Characterization of a Novel Group of Shigella flexneri 1c Strains Exhibiting Cytotoxic Activity Against Mammalian Cells

Abstract

with 286 and 238 treated patients with pm have been analysed. Both compared periods were characterized with low percent (55.2% and 50.4%) of aetiologicaly confirmed cases, Str. pneumoniae as the most frequent aetiologic agent (58.2% and 41.7%) and similar total representation (86.7% and 90.0%) of the three dominant causative agents among the isolates, as well as the age of patients (≤1 and ≥≥ years) with increased risk for unfavourable outcome (27.9% and 24.8%). By using of disc diffusion method an increase in cephalosporin resistant strains of Str. pneumoniae was not registered; C3RSP isolates were unfrequent in the period analysed (8.6%), but in 5.3% more of patients with disc-diffusion sensitive strains clinical inefficiency with slower than expected improvement of CSF findings forceing need for additional antibiotic treatment and no effect on the final outcome of disease, with similar rate in the groups compared, was noted. Differences regarding the outcome (death rate with 13.3% and 12.2%, and sequellae in 8.9% and 7.7%), time to CSF sterilization in aetiologicaly confirmed cases, normalization of CSF biochemical characteristics, clinical response and final cure (after one year follow-up available data were similar as well) between the two compared periods were not found. Despite widespread use of cephalosporins in our population and the third generation parenteral cephalosporins in our institution in the past 10 year period, decrease of its clinical and microbiological efficacy for the treatment of pm, especialy for the most frequent aetiological agents of bacterial meningitis was not registered, therefore there is no need to change this practice.