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Amaç: Klebsiella pneumoniae ve Acinetobacter baumannii başta olmak üzere dirençli gram negatif mikroorganizmalar yaşamı tehdit eden enfeksiyonlara neden olmaktadır. Bu nedenle Klinik izolatların antibiyotik duyarlılıklarının en kısa sürede ve doğru tespiti kritik öneme sahiptir. Günümüzde karbapenem direnci fenotipik ve/veya genotipik yöntemlerle belirlenmektedir. Fenotipik yöntemlerde (disk difüzyon, mikrodilüsyon) için, hem özgüllük hem de duyarlılık açısından farklılıklar sıklıkla ortaya çıkabilmektedir. Nispeten daha güvenilir sonuçlar veren polimeraz zincir reaksiyonu gibi moleküler metotlar ise iş gücü gerektiren ve yüksek maliyetli yöntemler olduğundan, antibiyotik direncini saptamaya yönelik hızlı, güvenilir ve ekonomik yeni yöntemlere ihtiyaç duyulmaktadır. Gereç ve Yöntem: Çalışmada kromojenik AST Fast ES/NF agar besiyerinin EUCAST standart disk difüzyon metoduyla antibiyotik duyarlılıklarının saptanmasında kullanımının uygunluğu araştırılmıştır. Karbapenem dirençli olduğu moleküler yöntem/otomatize sistemle belirlenen dört K.pneumoniae ve beş A.baumannii izolatıyla çalışılmıştır. Sonuç ve Tartışma: Çalışma sonucunda AST Fast ES/NF agar besiyerinde inhibisyon zon çaplarının 4-6 saat içerisinde ölçülebilir duruma geldiği belirlenmiş ve üretici firmanın önerilene uygun şekilde izolatların duyarlılıkları belirlenmiştir. MHA kullanılarak gerçekleştirilen disk difüzyon test sonuçlarının, AST Fast ES/NF agar kromojenik besiyeriyle elde edilen sonuçlar ile büyük oranda uyumlu olduğu belirlenmiştir. Standart disk difüzyon test yönteminde önerilen inkübasyon süresinin 16-20 saat olduğu ve ancak bu süre sonunda duyarlılık kategorisinin belirlendiği düşünüldüğünde kromojenik besiyerinin zaman açısından önemli bir avantaj sağlayabileceği düşünülmektedir. Anahtar Kelimeler: Acinetobacter baumanni, AST Fast agar, disk difüzyon metodu, kromojenik besiyeri, Klebsiella pneumoniae

Objectives Candida spp. are clinically important pathogens that cause difficulties for treatment by biofilm formation. Considering antifungal resistance rates and the limitations in the discovery of new antifungals, the antifungal and antibiofilm effects of various drugs used for different therapeutic purposes are becoming more important. The goal of our study was to determine the antifungal and antibiofilm effects of the selective serotonin reuptake inhibitors (SSRIs), namely sertraline (SRT), paroxetine (PRX), and fluoxetine (FLX) alone and in combination with fluconazole (FLC) against Candida spp. Materials and methods Twenty Candida spp. strains isolated from clinical samples from Ege University Hospital were identified by the Dalmau method and matrix-assisted laser desorption ionization time of flight mass spectrometry. The minimum inhibitory concentrations (MICs) of the SSRIs and FLC were detected by broth microdilution method. Synergistic interactions between the SSRIs and FLC were investigated by checkerboard assay. The antibiofilm effects of the SSRIs were determined by spectrophotometric microplate method. Results Among the isolates, five different Candida spp. (C. albicans, C. glabrata, C. krusei, C. tropicalis, and C.parapsilosis) were identified. The MICs of the SSRIs ranged between 16-512 μg/mL. While SRT showed the highest antifungal effect, the antibiofilm efficacy of FLX was higher than that of the other agents. Moreover, FLX and PRX showed a synergistic effect with FLC in 13 and 19 isolates, respectively. Four isolates were strong biofilm producers while nine isolates were moderate biofilm producers. C. parapsilosis strains showed higher biofilm production than the other species. At MIC/2 concentration, FLX and SRT alone inhibited mature biofilms in six and five isolates, respectively, while PRX caused increases biofilm formation in seven isolates. Conclusion This study revealed that MIC/2 concentrations of SSRIs could have antifungal and antibiofilm effects. SRT and FLX alone or in combination with antifungals may possibly have therapeutic potential for combating fungal infections.

Pseudomonas aeruginosa is one of the most important causes of hospital infections. Although different antibiotic groups are used for the treatment of P.aeruginosa infections, quinolone groups are distinguished by the advantages of oral administration. However, in recent years, resistance against members of this group has made treatment more difficult. The aim of this study was to investigate the epidemiological relationship and possible mechanisms of resistance in ciprofloxacin resistant P. aeruginosa isolates from Ege University Hospital. The identification of P.aeruginosa bacteria isolated from clinical samples in Ege University Medical Faculty Medical Microbiology Laboratory was determined by VITEK MS automated systems by VITEK compact, antimicrobial susceptibility. The epidemiological relationships of the ciprofloxacin resistant isolates were determined by Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The presence of qnrA, qnrB, qnrS, qepA genes, the quinolone resistance genes and nfxB, mexR, the regulatory genes of the efflux pump, was determined by PCR. The phenylalanine-arginine β-naphthylamide (PAβN) assay was used to determine the activation of the efflux pump. Twenty-two isolates (26.5 %) were found resistant to ciprofloxacin. According to the ERIC-PCR results, 11 unrelated clones were detected. Ciprofloxacin minimum inhibitory concentration (MIC) values were decreased 2-64 times in 10 isolates in the presence of PAIN. No ciprofloxacin MIC change was detected in one isolate. The presence of pump regulatory genes was determined in 10 of the 11 representative isolates, while only qnrB of the genes associated with quinolone resistance was detected in seven representative isolates. qnrA, qnrS, qepA genes were not detected in any isolate. Ciprofloxacin resistant P.aeruginosa isolates are isolated from our hospital. It is noteworthy that the isolates belonging to different genetic groups are in circulation in clinics. Basic resistance mechanisms are thought to be efflux pumps and qnrB genes.

