Carbapenem-resistant Klebsiella pneumoniae outbreak with monoclonal spread: Evaluation of resistance genes and ceftazidime-avibactam susceptibility.

PURPOSE: The aim of this study was to investigate ceftazidime-avibactam (CAZ-AVI) susceptibility, carbapenemase genes, and clonal relationship in carbapenem-resistant Klebsiella pneumoniae (CrKp) isolates. METHODS: A total of 28 non-repetitive CrKp isolates with positive carbapenemase production determined by the modified carbapenem inactivation method (mCIM), were included in the study. Identification of the isolates was performed with MALDI-TOF MS (VITEK-MS, bioMerieux, France). The automated system (VITEK-2, bioMerieux) and gradient diffusion test (Etest, bioMerieux) were used to determine antibiotic susceptibility. The mCIM was performed according to CLSI (2021) recommendations. CAZ-AVI susceptibility was carried out using the standard disc diffusion method. Results were evaluated according to EUCAST 2022 criteria. The blaOXA-48, blaNDM, blaKPC, blaIMP and blaVIM genes were investigated by multiplex PCR. The clonal relationship between isolates was determined by both AP-PCR and PFGE methods. RESULTS: Of the total 28 isolates, 89.3% were susceptible to CAZ-AVI. blaOXA-48 gene was found in 85.7% of the isolates, blaOXA-48+blaNDM gene in 10.7%, and blaNDM gene in 3.6%. blaKPC, blaIMP and blaVIM genes were not detected. Three clusters with three different genotypes were determined by the PFGE method. The largest cluster was Genotype A (n:24), followed by Genotype B (n:3), and Genotype C (n:1). AP-PCR was highly compatible with PFGE. The isolates of Genotype A, mostly from the intensive care unit (ICU), were evaluated as outbreak strains with monoclonal dissemination. CONCLUSIONS: OXA-48 remains the most frequently detected enzyme in CrKp strains in our country. The ceftazidime-avibactam susceptibility rate of 89.3% indicates that this antibiotic is still effective against CrKp isolates. The unnoticed outbreak detected in our study revealed the severity of intra-hospital cross-contamination affecting different wards, including the ICU. Therefore, in order to limit the spread of CrKp isolates, it is of great importance to implement strict infection control measures, and molecular surveillance programs, especially in the ICU.

[A Case of Mycobacterium abscessus Identified by Suspicious Gram Staining in the Blood Culture of a Patient with Chronic Renal Failure]. / Kronik Böbrek Yetmezlikli Hastanin Kan Kültüründe Süpheli Gram Boyamasi ile Tanimlanan Mycobacterium abscessus Olgusu.

Mycobacterium abscessus (M.abscessus), which is from the group of non-tuberculosis mycobacteria and is widely found in the natural environment, has been reported with increasing frequency as the causative agent of various infections; especially in the lower respiratory tract and in immuncompromised people. In this report, a case of M.abscessus, which developed tubular adenoma, pancytopenia and sepsis on the basis of chronic renal failure (CRF) was diagnosed by suspecting the causative agent in the Gram stain examination prepared from blood culture, was presented. A 49-year-old patient with CRF, who had complaints of weight loss, weakness, and loss of appetite for the last six months, admitted to the emergency department with a 7-8-day history of severe diarrhea and fever. Besides other tests, as the white blood cell count was 1.6 x 103/µl, neutrophil count was 80.6%, hemoglobin was 9.3 g/ dl and the platelet value was 36 x 103/µl in the blood samples, the patient was first taken into internal medicine service and then to the intensive care unit with a preliminary diagnosis of hypotension and sepsis. Meropenem and teicoplanin were started with the preliminary diagnosis of peritonitis in the internal medicine service. In addition to other tests, on the fifth day of antibiotic treatment, two consecutive sets of blood cultures were taken and sent to the microbiology laboratory. A positive signal was obtained from two aerobic blood culture samples at 42 and 45 hours of incubation in the BacT/Alert device. No bacteria were observed in the Gram staining of these samples and Erhlich Ziehl Neelsen (EZN) staining was performed because the structures considered as dye residues were noted as a result of the examination. Acid-fast bacteria were observed in the EZN-stained slide examination, and a panic report was given to the clinician. The patient died shortly after the notification was made in the evening hours. On culture plates inoculated after a positive signal, at the end of two days of aerobic incubation at 37 °C, small smooth S colonies grew on chocolate and sheep blood agar. Growing bacteria were detected as positive by EZN staining and identified as M.abscessus with 99.9% confidence by MALDI-TOF MS. After the bacterium was named as M.abscessus, the isolates were sent to the tuberculosis central laboratory of Süreyyapasa Chest Diseases and Thoracic Surgery Hospital for molecular typing. After DNA extraction from the growing colonies and polymerase chain reaction (PCR), they were typed using the GenoType NTM-DR (Hain Lifescience GmbH, Germany) kit and identified as M.abscessus, consistent with the MALDITOF MS result. After the species level identification, the erm, rrl (clarithromycin, azithromycin), and rrs (kanamycin, amikacin, and gentamicin) genes were investigated in the isolate, and it was determined that the bacteria were resistant to macrolides and sensitive to aminoglycosides. In the clinic, it should be noted that, non-tuberculous mycobacteria may play a role as an agent in immunocompromised people. On the other hand, it should be considered that non-tuberculosis bacteria may be the causative agent, with gram-positive bacilli appearing as stain residues or pale staining in Gram stains made from samples of such patients. As in this case, if the agent is seen as dye residue in blood culture Gram staining samples, it may be life-saving to suspect the agent and to report the result to the clinician accurately and quickly after EZN staining.

