Risk factors and clinical characteristics of Stenotrophomonas maltophilia infections in neonates

BackgroundThe aim of this study was to review the risk factors and clinical, bacteriological, and epidemiological characteristics of Stenotrophomonas maltophilia infections in our neonatal intensive care unit.MethodsA retrospective matched case–control study was performed by comparing 23 cases of S maltophilia with 45 controls to identify the potential risk factors. To identify the case patients, the admission and medical records of patients in the neonatal intensive care unit and records from the Microbiology Department were reviewed between 2003 and 2008.ResultsSepsis in two neonates (9%), conjunctivitis in two neonates (9%), and ventilator-associated pneumonia in 19 (82%) neonates were determined. Invasive-procedures, exposure to aminoglycoside and carbapenem, total parenteral nutrition, histamine 2 blockers, exposure to steroids, cholestasis, and duration of hospitalization were significantly associated with S maltophilia infections (p<0.05). On multivariate analysis, invasive procedures (odds ratio, 18.81) and duration of hospitalization (odds ratio, 1.06) were determined to be the risk factors for S maltophilia infection. The most active antimicrobial agent was trimethoprim/sulfamethoxazole (87%) for S maltophilia infection, and the mortality rate was 17%.ConclusionsNeonatologists should avoid from unnecessary invasive procedures and broad-spectrum antibiotics to reduce S maltophilia infections. Invasive procedures should be finished in the shortest time possible. Agent/factor-specific antibacterial treatment should be administered. Patients being discharged as early as possible will also reduce infection frequency. Stenotrophomonas maltophilia should be considered in patients with high Stenotrophomonas infection risk factors

Comparison of three different methods in investigating the molecular epidemiology of carbapenem-resistant acinetobacter baumannii clinical isolates

The aim of the study was to evaluate the relationship between carbapenem-resistant Acinetobacter baumannii isolates carrying oxacillinase-type carbapenemase genes with "international high -risk clones" (IC I, II, and III) by different molecular epidemiological methods and to statistically compare the con - cordance and discrimination power of the methods. Carbapenem-resistant and moderately susceptible A.baumannii isolates from non -repeating blood cultures of 72 patients were included in the study. The presence of " bla OXA-23 , bla OXA-24 , bla OXA-51 ve bla OXA-58 " genes within OXA-type carbapenemases was de - tected by polymerase chain reaction (PCR) method and confirmed by DNA sequence analysis. Pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and matrix -assisted laser desorption/ ionization time- of -flight mass spectrometry (MALDI-TOF MS) analyses were performed to evaluate the clonal relations of IC I, II and III clones together with clinical isolates. In the statistical comparison of the methods, discrimination power was evaluated by Simpson index of diversity (SID) and concordance by "Wallace coefficient". All of the isolates were found to carry bla OXA-23 and bla OXA-51 genes. As a result of the bioinformatic analysis of the four isolates selected for sequence analysis; bla OXA-23 and bla OXA-51 genes were detected in the selected isolates, and the analysis of two isolates carrying bla OXA-51 gene showed 99% similarity with bla OXA-92 gene. The isolates were clustered into five pulsotypes (A, B, C, D and E) according to >= 85% similarity coefficient by PFGE. The isolates and RUH 875, RUH 134, LUH 5875 strains belonging to high -risk clones ICI, ICII and ICIII, respectively, were divided into five main groups [A (n= 58), B (n= 8), C (n= 4), D (n= 4) and E (n= 1)] and 10 subgroups (A1, A2, A4, A5, A6, A9, B1, B4, C3, D1) by PFGE. IC clone III (E1) and seven strains showed singleton PFGE profiles (A3, A7, A8, B2, B3, C1, C2). ICII was found in A5 subtype, ICI in C1 subtype and ICIII in E1 subtype. By PFGE subtype groups, 18 pulsotypes were determined and ST1, ST2, ST81, ST157 and ST604 sequence types were found in 20 isolates randomly selected from pulsotypes according to MLST Pasteur scheme ( cpn 60, fus A, glt A, pyr e , rec A, rpl B, rpo B). Principal component analysis (PCA) of the spectra of 72 A. baumannii isolates and ICI, ICII and ICIII clones was performed by MALDI-TOF MS. In PCA analysis, the cluster distance level was defined as 1.5 and the isolates were divided into three clusters. IC clone I, II and III together with 70 clinical isolates were grouped in one cluster, while two clinical isolates (AB083 and AB0115) formed singleton clusters. There was no significant agreement between MALDI-TOF MS; MLST and PFGE data according to Wallace coefficient. It was found that PFGE method gave significant results in terms of discrimination power with SID coefficient, MALDI-TOF MS PCA analysis had the lowest discrimination power value, and the Wallace coefficient result of PFGE and MLST was concordant. In conclusion, MALDI-TOF MS may not function as a gold standard method like PFGE and MLST for epidemiological analysis in A.baumannii species and the epidemiological typing protocols used for MALDI-TOF MS need to be improved and developed

