Bacterial growth in ampholytic disinfectant solutions.

Large numbers of live bacteria were isolated from solutions of 2 ampholytic disinfectants supplied from a built-in predosing system. They were resistant to and proliferated in these disinfectants. Bacteria were eradicated by employing a 3rd type of ampholytic disinfectant in the system.

A modified india-ink immunoreaction for the detection of encephalitozoonosis.

A modified india-ink immuno technique is described. The use of a moist chamber is not required and the visualisation of both positive and negative results facilitates more rapid and confident reading of the test.

Inhibition of bacteria in mouse drinking water by chlorination.

Experience with the use of mouse drinking water containing chlorine is discussed. With an initial concentration of 5 p.p.m. bacteria were recovered from the bottles after 7 days and there was considerable growth in untreated bottles. Above this concentration no bacteria survived. It is recommended that 15-20 p.p.m. chlorine are used for practical purposes.

India-ink immunoreaction for encephalitozoonosis: phototechnique.

We present photographs of an immunoreaction which has to be viewed as a vet preparation under highpower oil-immersion microscopy. The difficulties of varying focal plane and constant movement of the specimen were overcome by the use of electronic flash.

The indirect india-ink immunoreaction for detection of antibodies to Encephalitozoon cuniculi in rat and mouse serum.

The direct india-ink immunoreaction and the india-ink immunoreaction inhibition tests are described and results are compared with those obtained by the indirect fluorescence antibody test. Titrations of seropositive samples were made by 2 methods and the titres obtained were similar. Some advantages of the india-ink immunoreaction as a diagnostic test are discussed.

Humoral immune response to natural infection with Encephalitozoon cuniculi in rabbits.

Sera from 4 generations of a family of rabbits having a natural Encephalitozoon cuniculi infection were investigated. Antibodies were demonstrated in a litter of newborn rabbits and in another litter 11 days old. Histoloigcal examination of the brains and kidneys of these animals failed to reveal lesions attributable to the disease. Sera from a further litter of 2 rabbits, taken at weekly intervals from 4 to 42 weeks of age, revealed a low initial antibody titre which regressed to an undetectable level. After an interval, titres rose and then plateaued to the end of the period of observation. Encephalitozoon cuniculi infections in the dams of all the litters were confirmed by antibody assay and by histology. Parallel titration of samples treated and not treated with 2-mercaptoethanol showed that the india-ink immunoreaction demonstrates only immunoglobulin G.

Encephalitozoon cuniculi antibodies in a specific-pathogen-free rabbit unit.

We describe our discovery of Encephalitozoon cuniculi antibodies in a specific-pathogen-free rabbit colony. Small-sized samples had failed to reveal the presence of infection with a prevalence of about 5%. Using an India ink immunoreaction test by which we were able to visualize both negative and positive reactions, we were able to undertake a 100% screen of the colony of more than 700 rabbits and to repeat this 4 weeks later when we had culled the positive reactors. By collating the results of those tests with the results of tests on previously collected samples, we have been able to discuss and observe age and sex susceptibilities and the mode of transmission of the naturally occurring disease.