HPLC-DAD elucidation of phenolic compounds from plant organ extracts with inhibitory effect on Escherichia coli replikative DNA polymerase IIIα (DnaE)

Bu yüksek lisans tezinde 11 bitkinin replikatif DNA polimeraz inhibisyonu, antimikrobial aktivite ve bazı kimysal içerikleri çalışılmıştır. Bitkilerden bazılarının tamamı, bazılarının meyve, yaprak, çiçek kısımları kullanıldı. Replikatif bakteriyal DNA polimeraz olarak Escherichia coli (E. coli) replikatif DNA polimeraz III? (DnaE) seçildi ve rekombinant üretildi. Bunun için DnaE'i kodlayan gen PZR ile çoğaltıldı ve pET-100 TOPO vektörüne klonlandı. Ni-afinite ile saflaştırıldı. 11 bitkinin metanol ve DMSO özütleri hazırlandı. Metanol özütleri DnaE karşı inhibisyonun belirlenmesi için primer uzatma deneylerinde kullanıldı. Bu amaçla sentetik olarak dizayn edilen ve florojenik primer ihtiva eden 45/20-mer DNA kullanıldı. Rosa canina bitkisinin çiçek kısmının DnaE üzerinde güçlü bir şekilde inhibisyon gösterdiği belirlendi. Sorbus caucasica ve Sorbus aucuparia bitkilerin yaprak ve meyvelerinin de inhibisyon gösterdiği belirlendi. Sorbus aucuparia (meyve, yaprak), Sorbus caucasica (meyve, yaprak) ve Rosa canina (çiçek, meyve) DMSO ekstraktlarının gram (+) ve gram (-) bakteriler üzerine antimikrobiyal testi yapıldı. Sorbus türlerinin ekstraktlarında gram (+) bakteriler üzerinde antimikrobiyal aktivitesi olmadığı gözlendi. Rosa canina meyve özütlerinin gram (+) ve gram(-) olmak üzere bu iki grup bakteri üzerinde antimikrobiyal aktivitesi olduğu belirlendi. İnhibisyon görülen bitkilerin metanol ekstraktları sıvı-sıvı ekstraksiyon yöntemi ile sulu ortamda sırasıyla dietil eter, etil asetat, bütanol ve kalan sulu kısım olmak üzere dört ayrı fraksiyona ayrıldı ve ardından HPLC-DAD ile bu ekstraktların fenolik bileşikleri aydınlatıldı. Rosa canina bitkisinin çiçek ve meyve özütlerinde gallik asit ve gallik asitin türevi olan ellacik asit bulundu. Sorbus aucuparia ve Sorbus causacisa bitkilerinin yaprak ve meyve özütlerinde klorojenik asit ve rutin bileşikleri bulundu. Inhibition of replicative bacterial DNA polymerase, antimicrobial activity and chemical compounds of eleven plants were investigated in this Master Thesis. The whole or some parts (such as leaf, flower and fruit) of plants were used in assay. E. coli replicative DNA polymerase III? (DnaE2) was selected to research inhibition affects of plant compounds and it was produced as recombinant. The gene coding DnaE2 was amplified from E. coli K12 genom by PCR and inserted into the pET100-TOPO expression vector. It was expressed in E. coli BL21 (DE3) and purified by Ni-affinity chromorography. Methanol and DMSO extracts of eleven plant samples were prepared. Methanol extracts were used to investigate their inhibitory affect on polymerase by primer extension assay and DMSO extracts were used to investigate the antimicrobial activity on selective microorganisms by agar diffusion methods. Flourogenic labeled 45/20-mer synthetic DNA used in primer extension assay. According to results, a strong inhibition against to DnaE2 was determined in flower exract of Rosa canina. At the same way, it was determined that Sorbus caucasica and Sorbus aucuparia had the same affect on DnaE2. Antimicrobial activity of Sorbus aucuparia (fruit and leaf), Sorbus caucasica (fruit and leaf) and Rosa canina (flower and fruit) was investigated for Gram (-) and Gram (+) microorganisms. There was no antimicrobial affects in Sorbus extract against to Gram (+), but fruit extract of Rosa canina had antimicrobial affect against to both Gram (+) and Gram (-). The plant extracts having inhibitory affect on DnaE2 was fractioned into four sub-fractions (in order to dietyl eter, etyl acetate, butanol and liquid part) by liquid-liquid extraction method prepared in water and then phenolic compounds in each fraction were identified by HPLC-DAD system. Gallic acid and its derivate (ellagic acid) were found in flower and fruit extracts of Rosa canina. Clorogenic and rutin compounds were found in leaf and fruit extract of Sorbus aucuparia and Sorbus caucasica

