[A morphological evaluation of the harmlessness of noninvasive recombinant Shigella strains]

The interaction of Shigella recombinant strains (with attenuating chromosomal mutations, with transposon-neutralized plasmid gene mutations, the hybrids of both strains), incapable of inducing keratoconjunctivitis in guinea pigs, with cells Hep-2 and enterocytes in the ligated loop of the small intestine of rabbits was studied. These strains retained, to varying extent, pronounced adhesiveness, but practically lost their invasiveness (though in Peyer's patches the translocation of bacteria by M-cells was observed) and cytotoxicity, as well as their capacity to multiply in epithelial cells and to cause destructive inflammation in the intestine. According to these criteria of evaluation, morphological investigations confirm the safety of the recombinant shigellae under study.