Browsing by Author "Yigin, Akin"

Now showing 1 - 6 of 6

distribution of Oxa-Type Carbapenemase Genes in Carbapenem-resistant Acinetobacter Baumannii strains: an Investigation by Real-Time Polymerase Chain Reaction Method
(Doc design informatics Co Ltd, 2019) Demir, Cemil; Yigin, Akin; Demir, Cemil
Objective: Carbapenems are the most important broad spectrum antimicrobials used in the treatment of Acinetobacter baumannii infections, but resistance to carbapenems is increasing worldwide. In this study, we aimed to investigate the distribution of OXA-type carbapenemase genes observed in carbapenem-resistant A. baumannii strains by real-time polymerase chain reaction (PCR) method and to provide epidemiological data. Methods: Between January 2016 and January 2018, 20 carbapenem-resistant A. baumannii strains from clinical specimens were included in the study. DNA isolations were performed, and distribution of OXA-type carbapenemase genes were examined using primers and TaqMan probes specific to genes of OXA-23, OXA-24, OXA-51 and OXA-58 carbapenemases by real-time PCR method. Results: Tigecycline was the best choice for carbapenem-resistant A. baumannii strains, of which 16 (80%) were susceptible to this antimicrobial. bla(OXA-51) was detected in all strains, while bla(OXA-24) was detected in only 1 (5%) strain. Of 20 strains, 10 showed the presence of bla(OXA-23) and bla(OXA-51) simultaneously. Conclusions: Simultaneous occurence of bla(OXA-23) and bla(OXA-51 )is remarkable in terms of distribution of OXA-type carbapenemases in carbapenem-resistant A. baumannii strains. Valuable epidemiological data can be obtained by performing routine surveillance of such strains by means of techniques that can produce fast and reliable results such as real-time PCR.
Efficacy of antimicrobial peptide LL-37 against biofilm forming Staphylococcus aureus strains obtained from chronic wound infections
(Elsevier, 2022) Demir, Cemil; Yigin, Akin; Demir, Cemil
The antimicrobial peptide LL-37 showed inhibitory effects against Staphylococcus aureus strains, which often responsible for wound infections. Understanding the molecular mechanisms of biofilm-containing wound infections is important. Thus, this study aimed to investigate both the antimicrobial and biofilm efficacy of LL-37 against biofilm-positive methicillin-susceptible S. aureus (MSSA) strains and biofilm-positive methicillin-resistant S. aureus (MRSA) strains obtained from chronic wound infections and its effect on different quorum sensing and virulence genes at suboptimal concentrations. Fifteen biofilm-forming MRSA and 15 biofilm-forming MSSA strains were included in this study. The minimum inhibitory concentration (MIC) values and biofilm formation were tested by microdilution methods. Real-time PCR was performed to determine gene expression levels. MIC values for LL-37 were 89.6 mg/L and 132.3 mg/L for MSSA and MRSA strains, respectively. No statistically significant difference was found between MRSA and MSSA strains in terms of the effect of LL-37 on biofilm formation. A statistically significant difference was found between MRSA and MSSA strains for atlA, RNAIII, and agrA gene expression levels following exposure to a suboptimal concentration of LL-37. Ultimately, the required LL-37 antimicrobial concentration was quite high; however, LL-37 antibiofilm concentration may be acceptable for use in humans against biofilm-forming MRSA and MSSA strains. This is the first study to investigate to effect of a suboptimal LL-37 concentration on gene expression levels of biofilm-forming MSSA and MRSA strains. LL-37 affected quorum sensing and biofilm producing mechanisms, even at suboptimal MIC concentrations.
An Enzyme-Linked Immunosorbent Assay for Brucella Specific Antibody and Real-Time PCR for Detecting Brucella Spp. in Milk and Cheese in Sanliurfa, Turkey
(UNIV AGRICULTURE, FAC VETERINARY SCIENCE, 2017) Gürbüz, Semra; Yigin, Akin; Gurbilek, Sevil Erdenlig; Gurbuz, Semra; Demirci, Mehmet; Keskin, Oktay; Tel, Osman Yasar
The objective of this study was to investigate the presence of anti-Brucella antibody and Brucella spp. DNA in cow, sheep and goat milk and in Urfa cheese collected from markets and bazaars in Sanliurfa, located in southeast of Turkey. A total of 258 samples consisting of 178 raw milk (48 cow milk, 65 sheep milk and 65 goat milk) samples and 80 Urfa cheese samples were investigated. Anti-Brucella antibody was detected by indirect ELISA (i-ELISA), and the presence of Brucella spp. DNA was screened by real time Polymerase Chain Reaction (RTPCR). 16.6% of the cow, 6.1% of the goat and 6.1% of the sheep milk and 16.25% of the cheese samples were found as positive for brucella antibodies by i-ELISA. The RT-PCR assay amplified Brucella DNA from 18.75, 7.6 and 6.1% cow, goat and sheep milk samples respectively. Brucella DNA was amplified from 22.5% cheese samples. The 11.2% and 13.9% of the samples were found as positive by i-ELISA and RT-PCR respectively. This study indicates that milk and milk products consumed in Sanliurfa poses a risk to public health in terms of brucellosis. The combining usage of both i-ELISA and RT-PCR methods could lead to more reliable results to detect anti-Brucella antibody and Brucella spp. DNA from milk and cheese samples. (C) 2016 PVJ. All rights reserved
