Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July – October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. Prevalence of AIV peaked in late summer. We detected 27 AIV subtypes during 2007 and 31 during 2008. Ten hemagglutinin (HA) subtypes were detected each year (i.e., H1, 3–8, and 10–12 during 2007; H1-8, 10 and 11 during 2008). All neuraminidase (NA) subtypes were detected during each year of the study. Subtype diversity varied between years and increased with prevalence into September. Predominant subtypes during 2007 (comprising ≥5% of subtype diversity) included H1N1, H3N6, H3N8, H4N6, H7N3, H10N7, and H11N9. Predominant subtypes during 2008 included H3N6, H3N8, H4N6, H4N8, H6N1, and H10N7. Additionally, within each HA subtype, the same predominant HA/NA subtype combinations were detected each year and included H1N1, H3N8, H4N6, H5N2, H6N1, H7N3, H8N4, H10N7, and H11N9. The H2N3 and H12N5 viruses also predominated within the H2 and H12 subtypes, respectively, but only were detected during a single year (H2 and H12 viruses were not detected during 2007 and 2008, respectively). Mallards were the predominant species sampled (63.7% of the total), and 531 AIV were isolated from this species (80.5% of the total isolates). Mallard data collected during both years adequately described the observed temporal and spatial prevalence from the total sample and also adequately represented subtype diversity. Juvenile mallards also were adequate in describing the temporal and spatial prevalence of AIV as well as subtype diversity.

Serologic testing to detect antibodies to avian influenza (AI) virus has been an underused tool for the study of these viruses in wild bird populations, which traditionally has relied on virus isolation and reverse transcriptase-polymerase chain reaction (RT-PCR). In a preliminary study, a recently developed commercial blocking enzyme-linked immunosorbent assay (bELISA) had sensitivity and specificity estimates of 82% and 100%, respectively, for detection of antibodies to AI virus in multiple wild bird species after experimental infection. To further evaluate the efficacy of this commercial bELISA and the agar gel immunodiffusion (AGID) test for AI virus antibody detection in wild birds, we tested 2,249 serum samples collected from 62 wild bird species, representing 10 taxonomic orders. Overall, the bELISA detected 25.4% positive samples, whereas the AGID test detected 14.8%. At the species level, the bELISA detected as many or more positive serum samples than the AGID in all 62 avian species. The majority of positive samples, detected by both assays, were from species that use aquatic habitats, with the highest prevalence from species in the orders Anseriformes and Charadriiformes. Conversely, antibodies to AI virus were rarely detected in the terrestrial species. The serologic data yielded by both assays are consistent with the known epidemiology of AI virus in wild birds and published reports of host range based on virus isolation and RT-PCR. The results of this research are also consistent with the aforementioned study, which evaluated the performance of the bELISA and AGID test on experimental samples. Collectively, the data from these two studies indicate that the bELISA is a more sensitive serologic assay than the AGID test for detecting prior exposure to AI virus in wild birds. Based on these results, the bELISA is a reliable species-independent assay with potentially valuable applications for wild bird AI surveillance.

Metal ion homeostasis is a critical function of many integral and peripheral membrane proteins. The genome of the etiologic agent of syphilis, Treponema pallidum, is compact and devoid of many metabolic enzyme genes. Nevertheless, it harbors genes coding for homologs of several enzymes that typically require either iron or zinc. The product of the tp0971 gene of T. pallidum, designated Tp34, is a periplasmic lipoprotein that is thought to be tethered to the inner membrane of this organism. T ransition metal ions are essential structural components and cofactors for many proteins in virtually all biological systems (36, 47, 65). As such, bacteria have evolved numerous systems for obtaining metal ions from their environments and hosts and for transporting these ions against steep concentration gradients. These mechanisms include TonB-type and ABC transporters, Ptype ATPases, proton/ion-driven symporters, and receptor/transporter systems for host metal-sequestering proteins such as transferrin and lactoferrin (31,47,60). However, because metal homeostasis involves maintaining a tight balance between physiological needs and undesirable metal toxicity, bacteria also harbor systems to expel excess metal ions, such as RND efflux pumps and export P-type ATPases (47,60).Treponema pallidum, the bacterial agent of syphilis, remains a significant threat to human health worldwide (11,13,30,61). T. pallidum is among the most poorly understood of all sexually transmitted pathogens, due largely to the historic inability to cultivate the spirochete in vitro and the consequent inability to apply contemporary genetic approaches to understand many aspects of treponemal biology and virulence. To circumvent these severe experimental obstacles, determining the structures and functions of selected treponemal proteins has been one fruitful avenue of investigation to garner new insights into T. pallidum membrane biology (7, 17-20, 44, 46, 48, 64).In comparison with other bacterial pathogens, one particularly enigmatic feature of T. pallidum appears to be its reduced need for metal ions (29). Understanding the molecular aspects of T. pallidum's apparently reduced metal ion requirement is an important aspect of better characterizing this human pathogen physiologically. The genome of T. pallidum contains only a few genes that encode iron-requiring proteins: tp0152, tp0612, tp0613, tp0615, tp0972, tp0991, and tp1038 (from UniProtKB annotations), as well as tp0053, tp0080, tp0735, tp0823, tp0842, tp0939, tp0991, and tp1038 (27, 29, 32, 33, 38, 54, 64). Also, the genes for several Zn 2ϩ -requiring enzymes are present in the T. pallidum genome, and at least two ABC-type transporters for Zn 2ϩ have been characterized (21,33,44).We previously presented evidence to support the hypothesis that the ca. 22-kDa Tp34 membrane lipoprotein of T. pallidum likely participates in metal ion homeostasis (17). Crystallographic studies of a water-soluble recombinant derivative of this protein (rTp34) demonstrated that it adopts an immunoglobulin-like fold and...

We investigated the feasibility of testing feathers as a complementary approach to detect low pathogenic influenza A viruses (IAVs) in wild duck populations. Feathers on the ground were collected at four duck capture sites during 2010 and 2011, in Minnesota, U. S. A. IAVs were isolated from both feathers and cloacal swabs sampled from ducks at the time of capture. Although virus isolation rates from feather and cloacal swabs were inconsistent between collections, the overall rate of isolation was greatest from the feather samples. Viruses isolated from feathers also reflected the subtype diversity observed in cloacal swab isolates but resulted in many more isolates that contained more than one virus. Our study suggests that testing feathers may represent an alternative noninvasive approach to recover viruses and estimate subtype abundance and diversity.

Blackbirds (Icteridae) annually damage US$5-8 million of ripening sunflower in the northern Great Plains. Baiting blackbirds with avicide-treated rice during spring migration might reduce the regional breeding population. In March and April 1996-1997, we simulated a baiting program in eastern South Dakota to compare attractiveness of rice-baited plots placed in fields of corn and soybean stubble. Blackbirds used plots in corn stubble more often than plots in soybean stubble and chose rice-baited plots over unbaited reference plots. We conclude that blackbirds can be successfully baited with avicide-treated rice placed in corn stubble. r