Identification of rickettsiae from wild rats and cat fleas in Malaysia

Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting.

Phylogenetic study of six species of Anopheles mosquitoes in Peninsular Malaysia based on inter-transcribed spacer region 2 (ITS2) of ribosomal DNA

Background

Molecular techniques are invaluable for investigation on the biodiversity of Anopheles mosquitoes. This study aimed at investigating the spatial-genetic variations among Anopheles mosquitoes from different areas of Peninsular Malaysia, as well as deciphering evolutionary relationships of the local Anopheles mosquitoes with the mosquitoes from neighbouring countries using the anopheline ITS2 rDNA gene.

Methods

Mosquitoes were collected, identified, dissected to check infection status, and DNA extraction was performed for PCR with primers targeting the ITS2 rDNA region. Sequencing was done and phylogenetic tree was constructed to study the evolutionary relationship among Anopheles mosquitoes within Peninsular Malaysia, as well as across the Asian region.

Results

A total of 133 Anopheles mosquitoes consisting of six different species were collected from eight different locations across Peninsular Malaysia. Of these, 65 ITS2 rDNA sequences were obtained. The ITS2 rDNA amplicons of the studied species were of different sizes. One collected species, Anopheles sinensis, shows two distinct pools of population in Peninsular Malaysia, suggesting evolvement of geographic race or allopatric speciation.

Conclusion

Anopheles mosquitoes from Peninsular Malaysia show close evolutionary relationship with the Asian anophelines. Nevertheless, genetic differences due to geographical segregation can be seen. Meanwhile, some Anopheles mosquitoes in Peninsular Malaysia show vicariance, exemplified by the emergence of distinct cluster of An. sinensis population.

Is there a risk of suburban transmission of malaria in Selangor, Malaysia?

Background

The suburban transmission of malaria in Selangor, Malaysia’s most developed and populous state still remains a concern for public health in this region. Despite much successful control efforts directed at its reduction, sporadic cases, mostly brought in by foreigners have continued to occur. In addition, cases of simian malaria caused by Plasmodium knowlesi, some with fatal outcome have caused grave concern to health workers. The aim of this study was to investigate the possibility of local malaria transmission in suburban regions of Selangor, which are adjacent to secondary rainforests.

Findings

A malaria survey spanning 7 years (2006 - 2012) was conducted in Selangor. A total of 1623 laboratory confirmed malaria cases were reported from Selangor’s nine districts. While 72.6% of these cases (1178/1623) were attributed to imported malaria (cases originating from other countries), 25.5% (414/1623) were local cases and 1.9% (31/1623) were considered as relapse and unclassified cases combined. In this study, the most prevalent infection was P. vivax (1239 cases, prevalence 76.3%) followed by P. falciparum (211, 13.0%), P. knowlesi (75, 4.6%), P. malariae (71, 4.4%) and P. ovale (1, 0.06%). Mixed infections comprising of P. vivax and P. falciparum were confirmed (26, 1.6%). Entomological surveys targeting the residences of malaria patients’ showed that the most commonly trapped Anopheles species was An. maculatus. No oocysts or sporozoites were found in the An. maculatus collected. Nevertheless, the possibility of An. maculatus being the malaria vector in the investigated locations was high due to its persistent occurrence in these areas.

Conclusions

Malaria cases reported in this study were mostly imported cases. However the co-existence of local cases and potential Plasmodium spp. vectors should be cause for concern. The results of this survey reflect the need of maintaining closely monitored malaria control programs and continuous extensive malaria surveillance in Peninsula Malaysia.

