Relationship of HeLa cell infectivity to biochemical, serological, and virulence characteristics of Yersinia enterocolitica

Abstract

Examination of 69 strains of Yersinia enterocolitica which represented 20 serotypes and nontypable isolates for HeLa cell infectivity by a roller tube technique that provided a quantitative index of infection showed that infectivity (index, greater than 3.50) was confined to strains of serotypes O:8, O:3, O:5, 27, O:9, O:1, O:1,2,3, O:2,3, O:4,32, and O:21. All strains that were HeLa positive were sucrose positive and negative for salicin, esculin, rhamnose, raffinose, melibiose, alpha-methylglucoside, and citrate. All HeLa-negative strains were either sucrose and salicin positive or were sucrose negative. Twenty-one strains were examined for virulence by the ability to produce guinea pig conjunctivitis and diarrhea in mice. Positive strains were limited to those that were HeLa positive and were autoagglutination positive and calcium dependent at 35 degrees C. There was no association between virulence and the ability to produce enterotoxin measured by the infant mouse assay. Loss of autoagglutinability and calcium dependency was accompanied by loss of virulence, but HeLa cell infectivity was unchanged. The results suggest that at least two properties are necessary for virulence: the presence of the V and W antigens, mediated by the same plasmid as autoagglutination and calcium dependency, and an invasive factor demonstrated in vitro by HeLa cell infectivity. These virulence properties are found in only certain biotypes of Y. enterocolitica.

Pathogenicity ofYersinia enterocoliticabiotype 1A

“…The ability of Y. enterocolitica to invade epithelial cells is an important correlate of virulence [46,91]. One reason that strains of biotype 1A have been considered to be avirulent is that they invade tissue culture cells to a lesser extent than pYV-bearing strains [88,89], although, paradoxically, pYV itself may retard cell invasion via the effects of translocated Yops on cytoskeletal proteins [2]. We have con¢rmed that biotype 1A strains penetrate HEp-2 To determine the number of intracellular bacteria, epithelial cells were incubated in fresh tissue culture medium containing 100 Wg ml 31 gentamicin for 90 min before the epithelial cells were lysed and the bacteria were enumerated.…”

Chromosome-mediated resistance of Yersinia enterocolitica serotype O9 to intracellular killing by mouse peritoneal macrophages

“…Yersinia enterocolitica is a known invasive enteropathogen causing enteric infection in humans [1]. Only strains belonging to certain serotypes and biotypes are potential pathogens because they possess the chromosomal background necessary for pathogenicity, including the capacity to invade mammalian ceils [2,3]. The ail locus is related to the invasive phenotype, and it has been uniquely mechanisms.…”

Isolation and identification of Yersinia enterocolitica and the Yersinia enterocolitica like bacteria

“…It has been claimed that potentially pathogenic strains of Y. enterocolitica may be screened using presumptive colonies on CIN agar as they will produce the typical reactions on KIA and urea agar slopes when incubated at 3YC, ferment sucrose at 22°C and will not ferment salicin at 35°C (Schiemann & Devenish 1982;Feeley & Schiemann 1984). This provides an extremely simple screening procedure, but the pathogenicity of strains determined in this way needs to be confirmed by other procedures.…”