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.     

Aspergillosis in hihi (Notiomystis cincta) on Mokoia Island

AIM: An intensive 2-year field study of 65 hihi (or stitchbirds) on Mokoia Island provided an opportunity to investigate the causes of mortality of this endangered species in a free-living environment. METHODS: The birds were observed daily during the breeding season (October to March) and every 4 weeks during the remainder of the year. Any abnormalities in behaviour, voice and body weight were recorded and all sick or dead birds which could be recovered were taken to the laboratory for necropsy. RESULTS: Thirty-one birds died during the period of this study. Aspergillosis was found to be the cause of death in six of nine adult birds examined post mortem. Some of the affected birds experienced subtle voice changes before becoming ill and all birds had granulomatous lesions in airsacs or lungs at necropsy. A further eight birds for which carcasses could not be found or which were autolysed showed similar clinical signs before death or disappearance. CONCLUSION: Because Aspergillus is an opportunist pathogen it seems likely that affected birds were immunosuppressed. This may have occurred during the breeding season which in this species is highly stressful. The presence of fungal material in bronchial exudate and the occurrence of the disease in mates, raises the possibility that aspergillosis in hihi may be contagious.     

Field investigation of Mycoplasma gallisepticum infections in house finch (Carpodacus mexicanus) eggs and nestlings.

We conducted a field study to investigate the occurrence of Mycoplasma gallisepticum (MG) in eggs and nestlings from nests of house finches (Carpodacus mexicanus). Forty-three nests were located between the months of April and August 1998 and were followed with one to three sampling efforts. Vitelline membrane of fresh eggs, whole embryos, or swabs from the choanal cleft or conjunctiva of nestlings were inoculated into mycoplasma broth for MG isolation and polymerase chain reaction (PCR) testing. No isolation of MG was made from 39 eggs or 110 nestlings sampled during the study. Pooled choanal and conjunctival swab samples from two broods of nestlings, however, tested positive for MG by PCR. None of the nestlings examined showed clinical signs of conjunctivitis, and no nestling mortality could be linked to MG infection. Serologic tests from 37 older nestlings were negative for antibodies to MG. The results suggest transmission of MG is occurring between breeding adults and their dependent offspring (pseudovertical transmission). Evidence supporting transovarian transmission of MG was not found in these house finches.     

Gut microbes limit growth in house sparrow nestlings (Passer domesticus) but not through limitations in digestive capacity

Recent research often lauds the services and beneficial effects of host‐associated microbes on animals. However, hosting these microbes may come at a cost. For example, germ‐free and antibiotic‐treated birds generally grow faster than their conventional counterparts. In the wild, juvenile body size is correlated with survival, so hosting a microbiota may incur a fitness cost. Avian altricial nestlings represent an interesting study system in which to investigate these interactions, given that they exhibit the fastest growth rates among vertebrates, and growth is limited by their digestive capacity. We investigated whether reduction and restructuring of the microbiota by antibiotic treatment would: (i) increase growth and food conversion efficiency in nestling house sparrows (Passer domesticus); (ii) alter aspects of gut anatomy or function (particularly activities of digestive carbohydrases and their regulation in response to dietary change); and (iii) whether there were correlations between relative abundances of microbial taxa, digestive function and nestling growth. Antibiotic treatment significantly increased growth and food conversion efficiency in nestlings. Antibiotics did not alter aspects of gut anatomy that we considered but depressed intestinal maltase activity. There were no significant correlations between abundances of microbial taxa and aspects of host physiology. Overall, we conclude that microbial‐induced growth limitation in developing birds is not driven by interactions with digestive capacity. Rather, decreased energetic and material costs of immune function or beneficial effects from microbes enriched under antibiotic treatment may underlie these effects. Understanding the costs and tradeoffs of hosting gut microbial communities represents an avenue of future research.     

Congenital neuropathy and dilution of feather melanin in nestlings of urban-breeding northern goshawks (Accipiter gentilis).

A pair of northern goshawks (Accipiter gentilis) breeding in a public park in the city center of Hamburg, Germany, raised 12 healthy and five aberrant offspring between 1996 and 2000. Aberrant nestlings (three males and two females) had pale silver-blue plumage and displayed severe locomotor disorders. Histopathologically, the defects were characterized by adendritic feather melanocytes and mild degeneration of the cerebellar white matter. Epidemiologic results were suggestive of a hereditary autosomal recessive defect, which may have originated from close inbreeding during the foundation of Hamburg's urban population of northern goshawks.     