Biodiversity and macroparasitic distribution of the wild rat population of Carey Island, Klang

A study to determine the diversity and distribution of ectoparasites and endoparasites infesting wild rat population of Carey Island was carried out from June to December 2010. A total of 81 rats were captured from various locations on Carey Island. Four rat species were identified namely, Rattus tiomanicus (45.7%), Rattus rattus diardii (25.9%), Rattus argentiventer (16%) and Rattus norvegicus (12.3%). Low diversity of ecto and endoparasites were observed infecting the rodent population with 8 ecto and 8 endoparasites species recorded. The ectoparasites recovered fell under 3 broad groups, namely mites (Laelaps nuttali, Laelaps echidninus, Laelaps sculpturatus, Listrophoroides sp. and Ornithonyssus bacoti), lice (Polyplax spinulosa and Hoplopleura pacifica) and tick (Ixodes granulatus) while endoparasites recovered were cestodes (Taenia taeniaformis and Hymenolepis diminuta) and nematodes (Nippostrongylus brasiliensis, Angiostrongylus malaysiensis, Mastophorus muris, Heterakis spumosa, Hepatojarakus malayae and Syphacia muris). The rat population was observed harbouring more than one parasite species. Analysis of data also showed neither intrinsic (host age, host sex) nor extrinsic (season) factors influenced the macroparasites community structure.

A new record for Lispe orientalis Wiedemann, 1824 (Diptera: Muscidae) from peninsular Malaysia

Lispe orientalis Wiedemann, 1824 is recorded for the first time in peninsular Malaysia. Specimens were collected from a mushroom cultivation farm in Genting Highlands, Pahang (3°25'18"N 101°47'48"E). Previously, this species had been recorded from Azerbaijin, India, Russia, Tajikistan, Thailand, Turkey and South Korea. The male of Lispe orientalis can be determined by the following characteristics: body non-metallic, ashy gray, third antennal segment black, R5 cell not narrow apically, hind metatarsus normal, legs entirely black, femora with long bristle-like hairs on av and pv surfaces, hind tibia without av and pv seta and the palpi orangish in colour.

Oxyspiruriasis in zoo birds

Oxyspiruriasis caused by the bird eyeworm, Oxyspirura mansoni, a thelaziid nematode, in three species of pheasants, 3 Chrysolophus pictus (golden pheasant), 7 Lophura nycthemera (silver pheasant) and 9 Phasianus colchicus (common pheasant) in Zoo Negara Malaysia are reported. Birds with the disease were treated with a solution of 0.5% iodine or 0.5% lysol. Antistress powder for 4 days in water and non-strep vitamin powder in water was also provided. Control measures included removal of the cockroach intermediate host, Pycnoscelus surinamensis (Surinam cockroach) from the vicinity of the birds. The golden pheasant is a new host for O. mansoni in peninsular Malaysia.

The cat fur mite, Lynxacarus radovskyi Tenorio, 1974 (Acarina: Astigmata: Listrophoridae) from cat, Felis catus in peninsular Malaysia

The cat fur mite, Lynxacarus radovskyi Tenorio, 1974 (Acarina: Astigmata: Listrophoridae) is reported from cats, Felis catus from three sites in peninsular Malaysia. The first site is a Malay village, Kampong Menteri in Taiping, Perak, where the mites were found on local pet cats. The other two sites are urban cities of Kuala Lumpur, in the Federal Territory and Georgetown, in the island of Penang. Mites from the urban areas were collected from stray cats. Although several ectoparasites (fleas, mites, ticks and lice) have been previously reported, L. radovskyi is recorded herein for the first time on cats from peninsular Malaysia.

The dog louse Heterodoxus spiniger from stray cats in Penang, Malaysia

Stray cats collected from Georgetown, Penang from 2008 to 2010 were screened for ectoparasites via fine-tooth combing. Two cats from a total 102 examined were infested with the dog louse, Heterodoxus spiniger. Both cats, a juvenile male and female were found in close contact with each other prior to capture. The number of lice ranged from 5 and 14 in the male and female cat respectively. Other ectoparasites recovered included the common cat flea, Ctenocephalides felis, one louse species Felicola subrostratus, one tick species Haemaphysalis bispinosa and one mite species of Listrophoridae. The present study reports for the first time the finding of H. spiniger on cats from peninsular Malaysia.

