RESUMO
Purpose: Many antimicrobial medications are available to combat infections. However, the indiscriminate use of antibiotics has produced antibiotic resistance in the case of many bacterial pathogens. This study focuses on the development of nanoparticles (NPs) that enhance the in vitro antibiotic activity of vancomycin against multi-drug resistant (MDR) organisms. Methods: Spherical shaped thioglycolic acid-stabilized silver nanoparticles (TGA-AgNPs) were prepared by using a simple chemical reduction method. Then, vancomycin was conjugated to the terminal carboxyl of TGA in the presence of N-Hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC). Afterwards, the antibacterial activity of these nanoconjugates was examined by using the minimum inhibitory concentration (MIC) assay against MDR bacteria. Results: The rate of vancomycin bound to the AgNPs was 19.6%. The MIC values of vancomycin (Van)-capped AgNPs against tested pathogens were in the range of (3.2, 1.6, 0.8, 0.4, 0.2, 0.1, 0.05, and 0.025 µl/ml). The MIC was 0.1 µg/ml for VRE, MIC≤0.02 µg/ml for MRSE, and 0.05 µg/ml for S. aureus. The MIC corresponded to the MBC for all bacterial species. Conclusion: This study indicated that some antimicrobial agents like vancomycin can be conjugated with AgNPs. This can lead to increased antimicrobial activity against MDR microorganisms.
RESUMO
BACKGROUND/AIM: Helicobacter pylori is a pathogen that colonizes a majority of the world's population. Genetic diversity within the virulence genes of bacteria such as cagPAI and vacA may have a modified effect on the pathogenic potential of the bacteria. This study aimed to investigate which genes can be suggested as potentially related virulence factors for H. pylori-associated active chronic gastritis and stomach adenocarcinoma in the northwest of Iran and south of Turkey. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded stomach biopsy tissue samples were obtained from Iranian and Turkish patients from selected geographical regions. The prevalence of selected cagPAI genes and vacA genotypes were studied in H. pylori-positive samples by using polymerase chain reaction and specific primers. RESULTS: Out of 320 patients, H. pylori was detected in 28.43% of patients. We found that the vacAs1, vacAm2, and cagA genes with mean prevalences of 82.41%, 71.42%, and 69.23%, respectively, were dominant in Iranian and Turkish patients. CONCLUSION: In the south of Turkey and northwest of Iran the studied genes were homogeneous and there were no significant differences in bacterial genetics. The results of this study indicate that cagA and vacAs1 are dominant genes in people with gastric disorders in our selected geographical regions.