Gram (-) microorganisms DNA polymerase inhibition, antibacterial and chemical properties of fruit and leaf extracts of Sorbus acuparia and Sorbus caucasica var. yaltirikii

BELDUZ, Ali Osman/0000-0003-2240-7568; k, selvi/0000-0002-9912-8586; SANDALLI, Cemal/0000-0002-1298-3687WOS: 000400604700017PubMed: 27859484Investigation of novel plant-based agents might provide alternative antibiotics and thus fight antibiotic resistance. Here, we measured the ability of fruit and leaf extracts of Sorbus aucuparia (Sauc) and endemic Sorbus caucasica var. yaltirikii (Scau) to inhibit nonreplicative (Klenow Fragment-KF and Bacillus Large Fragment-BLF) and replicative (DnaE and PolC) bacterial DNA polymerases along with their antimicrobial, DPPH free radical scavenging activity (RSA), and chemical contents by total phenolic content and HPLC-DAD analysis. We found that leaf extracts had nearly 10-fold higher RSA and 5-fold greater TPC than the corresponding fruit extracts. All extracts had large amounts of chlorogenic acid (CGA) and rutin, while fruit extracts had large amounts of quercetin. Hydrolysis of fruit extracts revealed mainly caffeic acid from CGA (caffeoylquinic acid) and quercetin from rutin (quercetin-3-O-rutinoside), as well as CGA and derivatives of CGA and p-coumaric acid. Plant extracts of Sorbus species showed antimicrobial activity against Gram-negative microorganisms. Scau leaf extracts exhibited strong inhibition of KF activity. Sauc and Scau leaf extracts also strongly inhibited two replicative DNA polymerases. Thus, these species can be considered a potential source of novel antimicrobial agents specific for Gram-negative bacteria.Scientific and Technical Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TUBITAK-113Z054]The Scientific and Technical Research Council of Turkey, Grant/Award Number: TUBITAK-113Z05

Carriage of Class 1 and 2 Integrons in Acinetobacter baumannii and Pseudomonas aeruginosa Isolated from Clinical Specimens and a Novel Gene Cassette Array: bla(OXA-11)-cmlA7

SANDALLI, Cemal/0000-0002-1298-3687WOS: 000332131600005PubMed: 24506715The dissemination of antibiotic resistance genes between bacteria leads to serious problems in the treatment of infectious diseases. It has been shown that resistance genes can also be carried by the integrons. There are limited studies regarding the carriage of class 1 and 2 integrons in Acinetobacter baumannii and Pseudomonas aeruginosa clinical strains in Turkey. the aims of this study were to investigate the carriage rates of class 1 and class 2 integrons in A.baumannii and P.aeruginosa strains isolated from clinical samples in Abant Izzet Baysal University Hospital, and to characterize the antibiotic resistance gene cassettes in these integrons by sequence analyses. A total of 137 strains (77 A.baumannii and 60 P.aeruginosa) isolated from various clinical specimens (56% were sputum, 19% wound, 11% urine, 11% blood, 3% catheter), between March 2010-December 2012, were included in the study. the identification and antibiotic susceptibility tests of the isolates were performed by Vitek 2 Compact (bioMerieux, France) and BD Phoenix 100 (Becton Dickinson, USA) systems. the presence of integrons were screened by PCR method using specific primer pairs