Potential application of Gustatory Receptor 1 (CmegGr1) gene as a molecular marker for identification of Chrysomya megacephala (Diptera: Calliphoridae)

@#Chrysomya megacephala larvae can easily be identified using cheap traditional microscopy techniques. Nevertheless, identification using taxonomy keys may be hampered, if the morphological characteristics of the larvae are incomplete, or immature for microscopic identification. To overcome the difficulty of species determination, molecular identification has gained relevance and is applied in forensic investigations. This study aimed to identify a novel target gene, known as the gustatory receptor 1 gene (CmegGr1), which has never been used for identification. The third instar larvae of Ch. megacephala (n = 30) and eight other forensically important fly species were obtained from two sources; rabbit carcasses and the Forensic Entomology Unit collection. Their DNAs were extracted and the CmegGr1 gene was amplified using polymerase chain reaction (PCR). The resulting sequences were subjected to phylogenetic analysis. A 209 bp fragment of the CmegGr1 gene was successfully amplified in 80% (24/30) of Ch. megacephala samples, while all of the non-Ch. megacephala species were not amplified. The phylogenetic analysis revealed that the evolutionary tree of CmegGr1 shares many traits with the 21a gustatory receptors of Calliphora stygia and Lucilia cuprina (Gr21a), which are also classified as necrophagous fly species. The high specificity of species identification was demonstrated in the present study using DNA barcoding, which led to the conclusion that the CmegGr1 gene could serve as an alternative marker for identifying Ch. megacephala.

Forensic entomology of high-rise buildings in Malaysia: Three case reports

The distributions of flies are not only confined to ground level but can also be at higher altitudes. Here, we report three forensic cases involving dipterans in high-rise buildings in Kuala Lumpur, Malaysia. Case 1 involved a corpse of adult female found at the top floor of a fifteen-story apartment. Case 2 dealt with a body of a 75-year-old female discovered in a bedroom on the eleventh floor of an eighteen-story building, while Case 3 was a 52-year-old male found in his fifth floor shop house. Interestingly, entomological analysis revealed that all corpses were infested with similar Dipterans: Megaselia scalaris (Loew) (Diptera: Phoridae), Synthesiomyia nudiseta (Wulp) (Diptera: Muscidae) and sarcophagid (Diptera: Sarcophagidae). The first two species were commonly associated with corpses found indoors at ground level. We noted the additional occurrence of blowflies Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) and Chrysomya rufifacies Macquart (Diptera: Calliphoridae) larvae in Case 2 and Case 3, respectively. Findings from this study are significant as they demonstrate that certain groups of fly can locate dead bodies even in high-rise buildings. Forensic entomofauna research on corpses found at high elevation is scarce and our study has highlighted the peculiarity of the fly species involved in Malaysia.

Dengue Infections And Circulating Serotypes In Negeri Sembilan, Malaysia

This study observed the pattern of reported dengue infections, clinical manifestations, and circulating dengue serotypes in Negeri Sembilan, Malaysia. The aim of this study was to determine the co-circulation of the four different dengue virus serotypes in Negeri Sembilan. We analyzed the surveillance data (VEKPRO) from Negeri Sembilan State Health Department and National Public Health Laboratory, Malaysia on reported dengue infections from 1st January 2010 to 31st December 2010. There were 1466 reported dengue infections, 1342 (91.5%) cases were dengue fever (DF) and 124 (8.5%) were dengue hemorrhagic fever (DHF). The mean age was 32.2± 15.8 years old and most were young adults, aged 15 years old and older. Males (p < 0.05), and those residing in Seremban district (p < 0.05) were more likely to get dengue infections. Symptoms presented upon admission were fever (100%), headache (99.9%), myalgia and arthralgia (98.8%), rash(24.2%), petechiae (16.0%),bleeding tendencies (7.0%) and neurological deficits(1.2%). All four dengue serotypes (DEN 1 – 4) were present, the pre-dominant serotype was DEN-3, noted in January, then existed together with DEN-2 until around May. DEN-1 was the most pre-dominant circulating dengue serotype afterwards, reaching a peak in December 2010. Dengue affected all age groups particularly young adults and males. Most cases reported were in urban areas and Seremban district. Most of the dengue infections occurred in the first half of the year, with the DEN-2 and DEN-3 serotypes being the most predominant.