Multiplication of the waterborne pathogen Cryptosporidium parvum in an aquatic biofilm system
1 School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA 6150, Australia
2 Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
3 South Australian Water Corporation, 250 Victoria Square, Adelaide, SA 5000, Australia
Parasites & Vectors 2013, 6:270 doi:10.1186/1756-3305-6-270Published: 19 September 2013
In natural aquatic environments biofilms are known to act as environmental reservoirs for Cryptosporidium parvum oocysts. However, the fate of these oocysts within biofilms has yet to be determined.
This study aimed to identify if biofilms have the ability to support the multiplication of Cryptosporidium by measuring the change in parasite number over time using quantitative polymerase chain reaction (qPCR) and detecting the possible extracellular developmental stages using a combination of confocal microscopy and immunolabelling techniques. Pseudomonas aeruginosa biofilm flow cell systems were established and C. parvum oocysts were constantly supplied over a six day period.
A significant (P < 0.001) increase in Cryptosporidium was detected as the biofilm matured, with the total number of C. parvum multiplying 2–3 fold during this period. With this, various Cryptosporidium developmental stages (sporozoites, trophozoites, type I and II meronts) were identified from the biofilm.
This is the first study demonstrating that biofilms not only serve as an environmental reservoir for oocysts, but are also capable of supporting the multiplication of Cryptosporidium over time in an aquatic environment.