targeting class 1 (intil1) and 2 (intl2) integrase regions. All the samples that revealed integron amplification were subjected to DNA sequence analysis, both in the forms of cloned products and PCR amplicons. in the study, the highest susceptibility rates were found against colistin (96%) and tigecycline (78%) in A.baumannii, and against piperacillin/tazobactam (97%) and piperacillin (93%) in P.aeruginosa isolates. the highest resistance rate was determined for piperacillin/tazobactam (95%) in A.baumannii strains. the presence of intl1 gene was detected in 33% (26/77) of A.baumannii and 10% (6/60) of P.aeruginosa isolates. When variable regions in intl1 positive strains were amplified by PCR, eight (8/77, 10%) A.baumannii and three (3/60, 5%) P.aeruginosa strains were found to harbor antibiotic resistance gene cassettes. Intl2 gene was not detected in any of the isolates. Resistance to piperacillin/tazobactam, ceftazidime, cefepime, ceftriaxone and ampicillin/sulbactam was detected as the common resistance pattern in all integron-positive A.baumannii strains, whereas resistance to ceftazidime, gentamicin and ciprofloxacin was the common pattern in all integron-positive P.aeruginosa strains. DNA sequence analysis of variable regions of integrons indicated that two separate gene cassette arrays (aacC1-aadAl and aac(3)-1) were carried by A.baumannii strains, and two types of gene cassette arrays (bla(OXA-30)-aadA1 and bla(OXA-11)-cmlA7) were carried by P.aeruginosa strains. To our best knowledge, this is the first report of the gene sequence of bia(OXA-11)-cmlA7 defined in an integron gene cassette of P.aeruginosa

Carriage of class 1 and 2 integrons in acinetobacter baumannii and pseudomonas aeruginosa isolated from clinical specimens a and a novel gene cassette array: blaOXA-11-cmlA7

Antibiyotik direnç genlerinin bakteriler arasındaki yayılımı, enfeksiyon hastalıklarının tedavisinde ciddi sorunlar oluşturmaktadır. Son zamanlarda bu genlerin integronlarda da taşındığı gösterilmiştir. Ülkemizde, Acinetobacter baumannii ve Pseudomonas aeruginosa klinik izolatlarında sınıf 1 ve sınıf 2 integron taşıyıcılığıyla ilgili çalışmalar sınırlı sayıdadır. Bu çalışmada, Abant İzzet Baysal Üniversitesi Hastanesinde, klinik örneklerden izole edilen A.baumannii ve P.aeruginosa suşlarında, sınıf 1 ve 2 integron taşıyıcılığının araştırılması ve antibiyotik direnç gen kasetlerinin dizi analiziyle karakterize edilmesi amaçlanmıştır. Çalışmaya, Mart 2010-Aralık 2012 tarihleri arasında çeşitli klinik örneklerden (%56 balgam, %19 yara, %11 idrar, %11 kan, %3 kateter) izole edilen 77 A.baumannii ve 60 P.aeruginosa olmak üzere toplam 137 suş dahil edilmiştir. İzolatların tanımlanması ve antibiyogramları Vitek 2 Compact (bioMérieux, Fransa) ve BD Phoenix 100 (Becton Dickinson, ABD) sistemleriyle yapılmıştır. Suşlarda integron varlığı, sınıf 1 (intI1) ve sınıf 2 (intI2) integraz bölgeleri için özgül primer çiftleri kullanılarak PCR yöntemiyle araştırılmış; integron amplifikasyonunun gerçekleştirildiği tüm örnekler, hem klonlanarak hem de PCR ürünü olarak DNA dizi analizine tabi tutulmuştur. Çalışmada, A.baumannii suşlarında en yüksek duyarlılık kolistin (%96) ve tigesiklin (%78), P.aeruginosa suşlarında ise piperasilin-tazobaktam (%97) ve piperasiline (%93) karşı saptanmış; buna karşın A.baumannii suşlarında en yüksek direnç oranı (%95) piperasilin/tazobaktama karşı gözlenmiştir. A.baumannii suşlarının %33 (26/77)’ünde, P.aeruginosa suşlarının ise %10 (6/60)’unda intI1 geni tespit edilmiş; intI1 pozitif suşlarda değişken bölgeler PCR ile çoğaltıldığında sekiz (8/77, %10) A.baumannii ve üç (3/60, %5) P.aeruginosa suşunun antibiyotik direnç