Anopheles sundaicus s.l. is a malaria vector in coastal areas of Southeast Asia. Previous studies showed at least four distinct species within the complex. The present study investigated the phylogeography and the status of A. sundaicus s.l. populations from Cambodia, Thailand, Malaysia and Indonesia with regard to A. sundaicus s.s. from Sarawak, Malaysian Borneo and A. epiroticus in Vietnam and Thailand. Three lineages recovered by analyses of Cyt-b and COI (mtDNA) confirmed the presence of A. sundaicus s.s. in Malaysian Borneo, the distribution of A. epiroticus from southern Vietnam to peninsular Malaysia, and recognised a distinct form in Indonesia that is named A. sundaicus E. The phylogenetic and demographic analyses suggest that the three species were separated during the Early Pleistocene (1.8-0.78 Myr) and experienced bottlenecks followed by a genetic expansion in more recent times. Based on the results and knowledge of the biogeography of the area, we hypothesise that the combination of cyclical island and refugium creation was the cause of lineage isolation and bottleneck events during the Pleistocene.
Meliponiculture, the keeping of domesticated stingless bees such as Geniotrigona thoracica (Smith, 1857) (Hymenoptera: Apidae), is an increasingly popular agricultural industry in Malaysia. This study reports the soldier fly (Diptera: Stratiomyidae) species of the genus Hermetia colonizing stingless bee colonies in Malaysia. The larvae were reared in the laboratory to the adult stage and identified through molecular and morphological approaches. Hermetia illucens (Linnaeus, 1758) and Hermetia fenestrata de Meijere, 1904 (Diptera: Stratiomyidae) were identified from the sample provided. Earlier records of stratiomyids in stingless bee nests were misidentified as H. illucens. This paper represents the first identified record of H. fenestrata colonizing a "spoiled" stingless bee colony. In addition, adult and larval morphological differences between both species and the roles of both species in bee nest decomposition are discussed.
Cancer still presents enormous challenges in the medical world. Currently, the search for
anticancer compounds has garnered a lot of interest, especially in finding them from the natural
sources. In this study, by using Sulforhodamine B (SRB) colorimetric assay, compounds,
extracted from supermeal worm (Zophobas morio) larvae using two types of acidified organic
solvent (ethanol and isopropanol), were shown to inhibit the growth of a breast cancer line,
MCF-7. A comparative study of the effect was carried out on a normal cell line, Vero. Results
showed that, the two types of extracts inhibits growth of MCF-7 cell at varying degrees, on
the other hand, have much less effect on Vero cell. Extracts analysed by UV-vis spectroscopy,
showed peaks in the range of 260 to 280 nm, inferring the presence of aromatic amino acids,
whereas the highest peak of 3.608 AU at 230 nm indicates the presence of peptide bonds. By
Raman spectroscopy, peaks are observed at 1349 cm-1, 944 cm-1 and 841 cm-1 indicating the
presence of Tyr, Try and Gly, confirming the UV-vis analyses. All results of analyses implied
that the anticancer compounds contain peptides.
Many studies have been done on various species of insects to investigate their potential use in industries. This is because insects have high protein content which could be further manipulated. Due to its eating habit, Zophobas morio larvae, also known as super mealworm has been shown to have high amylase activity. In this study, amylase from super mealworm has been immobilized via Cross-Linked Enzyme Aggregates (CLEA) technique and its kinetic performance, evaluated. CLEA is one of the best immobilization method with respect to enzyme stability and reusability. Kinetic performance of both free and CLEA-amylase were evaluated based on the Michaelis-Menten model. Results obtained based on Hanes-Woolf, LineweaverBurk, Eadie-Hofstee and Hyperbolic Regression plots showed that the kinetic parameters, Vmax and KM, changed upon immobilization. For CLEA-amylase, Hanes-Woolf plot showed the bestfitted model based on R2 with Vmax= 1.068 mM/min and KM= 0.182 mM, however, LineweaverBurk plot was used to obtain the kinetic parameters for free amylase, with Vmax and KM of 17.230 mM/min and 2.470 mM, respectively. Thus it is observed that upon immobilization, Vmax for amylase dropped appreciably, however, much lower substrate concentration is needed to saturate the enzymatic sites to reach its maximum catalytic efficiency. The result from this study might open the new path in discovering the potential use of insects in industrial applications, for example, making use of the recovered enzymes in the detergent industry.
