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Great
Lakes Ballast Technology Ivor Knight, Principal Investigator email
Detection and Enumeration of Fecal Indicators and Pathogens in the Ballast Water of Transoceanic Cargo Vessels Entering the Great Lakes Knight IT, Wells CS, Wiggins B, Russell H, Reynolds KA & Huq A Presented
at the General Meeting of the American Society for Microbiology,
Chicago, IL, 1999 Water and sediment in the ballast tanks of commercial cargo vessels may serve as a means of transport for waterborne pathogens from the port where ballast loading occurs to the port where ballast is discharged. In order to assess the potential for transport of human pathogens in ballast water, a study was designed to sample the ballast water and sediment in transoceanic cargo vessels entering the Great Lakes and test for the presence of fecal indicating organisms and selected human pathogens. During the 1997 and 1998 shipping seasons, samples were retrieved from 28 transoceanic vessels as they passed through the Saint Lawrence Seaway, en route to ports in the Great Lakes. One to two ballast tanks were sampled per vessel and 4 to 40 L per tank was removed for detection and/or enumeration of fecal indicating bacteria and selected human pathogens. A rapid method was devised for aseptically retrieving samples from the bottom of a ballast tank, via the sounding tube on the deck of the vessel. A combination of culture, immunological and molecular methods was used to detect or enumerate the following indicator groups or organisms: fecal coliforms, fecal streptococci, Clostridium perfringens, Salmonella spp., E. coli,,Vibrio cholerae, Cryptosporidium spp., Giardia spp., Hepatitis A virus, and enteroviruses. Whole water samples were shipped from the sampling site for immediate culture or were concentrated on site by filtration for extraction and analysis of microorganisms or specific target molecules. With the exception of Hepatitis A virus, all target organisms were detected in one or more samples of ballast water. Detection of pathogens did not correlate well with levels of indicator organisms. Extensive sample cleanup was required for the application of molecular methods, due to inhibiting compounds encountered in ballast water and sediment. This study resulted in the development of new sampling and analytical techniques for microbiological examination of ballast water and provides initial results for future studies evaluating the potential public health risks associated with ballast water discharge.
Detection and Enumeration of Pathogenic Bacteria in Ballast Water of Transoceanic Vessels Entering the Great Lakes and Resistance to Common Antibiotics Zo Y, Grimm C, Matte M, Matte G, Knight IT, Huq A & Colwell RR Presented
at the General Meeting of the American Society for Microbiology,
Chicago, IL, 1999 Ballast water
samples from ships entering the Great Lakes in 1997 and 1998 were
examined for three pathogenic bacterial species, Vibrio cholerae,
Escherichia coli and Salmonella typhi, to assess the potential of
ballast water as a vehicle for inter-continental transmission of
these species. Water samples were concentrated by membrane filtration
and inoculated into enrichment media followed by culturing on plates
appropriate for each species. Bacterial isolates characterized by
conventional biochemical tests. V. cholerae was isolated from one
of the samples by culture, and three samples were positive for V.
cholerae by direct fluorescent antibody direct viable count (DFA-DVC).
E. coli strains were isolated from 4 of the ballast water samples.
S. typhi was not isolated from any of the samples. Polymerase chain
reaction (PCR) specific for ctxA and tcp genes showed neither to
be present in the V. cholerae isolate. Preliminary results of genotyping
by ERIC-PCR suggest a close relationship with the strain to an environmental
V. cholerae isolated from India. Among the four E. coli isolates,
none was O157. Interestingly, antibiotic-resistance was detected
in all 6 samples tested. Resistance to cephalothin was common to
those samples while resistance to ampicillin and vancomycin was
present in 4 samples. Least frequent was resistance to streptomycin
(50%). In conclusion, the presence of V. cholerae O1 cells in ballast
water and the isolation of V. cholerae and E. coli species from
these samples demonstrates survival of pathogenic bacteria in ballast
water that can serve as a potential source of such pathogens.
Detection of Human Pathogenic Protozoa and Viruses in Ballast Water Using Conventional and Molecular Methods Reynolds KA, Knight IT, Wells CS, Pepper IL & Gerba CP Presented
at the General Meeting of the American Society for Microbiology,
Chicago, IL, 1999 Recently, concern has been raised over the potential transport of human viral and protozoan pathogens in ballast water of transoceanic cargo ships entering the Great Lakes region of the United States. Discharge of human pathogens into source and recreational waters may lead to significant economic, ecological, and public health considerations. During the period from September, 1997 to September, 1998, approximately 40 L of ballast water from 18 sites were concentrated for human pathogenic viruses and protozoa using electropositively charged and wound polypropylene filters, respectively. Following elution and further concentration, detection methods used to survey this novel environment included conventional cultural techniques and immunofluorescent microscopy, as well as molecular based procedures. Molecular and cultural methods were sometimes limited by toxic or inhibitory compounds naturally present in the ballast water, necessitating the use of an integrated cell culture/ PCR (ICC/PCR) technique for viable virus detection. Of the 18 samples examined, three were found to harbor either a viral or protozoan pathogen while two contained both a human viral and protozoan pathogen simultaneously. Two samples were confirmed positive for the presence of enteroviruses, at a concentration of 9.6 mpn/100L and 16/100L. Cryptosporidum spp. was also isolated from two ballast samples, at a concentration of 25.6 and 40 oocysts/100 L. Giardia spp. was isolated from one ballast sample at a concentration of 41.7 cysts/100 L. The use of ICC/PCR enabled the detection of pathogens that were otherwise not detectable by either method alone.
Northeast-Midwest Institute Biological Pollution Contacts Nicole Mays - Policy Analyst (Ph. 202-544-5200) Biological Pollution | Northeast-Midwest Home | Top of Page Great Lakes Ballast Technology Demonstration Project
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