SALMONELLA-INDUCED CHANGES OF THE RAT INTESTINAL MICROBIOTA

. The gut microbiome profoundly affects the body functioning: it participates in host protection against pathogenic microorganisms, metabolic events, inhibition of inflammatory responses, formation of innate and adaptive immune response in the intestinal mucosa. One of the causes altering microbiota community is due to antibiotics. Therefore, the processes of antibiotics interaction from Salmonella Enteritidis and Salmonella Typhimurium with representatives of normal intestinal microflora are of particular interest. Materials and methods. The quantitative and qualitative analysis of the wall microbiota composition in rats was evaluated by bacteriological method, the statistical data analysis was performed using the StatSoft Statistica v12. Results & discussion. Inoculation of vancomycin and S. Enteritidis, S. Typhimurium in groups II, III, quantitatively E. coli level 10-, 7- and 110-fold, (p≤0.05). The count of P. Aeruginosa III The count of Bacteroides spp. The count of E. Faecalis E. Faecium 861-, 6- and several thousand II, III, IV), The count of Proteus spp. markedly in group II 27-fold rapidly in group IV Group revealed a sharp decline in level of Enterobacter spp. and Klebsiella spp. by 847-and 150-fold, in group II they were by 7- and 46-fold, respectively (p≤0.05). The count of Staphylococcus spp. by 10-fold only in group II. several thousand-fold and 40 times (groups VII and VIII, respectively) (p≤0.05). The count of S. enteritidis and S. typhimurium in groups VII and VIII decreased rapidly (p≤0.05). Conclusions. Inoculation of B. fragilis can be used in treatment of inflammatory bowel diseases or disorders with impaired gut barrier function methods for their correction". Acclimatization of animals (quarantine) lasted 7 days 29 before the study. All experiments were conducted in the autumn-winter period in the 30 vivarium of Zaporizhia State Medical University. Rats were at an air temperature of 31 18-21 C, in natural light during daylight 7-00 - 17-00, with free access to food and 32 water. Experimental work with rodents was carried out in accordance with the 33 provisions of the "European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes" (Strasbourg, 1986). All rodents, except group I (control, intact), received vancomycin and/or suspension of 36 microorganisms. In order to quickly internalize the bacteria in the intestinal mucosa, the suspension with salmonella was administered orally using a probe with a volume 38 of 5 ml size 16-18, length 5-7.5 mm, tip size 2.25. Vancomycin was administered to animals at the rate of 50 mg per kg of body weight, suspensions of microorganisms - 40 in an amount of 15 ml with a concentration of 3x10 8 CFU/g. Thus, to simulate the 41 imbalance of the intestinal microflora, vancomycin (TEVA, № UA/8995/01/02) was introduced to group II rodents, S. Enteritidis suspension was introduced to group III, and S. Typhimurium suspension was introduced to group IV. Animals V and VI of experimental groups received vancomycin on the first day, but group V after 24 h was administered a suspension of S. Enteritidis , and rats of group VI - a suspension of S. typhimurium . Rodents of groups VII and VIII indicate the possibility of using B. Fragilis to correct salmonella- induced changes in the intestinal microbiome. We observed a decrease in the level of Salmonella spp., E. Coli, P. Aeruginosa, spp., spp., as well as an increase in Bacteroides spp., and the quantitative content of microorganisms in the development of salmonella-induced disease shown The frequency of excretion of microorganisms in the parietal contents of the intestine of rats with the introduction of Salmonella, B. Fragilis on the background of vancomycin

participates in metabolic processes, inhibition of pro-inflammatory reactions, in the 2 formation of innate and adaptive immune response in the intestinal mucosa [8,16,18,3 32]. The most important function of the intestinal microbiome is to protect the body 4 from pathogenic microorganisms -pathogens of bacterial intestinal infections [31, 5 38]. It is known that dysbiotic changes in the intestine lead to increased susceptibility 6 to pathogenic bacterias, such as salmonella [15,22], which are the etiological factor 7 of gastroenteritis [36]. One of the most common causes of microbiota changes is the 8 use of antibiotics [5,26,41]. Therefore, of particular interest are the processes of 9 interaction of antibiotics, Salmonella enteritidis and Salmonella typhimurium with 10 representatives of the normal intestinal microbiota [3,11,39]. Therefore, in our work, 11 vancomycin was used to induce dysbiotic changes in the intestinal microflora, which 12 acts against gram-positive bacteria and does not affect gram-negative (salmonella). 13 We also paid attention to determining the quantitative and species composition of the 14 microbiota in salmonella-induced intestinal inflammation, which created the basis for 15 further study of the molecular mechanisms of interaction of Salmonella enteritidis 16 and Salmonella typhimurium with microbiota and gut-associated lymphoid tissue 17 (GALT).

18
The aim: to analyze changes in the quantitative and species composition of the 19 microbiota of the small intestine in rats with salmonella-induced inflammation of the 20 intestine on the background of the introduction of vancomycin and B. fragilis.   Results and discussion.

95
The data obtained during the studies showed that with the introduction of 96 vancomycin and bacterial agents, the quantitative and qualitative composition of the 97 representatives of the parietal microbiota changed dramatically (Table 1) increase in the number of pseudomonads when administered to rats S. Enteritidis [4].

106
The number of representatives of Bacteroides spp. significantly decreased several 107 thousand times (group II) and 70 and 87 times (groups III and IV) (p≤0.05) ( Table 1).

108
Our data are consistent with the results of researchers who studied the composition of Parkes et al. (2012)  proteases were isolated with a frequency of 22 and 78% in groups III, IV (Table 3).

119
According to the literature data when administered to mice vancomycin, as well as 120 salmonella, the content of Proteus spp. increased by 4 and 48 times [24], which is 121 similar to the data obtained during our experiment. In group III there was a sharp   in the number of representatives of this genus [19].  According to data provided by Turnbaugh et al. (2006), when administered to spp. In 9 and 10 times (p≤0.05) (see Table 1). spp., which confirms our data [37]. and Klebsiella increased in 6 times, which is fully consistent with our results [14]. 192 According to the literature, when co-administered to rats vancomycin and salmonella, 193 the number of peptostreptococci decreased in 5 times [13]. These data do not Candida was 57% (group V) and staphylococci -95% in the VI experimental group 198 (Table 3). The amount of Salmonella spp. significantly decreased only in group V in 199 7 times (p≤0.05). However, the data obtained by Barthel et al. (2003), when    Table 4.   Notes: * the significance of differences in the parameters p≤0.05 in relation to the control; a reliability of parameters on    Table 4.