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S Kocagöz

Publications and source records attributed to S Kocagöz.

At least 19 recordsLinked to original sources
PubMed2004

Bloodstream infections caused by Staphylococcus aureus in a university hospital in Turkey: clinical and molecular epidemiology of methicillin-resistant Staphylococcus aureus.

In total, 177 patients with bloodstream infections caused by Staphylococcus aureus (BSISA) were investigated prospectively between June 1999 and June 2001. Of these, 19.8% had community-acquired BSISA, while 80.2% had nosocomial BSISA. Surgical intervention, foreign body, mechanical ventilation, total parenteral nutrition, and previous antibiotic treatment were found to be important risk factors for the nosocomial BSISA group. Secondary BSISA formed a greater proportion (62.9%) of community-acquired infections than of nosocomial infections (26.8%; p 0.0001). Catheter-related nosocomial BSISA was observed in 72.1% of patients. The suppurative complication rate was significantly higher among community-acquired infections (22.9%) than among nosocomial infections (6.3%; p 0.008). Of the nosocomial BSISA, 65.5% were methicillin-resistant. Analysis of 80 methicillin-resistant S. aureus isolates by pulsed-field gel electrophoresis identified ten main clones (A-J), but 61 (76.3%) of the 80 isolates belonged to clone A.

Adult↗
PubMed2002

Outbreak of nosocomial fungemia caused by Candida glabrata.

An outbreak of Candida glabrata fungemia that was thought to be associated with bottles used for milk feeds occurred at our children's infectious diseases clinic. This cluster of cases was investigated using a case-control study. Isolates were identified by conventional methods and karyotyped using pulsed-field gel electrophoresis (PFGE) of genomic DNA. Potential risk factors for nine hospitalized children with candidemia and 14 controls were long-term hospitalization and treatments with more than two antibiotics. Electrophoretic karyotyping showed a single chromosomal pattern for these outbreak isolates and, in addition, they all had the same antifungal susceptibility results. These findings suggest that clonal dissemination of a single strain was responsible for this outbreak. Karyotyping by PFGE appears to be a useful molecular typing method for strains of C. glabrata.

Antifungal Agents↗
PubMed2002

In vitro activities of new quinolones against Brucella melitensis isolated in a tertiary-care hospital in Turkey.

We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucella melitensis. According to their minimum inhibitory concentration for 90% growth (MIC(90)) values, the most active agent was found to be sparfloxacin (MIC(90) 0.12 mg/L) followed by levofloxacin, ciprofloxacin, ofloxacin (MIC(90) 0.50 mg/L) and grepafloxacin (MIC(90) 1 mg/L), gemifloxacin (MIC(90) 2 mg/L) and gatifloxacin (MIC(90) 4 mg/L).

Anti-Infective Agents↗
PubMed2001

Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns.

Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

4-Quinolones↗
PubMed2001

Epidemiology of penicillin resistance in Streptococcus pneumoniae isolates in Kayseri, Turkey.

OBJECTIVE: To determine the penicillin resistance and serotype distribution of Streptococcus pneumoniae strains and to identify clonal relationships of isolates resistant to penicillin by means of pulsed-field gel electrophoresis (PFGE). METHODS: In total, 193 S. pneumoniae strains were isolated from clinical specimens between November 1997 and January 2000. Susceptibility testing was carried out by E test, and serotyping by the Quellung reaction. Clonal relationship was analyzed by using PFGE with smaI endonuclease. RESULTS: Of the S. pneumoniae isolates, 23% were intermediately resistant to penicillin. There were no high-level resistant pneumococci. The majority of isolates intermediately resistant to penicillin were of serogroups/serotypes 19, 23, 14 and 1, in descending order of frequency. There were eight major clones in strains intermediately resistant to penicillin. It was seen that serogroups in the 23-valent polysaccharide vaccine, 7-valent, 9-valent, and 11-valent vaccine formulations caused 92%, 75%, 78% and 87% of pneumococcal diseases in our region, respectively. CONCLUSION: Penicillin resistance in S. pneumoniae is relatively uncommon in Kayseri. All vaccine formulations can prevent the majority of pneumococcal diseases, and there is genetic heterogeneity in intermediately penicillin-resistant pneumococci in this region.

