Genetic variability of wildlife-derived Sarcoptes scabiei determined by the ribosomal ITS-2 and mitochondrial 16S genes

The genetic characteristics of Sarcoptes scabiei from Chinese serow (Capricornis milneedwardsii) and goral (Naemorhedus goral arnouxianus) compared with other mites from different hosts and geographic locations using ITS2 and cox1 sequences

Scabies is a common parasitic disease in many mammalian species, caused by the infestation of Sarcoptes scabiei. There is no consistent conclusion on whether Sarcoptes mites from different hosts or geographic locations have apparent genetic divergence. In this study, we collected and morphologically identified S. scabiei from Chinese serow and goral, and we described the genetic diversity of S. scabiei and other mites based on phylogenetic analyses of the ITS2 and cox1 sequence fragments, including data available in GenBank. The mites isolated from Chinese serow and goral were S. scabiei, and they were morphologically similar. The phylogenetic trees and haplotype networks showed that S. scabiei from other locations worldwide did not cluster according to host divergence or geographical distribution. Additionally, the Fst values were - 0.224 to 0.136 and - 0.045 to 1 between S. scabiei from different hosts, including humans and domestic and wild animals, based on partial ITS and cox1 sequences. Worldwide S. scabiei samples formed three clusters (with H2, H5, and H12 at their centers) in the ITS and one cluster (with C9 at the center) in the cox1 haplotype phylogenetic network. The S. scabiei collected from Chinese serow and goral were morphologically similar and had the same genotype. A study on the genetic characteristics of S. scabiei from Chinese serow and goral together with other mites from different hosts and geographic locations around the world showed no obvious divergence. These findings indicated that scabies likely is a zoonotic disease and that the global prevalence of scabies is probably related to the worldwide trade of domestic animals.

Prevalence and molecular characterization of Sarcoptes scabiei from vicuñas (Vicugna vicugna) from Southern Peruvian Andes

Sarcoptic mange is a disease caused by an infectious parasite in the vicuñas (Vicugna vicugna) from South America. Although molecular studies have provided much information about the epidemiology of this disease, this information is still unknown in vicuñas. This study determined the prevalence and molecular characterization of Sarcoptes scabiei from vicuñas from Southern Peruvian Andes. During the 2018 shearing season, 181 vicuñas were clinically evaluated for lesions compatible with mange. Sarcoptes scabiei was detected in 35 (19.3%) vicuñas, and 50 mites from 25 vicuñas were selected for molecular analyses of the mitochondrial (cox1) and nuclear (ITS2) genetic markers. Molecular analyses of the cox1 and ITS2 sequences showed an identity of 94–99% and 99.8–100% with previous S. scabiei sequences registered in the GenBank, respectively. Sequence polymorphisms were more evident in the ITS2 than in the cox1, but only the cox1 had an association with the host. Phylogenetic analysis of S. scabiei cox1 sequences from vicuñas showed a cluster with S. scabiei cox1 sequences from canids, suggesting that the origin of S. scabiei from vicuña is associated with canid mites. This research is the first molecular analysis of S. scabiei from vicuñas. Future molecular studies will be necessary to determine the species variety, geographic segregation and host–parasite adaptation for this vicuña's mite.

Second internal transcribed spacer (ITS-2) as genetic marker for molecular characterization of Sarcoptes scabiei in rabbits from several areas of East Java, Indonesia

OBJECTIVES

The purpose of this study is to use the second internal transcribed spacer (ITS-2) to determine the molecular characteristics of Sarcoptes scabiei in rabbits from several areas of East Java.

METHODS

Collecting S. scabiei mites from rabbits with clinical signs of scabies; DNA extraction with minikit QIAamp DNA; polymerase chain reaction amplification; nucleotide sequence analysis; homology and phylogenetic tree using the Neighbor-Joining method in the program molecular evolutionary genetics analysis-7 (MEGA-7).

RESULTS

Sequence analysis of ITS-2 S. scabiei from five regions in East Java showed an identity >91.23% with isolates from China (KX695125.1). The phylogenetic analysis of ITS-2 S. scabiei from Mojokerto rabbits has a close relationship with AB82977.1; Surabaya and Nganjuk rabbits are closely related to KX695125.1; while Sidoarjo and Pasuruan rabbits are closely related to EF514469.2. and AB369384.1.

CONCLUSIONS

The homology analysis of all samples showed identity of more than 91.23% with isolate China (KX695125.1). The sequences of ITS-2 gen of S. scabiei from rabbits in several areas were relatively close to S. scabiei obtain various hosts from National Centre for Biotechnology Information (NCBI) data.