Surveillance for Avian Bornavirus in Colorado and Wyoming, USA, Raptor Populations.

Avian bornavirus (ABV) is known to infect at least 80 avian species and is associated with avian bornaviral ganglioneuritis (ABG). Avian bornaviral ganglioneuritis is characterized by a lymphoplasmacytic infiltration of the nervous tissue, mainly affecting the nerves that supply the gastrointestinal tract of birds. This disease is diagnosed commonly in psittacines under human care and has been demonstrated in wild bird species; however, its occurrence in raptors is largely unknown. Because of the commonality of ABV in the pet bird population, there is concern about the spread of this virus to other companion avian species, such as falconry birds, as well as wildlife. This prospective study used reverse-transcription quantitative PCR (RT-qPCR) to survey free-ranging Colorado and Wyoming, US, raptor populations for ABV. Quantitative PCR was performed on mixed conjunctival-choanal-cloacal swabs collected from live birds (n=139). In dead birds, a combination of mixed swabs (n=265) and tissue samples of the brain (n=258), heart (n=162), adrenal glands (n=162), liver (n=162), kidney (n=139), spinal cord (n=139), and brachial plexus (n=139) were evaluated. All 1,565 swab and tissue samples RT-qPCR results from the 404 birds evaluated were negative. Based on these results and a lack of clinical signs suggestive of ABG, ABV is likely not a prevalent pathogen in Colorado and Wyoming raptor populations at this time.

A Biologically Degradable and BioseniaticTM Feedstock for the High-Quality 3D Printing of Anatomical Models.

A Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) -based filament was evaluated as an alternative feedstock for Fused Deposition Modeling (FDM) of instructional and clinical medical specimens. PHBHHx-based prints of domestic cat vertebrae, skull bone, and an aortic arch cast were found comparable to conventional materials. PHBHHx-based filament and extrudate samples were evaluated for biological degradability, to meet the BioseniaticTM standard, defined by the University of Georgia New Materials Institute. Both samples achieved more than 90% mineralization within 32 days in industrial composting conditions.

Neuropathology of feral conures with bromethalin toxicosis.

Bromethalin is a widely used neurotoxic rodenticide sometimes affecting nontarget wildlife. However, the effects of bromethalin on avian species are largely unknown. Here, we report the neuropathology of 14 feral conures (Psittacara sp.) with bromethalin toxicosis. Clinically, all birds presented with different degrees of paraparesis that sometimes progressed to dysphagia, ataxia, and tetraparesis. Histologically, there was astrogliosis, pallor, and vacuolation of white matter in the brain. This was usually more prominent in the medial longitudinal fasciculus, pons, optic tectum, cerebellar peduncle, and ventral funiculus. In most affected areas, there was loss of oligodendrocytes, and axons had extensive myelin loss or marked intramyelinic edema with splitting of myelin sheaths at the intraperiod line. Conures with bromethalin toxicosis had neuropathological changes similar to those of mammals exposed to bromethalin but with a characteristic distribution, probably related to higher susceptibility to cytotoxic edema in certain regions of the avian brain.

Chlamydia buteonis in birds of prey presented to California wildlife rehabilitation facilities.

