Development, characterization, and in vivo assessment of mucoadhesive nanoparticles containing fluconazole for the local treatment of oral candidiasis

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis

Kan kültürlerinden izole edilen Klebsiella pneumoniae suşlarında genişlemiş spektrumlu beta-laktamaz varlığının araştırılması ve tiplendirilmesi

The aim of this study was to investigate and type the extended spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae strains isolated from blood cultures. Following the detection of antibiotic susceptibilities in 32 Kpneumoniae isolates, ESBL were detected in 13 (41%) of them by using double disc synergy test. Minimum inhibition concentrations for ceftazidime, cefotaxime, and aztreonam of ESBL positive strains were determined by E-test. After the extraction of the enzymes, the types of ESBLs were investigated by isoelectric focusing method. It was seen that, of all ESBL positive strains, one strain had four bands, one had three bands, six strains had two bands, and each of the others had only one beta-lactamase band. The results of polymerase chain reaction (PCR) revealed blaSHV in ten samples, bla SHV in six samples, and bla SHV with blaTEM in four samples. Ten SHV enzymes were typed as ESBL by PCR-RFLP (restriction fragment lenght polymorphism) method. The results of isoelectric focusing, PCR and RFLP performed in these ESBL positive K.pneumoniae isolates showed that the ESBL types could be SHV-2, SHV-5 and SHV-12 in the tested strains. It should always be taken into consideration that K.pneumoniae isolates could produce ESBLs and antibiotic treatment protocols should be adjusted in accordance.Bu çalışmada kan kültürlerinden izole edilen Klebsiella pneumoniae suşlarında genişlemiş spektrumlu beta-laktamaz (GSBL) enzimlerinin araştırılması ve tiplendirilmesi amaçlanmıştır. Kan kültürlerinden izole edilen 32 Kpneumoniae suşunun antibiyotik duyarlılıkları belirlendikten sonra, çift disk sinerji testi ile 13 izolatta (%41) GSBL varlığı saptanmış, GSBL pozitif bulunan izolatların seftazidim, sefotaksim ve aztreonam minimum inhibisyon konsantrasyonu değerleri E-test ile belirlenmiştir. Suşlardan beta- laktamaz ekstraksiyonu yapılarak izoelektrik odaklama yöntemi ile enzimlerin tipleri araştırılmıştır. GSBL pozitif olan suşlardan birinde dört, birinde üç, altısında iki adet bant paterni gözlenirken, diğerlerinde birer adet bant paterni belirlenmiştir. GSBL pozitif 13 örnek için uygulanan polimeraz zincir reaksiyonu (PCR) sonuçlarına göre; 10 örnekte blaSHV, altı örnekte bla SHV, dört örnekte ise blaSHV ve bla SHV genleri birlikte saptanmıştır. PCR-RFLP (restriction fragment lenght polymorphism) yöntemiyle 10 SHV enziminin GSBL tipinde olduğu gözlenmiştir. Sonuç olarak, kan kültürlerinden izole edilen K.pneumoniae suşlarından ekstrakte edilen GSBL enzimlerinin tiplendirildiği bu çalışmada, izoelektrik noktaları, PCR ve RFLP sonuçları dikkate alındığında, enzim tiplerinin SHV-2, SHV-5 ve SHV-12 olabileceği düşünülmüştür. Bu bilgiler ışığında hastane enfeksiyonlarından izole edilen K.pneumoniae suşlarının GSBL üretebileceği göz önüne alınmalı ve tedavi protokolleri buna göre düzenlenmelidir

GSBL Pozitif Escherichia coli ve Klebsiella pneumoniae İzolatlarında Efluks Pompası Aracılığı ile Gelişen Florokinolon Direncinin Fenil Arginin Beta Naftilamit ile Araştırılması

In Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae strains, fluoroquinolone resistance is acquired mostly by target mutations in topoisomerase genes and increased expression of efflux pumps. ESBL positive 65 E. coli and 48 K. pneumoniae strains isolated in Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Ege University were investigated in this study. 58 E. coli and 21 K. pneumoniae isolates displayed reduced susceptibility (intermediately-resistant or resistant) to ciprofloxacin or nalidixic acid by disc diffussion method. Ciprofloxacin, Phenyl-arginine-beta-naphthylamide (Phe-Arg-?-naphthylamide-P?NA) and nalidixic acid MIC values of these isolates were determined. the changes in nalidixic acid and ciprofloxacin MIC values in the presence of fixed concentration of P?NA (20 µg/mL) were investigated. Among 21 K.pneumoniae isolates, at least four fold reductions were observed in MIC values of ciprofloxacin, nalidixic acid and both for four, five and two isolates respectively. Among 58 E. coli isolates, at least four fold reductions were observed in MIC values of ciprofloxacin, nalidixic acid and both for eight, four and three isolates respectively. This result was evaluated to be indicative for presence of efflux pump mediated resistance in these isolates.Genişlemiş Spektrumlu Beta-Laktamaz (GSBL) sentezleyen Escherichia coli ve Klebsiella pneumoniae izolatlarında florokinolon direnci genellikle topoizomeraz genlerindeki nokta mutasyonlar ve efluks pompalarının artan ekspresyonu sonucu ortaya çıkar. Bu çalışmada Ege Üniversitesi Tıp Fakültesi, Mikrobiyoloji ve Klinik Mikrobiyoloji Anabilim Dalı'nda izole edilen GSBL pozitif 65 E.coli ile 48 K. pneumoniae izolatı incelendi. 58 E. coli ve 21 K. pneumoniae izolatının siprofloksasin veya nalidiksik aside azalmış duyarlılık sergilediği (dirençli veya orta duyarlı) disk difüzyon yöntemi ile saptandı. Bu izolatların siprofloksasin, nalidiksik asit ve Phenyl-arginine-beta-naphthylamide (Phe-Arg-?- naphthylamide-P?NA) MİK değerleri belirlendi. Sabit konsantrasyondaki (20 µg/mL) P?NA'nın, siprofloksasin ve nalidiksik asit MİK değerlerinde oluşturduğu değişim araştırıldı. 21 K. pneumoniae izolatının 4 tanesinde sadece siprofloksasin, 5 tanesinde sadece nalidiksik asit, 2 tanesinde hem nalidiksik asit hem de siprofloksasin; 58 E. coli izolatının 8 tanesinde sadece siprofloksasin, 4 tanesinde sadece nalidiksik asit, 3 tanesinde hem nalidiksik asit hem de siprofloksasin MİK değerlerinde en az 4 katlık azalma gözlendi. Bu sonuçlar, sözü edilen izolatlarda efluks pompası aracılığı ile gelişen direncin göstergesi olarak değerlendirildi

Extended spectrum beta-lactamase types in Klebsiella pneumoniae strains isolated from blood cultures

Bu çalışmada kan kültürlerinden izole edilen Klebsiella pneumoniae suşlarında genişlemiş spektrumlu beta-laktamaz (GSBL) enzimlerinin araştırılması ve tiplendirilmesi amaçlanmıştır. Kan kültürlerinden izole edilen 32 Kpneumoniae suşunun antibiyotik duyarlılıkları belirlendikten sonra, çift disk sinerji testi ile 13 izolatta (%41) GSBL varlığı saptanmış, GSBL pozitif bulunan izolatların seftazidim, sefotaksim ve aztreonam minimum inhibisyon konsantrasyonu değerleri E-test ile belirlenmiştir. Suşlardan beta- laktamaz ekstraksiyonu yapılarak izoelektrik odaklama yöntemi ile enzimlerin tipleri araştırılmıştır. GSBL pozitif olan suşlardan birinde dört, birinde üç, altısında iki adet bant paterni gözlenirken, diğerlerinde birer adet bant paterni belirlenmiştir. GSBL pozitif 13 örnek için uygulanan polimeraz zincir reaksiyonu (PCR) sonuçlarına göre; 10 örnekte blaSHV, altı örnekte bla SHV, dört örnekte ise blaSHV ve bla SHV genleri birlikte saptanmıştır. PCR-RFLP (restriction fragment lenght polymorphism) yöntemiyle 10 SHV enziminin GSBL tipinde olduğu gözlenmiştir. Sonuç olarak, kan kültürlerinden izole edilen K.pneumoniae suşlarından ekstrakte edilen GSBL enzimlerinin tiplendirildiği bu çalışmada, izoelektrik noktaları, PCR ve RFLP sonuçları dikkate alındığında, enzim tiplerinin SHV-2, SHV-5 ve SHV-12 olabileceği düşünülmüştür. Bu bilgiler ışığında hastane enfeksiyonlarından izole edilen K.pneumoniae suşlarının GSBL üretebileceği göz önüne alınmalı ve tedavi protokolleri buna göre düzenlenmelidir.The aim of this study was to investigate and type the extended spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae strains isolated from blood cultures. Following the detection of antibiotic susceptibilities in 32 Kpneumoniae isolates, ESBL were detected in 13 (41%) of them by using double disc synergy test. Minimum inhibition concentrations for ceftazidime, cefotaxime, and aztreonam of ESBL positive strains were determined by E-test. After the extraction of the enzymes, the types of ESBLs were investigated by isoelectric focusing method. It was seen that, of all ESBL positive strains, one strain had four bands, one had three bands, six strains had two bands, and each of the others had only one beta-lactamase band. The results of polymerase chain reaction (PCR) revealed blaSHV in ten samples, bla SHV in six samples, and bla SHV with blaTEM in four samples. Ten SHV enzymes were typed as ESBL by PCR-RFLP (restriction fragment lenght polymorphism) method. The results of isoelectric focusing, PCR and RFLP performed in these ESBL positive K.pneumoniae isolates showed that the ESBL types could be SHV-2, SHV-5 and SHV-12 in the tested strains. It should always be taken into consideration that K.pneumoniae isolates could produce ESBLs and antibiotic treatment protocols should be adjusted in accordance

