Geology topics

D.J. Shadduck

Publications and source records attributed to D.J. Shadduck.

8 recordsLinked to original sources

USGS2006

Persistence of Pasteurella multocida in wetlands following avian cholera outbreaks

Avian cholera, caused by Pasteurella multocida, affects waterbirds across North America and occurs worldwide among various avian species. Once an epizootic begins, contamination of the wetland environment likely facilitates the transmission of P. multocida to susceptible birds. To evaluate the ability of P. multocida serotype-1, the most common serotype associated with avian cholera in waterfowl in western and central North America, to persist in wetlands and to identify environmental factors associated with its persistence, we collected water and sediment samples from 23 wetlands during winters and springs of 1996a??99. These samples were collected during avian cholera outbreaks and for up to 13 wk following initial sampling. We recovered P. multocida from six wetlands that were sampled following the initial outbreaks, but no P. multocida was isolated later than 7 wk after the initial outbreak sampling. We found no significant relationship between the probability of recovery of P. multocida during resampling and the abundance of the bacterium recovered during initial sampling, the substrate from which isolates were collected, isolate virulence, or water quality conditions previously suggested to be related to the abundance or survival of P. multocida. Our results indicate that wetlands are unlikely to serve as a long-term reservoir for P. multocida because the bacterium does not persist in wetlands for long time periods following avian cholera outbreaks.

Journal of Wildlife Diseases↗

USGS2005

Avian cholera in waterfowl: the role of lesser snow and Ross's geese as carriers of avian cholera in the Playa Lakes region

We collected samples from apparently healthy geese in the Playa Lakes Region (USA) during the winters of 2000a??01 and 2001a??02 to determine whether carriers of Pasteurella multocida, the bacterium that causes avian cholera, were present in wild populations. With the use of methods developed in laboratory challenge trials (Samuel et al., 2003a) and a serotype-specific polymerase chain reaction method for identification of P. multocida serotype 1, we found that a small proportion of 322 wild birds (<5%) were carriers of pathogenic P. multocida. On the basis of serology, an additional group of these birds (<10%) were survivors of recent avian cholera infection. Our results confirm the hypothesis that wild waterfowl are carriers of avian cholera and add support for the hypothesis that wild birds are a reservoir for this disease. In concert with other research, this work indicates that enzootic infection with avian cholera occurs in lesser snow goose (Chen caerulescens caerulescens) populations throughout their annual cycle. Although fewer Rossa??s geese (Chen rossii) were sampled, we also found these birds were carriers of P. multocida. Even in the absence of disease outbreaks, serologic evidence indicates that chronic disease transmission and recent infection are apparently occurring year-round in these highly gregarious birds and that a small portion of these populations are potential carriers with active infection.

Colorado, Kansas, New Mexico, Oklahoma, Texas↗

USGS2004

Are wetlands the reservoir for avian cholera?

Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995a??98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

California, Minnesota, Missouri, Nebraska, Nevada,↗

USGS2003

Comparison of methods to detect Pasteurella multocida in carrier waterfowl

We conducted laboratory challenge trials using mallard ducks (Anas platyrhynchos) to compare methods for detecting carriers of Pasteurella multocida, the bacterium that causes avian cholera, in wild birds. Birds that survived the initial infection were euthanized at 2-4 wk intervals up to 14 wk post challenge. Isolates of P. multocida were obtained at necropsy from 23% of the birds that survived initial infection. We found that swab samples (oral, cloacal, nasal, eye, and leg joint) were most effective for detecting carrier birds up to 14 wk post infection. No detectable differences in isolation were observed for samples stored in either 10% dimethysulfoxide or brain heart infusion broth. The frequency of detecting carriers in our challenge trials appeared to be related to mortality rates observed during the trial, but was not related to a number of other factors including time after challenge, time delays in collecting tissues postmortem, and route of infection. In our trials, there was little association between antibody levels and carrier status. We concluded that swabs samples collected from recently dead birds, stored in liquid nitrogen, and processed using selective broth provide a feasible field method for detecting P. multocida carriers in wild waterfowl.

