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Objective: This study aimed to identify subspecies of Mycobacterium abscessus complex (MABC) isolates from clinical samples by a molecular technique and to determine mutations responsible for macrolide and aminoglycoside resistance. We also aimed to investigate the correlation of phenotypic and molecular test results by examining the resistance to antimicrobial agents according to CLSI standard using the liquid microdilution test. Methods: 27 MABC isolates from clinical samples were examined. Molecular subspecies identification and mutations responsible for aminoglycoside (rrs mutation) and macrolide resistance (rrl mutation) were determined using the GenoType NTM-DR test. The resistance phenotypes of the strains to various antimicrobial agents were investigated by the Sensititre™ RAPMYCOI AST microdilution test. Results: Of the 27 isolates tested, 21 were M. abscessus subsp. abscessus, three were M. abscessus subsp. bolletii, and three were M. abscessus subsp. massiliense; rrs and rrl mutations were not observed in any strains. Except for one isolate, all M. abscessus subsp. abscessus strains showed the erm(41) T28 genotype, which indicates inducible macrolide resistance. The correlation between the GenoType NTM-DR and phenotypic susceptibility test results was 81% (k=0.5, p=0.02) for inducible macrolide resistance and 89% for acquired macrolide resistance. The most effective antimicrobial agents were amikacin, cefoxitin, imipenem, linezolid, and tigecycline. Conclusion: Although the GenoType NTM-DR test is reliable in identifying and detecting molecular macrolide and aminoglycoside resistance, there were discrepancies in the results. We recommend confirming the results with the phenotypic susceptibility method after growth on culture. Although the M. abscessus complex is resistant to many antimicrobial agents, it has shown high sensitivity to amikacin, cefoxitin, imipenem, linezolid, and tigecycline. High levels of inducible macrolide resistance in isolates indicate the importance of subtyping and sensitivity testing of isolates in patients where culture conversion has not been achieved. [ABSTRACT FROM AUTHOR]

Copyright of Ümraniye Pediatri Dergisi is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Although Coagulase Negative Staphylococci (CoNS) species are among the microbiota members of the skin and mucosal surfaces, they cause infections especially related to medical devices such as catheters. Nowadays, antibiotic resistance is an important public health problem and rational use of antibiotics is of great importance in the treatment of bloodstream infections caused by CoNS species. The aim of this study was to investigate the antibiotic resistance profile and some virulence genes of CoNS isolates that cause catheter related bacteremia. Methods: In our study, 43 CoNS strains isolated from patients hospitalized in Manisa Celal Bayar University Hospital between 2016-2017, were evaluated for their susceptibility to ampicillin, clindamycin, mupirocin, linezolid, tigecycline, tetracycline, cefotaxime, gentamicin, vancomycin, ciprofloxacin, erythromycin and fusidic acid. The presence of clonal relationships and some virulence factors were also investigated. Susceptibility of cefoxitin (methicillin) was determined by disk diffusion and susceptibilities of other antibiotics were determined by microdilution method. AacA-aphD and aphA3 for aminoglycoside resistance, mecA and mecC for methicillin resistance, tetK and tetM for tetracycline resistance, ermA, ermB, ermC, msrA for macrolidelincosamide- streptogramin (MLS) type B resistance, icaA, IS256, nucA and sasX virulence genes were investigated by polymerase chain reaction (PCR). Clonal relationships at species level were examined by Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR. Results: Considering all species of CoNS examined, the highest and the lowest resistance rates were observed for ampicilin (93 %) and linezolid (2 %), respectively. There wasn't any resistant CoNS isolate to tigecycline and vancomycin. We found that all the examined CoNS species were generally clustered in different clones. We detected mecA, aacA-aphD, aphA3, ermB, ermC and msrA antibiotic resistance genes as well as icaA, IS256 and sasX virulence genes in the studied strains. Conclusion: The results of our study revealed that the examined CoNS isolates causing bacteremia had acquired resistance to commonly used antibiotics and that these strains harboring various virulence genes. Therefore, those isolates and their infections should be carefully monitored. [ABSTRACT FROM AUTHOR]

Objective: The isolation of microorganisms in joint fluid samples is one of the most important laboratory findings guiding the treatment. Knowing the distribution of the isolated microorganisms allows for the correct empirical approach to treatment. The frequency of MRSA isolation from joint fluid cultures is increasing, and MRSA infections are increasing in importance among infectious arthritis cases. This study aimed to determine the distribution of microorganisms that grew in joint fluid cultures and the antibiotic susceptibility patterns of staphylococci grown in these cultures. Methods: Our study is retrospective and planned to cover the years between 2015 and 2019. Of the synovial fluid samples sent to the Microbiology Laboratory, 103 samples with growth in culture were included in the study. Bacteria isolated from the samples were identified with the MALDI-TOF MS device and were evaluated for antimicrobial susceptibility in the automated system. Results: Samples of 103 patients were included in the study. While 19 of the patients included in the evaluation had a history of joint replacement, 84 patients had natural joint involvement. Generally, S. aureus ranked first in both group samples (41.7% and 42.2%). Coagulase-negative staphylococci and streptococci came second and third, respectively. Gram-negative bacilli were in fourth place (10.8%) in samples belonging to natural joints. In comparison, only one growth (5.3%) was detected in samples of patients with a prosthetic history. However, no statistically significant difference was found between the natural joint and prosthesis in terms of pathogen distribution (p> 0.05). All MRSA isolates were susceptible to vancomycin, teicoplanin, linezolid, daptomycin, and tigecycline. No MRCNS isolate was resistant to vancomycin, tigecycline, and trimethoprim/sulfamethoxazole. Conclusion: We think that our study will contribute to the literature on the distribution of infectious arthritis agents, the evaluation of antimicrobial resistance profiles of these agents, and empirical antimicrobial selection. [ABSTRACT FROM AUTHOR]

