Background: Candidiasis includes a range of opportunistic fungal diseases that appear in various forms such as oral thrush and stomatitis in the elderly. Recently, the resistance of Candida species to antibiotics selected to treat oral infections has increased significantly. Objectives: This study aimed to determine the antagonistic effects of probiotics on oral candidiasis in the elderly. Patients and Methods: Swab samples from the saliva and mouth of 72 elders residing in the elderly care centers in Gorgan were cultured in Sabouraud dextrose agar (SDA). The Candida spp. and Candida albicans were identified by culturing in CHROMagar Candida medium and using a PCR identification kit and API 20CAUX system. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of nystatin and itraconazole based on the CLSI document. The well -diffusion method and the modified agar method were applied to separate dairy -isolated probiotics from cultures in MRS and M17 media and to study their antimicrobial effect. Results: Overall, 47 Candia isolates in seven different species were diagnosed. The MICs of itraconazole and nystatin were within

Background: The oral and dental infections that are mainly caused by bacterial biofilms are among the most prevalent human infections worldwide. Objectives: The present study aimed to investigate the in vitro and in vivo inhibitory and anti-biofilm effects of oregano essential oil on the Streptococcus mutans isolates obtained from elementary school students. Methods: This experimental study was conducted on 150 samples collected from the buccal and lingual surfaces of the posterior teeth of elementary school students. S. mutans strains were identified using conventional microbiological and biochemical tests, and biofilm formation was assessed using the microtiter plate assay. The minimum inhibitory concentration (MIC) of the oregano essential oil against the isolates was determined using the broth microdilution method. In addition, the effective constituents of the essential oil were measured via gas chromatography-mass spectroscopy. The in vitro and in vivo anti-biofilm activities of the oregano essential oil were also evaluated using the modified microtiter plate assay and on the tooth surfaces of male NMRI mice, respectively. Results: The frequency of S. mutans was 15.3%, 87% of which were capable of biofilm formation. The MIC of the oregano essential oil was 50 µl/ml against the S. mutans isolates, and 82% of the isolates did not grow at the concentrations of ≥ 512 µl/ml. However, none of the isolates were capable of biofilm formation at the MIC and sub-MIC concentrations of the essential oil. Limonene and myrcene were the most effective constituents of the essential oil. Furthermore, a significant correlation was observed between treatment with the oregano essential oil and biofilm formation by the streptococci isolates (P = 0.05). Conclusions: According to the results, the presence of biofilm and incidence of dental caries were significantly correlated. Moreover, the essential oil of oregano and its main constituents had potent anti-biofilm and antibacterial properties and could be utilized for the production of new plant-based mouthwashes.

Background: This study aimed to determine antibacterial activity of ethanolic extract of Matricaria chamomilla (chamomile), Malva sylvestris, and Capsella bursa-pastoris against multidrug-resistant (MDR) clinical isolates of Pseudomonas aeruginosa. Methods: The plants were collected from Ziarat village of Gorgan, Iran in April 2019. The required parts of the plants were separated and completely dried in the shade. After grinding, extraction was performed by maceration method. The extract was dried at 37°C for 24 hours. To obtain a concentration of 50 mg/mL of each extract, 500 mg of the dried plant extract was dissolved in 10 mL 5% dimethyl sulfoxide and sterilized by filtration through a 0.45 µm membrane filter. For the antibacterial assay, agar well diffusion and broth microdilution methods were used. Results: Based on the results, ethanolic extracts of M. sylvestris and Capsella bursa-pastoris did not show any antibacterial activity against MDR P. aeruginosa isolates in both antibacterial assays. No inhibitory effect was observed for ethanolic extract of chamomile against P. aeruginosa isolates in agar well diffusion method as well. In broth microdilution method, the extract of chamomile leaves showed inhibitory effect and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined as 12.5 and 25 mg/mL, respectively. Conclusions: In this study, the extract of ethanolic chamomile leaves showed antibacterial activity against the MDR P. aeruginosa isolates. Thus, it can be used in the production of antibacterial agents, and it is a good option for protection against pathogenic microorganisms, as well as P. aeruginosa.

No abstract

Background: Candidiasis is a spectrum of opportunistic fungal diseases that can manifest in drug addicts in various forms, such as stomatitis. Objectives: This study aimed to determine the prevalence of oral candidiasis caused by Candida glabrata in addicts and examine the susceptibility of isolates to two azoles. Patients and Methods: After taking oral samples from 131 drug addicts suspected of having oral candidiasis, Candida species were identified by culture on chromogenic Candida agar, carbohydrate-assimilation (API test), and polymerase chain reaction. The minimum inhibitory concentrations (MICs) of fluconazole and voriconazole against the isolates were determined using the broth microdilution method. Data were analyzed by SPSS (version 23) using the t-test and one-way analysis of variance. A P value of less than 0.05 was considered statistically significant. Results: Overall, 22.2% of the isolates were C. glabrata, which was more abundant among opiate addicts. Among these isolates, 61.1% were resistant to fluconazole and 44.4% were resistant to voriconazole. The MIC90 of voriconazole was 8 µg/mL, which was 16 times less than that of fluconazole (128 µg/mL). There was no statistically significant difference between the frequency of fluconazole-and voriconazole-resistant isolates (P > 0.05). Conclusions: Oral candidiasis was a common problem among drug addicts. In addition, the prevalence of azole-resistant C. glabrata isolates was high among these individuals.

