Sonnei Dysentery Morbidity in Khabarovsk and Khabarovsk Region Due to Atypical Mannitol-Negative Causative Agent

Abstract

Aim. Determine features of epidemic process (EP) of Sonnei dysentery in Khabarovsk Region in 2012 - 2014 due to atypical causative agent. Materials and methods. Detailed characteristics of 161 cultures of Shigella sonnei isolated from 81 patients from epidemic focus in children boarding school in Bikin as well as from 22 patients from sporadic and group foci of dysentery in Khabarovsk (biochemical type, colicin-genotype, spectrum of drug resistance) is given. Molecular-biologic subtyping was carried out for 11 strains by Pulsed Field Gel Electrophoresis method (PFGE). Results. Materials of observation of a prolonged foci of Sonnei dysentery with contact-domestic transmission route of the infection in children boarding house for disabled (October 2012 - September 2014) are presented. The diseases are etiologically connected with atypical mannitol-negative types of shigella isolated for the first time in 40 years of observation in Khabarovsk region. Epidemic process of shigellosis was supported by prolonged carriership of the causative agent in patients and special contingent of the nursing home. Shigella cultures isolated in the focus belonged to the same colicin-genotype and 2 distinct drug resistance clones, but a single genotype established by PFGE method. Conclusion. Results of the studies give evidence on the importance of determination of traditional phenotypic and contemporary genotypic variants of shigella and the necessity of search for arguments, additional methodic approaches for establishing similarities and differences of shigella isolates from within the same outbreak of the diseases as well as for comparison of strains circulating in different territories.