Displaying all 16 publications

Abstract:
Sort:
  1. [Macrostyophora durdeni n. sp. A new plea from Sabah (Borneo) and sympatric species (Siphonaptera: Ceratophyllidae, Pygiopsyllidae)]
    Beaucournu JC, Wells K
    Parasite, 2009 Dec;16(4):283-7.
    PMID: 20092059
    We report on fleas collected from small mammals in a lower mountane rainforest in the Crocker Range National Park, Sabah, Borneo. Macrostylophora durdeni n. sp., collected from Dremomys everetti and, of minor importance, Tupaia montana, is described. Further records include Gryphopsylla jacobsoni segragata and Lentistivalius vomerus from T. montana.
  2. [A redescription of Macrostylophora borneensis (Jordan, 1926) (Siphonaptera-Ceratophyllidae-Ceratophyllinae), a flea of the Malaysian sub-region and description of an allied species]
    Beaucournu JC, Wells K
    Parasite, 2005 Dec;12(4):293-8.
    PMID: 16402560
    This note redescribes M. borneensis and describes M. traubi n. sp. based on the known specimens from the two sampling localities (holotype from Mount Murud and further recorded from Mount Kinabalu by Traub). The clearly allied, but clearly distinct species for the two localities, were recorded.
  3. [Three new species of the genus Medwayella Traub, 1972 (Insecta: Siphonaptera: Pygiopsyllidae) from Sabah (eastern Malaysia, Borneo)]
    Beaucournu JC, Wells K
    Parasite, 2004 Dec;11(4):373-7.
    PMID: 15638138
    Medwayella traubiana n. sp., M. pfeifferi n. sp. and M. sabahae n. sp. (Pygiopsyllidae) are described from Sabah (north of Borneo island), the first two on Tupaia tana (Scandentia), the last on Sundasciurus lowii (Rodentia). Sex male is only identified, because these fleas have been collected in sympatry, or even in syntopy. Their determination is based on segment IX and aedeagus. If M. traubiana and M. pfeifferi are related to some known species, M. sabahae is clearly distinct from other Medwayella.
  4. [Macrostylophora kinabaluae n. sp. (Insecta: Siphonaptera: Ceratophyllidae), a new flea from Sabah (Borneo, Eastern Malaysia)]
    Beaucournu JC, Wells K
    Parasite, 2005 Sep;12(3):237-40.
    PMID: 16218211
    This species, known only by a single male, is described from Mount Kinabalu and thus is recorded from the same area as Macrostylophora borneensis (Jordan, 1926), teste Traub (1972). It is distinguished from its congeneric and characterized by the absence of eriged setae on the thorax and first abdominal tergits, as well as by the shape of terminal segments and the phallosom. Macrostylophora kinabaluae was found to parasitize the Sciurid rodent Callosciurus prevostii that is widespread throughout most areas in the Malaysian subregion.
  5. Host specificity and niche partitioning in flea-small mammal networks in Bornean rainforests
    Wells K, Lakim MB, Beaucournu JC
    Med Vet Entomol, 2011 Sep;25(3):311-9.
    PMID: 21219372 DOI: 10.1111/j.1365-2915.2010.00940.x
    The diversity of ectoparasites in Southeast Asia and flea-host associations remain largely understudied. We explore specialization and interaction patterns of fleas infesting non-volant small mammals in Bornean rainforests, using material from a field survey carried out in two montane localities in northwestern Borneo (Sabah, Malaysia) and from a literature database of all available interactions in both lowland and montane forests. A total of 234 flea individuals collected during our field survey resulted in an interaction network of eight flea species on seven live-captured small mammal species. The interaction network from all compiled studies currently includes 15 flea species and 16 small mammal species. Host specificity and niche partitioning of fleas infesting diurnal treeshrews and squirrels were low, with little difference in specialization among taxa, but host specificity in lowland forests was found to be higher than in montane forests. By contrast, Sigmactenus alticola (Siphonaptera: Leptopsyllidae) exhibited low host specificity by infesting various montane and lowland nocturnal rats. However, this species exhibited low niche partitioning as it was the only commonly recorded flea from rats on Borneo. Overall complementary specialization was of intermediate intensity for both networks and differed significantly from random association; this has important implications for specific interactions that are also relevant to the potential spread of vector-borne diseases.
