Biofilms Reduce Solar Disinfection of Cryptosporidium parvum Oocysts

DiCesare, E. A. Wolyniak; Hargreaves, Bruce R.; Jellison, Kristen L.

doi:10.1128/aem.08019-11

Cited by 16 publications

(3 citation statements)

References 31 publications

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“…These sponge-associated oocysts are provided with UV light protection by the sponge biomass whereby viability can be maintained for longer periods thereby increasing the potential for both human and zoonotic infections (DiCesare et al, 2012) and is a potential hazard to Lake Buhi's residents, fishermen, and tourists. Results of the study show that freshwater sponges could be utilized as bioindicators of the microbiological quality of natural water resources.…”

Section: Resultsmentioning

confidence: 99%

First report of Cryptosporidium hominis in a freshwater sponge

Masangkay

Milanez

Tsiami

et al. 2020

Science of The Total Environment

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Identification of Cryptosporidium oocyst is essential in ensuring water quality fit for human use, consumption, and recreation. This communication proposes the supplemental analysis of substrateassociated biofilms, in particular, freshwater sponges in improving case finding of waterborne-protozoan pathogens (WBPP) in environmental aquatic samples. In this study, a small portion of a mature freshwater sponge under the Genus Radiospongilla was subjected to microscopic and molecular analysis to identify the presence of Cryptosporidium. Microscopic screening with modified Kinyoun's staining (MK) and microscopic confirmation using direct antibody fluorescent testing (IFT) returned with Cryptosporidium spp. positive findings. Molecular investigation resulted in the confirmation of Cryptosporidium hominis upon sequencing of PCR products and phylogenetic analysis. This is the first report of a pathogenic protozoan, C. hominis isolated from a freshwater sponge. The results of this study provide evidence of the value of expanding water quality assessment strategies to the analysis of substrate-associated biofilms and sponges in improving case finding of WBPP in natural aquatic environments.

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Section: Resultsmentioning

confidence: 99%

First report of Cryptosporidium hominis in a freshwater sponge

Masangkay

Milanez

Tsiami

et al. 2020

Science of The Total Environment

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“…A gram of feces from an infected host, during peak shedding, may contain as many as 10 7 oocysts for several days, with daily output exceeding 10 9 oocysts (54, 55), while the infectious dose for humans can be as low as 10 oocysts (56,57). Furthermore, association with biofilms may provide shelter for oocysts and has been shown to protect oocysts from damage due to solar UV radiation exposure (58). Thus, given the importance of biofilms in the fate and transport of oocysts in environmental ecosystems, understanding the mechanisms of oocyst attachment to biofilms will provide a foundation for future innovations in parasite detection and treatment technologies to protect public health.…”

Section: Discussionmentioning

confidence: 99%

Pseudo-Second-Order Calcium-Mediated Cryptosporidium parvum Oocyst Attachment to Environmental Biofilms

Luo

Jedlicka

Jellison

2017

Appl Environ Microbiol

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Cryptosporidium parvum oocysts are able to infect a wide range of mammals, including humans, via fecal-oral transmission. The remobilization of biofilmassociated C. parvum oocysts back into the water column by biofilm sloughing or bulk erosion poses a threat to public health and may be responsible for waterborne outbreaks; thus, the investigation of C. parvum attachment mechanisms to biofilms, particularly the physical and chemical factors controlling oocyst attachment to biofilms, is essential to predict the behavior of oocysts in the environment. In our study, biofilms were grown in rotating annular bioreactors using prefiltered stream water (0.2-m retention) and rock biofilms (6-m retention) until the mean biofilm thickness reached steady state. Oocyst deposition followed a calcium-mediated pseudo-second-order kinetic model. Kinetic parameters (i.e., initial oocyst deposition rate constant and total number of oocysts adhered to biofilms at equilibrium) from the model were then used to evaluate the impact of water conductivity on the attachment of oocysts to biofilms. Oocyst deposition was independent of solution ionic strength; instead, the presence of calcium enhanced oocyst attachment, as demonstrated by deposition tests. Calcium was identified as the predominant factor that bridges the carboxylic functional groups on biofilm and oocyst surfaces to cause attachment. The pseudo-second-order kinetic profile fit all experimental conditions, regardless of water chemistry and/or lighting conditions. IMPORTANCE The cation bridging model in our study provides new insights into the impact of calcium on the attachment of C. parvum oocysts to environmental biofilms. The kinetic parameters derived from the model could be further analyzed to elucidate the behavior of oocysts in commonly encountered complex aquatic systems, which will enable future innovations in parasite detection and treatment technologies to protect public health.KEYWORDS attachment, biofilms, calcium, Cryptosporidium C ryptosporidium is a protozoan pathogen transmitted through either direct contact or ingestion of contaminated food and/or water (1). There are currently 26 identified species of Cryptosporidium that infect a wide range of animal hosts, with C. hominis and C. parvum the most common species associated with human infection (2). Infection can lead to cryptosporidiosis, a severe diarrheal disease that lasts 1 to 2 weeks for immunocompetent people but may be fatal for the elderly, infants, or immunocompromised people. Contaminated drinking water has been linked to major outbreaks of cryptosporidiosis (3-6); therefore, development of improved methods for assessing the levels of Cryptosporidium in source waters is important to protect public health.A number of studies have been performed to assess the conditions under which Cryptosporidium can be selectively removed and subsequently detected in environmental waters. A wide variety of surfaces and filter media have been assessed. Attach-