Electrophoresis, Gel, Pulsed-Field↗
PubMed2000

Susceptibility testing of voriconazole, fluconazole, itraconazole and amphotericin B against yeast isolates in a Turkish University Hospital and effect of time of reading.

Voriconazole is a promising azole effective against a variety of fungi, including yeasts. In this study, we tested in vitro activities of voriconazole, fluconazole, itraconazole and amphotericin B against some ATCC and reference strains and 250 clinical yeast isolates. We also evaluated the effect of time of reading on MIC results. Voriconazole was the most active agent against Candida and Trichosporon isolates, including the putatively fluconazole-resistant C. krusei (MIC(90) 0.25 microg/ml) and C. glabrata (MIC(90) 0.5 microg/ml). Amphotericin B MICs were scattered in a considerably narrow range in both RPMI 1640 and Antibiotic Medium 3. MICs at 24 hours and 48 hours were similar in general for all antifungals tested. The highest percentage of strains that showed 24-hour and 48-hour MICs within +/-1-log(2) dilution was observed for amphotericin B tested in RPMI (99%), and the lowest for amphotericin B tested in Antibiotic Medium 3 (80%). In conclusion, voriconazole is very effective against a wide spectrum of Candida species and 24-hour readings could substitute 48-hour MIC evaluation.

Amphotericin B↗
PubMed2000

Surveillance of antimicrobial resistance among gram-negative isolates from intensive care units in eight hospitals in Turkey.

With the participation of eight major reference hospitals in Turkey, 749 aerobic Gram-negative isolates obtained from 473 intensive care patients in 1997 were tested for their susceptibility to 13 commonly employed antibacterial agents. The frequency with which species were isolated and resistance rates were compared with data from the previous 2 years. Imipenem was the most active agent against the majority of isolates (75%), followed by ciprofloxacin, cefepime and amikacin. The per cent susceptibility to all antibiotics declined from 1995 to 1996. With the exception of imipenem, for which there was no change in resistance, the per cent susceptibility somewhat increased in 1997. However, it was still lower than in 1995.

Anti-Bacterial Agents↗
PubMed2000

Analysis of a mini-outbreak of methicillin-resistant Staphylococcus aureus in a surgical ward by using arbitrarily primed-polymerase chain reaction.

In November 1995, an increase was noticed in the number of methicillin-resistant Staphylococcus aureus (MRSA) isolates from a surgical ward at Hacettepe University Hospital. All MRSA isolates obtained from clinical specimens in this ward (14 MRSA isolates from wound cultures of 10 patients) were collected prospectively for 10 weeks. Surveillance cultures were taken from ward personnel (nose cultures from 4 physicians, 7 nurses, 1 secretary, 1 waiter), 2 surgical dressing containers and 1 nebulizer. MRSA was isolated from one of the surgical dressing containers, the nebulizer and nose cultures of 3 physicians, 3 nurses and the ward secretary. Arbitrarily primed polymerase chain reaction (AP-PCR) analysis showed that most MRSA isolates belonged to 2 major clones (pattern A, pattern B). Pattern A was the most frequent one and was present in 4 clinical isolates, surgical dressing container-1. Pattern B was identified in 3 clinical isolates and nose culture of physician-3. AP-PCR analysis revealed that this mini-MRSA outbreak was caused by contamination of surgical dressing container with MRSA and nasal MRSA carriage in ward staff. AP-PCR seems to be a valuable typing method for analysis of nosocomial MRSA outbreaks because of its simplicity and rapidity.

Adolescent↗
PubMed2000

Antimicrobial resistance of gram-negative isolates from intensive care units in Turkey: comparison to previous three years.

