Determination of amphotericin B antifungal susceptibility in Candida strains using an inverted microscope.

INTRODUCTION: Invasive Candida infections have recently shown a significant increase in prevalence and are associated with high mortality rates. Initiating early antifungal treatment in patients with candidemia is vital. The aim of our study was to compare the antifungal susceptibility results of a new method called Flat Plate Method modified from reference "Clinical and Laboratory Standards Institute (CLSI) microdilution method by us with Sensitititre Yeast One colorimetric method and the reference CLSI method. METHODOLOGY: We tested 100 Candida isolates from blood cultures. We followed the CLSI M27-A3 (reference method for broth dilution antifungal susceptibility testing of yeasts; third edition) guidelines for testing in vitro susceptibility to amphotericin B. In the Flat Plate method, 96-well plates were used for evaluation with an inverted microscope. Minimum inhibitory concentration (MIC) values in the SYO method were measured following the manufacturer's instructions. The MIC values obtained by all three methods were considered compatible if they were within ± 2 dilution limits. RESULTS: The SYO method detected C. albicans and C. glabrata with 100% essential agreement, whereas there was 96.29% essential agreement in the case of C. parapsilosis. In the Flat Plate method, the essential agreement with amphotericin B was 91.42%, for C. albicans isolates and 89.47%.for C. glabrata strains. CONCLUSIONS: When determining early antifungal susceptibility using the Flat Plate method, the results are obtained quickly, with high accuracy, and without incurring additional costs. However, there is a need for comprehensive studies comparing different antifungals.

Effect of antinuclear antibody positivity on antineutrophil cytoplasmic antibody results by indirect immunofluorescence assay.

BACKGROUND: The indirect immunofluorescence assay (IIFA) utilizing antineutrophil cytoplasmic antibodies (ANCA) is widely used as a diagnostic test for autoimmune vasculitis. The presence of antinuclear antibodies (ANA) might lead to a misleading interpretation of ANCA. This study aims to explore the impact of the presence of ANA on the interpretation of ANCA. METHODS: This retrospective research examined samples negative for antiMPO and antiPR3 ANCA by IIFA and explored correlations between the ANA-IIFA results and the ANCA interpretation frequencies. Our analysis involved the use of suitable statistical methods, including Chi-square and kappa statistics. RESULTS: Up to 75.2% of the ANCA-IIFA-positive samples exhibited a positive p-ANCA pattern when using the ethanol-fixed substrate, with c-ANCA positivity at 24.8%. In the ANA-IIFA-positive samples, ~77.3% displayed p-ANCA patterns on ethanol-fixed substrates. A comparison between the ANA-IIFA titers and the p-ANCA results revealed that p-ANCA positivity was notably more common in samples with higher titers, and this correlation was found to be statistically significant. CONCLUSION: Positive ANA results by IIFA tests are linked to a higher incidence of p-ANCA interpretation, particularly in cases with higher titer patterns. This insight aids laboratories in establishing effective workflows to investigate potential p-ANCA interference.

[Investigation of O25b-ST131 Clone Frequency and Presence of Carbapenem and Fosfomycin Resistance Genes in Escherichia coli Isolates: First Detection of fosA3 from Escherichia coli O25bSTf131 Clone from Türkiye]. / Escherichia coli Izolatlarinda O25b-ST131 Klonu Sikligi ile Karbapenem ve Fosfomisin Direnç Genlerinin Varliginin Arastirilmasi: Escherichia coli O25b-ST131 Izolatlarinda Türkiye'den Ilk fosA3 Tespiti.

