Ancylostoma ceylanicum: The Neglected Zoonotic Parasite of Community Dogs in Thailand and Its Genetic Diversity among Asian Countries

Ancylostoma ceylanicum is a zoonotic helminth that is commonly found in domestic dogs and cats throughout Asia but is largely neglected in many countries. This study aimed to confirm the species of hookworm in dogs and soil environments and investigate the evolutionary analyses of A. ceylanicum among Thai and Asian populations. In a total of 299 dog fecal samples and 212 soil samples from 53 temples, the prevalence rates of hookworm infection by microscopic examination were 26.4% (79/299) and 10.4% (22/212) in dog and soil samples, respectively. A PCR-RFLP targeting the ITS region was then utilized to identify the hookworm species. In dogs, A. ceylanicum was the main hookworm species, and the rates of A. ceylanicum and A. caninum infections were 96.6% and 3.5%, respectively. The genetic characterization and diversity indices of the A. ceylanicumcox1 gene among Thai and Asian populations were evaluated. Nine haplotypes were identified from Thai A. ceylanicum, in which the haplotype diversity and the nucleotide diversity were 0.4436 and 0.0036, respectively. The highest nucleotide diversity of Chinese A. ceylanicum populations suggested that it could be the ancestor of the populations. Pairwise fixation indices indicated that Thai A. ceylanicum was closely related to the Malaysian population, suggesting a gene flow between these populations. The temples with hookworm-positive dogs were associated with the presence of hookworm-contaminated soil, as these levels showed an approximately four-fold increase compared with those in temples with hookworm-negative dogs (OR = 4.38, 95% CI: 1.55–12.37). Interestingly, the genotypes of A. ceylanicum in the contaminating soil and infecting dogs were identical. Therefore, increased awareness and concern from the wider public communities with regard to the responsibility of temples and municipal offices to provide proper deworming programs to community dogs should be strongly endorsed to reduce the risk of the transmission of this zoonotic disease. In addition, parasitic examination and treatment should be strongly implemented before dogs are imported and exported worldwide

Involvement of CD4+ Foxp3+ Regulatory T Cells in Persistence of Leishmania donovani in the Liver of Alymphoplastic aly/aly Mice

Visceral leishmaniasis (VL) is a chronic and fatal disease in humans and dogs caused by the intracellular protozoan parasites, Leishmania donovani and L. infantum (L. chagasi). Relapse of disease is frequent in immunocompromised patients, in which the number of VL cases has been increasing recently. The present study is aimed to improve the understanding of mechanisms of L. donovani persistence in immunocompromised conditions using alymphoplastic aly/aly mice. Hepatic parasite burden, granuloma formation and induction of regulatory T cells were determined for up to 7 months after the intravenous inoculation with L. donovani promastigotes. While control aly/+ mice showed a peak of hepatic parasite growth at 4 weeks post infection (WPI) and resolved the infection by 8 WPI, aly/aly mice showed a similar peak in hepatic parasite burden but maintained persistent in the chronic phase of infection, which was associated with delayed and impaired granuloma maturation. Although hepatic CD4+Foxp3+ but not CD8+Foxp3+ T cells were first detected at 4 WPI in both strains of mice, the number of CD4+Foxp3+ T cells was significantly increased in aly/aly mice from 8 WPI. Immunohistochemical analysis demonstrated the presence of Foxp3+ T cells in L. donovani-induced hepatic granulomas and perivascular neo-lymphoid aggregates. Quantitative real-time PCR analysis of mature granulomas collected by laser microdissection revealed the correlation of Foxp3 and IL-10 mRNA level. Furthermore, treatment of infected aly/aly mice with anti-CD25 or anti-FR4 mAb resulted in significant reductions in both hepatic Foxp3+ cells and parasite burden. Thus, we provide the first evidence that CD4+Foxp3+ Tregs mediate L. donovani persistence in the liver during VL in immunodeficient murine model, a result that will help to establish new strategies of immunotherapy against this intracellular protozoan pathogen

Occurrence and Risk Factors Associated with <i>Platynosomum illiciens</i> Infection in Cats with Elevated Liver Enzymes

