Imported case of Leishmania tropica cutaneous leishmaniasis in a 10-year-old child in Malaysia

@#The present paper reported a first imported case of cutaneous leishmaniasis in a 10-yearold child who returned from Saudi Arabia to Malaysia. Six weeks after his travel to Malaysia, two erythematous dermal nodules were developed over his right cheek and chin. Occurrence of intracellular amastigote of Leishmania was observed through examination of skin biopsy with hematoxylin and eosin stain. Furthermore, molecular analysis of ribosomal internal transcribed spacer 1 (ITS1) of Leishmania spp. confirmed the child was infected with Leishmania tropica. The child was given oral fluconazole and he had a 80% recovery before he went back to Saudi Arabia.

Serological survey of canine vector-borne diseases in two animal shelters in central Peninsular Malaysia

@#Canine vector-borne diseases (CVBDs) are increasingly becoming a cause for global concern because of their high morbidity and mortality rates in dogs. However, information on their occurrence in Malaysia is still scanty. In this study, a total of 103 dog blood samples were collected from two animal shelters in central Peninsular Malaysia and tested for the antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi, and the antigen of Dirofilaria immitis. Of the 103 tested dogs, 44.7% (46) were found to be seropositive for Ehrlichia spp., 30.1% (31) for Anaplasma spp. and 13.6% (14) for D. immitis. Co-infections of Anaplasma spp. + Ehrlichia spp. (18.5%, 19) were most prevalent, followed by Anaplasma spp. + D. immitis (1.9%; two) and D. immitis + Ehrlichia spp. (1.0%; one). Furthermore, three dogs (2.9%) were also found to have triple infection, testing seropositive for Ehrlichia spp., Anaplasma spp. and D. immitis. The dogs which were found to be seropositive with at least one pathogen were 66.7% (32/51) at shelter A, and 55.8% (29/52) at shelter B. Serological evidence showed that the exposure of major vector-borne diseases in dogs in shelters was relatively high in the surveyed areas. Routine detection and control of vector-borne diseases are of paramount importance for reducing the risk of CVBDs transmission in dogs and humans.

Bioefficacy of mosquito mat vaporizers and associated metabolic detoxication mechanisms in Aedes aegypti (Linnaeus) in Selangor, Malaysia: A statewide assessment

@#This study aims to examine the efficacy of mosquito mat vaporizers on Aedes aegypti and their associated metabolic detoxication mechanisms. For this purpose, Aedes aegypti (Linnaeus) was collected from nine districts in Selangor, Malaysia and tested with mosquito vaporizing mat bioassays. The same populations were also subjected to biochemical assays to investigate activities of detoxifying enzymes, namely non-specific esterase (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO). The efficacy of Ae. aegypti on the active ingredients tested in decreasing order were d- allethrin > dimefluthrin > prallethrin with PBO > prallethrin. The results further indicated significant enhancement mean levels of EST, GST and MFO in pyrethroid-resistant populations. The mortality rate of Ae. aegypti in response to pyrethroid active ingredients was associated with MFO activity, suggesting it is an important detoxification enzyme for the populations tested. In view of the presence of resistance against household insecticide products, pyrethroid efficacy on Ae. aegypti populations needs to be monitored closely to ensure the implementation of an effective vector control program in Malaysia.

Blockade of IL-27 signaling ameliorates herpes stromal keratitis with upregulated CD4+ Foxp3+ regulatory T cells influx in mice

Purpose: The purpose of this study was to investigate the production of IL-27 p28 and EBI3 in the ocular inflammatory sites, and the role of IL-27 signaling in a model of HSV-1 induced herpetic stromal keratitis (HSK). Methods: The BALB/c mice were injected intraperitoneally (24 h before infection) with anti-IL-27 antibody or IgG antibody as control, infected with HSV-1 via corneal scarification, and then injected intraperitoneally with anti-IL-27 antibody or IgG antibody at 1, 3, and 5 days postinfection. Slit lamp and histopathology were used to assess disease outcome. The levels of IL-27 p28 and EBI3 in corneas were determined by western blotting and immunofluorescence. Furthermore, viral titers were determined, and immune cell infiltrates were collected and analyzed by flow cytometry. Results: We found that the levels of IL-27 p28 and EBI3 in corneas were elevated significantly at the peak of HSK, and both of them were expressed simultaneously in the epithelium, stroma, and endothelium of corneas. In the group of anti-IL-27 treatment, the severity of the corneal lesion and CD4+ T cells infiltration were significantly decreased, and the percentage of CD4+ Foxp3+ Tregs was upregulated markedly in the spleen, DLNs and cornea of HSK mice compared to IgG treatment. Conclusion: These results provided evidence that IL-27 as a pathogenic pro-inflammatory cytokine controlled CD4+ Foxp3+ Tregs production in HSK, which ultimately resulted in promoting the progression of HSK and poor prognosis.

Prevalence and risk factors of Toxoplasma infection – an update in Malaysian pregnant women

@#Toxoplasma gondii is a protozoan parasite that is capable of causing a zoonotic disease, known as toxoplasmosis. Vertical transmission of T. gondii from the mother to the fetus, during pregnancy may cause severe complications to the developing fetus. This current study aimed to determine the seroprevalence and investigate the associated risk factors of Toxoplasma infection in pregnant women (n=219) visiting the antenatal clinic at UMMC. While the elevated level of anti-Toxoplasma IgG and IgM antibodies indicates the presence of infection, it fails to differentiate between a past and a recent infection. Thus, the study also demonstrates the usefulness of IgG avidity in validating the timing of infection. The serum samples were tested for the presence of anti-Toxoplasma IgG and IgM antibodies by ELISA test, and the seropositive samples for both anti-Toxoplasma IgG and IgM antibodies were further evaluated by IgG avidity. The results showed that the overall prevalence of T. gondii seropositivity was 34.7%. Of these, 30.6% (67/219) were positive for anti-Toxoplasma IgG antibody only, 2.3% (5/219) were positive for anti-Toxoplasma IgM only, and the remaining 1.8% (4/219) was positive for both anti-Toxoplasma IgG and IgM antibodies. All of the pregnant women who were positive for both anti-Toxoplasma IgG and IgM antibody were found to have past infection when evaluated by IgG avidity. In this study, Malay ethnicity and the number of existing previous children were significantly associated with T. gondii seropositivity (p<0.05). Based on these findings, information and education on the transmission and prevention of congenital toxoplasmosis are very crucial as a public health effort towards a healthier society.

Observations of scrotal mass, liver mass, haemolytic jaundice, and central vestibular disorder in Brugia pahangi-infected dogs

@#Brugia pahangi is known to infect humans and dogs. Its associated symptoms and complications, however, have not been fully understood in dogs. Herein, we reported the observations of B. pahangi infections in dogs with scrotal mass, liver mass, haemolytic jaundice, and central vestibular disorder.

Genetic diversity of Merozoite Surface Protein-1 gene block 2 allelic types in Plasmodium falciparum isolates from Malaysia and Thailand

@#Malaria is the most common vector-borne parasitic disease in Malaysia and Thailand, especially in Malayan Borneo and along the Thailand border areas, but little is known about the genetic diversity of the parasite. Present study aims to investigate the genetic diversity of Plasmodium falciparum isolates in these two countries and eventually contributes to more effective malaria control strategies, particularly in vaccine and antimalarial treatment. One hundred and seventy three P. falciparum isolates were collected from Malaysia (n = 67) and Thailand (n = 106) and genotyped using nested PCR targeting the polymorphic region of MSP-1, block 2. Sequence analysis was conducted to investigate the allele diversity of the isolates. Three allelic families were identified in Malaysian and Thailand P. falciparum isolates, MAD20, K1 and RO33. Sequence analysis revealed that there were 5 different MAD20, 1 K1 and 2 different RO33 for Malaysian isolates. Thailand isolates exhibited greater polymorphism because there were 13 different MAD20, 6 different K1 and 2 different RO33 identified in this study. Multiclonal infections were observed for the isolates in both countries, however, low multiplicity of infection (MOI) was observed for Malaysian (1.1) and Thailand (1.2) isolates. Phylogenetic analysis showed that P. falciparum isolates of Malaysia and Thailand were clustered in the same group for all the allelic families. Population structure of P. falciparum isolates in Malaysia and Thailand exhibit extensive genetic polymorphism but showed high similarities as well as comparable MOI.

DNA barcoding relates Trichuris species from a human and a man’s best friend to non-human primate sources

@#Trichuris trichiura, the whipworm of humans, is one of the most prevalent soiltransmitted helminths (STH) reported worldwide. According to a recent study, out of 289 STH studies in Southeast Asia, only three studies used molecular methods. Hence, the genetic assemblages of Trichuris in Southeast Asia are poorly understood. In this study, we used partial mitochondrial DNA (cytochrome c oxidase subunit 1 or COI) sequences for analysis. Trichuris grouped in a same clade with different hosts indicate the potential of cross infection between hosts. Based on COI, the adult Trichuris isolated from a Malaysian patient was most closely related to Trichuris isolated from Papio anubis (olive baboons) from the USA. The Trichuris isolated from the dog from Malaysia was genetically similar to a Trichuris species isolated from Macaca silenus (lion-tailed macaque) from Czech Republic. Both the human and dog isolated Trichuris grouped in clades with different hosts indicating the potential of cross infection between hosts. Specific PCR primers based on the partial COI of T. trichiura isolated from African green monkey and T. serrata were designed and successfully amplified using multiplex PCR of the pooled DNA samples. Our results suggest a complex parasite-host relationship, and support the theory of cross infection of Trichuris between humans and non-human primates as suggested in previous publications.

Nematode control failure due to anthelmintic resistance in a sheep farm in Malaysia: First identification of the F200Y mutation in the isotype 1 β-tubulin gene

@#This paper reports total nematode anthelmintic resistance towards albendazole, fenbendazole, levamisole and ivermectin in a commercial sheep farm located in Terengganu, Malaysia. Faecal Egg Count Reduction Test (FECRT) was conducted on 25 sheep, where five sheep in each group were treated with the respective four anthelmintics based on live bodyweight. The balance of five sheep placed in the control group were not treated with any anthelmintics. At day 13 post-treatment, faecal egg count was conducted and nematode worm egg count reduction percentage was calculated to determine the resistance status towards the respective anthelmintics tested. Results showed that nematodes were resistant to all the anthelmintics tested, namely albendazole, fenbendazole, levamisole and ivermectin with reduction percentage of 87%, 46%, 94% and 68%, respectively. Subsequently, the third stage larvae of Haemonchus contortus and Trichostrongylus colubriformis recovered from post-treatment faecal cultures were subjected to allele-specific polymerase chain reaction (AS-PCR) assay to determine the presence of the benzimidazole resistance gene. This study reports the occurrence of the classical F200Y mutation in the isotype 1 β- tubulin gene, for the first time in Malaysia.

Soil-Transmitted Helminths in Malaysia landscape: an aborigines study

Soil-transmitted helminths (STH) is a group of parasitic nematodes, including Trichuris trichiura, Ascaris lumbricoides, Ancylostoma duodenale and Necator americanus, which can cause gastrointestinal disorders in humans. STH is prevalent among neglected communities in both developing and developed countries. This present study aims to determine the current prevalence of STH infections in Aboriginal population after mass delivering of antihelminthic drugs was proposed by WHO in 2005 and a health education learning package (HELP) was initiated in Malaysia in 2012. A total of 235 human fecal samples were collected and a pre-tested questionnaire was given to gather information about the socio-demographic of the Aborigine communities living in Kedah and Selangor, Malaysia. The samples were screened by a direct-fecal smear and confirmed by formalin-ether sedimentation methods. From human faeces, 81.7% was found to be infected with one or more STH species. T. trichiura was the most commonly detected (76.6%), followed by hookworms (26.4%) and A. lumbricoides (19.1%). Triple infections were found in 6.4% of the studied population. Univariate analysis showed that individuals with age group, male, presence of indoor toilet, family size with <7 members and bad living habits (i.e., without antihelminthic drugs) were significantly associated with STH infections. The analysis further showed that walking barefoot was the significant contributing factor to hookworm infections. The high prevalence of human STH infections is alarming. Thus, the urgency in implementing health education related behavioral practice and hygiene to reduce disease burden in these rural communities are a crucial need.

Titiwangsa Lake a source of urban parasitic contamination

Urban recreational lake acts as a source of waterborne parasites contamination, as reported in 2013 in Petaling Jaya, Selangor, Malaysia. This scenario will lead to the transmission of waterborne diseases due to exposure of water-related activities by humans. This study was conducted to reveal the occurrence of common waterborne parasites in a urban lake (i.e. Titiwangsa Lake). The lake is situated in the city of Kuala Lumpur and is known to be overcrowded with vast activities participated by both local and tourist. Results of study showed the presence of Cryptosporidium, Giardia, free-living amoeba, and helminthlike ova from the lake.

A preliminary screening of potentially antimalarial plants against Plasmodium falciparum in vitro

Plasmodium is a blood protozoan parasite that is responsible for malaria. To date, Plasmodium falciparum has shown multi-drug resistance, particularly in Thailand, Myanmar and Malaysia. The aim of the study is to screen the plant extracts that can effectively inhibit P. falciparum 3D7, a common lab strain malaria parasite. Nine plants were collected and processed through maceration using hexane, chloroform and ethanol, resulting in 24 crude plant extracts. Of these, extracts from Artabotrys crassifolius, Pericampylus glacus and Leuconotis eugeniifolia showed promising antiplasmodial activities at IC50 of 15.32 to 39.75 μg/mL in a modified schizont maturation assay. Further studies are warranted to explore its efficacies and lead compounds of these three plant extracts for the development of antiplasmodial drugs.

First molecular genotyping of A302S mutation in the gamma aminobutyric acid (GABA) receptor in Aedes albopictus from Malaysia

Given the lack of molecular evidence in altered target-site insecticide resistance mechanism in Aedes albopictus (Skuse) worldwide, the present study aims to detect the presence of A302S mutation in the gene encoding the gamma aminobutyric acid receptor resistant to dieldrin (Rdl) in Ae. albopictus for the first time from its native range of South East Asia, namely Malaysia. World Health Organization (WHO) adult susceptibility bioassay indicated a relatively low level of dieldrin resistance (two-fold) in Ae. albopictus from Petaling Jaya, Selangor. However, PCR-RFLP and direct sequencing methods revealed the presence of the A302S mutation with the predomination of heterozygous genotype (40 out of 82 individuals), followed by the resistant genotype with 11 individuals. This study represents the first fieldevolved instance of A302S mutation in Malaysian insect species.

Allergens of Bipolaris species.

Skin prick tests done previously revealed a significantly higher percentage of sensitization to an extract of Bipolaris sp. among atopic individuals (34/147, 23.1%) compared to non-atopic individuals. Bipolaris-specific IgE levels were quantified in sera from a representative group of 38 individuals using the Fluorescence Allergosorbent Test (FAST). Result obtained by FAST were found to be comparable to the skin prick test results (r2 = 0.60, p < 0.001 for IgE levels vs wheal sizes; r2 = 0.44, p < 0.001 for IgE levels vs erythema sizes). Characterisation of the extract's allergenic component by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed 28 protein bands with molecular weights (MW) ranging from 11 kDa to above 100 kDa. Immunoblotting with sera of 10 Bipolaris-sensitive (skin prick test, 3 +) individuals showed that Bipolaris spore extract contained at least 4 IgE binding proteins (MW 11-13 kDa, 16-17 kDa, 20-22 kDa and 36 kDa). All 10 sera reacted to the protein at MW 20-22 kDa, 2 sera with MW 11-13 kDa, 3 sera with 16-17 kDa and 6 sera with 36 kDa. This study has thus demonstrated that spores of Bipolaris sp. contain allergenic components which may elicit IgE-mediated reactions.

House dust mite allergen levels in a Singapore hospital.

House dust mite allergens constitute one of the most important allergens in house dust. In this study, the levels of two common dust mite allergens, Der p I and Der f I, in a general hospital in Singapore were evaluated. Our results showed that these allergens were detected in 42/74 (or 57%) of the dust samples. Der p I was found to be the predominant allergen detected (p < 0.001). The allergen levels were, however, low with only 1/74 having a Der p I concentration above 2 micrograms g-1 dust. None of the samples had Der f I concentrations above this level. Of the various niches studied (mattresses, pillows, sofas, carpets, blinds and floors), the blinds and floors had the lowest concentration of allergen (p < 0.05). These low levels in the hospital compared to homes were attributed to the vigorous cleaning schedule in the hospital, the use of plastic to encased mattresses and pillows, vinyl covered sofas and vinyl lined floors. These practices may be adopted in the home as a means to reduce mite allergen exposure.