Molecular and phylogenetic characterization of zoonotic Trichostrongylus species from goats for the first time in Bangladesh

Molecular Characterization and Analysis of Human Trichostrongylus Species in an Endemic Region of Iran Based on COX 1 Gene; A Cross-Sectional Study

Background and Aims

Trichostrongylus species are the causative agents of zoonotic disease, which has been frequently reported from animals in Iran. The aim of this study was to identify, molecular characterization and analysis of Trichostrongylus species isolated from humans, in an endemic region, based on cytochrome c oxidase (COX) 1.

Methods

A total of 206 fresh stool samples were collected from residents of endemic villages of sampling area. All samples had been examined using conventional parasitological methods, along with the PCR technique. After amplification and sequencing of a discriminative region of COX1 gene, the phylogeny relationship, haplotype network, and molecular diversity between Trichostrongylus spp., were scrutinized using PopART networking, DnaSP v.6, and MEGA10 software.

Results

In total, from 206 fecal samples, 71 people (34.4%) were infected with Trichostrongylus spp. The ~700-bp fragment of the COX1 was amplified in all 71 morphological positive samples, however, 33 samples were successfully sequenced, belonging to Trichostrongylus spp. In this study, T. colubriformis was the predominant species and one sequence was characterized as T. vitrinus. Our sequences were grouped together with sequences, which were obtained from animals in the same region (97.17% similarity). In total, 26 haplotypes were identified and haplotype diversity ranged from 0.988 ± 0.012.

Conclusions

In view of the importance of Trichostrongylosis to public health as zoonotic infection, information about its prevalence in animal and human populations can provide valuable information on how different types of this parasite are transmitted between people and animal's host.

Molecular characterization and genetic variability of Toxocara vitulorum from naturally infected buffalo calves for the first time in Bangladesh

Toxocara vitulorum is one of the deadliest parasite of buffalo calves in Bangladesh. This study was conducted to explore genetic variability within and among the T. vitulorum populations in buffalo calves of Bangladesh. Genomic DNA was extracted, ITS2, COX1 and NAD1 gene were amplified and sequenced. Distinct 29 ITS2, 21 unique NAD1 and 24 COX1 genotypes were detected among the T. vitulorum of different geographic regions. These three gene genotypes similarities ranged from 97 to 99%, when these were compared to best hit scoring T. vitulorum sequences retrieved from GenBank. A total of 12 and 6 unique haplotypes were detected for COX1 and NAD1 gene sequences. The average nucleotide and haplotype diversity for COX1 and NAD1 were 0.0931 & 0.89493 and 0.00658 & 0.77895 respectively and the recorded values were more dispersed than previously published values. The pairwise Nst values ranged from −0.050 to 0.602 and Fst from −0.050 to 0.600 between all the T. vitulorum genotypes indicated huge genetic differentiation which were reportedly higher than other published reports Fst values. This is the first report of T. vitulorum on the basis of COX1 gene in Bangladesh. The study findings will be helpful for further extensive epidemiological studies regarding anthelmintic resistance, control and prevention of T. vitulorum infection in buffalo calves.

Revealing the associated microflora hosted by the globally significant parasite Trichostrongylus colubriformis

Trichostrongylus colubriformis is a parasitic helminth that primarily infects small ruminants, causing substantial economic losses in the livestock industry. Exploring the microbiome of this helminth might provide insights into the potential influence of its microbial community on the parasite's survival. We characterised the intestinal microbiome of T. colubriformis that had been collected from the duodenum of sheep, and compared the helminth microbiome with the duodenal microbiome of its host, aiming to identify contributions from the helminth's environment. At the same time, we explored the isolation of fastidious organisms from the harvested helminth. Primary alpha and beta diversity analyses of bacterial species revealed statistically significant differences between the parasite and the host, in terms of species richness and ecological composition. 16S rRNA differential abundance analysis showed that Mycoplasmoides and Stenotrophomonas were significantly present in T. colubriformis but not in the duodenal microbiome of the sheep. Furthermore, two bacteria, Aeromonas caviae and Aeromonas hydrophila, were isolated from T. colubriformis. Examinations of the genome highlight differences in genome size and profiles of antimicrobial resistance genes. Our results suggest that T. colubriformis carries a specific bacterial community that could be supporting the helminth's long-term survival in the host's digestive system.