Platynosomum spp., a hepatic trematode, causes fatal hepatobiliary disease in cats. Feline platynosomiasis is often underestimated due to a lack of awareness and diagnostic challenges. This study aimed to investigate the occurrence, factors, and clinicopathological abnormalities associated with Platynosomum spp. infection in cats with elevated serum ALT levels. Platynosomum infection was determined using zinc sulfate flotation and formalin–ether sedimentation. DNA sequence analysis of PCR products from the Platynosomum internal transcribed spacer 2 (ITS2) region and cox1 gene was used to identify Platynosomum species. Of a total of 43 cat fecal samples, the proportion of Platynosomum spp. infection by microscopic examination was 11.63% (5/43). All PCR-positive samples were molecularly identified as Platynosomum illiciens. From the logistic regression analysis, the odds of Platynosomum infection in cats without a deworming program were 16 times higher than those of regularly dewormed cats. Demographic data, housing conditions, and predatory behavior were not significantly associated with the infection. Regarding blood profiles, infected cats had higher eosinophil counts (p = 0.014), with no significant differences in ALT (p = 0.791) or ALP (p = 0.970) levels compared to non-infected cats. Our findings demonstrate that eosinophilia in cats with increased serum ALT may suggest P. illiciens infection in endemic areas. We strongly recommend a regular deworming program to mitigate the risk of P. illiciens infection

Preclinical Evaluations of Modified Rice Hydrogel for Topical Ophthalmic Drug Delivery of Praziquantel on Avian Philophalmiasis

The present study aims to evaluate the efficacy of a novel drug delivery system of the modified rice hydrogel containing praziquantel (PZQ) against Philophthalmus gralli isolated from ostrich eyes and determine the toxicity of the preparation on chicken eye model. The parasiticidal activity of PZQ (0, 1, 10, and 100 µg/mL) was tested on P. gralli. The ophthalmic antiparasitic hydrogel was formulated with appropriate amount of PZQ and chemically modified rice gel. The parasitic morphology after exposure with the preparation was examined under scanning electron microscope (SEM). The anthelminthic efficacy of the preparation on motility and mortality of parasites was performed by visual inspection and vital dye staining. The ocular irritation of the preparation was evaluated for 21 days using standard avian model followed by OECD 405. The results demonstrated that the parasiticidal activity of PZQ against P. gralli appears to be in a concentration- and time-dependent manner. In addition, the concentration of PZQ 10 µg/mL (Chi squared test, p = 0.003) and exposure time for 24 h (log-rank test, p = 0.0004) is sufficient to kill parasites, when statistically compared to negative control group. Rice hydrogel containing a lethal concentration of 10 µg/mL PZQ was successfully prepared. The preparation illustrated good parasitic killing and motile inhibiting effect on P. gralli compared with PZQ 10 µg/mL and its control (p &lt; 0.05). An appearance under SEM of non-viable parasite after being incubated with the preparation, showing parasitic deformity, was observed comparing with the viable parasite in 0.9% normal saline solution (NSS). Moreover, no irritation of chicken eyes was also observed. Our results contribute to understanding the efficacy and the safety of the rice hydrogel of PZQ which have a predictive value for controlling P. gralli on the animal eyes. However, the pharmacological application needs to be further investigated for the best possible therapeutic approach

DS1-4_JVDI_10.1177_1040638718773810 – Supplemental material for Development of in situ hybridization for detection of elephant endotheliotropic herpesvirus in Asian elephants

<p>Supplemental material, DS1-4_JVDI_10.1177_1040638718773810 for Development of in situ hybridization for detection of elephant endotheliotropic herpesvirus in Asian elephants by Varankpicha Kochakul, Kittikorn Boonsri, Saruda Tiwananthagorn, Chalermchart Somgird, Chatchote Thitaram, Kidsadagon Pringproa in Journal of Veterinary Diagnostic Investigation</p

Localization of Foxp3-expressing cells in <i>L. donovani</i>-infected granuloma of <i>aly/aly</i> mice.

<p>Representative “Mature granuloma” in the liver sections of <i>aly/aly</i> mice at 12 WPI using single and double immunostaining. (A) Foxp3⁺ cells (green; upper left), CD3⁺cells (red; upper right) and a merged image (lower) showed CD3⁺Foxp3⁺ (yellow arrows) and CD3⁺Foxp3⁻ (pink arrows) cells. (B) Foxp3⁺ cells (green; upper left), <i>Leishmania</i> amastigotes (red; upper right) and a merged image (lower). Arrows indicated the positive stained cells.</p