Escherichia coli ST131 clone was first reported in 2008 and defined as a 'high-risk pandemic clone'. This clone plays a critical role in the spread of antimicrobial resistance worldwide. It was reported in many studies that the E.coli ST131 clone is widespread worldwide and can carry virulence and antibiotic resistance genes. E.coli ST131 clone is associated with a fluoroquinolone and broad-spectrum cephalosporin resistance. The agents used in the treatment of infections caused by the E.coli ST131 clone are limited. For this reason, monitoring the resistance status of these limited agents is crucial. In this study, we aimed to investigate the prevalence of the O25b-ST131 clone, and the presence of carbapenem and fosfomycin resistance genes in fluoroquinolone-resistant E.coli isolates isolated from mid-stream urine samples. For the detection of the O25b-ST131 clone in fluoroquinolone-resistant E.coli isolates, amplification was performed with primers O25pabBspe-F and O25pabBspe-R. For the determination of resistance genes, carbapenem resistance genes blaNDM, blaVIM, blaKPC, blaIMP, and blaOXA-48 in carbapenem resistant isolates and plasmid-mediated fosfomycin resistance genes fosA3 and fosC2 in fosfomycin resistant isolates were investigated by multiplex PCR method. According to PCR results, the prevalence of E.coli O25b-ST131 isolates was 51.2%. Carbapenem resistance rate was 3.41%, and fosfomycin resistance rate was 3.41% in fluoroquinolone-resistant E.coli isolates. Carbapenem and fosfomycin resistance rates in E.coli O25bST131 isolates were determined as 0.83% and 2.5%, respectively. At least one of the carbapenem-resistance genes (blaNDM and/or blaOXA-48) was detected in six of the eight carbapenem-resistant isolates. Fosfomycin resistance gene fosA3 was seen in four of eight fosfomycin-resistant isolates. fosC2 gene was not detected in any of the isolates. In addition, the plasmid-mediated fosfomycin resistance gene fosA3 was detected in an E.coli O25b-ST131 isolate, and this result was confirmed by sequence analysis. To the best of our knowledge, this is the second report about fosA3 positivity in E.coli ST131 isolates from the world and the first reported from Europe and Türkiye. As a result, approximately half of the fluoroquinolone-resistant E.coli isolates were identified as E.coli ST131 clones. Despite the high rate of this clone, the carbapenem and fosfomycin resistance rates are still relatively low, which is pleasing for the future of treatment. However, it should not be forgotten that resistance rates and the prevalence of resistance genes should be constantly monitored.

Molecular epidemiology of Coxiella burnetii detected in humans and domestic ruminants in Turkey.

Q fever is a zoonotic disease that is known to be widespread throughout the world by many researches since its discovery in 1935 and it is important in terms of animal and public health. Coxiella burnetii, which is the etiological agent of the disease, is an obligate intracellular pathogen. While the disease generally manifests itself with abortion in animals, disease manifests as atypical pneumonia or granulomatous hepatitis in the acute form and as endocarditis in the chronic form in humans. Its presence in Turkey has been shown with a large number of studies. The aim of this study was to show the genotypic relationship with MLVA analysis of C. burnetii samples found in cattle, sheep and goat samples in Erzurum and Samsun Veterinary Control Institutes and blood samples collected from humans with atypical pneumonia findings. In the study, MLVA analyses of 100 positive samples from 50 cows, 41 sheep and 9 goats from Northeast Anatolia and Black Sea regions and C. burnetii positive samples found in 6 individuals with atypical pneumonia were performed. As a result of the study, it was found that 106 C. burnetii samples had belong to 16 genotype groups. It was found that genotype XVI was the most prevalent among these groups and it was seen in both regions. In addition to this, genotype IX profile was the second largest group with 83.3% (5/6) of human samples. In this study, the genotypes common in the regions were determined and a data source was created for possible outbreaks.

16s rRNA-based phylogenetic analyses of Elizabethkingia anophelis: Detection of Elizabethkingia anophelis, a rare infectious agent from blood and determination of antibiotic susceptibility in Turkey.

PURPOSE: Elizabethkingia anophelis was firstly isolated from the midgut of the Anopheles gambiae mosquito in 2011. After this year, it was isolated in some intensive care cases in Africa and Asia. This study, it was aimed to confirm the identification of E. anophelis in the blood of a pediatric patient. METHODS: After the suspicious bacteria were grown on blood agar, MALDI-TOF MS and 16s rRNA gene sequencing methods were used to identify and an antibiotic susceptibility test was carried out by Vitek 2 Compact system according to the EUCAST. Finally, a phylogenetic tree was created based on the 16s rRNA gene region. RESULTS: The isolate was identified as E. anophelis by both methods. It was found to be resistant to all beta-lactam antibiotics and also susceptible to ciprofloxacin and levofloxacin. According to the 16S rRNA-based phylogenetic tree, our isolate clustered within a branch containing other E. anophelis. CONCLUSION: These findings will guide clinicians in choosing which antibiotic to choose if they encounter this agent. Also, the clinicians should be vigilant against this agent, as it is a newly emerging infectious agent in Turkey.

