Response of some strains of Newcastle disease and fowl-plague viruses to two quinones

Summary Comparative studies of the response of some Egyptian strains of Newcastle disease and fowl-plague viruses to tolu- and thymoquinones revealed that the two quinones appreciably reduced the infectivity, but not the hemagglutinative powers of the virus strains, toluquinone being more effective in this respect than thymoquinone. The different viruses or virus strains responded differently to the two quinones.     

Effect of some chemicals on the hemagglutination activities and infectivity to chick embryos of different strains of Newcastle disease and fowl-plague viruses

Summary Crystal violet in concentrations above 100 p.p.m. induced appreciable inhibition of the hemagglutination and infectivity powers of the various strains of Newcastle disease and fowl-plague viruses being tested.     

Effect of some chemicals on the hemagglutination activities and infectivity to chick embryos of different strains of Newcastle disease and fowl-plague viruses

Summary Ascorbic acid reduced the agglutination activities of the various strains of Newcastle disease and fowl-plague viruses used but was in-effective with respects to their infectivity powers.     

Effect of different strains of newcastle disease and fowl-plague viruses on a group of sulphonphthalein dyes

Summary Strains of fowl-plague or Newcastle disease viruses may be easily separated by examining the rate of discharge of certain dyes of the sulphonphthalein group when inoculated with each virus strain into the allantoic fluid of chick embryos.     

Genotypic and pathotypic characterization of Newcastle disease viruses from India

Newcastle disease virus (NDV) is an avian paramyxovirus that causes significant economic losses to the poultry industry in most parts of the world. The susceptibility of a wide variety of avian species coupled with synanthropic bird reservoirs has contributed to the vast genomic diversity of this virus as well as diagnostic failures. Since the first panzootic in 1926, Newcastle disease (ND) became enzootic in India with recurrent outbreaks in multiple avian species. The genetic characteristics of circulating strains in India, however, are largely unknown. To understand the nature of NDV genotypes in India, we characterized two representative strains isolated 13 years apart from a chicken and a pigeon by complete genome sequence analysis and pathotyping. The viruses were characterized as velogenic by pathogenicity indices devised to distinguish these strains. The genome length was 15,186 nucleotides (nt) and consisted of six non-overlapping genes, with conserved and complementary 3' leader and 5' trailer regions, conserved gene starts, gene stops, and intergenic sequences similar to those in avian paramyxovirus 1 (APMV-1) strains. Matrix gene sequence analysis grouped the pigeon isolate with APMV-1 strains. Phylogeny based on the fusion (F), and hemagglutinin (HN) genes and complete genome sequence grouped these viruses into genotype IV. Genotype IV strains are considered to have "died out" after the first panzootic (1926-1960) of ND. But, our results suggest that there is persistence of genotype IV strains in India.     

Antigenic variation of Newcastle disease viruses isolated from wild ducks in Japan

Nineteen strains of Newcastle disease virus (NDV) isolated from wild ducks in Japan were placed into 4 distinct antigenic groups on the basis of their reactivities to 8 monoclonal antibodies against the HN molecule of NDV in hemagglutination inhibition tests. The NDV strains of duck origin were antigenically distinct from NDV-B1 and NDV-Miyadera originated from chickens, and varied in their virulence to chicken embryos. No apparent correlation was found between the antigenicity of the HN molecule and virulence.     

Resistance patterns to various organophosphorus insecticides in some strains of houseflies

The susceptibility of one susceptible and six resistant strains of houseflies to 13 organophosphorus compounds was measured with a contact method. Five of the strains had been selected, both in the field and in the laboratory, with diazinon, parathion or malathion. One strain had been strongly selected with -BHC. The susceptibility of the strains is shown in Fig. 1. The BHC selected strain had only a low level of resistance to organophosphates. Higher levels were present in all organophosphate selected strains, each of which exhibited its own characteristic resistance pattern. This indicates that a relatively large number of resistance mechanisms may be present.As resistance to the thiophosphates is of the same order of magnitude as that to their oxygen analogues, it follows that the resistance mechanism is not a slower conversion of the thiophosphates into the phosphates. Resistance to a number of dimethyl compounds is low, and little difference is present between the resistant strains. This resistance is probably brought about mainly by less specific factors. The genetical basis of the low aliesterase content of the phosphate resistant strains is discussed.

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Zusammenfassung Die Empfindlichkeit eines normal-sensiblen und von sechs resistenten Stubenfliegen-Stämmen gegenüber 13 organischen Phosphorverbindungen wurde mit Hilfe einer Kontakt-Methode gemessen. Fünf dieser Stämme waren sowohl im Freiem wie auch im Labor, mit Diazinon, Parathion oder Malathion selektiert worden. Ein Stamm war stark mit -BHC selektiert worden. Die Empfindlichkeit der Stämme ist in Fig. 1 dargestellt. Der mit -BHC selektierte Stamm wies nur eine niedrige Resistenz gegenüber den organischen Phosphorverbindungen auf. Höhere Resistenz wurde in den mit organischen Phosphorverbindungen selektierten Stämmen gefunden; jeder dieser Stämmen zeigte eine eigene, charakteristische Form der Resistenz. Dies deutet darauf hin, daß eine relativ grössere Zahl von Resistenz-mechanismen vorhanden ist.Aus der Tatsache, daß Resistenz gegen die Thioverbindungen und ihre entsprechenden Sauerstoff-Analoge ungefähr gleich groß ist, wird geschlossen, daß eine langsamere Umwandlung in die Phosphate als Resistenz-mechanismus nicht in Betracht kommen kann.Die Resistenz gegenüber einigen Methyl-verbindungen ist gering, und in den einzelnen Stämmen nur wenig verschieden. Diese Resistenz wird wahrscheinlich durch weniger spezifisische Faktoren verursacht. Die genetische Grundlage des niedrigen Ali-esterasen-gehalts in den Phosphat-resistenten Stämmen wird diskutiert.