California, Nebraska↗

USGS2003

Characterization of Pasteurella multocida isolates from wetland ecosystems during 1996 to 1999

We cultured 126 Pasteurella multocida isolates, 92 from water and 34 from sediment samples collected from wetlands in the Pacific and Central flyways of the United States between 1996 and 1999. Most (121) of the isolates were P. multocida serotype 1, but serotypes 3, 3/4, 10, and 11 were also found. Many (82) of the isolates were further characterized by DNA fingerprinting procedures and tested in Pekin ducks for virulence. Almost all the serotype 1 isolates we tested caused mortality in Pekin ducks. Serotype 1 isolates varied in virulence, but the most consistent pattern was higher mortality in male ducks than in females. We found no evidence that isolates found in sediment vs. water, between Pacific and Central flyways, or during El Nino years had consistently different virulence. We also found a number of non-serotype 1 isolates that were avirulent in Pekin ducks. Isolates had DNA fingerprint profiles similar to those found in birds that died during avian cholera outbreaks.

Journal of Wildlife Diseases↗

USGS2002

A serotype-specific polymerase chain reaction for identification of Pasteurella multocida serotype 1

A serotype-specific polymerase chain reaction (PCR) assay was developed for detection and identification of Pasteurella multocida serotype 1, the causative agent of avian cholera in wild waterfowl. Arbitrarily primed PCR was used to detect DNA fragments that distinguish serotype 1 from the other 15 serotypes of P. multocida (with the exception of serotype 14). Oligonucleotide primers were constructed from these sequences, and a PCR assay was optimized and evaluated. PCR reactions consistently resulted in amplification products with reference strains 1 and 14 and all other serotype 1 strains tested, with cell numbers as low as 2.3 cells/ml. No amplification products were produced with other P. multocida serotypes or any other bacterial species tested. To compare the sensitivity and further test the specificity of this PCR assay with traditional culturing and serotyping techniques, tissue samples from 84 Pekin ducks inoculated with field strains of P. multocida and 54 wild lesser snow geese collected during an avian cholera outbreak were provided by other investigators working on avian cholera. PCR was as sensitive (58/64) as routine isolation (52/64) in detecting and identifying P. multocida serotype 1 from the livers of inoculated Pekins that became sick or died from avian cholera. No product was amplified from tissues of 20 other Pekin ducks that received serotypes other than type 1 (serotype 3, 12 × 3, or 10) or 12 control birds. Of the 54 snow geese necropsied and tested for P. multocida , our PCR detected and identified the bacteria from 44 compared with 45 by direct isolation. The serotype-specific PCR we developed was much faster and less labor intensive than traditional culturing and serotyping procedures and could result in diagnosis of serotype 1 pasteurellosis within 24 hr of specimen submission.

Avian Diseases↗

USGS1999

Antibodies against Pasteurella multocida in snow geese in the western arctic

To determine if lesser snow geese (Chen caerulescens caerulescens) are a potential reservoir for the Pasteurella multocida bacterium that causes avian cholera, serum samples and/or pharyngeal swabs were collected from > 3,400 adult geese breeding on Wrangel Island (Russia) and Banks Island (Canada) during 1993-1996. Pharyngeal swab sampling rarely (> 0.1%) detected birds that were exposed to P. multocida in these populations. Geese with serum antibody levels indicating recent infection with P. multocida were found at both breeding colonies. Prevalence of seropositive birds was 3.5% at Wrangel Island, an area that has no recorded history of avian cholera epizootics. Prevalence of seropositive birds was 2.8% at Banks Island in 1994, but increased to 8.2% during 1995 and 1996 when an estimated 40,000-60,000 snow geese were infected. Approximately 50% of the infected birds died during the epizootic and a portion of the surviving birds may have become carriers of the disease. This pattern of prevalence indicated that enzootic levels of infection with P. multocida occurred at both breeding colonies. When no avian cholera epizootics occurred (Wrangel Island, Banks Island in 1994), female snow geese (4.7%) had higher antibody prevalence than males (2.0%).

Journal of Wildlife Diseases↗

USGS1997

Pasteurella multocida serotype 1 isolated from a lesser snow goose

Pharyngeal swabs were collected from 298 lesser snow geese (Chen caerulescens caerulescens) at Banks Island (Northwest Territories. Canada) in the summer of 1994. Pasteurella multocida serotype 1 was isolated from an adult male bird and P. multocida serotype 3 was isolated from an adult female goose. Pathogenicity of the serotype 1 isolate was confirmed by inoculation in Pekin ducks (Anas platyrhynchos). The serotype 3 isolate was non-pathogenic in Pekin ducks. This is the first documented isolation of pathogenic P. multocida serotype 1 from apparently healthy wild snow geese.

Northwest Territories↗