Parasites and blood-meal hosts of the tsetse fly in Tanzania: a metagenomics study

Abstract

Background Tsetse flies can transmit various Trypanosoma spp. that cause trypanosomiasis in humans, wild animals, and domestic animals. Amplicon deep sequencing of the 12S ribosomal RNA (rRNA) gene can be used to detect mammalian tsetse hosts, and the 18S rRNA gene can be used to detect all associated eukaryotic pathogens, including Trypanosoma spp. Methods Tsetse flies were collected from the Serengeti National Park (n = 48), Maswa Game Reserve (n = 42), and Tarangire National Park (n = 49) in Tanzania in 2012–13. Amplicon deep sequencing targeting mammal-specific 12S rRNA and 18S rRNA genes was performed to screen the blood-feeding sources of tsetse flies and eukaryotic parasites in tsetse flies, respectively. Results 12S rRNA gene deep sequencing revealed that various mammals were blood-feeding sources of the tsetse flies, including humans, common warthogs, African buffalos, mice, giraffes, African elephants, waterbucks, and lions. Genes of humans were less frequently detected in Serengeti (P = 0.0024), whereas African buffaloes were detected more frequently as a blood-feeding source (P = 0.0010). 18S rRNA gene deep sequencing showed that six tsetse samples harbored the Trypanosoma gene, which was identified as Trypanosoma godfreyi and Trypanosoma simiae in subsequent ITS1 gene sequencing. Conclusions Through amplicon deep sequencing targeting the 12S rRNA and 18S rRNA genes, various mammalian animals were identified as blood-meal sources, and two Trypanosoma species were detected in tsetse flies collected from the Maswa Game Reserve, Serengeti National Park, and Tarangire National Park in Tanzania. This study illustrates the patterns of parasitism of tsetse fly, wild animals targeted by the fly, and Trypanosoma spp. carried by the fly in Tanzania. It may provide essential data for formulating better strategies to control African trypanosomes. Graphical Abstract

X-rays are as effective as gamma-rays for the sterilization of Glossina palpalis gambiensis Vanderplank, 1911 (Diptera: Glossinidae) for use in the sterile insect technique

“…This difference in activity between irradiated and non-irradiated males could explain the longer survival of irradiated males. While these laboratory results could be perceived as a potentially negative consequence that may reduce mating or mate-seeking in the wild, the presence of various wild animals as feeding hosts could counterbalance this effect, increasing the likelihood of encounters with wild females and competition with wild male counterparts 59 , 60 . Indeed, when monitoring the experiment on survival under starvation, the irradiated starved flies attempt to bite the operator, suggesting that in the field, they will be active in the presence of hosts.…”

Metabarcoding of bacteria and parasites in the gut of Apodemus agrarius

“…The ‘very high sensitivity/slow’ mode was used, with a minimum overlap of 90 bp. The sequences in the database that showed the highest homology were selected in the final taxonomic identification result [ 34 ].…”

“…For the eukaryotic microbiome study, the 18S rRNA gene V9 region was amplified by PCR using the primers 1391f (5′-TCGTCGGCAGCGTCAGATG TGTATAAGAGACAG GTACACACCGCCCGTC-3′) and EukBr (5′-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGTGATC CTTCTGCAGGTTCACCTAC-3′) [ 29 ]. For the bacterial microbiome study, the 16S rRNA gene V4 region was amplified by PCR using the primers 515F (5′-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGGTGCCAGCMGCCGCGGTAA-3′) and 806R (5′-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGGGACTACHVGGGTWTCTAAT-3′) [ 30 ].…”