[Resistance to ciprofloxacin of Neisseria gonorrhoeae strains isolated in Poland in 2012-2013].

Introduction: Ciprofloxacin is commonly used in Poland specially for the treatment of urinary tract infections including urethritis. Patients are often treated without pathogen identification and antimicrobial resistance tests. Neisseria gonorrhoeae infection is one of the most common causes of urethritis in Poland. The resistance of bacteria to a wide range of antibiotics including ciprofloxacine makes the therapy of gonorrhoea more difficult. The mechanism of ciprofloxacine action depends on inactivation of bacterial topoisomerase II (gyrase) and topoisomerase IV. A resistance to ciprofloxacine occurring in Neisseria gonorrhoeae is mainly due to mutations in bacterial gyrA (encoding topoisomerase II) and/or parC (encoding topoisomerase IV ) genes. High level resistance is an effect of combination of three or four mutations. Another, less important mechanism of ciprofloxacin resistance, that can coexist with mutations in gyrA and parC genes related to the overproduction of membrane pumps proteins.

Material and methods: 65 Neisseria gonorrhoeae strains isolated from patients of Department of Dermatology and Wenereology in Warsaw in the second half of 2012 and first of 2013 was investigated. The strains were cultured on chocolate agar plates in a 5% CO2 atmosphere at 37 degrees C and identified by colony morphology, Gram stain and oxidase reaction, followed by carbohydrate utilization test. Ciprofloxacin susceptibility was determined by E-Tests (bioMerieux). Bacteria were incubated at 35 degrees C in 5% CO2 for 24 h on chocolate agar plates. Tests were performed according to producers recommendations. The results (sensitive or resistant) were interpreted according to EUCAST recommendations.

Results: The MIC (Minimal inhibitory concentration) of Ciprofloxacin in investigated strains ranged from 0,002 to > 32 mg/L, MIC50 = 8 mg/L, MIC90 = > 32 mg/L. It was shown that only 38.5% of the strains were sensitive to ciprofloxacin according to EUCAST criteria from 2013 year.

Conclusions: Due to the high percentage of ciprofloxacin resistant Neisseria gonorrhoeae strains (more than 61%) the antibiotic should not be used for the treatment of gonorrhoea in Poland.