Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.
Danielle Levesque is an Assistant Professor at the University of Maine, USA, where she studies hibernation and torpor in mammals. She received her Bachelor's degree in Wildlife Biology from McGill University, Canada, in 2006, before completing her PhD with Barry Lovegrove at the University of KwaZulu-Natal, South Africa, in 2014. She then completed a Postdoctoral Fellowship at University of Malaysia Sarawak with Andrew Alek Tuen before moving to Maine in 2015.
Enterococcus gallinarum is a gram positive facultatively anaerobic bacteria that is typically found in mammalian intestinal tracts. It is generally not considered pathogenic to humans and is rarely reported. Here, we present the draft genome sequence data of Enterococcus gallinarum strain EGR748 isolated from a human clinical sample, and sequenced using the Illumina HiSeq 4000 system. The estimated whole genome size of the strain was 3,730,000 bp with a G + C content of 40.43%. The de novo assembly of the genome generated 55 contigs with an N50 of 208,509 bp. In addition, the Maximum Likelihood phylogenetic analysis based on the 16S rRNA sequence data accurately clustered EGR748 with other E. gallinarum strains. The data may be useful to demonstrate the capacity of this enterococcal species becoming the causal agents of nosocomial blood-stream infections. The genome dataset has been deposited at DDBJ/ENA/GenBank under the accession number JAABOR000000000.
This data article presents on the ectoparasites infestation on small mammals in Peninsular Malaysia. The dataset on ectoparasites infestation is important because it raises a major medical concern regarding the spread of potentially zoonotic disease from wildlife to human. Tick and chigger are the primary ectoparasites as reservoirs of vector-borne diseases found on small mammals in Malaysia. These small mammals that are infested with ectoparasites occupy various types of habitats, including human settlements, could be of community health risks as the carriers of potentially zoonotic diseases. Field samplings were conducted from February 2015 to February 2016 in three different ecological habitats of mixed dipterocarp forest, coastal forest and insular forest, in Terengganu, Malaysia. A total of 35 and 22 species of bats and rodents respectively were captured and examined for ectoparasites. Twenty-three species of bats and 16 species of small mammal were recorded as hosts for at least one species of ectoparasites. These findings show that the highest ectoparasite infestation occurred on bat community.
Unsustainable hunting is emptying forests of large animals around the world, but current understanding of how human foraging spreads across landscapes has been stymied by data deficiencies and cryptic hunter behaviour. Unlike other global threats to biodiversity like deforestation, climate change and overfishing, maps of wild meat hunters' movements-often based on forest accessibility-typically cover small scales and are rarely validated with real-world observations. Using camera trapping data from rainforests across Malaysian Borneo, we show that while hunter movements are strongly correlated with the accessibility of different parts of the landscape, accessibility measures are most informative when they integrate fine-scale habitat features like topography and land cover. Measures of accessibility naive to fine-scale habitat complexity, like distance to the nearest road or settlement, generate poor approximations of hunters' movements. In comparison, accessibility as measured by high-resolution movement models based on circuit theory provides vastly better reflections of real-world foraging movements. Our results highlight that simple models incorporating fine-scale landscape heterogeneity can be powerful tools for understanding and predicting widespread threats to biodiversity.
Oral cancer is one of the common cancer cases identified in the developing countries. Genetic mutation and overexpression of certain genes and proteins have been associated in the development of this cancer. Notch signalling pathway is normally involved in controlling the development process of vertebrates and invertebrates; however, deregulation of this pathway was found to be responsible in the formation of certain cancers including oral cancers. Activation of this pathway requires binding of the ligands to its receptors. Four NOTCH receptors (NOTCH 1, 2, 3 and 4) have been identified in mammals. Disruptions within these molecules might interfere with the normal functions of Notch signalling pathway. Hence, this study was conducted to detect mutations of NOTCH1 and NOTCH2 receptor genes which might be occurring in the oral cancer cases obtained from the local population. DNA extracted from fresh-frozen tissue biopsy of the tongue and buccal mucosa from 10 confirmed cases of oral cancer were subjected for polymerase chain reaction (PCR) amplification using the specific sets of primers. The PCR products were sent for sequencing before final results were analysed.
Due to time and cost limitation, only two out of four NOTCH receptor genes; NOTCH1 and NOTCH2, were used in this analysis. The results revealed absence of nucleotide changes for both NOTCH receptor genes amplified from these oral cancer samples. More samples and further analysis looking into other regions in these genes are required to conclude the involvement of NOTCH receptor genes mutation in causing oral cancer.
