Molecular Department, Vector and Vector Borne Diseases Institute, Majani Mapana, Off Korogwe Road, Box 1026, Tanga, Tanzania.
USC1342 INRA, UMR113 IRD-CIRAD-SupAgro-UM2, Symbioses Tropicales et Méditerranéennes, Campus de Baillarguet, TA A-82/J, F-34398, Montpellier Cedex 5, France.
BMC Microbiol. 2018 Nov 23;18(Suppl 1):164. doi: 10.1186/s12866-018-1288-3.
Glossina pallidipes is a haematophagous insect that serves as a cyclic transmitter of trypanosomes causing African Trypanosomiasis (AT). To fully assess the role of G. pallidipes in the epidemiology of AT, especially the human form of the disease (HAT), it is essential to know the microbial diversity inhabiting the gut of natural fly populations. This study aimed to examine the diversity of G. pallidipes fly gut bacteria by culture-dependent approaches.
113 bacterial isolates were obtained from aerobic and anaerobic microorganisms originating from the gut of G. pallidipes. 16S rDNA of each isolate was PCR amplified and sequenced. The overall majority of identified bacteria belonged in descending order to the Firmicutes (86.6%), Actinobacteria (7.6%), Proteobacteria (5.5%)and Bacteroidetes (0.3%). Diversity of Firmicutes was found higher when enrichments and isolation were performed under anaerobic conditions than aerobic ones. Experiments conducted in the absence of oxygen (anaerobiosis) led to the isolation of bacteria pertaining to four phyla (83% Firmicutes, 15% Actinobacteria, 1% Proteobacteria and 0.5% Bacteroidetes, whereas those conducted in the presence of oxygen (aerobiosis) led to the isolation of bacteria affiliated to two phyla only (90% Firmicutes and 10% Proteobacteria). Phylogenetic analyses placed these isolates into 11 genera namely Bacillus, Acinetobacter, Mesorhizobium, Paracoccus, Microbacterium, Micrococcus, Arthrobacter, Corynobacterium, Curtobacterium, Vagococcus and Dietzia spp.which are known to be either facultative anaerobes, aerobes, or even microaerobes.
This study shows that G. pallidipes fly gut is an environmental reservoir for a vast number of bacterial species, which are likely to be important for ecological microbial well being of the fly and possibly on differing vectorial competence and refractoriness against AT epidemiology.
采采蝇是一种吸血昆虫，它是传播引起非洲锥虫病（AT）的锥虫的循环传播媒介。为了充分评估采采蝇在 AT 流行病学中的作用，特别是人类形式的疾病（HAT），了解栖息在自然蝇种群肠道中的微生物多样性至关重要。本研究旨在通过依赖培养的方法来研究采采蝇肠道细菌的多样性。
从采采蝇肠道中的需氧和厌氧微生物中获得了 113 个细菌分离株。对每个分离株的 16S rDNA 进行 PCR 扩增和测序。鉴定出的细菌绝大多数依次属于厚壁菌门（86.6%）、放线菌门（7.6%）、变形菌门（5.5%）和拟杆菌门（0.3%）。在厌氧条件下进行富集和分离时，Firmicutes 的多样性更高。在无氧（厌氧）条件下进行的实验导致分离出属于四个门的细菌（83%Firmicutes，15%Actinobacteria，1%Proteobacteria 和 0.5%Bacteroidetes），而在有氧（需氧）条件下进行的实验仅导致分离出属于两个门的细菌（90%Firmicutes 和 10%Proteobacteria）。系统发育分析将这些分离株归入 11 个属，即芽孢杆菌属、不动杆菌属、中慢生根瘤菌属、副球菌属、微杆菌属、微球菌属、节杆菌属、棒杆菌属、短小杆菌属、魏斯氏菌属和迪茨氏菌属，这些菌属已知为兼性厌氧菌、好氧菌甚至微需氧菌。
本研究表明，采采蝇肠道是大量细菌的环境储库，这些细菌可能对蝇的生态微生物健康以及对 AT 流行病学的不同媒介效能和抗性至关重要。