Chlamydial infections, caused by a group of obligate, intracellular, gram-negative bacteria, have health implications for animals and humans. Due to their highly infectious nature and zoonotic potential, staff at wildlife rehabilitation centers should be educated on the clinical manifestations, prevalence, and risk factors associated with Chlamydia spp. infections in raptors. The objectives of this study were to document the prevalence of chlamydial DNA shedding and anti-chlamydial antibodies in raptors admitted to five wildlife rehabilitation centers in California over a one-year period. Chlamydial prevalence was estimated in raptors for each center and potential risk factors associated with infection were evaluated, including location, species, season, and age class. Plasma samples and conjunctiva/choana/cloaca swabs were collected for serology and qPCR from a subset of 263 birds of prey, representing 18 species. Serologic assays identified both anti-C. buteonis IgM and anti-chlamydial IgY antibodies. Chlamydial DNA and anti-chlamydial antibodies were detected in 4.18% (11/263) and 3.14% (6/191) of patients, respectively. Chamydial DNA was identified in raptors from the families Accipitridae and Strigidae while anti-C.buteonis IgM was identified in birds identified in Accipitridae, Falconidae, Strigidae, and Cathartidae. Two of the chlamydial DNA positive birds (one Swainson's hawk (Buteo swainsoni) and one red-tailed hawk (Buteo jamaicensis)) were necropsied, and tissues were collected for culture. Sequencing of the cultured elementary bodies revealed a chlamydial DNA sequence with 99.97% average nucleotide identity to the recently described Chlamydia buteonis. Spatial clusters of seropositive raptors and raptors positive for chlamydial DNA were detected in northern California. Infections were most prevalent during the winter season. Furthermore, while the proportion of raptors testing positive for chlamydial DNA was similar across age classes, seroprevalence was highest in adults. This study questions the current knowledge on C. buteonis host range and highlights the importance of further studies to evaluate the diversity and epidemiology of Chlamydia spp. infecting raptor populations.

Comparative Study of the Biological Degradation of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) Microbeads in Municipal Wastewater in Environmental and Controlled Laboratory Conditions.

From April to June 2019, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3(HA)) microbead samples were exposed to an operational wastewater reclamation facility (WWRF) in an aerobic aeration basin in Athens, Georgia. Samples were withdrawn from the facility over a 13-week timeframe, and the particles were examined by Raman microscopy and thermogravimetric analysis/mass spectroscopy (TGA/MS) coupled with differential scanning calorimetry (DSC). The activated sludge from this facility was also used as an inoculum to examine carbon mineralization under controlled respirometry experiments to corroborate biological degradation rates determined from both the environmental and laboratory approach. Respirometry, Raman microscopy, and TGA/MS-DSC methods all measured similar biodegradation timelines for microbeads bound to an epoxy substrate, indicating that the three methods are temporally comparable and may be used to measure material biological degradation. Samples of epoxy-bound P3(HA) microbeads, free microbeads, the P3(HA) film, and poly(lactic acid) (PLA) film demonstrated carbon mineralization of 90.0, 89.4, 95.0, and 8.15%, respectively, relative to the cellulose positive control. Using a modified Gompertz growth model, the biological degradation rate coefficients (Rm) were determined for cellulose, P3(HA) film, epoxy-bound P3(HA) microbeads, and free P3(HA) microbeads and found to be 31.6, 30.2, 17.5, and 18.7 mL CO2·g-1·day-1, respectively. Moreover, P3(HA) microbeads can efficiently mineralize in WWRF infrastructure at a rate comparable to cellulose.

Insights on Immune Function in Free-Ranging Green Sea Turtles (Chelonia mydas) with and without Fibropapillomatosis.

Chelonid alphaherpesviruses 5 and 6 (ChHV5 and ChHV6) are viruses that affect wild sea turtle populations. ChHV5 is associated with the neoplastic disease fibropapillomatosis (FP), which affects green turtles (Chelonia mydas) in panzootic proportions. ChHV6 infection is associated with lung-eye-trachea disease (LETD), which has only been observed in maricultured sea turtles, although antibodies to ChHV6 have been detected in free-ranging turtles. To better understand herpesvirus prevalence and host immunity in various green turtle foraging aggregations in Florida, USA, our objectives were to compare measures of innate and adaptive immune function in relation to (1) FP tumor presence and severity, and (2) ChHV5 and ChHV6 infection status. Free-ranging, juvenile green turtles (N = 45) were captured and examined for external FP tumors in Florida's Big Bend, Indian River Lagoon, and Lake Worth Lagoon. Blood samples were collected upon capture and analyzed for ChHV5 and ChHV6 DNA, antibodies to ChHV5 and ChHV6, in vitro lymphocyte proliferation using a T-cell mitogen (concanavalin A), and natural killer cell activity. Despite an overall high FP prevalence (56%), ChHV5 DNA was only observed in one individual, whereas 20% of turtles tested positive for antibodies to ChHV5. ChHV6 DNA was not observed in any animals and only one turtle tested positive for ChHV6 antibodies. T-cell proliferation was not significantly related to FP presence, tumor burden, or ChHV5 seroprevalence; however, lymphocyte proliferation in response to concanavalin A was decreased in turtles with severe FP (N = 3). Lastly, green turtles with FP (N = 9) had significantly lower natural killer cell activity compared to FP-free turtles (N = 5). These results increase our understanding of immune system effects related to FP and provide evidence that immunosuppression occurs after the onset of FP disease.

