8 research outputs found
Performance evaluation of the BD phoenix automated microbiology system in meropenem susceptibility testing of clinical Pseudomonas aeruginosa isolates
Antimicrobial and antioxidant activity of the essential oil of the Turkish endemic species Achillea Phrygia Boiss. & Bal.
Ozkan, Gulcan/0000-0002-3333-7537;WOS: 000337670700006The essential oil obtained from the dried flowering aerial parts of Achillea phrygia Boiss & Bal. by hydrodistilation was analysed by gas chromotography-mass spectrometry. Camphor (35.55 %), 2-furaldehyde (16.59 %) and 1,8-cineol (eucalyptol) (10.12 %) were detected as the major components of the essential oil. Essential oil of the plant was also tested for antimicrobial activity using the disc-diffusion method against 6 reference bacterial strains and 65 clinical bacterial isolates. Essential oil of A. phrygia showed antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive S. aureus (MSSA), Acinetobacter baumannii and bacterial strains as S. aureus ATCC 25923, S. aureus ATCC 43300, Acinetobacter baumannii ATCC 19606. in additionally, the essential oil were not effective against bacterial strains as Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212. Morover, the total antioxidant capacity and the scavenging effect on 2,2diphenil-1-picrylhydrazyl (DPPH) radicals of the essential oil were also evaluated. the radical scavenging activity of A. phrygia essential oil was 40.43 %.Research Funds of the University of Ondokuz Mayis, Samsun, TurkeyOndokuz Mayis UniversityThe authors are thankful to Prof. Dr. Sezai Ercisli for it's help regarding the antioxidant analysis. Financial support made by the Research Funds of the University of Ondokuz Mayis, Samsun, Turkey is gratefully acknowledged
An evaluation of false-positive rifampicin resistance on the Xpert MTB/RIF
BACKGROUND Mycobacterium tuberculosis (MTB) is one of the most significant causes of mortality and morbidity. Early diagnose is important especially in multiple drug resistant tuberculosis to avoid transmission. Traditional techniques requires at least one to three weeks for diagnosis of tuberculosis. Diagnostic delays with multiple drug resistant tuberculosis are associated with worse clinical outcomes and increased transmission The Xpert MTB/RIF assay is one of the new diagnostic device for the diagnosis of tuberculosis and rapid detection of rifampicin resistance. OBJECTIVE We assessed the performance of Xpert MTB/RIF assay for detecting rifampicin resistance using phenotypic drug susceptibility tests as automated BD MGIT 960. METHODS Total of 2136 specimens were included in the study. Xpert MTB/RIF testing was performed on samples, using version 4 cartridges, according to the manufacturer's recommendations. The MTBC culture and first-line phenotypic DST were performed in automated BD MGIT 960 (Becton & Dickinson, USA) according to the recommendations of the manufacturer. Agar proportion was used in the case of inconsistency for rifampicin resistance. FINDINGS Thirty-four samples (19 respiratory and 15 nonrespiratory samples) were determined as positive for M. tuberculosis complex by Xpert MTB/RIF (Cepheid GeneXpert® System, USA). Xpert MTB/RIF assay detected 4/34 (11.7%) specimens as rifampicin resistant. One of the rifampicin resistant isolates was determined susceptible in MGIT 960 automated system. This isolate was also tested with agar proportion method and found susceptible to rifampicin. MAIN CONCLUSION The Xpert MTB/RIF assay can be used as first-line assay for the detection of M. tuberculosis. However, microbiologists must be aware of the limitations of the assay
Investigation of plasmid-mediated quinolone resistance in pseudomonas aeruginosa strains isolated from cystic fibrosis patients