Two Cases of Vulvovaginitis Caused by Shigella flexneri and Shigella sonnei: a Case Report

Vulvovaginitis caused by Shigella species (Shigella spp.) has rarely been reported. This paper describes two cases of prepubertal vulvovaginitis, presenting with a bloody and purulent vaginal discharge, separately caused by ampicillin-resistant Shigella flexneri and trimethoprim-sulfomethoxazole-resistant Shigella sonnei. Our conclusions are that Shigella spp. is the potential cause of vulvovaginitis in prepubertal girls in developing countries where these pathogens are endemic, and identification of the bacteria and making antibiotic susceptibility testing in these cases should not be overlooked

Investigation of Integrons, sul1-2 and dfr Genes in Trimethoprim-Sulfametoxazole-Resistant Stenotrophomonas maltophilia Strains Isolated from Clinical Samples

Nonfermentatif gram-negatif basil olan Stenotrophomonas maltophilia, hastane enfeksiyonları ve fırsatçı enfeksiyonlar açısından giderek artan bir öneme sahiptir. Çeşitli mekanizmaları kullanarak aminoglikozidler, beta-laktamlar, tetrasiklinler gibi birçok geniş spektrumlu antibiyotiğe direnç gösterir. Bu durum klinisyenlerin ampirik tedavi seçeneklerini oldukça kısıtlayabilmektedir. Trimetoprim-sülfametoksazol (SXT), hem yüksek etki gücü hem de geniş bir hasta yelpazesinde kullanılabildiği için S.maltophilia enfeksiyonlarının tedavisinde ilk tercih olarak önerilen antibiyotiktir. Ancak son yıllarda farklı coğrafi bölgelerde yapılan çalışmalarda bu antibiyotiğe karşı da direnç görüldüğü bildirilmeye başlanmıştır. Bu çalışmada SXT’ye dirençli S.maltophilia izolatlarında, bu dirence neden olduğu bilinen sul1, sul2, dfrA9, dfrA10, dfrA20 genlerinin ve sınıf I, II integron gen kasetlerinin araştırılması amaçlanmıştır. Çalışmaya, Karadeniz Teknik Üniversitesi Tıp Fakültesi, Farabi Hastanesi Tıbbi Mikrobiyoloji Anabilim Dalı Laboratuvarında, Ocak 2006-Ekim 2011 tarihleri arasında 339 hastaya ait çeşitli klinik örneklerden izole edilen 618 S.maltophilia suşu dahil edilmiştir. İzolatlar, konvansiyonel yöntemlere ilaveten Phoenix otomatize sistemi (Becton Dickinson, ABD) ile de tanımlanmış; otomatize sistem ve agar dilüsyon yöntemi ile 32 hasta izolatında (32/339, %9.4) SXT direnci saptanmıştır. Bu suşların 29 (%90.6)’u hastane, 3 (%9.4)’ü toplum kaynaklı enfeksiyonlardan izole edilmiştir. SXT-dirençli 32 farklı S.maltophilia izolatında dirence neden olduğu bilinen sul1, sul2, dfr genleri ve sınıf I ve II integron gen kasetleri özgül primerler kullanılarak polimeraz zincir reaksiyonu yöntemiyle araştırılmış, ardından amplifiye edilen ürünlerin nükleotid dizi analizleri yapılmıştır. Bu işlemlerin sonucunda bir izolatta sınıf I integron gen kaseti ve sul1 geninin varlığı tespit edilmiştir. Gen kasetinin nükleotid dizi analizi incelendiğinde, sırasıyla beta-laktamaz enzimlerinden biri olan oksasilinaz (oxa-2), aminoglikozid direncine neden olan aminoglikozid 6’-N-asetiltransferaz [aac(6’)-IIc] ve kuaterner amonyum bileşikleri direnç genlerini (qacF) taşıdığı saptanmıştır. Sonuç olarak, S.maltophilia’da integron sınıf I gen kasetinin sahip olduğu oxa2, aac(6’)-IIc ve qacF gen dizilimi, bizim bildiğimiz kadarıyla ilk kez tanımlanmıştır. İntegron sınıf I gen kaseti ve sul1 geninin birlikteliğinin, S.maltophilia’da çoğul antibiyotik direnci gelişmesine aracılık edebileceği ve direncin yayılmasında kaynak oluşturabileceği göz önünde bulundurulmalıdır.Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad- spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. In recent years, however, studies in different geographical regions have started to report resistance to SXT. In this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class I, class II integron gene cassettes which are known to play role in SXT resistance among SXT- resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. The isolates were identified by both conventional methods and the Phoenix automated identi- fication system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. The genes which are known as SXT resist- ance determining genes including sul1, sul2, dfr genes, and class I and class II integron gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integron gene cassette and sul1 gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase (oxa2) type of beta-lactamase, an aminoglycoside 6'-N-acetyltransferase [aac(6')-IIc], leading to resistance of aminoglycosides, and a quaternary ammonium compounds resistance gene (qacF), respectively. In conclusion, to best of our knowledge the sequences of class I integron gene cassette including oxa2, aac(6')-IIc, qacF genes were identified in S.maltophilia for the first time. It should be kept in mind that the co-presence of a class I integron gene cassette and the sul1 gene in S.maltophilia may lead to the development of multi-drug resistance and may act as a potential source for the dissemination of resistance