Are aerosol control devices effective in preventing the spread of dental aerosol?

Background: In dental clinics, aerosols produced from dental instruments have become a matter of concern following breakout of coronavirus disease 19 (COVID-19) evolving into a pandemic. This study compared aerosol reduction systems and in terms of their ability to reduce Enterococcus faecalis (E. faecalis) contaminated aerosol in a simulated dental office set-up. Methods: Closed clinic model with manikin and mandibular molar typodont was simulated. For 10 min, the air and water dispersed by the rotating bur mounted on an aerator was contaminated by pouring the suspension containing 1-3 × 108 CFU/mL E. faecalis directly on the bur. During and after the procedures, the air within the cabin was also sampled. CFU count was recorded and scored. The mean CFU scores obtained from agar plate count and air sampling device was compared using Kruskal-Wallis H test among groups with 5% significance threshold. Results: The use of WS Aerosol Defender device led to greater CFU scores on the agars levelled to patient's chest compared to other directions (p = 0.001). Combined use of VacStation and WS Aerosol Defender resulted in significantly decreased CFU score in the air samples compared to experimental and positive control groups (p = 0 < 0.05). Conclusions: Although the devices prevented the spread of aerosol around the patient to some extent, they could not completely eliminate the contaminated aerosol load in the cabin environment.

Multicenter evaluation of AYC.2.2 agar for the isolation of mycobacteria from clinical samples.

PURPOSE: The aim of this multicenter study is to evaluate AYC.2.2 agar for the isolation of mycobacteria from clinical samples. METHODS: Totally 5559 media were tested in 7 centers. AYC.2.2 agar media for the study were prepared by C1 and sent to other centers under appropriate conditions. Other media except AYC.2.2 agar were purchased commercially. The media were subjected to routine laboratory operations in the center where they were sent. After the samples received for routine processing (in all centers, samples were processed with the same method (NALC-NaOH)), they were cultivated on routine media and AYC.2.2 agar afterward. RESULTS: C1: Average growth time was determined as 12.74±3.74 days with MGIT 960 system; 24.42±4.75 days with LJ and 24.37±4.96 days with AYC.2.2 agar. C2: Average growth time was determined as 18.25±9.32 days with TK-Medium, 28.73±7.44 days with LJ, and 31.72±6.35 days with AYC.2.2 agar. C3: Average growth time was determined as 20.48±7.24 days with Ogawa medium, 20.74±7.12 days with LJ, and 20.26±7.43 days with AYC.2.2 agar. C4: Average growth time was determined as 15.27±6.37 days with MGIT 960 system, 22.14±9.1 days with LJ, and 22±8.45 days with AYC.2.2 agar. C5: Average growth time was determined as 13±4.24 days with MGIT 960 system, 32.16±6.23 days with LJ, and 33±5.73 days with AYC.2.2 agar. C6: Average growth time was determined as 9±3.11 days with MGIT 960 system, 18.68±5.32 days with LJ, and 18.34±4.63 days AYC.2.2 agar. C7: Average growth time was determined as 14.74±7.65 with MGIT 960 system, 26.01±8.21 days with LJ, and 26.24±7.88 days with AYC.2.2 agar. CONCLUSIONS: In conclusion, similar results were obtained with LJ and Ogawa media and AYC.2.2 agar. Furthermore, more studies should be conducted for isolation of M. tuberculosis and performing antibiotic susceptibility tests using AYC.2.2 agar before it can be used as a routine media in the laboratories.

Prevalence of Fosfomycin Resistance Among Enterobacterales Isolates in A Tertiary Care Hospital from Turkey.