Presence of biofilm and adhesin genes in Staphylococcus aureus strains taken from chronic wound infections and their genotypic and phenotypic antimicrobial sensitivity patterns
(2020) Demir, Cemil; Çetik Yıldız, Songül; Yigin, Akin; Tokman, Hrisi Bahar; Cetik Yildiz, Songul
The purpose of this research was to examine biofilm (icaA, icaD and bap) and adhesin (clfA, fnbA, cna) genes, and also assess the genotypic and phenotypic antimicrobial resistance patterns of Staphylococcus aureus strains taken from wound specimens in Mardin, Turkey. A total of 220 wound specimens were investigated. The biofilm forming ability and resistance pattern for eleven antimicrobial agents were investigated by conventional and multiplex PCR methods. S. aureus were taken from 112 (50.9%) of 220 wound specimens. Moreover, biofilm production was found in 79 (70.5%) of the 112 S. aureus isolates. 97 (86.6%) strains of all isolates were positive for icaA and icaD, and 15 (13.4%) for bap. The adhesin genes, cna, fnbA and clfA were detected in 98 (87.5%), 87 (77.7%), and 75 (66.9%) strains, respectively. The numbers of MSSA and MRSA bearing antimicrobial resistance genes were 19 (16.96%) and 32 (28.57%) for blaZ, 9 (8.04%) and 17 (15.18%) for tetK, 6 (5.36%) and 14 (12.5%) for ermC, 2 (1.79%) and 7 (6.25%) for tetM, 0 (0%) and 5 (4.46%) for mecA, 2 (1.79%) and 4 (3.57%) for ermA, 1 (0.89%) and 2 (1.79%) for both tetK and tetM, respectively. Our findings indicate that multiplex PCR is a suitable way for identifying biofilm and adhesin producing S. aureus. Our data also provided a country-wide oversight of the S. aureus antimicrobial resistance gene profiles for the properly therapy of patients and to control the spreading of the resistance genes.
Presence of Biofilm and Adhesin Genes in Staphylococcus aureus Strains Taken from Chronic Wound Infections and their Genotypic and Phenotypic Antimicrobial Sensitivity Patterns
(Photodiagnosis and Photodynamic Therapy, 2020) Demir, Cemil; Demirci, Mehmet; Yigin, Akin; Bahar Tokman, Hrisi; Çetik Yıldız, Songul
The aim of this study was to investigate some biofilm (icaA, icaD and bap) and some adhesion (clfA, fnbA, cna) genes, and also evaluate the phenotypic and genotypic antimicrobial resistance patterns of Staphylococcus aureus strains isolated from wound samples in Mardin, Turkey. A total of 220 wound samples were studied. The biofilm forming ability and resistance pattern for eleven antimicrobial agents were investigated by conventional and multiplex PCR methods. S. aureus was isolated from 112 (50.9%) of 220 wound samples. Moreover, biofilm production was found in 79 (70.5%) of the 112 S. aureus isolates. 97 (86.6%) strains of all isolates were positive for icaA and icaD, and 15 (13.4%) for bap. The adhesin genes, cna, fnbA and clfA were detected in 98 (87.5%), 87 (77.7%), and 75 (66.9%) strains, respectively. The numbers of MSSA and MRSA carrying antimicrobial resistance genes were 19 (16.96%) and 32 (28.57%) for blaZ, 9 (8.04%) and 17 (15.18%) for tetK, 6 (5.36%) and 14 (12.5%) for ermC, 2 (1.79%) and 7 (6.25%) for tetM, 0 (0%) and 5 (4.46%) for mecA, 2 (1.79%) and 4 (3.57%) for ermA, 1 (0.89%) and 2 (1.79 %) for both tetK and tetM, respectively. Our findings indicate that multiplex PCR is a reliable method for identifying biofilm and adhesin producing S. aureus. Our data also provided a nationwide surveillance of the antimicrobial resistance gene profiles of S. aureus for the accurate treatment of patients and to control the dissemination of the resistance genes.
Simultaneous Screening of Total Aflatoxins (B₁, B₂, G₁, G₂) and Ochratoxin A (OTA) in Coffee Samples
(Parlar Scientific Publications (p S P), 2019) Gürbüz, Semra; Temamogullari, Fusun; Yigin, Akin; Gurbuz, Semra
The aim of this survey was to determine the occurrence of total aflatoxins (B-1, B-2, G(1), and G(2)) and ochratoxin A (OTA) from different coffee brands and types in the southeastern region of Turkey. Coffee samples (deep-roasted coffee (it is called 'mirra' in Turkey), powdered Turkish coffee, green coffee beans and instant coffee) were collected from supermarkets, retail coffee shops, cafes and touristic bazaars. Total aflatoxins and OTA were microbiologically detected by solid phase direct ELISA. The survey included 90 coffee samples. Survey results demonstrated that 39 (43%) were positive for the presence of total aflatoxins and 36 (%40) out of the 90 samples were positive for the presence of OTA. Total aflatoxin concentrations were found in the range 0.08 - 42.81 mu g kg(-1), only 11 of them exceeded the maximum limit of 10 mu g kg(-1) which is allowed by the European Union for total aflatoxins. OTA levels were range from 0.10 to 41.28 mu g kg(-1); only 9 of the samples exceeded the maximum allowed a limit of 5.0 mu g kg(-1), which is set by the Turkish Food Codex and the European Union. The mean relative humidity level of coffee samples was 5.35. The results of this study has shown the significance of government control programmes in coffee production and sale. This study assessed for occurrence of total aflatoxins and OTA in coffee from different types and brands of coffee.