Pseudomonas aeruginosa doğada yaygın olarak bulunan ve ciddi nozokomiyal enfeksiyonlara neden olan bir bakteridir. Birçok antibakteriyel ajana karşı intrensek dirence sahip olması nedeniyle P.aeruginosa ile oluşan enfeksiyonların tedavisinde zorluklar yaşanmaktadır. Kinolonlar, özellikle siprofloksasin, tedavide kullanılan önemli ajanlardandır. Ancak kinolonlara da direnç gelişmesi önemli bir sorundur. Kinolonlara direnç sıklıkla kromozomal mutasyon ve dışa-atım pompaları aracılığıyla olmaktadır. Son yıllarda Enterobacteriaceae ailesi üyelerinde plazmid aracılı kinolon direnci de saptanmış; bu dirence neden olan gen ailesi qnr olarak adlandırılmıştır. Ayrıca yine plazmid ile aktarılan ve aminoglikozid direnci ile birlikte kinolon direncine de neden olan aac(6’)-Ib-cr gen bölgesi de Enterobacteriaceae ailesine ait bakteriyel izolatlarda tespit edilmiştir. Yapılan sınırlı sayıdaki çalışmada, P.aeruginosa izolatlarında qnr gen bölgesinin varlığı ve aac(6’)-Ib-cr gen bölgesi henüz gösterilememiştir. Bu çalışmada, kistik fibrozisli olgulardan izole edilen P.aeruginosa suşlarında plazmid aracılı florokinolon direncinin araştırılması amaçlanmıştır. Çalışmaya, hastaların solunum yolu örneklerinden izole edilen 110 P.aeruginosa suşu dahil edilmiş ve izolatların siprofloksasin duyarlılıkları CLSI önerileri doğrultusunda Kirby-Bauer disk difüzyon yöntemiyle çalışılmıştır. Suşlarda qnrA, qnrB, qnrC, qnrS ve aac(6’)-Ib-cr gen bölgelerinin varlığı, bu bölgeler için özgül primer çiftleri kullanılarak multipleks polimeraz zincir reaksiyonu yöntemiyle araştırılmıştır. Çalışmada pozitif kontrol olarak Escherichia coli J53 pMG252 (qnrA1 pozitif), E.coli J53 pMG252 (qnrS1 pozitif), E.coli J53 pMG258 (qnrB1 ve aac(6’)-Ib-cr pozitif), Klebsiella pneumoniae ref.15 (qnrB pozitif), Enterobacter cloacae ref.287 (qnrS pozitif), E.coli ref.20 (qnrA pozitif) ve pHS11 plazmidinin (qnrC pozitif) konjugasyon yoluyla aktarıldığı E.coli DH10 suşu kullanılmıştır. P.aeruginosa klinik izolatlarının 13’ü siprofloksasine dirençli, yedisi orta duyarlı ve 90’ı duyarlı olarak bulunmuştur. Çalışma sonucunda test edilen toplam 110 P.aeruginosa izolatında hem qnr gen bölgesi hem de aac(6’)-Ib-cr gen bölgesi tespit edilememiştir. Bununla birlikte bu bulgunun daha çok klinik izolat içeren araştırmalarla desteklenmesi P.aeruginosa izolatlarında kinolon direncinin belirlenmesi ve önlenmesinde önemli olacaktır.Pseudomonas aeruginosa which is widely found in the environment, may lead to serious nosocomial infections. Due to its intrinsic resistance to many antibacterial agents, treatment of P.aeruginosa infections usually present difficulty. Quinolones, especially ciprofloxacin, are crutial antibiotics for the treatment of P.aeruginosa infections. However resistance developing to quinolones may become an important problem. Resistance to quinolones is often a result of chromosomal mutations and by the effect of efflux pumps. Recently plasmid-mediated quinolone resistance have been reportedin the members of Enterobacteriaceae family. The gene responsible for this resistance is called qnr. In addition to qnr genes there is also another gene called aac(6’)-Ib-cr responsible for plasmid-mediated quinolone resistance and aminoglycoside resistance. Limited studies which to screen P.aeruginosa strains for the presence of qnr gene region, revealed no positivity. The aim of this study was to investigate the plasmid-mediated quinolone resistance in P.aeruginosa strains isolated from cystic fibrosis patients. A total of 110 P.aeruginosa strains isolated from respiratory tract specimens from the patients were included in the study. Ciprofloxacin susceptibilities of the isolates were detected by Kirby-Bauer disk diffusion method according to CLSI guidelines. The presence of qnrA, qnrB, qnrC, qnrS and aac(6’)-Ib-cr genes were searched by multiplex polymerase chain reaction (PCR) with the use of specific individual primer pairs. As positive control strains, Escherichia coli J53 pMG252 (qnrA1 positive), E.coli J53 pMG252 (qnrS1 positive), E.coli J53 pMG258 (qnrB1 and aac(6’)-Ib-cr positive), Klebsiella pneumoniae ref.15 (qnrB positive), Enterobacter cloacae ref.287 (qnrS positive), E.coli ref.20 (qnrA positive) and E.coli DH10 conjugated with pHS11 plasmid (qnrC positive) were used. Of 110 P.aeruginosa clinical isolates, 13 were found resistant to ciprofloxacin, while 7 were intermediate. However multiplex PCR yielded no positivity in terms of qnrA, qnrB, qnrC, qnrS and aac(6’)-Ib-cr gene regions. In conclusion, although our results indicated that none of the tested P.aeruginosa strains harboured those genes, further multicenter studies with large numbers of isolates are needed to confirm these results
