Co-localized Crassostrea virginica and Crassostrea ariakensis oysters differ in bioaccumulation, retention and depuration of microbial indicators and human enteropathogens.
OBJECTIVE
To evaluate the bioaccumulation, retention and depuration rates of nine pathogens and surrogates when two oyster species were co-localized in tanks of seawater.


RESULTS
Crassostrea ariakensis (n = 52) and Crassostrea virginica (n = 52) were exposed to five virus types, two protozoan and two microsporidian species for 24 h. Oysters were then placed in depuration tanks, and subsets were removed and analysed for micro-organisms at weekly intervals. The odds of C. ariakensis oysters harbouring mouse norovirus-1 (MNV-1), human norovirus (NoV) or haepatitis A virus (HAV) were significantly greater than the odds of C. virginica oysters harbouring the same viruses (MNV-1 OR = 5.05, P = 0.03; NoV OR = 6.97, P = 0.01; HAV OR = 7.40, P < 0.001). Additionally, compared to C. virginica, C. ariakensis retained significantly higher numbers of transmissive stages of all protozoan and microsporidian species (P < 0.01). Crassostrea ariakensis oysters are also capable of retaining multiple human pathogens for at least 1 month.


CONCLUSIONS
Crassostrea ariakensis oysters were statistically more likely to harbour enteropathogens and microbial indicators, compared to C. virginica. Individual C. ariakensis were also statistically more likely to retain multiple viruses, protozoa and microsporidia than C. virginica, highlighting the role the species may play in the transmission of multiple diseases.


CONCLUSIONS
Nonnative Crassostrea ariakensis oysters are under review for their introduction into the Chesapeake Bay. The results of this study suggest that nonnative C. ariakensis oysters may present a serious public health threat to people consuming the oysters raw from contaminated sites.
Nappier
S P
SP
Department of Environmental Health Sciences, Division of Environmental Health Engineering and the Johns Hopkins Center for Water and Health, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205-2103, USA.
Graczyk
T K
TK
Tamang
L
L
Schwab
K J
KJ
D000818:Animals; D049896:Crassostrea / Q000469:parasitology* / Q000821:virology*; D016785:Cryptosporidium parvum / Q000302:isolation & purification; D016829:Giardia lamblia / Q000302:isolation & purification; D030041:Hepatitis A virus / Q000302:isolation & purification; D016015:Logistic Models; D016814:Microsporidia / Q000302:isolation & purification; D029322:Norovirus / Q000302:isolation & purification; D012367:RNA, Viral / Q000302:isolation & purification; D012623:Seawater
D012367:RNA, Viral