Distribution of bla(OXA) Genes in Acinetobacter baumannii Strains: A Multicenter Study

Acinetobacter baumannii is the most important agent of nosocomial infections within the Acinetobacter genus. This gram-negative coccobacillus is intrinsically resistant to many antibiotics used in antimicrobial therapy, and capable of developing resistance including carbapenems. The objective of this study was to develop a multiplex real time polymerase chain reaction (qPCR) kit for OXA subgroups in A.baumannii, and to investigate the distribution of OXA subgroups in A.baumannii strains isolated from geographically different regions of Turkey. A total of 834 A.baumannii clinical isolates collected from different state and university medical centers in 13 provinces (Afyonkarahisar, Ankara, Bolu, Elazig, Erzurum, Isparta, Istanbul, Kahramanmaras, Konya, Sakarya, Van) between 2008-2011, were included in the study. The isolates were identified by conventional methods and automated systems [Vitek2 (bioMerieux, ABD) and Phoenix (BD Diagnostic, MD)]. The susceptibility profiles of the isolates were studied with automated systems and standard disc diffusion method. All samples were subjected to qPCR to detect bla(OXA-51-like), bla(OXA-23-like) and bla(OXA-58-like) genes. A conventional PCR method was also used to detect bla(OXA-24-like) gene. The resistance rates observed during the study period were as follows: 96.8% for amoxicillin-clavulanate, 86.8% for ciprofloxacin, 74.7% for gentamicin, 71.7% for amikacin, 73.5% for cefaperozone-sulbactam, 72.1% for imipenem and 73% for meropenem. Six hundred and two (72.2 %) isolates were resistant to both imipenem and meropenem. Colistin was found to be the most effective antibiotic against A.baumannii isolates with 100% susceptibility rate. All isolates were positive for bla(OXA-51-like) gene, however bla(OXA-24-like) gene could not be demonstrated in any isolate. Total positivity rates of bla(OXA-23-like) and bla(OXA-58-like) genes were found as 53.7% and 12.5%, respectively, while these rates were 74.4% and 17.3% in carbapenem-resistant isolates, respectively. Twenty-five isolates were positive-for both bla(OXA-23-like) and bla(OXA-58-like) genes. All of the carbapenem-resistant isolates have OXA type genes like with the exception of bla(OXA-24-like) gene. The positivity rates for bla(OXA-23-like) and bla(OXA-58-like) genes varied for each center. In addition, there was a decrease in the frequency of bla(OXA-58-like) gene, however both bla(OXA-23-like) gene and carbapenem resistance rates increased during the study period. In conclusion, high rates of resistance to carbapenems were also remarkable but A.baumannii strains keep on sensitivity to colistin. Both bla(OXA-23-like) and bla(OXA-58-like) genes were shown to be widespread in carbapenem-resistant A.baumannii clinical isolates. However, bla(OXA-23-like) gene positive strains were increased throughout the study. Currently, multiplex qPCR is the best way for rapid diagnosis of resistant bacteria for prevention of hospital-acquired infections. The multiplex qPCR kit developed in this study could be useful for rapid diagnosis and identify the frequencies of bla(OXA-23-like), bla(OXA-51-like) and bla(OXA-58-like) genes in carbapenem-resistant A.baumannii clinical isolates

Changes in Antibiotic Resistance of Pseudomonas aeruginosa Isolates Over the Past 11 Years in Turkey: A Meta-Analysis

