Nevriye Gönüllü

Dissemination of CTX-M-15 β-Lactamase Genes Carried on Inc FI and FII Plasmids among Clinical Isolates of Escherichia coli in a University Hospital in Istanbul, Turkey

ABSTRACT The CTX-M-1 group was found in 86.8% of the Escherichia coli isolates from Istanbul. A subset study revealed all isolates carrying blaCTX-M-15 genes flanked by the insertion element ISEcp1. Plasmid typing of transconjugates carrying blaCTX-M-15 showed that most isolates belonged to the Inc/rep FII group but that one isolate also belonged to the FI group.

Ralstonia pickettii Traced in Blood Culture Bottles

ABSTRACT Over a 9-month period, 14 strains of Ralstonia pickettii were isolated from various biological samples inoculated in a blood culture medium. Molecular epidemiological investigation confirmed the relatedness of the strains. The source of the contamination proved to be the blood culture bottle caps.

In vitro activity of telithromycin compared with macrolides and fluoroquinolones against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis.

The in vitro activity of telithromycin was compared with erythromycin A, azithromycin, clarithromycin, moxifloxacin, gemifloxacin, levofloxacin, ciprofloxacin, penicillin G, ampicillin, cefuroxime and ceftriaxone against 336 consecutive strains (83 Streptococcus pneumoniae, 168 Haemophilus influenzae and 85 Moraxella catarrhalis) isolated from patients with community-acquired respiratory tract infections. Telithromycin (MIC(90), 0.008 mg/l) was the most active drug against S. pneumoniae. Telithromycin was also highly active against M. catarrhalis (MIC(90), 0.06 mg/l), but less active against H. influenzae (MIC(90), 4 mg/l).

Use of INNO-LIPA assay for rapid identification of mycobacteria.

Using 106 clinical isolates of mycobacteria, we showed that INNO-LIPA Mycobacteria assay is an excellent tool to rapidly identify the most frequently isolated nontuberculous mycobacteria, in one procedure. It may be used as an additional technique to AccuProbe assay, which remains the fastest and the cheapest tool for a rapid and accurate identification of the M. tuberculosis complex.

Comparison of in vitro activities of tigecycline with other antimicrobial agents against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in two university hospitals in Istanbul, Turkey.

Background: We compared the in vitro activities of tigecycline with those of other agents against 97 Streptococcus pneumoniae, 140 Haemophilus influenzae and54 Moraxella catarrhalis strains isolated in two large university hospitals in Istanbul. Methods: For analysis, the agar dilution method was used. Results: For S. pneumoniae isolates, 32% were not susceptible to penicillin (28.9% intermediate and 3.1% resistant). Cefotaxime, telithromycin, moxifloxacin and linezolid were fully active. Tigecycline had a 90% minimum inhibitory concentration (MIC90) of 0.12 μg/ml. For H. influenzae, 8.57% were not susceptible to ampicillin, among which 8 possessed β-lactamase (5.7%). Four (2.87%) H. influenzae isolates with β-lactamase-negative and ampicillin-resistant phenotype were found. All isolates were susceptible to ceftriaxone, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin. MIC90 for tigecycline was 0.5 μg/ml. Of 54 M. catarrhalis isolates, 88.9% possessed β-lactamase. Tigecycline and fluoroquinolones were highly active (MIC90 ≤0.12 μg/ml). Conclusions: Linezolid, telithromycin, newer fluoroquinolones and tigecycline all have excellent in vitro activities against the 3 respiratory pathogens.

Susceptibilities of Neisseria gonorrhoeae and Ureaplasma urealyticum isolates from male patients with urethritis to several antibiotics including telithromycin.

Background: The minimal inhibitory concentrations (MICs) of erythromycin, azithromycin, clarithromycin, telithromycin, tetracycline, doxycycline, ciprofloxacin, ofloxacin, norfloxacin, levofloxacin, gemifloxacin and moxifloxacin against 78 Neisseria gonorrhoeae and 31 Ureaplasma urealyticum strains, which were isolated from patients with urethritis in Istanbul, were determined and compared. Additionally, the activities of penicillin and ceftriaxone against N. gonorrhoeae strains were explored. Methods: MICs were determined by agar and broth dilution methods for N. gonorrhoeae and U. urealyticum, respectively. Results: The susceptibility rates for penicillin and tetracycline in N. gonorrhoeae strains were 35.9 and 24.3%, respectively. All gonococcal strains were susceptible to ceftriaxone, with very low MICs (MIC90 0.008 µg/ml). Telithromycin was highly active against N. gonorrhoeae and U. urealyticum strains (MIC90 0.25 µg/ml for both). Ciprofloxacin was the most active quinolone against N. gonorrhoeae (MIC90 0.008 µg/ml) while quinolone resistance was detected in a single strain (1.3%). Conclusions: Tetracycline and penicillin should not be the option in empirical treatment of N. gonorrhoeae infections due to the very low susceptibility rates. Ceftriaxone continues to be the first choice antibiotic in the treatment of gonococcal urethritis.