[Evaluation of In vitro Efficacy of Meropenem/Colistin and Meropenem/Fosfomycin Combinations on Multidrug Resistant Gram-Negative Bacilli]. / Çok Ilaca Dirençli Gram-Negatif Basillerde Meropenem/Kolistin ve Meropenem/Fosfomisin Kombinasyonlarinin In vitro Etkinliginin Degerlendirilmesi.

The rate of extensively drug-resistant and pan-resistant gram-negative rods isolated as infectious agents is increasing around the world and in Türkiye. One of the important options in the treatment of these infections is the combined use of antibiotics. Therefore, the aim of this study was to investigate the in vitro effect of meropenem/colistin and meropenem/fosfomycin combinations on carbapenem-resistant gram-negative bacilli isolated as infectious agents. Escherichia coli (n= 6), Klebsiella pneumoniae (n= 10), Pseudomonas aeruginosa (n= 5), and Acinetobacter baumannii (n= 6) isolates were recovered from blood and tracheal aspirate samples of patients hospitalized in our hospital's intensive care unit were included in the study. In the first stage of the combination study, minimal inhibitory concentrations (MIC) were investigated by broth microdilution for meropenem and colistin, and agar dilution methods for fosfomycin. In the second stage of the study, synergy, partial synergy, indifference, and antagonistic effects were investigated with the checkerboard method for the meropenem/colistin combination and the agar dilution method for the meropenem/fosfomycin combination. The checkerboard results were interpreted as follows: fractional inhibitory concentration index (FICI) values ≤ 0.5 synergy, < 0.5-≤ 1 partial synergy, > 1-≤ 4 indifference and FIC values of > 4 antagonism. MIC values obtained in the study were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Of the 27 isolates studied with the broth microdilution method, 63% were found to be colistin-resistant and 37% susceptible. The MIC values of fosfomycin against Enterobacterales group bacteria were found to be in the range of 2-2048 mg/L. Two of the six E.coli isolates and nine of the 10 K.pneumoniae isolates were found to be resistant to fosfomycin (IV). The MIC values of ≥ 128 mg/L were found in all 11 non-fermentative gram-negative rods with intrinsic resistance to fosfomycin. In the combination of meropenem/ colistin, synergy and partial synergy were observed in 11 (40.7%) of 27 isolates, an indifference effect was observed in 13 (48.2%), and antagonistic effects were observed in three (11.1%) of the isolates. The synergy and partial synergy effects of this combination were 37.5% for Enterobacterales group bacteria, 50% for E.coli, and 30% for K.pneumoniae. Regarding the 11 non-fermentative gram-negative rods included in the study, 83.3% synergy and partial synergy was found in A.baumannii for the meropenem/colistin combination, while no synergy and partial synergistic effect was found in P.aeruginosa. Meropenem/fosfomycin synergy and partial synergy effects were 83.3% (5/6) for E.coli, 100% (8/8) for K.pneumoniae, 100% (6/6) for A.baumannii, and 25% (1/4) for P.aeruginosa. In all of the isolates studied, meropenem/fosfomycin combination was found to be more effective than the meropenem/colistin combination. It would be meaningful to support these data obtained in vitro with clinical efficacy results to be obtained as a result of the application of antibiotics in vivo, taking into account the pharmacokinetic and pharmacodynamic properties of the antibiotics used in this study.

Investigation of in vitro efficacy of meropenem/polymyxin B and meropenem/fosfomycin combinations against carbapenem resistant Klebsiella pneumoniae strains.