Objective: Acinetobacter baumannii is an important causative agent of ventilation-associated pneumonia capable of long-term survival in the hospital setting. Increasing resistance to antibiotics effective against this pathogen is of concern. In this study, the antibiotic resistance profiles of A. baumannii strains grown in endotracheal aspirate (ETA) cultures in intensive care units and the effect of the COVID-19 pandemic on the resistance profiles in our province where the highest number of cases were observed in our country for a long time were investigated. Methods: Our study included 74 A. baumannii isolates isolated from ETA samples that was sent to our laboratory from the intensive care units of Bafra State Hospital between January 2019 and December 2020. Bacteria were identified using conventional methods and a semi automatic bacterial identification system Vitek-2 (bioMérieux, France). The antibiotic susceptibility tests of the isolated strains were studied in accordance with the European Committee for Antimicrobial Susceptibility Testing (EUCAST) standards. Antibiotic susceptibility of A. baumannii strains was tested with Vitek-2 system. Results: The mean age and standard deviations of 18 patients before the COVID-19 pandemic and 56 patients after the pandemic were found to be 83,0 ± 8,3 and 70,5 ± 14,9 (p<0,001), respectively. A statistically significant difference was found between the distributions of gender by years (p= 0,025). While 55,6% of the patients were female in 2019, 73,2% of the patients in 2020 were male. There was no difference between the two periods in terms of death rates (p=0,628) and respiratory support needs (p=0,191). It was determined that the pandemic increased the number of isolated A. baumannii by 311%. For the two periods, resistance was the greatest for piperacillin/tazobactam, ceftazidime, ciprofloxacin and against imipenem. Examinig the two periods, amikacin resistance was seen to a lesser extent in 2020. A statistically significant difference was found between tigecycline resistance rates by years (p<0,001). While the tigecycline susceptibility of strains was 88,9% in 2019, it was found to be 26,8% in 2020. 11,1% of the strains in 2019 and 64,3% in 2020 were found to be moderately susceptible. In this study, colistin resistance was observed in one (1,4%) of all isolates, while tigecycline resistance was detected in five isolates (6,8%). One isolate (1,4%) was susceptible to all antibiotics except ceftazidime. When the multi-antibiotic resistance of 73 A. baumannii isolates was examined, multidrug resistant (MDR) was 22,9% (n:17), extensive drug resistance (XDR) was 74,3% (n:55), pandrug resistance (PDR) was 1,4% (n:1). Although there was a statistical difference in amikacin, meropenem and tigecycline resistances before and after the pandemic, no difference was found between the resistance patterns (p=0,281). Conclusion: It has been observed that the most effective antibiotics against A. baumannii are colistin and tigecycline. It was determined that the COVID-19 pandemic did not change the resistance pattern rates. It is thought that success in fighting this infection will increase when each hospital determines its own resistance patterns, updates empirical treatment protocols based on their results, and clinicians use appropriate antibiotics early. [ABSTRACT FROM AUTHOR]

Introduction: Carbapenem-resistant (CR) Klebsiella pneumoniae is one of the most common CR Enterobacteriaceae species and is resistant to many antibiotics. Generally, combined use of antibiotics is preferred during infections of these microorganisms. This study aimed to demonstrate the in vitro synergy between meropenem (MEM), fosfomycin (FOS), colistin (CS), and tigecycline (TGC) in CR-K. pneumoniae (Kp) strains. Materials and Methods: A total of 52 CR-Kp strains were included. MicroScan WalkAway (Beckman Culture) plus system were used to identify strains. Antibiotic susceptibilities of the isolates were detected in the MicroScan WalkAway device (Beckman Culture) using MicroScan Gram-negative panel type 44 (Beckman Culture), and the minimal inhibitory concentrations (MIC) of antibiotics and extended-spectrum beta-lactamases (ESBL) formation were detected. Synergy studies were performed by the microdilution checkerboard method. A fractional inhibitory concentration index was used to interpret the results. Results: Of 52 strains, 11 had only carbapenem (MEM) resistance. Twenty-three of strains were also resistant to FOS, 27 to CS, and eight to TGC. When antibiotic combinations were compared, MEM + FOS, MEM + CS, and CS + TGC showed the best synergy in our strains. By contrast, the lowest synergy was observed with MEM + TGC, and the difference was significant (p50% synergistic effect in these strains. Conclusion: This study showed that high FOS and CS resistance was also present in our CR-Kp strains. However, even in case of resistance to one or more of the antibiotics mentioned in this study, the results showed that, in combination with these antibiotics, especially MEM + FOS, MEM + CS, and CS + TGC, a significant amount of in vitro synergy can be achieved.

Objective: In this study, it was aimed to investigate the change of antibiotic susceptibility of Acinetobacter baumannii strains over the years and to help develop antibiotic use policy by determining the multiple antibiotic resistance rate. Methods: Acinetobacter species isolated from various clinical samples sent to Necip FazılCity Hospital Microbiology Laboratory between January 2013 and December 2018 were included. Vitek 2 Compact (bioMérieux-SE, France) automated systems were used for the identification and antibiotic susceptibility of the isolates. Results: Acinetobacter isolates were isolated at the most from tracheal aspirate samples (n=73; 35%) and samples sent from Anesthesia and Reanimation intensive care unit(n=160; 68%). The distribution of antibiotic sensitivity percentages (%) was given as yearly, three-year averages for 2013-2015, 2016-2018, and the total average for 2013-2018. In the study period, the highest sensitivity was determined to colistin at 97% and the lowest to ceftriaxone at 5%. When the antibiotic sensitivity rates of A. baumannii are evaluated roughly; In the period of 2016-2018, compared to 2013-2015, there was a decrease in sensitivity to amikacin, ampicillin-sulbactam, cefepime, ceftriaxone, colistin and tigecycline, while sensitivity to other antibiotics was observed. Multiple antibiotic resistance was examined in a total of 237 A. baumannii isolated. Multidrug resistant (MDR) resistance was 92%, Extensively Drug Resistant (XDR) resistance was 84% and Pan Drug Resistant(PDR) resistance was 3%. Conclusion: It is observed that resistance against some antibiotics has increased in A. baumannii over the years, and resistance to some antibiotics has decreased. It seems that our XDR resistance rate is very high. Our PDR resistance rate is higher than that of America, but lower than many European countries. In the other hand our result is lower than the average of Turkey. [ABSTRACT FROM AUTHOR]

Aim: Tigecycline has been approved by the Food and Drug Administration for the treatment of complicated intra-abdominal infections, skin and soft tissue infections and community-acquired pneumonia. In our study, we examined the efficacy of tigecycline in clinical practice and reported real life data from our hospital over a period of five years. Methods: The study was conducted between 2008 and 2013 on patients who received tigecycline for longer than 48 hours in Ankara Training and Research Hospital. Clinical success was defined as clinical recovery and microbiological cure in patients who used tigecycline. Any reason for discontinuation of tigecycline treatment was considered a clinical failure. Results: In our hospital, 320 patients were administered tigecycline between 2008 and 2013. Tigecycline was mainly used for pneumonia and skin and soft tissue infections. Tigecycline was used as monotherapy in 174 patients (54.1%). The most frequently isolated agent in tigecycline-treated patients was Acinetobacter baumannii (43.4%) followed by Enterococcus (6.9%). A change in treatment was not considered necessary in 243 (75.9%) patients who received tigecycline, while it was changed in 77 patients (24.1%). Conclusion: In conclusion, the use of tigecycline can be an effective treatment choice, either as monotherapy or as a combination antibiotic therapy.