World Health Organization (WHO) estimated over 100 million dengue infections to happen annually worldwide involving more than 2.5 billion people. Temephos or abate is a larvicide that has been used in vector control to eradicate mosquito larvae. Though practically low risk, there had been resistance problem reported with continuous use. This study seeks to find an effective and safer alternative to abate by assessing the use of ethanolic extract of Murraya koenigii leaves as larvicidal agent against Aedes aegypti. M.koenigii leaves were macerated for 3 days with absolute ethanol and evaporated using rotary vapor to produce the crude extract. The crude extract was subjected to phytochemical screening using standard qualitative method. For bioassay, the crude
extract underwent a serial dilution to produce 3 concentrations of 100 ppm (C1), 50 ppm (C2) and 10 ppm (C3) with abate and absolute ethanol as negative and positive control respectively. Bioassay for larvicidal effect was conducted in accordance to WHO standard method. Phytochemical screening of ethanolic extract of M. koenigii leaves revealed the presence of alkaloid, steroid and saponin. The bioassay shows that after 24 hours, the mortality rate of C1, C2 and C3 larvae were 100%, 38% and 0% and when further extended to 48 hours, the rate increased to 100% and 46% for C2 and C3 respectively. The LC50 and LC99 post 24 hours were 54.489 ppm and 93.961 ppm respectively whilst at post 48 hours, the LC50 and LC99 were 10.263 ppm and 16.176 ppm respectively. The results show that up to 48 hours duration of exposure, the mortality
rate increase whilst the lethal concentration (LC50 and LC99) decreases. Upon examination on larvae deformities at post 24 and 48 hours, all test concentrations and negative control exhibit normal morphology. Positive control, however, exhibit deformities characterized by twisted and fragmented insides. When statistically analyzed, C1 larvicidal activity was proven comparable with abate at 24 hours while C2 needed 48 hours exposure to be on par. Based on the results, it could be argued that the ethanolic extract of M.koenigii leaves does hold promising value to be further developed as larvicidal.
Introduction Strongyloides stercoralis is an intestinal helminth that infects humans
through contact with soil containing the larvae.
Methods A systematic search was performed for relevant titles, abstract and keywords
in database from Cochrane Library, PLOS One, PubMed and several other
sources in October 2017 based on PICO strategy. Out of 511 papers that were
evaluated for possible inclusion, final assessment for eligibility has yielded a
total of 17 papers to be included which were found suitable for analysis
covering period from 2012 till 2016.
Results A major challenge of giving an overview of prevalence data for S. stercoralis
lies in the low sensitivity of diagnostic method used which resulted in very
low prevalence in certain countries. Cambodia and Laos presented with high
prevalence ranging from 17.4% to 45.9% by using high sensitivity of
diagnostic methods. The current prevalence situation of S. stercoralis in
Southeast Asia still have wide gaps remains due to several reasons.
Conclusions The information we have today only scratches the surface which cannot truly
reflect the true burden of S. stercoralis in Southeast Asia The main risk factor
is personal hygiene practices especially amongst males.
Dengue is a serious mosquito borne disease common in tropical and sub-tropical countries including Malaysia. There is at present a lack of specific treatment and an effective tetravalent vaccine against dengue. The control of dengue depends solely on the suppression of the two most important vectors namely, Aedes aegypti and Ae albopictus. Despite intensive and extensive control efforts by health agencies, the disease continues to spread. This paper updates various innovations on control of dengue vectors. Gene-based sterile insect technique using the RIDL technology for both Aedes aegypti & Ae albopictus control has now been actively researched and field trials are pursued to evaluate the effectiveness of the technology. The release of Wolbachia-infected Ae aegypti is another dengue control innovation. The infected mosquito cannot support development of dengue virus and has shorter life span. Other innovations include: auto-dissemination of insect control agents using ovitrap, autocidal adult and larva trap, outdoor residual spraying, insecticidal paint and biocontrol agent. In other innovation, outbreak prediction capability is enhanced by developing model based on environmental data and analysis utilising neural network.