Life-history parameters of Culicoides (Avaritia) imicola Kieffer in the laboratory at different rearing temperatures

This laboratory study investigates the sub-adult developmental cycle of field collected Culicoides (Avaritia) imicola Kieffer (Diptera; Ceratopogonidae). The period required from blood-feeding field-collected females to the production of progeny adults occupied 34–56 days at 20 °C, 15–21 days at 25 °C and 11–16 days at 28 °C, demonstrating clear temperature dependence. When reared at 28 °C, C. imicola demonstrated higher variability in fecundity (between 2.4 and 20.6 eggs/female) and lower hatching rates (50.0–62.2%), although larval survival rates to pupation were low at all temperatures (20–30%). Similarly, the mean emergence rate from pupae was the highest at lower temperatures. These results highlight the difficulty in establishing and maintaining a laboratory colony of this species from field-collected material and results are discussed in reference to future research directions that may aid this process.     

An aspermia rat mutant (as/as) with spermatogenic failure at meiosis.

A newly identified aspermia rat mutant was investigated on testicular histology and mode of inheritance of the defect. Average testis weight of mutants was about one-third of that of phenotypically normal males. Spermatogenesis was interrupted at meiosis. Pachytene spermatocytes significantly decreased in number. Secondary spermatocytes and few round spermatids were seen, but no elongated spermatids and sperms were observed. A large basophilic inclusion-like body existed in the cytoplasm of late pachytene spermatocytes. Genetic analysis revealed an autosomal recessive transmission of the defect. Aspermia (As) was designated for the locus.     

Effects of a second mutant allele (V199I) at the PRKAG3 (RN) locus on carcass composition in pigs

The effect of a second mutant allele (V199I, here denoted rn*) at the PRKAG3 (RN) locus on carcass composition was determined in 334 pigs, entire males and females, from crosses between Swedish Hampshire (H) and Finnish Landrace (L) (H × LH; LH × H; LH × LH). Pigs were classified according to DNA test into the following PRKAG3 genotypes: RN⁻/RN⁻ (23%), RN⁻/rn⁺ (24%), RN⁻/rn* (33%), rn⁺/rn⁺ (8%), rn⁺/rn* (9%) and rn*/rn* (2%). The pigs were slaughtered at a commercial slaughterhouse and assessed 24 h postmortem. Right sides were fabricated into primary wholesale cuts, then further processed into defatted hams and loins, and a subset of hams (n = 122) was dissected into the five major individual muscles. The genotype frequencies for the subsample were RN⁻/RN⁻ (27%), RN⁻/rn⁺ (20%), RN⁻/rn* (35%), rn⁺/rn⁺ (9%), rn⁺/rn* (8%) and rn*/rn* (1%). Weights were recorded for meat and bone in ham and loin, fat in ham, back and shoulder and the individual dissected muscles. The genotype effect was significant (P < 0.05) for estimated lean meat content and the proportions of meat and bone and fat in ham and loin (of carcass weight). Also, the content of meat and bone in ham and loin, in proportion of whole ham and loin, respectively, differed significantly (P < 0.01) between genotypes. Estimated lean meat content was highest for RN⁻/RN⁻ (63.0%) and RN⁻/rn⁺ (63.1%) and lowest in the combined group rn*/⁻ (rn⁺/rn* and rn*/rn*, 61.7%); RN⁻/rn* (62.5%) and rn⁺/rn⁺(62.1%) were intermediate. The same results were found for meat and bone in ham and loin, as a proportion of whole ham and loin, respectively. RN⁻/RN⁻ and RN⁻/rn⁺ did not differ in any trait; however, they produced carcasses with the lowest proportions of fat within loin and the major wholesale cuts (ham, loin and shoulder). The carcass percentage of meat and bone in ham was higher in the three RN⁻/ genotypes (RN⁻/RN⁻, RN⁻/rn⁺ and RN⁻/rn*, P < 0.05) than in the rn*/⁻ group, whereas rn⁺/rn⁺ did not (P > 0.05) differ from any of the other genotypes. RN⁻/rn⁺ and RN⁻/rn* had higher (P < 0.05) proportion of meat and bone in loin compared to the rn*/⁻ group. We conclude that the second mutant allele found at the PRKAG3 (RN) locus, rn*, decreased the lean meat content compared with the two other alleles (RN⁻, rn⁺). The RN⁻/RN⁻ and RN⁻/rn⁺ genotypes were leanest, followed by RN⁻/rn* and rn⁺/rn⁺, and rn⁺/rn* and rn*/rn* were the fattest.     

