Michael H. Ziccardi

EPIDEMIOLOGY AND DIAGNOSIS OF MYCOBACTERIUM TUBERCULOSIS IN CAPTIVE ASIAN ELEPHANTS (ELEPHAS MAXIMUS)

Abstract The deaths of two Asian elephants (Elephas maximus) in August 1996 led the United States Department of Agriculture to require the testing and treatment of elephants for tuberculosis. From August 1996 to September 1999, Mycobacterium tuberculosis infection was confirmed by culture in 12 of 118 elephants in six herds. Eight diagnoses were made antemortem on the basis of isolation of M. tuberculosis by culture of trunk wash samples; the remainder (including the initial two) were diagnosed postmortem. We present the case histories, epidemiologic characteristics, diagnostic test results, and therapeutic plans from these six herds. The intradermal tuberculin test, enzyme-linked immunosorbent assay serology, the blood tuberculosis test, and nucleic acid amplification and culture are compared as methods to diagnose M. tuberculosis infection in elephants.

An experimental soft-release of oil-spill rehabilitated American coots (Fulica americana): II. Effects on health and blood parameters

The Unocal-Metrolink oil spill of 21 February 1995 resulted in approximately 7800 barrels of San Joaquin crude oil being deposited into the San Gabriel River in Huntington Beach, CA, USA. In order to determine long-term pathological effects of oil exposure and rehabilitation, hematological and serum biochemical parameters for both rehabilitated (RHB) American coots (Fulica americana) and reference (REF) coots were examined every 3-4 weeks (56, 81, 108 and 140 days post oil exposure) after birds were cleaned, rehabilitated and soft-released. Most significant differences in monthly comparisons between RHB and REF birds occurred 56 days following oil exposure. Total white blood cell (WBC) count, albumin:globulin (A:G) ratio and calcium concentration were higher in RHB birds compared to REF birds 56 days post oil exposure. In addition, mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and creatine kinase activities, and creatinine, total protein (TP) and globulin concentrations were lower in RHB birds. Blood results from 56 days post oil exposure for RHB coots which subsequently died were compared to blood results from days 108 and 140 for REF coots which survived. Oiled and rehabilitated birds which died had significantly higher WBCs, packed cell volume, TP and globulin concentrations, and lower A:G ratio, MCH, MCHC, glucose and sodium concentrations compared to REF birds which survived. Blood result differences detected at 3-4-week intervals between RHB and REF survivors, and differences detected between RHB coots which died and REF coots which survived, suggested that RHB coots developed an inflammatory response (infectious or non-septic) and, concurrently, may have experienced decreased immune responsiveness. Additionally, RHB coots experienced either an iron (Fe) utilization or Fe metabolism problem. These pathophysiological mechanisms were consistent with increased hemosiderin (stored Fe) present in the liver, spleen and kidney of necropsied RHB birds, and may have contributed to RHB coot mortality. When blood parameter differences were examined for their impact on survival time, it was determined that RHB coots had shorter survival times if they had very high cholesterol (> or =449 mg/dl) or chloride (> or =110 MEQ/l) concentrations on day 56 post oil exposure. Interestingly, the lack of differences between RHB and REF coots from day 81 through day 140 suggested that, from a hematologic and clinical chemistry perspective, coots which were oiled, rehabilitated, released and survived at least 3.5 months could not be differentiated from wild (REF) coots. From these findings it appears that blood analysis, coupled with post-release survival data, may help discern reasons for increased mortality of oiled and rehabilitated birds, compared to non-oiled reference birds.

THE STRESS RESPONSE TO ENVIRONMENTAL CHANGE IN CAPTIVE CHEETAHS (ACINONYX JUBATUS)

Abstract The captive North American cheetah (Acinonyx jubatus) population is not self-sustaining because of high prevalences of unusual diseases and poor reproductive success. Cheetahs are commonly moved between zoos for breeding purposes to maintain genetic diversity within the captive population, and movement may exacerbate infertility and disease. Fecal corticoids were analyzed by radioimmunoassay to measure the stress response of cheetahs to movement between facilities. Fecal samples were collected from 15 cheetahs for 14 days before movement and for at least 30 days after movement. For each cheetah, premovement fecal corticoid concentrations were used to determine baseline and then compared with trends in postmovement concentrations. In general, postmovement corticoid concentrations either increased (n = 8), did not change (n = 2), or decreased (n = 5). Although individual animal differences occurred, corticoid concentrations increased for most animals moved on-exhibit and decreased in animals moved off-exhibit. Animals moving on-exhibit had an 18-times greater risk of having corticoids elevated more than two standard deviations above baseline for 30 days after movement compared with animals that moved off-exhibit. In addition, greater day-to-day variation in corticoids occurred in animals moved on-exhibit. In general, animals with initially low baseline corticoid concentrations had a greater postmovement corticoid response than cheetahs with initially high baseline levels. These results indicate that some cheetahs have a prolonged stress response when moved between facilities, and the magnitude and character of this response is influenced by the exhibit environment.

