Identifying Primates and Examining Nest Characteristics of Orang Utan in Sungai Rawog Conservation Area

The decline in the population of primates is a serious concern and is primarily attributed to various anthropogenic factors. This study focuses on the primate diversity and nest characteristics of Orangutan within the Sungai Rawog Conservation Area (SRCA). Its goals are to identify primate species and categorize orangutan nests in SRCA. This study was conducted for five days by using a non-invasive sampling method which are by employed direct observation along main roads and cruising the river. Data collected included primate species and orangutan nest counts. For nest characteristics, the location and successional stages of orangutan nests were determined to study their features. As a result, three species of primates were identified which are Long-Tailed Macaque (Macaca fascicularis), Eastern Grey gibbon (Hylobates funereus) and Borneon Orangutan (Pongo pygmaeus). Forty-five orangutan nests were counted along the main roads and trails. Trail 1 to trail 5 consist of the highest number of Orangutan nest count compared to other trails. From the observation, most of the Orangutan’s nest were built at the edge of the branch tree and the most common successional stage is at the stage in which the structure of the nest has completely ruptured and only left with few branches and twigs. While the least observed successional stage was at the stage in which the nests are quite old and the leaves used in building the nests were brown in colour. The findings imply that the movement of primates is affected by the availability of food and the size of their home ranges. Primates observed less frequently in certain regions are closely tied to their established home ranges and their patterns of movement. The lack of sufficient food resources in these areas serves as a significant factor contributing to the reduced sightings of primates. The method by which an orangutan constructs its nest can vary based on several factors, such as individual preferences, environmental characteristics, and ecological conditions. This information will help to provide baseline data to enhance conservation efforts

A genome resequencing-based genetic map reveals the recombination landscape of an outbred parasitic nematode in the presence of polyploidy and polyandry

The parasitic nematode Haemonchus contortus is an economically and clinically important pathogen of small ruminants, and a model system for understanding the mechanisms and evolution of traits such as anthelmintic resistance. Anthelmintic resistance is widespread and is a major threat to the sustainability of livestock agriculture globally; however, little is known about the genome architecture and parameters such as recombination that will ultimately influence the rate at which resistance may evolve and spread. Here we performed a genetic cross between two divergent strains of H. contortus, and subsequently used whole-genome re-sequencing of a female worm and her brood to identify the distribution of genome-wide variation that characterises these strains. Using a novel bioinformatic approach to identify variants that segregate as expected in a pseudo-testcross, we characterised linkage groups and estimated genetic distances between markers to generate a chromosome-scale F1 genetic map. We exploited this map to reveal the recombination landscape, the first for any parasitic helminth species, demonstrating extensive variation in recombination rate within and between chromosomes. Analyses of these data also revealed the extent of polyandry, whereby at least eight males were found to have contributed to the genetic variation of the progeny analysed. Triploid offspring were also identified, which we hypothesise are the result of nondisjunction during female meiosis or polyspermy. These results expand our knowledge of the genetics of parasitic helminths and the unusual life-history of H. contortus, and enhance ongoing efforts to understand the genetic basis of resistance to the drugs used to control these worms and for related species that infect livestock and humans throughout the world. This study also demonstrates the feasibility of using whole-genome resequencing data to directly construct a genetic map in a single generation cross from a non-inbred non-model organism with a complex lifecycle

A method for single pair mating in an obligate parasitic nematode

Parasitic nematode species have extremely high levels of genetic diversity, presenting a number of experimental challenges for genomic and genetic work. Consequently, there is a need to develop inbred laboratory strains with reduced levels of polymorphism. The most efficient approach to inbred line development is single pair mating, but this is challenging for obligate parasites where the adult sexual reproductive stages are inside the host, and thus difficult to experimentally manipulate. This paper describes a successful approach to single pair mating of a parasitic nematode, Haemonchus contortus. The method allows for polyandrous mating behaviour and involves the surgical transplantation of a single adult male worm with multiple immature adult females directly into the sheep abomasum. We used a panel of microsatellite markers to monitor and validate the single pair mating crosses and to ensure that the genotypes of progeny and subsequent filial generations were consistent with those expected from a mating between a single female parent of known genotype and a single male parent of unknown genotype. We have established two inbred lines that both show a significant overall reduction in genetic diversity based on microsatellite genotyping and genome-wide single nucleotide polymorphism. There was an approximately 50% reduction in heterozygous SNP sites across the genome in the MHco3.N1 line compared with the MoHco3(ISE) parental strain. The MHco3.N1 inbred line has subsequently been used to provide DNA template for whole genome sequencing of H. contortus. This work provides proof of concept and methodologies for forward genetic analysis of obligate parasitic nematodes

