Biomedical subjects

Jennifer L McDonald

Publications and source records attributed to Jennifer L McDonald.

3 recordsLinked to original sources

PubMed2006

Identifying sources of fecal contamination inexpensively with targeted sampling and bacterial source tracking.

Most bacterial source tracking (BST) methods are too expensive for most communities to afford. We developed targeted sampling as a prelude to BST to reduce these costs. We combined targeted sampling with three inexpensive BST methods, Enterococcus speciation, detection of the esp gene, and fluorometry, to confirm the sources of fecal contamination to beaches on Georgia's Jekyll and Sea Islands during calm and stormy weather conditions. For Jekyll Island, the most likely source of contamination was bird feces because the percentage of Ent. faecalis was high (30%) and the esp gene was not detected. For the Sea Island beach during calm conditions, the most likely sources of fecal contamination were leaking sewer lines and wildlife feces. The leaking sewer lines were confirmed with fluorometry and detection of the esp gene. For the Sea Island beach during stormflow conditions, the most likely sources of fecal contamination were wildlife feces and runoff discharging from two county-maintained pipes. For the pipes, the most likely source of contamination was bird feces because the percentage of Ent. faecalis was high (30%) and the esp gene was not detected. Sediments were also a reservoir of fecal enterococci for both Jekyll and Sea Islands. Combining targeted sampling with two or more BST methods identified sources of fecal contamination quickly, easily, and inexpensively. This combination was the first time targeted sampling was conducted during stormy conditions, and the first time targeted sampling was combined with enterococcal speciation, detection of the esp gene, and fluorometry.

Animals↗

PubMed2003

Utilization patterns of second-line antibiotics in a health plan setting.

Increased utilization of second-line antibiotics where first-line agents are appropriate, and the use of antibiotics for viral infections, are leading to the development of resistance. This retrospective study evaluated antibiotic utilization patterns of cephalosporins, macrolides, and quinolones for community-acquired infections in a health plan's patient population. Patients were identified through the health plan's computerized pharmacy claims database. Patients were considered eligible if they had been enrolled with the health plan for at least one year, and had a prescription claim for a cephalosporin, macrolide, or quinolone antibiotic between February 1, 2001 and April 30, 2001. Six hundred fifty patients were randomly selected to undergo chart review. A total of 128 patients (25.2%) from an eligible cohort of 508 health plan members had no documented diagnosis of infection in their chart. Gram staining was checked in 14 patients. Cultures were ordered for only 19 patients. Comparisons were made with regard to first-, second-, and third-line drug use in select documented infections. Of all the patients in the study, only 10.4% (53/508) had chart documentation of previous antibiotic failure. Of the 456 patients who had documentation, 63% had no known antibiotic allergies, and 19% had allergies to penicillin. The results of this study will be used to educate providers and consumers on appropriate antibiotic prescribing.

Anti-Bacterial Agents↗

PubMedDate not supplied

Targeted sampling protocol as prelude to bacterial source tracking with Enterococcus faecalis.

Recent studies suggest that host origin databases for bacterial source tracking (BST) must contain a large number of isolates because bacterial subspecies change with geography and time. A new targeted sampling protocol was developed as a prelude to BST to minimize these changes. The research was conducted on the Sapelo River, a tidal river on the Georgia coast. A general sampling of the river showed fecal enterococcal numbers ranging from <10 (below the limit of detection) to 990 colony-forming units (CFU) per 100 mL. Locations with high enterococcal numbers were combined with local knowledge to determine targeted sampling sites. Fecal enterococcal numbers around one site ranged from <10 to 24,000 CFU per 100 mL. Bacterial source tracking was conducted to determine if a wastewater treatment facility at the site was responsible for this contamination. The fecal indicator bacterium was Enterococcus faecalis. Ribotyping, automated with a RiboPrinter (DuPont Qualicon, Wilmington, DE), was the BST method. Thirty-seven ribotypes were observed among 83 Ent. faecalis isolates obtained from the Sapelo River and the wastewater lagoon. Sixteen ribotypes were associated with either the river or the lagoon, and only five ribotypes (14%) were shared. Nevertheless, these five ribotypes represented 39 of the 83 Ent. faecalis isolates, almost a majority (47%). These results suggest that the fecal contamination in the river came from the wastewater treatment facility. As a prelude to BST, targeted sampling minimized subspecies changes with geography and time, and eliminated the need for a permanent host origin database by restricting BST to a small geographic area and requiring sampling to be completed in one day.

Animals↗