Acute experimental peritonitis: microecological indexes, species composition and population level of large intestine microbiota of experimental animals after 6 hours of initiation

Abstract

The aim of research. This experimental issue deals with microbiological investigation of quantitative and qualitative composition of large intestinal cavity microflora in albino rats with acute experimental peritonitis (AEP) within 6 hours of its initiation. Methods. Case-control experimental study conducted on white 25 albino rats with weight from 200 to 220 g: 10 intact animals (control group) and 15 rats in basic group with acute experimental peritonitis (AEP). The content of large intestine served as research material for microbiological investigation with obtaining pure cultures of microorganisms. Population level of microflora of large intestine content displayed in logarithm of colony-forming units (lg CFU/g). In the current study, few important indexes had used for evaluation of character of microbiota violations - constancy index, Margalef index, Berger-Parker index, Simpson index. Results. It had observed the reduction of dominant Bifidobacteria on 33,5%, Lactobacilli on 36,72%, Peptostreptococci in 2 times and Enterococci in 2,5 times in the large intestine cavity of experimental animals with AEP within 6 hours. However, quantitative dominance in microbiocenosis of large intestine cavity increases for opportunistic Bacteroides in 38,55%, Peptococci in 2,97 times, E. coli in 9,17% and Proteus in 59,37%. At the same time there significantly increased role of opportunistic Enterobacteriaceae in the formation of microbiota of large intestine cavity in animals with AEP after 6 hours: Bacteroides - by 42,86%, Peptococci - in 3 times, Escherichia coli - by 10,53%. Opportunistic pathogenic Enterobacteriacea (genus Klebsiella, Edwardsiella), which contaminate and colonize the large intestine cavity, reach a moderate population level and microecological indexes. Conclusions. The study of qualitative and quantitative composition, microecological indexes and coefficients that demonstrated interactions and co-existence of dominant, residual and random gut microflora of albino rats with AEP established minor violations of species composition within 6 hours after modelling: deficiency of Bifidobacteria, Lactobacilli, Peptostreptococci on the background of the increased number of opportunistic pathogenic bacteria. The development of acute experimental peritonitis in 6 hours accompanied by the formation of dysbiosis in the cavity of large intestine of first (30,0%), second (60,0%) and fourth (10,0%) degrees.