INCIDENCE DENSITY, PROPORTIONATE MORTALITY, AND RISK FACTORS OF ASPERGILLOSIS IN MAGELLANIC PENGUINS IN A REHABILITATION CENTER FROM BRAZIL

Aspergillosis in a colony of Humboldt penguins (Spheniscus humboldti) in a french zoological park: evaluation of environmental exposure

Aspergillosis is a major health problem in captive penguins due to the inhalation and the development of airborne spores of opportunistic environmental molds of the genus Aspergillus. Diagnosis is often delayed and treatments, based on the use of azole antifungals, are not fully effective. This study assesses the risk of exposure to Aspergillus sp. and determines the environmental reservoirs in the direct environment of a colony of Humboldt penguins (Spheniscus humboldti) in a zoological park in Paris, and the risk of contamination with resistant isolates. Every 15 days between February and May 2022, environmental samples (air and subtract from the nests, pond water, pigeon and penguin droppings) were carried out in the penguin enclosure as well as clinical samples (one-time non-invasive sampling on chicks), and screened for Aspergillus sp. conidia. From 191 environmental samples, 264 strains of Aspergillus including 221 strains of A. fumigatus were isolated, mostly from ambient air, in the nests, and pond water. No "at risk" areas in the penguin environment have been highlighted, nor an increased risk because of the proximity with urban wild birds. However, the load of airborne Aspergillus in the nests increased significantly with outdoor temperature. Of the 221 strains isolated, we identified only one azole-resistant strain, displaying the TR34/L98H mutation in the cyp51A gene. This low prevalence of resistant strains may probably be partly explained by the urban location of the zoological park, surrounded by kilometers of urban areas without agricultural activities.

APPLICATION OF A NOVEL ASPERGILLUS LATERAL-FLOW DEVICE IN THE DIAGNOSIS OF ASPERGILLOSIS IN CAPTIVE GENTOO PENGUINS (PYGOSCELIS PAPUA PAPUA)

Aspergillosis is the primary fungal disease affecting captive penguins globally. Its diagnosis remains challenging, and currently no tests are both sensitive and specific for the detection of early infection. The present study evaluated a recently developed Aspergillus lateral-flow device (AspLFD) for the detection of Aspergillus spp. antigen in plasma and glottis mucus from captive penguins. In a pilot retrospective study, banked frozen plasma samples from captive penguins were reviewed: samples from 11 gentoo penguins (Pygoscelis papua papua) and 4 king penguins (Aptenodytes patagonicus) fulfilled the inclusion criteria and were used in the analysis. Positive plasma AspLFD test results were found in 80% (four of five) of the aspergillosis-positive cases tested. All of the aspergillosis-negative cases tested negative (10 of 10) on the AspLFD test. In a cohort prospective study, paired plasma and glottis swab samples were opportunistically and nonrandomly collected from captive gentoo penguins. In total, 26 penguins were tested. In the negative control group, AspLFD test was negative on plasma and swab in 100% of birds (14 of 14). In the aspergillosis-positive group, AspLFD test was positive on plasma samples from 33% (4 of 12) of birds, on swab samples from 50% (6 of 12) of birds, and on either plasma or swab samples from 75% (9 of 12) of birds. The AspLFD is currently used for the diagnosis of aspergillosis in humans and also shows promise for use in penguins. Larger prospective studies are recommended.

Nationwide Survey about the Occurrence of Aspergillosis in Captive Penguins in Zoos and Aquariums in Japan