gen kaseti taşıdığı belirlenmiştir. Suşların hiçbirisinde intI2 geni saptanmamıştır. İntegron pozitif olan tüm A.baumannii suşlarında piperasilin/tazobaktam, seftazidim, sefepim, seftriakson ve ampisilin/sulbaktama karşı, integron pozitif tüm P.aeruginosa suşlarında ise seftazidim, gentamisin ve siprofloksasine karşı ortak direnç paterni tespit edilmiştir. İntegronların DNA dizi analizleri, A.baumannii [aacC1-aadA1 ve aac(3)-1] ve P.aeruginosa (blaOXA-30-aadA1 ve blaOXA-11-cmlA7) suşlarının ikişer farklı gen kaset dizisi taşıdığını göstermiştir. Ulaşabildiği kadarıyla, P. aeruginosa integron gen kaseti içerisinde tanımlanan blaOXA-11-cmlA7 gen dizilimi ilk kez bu çalışma ile tanımlanmış ve yeni bir gen dizilimi olarak literatüre sunulmuştur.The dissemination of antibiotic resistance genes between bacteria leads to serious problems in the treatment of infectious diseases. It has been shown that resistance genes can also be carried by the inte- grons. There are limited studies regarding the carriage of class 1 and 2 integrons in Acinetobacter bau- mannii and Pseudomonas aeruginosa clinical strains in Turkey. The aims of this study were to investigate the carriage rates of class 1 and class 2 integrons in A.baumannii and P.aeruginosa strains isolated from clinical samples in Abant Izzet Baysal University Hospital, and to characterize the antibiotic resistance gene cassettes in these integrons by sequence analyses. A total of 137 strains (77 A.baumannii and 60 P.aeruginosa) isolated from various clinical specimens (56% were sputum, 19% wound, 11% urine, 11% blood, 3% catheter), between March 2010-December 2012, were included in the study. The identifica- tion and antibiotic susceptibility tests of the isolates were performed by Vitek 2 Compact (bioMérieux, France) and BD Phoenix 100 (Becton Dickinson, USA) systems. The presence of integrons were screened by PCR method using specific primer pairs targeting class 1 (intI1) and 2 (intI2) integrase regions. All the samples that revealed integron amplification were subjected to DNA sequence analysis, both in the forms of cloned products and PCR amplicons. In the study, the highest susceptibility rates were found against colistin (96%) and tigecycline (78%) in A.baumannii, and against piperacillin/tazobactam (97%) and piperacillin (93%) in P.aeruginosa isolates. The highest resistance rate was determined for piperacil- lin/tazobactam (95%) in A.baumannii strains. The presence of intI1 gene was detected in 33% (26/77) of A.baumannii and 10% (6/60) of P.aeruginosa isolates. When variable regions in intI1 positive strains were amplified by PCR, eight (8/77, 10%) A.baumannii and three (3/60, 5%) P.aeruginosa strains were found to harbor antibiotic resistance gene cassettes. IntI2 gene was not detected in any of the isolates. Resistance to piperacillin/tazobactam, ceftazidime, cefepime, ceftriaxone and ampicillin/sulbactam was detected as the common resistance pattern in all integron-positive A.baumannii strains, whereas resist- ance to ceftazidime, gentamicin and ciprofloxacin was the common pattern in all integron-positive P.aeruginosa strains. DNA sequence analysis of variable regions of integrons indicated that two separate gene cassette arrays (aacC1-aadA1 and aac(3)-1) were carried by A.baumannii strains, and two types of gene cassette arrays (blaOXA-30-aadA1 and blaOXA-11- cmlA7) were carried by P.aeruginosa strains. To our best knowledge, this is the first report of the gene sequence of blaOXA-11-cmlA7 defined in an integron gene cassette of P.aeruginosa

Characterization of Class 1 and Class 2 lntegron Gene Cassettes in Escherichia coil Strains Isolated From Urine Cultures: A Multicenter Study

