scholarly journals First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil

2008 ◽  
Vol 6 (4) ◽  
pp. 527-532 ◽  
Author(s):  
Diego Averaldo Guiguet Leal ◽  
Mirna Aparecida Pereira ◽  
Regina Maura Bueno Franco ◽  
Nilson Branco ◽  
RomeuCantusio Neto
Keyword(s):  
Hepatitis A Virus ◽  
Cryptosporidium Oocyst ◽  
Coastal Region ◽  
Tween 80 ◽  
Public Health Importance ◽  
First Report ◽  
Cryptosporidium Oocysts ◽  
Thermotolerant Coliforms ◽  
Seawater Quality ◽  
Crassostrea Rhizophorae

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from São Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.

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

2021 ◽  
Vol 9 (7) ◽  
pp. 1463
Author(s):  
Tamirat Tefera Temesgen ◽  
Kristoffer Relling Tysnes ◽  
Lucy Jane Robertson
Keyword(s):  
Oxidative Stress ◽  
Stress Responses ◽  
Target Genes ◽  
Cryptosporidium Oocyst ◽  
Drinking Water Treatment ◽  
Proof Of Concept ◽  
Environmental Matrices ◽  
Oocyst Wall ◽  
Novel Approach ◽  
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.

scholarly journals Potentially Infectious Novel Hepatitis A Virus Strains Detected in Selected Treated Wastewater Discharge Sources, South Africa

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1468
Author(s):  
Saïd Rachida ◽  
Maureen Beatrice Taylor
Keyword(s):  
South Africa ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Wastewater Discharge ◽  
Public Health Importance ◽  
Symptomatic Disease ◽  
Before And After ◽  
Amino Acid Mutations

Hepatitis A virus (HAV) is a waterborne pathogen of public health importance. In South Africa (SA), unique HAV subgenotype IB strains have been detected in surface and wastewater samples, as well as on fresh produce at the point of retail. However, due to the use of molecular-based assays, the infectivity of the detected strains was unknown. Considering the potential shift of HAV endemicity from high to intermediate, which could increase the risk of severe symptomatic disease, this study investigated the identity of HAV strains detected before and after viability treatment of selected wastewater discharge samples. For one year, 118 samples consisting of sewage, treated wastewater discharge and downstream dam water were collected from five wastewater treatment plants (WWTP 1, 2, 3, 4 and 5). Unique HAV IB strains were detected in samples from all five WWTPs, with 11 of these strains carrying amino acid mutations at the immunodominant and neutralisation epitopes. A quasispecies dynamic of HAV has also been detected in sewage samples. The subsequent application of viability PCR revealed that potentially infectious HAV strains were discharged from WWTP 1, 2, 4 and 5 into the dam. Therefore, there is a potential risk of HAV exposure to communities using water sources downstream the WWTPs.

Determination of the Recovery Efficiency of Cryptosporidium Oocysts and Giardia Cysts from Seeded Bivalve Mollusks

2013 ◽  
Vol 76 (1) ◽  
pp. 93-98 ◽  
Author(s):  
FRANCISKA M. SCHETS ◽  
HAROLD H. J. L. van den BERG ◽  
ANA MARIA de RODA HUSMAN
Keyword(s):  
Quantitative Assessment ◽  
Intestinal Parasites ◽  
Cryptosporidium Oocyst ◽  
Immunomagnetic Separation ◽  
Giardia Cyst ◽  
Bivalve Mollusks ◽  
Recovery Efficiency ◽  
Risk Of Infection ◽  
Cryptosporidium Oocysts