Objective: Urinary tract infections are one of the most common causes of morbidity around the world. Fosfomycin is a specific broad-spectrum antibiotic used to treat these infections. However, in recent years, many studies have reported increased fosfomycin resistance in Enterobacterales isolates. Therefore, this study aimed to evaluate the distribution of pathogens isolated from urine samples and find the fosfomycin resistance rates over nine years (2012-2020). Materials and Methods: A total of 18,884 uropathogenic Enterobacterales isolates were included in the study between 2012 and 2020. The isolates were identified by VITEK® 2 Compact (bioMérieux, Marcy l'Etoile, France), and the antimicrobial susceptibilities of the isolates were also evaluated using the VITEK® MS automated system (bioMérieux, Marcy l'Etoile, France). Results: Escherichia coli (64.04%) was the most common bacteria among Enterobacterales. Fosfomycin resistance rates were 1.98%, 21.64%, and 10.36% in E. coli, Klebsiella pneumoniae, and all bacteria, respectively. The 34.97% of isolates were extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales, and the fosfomycin resistance rate was 13.08% in these isolates. In addition, fosfomycin resistance rates were found as 3.06% and 23.84% in ESBL-producing E. coli and ESBL-producing K. pneumoniae, respectively. Conclusion: Fosfomycin seems a good option for effectively treating UTIs caused by E. coli. On the other hand, we found that fosfomycin resistance tends to increase over the years. Therefore, we recommend further studies to evaluate fosfomycin resistance.

Investigation of NDM, VIM, KPC and OXA-48 genes, blue-carba and CIM in carbapenem resistant Enterobacterales isolates.

INTRODUCTION: Carbapenem resistance is an emerging problem in Enterobactarales. We aimed to investigate the presence of carbapenemase genes blaNDM, blaKPC, blaVIM and blaOXA-48 and evaluate the phenotypic blue-carba method and carbapenem inactivation method (CIM) in Enterobacterales isolates. METHODOLOGY: Total of 153 Enterobacterales isolates were tested in the study. Presence of blaNDM, blaKPC, blaVIM and blaOXA-48 genes was investigated by polymerase chain reaction (PCR) method. Carbapenemase production of the isolates was also tested by blue-carba method and CIM. RESULTS: The presence of blaOXA-48 gene was detected in 110 (71.4%) and blaNDM gene was detected in 2 (1.3%) of the Enterobacterales isolates by PCR method. None of the isolates were positive for blaKPC and blaVIM genes. The 121 (78.54%) of the isolates were found to be positive by blue-carba method and CIM. And 105 (68.18%) of the isolates were determined as positive by both PCR, blue-carba and CIM. CONCLUSIONS: In our study, 112 (72.7%) of the Enterobacterales isolates were found to be positive for carbapenemase genes (blaoxa-48 and blaNDM), and 121 (78.57%) of different isolates were found to be positive for blue-carba and CIM. However, 105 (68.18%) of the carbapenem resistance isolates found to be positive for all three methods.

Enterococcus hirae as a cause of bacteremic urinary tract infection: first case report from Turkey.

INTRODUCTION: Enterococcus hirae (E. hirae) constitutes less than 1% of the enterococci strains in human clinical specimens. In this article, we report the first case of urinary tract infection-related bacteremia due to E. hirae from Turkey. CASE PRESENTATION: A 74-year-old male patient with a history of coronary artery disease, hypertension, and chronic renal failure was admitted to the emergency department with abdominal pain, dysuria, and fever. The urine sample collected from the urinary catheter resulted as ampicillin-sensitive E. hirae. On the 4th day of hospitalization, E. hirae growth with the same sensitivity pattern was also reported in blood culture. Intravenous ampicillin 4×2 g/day treatment was initiated. There was no growth in subsequent blood and urine cultures. Fever resolved and general condition improved. The patient was discharged on the thirteenth day with clinical improvement after moxifloxacin treatment for four days and ampicillin treatment for nine days. DISCUSSION: The patient's medical history included risk factors for enterococcal bacteremia. There are a limited number of reports in the literature describing human infections caused by E. hirae. The reason for the rare isolation of E. hirae from clinical specimens may be the difficulty of identifying with standard diagnostic approaches. CONCLUSIONS: For diagnostic purposes, as in our case, rapid and high sensitive diagnostic methods such as Matrix-assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) and molecular techniques may be useful to guide the selection of the least toxic and optimal duration of antibiotic treatment.