The incidence of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is increasing worldwide, and very limited number of effective antibiotics are available for therapy. In our study, the in vitro efficacy of meropenem/polymyxin B and meropenem/fosfomycin combinations against CRKP strains was investigated. The efficiency of meropenem/polymyxin B and meropenem/fosfomycin combinations was tested by checkerboard microdilution and checkerboard agar dilution methods, respectively, against 21 CRKP strains containing major carbapenem resistant genes (7 blaKPC, 7 blaOXA-48 gene, and 7 blaOXA-48+ blaNDM), and seven additional CRKP strains without carbapenemase genes.Among the 28 CRKP strains, the meropenem/polymyxin B combination was synergistic in ten (35.7%), partially synergistic in 12 (42.8%), and indifferent in six (21.4%) isolates. The meropenem/fosfomycin combination was found to be synergistic in three isolates (10.7%), partially synergistic in 20 (71.4%), and indifferent in five (17.8%). In 21 strains containing carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations exhibited synergistic/partial synergistic effects in 15 (71.4%) and 16 (76.2%) strains, respectively, compared to 100% synergistic/partial synergistic efficiency in both combinations in seven strains free of carbapenemase genes. No antagonistic effect was detected in either combination.Regardless of presence or absence of carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations both demonstrated high synergistic and partial synergistic activity against 78.4% and 82.1% of CRKP strains, respectively. Also, they have no antagonistic effects and can be used successfully to prevent therapeutic failure with monotherapy, according to our in vitro studies.

Evaluation of Broth Disk Elution Method to Determine Colistin Resistance in Klebsiella pneumoniae and Escherichia coli Strains.

BACKGROUND: The reference broth microdilution (rBMD) method for the determination of colistin resistance is very laborious and time consuming, and many manual errors can occur. There are also limitations in detection of colistin heteroresistance. Therefore, alternative methods with satisfactory performance are required for routine laboratory work. In our study, the colistin broth disk elution (CBDE) method recommended by the Clinical and Laboratory Standards Institute (CLSI) for the detection of colistin resistance in routine applications was compared with rBMD. The compatibility and error rates of the method were evaluated and its usability in routine laboratory studies was examined. METHODS: Eighty-nine multidrug resistant Klebsiella pneumoniae and five Echerichia coli strains isolated from various clinical specimens were included in the study. Identification of strains and antibiotic susceptibility tests were performed with MALDI-TOF MS (bioMerieux, France) and Vitek-2 (bioMerieux) system. Minimum inhibitory concentration (MIC) was studied in 0.125 - 128 mg/L dilution range by using polystyrene microplate and colistin sulfate salt according to ISO-standard (20776-1) recommendations for the reference BMD test. The CBDE method was performed according to the CLSI recommendations. Isolates with MIC ≤ 2 mg/L were considered susceptible, while isolates with MIC > 2 mg/L were considered resistant according to EUCAST recommendations. The performance of the CBDE method was evaluated according to ISO criteria (Categorical agreement > 90%; major error and very major error rates < 3%). RESULTS: Categorical agreement for all 58 and 36 isolates found to be resistant and susceptible, respectively, by rBMD was found to be 100% with CBDE test. Since < 1 and > 4 µg/mL values could not be determined with the CBDE method, essential agreement (EA) could not be calculated. No major or very major errors were detected. CONCLUSIONS: Our results showed that the performance of the CBDE test is good when compared to the rBMD method. According to our data, we believe that the CBDE method can be used in routine laboratories for the detection of colistin resistance.

Performance of the Rapidec®Carba NP assay for the detection of different carbapenemases in Klebsiella pneumoniae and Escherichia coli strains.

PURPOSE: The spread of infections caused by Enterobacterales strains resistant to carbapenems is a global public health problem, and early detection of carbapenemases is very important to prevent their spread. The rapid detection of carbapenemase production with the new commercial assay Rapidec® Carba NP test is based on the biochemical detection of imipenem hydrolysis. Our study aims to evaluate the performance of the Rapidec® Carba NP test in OXA-48 positive isolates highly prevalent in our country and also in isolates with more than one carbapenemase gene that have an increased prevalence and to examine whether it can be used for confirmation of carbapenemase positivity in the routine laboratory. METHODS: A total of 97 strains of 94 carbapenem-resistant Klebsiella pneumoniae and three carbapenem-resistant Escherichia coli isolated from various clinical specimens were included in the study. The results of the Rapidec® Carba NP assay were compared with those obtained by the multiplex PCR test. RESULTS: The sensitivity of the Rapidec® Carba NP test was 97.8% for all carbapenemase-positive isolates. Of 90 PCR positive isolates, one OXA-48 and one OXA-48 â€‹+ â€‹NDM positive isolates were negative with Rapidec® Carba NP test. CONCLUSIONS: The positive results detected by the Rapidec® Carba NP test make an important contribution to the early detection of carbapenemase production and infection control practices. Since two carbapenemase positive isolates were found to be negative with the Rapidec® Carba NP test in our study, it was concluded that negative results of carbapenem-resistant isolates obtained with this assay should be confirmed with an additional carbapenemase detection method to exclude false-negative results.