Molecular Assessment of Chelonid Alphaherpesvirus 5 Infection in Tumor-Free Green (Chelonia mydas) and Loggerhead (Caretta caretta) Sea Turtles in North Carolina, USA, 2015-2019.

Fibropapillomatosis is associated with chelonid alphaherpesvirus 5 (ChHV5) and tumor formation in sea turtles. We collected blood samples from 113 green (Chelonia mydas) and 112 loggerhead (Caretta caretta) turtles without fibropapillomatosis, including 46 free-ranging turtles (20 green turtles, 26 loggerheads), captured in Core Sound, North Carolina, and 179 turtles (93 green turtles, 86 loggerheads) in rehabilitative care in North Carolina. Blood samples were analyzed for ChHV5 DNA using quantitative polymerase chain reaction (qPCR), and for antibodies to ChHV5 peptides using an enzyme-linked immunosorbent assay (ELISA). None of the samples from foraging turtles tested positive for ChHV5 by qPCR; ELISA was not used for foraging turtles. Samples from 18/179 (10.1%) rehabilitating turtles tested positive for ChHV5 using qPCR, and 32/56 (57.1%) rehabilitating turtles tested positive for antibodies to ChHV5 using ELISA. Five turtles that tested positive by qPCR or ELISA at admission converted to being undetectable during rehabilitation, and five that initially tested negative converted to being positive. Both sea turtle species were significantly more likely to test positive for ChHV5 using ELISA than with qPCR (p < 0.001). There was no difference in the proportions of green turtles versus loggerheads that tested positive for ChHV5 using qPCR, but loggerheads were significantly more likely than green turtles to test positive for ChHV5 using ELISA. This finding suggests that loggerheads infected with ChHV5 at some point in their life may be more able than green turtles to mount an effective immune response against recrudescent infection, pointing to species-specific genetic differences in the two species' immune response to ChHV5 infection. This is the first study to analyze antibodies to ChHV5 in loggerhead turtles and represents the most complete dataset on ChHV5 DNA detection in sea turtles encountered in the more northern latitudes of their western Atlantic habitat.

Necrotizing Ventriculitis in Fledgling Chimney Swifts (Chaetura Pelagica) Associated With a Novel Adenovirus, Chimney Swift Adenovirus-1 (CsAdV-1).

Five chimney swift fledglings died following a progressive loss of appetite and condition while being cared for by an experienced wildlife rehabilitator. All animals had severe necrotizing and heterophilic ventriculitis, with myriad epithelial cells characterized by karyomegaly with intranuclear inclusion bodies. Transmission electron microscopy showed distention of epithelial cell nuclei and chromatin peripheralization by nonenveloped, icosahedral, 75- to 85-nm-diameter virions. Degenerate nested PCR for a highly conserved region of the adenovirus DNA polymerase gene was positive. BLAST analysis of the amplicon sequence indicated the presence of a novel adenovirus, with 74% homology to Antarctic penguin adenoviruses and 72% homology to a bat adenovirus, at low query coverages of only 65% and 63%, respectively. BLAST analysis of the predicted amino acid sequence generated the highest scores for squamate adenoviruses at 100% query coverage. Based on phylogenetic analysis of the partial amino acid sequence of the DNA polymerase, the chimney swift virus was a novel adenovirus most closely related to the Atadenovirus genus. Using a probe based on the novel viral sequence, DNA in situ hybridization identified viral nucleic acid in the nucleus. While the tentatively named chimney swift adenovirus-1 (CsAdV-1) is so far classified with the Atadenoviruses, it is relatively divergent from other members of that genus and may represent the first identified member of a new genus of Adenoviruses.