Ay Altintop, Yasemin/0000-0002-6586-5561WOS: 000378184000001PubMed: 27175490Escherichia coli is the most common pathogen isolated from both nosocomial and community acquired urinary tract infections. Although there are many studies from different centers concerning the antibiotic susceptibility of E.coli isolates in Turkey, the studies are quite few about class 1 and class 2 integron cassettes in clinical E.coli isolates from urinary samples. the aim of the study was to investigate the antibiotic susceptibility and the carriage of integron gene cassettes in E.coli strains isolated from urinary samples. A total of 626 E.coli strains isolated from urine cultures in microbiology laboratories located at 10 provinces from different regions of Turkey (Denizli, Ankara, Kayseri, Nigde, Sanliurfa, Kahramanmaras, Tokat, Malatya, Konya and Trabzon) between June 2011-June 2012 were included in the study. the identification and antibiotic susceptibility testing of the isolates were studied by conventional methods as well as Vitek (R) 2 Compact (bioMerieux, France) and BD Phoenix (TM) 100 (Becton Dickinson, USA) systems. the antibiotic susceptibilities of all the isolates were retested by Kirby-Bauer disk diffusion method according to CLSI recommendations in the main center of the study in order to achive the standardization. the presence of integrons was detected with polymerase chain reaction (PCR) method by using specific primers targeting class 1 (intl1) and class 2 (intl2) integrase gene regions. After integron amplification the samples were cloned and subjected to DNA sequencing. When the antibiotic susceptibility of the isolates were evaluated, the highest resistance was observed against most commonly used empirical antibiotics namely ampicillin and trimethoprim-sulfamethoxazole (SXT) with the mean rate of 58.6% (range: 43.8%-73.2%) and 41.2% (range: 35.4%-45.8%), respectively. the most effective antibiotics detected against the isolates were imipenem and amikacin with the lowest resistance rates of 0.2% (range: 0%-1.1%) and 0.6% (range: 0%-3.2%), respectively. the frequency of positive Intl1 gene and class 1 integron gene cassettes were found as 25.8% (162/626) and 16.6% (104/626), respectively, whereas the frequency of positive intl2 gene II and class 2 integron gene cassettes were 5.1% (32/626) and 3% (19/626), respectively. the lowest intl1 gene frequency was detected in the isolates from Kayseri (16.6%) and the highest in the isolates from Kahramanmaras (35.4%) provinces. While there was no intl2 gene in the isolates from Denizli and Kayseri, the highest frequency was 12.1% in the isolates from Sanliurfa province. dfrA1 gene, the most frequent gene among integron gene cassettes was positive in 31 class 1 integron gene cassette alone, and positive with aadA1 gene in 18 class 1 integron gene cassettes. dfrA1 gene was positive with aadA1 a just in one isolate. dfrA17 allele was positive in one isolate alone, in 28 isolates with aadA1, and in 15 isolates with aadA5. aadA1 gene was detected in four isolates. dfrA17-sat-aadA5 co-existence was detected among class 2 integron gene cassette in isolates from six provinces. dfrA1-sat-aadA1 was detected in one isolate from Ankara province and dfrA1 was detected in one isolate in Nigde province only. As a result, dfrA1 and aadA1 genes are the most common types of genes among class 1 and class 2 integron gene cassettes in E.coli isolated from urine cultures. It was concluded that high resistance against streptomycin (31.2%) and SXT (41.2%) supported the dissemination of integron-mediated genes dfr, sul1 and aad in the isolates

