Extended spectrum beta lactamase production and antibiotic susceptibilities of Escherichia coli and Klebsiella pneumoniae strains

AMAÇ: Bu çalışmada Tavşanlı Devlet Hastanesi Mikrobiyoloji Laboratuvarı'na gönderilen çeşitli klinik örneklerden izole edilen Escherichia coli ve Klebsiella pneumoniae suşlarının antibiyotik duyarlılıkları retrospektif olarak incelenmesi, bu mikroorganizmaların genişlemiş spektrumlu beta laktamaz (GSBL) üretimlerinin belirlenmesi amaçlanmıştır. YÖNTEMLER: Kültürlerin tümü etken ve antibiyotik duyarlılıkları açısından irdelenmiştir. Bakterilerin tanımlanmasında çeşitli biyokimyasal testler ve BBL Crystal E/NF (Beckton Dickinson, ABD) sistemi kullanılmıştır.Antibiyotik duyarlılığı Müller-Hinton Agarda disk diffüzyon yöntemi ile CLSI kriterleri doğrultusunda değerlendirilmiştir. GSBL üretiminin araştırılması için çift disk sinerji yöntemi kullanılmıştır. BULGULAR: Klinik örneklerden izole edilen 426 E. coli ve 56 K. pneumoniae suşu çalışmaya dahil edilmiştir. E. coli ve K. pneumoniae suşları gönderildiği örnek türüne göre değerlendirildiğinde en fazla idrar örneğinden izole edildikleri görülmektedir. Bu bakterilerin en fazla duyarlı oldukları antibiyotiklerin imipenem, amikasin ve sulbaktam/sefoperazon oldukları belirlenmiştir.Duyarlılığın en düşük olduğu antibiyotik ise ampisilindir.GSBL üretim oranı E. coli'de %15, K. pneumoniae'de % 36 olarak tespit edilmiştir. SONUÇ: Tedavisi pahalı ve güç enfeksiyonlara neden olan, GSBL üreten E. coli, K. pneumoniae ve diğer Gram negatif enterik bakterilerin GSBL üretim oranları, her merkez tarafından izlenmeli, tedavide tercih edilen geniş spektrumlu beta laktam antibiyotikler dikkatlice kullanılmalı, yatan hastalar izole edilmeli, risk altındaki bölümlerinde sürveyans çalışması yapılmalıdır. OBJECTIVE: In this study it was aimed to investigate the antibiotic susceptibilities and extended spectrum beta lactamase production of Escherichia coli and Klebsiella pneumoniae strains isolated from miscellaneous clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. METHODS: Pathogenic bacteria isolated from respective cultures were identified and subsequently evaluated for antimicrobial susceptibility. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD) system was used. Antibiotic susceptibilities were investigated according to CLSI criteria on Mueller Hinton agar by disc diffusion method. Double disc synergy method was used to investigate extended spectrum beta lactamase (ESBL) production. RESULTS: 426 E. coli and 56 K. pneumoniae strains isolated from clinical samples were included in the study. E. coli and K. pneumoniae strains were mostly isolated from urine according to clinical samples.The most effective antibiotics against these bacteria were imipenem, amikacine and sulbactam/cefoperazone. The least susceptibility was against ampicillin. ESBL production rate was found to be 15% in E. coli and 36% K. pneumoniae. CONCLUSION: ESBL producing E. coli and K. pneumoniae, which are the reason of expensive therapy and difficulties in treatment of infections should be monitored for ESBL production ratios by all of the centers, extended spectrum beta lactam antibiotics should bu used carefully in treatment, hospitalized patients should be isolated and surveillance should be done in the units under risk

Notes bibliographiques

Notes bibliographiques. In: Revue d'histoire de la pharmacie, 70ᵉ année, n°254, 1982. p. 229

Entrepreneurial orientation and performance of Turkish manufacturing FDI firms: An empirical study

