Escherichia coli strains isolated from case of colibacillosis in Russian poultry farms in the region of Perm Krai were analyzed for their sensitivity to main antibiotics and bacteriocins. Sensitivity profiles for 9 antibiotics and 20 bacteriocins were determined with the disc diffusion method and the overlay test, respectively. Further, with the PCR the presence of several bla and integron 1 genes was revealed and the phylogenetic group for each strain determined. Among the 28 studied E. coli strains 85.7% were resistant to at least three antibiotics, 53.6% to five or more drugs, and 10.7% to eight antibiotics. PCR revealed that the blaTEM gene was harbored by 71.4% of strains and the blaCTX-M gene by 53.6% of strains. The class 1 integrons were found in 28.6% of strains. All of the studied strains were insensitive to ten or more bacteriocins. More than 90% of the studied strains were insensitive to pore-forming colicins of group A and B colicins, while 60.7% were insensitive to colicins with DNase and RNase activity. All of the analyzed strains were insensitive to at least two of the tested microcins. Neither the antibiotic resistance profile nor the bacteriocin resistance profile correlated with phylogenetic group of the strains. Thus, the studied strains were shown to possess high levels of multiple resistance to antibiotics and insensitivity to bacteriocins.

The aim of the study was to evaluate the genetic affinity of uropathogenic E. coli cultures (UPEC) and to identify the major types of extended spectrum beta-lactamases (ESBL) found among nosocomial isolates. A molecular typing of UPEC (n=93) isolated from patients with urinary tract infections (UTI) who were hospitalised in nine medical facilities (MO) in Perm was performed. It was found that 69.89% of the cultures had individual RAPD/ERIC profiles, the remaining 30.10% were distributed among 13 genome groups. Most frequently blaCTX-M-1 was detected individually or in combination with other beta-lactamase genes (n=23, 79.31% of ESBL phenotype-positive isolates), genes were detected in seventeen cases (58.62%) blaTEM and/or blaOXA, the blaCMY fragment was found in only three isolates (10.34%), blaSHV was missing in this isolates. It was shown that in two thirds of the cases the pathogens of the infection process are representatives of the endogenous intestinal microbiota of the patients, in other cases an exogenous infection occurs. The proportion of “circulating” (possibly hospital) isolates in the spectrum of UTI increased in the series: therapy departments - surgery departments - intensive care units. In addition, in multidisciplinary hospitals there are conditions for cross-infections of patients, but the epidemiological chains of episodes of UTI are short and concise. It has been shown that the probability of infection with E. coli producing CTX-M or OXA enzymes is significantly higher in the intensive care unit than in surgery or therapy departments. The data obtained complement the understanding of the epidemiology of UTI caused by E. coli and can be used as an aid in the planning and implementation of methods for the prevention and control of nosocomial UTI.

The effect of oral administration of Escherichia coli ŽP strain carrying a conjugative plasmid encoding the colicin E7 on the composition of the intestinal chyme microbiota of chickens was studied. It was shown that E. coli ŽP was present in the chyme of chickens 6-24 days of age in all experimental groups. In the microbiota of the control group (not administered with the ŽP strain) the Firmicutes phylum, as well as Proteobacteria (E. coli), Actinobacteria (Eubacterium spp.) and, to a lesser extent, Bacteroidetes were found. In the experimental groups the proportion of Firmicutes, represented by the Lactobacillus, Bacillus and Clostridium genera, was higher than in the control group. Our results showed that the use of E. coli ŽP helps to maintain a dynamic state of the microbiota, in all experimental groups, including the group, which was administered an APEC strain.

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