SENSITIVITY OF INTESTINAL ESCHERICHIA COLI STRAINS ISOLATED FROM PIGS TO FLORFENICOL
S. Yordanov, A. Dimitrova, T. Popova, K. Petkova, T. Savova, R. Bankova
Abstract: On the classical disk diffusion method are tested 62 strains of Escherichia coli, isolated during the period 2011–2015 from suckling and grower pigs for sensitivity to 24 antimicrobial means. The inhibitory areas are reported and interpreted in accordance with the three-degree system of Bauer-Kirby.
It was found that in 2011 and 2012 the sensitivity of E. coli strains to antimicrobial means increased from 10 n. (50%) of 17 n. (77.3%), as to the extent of 51% to 100%, respectively, to 7 (35%) and 11 (50%) of the means, from which the most common: enrofloxacin, pefloxacin, norfloxacin; florfenicol;
amikacin, gentamicin, kanamycin; cefquinome and sulfamethoxazole + trimethoprim. Over the same period, E. coli strains were resistant in the highest degree to ampicillin, oxytetracycline, doxycycline, erythromycin, tylosin, tilmicosin; tiamulin; spectinomycin and streptomycin. The part of antimicrobials to which E. coli strains in 2013 were sensitive is 15 n. (65.2%), while in 2014 17 n. (73.9%), but the means to which strains are sensitive from 51% - 100% decrease from 11 n. (47.8%) to 4 n. (17.4%). At the same time the means to which the strains are resistant has increased from 16 (69.6%) to 18 (78.3%). In 2015, strains exhibit sensitivity to small part of the used antimicrobials (12 n. / 52.2%) and are resistant to most of the means (16 n. / 69.6%) including to 11 n. (47.8%) in degree from 51 to 100%. In the period 2011 - 2014 the part of florfenicol susceptible E. coli strains decreased from 80% to 60.8%, and in 2015 increase to 85.7%, and the proportion of resistant strains have relatively low
values are not always the inverse of cases of sensitive strains (80%; 0%; 79.9%: 6.7%; 64.6%: 11.8%; 60.8%: 5.6% and 85.7%: 0%).
It was found that in 2011 and 2012 the sensitivity of E. coli strains to antimicrobial means increased from 10 n. (50%) of 17 n. (77.3%), as to the extent of 51% to 100%, respectively, to 7 (35%) and 11 (50%) of the means, from which the most common: enrofloxacin, pefloxacin, norfloxacin; florfenicol;
amikacin, gentamicin, kanamycin; cefquinome and sulfamethoxazole + trimethoprim. Over the same period, E. coli strains were resistant in the highest degree to ampicillin, oxytetracycline, doxycycline, erythromycin, tylosin, tilmicosin; tiamulin; spectinomycin and streptomycin. The part of antimicrobials to which E. coli strains in 2013 were sensitive is 15 n. (65.2%), while in 2014 17 n. (73.9%), but the means to which strains are sensitive from 51% - 100% decrease from 11 n. (47.8%) to 4 n. (17.4%). At the same time the means to which the strains are resistant has increased from 16 (69.6%) to 18 (78.3%). In 2015, strains exhibit sensitivity to small part of the used antimicrobials (12 n. / 52.2%) and are resistant to most of the means (16 n. / 69.6%) including to 11 n. (47.8%) in degree from 51 to 100%. In the period 2011 - 2014 the part of florfenicol susceptible E. coli strains decreased from 80% to 60.8%, and in 2015 increase to 85.7%, and the proportion of resistant strains have relatively low
values are not always the inverse of cases of sensitive strains (80%; 0%; 79.9%: 6.7%; 64.6%: 11.8%; 60.8%: 5.6% and 85.7%: 0%).
Keywords: colibacillosis; E. coli; florfenicol; pigs; sensitivity
Date published: 2017-11-09
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