Advances in Oiled Bird Emergency Medicine and Management

Abstract Oil spills affect aquatic birds on individual, population, and ecosystem levels. Communities have responded to environmental accidents and have cared for oiled birds for as long as the damaging effects of oil exposure have been realized. Not until the Exxon Valdez disaster occurred, however, was there the political climate necessary to facilitate and fund organized oiled wildlife responses in the United States. Federal and California law now supports the infrastructure necessary to respond rapidly and efficiently to oil spills affecting wildlife. This improved infrastructure has resulted in access to appropriately designed and equipped facilities, trained staff and volunteers, and research improving medical management and bird survival.

Fishing gear-related injury in California marine wildlife.

We reviewed medical records from select wildlife rehabilitation facilities in California to determine the prevalence of injury in California Brown Pelicans (Pelecanus occidentalis), gulls (Larus spp.), and pinniped species (Zalophus californianus, Mirounga angustirostris, and Phoca vitulina) due to fishing gear entanglement and ingestion from 2001 to 2006. Of 9,668 Brown Pelican, gull, and pinniped cases described during the 6-yr study period (2001–06), 1,090 (11.3%) were fishing gear–related. Pelican injuries caused by fishing gear were most common in the Monterey Bay region, where 59.6% of the pelicans rescued in this area and admitted to a rehabilitation center were injured by fishing gear over the 6-yr period. The highest prevalence of fishing gear–related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds were seen in the San Diego region (3.7%). Despite these higher prevalences of gull and pinniped fishing gear–related injuries in these specific regions, there was no statistical significance in these trends. Juvenile gulls and pinnipeds were more commonly injured by fishing gear than adults (gulls: P=0.03, odds ratio=1.29; pinnipeds: P=0.01, odds ratio=2.07). Male pinnipeds were twice as likely to be injured by fishing gear as females (P<0.01, odds ratio=2.19). The proportion of fishing gear–related injury cases that were successfully rehabilitated and released (percentage of cases successfully rehabilitated to the point of release out of the total number of fishing gear–related injury cases) was high in all three species groups (pelicans: 63%; gulls: 54%; pinnipeds: 70%). Fishing gear–related injuries in Brown Pelicans and gulls were highest in the fall, but there was only a significant difference between seasons for fishing gear–related injuries in pelicans. Fishing gear–related injuries in pinnipeds most commonly occurred in summer; however, a statistical difference was not detected between seasons for pinnipeds. Derelict fishing gear—lost, abandoned or discarded sport and commercial line, nets, traps, etc.—in the marine environment is a significant cause of injury in California coastal marine wildlife. We evaluated data for stranded animals only; our results may underestimate the true number of coastal marine animals injured by lost or discarded fishing gear in California.

Description of Novel Babesia Species and Associated Lesions from Common Murres (Uria aalge) from California

Abstract A novel Babesia species is described from blood collected from 3 common murres (also known as common guillemots) (Uria aalge) from California. This is the first report of a Babesia species from the Alcidae and the second from the Charadriiformes. Babesia uriae n. sp. is morphologically similar to several other avian Babesia species but can be differentiated from Babesia bennetti, the only other species from a host in the Charadriiformes, by size of round and amoeboid forms. Phylogenetic analysis of near–full length 18S rRNA, ITS-1, 5.8S rRNA, and ITS-2 sequences indicated that the Babesia sp. from the common murre is closely related to Babesia poelea, a parasite of brown boobies (Sula leucogaster).

Zoonotic pathogens isolated from wild animals and environmental samples at two California wildlife hospitals.

OBJECTIVE To determine types and estimate prevalence of potentially zoonotic enteric pathogens shed by wild animals admitted to either of 2 wildlife hospitals and to characterize distribution of these pathogens and of aerobic bacteria in a hospital environment. DESIGN Cross-sectional study. SAMPLE Fecal samples from 338 animals in 2 wildlife hospitals and environmental samples from 1 wildlife hospital. PROCEDURES Fecal samples were collected within 24 hours of hospital admission. Environmental samples were collected from air and surfaces. Samples were tested for zoonotic pathogens via culture techniques and biochemical analyses. Prevalence of pathogen shedding was compared among species groups, ages, sexes, and seasons. Bacterial counts were determined for environmental samples. RESULTS Campylobacter spp, Vibrio spp, Salmonella spp, Giardia spp, and Cryptosporidium spp (alone or in combination) were detected in 105 of 338 (31%) fecal samples. Campylobacter spp were isolated only from birds. Juvenile passerines were more likely to shed Campylobacter spp than were adults; prevalence increased among juvenile passerines during summer. Non-O1 serotypes of Vibrio cholerae were isolated from birds; during an oil-spill response, 9 of 10 seabirds screened were shedding this pathogen, which was also detected in environmental samples. Salmonella spp and Giardia spp were isolated from birds and mammals; Cryptosporidium spp were isolated from mammals only. Floors of animal rooms had higher bacterial counts than did floors with only human traffic. CONCLUSIONS AND CLINICAL RELEVANCE Potentially zoonotic enteric pathogens were identified in samples from several species admitted to wildlife hospitals, indicating potential for transmission if prevention is not practiced.

