Residues of organochlorines in mallards and blue-winged teal collected in Colombia and Wisconsin, 1984-1989.

We compared the seasonal concentrations of 12 organochlorine (OC) compounds in samples of breast muscle, associated skin, and subcutaneous fat of blue-winged teal (Anas discors) collected in Ciénaga Grande de Santa Marta, Colombia (1987-1988), and of mallards (Anas platyrhynchos) and blue-winged teal collected in Wisconsin (1984-1989). Although these species have similar feeding habits and overlapping breeding distributions, their winter ranges differ markedly. Most blue-winged teal winter in the Neotropics, whereas most mallards remain in the temperate regions of North America. A seasonal comparison of OC exposure in these species may help determine the geographic origins of contamination. All examined OCs were found to be below concentrations known to affect reproduction in waterfowl. DDE was most often detected in blue-winged teal and PCBs, in mallards. DDE exposure may have predominantly occurred outside of Wisconsin. The DDE concentration in blue-winged teal samples collected in Wisconsin in the spring (GM=0.406 microg/g) were greater (P<0.001) than in the fall (GM=0. 033 microg/g) and greater than the concentrations in mallard samples from the spring (GM=0.058 microg/g; P<0.001). Ciénaga Grande, however, was not a source of DDE contamination. The DDE concentrations in blue-winged teal samples from Ciénaga Grande did not differ between the spring (GM=0.037 microg/g) and the fall (GM=0. 039 microg/g) and were lower (P<0.001) than the concentration in blue-winged teal samples from Wisconsin in the spring. In contrast, PCB contamination seemed to have occurred in Wisconsin and affected mostly mallards. PCBs were not detected in the samples from Colombia and were detected in only five (8.3%) of the blue-winged teal samples from Wisconsin (GM=0.025 microg/g), however, those compounds were detected in 47% of the mallard samples collected in Wisconsin (GM=0.272 microg/g). DDE and PCB concentrations were greater (P=0.0) in mallard samples collected from wetlands adjacent to Lake Michigan than in samples from inland wetlands.

Toxicity and reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in ring-necked pheasant hens.

Hen pheasants (Phasianus colchicus) injected with graded single doses of TCDD (6.25, 25, or 100 micrograms/kg) exhibited delayed-onset body weight loss and mortality--classic signs of the wasting syndrome. The lowest single dose of TCDD to produce this effect was 25 micrograms/kg. When hen pheasants were treated weekly with far lower doses of TCDD (0.01-1.0 microgram/kg/wk) for 10 wk, signs of the wasting syndrome and mortality were also produced. The lowest cumulative TCDD dose required to produce the response, using a weekly dosing regimen, was 10 micrograms/kg. Furthermore, using this dosing regimen, egg production by hens treated with a cumulative TCDD dose of 10 micrograms/kg was reduced, as was hatchability of their eggs. We conclude that hen pheasants are responsive to the overt toxic effects of TCDD and that the lowest cumulative dose of TCDD that produces overt signs of toxicity, 10 micrograms/kg, also reduces egg production and egg hatchability.

Development of a diagnostic test for Johne's disease using a DNA hybridization probe.

A DNA probe, M13 mpHAW71, that detects Mycobacterium paratuberculosis in the fecal material of infected animals was developed for use in the diagnosis of Johne's disease. The probe detected as few as 10(5) M. paratuberculosis when hybridized under stringent conditions to total genomic DNA purified from bovine fecal material. When the probe was used diagnostically, it did not differentiate members of the Mycobacterium avium-M. intracellulare-M. paratuberculosis complex. Compared with culturing, the DNA probe identified 34.4% more mycobacterium-containing fecal samples, and testing took only 72 h to complete.

Accidental self-inoculation with Mycobacterium paratuberculosis bacterin (Johne's bacterin) by veterinarians in Wisconsin.

We surveyed Wisconsin veterinarians to assess the frequency and severity of accidental self- and other human exposure to Mycobacterium paratuberculosis bacterin (Johne's bacterin). Of 199 veterinarians administering the bacterin to cattle, 22 reported one or more exposures, including 19 needle-stick exposures, 8 skin surface exposures, and 2 oral mucosa exposures. The mean incidence of needle sticks was 5.5/100 veterinarians/year of bacterin use or 1/1,000 doses administered. The mean total doses given in the needle-stick exposure group was 276 +/- 318 vs 80 +/- 268 in the group without needle-stick exposure, and the mean number of months administering the bacterin was 21.7 and 16.1, respectively; 63% of needle-stick exposures took place during the injection process. Five adverse reactions were reported, and each resulted from needle-stick exposure. The only systemic reaction followed an exposure to the original bacterin formulation of sonically ruptured M paratuberculosis in Freund incomplete adjuvant. The remaining reactions were to the current formulation of whole killed M paratuberculosis in mineral oil and ranged from a small nodule persisting for 4 to 6 months to painful inflammation of a finger persisting for 24 months. We anticipate an increase in incidence of these minimally debilitating injuries as the use and distribution of the bacterin expands. For hand wounds, we recommend conservative management. Surgical intervention should be considered if a granuloma persists and causes the patient functional difficulty.

Rapid lysis technique for mycobacterial species.

The lysis of mycobacterial cells typically has been difficult and time-consuming. We report a method for the physical rupture of Mycobacterium paratuberculosis and several other members of the family Mycobacteriaceae using a Mini-Beadbeater cell disrupter (Biospec Products; Bartlesville, Okla.) and zirconium beads, a process which yields DNA and RNA of high molecular weight and in greater quantity than that obtained by rupture in a Ribi pressure cell.