  6. Fulltext Monte Carlo Simulations for the Detection of Buried Objects Using Single Sided Backscattered Radiation
    Yip M, Saripan MI, Wells K, Bradley DA
    PLoS One, 2015;10(9):e0135769.
    PMID: 26348619 DOI: 10.1371/journal.pone.0135769
    Detection of buried improvised explosive devices (IEDs) is a delicate task, leading to a need to develop sensitive stand-off detection technology. The shape, composition and size of the IEDs can be expected to be revised over time in an effort to overcome increasingly sophisticated detection methods. As an example, for the most part, landmines are found through metal detection which has led to increasing use of non-ferrous materials such as wood or plastic containers for chemical based explosives being developed.
  7. Ectoparasite infestation patterns of domestic dogs in suburban and rural areas in Borneo
    Wells K, Beaucournu JC, Durden LA, Petney TN, Lakim MB, O'Hara RB
    Parasitol Res, 2012 Aug;111(2):909-19.
    PMID: 22526293 DOI: 10.1007/s00436-012-2917-7
    Domestic dogs, Canis lupus, have been one of the longest companions of humans and have introduced their own menagerie of parasites and pathogens into this relationship. Here, we investigate the parasitic load of 212 domestic dogs with fleas (Siphonaptera) chewing lice (Phthiraptera), and ticks (Acarina) along a gradient from rural areas with near-natural forest cover to suburban areas in Northern Borneo (Sabah, Malaysia). We used a spatially-explicit hierarchical Bayesian model that allowed us to impute missing data and to consider spatial structure in modelling dog infestation probability and parasite density. We collected a total of 1,968 fleas of two species, Ctenocephalides orientis and Ctenocephalides felis felis, from 195 dogs (prevalence, 92 %). Flea density was higher on dogs residing in houses made of bamboo or corrugated metal (increase of 40 % from the average) compared to timber or stone/compound houses. Host-dependent and landscape-level environmental variables and spatial structure only had a weak explanatory power. We found adults of the invasive chewing louse Heterodoxus spiniger on 42 dogs (20 %). The effect of housing conditions was opposite to those for fleas; lice were only found on dogs residing in stone or timber houses. We found ticks of the species Rhipicephalus sanguineus as well as Haemaphysalis bispinosa gp., Haemaphysalis cornigera, Haemaphysalis koenigsbergi, and Haemaphysalis semermis on 36 dogs (17 %). The most common tick species was R. sanguineus, recorded from 23 dogs. Tick infestations were highest on dogs using both plantation and forest areas (282 % increase in overall tick density of dogs using all habitat types). The infestation probability of dogs with lice and ticks decreased with elevation, most infestations occurred below 800 m above sea level. However, the density of lice and ticks revealed no spatial structure; infestation probability of dogs with these two groups revealed considerable autocorrelation. Our study shows that environmental conditions on the house level appeared to be more influential on flea and lice density whereas tick density was also influenced by habitat use. Infestation of dogs with Haemaphysalis ticks identified an important link between dogs and forest wildlife for potential pathogen transmission.
  8. Whipworms of south-east Asian rodents are distinct from Trichuris muris
    Ribas A, Wells K, Morand S, Chaisiri K, Agatsuma T, Lakim MB, et al.
    Parasitol Int, 2020 Aug;77:102128.
    PMID: 32330535 DOI: 10.1016/j.parint.2020.102128