Comparison of syphilis seropositivity between non-immigrant and immigrant populations in the Anatolian side of Istanbul, Turkiye: Results of five-years retrospective study.

OBJECTIVE: Our study aimed to evaluate the seropositivity for syphilis in non- immigrant and immigrant populations and compare the results regarding demographic data. METHODS: In accordance with the reverse algorithm, syphilis tests were performed between May 2014 and December 2018 in hospitals in our service zone for syphilis screening or symptomatic disease. RESULTS: A total of 135.328 non- immigrant and 6.641 immigrant were screened for syphilis. Seropositivity rates were 1.3% in the non- immigrant and 3.8% in immigrant groups (p=0.0001). There was a statistically significant difference in terms of seropositivity rates between the various age groups in the local group and immigrant groups (except 18 25 age group) (p<0.05). Syphilis seropositivity rates were found to be lower in indigenous population than immigrant groups according to the years tested (p=0.0001). The seropositivity rates were 2.4% and 3.2% among the males (p=0.025) and 0.6% and 4.0% among females (p=0.0001) in non-immigrantand immigrant groups, respectively. Whereas, 0.6% of pregnant women in the local group and 3.7% of pregnant women in immigrant groups were seropositive for syphilis (p=0.0001). Among the HIV positive group, syphilis seropositivity was only observed in the non-immigrant group with a rate of 23.0% (p=0.0001). CONCLUSION: The antibodies against syphilis were found more frequently in immigrants than non-immigrant. Among the HIV positive individuals syphilis seropositivity was only observed in the non-immigrant group.

Detection of colistin resistance among multidrug-resistant Klebsiella pneumoniae and Escherichia coli clinical isolates in Turkey.

In this study investigation of plasmid-mediated mcr 1-5 resistance genes was performed among multidrug-resistant (MDR) colistin sensitive and resistant Klebsiella pneumoniae and Escherichia coli strains isolated in our laboratory. We aimed to evaluate automated system (Vitek-2), broth microdilution (BMD) reference method and chromogenic media performance. Totally 94 MDR K. pneumoniae and six E. coli isolates were included in the study. CHROMID® Colistin R agar (COLR) (bioMerieux, France) was used to determine the colistin resistance by chromogenic method. Standard PCR amplification was performed using specific primers to screen the plasmid-mediated mcr 1-5 genes. Sixty-one isolates were resistant to colistin and 39 were susceptible with reference BMD. The essential and categorical agreement of Vitek-2 was determined as 100 and 99%. The sensitivity of COLR medium was 100%, the specificity was 97.5%. In our study mcr-1 was detected in eight isolates, while other mcr genes were not detected. Due to the high sensitivity and specificity of the COLR medium, it can be used in routine diagnostics for the detection of colistin resistance. In our study we detected 8% prevalence of mcr-1 among MDR strains however, two mcr-1 positive isolates were found sensitive to colistin by BMD.

[Evaluation of the Two Commercial Methods Based on Broth Microdilution Against Reference Microdilution Method for Klebsiella pneumoniae Isolates]. / Klebsiella pneumoniae Izolatlarinda Sivi Mikrodilüsyon Temelli Iki Ticari Sistemin Referans Mikrodilüsyon Yöntemine Göre Degerlendirilmesi.

A rapid and reliable method for antimicrobial susceptibility test of colistin is needed because of increasing numbers of multi-resistant gram negative bacterial infections and simultaneus increasing of colistin resistance. Although broth microdilution (BMD) is recommended by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) as a reference method, the use in routine laboratory practice is limited because of the difficulties in application and time-consuming characteristics. Recently, many BMD based commercial products were developed. The study was aimed to compare the results of the two commercial systems available for the detection of colistin sensitivity with the reference method. Totally 38 Klebsiella pneumoniae strains isolated from various clinical specimens between 2017-2018 were included in our study. Identification and antibiotic susceptibility tests were performed with "matrix-assisted laser desorption/ionization timeof-flight, mass spectrometry (MALDI-TOF MS)" and Vitek-2 (bioMérieux, Marcyl'Etoile, France) systems. BMD tests were performed with Sensititre (Sensititre custom plate, Thermo Fisher Scientific, UK) and Micronaut MIC-Strip (Merlin Diagnostika GmbH, Germany) kits. Commercial BMD assays containing dehydrated colistin in the concentration range of 0.0625-128 mg/L were tested with 0.5 McFarland bacterial suspensions prepared according to the manufacturer recommendations. The reference BMD test was performed by following the recommendations of the International Organization for Standardization (ISO-20776-1). ATCC 25922 colistin-susceptible Escherichia coli and NCTC 13846 (mcr-1 positive) colistin-resistant E.coli strains were used as the quality control strains. According to the recommendations of EUCAST version 9.0, strains with minimum inhibitory concentration value of ≤ 2 mg/L were considered susceptible and strains > 2 mg/L as resistant. Thirty-five isolates were resistant to colistin by the reference method and three of them were susceptible. The Sensititre kit detected a very major error (2.8%) in one isolate; no major or very major errors were detected for the Micronaut kit. The essential and categorical agreement of the Sensititre and Micronaut kits with the reference method was defined as 74-76% and 97-100%, respectively. Colistin is the last agent for the treatment of the multi drug resistant severe bacterial infections so major and very major error for colistin should be considered equally serious. Although a very major error was detected by the Sensititre kit in one isolate, the categorical agreement of both commercial kits was greater than 90% when compared with the reference method. It was concluded that, commercially available, BMD based systems that do not require additional equipment and experience can be routinely used.