Efficacy of Fipronil (9.8% w/w) + (S)-Methoprene (8.8% w/w) and Imidacloprid (8.8% w/w) + Permethrin (44% w/w) against Dermacentor variabilis (American Dog Tick) on Dogs.

This study evaluated overall efficacy, percentage of dogs free of live ticks, retention of ticks, and efficacy against retained ticks of fipronil (9.8% w/w) + (S)-methoprene (8.8% w/w) and imidacloprid (8.8% w/w) + permethrin (44% w/w) spot-on topical solutions against Dermacentor variabilis infesting dogs. Fipronil + (S)-methoprene provided significantly (P less than .05) greater tick control compared with the control dogs for the entire 30-day study period. Conversely, the combination product of imidacloprid + permethrin demonstrated activity significantly (P less than .05) different from control dogs only up to day 23. Significantly (P less than .05) more dogs treated with fipronil + (S)-methoprene were free of live ticks compared with controls on days 3, 9, and 16. There was never a significant difference (P greater than .05) between control and imidacloprid + permethrin-treated dogs in numbers of dogs free of live ticks. After the initial 10-minute tick exposure, lower numbers of ticks were retained on the imidacloprid + permethrin-treated dogs than on the fipronil + (S)-methoprene-treated dogs. However, when evaluating the effectiveness of the acaricides on "retained ticks," it appears that while some of the ticks were rapidly knocked down on the imidacloprid + permethrin-treated dogs, efficacy against ticks still retained at 10 minutes was never greater than 50%.     

Inter-individual variation in provisioning rate,prey size and number,and links to total prey biomass delivered to nestlings in the Collared Flycatcher (Ficedula albicollis)

Background: In bird species where offspring growth and survival rely on parents' food provisioning, parents can maximise their fitness by increasing the quantit...     

Morphologic heterogeneity of a strain of swine influenza virus (A/swine/Wisconsin/1/68, Hsw1N1) propagated at different temperatures.

Strain A/swine/Wisconsin/1/68 (WI/68) swine influenza virus (SIV) was propagated in embryonating chicken eggs at 33, 35, or 37 C. The SIV harvested from eggs incubated at 33 C invariably had higher hemagglutination (HA) and egg infectivity titers than did SIV propagated in eggs at the 2 higher temperatures. When SIV inoculum propagated at 33 C was inoculated into separate groups of eggs and incubated at 33, 35, and 37 C, the SIV harvested from inoculum incubated at the 2 higher temperatures had significantly lower infectivity and HA titers than did that propagated at 33 C. By electron microscopy (EM), viral particles of Wi/68 were of various sizes and shapes regardless of the temperature used to propagate the virus. However, in contrast to what was seen in SIV harvested from innoculum incubated at 33 C incubation, pleomorphic shapes and particles with surface abnormalities were much more frequent in SIV harvested from inoculums kept at the 2 higher temperatures. Approximately one-third of the particles from 35 and 37 C incubation either were spikeless or were relatively deficient in surface spikes.     

VMSTP Combined Degree Training (VMD/PhD): key features of the program at the University of Pennsylvania

The Veterinary Medical Scientist Training Program (VMSTP), a combined degree program at the University of Pennsylvania School of Veterinary Medicine (Penn), has been in existence for approximately 35 years and has an excellent track record of producing veterinary physician-scientists. There are a number of key features of the program that I believe have been crucial to its success. Many of these features relate to how the PhD training component of the combined degree program is accomplished. Rather that describing the veterinary training component of the program, I will describe the PhD training component and how this training intersects with the veterinary curriculum. The key features of the VMSTP program at Penn are (1) admitting the right candidates, (2) placing the PhD training component of the program in the hands of individual graduate groups, (3) being committed to PhD training of veterinary students that is not compromised in terms of quality or time, (4) devising mechanisms to interdigitate VMD and PhD training to generate synergy between the programs, (5) providing continual advice to students from numerous perspectives, and (6) providing the monetary and emotional support needed for the long-term commitment students must make in order to complete the program.     

