Detection of Entamoeba histolytica in experimentally induced amoebic liver abscess: comparison of three staining methods

Studies on the Probiotic, Adhesion, and Induction Properties of Artisanal Lactic Acid Bacteria: to Customize a Gastrointestinal Niche to Trigger Anti-obesity Functions

The primary goals of this work are to explore the potential of probiotic lactic acid bacteria's (LAB) mucin/mucus layer thickening properties and to identify anti-obesity candidate strains that improve appropriate habitat for use with the Akkermansia group population in the future. The HT-29 cell binding, antimicrobial properties, adhesion to the mucin/mucus layer, growth in the presence of mucin, stability during in vitro gastrointestinal (GI) conditions, biofilm formation, and mucin/mucus thickness increment abilities were all assessed for artisanal LAB strains. Sixteen LAB strains out of 40 were chosen for further analysis based on their ability to withstand GI conditions. Thirteen strains remained viable in simulated intestinal fluid, while most showed high viability in gastric juice simulation. Furthermore, 35.9-65.4% of those 16 bacteria adhered to the mucin layer. Besides, different lactate levels were produced, and Streptococcus thermophilus UIN9 exhibited the highest biofilm development. In the HT-29 cell culture, the highest mucin levels were 333.87 µg/mL with O. AK8 at 50 mM lactate, 313.38 µg/mL with Lactobacillus acidophilus NRRL-B 1910 with initial mucin, and 311.41 µg/mL with Lacticaseibacillus casei NRRL-B 441 with initial mucin and 50 mM lactate. Nine LAB strains have been proposed as anti-obesity candidates, with olive isolates of Lactiplantibacillus plantarum being particularly important due to their ability to avoid mucin sugar consumption. Probiotic LAB's attachment to the colonic mucosa and its ability to stimulate HT-29 cells to secrete mucus are critical mechanisms that may support the development of Akkermansia.

Diversity and Plasticity of Virulent Characteristics of Entamoeba histolytica

The complexity of clinical syndromes of amebiasis, caused by the parasite Entamoeba histolytica, stems from the intricate interplay between the host immune system, the virulence of the invading parasite, and the surrounding environment. Although there is still a relative paucity of information about the precise relationship between virulence factors and the pathogenesis of Entamoeba histolytica, by accumulating data from clinical and basic research, researchers have identified essential pathogenic factors that play a critical role in the pathogenesis of amebiasis, providing important insights into disease development through animal models. Moreover, the parasite's genetic variability has been associated with differences in virulence and disease outcomes, making it important to fully understand the epidemiology and pathogenesis of amebiasis. Deciphering the true mechanism of disease progression in humans caused by this parasite is made more difficult through its ability to demonstrate both genomic and pathological plasticity. The objective of this article is to underscore the heterogeneous nature of disease states and the malleable virulence characteristics in experimental models, while also identifying persistent scientific issues that need to be addressed.

Lead induced disorders of lipid metabolism and glycometabolism in the liver of developmental Japanese quails (Coturnix japonica) via inhibiting PI3K/Akt signaling pathway

The lead (Pb) contamination is considered a lethal threat to birds. However, Pb-induced hepatotoxicology especially its impacts on metabolic processes in the liver of birds is not yet fully understood. Therefore, we tried to determine the toxicological effects of Pb exposure on hepatic carbohydrate and lipid metabolism via Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway by using an animal model- Japanese quail (Coturnix japonica). One-week old female Japanese quails were randomly allocated into four groups and fed with 0, 50 ppm, 500 ppm and 1000 ppm Pb drinking water respectively for 49 days. The results showed that Pb accumulated in the liver as a dose-dependent manner. Exposure to high dose of Pb (500 and 1000 ppm Pb) led to severe histopathological damages characterized by irregularity and dilation of liver sinusoids, hepatic lipid vacuolization and hepatocellular cytoplasm hyalinization. Meanwhile, Pb exposure caused glycogen increase and lipid droplets decrease in the liver. Pb exposure was also attributable to a decreased triglyceride level in the plasma. In addition, the transcriptional levels of PI3K and Akt in the liver were downregulated by Pb exposure. Subsequently, the mRNA expressions of genes related with glycometabolism in the liver were remarkably altered and the mRNA levels of genes involved in fat synthesis and oxidation in the liver were also markedly changed. it seems that Pb could lead to liver metabolic disorder through structural damages and PI3K/Akt signaling pathway disruption.

