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Acta Tropica Mar 2024Strongyloidiasis, caused by the nematode Strongyloides stercoralis, remains a threat to global public health, and a vaccine would be useful to control the disease,...
Strongyloidiasis, caused by the nematode Strongyloides stercoralis, remains a threat to global public health, and a vaccine would be useful to control the disease, especially in developing countries. This study aimed to evaluate the efficacy of recombinant proteins, A133 and Ss-IR, as potential vaccine candidates against strongyloidiasis by investigating the humoral and cellular immune responses in immunized mice. Respective antigens were adjuvanted with Complete Freund's Adjuvant (prime) and Incomplete Freund's Adjuvant (boost) and administered intraperitoneally (prime) and subcutaneously (boost) to female BALB/c mice. For antigen-only doses, only antigens were injected without adjuvants. Altogether, 1 prime dose, 4 booster doses, and 2 antigen-only doses were administered successively. ELISAs were conducted to assess the antibody responses, along with flow cytometry and cytokine ELISA to elucidate the cellular immune responses. Results showed that A133 and Ss-IR induced the production of IgG1 and IgG2a, with A133 generating more robust IgG2a responses than Ss-IR. Flow cytometry findings indicated that effector CD8T-cells and memory B-cells activity were upregulated significantly for A133 only, whereas cytokine ELISA demonstrated that a Th1/Th2/Th17 mixed cell responses were triggered upon vaccination with either antigen. This preliminary study illustrated the good potential of recombinant A133 and Ss-IR as vaccine candidates against S. stercoralis. It provided information on the probable immune mechanism involved in host defence and the elicitation of protection against S. stercoralis.
Topics: Female; Animals; Mice; Strongyloides stercoralis; Immunoglobulin G; Strongyloidiasis; Immunization; Vaccination; Adjuvants, Immunologic; Cytokines; Vaccines; Mice, Inbred BALB C
PubMed: 38246399
DOI: 10.1016/j.actatropica.2024.107122 -
Parasitology Research Jan 2024Strongyloidiasis is a neglected tropical disease caused mainly by Strongyloides stercoralis, a nematode that can persist for decades in the human host with a very low...
Strongyloidiasis is a neglected tropical disease caused mainly by Strongyloides stercoralis, a nematode that can persist for decades in the human host with a very low parasitic burden and without specific symptoms. Hence, it is difficult to diagnose and control. Larval concentration and culture methods with fecal samples show higher sensitivity for the diagnosis of Strongyloides-infected individuals; however, these techniques are not routinely used, primarily due to the challenges associated with processing a substantial volume of fecal samples. In the current study, we comparatively evaluated the sensitivity and applicability of modifications made to the Rugai parasitological method for the diagnosis of strongyloidiasis in fecal samples of experimentally infected rats and in 68 individuals from an urban community close to Maceió, Brazil. The presence and quantity of parasite larvae in the feces were comparatively evaluated using different parasitological techniques. In the experimental model, we demonstrated that the modified Rugai technique (RMOD) allowed for significantly higher recovery of larvae than the original Rugai technique (RO). Moreover, the sediment was cleaner and easier to evaluate using optical microscopy. Compared to other parasitological techniques, such as agar-plate culture (A-PC) and spontaneous sedimentation (SS), the RMOD technique showed higher sensitivity in the detection of larvae in all infected groups and presented comparatively better performance, especially in rats with a low parasite burden. In the human population, among the 68 stool samples evaluated, Strongyloides larvae were detected in the feces of six individuals with an estimated prevalence of 8.82%. However, the performance of each parasitological method was remarkably different. SS identified Strongyloides larvae in only two individuals and A-PC in three, whereas RMOD was able to identify six infected individuals, resulting in sensitivities of 33.3%, 50%, and 100%, respectively. In conclusion, the modifications introduced to the Rugai technique resulted in improved sensitivity for the detection of Strongyloides spp. infections, especially in stool samples with a low parasite burden, in comparison with other routinely used parasitological techniques.
Topics: Humans; Rats; Animals; Strongyloidiasis; Sensitivity and Specificity; Strongyloides stercoralis; Agar; Feces; Larva
PubMed: 38233532
DOI: 10.1007/s00436-023-08111-y -
Parasites & Vectors Jan 2024Strongyloidiasis is a neglected tropical disease (NTD) that is caused mainly by Strongyloides stercoralis, with an estimated 600 million people infected worldwide, and...
BACKGROUND
Strongyloidiasis is a neglected tropical disease (NTD) that is caused mainly by Strongyloides stercoralis, with an estimated 600 million people infected worldwide, and in fewer cases by Strongyloides fuelleborni fuelleborni and Strongyloides fuelleborni kellyi. A number of studies have been conducted on the genetic diversity of S. stercoralis in East and Southeast Asia; however, there is very limited corresponding information from West Asian countries, including Iran.