    The whipworm Trichuris muris is known to be associated with various rodent species in the northern hemisphere, but the species identity of whipworm infecting rodents in the Oriental region remains largely unknown. We collected Trichuris of Muridae rodents in mainland and insular Southeast Asia between 2008 and 2015 and used molecular and morphological approaches to identify the systematic position of new specimens. We discovered two new species that were clearly distinct from T. muris, both in terms of molecular phylogenetic clustering and morphological features, with one species found in Thailand and another one in Borneo. We named the new species from Thailand as Trichuris cossoni and the species from Borneo as Trichuris arrizabalagai. Molecular phylogeny using internal transcribed spacer region (ITS1-5.8S-ITS2) showed a divergence between T. arrizabalagai n. sp., T. cossoni n. sp. and T. muris. Our findings of phylogeographically distinct Trichuris species despite some globally distributed host species requires further research into the distribution of different species, previously assumed to belong to T. muris, which has particular relevance for using these species as laboratory model organisms.
  9. Fulltext Description of Sarcocystis scandentiborneensis sp. nov. from treeshrews (Tupaia minor, T. tana) in northern Borneo with annotations on the utility of COI and 18S rDNA sequences for species delineation
    Ortega Pérez P, Wibbelt G, Brinkmann A, Galindo Puentes JA, Tuh FYY, Lakim MB, et al.
    Int J Parasitol Parasites Wildl, 2020 Aug;12:220-231.
    PMID: 32695576 DOI: 10.1016/j.ijppaw.2020.07.003
    Sarcocystis scandentiborneensis sp. nov. was discovered in histological sections of striated musculature of treeshrews (Tupaia minor, T. tana) from Northern Borneo. Sarcocysts were cigar-shaped, 102 μm-545 μm long, and on average 53 μm in diameter. The striated cyst wall varied in thickness (2-10 μm), depending on whether the finger-like, villous protrusions (VP) were bent. Ultrastructurally, sarcocysts were similar to wall type 12 but basal microtubules extended into VPs that tapered off with a unique U-shaped, electron-dense apical structure. In phylogenetic trees of the nuclear 18S rRNA gene, S. scandentiborneensis formed a distinct branch within a monophyletic subclade of Sarcocystis spp. with (colubrid) snake-rodent life cycle. We mapped all intraspecific (two haplotypes) and interspecific nucleotide substitutions to the secondary structure of the 18S rRNA gene: in both cases, the highest variability occurred within helices V2 and V4 but intraspecific variability mostly related to transitions, while transition/transversion ratios between S. scandentiborneensis, S. zuoi, and S. clethrionomyelaphis were skewed towards transversions. Lack of relevant sequences restricted phylogenetic analysis of the mitochondrial Cytochrome C oxidase subunit I (COI) gene to include only one species of Sarcocystis recovered from a snake host (S. pantherophisi) with which the new species formed a sister relationship. We confirm the presence of the functionally important elements of the COI barcode amino acid sequence of S. scandentiborneensis, whereby the frequency of functionally important amino acids (Alanine, Serine) was markedly different to other taxa of the Sarcocystidae. We regard S. scandentiborneensis a new species, highlighting that structurally or functionally important aspects of the 18S rRNA and COI could expand their utility for delineation of species. We also address the question why treeshrews, believed to be close to primates, carry a parasite that is genetically close to a Sarcocystis lineage preferably developing in the Rodentia as intermediate hosts.
  10. Fulltext Bartonella and Rickettsia in arthropods from the Lao PDR and from Borneo, Malaysia
    Kernif T, Socolovschi C, Wells K, Lakim MB, Inthalad S, Slesak G, et al.
    Comp Immunol Microbiol Infect Dis, 2012 Jan;35(1):51-7.
    PMID: 22153360 DOI: 10.1016/j.cimid.2011.10.003
    Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors Ctenocephalides orientis and Ctenocephalides felis felis were infected with R. felis. The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsia detected in two Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both R. felis and B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas.
  11. A cyst-forming coccidian with large geographical range infecting forest and commensal rodents: Sarcocystis muricoelognathis sp. nov
    Qin T, Ortega-Perez P, Wibbelt G, Lakim MB, Ginting S, Khoprasert Y, et al.
    Parasit Vectors, 2024 Mar 15;17(1):135.
    PMID: 38491403 DOI: 10.1186/s13071-024-06230-8
    BACKGROUND: The geographic distribution and host-parasite interaction networks of Sarcocystis spp. in small mammals in eastern Asia remain incompletely known.