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.

Mutant p53 drives multinucleation and invasion through a process that is suppressed by ANKRD11

Mutations of p53 in cancer can result in a gain of function associated with tumour progression and metastasis. We show that inducible expression of several p53 'hotspot' mutants promote a range of centrosome abnormalities, including centrosome amplification, increased centrosome size and loss of cohesion, which lead to mitotic defects and multinucleation. These mutant p53-expressing cells also show a change in morphology and enhanced invasive capabilities. Consequently, we sought for a means to specifically target the function of mutant p53 in cancer cells. This study has identified ANKRD11 as a key regulator of the oncogenic potential of mutant p53. Loss of ANKRD11 expression with p53 mutation defines breast cancer patients with poor prognosis. ANKRD11 alleviates the mitotic defects driven by mutant p53 and suppresses mutant p53-mediated mesenchymal-like transformation and invasion. Mechanistically, we show that ANKRD11 restores a native conformation to the mutant p53 protein and causes dissociation of the mutant p53-p63 complex. This represents the first evidence of an endogenous protein with the capacity to suppress the oncogenic properties of mutant p53.

Exceptionally aggressive pigmented villonodular synovitis of the hip unresponsive to radiotherapy

Pigmented villonodular synovitis (PVNS) is a rare benign neoplastic proliferation of synovial tissue which is typically localised and usually responds well to surgery and/or radiotherapy. We present a case of unusually aggressive of PVNS of the hip in a 73-year-old woman.

Nosocomial nasal myiasis in an intensive care unit

A 73-year-old Chinese man was admitted to the Accident and Emergency Premorbid Ward of a local hospital in Malaysia. The patient complained of shortness of breath with cough and was in a semi-conscious state. He was later admitted to an intensive care unit (ICU) of the hospital. Six days after admission 5-6 maggots were recoverd from the nasal cavity. The maggots were identified as the third-instar larvae of Lucilia cuprina Wiedmann (Diptera: Calliphoridae) based on the morphological characteristics. This patient was classified as having nosocomial myiasis. The presence of the third instar larvae indicated that the infestation was not more than three to four days. An adult sarcophagid identified as Parasarcophaga ruficornis (Fabricius) caught in the ICU where the patient was warded provided further evidence of the potential for the nosocomial infestation.

Infestation with the cat flea, Ctenocephalides felis felis (Siphonaptera: Pulicidae) among students in Kuala Lumpur, Malaysia

This paper reports six male undergraduate students living at a local university hostel who were infested with cat fleas (Siphonaptera: Pulicidae: Ctenocephalides felis felis) in February 2009. All of them suffered from maculopapular rashes and severe pruritus after the bites. Investigation revealed the presence of a stray cat in the hostel building; five of the students had a history of contact with the cat. Six cat fleas were collected at the hostel and identified as C. felis felis. Most of the students were not aware of this infestation and did not seek medical treatment.

First report of the house fly larvae, Musca domestica (Linnaeus) (Diptera: Muscidae) associated with the monkey carcass in Malaysia

A study on insect succession of monkey carcass in a forested area in Ulu Gombak, Selangor, Malaysia was conducted from 9 May to 18 June 2007. The third instar of the housefly, Musca domestica (Linnaeus) (Diptera: Muscidae) were only found on dry stage of a decomposed (Day-33) monkey carcass (Macaca fascicularis Raffles). This observation revealed that M. domestica maggots were found together with other muscid fly maggots, Hydrotaea (=Ophyra) spinigera (Stein) (Diptera: Muscidae) on dry stage of a carcass. However, the role of M. domestica on forensic entomological study remains unknown. This study recorded the first finding of M. domestica maggots on primate carcass in Malaysia.

New mosquito species records (Diptera: Culicidae) from Singapore

Nine species of mosquitoes in eight genera are recorded for the first time in Singapore. An additional two species were overlooked in a 1986 checklist for mosquitoes in Singapore, and one was described after 1986. Location and habitat data are provided for the nine new records. With the inclusion of these new records the number of species reported from Singapore is 137.

