Candida albicans infection in free-living populations of hihi (stitchbird; Notiomystis cincta)

Abstract

AIM: To describe the occurrence of candidiasis in hihi (stitch-bird; Notiomystis cincta) nestlings, and investigate the carriage and impact of Candida albicans infection in a free-living population of hihi.

METHODS: Mortality of nestlings was investigated in a reintroduced population of the endangered, endemic hihi at Zealandia: Karori Sanctuary, Wellington, New Zealand. Oral and faecal samples were collected from live hihi nestlings, for microbiological examination, between October 2008 and April 2009. All hihi that died and could be recovered were submitted to the New Zealand Wildlife Health Centre (NZWHC) at Massey University, for post-mortem examination. The results were compared with data obtained retrospectively from the National Wildlife Mortality (NWM) database for two other reintroduced populations of hihi on Mokoia and Tiritiri Matangi Islands.

RESULTS: Fifty chicks fledged from 82 eggs hatched during the 2008–2009 breeding season at Zealandia: Karori Sanctuary. Thirty-four live nestlings were sampled from 11 nests, and C. albicans was isolated from gastrointestinal swabs of 13 live nestlings from four nest sites. Eight (62%) of those nestlings survived to fledge, compared with 17/21 (81%) of those that tested negative (p=0.254; Fisher's exact test). Of the 32 hihi nestlings that died during the period of the study, 25 were recovered for necropsy. Histopathological examination revealed candidiasis was a factor in the deaths of four nestlings. An adult hihi that died during the period of the study at Zealandia: Karori Sanctuary was also found to have candidiasis. Retrospective analysis of data from the NWM database revealed candidiasis was also a factor in the deaths of five nestlings aged between 1 and 10 days from Mokoia Island, and of three nestlings <5 days old and one adult from Tiritiri Matangi Island.

CONCLUSIONS: Candida albicans was isolated from 38% of hihi nestlings sampled in this study, and vertical transmission of this organism from parent to offspring is likely to occur. Some colonised nestlings developed ventriculitis associated with Candida spp., but survival to fledging was not significantly different between nestlings that tested positive or negative, although the fate of birds following fledging was unknown.     

Effects of two large doses of equine recombinant growth hormone on clinical, haematological and serum biochemical variables in adult horses

Objective To evaluate the clinical, haematological, and serum biochemical effects of two large doses of recombinant equine growth hormone.
Design Duplicated Latin square.
Sample population
Three Thoroughbred and three Standardbred mares aged between 12 and 17 years.
Procedure Two horses were randomly assigned into one of three groups. On each of three successive days, each horse pair received one of two dosages of growth hormone or a saline placebo so that by the end of the experiment all three horse pairs had received both dosages and the saline placebo. Dose rates selected were 50 μg/kg, and 100 μg/kg. A clinical examination was performed and a venous blood sample drawn for a complete blood count and serum biochemical analysis before administration of growth hormone and at 1, 2, 3, 4, 6, 8 and 24 h after injection. Data were analysed by a repeated measures analysis of variance assessing the effects of dose and time.
Results There was an effect of time on a number of clinical, haematological, and serum biochemical variables. There were significant effects of growth hormone on heart rate and serum glucose concentration but values for both variables remained within the reference range.
Conclusion The results of the present study suggest that equine recombinant growth hormone has a wide margin of safety and show that the single administration of up to five times the recommended dose rate has no significant effects on clinical, haematological, or serum biochemical variables.     

Blindness in goats following ingestion of Stypandra glauca

Twenty-seven of 427 Angora goats of mixed age became blind within a week of consuming large amounts of Stypandra glauca ("nodding blue lily"). A further 200 goats were depressed for several weeks, but most subsequently recovered. Blindness was associated with optic nerve neuropathy which is postulated to have followed compression of the optic nerves within the bony optic canals as a result of severe myelin oedema. Histologically, the intracanalicular portion of the optic nerve was sclerotic, while the intracranial portion of the optic nerve and the optic tracts were degenerating. The retrobulbar portion of the optic nerve was relatively unaffected. In addition, multifocal retinal photoreceptor degeneration was found ophthalmoscopically and histologically. The syndrome was not reproduced during a trial in which 2 goats were fed 4 and 20 kg of S. glauca harvested after it had finished flowering, more than 3 weeks after the first natural cases of blindness. Based on epidemiological and pathological data we propose that S. glauca is toxic to stock, but only for a short period while flowering in spring.     

Seroprevalence in Household Raised Pigs Indicate High Exposure to GII Noroviruses in Rural Nicaragua

Information about porcine norovirus (PoNoV), genetically similar to human NoV (HuNoV), is limited from rural areas where household‐raised pigs are heavily exposed to faecal material which could facilitate transmission. Histo‐blood group antigens (HBGAs) are known susceptibility factors to NoV in humans and in a germfree piglet model but their role in susceptibility in the porcine population remains unknown. This study reports: (i) the seroprevalence and antibody titres to human norovirus (NoV) VLPs in household raised pigs; (ii) the distribution of HBGAs in relation to NoV IgG antibody titres and further characterization by blocking of GII.4 VLP binding to pig gastric mucins (PGM). The majority of pigs were seropositive to all three VLPs tested (58–70%) with seropositivity and cross‐reactivity increasing significantly with age. However, pig sera could not block the binding of NoV GII.4 VLPs (Dijon) to PGM suggesting no previous infection with this genotype. The majority of the pigs were H‐positive (84%), a susceptibility factor for human infections. IgG antibody titres were however higher in H‐negative (GMT = 247) as compared with H‐positive (GMT = 57) pigs, but after age stratification, this difference in antibody titres was only observed in pigs ≤1 month of age. In conclusion, serological data show that the porcine population of Nicaragua is highly exposed to NoV infections, and the association to HBGAs warrants further investigation.     