The purpose of this paper is to examine the behavior of emerging market-based foreign direct investment firms from the perspective of international entrepreneurship. Based on the previous literature we have identified the dimensions of international entrepreneurship as proactiveness, risk taking and innovation. We collected data from 94 Turkish manufacturing foreign direct investment firms on these dimensions by means of cross-sectional survey. Utilizing the collected data, this study shows that sampled FDI firms' entrepreneurial orientations are high oil the overall. Widely recognized dimensions of international entrepreneurial orientation (i.e., innovation, proactiveness, and risk taking) are applicable to explain Turkish firms' behavior Two dimensions of entrepreneurial orientation, innovation and proactiveness positively and significantly affect performance of foreign equity ventures

A Real-Time PCR Assay for the Quantification of Hepatitis B Virus DNA and Concurrent Detection of YMDD Motif Mutations

Monitoring therapy in chronic hepatitis B patients receiving lamivudine therapy, is done by two different assays; determination of viral load and genotypic resistance. These methods are labor intensive and time consuming. It was aimed to develop an assay to quantitate hepatitis B virus (HBV) DNA in serum and detect YMDD (thyrosine, methionine, aspartate, aspartate) motif mutations in the same run. The assay was based on real-time polymerase chain reaction (Rt-PCR) with YMDD-specific hybridization probes. Determination of YMDD motif was done by melting temperature analysis. External standard curve was used for quantifying viral DNA, which was generated by standard sera (VQC S2220) including HBV-DNA between concentrations of 1000 to 3 million copies/ml. The assay was compared with commercial quantitative kit (Artus HBV RG PCR; Qiagen, Germany), commercial line prob assay (INNO-LiPA HBV DR v1.0; Innogenetics, Belgium) and direct DNA sequencing method. Thirty-eight serum samples obtained from 20 chronic hepatitis B patients (7 female, 13 male; age range: 27-70 years) treated with only lamivudine and were negative for HIV and HCV antigen and antibodies were tested in the study. The analytical sensitivity of the assay was found as 200 copies/ml, with a dynamic range of 1 x 10(3) to 3 x 10(7) copies/ml. PCR efficiency of the in-house assay was found to be 1.98. Comparison of log(10) HBV-DNA concentrations determined by the in-house and commercial quantitative kits showed a significant correlation (r = 0.681). Melting temperature (T-m) analysis was used for the YMDD motif determination and found to be 59.86 degrees C for YMDD, 56.34 degrees C for YVDD and 55.10 degrees C for YIDD. The results of the in-house assay, DNA sequencing and LiPA were concordant in samples with homogeneous virus population, and in-house assay could also detect the major type of YMDD motif in mixed viral populations The Rt-PCR method which was developed in this study is a rapid, accurate and reproducible method for quantifying HBV-DNA and detecting the predominant YMDD motif in the same run in two hours duration. It was concluded that this method may be a convenient tool for monitoring HBV-infected patients receiving lamivudine treatment

First determination of azole resistance in Aspergillus fumigatus strains carrying the TR34/L98H mutations in Turkey

Aspergillus fumigatus is the most important etiological agent of invasive aspergillosis. Recently, an increasing number of azole-resistant A. fumigatus isolates have been described in various countries. The prevalence of azole resistance was investigated in this study using our culture collection of A. fumigatus isolates collected between 1999 and 2012 from clinical specimens. Seven hundred and forty-six A. fumigatus isolates, collected from 419 patients, were investigated. First, all isolates were screened for resistance to itraconazole by subculturing on Sabouraud dextrose agar that contained 4 mg/L itraconazole. For isolates that grew on the itraconazole containing agar, the in vitro activities of amphotericin B, itraconazole, voriconazole and posaconazole were determined using the Clinical and Laboratory Standards Institute (CLSI) M38-A reference method. After PCR amplification, the full sequence of the cyp51A gene and its promoter region was determined for all in vitro azole-resistant isolates. Itraconazole resistance was found in 10.2% of the A. fumigatus isolates. From 2000 onwards, patients were observed annually with an itraconazole-resistant isolate. According to in vitro susceptibility tests, amphotericin B exhibited good activity against all isolates whereas the azoles were resistant. Sequence analysis of the promoter region and CYP51A gene indicated the presence of TR34/L98H in 86.8% (n - 66) of isolates. This initial analysis of the resistance mechanism of A. fumigatus from Turkey revealed a common TR34/L98H mutation in the cyp51A gene. (C) 2015, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved

Investigation of methicillin resistant Staphylococcus aureus in neonatal intensive care unit

