Latent equid herpesviruses 1 and 4: detection and distinction using the polymerase chain reaction and co-cultivation from lymphoid tissues.
The polymerase chain reaction (PCR) and co-cultivation were used to identify the lymphoreticular system as the site of latency of equid herpesvirus I (EHV-1). Primers for PCR were designed from aligned nucleotide sequences of the glycoprotein gB genes to amplify the same region of both the EHV-1 and EHV-4 genomes. Subsequent restriction digests using specific enzymes distinguished the amplified fragments of the EHV-1 genome from those of the EHV-4 genome. Ten weeks following an experimental infection of five ponies with EHV-1, latent virus was detected by PCR and recovered by co-cultivation, predominantly from lymphoid tissues draining the respiratory tract. Significantly, latent EHV-1 also persisted in peripheral blood leukocytes (PBL). Latent EHV-4, presumably from a preceding natural infection, was also detected in some tissues, including PBL, from all animals. Of additional interest was the recovery of EHV-1 and -4 only in the presence of the ubiquitous EHV-2.
Royal Veterinary College, London, U.K.
H M
HM
Welch
C G
CG
Bridges
A M
AM
Lyon
L
L
Griffiths
N
N
Edington
D000208:Acute Disease; D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D006564:Herpesviridae / Q000235:genetics / Q000302:isolation & purification*; D006566:Herpesviridae Infections / Q000382:microbiology / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000235:genetics / Q000302:isolation & purification*; D006734:Horse Diseases / Q000382:microbiology*; D006736:Horses; D007962:Leukocytes / Q000382:microbiology; D008221:Lymphoid Tissue / Q000382:microbiology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012137:Respiratory System / Q000382:microbiology; D015183:Restriction Mapping
D004279:DNA, Viral