Joko Prastowo

Knockdown resistance ( kdr ) of the voltage-gated sodium channel gene of Aedes aegypti population in Denpasar, Bali, Indonesia

BackgroundAedes aegypti is the main vector of several arthropod-borne viral infections in the tropics profoundly affecting humans, such as dengue fever (DF), West Nile (WN), chikungunya and more recently Zika. Eradication of Aedes still largely depends on insecticides, which is the most cost-effective strategy, and often inefficient due to resistance development in exposed Aedes populations. We here conducted a study of Ae. aegypti resistance towards several insecticides regularly used in the city of Denpasar, Bali, Indonesia.MethodsAedes aegypti egg samples were collected with ovitraps and thereafter hatched in the insectary of the Gadjah Mada University. The F0 generation was used for all bioassay-related experiments and knockdown resistance (kdr) assays.ResultsResults clearly showed resistance development of Ae. aegypti against tested insecticides. Mortalities of Ae. aegypti were less than 90% with highest resistance observed against 0.75% permethrin. Mosquitoes from the southern parts of Denpasar presented high level of resistance pattern in comparison to those from the western and northern parts of Denpasar. Kdr analysis of voltage-gated sodium channel (Vgsc) gene showed significant association to S989P and V1016G mutations linked to resistance phenotypes against 0.75% permethrin. Conversely, Ae. aegypti F1534C gene mutation did not result in any significant correlation to resistance development.ConclusionsPeriodically surveillance of insecticide resistances in Ae. aegypti mosquitoes will help local public health authorities to set better goals and allow proper evaluation of on-going mosquito control strategies. Initial detection of insecticide resistance will contribute to conduct proper actions in delaying mosquito resistance development such as insecticide rotation or combination of compounds in order to prolong chemical efficacy in combating Ae. aegypti vectors in Indonesia.

In vitro potential anthelmintic activity of Biophytum petersianum on Haemonchus contortus

Aim: Haemonchus contortus is a major problem in small ruminants in Indonesia. The frequent use of the anthelmintic drugs has given rise to drug-resistant populations which increase the need for new anthelminthic compounds, particularly from endemic plants. This study evaluated the in vitro effects of Biophytum petersianum crude aqueous extract (BAE) as an anthelmintic compound against H. contortus adult worm isolated from goats. Materials and Methods: Adult worm collected from naturally infected abomasums were obtained from slaughtered goats on the day of slaughter. BAE was prepared in six different concentrations (10, 20, 40, 60, 80, and 100 mg/ml) which were tested for their efficacies on ten actively moving worms. Ivermectin (1 mg/ml) was included as a reference drug, while saline water was included as a control. The dead worms from anthelmintic test then went through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM). Results: Highest mean mortality in treatments group both at 2 h and 4 h observations was BAE 10%. The SDS-PAGE analysis revealed the presence of five protein bands with molecular weights 9.3, 17.1, 50.0, 63.2, and 72.7 kDa based on BAE 10%. The SEM changes observed in the in vitro trials revealed the occurrence of interactions between the BAE and the cuticle. Conclusion: The SEM and SDS-PAGE analysis revealed ultrastructural structural changes and the decrease numbers of polypeptides on treated worms when compared to the control worms. It can thus be concluded that the BAE exhibits good anthelmintic activity against H. contortus adult worm.

Aedes aegypti resistance development to commonly used insecticides in Jakarta, Indonesia

Aedes aegypti is the primary vector of various relevant arthropod-borne viral infectious diseases worldwide. The mosquito control is still mainly performed by using insecticides but their effectiveness is increasingly questioned nowadays. We here conducted a study on Ae. aegypti resistance development towards several commonly used insecticides in the capital city of Jakarta, Indonesia. In order to achieve this goal, Ae. aegypti eggs from Jakarta were collected with ovitraps and hatched in the insectary of the Gadjah Mada University, Indonesia. The F0 generations were used for WHO resistance tests and knockdown resistance (kdr) assays. Presented results clearly showed that there was resistance development of Ae. aegypti populations to the here tested pyrethroid insecticides (i. e. permethrin). Observed mortalities were less than 90% with highest resistance against 0.75% permethrin concentrations. Furthermore, a significant association of V1016G gene mutations with resistance phenotypes to 0.75% permethrin was observed. Nevertheless, the F1534C mutation did not show a significant correlation to resistance development. In conclusion, our results show that populations of Ae. aegypti mosquitoes within the city of Jakarta have developed resistance against several routinely used pyrethroid insecticides in local performed control programs. Thus, the regular verification/assessment of resistance development status will hopefully help in the future to assist local public health authorities in their mosquito control programs by recommending and managing the rotation of different routinely used insecticides with diverse effector mechanisms in order to delay Ae. aegypti resistance development.

