Deniz Gür

OXA-11, an extended-spectrum variant of OXA-10 (PSE-2) beta-lactamase from Pseudomonas aeruginosa.

Pseudomonas aeruginosa 455, isolated in Ankara, Turkey, produced a pI 6.2 beta-lactamase determined by plasmid pMLH53 and resisted all beta-lactams except carbapenems. This beta-lactamase, named OXA-14, corresponded to OXA-10 (PSE-2) except that aspartate replaced glycine at position 157 and thus is intermediate between OXA-10 and OXA-11, which has aspartate at position 157 and a further substitution at position 143.

Quinolones in treatment of human brucellosis: comparative trial of ofloxacin-rifampin versus doxycycline-rifampin.

Quinolones have been reported to be active against Brucella species in vitro. In this prospective randomized study, the efficacy and safety of the combination of ofloxacin plus rifampin were compared with the efficacy and safety of doxycycline plus rifampin, both combinations administered for a 6-week period in treatment of brucellosis. Sixty-one patients were enrolled in the study, and 49 had blood or bone marrow cultures positive for Brucella melitensis. Thirty patients received 200 mg of doxycycline plus 600 mg of rifampin once daily, and 31 patients were treated with 400 mg of ofloxacin plus 600 mg of rifampin once daily for 6 weeks. Nine patients in each group had complications of the disease. There was one therapeutic failure in the ofloxacin-rifampin treatment group, and one patient from each group relapsed (3.3% of those in the doxycycline-rifampin treatment group versus 3.2% of those in the ofloxacin-rifampin treatment group). Gastric discomfort was the major side effect observed in 13 patients (43.3%) who received doxycycline plus rifampin, whereas only 2 patients (6.5%) treated with ofloxacin plus rifampin complained of gastric irritation. These results suggest that the combination of ofloxacin plus rifampin administered for 6 weeks is as effective as doxycycline plus rifampin given for the same period, regardless of the presence of complications of the disease.

Geographic variation in the frequency of isolation and fluconazole and voriconazole susceptibilities of Candida glabrata: an assessment from the ARTEMIS DISK Global Antifungal Surveillance Program

Geographic differences in frequency and azole resistance among Candida glabrata may impact empiric antifungal therapy choice. We examined geographic variation in isolation and azole susceptibility of C. glabrata. We examined 23 305 clinical isolates of C. glabrata during ARTEMIS DISK global surveillance. Susceptibility testing to fluconazole and voriconazole was assessed by disk diffusion, and the results were grouped by geographic location: North America (NA) (2470 isolates), Latin America (LA) (2039), Europe (EU) (12 439), Africa and the Middle East (AME) (728), and Asia-Pacific (AP) (5629). Overall, C. glabrata accounted for 11.6% of 201 653 isolates of Candida and varied as a proportion of all Candida isolated from 7.4% in LA to 21.1% in NA. Decreased susceptibility (S) to fluconazole was observed in all geographic regions and ranged from 62.8% in AME to 76.7% in LA. Variation in fluconazole susceptibility was observed within each region: AP (range, 50-100% S), AME (48-86.9%), EU (44.8-88%), LA (43-92%), and NA (74.5-91.6%). Voriconazole was more active than fluconazole (range, 82.3-84.2% S) with similar regional variation. Among 22 sentinel sites participating in ARTEMIS from 2001 through 2007 (84 140 total isolates, 8163 C. glabrata), the frequency of C. glabrata isolation increased in 14 sites and the frequency of fluconazole resistance (R) increased in 11 sites over the 7-year period of study. The sites with the highest cumulative rates of fluconazole R were in Poland (22% R), the Czech Republic (27% R), Venezuela (27% R), and Greece (33% R). C. glabrata was most often isolated from blood, normally sterile body fluids and urine. There is substantial geographic and institutional variation in both frequency of isolation and azole resistance among C. glabrata. Prompt species identification and fluconazole susceptibility testing are necessary to optimize therapy for invasive candidiasis.

A prospective study of etiology of childhood acute bacterial meningitis, Turkey.

Vaccines to prevent bacterial meningitis in this region must provide reliable protection against serogroup W-135.

Antibiotic resistance in the southeastern Mediterranean--preliminary results from the ARMed project.

Sporadic reports from centres in the south and east of the Mediterranean have suggested that the prevalence of antibiotic resistance in this region appears to be considerable, yet pan-regional studies using comparable methodology have been lacking in the past. Susceptibility test results from invasive isolates of Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Enterococcus faecium and faecalis routinely recovered from clinical samples of blood and cerebrospinal fluid within participating laboratories situated in Algeria, Cyprus, Egypt, Jordan, Lebanon, Malta, Morocco, Tunisia and Turkey were collected as part of the ARMed project. Preliminary data from the first two years of the project showed the prevalence of penicillin non-susceptibility in S. pneumoniae to range from 0% (Malta) to 36% (Algeria) [median: 29%] whilst methicillin resistance in Staphylococcus aureus varied from 10% in Lebanon to 65% in Jordan [median: 43%]. Significant country specific resistance in E. coli was also seen, with 72% of isolates from Egyptian hospitals reported to be resistant to third generation cephalosporins and 40% non-susceptible to fluoroquinolones in Turkey. Vancomycin non-susceptibility was only reported in 0.9% of E. faecalis isolates from Turkey and in 3.8% of E. faecium isolates from Cyprus. The preliminary results from the ARMed project appear to support previous sporadic reports suggesting high antibiotic resistance in the Mediterranean region. They suggest that this is particularly the case in the eastern Mediterranean region where resistance in S. aureus and E. coli seems to be higher than that reported in the other countries of the Mediterranean.

