A comparison of the efficacy of pulsed UV light and pulsed plasma gas-discharge systems for the novel inactivation of Cryptosporidium spp. and other clinically relevant microorganisms in drinking water

Author(s):  
J.C. Hayes ◽  
A.M. Fogarty ◽  
E. Clifford ◽  
N.J. Rowan
2015 ◽  
Vol 78 (12) ◽  
pp. 2247-2252 ◽  
Author(s):  
L. LE GOFF ◽  
B. HUBERT ◽  
L. FAVENNEC ◽  
I. VILLENA ◽  
J. J. BALLET ◽  
...  

Cryptosporidium spp., a significant cause of foodborne infection, have been shown to be resistant to most chemical food disinfectant agents and infective for weeks in irrigation waters and stored fresh vegetal produce. Pulsed UV light (PL) has the potential to inactivate Cryptosporidium spp. on surfaces of raw or minimally processed foods or both. The present study aimed to evaluate the efficacy of PL on viability and in vivo infectivity of Cryptosporidium parvum oocysts present on raspberries, a known source of transmission to humans of oocyst-forming apicomplexan pathogens. The skin of each of 20 raspberries was experimentally inoculated with five 10-μl spots of an oocyst suspension containing 6 × 107 oocysts per ml (Nouzilly isolate). Raspberries were irradiated by PL flashes (4 J/cm2 of total fluence). This dose did not affect colorimetric or organoleptic characteristics of fruits. After immunomagnetic separation from raspberries, oocysts were bleached and administered orally to neonatal suckling mice. Seven days after infection, mice were euthanized, and the number of oocysts in the entire small intestine was individually assessed by immunofluorescence flow cytometry. Three of 12 and 12 of 12 inoculated mice that received 10 and 100 oocysts isolated from nonirradiated raspberries, respectively, were found infected. Four of 12 and 2 of 12 inoculated mice that received 103 and 104 oocysts from irradiated raspberries, respectively, were found infected. Oocyst counts were lower in animals inoculated with 103 and 104 oocysts from irradiated raspberries (92 ± 144 and 38 ± 82, respectively) than in animals infected with 100 oocysts from nonirradiated raspberries (35,785 ± 66,221, P = 0.008). PL irradiation achieved oocyst reductions of 2 and 3 log for an inoculum of 103 and 104 oocysts, respectively. The present pilot-scale evaluation suggests that PL is an effective mode of decontamination for raspberries and prompts further applicability studies in industrial contexts.


2007 ◽  
Vol 70 (12) ◽  
pp. 2805-2810 ◽  
Author(s):  
N. J. ROWAN ◽  
S. ESPIE ◽  
J. HARROWER ◽  
J. G. ANDERSON ◽  
L. MARSILI ◽  
...  

A pulsed-plasma gas-discharge (PPGD) system was developed for the novel decontamination of chilled poultry wash water. Treatment of poultry wash water in the plasma generation chamber for up to 24 s at 4°C reduced Escherichia coli NCTC 9001, Campylobacter jejuni ATCC 33560, Campylobacter coli ATCC 33559, Listeria monocytogenes NCTC 9863, Salmonella enterica serovar Enteritidis ATCC 4931, and S. enterica serovar Typhimurium ATCC 14028 populations to non-detectable levels (≤8 log CFU/ml). Although similar PPGD treatments at 4°C also produced significant reductions (≥3 log CFU/ml) in recalcitrant B. cereus NCTC 11145 endospore numbers within 30 s, the level of endospore reduction was dependent on the nature of the sparged gas used in the plasma treatments. Scanning electron microscopy revealed that significant damage occurred at the cellular level in PPGD-treated test organisms. This electrotechnology delivers energy in intense ultrashort bursts, generating products such as ozone, UV light, acoustic and shock waves, and pulsed electric fields that have multiple bactericidal properties. This technology offers an exciting complementary or alternative approach for treating raw poultry wash water and for preventing cross-contamination in processing environments.


2021 ◽  
Vol 9 (4) ◽  
pp. 813
Author(s):  
Jana Ježková ◽  
Zlata Limpouchová ◽  
Jitka Prediger ◽  
Nikola Holubová ◽  
Bohumil Sak ◽  
...  

Cryptosporidium spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel Cryptosporidium species adapted to nutrias (Myocastor coypus). A total of 150 faecal samples of feral nutria were collected from locations in the Czech Republic and Slovakia and examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, and gp60 loci. Molecular analyses revealed the presence of C. parvum (n = 1), C. ubiquitum subtype family XIId (n = 5) and Cryptosporidium myocastoris n. sp. XXIIa (n = 2), and XXIIb (n = 3). Only nutrias positive for C. myocastoris shed microscopically detectable oocysts, which measured 4.8–5.2 × 4.7–5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5–6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at SSU, actin, and HSP70 loci demonstrated that C. myocastoris n. sp. is distinct from other valid Cryptosporidium species.


1995 ◽  
Vol 50 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Andreas Karst ◽  
Burkhardt Broschk ◽  
Joseph Grobe ◽  
Duc Le Van

Reaction of the cyclotetraphosphane (PCF3)4 or of a mixture of (PCF3)4 and (PCF3)5 with 2,3-dimethyl-1,3-butadiene or isoprene at 25 °C leads to the [4 + 2]-cycloadducts of bis(trifluoromethyl) diphosphene and the phospholene derivatives 2a and 2b, respectively, in the molar ratio diphosphinine/phospholene = 1/2. The analogous reactions of the cycloarsanes (AsCF3)4,5 give the Diels/Alder compounds 4 and 5 of bis(trifluoromethyl)diarsene in 90% yield without arsolene formation. Cyclopentadiene, 1,3-cyclohexadiene and cis or trans piperylene do not react with (AsCF3)4,5, up to temperatures of 60 °C. However, the corresponding [4 + 2]-cycloadducts 6 - 8 are produced by irradiation of the reaction mixture with UV light. The novel phospholenes 2a and 2b as well as the diarsinines 4 - 8 have been characterized by spectroscopic data (MS, NMR, IR). 2a was coordinated as a phosphane ligand to the pentacarbonylchromium fragment by reaction with the photochemically generated complex Cr(CO)5 · THF to afford the new compound (3).


Author(s):  
Tuğba Sağlam ◽  
Serdar Düşen ◽  
Meral Apaydın Yağcı ◽  
Abdülkadir Yağcı

Objective: The aim of this study was to assess both the presence and seasonal variability of Cryptosporidium spp. and Giardia spp. in Eğirdir Lake within the borders of Isparta province, which is used for drinking, agricultural irrigation and recreational purposes. Method: The research was carried out between July 2016 and January 2017 and water samples were taken from five different stations in three different seasons in Lake Eğirdir. After direct microscopic examination of the samples (Native-Lugol method), they were stained with Modified Acid Fast (MAF), and examined under the light microscope for parasites. Results: Cryptosporidium spp and Giardia spp were detected in 15 water samples in summer months, with an average density of 99.2% and 93.3% respectively, in Lake Eğirdir. In addition, both parasites were also detected intensively in autumn and winter Conclusion: The use of Lake Eğirdir for daily needs of people, agriculture andrecreational purposes cause increase in protozoal density. Thus, it is necessary to conduct parasitological studies on Lake Eğirdir, especially during the periods of swimming tourism, to determine the protozoal epidemiology in humans and animals. In addition, it is important to carry out adequate disinfection processes and plan the necessary control programs in terms of public health in the regions where Lake Eğirdir is used as drinking water.


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