ÖzetBu çalışmada, Sinop'da yetişen 15 farklı bitki türünden elde edilen metanol ekstraktların antimikrobiyal aktiviteleri 3 Grampozitif (Staphylococcus aureus ATCC 6538, Micrococcus luteus ATCC 9345, Bacillus cereus ATCC 7064), 2 Gram-negatif (Escherichia coli ATCC 11293 ve Enterococcus faecalis ATCC 51299) ve 3 maya (Candida krusei ATCC 6258, C. parapilosis ATCC 22019 ve C. albicans ATCC 14053) suşlarına karşı disk difüzyon yöntemi kullanılarak test edildi. Antimikrobiyal etkisi incelenen bitki türlerinin tümünün bir veya daha fazla mikroorganizmaya karşı etkili olduğu bulundu. Ayrıca, Sinop'a endemik olan Crocus speciosus subsp. xantholaimos'ın test edilen Gram-pozitif ve Gram-negatif bakterilere karşı yüksek antibakteriyal aktiviteye sahip olduğu belirlendi. Buna karşın, Laurus nobilis yaprak ve meyve özütleri 3 Candida türüne karşı daha yüksek antifungal aktivite gösterdi. Genel olarak bu çalışmadan elde edilen sonuçlar, incelen bitki ekstraktlarının antibakteriyal ve antifungal aktiviteleri arasında önemli bir farkın olmadığını gösterdi.Anahtar Sözcükler: Antimikrobiyal etki, Disk difüzyon yöntemi, Endemik, C. speciosus subsp. xantholaimos AbstractIn the present study, the antimicrobial activities of 15 different plant species growing in Sinop were tested against 3 Grampositive (Staphylococcus aureus ATCC 6538, Micrococcus luteus ATCC 9345, Bacillus cereus ATCC 7064), 2 Gram-negative (Escherichia coli ATCC 11293 and Enterococcus faecalis ATCC 51299) and 3 yeast (Candida krusei ATCC 6258, C. parapilosis ATCC 22019 and C. albicans ATCC 14053) strains by using disc diffusion method. It was found that all examined plant species in point of the antimicrobial activity was effective against one or more species of microorganisms. Additionally, it was determined that Crocus speciosus subsp. xantholaimos endemic to Sinop had high antimicrobial activity against tested Gram-positive and Gramnegative bacteria. However, the leaf and fruit extracts of Laurus nobilis displayed higher antifungal activity against 3 Candida species. In general, the results of the study showed that there was no significant difference between antibacterial and antifungal activities of the investigated plant extracts.

Staphylococcus aureus is the most prevalent human pathogenic microorganism worldwide. In the present study, a total of 57 S. aureus strains, including 54 clinical isolates obtained from dental hospitals and three reference strains were characterized by phenotypic characteristics and SDS-PAGE protein profiling. Out of the 132 clinical specimens, 54 S. aureus strains were isolated and identified according to their morphological and physiological characteristics. The strains were tested against 13 standard antibiotics by using disc diffusion procedure. Antibiogram results showed that the highest resistance among the isolates was determined against ampicillin (83.6 %), whereas they were susceptible to sulfamethoxazole/trimethoprim, cefoperazone/sulbactam, vancomycin and imipenem. In addition, multidrug resistance index values of 12 (22.2 %) of the isolates were higher than the reference value of 0.2. The numerical analysis of wholecell protein profiles of S. aureus strains revealed 2 major clusters at similarity levels of 57 % or above. Furthermore, the numerical analysis of extra-cellular protein profiles of S. aureus strains yielded 2 major clusters at similarity levels of 48 % or above. In conclusion, the present findings revealed that use of conventional methods with the numerical analysis of whole-cell and extra-cellular protein profiles might be useful for the more reliable identification of S. aureus strains isolated from tooth decay.