Detection of Toxoplasma gondii copro-prevalence by polymerase chain reaction using repetitive 529 bp gene in feces of pet cats (Felis catus) in Yogyakarta, Indonesia

Aim: The aim of this research was to determine the copro-prevalence of Toxoplasma gondii using polymerase chain reaction (PCR) with repetitive 529 bp gene and to construct the phylogenetic tree of Toxoplasma oocyst from pet cats in Yogyakarta. Materials and Methods: 9 of 132 pet cat samples which serologically positive for Toxoplasma were used in this research. To determine the copro-prevalence of T. gondii in pet cat, 10 g of feces samples taken from practitioners and household cats in Yogyakarta were used in the PCR method utilizing repetitive 529 bp gene sequences. Results: The result shows that copro-prevalence by PCR using repetitive 529 bp gene was 33.3% (3/9). The phylogenetic tree of Toxoplasma grouped into two clades, which clade 1 consists of Toxoplasma isolates collected from pet cats in Yogyakarta Indonesia and T. gondii isolates from China and in clade 2 consist of the T. gondii isolates from India. Conclusion: Copro-prevalence of T. gondii in pet cats in Yogyakarta by means of PCR using repetitive 529 bp gene is around 33.3%.

Morphology and morphometry of Haemonchus contortus exposed to Gigantochloa apus crude aqueous extract

Aim: Haemonchus contortus is the most pathogenic nematode infesting the digestive tract of goats and sheep worldwide leading to a tremendous loss in a variety of routes. Economic losses due to haemonchosis in subtropic and tropic areas are usually caused by poor weight gain, minimized growth, loss of production, and mortality. The prevalence of haemonchosis in Indonesia is 89.4% in goat, and annual loss achieved 1 million US dollars. This study evaluated in vitro effects of Gigantochloa apus crude aqueous extract as an anthelmintic on H. contortus morphology and morphometry. Materials and Methods: Bligon goats which are naturally infected were collected from slaughtered goat from local slaughterhouses, namely Besi Sleman. Bligon goat’s abomasum part was carefully examined and transported to the Parasitology Laboratory, University of Gadjah Mada, Yogyakarta. H. contortus was obtained from 4 to 6-month-old female goat from slaughterhouses in Yogyakarta area. H. contortus was collected from abomasum and put into a Petri dish containing 0.62% water saline. The number of H. contortus used for each concentration is 25. H. contortus was soaked in each concentration for 4 h. The figure of the parasites or parts of parasites was captured using camera Lucida, and they were measured using both objective micrometer and objective ocular micrometer. All the capturing processes were done with the help of Olympus Digital Camera under Olympus CX21 microscopic. Parasite morphology was identified in morphological and morphometric characters. Result: Morphology of H. contortus revealed the cervical papillae bulge appears unclear shape and anterior end is more tapered. Vulvar flab control is not tapered, but vulvar flab which gets aware of G. apus crude aqueous extract looks more pointed. The gubernaculum appears irregular compared to gubernaculum control which tends to be more compact, and the posterior end form appears irregular more than posterior end control. Morphometry study of H. contortus indicates that it has a significant difference for body length, body width, cervical papillae, and spicule length in the male. Conclusion: G. apus crude aqueous extract activity revealed morphology change such as cervical papillae, vulvar flab, gubernaculum, posterior end, and reduced morphometry measurement of H. contortus adult worms, notably in body length, body width, cervical papillae width, gubernaculum, and spicule length in males and body length, body width, cervical papillae width, and vulva length in females.

Trypanosoma evansi Detection and Vector Identification in Central Java and Yogyakarta, Indonesia

Trypanosomiasis or surra is a protozoa disease, caused by Trypanosoma evansi. It affects a large number of wild and domesticated animals in Indonesia, especially cattle, buffalo, and horse. Several species of hematophagous flies, including tabanids and Stomoxys, are implicated in transferring infection from host to host, acting as mechanical vectors. The aim of this research was to explore the vectors, flies identification, and Trypanosoma detection. Fly samples were collected from Central Java and Yogyakarta by using NZ-1 trap to study their presence, abundance, seasonal variation, and species diversity. Trypanosomes were collected from the cattle in those areas during the months of May 2016 to September 2016. The trap installations were done in the morning and finished in the afternoon; observations were conducted in the morning at 8 a.m., in the noon at 12 p.m., and in the afternoon at 6 p.m. Types of flies caught in Yogyakarta and Brebes, Central Java, were Tabanus rubidus (16.9% and 22.5%), Tabanus striatus (5.4% and 3.6%), Stomoxys calcitrans (51.2% and 42.3%), Haematobia irritans (19.6% and 26.1%), and Hippobosca sp. (6.9% and 5.4%). By using primer ESAG 6/7 in the PCR detection, it detected 450 bp bands, and ITS-1 primer showed 237 bp bands. Many flies were caught in the morning and afternoon, since it was quite hot during August to October (dry season). These results can be used as a baseline data and surra control program as well.