Browsing by Author "Morgan K"

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    Development of a qPCR molecular diagnostic assay for the detection of kiwi Eimeria species and its application to determine tissue-specificity of species causing coccidiosis in North Island brown kiwi (Apteryx mantelli)
    (Springer-Verlag GmbH Germany, 2025-07-04) Scheltema E; Morgan K; Hunter S; Mackay J; Singh P; Howe L
    Juvenile kiwi (Apteryx spp.) within captive-rearing programmes commonly suffer from coccidiosis, which primarily affects the intestine but can also impact other organs, such as the kidneys, liver, lung, and spleen (Morgan et al. Avian Pathol 42:137–146 2013). In some immune-compromised birds, disease causes significant morbidity and, occasionally, mortality (Morgan et al. NZVJ 62:315–320 2014); however, understanding of the biology of disease-causing Eimeria species in kiwi is limited. A probe-based qPCR assay targeting a 115-bp fragment of the Eimeria mitochondrial cytochrome c oxidase I (CO1) gene was developed to identify three distinct kiwi Eimeria species: the two species most commonly recovered from faeces, Eimeria kiwii and Eimeria apteryxii, as well as the newly described species, Eimeria koka (Scheltema et al. Syst Parasitol 102:30 2025). The qPCR assay was then applied to retrospectively analyse formalin-fixed paraffin-embedded intestine, kidney, liver, lung, and spleen tissues from ten historic post-mortem cases from kiwi diagnosed with extraintestinal coccidiosis. This novel assay detected infection more often (33/47 tissues) than manual histopathological identification (25/47 tissues). Only one species, E. koka, was detected in extraintestinal tissues with the highest prevalence (9/10) in kidney tissues. In contrast, E. kiwii was reliably detected in 8/9 intestinal tissues but was not detected in the other tissues tested. E. apteryxii was not detected in any of the tissues analysed. These findings suggest that kiwi are infected by at least one intestinal and one renal-specific species, the latter of which is suspected to disseminate under certain conditions to other organs of the body.
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    Morphological and molecular description of a novel species of Eimeria (Apicomplexa) that infects extraintestinal tissues of kiwi (Aves: Apteryx spp.)
    (Springer Nature, Heidelberg, Germany, 2025-06) Scheltema E; Morgan K; Singh P; Adlington B; Howe L
    Coccidia (Apiconmplexa) are naturally occurring and occasionally detrimental parasites of kiwi (Apteryx spp.), a unique, flightless bird species dependent upon conservation efforts for survival. Using morphological and molecular data, a new coccidia species, Eimeria koka n. sp., isolated from two closely related but geographically isolated kiwi host species, Apteryx rowi Tennyson et al. (rowi) and Apteryx mantelli Bartlett (North Island brown kiwi), is described. Oocysts are oval (20.8 × 15.9 μm) with a mean L/W ratio of 1.3, and a distinctive rough, crenellated brown oocyst wall (mean 1.2 μm), an oocyst residuum, 1–2 polar granules, and no micropyle. Sporocysts are ellipsoidal (11.6 × 6.3 μm) with a Stieda body and sporocyst residuum. Phylogenetic analysis of the cytochrome C oxidase subunit 1 (CO1) placed E. koka n. sp. in a separate clade to other Eimeria species previously identified from kiwi (Coker et al., Syst Parasitol 100(3):269–281, 2023). Comparison of DNA from oocysts with infected tissues from a single juvenile North Island brown kiwi confirmed parasitism of the kidney and lung tissues. This is the first Eimeria species identified from extraintestinal tissues in kiwi. Further molecular studies are recommended to determine the tissue distribution of E. kokan. sp. and other Eimeria species in kiwi.