Ahmed Tabbabi

First report on natural infection of Phlebotomus sergenti with Leishmania promastigotes in the cutaneous leishmaniasis focus in southeastern Tunisia.

During September 2010, 133 female sand flies were caught inside houses of patients with cutaneous leishmaniasis in the focus for this disease in southeastern Tunisia and subsequently dissected. One specimen was positive for Leishmania protozoa. This sand fly species was identified as Phlebotomus sergenti, and the parasite was identified as L. tropica. This is the first report of P. sergenti involvement in transmission of L. tropica in Tunisia.

Habitats of the sandfly vectors of Leishmania tropica and L. major in a mixed focus of cutaneous leishmaniasis in southeast Tunisia.

From 2009 to 2010, 3129 sandflies were caught in CDC light traps placed in various habitats in Ghomrassen, Tataouine governorate, southeast Tunisia, a mixed focus of human cutaneous leishmaniasis caused by Leishmania tropica and Leishmania major. Species diversity was quantified in anthropogenic, semi-anthropogenic and semi-natural locations. Sandflies were identified according to morphological characters and also by the comparative sequence analysis of a fragment of the mitochondrial cytochrome b gene to distinguish between two putative local vectors of L. tropica, namely Phlebotomus chabaudi and Phlebotomus riouxi. The lowest sandfly diversities were found in L. major sites, where the incriminated vector P. papatasi predominated in the burrows of the rodent reservoir hosts (Meriones) as well as inside and outside houses of human cases. In L. tropica sites, the incriminated peri-domestic vector Phlebotomus sergenti was the most abundant species inside houses, whereas P. riouxi or P. chabaudi was the dominant species in the semi-natural rocky habitats favoured by the putative rodent reservoir, Ctenodactylus gundi. All specimens of P. chabaudi identified molecularly had the diagnostic cytochrome b characters of P. riouxi, indicating either that the latter represents only a geographical variant of P. chabaudi or that these two species may sometimes hybridize.

Larval habitats characterization and species composition of Anopheles mosquitoes in Tunisia, with particular attention to Anopheles maculipennis complex.

In Tunisia, malaria transmission has been interrupted since 1980. However, the growing number of imported cases and the persistence of putative vectors stress the need for additional studies to assess the risk of malaria resurgence in the country. In this context, our aim was to update entomological data concerning Anopheles mosquitoes in Tunisia. From May to October of 2012, mosquito larval specimens were captured in 60 breeding sites throughout the country and identified at the species level using morphological keys. Environmental parameters of the larval habitats were recorded. Specimens belonging to the An. maculipennis complex were further identified to sibling species by the ribosomal deoxyribonucleic acid (rDNA)-internal transcribed spacer 2 (ITS2) polymerase chain reaction (PCR) technique. In total, 647 Anopheles larvae were collected from 25 habitats. Four species, including An. labranchiae, An. multicolor, An. sergentii, and An. algeriensis, were morphologically identified. rDNA-ITS2 PCR confirmed that An. labranchiae is the sole member of the An. maculipennis complex in Tunisia. An. labranchiae was collected throughout northern and central Tunisia, and it was highly associated with rural habitat, clear water, and sunlight areas. Larvae of An. multicolor and An. sergentii existed separately or together and were collected in southern Tunisia in similar types of breeding places.

A Review of Anopheles Maculipennis Complex in North Africa

The identification of species that belong to Maculipennis complex is very difficult because of the morphological similarity within this group. The molecular identification of species belonging this complex showed the existence of a single species called Anopheles labranchiae in Tunisia, Algeria and Morocco. This is important information for malaria control in the North Africa. The arid climate of Lybia excluded the members of Maculipennis complex except An. labranchiae and An. sacharovi. In the neighboring country, no species of this complex has been identified in Egypt. The accurate and correct identification of mosquito vectors is very important for the implementation and development of vector control strategies. To cite this article [Tabbabi, A., & Bekhti, K. (2017). A Review of Anopheles maculipennis Complex in North Africa. The Journal of Middle East and North Africa Sciences, 3(6), 1-5]. (P-ISSN 24129763) (e-ISSN 2412-8937). www.jomenas.org. 1

Fitness Cost in Laboratory Selected Strain of the Potential Mosquito Vector of West Nile Virus (Culex Pipiens) Associated with Resistance to the Insecticide Temephos

The fitness cost associated with resistance genes was investigated on mosquito’s viability. We studied four fitness parameters in a laboratory-selected strain of Culex pipiens associated with resistance to the insecticide temephos. S-Lab was the susceptible strain used for comparison. Two genes are involved in resistance to organophosphate (OP) insecticides: Ace-1 and Ester. After 5 generations of pressure, the temephos resistance ratio increased to 60.51 at RR95, exhibited a deficiency in the following two parameters: female fecundity (χ2=infini; dl=1; P<<0.05) and mortality rate (P<<0.05). Characterizations of resistance mechanisms indicate that resistance Ace-1 alleles coding for a modified acetylcholinesterase were associated with a higher mortality rate and lower fecundity. Several previous studies were used to compare and discuss our results. To cite this article [Tabbabi, A., & Ben Cheikh, H. (2017). Fitness Cost in Laboratory Selected Strain of the Potential Mosquito Vector of West Nile Virus (Culex pipiens) Associated with Resistance to the Insecticide Temephos. The Journal of Middle East and North Africa Sciences, 3(5), 10-15]. (P-ISSN 24129763) (e-ISSN 2412-8937). www.jomenas.org. 3

