The aim of this study was to identify methicillin-resistant Staphylococcus aureus (MRSA) strains gathered from 2002 to 2006 from milk samples in Aydin region in Turkey. Among 93 S. aureus strains isolated from bovine milk with mastitis, 16 were resistant to methicillin. Methicillin-resistant S. aureus strains were studied further for their staphylococcal cassette chromosome mec (SCCmec) types, pulsotypes, spa and MLST types, antimicrobial susceptibilities, mechanisms of resistance and presence of Panton-Valentine leucocidin (PVL) toxin gene. The MRSA strains were multi-drug resistant. The susceptibility rates to antimicrobials tested were 0%, 0%, 0%, 0%, 6.25%, 16.25% and 56.25% for erythromycin, clindamycin, chloramphenicol, gentamicin, tetracyclin, ciprofloxacin and vancomycin, respectively. All tetracycline and gentamicin resistant strains carried tet(M) and aac(6)-aph(2) gene, respectively. Among macrolide-resistant isolates, nine had erm(A), and seven had both erm(A) and erm(B) genes. The molecular characterization by pulsed-field gel electrophoresis showed presence of three pulsotypes with their variants. The pulsotype B strains were type IV with SCCmec typing, and representative of pulsotype B was t190 by spa typing and ST8 by MLST typing. The strains with pulsotype A and C were SCCmec III, and representative of these pulsotypes was t030 by spa typing. The MLST type of pulsotype A was ST239 and pulsotype C was one allele variant of ST239. None of the isolates harboured the PVL gene. Presence of hospital-related MRSA strains may indicate transmission of these strains between human and animals. In case of clonal spread beside the infected animals' treatment of MRSA carrier, farm workers should also be considered. Hygienic measures and rational antibiotic use may avoid resistance selection, clonal dissemination of resistant strains and decrease losses because of mastitis in dairy herds.

A collection of 57 enterococcal isolates from different origin (including river, treatment plant, spring and garbage water, soil, animal, and vegetables from Aydın) was screened for the production of bacteriocins. Enterococci were identified at species levels as Enterococcus faecium (34), E. hirae (6), E. casseliflavus (4), E. durans (4), E. faecalis (4), E. mundtii (3) and E. avium (2). Of the 57 isolates 40 of them inhibited the growth of at least one indicator bacterium. Based on our PCR results 54 strains possesed enterocin genes. The genes of entA and entB were the most frequently detected structural genes among the PCR positive strains (54 and 53 strains, respectively) and the entB gene was always associated with entA gene. The highest combination of enterocin genes (24 of 54 strains) detected was entA, entB, entP and entL50A/B. The enterocins AS-48 and CylL LS genes were not found. Three enterococcal isolates, 2 E. faecium and 1 E. hirae were not harbour any of tested enterocin genes. No correlation between the presence of enterocin structural genes and the origin of the strain was detected, also no relationship seemed to exist between the tested enterocin genes and the activity spectra of isolates. Genes encoding bacteriocins are widely disseminated among enterocci from different origin and more studies should be done for evaluate industrial potential of bacteriocins.

Among clinical isolates of P. aeruginosa from patients with DFIs, three virulence genes that can play important roles in tissue penetration (fliC), tissue damage and survival under anaerobic condition (phzS) and cell death (toxA) were significantly more common than isolates from other infections. The Multilocus sequence typing (MLST) analysis of diabetic foot isolates failed to point/indicate the existence of a specific clone or was not able to characterize/identify a specific clone/clonal complex group. Development of new agents to inhibit the synthesis of these genes may improve outcomes in DFIs treatment.