Investigation of the frequency and distribution of beta-lactamase genes in the clinical isolates of acinetobacter baumannii collected from different regions of Turkey: a multicenter study

WOS: 000387771500001PubMed: 28124956The diversity and distribution of TEM, SHV and CTX-M type of extended-spectrum beta-lactamases (ESBLs) are important for the treatment and control of infections. Determination of ESBL genes in clinical isolates by polymerase chain reaction (PCR) and DNA sequencing can obtain useful data for their molecular epidemiology and risk. The aim of this study was to investigate the frequency of beta-lactamase genes in Acinetobacter baumannii strains isolated from different regions of Turkey. A total of 519 A. baumannii strains collected from hospitals located at 12 different provinces of Turkey (Bolu (n=67), Tokat (n=47), Trabzon (n=25), Ordu (n=27), Diyarbakir (n=47), Nigde (n=31), Kayseri (n=36), Ankara (n=41), Kirikkale (n=26), Kahramanmaras (n=25), Mersin (n=40), Istanbul (n=107)] between 2011-2012 period were included in the study. Identification of the isolates were performed by both conventional methods and automated systems, VITEK2 Compact (BioMerieux, France) and API 32GN (BioMerieux, France). Disc diffusion method was used for the detection of antibiotic susceptibilities of the isolates and the results were evaluated according to CLSI (Clinical and Laboratory Standards Institute) criteria. Tigecycline and colistin sensitivities of the isolates were evaluated according to BSAC (British Society for Antimicrobial Chemotherapy) criteria. The presence of beta-lactamase genes, namely bla(oxa-51), bla(TEM), bla(SHV), bla(CTX-M1), bla(CTX-M2), bla(GES) and bla(VIM) were detected by PCR. In our study, the resistance rates against colistin, tigecycline, ampicillin-sulbactam, amoxicillin-clavulanic acid, cefoperazone/sulbactam, tobramycin, ceftriaxone, piperacillin-tazobactam, gentamicin, ampicillin, tetracycline, cefepime, piperacillin, amikacin, trimethoprim-sulfamethoxazole, meropenem, levofloxacin, ciprofloxacin, imipenem and ceftazidime were detected as; 0.6%, 2.7%, 11.9%, 15.2%, 21%, 22.9%, 23.9%, 48.6%, 59.5%, 61.8%, 66.3%, 67.8%, 69.2%, 71.1%, 77.5%, 78.6%, 81.1%, 82.9%, 87.5% and 89.4%, respectively. All of the isolates (100%) were OXA-51 positive, while 443 (85.4%) out of 519 strains harbored other beta-lactamase genes searched in the study. When the distribution of the genes were evaluated, bla(TEM-1) was found as the predominant one with a frequency rate of 55.7% (n=289/519), followed by bla(CTX-M2) (63/519, 12.1%), bla(CTX-M1) (42/519, 8.1%), bla(SHV) (40/519, 7.7%), bla(GES) (8/519, 1.5%) and bla(VIM) (1/519, 0.2%). Cooccurence of ESBL genes was detected in 16.3% (72/443) of the strains, being mostly TEM+CTX-M2 (20/72, 27.8%), TEM+SHV (11/72, 15.3%) and TEM+CTX-M1 (10/72, 13.9%). In addition, it was noted that the distribution of ESBL genes between isolates showed differences according to the provinces. Accordingly, none of the strains isolated from four provinces (Bolu, Nigde, Mersin, Kahramanmaras) and from three provinces (Bolu, Kahramanmaras, Diyarbakir) harbored bla(CTX-M1/M2) and bla(SHV) genes, respectively. The bla(TEM) gene was detected in isolates collected from all of the provinces, with a highest frequency in Nigde (28/31, 90.3%) and lowest in Trabzon (1/25, 4%). The presence of GES-11 type ESBLs was found only in the isolates sent from Nigde province (8/31; 25.8%). Screening of metallo-beta-lactamase VIM gene also yielded a single positive result amongst only Nigde isolates (1/31; 3.2%), and this gene was identified as VIM-5 type by DNA sequencing. This study which is the first comprehensive national research to characterize ESBLs in A. baumannii isolates by molecular methods, showed that the most prevalent ESBL type is TEM (289/519, 55.7%) amongst A. baumannii strains isolated from different regions of our country. The data of our study is parallel to the results of previous studies carried out from Turkey