We surveyed the facilities that were members of the Japan Association of Zoos and Aquariums to clarify the incidence of aspergillosis, which is a major cause of death in captive penguins, and to discern effective preventive measures. Responses were obtained for 2910 penguins in 64 facilities; 73 penguins (2.5%) in 35 facilities had died from aspergillosis during the past 5 years from April 2016 to March 2021. Answers to questions about the rearing environment indicated that aspergillosis occurred significantly more often in facilities where penguins were reared outdoors, were in contact with soil, or were moved outside of the rearing enclosure. Answers to questions about their dead penguins indicated that 76% may have been at individual risk (e.g., young age, old age, molting period, and breeding season) and 54% were thought to be reared in uncomfortable environments (e.g., high temperature, high humidity). Aspergillosis may occur when individual risk factors and uncomfortable environmental factors are added to the risk factors of exposure to Aspergillus, such as the presence of soil. These conditions must be recognized as risk factors for aspergillosis, and appropriate preventive measures, such as avoiding penguin contact with the soil where Aspergillus is expected to be present, can minimize aspergillosis-related deaths.

Pulmonary Aspergillosis in Humboldt Penguins—Susceptibility Patterns and Molecular Epidemiology of Clinical and Environmental Aspergillus fumigatus Isolates from a Belgian Zoo, 2017–2022

Aspergillus fumigatus is the main causative agent of avian aspergillosis and results in significant health problems in birds, especially those living in captivity. The fungal contamination by A. fumigatus in the environment of Humboldt penguins (Spheniscus humboldti), located in a Belgian zoo, was assessed through the analysis of air, water, sand and nest samples during four non-consecutive days in 2021–2022. From these samples, potential azole-resistant A. fumigatus (ARAF) isolates were detected using a selective culture medium. A total of 28 veterinary isolates obtained after necropsy of Humboldt penguins and other avian species from the zoo were also included. All veterinary and suspected ARAF isolates from the environment were characterized for their azole-resistance profile by broth microdilution. Isolates displaying phenotypic resistance against at least one medical azole were systematically screened for mutations in the cyp51A gene. A total of 14 (13.6%) ARAF isolates were identified from the environment (n = 8) and from Humboldt penguins (n = 6). The TR34/L98H mutation was observed in all resistant environmental strains, and in two resistant veterinary strains. To the best of our knowledge, this is the first description of this mutation in A. fumigatus isolates from Humboldt penguins. During the period 2017–2022, pulmonary aspergillosis was confirmed in 51 necropsied penguins, which reflects a death rate due to aspergillosis of 68.0%, mostly affecting adults. Microsatellite polymorphism analysis revealed a high level of diversity among environmental and veterinary A. fumigatus isolates. However, a cluster was observed between one veterinary isolate and six environmental strains, all resistant to medical azoles. In conclusion, the environment of the Humboldt penguins is a potential contamination source of ARAF, making their management even more complex.

Aspergillosis in free-ranging Magellanic penguins

We evaluated the mortality due to aspergillosis in free-ranging Magellanic penguins during their migration and the reproductive season. A total of 98 carcasses of penguins were collected along 370 km of coastline in Southern Brazil, between June 2017 and October 2019, and from reproductive colonies in Patagonian Argentina, in January 2019. All animals were necropsied, and only proven cases were computed. Aspergillosis was diagnosed in 2.5% of the penguins evaluated during their migration route. Our study, of the Southern coast of Brazil, is the first to demonstrate that aspergillosis is an important cause of mortality in free-ranging penguins. The implications of these findings in the One Health context are discussed.

Challenges to establish the diagnosis of aspergillosis in non-laboratory animals: looking for alternatives in veterinary medicine and demonstration of feasibility through two concrete examples in penguins and dolphins

Aspergillosis remains difficult to diagnose in animals. Laboratory-based assays are far less developed than those for human medicine, and only few studies have been completed to validate their utility in routine veterinary diagnostics. To overcome the current limitations, veterinarians and researchers have to propose alternative methods including extrapolating from human diagnostic tools and using innovative technology. In the present overview, two specific examples were complementarily addressed in penguins and dolphins to illustrate how is challenging the diagnosis of aspergillosis in animals. Specific focus will be made on the novel application of simple testing in blood based on serological assays or protein electrophoresis and on the new information garnered from metabolomics/proteomics to discover potential new biomarkers. In conclusion, while the diagnostic approach of aspergillosis in veterinary medicine cannot be directly taken from options developed for human medicine, it can certainly serve as inspiration.

