Life-span of in vitro differentiated Plasmodium falciparum gametocytes

Malaria Journal

Research

Benjamin Mordmüller¹  Albert Lalremruata¹  Jana Held¹  Peter G. Kremsner¹  Tamirat Gebru² 

[1] Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany;German Centre for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany;Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany;German Centre for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany;Department of Medical Laboratory Sciences, College of Medical and Health Sciences, Haramaya University, Harar, Ethiopia;

关键词: Malaria;    Clinical isolate;    Gametocytogenesis;    Gametocyte viability;    Gametocyte circulation time;    Gametocyte longevity;    Exflagellation;   

DOI  :  10.1186/s12936-017-1986-6

 received in 2017-05-24, accepted in 2017-08-07,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe sexual stages (gametocytes) of Plasmodium falciparum do not directly contribute to the pathology of malaria but are essential for transmission of the parasite from the human host to the mosquito. Mature gametocytes circulate in infected human blood for several days and their circulation time has been modelled mathematically from data of previous in vivo studies. This is the first time that longevity of gametocytes is studied experimentally in vitro.MethodsThe in vitro longevity of P. falciparum gametocytes of 1 clinical isolate and 2 laboratory strains was assessed by three different methods: microscopy, flow cytometry and reverse transcription quantitative real-time PCR (RT-qPCR). Additionally, the rate of gametocytogenesis of the used P. falciparum strains was compared.ResultsThe maximum in vitro lifespan of P. falciparum gametocytes reached almost 2 months (49 days by flow cytometry, 46 days by microscopy, and at least 52 days by RT-qPCR) from the starting day of gametocyte culture to death of last parasite in the tested strains with an average 50% survival rate of 6.5, 2.6 and 3.5 days, respectively. Peak gametocytaemia was observed on average 19 days after initiation of gametocyte culture followed by a steady decline due to natural decay of the parasites. The rate of gametocytogenesis was highest in the NF54 strain.ConclusionsPlasmodium falciparum mature gametocytes can survive up to 16–32 days (at least 14 days for mature male gametocytes) in vitro in absence of the influence of host factors. This confirms experimentally a previous modelling estimate that used molecular tools for gametocyte detection in treated patients. The survival time might reflect the time the parasite can be transmitted to the mosquito after clearance of asexual parasites. These results underline the importance of efficient transmission blocking agents in the fight against malaria.

【 授权许可】

CC BY   
© The Author(s) 2017