No abstract

Aflatoxins, toxic metabolites of Aspergillus flavus or Aspergillus parasiticus, cause poor feed utilization, decreased weight gains, depressed immune function, liver dysfunction, coagulation abnormalities, and death in a wide variety of species including humans. Conservationists have become concerned that increasingly popular wildlife feeding or baiting practices could expose wildlife to toxic amounts of aflatoxin-contaminated grains. In particular, the effects of aflatoxins on the wild turkey (Meleagris gallopova silvestris) are of concern because the conspecific domestic turkey is highly susceptible to aflatoxins. To evaluate the effect of dietary aflatoxin on wild turkeys, four groups of 4-mo-old wild turkeys were fed diets containing either 0, 100, 200, or 400 g aflatoxin/kg feed for 2 wk in September and October 1996. Aflatoxin-fed poults had decreased feed consumption and weight gains as compared with control poults. Decreased liverto-body weight ratios, liver enzyme alterations, slightly altered blood coagulation patterns, and mild histologic changes indicated low-level liver damage. Compromise of cell-mediated immunity was indicated by decreased lymphoblast transformation. The effects were apparent in all treatment groups to variable levels, but significant differences most often were found at 400 g aflatoxin/kg feed. This study shows that short-term aflatoxin ingestion by wild turkeys can induce undesirable physiologic changes; therefore, exposure of wild turkeys to feeds containing aflatoxin levels of 100 g aflatoxin/kg feed or more should be avoided.

In conscious rats, intravenous (i.v.) administration of the hexapeptide Ac-RYYRWK-NH 2 , a partial agonist of the nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor, produces a selective water diuresis without marked cardiovascular or behavioral effects. The present study examined the in vitro and in vivo pharmacodynamic profile of the novel and potentially metabolically stable NOP receptor ligand ZP120 (Ac-RYYR-WKKKKKKK-NH 2 ), which was created by conjugation of a structure-inducing probe (SIP) (i.e., K 6 sequence) to Ac-RYYRWK-NH 2 . In cells transfected with human NOP receptors, both Ac-RYYRWK-NH 2 and ZP120 displaced [ 3 H]N/OFQ (both peptides, pK i ϭ 9.6), and similar to N/OFQ inhibited forskolininduced cAMP formation (Ac-RYYRWK-NH 2 , pEC 50 ϭ 9.2; ZP120, 9.3; N/OFQ, 9.7). In the mouse vas deferens assay (MVD), Ac-RYYRWK-NH 2 and ZP120 behaved as partial agonists, inhibiting electrically induced contractions with similar pEC 50 values (9.0 and 8.6, respectively) but with submaximal efficacy compared with N/OFQ. In MVD, both peptides blocked the responses to N/OFQ, with ZP120 being approximately 50-fold more potent than Ac-RYYRWK-NH 2 . In vivo, doseresponse studies in rats showed that at doses (i.v. bolus or i.v. infusion) that produced a sodium-potassium-sparing aquaresis, ZP120 and Ac-RYYRWK-NH 2 elicited a mild vasodilatory response without reflex tachycardia. However, the renal responses to ZP120 were of greater magnitude and duration. Finally, each peptide blocked the bradycardia and hypotension to N/OFQ in conscious rats, but the effect of ZP120 was of much greater duration. Together, these findings demonstrate that ZP120 is a novel, functionally selective SIP-modified NOP receptor partial agonist with increased biological activity and sodium-potassium-sparing aquaretic activity, the actions of which may be useful in the management of hyponatremia/ hypokalemia in water-retaining states.

The population health of endangered Key deer (Odocoileus virginianus clavium) was monitored from 10 February 1986 to 28 September 2000 by necropsy of animals that were killed by vehicles, euthanized because of terminal injuries or disease conditions, or found dead. The predominant mortality factor during the period was collision with motor vehicles; however, several infectious diseases were diagnosed, including infections with Arcanobacterium pyogenes, Haemonchus contortus, Salmonella spp., and Mycobacterium avium subsp. paratuberculosis. During the period monitored, the only infectious disease that was thought to have affected population dynamics was haemonchosis. Nevertheless, several of the observed diseases have potential to impact viability of the Key deer population under appropriate environmental conditions.

Salmonella infections have been implicated in large-scale die-offs of wild birds in the United States. Although we know quite a bit about the epidemiology of Salmonellainfection among domestic fowl, we know little about the incidence, epidemiology, and genetic relatedness of salmonellae in nondomestic birds. To gain further insight into salmonellae in these hosts, 22Salmonella isolates from diseased nondomestic birds were screened for the presence of virulence and antibiotic resistance-associated genes and compared genetically using pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA analysis. Of the 22 Salmonella isolates examined, 15 were positive for the invasion gene invA and the virulence plasmid-associated genes spvC and pef. Most (15 of 22) were generally sensitive to antibiotics. However, twoSalmonella isolates from pet birds were identified asSalmonella enterica serovar Typhimurium DT104. Despite the general susceptibility of these Salmonella isolates to most antimicrobial agents, antibiotic resistance-associated genesintI1, merA, and aadA1 were identified in a number of these isolates. Five distinctXbaI and nine distinct BlnI DNA patterns were observed for the 22 Salmonella isolates typed by PFGE. PFGE analysis determined that Salmonella isolates from passerines in Georgia and Wyoming were genetically related.