This study aimed to develop fluconazole loaded buccal mucoadhesive oral strip for local treatment of oral candidiasis. Oral strip was prepared by solvent casting method with different polymer combinations and evaluated for weight, thickness, drug content, tensile strength, swelling behavior, in vitro disintegration time and drug release, ex vivo mucoadhesive performance, stability study, ex vivo drug diffusion and in vitro antifungal activity. Oral strips were smooth and elegant in appearance; were uniform in thickness, weight and drug content. The disintegration time was within the range of 23–28 s. The release rates of fluconazole from oral strips reached ?96%. The optimum formulation was stable for 6 months. The in vitro antifungal activity studies showed the efficacy of the oral strip against Candida albicans for an extended period. Cytotoxicity was also studied, and no cytotoxic effect was observed at the tested concentration. The developed oral strip can be a promising delivery system in oral candidiasis. © 2018 12/ECZ/010 This study was supported by a research grant from Ege University ( 12/ECZ/010 ). We would like to acknowledge Ege University Pharmaceutical Sciences Research Center (FABAL) for enabling us to use its laboratory instruments (Nüve Stability Cabin).

Klebsiella pneumoniae insan normal mikrobiyotasında yer alan, fırsatçı patojen olarak özellikle hastane enfeksiyonu yapan Enterobacteriaceae familyası üyesidir. Özellikle karbapenem grubu antibiyotiklere dirençli K.pneumoniae izolatlarının ortaya çıkması nedeniyle hastanede yatış süreleri, mortalite ve morbidite artışları gözlenmektedir. Ülkeler, bölgeler hatta sağlık kuruluşları arasında bile farklı direnç oranları gözlenmekle birlikte, son 10 yıllık dönemde karbapenem dirençli suşların oranlarında hızlı bir artış görülmektedir. Karbapenem dirençli suşların hızlı ve doğru tespiti, etken oldukları enfeksiyonların tedavisinde, uygun antibiyotik ve kombinasyonların belirlenebilmesi, başarı oranının artırılması açısından oldukça önem taşımaktadır. Bu çalışmanın amacı, karbapenem dirençli K.pneumoniae izolatlarındaki karbapenemaz varlığı ve tiplerini araştırarak, bu amaçla kullanılabilecek ticari bir ürün olan "MASTDISCS(TM) ID carbapenemase detection disc set'' ve görece yeni bir yöntem olan "Carbapenem Inactivation Method (CIM)" yöntemlerinden elde edilecek sonuçların polimeraz zincir reaksiyonu (PCR) yöntemiyle karşılaştırmasının yapılmasıdır. Bu amaçla, ertapenem, meropenem ve imipenem antibiyotiklerinden herhangi birine dirençli olduğu saptanan 2015-2016 yılları arasında izole edilen 54 K.pneumoniae izolatı çalışmaya dahil edilmiştir. İzolatların tür düzeyinde tanımlanması VITEK MS ile yapılırken, antibiyotik duyarlılık testleri ise VITEK 2 Compact® otomatize sistemi kullanılarak gerçekleştirilmiştir. Otomatize sistemde karbapenem dirençli olduğu saptanan izolatlarda gradiyent test yöntemiyle "The European Committee on Antimicrobial Susceptibility Testing (EUCAST)" önerileri doğrultusunda minimum inhibitör konsantrasyonu (MİK) değerleri belirlenmiştir. Bu izolatlarda blabla "MASTDISCS(TM) ID carbapenemase detection disc set" ve "Carbapenem Inactivation Method (CIM)" yöntemleriyle araştırılmış ve izolatların klonal ilişkisini saptamak için REP-PCR uygulanmıştır. Elli dört K.pneumoniae izolatı karbapenem dirençli olarak belirlenirken, imipenem, meropenem ve ertapenem MİK ve MİK değerleri 32 µg/ml olarak belirlenmiştir. İzolatların 33'ünde yalnız blayalnız blabla klon gözlenmiştir. "MASTDISCS(TM) ID carbapenemase detection disc set" karbapenemaz üreten izolatların tamamını saptayabilirken, metallo beta-laktamaz (MBL) ve OXA-48 enzim birlikteliği olan izolatlarda OXA-48 ayrımını yapmada yetersiz kaldığı gözlenmiştir. CIM yöntemi OXA-48 içeren izolatlarda oldukça düşük oranda (%46.15) pozitif sonuç verirken, blabaşarılı olarak bulunmuştur. Çalışmamız kapsamında, Mastdiscs-ID yönteminin, ülkemizde prevalansı yüksek olan bla, bla , bla , bla genleri PCR ile araştırılmıştır. Karbapenem dirençli izolatlarda fenotipik olarak enzim tiplendirilmesi belirlenirken, 19 izolatta her iki genin birlikte bulunduğu saptanmıştır. İzolatların hiçbirinde, , bla , bla , ikisinde genlerine rastlanmamıştır. İzolatlar REP-PCR yöntemiyle değerlendirildiğinde, altı ana içeren izolatlarda saptama oranı (%85.71) daha varlığını saptamada başarıyla kullanılabileceği sonucuna varılmıştır, Being a member of the Enterobacteriaceae family, Klebsiella pneumoniae is an opportunistic pathogen that inhabits normal human microbiota and causes predominantly hospital-acquired infections. The emergence of K.pneumoniae isolates which are resistant particularly to the carbapenem group of antibiotics has led to an increase in hospitalization period, mortality and morbidity. Although different rates of resistance are observed between countries, regions and even healthcare facilities, there has been a rapid increase in the prevalence of carbapenem-resistant strains in the last 10 years. Fast and correct identification of carbapenem-resistant strains is important for the successful treatment of infections caused by these resistant bacteria. The objective of this study was to investigate the presence and the types of carbapenemases in carbapenem-resistant K.pneumoniae strains using “MASTDISCS™ ID carbapenemase detection disc set”, a commercial product that can be used for this purpose, and “Carbapenem Inactivation Method (CIM)”, a relatively new method, and compare the results of these methods by polymerase chain reaction (PCR). For this purpose, we used 54 K.pneumoniae strains isolated in 2015-2016, that were resistant to any of the ertapenem, meropenem or imipenem antibiotics. The identification of the strains was performed using VITEK MS and their antibiotic susceptibility tests were carried out using the VITEK 2 Compact® automated system. For the strains that were found resistant to carbapenems in the automated system, the minimum inhibitor concentration (MIC) values were determined by the gradient testing method according to the recommendations of “The European Committee on Antimicrobial Susceptibility Testing (EUCAST)”. The blaOXA-48, blaIMP, blaNDM, blaVIM, and blaSIM genes were investigated with PCR among these isolates. Phenotypic enzyme typing was performed in the carbapenem-resistant strains using the “MASTDISCS™ ID carbapenemase detection disc set” and “Carbapenem Inactivation Method (CIM)”. REP-PCR was used to reveal clonal relationship of the isolates. The 54 K.pneumoniae isolates were found as resistant to carbapenem and the MIC50 and MIC90 values of imipenem, meropenem and ertapenem were 32 µg/ml. Only 33 of the strains had blaOXA-48 and two of them had only blaNDM, the remaining 19 strains had both of these two genes. The blaIMP, blaVIM and blaSIM genes were not encountered in any of the isolates. When the isolates were assessed by the REPPCR method, six main clones were detected. The “MASTDISCS™ ID carbapenemase detection disc set” was able to detect all the carbapenemase producing strains and it remained incapable of distinguishing OXA-48 in the strains which had both OXA-48 and metallo beta lactamase (MBL) enzymes. The CIM method showed a low rate of positivity (46.15%) in the strains containing blaOXA-48, but was found much more successful in the strains containing blaNDM with a detection rate of 85.71%. In this study, it was concluded that the Mastdiscs-ID method could be successfully used to detect the presence of blaOXA-48 which has a high prevalence in our country.

