Influence of enterococci on the sensitivity of opportunistic microflora to antibiotics

The article presents the results of determining the ability of enterococci isolated from traditional Carpathian cheese to affect the antibiotic sensitivity of opportunistic gram-positive and gram-negative microorganisms, particularly test strains of S. aureus and E. coli. It was found that enterococci had different effects on the sensitivity of opportunistic pathogens to different groups of antimicrobial drugs. In particular, co-cultivation of S. aureus with enterococci did not affect the change in sensitivity to amoxicillin and glycopeptides (vancomycin). In the study of aminoglycosides, it was found that the sensitivity of staphylococcus to gentamicin increased when co-cultured with strains of E. faecium SB12 and E. durans SB18 by 14.8 (P < 0.05) and 13.1 % (P < 0.01), respectively. The tendency to increase the sensitivity of staphylococcus to streptomycin was also observed in cultivation with E. faecium SB12 and E. durans SB18. Concerning macrolides, in particular erythromycin, only one strain of E. durans SB18 caused a 3.2 % increase in staphylococcal susceptibility, and a probable increase in staphylococcal susceptibility was found in fluoroquinolones. In particular, the sensitivity of staphylococci to enrofloxacin and norfloxacin increased by 7.6 and 5.3 %, respectively (P < 0.05). The antibiotic susceptibility of E. coli with enterococci found a slight increase in sensitivity to penicillins when co-cultured with strains of E. faecium SB12 and E. durans SB18. Thus, the antibiotic sensitivity of E. coli increased by 5.1 and 7.5 %, respectively. In addition, the sensitivity of E. coli to aminoglycosides (streptomycin) increased under co-cultivation with E. durans SB6 and SB18 strains by 7, 5, and 9.7 %, respectively (P < 0.05). In addition, when co-cultured with E. faecium SB12 and E. durans SB18 strain, the sensitivity of E. coli to enrofloxacin increased by 7.6 and 5.3 %, respectively (P < 0.05), and to norfloxacin – by 3, 8, and 4.9 %. Co-cultivation with E. durans SB6 and E. faecium SB12 strains increased the sensitivity of E. coli to ẞ-lactam antibiotics, in particular, cefazolin by 9.1 % (P < 0.05), and in co-cultivation with E. durans SB18 – at 14.1% (P < 0.01).