Cryptosporidium oocysts on fresh produce from areas of high livestock production in Poland

Samples of fresh vegetables and soft fruit were collected from farmers' markets in the Lublin Area of Poland during 2006–2007; the produce was grown in areas of high to moderate livestock production. Cryptosporidium sp. oocysts were eluted from food surfaces, separated from residual food materials by IMS and identified by immunofluorescence and Nomarski differential interference contrast microscopy. Cryptosporidium sp. oocysts were detected in 6 of 128 vegetable samples (range 1–47 oocysts), but not in any of 35 fruit samples. Both empty and intact oocysts were detected. Species identity of oocyst-positive samples was performed by molecular analysis at four genetic loci. One of two 18S rRNA loci amplified DNA from 5 of the 6 oocyst-positive samples, but insufficient DNA for RFLP or sequencing analysis was available from 4 of these samples. An oocyst-positive celery sample generated an RFLP pattern consistent with C. parvum at two loci, but insufficient DNA was available for subtyping (GP60 sequencing) this isolate. Oocyst-contaminated foods originated from districts with the highest numbers of homesteads possessing cattle herds and no contaminated produce was detected from districts containing lower numbers of cattle-owning homesteads, strengthening the assumption that the origin of the contamination was livestock. The results of this study strengthen the evidence for the potential for zoonotic foodborne transmission of Cryptosporidium.