Objectives The aim of this study was to determine the antibiotic resistance profile, clonal relation and efficacy of antibiotic combinations in nosocomial multidrug resistant (MDR) Acinetobacter baumannii. Materials and methods Antibiotic susceptibilities of 84 MDR A. baumannii against tigecycline (TGC), colistin (CL), amikacin (AK), ciprofloxacin (CIP), meropenem (MR), moxifloxacin (MXF), rifampicin (RF) were determined by microdilution method. Clonal relationship was investigated by genotyping using AP-PCR and antibiotyping. Interactions of antibiotic combinations were tested against clonally unrelated strains by the checkerboard (CB) method. The efficacy of the best combinations was also assesed on a selected isolate by the time-kill (TK) method. Results CIP, RF, MXF, MR, AK resistance was found as 90.47%; 47.62%; 22.62%; 58.33%; 50% respectively; however; CL and TGC were not ascertained. The isolates were distinguished as 25 different antibiotypes and 15 varied molecular patterns. The best synergistic effect was detected in combinations of CL with RF (100%) and MR (100%), in combinations of TGC with RF (53%) against clonally unrelated 15 MDR A. baumannii isolates by the CB method. While CL-RF and CL-MR showed synergy by TK method like CB, on the other hand TGC-RF indicated additive interactions by TK. Conclusion In this study, both synergy tests showed that CL in combination with RF would be a good option in MDR A. baumannii.

The purpose of this study was to develop a suitable mucoadhesive in situ gel formulation of clotrimazole (CLO) for the treatment of vaginal candidiasis. For this aim, the mixture of poloxamer (PLX) 407 and 188 were used to prepare in situ gels. Hydroxypropyl methylcellulose (HPMC) K100M or E50 was added to in situ gels in 0.5% ratio to improve the mucoadhesive and mechanical properties of formulations and to prolong the residence time in vaginal cavity. After the preparation of mucoadhesive in situ gels; gelation temperature/time, viscosity, mechanical, mucoadhesive, syringeability, spreadibility and rheological properties, in vitro release behavior, and anticandidal activities were determined. Moreover vaginal retention of mucoadhesive in situ gels was investigated with in vivo distribution studies in rats. Based on the obtained results, it was found that gels prepared with 20% PLX 407, 10% PLX 188 and 0.5% HPMC K100M/E50 might be suitable for vaginal administration of CLO. In addition, the results of in vivo distribution studies showed that gel formulations remained on the vaginal mucosa even 24 h after application. In conclusion, the mucoadhesive in situ gels of CLO would be alternative candidate for treatment of vaginal candidiasis since it has suitable gel properties with good vaginal retention.

WOS: 000435396300005, PubMed ID: 30020039, Introduction: Increased tuberculosis prevalence, and isolation of multidrug resistant (MDR) Mycobacterium tuberculosis strains frequently as causative organisms from tuberculosis infections are resulted in increasing need of new anti-tuberculosis drugs. Nowadays, fluoroquinolones known to have fewer side effects than the other drugs used in treatment of tuberculosis are sometimes assessed even as first-line anti-tuberculosis drugs due to their in vitro and in vivo strong activity. It was aimed in this study to investigate phenotypically the fluoroquinolone susceptibility in MDR and non-MDR M. tuberculosis isolates. Materials and Methods: A total of 126 MDR and non-MDR M. tuberculosis isolates from mycobacteriology laboratory of two hospitals in the Aegean Region of Turkey were included in the study. Ciprofloxacin (CIP), levofloxacin (LEV) and moxifloxacin (MXF) susceptibilities were assessed by agar proportion method according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Results: Twelve (15.2%), 5 (6.3%) and 4 (5.1%) of the MDR M. tuberculosis strains were resistant to CIP, LEV, MXF, respectively [resistance breakpoints (mu g/mL); CIP (> 2), LEV (> 1), MXF (> 0.5)] while non-MDR strains were susceptible to CIP, LEV, MXF. Conclusion: Consequently, although high fluoroquinolone susceptibilities were evaluated as a pleasing data in this study, to preserve their efficiency for many years steadily, quinolone usage and resistance increment in MDR M. tuberculosis isolates should be monitored elaborately., Ege University Scientific Research Projects Foundation (EGE-BAP) Committee [06-ECZ-007], Authors would like to thank to Ege University Scientific Research Projects Foundation (EGE-BAP) Committee for their financial supports (Project Number: 06-ECZ-007).