pAspergillosis in a colony of Humboldt penguins (Spheniscus humboldti) under managed care: a clinical and environmental investigation in a French zoological park

Aspergillosis is pervasive in bird populations, especially those under human care. Its management can be critically impacted by exposure to high levels of conidia and by resistance to azole drugs. The fungal contamination in the environment of a Humboldt penguin (Spheniscus humboldti) group, housed in a French zoological park next to numerous large crop fields, was assessed through three serial sessions of surface sampling in nests, in 2018-20: all isolates were counted and characterized by sequencing. When identified as A. fumigatus, they were systematically screened for resistance mutations in the cyp51A gene and tested for MICs determination. In the same time, the clinical incidence of aspergillosis was evaluated in the penguin population by the means of systematic necropsy and mycological investigations. A microsatellite-based analysis tracked the circulation of A. fumigatus strains. Environmental investigations highlighted substantial increase of the fungal load during the summer season (>12-fold vs. the other timepoints) and large overrepresentation of species belonging to the Aspergillus section Fumigati, ranging from 22.7 to 94.6% relative prevalence. Only one cryptic species was detected (A. nishimurae), and one isolate exhibited G138S resistance mutation with elevated MICs. The overall incidence of aspergillosis was measured at ∼3.4% case-years, and mostly in juveniles. The analysis of microsatellite polymorphism revealed a high level of genetic diversity among A. fumigatus clinical isolates. In contrast, one environmental strain appeared largely overrepresented during the summer sampling session. In all, the rural location of the zoo did not influence the emergence of resistant strains.

Assessment of the Safety and Efficacy of an Oral Probiotic-Based Vaccine Against Aspergillus Infection in Captive-Bred Humboldt Penguins (Spheniscus humboldti)

Aspergillosis is a fungal infection caused mainly by Aspergillus fumigatus that often results in respiratory disease in birds. Aspergillosis is a major cause of morbidity and mortality in captive-bred penguin species. Currently, there is no registered vaccine to prevent aspergillosis. Recent research demonstrated that oral administration of gram-negative bacteria expressing high levels of galactose-α-1,3-galactose (α-Gal) modulates anti-α-Gal immunity and protects turkeys from clinical aspergillosis caused by experimental A. fumigatus infection. The role of anti-α-Gal immunity in penguins has not been studied. Here, we tested the distribution of α-1,3-galactosyltransferase (α1,3GT) genes in the fecal microbiome of Humboldt penguins (Spheniscus humboldti). The occurrence of natural anti-α-Gal antibodies (Abs) in sera and eggs of healthy Humboldt penguins was also assessed. A trial was then conducted to test whether oral administration of Escherichia coli Nissle, expressing high α-Gal levels, modulates anti-α-Gal immunity in a colony of Humboldt penguins. Animals in the vaccination and placebo groups were evaluated before the trial and followed for one year for aspergillosis detection using a diagnostic panel including computed tomography scans, capillary zone electrophoresis, 3-hydroxybutyrate levels, and anti-A. fumigatus Abs. Anti-α-Gal Abs were detected in sera (IgM and IgY) and eggs (IgY) of healthy penguins. Microbiota analysis and functional predictions revealed the presence of α1,3GT genes in the microbiota of Humboldt penguins and other penguin species. A strong decrease in anti-α-Gal IgM levels was observed in all animals in the placebo group three months after vaccination protocol. This decrease was not observed in E. coli Nissle-treated penguins. After the vaccination protocol, we found a positive correlation between anti-E. coli IgY and anti-α-Gal IgY in the E. coli Nissle group, suggesting a correlation between the presence of the bacteria and these Abs. During the study period, three penguins exhibited respiratory signs consistent with aspergillosis. Two were from the placebo group whose symptoms resolved with specific treatments, while a single vaccinated individual developed fatal respiratory aspergillosis eight months after the trial. We conclude that E. coli Nissle represents a safe potential probiotic with a protective effect against aspergillosis in Humboldt penguins that deserves to be further explored for therapeutic uses in these animals.