METHODS
For Strongyloides worms collected from patients in southwestern Iran, the hypervariable regions I (HVR-I) and IV (HVR-IV) of the nuclear 18S ribosomal DNA (rDNA) locus (SSU) and a fragment of the subunit 1 mitochondrial cytochrome c oxidase gene (cox-1) were sequenced. For a subset of the worms, whole-genome sequencing data were generated.
RESULTS
The cox-1 sequences of 136 worms isolated from 23 patients indicated that all isolates were S. stercoralis. Among the cox-1 sequences, 33 polymorphic sites and 13 haplotypes were found. The phylogenetic analysis demonstrated that some sequences clustered fairly closely with sequences from humans and dogs from other parts of the world, while others formed a separate, Iran-specific group. Among 64 S. stercoralis analyzed, we found three of the previously described SSU HVR-I haplotypes, with haplotype II being the most frequent haplotype. In contrast to Southeast Asia, where S. stercoralis heterozygous for different haplotypes at the HVR-I locus are rare, we found 20 worms to be heterozygous for two different HVR-I haplotypes, 18 of which fell into the Iran-specific cox-1 cluster. SSU-heterozygous worms also showed elevated heterozygosity at the whole-genome level.
CONCLUSIONS
We conclude that the S. stercoralis population from the Khuzestan province shares much of the genetic diversity with the population in Southeast Asia, but there is an indication of additional genetic input. There appears to be some population structure with different subpopulations, which however do interbreed at least occasionally.
Topics: Humans; Animals; Dogs; Strongyloides stercoralis; Genotype; Phylogeny; Iran; Strongyloidiasis; Strongyloides; Feces
PubMed: 38229164
DOI: 10.1186/s13071-023-06103-6 -
Veterinary Research Jan 2024Carbonyl-reducing enzymes (CREs) catalyse the reduction of carbonyl groups in many eobiotic and xenobiotic compounds in all organisms, including helminths. Previous...
Flubendazole carbonyl reduction in drug-susceptible and drug-resistant strains of the parasitic nematode Haemonchus contortus: changes during the life cycle and possible inhibition.
Carbonyl-reducing enzymes (CREs) catalyse the reduction of carbonyl groups in many eobiotic and xenobiotic compounds in all organisms, including helminths. Previous studies have shown the important roles of CREs in the deactivation of several anthelmintic drugs (e.g., flubendazole and mebendazole) in adults infected with the parasitic nematode Haemonchus contortus, in which the activity of a CRE is increased in drug-resistant strains. The aim of the present study was to compare the abilities of nematodes of both a drug-susceptible strain (ISE) and a drug-resistant strain (IRE) to reduce the carbonyl group of flubendazole (FLU) in different developmental stages (eggs, L1/2 larvae, L3 larvae, and adults). In addition, the effects of selected CRE inhibitors (e.g., glycyrrhetinic acid, naringenin, silybin, luteolin, glyceraldehyde, and menadione) on the reduction of FLU were evaluated in vitro and ex vivo in H. contortus adults. The results showed that FLU was reduced by H. contortus in all developmental stages, with adult IRE females being the most metabolically active. Larvae (L1/2 and L3) and adult females of the IRE strain reduced FLU more effectively than those of the ISE strain. Data from the in vitro inhibition study (performed with cytosolic-like fractions of H. contortus adult homogenate) revealed that glycyrrhetinic acid, naringenin, mebendazole and menadione are effective inhibitors of FLU reduction. Ex vivo study data showed that menadione inhibited FLU reduction and also decreased the viability of H. contortus adults to a similar extent. Naringenin and mebendazole were not toxic at the concentrations tested, but they did not inhibit the reduction of FLU in adult worms ex vivo.
Topics: Female; Animals; Mebendazole; Haemonchus; Vitamin K 3; Anthelmintics; Larva; Glycyrrhetinic Acid
PubMed: 38225645
DOI: 10.1186/s13567-023-01264-9 -
Intensive Care Medicine Feb 2024
Topics: Humans; Animals; Strongyloides stercoralis; Bronchoalveolar Lavage; Dimercaprol; Respiratory Distress Syndrome
PubMed: 38224349
DOI: 10.1007/s00134-023-07315-1 -
World Journal of Hepatology Dec 2023is a parasitic infection caused by a roundworm that is transmitted through soil contaminated with larvae. It can infrequently cause hepatic abscesses in...
BACKGROUND
is a parasitic infection caused by a roundworm that is transmitted through soil contaminated with larvae. It can infrequently cause hepatic abscesses in immunocompromised patients and is rarely reported to form hepatic lesions in immunocompetent hosts.
CASE SUMMARY
We present a case study of a 45-year-old female who presented with right upper quadrant abdominal pain and constitutional symptoms for several weeks. Cross-sectional imaging identified several malignant-appearing liver masses. Further investigation, including serological testing and histopathologic examination, revealed the presence of serum antibodies and hepatic granulomas with extensive necrosis. Following treatment with ivermectin for 2 wk, there was complete resolution of the liver lesions and associated symptoms.