肉鸡日粮中赖氨酸与精氨酸适宜比例的研究

将２５０只１日龄健康肉用雏鸡随机分为五组,分别饲喂赖氨酸,精氨酸比例为１．４８：１,１．２２：１,１．１８,１：１．１４５和１：１．７５的玉米－豆粕型日粮。试验结果表明,不同Ｌ／Ａ比例对肉鸡的生产性能有显著影响。在美国ＮＲＣ推荐的需要量基础上提高日粮赖氨酸含量,将导致肉鸡生产性能下降;而提高精氨酸含量至需要量的１５０％,对肉鸡的生产性能无不良影响。     

Abundance of intestinal Na+/glucose cotransporter (SGLT1) in roe deer (Capreolus capreolus)

Introduction Based on morphological and physiological differences in their digestive systems H ofmann and S tewart (1972) classified ruminants into three feeding types: concentrate selectors (CS), grass and roughage eaters (GR) and intermediate, opportunistic, mixed feeders (IM). In evolutionary terms CS most closely resemble the original ruminants (H ofmann 1989). They have a relatively small forestomach with large openings between the different parts of the stomach. The retention time of ingesta is short and therefore less suited to optimizing cellulose digestion. They have relatively large saliva glands, producing high volumes of saliva (F ickel et al. 1998), which may facilitate the passage of soluble nutrients down their highly developed ventricular groove. The CS ruminants choose easily digestible forage, especially dicotyledons, which are rich in soluble plant cell contents (PCC, T ixier et al. 1997; D uncan et al. 1998). With evolution, the forestomach of the ruminants became larger relative to body size, and also more subdivided. These evolutionary adaptations optimized the selective retention of feed particles and increased retention time, leading to improvement of cellulose digestion. Large GR are well adapted to digest plant cell walls (PCW), i.e. structural carbohydrates (cellulose); they consequently feed mainly on monocotyledons. Roe deer (Capreolus capreolus) are very small ruminants which select concentrated feed. As energy requirements increase proportional to metabolic body weight (K leiber 1961) roe deer require relatively more energy per unit body mass for maintenance compared to that required by large ruminants (V an S oest 1994; D uncan et al. 1998). Easily digestible forage is not sufficient to satisfy the energy requirements of roe deer. It is proposed therefore that these animals may have other methods of avoiding energy losses due to microbial fermentation, either bypassing nutrients down the ventricular groove (rumen bypass) or by ruminal escape of unfermented and/or partially fermented nutrients (H ofmann 1989). The relatively high content of polyunsaturated fatty acids present in the depot fat of roe deer due to only partial rumen biohydrogenation (M eyer et al. 1998) supports the alternative hypothesis of rumen bypass or ruminal escape. Once reaching the small intestine, partially fermented or bypassed soluble carbohydrates can be further hydrolysed by maltase and sucrase to monosaccharides. These monosaccharides are then available for absorption. The intestinal sodium-dependent glucose cotransporter (SGLT1) in the brush border membrane (BBM) of the enterocytes is a stable indicator for the presence of sugars in the small intestine. The expression and activity of SGLT1 protein are regulated by the level of sugars reaching the small intestine (F erraris and D iamond 1989). Infusion of d -glucose into the intestinal lumen of ruminant sheep for 2 h stimulates the expression of SGLT1 which can be detected 4 days later in the newly formed mature enterocytes (S hirazi -B eechey et al. 1995). When dietary carbohydrate is removed, it takes 3 days before the brush border glucose uptake capacity decreases significantly from control values (F erraris 1994). This reflects the time of physiological cell renewal. In GR, such as sheep, the capacity of the intestine to absorb sugars decreases up to 500-fold during development (S hirazi -B eechey et al. 1995). This decrease in the intestinal absorptive capacity is a reflection of the decline in SGLT1 transport activity and protein abundance. It is not due to modifications in the structure of the absorptive surface and cannot be explained in terms of an age-related process (S hirazi -B eechey et al. 1991). It has been shown that there is a direct correlation between the level of monosaccharides reaching the lumen of the small intestine and the expression of functional SGLT1 protein (D yer et al. 1997). Therefore in this study we aimed to investigate the presence of functional SGLT1 in the small intestine of roe deer as a stable indicator of the availability of glucose in the luminal content of the small intestine. The presence of SGLT1 protein in the small intestine will support the hypothesis of rumen bypass and/or ruminal escape of nutrients. Furthermore we measured the maltase activities in the BBM, as part of the carbohydrates reach the intestinal lumen as polysaccharides and have to be broken down to monosaccharides before absorption.