Christine O. Dawson

The perfect states of Keratinomyces ajelloi van-Breuseghem, Trichophyton terrestre Durie & Frey and Microsporum nanum Fuentes

During investigations of soil samples from various districts in the West of Scotland using Vanbreuseghems (1952) hair-bait method, Keratinomyces ajelloi, Trichophyton terrestre, Microsporum gypseum and Arthroderma curreyi were isolated. These fungi, and Microsporum nanum isolated from ringworm-infected pigs in Kenya, have been studied in culture on unsterilised soil. Descriptions are given of the perfect stages of K. ajelloi and M. nanum which were obtained in soil culture and that of T. terrestre which arose spontaneously in an agar slope culture. It is proposed that the perfect forms of K. ajelloi and T. terrestre be included in the genus Arthroderma Currey as A. uncinatum sp. nov. and A. quadrifidum sp. nov. respectively, and that the perfect form of M. nanum be put in the genus Nannizzia Stockdale as N. obtusa sp. nov.

Environmental conditions affecting sexual reproduction in species of Arthroderma and Nannizzia

A report is given of laboratory studies on the conditions affecting sexual reproduction of certain keratinophilic fungi cultured on keratinous bait on soil. It is shown that the type of soil used as substrate is not critical but that results are less satisfactory if it is in a sterile condition. The type of keratin bait is important, horse mane or tail hair being very satisfactory and adult human hair unsatisfactory for most keratinophilic fungi. Temperature is also important and the optimum range varies with the species.

Precipitins to Micropolyspora faeni in the adult cattle of selected herds in Scotland and north‐west England

Sera from all housed adult cattle in twelve herds were examined for precipitating antibody to Micropolyspora faeni at the beginning of winter and approximately 5 months later in the spring; during this time they had been fed hay. Six of these herds were owned by farmers with farmers lung. The average incidence of precipitins was 33% on the first occasion and 47% on the second occasion. After the winter there was a statistically significant increase in the number of animals with precipitins in five herds. A positive correlation was shown between the incidence of precipitins and age.

Two new species of Arthroderma isolated from soil from rabbit burrows

Two hitherto unknown keratinophilic fungi were isolated, using Vanbreuseghems hair bait technique (1952), from soil samples collected from rabbit burrows and were also obtained from the hair of wild rabbits. The fungi are heterothallic and form their perfect states on keratinaceous bait on soil. According to the morphology of their cleistothecia they belong to the genus Arthroderma and are named A. cuniculi sp. nov. and A. multifidum sp. nov.

Peyronellaea glomerata infection of the ear pinna in goats

The isolation of Peyronellaea glomerata from lesions on the pinnae of the ears of goats is reported and, for the first time in the veterinary field, histopathological evidence is presented implicating this fungus as the cause of a pathological condition.

Farmer's lung: a comparison of simple diagnostic techniques and antigen preparation in human and bovine disease

The detection of precipitins to Micropolyspora faeni antigens by simple serological techniques was studied with human and bovine sera. We present data on the relative sensitivities of two gel‐diffusion tests, one large‐scale, the other using semi‐micro methods to conserve antigen in the diagnosis of human and bovine disease. Eight antigenic preparations of M. faeni are described, together with the detailed serology of eight human cases of farmers lung. The results indicate that the use of more than one antigenic preparation is necessary in any screening programme for the detection of precipitins to M. faeni in either the human or bovine disease.

Identification of Candida albicans in primary culture.

A new technique is described for direct inoculation of swabs from suspected cases of candidiasis. It enables Candida albicans to be identified (usually within 24 hrs.) by inspection of the primary culture for chlamydospores. The medium used is Czapek Dox (Oxoid) agar which has not previously been reported to induce chlamydospore formation by C. albicans.

Studies on the incidence and titres of precipitating antibody to Micropolyspora faeni in sera from adult cattle

Abstract Over 2 consecutive years, serum samples, taken in autumn and spring from all housed adult cattle in 16 herds, were examined for the presence and amount of precipitating antibody to Micropolyspora faeni. Exposure to the allergen over the winter months resulted in a rise in the number of cattle with antibody and in the serum titres. Over the summer the number of positive cattle and titres fell but this period of non-exposure was insufficient to restore some of the herds to their original state, showing that the effects of exposure can be cumulative from one year to the next. Studies on paired serum samples clarified the seasonal changes in antibody in herds and showed the importance of titre in determining whether antibody is liable to be retained over the summer. Some measure of the amount of exposure to which a herd has been subjected can be obtained from the percentage of positive cattle and the titres of the sera. From this data it is also possible to identify herds liable to be at risk if subjected to further heavy exposure. Culling of high titre animals in such herds is suggested as a possible control measure.

The prevalence of serum precipitating antibody to Aspergillus fumigatus in adult cattle in Britain

The prevalence of precipitating antibody to A. fumigatus in 3509 sera from adult cattle in 44 herds was 25 per cent. Only 19 per cent of sera from grazing or recently housed animals were positive compared with 30 per cent of those taken towards the end of the winter. Mouldy hay was the most likely source of A. fumigatus antigens although a positive correlation between the prevalence of precipitins and either the mouldiness of the hay or the frequency of coughing in the springtime was not established. However, there was a positive correlation between the age of cattle sampled and the prevalence of antibodies. Mycotic abortion had been confirmed in only one of 6 herds in which more than 80 per cent of the cows were seropositive and so it can be inferred that the presence of serum precipitating antibody is of very little value in the diagnosis of mycotic abortion resulting from A. fumigatus infection.