Molecular epidemiology of aspergillosis in Magellanic penguins and susceptibility patterns of clinical isolates

Aspergillus section Fumigati is reported in up to 99% of aspergillosis cases in penguins. So far, no data regarding molecular epidemiology and azole resistance are available for A. fumigatus isolates collected from Magellanic penguins. The aim of this work was to perform molecular identification of Aspergillus section Fumigati at species level, to genotype those isolates using microsatellite markers, to evaluate the in vitro susceptibility patterns of A. fumigatus sensu stricto, and to characterize the cyp51A gene in clinical A. fumigatus strains isolated from Magellanic penguins with proven aspergillosis. All 34 isolates included in the study were identified as A. fumigatus sensu stricto. Analyzing the genetic diversity of the isolates of A. fumigatus sensu stricto, we identified two possible outbreaks in the rehabilitation center and we also observed the maintenance of clonal strains through the years. One A. fumigatus sensu stricto isolate was resistant to posaconazole, but the mutations found in the cyp51A gene of this isolate have not been described as conferring phenotypic resistance, suggesting that other mechanisms of resistance could be involved in the resistance of this isolate. With this study we were able to understand the molecular diversity of Aspergillus fumigatus isolates collected from Magellanic penguins, to characterize them and to associate them with the described global population of Aspergillus fumigatus.

Aspergillosis in albatrosses

Aspergillosis is a respiratory fungal disease of importance in captive marine birds. The aim of this study was to describe the occurrence of aspergillosis in Thalassarche melanophris during rehabilitation events and to identify the etiological agent. All the albatrosses that were received for rehabilitation and died within a 2-year period were included in the study. The proportionate mortality rate caused by aspergillosis was 21.4% (3/14). One of the etiological agents was Aspergillus flavus/oryzae lineage, and the other was A. fumigatus sensu stricto. Our study suggests that aspergillosis can act as a limiting factor in the rehabilitation of albatrosses.

THE ISOLATION AND ANTIMICROBIAL SENSITIVITY OF ASPERGILLUS FUMIGATUS FROM FROZEN RESPIRATORY TISSUES OF PENGUINS FROM ZOOLOGICAL COLLECTIONS IN THE UNITED KINGDOM, 2007-2018

Fifty-eight frozen postmortem lung and air sac samples were collected from penguins housed at 21 zoological collections throughout the United Kingdom, from 2007 to 2018. Aspergillus fumigatus, a significant respiratory pathogen of penguins in captivity, was isolated from 15 of the 22 penguins with gross lesions. Of the penguins with gross lesions of aspergillosis at postmortem examination, the pathogen was cultured from 63.6% (15 of 22) of frozen samples. Aspergillus fumigatus was cultured from 2.7% (1 of 36) of tissues collected from penguins without gross lesions at postmortem. Additionally, of 18 fresh samples that cultured A. fumigatus at the time of postmortem, 15 samples (83%) yielded isolates that were successfully cultured from frozen tissue. Minimum inhibitory concentration (MIC) data demonstrated that all isolates were susceptible to terbinafine and voriconazole, and all were resistant to itraconazole, using published MIC cutoff values. Comparison isolates from fresh tissues had identical antimicrobial susceptibility to isolates from the same tissues after being frozen. This study demonstrates that A. fumigatus can be isolated from frozen respiratory tissues of penguins, even after freezing for more than 10 yr.

Aspergillosis in Wild Birds

The ubiquitous fungi belonging to the genus Aspergillus are able to proliferate in a large number of environments on organic substrates. The spores of these opportunistic pathogens, when inhaled, can cause serious and often fatal infections in a wide variety of captive and free-roaming wild birds. The relative importance of innate immunity and the level of exposure in the development of the disease can vary considerably between avian species and epidemiological situations. Given the low efficacy of therapeutic treatments, it is essential that breeders or avian practitioners know the conditions that favor the emergence of Aspergillosis in order to put adequate preventive measures in place.