Resistance rates to selected antibiotics of gram-negative bacteria isolated from intensive care units (ICU) of 16 Turkish hospitals during 1998 were evaluated and compared to data from the previous 3 years. Antibiotic susceptibilities to imipenem, ceftazidime, ceftazidime-clavulanate, cefoperazone-sulbactam, ceftriaxone, cefepime, cefodizime, cefuroxime, piperacillin-tazobactam, ticarcillin-clavulanate, gentamicin, amikacin and ciprofloxacin were determined by Etest. A total of 1,404 isolates from 1,060 patients were collected, mainly from urinary and respiratory tracts. As in the previous 3 years, Pseudomonas spp. was the most frequently isolated gram-negative species (29.7%), followed by Escherichia coli, Acinetobacter and Klebsiella spp. Imipenem was the most active in vitro agent (73.4% susceptible), followed by ciprofloxacin (60.6%), cefoperazone-sulbactam (58.7%), cefepime (56.7%), piperacillin-tazobactam (55.0%) and amikacin (54.7%). In 1996, a decline in susceptibility rates of all antibiotics was evident. With the exception of imipenem, resistance to which remained stable, rates somewhat increased in 1997. In 1998, susceptibility to imipenem and cefepime remained stable, amikacin resistance tended to increase and susceptibility rates to other antibacterials showed a favorable increase. These results may in part be due to the implementation of a surveillance program and increased understanding of the magnitude of the resistance problem.

Anti-Bacterial Agents↗
PubMed1999

A surveillance study of antimicrobial resistance of gram-negative bacteria isolated from intensive care units in eight hospitals in Turkey.

This study was carried out with the participation of eight hospitals in Turkey to determine the frequency of gram-negative bacteria isolated in intensive care units (ICU) and to compare their resistance rates to selected antibiotics. Aerobic gram-negative bacteria isolated from ICUs during 1996 were studied. Antibiotic susceptibilities to imipenem, ceftazidime, ceftazidime-clavulanate, ceftriaxone, cefotaxime, cefepime, cefodizime, cefuroxime, piperacillin/tazobactam, amoxycillin-clavulanate, gentamicin, amikacin and ciprofloxacin were determined by Etest. A total of 748 isolates were obtained from 547 patients. The majority of organisms were isolated from the respiratory (38.8%) and urinary tracts (30.9%). Pseudomonas spp. were the most frequently isolated gram-negative species (26.8%), followed by Klebsiella spp. (26.2%). Escherichia coli, Acinetobacter spp. and Enterobacter spp. were the other commonly isolated organisms. High resistance rates were observed for all antibiotics studied. Imipenem appeared to be the most active agent against the majority of isolates. Although resistance rates exceeded 50%, ciprofloxacin, cefepime and amikacin were found to be relatively effective. Extended-spectrum beta-lactamase (ESBL) production appeared to be a major mechanism of resistance to beta-lactam antibiotics. In contrast to ceftazidime-clavulanate, piperacillin/tazobactam showed poor activity against organisms thought to produce ESBL, suggesting the presence of an enzyme resistant to tazobactam action. This study has yielded high rates of resistance in aerobic gram-negative isolates from ICUs in Turkey. High resistance rates to all the other antibacterials studied leave imipenem as the only reliable agent for the empirical treatment of ICU infections in Turkey.

Drug Resistance, Microbial↗
PubMed1998

Comparison of cytochemical staining, immunofluorescence and PCR for diagnosis of pneumocystis carinii on sputum samples.

Detection of P. carinii has increased with the use of polymerase chain reaction (PCR), particularly in sputum samples. In this study, sputum samples obtained from 30 immunosuppressed patients with respiratory symptoms (12 HIV-infected) were tested by standard cytochemical staining (Giemsa and methenamine silver), immunofluorescence (IF) staining and PCR for detection of P. carinii and the results were compared. Pneumocystis carinii was detected in 4, 8 and 13 sputum samples by cytological staining, IF test and PCR, respectively. Specific amplification bands were obtained in all sputum samples that were positive by both other tests. All tests gave negative results in sputum samples obtained from 5 HIV-infected asymptomatic patients and 22 non-immunosuppressed tuberculosis patients. Our observations suggest that PCR results were well correlated with P. carinii pneumonia (PCP), especially in non-HIV-infected patients. However, PCR positivity obtained in HIV-infected patients could be misleading in the diagnosis of PCP without careful clinical evaluation. Positive results obtained by Giemsa staining or IF test confirm diagnosis of PCP authoritatively. As a result, we suggest testing sputum samples by both PCR and IF techniques for detection of P. carinii.

AIDS-Related Opportunistic Infections↗
PubMed1997

In vitro activity of a new echinocandin, LY303366, compared with those of amphotericin B and fluconazole against clinical yeast isolates.