[Investigation of Anti-HCV S/CO Value in Detecting Viremia in Patients with Hepatitis C Virus Infection]. / Hepatit C Virüsü Enfeksiyonu Olan Hastalarda Viremi Tespitinde Anti-HCV S/CO Degerinin Arastirilmasi.

Anti-HCV and HCV RNA tests are used in laboratory diagnosis of hepatitis C virus (HCV) infections. False positive results are frequently observed in anti-HCV tests used as screening tests in societies with low prevalence of HCV. The HCV RNA test, which is a confirmatory test, is not performed in every laboratory because it is a high-cost and high-tech test, which can lead to delay in the diagnosis and treatment of patients. In this study, it was aimed to obtain an optimal anti-HCV S/CO value in our laboratory for demonstrating true antibody positivity and viremia in patients by analyzing the relationship between anti-HCV, alanine aminotransferase (ALT) and HCV RNA using retrospective data. Between July 2014 and July 2017, 754.190 anti-HCV tests were performed. Patients aged 18 years or older who were reactive with anti-HCV and those with simultaneous HCV RNA and ALT prompts were included in the study. The second generation CMIA (Abbott, USA) method was used for anti-HCV detection. For quantitative HCV RNA analysis, viral nucleic acid extraction was performed with the QIAsymphony SP/AS (Qiagen, Germany) using the QIAsymphony DSP Virus/Pathogen Midi Kit; and PCR was performed by Rotor-Gene Q (Qiagen, Germany) using Artus HCV QS-RGQ kit. ARCHITECT c and AEROSET systems (Abbott, USA) were used for ALT measurement. HCV genotype determination (622 cases) was performed using GenoSen's HCV Genotyping 1/2/3/4 RG qualitative real time PCR kit (Corbett Research, Australia) and GEN-C 2.0 Reverse Hybridization Strip Assay (NLM Diagnostics, Italy) kit at different periods covered by our study. The optimal threshold value for the relationship between anti-HCV, ALT and HCV RNA was selected based on ROC analysis. Statistical significance was accepted as p<0.05. Of the anti-HCV test results, 10.679 were found to be reactive. 1754 data of 1290 cases with anti-HCV reactivity who were simultaneously tested for HCV RNA and ALT in the same serum were evaluated. Of these, 742 (42%) were found to be HCV RNA positive and 1012 (58%) were found to be HCV RNA negative. ALT and anti-HCV levels of those who were positive for HCV RNA were significantly higher than those with negative HCV RNA (p= 0.001). The threshold point for anti-HCV S/CO according to HCV RNA was found to be 7.13 (sensitivity of 97.4%, specificity of 50.3%, positive predictive value 58.9%, negative predictive value 96.4%), and the cut-off point for ALT was found to be 27.5 IU/L (sensitivity of 77.6%, specificity of 80.8%). For HCV RNA positivity, the area under the ROC curve for anti-HCV and ALT was significantly higher than 0.5 (p= 0.001). No statistically significant difference was found between HCV genotypes in terms of ALT and anti-HCV levels. By using our new threshold in the laboratory workflow, the need to verify with HCV RNA can be reduced, especially in some patients who have been screened for antiHCV for screening purposes. Anti-HCV values below 7.13 S/CO, considering the high negative predictive value of this threshold; a false positive result in a patient presenting for screening can be predicted without waiting for the HCV RNA result. In anti-HCV reactivities determined above 7.13, the possibility of absence of viremia should be considered due to the low positive predictive value.

Investigation of Fibronectin Binding Protein (FBP) and Panton Valentine Leukocidin (PVL) Viulance Factors in Clinical Methicillin Sensitive and Resistant Staphylococcus Aureus Strains.