Entamoeba histolytica and Probable Effect on Production Microsatellite Instability in Colorectal Cancer

The mortality rate of Entamoeba histolytica is still high and approximately 100,000 per year. Environmental factors and different pathogens can cause microsatellite instability (MSI) positive, which may be one reason for colorectal cancer. MSI status can play an essential role in treatment. Moreover, E. histolytica might be one of the pathogens which raise the incidence of colorectal cancer. Therefore, the probable relationship of E. histolytica with MSI production was evaluated. Four hundred samples of colorectal biopsies based on pathological reports were divided into four groups: colitis, polyps, hyperplasia or dysplasia, and adenocarcinoma. The prevalence of E. histolytica was examined with PCR and immunohistochemical staining (IHC) for the light chain lectin HK-9. The adenocarcinoma formalin-fixed paraffin-embedded colorectal tumours sections were tested for MSI genes. We detected E. histolytica in 6% and 4% of colitis samples by PCR and IHC technique, respectively. However, it did not identify in polyp and hyperplasia samples. The MSI test was examined in the colorectal cancer group, which became positive in 19%. Entamoeba histolytica was detected in 26.3% (5/19) of MSI-positive and 2.5% (2/81) of MSI-negative cases by IHC technique however was not identified by PCR assay in this group. It is concluded PCR and IHC assay is recommended as complementary tests in colitis biopsies. Simultaneous PCR and IHC negative results could confirm the non-existence of the parasite with more confidence. Consequently, E. histolytica might be one of the biotic  factors which raise the incidence of colorectal cancer because of the coincidence of the IHC positive results in MSI-positive adenocarcinoma.

Histologic features of colonic infections

Background

The histopathologic diagnosis of infectious colitis remains relevant despite recent advances in microbiologic techniques.

Objective

This article aims to describe the histologic features of selected infectious diseases of the colon.

Materials and methods

Existing reports on histopathologic and clinical aspects of colonic infectious agents were reviewed.

Results

While histology alone may not be as sensitive as current microbiologic methods, tissue identification of infectious agents still plays an important role in patient care. Infectious colitis can have a variety of clinical manifestations, ranging from strongyloidiasis, which can cause a smoldering, subclinical infection for decades, to syphilis, which can clinically mimic cancer or inflammatory bowel disease. Therefore, the histopathologic identification of infection as the cause of a patient’s colitis has a considerable impact on treatment decisions. Morphologic overlap can occur between infection and other diseases, however. Moreover, some infections can elicit various tissue responses beyond acute colitis. Immunosuppressed patients may not mount an inflammatory response to pathogens such as cytomegalovirus or adenovirus. Sexually transmitted proctocolitis can cause plasma-cell-rich inflammation. Gastrointestinal histoplasmosis is more likely to cause diffuse histiocyte infiltration rather than the expected granuloma formation. In some cases, ancillary tests are useful, but equivocal results can cause diagnostic dilemmas.

Conclusion

Given the range with which colonic infectious disorders can manifest, pathologists should be aware of the typical features of infectious colitis, as well as findings beyond the classic morphologies.

Immune Response to the Enteric Parasite Entamoeba histolytica

Entamoeba histolytica is a protozoan parasite responsible for amoebiasis, a disease with a high prevalence in developing countries. Establishing an amoebic infection involves interplay between pathogenic factors for invasion and tissue damage, and immune responses for protecting the host. Here, we review the pathogenicity of E. histolytica and summarize the latest knowledge on immune response and immune evasion mechanisms during amoebiasis.

Anti-Tumor Effect of Celastrol on Hepatocellular Carcinoma by the circ_SLIT3/miR-223-3p/CXCR4 Axis

Background

Celastrol is a potential anti-tumor agent in hepatocellular carcinoma (HCC). Identifying the molecular determinants of the anti-HCC effect of celastrol is still challenging. In this study, we undertook to associate circular RNAs (circRNAs) with the anti-HCC molecular determinants of celastrol.