ÖZAmaç: Bu çalışmanın amacı, yeşil kimya yöntemiyle çinko oksit nanopartiküllerini (ZnONPs) sentezlemek ve bu nanopartiküllerin anti-bakteriyel ve anti-kanser etkilerini incelemektir. Gereç ve Yöntemler: Çinko iyonları ve sulu enginar yaprağı (Cynara scolymus) ekstraktı kullanılarak ZnONPs yeşil kimya yöntemiyle sentezlendi. ZnONPs oluşumunun doğrulanması ve karakterizasyonu için morötesi-görünür bölge spektroskopisi (UV-Vis), Fourier dönüşümü kızılötesi spektroskopisi (FTIR), taramalı elektron mikroskobu (SEM), zetasizer ve Enerji dağınım X-ışını spektroskopisi (EDX) analizleri kullanıldı. ZnONPs'nin 4 farklı bakteri türü (E. coli, S. aureus, P. aeruginosa ve E. faecalis) üzerindeki antibakteriyel aktiviteleri, minimal inhibe edici konsantrasyon (MİK) ve kuyucuk difüzyon yöntemiyle ölçüldü. ZnONPs'nin HT-29 insan kolon kanseri hücreleri üzerindeki sitotoksik etkileri konsantrasyon ve zamana bağlı olarak olarak belirlendi. Bulgular: UV-Vis spektrumunda ZnO'ya spesifik olan 320-335 nm aralığında absorbans artışı gözlemlendi. FTIR spektrumunda 426 cm -1 ve 540 cm -1 'de ZnO'ya ait gerilme titreşimleri belirlendi. SEM analizinde partikül boyutu 276-309 nm ölçüldü. ZnONPs'nin zeta-sizer analizlerinde partikül büyüklüğü 137,8 nm ve partikül yükü -6,34 meV olarak bulundu. Antibakteriyel aktivite ölçümlerinde, sentezlenen nanopartiküllerin E. coli ve S. aureus'ta bakteriyel aktivite inhibisyonu sağladığı tespit edildi. ZnONPs HT-29 kolon kanseri hücreleri üzerinde 10 µg/mL'den daha yüksek konsantrasyonlarda sitotoksik etki gösterdi. Sonuç: ZnONPs'nin düşük maliyetle hazırlanabileceği ve klinik tedavilerde yeni ilaç formülasyonları için taşıyıcı sistem olarak kullanılma potansiyeline sahip olduğu bu çalışma ile gösterilmiştir. ABSTRACTAim: The aim of this study is to synthesize zinc oxide nanoparticles (ZnONPs) by green chemistry method and investigate anti-bacterial and anticancer effects of these nanoparticles. Material and Methods: ZnONPs were synthesized by the green chemistry method using zinc ions and aqueous artichoke leaf (Cynara scolymus) extract. Ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), zetasizer and energy dispersive X-ray spectroscopy (EDX) were used to confirm the formation and characterization of ZnONPs. Antibacterial activities of ZnONPs on four different bacteria species (E. coli, S. aureus, P. aeruginosa and E. faecalis) were measured by minimal inhibitory concentration (MIC) and agar well diffusion method. Cytotoxic effects of ZnONPs on HT-29 human colon cancer cells were determined as concentration and time dependent. Results: In the UV-Vis spectrum, absorbance increase was observed in 320-335 nm range which is specific to ZnO. In the FTIR spectrum, stretching vibrations of ZnO were determined in 426 cm -1 and 540 cm -1 . The particle size was 276-309 nm in SEM analysis. In the zeta-sizer measurements of ZnONPs, the particle size was 137.8 nm and the particle charge was -6.34 meV. In the antibacterial activity measu...

Staphylococcus aureus is one of the most frequent agents causing hospital infections. S.aureus has a great ability to adapt itself to variety of conditions and successful clones can be epidemic and even pandemic by its ability spread from one continent to another. The aims of this study were to detect spa types of 397 methicillin-resistant S.aureus (MRSA) strains isolated from 12 centers in different geographical regions of Turkey from 2006 to 2008, and to investigate their clonality by PFGE and MLST typing. Additionally, 91 MRSA from four of those 12 centers isolated during 2011 were also studied for their spa types. PFGE profiles indicated the presence of a major pulsotype, namely pulsotype A with a rate of 91.4% (363/397), followed by pulsotype B (n= 18, 4.5%) and pulsotype C (n= 11, 2.8%). Among isolates tested 363 (91.4%) were SCCmec type III, 30 (7.6%) were SCCmec type IV. Sequence analysis of representative isolates revealed that ST239 (85.1%) was the most common MLST type followed by two MLST types ST737 (4%), and ST97 (2.8%), both SCCmec type IV. Two isolates were ST80 with SCCmec type IV. Of 397 isolates, 338 (85.1%) were t030, followed by t005 (2.5%) and t632 (2%). Among MRSA isolated during 2011, 64 (70.3%) of 91 were t030, 4 (4.4%) were t005, 2 (2.2%) were t015, and 2 (2.2%) were t1094. Among centers the t030 prevalence of 2006-2008 isolates ranged from 59-100%. The highest t030 prevalence was found in Ankara (100%) and lowest in Trabzon (59%) provinces which are located at central and northestern Anatolia, respectively. In Istanbul province, the prevalence of t030 was 94.5% among 2006-2008 isolates which decreased to 55.5% among 2011 isolates. Also a decrease in t030 rates was observed among samples from Konya and Trabzon but not from Aydin. Our results showed that the most common MRSA clone in Turkey is ST 239-SCCmec type III, t030 which persisted during the six years of the study period. Presence of PVL toxin gene was tested by PCR and 5 (3%) isolates found to be positive, of them two were SCCmec Type IV-ST80 and three were SCCmec Type III-ST239. This study is the largest epidemiological survey ever done in Turkey which showed presence of a hospital Turkish clone TR09 (ST239-SCCmecIII-t030) and a community clone TR10 (ST737-SCCmecIV-t005) largely disseminated in Turkey.