在马拉维恩科塔科塔野生动物保护区的野生采采蝇中进行聚合酶链反应鉴定。
Polymerase chain reaction identification of in wild tsetse flies from Nkhotakota Wildlife Reserve, Malawi.
作者信息
Musaya Janelisa, Chisi John, Senga Edward, Nambala Peter, Maganga Emmanuel, Matovu Enock, Enyaru John
机构信息
Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi.
Mikolongwe Veterinary College of Agriculture and Food Security, Limbe, Malawi.
出版信息
Malawi Med J. 2017 Mar;29(1):5-9.
BACKGROUND
is the causative agent of acute human African trypanosomiasis. Identification of in tsetse populations is essential for understanding transmission dynamics, assessng human disease risk, and monitoring spatiotemporal trends and impact of control interventions. Accurate detection and characterisation of trypanosomes in vectors relies on molecular techniques. For the first time in Malawi, a molecular technique has been used to detect trypanosomes in tsetse flies in Nkhotakota Wildlife Reserve.
METHODS
A polymerase chain reaction (PCR) technique was used to identify the serum resistance associated () gene of in tsetse flies. Of 257 tsetse flies that were randomly caught, 42 flies were dissected for microscopic examination. The midguts of 206 flies were positive and were individually put in eppendorf tubes containing phosphate-buffered saline (PBS buffer) for DNA extraction. Internal transcribed spacer (ITS)-PCR was first used to isolate all trypanosome species from the flies. TBR PCR was then used to isolate the group. -positive samples were further evaluated by SRA PCR for the presence of the gene.
RESULTS
Of 257 flies caught, 185 (72%) were and 72 (28%) were . Three were tenerals and 242 were mature live flies. Of the 242 flies dissected, 206 were positive, representing an 85.1% infection rate. From 206 infected flies, 106 (51.5%) were positive using ITS-PCR, 68 (33.0%) being mixed infections, 18 (8.7%) 9 (4.4%) , 4 (1.9%) , 3 (1.5%) , 3 (1.5%) , and 1 (0.4%) . When subjected to TBR PCR, 107(51.9%) were positive for . Of the 107 positive samples, 5 (4.7%) were found to have the gene.
CONCLUSIONS
These results suggest that wild tsetse flies in Malawi are infected with human-infective trypanosomes that put communities around wildlife reserves at risk of human African trypanosomiasis outbreaks. Further studies need to be done to identify sources of blood meals for the flies and for surveillance of communities around wildlife reserves.
背景
布氏锥虫是人类非洲锥虫病的病原体。鉴定采采蝇种群中的布氏锥虫对于了解传播动态、评估人类疾病风险以及监测时空趋势和控制干预措施的影响至关重要。在媒介中准确检测和鉴定锥虫依赖于分子技术。在马拉维，首次使用分子技术在恩科塔科塔野生动物保护区的采采蝇中检测锥虫。
方法
采用聚合酶链反应（PCR）技术鉴定采采蝇中布氏锥虫的血清抗性相关（）基因。在随机捕获的257只采采蝇中，解剖42只进行显微镜检查。206只采采蝇的中肠呈阳性，将它们分别放入含有磷酸盐缓冲盐水（PBS缓冲液）的微量离心管中进行DNA提取。首先使用内转录间隔区（ITS）-PCR从采采蝇中分离所有锥虫种类。然后使用TBR PCR分离布氏锥虫组。对阳性样本进一步通过SRA PCR评估基因的存在情况。
结果
在捕获的257只采采蝇中，185只（72%）为冈比亚采采蝇，72只（28%）为莫氏采采蝇。3只为 tenerals，242只为成熟活蝇。在解剖的242只采采蝇中，206只呈阳性，感染率为85.1%。在206只感染的采采蝇中，106只（51.5%）使用ITS-PCR呈阳性，68只（33.0%）为混合感染，18只（8.7%）为布氏锥虫，9只（4.4%）为刚果锥虫，4只（1.9%）为西氏锥虫，3只（1.5%）为伊氏锥虫，3只（1.5%）为路氏锥虫，1只（0.4%）为其他锥虫。当进行TBR PCR时，107只（51.9%）布氏锥虫呈阳性。在107个阳性样本中，5只（4.7%）被发现含有基因。
结论
这些结果表明，马拉维的野生采采蝇感染了可感染人类的锥虫，这使野生动物保护区周边社区面临人类非洲锥虫病暴发的风险。需要进一步开展研究，以确定采采蝇的血餐来源，并对野生动物保护区周边社区进行监测。
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