Pseudomonas aeruginosa izolatların sahip oldukları direnç mekanizmalarının çeşitliliği ve artan direnç oranları tedavide ciddi sorunlara yol açmaktadır. Bakterinin antibiyotiklere direnci hastanın özelliğine ve antibiyotik kullanım politikalarına bağlı olarak ülkeye, bölgeye, hastaneye ve kliniğe göre değişebilmekte, hatta tedavi sırasında da değişiklik gösterebilmektedir. Bu meta-analiz çalışmasında, P.aeruginosa izolatlarında antibiyotik direnç değişiminin son 11 yıldaki durumunun değerlendirilmesi amaçlanmıştır. Meta-analiz çalışması, PRISMA bildirisine uygun olarak planlanmış ve uygulanmıştır. Buna göre çalışmamızda literatür tarama, kabul ve red kriterlerinin belirlenmesi, makale incelenmesi, veri toplanması ve istatistiksel analizler yapılmıştır. Literatür taramada iki ulusal (ULAKBİM ve Türk Medline) ve bir uluslararası (PubMed) veritabanı kullanılmıştır. Literatürler, dışlama kriterleri göz önünde tutularak incelenmiş, çalışma verileri toplanmış ve istatistiksel analiz gerçekleştirilmiştir. Literatürlerden elde edilen veriler ortak bir birim altında toplanarak değerlendirilmiştir. %95 güven aralığında yapılan hesaplamalarda p 0.05). 2007-2009 yılları arasında karbapenem direncinde, özellikle de imipeneme karşı dirençte artış izlenmiş; ancak imipenem ve meropenem direnç değişimi istatistiksel olarak anlamlı bulunmamıştır (p= 0.254, p= 0.499). 11 yıllık süreçte imipenem ve meropenem direnç oranı sırasıyla %29.4 ve %32.1 olarak saptanmıştır. Son 4 yıllık dönemde sefalosporinlerden sefepim ve monobaktam dışındaki antibiyotik gruplarında bildirilen direnç oranlarında azalma görülmüştür. Sefepim ve seftazidim direnç oranları sırasıyla %41.4 ve %43.9 olarak bulunmuştur. Son 4 yılda aminoglikozid grubu antibiyotiklerden amikasin, gentamisin, netilmisin ve tobramisin için bildirilen direnç oranlarında azalma izlenmiş, ancak bu azalma istatistiksel olarak anlamlı bulunmamıştır (p> 0.05). Mevcut veriler ışığında, ülkemizde P.aeruginosa'nın antibiyotik direncinin azalma eğiliminde olduğu söylenebilir. Henüz yolun başında olmakla birlikte, akılcı ve kısıtlı antibiyotik kullanım politikalarının, direncin azalmasına katkı sağladığı ifade edilebilir; ancak direncin makul düzeylere gerilemesi için yeni ve sürdürülebilir politikaların hayata geçirilmesi gereklidirThe increased antibiotic resistance and diversity of resistance mechanisms in clinical isolates of Pseudomonas aeruginosa lead to serious problems in treatment. Bacterial resistance against antibiotics can be infl uenced by patient characteristics, antibiotic usage policy depending on the country, region, hospital, clinics and even may vary during treatment. In this meta-analysis study, we aimed to evaluate the trends in P.aeruginosa antibiotic resistance over the past 11 years. The study was planned and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the literature search method, criteria for inclusion and exclusion, evaluation of publications, data collection, and statistical analysis were performed. To identify relevant publications, two national databases (ULAKBIM and TURK MEDLINE) and one international database (PubMed) were searched. Published manuscripts were evaluated for exclusion criteria, after the study data were collected, and statistical analyses were performed. The data obtained from the literature were assessed under a common unit. The calculations made in the 95% confi dence interval value of p<= 0.05 was considered statistically signifi cant. As a result of exclusion criteria, meta-analysis was performed for 48 studies published between 2003 and 2013. For the evaluation of the changes in antibiotic resistance of P.aeruginosa isolates over time, studies were divided into three groups according to the year of publication. The number of publications was relatively consistent over the course of the study period with 17 studies published in 2003-2006; 14 in 2007-2009, and 17 in 2010-2013. There were signifi cant changes in antibiotic resistance results within years however, none of these differences were statistically signifi cant (p> 0.05). Carbapenem resistance, especially imipenem resistance, increased between 2007 and 2009, however, the changes were not statistically signifi cant for either imipenem or meropenem (p= 0.254, p= 0.499, respectively). Through the 11-year period, the resistance rates for imipenem and meropenem were 29.4% and 32.1%, respectively. In the last 4 years of the study period, notable decrease were reported in antibiotic groups except for cefepime from cephalosporins and monobactam; the resistance rates for cephalosporins remained unchanged during this time period. The reported resistance rates for cefepime and ceftazidime were 41.4% and 43.9%, respectively. Similar decreases in resistance to aminoglycoside antibiotics, including amikacin, gentamicin, netilmicin, and tobramycin, were also seen, however, these changes were not statistically signifi cant (p> 0.05). The current data suggested that antibiotic resistance in P.aeruginosa has a tendency to decrease in our country. Though being at the bottom of the ladder, it can be expressed that rational and restricted use of antibiotics policy, contributed to the strength of the decrease; however for the decline of resistance to a reasonable level, new and sustainable policy is necessary to be implemente

