Browsing by Author "Pas A"
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- ItemA lower motor neuron disease in takahē (Porphyrio hochstetteri) is an endoplasmic reticulum storage disease.(Taylor and Francis Group, 2023-03-30) Jolly RD; Perrott MR; Alley MR; Hunter SA; Pas A; Beard H; Hemsley KM; Greaves GAIMS: To investigate the pathogenesis of a disease in takahē (Porphyrio hochstetteri) with intracytoplasmic inclusion bodies in lower motor neurons. METHODS: Four birds aged between 5 and 12 years, from three different wildlife sanctuaries in New Zealand were examined. Of these, only one had signs of spinal dysfunction in the form of paresis. Stained paraffin sections of tissues were examined by light microscopy and immunostained sections of the ventral horn of the spinal cord by confocal microscopy. Epoxy resin sections of the spinal cord from the bird with spinal dysfunction were examined by electron microscopy. RESULTS: Two types of inclusion bodies were noted, but only in motor neurons of the ventral spinal cord and brain stem. These were large globoid eosinophilic bodies up to 5 µm in diameter, and yellow/brown granular inclusions mostly at the pole of the cell. The globoid bodies stained with Luxol fast blue but not with periodic acid Schiff (PAS), or Sudan black. The granular inclusions stained with Luxol fast blue, PAS and Sudan black. Both bodies were slightly autofluorescent. On electron microscopy the globoid bodies had an even electron-dense texture and were bound by a membrane. Beneath the membrane were large numbers of small intraluminal vesicles. The smaller granular bodies were more heterogeneous, irregularly rounded and membrane-bound accumulations of granular electron-dense material, often with electron-lucent vacuoles. Others were more vesicular but contained varying amounts of electron-dense material. The large globoid bodies did not immunostain for lysosomal markers lysosomal associated protein 1 (LAMP1) or cathepsin D, so were not lysosomal. The small granular bodies stained for cathepsin D by a chromogenic method.A kindred matrix analysis showed two cases to be as closely related as first cousins, and another case was almost as closely related to one of them, but the fourth bird was unrelated to any other. CONCLUSIONS: It was concluded that this was an endoplasmic reticulum storage disease due to a specific protein misfolding within endoplasmic reticulum. It was rationalised that the two types of inclusions reflected the same aetiology, but that misfolded protein in the smaller granular bodies had entered the lysosomal system via endoplasmic reticulum autophagy. Although the cause was unclear, it most likely had a genetic aetiology or predisposition and, as such, has clinical relevance.
- ItemA single genotype of Chlamydia psittaci (ST27) found in multiple species of birds in a zoological collection in New Zealand(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-06-02) Gedye K; Kulkarni P; Soon XQ; Pas A; Jensen M; Gartrell BDAims: To investigate the genotypes of Chlamydia psittaci in birds associated with two clusters of disease from a zoological collection in New Zealand. Materials and methods: Samples were collected over two time periods from birds resident at Auckland Zoo (Auckland, NZ). In 2016, two little penguins/kororā (Eudyptula minor) showed respiratory disease on admission to the zoo hospital. Post-mortem samples of liver and lung were collected from the penguins and from 10 other birds from the zoo’s collection that died without clinical signs. Further, 128 conjunctival, choanal and cloacal swabs were collected from 27 different bird species, all housed within the zoo and without clinical signs. In 2019, a cluster of deaths of four diamond doves (Geopelia cuneata) and two superb parrots (Polytelis swainsonii) occurred in one mixed-species aviary. Twenty post-mortem samples were collected from these birds and other birds that died around the same time across the zoo. DNA was extracted from all samples and initially tested for C. psittaci using a high-resolution melting quantitative PCR (HRM qPCR) protocol. We applied multi-locus sequence typing (MLST) on 10 C. psittaci-positive samples from four different avian species, including one sample from 2016 (little penguin) and nine post-mortem samples from 2019. Results: C. psittaci was detected in 14/140 (0.10; 95% CI = 0.061–0.161) of the samples from 2016 from seven species. A penguin sample was sequenced aligning with ompA genotype B and was later characterised by MLST as C. psittaci strain ST27. With the exception of the sample from the sick penguin, the positive results yielded very low DNA copy numbers in the HRM qPCR, potentially indicating latent infections. In the 2019 cluster, C. psittaci was detected in 9/20 post-mortem samples from three bird species (diamond dove, superb parrot, and zebra finch (Taeniopygia guttata)). All nine sample sequences aligned with ompA genotype B and were characterised by MLST as C. psittaci strain ST27. Conclusions and clinical relevance: C. psittaci was present within the zoological collection in a variety of bird species associated with two disease clusters. Most of these infections were asymptomatic, but a cluster of deaths due to avian chlamydiosis in 2019 affecting three species of birds was due to a single genotype, ST27, that was also present in a wild penguin in 2016. This provides evidence of pathogenicity in birds for this genotype.