Being a member of the Enterobacteriaceae family, Klebsiella pneumoniae is an opportunistic pathogen that inhabits normal human microbiota and causes predominantly hospital-acquired infections. The emergence of K.pneumoniae isolates which are resistant particularly to the carbapenem group of antibiotics has led to an increase in hospitalization period, mortality and morbidity. Although different rates of resistance are observed between countries, regions and even healthcare facilities, there has been a rapid increase in the prevalence of carbapenem-resistant strains in the last 10 years. Fast and correct identification of carbapenem-resistant strains is important for the successful treatment of infections caused by these resistant bacteria. The objective of this study was to investigate the presence and the types of carbapenemases in carbapenem-resistant K.pneumoniae strains using "MASTDISCS™ ID carbapenemase detection disc set", a commercial product that can be used for this purpose, and "Carbapenem Inactivation Method (CIM)", a relatively new method, and compare the results of these methods by polymerase chain reaction (PCR). For this purpose, we used 54 K.pneumoniae strains isolated in 2015-2016, that were resistant to any of the ertapenem, meropenem or imipenem antibiotics. The identification of the strains was performed using VITEK MS and their antibiotic susceptibility tests were carried out using the VITEK 2 Compact® automated system. For the strains that were found resistant to carbapenems in the automated system, the minimum inhibitor concentration (MIC) values were determined by the gradient testing method according to the recommendations of "The European Committee on Antimicrobial Susceptibility Testing (EUCAST)". The blaOXA-48, blaIMP, blaNDM, blaVIM, and blaSIM genes were investigated with PCR among these isolates. Phenotypic enzyme typing was performed in the carbapenem-resistant strains using the "MASTDISCS™ ID carbapenemase detection disc set" and "Carbapenem Inactivation Method (CIM)". REP-PCR was used to reveal clonal relationship of the isolates. The 54 K.pneumoniae isolates were found as resistant to carbapenem and the MIC50 and MIC90 values of imipenem, meropenem and ertapenem were 32 µg/ml. Only 33 of the strains had blaOXA-48 and two of them had only blaNDM, the remaining 19 strains had both of these two genes. The blaIMP, blaVIM and blaSIM genes were not encountered in any of the isolates. When the isolates were assessed by the REP-PCR method, six main clones were detected. The "MASTDISCS™ ID carbapenemase detection disc set" was able to detect all the carbapenemase producing strains and it remained incapable of distinguishing OXA-48 in the strains which had both OXA-48 and metallo beta lactamase (MBL) enzymes. The CIM method showed a low rate of positivity (46.15%) in the strains containing blaOXA-48, but was found much more successful in the strains containing blaNDM with a detection rate of 85.71%. In this study, it was concluded that the Mastdiscs-ID method could be successfully used to detect the presence of blaOXA-48 which has a high prevalence in our country.

WOS: 000337705100001, PubMed ID: 24914716, The aim of the present study was to evaluate chitosan as a vaginal mucoadhesive gel base for econazole nitrate and miconazole nitrate. To this aim, different types of chitosan with different molecular masses and viscosity properties [low molecular mass chitosan (viscosity: 20,000 mPa s), medium molecular mass chitosan (viscosity: 200,000 mPa s), high molecular mass chitosan (viscosity: 800,000 mPa s)] have been used. First, rheological studies were conducted on chitosan gels. Mechanical, syringeability and mucoadhesive properties of chitosan gels were determined. Release profiles of econazole nitrate and miconazole nitrate from chitosan gels were obtained and evaluated kinetically. In addition, anticandidal activities of formulations were determined. Finally, vaginal retention of chitosan gels in rats was evaluated by in vivo distribution studies. Based on the results, it can be concluded that gels prepared with medium molecular mass chitosan might be effectively used for different antifungal agents in the treatment of vaginal candidiosis, since it has high mucoadhesiveness, suitable mechanical and release properties with good vaginal retention., Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106/S/196], This work is a part of the authors' research project (No. 106/S/196) supported by the Scientific and Technological Research Council of Turkey (TUBITAK).

WOS: 000414976900040, PubMed ID: 29151338, Background/aim: The Aegean Region is the second-ranking region in Turkey according to the Human Development Index and population density and it hosts 1/8 of Turkey's population. Izmir is the largest city of the region, receiving internal migration both from inside and outside the region. The tuberculosis incidence in Izmir is lower than overall in Turkey: 17.7/100,000 in 2011. Our aims were to determine genotypes of Mycobacterium tuberculosis isolates; to explore possible associations between genotypes with case-demographic data, clinical presentation, and antimicrobial susceptibility patterns; and to determine variations in genotype distribution of strains isolated in Ege University Hospital, Izmir. Materials and methods: Forty-nine M. tuberculosis isolates from 49 patients in 1996-2000 and 421 M. tuberculosis isolates from 421 patients in 2009-2014 were spoligotyped. Drug susceptibility testing and demographic data of the 421 isolates were investigated. Chi-square, Student's t, and Mann-Whitney U tests were used for analyses. Results: Among the 470 M. tuberculosis strains, 132 different spoligopatterns were identified and 46 different clusters for 384 strains were determined. The most predominant spoligotypes were ST53 (n = 116; 24.7%) and ST41 (n = 38; 8.1%), followed by ST50 (5.7%), ST284 (4.7%), and ST4 (4.3%), respectively. ST53 was the most predominant type in both sexes. Multidrug resistance (MDR) was determined in 12 isolates, of which six were ST1. Conclusion: As a consequence of worldwide migration and increasing status of HIV-infected hosts, the increasing prevalence of Beijing strains with higher MDR rates may threaten disease control programs. With its increasing trend, ST284 could replace ST41 in the following years in this region., Ege University Scientific Research Project Committee [2009-TIP-071, 2010-TIP-022, 014-ECZ-019], This study was funded by the Ege University Scientific Research Project Committee (2009-TIP-071, 2010-TIP-022, and 2014-ECZ-019). The authors would like to thank Health Technician Senay Yildirim for her assistance in the laboratory processes, and also thank the Pharmaceutical Science Research Center (FABAL) of the Ege University Faculty of Pharmacy for their equipmental support.

WOS: 000398275000003, Objectives: The aim of this study was to determine the antibiotic resistance profile, clonal relation and efficacy of antibiotic combinations in nosocomial multidrug resistant (MDR) Acinetobacter baumannii. Materials and Methods: Antibiotic susceptibilities of 84 MDR A. baumannii against tigecycline (TGC), colistin (CL), amikacin (AK), ciprofloxacin (CIP), meropenem (MR), moxifloxacin (MXF), rifampicin (RF) were determined by microdilution method. Clonal relationship was investigated by genotyping using AP-PCR and antibiotyping. Interactions of antibiotic combinations were tested against clonally unrelated strains by the checkerboard (CB) method. The efficacy of the best combinations was also assesed on a selected isolate by the time-kill (TK) method. Results: CIP, RF, MXF, MR, AK resistance was found as 90.47%; 47.62%; 22.62%; 58.33%; 50% respectively; however; CL and TGC were not ascertained. The isolates were distinguished as 25 different antibiotypes and 15 varied molecular patterns. The best synergistic effect was detected in combinations of CL with RF (100%) and MR (100%), in combinations of TGC with RF (53%) against clonally unrelated 15 MDR A. baumannii isolates by the CB method. While CL-RF and CL-MR showed synergy by TK method like CB, on the other hand TGC-RF indicated additive interactions by TK. Conclusion: In this study, both synergy tests showed that CL in combination with RF would be a good option in MDR A. baumannii., Ege University Scientific Research ProjectEge University [10ECZ023], This study was supported as an Ege University Scientific Research Project (10ECZ023). The authors would like to thank to Prof. Zeki Topcu for helping in molecular part of the study.