Copyright of ANKEM Antibiyotik & Kemoterapi Dergisi is the property of ANKEM Antibiyotik & Kemoterapi Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Tepecik Education & Research Hospital / İzmir Tepecik Eğitim ve Araştırma Hastanesi Dergisi is the property of Logos Medical Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The aim of this study was to evaluate the in vitro antimicrobial efficacy of tigecycline in methicillin-resistant staphylococci isolated from patients hospitalized in intensive care units. Methods: We investigated methicillin-resistant staphylococci isolated from blood, wound, urine, catheter tips, endotacheal aspiration fluids (ETA), and sputum specimens of patients hospitalized in the coronary and surgical intensive care units at İstanbul University Cardiology Institute, between June 2014 and December 2015. All staphylococci were identified by the conventional methods and susceptibility testing was performed using Mueller-Hinton Agar by the Kirby-Bauer disc diffusion method. Results: Of 67 methicillin-resistant staphylococci, 37 (55.2%) were Staphylococcus aureus (MRSA) and 30 (44.8%) were coagulase negative staphylococci (MRCNS). MRSA were isolated from blood (20), wound (10), ETA (3), urine (2), catheter tips (1) and sputum (1). MRCNS were also identified in blood (20) and wound (10). All staphylococci were susceptible to tigecycline. Conclusion: In our study, tigecycline was effective against all methicillin resistant staphylococci. Tigecycline can be an alternative to other drugs against infections caused by methicillin-resistant staphylococci.

Introduction: Bacteria of the genus Klebsiella are important causes of nosocomial infections. These bacteria may develop resistance in different ways, with extended-spectrum beta-lactamase (ESBL) production being the most common. The aim of this study was to evaluate resistance status of Klebsiella isolates obtained from different intensive care units and various clinical samples. Materials and Methods: Resistance rates of Klebsiella spp. strains isolated from bacteriologic cultures of patients in intensive care units between 2014 and the first six months of 2017 were evaluated retrospectively. Blood, urine, bronchoalveolar lavage, cerebrospinal fluid, and tracheal aspirate samples were cultured. Intensive care patients aged ≥18 years were included. Only the first isolate from each patient was included; subsequent isolates from the same patient were excluded. Results:A total of 443 patients were included in the study. Of the Klebsiella-positive samples, 31.8% (n=141) were tracheal aspirate, 23.7% (n=105) were blood, 23.3% (n=103) were urine, 9.0% (n=40) were sputum, and 12.2% (n=54) were other samples. The majority of cases were K. pneumoniae (89.7%, n=397), followed by K. oxytoca (7%, n=31), K. ozaenae (2.9%, n=13), K. granulomatis (0.2%, n=1), and K. ornithinolytica (0.2%, n=1). Of the 443 isolates, 54.4% (n=241) were ESBL-producing while 45.6% (n=202) were non-ESBL-producing. Mortality rates were 60% among patients with ESBL-positive Klebsiella and 47.5% among patients with ESBL-negative Klebsiella (p=0.008). Conclusion: The antibiotic resistance of ESBL-positive Klebsiella isolates in our hospital was higher than resistance rates in the literature. To overcome this resistance issue, each hospital must know its own resistance rates and establish policies for the rational use of antibiotics.

