Background/aim: Escherichia coli is the most frequent cause of urinary tract infections. We investigated the possible associations between the origin of strains, antimicrobial resistance, the presence of urovirulence factors, and biofilm-forming ability.Materials and methods: Antibiotic susceptibility of E. coli strains was tested by disk diffusion method. Hemagglutination assays were performed for phenotypic characterization of the cell surface. Multiplex PCR was used for detection of virulence genes and for determination of phylogenetic relationships. Results:The resistance to ampicillin (55.5%) and tetracycline (39.3%) was significantly more frequent than to other antimicrobial agents. The fim gene was present in 92.5% of strains. The sfa and pap genes were found in 53.8% and 38.7% of strains, respectively. The pap gene was significantly less frequently detected in strains from dialysis patients. The hly gene was present in 18.5% of strains. The aer gene was detected in 52.6% and cnf in 12.1%, while afa was detected in 4.6% of strains. Most strains belonged to the B2 and D phylogenetic groups. The aer gene was significantly associated with strains producing strong biofilms. Conclusion:The E. coli strains causing cystitis in hospitalized patients differed in terms of resistance to antibiotics, virulence genes, and potential for biofilm formation.

Background/aim: Biofilm on urinary catheters results in persistent infections that are resistant to antibiotics. In this study, phytochemicals were assessed as alternative antimicrobials in preventing and inactivating E. coli biofilm on urinary catheters.Materials and methods: Biofilm prevention was tested using catheter fragments inoculated with E. coli and treated with transcinnamaldehyde, p-coumaric, and ferulic acids (0%, 0.1%, 0.25%, and 0.5%) for 0, 1, 3, and 5 days. Inactivation of E. coli biofilm with the same agents at concentrations of 0%, 1%, 1.25%, or 1.5% used for 0, 1, 3, or 5 days was also evaluated.Results: All used concentrations of trans-cinnamaldehyde prevented and effectively inactivated E. coli biofilm formed on urinary catheter fragments. p-Coumaric (0.25% and 0.5%) and ferulic acids (0.5%) had preventive action on E. coli biofilm formation in urinary catheter fragments. The number of uropathogenic E. coli cells in biofilm formed in the lumen of a urinary catheter was significantly reduced in the presence of p-coumaric and ferulic acids, but complete inactivation of the biofilm formed was not observed, as opposed to the use of trans-cinnamaldehyde. Conclusion:The obtained results indicate that phytochemicals may be an important source of antibiofilm agents that have preventive action on E. coli biofilm formation on urinary catheters.

Propolis is a product of the vital activity of the honey bee Apis mellifera. Bees produce propolis by mixing substances gathered from budding plants, flower buds and resinous exudates. They thus produce a material suitable for closing gaps, embalming dead insects within the beehive and protection from invasion by microorganisms and insects. This activity of propolis results from its composition. Raw propolis is typically composed of 50 % plant resins, 30 % waxes, 10 % essential and aromatic oils, 5 % pollens and 5 % other organic substances [1]. Propolis possessed a variety of biological and pharmacological effects, such as antibacterial, antioxidant, antitumour, antiinflammatory and immunomodulatory. However, propolis could not be used as a raw material, so it must be purified by extraction to remove the inert material and preserve the polyphenolic fraction, which is primarily responsible for its activity [1,2]. Generally, ethanol is the best solvent for propolis preparation, but other solvents such as ethyl ether, water, methanol and chloroform could also be used for extraction and identification of propolis constituents [3]. More than 300 different compounds have been identified in propolis, including phenols, tannins, polysaccharides, terpenes, aliphatic acids, esters, aromatic acids, fatty acids, aldehydes, amino

Staphylococcus aureus is arguably the most important pathogen involved in bovine mastitis. The aim of this study was to determine the virulence gene profiles of 124 Staph. aureus isolates from subclinical mastitis in cows in eastern Poland. The presence of 30 virulence genes encoding adhesins, proteases and superantigenic toxins was investigated by PCR. The 17 different combinations of adhesin genes were identified. Occurrence of eno (91·1%) and fib (82·3%) genes was found to be common. The frequency of other adhesion genes fnbA, fnbB, ebps were 14·5, 50, 25%, respectively, and for cna and bbp were 1·6%. The etA and etD genes, encoding exfoliative toxins, were present in genomes of 5·6 and 8·9% isolates, respectively. The splA and sspA, encoding serine protease, were detected in above 90% isolates. The most frequent enterotoxin genes were sei (21%), sem (19·4%), sen (19·4%), seg (18·5%) and seo (13·7%). The tst gene was harboured by 2·4% isolates. The 19 combinations of the superantigenic toxin genes were obtained and found in 35·5% of isolates. Three of them (seg, sei, sem, sen, seo; sec, seg, sei, sem, sen, seo and seg, sei, sem, sen) were the most frequent and found in 16·1% of the isolates. The most common virulotype, present in 17·7% of the isolates, was fib, eno, fnbB, splA, splE, sspA. The results indicate the variation in the presence of virulence genes in Staph. aureus isolates and considerable diversity of isolates that are able to cause mastitis in cows.

The aim of this study was to examine phenotypic and genotypic antimicrobial resistance of staphylococci from milk samples from cows with subclinical and clinical mastitis and from cows without mastitis symptoms to methicillin, tetracyclines, macrolides and lincosamides (ML). Of 207 strains, including 34 S. aureus and 173 coagulase-negative staphylococci (CNS), 11 (6.4%) CNS strains were phenotypically resistant to methicillin. The mecA gene was detected by PCR only in two S. xylosus strains and one strain of S. epidermidis and S. simulans. No methicillin-resistant S. aureus strains were observed. In methicillin-resistant strains with mecA, gene resistance to other investigated antibiotics was not observed. Phenotypic resistance to tetracycline was detected in 11.0% of CNS strains and 47.4% of them carried the tetK gene. Of 173 CNS strains studied, 27 (15.6%) were resistant to at least one ML antibiotic. The resistance gene ermC was detected in 55.5% of the 27 ML-resistant strains. The ermA and ermB genes were detected in 14.8% and 11.1% of ML-resistant CNS strains, respectively. Antimicrobial resistance to methicillin, tetracyclines and macrolides was detected more frequently in staphylococcal strains from clinical mastitis compared to animals with subclinical symptoms and without mastitis, while the resistance to lincosamides showed a similar frequency in all groups of cows. In conclusion, CNS species from bovine milk differ in phenotypic and genotypic antimicrobial resistance profiles, and the use of PCR technique alone for the detection of methicillin, macrolide, lincosamide and tetyracycline resistance in CNS from cattle is not reliable.