The intestinal parasites Cryptosporidium and Giardia are transmitted by water and food and cause human gastroenteritis. Filter-feeding bivalve mollusks, such as oysters and mussels, filter large volumes of water and thus concentrate such pathogens, which makes these bivalves potential vectors of disease. To assess the risk of infection from consumption of contaminated bivalves, parasite numbers and parasite recovery data are required. A modified immunomagnetic separation (IMS) procedure was used to determine Cryptosporidium oocyst and Giardia cyst numbers in individually homogenized oysters (Crassostrea gigas) and mussels (Mytilus edulis). About 12% of the commercial bivalves were positive, with low (oo)cyst numbers per specimen. The recovery efficiency of the IMS procedure was systematically evaluated. Experiments included seeding of homogenized bivalves and whole animals with 100 to 1,000 (oo)cysts. Both seeding procedures yielded highly variable recovery rates. Median Cryptosporidium recoveries were 7.9 to 21% in oysters and 62% in mussels. Median Giardia recoveries were 10 to 25% in oysters and 110% in mussels. Giardia recovery was significantly higher than Cryptosporidium recovery. (Oo)cysts were less efficiently recovered from seeded whole animals than from seeded homogenates, with median Cryptosporidium recoveries of 5.3% in oysters and 45% in mussels and median Giardia recoveries of 4.0% in oysters and 82% in mussels. Both bivalve homogenate seeding and whole animal seeding yielded higher (oo)cyst recovery in mussels than in oysters, likely because of the presence of less shellfish tissue in IMS when analyzing the smaller mussels compared with the larger oysters, resulting in more efficient (oo)cyst extraction. The data generated in this study may be used in the quantitative assessment of the risk of infection with Cryptosporidium or Giardia associated with the consumption of raw bivalve mollusks. This information may be used for making risk management decisions.

Cryptosporidium oocyst shedding in buffalo calves in Haryana: A case study

2018 ◽  
Author(s):  
Krutanjali Swain ◽  
Abhilash Routray ◽  
Saraswat Sahoo and Subha Ganguly
Keyword(s):  
Cryptosporidium Oocyst ◽  
Buffalo Calves ◽  
Concentration Technique ◽  
Cryptosporidium Oocysts ◽  
Oil Immersion ◽  
Neonatal Diarrhoea ◽  
Conventional Microscopy ◽  
Animal Sciences ◽  
Acid Fast Staining

Bovine cryptosporidiosisis primarily associated with neonatal diarrhoea with higher morbidity than mortality in young calves till they attain immunological maturity. The present investigation relates to a report on the shedding of Cryptosporidium oocyst in two buffalo calves of buffalo farm, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar from 1st days up to 3 month of age at 15 days interval using simple conventional microscopy. By using formol-ether concentration technique followed by modified Ziehl-Neelsen (ZN) acid fast staining, Cryptosporidium oocysts were concentrated and identified. The Cryptosporidium oocysts appeared as reddish pink coloured bodies against a bluish/greenish coloured background at oil immersion using ZN staining kit. The maximum oocyst shedding was observed (2.3 oocyst / field) during 16 to 30 days of age. The oocyst shedding gradually decreased with increase in age afterwards clearly indicating the disease of young buffalo calves.

scholarly journals Cryptosporidium infection in non-human hosts in Malawi

2009 ◽  
Vol 76 (4) ◽  
Author(s):  
Z. Banda ◽  
Rosely A.B. Nichols ◽  
A.M. Grimason ◽  
H.V. Smith
Keyword(s):  
Cryptosporidium Parvum ◽  
Rainy Season ◽  
18S Rrna ◽  
Cryptosporidium Oocyst ◽  
Dry Season ◽  
Cool Season ◽  
Cryptosporidium Hominis ◽  
Adult Cattle ◽  
Faecal Samples ◽  
Cryptosporidium Oocysts

Of 1 346 faecal samples from the Chikwawa and Thyolo districts of Malawi, analysed for the presence of Cryptosporidium oocysts between October 2001 and May 2003, 61.3 % were from cattle (29.8 % of these were from calves < 6 months old). Cryptosporidium oocysts were detected during all three seasons studied in Chikwawa and Thyolo. In Chikwawa, 13.6 % of adult cattle and 11.7 % of calves were infected, compared to 28.9 % of adult cattle and 36.7 % of calves in Thyolo. Dependent on season, between 7.8 % and 37.7 % (Chikwawa) and 16.7 % and 39.3 % (Thyolo) of cattle samples contained oocysts. In Chikwawa, the highest percentage of infections occurred in the cool season, whereas in Thyolo, the highest percentage of infections occurred in the dry season. Faecal samples from goats [n = 225], pigs [n = 92], sheep [n = 6]), rabbits, guinea pigs, chickens, ducks, turkeys, doves and guinea fowls were also analysed. Up to 5.6 % of goat samples contained oocysts in Chikwawa, compared to between 16.7 % and 39.3 % in Thyolo. Again, in Chikwawa, the highest percentage of infections occurred in the cool season and the lowest in the rainy season, whereas, in Thyolo, the highest percentage of infections occurred in the dry season and the lowest in the cool season. In pigs, more infections were detected in the dry season in Chikwawa, but infections in the cool season were similar (17.7 %), whereas in Thyolo, infections occurred in all three seasons (17.9 % in the rainy season, 25 % in the cool season and 60 % in the dry season). Often diarrhoeic, oocyst positive cattle faecal samples collected from Chikwawa and subjected to PCR-RFLP, four oocyst positive samples (two from heifers, one from a cow and one unknown) were amplified at an 18S rRNA and Cryptosporidium oocyst wall protein (COWP) loci. RFLP of the 18S rRNA locus indicated that Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium bovis and / or Cryptosporidium ryanae DNA, or a mixture of them was present. Cryptosporidium parvum DNA was identified in one sample that amplified at the COWP locus, indicating the presence of the major zoonotic Cryptosporidium species in Malawi.