Amaç: Acinetobacter türleri doğada yaygın olarak bulunan Gram negatif kokobasillerdir. Hastane enfeksiyonlarına ve toplumsal kaynaklı enfeksiyonlara yol açabilen bu bakterinin tedavisinde kullanılan antibiyotik seçeneklerinin giderek azalması endişe yaratmaktadır. Son yıllarda özellikle yoğun bakım üniteleri başta olmak üzere hastane enfeksiyonlarında en sık izole edilen etkenlerin başında A. baumannii suşları gelmektedir. Çoğul antimikrobiyal direnç, polimiksinler gibi eski ve tigesiklin gibi yeni antibiyotiklerin araştırılıp geliştirilmesini zorunlu kılmıştır. Gram negatif bakterilerde gelişen çoğul direnç fenotipleri nedeniyle polipeptit yapılı bir antibiyotik olan kolistinin (polimiksin E) önemi tekrar artmaya başlamıştır. Ancak, ülkemizde çoğul dirençli suşlara karşı bu antibiyotiğin etkinliğini bildiren çalışma sayısı oldukça kısıtlıdır. Tigesiklin, A. baumannii'nin de içinde bulunduğu dirençli Gram negatif bakterilerin neden olduğu enfeksiyonların tedavisinde ümit veren yeni, yarı sentetik bir tetrasiklindir. Yöntem: Çalışmamız, Şubat 2011 - Şubat 2012 tarihleri arasında Kahramanmaraş Üniversitesi Tıp Fakültesi Hastanesi Týbbi Mikrobiyoloji Laboratuvarýna çeþitli kliniklerden gönderilen farklý örneklerden soyutlanan 100 adet çoðul dirençli A. baumannii izolatý ile yapýlmýþtýr. Bakterilerin tanýmlanmasý konvansiyonel mikrobiyolojik yöntemler ve tam otomatik bakteri tanýmlama sistemi Vitek-2 (bioMérieux, Fransa) kullanýlarak yapýlmýþtýr. Çoðul dirençli olduðu saptanan 100 A. baumannii suþunun kolistin ve tigesikline karþý duyarlýlýklarý Vitek-2 (bioMérieux Fransa), disk difüzyon ve E-test yöntemleriyle test edilmiþtir. Bulgular: Sonuç olarak disk difüzyon yöntemi ile test edilen çoğul dirençli suşların %88'i kolistine, %84'ü tigesikline duyarlı bulunmuştur. Vitek-2 (bioMérieux Fransa) yöntemi ile test edilen çoğul dirençli suşların ise %100'ü kolistine, %92'si ise tigesikline duyarlı bulunurken; E-test yöntemi ile tigesiklin ve kolistine %100 duyarlılık tespit edilmiştir. Sonuç: Disk difüzyon, E test ve otomatize sistem yöntemlerinin birbirleri ile uyumunu karşılaştırdığımızda; E test ve otomatize sistem sonuçlarının disk difüzyona göre daha uyumlu olduğu gözlenmiştir. Kolistin ve tigesiklinin A. baumannii'ye karşı etkinliği oldukça yüksek bulunmuştur. Objective: Acinetobacter ssp., Gram negative cocobacilli, are widely found in nature. The decrease in treatment options against this organism which can lead nosocomial and community-acquired infections is a concern. In recent years, A. baumannii strains are among the most frequently isolated organisms in hospital infections, especially intensive care units. Multiple antimicrobial resistance has forced to be explored and improved antibiotics such as tigecycline and polymyxins (antibiotics such as tigecylines (new) and polymyxins (old)). Due to the multiple resistance phenotypes that developed in Gram negative bacteria, the importance of colistin (polymyxin E), an antibiotic with a polypeptide structure, has begun to increase. However, the number of studies reporting the efficacy of this antibiotic against multiple-resistant strains is rather limited in our country. Tigecycline is a new, semisynthetic tetracycline that promises to treat infections caused by resistant Gram negative bacteria, including A. baumannii. Methods: Our study was carried out with 100 multiple-resistant A. baumannii strains isolated from different samples sent from different clinics to Kahramanmaraş University, Medical Faculty Hospital, Medical Microbiology Laboratory between February 2011 and February 2012. Identification of the bacteria was carried out using conventional microbiological methods and a fully automated bacterial identification system Vitek 2 (bioMérieux, France). Sensitivities of 100 multidrug resistant A. baumannii strains to colistin and tigecycline were tested by Vitek 2 (bioMeriéux, France), disc diffusion and E-test methods. Results: As a result, 88% of the multiple-resistant strains tested by disk diffusion method were found to be sensitive to colistin and 84% to tigecycline. While 100% of the multi-resistant strains tested by Vitek 2 (bioMérieux, France) were found to be sensitive to colistin and 92% to tigecycline; 100% sensitivity to tigecycline and colistin was detected by E-test method. Conclusion: When we compared the compatibility of disc diffusion, E-test and automated system methods with each other, E-test and automated system results were observed to be more compatible than disc diffusion method. The effectiveness of colistin and tigecycline against A. baumannii was found to be quite effective. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the in vitro antimicrobial efficacy of tigecycline in methicillin-resistant staphylococci isolated from patients hospitalized in intensive care units. Methods: We investigated methicillin-resistant staphylococci isolated from blood, wound, urine, catheter tips, endotacheal aspiration fluids (ETA), and sputum specimens of patients hospitalized in the coronary and surgical intensive care units at İstanbul University Cardiology Institute, between June 2014 and December 2015. All staphylococci were identified by the conventional methods and susceptibility testing was performed using Mueller-Hinton Agar by the Kirby-Bauer disc diffusion method. Results: Of 67 methicillin-resistant staphylococci, 37 (55.2%) were Staphylococcus aureus (MRSA) and 30 (44.8%) were coagulase negative staphylococci (MRCNS). MRSA were isolated from blood (20), wound (10), ETA (3), urine (2), catheter tips (1) and sputum (1). MRCNS were also identified in blood (20) and wound (10). All staphylococci were susceptible to tigecycline. Conclusion: In our study, tigecycline was effective against all methicillin resistant staphylococci. Tigecycline can be an alternative to other drugs against infections caused by methicillin-resistant staphylococci. [ABSTRACT FROM AUTHOR]

Raoultella species are gram-negative, non-motile bacilli primarily considered to be environmental bacteria. R. planticola is a rare cause of human infections. Here in we report a case of complicated skin and soft tissue infection, necrotizing fasciitis with a rare etiologic agent R. planticola, treated with tigecycline. A 32-year-old male admitted to the emergency service with complaints of swelling in the neck, pain and a purulent wound on the mandible. He also had toothache for the last three weeks for which he was prescribed metronidazole and non-steroid anti-inflammatory drug by another doctor. He was internalized in the Plastic and Reconstructive Surgery clinic and debridement was performed and empirical antibiotic was started. Bacteriological culture revealed Acinetobacter baumannii and R. planticola. The case was successful treated with tigecycline. Necrotizing fasciitis may be fulminant and invasive in the diabetic host. To our knowledge this was the first R. planticola case treated successfully treated with tigecycline. In addition, it emphasizes once again the importance of bacteriological sampling in the management of necrotizing fasciitis and complicated soft tissue infection.

Descending necrotizing mediastinitis (DNM) is caused by aerobic and anaerobic bacteria as a rare but severe complication of oropharyngeal abscesses developing secondary to odontogenic infections. Patients with hypersensitivity reaction to beta-lactam antibiotics pose challenges in the treatment. To our knowledge, only two cases of postoperative mediastinitis treated with tigecycline have been reported in the English medical literature to date. In this paper, we present a case of descending mediastinitis developing one week after dental extraction. The patient was given tigecycline treatment with the diagnosis of complicated deep neck infection, which progressed to descending mediastinitis because of severe allergic reaction to beta-lactam group antimicrobials. He successfully recovered after early surgical drainage and debridement together with four weeks of tigecycline therapy. Tigecycline may be an alternative option for treatment of odontogenic infections and descending mediastinitis in beta-lactamallergic patients. It may be used effectively and successfully with concurrent standard early surgical intervention in selected patients, especially in those with severe hypersensitivity reaction.

