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Year : 2005  |  Volume : 23  |  Issue : 1  |  Page : 69--70

Invasiveness - An indicator of differentiation of virulent and non virulent isolates of Yersinia enterocolitica

M Lal 
 Department of Microbiology, Christian Medical College, Ludhiana - 141 008, Punjab, India

Correspondence Address:
M Lal
Department of Microbiology, Christian Medical College, Ludhiana - 141 008, Punjab
India

How to cite this article:
Lal M. Invasiveness - An indicator of differentiation of virulent and non virulent isolates of Yersinia enterocolitica.Indian J Med Microbiol 2005;23:69-70

How to cite this URL:
Lal M. Invasiveness - An indicator of differentiation of virulent and non virulent isolates of Yersinia enterocolitica. Indian J Med Microbiol [serial online] 2005 [cited 2020 Dec 4 ];23:69-70
Available from: https://www.ijmm.org/text.asp?2005/23/1/69/13883

Full Text

Dear Editor,

Yersinia enterocolitica, an emerging pathogen has been implicated as causative agent for a number of clinical manifestations predominantly diarrhoea. Invasiveness into epithelial cells is an important pathogenic mechanism of enteric bacteria, including strains of Shigella, Salmonella, Escherichia coli and Yersinia.[1] Clinically, the invasive bacteria are capable of producing dysentery like disease or exudative diarrhoea. Pathogenic Y.enterocolitica strains are characterized by their ability to adhere to and invade epithelial cells.[2] Demonstration of epithelial invasiveness of Enterobacteriacea can be done by Sereny test.[3] To assess the relative importance of Sereny test twelve isolates of Y.enterocolitica were tested by Sereny test to determine the virulence of these micro organisms. Guinea pigs weighing about 400g were injected 50mg of iron dextran intraperitoneally on first day and 50mg of desferal intraperitoneally on the second day preceding bacterial inoculation to increase susceptibility of the animals to infection. A volume of 25 µL containing 109 organisms were put into right conjunctival sac of a group of three guinea pigs for each isolate. Control animals were given culture of Shigella dysteriae as positive control, while the uninoculated left eye of each animal used in the test served as negative control. Animals were examined daily for 5 to 7 days for the evidence of conjunctivitis.

One isolate produced definite, three mild and three minimum conjunctivitis while five isolates did not produce any conjunctivitis. Either absence or mild keratoconjunctivitis might be due to absence of plasmid in the isolates tested in this study. Sereny positive isolates were found to be virulent when tested in mice for diarrhoea and death. The observation is supported by Schiemann and Devenish[4] who suggested that invasiveness of Y.enterocolitica for HeLa cells was not dependent on plasmid. As for Y.enterocolitica, invasiveness test may contribute to the diagnosis of invasive Y.enterocolitica as a cause of exudative diarrhoea.

References

1Maki M, Gronroos P, Vesikari T. In vitro invasiveness of Y.enterocolitica isolated from children with diarrhoea. J Infect Dis 1978;138:677-680.
2Vishnubhatla A, Fung DYC, Oberst RD, Hays MP, Nagaraja TG, Flood SJA. Rapid 5' nuclease (TaqMan) assay for detection of virulent strains of Yersinia enterocolitica. A EM 2000;66(9):4131-4135.
3Sereny B. Experimental Shigella keratoconjunctivitis. Acta Microbiol Acad Sci 1955;2:293-296.
4Schiemann DA, Devenish JA. Virulence of Y.enterocolitica determined by lethality in Mongolian Gerbils by Sereny Test. Infect Immun 1980;29;500-506.