Antibiotic Resistance Patterns of Escherichia coli Strains Isolated from Urine Cultures in Turkey: A Meta-Analysis

Escherichia coli is the most frequently isolated microorganism from both community-acquired and nosocomial urinary tract infections in Turkey. A large number of studies concerning antibiotic susceptibility of E.coli have been published from differrent centers throughout the country. The aim of this study was to evaluate the antibiotic resistance patterns of E.coli strains isolated from urine cultures by a meta-analysis in published medical literature between the years of 1996-2012 in Turkey. The study was planned and conducted in accordance with the declaration of PRISMA and describes the methods of literature search, the determining criteria for infusion and evaluation of articles, data collection and statistical analysis. To find the published series Google Scholar and PubMed international databases were used to access published manuscripts evaluated according to the determined criteria for acceptance and rejection. For each study, general data and antibiotic resistance rates were collected as a common unit. Publications considered as lacking in appropriate content was eliminated from the study. Statistical analysis of the data obtained were 95% confidence intervals, and p <= 0.05 value was considered as significant difference. A total of 228 articles were found to be published during 1996-2012 period, while 101 of them were included in the meta-analysis according to the eligibility criteria. The analyses indicated that nitrofurantoin and piperacillin resistance rates have been decreased, whereas ciprofloxacin, cefepime, co-trimoxazole and extended-spectrum beta-lactamase (ESBL) positivity rates have been increased during the study period. The increases in the rates of ciprofloxacin and cefepime resistance and and ESBL production were statistically-significant (p < 0.05). A significant reduction in resistance rates for ampicilin, amoxicillin-clavulanate, and amikacin was noted in pediatric patients between 2002-2012. Ceftriaxone, imipenem, gentamicin and amikacin resistance were not homogenous between the geographical regions, and statistically significant differences were observed for amoxicillin-clavulanate, cefuroxime and ciprofloxacin resistance rates (p < 0.05). Antibiotic resistance rates, except for imipenem, in bacterial strains, isolated from hospitalized patients were found significantly higher in strains obtained from outpatients. The differences between those groups were significant in terms of ampicilin, amoxicillin-clavulanate, cefuroxime, ceftriaxone, trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin, amikacin and cefepime resistances (p < 0.05). It has been noted that antibiotic resistance patterns of E.coli strains isolated from urine cultures between 1996-2012 demonstrated significant variability, and many studies were based only on laboratory data. The results of this meta-analysis demonstrated that the resistance rates in commonly-used antibiotics for empirical therapy were high. In conclusion, information obtained by systematic evaluation of national data will be valuable for the determination of optimal antibiotic regimens and in prevention of unnecessary antibiotic use

Changes in Antibiotic Resistance of Pseudomonas aeruginosa Isolates Over the Past 11 Years in Turkey: A Meta-Analysis

The increased antibiotic resistance and diversity of resistance mechanisms in clinical isolates of Pseudomonas aeruginosa lead to serious problems in treatment. Bacterial resistance against antibiotics can be influenced by patient characteristics, antibiotic usage policy depending on the country, region, hospital, clinics and even may vary during treatment. In this meta-analysis study, we aimed to evaluate the trends in P.aeruginosa antibiotic resistance over the past 11 years. The study was planned and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the literature search method, criteria for inclusion and exclusion, evaluation of publications, data collection, and statistical analysis were performed. To identify relevant publications, two national databases (ULAKBIM and TURK MEDLINE) and one international database (Pub Med) were searched. Published manuscripts were evaluated for exclusion criteria, after the study data were collected, and statistical analyses were performed. The data obtained from the literature were assessed under a common unit. The calculations made in the 95% confidence interval value of p 0.05). Carbapenem resistance, especially imipenem resistance, increased between 2007 and 2009, however, the changes were not statistically significant for either imipenem or meropenem (p= 0.254, p= 0.499, respectively). Through the 11-year period, the resistance rates for imipenem and meropenem were 29.4% and 32.1%, respectively. In the last 4 years of the study period, notable decrease were reported in antibiotic groups except for cefepime from cephalosporins and monobactam; the resistance rates for cephalosporins remained unchanged during this time period. The reported resistance rates for cefepime and ceftazidime were 41.4% and 43.9%, respectively. Similar decreases in resistance to aminoglycoside antibiotics, including amikacin, gentamicin, netilmicin, and tobramycin, were also seen, however, these changes were not statistically significant (p> 0.05). The current data suggested that antibiotic resistance in P.aeruginosa has a tendency to decrease in our country. Though being at the bottom of the ladder, it can be expressed that rational and restricted use of antibiotics policy, contributed to the strength of the decrease; however for the decline of resistance to a reasonable level, new and sustainable policy is necessary to be implemented

