Şeymanur Çobanoğlu

Bu çalışmada, Erzurum Ovasından toplanan toprak ve su örneklerinde mikroplastik birikimi araştırılmıştır. Tespit edilen mikroplastiklerin boyutları ve morfolojileri ışık mikroskobu ile, karakterizasyonları ise taramalı elektron mikroskobu (SEM) ve Fourier dönüşümlü kızılötesi spektroskopisi (FT-IR) teknikleri ile belirlenmiştir. Sonuçlarda, boyutları 1 mm ile 10 mm arasında değişen mikroplastiklerin stiren bütadien, mikrokristal mumlar, yüksek yoğunluklu polietilen, akrilonirtil butadiedn stiren ve polipropilen gibi polimerlerden oluştuğu görüldü. Bu sonuçlar, Erzurum Ovasında mikroplastik kirliliğine dikkat çeken ilk rapor olma özelliği açısından önemlidir.

Nowadays, due to the rapid spread of antibiotic resistance and the difficulty of discovering new antimicrobial agents, the reuse and combinational strategies of old antibiotics have come to the fore. In this study, we investigated the combinational efficacy of nisin and chloramphenicol against the ATCC 6538 strain of Staphylococcus aureus. The MIC values of nisin and chloramphenicol were >64 and 32 µg/mL, respectively. The checkerboard assay was carried out for the inspection of synergism between nisin and chloramphenicol. Furthermore, the crystal violet assay was employed to assess antibiofilm effects. Additionally, the expressions of various virulence genes (agrA, spa, icaA and saeR) were investigated using the colony biofilm assay and qRT-PCR methods. In combination application, MIC values of nisin and chloramphenicol was decreased. In addition, biofilm formation was decreased.It was shown that the expression level of the agrA gene decreased compared to the control in the nisin, chloramphenicol and combinational applications. The expression levels of other genes were increased compared to the control. The results showed that the activities of nisin and chloramphenicol combinations had synergistic and antibiofilm activity. This study sheds light on the combinatorial use of older antibiotics.

This study investigated the antimicrobial and antibiofilm activities of Ferula species (sp.) obtained from Erzurum province. Antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Candida albicans, and Candida tropicalis were determined by agar well diffusion assay. Ethyl acetate extract showed antimicrobial activity against S. aureus, and methanol extract showed antimicrobial activity against E. coli and C. albicans with a zone diameter of 21, 18, and 15 mm, respectively. The extract's minimum inhibitory concentrations (MIC) were 16, 32, and 32 μg/mL ml for S. aureus, E. coli, and C. albicans, respectively. Furthermore, it was determined for the first time that Ferula sp. extracts were effective against biofilm formations of S. aureus and C. albicans. In the light of these results, we think that extracts of Ferula sp. contain potential candidate molecules against biofilm-associated infections, and further characterization studies are needed.

Integrative production of new nanocomposites has been used to enhance favorable features of biomaterials for unlocking ultimate potential of different molecules. In the present study, advantageous properties of diamond like carbons (DLC) and germanium (Ge) like greater biocompatibility and antibacterial attributes were aimed to combined into a thin film. For this purpose, 400 nm DLC–Ge nanocomposite was coated on the borosilicate glasses via the magnetron sputtering and surface characteristics was analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and The Raman spectrum. Biocompatibility analysis were performed by 3‐(4,5‐Dimethylthiazol‐2‐yl) (MTT) cell viability assay and Hoechst 33258 fluorescent staining genotoxicity assessments on the human fibroblast cell line (HDFa). Finally, antibacterial properties of DLC–Ge nanocomposite coatings were investigated by Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923) bacterial attachment analysis. As a result of magnetron sputtering coating, nearly 400 nm thick DLC–Ge nanocomposite film showed a smooth, a non‐porous, and a dense characteristic. Cell viability analysis showed that Ge–DLC coatings permits %95 cell surface growth of fibroblast cells. Also, there were no significant difference in aspect of nuclear abnormalities compared to the (−) control which showed nonmutagenic features of the thin film. Finally, antibacterial attachment analysis put forth that Ge–DLC coatings inhibits bacterial adhesion as %40 and %25 rates for P. aeruginosa and S. aureus bacterial strains, respectively. From these results, DLC–Ge nanocomposites could be proposed as a potential new biomaterial for various biomedical applications.

Nowadays, natural microbial pigments are emerging as potential candidate therapeutic agents that can be used in antibiotic resistance. In this paper, we report the antimicrobial activity of green algae pigments. Green algae SC3 isolate was isolated from soil in Erzurum. Pigments extracted by methanol: dimethyl sulfoxide solvents were partially characterized by Thin Layer Chromatography (TLC), UV-Absorbance, and Fourier-transform infrared spectroscopy (FTIR). The antimicrobial activity of pigments was determined with agar well diffusion and microbroth assays against Pseudomonas aeruginosa (ATCC 27853 and clinic isolate), Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). To identify green algae, total DNA was isolated and both 18S rRNA and 16S rRNA for the chloroplast genome were amplified using universal primers. Thus, this alga was identified as Auxenochlorella protothecoides and submitted to Genbank (Accession number: MW139225 and MW063613). According to our results, the best antimicrobial activity was recorded against P. aeruginosa. Our results show for the first time the antimicrobial activity of the total pigments from A. protothecoides green algae.

Infections from multi-drug resistant bacteria and biofilms constitute a serious problem worldwide. There is a need for new antibacterial and antibiofilm compounds in the fight against infectious diseases. In recent years, pigment-producing microorganisms have drawn a great deal of attention as a promising source for antibacterial and antibiofilm compounds. Here, we report the antibacterial and antibiofilm activity of pigments synthesized by bacteria isolated from soil. This study aimed to perform an evaluation of the antibacterial, antibiofilm, and characteristic of crude pigments from Rhodococcus sp. SC1 isolates. The total pigment extract exhibited antibacterial activity against Gram-positive and Gram-negative reference bacteria with required minimum inhibitory concentration (MIC) values ranging from 64 to 256 µg/ml. Moreover, it reduced biofilm formation of Gram-negative reference bacteria at sub-MIC concentration. For characterization of the pigments, UV-absorbance, thin layer chromatography, fourier transform infrared spectroscopy, and QTOF-LC/MS analyses were performed. The results of this study showed that pigments of Rhodococcus sp. SC1 isolates can be a candidate for medical applications.