    METHODS: Experimental infections, morphological and molecular characterizations were used for discrimination of a new Sarcocystis species isolated from colubrid snakes and small mammals collected in Thailand, Borneo and China.

    RESULTS: We identified a new species, Sarcocystis muricoelognathis sp. nov., that features a relatively wide geographic distribution and infects both commensal and forest-inhabiting intermediate hosts. Sarcocystis sporocysts collected from rat snakes (Coelognathus radiatus, C. flavolineatus) in Thailand induced development of sarcocysts in experimental SD rats showing a type 10a cyst wall ultrastructure that was identical with those found in Rattus norvegicus from China and the forest rat Maxomys whiteheadi in Borneo. Its cystozoites had equal sizes in all intermediate hosts and locations, while sporocysts and cystozoites were distinct from other Sarcocystis species. Partial 28S rRNA sequences of S. muricoelognathis from M. whiteheadi were largely identical to those from R. norvegicus in China but distinct from newly sequenced Sarcocystis zuoi. The phylogeny of the nuclear 18S rRNA gene placed S. muricoelognathis within the so-called S. zuoi complex, including Sarcocystis attenuati, S. kani, S. scandentiborneensis and S. zuoi, while the latter clustered with the new species. However, the phylogeny of the ITS1-region confirmed the distinction between S. muricoelognathis and S. zuoi. Moreover, all three gene trees suggested that an isolate previously addressed as S. zuoi from Thailand (KU341120) is conspecific with S. muricoelognathis. Partial mitochondrial cox1 sequences of S. muricoelognathis were almost identical with those from other members of the group suggesting a shared, recent ancestry. Additionally, we isolated two partial 28S rRNA Sarcocystis sequences from Low's squirrel Sundasciurus lowii that clustered with those of S. scandentiborneensis from treeshews.

    CONCLUSIONS: Our results provide strong evidence of broad geographic distributions of rodent-associated Sarcocystis and host shifts between commensal and forest small mammal species, even if the known host associations remain likely only snapshots of the true associations.

