1. Diagnosis of Taenia solium infections based on 'mail order' RNA-sequencing of single tapeworm egg isolates from stool samples
- Author
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Henrik Sadlowski, Veronika Schmidt, Jonathan Hiss, Johannes A. Kuehn, Christian G. Schneider, Gideon Zulu, Alex Hachangu, Chummy S. Sikasunge, Kabemba E. Mwape, Andrea S. Winkler, and Markus Schuelke
- Subjects
Physiology ,Molecular biology ,Eggs ,RC955-962 ,Biochemistry ,Feces ,Database and Informatics Methods ,Sequencing techniques ,Medical Conditions ,Reproductive Physiology ,Arctic medicine. Tropical medicine ,Zoonoses ,Taenia solium ,Medicine and Health Sciences ,Energy-Producing Organelles ,High-Throughput Nucleotide Sequencing ,RNA sequencing ,Genomics ,Mitochondrial DNA ,Mitochondria ,Nucleic acids ,Infectious Diseases ,Helminth Infections ,Public aspects of medicine ,RA1-1270 ,Cellular Structures and Organelles ,Sequence Analysis ,Research Article ,Neglected Tropical Diseases ,Forms of DNA ,Bioinformatics ,Bioenergetics ,Research and Analysis Methods ,DNA, Mitochondrial ,Species Specificity ,Diagnostic Medicine ,parasitic diseases ,Genetics ,Parasitic Diseases ,Animals ,Humans ,Postal Service ,Ovum ,Taeniasis ,Sequence Analysis, RNA ,Public Health, Environmental and Occupational Health ,Biology and Life Sciences ,DNA ,Cell Biology ,Tropical Diseases ,Molecular biology techniques ,RNA, Helminth ,Sequence Alignment - Abstract
Combined community health programs aiming at health education, preventive anti-parasitic chemotherapy, and vaccination of pigs have proven their potential to regionally reduce and even eliminate Taenia solium infections that are associated with a high risk of neurological disease through ingestion of T. solium eggs. Yet it remains challenging to target T. solium endemic regions precisely or to make exact diagnoses in individual patients. One major reason is that the widely available stool microscopy may identify Taenia ssp. eggs in stool samples as such, but fails to distinguish between invasive (T. solium) and less invasive Taenia (T. saginata, T. asiatica, and T. hydatigena) species. The identification of Taenia ssp. eggs in routine stool samples often prompts a time-consuming and frequently unsuccessful epidemiologic workup in remote villages far away from a diagnostic laboratory. Here we present “mail order” single egg RNA-sequencing, a new method allowing the identification of the exact Taenia ssp. based on a few eggs found in routine diagnostic stool samples. We provide first T. solium transcriptome data, which show extremely high mitochondrial DNA (mtDNA) transcript counts that can be used for subspecies classification. “Mail order” RNA-sequencing can be administered by health personnel equipped with basic laboratory tools such as a microscope, a Bunsen burner, and access to an international post office for shipment of samples to a next generation sequencing facility. Our suggested workflow combines traditional stool microscopy, RNA-extraction from single Taenia eggs with mitochondrial RNA-sequencing, followed by bioinformatic processing with a basic laptop computer. The workflow could help to better target preventive healthcare measures and improve diagnostic specificity in individual patients based on incidental findings of Taenia ssp. eggs in diagnostic laboratories with limited resources., Author summary Taeniasis is an infection of the intestine with tapeworms such as Taenia saginata (beef tapeworm), Taenia solium (pork tapeworm), or Taenia asiatica (Asian tapeworm). In the case of pork tapeworm in particular, infected individuals excrete thousands of eggs in their feces, which can cause cysticercosis if ingested by mouth and develop into larvae. Infection can occur through contaminated vegetables, but also by unwashed hands that had contact with Taenia eggs, including auto-infection. The larval cysts are deposited throughout the body, including the brain (neurocysticercosis), which is a common cause of epilepsy worldwide. Stool microscopy is the standard method for detecting taeniasis, but it cannot distinguish between infection with the beef and the more dangerous pork tapeworm. We have now developed a next-generation sequencing method that allows us to determine the genetic code of the tapeworm’s mitochondrial DNA from just two eggs in a stool sample. The sequence obtained makes it possible to uniquely identify the Taenia subspecies, treat patients appropriately, and inform public health efforts of endemic regions in order to eradicate this infection, as proposed by WHO.
- Published
- 2021