Aspergillosis, Avian Species and the One Health Perspective: The Possible Importance of Birds in Azole Resistance

The One Health context considers health based on three pillars: humans, animals, and environment. This approach is a strong ally in the surveillance of infectious diseases and in the development of prevention strategies. Aspergillus spp. are fungi that fit substantially in this context, in view of their ubiquity, as well as their importance as plant pathogens, and potentially fatal pathogens for, particularly, humans and avian species. In addition, the emergence of azole resistance, mainly in Aspergillus fumigatus sensu stricto, and the proven role of fungicides widely used on crops, reinforces the need for a multidisciplinary approach to this problem. Avian species are involved in short and long distance travel between different types of landscapes, such as agricultural fields, natural environments and urban environments. Thus, birds can play an important role in the dispersion of Aspergillus, and of special concern, azole-resistant strains. In addition, some bird species are particularly susceptible to aspergillosis. Therefore, avian aspergillosis could be considered as an environmental health indicator. In this review, aspergillosis in humans and birds will be discussed, with focus on the presence of Aspergillus in the environment. We will relate these issues with the emergence of azole resistance on Aspergillus. These topics will be therefore considered and reviewed from the “One Health” perspective.

Antifungal susceptibility profile of Aspergillus fumigatus isolates from avian lungs

ABSTRACT: Susceptibility testing is essential to inform the correct management of Aspergillus infections. In this study we present antifungal susceptibility profile of A. fumigatus isolates recovered from lungs of birds with and without aspergillosis. Fifty three isolates were tested for their antifungal susceptibility to voriconazole (VRC), itraconazole (ITZ), amphotericin (AMB) and caspofungin (CSP) using the M38-A2 broth microdilution reference method. Five isolates were resistant to more than one antifungal drug (CSP + AMB, VRC + ITZ and AMB + ITZ). Fifteen (28%) isolates with susceptible increased exposure (I) to ITZ were sensible to VRC. Resistance to AMB (>2μg/mL) was observed in only four isolates. Eleven (21%) A. fumigatus present resistance to ITZ (13%) and VRC (8%). Fungal isolation from respiratory samples has been regarded as being of limited usefulness in the ante mortem diagnosis of aspergillosis in birds. However, the results suggest that the detection and antifungal susceptibility profile may be helpful for monitoring of therapy for avian species and where antifungal resistance might be emerging and what conditions are associated to the event.

Application of different pharmacokinetic models to describe and predict pharmacokinetics of voriconazole in magellanic penguins following oral administration

Aspergillosis is a condition causing serious morbidity and mortality in captive penguins and other bird species. It can be treated with antifungal drugs, such as voriconazole. However, the pharmacokinetics of voriconazole are variable between different animal and bird species. Therefore, the pharmacokinetics of voriconazole were investigated in this study in Magellanic penguins. Pharmacokinetic models were constructed and applied to predict the pharmacokinetics of voriconazole during long-term treatment in Magellanic penguins, since the voriconazole treatment duration in chronic aspergillosis cases can last up to several months. Plasma voriconazole concentration-time data from adult Magellanic penguins (Spheniscus magellanicus; n = 15) following a single oral (PO) dose of either 2.5 mg/kg or 5 mg/kg in a herring in three separate study periods 7-12 months apart were collected. Mean plasma voriconazole concentrations were above the targeted MIC for Aspergillus fumigatus for 2 hr following a single 2.5 mg/kg voriconazole dose while the plasma concentrations exceeded the MIC for least 24 hr following a 5 mg/kg dose. Nonlinear mixed-effects modeling was used to fit two pharmacokinetic models, one with first-order and another with saturable elimination, to the single-dose data. Fits were good for both, as long as dose was included as a covariate for the first-order model so that clearance was lower and the half-life longer for animals receiving the 5 mg/kg dose. Although the single-dose data suggested saturated elimination at higher concentrations, the model with saturable elimination did not predict plasma voriconazole concentrations well for a clinical aspergillosis case receiving long-term treatment, possibly because of induction of metabolizing enzymes with chronic exposure. Pharmacokinetic models should accurately predict plasma drug concentrations for different dosage regimens in order to be applicable in the field. Future studies should focus on determining clearance at steady-state to be able to refine the pharmacokinetic models presented here and improve model performance for long-term oral voriconazole administration in Magellanic penguins.