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“…However, investigations delving into interactions with biofilms are limited (14,57). Seasonal changes influencing biofilm profile and retention of Cryptosporidium oocysts have been described [53,54]; water depth influences biofilm thickness and other biologic masses like freshwater sponges may facilitate protection against UV radiation, although largely known as requiring an animal cell for its complex biological progression [31,32,55,56], Cryptosporidium excystation and developmental stages have been demonstrated in in-vitro Pseudomonas aeruginosa biofilms [14] and even in in-vitro axenic cultures [57]. It is, therefore, of great interest, to further expand Cryptosporidium investigations in biofilms in aquatic and fluid systems.…”

Section: Water Quality Assessment Strategies and Multi-spatial Distrimentioning

confidence: 99%

Multi-spatial contamination of environmental aquatic matrices with Cryptosporidium: a climate, health, and regulatory framework for the Philippines

et al. 2020

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Background Cryptosporidium is a waterborne global pathogen causing diarrhea primarily in infants and immunocompromised individuals. The Philippines is a tropical country susceptible to the influences of climate change and water crises. To date, the country has no existing epidemiologic data, regulation, or strategy for monitoring Cryptosporidium in freshwater systems. We, therefore, endeavored to provide evidence on the multi-spatial contamination of Cryptosporidium in environmental aquatic matrices using low-cost, user-friendly, and sustainable strategies and submit implications on the presence of Cryptosporidium in freshwater systems in a climate, health, and regulatory framework. Results Here, we present the microscopic detection of Cryptosporidium oocysts in low-volume (50 mL) environmental samples of surface water (SW), sediments (BW), and substrate-associated biofilm (SAB) and in 1 L bulk SW investigated by PCR. The multi-spatial distribution of Cryptosporidium oocysts in the low-volume (50 ml) aquatic matrices based on microscopy was highest at 69% (20/29) in SW and lowest at 50% (13/26) in BW. Immunofluorescence technique provided the highest microscopic positivity rate with 59% (17/29), 38% (10/26), and 50% (10/20) detection in SW, BW, and SAB, respectively. The detection and identification of Cryptosporidium in 1 L bulk SW by PCR and sequence analysis was recorded in total at 21% (6/29) in sampling sites where the differential identification of C. parvum, C. hominis, and Cryptosporidium spp. was 7% (2/29), 10% (3/29), and 3% (1/29), respectively. Conclusions We report the microscopical and first molecular epidemiologic data of Cryptosporidium from the most significant environmental freshwater systems in the Philippines. The presence of the two main human and animal pathogenic species C. parvum and C. hominis from the largest lakes and major water reservoirs in the country calls for sustainable solutions in safeguarding the quality of freshwater resources in a climate, health, and regulatory approach.

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Biofilms Reduce Solar Disinfection of Cryptosporidium parvum Oocysts

Cited by 16 publications

References 31 publications

First report of Cryptosporidium hominis in a freshwater sponge

First report of Cryptosporidium hominis in a freshwater sponge

Pseudo-Second-Order Calcium-Mediated Cryptosporidium parvum Oocyst Attachment to Environmental Biofilms

Multi-spatial contamination of environmental aquatic matrices with Cryptosporidium: a climate, health, and regulatory framework for the Philippines

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