Person: KARAASLAN, ELİF
Now showing 1 - 10 of 14
- PublicationMetadata onlyÇEVRESEL KAYNAKLI SUŞLARDA ANTİBİYOTİK DİRENÇ GENLERİNİN ARAŞTIRILMASI VE BİYOFİLM OLUŞTURMA POTANSİYELLERİNİN ARAŞTIRILMASI(2014-04-18) KARAASLAN, ELİF; DÖŞLER, SİBEL; KARAASLAN, ELİF
- PublicationMetadata onlyÇevreden izole edilen suşların antimikrobiyal direnç durumlarının araştırılması ve klinik suşlarla karşılaştırılması(2012-11-07) KARAASLAN, ELİF; DÖŞLER, SİBEL; KARAASLAN, ELİF
- PublicationMetadata onlyAntibacterial and anti-biofilm activities of melittin and colistin, alone and in combination with antibiotics against Gram-negative bacteria(2016-01-01T00:00:00Z) Dosler, Sibel; Karaaslan, ELİF; Gerceker, A. Alev; KARAASLAN, ELİFIn vitro antibacterial and anti-biofilm activities of antimicrobial cationic peptides (AMPs) melittin and colistin both alone and in combination with antibiotics were evaluated against clinical isolates of Gram-negative bacteria. Minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIG) index were determined by the microbroth dilution and chequerboard techniques, respectively. The time-kill curve (TKC) method was used for determining the bactericidal activities of AMPs alone and in combination. Measurements of anti-biofilm activities were performed spectrophotometrically for both inhibition of attachment and 24-hour biofilm formation at MIC or subMIC. According to MIC, values, the most active agents against Pseudomonas aeruginosa, Escherichia colt and Klebsiella pneumoniae were colistin, imipenem and ciprofloxacin, respectively. In combination studies, synergistic effects were mostly seen with colistin imipenem against E. coif and K. pneumoniae (50 and 54%, respectively), colistin ciprofloxacin against P. aeruginosa (77%). In TKC studies, synergism was observed with almost all expected combinations, even more frequently than chequerboard method. All of the antimicrobial agents were able to inhibit attachment and 24-hour biofilm formation between 0-57% at 1/10 x MIC and 7-73% at 1 x or 1/10 x MIC, respectively. AMPs seem to be a good candidate for antimicrobial chemotherapy with their antibacterial and anti-biofilm activities as a single agent or in combination with antibiotics.
- PublicationMetadata onlyInvestigation Of The Cellular And Humoral Immune Responses Against Nucleoprotein Of Crimean Congo Hemorrhagic Fever Virus (CCHFV)(2019-05-10) ÇETİN, NESİBE SELMA; KARAASLAN, ELİF; DOYMAZ, MEHMET ZİYA; KILIÇ, ALİ OSMAN; ÇETİN, NESİBE SELMA; KARAASLAN, ELİF; DOYMAZ, MEHMET ZIYA
- PublicationMetadata onlyINVESTIGATION OF HUMORAL RESPONSE RAISED AGAINST BACTERIALLY EXPRESSED NUCLEOPROTEIN OF CRIMEAN CONGO HEMORRHAGIC FEVER VIRUS(2016-04-27) KARAASLAN, ELİF; ÇETİN, NESİBE SELMA; KILIÇ, ALİ OSMAN; DOYMAZ, MEHMET ZİYA; KARAASLAN, ELİF; ÇETİN, NESİBE SELMA; DOYMAZ, MEHMET ZIYA
- PublicationMetadata onlyIn vitro activities of colistin in combination with doripenem, doxycyline and rifampin against multidrug resistant isolates of Pseudomonas aeruginosa and Acinetobacter baumanii(2017-07-09) KARAASLAN, ELİF; DÖŞLER, SİBEL; KARAASLAN, ELİF
- PublicationMetadata onlyImmunological Characteristics of Nonstructural Proteins of Crimean-Congo Hemorrhagic Fever Virus(2017-09-10) KARAASLAN, ELİF; DOYMAZ, MEHMET ZİYA; KARAASLAN, ELİF; DOYMAZ, MEHMET ZIYA
- PublicationMetadata onlyDetailed Immonological Analysıis of Recombinant Crimean Congo Hemorrhagic Fever Virus Nucleoprotein(2019-04-28) KARAASLAN, ELİF; ÇETİN, NESİBE SELMA; Hasanoğlu, Sevde; KILIÇ, ALİ OSMAN; KALKAN, AHMET; ÖZDARENDELİ, AYKUT; DOYMAZ, MEHMET ZİYA; KARAASLAN, ELİF; ÇETİN, NESİBE SELMA; DOYMAZ, MEHMET ZIYA
