Cüneyt Özakın

Dr. Cüneyt Özakın

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 July 2024 in Scientific Reports
Verified
Journal Article
Open access
PDF file
NTNazmiye Ülkü Tüzemen
Nazmiye Ülkü Tüzemen
UOUgur Onal
Ugur Onal
OMOsman Merdan
Osman Merdan
BABekir Akca
Bekir Akca
BEBeyza Ener
Beyza Ener
EAEMİN HALİS Akalin
EMİN HALİS Akalin
Carbapenem-resistant Klebsiella pneumoniae (CPKP) infections seriously threaten global public health. The main objective of this study was to assess the in-vitro synergistic activity of ceftazidime–avibactam (CZA) in combination with colistin (COL), amikacin (AK), gentamicin (GEN), and fosfomycin (FOS) against CPKP isolates. The secondary goal was to determine the antibiotic susceptibility performance of BD Phoenix. OXA-48 (49.1%) was the predominant carbapenemase, followed by KPC (29.1%). We used the broth microdilution (BMD) method to determine the minimum inhibitory concentrations (MICs) of CZA, COL, AK, and GEN. Meanwhile, the MICs of FOS were determined by the agar dilution (AD) method. To examine the antibacterial activity of CZA, we conducted a checkerboard assay (CBA) with COL, AK, GEN, and FOS against CRKP isolates. We randomly selected three strains and performed synergy testing via time-kill assay (TKA). CRKP isolates were 89.1% susceptible to CZA, 16.4% to COL, 21.8% to GEN, and 29.1% to AK using BMD, 47.3% to FOS by AD. The most synergistic effects were observed in the combination of CZA-COL (78.2%) and CZA-FOS (63.6%). Given the limited therapeutic options for treating severe CRKP infections, combining CZA with COL and FOS may enhance in-vitro activity against clinical CRKP isolates.

12 December 2022 in Annals of Medicine
Verified
Journal Article
Open access
GHGulsen Hascelik
Gulsen Hascelik
GSGuner Soyletir
Guner Soyletir
ZGZeynep Gulay
Zeynep Gulay
BSBanu Sancak
Banu Sancak
AYAkgun Yaman
Akgun Yaman
MCMehmet Ceyhan
Mehmet Ceyhan
To evaluate the serotype distribution and antibiotic resistance in pneumococcal infections in adults and to provide a perspective regarding serotype coverage of both current and future pneumococcal...

10 December 2013 in BMC Infectious Diseases
Verified
Journal Article
Open access
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BSBanu Sancak
Banu Sancak
SYServer Yagci
Server Yagci
DGDeniz Gür
Deniz Gür
ZGZeynep Gülay
Zeynep Gülay
DODilara Ogunc
Dilara Ogunc
VKVolkan Korten
Volkan Korten
The aim of this study was to determine the distribution of vancomycin and daptomycin MICs among methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, the prevalence of heterogeneous vancomycin-intermediate S. aureus (hVISA) and the relationship between hVISA and vancomycin MIC values.