Evaluation of Chlorpyrifos Resistance and Biochemical Mechanisms of Culex pipiens in Five Localities of Grand Tunis Area, Northeast Tunisia

Five Culex pipiens samples were collected at preimaginal stages from breeding sites in 5 localities of Grand Tunis area, Northeast Tunisia, between March 2002 and November 2005. Larvae were used for bioassays using ethanol solutions of chlorpyrifos and propoxur insecticides. All samples were resistant to chlorpyrifos (RR>1, p 1,000-fold) were recorded in samples # 2, 4, and 5. Our synergist study showed that the increased detoxification by EST (and/or GST) had only a minor role in the chlorpyrifos resistance, although several overproduced esterases, known to be involved in the OPs resistance, were detected in all the resistant field samples. The mortality due to propoxur was significantly correlated with the LC50 of chlorpyrifos and indicated an insensitive AChE.

New Esterases Amplification Involved in Organophosphate Resistance in Culex Pipiens Mosquitoes from Tunisia

In Tunisia, the mosquito Culex pipiens shows various organophosphate resistance alleles at Ester locus. Resistance to the organophosphate chlorpyrifos was investigated in one population of Culex pipiens collected in northwestern Tunisia. High resistance to chlorpyrifos was observed and new esterases were detected. These results must be considered in future mosquito control programs since detected esterases can lead to high resistance to several organophosphorus insecticides. To cite this article [Tabbabi, A., Daaboub, J., Laamari, A., & Ben Cheikh, H. (2016). New Esterases Amplification Involved in Organophosphate Resistance in Culex Pipiens Mosquitoes from Tunisia. The Journal of Middle East and North Africa Sciences, 2(12), 1-2]. (P-ISSN 24129763) (e-ISSN 2412-8937). www.jomenas.org. 1

First study of susceptibility and resistance status to pyrethroids insecticides in Anopheles (Cellia) sergentii (Theobald, 1907) from Southern Tunisia

Background Insecticide resistance is an important threat to malaria control. Anopheles (An.) sergentii proved to be the number one vector in the oases and may be of a particular interest in projection of the future trends of the disease in Tunisia. Objectives Resistance status to pyrethroids insecticides in An. sergentii was evaluated for the first time in Tunisia. Methods Diagnostic resistance tests to pyrethroids insecticides were conducted on late third and early fourth larvae of An. sergentii collected in Southern Tunisia. Results The level of resistance to permethrin and deltamethrin varied from 1.9 to 5.77 and from 2.75 to 4.63, respectively. The highest resistance was recorded in sample # 3 to the two used insecticides. Synergists showed that esterases and glutathione-S-transferase were not involved in the resistance to any of the evaluated insecticides. In contrast, cytochrome-P450 monooxygenases played a role in the detoxification of two among three studied samples. Positive correlations between larval tolerance to both Permethrin/DDT and Deltamethrin/DDT were recorded indicated target site insensitivity. Conclusion Continued monitoring of insecticide susceptibility and generating complementary data on mechanisms of resistance using molecular and biochemical methods is essential to ensure early detection of insecticide resistance in potential malaria vectors in Tunisia.

First studies showing high temephos resistance in Anopheles labranchiae (Diptera: Culicidae) from Tunisia

Background Despite the public health importance of Anopheles (An.) labranchiae, their resistance status to temephos insecticide has not, to our knowledge, been explored. Objectives The present study was carried out to determine the temephos resistance status of field populations of An. labranchiae from Tunisia. Methods Six field populations of An. labranchiae were collected as larvae from breeding sites of Northern and Central Tunisia. All the tests were carried out according to the WHO method. Results Results reported that the majority of field populations showed low and medium resistance ratios (6.2<RR50< 29.8) to temephos insecticide tested except for the strain # 1 which had interestingly a very high resistance with RR50 of 624 never detected in Tunisia and North Africa even on other species of mosquitoes Conclusion The resistance ratios of this species were higher than recorded in other countries. Biochemical and molecular studies would be of great importance to identify the mechanisms involved in the recorded resistance to temephos.

Temephos Resistance in Three Populations of Culex pipiens Collected from Three Districts of Southern Tunisia and its Significance for the Resistance Mechanism

Objectives: The aim of this study was to investigate the resistance to temephos (OP) in three populations of Culex pipiens collected from three districts of Southern Tunisia and its significance for the resistance mechanism. Methods: Resistance to temephos insecticide was studied on Culex pipiens mosquitoes collected in three localities of Southern Tunisia. Larvae were used for different bioassays and adults were stored in -80°C for esterases identification. Results: Bioassays revealed the susceptibility of sample # 3. The weakest resistance was recorded in sample # 3 (RR50 = 0.68) and the strongest resistance for the sample # 2 (RR50 = 3.6). At LC95, two samples (# 1, and 3) were susceptible. The use of synergists showed the non-involvement of resistance mechanisms inhibited by DEF and Pb. Our investigation reported that temephos resistance could be explained by the two most common mechanisms of resistance to OP (overproduced esterases and AChE 1 mutation). Conclusion: Both detoxification mechanisms and target site alteration were involved in the resistance to temephos as reported in our study. These results are very important for the implementation and development of vector control strategies