CONCLUSION
This case highlights the importance of considering parasitic infections, such as , in the differential diagnosis of hepatic masses. Early recognition and appropriate treatment can lead to a favorable outcome and prevent unnecessary invasive procedures. Increased awareness among clinicians is crucial to ensure the timely diagnosis and management of such cases.
PubMed: 38223414
DOI: 10.4254/wjh.v15.i12.1338 -
Helminthologia Dec 2023Rhesus macaques ( are distributed across Nepal in close association with humans and with a high probability of sharing of soil-transmitted intestinal helminth parasites....
Rhesus macaques ( are distributed across Nepal in close association with humans and with a high probability of sharing of soil-transmitted intestinal helminth parasites. This study was carried out to determine the prevalence, richness and risk factors of gastrointestinal (GI) helminth parasites among rhesus macaques and humans in the Daunne Forest area, a community managed forest in the central mid-hills of Nepal. A total of 190 fecal samples, including 120 samples from rhesus macaques residing around the Daunne Devi Temple and in the surrounding forest, and 70 from local people, were microscopically examined by direct wet mount, floatation and sedimentation methods. Seasonal and age-sex based variations in helminth parasite prevalence were analyzed. Among the rhesus macaques, the total parasite prevalence was 39.2 %. sp. accounted for the highest prevalence (19.17 %) followed by sp. (13.33 %), hookworm (10.83 %) and sp. (4.17 %). Among the humans, (11.3 %) was the only parasite detected. The Sorenson's coefficient of similarity of GI parasites between the macaques and local people at the generic level was 0.4. Mean parasite richness for the macaques was 1.21 ± 0.41 (SD) per infected sample. Parasite prevalence in the summer season (41.4 %) was higher than in the winter season (36 %). Adult macaques (41.67 %) had higher GI parasite prevalence than the young (30.77 %) and infants (27.27 %). Among the adult macaques, the prevalence rate was significantly higher (=0.005) in females (52.46 %) than in males (22.86 %). Our results indicate that the temple rhesus macaques have a high prevalence of GI helminth parasites and could pose a potential zoonotic risk. As such, the need for routine monitoring and an effective management strategy is essential.
PubMed: 38222485
DOI: 10.2478/helm-2023-0037 -
Helminthologia Dec 2023This study aimed to identify the helminth parasites of invasive anuran species in selected barangays in Butuan City, Philippines. In urbanized areas, invasive species...
This study aimed to identify the helminth parasites of invasive anuran species in selected barangays in Butuan City, Philippines. In urbanized areas, invasive species dominate anuran diversity, and one of the primary threats they pose to native wildlife is the transmission of diseases and parasites. Out of the 91 collected individuals of invasive anuran species, was the most abundant (88 %), followed by (12 %) and (3 %). The study identified five species of parasites, with sp. being the most prevalent (17.58 %), followed by sp. (16.5 %), (14.3 %), sp. (6.6 %), and (3.30 %), respectively. sp. also had the highest intensity (7.67), followed by a sp. (5), (3.33), (3.30), and a sp. (2.73). This parasitological survey revealed that had the highest prevalence and infection of parasites, and residential areas had the highest parasite prevalence among the habitat types. Adult hosts were found to harbor a higher prevalence and intensity, and male hosts had a higher prevalence. The results highlight the high risk of parasite transmission from anurans to other animals and emphasize the need for the community to control the population of invasive anuran species for the safety of native anurans and to prevent zoonotic transmission to other animals and humans.
PubMed: 38222484
DOI: 10.2478/helm-2023-0040 -
Revista Do Instituto de Medicina... Jan 2024[This corrects the article doi: 10.1590/S1678-9946202365001].
[This corrects the article doi: 10.1590/S1678-9946202365001].
PubMed: 38198378
DOI: 10.1590/S1678-9946202466001err -
International Medical Case Reports... 2024We report a fatal case of massive airway bleeding caused by pulmonary strongyloidiasis in a patient with a transplanted kidney.
INTRODUCTION
We report a fatal case of massive airway bleeding caused by pulmonary strongyloidiasis in a patient with a transplanted kidney.
CASE PRESENTATION
A 47-year-old male, regularly taking immunosuppressants post-kidney transplant, visited our hospital with symptoms of abdominal bloating, nausea, and emesis persisting for three days. After hospitalization, he developed a cough, hemoptysis, and respiratory failure. Sputum analysis confirmed an infestation with Strongyloides stercoralis. Despite receiving albendazole therapy and bronchoscopic management for bronchial hemorrhage, the patient ultimately died due to acute respiratory and circulatory collapse triggered by severe airway bleeding.
CONCLUSION
Patients undergoing immunosuppressive therapy following kidney transplantation are at increased risk for disseminated strongyloidiasis. Consequently, infectious disease screening prior to transplantation, along with essential preventive pharmacotherapy, is of paramount importance.
PubMed: 38196944
DOI: 10.2147/IMCRJ.S442535