Investigation of the bactericidal effects of vancomycin and quinupristin / dalfopristin on Staphylococcus aureus isolates

The present study aimed to determine the correlation between the bactericidal activity of vancomycin and quinupristin/dalfopristin (Q/D) on Staphylococcus aureus isolates and their minimal inhibition concentrations. The in-vitro susceptibilities of the 99 S. aureus isolates to vancomycin and Q/D were investigated by agar dilution. Thirty methicillin-resistant S. aureus (MRSA) and 30 methicillin-susceptible S. aureus (MSSA) vancomycin and Q/D susceptible isolates were involved in time-kill studies. While both MRSA and MSSA isolates were susceptible to vancomycin, 96% of both isolates were determined as susceptible to Q/D. In the time-kill test, after 6 h of incubation vancomycin exhibited a bactericidal activity of 90% on MRSA and 100% on MSSA isolates. On the other hand, in the same incubation period Q/D was 47% and 93% bactericidal for MRSA and MSSA isolates, respectively. After 24 h of incubation, while vancomycin was bactericidal for all MRSA and MSSA isolates, Q/D exhibited a bactericidal activity of 93% on MRSA isolates and 97% on MSSA isolates.The present study aimed to determine the correlation between the bactericidal activity of vancomycin and quinupristin/dalfopristin (Q/D) on Staphylococcus aureus isolates and their minimal inhibition concentrations. The in-vitro susceptibilities of the 99 S. aureus isolates to vancomycin and Q/D were investigated by agar dilution. Thirty methicillin-resistant S. aureus (MRSA) and 30 methicillin-susceptible S. aureus (MSSA) vancomycin and Q/D susceptible isolates were involved in time-kill studies. While both MRSA and MSSA isolates were susceptible to vancomycin, 96% of both isolates were determined as susceptible to Q/D. In the time-kill test, after 6 h of incubation vancomycin exhibited a bactericidal activity of 90% on MRSA and 100% on MSSA isolates. On the other hand, in the same incubation period Q/D was 47% and 93% bactericidal for MRSA and MSSA isolates, respectively. After 24 h of incubation, while vancomycin was bactericidal for all MRSA and MSSA isolates, Q/D exhibited a bactericidal activity of 93% on MRSA isolates and 97% on MSSA isolates

Fusidik asit ve siprofloksasin ile indüklenen sıçan karaciğer mikrozomal sitokrom P-450' nin spektral değişikliklerinin karşılaştırılması

Fusidic acid and ciprofloxacin are antibacterial agents which have different structures and modes of action. in this study, the levels of binding of fusidic acid and ciprofloxacin as a substrate to rat liver microsomal cytochrome P-450 which is the most important oxidative biotransformation enzyme system was investigated. It was determined that ciprofloxacin showed more affinity as a substrate for cytochrome P-450 than fusidic acid.Bu çalışmada, farklı yapı ve etki mekanizmalarına sahip antibakteriyel ilaçlardan fusidik asit ve siprofloksasinin, önemli bir biyotransformasyon enzim sistemi olan sitokrom P-450 ile substrat olarak bağlanmaları sıçan karaciğer mikrozomlarında araştırılmıştır. Siprofloksasinin fusidik aside oranla sitokrom P-450'ye substrat olarak ilgisinin daha fazla olduğu saptanmıştı