Phenotypes and Genotypes of Macrolide-Resistant Streptococcus Pneumoniae

BACKGROUND Macrolide resistance in Streptococcus pneumoniae (S. pneumoniae) is a worldwide problem. AIMS The aim of this work was to analyze the phenotypes, genotypes, and clonal relatedness among macrolide-resistant S. pneumoniae strains isolated from various clinical specimens in our hospital. STUDY DESIGN Cross-sectional study. METHODS 80 non-duplicate S. pneumoniae strains were analyzed by polymerase chain reaction for both the erm (B) and mef (A) genes. RESULTS Macrolide resistance was observed in 22.5% (18 strains) of strains. Two (11.2%) isolates possessed mef (A), eight possessed erm (B) (44.4%) and eight strains (44.4%) were positive for both erm (B) and mef (A) genes. Although BOX-PCR of 18 macrolide-resistant strains revealed 11 band patterns, they clustered as seven clones with a genetic distance >10% to each other. Eight isolates possessed both erm (B) and mef (A) genes and belonged to a single clone (44.44% of all macrolide-resistant strains). CONCLUSION Increased positivity rates for both resistance genes have also been reported from other hospitals in Turkey, but this is the first study from Turkey showing the clonal dissemination of both resistance genes.

Oropharyngeal flora changes after tonsillectomy

Objective: We aimed to investigate the effect of tonsillectomy on oropharyngeal flora in children who underwent tonsillectomy for chronic recurrent tonsillitis. Study Design and Setting: A prospective study was performed comprising patients with chronic recurrent tonsillitis who underwent tonsillectomy at the Department of Otolaryngology, Cerrahpasa Medical School. Incisional core biopsies of excised tonsils were also performed. Swabs and core biopsy specimens were transferred and maintained in Stuarts medium and sent to the Department of Microbiology and Clinical Microbiology at Cerrahpasa Medical School for microbiologic evaluation. Subjects and Methods: Oropharyngeal swabs and tonsillar core biopsy specimens from 31 patients operated on for recurrent tonsillitis were cultured. Follow-up oropharyngeal swabs were cultured one month after tonsillectomy. Results: There was no significant difference between the preoperative and postoperative isolation rate of the potentially pathogenic bacteria. Normal aerobic flora did not change significantly. However, the isolation rate of the Neisseria species dropped (P = 0.097) but did not reach statistical significance. Among anaerobes, Bacteroides fragilis, one of the major anaerobic bacteria, dropped significantly (P = 0.007). The Propionibacterium acnes isolation rate increased significantly (P = 0.009). Conclusion: Oropharyngeal anaerobic bacterial flora decreases after tonsillectomy in recurrent tonsillitis patients. The isolation rate for bacteria of the normal flora and potentially pathogenic bacteria does not change. Tonsils with recurrent infections may become a nidus for anaerobic bacteria. In patients with chronic recurrent tonsillitis, tonsillectomy may help change anaerobic bacterial oropharyngeal flora to the normal flora found in healthy individuals.

Moxifloxacin activity against clinical isolates compared with the activity of ciprofloxacin.

The activity of moxifloxacin, a new 8-methoxyquinolone, was compared in vitro with the activity of ciprofloxacin against clinical strains isolated from various sites of infection. The mode MIC values of moxifloxacin were superior to those of ciprofloxacin against Streptococcus pneumoniae, methicillin-susceptible and -resistant Staphylococcus aureus, Enterococcus spp., Escherichia coli and Acinetobacter spp., while ciprofloxacin was more active against Klebsiella pneumoniae and Pseudomonas spp. Both antibiotics had similar activity against Haemophilus influenzae, Moraxella catarrhalis and Enterobacter spp.

Effect of nasal mometasone furoate on the nasal and nasopharyngeal flora

OBJECTIVE Mometasone furoate (MF) is one of the commonly used topical steroids, particularly for patients with allergic rhinitis. However, its effect on the colonization of bacteria that may cause superinfections by suppressing the local immunity is not known. Thus, we investigated the effect of MF use on the nasal and nasopharyngeal microbial flora. MATERIALS AND METHODS Swab samples were taken from 35 patients who required MF monotherapy, just before and after one month of the treatment. Samples were maintained in Stuarts medium. Each swab was transferred to 1ml of a sterile saline solution, then into the standard agar. After incubation under 5% carbon dioxide at 37°C, colony number was detected per ml. RESULTS Colony counts of nasal or nasopharyngeal microbial flora did not show any statistically significant alteration with one month use of MF. However, an increase in potential pathogens as well as normal flora bacteria was determined in five of the patients and six patients acquired new nasopharyngeal potential pathogens, mostly Moraxella catarrhalis, Pseudomonas aeruginosa and Staphylococcus aureus, following the use of MF. CONCLUSION The use of MF for one month did not statistically significantly change the nasal and nasopharyngeal flora. This study indicates that MF could be increase the colonization of the potential pathogens in some of the patients at the subclinical level particularly in the nasopharyngeal area.