Evidence of bromethalin toxicosis in feral San Francisco "Telegraph Hill" conures.

During 2018, four free-ranging conures, from a naturalized flock in San Francisco, presented with a characteristic set of neurologic signs that had been reported in other individuals from this flock. The cause of morbidity or mortality in historic cases has not been identified. From these four subjects, fresh feces were collected during their initial days of hospitalization and submitted to the University of Georgia Infectious Diseases Laboratory and Center for Applied Isotope Studies for bromethalin and desmethyl-bromethalin quantitation. Using High Performance Liquid Chromatography, the laboratory detected bromethalin, a non-anticoagulant, single-dose rodenticide, in fecal samples from three subjects; half of these samples were also positive for desmethyl-bromethalin, bromethalin's active metabolite. In three subjects that died, the UGA laboratory screened brain and liver samples and found bromethalin in all samples; desmethyl-bromethalin was detected in all but one brain sample, which was below the detection limit. Our findings suggest the conures are more resistant to bromethalin than are other species in which bromethalin has been studied, and/or that the conures may be ingesting the toxin at a sublethal dose. More data is needed to better assess the long-term effects of bromethalin on animals exposed at the subacute/chronic levels, and also to better understand the compartmentalization of bromethalin and desmethyl-bromethalin in a wider variety of species.

Ingested Micronizing Plastic Particle Compositions and Size Distributions within Stranded Post-Hatchling Sea Turtles.

From July 2015 to November 2016, 96 post-hatchling sea turtles were collected from 118 km of the Atlantic coastline in Florida, USA, including loggerhead, green, and hawksbill sea turtle species. Forty-five of the recovered turtles were rehabilitated and released, but the remaining 52 died and were frozen. At necropsy, the gastrointestinal tracts of most the turtles contained visible plastic, and collected particles of 27 individuals were chemically characterized by Raman microscopy as polyethylene, polypropylene, polyethylene terephthalate, and polystyrene. Mesoparticle plastic fragments 1.0-8.7 mm, microparticle fragments 20-1000 µm, and nanoparticles 5-169 nm were identified in the turtles. Polyethylene and polypropylene were the most common plastics ingested from specimens representing 54.1 and 23.7% of the total observed mesoparticles and 11.7 and 21.0% of the total observed microparticles, respectively. A plastic-to-body mass ratio of 2.07 mg/g was determined for this group. The authors suggest that ingestion of micronizing plastic by post-hatchling sea turtles is likely a substantial risk to survival of these endangered and threatened species. This study also provides some of the first evidence for the formation of nanoscopic plastic particles that we theorize forms in the post-hatchling and juvenile environment and are present post-ingestion.

CHLAMYDIA PSITTACI IN FERAL ROSY-FACED LOVEBIRDS ( AGAPORNIS ROSEICOLLIS) AND OTHER BACKYARD BIRDS IN MARICOPA COUNTY, ARIZONA, USA.

In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds ( Agapornis roseicollis) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci. In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird species visiting backyard bird feeders to determine the prevalence of DNA and the seroprevalence of antibodies to C. psittaci using real-time PCR-based testing and elementary body agglutination, respectively. Chlamydia psittaci DNA was present in conjunctival-choanal or cloacal swabs in 93% (43/46) of lovebirds and 10% (14/142) of sympatric birds. Antibodies to C. psittaci were detected in 76% (31/41) of lovebirds and 7% (7/102) of sympatric birds. Among the sympatric birds, Rock Doves ( Columba livia) had the highest prevalence of C. psittaci DNA (75%; 6/8) and seroprevalence (25%; 2/8). Psittacine circovirus 1 DNA was also identified, using real-time PCR-based testing, from the same swab samples in 69% (11/16) of species sampled, with a prevalence of 80% (37/46) in lovebirds and 27% (38/142) in sympatric species. The presence of either Rosy-faced Lovebirds or Rock Doves at residential bird feeders may be cause for concern for epizootic and zoonotic transmission of C. psittaci in this region.