Epidemiological and clinical characteristics and management of oropharyngeal tularemia outbreak.

BACKGROUND/AIM: The purpose of this study was to determine the epidemiological and clinical characteristics of patients diagnosed with tularemia and the effectiveness of the administered treatments. MATERIALS AND METHODS: Patients treated in our hospital between January 2009 and March 2011 and diagnosed with tularemia were evaluated retrospectively. Patients' epidemiological and clinical characteristics, administered treatments, and posttreatment findings were recorded on patient monitoring forms. RESULTS: At anamnesis, 29% of patients used water from wells and 71% used water from the network supply; moreover, 48.4% had a history of contact with animals and 87.1% a history of lethargy. At physical examination, 96.8% had a mass in the neck and 90.3% had fever. Gentamycin + doxycycline therapy was administered to 45.2% of patients, while levofloxacin, gentamycin, and streptomycin were used for the other patients. After treatment, neck masses persisted in 48.4% of patients and complaints of lethargy and fever in 6.5%. Treatment of these patients was initiated once tularemia had been diagnosed, as test results were announced about 3 weeks later. Lymphadenopathy excision was performed on 19.4% of patients in whom neck mass persisted. CONCLUSION: Appropriate empiric antibiotherapy should be commenced in patients presenting with neck mass, fever, and lethargy in regions with tularemia epidemics.

[Detection of the first QnrS gene positivity in aquatic Aeromonas spp. isolates in Turkey]. / Türkiye'de su kaynakli Aeromonas spp. izolatlarinda saptanan ilk QnrS gen pozitifligi.

Aeromonas spp. are oxidase positive, gram-negative, facultative anaerobic bacilli that are widely distributed in aquatic environments. A.hydrophila, A.sobria and A.bestiarum may cause severe infections in both human and cold-blooded animals. Environmental persistance of quinolones that are widely used in both human and veterinary medicine plays an important role in the selection of resistant mutants. Plasmid-mediated resistance is one of the main mechanisms involved in quinolone resistance, and qnr, qepA, aac(6')-Ib-cr, oqxAB genes are identified as resistance determinants. Determination of various types of qnr gene in different bacteria mainly in Enterobacteriaceae, suggests that they are widely distributed in nature. Recently, plasmid-mediated quinolone resistance was defined among Aeromonas species isolated from water. The aim of this study was to investigate the presence of qnr genes among aquatic Aeromonas spp. in Turkey. A total of 45 Aeromonas strains isolated from water and fishes collected from three different geographical regions (Aegean, Mediterranean and Blacksea) in Turkey, were included in the study. The isolates were identified at species level by the use of 16S rDNA-RFLP (Restriction fragment length polymorphism) analysis and multiplex polymerase chain reaction (M-PCR). Among the isolates, 20 were identified as A.sobria, 10 as A.hydrophila, nine as A.salmonicida, four as A.bestiarum and two as A.veronii. The plasmid-mediated quinolone resistance determinants, qnrA, qnrB, qnrC and qnrS genes, were investigated by M-PCR, and sequence analysis was performed for nine qnr-positive isolates. According to the sequence analysis of the genes, qnr genes were characterized in six A.sobria, in two A.bestiarum and in one A.hydrophila isolate (9/45; 20%). When the sequence was compared with GenBank database, this gene was found as qnrS2. All qnrS-positive Aeromonas spp. isolates were ciprofloxacin-susceptible, while five of them were resistant to nalidixic acid. This study is the first research about the plasmid-mediated quinolone resistance and the presence of qnrS2 genes among Aeromonas spp. isolated from fishes and water in Turkey. In conclusion, various resistance genes of aquatic bacteria may constitute a potential risk for the transmission of those genes to other bacteria as well as clinical isolates.