Vector control is still the principal method to control dengue and chemical insecticides, especially the
pyrethroids such as permethrin are the forerunners of mosquito control agent. Intensive and extensive use
of pyrethroids often result in resistance, thereby hampering control efforts. The present study was
conducted to evaluate the susceptible status of Aedes aegypti, the primary vector of dengue against
permethrin. A nationwide mosquito sampling via ovitrapping was conducted in 12 dengue hotspots across 5
states in Peninsular Malaysia. Field collected Aedes eggs were hatched and reared until L3 larval and further
identified it species. Adult F0 Aedes aegypti were reared until F1 progeny and the female were used in
adult assay, performed according to World Health Organization (WHO) protocol as to determine the
resistance level. The laboratory strain maintained for more than 1000 generations that were susceptible to
permethrin served as the control strain. Evaluation of resistance ratio was assessed by comparing the
knockdown rate with laboratory susceptible strain. In this present study, 70% ofAe. aegypti population from
dengue hotspots was highly resistance to permethrin. The study clearly demonstrated that widespread of
permethrin resistant Ae. aegypti in Malaysian mosquito’s population, indicating the need of implementing
an efficient pyrethroid resistance management.
Introduction: Entomological surveillance is crucial to determine the abundance of dengue vector and to evaluate breeding areas of Aedes aegypti and Aedes albopictus. The objective of this study is to determine the distribution and breeding preference for both Ae. aegypti and Ae. albopictus in dengue endemic areas. Materials and Methods: Ovitraps surveillance was conducted in two dengue endemic areas; AU2, Keramat and Seksyen 7, Shah Alam, Selangor. A minimum number of 100 ovitraps were deployed for 5 days in the study sites. Samples collected were brought back to the lab and all larvae recovered were identified to species level. Results: The ovitap index (OI) in both localities exceeded the transmission threshold of 10% with the OI recorded ranged from 42.3-79.8% in AU2, Keramat and 16.7-42.9% in Seksyen 7, Shah Alam. Ae. albopictus was the dominant species in AU2 Keramat with the highest ratio Ae. aegypti to Ae. albopictus recorded was 1.00:22.79. Nonetheless, in Seksyen 7, Shah Alam the difference in Ae. aegypti to Ae. albopictus ratio is not really prominent with 1.00:3.61 for ovitraps deployed outdoor and 3.40:1.00 for ovitraps set indoor. It was determined that single infestation of either Ae. aegypti or Ae. albopictus is more frequent for ovitraps deployed indoor and/or outdoor, respectively. It was also determined that mixed infestations were found in this study indicating that both species can oviposit in the same container. Conclusion: This study indicates that OI is still above transmission threshold in both study sites. While Ae. aegypti and Ae. albopictus remain as a dominant indoor and outdoor breeder, respectively, mixed breeding of Aedes species in a same container was also observed.
Background: The present study describes the morphology of sparganum (larva) of the Malaysian Spirometra spp. collected from naturally infected frogs (Rana cancrivora) from rice fields in Tanjung Karang, Malaysia.
Materials and Methods: Spargana of Spirometra spp. collected from naturally infected frogs (Rana cancrivora) were used for the morphological studies. Stretched on a metal ruler, measurements of the worm were recorded. Specimens were stained in Alum-carmine.
Results: The length of the body ranged from 11-50 mm and the width ranged from 0.5-1.5 mm. Specimens stained with Alum-carmine showed ridges (formation of segments) on the surface of the body, and no sexual organs in the body.
Conclusion: The Malaysian Spirometra spp. are similar in measurement and morphology to Spirometra erinacei but further studies are required for confirmation.
Traditional healers in Sarawak, Malaysia, use plants such as Picria fel-terrae, Linariantha bicolor and Lansium domesticum to treat gastrointestinal infections. This study aimed to test whether their nematocidal activities could be confirmed in vitro using highly standardised Caenorhabditis elegans models. We applied eight different ethanol solubilised plant extracts and two commercial anthelmintic drugs to larval and adult stages of C. elegans in vitro. Seven C. elegans strains were evaluated, one wild type and six strains with GFP-tagged stress response pathways to help characterise and compare the pathways affected by plant extracts. Our in vitro screen confirmed that both of the commercial anthelmintic drugs and five of the eight traditionally used plant extracts had significant nematocidal activity against both larval and adult C. elegans. The most effective extracts were from P. fel-terrae. The plant extracts triggered different stress response pathways from the commercial anthelmintic drugs. This study showed that using traditional knowledge of plant medicinal properties in combination with a C. elegans in vitro screen provided a rapid and economical test with a high hit rate compared with the random screening of plants for nematocidal activities. The use of transgenic C. elegans strains may allow this approach to be refined further to investigate the mode of action of active extracts.
