Epidemiology and risk factors for invasive candidiasis

The number of immunosuppressive patients has increased significantly in recent years. These patients are at risk for opportunistic infections, especially fungal infections. Candidiasis is one of the most frequent fungal infections determined in these immunosuppressive patients and its epidemiology has changed over the last two decades. Recently, new antifungal agents and new therapy strategies such as antifungal prophylaxis, secondary prophylaxis, and preemptive therapy have come into use. These changes resulted in the alteration of Candida species causing invasive infections. The incidence of Candida albicans was decreased in many countries, especially among patients with immunosuppressive disorders, while the incidence of species other than C. albicans was increased. In this review, incidence, risk factors, and species distribution of invasive candidiasis are discussed

Pseudomonas Aeruginosa'da beta-laktamaz aktivitesi ve antipseudomonal ajanlara karşı direncin araştırılması

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.ÖZET Fırsatçı bir patojen olan P. aeruginosa, özellikle nozokomiyal infeksiyonlarda sık rastlanan bir etken olarak karşımıza çıkması ve yüksek mortalite oranlarına sahip infeksiyonlara yol açması nedeniyle önem kazanmaktadır. /'. aeruginosa infeksiyonlarının tedavisinde antipseudomonal beta-laktam antibiyotiklerle, aminoglikozit grubu antibiyotiklerin kombine kullanımı güncelliğini korumakla birlikte, son derece hızlı ve hatta tedavi sırasında gelişen direnç sorunu nedeniyle kombine tedaviler bile etkisiz kalabilmektedir. Pseudomonas aeruginosa infeksiyonlannda beta-laktam antibiyotiklere direnç gelişiminde bu bakterinin beta- laktamaz enzimi salgılamasının yanı sıra, dış membran geçirgenliğinde azalmaya yol açan değişiklikler de önemlidir. Bu çalışmada, çeşitli klinik örneklerden soyutlanan /'. aeruginosa kökenlerinde, beta- laktam direncine neden olabilen beta-laktamaz enzim üretimi ve beta-laktam ve diğer antipseudomonal antibiyotiklere karşı direnç durumu araştırıldı. 108 P. aeruginosa kökeninin 58'inde (%54) beta-laktamaz enzimi olumlu, 50'sinde (%46) olumsuz bulundu. Beta-laktamaz olumlu ve olumsuz grupta beta-laktam antibiyotiklere karşı direnç ayrı ayrı saptandı. imipenem direnci, beta-laktamaz olumlu ve olumsuzlarda sırasıyla; %16 ve %18, aztreonam direnci; %14 ve %12, piperasilin direnci; %48 ve %14, seftazidim direnci; %42 ve %22 olarak saptandı. Beta-laktamaz üretimine bakılmaksızın tüm grupta; seftazidime %32, piperasiline %31, imipeneme %17, aztreonama %13, tobramisine %39, amikasine %14, ofloksasine %39 ve siprofloksasine %35 oranında direnç belirlendi. 4

Comparison of Tigecycline and Vancomycin Activities in an In Vitro Biofilm Model Generated with Methicillin-Resistant Staphylococcus aureus

Today, the most common cause of bloodstream infections, which led to high mortality, prolonged hospitalization and increased costs are the intravenous catheters. Among the microorganisms associated with catheter infections, staphylococci took the first place and because of their biofilm-forming properties they cause serious problems in treatment and management of the patients. Although the drug of choice in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection is vancomycin, its effect on the bacterial biofilm is known to be low. Tigecycline, newly used in our country is a well tolerated glycylcycline antibiotic. In this study, we aimed to compare the efficacy of tigecycline and vancomycin in an in vitro MRSA biofilm model. The study consisted of 10 MRSA strains, which were detected as causative agents of catheter-related infections in our hospital. The methicillin resistance of the strains were performed by disk diffusion test with oxacillin (1 mu g) disks and the biofilm forming capacity of the strains was evaluated using the Congo red agar method. The silicone disks with created biofilm layer were exposed to tigecycline (2 mg/ml) and vancomycin (2 mg/ml) for 24 hours and for 5 days 4-hours per day in a model of antibiotic lock therapy. The present study showed that, after incubating the silicon discs in antibiotic solution for 24 hours, colony forming unit counts of MRSA decreased from 10(5) cfu/ml to 510 cfu/ml in the tigecycline group and from 105 cfu/ml to 3.800 cfu/ml in the vancomycin group and remained the same in the control (10(5) cfu/ml) group (p < 0.001). In the antibiotic lock therapy model, incubation with antibiotics for 4 hours per day, yielded that the average growth was 1.800 cfu/ml in the tigecycline group and 8.700 cfu/ml in the vancomycin group, which was statistically significant (p<0.001). No growth was detected in the tigecycline group (0 cfu/ml) while in vancomycin group number of colonies in second, thirth and fourth days were 2.000, 260, 80 cfu/ml, respectively, no growth was seen in the fifth day. From the first day until the fourth day tigecycline was statistically more effective than vancomycin (p<0.001, p<0.001, p<0.001, p=0.013, according to days respectively). As a result, it was determined that tigecycline showed a higher effect on MRSA biofilm layer created on silicon discs and the results suggested that tigecycline might be a good alternative in the treatment of catheter infections