Abdurrahman Kiremitci

Optimum Detection Times for Bacteria and Yeast Species with the BACTEC 9120 Aerobic Blood Culture System: Evaluation for a 5-Year Period in a Turkish University Hospital

ABSTRACT We tracked and documented the time of positivity of blood cultures by using the BACTEC 9120 (Becton Dickinson Diagnostic Instrument Systems) blood culture system over a 5-year study period. A 7-day protocol of the incubation period was selected, and a total of 11,156 blood cultures were evaluated. The clinically significant microorganisms (32.95%) were isolated in 3,676 specimens. Gram-positive and -negative bacterial isolation rates were found to be 41.07 and 44.88%, respectively. Yeasts were found in 14.03% of all pathogens. Both the false-positivity and -negativity rates were very low (0.1 and 0.3%, respectively). The mean detection times for all of the pathogens were determined to be 19.45 h. Yeasts, nonfermentative gram-negative bacteria, and Brucella melitensis strains were isolated within 5 days. By taking these data into account, we decided to establish a 5-day-incubation protocol in our laboratory instead of the 7 days that are commonly used.

Frequency and risk factors of dermatophytosis in students living in rural areas in Eskişehir, Turkey.

Our study included 2384 students from five villages around Eskişehir, Turkey. We asked every student for their personal identification and also for their sanitation in order to get an idea about dermatophytosis. Samples taken from suspicious lesion were collected and inoculated onto Sabouraud dextrose agar slants. For identification of fungi which were grown, macroscopic appearance of colonies, microscopic examination and biochemical tests were used. We found suspicious lesions in 245 (10.3%) and diagnosed dermatophytosis in 86 (3.6%) of the students. The dermatophyte species were Trichophyton rubrum 37 (43%) at first, Trichophyton mentagrophytes 17 (19.8%), Microsporum canis 11 (12.8%), Microsporum gypseum 8(9.3%), Epidermophyton floccosum 6 (7%), Trichophyton verrucosum 6 (7%) and Trichophyton violaceum 1 (1.1%). Tinea pedis (59.3%) was the most frequent clinic form of dermatophytosis, followed by tinea corporis (22.1%), tinea capitis (9.3%), tinea manum (7.0%) and tinea unguium (2.3%). Older age, male gender, poor hygiene, living in dormitory, low level mother education, history of dermatophytosis within family and sanitary conditions were computed as independently variables associated with dermatophytosis infection. For prevention and control of dermatophyte infection in children living rural areas, field studies should be done and sanitary conditions should be improved.

Antifungal Activity of Caspofungin in Combination with Amphotericin B against Candida glabrata: Comparison of Disk Diffusion, Etest, and Time-Kill Methods

ABSTRACT The in vitro activities of caspofungin plus amphotericin B against 50 Candida glabrata isolates were evaluated by the time-kill, disk diffusion, and Etest methods. In vitro experiments showed a positive interaction. Even though each of these methods uses different conditions and endpoints, the results of the different methods frequently agreed.

Correlation between broth microdilution and disk diffusion methods for antifungal susceptibility testing of caspofungin, voriconazole, amphotericin B, itraconazole and fluconazole against Candida glabrata

Candida glabrata is one of the most frequent organisms isolated from superficial and invasive fungal infections, after Candida albicans. This organism also exhibits intrinsically low susceptibility to azole antifungals and treatment often fails. The microdilution method is not very practical for use in routine susceptibility testing in the clinical laboratory, thus necessitating the use of other methods. In this study, we compared the in vitro activity of five antifungal agents in three different groups (echinocandin, polyene and azole) against 50 C. glabrata isolates by broth microdilution and disk diffusion methods recommended by Clinical Laboratory Standards Institute CLSI M27-A3 and CLSI M44-A, respectively. All the isolates were susceptible to amphotericin B (100%) and 98% of the isolates were susceptible to caspofungin by the broth microdilution method. Within the azole group drugs, voriconazole was the most active followed by fluconazole and itraconazole in vitro. The highest rate of resistance was obtained against itraconazole with a high number of isolates defined as susceptible-dose dependent or resistant. Although the disk diffusion method is easy to use in clinical laboratories, it shows very poor agreement with the reference method for fluconazole and itraconazole against C. glabrata (8% and 14%, respectively).

Tigecycline treatment of multi-drug-resistant Corynebacterium jeikeium infection in a child with relapsing and refractory acute lymphoblastic leukemia.

