R. Lederer

Pathology associated with endogenous development of haematozoa in birds from southeast Queensland

A study was undertaken on the pathology and associated schizont morphology of apicomplexan species of avian haematozoa. Some 32 birds from the families Artamidae, Meliphagidae, Oriolidae, Podargidae, Columbidae, Alcedinidae and Psittacidae were identified as having schizonts in various tissues. Based on blood stages observed, the probable relationship to tissue stages was considered. The majority of schizonts were referable to the genera Leucocytozoon and Haemoproteus. The comparative morphology of tissue stages previously described in the literature is discussed and the involvement of protozoa other than haematozoa considered. The naturally occurring infections in wild birds described in this study represent previously unreported data on the life-cycle stages involved. Some schizonts measured up to 640 μm. While pathological changes in some hosts were noticeable, in others no significant findings were observed. The role of endogenous stages in avian morbidity is discussed briefly.

Blood parasites of birds from south-east Queensland

Abstract A total of 3059 individual birds, presented as clinical cases to the Currumbin Wildlife Sanctuary, Gold Coast, Queensland, was examined for the presence of blood parasites at the International Reference Centre for Avian Haematozoa, Queensland Museum. Birds examined represent members of 40 families, 102 genera and 133 species, of these, 350 (11.4%) individuals were found to harbour one or more species of haematozoa. At least four new species of parasites have been identified. The highest occurrence of infection was found with species of Leucocytozoon (51.1% of infected birds), followed by Haemoproteus (31.4%). Plasmodium spp. occurred in 10.9% of birds examined but specific identity for this genus was limited because of the low levels of parasitaemia and a lack of developmental stages required to characterise each species. The information provided by this survey and those planned for other regions of Australia will be of significance to conservation strategies that involve captive breeding and translocation of endangered species of birds.

Pancreatic histopathology of diabetic Burmese and non-Burmese cats

Numerous genes of E. coli encode proteins putatively important to urovirulence,for example, adhesins and protectins. Human, canine, and feline urinary E. coli isolates have been characterized on the basis of their extended urovirulence genotypes in studies that typically test for the presence or absence of about 25 of these genes. It has been reported recently that extended urovirulence genotypes of canine and feline urinary E. coli isolates overlap with, and are essentially indistinguishable from, those of human strains that cause serious extraintestinal infections. On the basis of these and other phylogenetic findings, concern has been expressed that some canine and feline uropathogenic E. coli strains pose a significant human health hazard. However, very few canine isolates and even fewer feline isolates have been adequately studied to date.

Severe pathology associated with protozoal schizonts in two pied currawongs (Strepera graculina) from Queensland.

isolates from either source which shared complete phenotypic homology. A high degree of phenotypic diversity was obtained with 17 Preston biotypes observed in chickens aind 13 in human beings, with only two common types, that is, 6404 and 6000, as was the case with phage-typing. Given the heterogeneous subspecies characteristics of thermophilic campylobacters, coupled with the relatively small number of antibiotic-resistant isolates which were further characterised, following the initial screen of 400 isolates in this study, it remains uncertain as to the association between fluoroquinolone-resistant isolates from human beings and poultry. The prevalence of antibiotic-resistant organisms was similar in both the people and chickens, with the exception of a higher rate of tetracycline resistance in chickens (11 per cent v 4 per cent) (Table 1). In addition, fluoroquinolone resistance was higher in the human isolates than in animal isolates, for example, MIC9o for ciprofloxacin was more than 32 [tg/ml in human beings and 4 .tg/ml in chickens (Table 2). The higher level of fluoroquinolone resistance in human beings may suggest possible acquistion of campylobacters from another source, where fluoroquinolones are more frequently used than in poultry production, for example, with small animals and pets. Skirrow (1981) reported that a small proportion of human infections are acquired from dogs. Alternatively, the higher level of resistance in human isolates may reflect increased selective pressure originating from greater exposure from prescribing practices, as fluoroquinolone usage may be greater in human clinical practice than in veterinary practice. However, as person-to-person transmission of campylobacters is not a well-recognised route of transmission, coupled with the fact that most cases of human campylobacteriosis are not treated with fluoroquinolones, this is less likely. In conclusion, it is difficult to deduce the origins of fluoroquinolone resistance in campylobacters in this study and, hence, it is important not only to consider the impact of fluoroquinolone resistance from poultry but also from other animal sources, especially domestic pets, in addition to human sources.

A new species of Leucocytozoon Berestneff, 1904 (Apicomplexa: Leucocytozoidae) from the avian family Artamidae.

A new species of the apicomplexan genus LeucocytozoonBerestneff, 1904, L. artamidis n. sp., is described from the Australian avian family Artamidae. Gametocytes and endogenous stages of the life-cycle are described together with early erythrocytic and leucocytic developing forms rarely described for species of this genus.