Epitopes on the peplomer protein of infectious bronchitis virus strain M41 as defined by monoclonal antibodies.

Sixteen monoclonal antibodies (Mcabs) were prepared against infectious bronchitis virus strain M41, all of them reacting with the peplomer protein. One of them, Mcab 13, was able to neutralize the virus and to inhibit hemagglutination. Competition binding assays allowed the definition of five epitopes, designated as A, B, C, D, and E, of which epitopes A and B are overlapping. Furthermore, the binding of Mcab 13 (epitope E) could be enhanced by the addition of Mcabs from group B, C, and D. A dot immunoblot assay was used to analyze the effect of denaturation on antibody recognition

Campylobacter DNA Is Present in Circulating Myelomonocytic Cells of Healthy Persons and in Persons with Guillain-Barre´ Syndrome

Campylobacter jejuni is the prime cause of foodborne bacterial gastroenteritis. An important complication of C. jejuni enteritis is Guillain-Barre´ syndrome (GBS), an immune-mediated disorder of the peripheral nerve. The presence of C. jejuni DNA in peripheral blood mononuclear cells (PBMC) of patients with GBS, patients with C. jejuni enteritis, and healthy subjects was studied. Two target genes, the flagellin and the ceuE genes, were used for polymerase chain reaction (PCR) identification of Campylobacter species in DNA extracted from PBMC. Approximately 30% of the healthy subjects and 50% of the patients with GBS had PBMC containing C. jejuni DNA as verified by Southern blot analysis or sequencing of the PCR products. Cell sorting revealed that Campylobacter DNA was present in CD14+ and CD33+ populations, indicating that cells from the myelomonocytic lineage are the Campylobacter DNA–carrying cells. These findings show that Campylobacter DNA is present in blood cells of healthy humans, although viable bacteria could not be demonstrated