Compendium of Measures to Control Chlamydia psittaci Infection Among Humans (Psittacosis) and Pet Birds (Avian Chlamydiosis), 2017.

Psittacosis, also known as parrot fever and ornithosis, is a bacterial infection that can cause severe pneumonia and other serious health problems in humans. It is caused by Chlamydia psittaci. Reclassification of the order Chlamydiales in 1999 into 2 genera (Chlamydia and Chlamydophila) was not wholly accepted or adopted. This resulted in a reversion to the single, original genus Chlamydia, which now encompasses all 9 species including Chlamydia psittaci. During 2003-2014, 112 human cases of psittacosis were reported to the Centers for Disease Control and Prevention through the Nationally Notifiable Diseases Surveillance System. While many types of birds can be infected by C psittaci, in general, the literature suggests that human cases can most often occur after exposure to infected parrot-type birds kept as pets, especially cockatiels, parakeets, and conures. In birds, C psittaci infection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, and humans become infected from exposure to these materials. This compendium provides information about psittacosis and avian chlamydiosis to public health officials, physicians, veterinarians, the pet bird industry, and others concerned with controlling these diseases and protecting public health. The recommendations in this compendium provide standardized procedures to control C psittaci infections. This document will be reviewed and revised as necessary, and the most current version replaces all previous versions. This document was last revised in 2010. Major changes in this version include a recommendation for a shorter treatment time for birds with avian chlamydiosis, additional information about diagnostic testing, including genotyping, clearer language associated with personal protective equipment recommended for those caring for confirmed or exposed birds, and incorporating a grading scale with recommendations generally based on the United States Preventive Services Task Force's methods.

Chlamydia psittaci comparative genomics reveals intraspecies variations in the putative outer membrane and type III secretion system genes.

Chlamydia psittaci is an obligate intracellular bacterium that can cause significant disease among a broad range of hosts. In humans, this organism may cause psittacosis, a respiratory disease that can spread to involve multiple organs, and in rare untreated cases may be fatal. There are ten known genotypes based on sequencing the major outer-membrane protein gene, ompA, of C. psittaci. Each genotype has overlapping host preferences and virulence characteristics. Recent studies have compared C. psittaci among other members of the Chlamydiaceae family and showed that this species frequently switches hosts and has undergone multiple genomic rearrangements. In this study, we sequenced five genomes of C. psittaci strains representing four genotypes, A, B, D and E. Due to the known association of the type III secretion system (T3SS) and polymorphic outer-membrane proteins (Pmps) with host tropism and virulence potential, we performed a comparative analysis of these elements among these five strains along with a representative genome from each of the remaining six genotypes previously sequenced. We found significant genetic variation in the Pmps and tbl3SS genes that may partially explain differences noted in C. psittaci host infection and disease.

Effect of West Nile virus DNA-plasmid vaccination on response to live virus challenge in red-tailed hawks (Buteo jamaicensis).

OBJECTIVE: To evaluate the safety and efficacy of an experimental adjuvanted DNA-plasmid vaccine against West Nile virus (WNV) in red-tailed hawks (Buteo jamaicensis). ANIMALS: 19 permanently disabled but otherwise healthy red-tailed hawks of mixed ages and both sexes without detectable serum antibodies against WNV. PROCEDURES: Hawks were injected IM with an experimental WNV DNA-plasmid vaccine in an aluminum-phosphate adjuvant (n = 14) or with the adjuvant only (control group; 5). All birds received 2 injections at a 3-week interval. Blood samples for serologic evaluation were collected before the first injection and 4 weeks after the second injection (day 0). At day 0, hawks were injected SC with live WNV. Pre- and postchallenge blood samples were collected at intervals for 14 days for assessment of viremia and antibody determination; oropharyngeal and cloacal swabs were collected for assessment of viral shedding. RESULTS: Vaccination was not associated with morbidity or deaths. Three of the vaccinated birds seroconverted after the second vaccine injection; all other birds seroconverted following the live virus injection. Vaccinated birds had significantly less severe viremia and shorter and less-intense shedding periods, compared with the control birds. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the WNV DNA-plasmid vaccine in red-tailed hawks was safe, and vaccination attenuated but did not eliminate both the viremia and the intensity of postchallenge shedding following live virus exposure. Further research is warranted to conclusively determine the efficacy of this vaccine preparation for protection of red-tailed hawks and other avian species against WNV-induced disease.

