Molecular Detection and Genetic Characterization of Zoonotic Hookworm in Semi-Domesticated Cats Residing in Monasteries in Bangkok, Thailand

Hookworm infections in carnivores in Iran: a One Health concern

BACKGROUND

Dogs and cats can harbor hookworms, which may contribute to zoonotic infections. This study investigates hookworm infections in carnivores from the Caspian Sea littoral region of northern Iran, focusing on molecular and morphological identification.

METHODS

A cross-sectional study was conducted between September 2015 and October 2024, involving 172 road-killed carnivores including 78 stray dogs (Canis familiaris), 62 golden jackals (Canis aureus), and 32 stray cats (Felis catus), all collected from the northern Iranian provinces of Guilan and Mazandaran.

RESULTS

Overall, 46 (26.74%) animals tested positive for hookworms. Among these, Ancylostoma caninum was found in dogs and golden jackals, Ancylostoma tubaeforme in cats, and Uncinaria stenocephala in dogs and golden jackals. Morphological analyses confirmed key differences between A. caninum and A. tubaeforme, including size, esophageal features, and bursal structure. Molecular identification was supported by 18S, ITS1-5.8S-ITS2 rDNA, 28S, and mitochondrial cytochrome c oxidase 1 (COX1) gene sequences, demonstrating high similarity with previously identified isolates in GenBank. Phylogenetic analysis of the ITS and COX1 sequences revealed distinct clades for each species, with A. caninum and A. tubaeforme clustering together in the Ancylostoma spp. group.

CONCLUSION

These results provide important insights into hookworm diversity and highlight the zoonotic risks posed by these parasites.

One Health, One Future: A Unified Approach to a Balanced Ecosystem

In the past few decades, disease spillovers between humans and wildlife have increased in both frequency and severity [...].

New insight into genetic diversity of zoonotic-potential Ancylostoma ceylanicum in stray cats living in Bangkok, Thailand, based on deep amplicon sequencing

AIMS

This study aimed to characterize feline hookworms from stray cats living in Bangkok.

METHODS AND RESULTS

A total of 56 hookworm-positive faecal samples were identified for hookworm species by using PCR targeting the ITS1, 5.8S, and ITS2 fragment and qPCR targeting ITS2. Of 56 samples, 96.4% (54/56) were identified as Ancylostoma ceylanicum and 1.8% (1/56) as Ancylostoma caninum. With qPCR, 89.3% (50/56) were identified as single A. ceylanicum infection and 5.4% (3/56) as coinfection of A. ceylanicum and A. caninum. For genetic characterization of A. ceylanicum, 10 samples were pooled, and the partial COI gene was amplified, followed by deep amplicon sequencing. Five pooled samples were analysed, and 99.73% were identified with A. ceylanicum sequences, which were allocated into 19 haplotypes (AC01-AC19). Genetic diversity findings for A. ceylanicum in Asia revealed that three of eight haplotypes considered of zoonotic significance occurred in humans, dogs, and cats, including haplotypes H01, H20, and H21. The predominant haplotype in this study, AC01, was clustered with H01-a zoonotic haplotype.

CONCLUSIONS

The diversity obtained by deep amplicon sequencing supported that the A. ceylanicum community had high genetic variation. Deep amplicon sequencing was a useful method to determine source, zoonotic potential, and host-parasite relationship.

Molecular identification and genetic diversity of zoonotic hookworm infections in domestic dogs from northeastern, Thailand

Hookworm infections remain a significant public health concern in tropical and subtropical regions, including Thailand. This study investigated the species and genetic diversity of hookworm infections in domestic dogs from northeastern Thailand. The molecular analysis focused on amplifying and sequencing specific regions of ribosomal RNA genes (ITS1-5.8S-ITS2 region) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene in hookworm larvae recovered from 21 domestic dog stool samples. Among 21 larvae (one larva per infected dog) analyzed, 14 had sequences identical to Ancylostoma caninum, and 7 showed sequences almost identical to Ancylostoma ceylanicum. Phylogenetic analysis of cox1 sequences placed A. caninum and A. ceylanicum in separate clades. The median-joining network of A. caninum cox1 sequences from Thailand showed high haplotype diversity and belonged to the same cluster as sequences from Australia while forming separate clusters from those of A. caninum samples from the USA. The available published A. ceylanicum cox1 sequences (n = 33), in combination with seven sequences in the present study, represented 15 haplotypes distributed among three clusters. Interestingly, A. ceylanicum sequences from dogs and humans shared the same haplotypes. These findings are crucial for recognizing the potential for zoonotic transmission, highlighting the necessity for targeted control measures, and increasing awareness among pet owners and healthcare professionals to mitigate the risk of hookworm transmission to humans.