Ectoparasite fauna of rodents and shrews from four habitats in Kuala Lumpur and the states of Selangor and Negeri Sembilan, Malaysia and its public health significance

A total of 204 rodents comprising 14 host species from four different habitats were examined. Nine rodent species were trapped from the forest and another five species were trapped from the coastal, rice field and urban habitats. Rattus rattus diardii (67%) was the predominant rodent species examined. Fifty six (47.3%) rodents and shrews were found to be infested with at least one of the 20 species of ectoparasite recovered. Mites belonging to the family Trombiculidae were the predominant ectoparasite species recovered. Ticks belonging to the family Ixodidae were recovered mainly from the forest dwelling rodents. Polyplax spinulosa and Hoplopleura pacifica were the common lice species found infesting the urban rodents. Xenopsylla cheopis was the only flea species recovered. The following ecto-parasites have been incriminated as important vectors or as mechanical carriers for the transmission of zoonotic diseases: Ixodes granulatus, Dermacentor sp. Haemaphysalis sp., Amblyomma sp. Ascoschoengastia indica, Leptotrombidium deliense, Ornithonyssus bacoti, Laelaps nuttalli, H. pacifica, P. spinulosa and Xenopsylla cheopis. Urban and forest rodents were significantly higher in ecto-parasitic infestation, compared to rats from the other two habitats. However, there was no significant statistical association between male and female rodents infested with ectoparasites.

Predation on pupa of Chrysomya rufifacies (Marquart) (Diptera: Calliphoridae) by parasitoid, Exoristobia philippinensis Ashmead (Hymenoptera: Encyrtidae) and Ophyra spinigera larva (Diptera: Muscidae)

A forensic entomological study was conducted using monkey carcasses (Macaca fascicularis Raffles) that were placed in either an outdoor or indoor environment at a coastal area in Tanjung Sepat, Selangor, Malaysia during May until August 2008. We collected pupae of Chrysomya rufifacies (Marquart) from the carcasses and kept them individually. The emergence of 13 parasitic microhymenopteran, from one of the pupae occurring within a week were identified as Exoristobia philippinensis Ashmead (Hymenoptera: Encyrtidae). Another observation was made whereby a pupa of C. rufifacies was predated by a muscid larva, Ophyra spinigera (Stein). The larva squeezed into the pupa and consumed the contents. This paper report C. rufifacies as a new host record for E. philippinensis in Malaysia and highlighted the predatory behavior of O. spinigera larva in natural environment.

First report of the signal fly, Scholastes sp. (Diptera:Platystomatidae) visiting animal carcasses in Malaysia

Signal fly, Scholastes sp. (Diptera: Platystomatidae) was observed associated with animal carcasses in Malaysia. The first observation was on a monkey carcass, which was killed by using a handgun and immediately placed in a forested area in Gombak, Selangor while the second observation was on a pig that died of natural causes and whose carcass was placed in an oil palm plantation in Tanjung Sepat, Selangor. Both animal carcasses were visited by Scholastes sp. flies during the fresh decomposition period. However, the role Scholastes flies in the decomposition process remains unknown. In this paper, we report the occurrence of Scholastes sp. on animal carcasses in Malaysia for the first time.

On the occurrence of Musca domestica L oviposition activity on pig carcass in peninsular Malaysia

A forensic entomological study conducted in an oil palm plantation in Tanjung Sepat, Selangor, Malaysia on 3 August 2007 revealed that a housefly, Musca domestica Linnaeus oviposited its eggs on a freshly dead pig. This finding indicated that housefly might play an important role in forensic investigation in determining post-mortem interval (PMI), although it was not yet found in human corpses or any animal carrion. This preliminary paper presented a first record of Musca domestica eggs found on animal carcass in the country.