Aim: Enterococci are members of human and animal intestinal flora and can cause intra-abdominal infections, endocarditis, urinary system infections and bacteremia. Particularly, Enterococcus faecalis(E.faecalis )and Enterococcus faecium (E. faecium) are among the leading pathogens isolated from nosocomial infections. Recently, increasing resistance in enterococci has become a serious problem all over the world and created the need for new antimicrobial agents. In this study, we aimed to investigate the in vitro activity of vancomycin, daptomycin, linezolid and tigecycline in E.faecium and E.faecalis strains. Material and Methods: Thirty-five E.faecium and 15 E.faecalis strains were included in the study. Of the isolated strains 14 (28%) were from rectal swab samples, 11 (2 %) were from urinary samples, 11 (22%) were from urinary catheter, nine (18%) were from blood, three (6%) were from wound samples, one (2 %) was from catheter and one(2 %) was from cerebrospinal fluid. Clinical samples were obtained from various services and intensive care units. Vancomycin, daptomycin, linezolid and tigecycline susceptibilities were investigated by E-test method. Results were evaluated according to the recommendations of Clinical and Laboratory Standards Institute(CLSI)and The European Committee on Antimicrobial Susceptibility testing (EUCAST). Results: In vitro resistance rates of the isolates to vancomycin was detected as 28%. Vancomycin resistance rate in E.faeciumstrains was 40%.All of the isolates were susceptible to daptomycin, linezolid and tigecycline. Vancomycin MIC50and MIC90 values for isolates were found as 1 μg/ml and >256μg/ml respectively with a MIC range of 0.25->256μg/ml. Tigecycline MIC50 and MIC90 valeus for isolates were found as 0.032 μg/ml and 0.064μg/ml respectively with a MIC range of 0.016-0.125μg/ml. Linezolid MIC50 and MIC90 valeus for isolates were found as 1 μg/ml and 1.5μg/ml respectively with a MIC range of 0.094-2μg/ml. Daptomycin MIC50 and MIC90 valeus for isolates were found as 1.5 μg/ml and 3μg/mlrespectivelywith a MIC range of 0.19-4μg/ml. MIC range, MIC50 and MIC90 values for daptomycin, MIC90 value for linezolid, MIC50 value for tygecycline, MIC range and MIC90 values for vancomycin were found higher in E.faecium strains. Conclusion: The results of the study demonstrated that daptomycin, linezolid and tigecycline may be a potential and reliable alternative drug for the treatment of infections caused by E.faecium and E.faecalis strains. Antibiotic susceptibility of enterococcal infections should be monitored regularly and empiric treatment should be planned according to this data. [ABSTRACT FROM AUTHOR]

Despite the increase of resistant microorganism-related infections in recent years, ongoing studies for the development of new antibiotics have been very limited. This article reviews the pharmacological properties and the clinical use of linezolid and tigecycline which are important choices for resistant nosocomial infections, in addition to ceftaroline, a newer drug that has not yet been in clinical use in our country. Linezolid, is the first drug of oxazolidinone class of antibiotics which inhibits bacterial protein synthesis. It has clinical indication for resistant gram-positive infections, including VRE, MRSA and resistant pnemococci, both in children and adults. Tigecycline binds bacterial ribosomal 30 S subunit like minocycline. It has a broad activity spectrum including resistant grampositive, gram-negative and anaerobic bacteria other than Pseudomonas aeruginosa. It has clinical use for resistant complicated skin soft tissue and intra-abdominal infections for adults. Ceftaroline, is the newest member of 5th generation cephalosporins. It has antimicrobial activity against resistant gram-positive microorganisms including methiciUine- and vancomycine-resistant Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Pediatric Infection / Çocuk Enfeksiyon Dergisi is the property of Journal of Pediatric Infection / Cocuk Enfeksiyon Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Problems are encountered in the therapy of enterococcal infections due to their intrinsic resistance to many antibiotics and increasing glycopeptide resistance in recent years. That is why clinical trials are required to test new antibiotics for the treatment. In this study, we investigated susceptibility to linezolid, daptomycin and tigecycline in vancomycin-resistant enterococci (VRE) strains. Methods: Totally, 58 of VRE strains obtained from various clinical specimens were included in the study. The strains identified as enterococci by conventional methods and Phoenix automated system (Becton Dickinson, USA) was utilized for further identification of the strains and determination of their resistance to vancomycin. Vancomycin resistance in these strains was confirmed by E-test. Using the same method 58 VRE strains were tested for linezolid and daptomycin and 47 VRE strains for tigecycline. Results: MIC50, MIC90 and MIC range for vancomycinresistant strains was detected as 0.75, 1.5, and 0047-2 μg/ml for linezolid; 1, 2 and 0.19-3 μg/ml for daptomycin and 0064, 0125, and 0.016-0.19 μg/ml for tigecycline, respectively. No strain resistant to linezolid, daptomycin; tigecycline was detected. Conclusion: Although linezolid maintains its importance as effective antibiotic for the treatment of infections caused by VRE, recently introduced daptomycin and tigecycline with their low MIC values occur as good treatment options. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is to investigate the sensitivity of enterococci isolated from infections in our region against daptomycin, tigecycline, quinupristin/dalfopristin and other antibiotics used in conventional treatment. Methods: Enterococcal species isolated from clinical specimens were identified by API® 20 Strep (bioMérieux, France) test kits. Antibiotic susceptibility testing of isolates was carried out according to the recommendations in Clinical and Laboratory Standards Institute (CLSI) document M100-S20. High-level aminoglycoside resistance was investigated by gentamicin (120 mg), and streptomycin (300 mg) disks and minimum inhibitory concentrations (MICs) to tigecycline and daptomycin were determined by the E-test® (AB Biodisk, Sweden) method. Results: A total of 98 enterococcal strains (55 Enterococcus faecium, 40 E. faecalis, 2 E. durans and 1 E. avium) have been identified. Fifty-nine (60%) of the strains were isolated from urine and the rest from blood, wounds, cerebrospinal fluid and vaginal samples. Isolation rate of E. faecium is significantly higher than E. faecalis in hospitalized patients. All strains were sensitive to linezolid and 3 (5.5%) isolates of E. faecium were resistant to both vancomycin and teicoplanin. The resistance of E. faecalis and E. faecium to penicillin and ampicillin were 10 (25%)/52 (94.5%) and 4 (10%)/51 (92.7%), respectively. High-level gentamicin/streptomycin resistance was found much higher in E. faecium (69.1%/43.6%) than E. faecalis (25%/27.5%) isolates. The MIC ranges for tigecycline were 0.023-3 µg/ml and 0.016-3 µg/ml for daptomycin. Conclusions: E. faecium was the most prevalent species isolated in hospitalized patients. Vancomycin resistance was low, but prevalence of the high-level aminoglycoside resistance and the resistance to antibiotics was high in these isolates. Rapid diagnosis of enterococci and determination of their antibiotic susceptibilities is important for implementation of appropriate treatment and management of infected patients with resistant strains. [ABSTRACT FROM AUTHOR]