Translational proteomic study to address host protein changes during aspergillosis

Aspergillosis is a fungal disease due to Aspergillus molds that can affect both humans and animals. As routine diagnosis remains difficult, improvement of basic knowledge with respect to its pathophysiology is critical to search for new biomarkers of infection and new therapeutic targets. Large-scale proteomics allows assessment of protein changes during various disease processes. In the present study, mass spectrometry iTRAQ® (isobaric tags for relative and absolute quantitation) protocol was used for direct identification and relative quantitation of host proteins in diseased fluids and tissues collected from an experimental rat model challenged with Aspergillus, as well as in blood obtained from naturally-infected penguins. In all, mass spectrometry analysis revealed that proteome during aspergillosis was mostly represented by proteins that usually express role in metabolic processes and biological process regulation. Ten and 17 proteins were significantly ≥4.0-fold overrepresented in blood of Aspergillus-diseased rats and penguins, respectively, while five and 39 were negatively ≥4.0-fold depleted within the same samples. In rat lungs, 33 proteins were identified with positive or negative relative changes versus controls and were quite different from those identified in the blood. Except for some zinc finger proteins, kinases, and histone transferases, and while three pathways were common (Wnt, cadherin and FGF), great inter-species variabilities were observed regarding the identity of the differentially-represented proteins. Thus, this finding confirmed how difficult it is to define a unique biomarker of infection. iTRAQ® protocol appears as a convenient proteomic tool that is greatly suited to ex vivo exploratory studies and should be considered as preliminary step before validation of new diagnostic markers and new therapeutic targets in humans.

Plasma protein electrophoresis as a prognostic indicator in Aspergillus species-infected Gentoo penguins (Pygoscelis papua papua)

BACKGROUND

Avian aspergillosis presents a significant threat to captive penguin populations. Currently, a lack of objective prognostic factors limits disease staging, objective reassessment throughout treatment, comparative evaluation of treatment regimes, and appropriate timing of euthanasia.

OBJECTIVE

The study objective was to investigate absolute and relative plasma protein fractions by agarose gel electrophoresis (EPH) as predictors of survival in Gentoo penguins (Pygoscelis papua papua) under treatment for aspergillosis.

METHODS

One hundred and eighty-three EPH profiles from individual clinical cases were examined retrospectively. Animal survival to 90 days post sampling was established from clinical records; birds either survived (n = 146) or died within 90 days (n = 37), and time to death was recorded.

RESULTS

Fourteen variables showed statistically significant differences (P < .05) between surviving and dying birds. Receiver operating characteristic curve analysis identified total albumin concentration (albumin + prealbumin) and albumin-to-globulin (A:G) ratio as having strongest discriminatory values (95% CI) at 0.788 (0.710-0.866) and 0.784 (0.696-0.871), respectively. Albumin (concentration and percentage of total protein) displayed moderate discriminatory value but additionally a weak positive correlation with time to death (95% CI); r = .353 (0.033-0.608) and .424 (0.116-0.658), respectively.

CONCLUSIONS

Optimized test cutoffs for total albumins, albumin (concentration and percentage of total protein), and A:G ratio achieved moderate sensitivity and specificity, strong negative predictive values, but weak positive predictive values due to a low prevalence of death. Selection of appropriate test cutoff values may provide valuable adjunctive prognostic tools for clinical decision-making when the prognosis is difficult to assess clinically.