Corynebacterium jeikeium has been recognized as an important cause of infection, particularly among neutropenic patients who have central venous catheter (CVC). Routine use of tigecycline in children is not yet approved. Here in we present a child with relapsed‐refractory lymphoblastic leukemia who was successfully treated with tigecyline due to multi‐drug‐resistant C. jeikeium sepsis without removal of CVC. Our case highlights the use of tigecycline where there are no alternatives. Further studies regarding the efficacy and safety of tigecycline in pediatric patients are needed. Pediatr Blood Cancer. 2010;55:349–351.

Evaluation of the GenoType Mycobacteria Direct assay for direct detection of the Mycobacterium tuberculosis complex obtained from sputum samples.

An increase in the prevalence of tuberculosis (TB) in recent years has accelerated the search for novel tools for the rapid diagnosis of TB infection. This study evaluated the GenoType Mycobacteria Direct (GTMD) assay (Hain Lifescience) for direct detection of the Mycobacterium tuberculosis complex (MTBC) from sputum samples and compared it with conventional methods. The GTMD test is a commercial assay produced using strip techniques and works based on a nucleic acid sequence-based amplification technique. This test allows 23S rRNA amplification-based detection of MTBC, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium kansasii and Mycobacterium malmoense directly from decontaminated clinical samples within 6 h. In the present study, 115 sputum samples were processed to detect acid-fast bacilli (AFB) using two microscopy methods (carbol fuchsin and fluorescent staining), two culture methods [Löwenstein-Jensen (LJ) and BACTEC 12B media] and the GTMD test. The results showed that 86 of the samples were positive by direct microscopy, 84 were positive by BACTEC 12B culture, 73 were positive by LJ culture and 95 were positive by the GTMD test. All of the isolates turned out to be MTBC. Moreover, the sensitivity and specificity of the GTMD test for MTBC in patients were 97 and 58 %, respectively, taking the culture combination as the gold standard. When the test was compared with culture of samples from anti-TB-treated patients, the sensitivity and specificity for the test were 100 and 15 %, respectively. Low specificity in treated people might arise from depressed proliferation of AFB. As the two methods target the same living bacilli, the difference is obviously notable. When the culture results and clinical findings of the patients were evaluated together (true-positive specimens), the sensitivity and specificity values of the GTMD test for all patients were 97 and 90 %, respectively. However, both of these values increased to 100 % for the patients receiving anti-TB treatment. These results implied that, to determine whether the patients sputum contains living AFB, more sensitive techniques should be employed during the follow-up of the patients. These observations suggest that the GTMD method can be useful for early diagnosis of clinically and radiologically suspicious TB cases where smears are negative for Mycobacterium. In addition, the use of a GTMD test in smear-positive cases is helpful and practical in order to identify MTBC quickly. This allows more rapid treatment decisions and infection control precautions.

Synergistic Activities of Three Triazoles with Caspofungin against Candida glabrata Isolates Determined by Time-Kill, Etest, and Disk Diffusion Methods

ABSTRACT Combinations of voriconazole, fluconazole, and itraconazole with caspofungin were evaluated against 50 Candida glabrata isolates by the time-kill, disk diffusion, and Etest methods. The majority of antifungal combinations were indifferent. By the time-kill method, synergistic activity was detected with eight (16%) of the caspofungin-voriconazole and seven (14%) of the caspofungin-fluconazole combinations, but synergy was not seen with the caspofungin-itraconazole combination. Further comparisons of the Etest and disk diffusion synergy techniques with the time-kill method are warranted.

Silver ion doped ceramic nano-powder coated nails prevent infection in open fractures: In vivo study §

BACKGROUND Despite improvement in operative techniques and antibiotic therapy, septic complications still occur in open fractures. We developed silver ion containing ceramic nano powder for implant coating to provide not only biocompatibility but also antibacterial activity to the orthopaedic implants. QUESTIONS/PURPOSES We hypothesised silver ion doped calcium phosphate based ceramic nano-powder coated titanium nails may prevents bacterial colonisation and infection in open fractures as compared with uncoated nails. METHODS 33 rabbits divided into three groups. In the first group uncoated, in the second group hydroxyapatite coated, and in the third group silver doped hydroxyapatite coated titanium nails were inserted left femurs of animals from knee regions with retrograde fashion. Before implantation of nails 50 μl solution containing 10(6)CFU/ml methicillin resistance Staphylococcus aureus (MRSA) injected intramedullary canal. Rabbits were monitored for 10 weeks. Blood was taken from rabbits before surgery and on 2nd, 6th and 10th weeks. Blood was analysed for biochemical parameters, blood count, C-reactive protein and silver levels. At the end of the 10 weeks animals were sacrificed and rods were extracted in a sterile fashion. Swab cultures were taken from intramedullary canal. Bacteria on titanium rods were counted. Liver, heart, spleen, kidney and central nervous tissues samples were taken for determining silver levels. Histopathological evaluation of bone surrounding implants was also performed. RESULTS No significant difference was detected between the groups from hematologic, biochemical, and toxicological aspect. Microbiological results showed that less bacterial growth was detected with the use of silver doped ceramic coated implants compared to the other two groups (p=0.003). Accumulation of silver was not detected. No cellular inflammation was observed around the silver coated prostheses. No toxic effect of silver on bone cells was seen. CONCLUSION Silver ion doped calcium phosphate based ceramic nano powder coating to orthopaedic implants may prevents bacterial colonisation and infection in open fractures compared with those for implants without any coating.