[Investigation of acid proteinase and phospholipase activity as virulence factors in clinical Aspergillus spp. isolates]. / Klinik Aspergillus spp. izolatlarinda virülans faktörü olarak asit proteinaz ve fosfolipaz aktivitelerinin arastirilmasi

Aspergillus spp. are widespread in nature and cause severe infections especially in immunocompromised patients. Aspergillus fumigatus complex is the most common species that causes infections in humans; however Aspergillus niger complex and Aspergillus flavus complex are the emerging agents that are isolated frequently from clinical specimens more recently. Besides the host factors such as immunosuppression, hematologic malignancy and corticosteroid use, fungal virulence factors such as elastase, acid protease and phospholipase enzymes are considered among the factors that affect the development of invasive aspergillosis. The aim of this study was to detect the acid proteinase and phospholipase enzyme activities in 30 A.fumigatus complex, nine A.flavus complex and four A.niger complex strains isolated from clinical specimens. Acid proteinase and phospholipase activities of the isolates were investigated by using bovine serum albumin agar (BSA), and egg yolk agar plates, respectively. Acid proteinase and phospholipase activity was detected in 76.7% (23/30) and 93.3% (28/30) of A.fumigatus complex isolates, respectively. None of the nine A.flavus complex isolates exhibited acid proteinase or phospholipase activity. Acid proteinase activity was not detected in any of the A.niger complex isolates (n= 4), however phospholipase activity was detected in one (25%) isolate. All of the acid proteinase positive A.fumigatus complex strains (n= 23) were also positive for phospholipase activity. In conclusion, further larger scale multicenter studies supported by clinical data, are needed to enlighten the roles of acid proteinase and phospholipase in the pathogenesis of infections due to Aspergillus spp.

[In Vitro Effect of Ankaferd Blood Stopper®, a Plant Extract Against Mycobacterium tuberculosis Isolates]. / Bir Bitki Ekstresi Olan Ankaferd Blood Stopper®'in Mycobacterium tuberculosis Izolatlarina Karsi In Vitro Etkinligi.

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 µg/ml for M.tuberculosis H37Rv strain which was susceptible to all anti-tuberculosis drugs, whereas it was determined as 21.88 µg/ml for INH-resistant ATCC 35822 and STR-resistant ATCC 35820 strains. The MIC values for 24 susceptible clinical isolates were as follows; 10.94 µg/ml (n= 17), 21.88 µg/ml (n= 6) and < 1.37 µg/ml (n= 1). When evaluating 17 MDR clinical isolates, MIC values were determined as 5.47 µg/ml (n= 1), 10.94 µg/ml (n= 5) and 21.88 µg/ml (n= 11). MIC values were ranging between < 1.37-21.88 µg/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 µg/ml. MIC value of the two sole STR-resistant isolates was 21.88 µg/ml. MIC values of the two sole ETM-resistant isolates were determined as 21.88 µg/ml and 10.94 µg/ml. MIC50 and MIC90 values for the tested bacteria were 10.94 µg/ml and 21.88 µg/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.

[Investigation of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae: a multicenter study]. / Enterobacteriaceae Üyelerinde Plazmid Aracili Kinolon Direnç Determinantlarinin Arastirilmasi: Çok Merkezli Bir Çalisma.

