidase in two rodent amoebic liver abscess models.

ABSTRACT: The protozoan Entamoeba histolytica is the etiological agent of amoebiasis, which can spread to the liver and form amoebic liver abscesses. Histological studies conducted with resistant and susceptible models of amoebic liver abscesses (ALAs) have established that neutrophils are the first cells to contact invasive amoebae at the lesion site. Myeloperoxidase is the most abundant enzyme secreted by neutrophils. It uses hydrogen peroxide secreted by the same cells to oxidize chloride ions and produce hypochlorous acid, which is the most efficient microbicidal system of neutrophils. In a previous report, our group demonstrated that myeloperoxidase presents amoebicidal activity in vitro. The aim of the current contribution was to analyze in vivo the role of myeloperoxidase in a susceptible (hamsters) and resistant (Balb/c mice) animal models of ALAs. In liver samples of hamsters and mice inoculated intraportally with Entamoeba histolytica trophozoites, the number of neutrophils in ALAs was determined by enzymatic activity. The presence of myeloperoxidase was observed by staining, and its expression and activity were quantified in situ. A significant difference existed between the two animal models in the number of neutrophils and the expression and activity of myeloperoxidase, which may explain the distinct evolution of amoebic liver abscesses. Hamsters and mice were treated with an MPO inhibitor (4-aminobenzoic acid hydrazide). Hamsters treated with ABAH showed no significant differences in the percentage of lesions or in the percentage of amoebae damaged compared with the untreated hamsters. ABAH treated mice versus untreated mice showed larger abscesses and a decreased percentage of damaged amoebae in these lesion at all stages of evolution. Further studies are needed to elucidate the host and amoebic mechanisms involved in the adequate or inadequate activation and modulation of myeloperoxidase.

SUBMITTER: Cruz-Baquero A

PROVIDER: S-EPMC5552100 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Different behavior of myeloperoxidase in two rodent amoebic liver abscess models.

Cruz-Baquero Andrea A Cárdenas Jaramillo Luz María LM Gutiérrez-Meza Manuel M Jarillo-Luna Rosa Adriana RA Campos-Rodríguez Rafael R Rivera-Aguilar Víctor V Miliar-García Angel A Pacheco-Yepez Judith J

PloS one 20170810 8

The protozoan Entamoeba histolytica is the etiological agent of amoebiasis, which can spread to the liver and form amoebic liver abscesses. Histological studies conducted with resistant and susceptible models of amoebic liver abscesses (ALAs) have established that neutrophils are the first cells to contact invasive amoebae at the lesion site. Myeloperoxidase is the most abundant enzyme secreted by neutrophils. It uses hydrogen peroxide secreted by the same cells to oxidize chloride ions and prod ...[more]

PMID: 28796788

Similar Datasets

Project description:BackgroundInfection with Entamoeba histolytica and associated complications are relatively rare in developed countries. The overall low prevalence in the Western world as well as the possibly prolonged latency period between infection with the causing pathogen and onset of clinical symptoms may delay diagnosis of and adequate treatment for amoebiasis. Amoebic liver abscess (ALA) is the most common extraintestinal manifestation of invasive amoebiasis. Pregnancy has been described as a risk factor for development of invasive amoebiasis and management of these patients is especially complex.Case presentationA 30-year-old Caucasian woman in early pregnancy presented to our emergency department with abdominal pain alongside elevated inflammatory markers and liver function tests. Travel history revealed multiple journeys to tropic and subtropic regions during the past decade and a prolonged episode of intermittently bloody diarrhea during a five month stay in Indonesia seven years prior to admission. Sonographic and magnetic resonance imaging revealed a 5?×?4 cm hepatic abscess. After ultrasound-guided transcutaneous liver drainage, both abscess fluids and blood cultures showed neither bacterial growth nor microscopic signs of parasitic disease. Serological testing confirmed an infection with Entamoeba histolytica, which was treated with metronidazole, followed by eradication therapy with paromomycin. Subsequent clinical, laboratory and imaging follow-up exams showed regression of the ALA. In addition, the pregnancy completed without complications and a healthy baby boy was born 7 months after termination of treatment.ConclusionsThis case of invasive amoebiasis in early pregnancy outside of endemic regions and several years after exposure demonstrates the importance of broad differential diagnostics in the context of liver abscesses. The complex interdisciplinary decisions regarding the choice of imaging techniques as well as interventional and antibiotic therapy in the context of pregnancy are discussed. Furthermore, we present possible explanations for pregnancy as a risk factor for an invasive course of amoebiasis.

Project description:BACKGROUND:Since 1985, amoebic liver abscess (ALA) has been a public health problem in northern Sri Lanka. Clinicians arrive at a diagnosis based on clinical and ultrasonographic findings, which cannot differentiate pyogenic liver abscess (PLA) from ALA. As the treatment and outcome of the ALA and PLA differs, determining the etiological agent is crucial. METHODS:All clinically diagnosed ALA patients admitted to the Teaching Hospital (TH) in Jaffna during the study period were included and the clinical features, haematological parameters, and ultrasound scanning findings were obtained. Aspirated pus, blood, and faecal samples from patients were also collected. Pus and faeces were examined microscopically for amoebae. Pus was cultured in Robinson's medium for amoebae, and MacConkey and blood agar for bacterial growth. ELISA kits were used for immunodiagnosis of Entamoeba histolytica infection. DNA was extracted from selected pus samples and amplified using nested PCR and the purified product was sequenced. RESULTS:From July 2012 to July 2015, 346 of 367 clinically diagnosed ALA patients admitted to Jaffna Teaching Hospital were enrolled in this study. Almost all patients (98.6%) were males with a history of heavy alcohol consumption (100%). The main clinical features were fever (100%), right hypochodric pain (100%), tender hepatomegaly (90%) and intercostal tenderness (60%). Most patients had leukocytosis (86.7%), elevated ESR (85.8%) and elevated alkaline phosphatase (72.3%). Most of the abscesses were in the right lobe (85.3%) and solitary (76.3%) in nature. Among the 221 (63.87%) drained abscesses, 93.2% were chocolate brown in colour with the mean volume of 41.22?±?1.16 ml. Only four pus samples (2%) were positive for amoeba by culture and the rest of the pus and faecal samples were negative microscopically and by culture. Furthermore, all pus samples were negative for bacterial growth. Antibody against E. histolytica (99.7%) and the E. histolytica antigen were detected in the pus samples (100%). Moreover, PCR and sequencing confirmed these results. CONCLUSION:To our knowledge, this is the first report from Sri Lanka that provides immunological and molecular confirmation that Entamoeba histolytica is a common cause of liver abscesses in the region.

Dataset Information

Different behavior of myeloperoxidase in two rodent amoebic liver abscess models.

Publications

Different behavior of myeloperoxidase in two rodent amoebic liver abscess models.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets