Dengue fever (DF) is currently one of the most important mosquito-borne diseases that affects humans. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by four serotypes of dengue viruses (DENV-1 to DENV-4). The main vector transmitting dengue is Aedes aegypti while Aedes albopictus acts as a secondary vector. As treatment is unavailable and the first dengue vaccine approved in Mexico, Dengvaxia® has yet to be accepted worldwide, prevention of the disease relies heavily on surveillance and control of mosquito vectors. A transgene driver, Wolbachia was found to limit the transmission of dengue virus in Aedes mosquitoes. Wolbachia alone was able to inhibit viral replication, dissemination and transmission in A. aeygpti mosquitoes in experimental studies. In A. albopictus, Wolbachia did not affect the replication of dengue virus but was able to reduce the viral infection of mosquito salivary glands and limit transmission. Studies on Wolbachia have all been carried out in adult Aedes mosquitoes, hence this study was conducted to determine the presence of dengue virus serotypes and Wolbachia in A. aegypti and A. albopictus larvae collected from ovitraps in four localities in Kuala Lumpur viz. Happy Gardens, IMU Bukit Jalil, Ampang and Taman Yarl. Another objective of this study was to determine the association between dengue virus serotypes and the presence of Wolbachia in A. aegypti and A. albopictus larvae. A total of 300 mosquito larvae was collected; 99 (Happy Gardens), 85 (Bukit Jalil), 73 (Ampang) and 43 (Taman Yarl). Out of 300 larvae collected, 284 were identified as A. albopictus and 16 others were identified as A. aegypti. Of the 284 A. albopictus larvae collected, 211 (74.3%) and 73 (25.7%) were found to be negative and positive for dengue virus respectively. The dengue serotypes detected were 2 DENV-2 (2.7%), 58 DENV-3 (79.5%) and 13 DENV-4 (17.8%). DENV-1 was not detected in any of the A. albopictus larvae. For A. aegypti, out of 16 A. aegypti larvae collected, 12 (75%) were found to be negative and 4 (25%) were positive for DENV-2. For the detection of Wolbachia in A. albopictus, 71 out of 284 (25%) and 213 (75%) larvae were found to be positive and negative for Wolbachia respectively. For A. aegypti, 4 (25%) and 12 (75%) out of 16 larvae were positive and negative for Wolbachia respectively. This is the first report of Wolbachia in A. albopictus and A. aegypti larvae in Malaysia. A chisquare test analysis to determine the association between dengue virus and Wolbachia in A. albopictus and A. aegypti larvae collected from the four localities in Kuala Lumpur showed that there was no association (χ2 = 3.080; df = 1; P > 0.05).

House dust mites and storage mites are well-known causes for allergenic diseases. The aim of this study was to investigate the immunogenic sites of Blomia tropicalis, Aleurogyphus ovatus and Glycycometus malaysiensis. The mites were maintained in a culture medium at 25ºC and 75% relative humidity. Mites were harvested either with heat escape or floatation method, purified, homogenized, quantified and used for the production of polyclonal antibody and immunostaining. For each species of mites, five male mice and five male rats were randomly selected and immunized intraperitoneally with respective crude mite extract at two-weekly intervals. Blomia tropicalis, A. ovatus or G. malaysiensis whole mites and paraffin-embedded mite sections were immunostained with the respective polyclonal antibody. The faecal pellets of mites were intensely stained for all the three species in the present study. The legs of sectioned A. ovatus were not immunogenic as compared with those of G. malaysiensis and B. tropicalis. The outer layer (cuticle) of whole mites and the eggs for these species were very immunogenic. Hence, the polyclonal antibodies obtained in this study may serve as potential tools in detecting the eggs and immature mites in environmental samples. Future studies should focus on the antigenic components of eggs since they were relatively abundant in dust and highly antigenic as seen in the present study.

Allergens of Dermatophagoides and Blomia species are well-characterized but not for other species. This study was conducted to determine the prevalence of allergic sensitization to house dust (HDM) and storage mites (SM). One hundred adult subjects (aged > 18) were recruited. The mite specific IgE of all allergic subjects were higher compared with healthy subjetcs despite being not statistically significant except for D. farinae and G. malaysiensis. The mean serum IgE levels against HDM and SM for allergic subjects were significantly higher compared with those in healthy subjects. They were mainly sensitized to Dermatophagoides farinae (35%) and Glycycometus malaysiensis (37%). Immunoblots revealed not all allergic subjects showed positive immuno-reactivity against the mites tested. Single or multiple bands were observed for different species. The subjects were commonly sensitized to Group 2 (9-12 kDa), 10 (38 kDa) and 18 (40-48 kDa) allergens. Twenty-one out of 60 allergic subjects were sensitized to either one or more species. The majority of them (71%) were sensitized to single species. The allergic subjects were mainly sensitized to D. pteronyssinus, followed by Tyrophagus putrecentiae and Aleuroglyphus ovatus. Seven were solely sensitized to HDM while 10 were solely sensitized to SM. Four subjects were sensitized to both. Preadsorption study revealed no cross-reactivity. There was difference between the prevalence and reactivity to allergens of HDM and SM in these subjects. Both ELISA and immunoblot did not correlate well but can complement each other in improving the detection of mite allergens to the species level.

Glycycometus malaysiensis is an allergenic domestic mite found in houses. G. malaysiensis is known to be highly similar to and is often mistaken as Blomia tropicalis, one of the major house dust mite species that causes asthma and allergic diseases in many tropical and subtropical regions. It was also suggested that these mites cross-react with each other and that the prevalence of G. malaysiensis might be higher than previous reports. A review on the taxonomic keys as well as light and scanning electron micrographs of G. malaysiensis are presented to appreciate the fine morphological structures of G. malaysiensis. The mouth, setae, legs (trochanter, femur, genu, tibia and tarsus) and the sexual organs (genital openings, genital setae and genital suckers) of G. malaysiensis are outlined. The morphology of G. malaysiensis is also compared with that of B. tropicalis to delineate the key features for the differentiation between these two mite species.

Cladosporium spores are ubiquitous in indoor and outdoor environment and may potentially trigger allergic responses upon inhalation. To date, there is limited investigation on the fate of Cladosporium spores after being inhaled into the respiratory tract. This study was conducted to investigate the interaction of Cladosporium sphaerospermum with Human Bronchial Epithelial Cells (BEAS-2B) and Human Pulmonary Alveolar Epithelial Cells (HPAEpiC). C. sphaerospermum conidia were harvested and co-cultured with BEAS-2B or HPAEpiC cells for 72 hours. At each time point (30 minutes, 2, 4, 24, 48 and 72 hours), adherence and invasion of the cells by C. sphaerospermum conidia (and hyphae) were investigated by immunofluorescence staining. This study demonstrated the adherence and internalization of C. sphaerospermum conidia within these epithelial cells. In addition, the conidia were able to germinate and invade the epithelial cells. The ability of the fungal conidia to adhere, internalize, germinate and invade both the bronchial and alveolar epithelial cells of the respiratory tract in vitro might contribute to the understanding of the pathogenesis of Cladosporium in respiratory infection and allergy in vivo. INTRODUCTION Cladosporium species is a member of the phylum Ascomycota. The common species include C. herbarum, C. cladosporioides and C. sphaerospermum. This genus has worldwide distribution. Aerobiological studies reported that majority of fungal spores in outdoor air is from the phyla Ascomycota and Basidiomycota, while Cladosporium is one of the most studied allergenic Ascomycetes fungi (Knutsen et al., 2012). Cladosporium spores are found abundantly in indoors and outdoors at approximately 18/m3 and 141/m3 respectively (Codina et al., 2008). As an imperfect dematiaceous fungus, Cladosporium species causes opportunistic infections such

Studies on parasite populations in Antarctic soils are scarce and thus little is known about the threat of these parasites towards either the natural fauna or human visitors. However, human presence in Antarctica, mainly through research and tourism, keeps increasing over time, potentially exposing visitors to zoonotic infections from Antarctic wildlife and environment. Most available literature to date has focused on faecal samples from Antarctic vertebrates. Therefore, this study addressed the possible presence of parasites in Antarctic soil that may be infectious to humans. Soil samples were obtained from five locations on Signy Island (South Orkney Islands, maritime Antarctic), namely North Point and Gourlay Peninsula (penguin rookeries), Pumphouse (relic coal-powered pump house), Jane Col (barren high altitude fellfield) and Berntsen Point (low altitude vegetated fellfield close to current research station). Approximately 10% of the soil samples (14/135) from 3 out of the 5 study sites had parasites which included Diphyllobotridae spp. eggs, Cryptosporidium sp., an apicomplexan protozoa (gregarine), Toxoplasma gondii, helminths (a cestode, Tetrabothrius sp., and a nematode larva) and mites. The presence of parasites in the 3 sites are most likely due to the presence of animal and human activities as two of these sites are penguin rookeries (North Point and Gourlay Peninsula) while the third site (Pumphouse Lake) has human activity. While some of the parasite species found in the soil samples appear to be distinctive, there were also parasites such as Cryptosporidium and Toxoplasma gondii that have a global distribution and are potentially pathogenic.