Fluoroquinolones which are in use since 1986, are effective agents both against gram-positive and gram-negative bacteria. Quinolones show bactericidal effect as a result of inhibition of DNA gyrase and topoisomerase IV enzymes. Main quinolone resistance mechanisms are chromosomal mutations in these enzymes and decreased intracellular accumulation due to efflux pumps or decreased membrane uptake. Recently a new quinolone resistance mechanism mediated by plasmids has been defined. These plasmids carry genes called as qnr. Qnr genes do not cause quinolone resistance but they cause decreased quinolone susceptibility and lead to higher minimum inhibitory concentrations. Currently there are qnrA, qnrB, qnrC, qnrD and qnrS genes. This study was aimed to investigate the presence of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae isolates collected from four different centers in Turkey. A total of 647 isolates (387 from Trabzon, Black Sea region; 82 from Canakkale, Trace region; 96 from Ankara, Central Anatolia region; 82 from Tokat, Black Sea region) belonging to the Enterobacteriaceae family collected between May-July 2009, were included in the study. Presence of qnrA, qnrB, qnrS and qnrC genes were investigated by multiplex polymerase chain reaction (PCR) method and confirmed by gene sequencing. The results of the PCR amplification revealed that 2 isolates were positive for qnrA, 12 isolates were positive for qnrB, 4 isolates were positive for qnrC and 10 isolates were positive for qnrS. However, the number of positive strains decreased with the use of gene sequencing, and this method led to the identification of qnrA1 in two isolates [Enterobacter cloacae (code. 796), Salmonella group B (code. 491)], qnrB1 in two isolates [Salmonella group B (code. 491), Citrobacter freundii (code. 768)], qnrB6 in one isolate [Escherichia coli (code. CC1800)], qnrB9 in one isolate [E.coli (code. CC1873)], qnrB24 in one isolate [Citrobacter koseri (code. MP5200)], qnrB27 in one isolate [C.freundii (code. 842)], qnrS1 in two isolates [E.coli (code. CC1705), E.coli (code.159)] and qnrB2 in one isolate [E.coli (code. 843)]. One of the isolates that carried the qnr gene was ciprofloxacin-resistant and two isolates were nalidixic-acid resistant. Transferable quinolone resistance due to the dissemination of qnr genes may have important impacts in terms of infection control and treatment problems. Survey of plasmid mediated quinolone resistance will help to determine the size of the issue and guide the measures that should be taken to avoid escalation of resistance and dissemination problem.

[Investigation of plasmid-mediated quinolone resistance in Pseudomonas aeruginosa strains isolated from cystic fibrosis patients]. / Kistik Fibrozisli Hastalardan Izole Edilen Pseudomonas aeruginosa Suslarinda Plazmid Aracili Kinolon Direncinin Arastirilmasi

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.

Effect of 1-(1-Naphtylmethyl)-piperazine, an efflux pump inhibitor, on antimicrobial drug susceptibilities of clinical Acinetobacter baumannii isolates.

In this study, the effects of 1-(1-naphtylmethyl)-piperazine (NMP), an efflux pump inhibitor, on antimicrobial drug susceptibilities of 42 clinical Acinetobacter baumannii isolates were investigated by the disc diffusion method. The inhibition zone diameters of antibiotic discs were tested in the presence and absence of NMP and then these zone diameters were compared. Presence of NMP restored ciprofloxacin susceptibility in 15 intermediate and 2 resistant isolates. One ciprofloxacin resistant isolate became intermediate in the presence of NMP. One isolate resistant to gentamicin became intermediate with NMP. Interestingly, one isolate susceptible to meropenem became resistant in the presence of NMP. Although NMP increased the inhibition zone diameters of some of the tested antibiotics against the resistant isolates, the increase was not enough to restore susceptibility. In conclusion, the presence of NMP increases the zone diameters of ciprofloxacin and levofloxacin. Intermediate strains become susceptible but the resistant isolates do not.

Antimicrobial activity of plant extract Ankaferd Blood Stopper.

The in vitro antimicrobial activity of Ankaferd Blood Stopper (ABS) was assessed on 102 clinical isolates from both Gram negative and Gram positive bacteria and four standard strains, including MRSA ATCC 43300, MSSA ATCC 25923, P. aeruginosa ATCC 27853 and E. coli ATCC 35218. ABS was significantly active against all bacteria investigated.

[Investigation of biofilm formation and relationship with genotype and antibiotic susceptibility of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis]. / Kistik fibrozlu hastalardan izole edilen Pseudomonas aeruginosa izolatlarinin biyofilm olusturma yeteneklerinin arastirilmasi ve bu özelligin genotip ve antibiyotik duyarliligi ile iliskisinin belirlenmesi.

