PubMed Health⌕ Search

Biomedical subjects

G Castrucci

Publications and source records attributed to G Castrucci.

At least 55 records · Page 3Linked to original sources
PubMed1986

A study of a herpesvirus isolated from dairy cattle with a history of reproductive disorders.

Three strains of herpesvirus were recovered from cows with vulvovaginitis. The three isolates (85/BH 16TV, 85/BH 17TV, 85/BH 18TV), when compared by cross serum neutralization (SN) tests, were found to be antigenically identical. They were serologically distinct from infectious bovine rhinotracheitis (IBR) virus and Bovid herpesvirus 2 (BHV2), while they cross reacted with bovine herpesvirus DN-599. Besides the serologic aspects, the three isolates appeared to share common biological, physical and morphological properties with the newly recognized bovine herpesviruses, of which DN-599 is a representative strain.

Animals↗
PubMed1985

A comparison of rotavirus strains of bovine, simian and porcine origin.

Three rotavirus strains of bovine, simian and porcine origin, respectively, were compared. The 3 viruses induced a classic rotaviral infection in newborn, conventionally reared calves. The cross neutralization tests revealed an antigenic identity of simian and porcine rotaviruses and a slight serologic correlation of these two viruses with the bovine rotavirus strain. However, in reciprocal cross protection tests carried out in calves, the simian rotavirus antiserum afforded weak protection to challenge infection with either the porcine or the bovine viruses. By contrast, the protective level of the bovine and the porcine rotavirus antisera was relatively high. It was speculated that the 81/36F bovine rotavirus could be considered, tentatively, as an antigenic reassortant rotavirus strain.

Animals↗
PubMed1984

Comparative studies of strains of infectious bovine rhinotracheitis virus isolated from latently infected calves.

Three strains (479 C, 778 TL, 982 LE) of infectious bovine rhinotracheitis (IBR) virus isolated from latently infected calves were compared with the prototype strain of IBR virus (LA strain) in studies which included restriction endonuclease analysis, experimental infection, and reciprocal cross protection tests in cattle. From the restriction endonuclease analysis it appeared that the 3 "latent" viruses were derived from the same isolate, and that it differed slightly from the LA strain. However, latency does not seem to have affected the pathogenicity or the immunogenicity of the virus. This is demonstrated by the identical clinical and virologic response of calves subjected to experimental infection with the various strains under study, and by the finding that when the LA strain and a "latent" strain (982 LE) were tested in cross protection tests in cattle, they proved to be mutually protective.

Animals↗
PubMed1984

The efficacy of colostrum from cows vaccinated with rotavirus in protecting calves to experimentally induced rotavirus infection.

Calves which were continuously fed colostrum from vaccinated cows for the first ten days of life, were fully refractory to experimental infection with strain 81/36 F of bovine rotavirus. By contrast, the response to virus exposure of calves which were treated with normal colostrum was identical to that of the control calves, in that they underwent severe diarrhea and a significant slowing of the growth rate. The antibody titer in the milk of vaccinated cows tends to decline rapidly so that it no longer provides any protective effect. Two alternatives were considered feasible in improving prophylaxis for rotavirus infections: (a) the continuous feeding of calves with 1st day colostrum as part of the ration throughout the period of greatest risk (first week of life), or (b) enhancing the efficacy of the vaccine in pregnant cows to the point where antibody concentration in the milk would remain at a protective level.

Animals↗
PubMed1984

A serologic survey of bovine rotavirus infection in Italy.

Serum neutralization tests conducted by microtiter procedure on 2970 serum samples from calves, heifers and adult cows from representative regions of Italy indicate that rotaviruses, and the infection which they cause, existed in Italy long before the virus was isolated. At the present time the infection is distributed fairly uniformly throughout the cattle population with both sexes and all age groups being equally susceptible.

Animals↗
PubMed1984

Comparative study of rotavirus strains of bovine and rabbit origin.

Newborn calves were susceptible to infection with a rotavirus strain isolated from rabbits and, conversely, rabbits 4-5 weeks of age became ill and some died when inoculated with the rotavirus strain of bovine origin. However, the latter isolate appeared to be more virulent than the rabbit isolate in either calves or rabbits. Moreover, in reciprocal cross protection tests, carried out in calves and in rabbits, the rabbit rotavirus antiserum afforded only weak protection to challenge infection with either the homologous or the heterologous virus. By contrast, the protective level of the bovine rotavirus antiserum was relatively high.

Animals↗
PubMed1984

Response of calves previously inoculated with inactivated herpes simplex virus to challenge exposure with Bovid herpesvirus 2.