An evaluation of false-positive rifampicin resistance on the Xpert MTB/RIF
<div><p> BACKGROUND Mycobacterium tuberculosis (MTB) is one of the most significant causes of mortality and morbidity. Early diagnose is important especially in multiple drug resistant tuberculosis to avoid transmission. Traditional techniques requires at least one to three weeks for diagnosis of tuberculosis. Diagnostic delays with multiple drug resistant tuberculosis are associated with worse clinical outcomes and increased transmission The Xpert MTB/RIF assay is one of the new diagnostic device for the diagnosis of tuberculosis and rapid detection of rifampicin resistance. OBJECTIVE We assessed the performance of Xpert MTB/RIF assay for detecting rifampicin resistance using phenotypic drug susceptibility tests as automated BD MGIT 960. METHODS Total of 2136 specimens were included in the study. Xpert MTB/RIF testing was performed on samples, using version 4 cartridges, according to the manufacturer's recommendations. The MTBC culture and first-line phenotypic DST were performed in automated BD MGIT 960 (Becton & Dickinson, USA) according to the recommendations of the manufacturer. Agar proportion was used in the case of inconsistency for rifampicin resistance. FINDINGS Thirty-four samples (19 respiratory and 15 nonrespiratory samples) were determined as positive for M. tuberculosis complex by Xpert MTB/RIF (Cepheid GeneXpert® System, USA). Xpert MTB/RIF assay detected 4/34 (11.7%) specimens as rifampicin resistant. One of the rifampicin resistant isolates was determined susceptible in MGIT 960 automated system. This isolate was also tested with agar proportion method and found susceptible to rifampicin. MAIN CONCLUSION The Xpert MTB/RIF assay can be used as first-line assay for the detection of M. tuberculosis. However, microbiologists must be aware of the limitations of the assay.</p></div
In vitro effect of ankaferd blood stopper®, a plant extract against Mycobacterium tuberculosis isolates
Dirençli Mycobacterium tuberculosis enfeksiyonlarının tedavisi, toksik yan etkileri olan antitüberküloz ilaçların kombinasyonunu gerektirdiğinden, güvenli ve etkili yeni ilaçlara gereksinim vardır. Alpinia officinarum, Glycyrrhiza glabra, Thymus vulgaris, Urtica dioica ve Vitis vinifera bitki ekstrelerinin bir karışımı olan Ankaferd Blood Stopper® (ABS), homeostatik ve antibakteriyel etkilere sahiptir. Ülkemizde ABS’nin standart solüsyonları, travmatik veya cerrahi sonrası kanama kontrolü amacıyla topikal olarak kullanılmaktadır. Bu çalışmada, M.tuberculosis izolatlarına karşı ABS’nin in vitro antitüberküloz etkinliğinin araştırılması amaçlanmıştır. Çalışmaya, 57 klinik izolat [17’si çok ilaca dirençli (ÇİD), biri izoniazid (INH) ve streptomisin (STR)’e dirençli, 11’i sadece INH’e dirençli, ikisi sadece STR’e dirençli, ikisi sadece etambutol (ETM)’e dirençli, 24’ü bütün ilaçlara duyarlı] ve üç standart suş [H37Rv (bütün ilaçlara duyarlı), ATCC 35822 (INH’e dirençli), ATCC 35820 (STR’e dirençli)] dahil edilmiştir. ABS MİK değerleri agar dilüsyon yöntemi kullanılarak tespit edilmiştir. Çalışmamızda, bütün ilaçlara duyarlı M.tuberculosis H37Rv suşu için ABS MİK değeri 10.94 ?g/ml olarak belirlenirken, INH dirençli ATCC 35822 ve STR dirençli ATCC 35820 suşları için 21.88 ?g/ml olarak saptanmıştır. Klinik izolatlar dikkate alındığında; duyarlı 24 suşun 17’sinde ABS MİK değeri 10.94 ?g/ml, altısında 21.88 ?g/ml ve birinde < 1.37 ?g/ml; ÇİD 17 suşun ise birinde 5.47 ?g/ml, beşinde 10.94 ?g/ml ve 11’inde 21.88 ?g/ml olarak bulunmuştur. Sadece INH direnci olan 11 izolatın MİK değerleri < 1.37-21.88 ?g/ml arasında değişiklik göstermiştir. Yalnızca STR’ye dirençli iki izolatın MİK değerleri 21.88 ?g/ml; yalnızca ETM’e dirençli iki izolatın MİK değerleri de 21.88 ?g/ml ve 10.94 ?g/ml olarak saptanmıştır. Hem INH hem de STR direnci olan bir izolatın MİK değeri ise 21.88 ?g/ml olarak izlenmiştir. Test edilen bakterilerin MİK50 ve MİK90 değerleri sırasıyla 10.94 ?g/ml ve 21.88 ?g/ml olarak tespit edilmiştir. Sonuç olarak çalışmamızda, ABS’nin topikal olarak kullanılan