Antibiotic resistance patterns of Escherichia coli strains isolated from urine cultures in Turkey: A meta-analysis

Escherichia coli ülkemizde hem hastane hem de toplum kaynaklı üriner sistem enfeksiyonlarında en sık izole edilen etkendir. Ülkemizde E.coli suşlarının antibiyotik duyarlılıkları ile ilgili farklı merkezlerde yapılmış çok sayıda yayın bulunmaktadır. Bu çalışma ile Türkiye’de 1996-2012 yılları arasında idrar kültürlerinden izole edilen E.coli suşlarının antibiyotik direnç değişimlerinin meta-analitik incelenmesi amaçlanmıştır. PRISMA bildirisine uygun olarak planlanan ve yürütülen meta-analiz çalışmamızda; literatür tarama, kabul ve red kriterlerinin belirlenmesi, makale incelenmesi, veri toplanması ve istatistiksel analiz yapılmıştır. Amaca bağlı olarak literatür taraması Google Scholar ve PubMed arama sayfalarında yapılmış; belirlenen kabul ve red kriterlerine göre uygun makaleler seçilerek incelenmiştir. Çalışmaların verileri ve antibiyotik direnç oranları ortak bir birim altında toplanmıştır. Verilerin toplanması aşamasında eksik bulunan bilimsel yayınlar değerlendirmeye alınmamıştır. Elde edilen verilerin istatistiksel analizleri %95 güven aralığında yapılmış; p≤ 0.05 değeri anlamlı düzeyde farklılık olarak kabul edilmiştir. Sonuçta 1996- 2012 yılları arasında yayınlanan 228 makaleye ulaşılmış; uygunluk kriterlerine göre bunlardan 101’ine meta-analiz uygulanmıştır. Yıllara göre; nitrofurantoin ve piperasilin antibiyotiklerine dirençte azalma, siprofloksasin, sefepim, kotrimoksazol ve genişlemiş spektrumlu beta-laktamaz (GSBL) oranlarında ise artma izlenmiştir. Siprofloksasin, sefepim ve GSBL oranlarındaki artış istatistiksel olarak anlamlı bulunmuştur (p< 0.05). 2002-2012 yılları arasında çocuk hastaların ampisilin, amoksisilin-klavulanat ve amikasin antibiyotiklerine karşı direnç oranlarında azalma saptanmış ve farkın anlamlı olduğu belirlenmiştir (p< 0.05). Coğrafi bölgeler arasında seftriakson, imipenem, gentamisin ve amikasin antibiyotik direncinin homojen olmadığı gösterilmiş ve amoksisilin-klavulanat, sefuroksim, siprofloksasin direncinde istatistiksel olarak anlamlı fark saptanmıştır (p< 0.05). Hastanede yatan hastalardan izole edilen suşların direnç oranları, imipenem haricinde, poliklinik hastalarının oranlarından daha yüksek bulunmuştur. Bu hastalar arasında ampisilin, amoksisilin-klavulanat, sefuroksim, seftriakson, trimetoprim-sülfametoksazol, gentamisin, siprofloksasin, amikasin ve sefepim dirençleri arasında anlamlı istatistiksel fark tespit edilmiştir (p< 0.05). 1996- 2012 yılları arasında idrar kültürlerinden izole edilen E.coli suşlarının antibiyotik direnç sonuçlarının oldukça farklı olduğu ve çok sayıda çalışmanın sadece laboratuvar verilerine dayandığı izlenmiştir. Yapılan meta-analize göre, ampirik tedavide sık kullanılan antibiyotiklere karşı direnç oranlarının yüksek olduğu dikkati çekmiştir. Sonuç olarak, ülkemiz verilerinin sistematik olarak değerlendirilmesiyle oluşan bilgi birikiminin, uygun antibiyotik seçiminde ve gereksiz antibiyotik kullanımının önlenmesinde değer taşıyacağı düşünülmüştür.Escherichia coli is the most frequently isolated microorganism from both community-acquired and nosocomial urinary tract infections in Turkey. A large number of studies concerning antibiotic suscepti- bility of E.coli have been published from differrent centers throughout the country. The aim of this study was to evaluate the antibiotic resistance patterns of E.coli strains isolated from urine cultures by a meta- analysis in published medical literature between the years of 1996-2012 in Turkey. The study was plan- ned and conducted in accordance with the declaration of PRISMA and describes the methods of literature search, the determining criteria for inlusion and evaluation of articles, data collection and statistical analysis. To find the published series Google Scholar and PubMed international databases were used to access published manuscripts evaluated according to the determined criteria for acceptance and rejection. For each study, general data and antibiotic resistance rates were collected as a common unit. Publications considered as lacking in appropriate content was eliminated from the study. Statistical analysis of the data obtained were 95% confidence intervals, and p&amp;#8804; 0.05 value was considered as significant dif- ference. A total of 228 articles were found to be published during 1996-2012 period, while 101 of them were included in the meta-analysis according to the eligibility criteria. The analyses indicated that nitro- furantoin and piperacillin resistance rates have been decreased, whereas ciprofloxacin, cefepime, co-tri- moxazole and extended-spectrum beta-lactamase (ESBL) positivity rates have been increased during the study period. The increases in the rates of ciprofloxacin and cefepime resistance and and ESBL production were statistically-significant (p&lt; 0.05). A significant reduction in resistance rates for ampicilin, amo- xicillin-clavulanate, and amikacin was noted in pediatric patients between 2002-2012. Ceftriaxone, imipenem, gentamicin and amikacin resistance were not homogenous between the geographical regions, and statistically significant differences were observed for amoxicillin-clavulanate, cefuroxime and ciprof- loxacin resistance rates (p&lt; 0.05). Antibiotic resistance rates, except for imipenem, in bacterial strains, isolated from hospitalized patients were found significantly higher in strains obtained from outpatients. The differences between those groups were significant in terms of ampicilin, amoxicillin-clavulanate, cefuroxime, ceftriaxone, trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin, amikacin and cefepime resistances (p&lt; 0.05). It has been noted that antibiotic resistance patterns of E.coli strains isolated from urine cultures between 1996-2012 demonstrated significant variability, and many studies were based only on laboratory data. The results of this meta-analysis demonstrated that the resistance rates in commonly-used antibiotics for empirical therapy were high. In conclusion, information obtained by systematic evaluation of national data will be valuable for the determination of optimal antibiotic regimens and in prevention of unnecessary antibiotic use