  12. Fulltext Euarchontan Opsin Variation Brings New Focus to Primate Origins
    Melin AD, Wells K, Moritz GL, Kistler L, Orkin JD, Timm RM, et al.
    Mol Biol Evol, 2016 Apr;33(4):1029-41.
    PMID: 26739880 DOI: 10.1093/molbev/msv346
    Debate on the adaptive origins of primates has long focused on the functional ecology of the primate visual system. For example, it is hypothesized that variable expression of short- (SWS1) and middle-to-long-wavelength sensitive (M/LWS) opsins, which confer color vision, can be used to infer ancestral activity patterns and therefore selective ecological pressures. A problem with this approach is that opsin gene variation is incompletely known in the grandorder Euarchonta, that is, the orders Scandentia (treeshrews), Dermoptera (colugos), and Primates. The ancestral state of primate color vision is therefore uncertain. Here, we report on the genes (OPN1SW and OPN1LW) that encode SWS1 and M/LWS opsins in seven species of treeshrew, including the sole nocturnal scandentian Ptilocercus lowii. In addition, we examined the opsin genes of the Central American woolly opossum (Caluromys derbianus), an enduring ecological analogue in the debate on primate origins. Our results indicate: 1) retention of ultraviolet (UV) visual sensitivity in C. derbianus and a shift from UV to blue spectral sensitivities at the base of Euarchonta; 2) ancient pseudogenization of OPN1SW in the ancestors of P. lowii, but a signature of purifying selection in those of C. derbianus; and, 3) the absence of OPN1LW polymorphism among diurnal treeshrews. These findings suggest functional variation in the color vision of nocturnal mammals and a distinctive visual ecology of early primates, perhaps one that demanded greater spatial resolution under light levels that could support cone-mediated color discrimination.
  13. Fulltext Diet and the evolution of ADH7 across seven orders of mammals
    Pinto SL, Janiak MC, Dutyschaever G, Barros MAS, Chavarria AG, Martin MP, et al.
    R Soc Open Sci, 2023 Jul;10(7):230451.
    PMID: 37448478 DOI: 10.1098/rsos.230451
    Dietary variation within and across species drives the eco-evolutionary responsiveness of genes necessary to metabolize nutrients and other components. Recent evidence from humans and other mammals suggests that sugar-rich diets of floral nectar and ripe fruit have favoured mutations in, and functional preservation of, the ADH7 gene, which encodes the ADH class 4 enzyme responsible for metabolizing ethanol. Here we interrogate a large, comparative dataset of ADH7 gene sequence variation, including that underlying the amino acid residue located at the key site (294) that regulates the affinity of ADH7 for ethanol. Our analyses span 171 mammal species, including 59 newly sequenced. We report extensive variation, especially among frugivorous and nectarivorous bats, with potential for functional impact. We also report widespread variation in the retention and probable pseudogenization of ADH7. However, we find little statistical evidence of an overarching impact of dietary behaviour on putative ADH7 function or presence of derived alleles at site 294 across mammals, which suggests that the evolution of ADH7 is shaped by complex factors. Our study reports extensive new diversity in a gene of longstanding ecological interest, offers new sources of variation to be explored in functional assays in future study, and advances our understanding of the processes of molecular evolution.
  14. Fulltext Harnessing inter-disciplinary collaboration to improve emergency care in low- and middle-income countries (LMICs): results of research prioritisation setting exercise
    Lecky FE, Reynolds T, Otesile O, Hollis S, Turner J, Fuller G, et al.
    BMC Emerg Med, 2020 08 31;20(1):68.
    PMID: 32867675 DOI: 10.1186/s12873-020-00362-7
    BACKGROUND: More than half of deaths in low- and middle-income countries (LMICs) result from conditions that could be treated with emergency care - an integral component of universal health coverage (UHC) - through timely access to lifesaving interventions.

    METHODS: The World Health Organization (WHO) aims to extend UHC to a further 1 billion people by 2023, yet evidence supporting improved emergency care coverage is lacking. In this article, we explore four phases of a research prioritisation setting (RPS) exercise conducted by researchers and stakeholders from South Africa, Egypt, Nepal, Jamaica, Tanzania, Trinidad and Tobago, Tunisia, Colombia, Ethiopia, Iran, Jordan, Malaysia, South Korea and Phillipines, USA and UK as a key step in gathering evidence required by policy makers and practitioners for the strengthening of emergency care systems in limited-resource settings.

    RESULTS: The RPS proposed seven priority research questions addressing: identification of context-relevant emergency care indicators, barriers to effective emergency care; accuracy and impact of triage tools; potential quality improvement via registries; characteristics of people seeking emergency care; best practices for staff training and retention; and cost effectiveness of critical care - all within LMICs.

    CONCLUSIONS: Convened by WHO and facilitated by the University of Sheffield, the Global Emergency Care Research Network project (GEM-CARN) brought together a coalition of 16 countries to identify research priorities for strengthening emergency care in LMICs. Our article further assesses the quality of the RPS exercise and reviews the current evidence supporting the identified priorities.

  15. Fulltext The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
    Hudson LN, Newbold T, Contu S, Hill SL, Lysenko I, De Palma A, et al.
    Ecol Evol, 2014 Dec;4(24):4701-35.
    PMID: 25558364 DOI: 10.1002/ece3.1303
    Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - http://www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
  16. Fulltext The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
    Hudson LN, Newbold T, Contu S, Hill SL, Lysenko I, De Palma A, et al.
    Ecol Evol, 2017 Jan;7(1):145-188.
    PMID: 28070282 DOI: 10.1002/ece3.2579
    The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links