Objective: Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant coagulase negative staphylococci (MRCNS) are important cause of infections worldwide. Vancomycin and other glycopeptide antibiotics are mainstay of therapy for infections caused by MRSA and MRCNS. High prevalence of methicillin resistant staphylococci strains led to increased use of vancomycin. This situation caused to reduction of glycopeptide susceptibility in methicillinresistant staphylococci. Treatment options of infections due to MRSA with reduced susceptibility to vancomycin are limited. Tigecycline should be take into consideration as an antimicobial therapeutic alternative for infecitons caused by MRSA and/or MRCNS. The aim of this study was to determine in vitro antimicrobial activity of tigecycline against methicillin-resistant staphylococci strains isolated from various clinical specimens. Method: Staphylococcus strains isolated at the Microbiology Laboratory of Konya Education and Research Hospital in between January and December in 2010. The isolated strains were identified by using both conventional methods and fully automated bacteria identification and susceptibility system (Phoenix 100, BD, Sparks, USA). Methicillin resistance was determined and evaluated according to Clinical and Laboratory Standards Institute (CLSI) instrucions by using disc diffusion method (oxacillin 1 µg and cefoxitin 30 µg discs) Minimum inhibitory concentration (MIC) values of tigecycline for isolated strains were detected with E-test method (bio-Merieux Marcy l'Etoile, France). Results: Of all the eighty five methicillin-resistant staphylococci strains 35 (41%) were identified as Staphylococcus aureus and 50 (59%) coagulase negative staphylococci. MIC values of tigecycline for the 35 MRSA isolates were MIC50: 0.094 µg/ml, MIC90: 0.5 µg/ml) and for the 50 MRCNS isolates were MIC50: 0.047 µg/ml, MIC90: 0.25 µg/ml. All isolates (100%) were found to be sensitive to tigecycline. Conclusion: Results of this study showed that tigecycline was effective in vitro antimicrobial activity against both MRSA and MRCNS isolates. Tigecycline may be preferred as a last choice in the treatment of resistant infections due to the MRSA and MRCNS that alternative antibiotics were all resistant. [ABSTRACT FROM AUTHOR]

Acinetobacter spp. are primarily associated with nosocomial infections and these isolates resistant to most antimicrobial agents. The present study was conducted to evaluate the in vitro susceptibility of tigecyline in multi-drug-resistant (MDR) and extreme-drug resistance (XDR) Acinetobacter strains by three different methods. MDR Acinetobacter isolates described in the study were resistant to at least three of the following antibiotics: imipenem, meropenem, ceftazidime, cefepime, aztreonam, piperacillin tazobactam, ciprofloxacin, tetracycline, ampicillin-sulbactam, trimethoprimsulfamethoxazole, amikacin, gentamicin and tobramycin. XDR was defined as resistance to all above antibiotics excluding colistin and tigecyline. Identification of Acinetobacter spp. were made conventional methods. Antibiotic susceptibility tests were performed according to the criteria of Clinical and Laboratory Standards Institute (CLSI). All of the isolates were found resistant to carbapenem. Disk diffusion, E-test and broth microdilution methods were used to evaluate the in vitro susceptibility of tigecyline. No tigecycline interpretative criteria universally accepted for Acinetobacter spp, therefore the Food and Drug Administration approved breakpoints for members of the family Enterobacteriaceae have been used. A total of 30 (five strains were MDR and 25 strains were XDR) Acinetobacter strains were isolated from various clinical specimens (8 paracentesis fluid, 8 blood, 7 tracheal aspirates, 5 wound, 2 urine, 2 catheter, 1 sputum) of hospitalized patients in Turgut Ozal Medical Center in 2008 year. All of the MDR and XDR strains were susceptible to tigecyline by broth microdilution method. Against Acinetobacter spp, an MIC range between 0.03 and 0.5 µg/ml was observed by broth microdilution and MIC50 and MIC90 values were determined as 0.12 µg/ml and 0.25 µg/ml, respectively. Twenty five strains (83%) were found susceptible to tigecyline when the disk diffusion brekpoints were considered as ≥16mm susceptible and ≤12mm resistant. Against Acinetobacter spp, an MIC range between 1 and 8 µg/ml was observed by E test. MICs of tigecycline determined by E test were 8 to 64 times higher and 30% (9/30) of the isolates were resistant to tigecycline by E test (MIC breakpoint 2 µg/ml ). Broth microdilution method must to use in the resistant Acinetobacter spp, by E test and disk diffusion method. [ABSTRACT FROM AUTHOR]

Copyright of Klimik Journal / Klimik Dergisi is the property of DOC Design & Informatics Co. Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Today, the most common cause of bloodstream infections, which led to high mortality, prolonged hospitalization and increased costs are the intravenous catheters. Among the microorganisms associated with catheter infections, staphylococci took the first place and because of their biofilm-forming properties they cause serious problems in treatment and management of the patients. Although the drug of choice in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection is vancomycin, its effect on the bacterial biofilm is known to be low. Tigecycline, newly used in our country is a well tolerated glycylcycline antibiotic. In this study, we aimed to compare the efficacy of tigecycline and vancomycin in an in vitro MRSA biofilm model. The study consisted of 10 MRSA strains, which were detected as causative agents of catheter-related infections in our hospital. The methicillin resistance of the strains were performed by disk diffusion test with oxacillin (1 μg) disks and the biofilm forming capacity of the strains was evaluated using the Congo red agar method. The silicone disks with created biofilm layer were exposed to tigecycline (2 mg/ml) and vancomycin (2 mg/ml) for 24 hours and for 5 days 4-hours per day in a model of antibiotic lock therapy. The present study showed that, after incubating the silicon discs in antibiotic solution for 24 hours, colony forming unit counts of MRSA decreased from 10(5) cfu/ml to 510 cfu/ml in the tigecycline group and from 105 cfu/ml to 3.800 cfu/ml in the vancomycin group and remained the same in the control (10(5) cfu/ml) group (p< 0.001). In the antibiotic lock therapy model, incubation with antibiotics for 4 hours per day, yielded that the average growth was 1.800 cfu/ml in the tigecycline group and 8.700 cfu/ml in the vancomycin group, which was statistically significant (p< 0.001). No growth was detected in the tigecycline group (0 cfu/ml) while in vancomycin group number of colonies in second, thirth and fourth days were 2.000, 260, 80 cfu/ml, respectively, no growth was seen in the fifth day. From the first day until the fourth day tigecycline was statistically more effective than vancomycin (p< 0.001, p< 0.001, p< 0.001, p= 0.013, according to days respectively). As a result, it was determined that tigecycline showed a higher effect on MRSA biofilm layer created on silicon discs and the results suggested that tigecycline might be a good alternative in the treatment of catheter infections.