Cryptosporidium is an intestinal protozoan parasite which causes diarrhoea in animals and has recently been reported to cause similar symptoms in man. Cryptosporidiosis is a zoonotic infection and the first human case was reported in 1976.2 Since then the number of cases has increased by the hundreds especially among patients with acquired immuno-deficiency syndrome (AIDS), as a result of the severe symptoms that they cause in the im-munosuppressed patients and also due to the better screening techniques which have been developed resulting in the detection of cases.3 To date 20 species of Cryptosporidium have been reported but these cannot be differentiated morphologically. The differences are based mainly on the host from which the parasites were recovered. The species responsible for causing infection in man is Cryptosporidium parvum.4 Of the 20 species reported several are invalid because the oocysts of some of them were found to be the same as the sporocyst of Sarcocystis. It is now concluded that there are only two species that infect mammals (C. Muris and C. parvum). (Copied from article).
Injury to a peripheral nerve leads to degeneration of the segment distal to the site of lesion, a process referred to as Wallerian degeneration. During Wallerian degeneration, axons and myelin sheaths undergo degeneration and are phagocytosed by macrophages and Schwann cells. The Schwann cells proliferate and the endoneurial tubes persist, together the whole structure is known as the band of Büngner. Within few hours, the damaged axons in the proximal stump initiate a regeneration response, with formation of new growth cones. During Wallerian degeneration, neurotrophins, neural cell adhesion molecules, cytokines and other soluble factors are upregulated to facilitate regeneration. The recovery of the target in mammals is often variable, but almost never complete. In humans, scar tissue forms at the site of lesion and this often results in poor recovery of the target. The major events underlying this regenerative process is highlighted and discussed in this review.
There is an urgent need to identify and understand the ecosystem services of pollination and seed dispersal provided by threatened mammals such as flying foxes. The first step towards this is to obtain comprehensive data on their diet. However, the volant and nocturnal nature of bats presents a particularly challenging situation, and conventional microhistological approaches to studying their diet can be laborious and time-consuming, and provide incomplete information. We used Illumina Next-Generation Sequencing (NGS) as a novel, non-invasive method for analysing the diet of the island flying fox (Pteropus hypomelanus) on Tioman Island, Peninsular Malaysia. Through DNA metabarcoding of plants in flying fox droppings, using primers targeting the rbcL gene, we identified at least 29 Operationally Taxonomic Units (OTUs) comprising the diet of this giant pteropodid. OTU sequences matched at least four genera and 14 plant families from online reference databases based on a conservative Least Common Ancestor approach, and eight species from our site-specific plant reference collection. NGS was just as successful as conventional microhistological analysis in detecting plant taxa from droppings, but also uncovered six additional plant taxa. The island flying fox's diet appeared to be dominated by figs (Ficus sp.), which was the most abundant plant taxon detected in the droppings every single month. Our study has shown that NGS can add value to the conventional microhistological approach in identifying food plant species from flying fox droppings. At this point in time, more accurate genus- and species-level identification of OTUs not only requires support from databases with more representative sequences of relevant plant DNA, but probably necessitates in situ collection of plant specimens to create a reference collection. Although this method cannot be used to quantify true abundance or proportion of plant species, nor plant parts consumed, it ultimately provides a very important first step towards identifying plant taxa and spatio-temporal patterns in flying fox diets.
Myiasis occurs when living tissues of mammals are invaded by eggs or larvae of flies, mainly from the order of Diptera. Most of the previousty reported cases are in the tropics and they were usually associated with inadequate personal hygiene, sometimes with poor manual dexterity. This report describes two cases of oral myiasis in cerebral palsy patients in Seremban General Hospital, Malaysia. This article also discusses the therapeutic property of maggots and highlights the importance of oral health care in the special needs patients.
Protein-based films are thin and flexible films derived from protein sources. They are
completely biodegradable and used in food engineering, packaging, drug recovery, and other
applications. In food packaging, gelatin is widely used due to properties such as low cost,
availability, functional attributes, mechanical (flexibility and tension) and optical (brightness
and opacity) strength, barrier against gas flow, and structural resistance to water and
microorganisms. Therefore, this paper reviews the characterisation of biodegradable
protein-based films from gelatin alternatives, mainly from fish and chicken skin, as food
packaging materials. The properties of film packaging derived from gelatin alternatives were
compared with films derived from mammalian gelatin. The findings showed that the blended
gelatin alternatives with polysaccharide improved physical properties such as water vapour
permeability, gas permeability, light transmission and transparency, thermal properties,
microstructure, colour, and heat sealability. Moreover, improvements in mechanical
properties such as tensile strength and elongation at break were also investigated. This review
also comes out with suggestions for future research on the compatibility between gelatin films
and food ingredients. This paper provides a comprehensive overview that promotes the
development of biodegradable blended films from gelatin alternatives for packaging
applications in the food industry and related fields.