Background: Candidiasis is a spectrum of opportunistic fungal diseases. The resistance of Candida to antibiotics is unfortunately increasing. Silybum marianum, which belongs to the Asteraceae family, is a wild plant growing in most parts of Iran. Objectives: The present study was conducted to investigate the effect of Silybum marianum extract, both individually and in combination with fluconazole, on the growth of drug-resistant clinical Candida isolates. Methods: Candida species isolated from 85 patients suspected of Candidisis was identified and cultured on CHROMagar Candida and API 20CAUX system. The test of susceptibility to fluconazole was performed using broth microdilution. The minimum inhibitory concentration (MIC) of Silybum marianum extract and its antagonistic effects were determined using the microdilution assay. Results: The highest resistance to fluconazole was reported in Candida glabrata (81.8%) and Candida albicans (72.9%). Variations in the MIC of the aqueous extract of Silybum marianum in a range of 4096-8 µL/mL showed that 77.8% of C. glabrata isolates and 88.6% of C. albicans isolates were resistant to fluconazole, and did not grow at a concentration of 2048 µL/mL; nevertheless, in the case of Silybum marianum extracts in combination with fluconazole, 89% of C. glabreta and 94.3% of C. albicans isolates were resistant to fluconazole, and stopped growing at concentrations of at least 128 µL/mL (P < 0.01). Conclusions: The aqueous extract of Silybum marianum seeds found to present proper inhibitory effects on clinical fluconazoleresistant Candida isolates at high concentrations. Silybum marianum extract in combination with fluconazole was found to have a more potent in-vitro activity than the extract and drug individually.

Background: Staphylococcus aureus is one of the main human pathogens which should be taken into account as one of the main hospital infections due to its colonization in the nose of carrier personnel.The present study aims to determine the frequency of resistance to mupirocin in the hospital carriers of Staphylococcus aureus, and to investigate the antimicrobial effect of Zinc Oxide nanoparticles on the growth of resistant strains. Methods: In this cross-sectional study, samples were taken from the anterior nasal part of 150 hospital staff in Gorgan, using a sterile swab. Being cultured on Mannitol salt agar, the suspected colonies were identified through Gram staining, as well as catalase, coagulase and DNase tests. Resistance of the strains to mupirocin was tested using microdilution Broth test. Besides, the antibacterial effect of Zinc Oxide nanoparticles(ZnONPs) on the mupirocin-resistant strains was also investigated using agar well diffusion method. Results: In this study, the frequency of Staphylococcus aureus was 32%, out of which 6.2% showed high resistance to mupirocin and 29.2% showed low resistance to this antibiotic. The results of this study showed that Zinc Oxide nanoparticles have the most inhibitory effect on the growth of mupirocin-resistant Staphylococcus aureus in the density of 400 mg/ml. Conclusion:The Zinc Oxide nanoparticle used in this study had a high antimicrobial activity against all the drug-resistant Staphylococcus aureus strains, and their bactericidal properties also increased by raising the density of the nanoparticle.

Background and objectives: The incidence of drug-resistant candidiasis has increased dramatically. This study aimed to evaluate antifungal effects of fluconazole alone and in combination with ibuprofen on isolates from patients with mucosal candidiasis. Methods: Candida species isolates from 142 patients with suspected mucosal (oral and vaginal) candidiasis were identified by culture on CHROMagar Candida medium and carbohydrate assimilation test using the API 20CAUX kit. Minimum inhibitory concentration (MIC) of fluconazole alone and in combination with ibuprofen was determined by the broth microdilution method. Results: Among isolates, 43.7% were identified as Candida species (Candida albicans, Candida glabrata, Candidia parapsilosis, Candida tropicalis, Candida guilliermondii and Candida kefyr). The highest rate of fluconazole resistance was observed among C. albicans (50%) isolates. MIC 90 of ibuprofenfluconazole combination against C. albicans isolates was 32 μg/mL, which was 8-fold less than that of fluconazole alone (MIC 90 =256 μg/mL) (P<0.01). Moreover, the MIC 90 of fluconazole-ibuprofen combination against C. parapsilosis isolates was 4-fold less than that of fluconazole alone. Conclusion: Our results revealed partial fluconazole resistance among Candida isolates from patients with mucosal candidiasis. However, the resistance rate decreased 2.5 fold following treatment with the ibuprofen-fluconazole combination. Therefore, it is recommended to further investigate the therapeutic potential of this drug combination for treatment of fungal infections, such as candidiasis.