solüsyonunun yaklaşık 16 kat dilüe edilmiş konsantrasyonu, tüberküloz basillerine karşı in vitro olarak etkili bulunmuş ve bu sonuç ABS’nin kütanöz tüberkülozda, özellikle ÇİD M.tuberculosis’in neden olduğu osteomiyelit ve lenfadenit gibi tüberküloz odaklarının cerrahi debridmanında antitüberküloz ilaçlarla birlikte destekleyici amaçla başarıyla kullanılabileceğini düşündürmüştür.Treatment of drug-resistant Mycobacterium tuberculosis infections requires combination of anti-tuberculosis drugs which have several toxic side effects. Thus there is a need for safer and effective new drugs. Ankaferd Blood Stopper® (ABS), which is a mixture of plant extracts prepared from Alpinia officinarum, Glycyrrhiza glabra, Thymus vulgaris, Urtica dioica and Vitis vinifera, has homeostatic and antibacterial effects. Standard solutions of ABS are already being used topically for post-traumatic and post-operative bleeding control in our country. This study was aimed to evaluate the in vitro activity of ABS against M.tuberculosis isolates. A total of 57 clinical isolates [17 multidrug resistant (MDR), 11 resistant to only isoniazid (INH), one resistant to INH and streptomycin (STR), two resistant only to STR, two resistant only to ETM, and 24 susceptible to all drugs] and three standard strains [H37Rv (susceptible to all drugs), ATCC 35822 (INH-resistant), ATCC 35820 (STR-resistant)] were included in the study. Agar dilution method was used to detect the MIC values of ABS. In the study, ABS MIC value was determined as 10.94 &#956;g/ml for M.tuberculosis H37Rv strain which was susceptible to all antituberculosis drugs, whereas it was determined as 21.88 &#956;g/ml for INH-resistant ATCC 35822 and STRresistant ATCC 35820 strains. The MIC values for 24 susceptible clinical isolates were as follows; 10.94 &#956;g/ml (n= 17), 21.88 &#956;g/ml (n= 6) and < 1.37 &#956;g/ml (n= 1). When evaluating 17 MDR clinical isolates, MIC values were determined as 5.47 &#956;g/ml (n= 1), 10.94 &#956;g/ml (n= 5) and 21.88 &#956;g/ml (n= 11). MIC values were ranging between < 1.37-21.88 &#956;g/ml among 11 INH-resistant isolates. These isolates were susceptible to other first line anti-tuberculosis drugs. MIC value of one isolate resistant to both of INH and STR was determined as 21.88 &#956;g/ml. MIC value of the two sole STR-resistant isolates was 21.88 &#956;g/ml. MIC values of the two sole ETM-resistant isolates were determined as 21.88 &#956;g/ml and 10.94 &#956;g/ml. MIC50 and MIC90 values for the tested bacteria were 10.94 &#956;g/ml and 21.88 &#956;g/ml, respectively. It was concluded that 16 fold diluted concentration of the topically used ABS solution was found to be active against tuberculosis bacilli in vitro. Thus ABS might be used as a supportive agent together with anti-tuberculous drugs during debridement of multiple drug-resistant M.tuberculosis caused osteomyelitis and lymphadenitis lesions
Antimicrobial resistance in Gram-negative hospital isolates: Results of the Turkish HITIT-2 surveillance study of 2007
Resistance rates to amikacin, ciprofloxacin, ceftazidime, cefepime, imipenem, cefoperazone/sulbactam and piperacillin/tazobactam in Escherichia coli (n = 438), Klebsiella pneumoniae (n = 444), Pseudomonas aeruginosa (n = 210) and Acinetobacter baumanni (n =200) were determined with E-test in a multicenter surveillance study (HITIT-2) in 2007. ESBL production in Escherichia coli and K. pneumoniae was investigated following the CLSI guidelines. Overall 42.0% of E.coli and 41.4% of K. pneumoniae were ESBL producers. In E. coli, resistance to imipenem was not observed, resistance to ciprofloxacin and amikacin was 58.0% and 5.5% respectively. In K. pneumoniae resistance to imipenem, ciprofloxacin and amikacin was 3.1%, 17.8% 12.4% respectively. In P. aeruginosa the lowest rate of resistance was observed with piperacillin/tazobactam (18.1%). A. baumanni isolates were highly resistant to all the antimicrobial agents, the lowest level of resistance was observed against cefoperazone/sulbactam (52.0%) followed by imipenem (55.5%). This study showed that resistance rates to antimicrobials are high in nosocomial isolates and show variations among the centers