BACKGROUND: We aimed to investigate the frequency of fibronectin binding protein (FBP), which is part of the first step of adhesion, and Panton-Valentine leukocidin (PVL) toxin, which contributes to the destruction of host leukocytes and tissue necrosis, in clinical S. aureus strains. METHODS: One hundred S. aureus strains were included in the study and distributed as follows; 33 from skinwound swabs and catheter tips (SWCT), 33 from body fluid and secretion specimens (BSFS) such as tracheal aspirate, sputum, and pleural effusion fluid, 18 from tissue biopsy specimens (TBS), 10 specimens from blood, and related specimens (BRS) such as bone marrow, and cerebral spinal fluid, and six specimens from mucosal membrane of pharynx, nose, and vagina (MMS). Methicillin resistance was tested by disk diffusion method. mecA (methicillin resistance coded gene), pvl and fnbA genes were investigated by using a PCR method. RESULTS: Thirty-seven strains (37.0%) were identified as methicillin resistant S. aureus (MRSA) and 63 (63.0%) as methicillin susceptible S. aureus (MSSA) strains. fnbA was more frequent in S. aureus isolates of MMSs (100.0%); followed by BRSs (80.0%), SWCTs (78.8%), TBS (72.3%), and BSFs (66.7%), whereas pvl gene was more frequent in isolates of BRS (60.0%), followed by TBSs (50.0%), SWCTs (33.4%), BSFs (30.3%), and MMSs (16.7%). fnbA existed in 85.7% of MSSA and 56.8% of MRSA in contrast to pvl, which was more frequent in MRSA (70.3%) than those of MSSA strains (17.4%). These differences were statistically significant (p < 0.05). CONCLUSIONS: Our different clinical specimens contained a high rate of fnbA (75.0%) and low-moderate frequency of pvl (37.0%). fnbA was most frequent in S. aureus of MMSs, followed by BRSs, and SWCTs, whereas pvl was ex-isted in high proportion in S. aureus of BRSs, followed by TBSs, and SWCTs. Presence of PVL in a high proportion in MRSA strains of superfical specimens such SWCT (24.4%) and deeper serious specimens such as BRS (16.3%) compared to MSSA strains from the same specimens, 3.2% and 0%, respectively, have shown that MRSA infections still threatens patients' lives and control of their spread is urgently needed.

Detection of upper limit of normal values of anti-DNase B antibody in children's age groups who were admitted to hospital with noninfectious reasons.

OBJECTIVE: Anti-streptolysin O (ASO) and anti-DNase B (ADB) titers are used for the diagnosis of poststreptococcal complications. Ranges of normal values of ASO and ADB titers vary, depending on age, population and different time intervals. Although many studies have been performed for determination of the ASO titer in our country, only a few studies have been conducted for specification the upper limit of normal for (ULN) ADB. In our study we aimed to determine the upper limit of normal of ADB antibody titers in children aged 5-15. METHODS: One hundred and twenty one children aged from 5-15 who were admitted to our outpatient clinic of Haydarpasa Numune Training and Research Hospital with noninfectious reasons between November 2013 and March 2014 were included in the study. Patients who met the following criteria were included in the study; absence of streptococcal infection in the last three months in physical examination and/or no growth of group A, C, and G of beta-haemolytic streptococci in throat culture, normal ranges of ASO and C reactive protein (CRP) levels. All serum samples were analyzed collectively by nephelometric method. The upper limit of normal value for anti-DNase B has been defined by separating the upper 20% from the lower 80% of all measurements. RESULTS: Anti-DNase B antibody levels were ranged between 50-576 IU/ml and its upper limit was 219.2 IU/ml. When analyzed according to age groups, anti-DNase B antibody levels in the group aged between 5-10, ranged between 50-576 IU/ml and its upper limit was 212.2 IU/ml, anti-DNase B antibody levels in the group aged 10-15, ranged between 50-408 IU/ml and its upper limit was 231.2 IU/ml (p=0.008). CONCLUSION: Based on our results, upper normal values ADB antibody showed variations with age in our results. Therefore national reference values should be detected by more comprehensive studies.

An association study of functional polymorphic genes IRF-1, IFNGR-1, and IFN-γ with disease progression, aspartate aminotransferase, alanine aminotransferase, and viral load in chronic hepatitis B and C.

