[Electrical resistance of bacterial culture suspension as indicator of epidemic and sporadic variants of Shigella].

For the first time method of measurement of electric resistance of bacterial suspension was used for differentiation of "epidemic" and "sporadic" (further used without quotes) variants of Shigella species. Study of 40 strains of S. flexneri and S. sonnei revealed significant differences in electric resistance of cultures isolated during epidemic outbreaks after the growth during 1 or 6 hours - 18.1+/-8.3 kOhm and 84.6+/-7.8 kOhm respectively (increase in 4.9-fold; p<0.01), while non significant differences were observed in cultures isolated from sporadic cases after the growth during 1 or 6 hours - 21.1+/-9.3 and 57.1+/-11.3 kOhm respectively (increase in 2.5-fold; p>0.05). Express-method for differentiation of epidemic and sporadic variants of Shigella can be useful for timely detection of outbreaks beginning (preoutbreak).