Detection of Wolbachia in wild mosquito populations from selected areas in Peninsular Malaysia by loop-mediated isothermal amplification (LAMP) technique.

Wolbachia, a naturally endosymbiotic bacteria, has shown its potential as one of biological control agents for vector borne diseases. Due to large number of mosquitoes involved in Wolbachia screening, Loop-mediated isothermal amplification (LAMP) is recommended as a convenient and time-saving technique. This study aimed to evaluate a newly developed LAMP assay for detection of Wolbachia by targeting 16S rDNA gene in samples of wild mosquito populations. The LAMP products were confirmed by colorimetric detection using hydroxy naphthol blue (HNB), digestion with RsaI restriction enzyme and gel electrophoresis. The restriction enzyme digestion of PCR products was performed to differentiate between Wolbachia supergroups A and B. Out of 765 mosquito samples tested, 349 (45.6%) and 237 (31%) of the samples were positive for LAMP and PCR techniques respectively. The prevalence of Wolbachia detected in mosquitoes was significantly higher using LAMP as compared to PCR. There is significant association between numbers of mosquitoes positive with Wolbachia detected using LAMP and PCR (χ2=61.31; df=1; p < 0.05) with a kappa (κ) value of 0.27 and Phi value, 0.283. This study highlighted the potential of LAMP as a sensitive, specific and rapid tool for screening of Wolbachia in mosquitoes, thus it presents as an alternative to PCR-based assays.

Domiciliary cockroaches found in restaurants in five zones of Kuala Lumpur Federal Territory, peninsular Malaysia.

The following domiciliary cockroaches were collected from restaurants in five zones of Kuala Lumpur Federal Territory, Malaysia using 1L glass beaker traps baited with ground mouse-pellets: Periplaneta americana (Linnaeus) (n = 820), Periplaneta brunnea Burmeister (n = 46), Blattella germanica (Linnaeus) (n = 12504), Supella longipalpa (Fabricius) (n = 321), Symploce pallens Stephens (n = 29) and Neostylopyga rhombifolia (Stoll) (n = 5). The following bacteria were isolated from 10 cockroach specimens: Enterobacter cloacae, Klebsiella pneumoniae ssp. pneumoniae, Klebsiella pneumoniae ssp. rhinoscleromatis and Serratia liquefaciens from 5 B. germanica; Acinetobacter calcoaceticus var. anitratus, Citrobacter diversus/amalonaticus, Escherichia vulneris and K.p. pneumoniae from 3 P. brunnea; and Citrobacter freundii, Enterobacter agglomerans 4, Escherichia adecarboxylate, E. vulneris, K. p. pneumonia, K. p. rhinoscleromatis and Proteus vulgeris from 2 P. americana.