BACKGROUND: Investigational approaches based on genome-wide association studies have proven useful in identifying genetic predictors for many diseases, including susceptibility to chronic hepatitis B and C. In these studies, the majority of genetic variants that have shown a positive association have been identified in genes involved in the immune response. In this study IFN-γ, IFNGR-1, and IRF-1 genes were analyzed for their role in susceptibility to the development of chronic hepatitis B and chronic hepatitis C in a Turkish population. METHODS: Polymorphic genes IRF-1 (-410, -388), IFNGR-1 (-56, -611), and IFN-γ (+874) were analyzed in a total of 400 individuals: 100 chronic hepatitis B patients, 100 hepatitis B carriers, 100 chronic hepatitis C patients, and 100 healthy controls. A single base primer extension assay was used. Correlations between genes and gender, viral load, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were also investigated. RESULTS: The IRF-1 gene at positions -388 and -410 were observed to be candidate gene markers for susceptibility to the development of chronic hepatitis B and C (p<0.05). IFN-γ +874 and IFNGR-1 (-56 and -611) correlated with chronic hepatitis B but not chronic hepatitis C. Correlation of functional genotype with viral load and AST and ALT levels revealed an association of IFN-γ +874 and IFNGR-1 -611 with chronic hepatitis C and IFN-γ +874 with viral load and chronic hepatitis B (p<0.05). CONCLUSIONS: Findings suggest that IFN-γ (+874), IRF-1 (-410, -388), and IFNGR-1 (-56, -611) are candidate gene markers for determining patient susceptibility to the development of chronic hepatitis B and C.

Prevalence of phenotypic resistance of Staphylococcus aureus isolates to macrolide, lincosamide, streptogramin B, ketolid and linezolid antibiotics in Turkey.

The incidence of drug-resistant pathogens differs greatly between countries according to differences in the usage of antibiotics. The purpose of this study was to investigate the phenotypic resistance of 321 methicillin resistance Staphylococcus aureus (MRSA) and 195 methicillin susceptible S. aureus (MSSA) in a total of 516 S. aureus strains to macrolide, lincosamide, streptogramin B (MLS B), ketolid, and linezolid. Disk diffusion method was applied to determine MLS B phenotype and susceptibility to different antibiotic agents. It was found that 54.6% of the isolates were resistant to erythromycin (ERSA), 48% to clindamycin, 55% to azithromycin, 58.7% to spiramycin, 34.7% to telithromycin, and 0.4% to quinupristin-dalfopristin, respectively. No strain resistant to linezolid was found. The prevalence of constitutive (cMLS B), inducible (IMLS B), and macrolides and type B streptogramins (M/MS B) among ERSA isolates (237 MRSA, 45 MSSA) was 69.6 %, 18.2%, and 12.2 % in MRSA and 28.9%, 40%, and 31.1% in MSSA, respectively. In conclusions, the prevalence of cMLS B was predominant in MRSA; while in MSSA strains, iMLS B and M/MS B phenotype were more higher than cMLS B phenotype resistance. The resistance to quinupristindalfopristin was very low, and linezolid was considered as the most effective antibiotic against all S.aureus strains.

Prevalence of phenotypic resistance of Staphylococcus aureus isolates to macrolide, lincosamide, streptogramin B, ketolid and linezolid antibiotics in Turkey

The incidence of drug-resistant pathogens differs greatly between countries according to differences in the usage of antibiotics. The purpose of this study was to investigate the phenotypic resistance of 321 methicillin resistance Staphylococcus aureus (MRSA) and 195 methicillin susceptible S. aureus (MSSA) in a total of 516 S. aureus strains to macrolide, lincosamide, streptogramin B (MLS B), ketolid, and linezolid. Disk diffusion method was applied to determine MLS B phenotype and susceptibility to different antibiotic agents. It was found that 54.6 percent of the isolates were resistant to erythromycin (ERSA), 48 percent to clindamycin, 55 percent to azithromycin, 58.7 percent to spiramycin, 34.7 percent to telithromycin, and 0.4 percent to quinupristin-dalfopristin, respectively. No strain resistant to linezolid was found. The prevalence of constitutive (cMLS B), inducible (IMLS B), and macrolides and type B streptogramins (M/MS B) among ERSA isolates (237 MRSA, 45 MSSA) was 69.6 percent, 18.2 percent, and 12.2 percent in MRSA and 28.9 percent, 40 percent, and 31.1 percent in MSSA, respectively. In conclusions, the prevalence of cMLS B was predominant in MRSA; while in MSSA strains, iMLS B and M/MS B phenotype were more higher than cMLS B phenotype resistance. The resistance to quinupristindalfopristin was very low, and linezolid was considered as the most effective antibiotic against all S.aureus strains.

Investigation of Panton-Valentine leukocidin genes and SCCmec types in clinical Staphylococcus aureus isolates from Turkey.