Characterization of Class 1 and Class 2 Integron Gene Cassettes in Escherichiacoli Strains Isolated From Urine Cultures: A Multicenter Study

Escherichia coli 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 çalışma olmakla birlikte, özellikle idrar kültürlerinde üreyen klinik E.coli izolatlarında sınıf 1 ve sınıf 2 integron taşıyıcılığıyla ilgili çalışmalar oldukça azdır. Bu çalışmada, idrar örneklerinden izole edilen E.coli suşlarının antibiyotik duyarlılıklarının ve integron gen kasetleri varlığının araştırılması amaçlanmıştır. Çalışmaya, Haziran 2011-Haziran 2012 tarihleri arasında, ülkemizin farklı bölgelerindeki 10 ilin (Denizli, Ankara, Kayseri, Niğde, Şanlıurfa, Kahramanmaraş, Tokat, Malatya, Konya ve Trabzon) 10 hastanesinde, mikrobiyoloji laboratuvarına gönderilen idrar örneklerinden izole edilen 626 E.coli suşu dahil edilmiştir. İzolatların tanımlanması ve antibiyogramları konvansiyonel yöntemler, Vitek® 2 Compact (bioMérieux, Fransa) ve BD Phoenix(TM) 100 (Becton Dickinson, ABD) sistemleriyle yapılmıştır. Standardizasyonun sağlanması amacıyla, tüm izolatların antibiyotik duyarlılığı, çalışmanın yapıldığı merkezde CLSI önerileri doğrultusunda KirbyBauer disk difüzyon yöntemiyle tekrarlanmıştır. Suşlarda integron varlığı, sınıf 1 (intI1) ve sınıf 2 (intI2) integraz gen bölgeleri için özgül primer çiftleri kullanılarak polimeraz zincir reaksiyonu (PCR) yöntemiyle araştırılmıştır. İntegron amplifi kasyonunun gerçekleştirildiği örnekler klonlanarak DNA dizi analizine tabi tutulmuştur. İzolatların antibiyotik direnç oranları incelendiğinde, en yüksek direncin, ampirik tedavide sık kullanılan ampisilin (ortalama direnç oranı: %58.6; aralık: %43.8-%73.2) ve trimetoprim-sülfametoksazol (SXT) (ortalama direnç oranı: %41.2; aralık: %35.4-%45.8) için saptandığı görülmüştür. İzolatlara karşı en etkin antibiyotiklerin ise imipenem (ortalama direnç oranı: %0.2; aralık: %0-%1.1) ve amikasin (ortalama direnç oranı: %0.6; aralık: %0-%3.2) olduğu belirlenmiştir. İzolatların intI1 geni pozitifl ik oranı %25.8 (162/626), sınıf 1 integron gen kaseti oranı ise %16.6 (104/626) olarak bulunmuş; bu oranlar intI2 geni ve sınıf 2 gen kaseti için sırasıyla %5.1 (32/626) ve %3 (19/626) olarak saptanmıştır. İntI1 geni pozitifl iği en düşük (%16.6) Kayseri, en yüksek (%35.4) Kahramanmaraş izolatlarında tespit edilmiştir. Denizli ve Kayseri izolatlarında intI2 geni görülmezken, en yüksek oran %12.1 ile Şanlıurfa izolatlarında belirlenmiştir. İntegron gen kasetleri içerisindeki genler incelendiğinde, en sık bulunan dfrA1 geni 31 adet sınıf 1 integron gen kasetinde tek başına, 18 adet sınıf 1 integron gen kasetinde aadA1 ile birlikte tespit edilmiş, sadece bir suşta aadA1a ile birlikte bulunmuştur. dfrA17 alelinin, bir suşta tek başına, 28 suşta aadA1 ile birlikte ve 15 suşta da aadA5 ile birlikte olduğu izlenmiştir. aadA1 ise tek başına dört suşta saptanmıştır. Sınıf 2 integron gen kasetlerinden dfrA17-sat-aadA5 birlikteliği altı merkeze ait izolatlarda, dfrA1-sat-aadA1 birlikteliği bir Ankara izolatında ve tek başına dfrA1 sadece bir Niğde izolatında tespit edilmiştir. Çalışmamızın verileri, idrar kültürlerinden izole edilen E.coli suşlarındaki sınıf 1 ve sınıf 2 gen kasetlerinde en sık rastlanan genlerin dfrA1 ve aadA1 olduğunu göstermiştir. Sonuç olarak, streptomisin (%31.2) ve SXT'e (%41.2) karşı rastlanan