Concentrated antigen of Herpes simplex virus (HSV) types 1 and 2, previously inactivated with Triton 100X, were inoculated into calves. Thirty-two days later the calves were challenge exposed either by the intradermal or the intravenous route with Bovid herpesvirus 2 (BHV 2). The HSV-immune calves responded to BHV 2 infection with clinical signs which were much less severe that those observed in the challenge control calves. The skin lesions in the calves exposed to intravenous inoculation of BHV 2, were fewer in the calves in the HSV-immune group, whereas they were heavily disseminated, covering the skin of the entire body, in the control calves. In the case of calves which received BHV 2 intradermally, the titer of the virus underwent a reduction of more than one log unit in the pre-immunized calves. The most significant serologic finding was that the HSV-preimmunized calves produced antibody to the BHV 2 challenge virus at an earlier time than did the control calves. The immunologic relationship between BHV 2 and HSV was confirmed by the results of this study.

Animals↗
PubMed1983

Reactivation of Bovid herpesvirus 1 and 2 and parainfluenza-3 virus in calves latently infected.

Two experiments were carried out to determine whether Bovid herpesvirus (BHV) 2 is able to induce a recurrent infection in experimentally infected calves. In the first experiment the stress induced by dexamethasone (DMS) treatment failed to reactivate the clinical condition or to induce shedding of BHV2. However, treatment with DMS reactivated a latent BHV1 infection in all calves previously inoculated with BHV2 and also in two noninoculated controls. Probably, because of the interference by BHV1 the study failed to resolve the question as to whether BHV2 could induce a recurrent infection. Consequently, a second experiment was performed using calves devoid of antibody to BHV1 and, therefore, probably, free of virus. By this study it was demonstrated that BHV2 can remain as a latent infection in cattle, which, when immunosuppressed as with DMS, can be reactivated. A finding of considerable interest in this experiment was that in 1 calf a concurrent piroplasma infection was also, unexpectedly, discovered. Recrudescence of latent BHV1 infection was induced by DMS treatment of calves possessing antibody to the virus. The infection once reactivated, was readily transmitted by contact to three other calves devoid of antibody to BHV1. In the same experiment Parainfluenza-3 (PI-3) virus was unexpectedly isolated from all calves. It was speculated that all calves were latently infected with PI-3 virus with concurrent infection by HBV1 acting as a stress inducing PI-3 reactivation. These studies seem to indicate that mixed infections could have an important role in the mechanism involved in the establishment of latent infections and viral reactivation.

Animals↗
PubMed1983

A study of cytopathic rotavirus strains isolated from calves with acute enteritis.

Nine cytopathic bovine rotavirus strains were isolated in MA-104 cell cultures from fecal specimens of dairy calves suffering from diarrhea. Isolation of the virus was accomplished from three outbreaks which occurred on dairy farms located in Central and Southern Italy. Fecal suspensions were treated with a high concentration (1000 micrograms/ml) of trypsin, and inoculated into MA-104 cell cultures grown out in Eagle's minimum essential medium (MEM) containing 5 micrograms/ml of the enzyme. Cytopathic effects (CPE), characterized by intracytoplasmic inclusion bodies of different sizes and shapes, were observed on the 1st passage with five of the strains and on the 2nd (2 strains) or the 3rd (2 strains) passage for the others. The presence of trypsin and the use of MA-104 cells appeared to be essential for the occurrence of CPE, inasmuch as no CPE was detected when trypsin was omitted in the MA-104 cell system. Replication failed to occur when primary bovine embryo kidney cell cultures with or without trypsin were used. Electron microscopy revealed the presence of particles with a typical rotavirus morphology. In MA-104 cells, the titre of virus reached its maximum 48 hr after inoculation. Small, clear-cut plaques were produced by the isolates in MA-104 cells under the overlay of MEM containing carboxymethyl cellulose, trypsin and DEAE-dextran. The nine rotavirus strains were antigenically related, whereas the relationship to either the Nebraska or the Compton rotaviruses was quite weak.

Acute Disease↗
PubMed1983

Experimental infection and cross protection tests in calves with cytopathic strains of bovine rotavirus.

Four cytopathic strains (81/32F, 81/36F, 81/40F, 82/80F) of bovine rotavirus were shown to be pathogenic for conventionally reared newborn calves. Calves were infected orally, using 3 calves for each isolate. All became febrile, were depressed and diarrhoeic. Two calves, one of which in the group of those infected with 81/36F isolate, and the other infected with strain 81/40F, were killed when moribund. A 3rd calf from the 81/36F infected group, died. At necropsy localized lesions of the small intestines, which are considered to be typical of rotavirus infection, were found. Virus was consistently isolated from the fecal samples of the inoculated calves up to 13 days post-inoculation. It was speculated that some differences existed in the virulence of the bovine rotaviruses tested. The cross protection tests revealed that 1 strain (81/36F) might be antigenically more complex than the others.

Animals↗