In vitro and in vivo evaluation of a potentiated miconazole aural solution in chronic Malassezia otitis externa in dogs.

This study assessed the in vitro and in vivo activity of an ear solution containing a third-generation chelating agent (Tricide) as an antimicrobial potentiator for miconazole in chronic Malassezia otitis. Thirty-one ears from 20 dogs were enrolled in the study. Fungal culture, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC) testing of miconazole with and without Tricide were performed on all ears. In a randomized, controlled, and blinded treatment trial the ears were treated either with 0.9% saline solution containing 0.01% miconazole, 0.03% dexamethasone and 540 microg/mL Tricide or the same solution without Tricide. Cytologic and auroscopic examinations were conducted on day 0, 14 and 28 and evaluated for number of yeast organisms, degree of erythema, hyperplasia and amount of discharge. The in vitro data was compared with Wilcoxon signed-rank test. The cytologic and auroscopic scores were compared between the visits and treatment groups at day 0, 14 and 28 using a Wilcoxon-Mann-Whitney test and repeated measures analysis. MIC and MFC were significantly (P < 0.0001) reduced when miconazole was combined with the chelating agent versus miconazole alone. The cytologic scores were significantly lower on days 14 (P = 0.0156) and 28 (P = 0.0280) for the group treated with Tricide. The auroscopic scores decreased significantly by the end of the trial compared to day 0, but the difference between the two groups was not significant. This study suggests that Tricide enhances in vitro activity and in vivo efficacy against Malassezia sp. in dogs with yeast otitis.

Genotyping of Chlamydophila psittaci by real-time PCR and high-resolution melt analysis.

Human infection with Chlamydophila (Chlamydia) psittaci can lead to psittacosis, a disease that occasionally results in severe pneumonia and other medical complications. C. psittaci is currently grouped into seven avian genotypes: A through F and E/B. Serological testing, outer membrane protein A (ompA) gene sequencing, and restriction fragment length polymorphism analysis are currently used for distinguishing these genotypes. Although accurate, these methods are time-consuming and require multiple confirmatory tests. By targeting the ompA gene, a real-time PCR assay has been developed to rapidly detect and genotype C. psittaci by light-upon-extension chemistry and high-resolution melt analysis. Using this assay, we screened 169 animal specimens; 98 were positive for C. psittaci (71.4% genotype A, 3.1% genotype B, 4.1% genotype E, and 21.4% unable to be typed). This test may provide insight into the distribution of each genotype among specific hosts and provide epidemiological and epizootiological data in human and mammalian/avian cases. This diagnostic assay may also have veterinary applications during chlamydial outbreaks, particularly with respect to identifying the sources and tracking the movements of a particular genotype when multiple animal facilities are affected.

West Nile virus seroconversion in penguins after vaccination with a killed virus vaccine or a DNA vaccine.

To investigate the serologic response of penguins to West Nile virus (WNV) vaccines, four species of exclusively indoor-housed penguins, negative for WNV by serology, were evaluated: Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), Gentoo (Pygoscelis papua), and Rockhopper (Eudyptes chrysoscome) penguins. Birds were inoculated with either a killed virus vaccine or a plasmid-mediated DNA WNV vaccine, and postinoculation serology was evaluated. Both vaccines induced seroconversion in all four species, and no adverse reactions were noted. Postvaccination serology results varied across species and vaccine types. However, in all four species, the killed virus vaccine resulted in a greater seroconversion rate than the DNA vaccine and in a significantly shorter time period. Additionally, the duration of the seropositive titer was significantly longer in those birds vaccinated with the killed virus vaccine compared with those vaccinated with the DNA vaccine. A subset of unvaccinated penguins serving as negative controls remained negative throughout the duration of the study despite the presence of WNV in the geographic locations of the study, suggesting that indoor housing may minimize exposure to the virus and may be an additional means of preventing WNV infection in penguins.