Occurrence and persistence of bacterial and viral faecal indicators in wastewater biofilms

2007 ◽  
Vol 55 (8-9) ◽  
pp. 377-385 ◽  
Author(s):  
S. Skraber ◽  
K. Helmi ◽  
R. Willame ◽  
M. Ferréol ◽  
C. Gantzer ◽  
...  
Keyword(s):  
Dynamic Equilibrium ◽  
Wastewater Treatment Plants ◽  
Plate Count ◽  
Cryptosporidium Oocysts ◽  
The Matrix ◽  
Thermotolerant Coliforms ◽  
Viral Indicators ◽  
The Stability ◽  
Faecal Indicators ◽  
Giardia Cysts

Biofilms within wastewater treatment plants can capture enteric microorganisms initially present in the water phase immobilising them either definitively or temporarily. Consequently, fates of microorganisms may totally change depending on whether they interact or not with biofilms. In this study, we assessed the stability of wastewater biofilms comparing the evolution of the concentrations of bacteria (heterotrophic plate count [HPC], thermotolerant coliforms [TC]) and viral (somatic coliphages [SC] and F-specific phages [F+]) indicators in the biofilms and in the corresponding wastewaters at 4 and 20 °C. Additionally, we assessed the monthly occurrence of these bacterial and viral indicators as well as of pathogenic protozoa (Cryptosporidium oocysts and Giardia cysts) in three native wastewater biofilms for four months. Our results show that viral indicators (SC and F+) persist longer in biofilms than in the corresponding wastewaters at 4 °C as well as at 20 °C. In contrast, persistence of bacterial indicators (TC and HPC) depends on both the temperature and the matrix. Differences between viral and bacterial persistence are discussed. Monthly analysis of native wastewater biofilms shows that bacterial and viral indicators, as well as Cryptosporidium oocysts and Giardia cysts, attach to wastewater biofilms to a concentration that remains stable in time, probably as a result of a dynamic equilibrium between attachment and detachment processes.

scholarly journals First Report of a Fruit Rot of Pumpkin Caused by Acidivorax avenae subsp. citrulli in Georgia

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 199-199 ◽  
Author(s):  
D. B. Langston ◽  
R. D. Walcott ◽  
R. D. Gitaitis ◽  
F. H. Sanders
Keyword(s):  
Polyclonal Antibodies ◽  
Pcr Amplification ◽  
Tween 80 ◽  
Soft Rot ◽  
Fruit Rot ◽  
Identification System ◽  
Banding Patterns ◽  
First Report ◽  
Microbial Identification ◽  
Necrotic Spots

In September 1998, a fruit rot was reported affecting pumpkin (Cucurbita pepo) in a commercial field in Terrell Co., Georgia. Symptoms on the surface of fruit occurred as round, necrotic spots or cracks a few millimeters in diameter. With age, the tissue surrounding these lesions became soft and wrinkled. A soft rot expanded into the flesh of the pumpkin, originating from the lesions observed on the surface. In time, infected pumpkins totally collapsed. V-shaped, necrotic lesions occurred at the margin of the leaf and extended inward toward the mid-rib. Samples were collected from the field and bacteria were isolated from fruit and leaf lesions onto King's medium B (1). The bacterium isolated was rod shaped, gram negative, nonflourescent, oxidase positive, Tween 80 positive, carboxymethyl cellulose positive, β-OH butyrate positive, and malonate negative. The bacterium reacted positively with polyclonal antibodies specific for the watermelon fruit blotch pathogen Acidivorax avenae subsp. citrulli and was identified as A. avenae subsp. citrulli by MIDI (Microbial Identification System, Newark, DE) according to statistical analysis of fatty acid data. Results from polymerase chain reaction (PCR) amplification of the bacterium isolated from pumpkin yielded 360-bp fragments that, when digested with the restriction enzyme HaeIII, had DNA banding patterns identical to those of stock A. avenae subsp. citrulli DNA. Koch's postulates were completed successfully with 2-week-old watermelon seedlings. This is the first report of A. avenae subsp. citrulli causing fruit rot of pumpkin in Georgia. Reference: (1) E. O. King et al. J. Lab. Clin. Med. 44:301, 1954.