The antibacterial activities of cetylpyridinium-montmorillonites (CP + -Mt) were tested on Staphylococcus aureus and Pseudomonas aeruginosa . The Mt were prepared by using the five different CP + amounts of 0.5, 0.7, 1.0, 1.5, and 2.0 times of cation exchange capacities (CEC) of Na + -Mt. Desorption of CP + from the surface was also determined by successive adsorption–desorption experiments. The antibacterial activity tests were conducted by using Na + -Mt and CP + -Mt through the disk diffusion (Kirby–Bauer) method against the P. aeruginosa ATCC 27853, and S. aureus ATCC 29213 strains. XRD analyses of the CP + -Mt showed that basal spacing regularly increased by increasing the amount of CP + cations. Adsorption/desorption studies revealed that desorption occurred only in 2.0 CEC CP + -Mt by dilution with water and in 1.0 CEC CP + -Mt at a pH of 2.0. Na + -Mt exhibited no antibacterial activity against both bacteria. All of the CP + -Mt samples prepared were active against S. aureus , whereas they had no antibacterial activity against P. aeruginosa . Minimum inhibitory concentration (MIC) was found to be 1 mg/plate against S. aureus , determined with 0.5 CEC CP + -Mt. Because nearly no desorption of CP + was observed, the antibacterial activity was attributed to the CP + bound to the Mt surface.

Objectives: The aim of this study was to determine the antibiotic resistance profile, clonal relation and efficacy of antibiotic combinations in nosocomial multidrug resistant (MDR) Acinetobacter baumannii. Materials and Methods: Antibiotic susceptibilities of 84 MDR A. baumannii against tigecycline (TGC), colistin (CL), amikacin (AK), ciprofloxacin (CIP), meropenem (MR), moxifloxacin (MXF), rifampicin (RF) were determined by microdilution method. Clonal relationship was investigated by genotyping using AP-PCR and antibiotyping. Interactions of antibiotic combinations were tested against clonally unrelated strains by the checkerboard (CB) method. The efficacy of the best combinations was also assesed on a selected isolate by the time-kill (TK) method. Results: CIP, RF, MXF, MR, AK resistance was found as 90.47%; 47.62%; 22.62%; 58.33%; 50% respectively; however; CL and TGC were not ascertained. The isolates were distinguished as 25 different antibiotypes and 15 varied molecular patterns. The best synergistic effect was detected in combinations of CL with RF (100%) and MR (100%), in combinations of TGC with RF (53%) against clonally unrelated 15 MDR A. baumannii isolates by the CB method. While CL-RF and CL-MR showed synergy by TK method like CB, on the other hand TGC-RF indicated additive interactions by TK. Conclusion: In this study, both synergy tests showed that CL in combination with RF would be a good option in MDR A. baumannii.

In Extended Spectrum Beta-Iactamase (ESBI) producing Escherichia coli and Klebsiella pneumoniae strains, fluoroquinolone resistance is acquired mostly by target mutations in topoisomerase genes and increased expression of efflux pumps. ESBI positive 65 E. coli and 48 K pneumoniae strains isolated in Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Ege University were investigated in this study. 58 E. coli and 21 K pneumoniae isolates displayed reduced susceptibility (intermediately-resistant or resistant) to ciprofloxacin or nalidixic acid by disc diffussion method. Ciprofloxacin, Phenyl-arginine-beta-naphthylamide (Phe-Arg-fi-naphthylamide-PfiNA) and nalidixic acid MIC values of these isolates were determined. The changes in nalidixic acid and ciprofloxacin MIC values in the presence of fixed concentration of PfiNA (20 pLg/ml) were investigated. Among 21 K.pneumoniae isolates, at least four fold reductions were observed in MIC values of ciprofloxacin, nalidixic acid and both for four, five and two isolates respectively. Among 58 E. coli isolates, at least four fold reductions were observed in MIC values of ciprofloxacin, nalidixic acid and both for eight, four and three isolates respectively. This result was evaluated to be indicative for presence of efflux pump mediated resistance in these isolates

The antibacterial effects of Cu 2+ -, Zn 2+ -, Ag + -, Ag 0 - and cetylpridinium-exchanged montmorillonites were tested on Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213 strains which are highly resistant to antibiotics and cause severe infections in hospitalized patients. The exchange reactions were carried out using heavy metal and cetylpridinium (CP) cations in amounts that are equal to or less than the amounts required forming a monolayer on montmorillonite surface. The amounts required for the monolayer formation were determined by conducting batch adsorption experiments. The antibacterial activity of the samples was detected by the disk diffusion method. Cu 2+ -, Ag + -exchanged and Ag 0 -covered montmorillonites had a good antibacterial effect against P. aeruginosa and S. aureus as did the Zn 2+ -exchanged montmorillonite against S. aureus . However, the CP-exchanged montmorillonite was ineffective for both of the bacterial species. Thus, the heavy metal exchanged montmorillonites could be used in pharmaceutical applications, personal care products, in the decontamination of P. aeruginosa reservoirs in hospitals, and also in aqueous based cleaning agents and liquid and bar soaps. Zn 2+ -exchanged montmorillonite has potentiality to be used as a low cost substitution to silver for applications against S. aureus .

