Browsing by Author "Kajanti, Inga"

Yersinia enterocolitica and Yersinia pseudotuberculosis are common zoonoses, which cause mainly enteritis for humans, but also serious sequalae such as reactive arthritis. Both species have a wide range of host species, and especially Y. enterocolitica is commonly isolated from swine. Swine is the major reservoir for human pathogenic strains of Y. enterocolitica. Yersinia is an interesting research target for antimicrobial resistance because of its high prevalence and ability to cause zoonoses. A straight connection between the use of antimicrobial drugs and antimicrobial resistance has been proven, and the amount of antimicrobial drugs used and the way they are used differs among different countries. Because antimicrobial resistance is a growing problem, it is important to examine and compare its occurence among different countries. The purpose of this research was to determine the MIC-values (Minimal Inhibitory Concentration) for Y. enterocolitica and Y. pseudotuberculosis strains isolated from Europe and Nigeria for 13 antimicrobial drugs using microtitration plates. The research involved 93 Belgian, 61 Russian, 105 Italian, 183 Finnish and 47 Nigerian Y. enterocolitica strains. From the 11 Y. pseudotuberculosis strains one was Belgian, four were Russian, one Italian and four Nigerian. All the Y. enterocolitica strains were bioserotype 4/O:3 and Y. pseudotuberculosis strains type 2/O:3 apart from the ones from Nigeria. From the Nigerian Y. enterocolitica strains 45 were bioserotype 2/O:9 and two type 4/O:3, all the Y. pseudotuberculosis strains were type 1/O:1. All the examined strains were resistant to ampicillin, which can be explained with the production of β-lactamases characteristic to Gram-negative bacteria. Some of the Y. enterocolitica strains were resistant to streptomycin, tetracycline, sulfamethoxazole, trimethoprim and chloramphenicol. From Belgian Y. enterocolitica strains 48 (52%) strains were resistant to two antimicrobial drugs and four (4%) to three different drugs including ampicillin. Five (8%) Russian Y. enterocolitica strains were resistant to two antimicrobial drugs including ampicillin. From Italian Y. enterocolitica strains 63 (61%) strains were resistant to 4–6 different drugs including ampicillin, 2 (2%) strains were resistant to 2–3 different drugs and 40 (38%) strains were resistant to only ampicillin. One (1%) of the Finnish strains was resistant to sulfamethoxazole. Two (4%) Nigerian Y. enterocolitica strains were resistant to four and one (2%) strain to two different antimicrobial drugs including ampicillin. Belgian and one of the Russian Y. pseudotuberculosis -srains were resistant to streptomycin. Of the Nigerian Y. pseudotuberculosis strains one strain was resistant to five and two strains to two different drugs. They showed resistance to streptomycin, sulfamethoxazole, trimethoprim and tetracycline. Statistically significant differences were seen especially between Italian and other countries strains. Resistant strains were concentrated to certain farms, which might reflect the effect of antimicrobial drugs use to the occurence of resistance.