The use of pulsed light to inactivate Cryptosporidium parvum oocysts on high-risk commodities (Cilantro, mesclun lettuce, spinach, and tomatoes)

Evaluation of the therapeutic efficacy of some essential oils in experimentally immunosuppressed mice infected with Cryptosporidium parvum

Cryptosporidiosis is a serious intestinal disease affecting mal-nourished children and immunocompromised individuals with severe fatal diarrhea. Our present work was done to evaluate the possible curative effects of different essential oils (Mint, Thyme, Chamomile and Basil) on Cryptosporidium parvum (C. parvum) in vivo compared with nitazoxanide (NTZ). Seventy immunosuppressed white Albino male mice were allocated in 7 groups as follows: group I infected and not treated (Positive control), group II (GII) treated with NTZ, group III (GIII) treated with Mint essential oil, group IV (GIV) treated with Thyme essential oil, group V (GV) treated with Chamomile essential oil, group VI (GVI) treated with Basil essential oil and group VII (GVII) naïve not infected mice (Negative control). Evaluation was done using parasitological, histopatholgical, serological as well as biochemical methods. All study groups revealed significant reduction (P value < 0.01) in the mean number of C. parvum oocysts in stool. Results of GII were the best with 87.7% reduction in the oocysts count followed by GIII (77.9%), GIV (74.7%), GVI (68.2%) and lastly GV (67.2%). Improvement of the histopathological damage in the small intestine was shown in treated groups. All treated mice showed significant upregulation in the interferon gamma (IFN-γ) levels, significant reduction in the malondialdehyde (MDA) levels and increase in superoxide dismutase (SOD) levels (P value < 0.0001). It is concluded that Mint, Thyme, Chamomile and Basil oils showed promising anti-cryptosporidial, anti-inflammatory and antioxidant functions.

Use of Oxidative Stress Responses to Determine the Efficacy of Inactivation Treatments on Cryptosporidium Oocysts

Cryptosporidium oocysts are known for being very robust, and their prolonged survival in the environment has resulted in outbreaks of cryptosporidiosis associated with the consumption of contaminated water or food. Although inactivation methods used for drinking water treatment, such as UV irradiation, can inactivate Cryptosporidium oocysts, they are not necessarily suitable for use with other environmental matrices, such as food. In order to identify alternative ways to inactivate Cryptosporidium oocysts, improved methods for viability assessment are needed. Here we describe a proof of concept for a novel approach for determining how effective inactivation treatments are at killing pathogens, such as the parasite Cryptosporidium. RNA sequencing was used to identify potential up-regulated target genes induced by oxidative stress, and a reverse transcription quantitative PCR (RT-qPCR) protocol was developed to assess their up-regulation following exposure to different induction treatments. Accordingly, RT-qPCR protocols targeting thioredoxin and Cryptosporidium oocyst wall protein 7 (COWP7) genes were evaluated on mixtures of viable and inactivated oocysts, and on oocysts subjected to various potential inactivation treatments such as freezing and chlorination. The results from the present proof-of-concept experiments indicate that this could be a useful tool in efforts towards assessing potential technologies for inactivating Cryptosporidium in different environmental matrices. Furthermore, this approach could also be used for similar investigations with other pathogens.