Amaç: Bu çalışmada, Salmonella spp. izolatlarının antibiyotik duyarlılıklarının, biyofilm oluşturma kapasitelerinin araştırılması ve ayrıca biyofilm oluşumuna çeşitli ortam koşullarının ve siprofloksasin (CIP) varlığının etkilerinin incelenmesi amaçlandı.Gereç ve Yöntem: Ege Üniversitesi Tıp Fakültesi Tıbbi Mikrobiyoloji Bakteriyoloji Laboratuvarı'nda 2012 yılında izole edilen 44 Salmonella spp. izolatı çalışmaya alındı. İzolatların CIP duyarlılıkları CLSI kriterlerine göre mikrodilüsyon yöntemi ile ve biyofilm oluşturma kapasiteleri kristal viyole kullanılarak spektrofotometrik mikroplak yöntemi ile araştırıldı. Daha sonra, farklı sıcaklık, NaCl konsantrasyonu, pH değeri uygulanan koşullar altında ve farklı konsantrasyonlarda CIP (1/2MİK, MİK, 2MİK) varlığında biyofilm oluşturma kapasiteleri araştırıldı. Orta ve güçlü düzeyde biyofilm oluşturabilen Salmonella izolatları için her bir parametrenin biyofilm oluşumuna etkisi diğer iki parametre sabit tutularak (sıcaklık: 4°C, 20 °C, 37°C, pH: 4, 6, 7.3, NaCl: %0.5, %4, %6) test edildi.Bulgular: Standart koşullarda (37°C, pH:7.3, NaCl: %0.5), orta düzeyde biyofilm (%59) ve güçlü biyofilm (%5) oluşturan 28 izolatın pH:6'da pH:4'e, %6 NaCl'de %4 NaCl'ye ve 20°C de 4°C'ye göre daha iyi biyofim oluşturduğu gözlendi. Bir Salmonella izolatında CIP direnci saptanırken, bir izolat da orta duyarlı olarak bulundu. CIP, orta düzeyde biyofilm oluşturan bir izolatta hem biyofilm üretimini azalttı hem de önceden oluşmuş biyofilm tabakası üzerinde inhibe edici etki gösterdi.Sonuç: Bu çalışma, incelenen Salmonella izolatlarının belirli çevre koşullarında daha fazla biyofilm oluşturarak yaşam şanslarını arttırabildiklerini ve CIP'nin biyofilm üretimi üzerine etkili olduğunu ortaya koymuştur., Objective: This study aimed to investigate the antibiotic susceptibility and biofilm forming capacity of isolates of Salmonella spp., and the effect of different environmental conditions and the presence of ciprofloxacin (CIP) on biofilm forming ability. Materials and Methods: Forty-four Salmonella spp. strains isolated in 2012 in Ege University, Faculty of Medicine, Bacteriology Laboratory of Department of Medical Microbiology, were included in this research. CIP susceptibilities were determined by microdilution method according to the CLSI recommendations and biofilm forming capacities were examined using crystal violet by spectrophotometric microplate method. Afterwards, the effects of different ambient temperatures, NaCl concentrations, pH values and presence of CIP (1/2MIC, MIC, 2MIC) on their biofilm forming capacities were assessed. The impact of each parameter on biofilm formation in Salmonella strains with moderate and strong biofilm forming capacities at standard conditions (pH 7.3- NaCl 0.5%- 37°C) were tested singly while the other two parameters were kept at fixed levels (temperature: 4°C, 20°C, 37°C; pH: 4, 6, 7.3; NaCl: 0.5%, 4%, 6%). Results: Under standart conditions, a total of 28 isolates of Salmonella spp. with moderate (59%) and strong biofilm (5%) forming capacities showed higher biofilm forming ability at pH 6, NaCl concentration of 6%, and ambient temperature of 20°C when compared with pH 4, NaCl concentration of 4%, and ambient temperature of 4°C. CIP resistance was found in one Salmonella spp. isolate, and one isolate demonstrated intermediate resistance to CIP. CIP inhibited both biofilm formation and showed inhibitory effect on pre-formed biofilm layer in a modarate biofilm producer. Conclusion: This study revealed that Salmonella isolates increased their changes of staying alive in certain conditions by increasing their biofilm forming ability and CIP was found to be effective on biofilm formation.

The emergence of phenotypic resistance to ciprofloxacin and levofloxacin in methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MRSA) strains was studied. Twenty MRSA and 77 methicillin-sensitive S.aureus (MSSA) strains susceptible to both quinolones were investigated for resistance after single step or serial passages. No growth of 20 MRSA strains was observed at 4×MIC of levofloxacin after 48 h incubation, but 4 of 77 (5%) MSSA strains grew at the same concentration. At 4×MIC concentration of ciprofloxacin, 10 MSSA (13%) and five MRSA (25%) strains were grown. In the serial passages of MRSA strains, resistance to ciprofloxacin was 75 and 5% for levofloxacin by the third passage. In the seventh passage this resistance was 100 and 15%, respectively. In MSSA strains, resistance to ciprofloxacin was 75 and 19% to levofloxacin at the third passage and at the seventh passage, 100 and 61%, respectively. Emergence of ciprofloxacin resistance was more common and developed more rapidly than resistance to levofloxacin in both MRSA and MSSA strains. © 2003 Elsevier Science B.V. and the International Society of Chemotherapy. All rights reserved.

WOS: 000365565100012, PubMed ID: 25303196, Objective: Stenotrophomonas maltophilia is an opportunistic pathogen found predominantly in the enviroment and hospital setting. Invasive procedures and treatment methods, instruments used for diagnosis and irrational antibiotic use play major roles in the spread of this pathogen. The study aimed to evaluate consecutive S maltophilia isolation from bronchoalveolar lavage samples during bronchoscopy procedure during a week. Methods: Four patients consecutively had S maltophilia isolated during bronchoscopy between September 8 and 15, 2012. The identification of the isolates and their antibiotic susceptibility were studied by automated Vitek version 2.0 (Biomerieux, France) system. The clonal relationship between the isolates was studied by enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR). Results: Four consecutive S maltophilia isolates had identical band patterns and showed clonal relatedness. Conclusion: Bronchoscopy is a common invasive procedure that is utilized in chest diseases departments and intensive care units (ICUs). Contamination may take place due to inappropiate use and cause spread of infectious pathogens. In the current study, we detected consecutive S maltophilia strains with identical band patterns isolated within a week. After appropiate disinfection and cleaning procedures, no further isolation was detected.