Investigation of integrons, sul1-2 and dfr genes in Trimethoprim-sulfametoxazole-resistant Stenotrophomonas maltophilia strains isolated from clinical samples

Nonfermentatif gram-negatif basil olan Stenotrophomonas maltophilia, hastane enfeksiyonları ve fırsatçı enfeksiyonlar açısından giderek artan bir öneme sahiptir. Çeşitli mekanizmaları kullanarak aminoglikozidler, beta-laktamlar, tetrasiklinler gibi birçok geniş spektrumlu antibiyotiğe direnç gösterir. Bu durum klinisyenlerin ampirik tedavi seçeneklerini oldukça kısıtlayabilmektedir. Trimetoprim-sülfametoksazol (SXT), hem yüksek etki gücü hem de geniş bir hasta yelpazesinde kullanılabildiği için S.maltophilia enfeksiyonlarının tedavisinde ilk tercih olarak önerilen antibiyotiktir. Ancak son yıllarda farklı coğrafi bölgelerde yapılan çalışmalarda bu antibiyotiğe karşı da direnç görüldüğü bildirilmeye başlanmıştır. Bu çalışmada SXT’ye dirençli S.maltophilia izolatlarında, bu dirence neden olduğu bilinen sul1, sul2, dfrA9, dfrA10, dfrA20 genlerinin ve sınıf I, II integron gen kasetlerinin araştırılması amaçlanmıştır. Çalışmaya, Karadeniz Teknik Üniversitesi Tıp Fakültesi, Farabi Hastanesi Tıbbi Mikrobiyoloji Anabilim Dalı Laboratuvarında, Ocak 2006-Ekim 2011 tarihleri arasında 339 hastaya ait çeşitli klinik örneklerden izole edilen 618 S.maltophilia suşu dahil edilmiştir. İzolatlar, konvansiyonel yöntemlere ilaveten Phoenix otomatize sistemi (Becton Dickinson, ABD) ile de tanımlanmış; otomatize sistem ve agar dilüsyon yöntemi ile 32 hasta izolatında (32/339, %9.4) SXT direnci saptanmıştır. Bu suşların 29 (%90.6)’u hastane, 3 (%9.4)’ü toplum kaynaklı enfeksiyonlardan izole edilmiştir. SXT-dirençli 32 farklı S.maltophilia izolatında dirence neden olduğu bilinen sul1, sul2, dfr genleri ve sınıf I ve II integron gen kasetleri özgül primerler kullanılarak polimeraz zincir reaksiyonu yöntemiyle araştırılmış, ardından amplifiye edilen ürünlerin nükleotid dizi analizleri yapılmıştır. Bu işlemlerin sonucunda bir izolatta sınıf I integron gen kaseti ve sul1 geninin varlığı tespit edilmiştir. Gen kasetinin nükleotid dizi analizi incelendiğinde, sırasıyla beta-laktamaz enzimlerinden biri olan oksasilinaz (oxa-2), aminoglikozid direncine neden olan aminoglikozid 6’-N-asetiltransferaz [aac(6’)-IIc] ve kuaterner amonyum bileşikleri direnç genlerini (qacF) taşıdığı saptanmıştır. Sonuç olarak, S.maltophilia’da integron sınıf I gen kasetinin sahip olduğu oxa2, aac(6’)-IIc ve qacF gen dizilimi, bizim bildiğimiz kadarıyla ilk kez tanımlanmıştır. İntegron sınıf I gen kaseti ve sul1 geninin birlikteliğinin, S.maltophilia’da çoğul antibiyotik direnci gelişmesine aracılık edebileceği ve direncin yayılmasında kaynak oluşturabileceği göz önünde bulundurulmalıdır.Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad- spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. In recent years, however, studies in different geographical regions have started to report resistance to SXT. In this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class I, class II integron gene cassettes which are known to play role in SXT resistance among SXT- resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. The isolates were identified by both conventional methods and the Phoenix automated identi- fication system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. The genes which are known as SXT resist- ance determining genes including sul1, sul2, dfr genes, and class I and class II integron gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integron gene cassette and sul1 gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase (oxa2) type of beta-lactamase, an aminoglycoside 6'-N-acetyltransferase [aac(6')-IIc], leading to resistance of aminoglycosides, and a quaternary ammonium compounds resistance gene (qacF), respectively. In conclusion, to best of our knowledge the sequences of class I integron gene cassette including oxa2, aac(6')-IIc, qacF genes were identified in S.maltophilia for the first time. It should be kept in mind that the co-presence of a class I integron gene cassette and the sul1 gene in S.maltophilia may lead to the development of multi-drug resistance and may act as a potential source for the dissemination of resistance

