Meryem Güvenir

Chemical composition and antimicrobial activity of the essential oil of Sideritis cypria Post endemic in Northern Cyprus

Abstract In this study, chemical composition and antimicrobial activity of the essential oil of Sideritis cypria, which is an endemic taxon in Northern Cyprus, were investigated. The essential oil obtained by hydrodistillation were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In general, the GC and GC-MS analysis illustrated that fifty compounds were identified representing 96.9% of the oil. Major components were epi-cubebol (11.9%), trans-piperitol (8.9%) and pinene (8.1%), respectively. The antimicrobial activity of the essential oil was tested by disc diffusion method against Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), Bacillus cereus (ATCC 10876), Staphylococcus aureus (ATCC 25923) bacteria and Candida albicans (ATCC 90028) yeast. The results showed that the inhibition zone of S. cypria essential oil against C. albicans at maximum dose (10 μl) was higher than positive control Nystatin. The oil showed similar inhibitory zone to that of the positive control (TMP-SMX) against B. cereus at maximum dosage 10 μl. In addition, the inhibitory effect of the oil against E. coli measured only at the 10 μl as 10.33 ± 0.58. Furthermore, the inhibition zones against S. aureus was ranged from 9.00 ± 2.00 to 24.00 ± 1.73 while P. aeruginosa was found to be resistant in all doses.

High Genetic Diversity among Stenotrophomonas maltophilia Isolates from Single Hospital: Nosocomial Outbreaks or Genotypic Profile Changes during Subcultures

Background Stenotrophomonas maltophilia is a non-fermentative gram-negative bacillus which is widely recognised as an important nosocomial pathogen causing pneumonia, blood-stream, wound and urinary tract infections, particularly in immunosuppressed patients. The aim of this study was to evaluate a nosocomial outbreak of by S. maltophilia in an intensive care unit of a tertiary hospital and evaluate unexpected multiclonality. Methods A total of 11 isolates from respiratory cultures in intensive care unit of a 24 bed tertiary hospital obtained over a one months period and one isolate obtained from the nebuliser during environmental screening were investigated. The bacteria were identified by Phoenix 100 system. The clonal relatedness was evaluated by PFGE and semi-automated repetitive sequence-based PCR. Genotyping tests were repeated for 10 serial subcultures. Results PFGE and DiversiLab yielded 10 genotypic profiles for 12 isolates. Four to eight different genotypes were observed from 10 subcultures of the same isolate. Conclusion We conclude that, high genetic diversity and supposed multiclonal appearance of the outbreak isolates may be due to changing profiles during subcultures most probably depending on hypermutation.

Effectiveness of non-fluoride and fluoride dentifrices for denture hygiene.

Abstract Objective: To compare the effectiveness of commonly used herbal/non-fluoride with fluoride dentifrices in order to eliminate pathogenic oral microorganisms from denture base material. Materials and methods: Heat-polymerized acrylic resin specimens (n = 288) were divided into three groups and each group inoculated with three various microorganisms (n = 96 for each) Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa). Contaminated specimens were randomly assigned to the application of six herbal/non-fluoride and three fluoride dentifrices. These specimens were divided into two groups: negative and positive control (n = 3 for each). All acrylic specimens were incubated at 37 °C for 24 h for samples inoculated with bacterial strains and 37 °C for 48 h for samples inoculated with yeast strains. After the incubation period, all brain–heart infusion broths that contained disinfectant acrylic specimens were cultured on 5% sheep blood agar for bacterial counts and Sabouraud dextrose agar for yeast counts. The number of colony-forming units per millilitre (CFU/mL) were calculated. The results were analysed by Mann–Whitney U and Kruskal–Wallis tests (p = .05). Results: Both herbal/non-fluoride and fluoride dentifrices were effective against Candida albicans. However, fluoride dentifrices were comparatively better than the herbal/non-fluoride dentifrices against Staphylococcus aureus and P. aeruginosa. Conclusions: Herbal dentifrices could be used, especially among the elderly who lack a degree of manual dexterity during the rinsing of dentifrice chemicals from their dentures.