Panton-Valentine leukocidin (PVL) is an important virulence determinant of Staphylococcus aureus. The aim of this study was to investigate the prevalence of PVL genes in clinical S. aureus isolates and to determine the staphylococcal chromosomal cassette mec (SCCmec) types of methicillin-resistant S. aureus (MRSA) strains obtained from inpatients and outpatients of two hospitals in Turkey. Of the 304 S. aureus strains (230 hospital acquired [HA] and 74 community-onset [CO]), 261 were MRSA and 43 were methicillin-sensitive S. aureus (MSSA). PVL positivity was determined in 12 (1 HA and 11 community acquired) strains. Eight were MRSA, and four were MSSA. Seven of the PVL-positive strains were isolated from wound specimens, four from urine, and one from synovial fluid. SCCmec type III (93.78%) was more prevalent among HA-MRSA strains, and SCCmec type IIIB (41.18%) was more prevalent among CO-MRSA strains. Pulsed-field gel electrophoresis patterns of the PVL-positive isolates were different. Our results indicate that PVL-positive strains are able to cause infection in nearly every system without the need for additional risk factors. Our PVL-positive CO-MRSA strains carry SCCmec types other than types IV and V. Due to the presence of PVL-positive strains in the hospitals, it is important to establish appropriate infection control measures to prevent their spread in the community and in hospitals.

[The therapeutic effect of normobaric oxygen in experimental peritonitis and the efficiency of rectal fever, WBC, CRP and procalcitonin in monitoring response of the therapy]. / Normobarik oksijenin deneysel peritonitin tedavisindeki yeri ve tedavinin izlenmesinde rektal ates, lökosit, CRP ve prokalsitoninin etkinligi.

BACKGROUND: It was investigated the effect of using normobaric oxygen (NO) in addition to antibiotherapy in experimental peritonitis and the changes of rectal fever (RF), WBC, CRP and procalcitonin levels were evaluated. METHODS: After the preliminary research of the normal values, rats were infected by E. coli intraperitoneally. Four groups were assigned into "no therapy", "given NO", "given antibiotic", "given antibiotic + NO" groups. RESULTS: The decline of RF and WBC levels on 3rd and 5th days was recorded in antibiotic + NO group versus the other groups. It was observed that group 4 was superior to the others. The positivity of periton cultures and the inflammation in the muscle were found to be less in antibiotic + NO group. No correlation was found between pathological and microbiological recovery and blood CRP level in all groups. But a significant decrease in blood procalcitonin level was determined in group 4 compared to the other groups. On day 3, procalcitonin and CRP levels increased with increasing WBC levels. On day 5, procalcitonin levels also decreased in groups with decreased WBC levels, but no significant correlation was found between CRP and WBC levels. CONCLUSION: It was concluded that using of NO in addition to antibiotherapy could increase the success rate of experimental intraabdominal sepsis therapy and blood procalcitonin and WBC levels could be more beneficial than CRP levels in monitoring of the severity of the sepsis.

Comparison of polymerase chain reaction and conventional methods in detecting methicillin-resistant Staphylococcus aureus.

BACKGROUND: Accurate and rapid detection of methicillin-resistant Staphylococcus aureus is very important in a clinical laboratory setting to avoid treatment failure. Conventional methods were compared against the gold standard polymerase chain reaction (PCR) technique to determine the best combination of the routine procedures. METHODOLOGY: Methicillin resistance was investigated in 416 clinical Staphylococcus aureus isolates by PCR, oxacillin agar screening (OAS), oxacillin disk diffusion (ODD) and cefoxitin disk diffusion (CDD) methods. RESULTS: Two hundred and ten (51%) out of 416 S. aureus strains were found to be mecA-positive by PCR. Sensitivity and specificity of the ODD, CDD and OAS methods were detected as follows: 100% and 89%, 99.50% and 100%, and 99.50% and 100%, respectively. CONCLUSION: Combining the ODD and CDD methods could be a good choice for detecting methicillin resistance in S. aureus strains where mecA PCR cannot be performed.

[Mupirocin resistance in methicillin-resistant Staphylococcus aureus strains isolated from wound infections]. / Yaralardan izole edilen metisiline dirençli Staphylococcus aureus suslarinda mupirosin direncinin arastirilmasi.

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important pathogen in community-acquired and nosocomial infections. The unique bactericidal action of mupirocin makes it one of the few antibiotics still effective against MRSA. The purpose of this study was to investigate the mupirocin resistance in MRSA strains isolated from wound infections of in- and out-patients of two distinct hospitals located in Ankara and Istanbul. A total of 143 MRSA strains were included in the study. Mupirocin resistance was investigated by Kirby-Bauer disk diffusion method and the results were confirmed by determination of the MIC values by E-test strips. Among 143 MRSA isolates, mupirocin resistance was detected by none of the methods, and overall mupirocin sensitivity was detected as 100 percent. The majority of mupirocin resistant MRSA is isolated from wound infections. The aetiology mostly depends on the increased topical use of the agent. The method used in the detection of mupirocin resistance and interpretation of the results are important parameters in the determination of mupirocin resistance in MRSA strains. Since there was no resistant strain among 143 clinical isolates obtained from two different hospitals, it was concluded that, mupirocin resistance is not an important problem in these regions currently, and mupirocin may be safely used in treating wound infections.