Tularaemia: A challenging zoonosis

In recent years, several emerging zoonotic vector-borne infections with potential impact on human health have been identified in Europe, including tularaemia, caused by Francisella tularensis.This remarkable pathogen, one of the most virulent microorganisms currently known, has been detected in increasingly new settings and in a wide range of wild species, including lagomorphs, rodents, carnivores, fish and invertebrate arthropods. Also, a renewed concern has arisen with regard to F. tularensis: its potential use by bioterrorists. Based on the information published concerning the latest outbreaks, the aim of this paper is to review the main features of the agent, its biology, immunology and epidemiology. Moreover, special focus will be given to zoonotic aspects of the disease, as tularaemia outbreaks in human populations have been frequently associated with disease in animals

Use of metagenomic microbial source tracking to investigate the source of a foodborne outbreak of cryptosporidiosis

Cryptosporidium is a protozoan parasite of global public health importance that causes gastroenteritis in a variety of vertebrate hosts, with many human outbreaks reported yearly, often from ingestion of contaminated water or food. Despite the major public health implications, little is typically known about sources of contamination of disease outbreaks caused by Cryptosporidium. Here, we study a national foodborne outbreak resulted from infection with Cryptosporidium parvum via romaine lettuce, with the main goal to trace the source of the parasite. To do so, we combined traditional outbreak investigation methods with molecular detection and characterization methods (i.e. PCR based typing, amplicon and shotgun sequencing) of romaine lettuce samples collected at the same farm from which the contaminated food was produced. Using 18S rRNA typing, we detected C. parvum in two out of three lettuce samples, which was supported by detections in the metagenome analysis. Microbial source tracking analysis of the lettuce samples suggested sewage water as a likely source of the contamination, albeit with some uncertainty. In addition, the high degree of overlap in bacterial species content with a public human gut microbial database corroborated the source tracking results. The combination of traditional and molecular based methods applied here is a promising tool for future source tracking investigations of food- and waterborne outbreaks of Cryptosporidium spp. and can help to control and mitigate contamination risks