The Antibiotic Resistance Patterns of Klebsiella pneumoniae Clinic Isolates: A Comprehensive Meta-Analysis

Background/Purpose: Recently, Klebsiella pneumoniae has become a health care concern due to its production of extended-spectrum beta-lactamase (ESBL) and its resistance to carbapenem. In Turkey, systematic meta-analyses investigating antibiotic resistance in K. pneumoniae are lacking.Methods: Consequently, we performed a systematic review of the literature followed by a metaanalysis to investigate antibiotic resistance in K. pneumoniae. This study was designed and conducted in accordance with the PRISMA guidelines. We identified observational studies published from 2000 to 2015 using the various search engines. In total, 2,225 articles were published during this study period, but we only included 25 in our meta-analysis because of eligibility criteria.Results: We observed a significant increase in antibiotic resistance (&gt;40%) to the following antibiotics: cefazolin, amoxicillin-clavulanic acid, cefuroxime, cefepime, ceftriaxone, and ceftazidime. Unfortunately, the majority of these antibiotics were commonly prescribed for the treatment of K. pneumoniae infections. The rate of bacterial ESBL production has been steadily increasing and in this study was calculated at 39.66% ± 12.46%. In this study, we observed &gt;30% resistance to ciprofloxacin. Furthermore, the rates of resistance to imipenem and meropenem were 5.1% and 3.4%, respectively.Conclusion: The data obtained from this study may be beneficial for prescribing appropriate antibiotics and preventing their unnecessary use. The frequent checks of resistance rates with new detailed report may suggest to the development of National Antibiotic Stewardship.</p