The influence of gestation feeding strategy on body composition of gilts at farrowing and response to dietary protein in a modified lactation

Previous experiments have indicated that reproductive function in lean, modern genotypes may be more dependent on body protein mass than, as previously believed, on body lipid reserves. This was investigated in a 3 x 2 factorial arrangement of treatments, involving 60 first-parity sows, comparing three pregnancy feeding strategies and two lactation diets. During pregnancy, sows were fed either a basal diet (5 g lysine/kg, 13 MJ of DE/kg [C]) or the same quantity of basal diet + energy source [E], or additional basal diet supplying both protein and energy [A]. The level of supplement for E and A was adjusted weekly to achieve a backfat thickness measurement (P2 position) of 28 mm at farrowing. Isoenergetic lactation diets were fed to appetite and provided either high (180 g CP/kg, 9 g lysine/kg [H]) or low lysine (120 g CP/kg, 6 g lysine/kg [L]). From d 21 of lactation, sows were separated from their litters and housed next to a boar for 8 h each day; final weaning occurred on d 31. Pregnancy treatment differences in backfat and weight were achieved, with C sows having less backfat on d 1 of lactation than E and A sows (E = 28.1, A = 28.0, C = 22.7 kg, P < 0.001). Sows fed additional basal diet were heavier than E sows, which were heavier than C sows (E = 190, A = 201, C = 178 kg, P < 0.001). Average feed intake over lactation showed a pregnancy feeding effect, with E sows eating less than A or C sows (E = 4.9, A = 5.2, C = 5.4 kg/d, P < 0.005). Total lactation weight loss was affected by pregnancy feeding (E = 18.0, A = 19.0, C = 8.4 kg, P < 0.05) and by lactation diet (L = 19.0, H = 11.3 kg, P < 0.05), whereas total lactation backfat loss was affected only by pregnancy treatment (E = 6.9, A = 6.5, C = 4.6 mm, P < 0.05). No pregnancy treatment or lactation diet effects were observed for litter performance. Lactation diet affected weaning-to-estrus interval, with more sows on the H diet coming into estrus within 6 d of partial weaning (P < 0.05), but there was no pregnancy treatment effect. Therefore, voluntary feed intake during lactation was suppressed by increased fat reserves at a limited body protein mass but not when body protein mass was also increased. Partial weaning-to-estrus interval was increased by reduced dietary protein.     

ANIMAL PREFERENCE IN RELATION TO THE CHEMICAL COMPOSITION AND DIGESTIBILITY OF VARIETIES OF COCKSFOOT

Assessments of animal preference (measured as mean % herbage removed) were made on varieties of cocksfoot in Yorkshire and in Scotland, and parallel chemical analyses were carried out. A similar range of varieties were examined at progressive stages of spring growth at Cambridge. In vitro digestibility tests were made also. In the Yorkshire trials, a significant positive relationship was established between soluble carbohydrates and animal preference and a negative correlation between fibre and animal preference. In Scotland, the relationship between soluble carbohydrate and animal preference was less pronounced. Animal preference in the spring was for the early varieties which have thick and succulent stems up to the stage of ear emergence. In the aftermath animal preferences were less marked.
In trials at Cambridge, the early varieties, notably Scotia, were higher than the late varieties both in digestibility and in soluble carbohydrates. This tendency was also present in Scotland but was less pronounced.     

Use of BACTEC radiometric culture method and polymerase chain reaction for the rapid screening of faeces and tissues for Mycobacterium paratuberculosis

SUMMARY The BACTEC radiometric culture method for detection of Mycobacterium paratuberculosis was evaluated on faeces from cattle on a farm in quarantine for Johne's disease. A multiplex polymerase chain reaction (PCR) based on the IS900 sequence specific for M paratuberculosis and a genus specific 16S rRNA region was developed and used to test cultures showing evidence of mycobacterial growth in the BACTEC liquid radiometric culture medium. Using the BACTEC - PCR combination, confirmation of M paratuberculosis from faeces and tissue of clinically affected animals was achieved within 2 to 4 weeks and 1 week, respectively, a substantial improvement on traditional culture and identification methods. The PCR provided rapid exclusion of M paratuberculosis when other Mycobacterium spp were grown. The radiometric culture medium proved to be very sensitive for culturing Mycobacterium spp.     

Cerebellar abiotrophy in crossbred cattle

Cerebellar abiotrophy affected 9 of 74 calves sired by a Poll Hereford bull over 2 successive calving seasons. The disease was characterised by episodes of recumbency and ataxia, with hypermetria and wide base stance. Clinical signs commenced between birth and 8 months of age. Two calves which were affected first at 8 months of age recovered clinically 9 months later. Histological lesions were found in the cerebellar cortex of 7 calves and consisted of segmental degeneration and loss of Purkinje cells, and axonal swellings. The clinical signs and pathological findings were consistent with bovine familial convulsions and ataxia, which has not been described previously in Australia. The clinical signs were not attributable to the lesions observed in the cerebellum and an underlying electrophysiological abnormality is proposed. The aetiology of the condition is probably genetic and appears to have a multifactorial basis.