Pseudomonas aeruginosa is a frequent cause of respiratory infections in cystic fibrosis (CF) patients. P. aeruginosa strains isolated from these patients have often a mucoid phenotype at advanced disease. This mucoid structure contains a dense amount of alginate type polysaccharide which facilitates bacterial attachment to lung epithelia and provides protection from the immune system due to biofilm formation. The aims of this study were to investigate the biofilm formation and the relation of this property with genotype and antibiotic susceptibilities of P. aeruginosa strains isolated from CF patients. The biofilm formation was determined by using the Congo Red agar and Christensen methods. RAPD-PCR (Random amplification of polymorphic DNA polymerase chain reaction) and disc diffusion methods were used for genotyping and antibiotic susceptibility testing, respectively. Biofilm production was found positive in 33.3% (20/60) of P. aeruginosa tested. While 9 of these 20 isolates were of mucoid colony morphotype, among the 40 biofilm negative isolates mucoid colony was detected in 16 of them. RAPD genotyping based on 70% similarity yielded 19 (A-S) clusters and subtypes related to five of these clusters (K1, K2, N1, N2, Q1, Q2, R1, R2, S1, S2) making up a total of 24 genotypes. Nine of these genotypes composed of biofilm positive isolates and 15 were biofilm negative ones. Most of the biofilm positive strains belonged to K1 (n = 5) and K2 (n = 6) genotypes while biofilm negative isolates were in the L (n = 8) and O (n = 7) genotypes. The comparison of antibiotic susceptibilities in both groups revealed no statistically significant difference (p > 0.0%). However, highest rate of resistance was detected for tobramycin and lowest rate for piperacillin/tazobactam. The data obtained from this study indicated that biofilm negative and positive P. aeruginosa isolates clustered in different groups. These results should be supported with larger scale multi-center studies which may provide information about P. aeruginosa dynamics in CF lungs.

[Investigation of antibacterial activity of sertralin]. / Sertralinin antibakteriyel etkinliginin arastirilmasi.

Sertralin is a psychotropic drug which acts by inhibiting the selective serotonin re-uptake in the synaptic area. Previous studies have shown that some antidepressant agents have antibacterial activity. The aim of this study was to investigate the in vitro antibacterial activity of sertralin. A total of 224 bacterial strains isolated from clinical specimens together with standard control strains were included to the study. The antibacterial activity of sertralin was determined by microdilution method in Mueller-Hinton broth according to the Clinical and Laboratory Standards Institute (CLSI) guideline. The minimum inhibitory concentration (MIC) values were found to be 4-32 microg/ml for 22 methicillin-susceptible Staphylococcus aureus strains, 16-32 microg/ml for 25 methicillin-resistant S. aureus strains, 8-32 microg/ml for 20 methicillin-resistant coagulase-negative staphylococci strains, 16-32 microg/ml for 4 vancomycin-susceptible Enterococcus faecalis strains, 0.5-32 microg/ml for 10 vancomycin-susceptible Enterococcus faecium strains, 2-8 microg/ml for 12 vancomycin-resistant E. faecium strains, 16-128 microg/ml for 21 Acinetobacter baumannii strains, 4->128 microg/ml for 20 Klebsiella pneumoniae strains, 0.25-128 microg/ml for 24 Escherichia coil strains, 64->128 microg/ml for 22 Pseudomonas aeruginosa strains, 128->128 microg/ml for 2 Proteus vulgaris strains, 64->128 microg/ml for 8 Proteus mirabilis strains, 32->128 microg/ml for 7 Stenotrophomonas maltophilia strains, 32-128 microg/ml for 21 Enterobacter cloacae strains and 8-128 microg/ml for 6 Enterobacter aerogenes strains. The MIC values of sertralin against standard strains were as follows; 16 microg/ml for S. aureus ATCC 29213 (methicillin-susceptible), 32 microg/ml for S. aureus ATCC 43300 (methicillin-resistant), 16 microg/ml for E. faecalis ATCC 29212, 32 microg/ml for K. pneumoniae ATCC 700603, 32 microg/ml for E. coli ATCC 25922 and > 128 microg/ml for P. aeruginosa ATCC 27853. Sertralin has showed antibacterial activity mainly against gram-positive bacteria, and it was surprising that MIC values of vancomycin-resistant enterococci were lower than those of vancomycin-susceptible ones. Further in vivo and in vitro studies are required to provide reliable data about the use of sertralin as an adjuvant agent in the antibacterial treatment of infections caused by multidrug-resistant bacteria.