Evaluation of 4 Handheld Blood Glucose Monitors for Use in Seabird Rehabilitation

Abstract Screening methods are needed for immediate field assessment of affected seabirds during oil spills. We compared the accuracies of 4 handheld blood glucose monitors—Accu-Chek Advantage, Glucometer Elite, Precision QID, and Sure Step—with that of Chemstrip bG for blood glucose determination in seabirds. Study subjects were 44 healthy, adult rhinoceros auklets (Cerorhinca monocerata) housed at a wildlife health center. Handheld monitors were at least as accurate as the commonly used Chemstrip bG method in estimating plasma blood glucose concentrations, although the glucose measurements were significantly lower (P < .05), averaging 33% lower, than those determined by the chemistry reference laboratory. Costs of monitors and test strips were similar, but the Accu-Chek Advantage and Precision QID monitors were the easiest to use and gave reliable glucose measurements (coefficients of variation, <7%). These 2 monitors were used in subsequent evaluations of the effect of anticoagulants and the effect of time interval between sample collection and blood glucose determination. Storage of blood in heparin was preferable to ethylenediamine tetra-acetic acid because it did not significantly (P > .05) alter blood glucose values. Storage of blood for up to 4 hours in a heparinized Microtainer tube at room temperature also produced minimal changes in glucose concentration. We found that electronic, handheld blood glucose monitors underestimate blood glucose concentrations of rhinoceros auklets by 33% in comparison with reference values. However, these monitors are reliable, give results comparable with the Chemstrip bG, and are potentially useful tools for screening purposes in the field during an oil spill.

MYCOBACTERIUM AVIUM SUBSPECIES PARATUBERCULOSIS AND MYCOBACTERIUM AVIUM SUBSP. AVIUM INFECTIONS IN A TULE ELK (CERVUS ELAPHUS NANNODES) HERD

Between 2 August and 22 September 2000, 37 hunter-killed tule elk (Cervus elaphus nannodes) were evaluated at the Grizzly Island Wildlife Area, California, USA, for evidence of paratuberculosis. Elk were examined post-mortem, and tissue and fecal samples were submitted for radiometric mycobacterial culture. Acid-fast isolates were identified by a multiplex polymerase chain reaction (PCR) that discriminates among members of the Mycobacterium avium complex (MAC). Histopathologic evaluations were completed, and animals were tested for antibodies using a Johnes enzyme–linked immunosorbent assay (ELISA) and agar gel immunodiffusion. In addition, 104 fecal samples from tule elk remaining in the herd were collected from the ground and submitted for radiometric mycobacterial culture. No gross lesions were detected in any of the hunter-killed animals. Mycobacterium avium subsp. paratuberculosis (MAP) was cultured once from ileocecal tissue of one adult elk and was determined to be a strain (A18) found commonly in infected cattle. One or more isolates of Mycobacterium avium subsp. avium (MAA) were isolated from tissues of five additional adult elk. Gastrointestinal tract and lymph node tissues from 17 of the 37 elk (46%) examined had histopathologic lesions commonly seen with mycobacterial infection; however, acid-fast bacteria were not observed. All MAC infections were detected from adult elk (P = 0.023). In adult elk, a statistically significant association was found between MAA infection and ELISA sample-to-positive ratio (S/P)≥0.25 (P=0.021); four of five MAA culture–positive elk tested positive by ELISA. Sensitivity and specificity of ELISA S/P≥0.25 for detection of MAA in adult elk were 50% and 93%, respectively. No significant associations were found between MAC infection and sex or histopathologic lesions. Bacteriologic culture confirmed infection with MAP and MAA in this asymptomatic tule elk herd. The Johnes ELISA was useful in signaling mycobacterial infection on a population basis but could not discriminate between MAA and MAP antibodies. The multiplex PCR was useful in discriminating among the closely related species belonging to MAC.

Application of the luciferase cell culture bioassay for the detection of refined petroleum products

A luciferase cell culture-based bioassay, developed to detect 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like activity of halo-genated and polycyclic aromatic hydrocarbons, was optimized to detect refined petroleum products and to determine their relative inducing potency. Quality control standards from 32 refined products (gasolines and diesels, jet fuels, lubricating oils, fuel oils and weathered products) and three commercial products were evaluated. Induction equivalents (I-EQs) were determined by direct comparison of the EC50 and EC20 values (based on the median and 20% TCDD maximal response, respectively) from dose-response curves for each product to those obtained with TCDD. Most petroleum products were active in the luciferase bioassay, with those products composed of fractions produced later in the distillation process (i.e. fuel oils) inducing higher levels. Additionally, weathering of products reduced their induction potency. Based on the high I-EQ estimates of many products, biological effects associated with exposure may have been previously underestimated using other diagnostic methods.