Identification of sources of Escherichia coli in South Carolina estuaries using antibiotic resistance analysis

The objective of this study was to assess and differentiate wild-caught South Carolina (SC) shrimps from imported shrimps on the basis of microbiological analysis. Seven wild-caught SC shrimp and 13 farm-raised imported shrimp samples were analyzed. Total plate counts from wild-caught shrimp samples ranged from 4.3 to 7.0 log10 CFU/g, whereas counts from imported shrimp samples ranged from 3.2 to 5.7 log10 CFU/g. There was no difference (P > 0.05) between total bacterial counts of wild-caught SC shrimp and farm-raised imported shrimp. However, the percentages of bacteria with reduced susceptibility towards ceftriaxone and tetracycline were higher (P < 0.05) for farm-raised shrimp than for wild-caught samples. Salmonella spp. detected only in one farm-raised sample was resistant to ampicillin, ceftriaxone, gentamicin, streptomycin, and trimethoprim. Vibrio vulnificus was detected in both wild-caught and farm-raised shrimp samples; however, only the isolate from farm-raised shrimp was resistant to nalidixic acid and trimethoprim. Escherichia coli detected in one wild-caught sample was resistant to ampicillin. Both Listeria spp. and Salmonella spp. were absent with wild-caught SC samples. Therefore, the presence of more ceftriaxone- and tetracycline-resistant bacteria and the observed antimicrobial resistance phenotypes of isolates from the imported shrimp may reflect the possible use of antibiotics in raising shrimp in those countries.

Download Full-text

Identification of the sources of fecal coliforms in an urban watershed using antibiotic resistance analysis

Water Research ◽

10.1016/s0043-1354(02)00139-2 ◽

2002 ◽

Vol 36 (17) ◽

pp. 4273-4282 ◽

Cited By ~ 110

Author(s):

John E Whitlock ◽

David T Jones ◽

Valerie J Harwood

Keyword(s):

Antibiotic Resistance ◽

Fecal Coliforms ◽

Urban Watershed ◽

Resistance Analysis ◽

Antibiotic Resistance Analysis

Download Full-text

Antibiotic Resistance Analysis ofEnterococciin Chester Creek

Impacts of Global Climate Change ◽

10.1061/40792(173)294 ◽

2005 ◽

Author(s):

Graham R. Stahnke ◽

William Schnabel ◽

Khrys Duddleston ◽

Tammie Wilson

Keyword(s):

Antibiotic Resistance ◽

Resistance Analysis ◽

Antibiotic Resistance Analysis

Download Full-text

Use of Antibiotic Resistance Analysis for Representativeness Testing of Multiwatershed Libraries

Applied and Environmental Microbiology ◽

10.1128/aem.69.6.3399-3405.2003 ◽

2003 ◽

Vol 69 (6) ◽

pp. 3399-3405 ◽

Cited By ~ 76

Author(s):

Bruce A. Wiggins ◽

Philip W. Cash ◽

Wes S. Creamer ◽

Scott E. Dart ◽

Preston P. Garcia ◽

...

Keyword(s):

Antibiotic Resistance ◽

Natural Waters ◽

Cross Validation ◽

Microbial Source Tracking ◽

Wild Animal ◽

Source Tracking ◽

Correct Classification ◽

Resistance Analysis ◽

Resistance Patterns ◽

Antibiotic Resistance Analysis

ABSTRACT The use of antibiotic resistance analysis (ARA) for microbial source tracking requires the generation of a library of isolates collected from known sources in the watershed. The size and composition of the library are critical in determining if it represents the diversity of patterns found in the watershed. This study was performed to determine the size that an ARA library needs to be to be representative of the watersheds for which it will be used and to determine if libraries from different watersheds can be merged to create multiwatershed libraries. Fecal samples from known human, domesticated, and wild animal sources were collected from six Virginia watersheds. From these samples, enterococci were isolated and tested by ARA. Based on cross-validation discriminant analysis, only the largest of the libraries (2,931 isolates) were found to be able to classify nonlibrary isolates as well as library isolates (i.e., were representative). Small libraries tended to have higher average rates of correct classification, but were much less able to correctly classify nonlibrary isolates. A merged multiwatershed library (6,587 isolates) was created and was found to be large enough to be representative of the isolates from the contributing watersheds. When isolates that were collected from the contributing watersheds approximately 1 year later were analyzed with the multiwatershed library, they were classified as well as the isolates in the library, suggesting that the resistance patterns are temporally stable for at least 1 year. The ability to obtain a representative, temporally stable library demonstrates that ARA can be used to identify sources of fecal pollution in natural waters.

Download Full-text

Experience with the antibiotic resistance analysis and DNA fingerprinting in tracking faecal pollution at two lake beaches

Water Science & Technology ◽

10.2166/wst.2007.757 ◽

2007 ◽

Vol 56 (11) ◽

pp. 51-58 ◽

Cited By ~ 10

Author(s):

T.A. Edge ◽

S. Hill ◽

G. Stinson ◽

P. Seto ◽

J. Marsalek

Keyword(s):

Antibiotic Resistance ◽

Dna Fingerprinting ◽

Microbial Source Tracking ◽

Source Tracking ◽

Faecal Contamination ◽

E Coli ◽

Resistance Analysis ◽

Antibiotic Resistance Analysis ◽

Environmental Challenge ◽

Made In

Posting or closing of swimming beaches because of faecal contamination is a widespread problem reported in many locations. In a risk-based approach to this problem, the risk to swimmers' health is assessed by field monitoring of indicator bacteria and the associated risks are managed by source controls and other remedial measures. In risk assessment, great advances have been made in recent years with the introduction of microbial source tracking (MST) techniques. Two such techniques, antibiotic resistance analysis and DNA fingerprinting, were applied in a study of causes of faecal contamination at two lake beaches in Toronto, Ontario. Both methods identified bird faeces as the dominant sources of E. coli. Coping with this type of pollution presents a major environmental challenge.

Download Full-text