Identification of the Midgut Microbiota of An. stephensi and An. maculipennis for Their Application as a Paratransgenic Tool against Malaria

The midgut microbiota associated with Anopheles stephensi and Anopheles maculipennis (Diptera: Culicidae) was investigated for development of a paratransgenesis-based approach to control malaria transmission in Eastern Mediterranean Region (EMR). Here, we present the results of a polymerase chain reaction (PCR) and biochemical-based approaches to identify the female adult and larvae mosquitoe microbiota of these two major malaria vectors, originated from South Eastern and North of Iran. Plating the mosquito midgut contents from lab-reared and field-collected Anopheles spp. was used for microbiota isolation. The Gram-negative and Gram-positive bacterial colonies were identified by Gram staining and specific mediums. Selected colonies were identified by differential biochemical tests and 16S rRNA gene sequence analysis. A number of 10 An. stephensi and 32 An. maculipennis adult mosquitoes and 15 An. stephensi and 7 An. maculipennis larvae were analyzed and 13 sequences of 16S rRNA gene bacterial species were retrieved, that were categorized in 3 classes and 8 families. The majority of the identified bacteria were belonged to the γ-proteobacteria class, including Pseudomonas sp. and Aeromonas sp. and the others were some closely related to those found in other vector mosquitoes, including Pantoea, Acinetobacter, Brevundimonas, Bacillus, Sphingomonas, Lysinibacillus and Rahnella. The 16S rRNA sequences in the current study aligned with the reference strains available in GenBank were used for construction of the phylogenetic tree that revealed the relatedness among the bacteria identified. The presented data strongly encourage further investigations, to verify the potential role of the detected bacteria for the malaria control in Iran and neighboring countries

Chemical Composition Profile of the essential oil from Hymenocrater bituminosus and their Health Functionality

Hymenocrater species are important medicinal and food plants. The aim of this work was to evaluate the potential of Hymenocrater bituminosus Fisch. & C.A.Mey. for the management of public health problems such as Alzheimer’s disease, obesity, Diabetes mellitus, and skin diseases through inhibition of targeted enzymes. Essential oil composition, antioxidant activity, and total bioactive contents of the plant were also determined. EO showed high α-glucosidase (40 mmol ACEs/g oil), α-amylase (9 mmol ACEs/g oil), acetylcholinesterase (3.8 mg GEs/g oil), butyrylcholinesterase (4.7 mg GEs/g oil), tyrosinase (45 mg KAEs/g oil), and lipase (1.5 mmol OEs/g oil) inhibitory activities. Methanolic extract exhibited strong antiradical (DPPH and ABTS) and reducing power (CUPRAC and FRAP) activities and high total phenolics content (120 mg GAEs/g extract). Gas chromatography/mass spectrometry analysis of EO showed the presence of α-pinene (18.2%), β-pinene (11.3%), trans-phytol (11.0%), and spathulenol (8.5%) as the major components. Results indicated that H. bituminosus has promising potential for possible uses in food and pharmaceutical industries due to its valuable phytoconstituents and biological activities

Modulation of malaria infection in Anopheles gambiae mosquitoes exposed to natural midgut bacteria

The development of Plasmodium falciparum within the Anopheles gambiae mosquito relies on complex vector-parasite interactions, however the resident midgut microbiota also plays an important role in mediating parasite infection. In natural conditions, the mosquito microbial flora is diverse, composed of commensal and symbiotic bacteria. We report here the isolation of culturable midgut bacteria from mosquitoes collected in the field in Cameroon and their identification based on the 16S rRNA gene sequencing. We next measured the effect of selected natural bacterial isolates on Plasmodium falciparum infection prevalence and intensity over multiple infectious feedings and found that the bacteria significantly reduced the prevalence and intensity of infection. These results contrast with our previous study where the abundance of Enterobacteriaceae positively correlated with P. falciparum infection (Boissiere et al. 2012). The oral infection of bacteria probably led to the disruption of the gut homeostasis and activated immune responses, and this pinpoints the importance of studying microbe-parasite interactions in natural conditions. Our results indicate that the effect of bacterial exposure on P. falciparum infection varies with factors from the parasite and the human host and calls for deeper dissection of these parameters for accurate interpretation of bacterial exposure results in laboratory settings