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The complete nucleotide sequence and organization of the Yersinia enterocolitica serotype 0:8 low-calciumresponse (LCR) plasmid, pYVe8081, were determined. The 67,720-bp plasmid encoded all the genes known to be part of the LCR stimulon except for ylpA. Eight of 13 intact open reading frames of unknown function identified in pYVe8081 had homologues in Yersinia pestis plasmid pCD1 or in Y. enterocolitica serotype 0:9 plasmid pYVe227. A region of approximately 17 kbp showed no DNA identity to pCD1 or pYVe227 and contained six potential new genes, a possible new replicon, and two intact insertion sequence (IS) elements. One intact IS element, ISYen1, was a new IS belonging to the IS256 family. Several vestigial IS elements appeared different from the IS distribution seen in the other LCR plasmids. The RepA proteins encoded by Y. enterocolitica serotype 0:8 pYVeWA and pYVe8081 were identical. The putative pYVe8081 replicon showed significant homology to the IncL/M replicon of pMU407.1 but was only distantly related to the replicons of pCD1 and pYVe227. In contrast, the putative partitioning genes of pYVe8081 showed 97% DNA identity to the spy/sopABC loci of pCD1 and pYVe227. Sequence analysis suggests that Yersinia LCR plasmids are from a common ancestor but that Y. enterocolitica serotype 0:8 plasmid replicons may have evolved independently via cointegrate formation following a transposition event. The change in replicon structure is predicted to change the incompatibility properties of Y. enterocolitica serotype 0:8 plasmids from those of Y. enterocolitica serotype 0:9 and Y. pestis LCR plasmids.Pathogenic Yersinia enterocolitica is a well-established foodborne pathogen (29). Infection usually results in a self-limiting gastroenteritis, but in immunocompromised individuals septicemia and hepatic abscesses may occur. Postinfection complications include arthritis and erythema nodosum (8). Y. enterocolitica is a serologically diverse species that includes saprophytes as well as pathogens. Certain serotypes are consistently associated with human infection (30). Serotypes 0:3 and 0:9 are most frequently isolated in Europe, Japan, and Canada, while serotype 0:8 causes most infections in the United States. Serotype 0:8 is also associated with more severe invasive disease (3, 5). So far, only one phenotypic trait has been identified in Y. enterocolitica 0:8 to account for these observed differences in pathogenicity (37).Essential virulence genes are carried on a ca.-70-kb plasmid in Y. enterocolitica, Yersinia pestis, and Yersinia pseudotuberculosis (42, 43). The virulence plasmid encodes virulence proteins called Yops (Yersinia outer proteins), a type III secretion system, the V antigen, and regulatory proteins. The virulence plasmid encodes the low-calcium response (LCR) (53), which refers to a complex response to in vitro growth conditions of temperature (37°C) and extracellular calcium concentration (less than 2.5 mM Ca 2ϩ ). Under these conditions, pathogenic Yersinia shifts from vegetative growth to the production a...

Abstract. Hepatitis E, which is enterically transmitted, is the most common cause of acute hepatitis in much of Asia. Phylogenetic analysis of several isolates of hepatitis E virus (HEV) from Asia suggests that transmission of this virus is geographically restricted. In Sarghoda, Pakistan, HEV Sar-55 was isolated from a 1987 outbreak. It belongs to the Central-Asian cluster of the Asian sub-genotype. We now report the complete sequence of a second Pakistan HEV from a 1988 outbreak in Abbottabad. The Abbottabad nucleotide sequence was compared with 15 other complete HEV sequences using statistical methods of phylogenetic analysis. The analysis showed that Abbottabad HEV belongs to the South Asia cluster of the Asian sub-genotype. The sequence differences of the 2 Pakistan isolates recovered only one year apart suggest that HEV of 2 distinct origins circulate in Pakistan.

Brucella group 3 antigens (Ags) are outer membrane proteins (OMPs) with a molecular mass ranging from 25 to 30 kDa. The OMPs are of interest partially because of their potential use as vaccine and diagnostic reagents. We used human convalescent antibody (Ab) to clone a gene that encoded a 28-kDa protein from a gt11 library of Brucella melitensis 16M genomic DNA. DNA sequence analysis revealed a single open reading frame that would encode a protein of 26,552 Da. The 28-kDa protein had a primary amino acid sequence that was 43% similar to a previously described Brucella abortus group 3 Ag, Omp25 (P. de Wergifosse, P. Lintermans,

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