Investigation of integrons, sul1-2 and dfr genes in trimethoprim-sulfametoxazole-resistant stenotrophomonas maltophilia strains isolated from clinical samples

SANDALLI, Cemal/0000-0002-1298-3687WOS: 000336195500002PubMed: 24819258Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad-spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. in recent years, however, studies in different geographical regions have started to report resistance to SXT. in this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class 1, class II integron gene cassettes which are known to play role in SXT resistance among SXT-resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. the isolates were identified by both conventional methods and the Phoenix automated identification system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. the genes which are known as SXT resistance determining genes including sul1, sul2, dfr genes, and class 1 and class II integron gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integron gene cassette and sull gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase (oxa2) type of beta-lactamase, an aminoglycoside 6'-N-acetyltransferase [aac(6')-IIc], leading to resistance of aminoglycosides, and a quaternary ammonium compounds resistance gene (qacF), respectively. in conclusion, to best of our knowledge the sequences of class I integron gene cassette including oxa2, aac(6')-IIc, qacF genes were identified in S.maltophilia for the first time. It should be kept in mind that the co-presence of a class 1 integron gene cassette and the su/1 gene in S.maltophilia may lead to the development of multi-drug resistance and may act as a potential source for the dissemination of resistance

A Case of Rhizobium radiobacter (Agrobacterium tumefaciens)-Related Bacteremia After Percutaneous Biliary Drainage Catheterization

Rhizobium spp., generally present in soil, is a gram-negative, catalase-, oxidase- and urease-positive, motile, non-fermentative, nonspore-forming rod, often known as a plant pathogen but rarely detected as the agent of infection in humans. In this article, we present an 83-year-old female patient with bile duct malignant neoplasm who underwent biliary drainage catheterization after detection of obstruction at the Klatskin level and developed catheter-related bacteremia caused by Rhizobium radiobacter. Identification and antibiotic susceptibility testing of the bacteria were performed using BD Phoenix automated microbiological system (Becton Dickinson, Sparks, MD). In conclusion, it should be kept in mind that R. radiobacter may rarely cause opportunistic infection, especially in immunocompromised patients. In the presence of catheter, it should be considered among the pathogens causing bacteremia