- ItemGut microbiota of the threatened takahē: biogeographic patterns and conservation implications(BioMed Central Ltd, 2022-12) West AG; DeLaunay A; Marsh P; Perry EK; Jolly M; Gartrell BD; Pas A; Digby A; Taylor MWBACKGROUND: The Aotearoa New Zealand takahē (Porphyrio hochstetteri), once thought to be extinct, is a nationally threatened flightless rail under intensive conservation management. While there has been previous research into disease-related microbes in takahē, little is known about the microbes present in the gastrointestinal tract. Given the importance of gut-associated microbes to herbivore nutrition and immunity, knowledge of these communities is likely to be of considerable conservation value. Here we examined the gut microbiotas of 57 takahē at eight separate locations across Aotearoa New Zealand. RESULTS: Faecal samples, taken as a proxy for the hindgut bacterial community, were subjected to 16S rRNA gene amplicon sequencing using Illumina MiSeq. Phylogenetic analysis of > 2200 amplicon sequence variants (ASVs) revealed nine main bacterial phyla (Acidobacteriota, Actinobacteriota, Bacteroidota, Campilobacterota, Firmicutes, Fusobacteriota, Planctomycetota, Proteobacteria, and Verrucomicrobiota) that accounted for the majority of sequence reads. Location was a significant effect (p value < 0.001, 9999 permutations) that accounted for 32% of the observed microbiota variation. One ASV, classified as Lactobacillus aviarius, was present in all samples at an average relative abundance of 17% (SD = 23.20). There was strong evidence (p = 0.002) for a difference in the abundance of the genus Lactobacillus between locations. A common commensal bacterium previously described in takahē, Campylobacter spp., was also detected in most faecal samples. CONCLUSIONS: Location plays a pivotal role in the observed variation among takahē gut bacterial communities and is potentially due to factors such as supplemental feeding and medical treatment experienced by birds housed in captivity at one of the eight sampled sites. These data present a first glimpse of the previously unexplored takahē gut microbiota and provide a baseline for future microbiological studies and conservation efforts.
- ItemMammal-related Cryptosporidium infections in endemic reptiles of New Zealand.(Springer Nature, 2023-05-01) Garcia-R JC; Pita AB; Velathanthiri N; Pas A; Hayman DTSNew Zealand's endemic reptile fauna is highly threatened and pathogens causing infectious diseases may be a significant risk to already endangered species. Here, we investigate Cryptosporidium infection in captive endemic New Zealand reptiles. We found two mammal-related Cryptosporidium species (C. hominis and C. parvum) and six subtypes from three gp60 families (Ib, Ig and IIa) in 12 individuals of captive endemic Tuatara, Otago and Grand skinks, and Jewelled and Rough geckos. Cryptosporidium serpentis was identified in two Jewelled geckos using 18S. In New Zealand, C. hominis and C. parvum are associated with infections in humans and introduced domestic animals but have also been recently found in wildlife. Our finding of Cryptosporidium infection in endemic reptiles can help inform strategies to monitor the conservation of species and manage potential introductions of pathogens to in-situ and ex-situ populations.
- ItemValidation of an Indirect Immunofluorescence Assay and Commercial Q Fever Enzyme-Linked Immunosorbent Assay for Use in Macropods(American Society for Microbiology, 2022-07) Tolpinrud A; Stenos J; Chaber A-L; Devlin JM; Herbert C; Pas A; Dunowska M; Stevenson MA; Firestone SM; Barrs, VRKangaroos are considered to be an important reservoir of Q fever in Australia, although there is limited knowledge on the true prevalence and distribution of coxiellosis in Australian macropod populations. Serological tests serve as useful surveillance tools, but formal test validation is needed to be able to estimate true seroprevalence rates, and few tests have been validated to screen wildlife species for Q fever. In this study, we modified and optimized a phase-specific indirect immunofluorescence assay (IFA) for the detection of IgG antibodies against Coxiella burnetii in macropod sera. The assay was validated against the commercially available ID Screen Q fever indirect multispecies enzyme-linked immunosorbent assay (ELISA) kit (IDVet, Grabels, France) to estimate the diagnostic sensitivity and specificity of each assay, using Bayesian latent class analysis. A direct comparison of the two tests was performed by testing 303 serum samples from 10 macropod populations from the east coast of Australia and New Zealand. The analysis indicated that the IFA had relatively high diagnostic sensitivity (97.6% [95% credible interval [CrI], 88.0 to 99.9]) and diagnostic specificity (98.5% [95% CrI, 94.4 to 99.9]). In comparison, the ELISA had relatively poor diagnostic sensitivity (42.1% [95% CrI, 33.7 to 50.8]) and similar diagnostic specificity (99.2% [95% CrI, 96.4 to 100]) using the cutoff values recommended by the manufacturer. The estimated true seroprevalence of C. burnetii exposure in the macropod populations included in this study ranged from 0% in New Zealand and Victoria, Australia, up to 94.2% in one population from New South Wales, Australia.
- ItemWhat's in a database? Insights from a retrospective review of penguin necropsy records in Aotearoa New Zealand(PLOS, 2025-04-30) Saverimuttu S; Hunter S; Gartrell B; McInnes K; Warren K; Pas A; Chatterton J; Yeap L; Jackson B; Raverty SWildlife necropsy databases often provide data for morbidity and mortality studies of free-ranging species, with implicit relevance for conservation goals, as well as domestic animal and human health. Retrospective reviews are a common way to derive insights from such opportunistic data, despite the methodological difficulties of performing these analyses, alongside findings being prone to bias. This study reviews morbidity and mortality data from Sphenisciformes of Aotearoa New Zealand, using records extracted and manually refined from submissions to the national Wildbase Pathology Register. The review corroborates the broader consensus that hoiho (yellow eyed penguin, Megadyptes antipodes) are most commonly diagnosed with infectious/inflammatory disease (43.1%, 422/978 diagnoses), kororā (blue penguin, Eudyptula minor) with traumatic injuries (42.9%, 156/364 diagnoses), and emaciation being a common finding across both species (33.9%, 393/1463 diagnoses). Further, there are marked spatiotemporal trends in submissions, driven primarily by the affected species and the submitting organisations, highlighting the biases within such databases that must be factored into the application of results. Typographical errors, redundancies from synonymous terms, and missing data are captured as barriers to performing manual reviews of free-text data. Overall, this study highlights strengths and limitations of storage and review of wildlife necropsy data while providing insight into threats faced by the penguins of Aotearoa.