Acinetobacter baumannii is an opportunistic human pathogen which causes life-threatening nosocomial infections such as ventilator-associated pneumonia, bacteremia, meningitis, urinary tract and wound infections. Treatment options are very limited for infections caused by multi-drug resistant (MDR) A.baumannii strains. Until recently, the majority of studies related to A.baumannii have focused on antibiotic resistance, treatment protocols and epidemiological data, however, there have been few studies addressing the virulence factors of this organism. The features such as biofilm formation, serum resistance, motility, efflux pumps and iron acquisition mechanisms help the bacterium to survive in adverse environmental conditions and facilitate the development of an infection. The aim of the present study was to investigate the basic characteristics that contribute to the virulence of clinically important MDR A.baumannii isolates. Sixty-five ciprofloxacin-imipenem-trimethoprim/sulfamethoxazole-resistant A.baumannii strains isolated from various clinical specimens between December 2011 and March 2012 at Ege University Faculty of Medicine, Department of Medical Microbiology were included in the study. The clonal relationship of the isolates was analyzed by PCR using Enterobacterial repetitive intergenic consensus (ERIC)-2 primer. Biofilm formation, serum resistance, twitching and swarming motility, efflux pump and siderophore production were sought in representatives of each clone. Investigated MDR A.baumannii isolates were classified into seven main clusters, and the largest cluster included 86% of the strains. The virulence-associated features were investigated in 16 representative strains, including sub-groups. Twelve, three and one of the examined strains were determined to be strong, intermediate and weak biofilm producers, respectively. Siderophore production was not encountered in any of the isolates. Of the sixteen strains, two, one and thirteen isolates were found to be resistant, moderately susceptible and susceptible to bactericidal effect of serum, respectively. In our study, swarming motility was observed in seven strains while twitching motility was observed in only one strain. Swarming was simultaneously detected with twitching in one isolate. The presence of an efflux pump was investigated with ciprofloxacin in 16 representative strains but none of them were positive. However, eflux pump was determined in two of the five doxycycline resistant strains. Biofilm production was the most commonly observed characteristic among the examined strains. In addition, serum resistance, swarming and an efflux pump which has a spectrum including tetracyclines, were also determined among features associated with virulence. While the biofilm production was encountered at the members of all clones, serum resistance was found only in the representatives of the most dominant clone. Motility and the presence of an efflux pump were not associated with a particular clone. MDR A.baumannii strains are among the most important agents of nosocomial infections in our hospital and all over the world. Revealing the characteristics that play a role in the pathogenesis of these isolates, will contribute to infection control measures and to the investigation of new treatment options.

Acinetobacter baumannii, ventilatörle ilişkili pnömoni, bakteriyemi, menenjit, üriner sistem ve yara enfeksiyonları gibi insan sağlığını tehdit eden önemli nozokomiyal enfeksiyonlara neden olan fırsatçı bir patojendir. Çok ilaca dirençli (ÇİD) A.baumannii suşlarının neden olduğu enfeksiyonlarda tedavi seçenekleri oldukça kısıtlıdır. Günümüze kadar A.baumannii izolatlarıyla yapılan çalışmaların çoğu antibiyotik direnci, tedavi protokolleri ve epidemiyolojik veriler üzerine odaklanmasına karşın, bu bakterinin virülans faktörleriyle ilgili çalışmaların sayısı azdır. Biyofilm oluşturma, serum direnci, hareket, efluks pompası ve demir kazanımı gibi özellikler, bakterinin olumsuz ortam koşullarında hayatta kalmasını ve enfeksiyon oluşturmasını kolaylaştırmaktadır. Bu çalışmada, klinik önemi gittikçe artan ÇİD A.baumannii izolatlarının virülansıyla ilişkili temel özelliklerin araştırılması hedeflenmiştir. Çalışmaya, Ege Üniversitesi Tıp Fakültesi, Tıbbi Mikrobiyoloji Anabilim Dalında Aralık 2011-Mart 2012 tarihleri arasında çeşitli klinik örneklerden izole edilen, siprofloksasin-imipenem-trimetoprim/sülfametoksazole dirençli 65 A.baumannii suşu alınmıştır. İzolatların klonal yakınlıkları, “Enterobacterial repetitive intergenic consensus (ERIC)” dizilerine özgü ERIC-2 primeri kullanılarak PCR ile incelenmiştir. Her klondan bir temsilci seçilerek, bu suşlarda biyofilm oluşturma, siderofor üretimi, serum direnci, “twitching (seğirme)” ve “swarming (yayılma)” hareketleri ile efluks pompası varlığı araştırılmıştır. Çalışmaya alınan ÇİD A.baumannii suşlarının yedi ana grup altın- da toplandığı, bu klonlardan en büyüğünün incelenen izolatların %86’sını kapsadığı belirlenmiştir. Alt gruplar da dahil olacak şekilde tüm klonlardan temsili birer suş alınarak, toplam 16 bakteride virülansla ilişkili özellikler araştırılmıştır. Biyofilm oluşturma kapasitesi incelenen bu suşlardan 12’sinin güçlü, üçünün orta, birinin ise zayıf biyofilm üreticisi olduğu belirlenirken, hiçbir suşta siderofor üretimi saptanamamış- tır. On altı suştan ikisinin, serumun bakterisidal etkisine dirençli, birinin orta duyarlı, 13’ünün ise duyarlı olduğu bulunmuştur. Çalışmamızda, sadece bir suşta “twitching”, yedi suşta ise “swarming” hareketi gözlenmiştir. “Twitching” görülen izolatta aynı zamanda “swarming” de saptanmıştır. Siprofloksasin ile efluks pompası varlığı araştırılan 16 suştan hiçbirinde bu yönde bir bulguya rastlanmazken, doksisikline dirençli beş suştan ikisinde efluks pompası tespit edilmiştir. İncelenen suşlarda, biyofilm oluşturmanın en yaygın gözlenen özellik olduğu, bunun yanı sıra serum direnci, “swarming” hareketi ve spektrumunda tetrasiklinleri içeren bir efluks pompasının da virülansla ilişkili özellikler arasında yer aldığı belirlenmiştir. Biyofilm oluşumuna tüm klonlarda, serum direncine ise sadece en baskın klonun temsilcilerinde rastlanmıştır. Hareket ve efluks pompası varlığı ise belirli bir klona özgü değildir. Hastanemizde olduğu gibi tüm dünyada nozokomiyal enfeksiyonların en önemli etkenlerinden olan ÇİD A.baumannii izolatlarının patojenitesinde rol oynayan özelliklerin ortaya konması, gerekli enfeksiyon kontrol önlemlerinin alınması ve yeni tedavi seçeneklerinin araştırılmasında yol gösterici olacaktır., Acinetobacter baumannii is an opportunistic human pathogen which causes life-threatening nosocomial infections such as ventilator-associated pneumonia, bacteremia, meningitis, urinary tract and wound infections. Treatment options are very limited for infections caused by multi-drug resistant (MDR) A.baumannii strains. Until recently, the majority of studies related to A.baumannii have focused on antibiotic resistance, treatment protocols and epidemiological data, however, there have been few studies addressing the virulence factors of this organism. The features such as biofilm formation, serum resistance, motility, efflux pumps and iron acquisition mechanisms help the bacterium to survive in adverse environmental conditions and facilitate the development of an infection. The aim of the present study was to investigate the basic characteristics that contribute to the virulence of clinically important MDR A.baumannii isolates. Sixty-five ciprofloxacin-imipenem-trimethoprim/sulfamethoxazole-resistant A.baumannii strains isolated from various clinical specimens between December 2011 and March 2012 at Ege University Faculty of Medicine, Department of Medical Microbiology were included in the study. The clonal relationship of the isolates was analyzed by PCR using Enterobacterial repetitive intergenic consensus (ERIC)-2 primer. Biofilm formation, serum resistance, twitching and swarming motility, efflux pump and siderophore production were sought in representatives of each clone. Investigated MDR A.baumannii isolates were classified into seven main clusters, and the largest cluster included 86% of the strains. The virulence-associated features were investigated in 16 representative strains, including sub-groups. Twelve, three and one of the examined strains were determined to be strong, intermediate and weak biofilm producers, respectively. Siderophore production was not encountered in any of the isolates. Of the sixteen strains, two, one and thirteen isolates were found to be resistant, moderately susceptible and susceptible to bactericidal effect of serum, respectively. In our study, swarming motility was observed in seven strains while twitching motility was observed in only one strain. Swarming was simultaneously detected with twitching in one isolate. The presence of an efflux pump was investigated with ciprofloxacin in 16 representative strains but none of them were positive. However, eflux pump was determined in two of the five doxycycline resistant strains. Biofilm production was the most commonly observed characteristic among the examined strains. In addition, serum resistance, swarming and an efflux pump which has a spectrum including tetracyclines, were also determined among features associ- ated with virulence. While the biofilm production was encountered at the members of all clones, serum resistance was found only in the representatives of the most dominant clone. Motility and the presence of an efflux pump were not associated with a particular clone. MDR A.baumannii strains are among the most important agents of nosocomial infections in our hospital and all over the world. Revealing the characteristics that play a role in the pathogenesis of these isolates, will contribute to infection control measures and to the investigation of new treatment options.

