Carriage of group B streptococci in pregnant women from the region of Krakow and their antibiotic resistance in the years 2008-2012.

The aim of the study was a retrospective analysis of the frequency of group B streptococci (Streptococcus agalactaie; GBS) carriage in pregnant women from the region of Krakow, together with an analysis of their drug resistance, carried out between 2008-2012. The study included 3363 pregnant women between 35 and 37 weeks of gestation, studied in accordance with the guidelines of the Polish Gynecological Society (2008). A high percentage of pregnant women who are carriers of group B streptococci was demonstrated. Each year covered by the study, it was in the range of 25-30%, with an average value equal to 28%. The results confirm the need for taking swabs from both the vagina and anus, since 15% of GBS-positive patients showed only rectal carriage. High percentage of isolates resistant to erythromycin was detected, which ranged from 22% to 29%, with an average value equal to 25%, as well as a high proportion of isolates resistant to clindamycin being 17-25%, with an average of 20%. The results indicate the need to standardize the methodology of collecting samples for GBS testing and introduce microbiological diagnostic standards in all gynecological and obstetric centers in Poland, in order to carry out a detailed epidemiological analysis in our country.