Methods

Cell colony formation, proliferation, migration, invasion and apoptosis were determined using the colony formation, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTS), transwell and flow cytometry assays, respectively. The levels of circRNA slit guidance ligand 3 (circ_SLIT3), miR-223-3p and C-X-C motif chemokine receptor 4 (CXCR4) were gauged by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Ribonuclease R (RNase R) and actinomycin D assays were performed to assess the stability of circ_SLIT3. Targeted relationships among circ_SLIT3, miR-223-3p and CXCR4 were confirmed by the dual-luciferase reporter assay. In vivo assays were performed to detect the roles of celastrol and circ_SLIT3 on tumor growth in vivo.

Results

Celastrol repressed HCC cell proliferation, migration, invasion, and enhanced apoptosis in vitro and suppressed tumor growth in vivo. Celastrol down-regulated circ_SLIT3 expression in HCC cells, and celastrol exerted an anti-tumor effect on HCC in vitro and in vivo by down-regulating circ_SLIT3. Mechanistically, circ_SLIT3 directly interacted with miR-223-3p, and circ_SLIT3 controlled CXCR4 expression by sponging miR-223-3p. Moreover, miR-223-3p was involved in the celastrol/circ_SLIT3-mediated regulation on HCC progression. Furthermore, celastrol exerted the anti-HCC effect in vitro through the miR-223-3p/CXCR4 axis.

Conclusion

Our present work first identified the circ_SLIT3/miR-223-3p/CXCR4 axis as a novel mechanism of the anti-HCC effect of celastrol, providing a new insight into the involvement of circRNAs in the anti-tumor molecular determinants of celastrol.

Iron-modulated virulence factors of Entamoeba histolytica

Entamoeba histolytica is a human parasite that causes amoebiasis, a disease that affects the colon and liver and is prevalent worldwide. This protozoan requires a high concentration of iron to survive and reproduce. Iron modulates the expression of parasite virulence factors, including hemoglobinases, hemoglobin-binding proteins and cysteine proteases, as well as proteins related to the amoebic cytoskeleton. This review summarizes the virulence factors that are affected by iron, resulting in upregulation or downregulation of E. histolytica genes. This review also discusses the functionality of iron in the mechanisms of pathogenesis.

Amoeboma in a Saudi resident: a case report

Introduction:

Amoebiasis is the third most frequent cause of mortality after malaria and schistosomiasis. In developed countries, amebiasis is also seen in migrants who have travelled to endemic areas. The factors responsible for its progression from intestinal amebiasis to an amebic liver abscess are not fully understood.

Case presentation:

A 54-year-old man presented with abdominal pain, fever and diarrhoea. Laparotomy confirmed an inflammatory mass involving the right colon, and he underwent a right hemicolectomy. He later developed abdominal distenstion due to an amoebic liver abscess and died from secondary nosocomial bacterial infection and surgical complications.

Conclusion:

Amoeboma is an uncommon manifestation of amoebiasis, and can mimic both carcinoma and inflammatory bowel disease; so, distinguishing between these two conditions is the key to providing appropriate therapy. Hepatic amoebiasis is the most common extraintestinal disease of invasive amoebiasis. This clinical report presents a case of an uncommon parasitic disease in Saudi Arabia and discusses the difficulties encountered while attempting to establish the correct diagnosis. Hence, a high index of suspicion is crucial for diagnosing Entamoeba histolytica to avoid unnecessary surgery and further complications.

Development of loop-mediated isothermal amplification for rapid detection of Entamoeba histolytica

OBJECTIVE

To develop a loop-mediated isothermal amplification (LAMP) assay for the detection of Entamoeba histolytica E. histolytica, the causative agent of amebiasis.

METHODS

The LAMP primer set was designed from E. histolytica hemolysin gene HLY6. Genomic DNA of E. histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions. Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.

RESULTS

Positive LAMP reactions turned turbid while negative ones remained clear. Upon addition of a fluorescent dye, all positive reactions turned green while the negative control remained orange under ambient light. After electrophoresis in 1.5% agarose gels, a ladder of multiple bands of different sizes can be observed in positive samples while no bands were detected in the negative control. The sensitivity of the assay was found to be 5 parasites per reaction which corresponds to approximately 15.8 ng/μ L DNA. The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species, Entamoeba dispar 39, and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.

CONCLUSIONS

The LAMP assay we have developed enables the detection of E. histolytica with rapidity and ease, therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.