The in vitro activity of LY303366, a new echinocandin derivative, was evaluated with 191 yeast isolates by a broth microdilution method. The MICs at which 50% of the isolates were inhibited were 0.125 microg/ml for Candida albicans and C. tropicalis, 0.25 microg/ml for C. krusei, C. kefyr, and C. glabrata, and 2.0 microg/ml for C. parapsilosis.

Amphotericin B↗
PubMed1995

Can penicillins and other beta-lactam antibiotics be used to treat tuberculosis?

An increase in the number of tuberculosis cases caused by multiple-drug-resistant strains of Mycobacterium tuberculosis has stimulated search for new antituberculous agents. Beta-lactam antibiotics, traditionally regarded as ineffective against tuberculosis, merit consideration. Four major penicillin-binding proteins (PBPs) with approximate molecular sizes of 94, 82, 52, and 37 kDa were detected by fluorography of [3H]penicillin-radiolabeled membrane proteins prepared from M. tuberculosis H37Ra. The presence of membrane-associated beta-lactamase precluded the use of membranes for assaying the binding affinities of beta-lactam antibiotics. Therefore, ampicillin affinity chromatography was used to purify these four PBPs from crude membranes in order to assay the binding affinities of beta-lactam antibiotics. Ampicillin, amoxicillin, and imipenem, beta-lactam antibiotics previously reported to be active in vitro against M. tuberculosis, bound to M. tuberculosis PBPs at therapeutically achievable concentrations. Binding of the 94-, 82-, and 52-kDa PBPs, but not the 37-kDa PBP, was associated with antibacterial activity, suggesting that these PBPs are the critical targets. Studies of mycobacterial cell wall permeability, which was assayed with a panel of reference cephalosporins and penicillins with different charge positivities, indicated that the rate of penetration of beta-lactam antibiotics to the target PBPs could not account for resistance. Resistance could be reversed with the beta-lactamase inhibitors clavulanate or sulbactam or could be circumvented by the use of a beta-lactamase-stable drug, imipenem, indicating that mycobacterial beta-lactamase, probably in conjunction with slow penetration, is a major determinant of M. tuberculosis resistance to beta-lactam antibiotics. These findings confirm in vitro data that M. tuberculosis is susceptible to some beta-lactam antibiotics. Further evaluation of these drugs for the treatment of tuberculosis in animal models and in clinical trials is warranted.

Animals↗
PubMed1993

Detection of Mycobacterium tuberculosis in sputum samples by polymerase chain reaction using a simplified procedure.

A repetitive sequence of Mycobacterium tuberculosis DNA was amplified by polymerase chain reaction (PCR), from sputum samples, for the diagnosis of pulmonary tuberculosis. The method of heating the sample in a boiling water bath to break down the bacterial cell wall and to release the DNA was compared with that of enzymatic lysis of bacteria and then phenol-chloroform extraction of DNA. Heating the sample was the better method with a sensitivity of approximately 10 microorganisms. A total of 78 sputum specimens prepared by heating were examined by PCR, and the results were compared with the results of acid-fast stained smears, cultures, and clinical data. M. tuberculosis was detected by PCR in all smear- and culture-positive and smear-negative, culture-positive cases. Additionally, PCR was capable of detecting four of nine cases which were smear and culture negative but clinically suspected of tuberculosis. DNA amplification by PCR is a sensitive and specific method for the diagnosis of tuberculosis, and with this simplified DNA isolation procedure it can be used in routine clinical practice.

Bacteriological Techniques↗
PubMed1988

[A new rapid antibiotic susceptibility test for enteric bacteria using a color change method].

The rapid antibiotic susceptibility tests that have been developed so far cannot be used in daily work, because of their many difficulties and disadvantages. We have developed a new antibiotic susceptibility test for enteric bacteria which gives the result in 4 hours, easy to perform and inexpensive. This method depends upon the mechanism which detects the acid formed by the bacteria, by the change of the color of the pH indicator in the medium. The susceptibility of 110 different isolates of enteric bacteria (E. coli, Klebsiella, Salmonella, Shigella, Proteus, Enterobacter) to ampicillin, amikacin, trimethoprim-sulfamethoxazole, cephradine, cefazolin, erythromycin, gentamicin, and ofloxacin is examined by this new "Rapid Color Change Test" and disc diffusion method. For most organisms tested, there was a good correlation between the results of the two methods. The overall agreement is found to be 91.43%.

Anti-Bacterial Agents↗