8 September 2021 in Journal of Chemotherapy
Verified
Journal Article
Closed access
PZPinar Zarakolu
Pinar Zarakolu
ÖEÖzgen Köseoğlu Eser
Özgen Köseoğlu Eser
BOBarış Otlu
Barış Otlu
ÖGÖznur Gürpınar
Öznur Gürpınar
CÖCüneyt Özakın
Cüneyt Özakın
SUSerhat Unal
Serhat Unal
The aim of this study was to determine the in-vitro activity of fosfomycin against Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) isolates and the frequency of OXA-48, NDM, KPC, VIM, IMP types of carbapenemases in the carbapenem-resistant (CR) groups. A total of 346 isolates (126 E. coli and 220 K. pneumoniae) from nosocomial bloodstream infections were included. Carbapenem and fosfomycin susceptibility were tested by Etest (bioMerieux, France) and agar dilution methods, respectively and evaluated in accordance with EUCAST criteria. The presence of OXA-48, NDM, KPC, VIM, IMP types of carbapenemases were conducted by using PCR method. Of the total 346 isolates, 185 (41 E. coli, 144 K. pneumoniae) were CR. Fosfomycin susceptibility of E. coli was higher than 95% and was not statistically significant between the CR and carbapenem-susceptible (CS) groups. Fosfomycin susceptibility of CS and CR K. pneumoniae was 90.7% and 69.4%, respectively, and statistically significantly lower in CR group. Of the total 185 CR isolates, 163 (32 E. coli, 131 K. pneumoniae) were producing carbapenemases. OXA-48 was the prominent carbapenemase type produced by E. coli (96.8%) and K. pneumoniae (70.9%). The frequency of NDM and KPC types produced by K. pneumoniae was 20.6% and 15.2%, respectively. Fosfomycin has substantial in-vitro activity against nosocomial CS and CR E. coli and CS K. pneumoniae bloodstream isolates. However, due to the risk of emerging resistance with fosfomycin monotherapy, combination therapy should be considered to obtain the possible additive or synergistic activity. Emerging fosfomycin resistance of CR K. pneumoniae isolates is alarming and OXA-48 is still the prominent carbapenemase type in Turkey.

1 January 2022 in International Journal of Nanomedicine
Verified
Journal Article
Open access
PDF file
ASAhmet Umit Sabancı
Ahmet Umit Sabancı
PAPerihan Erkan Alkan
Perihan Erkan Alkan
CMCem Mujde
Cem Mujde
HPHivda Ulbegi Polat
Hivda Ulbegi Polat
COCemre Ornek
Cemre Ornek
STSEHIME TEMEL
SEHIME TEMEL
Purpose: SARS-CoV-2-infected individuals may be asymptomatic, and therefore, the virus is highly contagious. We aimed to develop an agent to control viral replication in the upper respiratory tract and to prevent progression of the disease into the lower airways as well as inter-individual transmission. For this purpose, we investigated the antibacterial and antiviral activities of our novel nanobubble ozonated hyaluronic acid-decorated liposomal (NOHAL) solution, developed by using nanotechnology. Methods: The MIC levels of NOHAL solution were determined on blood agar cultures of Staphylococcus aureus (ATCC 6538), Streptococcuspneumoniae (ATCC 49619) and Escherichia coli (ATCC 25922). The in vitro anti-viral activity of NOHAL solution was studied using recombinant SARS-CoV-2 copies of the original virus, grown in Vero cells generated by reverse genetic technology. Human primary lung epithelial cells obtained by bronchoscopy or lung resection were used for cell viability tests using flow cytometry analysis. The cytotoxicity testing was performed using the BALB/c 3T3 (CCL-163) cell line. Skin, oral, nasal and ocular irritation tests were performed using New Zealand albino rabbits, Syrian hamsters, BALB c mice and New Zealand albino rabbits of both sexes. Results: Bacterial growth was prevented by NOHAL solution in a time-/dose-dependent manner. In vivo or in vitro experiments did not show any toxicity of NOHAL solution. No cytotoxicity was recorded on cell viability. No skin, oral, nasal or ocular toxicities were recorded. In addition, in a SARS-CoV-2 mouse infection model, NOHAL solution diminished the viral RNA levels effectively in nasopharyngeal and lung samples after its prophylactic intranasal application. Conclusion: NOHAL solution has the potential to reduce or prevent the spread of SARS-CoV-2 through the nose and/or oral cavity. The clinical efficacy of this solution needs to be tested in order to determine its efficacy in the early phase of COVID-19.

1 December 2020 in Leukemia Research
Verified
Journal Article
Closed access
TKTugcan Alp Kirkizlar
Tugcan Alp Kirkizlar
EAEMİN HALİS Akalin
EMİN HALİS Akalin
HKHakki Onur Kirkizlar
Hakki Onur Kirkizlar
FÖFahir Özkalemkaş
Fahir Özkalemkaş
VOVildan Ozkocaman
Vildan Ozkocaman
RARıdvan Ali
Rıdvan Ali