Lemuricola (Protenterobius) nycticebi is the only pinworm species known to infect strepsirrhine primates outside Africa, and the only pinworm species yet described in slow lorises. Here, we provided a detailed morphological comparison of female and male worms, and a first description of fourth-stage larvae collected from free-living slow lorises (Nycticebus menagensis) in Sabah, Malaysian Borneo. Using mitochondrial and nuclear markers, we also reconstructed the species' phylogenetic relationship with other pinworms infecting primates. Both morphological and molecular results indicated a distinct association between L. (P.) nycticebi and its host. However, while taxonomy identified this species as a member of the Lemuricola clade and grouped pinworms infecting lemurs and slow lorises together, phylogenetic reconstruction split them, placing L. (P.) nycticebi within the Enterobius clade. Our results suggest that L. (P.) nycticebi may represent a different taxon altogether, and that it is more closely related to pinworm species infecting Old World primates outside Madagascar. Pongobius pongoi (Foitová et al., 2008) n. comb. is also proposed.
Due to their unusual life cycle that includes parasitic larval and free living adult stages, gnathiid isopods are typically overlooked in biodiversity surveys, even those that focus on parasites. While the Philippines sits within the region of highest marine biodiversity in the world, the coral triangle, no gnathiid species have been identified or described from that region. Here we present the first records of two gnathiid species collected from the Visayas, central Philippines: Gnathia malaysiensis Müller, 1993, previously described from Malaysia, and G. camuripenis Tanaka, 2004, previously described from southern Japan. This paper provides detailed morphological redescriptions, drawings and scanning electron microscope images as well as the first molecular characterisation of both species, Furthermore, a summary of the Central-Indo Pacific Gnathia species is provided.
Within host communities, related species are more likely to share common parasitic agents, and as a result, morphological similarities have led researchers to conclude that parasites infecting closely related hosts within a community represent a single species. However, genetic diversity within parasite genera and host range remain poorly investigated in most systems. Strongyloides is a genus of soil-transmitted nematode that has been reported from several primate species in Africa and Asia, and has been estimated to infect hundreds of millions of people worldwide, although no precise estimates are available. Here we describe a case of infection with a cryptic species of Strongyloides in a Bornean (Philippine) slow loris (Nycticebus menagensis) living within a diverse community of several primate species in the Lower Kinabatangan Wildlife Sanctuary, Malaysian Borneo. Fresh fecal samples were collected from five primate species and nematode larvae cultured from these samples were selected for phylogenetic analyses. Sequences obtained for most larvae were identified as S. fuelleborni, grouping into three different clusters and showing no aggregation within specific hosts or geographic location. In contrast, a set of parasite sequences obtained from a slow loris clustered closely with S. stercoralis into a different group, being genetically distinct to sequences reported from other primate hosts, humans included. Our results suggest that although S. fuelleborni infects all haplorrhines sampled in this primate community, a different species might be infecting the slow loris, the only strepsirrhine in Borneo and one of the least studied primates in the region. Although more data are needed to support this conclusion, we propose that Strongyloides species in primates might be more diverse than previously thought, with potential implications for ecological and evolutionary host-parasite associations, as well as epidemiological dynamics.
The antioxidant role of sulfite reductase (SiR) derived from Arthrospira platensis (Ap) was identified through a short peptide, TL15. The study showed that the expression of ApSiR was highly expressed on day ten due to sulfur deprived stress in Ap culture. TL15 peptide exhibited strong antioxidant activity when evaluated using antioxidant assays in a concentration ranging from 7.8 and 125 μM. Further, the cytotoxicity of TL15 peptide was investigated, even at the higher concentration (250 μM), TL15 did not exhibit any toxicity, when tested in vitro using human leucocytes. Moreover, a potential reduction in reactive oxygen species (ROS) production was observed due to the treatment of TL15 peptide (>15.6 μM) to H2O2 exposed leucocytes. For the in vivo assessment of TL15 toxicity and antioxidant ability, experiments were performed in zebrafish (Danio rerio) larvae to analyse the developmental toxicity of TL15 peptide. Results showed that, exposure to TL15 peptide in tested concentrations ranging from 10, 20, 40, and 80 μM, did not affect the development and physiological parameters of the zebrafish embryo/larvae such as morphology, survival, hatching and heart rate. Fluorescent assay was performed using DCFH-DA (2,7-dichlorodihydrofluorescein diacetate) to examine the production of intracellular reactive oxygen species (ROS) in zebrafish treated with TL15 peptide during the embryo-larval stages. Fluorescent images showed that pre-treatment with TL15 peptide to attenuate the H2O2 induced ROS levels in the zebrafish larvae in a dose-dependent manner. Further to uncover the underlying biochemical and antioxidant mechanism, the enzyme activity of superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) levels were studied in zebrafish larvae. TL15 pre-treated groups showed enhanced antioxidant enzyme activity, while the hydrogen peroxide (H2O2) exposed larvae showed significantly diminished activity. Overall results from the study revealed that, TL15 act as a potential antioxidant molecule with dose-specific antioxidant property. Thus, TL15 peptide could be an effective and promising source for biopharmaceutical applications.
