"phiKZ-like viruses", a proposed new genus of myovirus bacteriophages.

The proposed phiKZ genus of myoviruses has 21 members. Phages are virulent, lyse Pseudomonas bacteria, and are characterized by very large heads and correspondingly high DNA contents. The genome of the type virus, phiKZ, has 306 ORFs and over 280 kbp and is the second-largest phage genome known. The phiKZ genus has very few relationships to other phages and includes three species and one possible species.

Hand contamination with hepatitis C virus in staff looking after hepatitis C-positive hemodialysis patients.

BACKGROUND: Hepatitis C virus (HCV) is a major cause of hepatitis in hemodialysis (HD) patients. Routes other than blood transfusion play a role in the spread of HCV in HD patients. Molecular studies of HCV implicate nosocomial transmission of the virus in HD units. We conducted a clinicovirological study in our HD unit to investigate if the hands of dialysis personnel could represent a mode of transmission of HCV among HD patients. METHODS: One liter of sterile water was used for each handwashing of dialysis personnel. The washing was collected in a sterile container and tested for HCV-RNA by polymerase chain reaction (PCR) within 3 h of collection. Eighty handwashings from nurses dialyzing HCV-positive patients (groupe A) and 100 handwashing from nurses dialyzing HCV-negative patients (group B) were tested for HCV-RNA. As a control, 60 handwashings were collected from the dialysis personnel before entering the dialysis unit (group C) and tested for HCV-RNA. RESULTS: HCV-RNA was positive in 19 (23.75%) of samples of group A, in 8 (8%) of samples of group B (p < 0.003) and in 2 (3.3%) of samples of group C (p < 0. 35). These two positive samples of group C were from nurses who had dialyzed HCV-negative patients. CONCLUSION: These results indicate the presence of HCV-RNA on the hands of some dialysis personnel in our HD unit, in spite fo adherence to the standard precautions. The hands of dialysis personnel are therefore a potential mode for facilitating transmission of HCV between HD patients.

Processing of envelope polypeptides of herpes simplex virus type 1. Demonstration of variation in different cell lines by high-performance liquid chromatography and radioimmunoprecipitation.

[35S]Methionine-labelled envelope polypeptides of herpes simplex virus type 1, strain F, propagated in mammalian cell culture of various origins, were separated by ion-exchange high-performance liquid chromatography on a TSK DEAE-3SW column. Analysis of the fractions by radioimmunoprecipitation followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis of the immunoprecipitates showed similarities as well as distinct differences in the number, migration patterns and molecular mass of the synthesized polypeptides, depending on the host cell. The results show that this method can be used to demonstrate species-specific or organ-specific differences in the processing of virus-specified polypeptides synthesized in host cells.

Development of a live cell culture camelpox vaccine.

A Saudi isolate of camel orthopoxvirus was serially propagated on monolayers of camel kidney cell cultures. The attenuation of the 78th passage was tested in two susceptible camels. Two other susceptible camels were inoculated with vaccinia virus four times propagated in camel kidney cell cultures. The four inoculated camels showed no postinoculation clinical symptoms and formed neutralizing antibodies against both the camel orthopox and vaccinia viruses. No postchallenge clinical symptoms were observed in these four camels, while two non-inoculated contact control camels showed typical symptoms of generalized camelpox. These results indicated the safety and potency of the 78th passage of the Saudi isolate of camel orthopoxvirus (designated Jouf-78) to be used for production of live attenuated cell culture camelpox vaccine. The field testing of the vaccine was carried out on two farms using at least 10(3) TCID50 as a recommended field dose. None of the inoculated camels showed any postvaccination reaction and the serological tests showed seroconversion of many vaccinated field camels. The relationship between camel orthopoxvirus and vaccinia virus as well as the advantages of the live attenuated camelpox vaccine are discussed.

Preliminary studies on enzootic bovine leukosis in Saudi dairy farms.

The occurrence of sporadic cases of enzootic bovine leukosis in commercial dairy farms in Saudi Arabia was recently confirmed and found to be associated with importation of breeding heifers. Immunodiffusion test was applied to screen the prevalence of infection with bovine leukemia virus among local traditional and dairy cattle. All the 102 examined local cattle were negative, while out of the 1329 tested dairy animals (originating from 23 farms), 268 (from 16 farms) showed precipitating activity. As an epizootiological model, all animals of an infected dairy farm were serologically examined. Out of the 560 originally imported cows and the 1849 animals born locally in the farm, 217 (39%) and 468 (25%) animals, respectively, were found positive. The correlation between the age of locally born animals and the occurrence of antibodies against bovine leukemia virus was discussed.