Uninfected Eggs Research Articles

Some effects of parasitism by Babesia caballi on the tropical horse tick, Dermacentor (= Anocentor) nitens

Studies of the tropical horse tick, Dermacentor (= Anocentor) nitens, infected with Babesia caballi showed that this protozoan parasite, a causal agent of equine piroplasmosis, is also a pathogen of its vector. In all tests, some infected ticks died 7–10 days after repletion and did not lay eggs. Also infected engorged females weighed less than uninfected engorged females and produced fewer eggs than uninfected females. Mortality occurred regularly in infected eggs though only rarely in uninfected eggs. Thus, the longevity of engorged females and the reproductive potential of D. nitens is reduced by infections of B. caballi.

Effect of interferon on deoxyribonuclease induction in chick fibroblast cultures infected with cowpox virus.

An exonuclease which degrades native deoxyribonucleic acid at pH 9.2 was induced in chick embryo fibroblast cultures and in human amnion cells by infection with cowpox virus. Highly purified chick embryo interferon suppressed the induction of the enzyme in the homologous cell system but not in the human amnion cell cultures. "Mock" interferon prepared from uninfected chicken eggs and purified in the same manner as biologically active interferon preparations had no effect on the induction of the enzyme.

Studies on the physiology of Rickettsiae. IV. Folic acids of Coxiella burnetii.

Mattheis, Martha S. (University of Kansas, Lawrence), M. Silverman, and D. Paretsky. Studies on the physiology of rickettsiae. IV. Folic acids of Coxiella burnetii. J. Bacteriol. 85:37-41. 1963.-Yolk, yolk sac, and embryo tissues of uninfected eggs, and those infected with Coxiella burnetii, were analyzed for folic acid derivatives by employing diethylaminoethyl (DEAE)-cellulose column chromatography. Infected tissues contained quantitatively less folate, but the elution profiles of both infected and uninfected tissues were identical. Purified C. burnetii contained some types of folate apparently unique to these rickettsiae, and not found in infected tissue. The major folate fraction of C. burnetii was partially characterized by (i) elution position from DEAE columns; (ii) treatment with conjugase; (iii) growth response by Lactobacillus casei, Streptococcus faecalis R, and Pediococcus cerevisiae; and (iv) response to oxidation, reduction, and formylation.

Effect of Dipping Eggs in Antibiotic Solutions on PPLO Transmission in Chickens

FFORTS by the authors2 to eliminate pleuropneumonialike organisms (PPLO) from eggs by treating infected hens failed to corroborate reports of successful results by others. The possibility that fertile hens' eggs infected with PPLO might be treated effectively by immersing them in antibiotic solutions appeared to be a more promising approach in the control of chronic respiratory disease (CRD). At the instigation of the senior author, three laboratory trials were done wherein moderate or small PPLO inoculums injected into the fresh yolk of uninfected fertile eggs previously dipped in antibiotics, failed to grow when the yolks were cultured after three weeks of incubation. The untreated eggs and the eggs with the heavier inoculums did yield the organism on culture.1 These encouraging results prompted further laboratory and field studies.

Application of the Immunofluorescent Technique in Testing the Purity of Sendai Virus

The fluorescent spot technique was developed so that the flocculation reaction between viral particles and antibodies could be seen quickly and simply on a glass slide. This technique was readily available for testing the purity of the Sendai virus during its purification. Immune serum prepared against normal sedimentable material of uninfected eggs was particularly useful to test for the presence of host components in purified viral suspensions. A highly purified fraction of high HA titer obtained by adsorption on, and elution from aluminum phosphate gel, was shown by this spot technique to be almost free from normal components. When such a purified preparation was used for HAI titration, the antibody titer was low because of the increased viral antigenic surface around the particles. The hemolytic properties known to be associated with Sendai virus were also reduced in such a purified preparation.

Inhibition of the cytochrome reductase activity associated with meningopneumonitis virus by fatty acids derived from infected allantoic fluids

A soluble lipoprotein occurs in the allantoic fluids of eggs infected with meningopneumonitis virus, the lipid portion of which consists largely of triglyceride. A similar substance is sometimes found, usually in much lower concentration, in the allantoic fluids of uninfected eggs. On treatment of crude infected allantoic fluids or of the isolated lipoprotein with pancreation, fatty acids are liberated and these inhibit the DPNH cytochrome c reductase activity associated with the purified virus. The inhibition is in part due to an effect of the fatty acid on the virus and in part to an effect on the cytochrome c. A virus-fatty acid mixture that appears to have lost most of its enzymatic activity can recover a part of the lost activity if serum albumin is added.

INFLUENZA

In addition to the cycles of growth shown by the influenza A virus during the first 24 hours of its residence in the fertile egg, cycles separated by longer time intervals have been noted between the 24th and 96th hours. These longer cycles are best seen when the eggs are incubated at 40 degrees C. Corresponding fairly accurately with these cycles of growth of the virus, wide cyclic variations in the rates of increase in oxygen consumption of the infected eggs have been found to occur. These variations are in striking contrast to the uniformity of increase noted in uninfected eggs. The variations in infectivity may be caused by periodic interference with virus multiplication by accumulated inactive virus particles. The variations in oxygen consumption probably are correlated with variations in the concentration of virus toxins.

Difference in Composition of the Allantoic Fluids of Eggs Infected with Virus and that of Normal Eggs

EARLY in the course of an investigation by the method of electrophoresis of Polson1 of the allantoic cavity fluid collected from developing chick embryos infected with different viruses by various routes, it was apparent that there is a marked difference between the fluid obtained from infected eggs and that from uninfected fertile eggs incubated in forced-draught incubators under identical conditions of temperature, humidity and time.

The Invasion of Helminth Eggs by Chytridiacean Fungi

The material forming the basis of this paper consists of the two fungi, Catenaria anguillulæ Sorokin and Rhizophidium carpophilum Zopf, which were found parasitic on the eggs of Dibothriocephalus latus in the Helminthology Department in March, 1927. The stool containing the eggs had been washed in laboratory tap water and this was evidently the vehicle of the fungus infection. A sediment obtained from one of the water tanks from which the laboratory is supplied was found to contain infusoria, rotifers and other forms likely to act as hosts for the fungi, and that this was the source of the original infection was proved on more than one occasion by placing some of the sediment in a petri dish along with some uninfected eggs of D. latus, when a new infection of both the fungi appeared in the eggs.In the following paper the fungi are described and an account is given of some experimental work that was carried out with a view to determining the possibility of employing such parasites as a control measure in helminthiasis.