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Parasites & Vectors Jul 2023Helminth infections are an important public health problem in humans and have an even greater impact on domestic animal and livestock welfare. Current readouts for...
BACKGROUND
Helminth infections are an important public health problem in humans and have an even greater impact on domestic animal and livestock welfare. Current readouts for anthelmintic drug screening assays are stage development, migration, or motility that can be subjective, laborious, and low in throughput. The aim of this study was to apply and optimize a fluorometric technique using resazurin for evaluating changes in the metabolic activity of Ascaris suum third-stage larvae (L3), a parasite of high economic relevance in swine.
METHODS
Ascaris suum L3 were mechanically hatched from 6- to 8-week embryonated and sucrose-gradient-enriched eggs. Resazurin dye and A. suum L3 were titrated in 96-well microtiter plates, and resazurin reduction activity was assessed by fluorometry after 24 h of incubation. Fluorescence microscopy was used to localize the resazurin reduction site within the larvae. Finally, we exposed A. suum L3 to various stress conditions including heat, methanol, and anthelmintics, and investigated their impact on larval metabolism through resazurin reduction activity.
RESULTS
We show that the non-fluorescent dye resazurin is reduced inside vital A. suum L3 to fluorescent resorufin and released into the culture media. Optimal assay parameters are 100-1000 L3 per well, a resazurin concentration of 7.5 µg/ml, and incubation at 37 °C/5% CO for 24 h. An intact L2 sheath around the L3 of A. suum completely prevents the uptake of resazurin, while in unsheathed L3, the most intense fluorescence signal is observed along the larval midgut. L3 exposed to methanol or heat show a gradually decreased resazurin reduction activity. In addition, 24 h exposure to ivermectin at 0.625 µM, mebendazole at 5 µM, and thiabendazole from 10 to 100 µM significantly decreased larval metabolic activity by 55%, 73%, and 70% to 89%, respectively.
CONCLUSIONS
Together, our results show that both metabolic stressors and anthelmintic drugs significantly and reproducibly reduce the resazurin reduction activity of A. suum L3, making the proposed assay a sensitive and easy-to-use method to evaluate metabolic activity of A. suum L3 in vitro.
Topics: Humans; Animals; Swine; Ascaris suum; Methanol; Anthelmintics; Xanthenes; Ascariasis; Larva
PubMed: 37468906
DOI: 10.1186/s13071-023-05871-5 -
International Journal of Surgery Case... Aug 2023Ascariasis is a helminthic infection of humans caused by Ascaris lumbricoides. Intestinal obstruction from ascariasis can result in a rare but severe and often fatal...
INTRODUCTION AND IMPORTANCE
Ascariasis is a helminthic infection of humans caused by Ascaris lumbricoides. Intestinal obstruction from ascariasis can result in a rare but severe and often fatal surgical emergency of intestinal perforation and peritonitis in endemic areas. There have been reports of ascariasis causing Small Bowel Obstruction (SBO) in children in endemic areas but this phenomenon has not been studied in adults. The objective of this study was to describe the case of ascariasis causing SBO in a 25-year-old female.
CASE PRESENTATION
A 25-year-old female from southwest Ethiopia presented with a complaint of intermittent crampy abdominal pain of 02 days duration associated with vomiting of ingested matter of 02 to 03 episodes, progressive abdominal distension and failure to pass feces and flatus. On examination, she was acutely sick looking. She has mild abdominal distention and a hyperactive bowel sound. Subsequently, she was resuscitated, broad spectrum antibiotic started, consent taken & operated. Patient discharged on the 7th postoperative day.
CLINICAL DISCUSSION
There have been reports of Ascariasis causing SBO in endemic areas of the tropics and sub-tropics. SBO secondary to the ascaris ball in an adult is very rare and is relevant to present as it adds key clinical lessons in the consideration as a differential diagnosis, investigation clues and patient management.
CONCLUSION
In a patient presented with symptoms and signs suggestive of bowel obstruction, Ascariasis should be considered as a differential diagnosis for those from endemic areas. The treating physician should have a high index of suspicion.
PubMed: 37437322
DOI: 10.1016/j.ijscr.2023.108486 -
Scientific Reports Jul 2023Soil-transmitted Helminth (STH) infections have been found associated with people living with human immunodeficiency virus (HIV) but little is known about the overall... (Meta-Analysis)
Meta-Analysis
Soil-transmitted Helminth (STH) infections have been found associated with people living with human immunodeficiency virus (HIV) but little is known about the overall burden of STH coinfection in HIV patients. We aimed to assess the burden of STH infections among HIV patients. Relevant databases were systematically searched for studies reporting the prevalence of soil-transmitted helminthic pathogens in HIV patients. Pooled estimates of each helminthic infection were calculated. The odds ratio was also determined as a measure of the association between STH infection and the HIV status of the patients. Sixty-one studies were finally included in the meta-analysis, consisting of 16,203 human subjects from all over the world. The prevalence of Ascaris lumbricoides infection in HIV patients was found to be 8% (95% CI 0.06, 0.09), the prevalence of Trichuris trichiura infection in HIV patients was found to be 5% (95% CI 0.04, 0.06), the prevalence of hookworm infection in HIV patients was found to be 5% (95% CI 0.04, 0.06), and prevalence of Strongyloides stercoralis infection in HIV patients was found to be 5% (95% CI 0.04, 0.05). Countries from Sub-Saharan Africa, Latin America & Caribbean and Asia were identified with the highest burden of STH-HIV coinfection. Our analysis indicated that people living with HIV have a higher chance of developing Strongyloides stercoralis infections and decreased odds of developing hookworm infections. Our findings suggest a moderate level of prevalence of STH infections among people living with HIV. The endemicity of STH infections and HIV status both are partially responsible for the burden of STH-HIV coinfections.
Topics: Animals; Humans; Prevalence; HIV; Soil; HIV Infections; Helminthiasis; Ascariasis; Hookworm Infections; Helminths; Strongyloidiasis; Coinfection; Feces; Ascaris lumbricoides
PubMed: 37422549
DOI: 10.1038/s41598-023-38030-y -
Current Allergy and Asthma Reports Jul 2023Helminth infections modify the natural history of allergic diseases, by either decreasing or increasing their symptoms. Several helminth components are involved in the... (Review)
Review
PURPOSE OF REVIEW
Helminth infections modify the natural history of allergic diseases, by either decreasing or increasing their symptoms. Several helminth components are involved in the increasing of the allergic response and symptoms, overcoming the concomitant immunosuppression of helminthiases. However, the role of individual IgE-binding molecules in this process remains to be defined.
RECENT FINDINGS
We updated the list of helminth allergens and IgE-binding molecules, their effects on asthma presentation, and their impact on allergy diagnosis. Data from genetic and epigenetic studies of ascariasis are analyzed. A new species-specific A. lumbricoides allergen has been discovered, with potential use in molecular diagnosis. Most helminth IgE-binding components are not officially classified as allergens in the WHO/IUIS database, although there is evidence of their influence increasing allergic manifestations. Further immunological characterization of these components is needed to better understand their mechanisms of action and evaluate the ways in which they can influence the diagnosis of allergy.
Topics: Animals; Humans; Allergens; Parasites; Immunoglobulin E; Hypersensitivity; Asthma
PubMed: 37269427
DOI: 10.1007/s11882-023-01089-8