- PublicationMetadata onlyComparison of antibacterial activities of polymyxin B and colistin against multidrug resistant Gram negative bacteria(2019-07-11T00:00:00Z) Doymaz, MEHMET ZİYA; Karaaslan, ELİF; DOYMAZ, MEHMET ZIYA; KARAASLAN, ELİFBackground: Polymyxin B and colistin have similar structures except for one amino acid. Usually, physicians choose either polymyxin B or colistin for treatment of infections caused by multidrug-resistant (MDR) organisms. The preference is based on previous experience. Not much data are found in the literature comparing the two drugs against the same microorganisms. In this study, we compared in vitro antimicrobial activities of the two polymyxins against a panel of highly resistant and susceptible microorganisms. Methods: Eighty-nine clinical isolates (27 Klebsiella pneumoniae, 31 Acinetobacter baumannii and 31 Pseudomonas aeruginosa) were tested in broth microdilution assays. Time-kill curve experiments were carried out on selected isolates. Results: Significantly lower MICs for polymyxin B than for colistin were found against all species tested including K. pneumoniae (p < .02), A. baumannii (p < .001) and P. aeruginosa (p < .01). The low MICs caused a change in categorical interpretations of only two K. pneumoniae and two P. aeruginosa. Similar results were obtained in time-kill curve experiments with both susceptible and resistant clinical isolates. Conclusions: Significantly lower MICs were found for polymyxin B against three of the most critical MDR species. Even though differences in categorical interpretations were not striking, lower MICs might be a critical consideration in clinical management of select cases where the concentration of these toxic antibiotics matters because of underlying co-morbidities. These results provide support to previous suggestions that re-consideration of breakpoint interpretations for polymyxins might be needed.
- PublicationMetadata onlyInhibition and destruction of Pseudomonas aeruginosa biofilms by antibiotics and antimicrobial peptides(2014-12-01T00:00:00Z) Dosler, Sibel; Karaaslan, Elif; KARAASLAN, ELİFPseudomonas aeruginosa is one of the major nosocomial pathogen that can causes a wide variety of acute and chronic infections P. aeruginosa is a dreaded bacteria not just because of the high intrinsic and acquired antibiotic resistance rates but also the biofilm formation and production of multiple virulence factors. We investigated the in vitro activities of antibiotics (ceftazidime, tobramycin, ciprofloxacin, doripenem, piperacillin and colistin) and antimicrobial cationic peptides (AMPs; LL-37, CAMA: cecropin(1-7)melittin A(2-9) amide, melittin, defensin and magainin-II) alone or in combination against biofilms of laboratory strain ATCC 27853 and 4 clinical strains of P. aeruginosa. The minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC) and minimum biofilm eradication concentrations (MBEC) were determined by microbroth dilution technique. The MBEC values of antibiotics and AMPs were 80->5120 and 640->640 mg/L, respectively. When combined with the LL-37 or CAMA at 1110x MBEC, the MBEC values of antibiotics that active against biofilms, were decreased up to 8-fold. All of the antibiotics, and AMPs were able to inhibit the attachment of bacteria at the 1110x MIC and biofilm formation at 1 x or 1110x MIC concentrations. Time killing curve studies showed 3-log10 killing against biofilms in 24 h with almost all studied antibiotics and AMPs. Synergism were seen in most of the studied combinations especially CAMA/LL-37 + ciprofloxacin against at least one or two strains- biofilms. Since biofilms are not affected the antibiotics at therapeutic concentrations, using a combination of antimicrobial agents including AMPs, or inhibition of biofilm formation by blocking the attachment of bacteria to surfaces might be alternative methods to fight with biofilm associated infections. (C) 2014 Elsevier Inc. All rights reserved.