In Vitro and In Vivo Efficacy of Monepantel (AAD 1566) against Laboratory Models of Human Intestinal Nematode Infections

Soil-transmitted helminthiases affect more than one billion people among the most vulnerable populations in developing countries. Currently, control of these infections primarily relies on chemotherapy. Only five drugs are available, all of which have been in use for decades. None of the drugs are efficacious using single doses against all soil-transmitted helminths (STH) species and show low efficacy observed against Trichuris trichiura. In addition, the limited availability of current drug treatments poses a precarious situation should drug resistance occur. Therefore, there is great interest to develop novel drugs against infections with STH. Monepantel, which belongs to a new class of veterinary anthelmintics, the amino-acetonitrile derivatives, might be a potential drug candidate in humans. It has been extensively tested against livestock nematodes, and was found highly efficacious and safe for animals. Here we describe the in vitro and in vivo effect of monepantel, on Ancylostoma ceylanicum, Necator americanus, Trichuris muris, Strongyloides ratti, and Ascaris suum, five parasite-rodent models of relevance to human STH. Since we observed that monepantel showed only high activity on one of the hookworm species and lacked activity on the other parasites tested we cannot recommend the drug as a development candidate for human soil-transmitted helminthiases

A modified larval migration assay for detection of resistance to macrocyclic lactones in Haemonchus contortus, and drug screening with Trichostrongylidae parasites

We have developed a modified migration assay system in 96-well plate format which is able to detect resistance to the macrocyclic lactone group of drugs in Haemonchus contortus. The assay involves exposure of infective stage larvae to drug for a 24 h period, then counting the numbers of larvae that are able to migrate through an agar and filter mesh system over a further 48 h. The agar barrier greatly increased the sensitivity of the assay for resistance detection compared to use of filter mesh alone. The assay was able to detect the presence of 10% resistant worms in an otherwise susceptible background. However, the assay was ineffective with Trichostrongylus colubriformis and Ostertagia circumcincta indicating that its usefulness for field monitoring will be restricted to situations where H. contortus is of most significance. A small-scale drug screening exercise showed that the assay identifies some anthelmintic activities distinct from those identified by larval development assays. The assay therefore also has a potential role in drug discovery programmes in screening for new anthelmintics

Principles for the use of macrocyclic lactones to minimise selection for resistance

Objective To provide principles for the appropriate use of avermectin/milbemycin or macrocyclic lactone (ML) anthelmintics in sheep, to ensure effective worm control and to minimise selection for ML resistance. Strategy The principles were based on an assessment of the information currently available. The MLs were categorised into three groups (ivermectin [IVM], abamectin [ABA] and moxidectin [MOX]) based on structural differences, persistence and efficacy against ML resistant strains. The reported order of activity or efficacy against ML resistant worm strains was IVM<ABA<MOX. General treatment schemes were considered for Australian conditions and were divided into the following situations: 1. quarantine treatment, 2. treatment on/to clean pasture, 3. treatment on/to safe pasture, 4. treatment on/to moderate/heavily contaminated pasture. For each of these situations a strategy was considered for farms where ML resistance was present or absent. It was assumed that resistance commonly occurs in some or all other broad spectrum anthelmintics, and even where ML resistance has been detected, the ML group remains the most effective. The guidelines provided are general and it is expected that state agencies and sheep/veterinary advisers would give specific advice to suit their environments and drug resistance/worm problems. Conclusions The primary recommendation is to use a mixture of effective drugs when treating sheep. However, unless the combination treatment is highly effective it is unlikely to delay selection for ML resistance if sheep are being treated and moved to a clean or safe pasture. Where possible, reliance on the ML anthelmintics should be reduced by not using them every year, not using them in low risk stock or by using narrow spectrum and low efficacy drugs such as naphthalophos when appropriate. Anthelmintic treatment should be given as part of a strategic worm control program. It is suggested that IVM-oral and IVM-capsules should not be used when ML resistance is present. In this situation MOX or ABA should be used in combination with other drugs, provided that the chosen ML is effective against the resistant parasite. It is essential to monitor the efficacy of ML and drug combinations by post-treatment worm egg counts, particularly when ML resistance has been detected