Tigecycline is a novel antibiotic and it is the first glycylcycline of the tetracycline antibiotic class. It exhibits potent in vitro activity against causative pathogens that are most frequently isolated in patients with community-acquired pneumonia. The objective of this study is to review the literature about the efficacy of tigecycline in community-acquired pneumonia. Two randomized clinical studies showed tigecycline was not inferior when compared with levofloxacin for the treatment of patients with bacterial community-acquired pneumonia requiring hospitalization. Tigecycline was generally well tolerated in patients with community-acquired pneumonia. Major adverse effects were primarily gastrointestinal in nature. Tigecycline offers an antibiotic option that can be used in hospitalized patients with mild to moderate community-acquired pneumonia.

The aim of this study was to determine whether vancomycin resistant Staphylococcus aureus (VRSA) and vancomycin intermediate susceptible S.aureus (VISA) strains were present among methicillin-resistant S.aureus (MRSA) strains isolated from patients hospitalised at intensive care units (ICU) of hospitals located at different regions of Turkey and to determine the minimum inhibitory concentration (MIC) values of teicoplanin, linezolid, tigecycline, quinupristin-dalfopristin and daptomycin, which are alternative drugs for the treatment of MRSA infections. A total of 260 MRSA clinical strains (isolated from 113 lower respiratory tract, 90 blood, 24 wound, 17 catheter, 13 nasal swabs, two urine and one CSF sample) were collected from nine health-care centers in eight provinces [Ankara (n= 52), Konya (n= 49), Antalya (n= 40), Istanbul (n= 7), Izmir (37), Diyarbakir (n= 15), Van (n= 12), Trabzon (n= 48)] selected as representatives of the seven different geographical regions of Turkey. Methicillin resistance was determined by cefoxitin disk diffusion in the hospitals where the strains were isolated and confirmed by oxacillin salt agar screening at the Refik Saydam National Public Health Agency. Screening for VISA and VRSA was conducted using the agar screening test and E-test. Susceptibility of the MRSA strains to other antibiotics was also determined by E-test method. None of the 260 MRSA strains were determined to be VRSA or VISA. All were susceptible to teicoplanin and linezolid, and susceptibility rates to daptomycin, tigecycline and quinupristin-dalfopristin were 99.6%, 96.9%, and 95%, respectively. Absence of VISA and VRSA among the MRSA strains surveyed currently seemed hopeful, however, continuous surveillance is necessary. In order to prevent the development of VISA and VRSA strains the use of linezolid, tigecycline, quinupristin-dalfopristin and daptomycin should be encouraged as alternative agents of treatment of MRSA infections.

After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed.

Acinetobacter baumannii is a frequent cause of nosocomial infections in most hospitals. Management of infections caused by these strains is difficult, as the strains often display multiple drug resistance, including carbapenem. Tigecycline which is a glycylcycline derivative has antimicrobial activity against many gram-positive and gram-negative organisms. In this study, in vitro activity of tigecycline and carbapenems against clinical isolates of A.baumannii strains were investigated. A total of 100 A.baumannii isolates were collected from hospitalized patients with documented nosocomial infections [pneumonia (n = 39), surgical wound infection (n = 32), bacteremia (n = 16), catheter infection (n = 6), urinary tract infection (n = 5), peritonitis (n = 1), eye infection (n = 1)] between October 2006 and June 2007. Only one isolate per patient was included to the study. Minimum inhibitory concentrations (MIC) of tigecycline were determined by E-test (AB Biodisk, Sweden). Carbapenem resistance of A.baumannii strains were determined by disk diffusion method. All of the 100 A.baumannii isolates (100%) were found susceptible to tigecycline (MIC values ≤ 2 µg/ml; MIC ranges: 0.032-1.5 µg/ml). Imipenem susceptibility test was performed for 95 strains, and 36 (37.9%) were found sensitive, 18 (18.9%) were intermediate sensitive, and 41 (43.2%) were resistant. Meropenem susceptibility test was performed for 87 strains, and 22 (25.3%) were found sensitive, 9 (10.3%) were intermediate sensitive, and 56 (64.4%) were resistant. Since tigecycline is found quite effective on nosocomial A.baumannii isolates, it may be considered as a treatment alternative in infections caused by carbapenem-resistant Acinetobacter spp.

