Concept: Liver abscess
Amoebic liver abscess (ALA) is the most common clinical manifestation of extraintestinal amoebiasis especially in developing countries, causing up to 100 000 fatal cases annually. Accurate and early diagnosis is important to prevent the disease complications, however its diagnosis still poses many challenges due to the limitations of the available detection tools. Pyruvate phosphate dikinase (PPDK), an excretory-secretory protein of E. histolytica, has been reported as a potential diagnostic marker for ALA, hence it may be exploited in the development of a new test for ALA.
Amoebic liver abscess (ALA) is the most common extra intestinal manifestation of invasive amoebiasis caused by Entamoeba histolytica. The lack of early and accurate diagnostic test to differentiate various causes of liver abscess necessitates more reliable laboratory diagnostic test. The present study was conducted to assess the applicability of Loop-Mediated Isothermal Amplification (LAMP) assay for detection of E. histolytica in ALA cases. Fifty patients (n = 50) with clinical suspicion of ALA were enrolled in the study. All the clinical samples were subjected to conventional PCR assay. LAMP assay was standardized and the results were compared with that of PCR assay. Out of fifty pus samples thirty-six (72 %, 36/50) were positive for E. histolytica with conventional PCR assay and forty-one (82 %, 41/50) were positive by LAMP assay. Thus, five additional positive cases, missed by conventional PCR were positive with LAMP assay. Apart from rapidity, operational simplicity of LAMP assay high specificity and sensitivity, one-step amplification, higher yield and immediate visual detection may serve as a better diagnostic tool for diagnosis of ALA.
It has been claimed that amoebic molecules such as amoebapore, galactose/N-acetyl galactosamine inhibitable lectin, and cysteine proteases are responsible for host tissue destruction and are present in both pathogenic E. histolytica and non-pathogenic E. dispar. Some reports have provided evidence that after infection with E. dispar, pathological changes may occur in some humans. The aim of this study was to evaluate E. dispar pathogenicity by comparing it to the pathogenicity of E. histolytica through liver abscesses induced in hamsters. Syrian golden hamsters were challenged by intrahepatic inoculation with the 03C E. dispar strain or with two strains of E. histolytica (HM1:IMSS and EGG) to compare their virulence grades. As control groups, we used bacterial flora and Pavlova’s modified medium. Lesions were verified at 1, 3 and 6 days after inoculation. Multiplex Polymerase Chain Reaction was performed to characterize each strain using EdP1/EdP2 and EhP1/EhP2 primers. The EGG and HM1:IMSS E. histolytica strains and 03C E. dispar were able to cause liver lesions. The EGG strain caused extensive hepatic abscesses, and trophozoites were found in the lesions throughout the three periods of study. The HM1:IMSS strain caused smaller abscesses when compared to EGG lesions; however, trophozoites were observed at 1 and 3 days after inoculation. The 03C E. dispar strain caused intermediate abscesses when compared to the others; trophozoites were observed in all periods analyzed. The EGG strain caused progressive evolution of the injury, which differed from the HM1:IMSS and 03C strains. These results strongly suggest that the 03C E. dispar strain is pathogenic in the experimental hamster model. Additional studies are necessary to identify potential factors that regulate the manifestation of virulence of this strain and others.
A 57-year-old man with no significant medical history was admitted to the hospital, with high-grade fever and right upper quadrant pain. He was found, on abdominal ultrasound, to have a right lobe hepatic cystic lesion. MRI of the abdomen confirmed a hepatic abscess. Cultures obtained under CT guidance showed the abscess to be caused by Fusobacterium necrophorum. This is a rare bacterium that can cause potentially fatal liver abscesses. Following drainage and intravenous antibiotic treatment, the patient improved and was discharged on a 4-week antibiotic course. An abdominal CT, performed 6 weeks after discharge, showed total resolution of the abscess. The patient had, 2 weeks prior to the development of the liver abscess, undergone routine dental cleaning. Neither upper respiratory symptoms nor sore throat had been identified prior to the presentation.
We report the first case of a healthy 23-year-old female who underwent an interventional radiology-guided embolization of a hepatic adenoma, which resulted in a gas forming hepatic liver abscess and septicemia byClostridium paraputrificum. A retrospective review of Clostridial liver abscesses was performed using a PubMed literature search, and we found 57 clostridial hepatic abscess cases. The two most commonly reported clostridial species areC. perfringensandC. septicum(64.9% and 17.5% respectively).C. perfringenscases carried a mortality of 67.6% with median survival of 11 h, and 70.2% of theC. perfringenscases experienced hemolysis. AllC. septicumcases were found to have underlying liver malignancy at the time of the presentation with a mortality of only 30%. The remaining cases were caused by variousClostridiumspecies, and this cohort’s clinical course was significantly milder when compared to the aboveC. perfringensandC. septicumcohorts.
To evaluate the risk of pyogenic liver abscess (PLA) in patients receiving endoscopic sphincterotomy (ES).
The neutrophil-to-lymphocyte ratio (NLR) is an effective predictor of mortality in patients with for various conditions. To date, there are no previous studies on NLR as a prognostic marker for pyogenic liver abscess (PLA), especially on admission to the emergency department (ED).
Entamoeba nuttalli is an intestinal protozoan with pathogenic potential that can cause amoebic liver abscess. It is highly prevalent in wild and captive macaques. Recently, cysts were detected in a caretaker of nonhuman primates in a zoo, indicating that E. nuttalli may be a zoonotic pathogen. Therefore, it is important to evaluate the pathogenicity of E. nuttalli in detail and in comparison with that of E. histolytica.
Clinically diagnosed amoebic liver abscess (ALA) caused by Entamoeba histolytica has been an important public health problem in Jaffna district, northern Sri Lanka for last three decades. In order to draw up a control strategy for elimination of this condition, knowledge of its epidemiology and factors associated with this condition in the local context is vital.
Entamoeba histolytica is the causative agent of human amoebiasis; it affects 50 million people worldwide and causes approximately 100,000 deaths per year. Entamoeba histolytica is an anaerobic parasite that is primarily found in the colon; however, for unknown reasons, it can become invasive, breaching the gut barrier and migrating toward the liver causing amoebic liver abscesses. During the invasive process, it must maintain intracellular hypoxia within the oxygenated human tissues and cellular homeostasis during the host immune defense attack when it is confronted with nitric oxide and reactive oxygen species. But how? This review will address the described and potential mechanisms available to counter the oxidative stress generated during invasion and the possible role that E. histolytica’s continuous endoplasmic reticulum (Eh-ER) plays during these events.