In vitro activity of ertapenem and other carbapenems against extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae clinical isolates in a tertiary care center in Turkey.

Objective: To evaluate the in vitro effect of ertapenem, imipenem and meropenem in clinical isolates of extended-spectrum β-lactamase (ESBL)-producing strains of Escherichia coli and Klebsiella pneumoniae. Design/methods: We studied 82 consecutive clinical isolates of ESBL-producing E. coli (n = 49) and K. pneumonia (n = 33) between February 2006 and September 2007. The minimum inhibitory concentration for each carbapenem was determined using the agar dilution method. Results: Eighty two consecutive microorganisms from sterile sites were evaluated. A total of 48.8% of patients had a history of surgical intervention, 78.0% needed urinary catheterization, 57.3% required vascular access and 40.3% mechanical ventilation; and 70.7% had a history of ICU stay. High resistance rates were shown for both E. coli and K. pneumoniae against cefepime (81.7%), ciprofloxacin (50.9%), tetracycline (75.0%), co-trimoxazole (47.4%), and gentamicin (48.7%). In addition, most K. pneumoniae and E. coli isolates were susceptible to amikacin (78.3%) and piperacilline-tazobactam (91.5%). Meropenem and imipenem showed activity against 100% of the isolates. Ertapenem showed activity against 100% of K. pneumoniae isolates, against 95.9% of E. coli isolates and against 97.5% of the 82 ESBL-producing microorganisms. Two E. coli isolates showed ertapenem resistance. Conclusion: In recent literature, carbapenems were the most active antimicrobial agents against ESBL-producing Enterobacteriaceae, as in our study. This is the first study on the in vitro activity of ertapenem against ESBL-producing E. coli and K. pneumoniae conducted in Turkey. In view of the serious infections caused by ESBL-producing microorganisms, therapeutic interventions are still problematic in serious clinical conditions. Ertapenem may be a good choice for treatment, with the additional advantage of being a once a day regimen.

Antibiotic prescribing patterns for sore throat infections in a university-based primary care clinic.

BACKGROUND Recent studies reveal that a high percentage (over 50%) of episodes for URTIs are treated with antibiotics, regardless of appropriateness or the necessity for prescription. We identified antibiotic prescriptions in a primary health care centre (PHC) and evaluated their suitability for sore throat infections. We also to explored whether symptoms, signs, diagnosis and antibiotics prescribed differed by gender. PATIENTS AND METHODS We collected data on all patients visiting the centre over a period of 12 weeks with a main complaint of sore throat who were prescribed antibiotics after taking a blood count and throat culture. Patients older than 16 years of age were included in the study irrespective of sex, nationality, marital status, occupation or location of residence. The chi square (χ2) statistical test was used in comparing categorical variables. A P value of <0.05 was considered significant. RESULTS During the period of study, 579 patients with upper respiratory tract infections (URTIs) presented to the health centre, from which 339 patients with a sore throat were enrolled. Of the study group, 48.7% (165) were male and 51.3% (174) female, with the majority of patients being under 30 years old (54.3%). Throat cultures were positive in 56 patients (16.5%). Most of patients were diagnosed as having pharyngitis (22.7%), and the most frequently prescribed medicine was an oral penicillin (39.1%). Two hundred eight-six patients (84.4%) had 2 or fewer Centor criteria. CONCLUSIONS Throat cultures were positive in only 16.5% of the patients prescribed antibiotics. This indicates that physicians in the health centre of the university are prescribing antibiotics inappropriately and inconsistently. This also highlights the need for more prescriber education, especially as the range of medications available to the general practitioner for prescribing increases.