The Effect of Ceftriaxone on the Composition of the Parietal and Cavitary Microllora of the Small Intestine of Wistar Rats

Abstract

The study examined the qualitative and the quantitative composition of the cavitary and parietal microflora of the small intestine under the influence of ceftriaxone in the monthly experiment on animals. The study was carried out on Wistar rats, divided into two groups. Control group (n=50) - animals were injected intramuscularly with a 1.0 ml physiological solution daily for 10 days. Experimental group (n=50) - animals were injected intramuscularly with ceftriaxone 15 mg/kg/day, daily for 10 days. Intestinal contents from the distal third of the small intestine were sent for a bacteriological study. The investigated material was inoculated on nutrient media to isolate nonfermenting gram-negative bacteria (NGNB, including pseudomonads), enterobacteria, bifidobacteria, lactobacilli, clostridia, escherichia, enterococci, staphylococci, yeast-like fungi. Antibacterial therapy with ceftriaxone causes more pronounced changes in the parietal microflora of the small intestine. After a course of antibacterial therapy, the cavitary microflora is restored faster than the parietal microflora (in particular, the amount of bifido- and lactobacilli). An increase in the incidence of E.coli with typical enzymatic properties in the small intestine (up to 10³-10⁵ cfu/g) has been revealed, especially in the parietal microflora. Ceftriaxone leads to a quantitative increase in opportunistic enterobacteria and non-fermenting gramnegative bacteria after the course of antibiotic therapy.