Detection of Cryptosporidium from Wastewater and Freshwater Environments

1986 ◽  
Vol 18 (10) ◽  
pp. 233-239 ◽  
Author(s):  
J. B. Rose ◽  
A. Cifrino ◽  
M. S. Madore ◽  
C. P. Gerba ◽  
C. R. Sterling ◽  
...  
Keyword(s):  
Fresh Water ◽  
Environmental Samples ◽  
Sucrose Gradient ◽  
Tween 80 ◽  
Oral Route ◽  
Sand Filters ◽  
Membrane Filters ◽  
Cryptosporidium Oocysts ◽  
Fluorescently Labelled Monoclonal Antibody ◽  
Freshwater Environments

Cryptosporidium is a coccidian protozoan and has recently been recognized as a cause of human gastroenteritis. The illness may be severe in immunocom-promised individuals and can result in death. The organism is monoxenous, and infective oocysts are shed in the feces, which are transmitted via the fecal-oral route. Therefore, Cryptosporidium may be a possible candidate as an etiological agent of waterborne or foodborne disease. Previously, the lack of methods for detection of this organism in diarrheal samples as well as environmental samples, has made it difficult to substantiate this premise. Detection of Cryptosporidium oocysts in water has now been accomplished using a filtration-elution procedure. A fluorescently-labelled monoclonal antibody which has been used for the detection of Cryptospori di urn in feces was also used to detect the oocysts in environmental samples. The method developed for detection of Cryptosporidium in water including: 1) filtration with polypropylene cartridge filters, 2) elution with Tween 80/detergent, 3) concentration with Sheather's flotation, and 4) detection on membrane filters, was evaluated and used to examine wastewater and fresh water for Cryptosporidiurn oocyst concentrations. Recovery from the sucrose gradient step averaged 72 – 82%. Overall recovery efficiencies ranged from 25 – 82% (average 50%), but were diminished with low seeds. Concentrations were found in ranges from 60 to 52,000 oocysts/gal in treated and raw sewage. In fresh water, oocysts numbered 8 to 22,000/gal and were concentrated in rapid sand filters averaging 59,000/gal in the backflush. Cryptosporidium may now be considered a potential waterborne parasite.

Microwave Inactivation of Cyclospora cayetanensis Sporulation and Viability of Cryptosporidium parvum Oocysts

2006 ◽  
Vol 69 (8) ◽  
pp. 1957-1960 ◽  
Author(s):  
YNES R. ORTEGA ◽  
JYEYIN LIAO
Keyword(s):  
Cryptosporidium Parvum ◽  
Propidium Iodide ◽  
Cryptosporidium Oocyst ◽  
Cooking Time ◽  
Cyclospora Cayetanensis ◽  
The Third ◽  
Infectivity Assay ◽  
Cryptosporidium Oocysts ◽  
Cryptosporidium Parvum Oocysts ◽  
Cooking Times

The efficacy of microwave heating on the viability of Cryptosporidium parvum oocysts and on the sporulation of Cyclospora cayetanensis oocysts for various periods of cooking times (0, 10, 15, 20, 30, and 45 s) at 100% power was determined. Cyclospora oocysts were stored in 2.5% dichromate at 23°C for 2 weeks, and sporulation rates were then determined. The 4′,6-diamidino-2-phenylindole and propidium iodide vital stain and the neonate animal infectivity assay determined Cryptosporidium oocyst viability. Cryptosporidium oocysts could be completely inactivated with as little as 20 s of cooking time, whereas Cyclospora sporulation was observed up to 45 s. Two of the examined microwave ovens were more effective at reducing sporulation and viability than the third one. Because of the variability of temperature achieved by the various ovens, cooking time was not an accurate parameter for parasite inactivation. Cryptosporidium oocysts could be inactivated only when temperatures of 80°C or higher were reached in the microwave ovens.

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