Developing novel fish gelatin films with better mechanical properties than mammalian gelatin is a challenging but promising endeavor. Studies were undertaken to produce fish gelatin films by combining treatments with different sugars (ribose and lactose) followed 'by' 'and' ultraviolet (UV) radiation, as possible cross-linking agents. Increase in tensile strength and percent elongation at break was recorded, which was more significant in films without sugars that were exposed to UV radiation. Films with added ribose showed decreased solubility after UV treatment and exhibited higher swelling percentage than films with added lactose, which readily dissolved in water. FTIR spectra of all the films showed identical patterns, which indicated no major changes to have occurred in the functional groups as a result of interaction between gelatin, sugars and UV irradiation. The results of this study could be explored for commercial use, depending on industrial needs for either production of edible films or for food packaging purposes.
Inactivation constant for V79 cells has been extracted from radiobiology experiments that utilize charged particles to irradiate mammal cells in vitro. Physical parameters such as effective charge, radiation mean free path and linear ionization which characterized protons and heluim-4 particles are determined using of standard values. The relationship between inactivation constant α and physical quality parameters have been determined, in this research, for protons and heluim-4 particles. This approach allows getting the characteristic biological response of inactivation of V79 cells in terms of each selected physical quality parameter. The best regression models are formulated for each obtained relationship.
Nuclear receptors (NRs) represent intracellular proteins that function as a signaling network of transcriptional factors to control genes in response to a variety of environmental, dietary, and hormonal stimulations or serve as orphan receptors lacking a recognized ligand. They also play an essential role in normal development, metabolism, cell growth, cell division, physiology, reproduction, and homeostasis and function as biological markers for tumor subclassification and as targets for hormone therapy. NRs, including steroid hormone receptors (SHRs), have been studied as tools to examine the fundamentals of transcriptional regulation within the development of mammals and human physiology, in addition to their links to disturbances. In this regard, it is widely recognized that aberrant NR signaling is responsible for the pathological growth of hormone-dependent tumors in response to SHRs dysregulation and consequently represents a potential therapeutic candidate in a range of diseases, as in the case of prostate cancer and breast cancer. On the other hand, phytosterols are a group of plant-derived compounds that act directly as ligands for NRs and have proven their efficacy in the management of diabetes, heart diseases, and cancers. However, these plants are not suggested in cases of hormone-dependent cancer since a certain group of plants contains molecules with a chemical structure similar to that of estrogens, which are known as phytoestrogens or estrogen-like compounds, such as lignans, coumestans, and isoflavones. Therefore, it remains an open and controversial debate regarding whether consuming a phytosterol-rich diet and adopting a vegetarian lifestyle like the Mediterranean diet may increase the risk of developing steroid hormone-dependent cancers by constitutively activating SHRs and thereby leading to tumor transformation. Overall, the purpose of this review is to better understand the relevant mechanistic pathways and explore epidemiological investigations in order to establish that phytosterols may contribute to the activation of NRs as cancer drivers in hormone-dependent cancers.
The mammalian intestine is one of the most rapidly self-renewing tissues, driven by stem cells residing at the crypt bottom. Paneth cells form a major element of the niche microenvironment providing various growth factors to orchestrate intestinal stem cell homeostasis, such as Wnt3. Different Wnt ligands can selectively activate β-catenin-dependent (canonical) or -independent (noncanonical) signaling. Here, we report that the Dishevelled-associated activator of morphogenesis 1 (Daam1) and its paralogue Daam2 asymmetrically regulate canonical and noncanonical Wnt (Wnt/PCP) signaling. Daam1/2 interacts with the Wnt inhibitor RNF43, and Daam1/2 double knockout stimulates canonical Wnt signaling by preventing RNF43-dependent degradation of the Wnt receptor, Frizzled (Fzd). Single-cell RNA sequencing analysis revealed that Paneth cell differentiation is impaired by Daam1/2 depletion because of defective Wnt/PCP signaling. Together, we identified Daam1/2 as an unexpected hub molecule coordinating both canonical and noncanonical Wnt, which is fundamental for specifying an adequate number of Paneth cells.
