African Journal of Parasitology Research

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (3), pp. 001-007, March, 2019. © International Scholars Journals

Full Length Research Paper

Heterogeneity of Anopheles Mosquitoes in Nyabushozi County, Kiruhura district, Uganda

R. Echodu¹, J. Okello-Onen²*, J. J. Lutwama³, J. Enyaru⁴, R. Ocan⁵, R. B. Asaba⁵, F. Ajuga⁵, C. Rubaire-Akiiki⁶, D. Bradley⁷, C. Mutero⁸, C. Kabonesa⁹ and J. Olobo¹⁰

¹Makerere University, Molecular Biology Programme, Uganda.

²Gulu University, Faculty of Science, Uganda.

³Uganda Virus Research Institute Entebbe, Uganda.

⁴Makerere University, Faculty of Science, Uganda.

⁵Makerere University, Institute of Environment and Natural Resources, Uganda.

⁶Makerere University, Faculty of Veterinary Medicine, Uganda.

⁷London School of Hygiene and Tropical Medicine, United Kingdom.

⁸International Water Management Institute (SIMA), Sri Lanka.

⁹Department of Women and Gender Studies, Faculty of Social Sciences, Makerere University, Uganda.

¹⁰Makerere University, Medical School, Department of Microbiology, Uganda.

Accepted 10 January, 2019

Abstract

The diversity of Anopheles mosquitoes was studied for seven months in eight villages in Nyabushozi County, Kiruhura District, Uganda. The aim of the study was to identify sibling species of Anopheles gambiae S.L, and the Anopheles funestus group using ribosomal DNA polymerase chain reaction assays. A total of 2566 female A. gambiae S.L, and 270 A. funestus group mosquitoes were collected in 24 households using pyrethrum spray catches, and from goat pens and cattle housing (kraals), using CDC light traps. More A. gambiae S.L, and A. funestus were caught in goat’s houses than in cattle kraals, probably due to the effect of weekly spraying of cattle. The densities of female A. gambiae S. L and A. funestus in all the eight villages studied were significantly influenced by rainfall. A. gambiae S.S. was the only sibling species within the A. gambiae complex identified by polymerase chain reaction assay. A. funestus was also identified by polymerase chain reaction and was found to be in sympathy with two other sibling species within the group, A. nopheles leesoni and A. nopheles parensis. Overall, A. gambiae S.S. was the most abundant species and probably contributed to most of the malaria transmission in Nyabushozi County, Kiruhura district.

Key words: Anopheles mosquitoes, heterogeneity, polymerase chain reaction, kiruhura district, Uganda.

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (3), pp. 001-007, March, 2019. © International Scholars Journals

Full Length Research Paper

Gonotrophic age structure of mosquitoes in the Culex pipiens complex (Diptera: Culicidae) and possible influences on host meal selection

L. O’Connor¹*, J. B. Gingrich¹, T. Unnasch² and H. K. Hassan²

¹Department of Entomology and Wildlife Ecology University of Delaware, Newark, DE 19716, USA.

²Divison of Geographical Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.

Accepted 04 January, 2019

Abstract

The age structure and mortality rates of Culex pipiens populations are critical to measures of vector capacity since each bloodmeal affords a chance of the female becoming infected. We examine the parous rate (proportion of females that had laid at least one egg boat) at two study sites to determine life-history parameters. Mosquitoes were collected using CO₂-baited CDC miniature light traps from June 15 to October 15 on a weekly basis from Cherry Island (2005 and 2006) and Cathedral Cemetery (2006) . Thirty females were dissected per site per week, collections permitting. The parous rate remained below 50% through the end of July (mid-season). In early August, parity rates averaged 65 percent, but increased to approximately 80% by mid - to late August (late season) among non-diapausing, host seeking females. This increase in percent parity through August and September suggested populations are gonotrophically older in the latter part of the season. The mean parous rate approximation was used to age-independent survival rates. By late August, average daily survival rate was greater than 90% of the population and remained high through the end of the biting season. Parous individuals with a longer lifespan are more likely to be infected since they by necessity had a bloodmeal and are therefore more likely to acquire and transmit disease.

Key words: Culex pipiens, parity, age-independent survival rate, gonotrophic age, host choice.

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (3), pp. 001-006, March, 2019. © International Scholars Journals

Full Length Research Paper

Response of Culex quinquefasciatus to deltamethrin in Lahore district

Hafiz Muhammad Tahir¹*, Abida Butt¹ and Shafaat Yar Khan²

¹Department of Zoology, University of the Punjab, Lahore, Pakistan.

²Department of Biological Sciences, University of Sarghoda, Pakistan.