The increasing prevalence of vancomycin-resistant enterococcus and methicillin-resistant staphylococcus infections has become a major therapeutic challenge and alternative therapy options are under consideration. In the present study, we aimed to evaluate the in vitro antibacterial activity of linezolid combined with ertapenem against two vancomycin-resistant Enterococcus faecium (VREF), two methicillin-resistant Staphylococcus aureus (MRSA) and two methicillin-resistant Staphylococcus epidermidis (MRSE) strains isolated from clinical specimens. In vitro activity of linezolid/ertapenem combination at 1/2 x MIC (minimal Inhibitory Concentration), 1 x MIC and 4 x MIC concentrations for each of the isolates was determined by time-kill curve method. At 1 x MIC and 4 x MIC concentrations, additive effect was detected for MRSA (at 6 and 24 h) and VREF (at 6 h) strains. Synergism was observed between two antibiotics at 4 x MIC concentration against one of the MRSE strains at 6th hour. Additive effect was determined at 6th and 24th hours in this strain at 1 x MIC concentration. No synergism was present in the other MRSE strain but additive interaction was detected at 6 h (1/2 x MIC) and 24 h (1 x MIC). Although these results support the use of linezolid/ertapenem combination in infections caused by resistant gram-positive strains, further in vitro and in vivo studies are necessary.

The aim of this study was to investigate and type the extended spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae strains isolated from blood cultures. Following the detection of antibiotic susceptibilities in 32 K. pneumoniae isolates, ESBL were detected in 13 (41%) of them by using double disc synergy test. Minimum inhibition concentrations for ceftazidime, cefotaxime, and aztreonam of ESBL positive strains were determined by E-test. After the extraction of the enzymes, the types of ESBLs were investigated by isoelectric focusing method. It was seen that, of all ESBL positive strains, one strain had four bands, one had three bands, six strains had two bands, and each of the others had only one beta-lactamase band. The results of polymerase chain reaction (PCR) revealed bla(SHV) in ten samples, bla(TEM) in six samples, and bla(SHV) with bla(TEM) in four samples. Ten SHV enzymes were typed as ESBL by PCR-RFLP (restriction fragment lenght polymorphism) method. The results of isoelectric focusing, PCR and RFLP performed in these ESBL positive K. pneumoniae isolates showed that the ESBL types could be SHV-2, SHV-5 and SHV-12 in the tested strains. It should always be taken into consideration that K. pneumoniae isolates could produce ESBLs and antibiotic treatment protocols should be adjusted in accordance.

The emergence of Staphylococcus aureus strains with intermediate resistance (VISA) and heterogen resistance (hVISA) to vancomycin leads to the occurence of severe therapeutic problems. The aim of this study was to investigate the vancomycin resistance in methicillin resistant S. aureus (MRSA) and coagulase-negative staphylococci (MRCoNS) isolated from clinical samples in Bacteriology Laboratory of Microbiology and Clinical Microbiology Department of Celal Bayar University Faculty of Medicine, Manisa (located in western Anatolia, Turkey). A total of 120 staphyloccoccal strains (92 MRSA and 28 MRCoNS) isolated from different clinical specimens (tracheal aspirate, blood, abscess, wound swabs, sputum, catheter tips, etc) between the period of June 2005 to December 2006 were included to the study. Vancomycin resistance were determined by agar screening method using brain hearth infusion agar plates containing 6 microg/mL vancomycin. Standard E-test and macro E-test methods were performed for 17 (14%) staphylococcal strains (10 MRSA and 7 MRCoNS) which had grown in agar screening plates. Vancomycin and teicoplanin minimal inhibitory concentration (MIC) ranges of those strains were found as 1.5-4 microg/mL and 2-4 microg/mL, respectively, by standard E-test method. In our study, no VISA and hVISA isolates were detected when MIC value ofor =8 microg/mL for vancomycin and teicoplanin, oror =12 microg/mL for teicoplanin only were accepted as the criteria for hVISA determination. Agar screening method which is preferably used in routine laboratories for practical and economical reasons, lower sensitivity and specificity than E-test. It can be concluded that, since agar screening method is not reliable for the detection of vancomycin resistance, further multi-center studies with the use of standard methods are needed in order to clarify the vancomycin resistance patterns of staphylococci in our country.