Increasing carbapenem resistance due to the clonal dissemination of oxacillinase (OXA-23 and OXA-58)-producing Acinetobacter baumannii: report from the Turkish SENTRY Program sites

A significant increase in carbapenem-resistance rates among Acinetobacter baumannii isolates collected in two Turkish medical centres was detected in the 2000-2006 period (20-60 %) by the SENTRY Antimicrobial Surveillance Program. Carbapenem-resistant strains from 2006 were evaluated for the presence of encoding genes and epidemic clonality. OXA-58-like and OXA-23-like carbapenemase-producing strains were detected in both medical institutions. Seventeen out of 18 strains from Ankara were positive for blaOXA-58 primers and belonged to the same clone, whilst 26 isolates (25 from Istanbul and one from Ankara) harboured blaOXA-23-like genes and showed identical or similar PFGE patterns. Isolates producing OXA-23-like carbapenemases were more resistant than OXA-58-like carbapenemase producers to non-carbapenem antimicrobial agents. Carbapenem resistance in these institutions was observed to be largely driven by the dissemination of clones producing OXA-type carbapenemases.

Prevalence of antimicrobial resistance in Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Streptococcus pyogenes: results of a multicentre study in Turkey

The in vitro activities of several antimicrobial agents against clinical isolates of Streptococcus pneumoniae (283), Haemophilus influenzae (272), Moraxella catarrhalis (179) and Streptococcus pyogenes (256) were determined in a multicentre study with the participation of five hospitals from four cities in Turkey. Penicillin resistance in S. pneumoniae was evaluated using the E-test and the remaining agents by disk diffusion. For S. pneumoniae overall 25.8% of the isolates were intermediately and 3.9% were highly resistant to penicillin and resistance to chloramphenicol, azithromycin and trimethoprim/sulphamethoxazole (TMP/SMX) was 3.8, 2.1 and 55.4%, respectively. Seven percent of H. influenzae produced beta-lactamase and all were susceptible to cefotaxime and azithromycin; the highest rate of resistance, 23.5%, was for TMP/SMX. Eighty-one percent of M. catarrhalis isolates produced beta-lactamase, 18.4% were resistant to TMP/SMX and all were susceptible to sulbactam/ampicillin combination. Resistance to chloramphenicol and azithromycin of S. pyogenes was 2.2 and 1.9%, respectively.

Antimicrobial susceptibility testing of Campylobacter jejuni: a comparison between Etest and agar dilution method

The susceptibility of Campylobacter jejuni strains (n = 50) against nine antimicrobials were determined in comparison with Etest (AB BIODISK, Solna, Sweden) and agar dilution method to further investigate the correlation between the two methods. All the strains were isolated from stool samples of patients with diarrhea in 1998 and found to be highly susceptible (>84%) to ampicillin, tetracycline, gentamicin, chloramphenicol, ciprofloxacin and erythromycin. The essential agreement between two methods was 66.6% (+/-1 log(2) dilution) and 85.5% (+/-2 log(2) dilution). The agreement of susceptibility categories was higher at 94.4%.

Evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight

Abstract Background. Pre-term birth and/or low birth weight (PTLBW) is a serious problem in developing countries. The absence of known risk factors in ∼ 50% of PTLBW cases has resulted in a continued search for other causes. The aim of this study was to examine the effect of periodontitis on pregnancy outcomes. Methods. Samples were taken from 50 pregnant women who underwent amniocentesis. Polymerase chain reaction was performed on amniotic fluid samples obtained during amniocentesis and on subgingival plaque samples to determine the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens. Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level were evaluated. Medical records were obtained after birth. Results. Social and demographic variables were similar among the Gingivitis (G), Localized Periodontitis (LP) and Generalized Periodontitis (GP) groups. Four subjects gave birth to PTLBW neonates. Campylobacter rectus, T. forsythia, P. gingivalis and F. nucleatum were detected in the amniotic fluid and subgingival plaque samples of three patients who gave birth to PTLBW neonates. The amniotic fluid sample from the fourth patient was not positive for any of the tested pathogens. Conclusion. These findings suggest that the transmission of some periodontal pathogens from the oral cavity of the mother may cause adverse pregnancy outcomes. The results contribute to an understanding of the association between periodontal disease and PTLBW, but further studies are required to better clarify the possible relationship.

Comparison of Etest, microdilution and colorimetric dilution with reference broth macrodilution method for antifungal susceptibility testing of clinically significant Candida species isolated from immunocompromised patients

Summary. Amphotericin B and fluconazole macrodilution minimum inhibitory concentration values of 101 Candida strains isolated from 91 immunocompromised patients were comparatively evaluated with the results of Etest, microdilution and colorimetric microdilution methods. The overall agreement rates of Etest, microdilution and colorimetric microdilution method with the reference macrodilution method were found to be acceptably high after an incubation period of 24 and 48 h (varying from 86 to 93% for amphotericin B and from 84 to 89% for fluconazole). In addition, the results pointed out relatively high minimum inhibitory concentration values of fluconazole for Candida krusei and Candida glabrata isolates. These methods are not only reliable alternatives to the present reference macrodilution method but are also easy‐to‐perform and less time‐consuming.