This study aimed to investigate and compare the proportion of AMR Escherichia coli (E. coli) between urban (Dompe in the Western province) and rural (Dambana in the Sabaragamuwa province) areas in Sri Lanka. The overall hypothesis of the study is that there is a difference in the proportion of AMR E. coli between the urban and the rural areas. Faecal samples were collected from healthy humans (n = 109), dairy animals (n = 103), poultry (n = 35), wild mammals (n = 81), wild birds (n = 76), soil (n = 80) and water (n = 80) from both areas. A total of 908 E. coli isolates were tested for susceptibility to 12 antimicrobials. Overall, E. coli isolated from urban area was significantly more likely to be resistant than those isolated from rural area. The human domain of the area had a significantly higher prevalence of AMR E. coli, but it was not significantly different in urban (98%) and rural (97%) areas. AMR E. coli isolated from dairy animals, wild animals and water was significantly higher in the urban area compared with the rural area. There was no significant difference in the proportion of multidrug resistance (MDR) E. coli isolated from humans, wild animals and water between the two study sites. Resistant isolates found from water and wild animals suggest contamination of the environment. A multi-sectorial One Health approach is urgently needed to control the spread of AMR and prevent the occurrences of AMR in Sri Lanka.
Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes that have independently evolved to catalyze the first step in tryptophan catabolism via the kynurenine pathway (KP). The depletion of tryptophan and formation of KP metabolites modulates the activity of the mammalian immune, reproductive, and central nervous systems. IDO and TDO enzymes can have overlapping or distinct functions depending on their expression patterns. The expression of TDO and IDO enzymes in mammals differs not only by tissue/cellular localization but also by their induction by distinct stimuli. To add to the complexity, these genes also have undergone duplications in some organisms leading to multiple isoforms of IDO or TDO. For example, many vertebrates, including all mammals, have acquired two IDO genes via gene duplication, although the IDO1-like gene has been lost in some lower vertebrate lineages. Gene duplications can allow the homologs to diverge and acquire different properties to the original gene. There is evidence for IDO enzymes having differing enzymatic characteristics, signaling properties, and biological functions. This review analyzes the evolutionary convergence of IDO and TDO enzymes as tryptophan-catabolizing enzymes and the divergent evolution of IDO homologs to generate an enzyme family with diverse characteristics not possessed by TDO enzymes, with an emphasis on the immune system.
The tin mining activities in the suburbs of Jos, Plateau State, Nigeria, have resulted in technical enhancement of the natural background radiation as well as higher activity concentrations of primordial radionuclides in the topsoil of mining sites and their environs. Several studies have considered the radiological human health risks of the mining activity; however, to our knowledge no documented study has investigated the radiological impacts on biota. Hence, an attempt is made to assess potential hazards using published data from the literature and the ERICA Tool. This paper considers the effects of mining and milling on terrestrial organisms like shrubs, large mammals, small burrowing mammals, birds (duck), arthropods (earth worm), grasses, and herbs. The dose rates and risk quotients to these organisms are computed using conservative values for activity concentrations of natural radionuclides reported in Bitsichi and Bukuru mining areas. The results suggest that grasses, herbs, lichens, bryophytes and shrubs receive total dose rates that are of potential concern. The effects of dose rates to specific indicator species of interest are highlighted and discussed. We conclude that further investigation and proper regulations should be set in place in order to reduce the risk posed by the tin mining activity on biota. This paper also presents a brief overview of the impact of mineral mining on biota based on documented literature for other countries.
Gut microbiota plays an important role in mammalian host metabolism and physiological functions. The functions are particularly important in young children where rapid mental and physical developments are taking place. Nevertheless, little is known about the gut microbiome and the factors that contribute to microbial variation in the gut of South East Asian children. Here, we compared the gut bacterial richness and composition of pre-adolescence in Northern Malaysia. Our subjects covered three distinct ethnic groups with relatively narrow range of socioeconomic discrepancy. These included the Malays (n = 24), Chinese (n = 17) and the Orang Asli (indigenous) (n = 20). Our results suggested a strong ethnicity and socioeconomic-linked bacterial diversity. Highest bacterial diversity was detected from the economically deprived indigenous children while the lowest diversity was recorded from the relatively wealthy Chinese children. In addition, predicted functional metagenome profiling suggested an over-representation of pathways pertinent to bacterial colonisation and chemotaxis in the former while the latter exhibited enriched gene pathways related to sugar metabolism.