yüksek direnç oranlarının, suşlardaki integron aracılı dfr, sul1 ve aad genlerinin yaygınlığını gösterdiği kanısına varılmıştırEscherichia coli is the most common pathogen isolated from both nosocomial and community acquired urinary tract infections. Although there are many studies from different centers concerning the antibiotic susceptibility of E.coli isolates in Turkey, the studies are quite few about class 1 and class 2 integron cassettes in clinical E.coli isolates from urinary samples. The aim of the study was to investigate the antibiotic susceptibility and the carriage of integron gene cassettes in E.coli strainsisolated from urinary samples. A total of 626 E.coli strains isolated from urine cultures in microbiology laboratories located at 10 provinces from different regions of Turkey (Denizli, Ankara, Kayseri, Niğde, Şanlıurfa, Kahramanmaras, Tokat, Malatya, Konya and Trabzon) between June 2011-June 2012 were included in the study. The identifi cation and antibiotic susceptibility testing of the isolates were studied by conventional methods as well as Vitek® 2 Compact (bioMérieux, France) and BD Phoenix(TM) 100 (Becton Dickinson, USA) systems. The antibiotic susceptibilities of all the isolates were retested by Kirby-Bauer disk diffusion method according to CLSI recommendations in the main center of the study in order to achive the standardization. The presence of integrons was detected with polymerase chain reaction (PCR) method by using specifi c primers targeting class 1 (intI1) and class 2 (intI2) integrase gene regions. After integron amplifi cation the samples were cloned and subjected to DNA sequencing. When the antibiotic susceptibility of the isolates were evaluated, the highest resistance was observed against most commonly used empirical antibiotics namely ampicillin and trimethoprim-sulfamethoxazole (SXT) with the mean rate of 58.6% (range: 43.8%-73.2%) and 41.2% (range: 35.4%-45.8%), respectively. The most effective antibiotics detected against the isolates were imipenem and amikacin with the lowest resistance rates of 0.2% (range: 0%-1.1%) and 0.6% (range: 0%-3.2%), respectively. The frequency of positive IntI1 gene and class 1 integron gene cassettes were found as 25.8% (162/626) and 16.6% (104/626), respectively, whereas the frequency of positive intI2 gene II and class 2 integron gene cassettes were 5.1% (32/626) and 3% (19/626), respectively. The lowest intI1 gene frequency was detected in the isolates from Kayseri (16.6%) and the highest in the isolates from Kahramanmaraş (35.4%) provinces. While there was no intI2 gene in the isolates from Denizli and Kayseri, the highest frequency was 12.1% in the isolates from Şanlıurfa province. dfrA1 gene, the most frequent gene among integron gene cassettes was positive in 31 class 1 integron gene cassette alone, and positive with aadA1 gene in 18 class 1 integron gene cassettes. dfrA1 gene was positive with aadA1a just in one isolate. dfrA17 allele was positive in one isolate alone, in 28 isolates with aadA1, and in 15 isolates with aadA5. aadA1 gene was detected in four isolates. dfrA17-sat-aadA5 co-existence was detected among class 2 integron gene cassette in isolates from six provinces. dfrA1-sat-aadA1 was detected in one isolate from Ankara province and dfrA1 was detected in one isolate in Niğde province only. As a result, dfrA1 and aadA1 genes are the most common types of genes among class 1 and class 2 integron gene cassettes in E.coli isolated from urine cultures. It was concluded that high resistance against streptomycin (31.2%) and SXT (41.2%) supported the dissemination of integron-mediated genes dfr, sul1 and aad in the isolate