In vitro efficacy of a buffered chelating solution as an antimicrobial potentiator for antifungal drugs against fungal pathogens obtained from horses with mycotic keratitis.

OBJECTIVE: To determine whether a novel third-generation chelating agent (8 mM disodium EDTA dehydrate and 20 mM 2-amino-2-hydroxymethyl-1, 3-propanediol) would act as an antimicrobial potentiator to enhance in vitro activity of antifungal medications against fungal isolates obtained from horses with mycotic keratitis. SAMPLE POPULATION: Fungal isolates (3 Aspergillus isolates, 5 Fusarium isolates, 1 Penicillium isolate, 1 Cladosporium isolate, and 1 Curvularia isolate) obtained from horses with mycotic keratitis and 2 quality-control strains obtained from the American Type Culture Collection (ATCC; Candida albicans ATCC 90028 and Paecilomyces variotii ATCC 36257). PROCEDURE: Minimum inhibitory concentrations (MICs) against fungal isolates for 4 antifungal drugs (miconazole, ketoconazole, itraconazole, and natamycin) were compared with MICs against fungal isolates for the combinations of each of the 4 antifungal drugs and the chelating agent. The Clinical and Laboratory Standards Institute microdilution assay method was performed by use of reference-grade antifungal powders against the fungal isolates and quality-control strains of fungi. RESULTS: Values for the MIC at which the antifungal drugs decreased the growth of an organism by 50% (MIC50) and 90% (MIC90) were decreased for the control strains and ophthalmic fungal isolates by 50% to 100% when the drugs were used in combination with the chelating agent at a concentration of up to 540 microg/mL. CONCLUSIONS AND CLINICAL RELEVANCE: The chelating agent increased in vitro activity of antifungal drugs against common fungal pathogens isolated from eyes of horses with mycotic keratitis.

Development and evaluation of an experimental model of cutaneous columnaris disease in koi Cyprinus carpio.

A reproducible, experimental model of columnaris disease was developed to study the pathogenesis of cutaneous disease associated with Flavobacterium columnare infection in koi (Cyprinus carpio). In experimental infections, lesions were usually restricted to skin and fins; gill necrosis was not a consistent finding. Cytologic and histopathologic examinations provided a presumptive diagnosis of columnaris disease. Specific detection of F. columnare was done using the polymerase chain reaction and DNA in situ hybridization (ISH). Polymerase chain reaction allowed the detection of F. columnare in fresh biological material and in formalin-fixed, paraffin-embedded tissues. The DNA ISH technique allowed the identification and localization of F. columnare in formalin-fixed, paraffin-embedded tissues. Using these molecular techniques, F. columnare was readily detected in skin specimens from infected fish; however, the bacterium was infrequently detected in specimens of liver, kidney, and spleen. These observations suggest that columnaris disease generally presents as a cutaneous disease that is unassociated with systemic infection in koi. Hematologic studies indicated that most infected koi developed microcytic, normochromic, nonregenerative anemia and leukopenia characterized by lymphopenia, mild neutrophilia, and monocytosis. Biochemical changes in diseased fish included significant hyperglycemia, hyponatremia, and hypochloridemia.

Persistent viral shedding during asymptomatic Aleutian mink disease parvoviral infection in a ferret.

A 2-year-old domestic ferret that appeared clinically healthy was repeatedly seropositive for Aleutian mink disease parvovirus (ADV) over a 2-year observation period. Antibody titers, determined by counter-immunoelectrophoresis, ranged from 1024 to 4096. Viral DNA also was identified in serum, urine, feces, and blood cell fractions by polymerase chain reaction analysis. Ultimately, DNA in situ hybridization revealed ADV DNA in histologic sections of various tissues and organs. These data indicate that this asymptomatic ferret was persistently infected with ADV.