Methicillin resistant Staphylococcus aureus (MRSA) strains lead to severe infections in immunosupressive patients, geriatric population and premature infants. 27 MRSA strains isolated in the Neonatal Intensive Care Unit was considered as an outbreak and it was aimed to investigate the genetic and epidemiologic relation of the MRSA outbreak. MecA gene was investigated in the S. aureus strains and pulsed field gel electrophoresis (PFGE) was used to investigate the genetic relation between outbreak strains. MecA gene was showed in all isolates. PFGE revealed that there were two different strains and most of the isolates (25/27) were owing to same clone. One of the samples were found closely related with the common strain and the other sample was found genetically unrelated. To terminate the outbreak; liquid baby food was gained to the baby food kitchen, no more new patient was imported to the neonatal unit and none of the patients were exported from neonatal unit to other clinics during outbreak, education about infection control precautions was given to all the staff and nursing bottle dishwasher was obtained. To manage and terminate the outbreak, besides the infection control precautions, tests to determine the genetic relation between outbreak strains which are done in the microbiology laboratory are needed. Molecular analysis of outbreak strains will contribute to prove the epidemiologic and evolution of outbreaks

Frequency of azole resistance in clinical and environmental strains of Aspergillus fumigatus in Turkey: a multicentre study

Objectives Aspergillus fumigatus causes several diseases in humans and azole resistance in A. fumigatus strains is an important issue. The aim of this multicentre epidemiological study was to investigate the prevalence of azole resistance in clinical and environmental A. fumigatus isolates in Turkey. Methods Twenty-one centres participated in this study from 1 May 2018 to 1 October 2019. One participant from each centre was asked to collect environmental and clinical A. fumigatus isolates. Azole resistance was screened for using EUCAST agar screening methodology (EUCAST E.DEF 10.1) and was confirmed by the EUCAST E.DEF 9.3 reference microdilution method. Isolates with a phenotypic resistance pattern were sequenced for the cyp51A gene and microsatellite genotyping was used to determine the genetic relationships between the resistant strains. Results In total, resistance was found in 1.3% of the strains that were isolated from environmental samples and 3.3% of the strains that were isolated from clinical samples. Mutations in the cyp51A gene were detected in 9 (47.4%) of the 19 azole-resistant isolates, all of which were found to be TR34/L98H mutations. Microsatellite genotyping clearly differentiated the strains with the TR34/L98H mutation in the cyp51A gene from the strains with no mutation in this gene. Conclusions The rate of observed azole resistance of A. fumigatus isolates was low in this study, but the fact that more than half of the examined strains had the wild-type cyp51A gene supports the idea that other mechanisms of resistance are gradually increasing

Frequency of azole resistance in clinical and environmental strains of Aspergillus fumigatus in Turkey: a multicentre study.

Objectives Aspergillus fumigatus causes several diseases in humans and azole resistance in A. fumigatus strains is an important issue. The aim of this multicentre epidemiological study was to investigate the prevalence of azole resistance in clinical and environmental A. fumigatus isolates in Turkey. Methods Twenty-one centres participated in this study from 1 May 2018 to 1 October 2019. One participant from each centre was asked to collect environmental and clinical A. fumigatus isolates. Azole resistance was screened for using EUCAST agar screening methodology (EUCAST E.DEF 10.1) and was confirmed by the EUCAST E.DEF 9.3 reference microdilution method. Isolates with a phenotypic resistance pattern were sequenced for the cyp51A gene and microsatellite genotyping was used to determine the genetic relationships between the resistant strains. Results In total, resistance was found in 1.3% of the strains that were isolated from environmental samples and 3.3% of the strains that were isolated from clinical samples. Mutations in the cyp51A gene were detected in 9 (47.4%) of the 19 azole-resistant isolates, all of which were found to be TR34/L98H mutations. Microsatellite genotyping clearly differentiated the strains with the TR34/L98H mutation in the cyp51A gene from the strains with no mutation in this gene. Conclusions The rate of observed azole resistance of A. fumigatus isolates was low in this study, but the fact that more than half of the examined strains had the wild-type cyp51A gene supports the idea that other mechanisms of resistance are gradually increasing