Surface engineering of super paramagnetic iron oxide nanoparticles (SPIONs) favor the tagging of any molecule or compound onto it, encapsulating them with a biopolymer make them biocompatible and favor slow release of loaded molecules. Recovery of SPIONs is easier as they obey to external magnetic field. In this study, SPIONS were used for mosquito larvicidal activity after surface engineered with oleic acid to favor the tagging of Cyfluthrin (mosquito larvicidal agent), it was then encapsulated with gum polysaccharide derived from Azadirachta indica and Araucaria heterophylla. Every stage of coreshell formation was microscopically and spectroscopically characterized. The coreshell SPIONs produced using Azadirachta indica and Araucaria heterophylla gum derived polysaccharide encapsulation were found to be the size around 80 nm. Thus, prepared coreshell SPIONs was subjected for mosquito larvicidal activity against Culex sp. The coreshell SPIONs was efficiently killing the mosquito larva and its impact was studied by percentage mortality studies.
Large amount of sodium hydroxide (NaOH) is consumed to remove the protein content in chitin biomass during deproteinization. However, excessive NaOH concentration used might lead to the reduction of cost effectiveness during chitin extraction. Hence, the present study aimed to extract and evaluate the physicochemical properties of chitin and chitosan isolated from superworm (Zophobas morio) larvae using 0.5M-2.0M of NaOH. The extracted chitin and chitosan were subjected to Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis, Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD). The 0.5M NaOH treatment resulted in the highest yield of chitin (5.43%), but produced the lowest yield (65.84%) of chitosan. The extracted chitin samples had relatively high degree of acetylation (DA) (82.39%-101.39%). Both chitin and chitosan showed smooth surface with tiny pores. The extracted chitin samples were confirmed as α-chitin based on the FT-IR and TGA. The chitin samples were amorphous with low degree of crystallinity. From TGA, the Chitosan 3 extracted was partially deacetylated. Both DPPH radical scavenging and ferric-chelating assay showed positive correlation with DD of chitosan isolates. However, the chitosan isolates were not fully dissolved, resulting in lower radical scavenging and ferric-chelating ability compared to commercial chitosan.
The effective control of Aedes mosquitoes using traditional control agents is increasingly challenging due to the presence of insecticide resistance in many populations of key mosquito vectors. An alternative strategy to insecticides is the use of toxic sugar baits, however it is limited due to short-term efficacy. Alginate-Gelatin hydrogel beads (AGHBs) may be an effective alternative by providing longer periods of mosquito attraction and control, especially of key vectors of dengue viruses such as Aedes aegypti and Aedes albopictus. Sodium alginate (ALG) and gelatin (GLN) are natural polymers, which can be a potential candidate to develop the AGHBs baits due to their biodegradability and environmental safety. Here we provide an assessment of the preparation of AGHBs optimized by varying the concentrations of ALG, GLN, and its cross-linking time (TIME). Fourier transform infrared spectroscopy (FTIR) analysis results in the determination of liquid bait loaded in the AGHBs. The evaluation of AGHBs' effectiveness as the potential baiting tool based on the mortality rate of mosquitoes after the bait consumption. The 100 % percent mortality of Aedes mosquitoes was obtained within 72 h of bait consumption. The field evaluation also justifies the applicability of AGHBs for outdoor applications. We conclude that the AGHBs are applicable as a baiting tool in carrying liquid bait in achieving mosquito mortality.
Larvae of Aedes albopictus Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall, Ae. albopictus may experience increased loss of immature stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of Ae. albopictus. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of Ae. albopictus and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
Hookworm-related cutaneous larva migrans (CLM) is characterized clinically by erythematous and slightly raised tracks, located especially on the feet. These tracks may be single or multiple, linear or serpiginous, more or less ramified and intertwined. The length is variable (up to many cm); the width ranges from 1 mm to 4 mm. Tracks are often accompanied by severe pruritus.