The increased rate of antimicrobial resistance in Acinetobacter baumannii made it necessary to reconsider old antibiotics such as polymyxins and develop new drugs such as tigecycline. The aim of this study was to investigate the susceptibility rates of multi-drug resistant A. baumannii clinical isolates to colistin, polymyxin B, and tigecycline by three different methods in microbiology laboratory of Gaziantep University Research Hospital, between September 2006 and April 2008. A total of 200 A. boumannii strains isolated from various clinical samples (tracheal aspirate, blood, sputum, surgical wound, catheter, pleural fluid, urine, and others) were included to the study. Identification of bacteria was performed by conventional microbiological methods and by an automatized identification system (Vitek 2, bioMerieux, France). Antimicrobial susceptibility pattern of A. baumannii isolates was determined by disc diffusion method and 95 multiple resistant A. baumannii isolates were identified. Susceptibilities of these multiple resistant bacteria to colistin, polymyxin B, and tigecycline were tested with disc diffusion, E-test, and broth microdilution methods. All of the isolates (100%) were sensitive to colistin with all three methods. Ninety-two (96.8%) of them were sensitive to polymyxin B with both disc diffusion and broth microdilution methods, and 90 (94.7%) of them were sensitive to polymyxin B with E-test. Eighty-three (87.4%) of them were sensitive to tigecycline by disc diffusion method, 78 (82.1%) by E-test, and 90 (94.7%) by broth microdilution method. No statistically significant difference was detected for the three methods in terms of susceptibility testing for polymyxin B (p > 0.05). However, while no significant difference wa detected for tigecycline susceptibility testing by disk diffusion and broth microdilution (p > 0.05), statistically significant difference was determined for broth microdilution and E-test methods (p = 0.000). In conclusion, comparison of disc diffusion, E-test, and broth microdilution methods yielded that all three methods were concordant to each other in terms of susceptibility testing of polymyxins. Susceptibility rate to tigecycline was found lower by E-test method than that obtained by other methods. These results emphasized that antimicrobial activities of colistin, polymyxin B and tigecycline against A. baumannii isolates obtained in our hospital were high, however, for tigecycline susceptibility testing against A. boumannii, disk diffusion or broth microdilution methods would rather be preferred.

Acinetobacter baumannii is an important pathogen, capable of survival for very long periods on various surfaces in the hospital environment. Tigecycline is a commonly used antimicrobial agent especially for the treatment of resistant infections. The aim of this study was to investigate the activity of tigecycline on both planktonic and sessile biofilm cells of A. baumannii strains isolated from blood cultures and to compare the efficiency in terms of biofilm synthesis. Tigecycline activity on 59 A. baumannii strains was examined by agar dilution technique. The ability of strains to form biofilm was evaluated by adherence on polystyrene surfaces in brain heart infusion broth supplemented with 0.25% glucose. Time-kill technique was used for determination of the time and concentration dependent activity of tigecycline on biofilm positive and negative strains. The planktonic cells in logarithmic growth phase were exposed to tigecycline at 0.5, 1, 2, 4, ve 8 x minimum inhibitory concentration (MIC) concentrations and colony counts were evaluated after 0, 2, 4, 6, 24 and 48 hours. The effect of tigecycline on sessile cells was studied on biofilm matrix composed around plastic beads. Tigecycline susceptibility rate of planktonic cells was 89.8% and MIC50 and MIC90 values were 1 and 2 microg/ml, respectively. Biofilm formation was detected in 52.5% of isolates and no significant correlation was found between MIC values and biofilm production of the strains (p > 0.05). Tigecycline showed a potent antibacterial activity against planktonic cells regardless of biofilm forming capability of strains. Biofilm inhibitory concentrations of sessile cells were elevated significantly. As a result, tigecycline showed a potent activity on planktonic A. baumannii cells however, the effect was decreased significantly on sessile cells in biofilm environment. The results suggest that, the possibility of decreased sensitivity of cells in biofilm environment should be considered as well as antibiotic sensitivity test results during the treatment of infections caused by A. baumannii.

Glycylcyclines are novel semisynthetic group of antibiotics that have been produced by substitution of glycylamido group at position 9 of tetracyclines. Tigecycline derived from minocycline is the first member of glycylcyclines. This new antibiotic has a broad spectrum of activity against variety of gram-positive and gram-negative bacteria and is not affected by known tetracycline resistance mechanisms. The aim of this study was to investigate the in-vitro activity of tigecycline as well as vancomycin, linezolid, quinupristin-dalfopristin and trimethoprim-sulphamethoxazole (TMP-SMX) against methicillin-resistant staphylococci isolated from clinical specimens of adult patients in Hacettepe University Hospital. For this purpose 127 Staphylococcus aureus (MRSA) and 42 coagulase negative staphylococci (MRCNS) which had been shown to be resistant to methicillin by disc diffusion method performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines, were evaluated. In these isolates minimum inhibitory concentration (MIC) values of tigecycline were detected by E-test; susceptibilities to linezolid, quinupristin-dalfopristin, TMP-SMX were detected by disc diffusion test. All of the isolates were searched for decreased susceptibility to vancomycin by agar screening method and MIC values of vancomycin were detected by E-test for the strains that grew on vancomycin agar plates. The range of MIC values of tigecycline were 0.032-1 microg/ml for the 127 MRSA isolates (MIC50 0.25 microg/ml, MIC90 0.75 microg/ml) and were 0.047-1 microg/ml (MIC50 0.25 microg/ml, MIC90 0.5 microg/ml) for the MRCNS isolates. All staphylococcal isolates were found to be susceptible to vancomycin, linezolid and quinupristin-dalfopristin. TMP-SMX resistance was detected in 7 (5.5%) MRSA and 26 (60.5%) MRCNS isolates. The results of this study demonstrated very good in-vitro activity of tigecycline against both MRSA and MRCNS isolates in our hospital. A remarkable finding of the present study was demonstration of the quite low rate of TMP-SMX resistance among MRSA isolates whereas MRCNS isolates showed high rate of resistance.

In order to detect the in vitro activity of tigecycline against multiple resistant gram-negative bacilli isolated in our hospital, tigecycline susceptibilities of clinical isolates of multiple and/or panresistant 100 Acinetobacter baumannii isolates, and 38 carbapenem resistant Klebsiella pneumoniae (17 of which were panresistant), obtained between January 2005 and August 2007, were evaluated by using E-test (AB Biodisc, Sweden). Carbapenem resistance rate was found to be 59% for A.baumannii, using Vitek2 Compact System (Bio-Merieux, France) which is present in our laboratory for routine use. Minimal inhibitory concentration (MIC) levels for tigecycline were < or =2 mcg/ml in 93% of the isolates while the MIC level was 3 mcg/ml for 7% of the isolates. Tigecycline MIC50 and MIC 90 values were 1.5 and 2 mcg/ml, respectively. Among K. pneumoniae the least resistance was detected against amikacin (52.6% resistant) while tigecycline MIC levels were between 0.13 mcg/ml and 2 mcg/ml. All of the K.pneumoniae strains were susceptible to tigecycline, and the MIC50 ve MIC90 values of these isolates were 1 mcg/ml and 1.5 mcg/ml, respectively. The in vitro susceptibility rates of tigecycline against multiple and/or panresistant A. baumannii and K. pneumoniae isolates are found to be promising for use in therapy.