Accepted 08 January, 2019

Abstract

In the present study, both male and females of Culex quinquefasciatus were sampled from five different localities of Lahore District of Punjab, Pakistan. (that is, Jaman, Mohlanwal, Noorpur Bhatta A1, Yohanaabad–2 and GCU Lahore). Bioassays against 5% deltamethrin were performed to evaluate the level of resistance in Culex quinquefasciatus against deltamethrin. For the adult bioassays standard protocol of WHO was adopted. Results of the bioassays showed that individuals of all populations were susceptible to 5% of deltamethrin. Male specimens from all populations showed significantly higher mortality as compared to females. Biochemical tests were performed to measure the esterase activity, both in males and females of C. quinquefasciatus. Significant variation was observed in the level of esterases in C. quinquefasciatus populations, collected from five different localities. Alpha naphthyl acetate was hydrolyzed faster than beta naphthyl acetate by mosquito homogenates of Yohanabad -2, GC University Lahore and Noorpur Bhatta A1 while mosquito homogenates of Mohlanwal and Jaman population hydrolyzed the beta naphthyl acetate faster than alpha naphthyl acetate. Only one band was observed in all populations for esterases A. For esterases B band pattern was similar in Yohanabad -2 and GC University. In these two populations there were three bands (B1, B2 & B3). In the population of Noorpur Bhatta A1, Mohlanwal and Jaman band B2 was absent. There was no resistance detected in C. quinquefasciatus from Jaman, Mohlanwal populations after 1 h exposure to 5% deltamethrin while population of GC University, Yohanabad and Noorpur Bhatta A1 showed a high level of tolerance to deltamethrin.

Keywords: Esterases, Culex quinquefasciatus, resistance, pyrethroids.

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (3), pp. 001-006, March, 2019. © International Scholars Journals

Full Length Research Paper

Fluorescence can be used to trace the fate of exogenous micro-organisms inside the alimentary tract of mosquitoes

Tomomitsu Satho¹, Hamady Dieng¹*, Tetsuya Mizutani², Yuki Eshita³, Takeshi Miyata¹, Parimal Talukder¹, Nobuhiro Kashige¹, Abu Hassan Ahmad⁴ and Fumio Miake¹

¹Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

²Virology 1, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan.

³Department of Infectious Diseases, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita 879-5593, Japan.

⁴School of Biological Sciences, University Sains Malaysia, 11800, Pulau Pinang Malaysia.

Accepted 04 January, 2019

Abstract

There is a great deal of current research interest in utilising bacteria for the control of intractable arthropod-borne diseases such as dengue. Although there is accumulating evidence that bacterial infection is a promising control strategy, most studies on bacteria-insect interactions lacked useful markers for detecting pathogenesis. This provided the impetus to investigate bacterial infection in the dengue vector Aedes albopictus. The infection persistence patterns in key organs of the alimentary canal of females were examined using a GFP-expressing strain of Escherichia coli (Migula). Just after feeding with sugar meal containing the bacteria, the crop and midgut as well as parts of the Malpighian tubules showed fluorescence. From 1 h onwards, bacterial populations declined sharply in both the midgut and crop, with complete elimination in the former but persistence of bacteria at 7 h post-feeding in the latter. After 24 h, neither organ retained the fluorescent marker. However, culture of homogenates of these organs in Luria-Bertani medium revealed the presence of a bacterial population in the crop, but not in the midgut. These observations suggest a difference in the potential physiological actions expressible by the two organs. In fact, both are storage sites for ingested fluids, but the midgut has greater physiological activity. Presumably, one of these activities contributed to eliminating GFP-expressing E. coli from the A. albopictus midgut after 24 h. The results of the present study using a fluorescent marker to detect infection may be useful for developing strategies to fully characterise the main steps involved in the bacterial infection process in insects.

Key words: Bacteria infection, fluorescent marker, crop, midgut, persistence.

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (2), pp. 001-011, February, 2019. © International Scholars Journals

Full Length Research Paper

Seroprevalence and virulence of Toxoplasma gondii in human and animal populations in a village in southeast Gabon

^{1, 2}Ngoubangoye B.¹Akue JP^*.^1,3,4Makouloutou P, ¹Bisvigou U

¹Laboratory of Parasitology, International Center for Medical Research of Franceville (CIRMF), Gabon.

²Ecole Inter - Etat  de Médicine Vétérinaire, Dakar,  Sénégal.

³Université Cheick Anta Diop, Département de Parasitologie, Dakar Sénégal.

⁴Institut de Recherche en Ecologie Tropicale, B.P. 13354 Libreville/Gabon.

Accepted 11 May, 2018 

Abstract

The seroprevalence of Toxoplasma gondii in animals and humans sharing the same biotope was examined, to determine the means of controlling this parasite in the tropical ecosystem. Humans (n=198) and animals (n=369) were tested simultaneously for the presence of anti-T. gondii antibodies. Human samples were tested using an enzyme-linked fluorescent assay (ELFA), while animal samples were analysed using the agglutination test. A bioassay using Swiss mice for testing strain virulence was also performed. Two people had IgM, the IgG isotype were found in 73.23% of humans, 92.85% of cats, 58.82% of dogs, 46.42% of chickens, 87.05% of goats and sheep, 6.66% of house rodents, 10.20% of wild rodents and 38.8% for bush meat consumed by villagers. A subsequent bioassay showed that one strain derived from chickens and one from small ruminants induced ascites in mice, while nine strains isolated from chickens and nine from small ruminants were asymptomatic despite the presence of anti-T. gondii antibodies in 95% of infected mice. These results suggest that the strains circulating in this environment might be complex. The high seroprevalence observed is associated with domestic cats and the spread of this parasite is due to the mode of management of domestic animals.

Key words: Biotope, T. gondii, circulation, IgG, virulence, Gabon.

African Journal of Parasitology Research ISSN 2343-6549 Vol. 6 (2), pp. 001-004, February, 2019. © International Scholars Journals