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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: VETERINARY RESEARCH FORUM
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,mastitis,Biofilm,Streptococcus,Antimicrobial susceptibility
- چکیده:
- چکیده انگلیسی: Streptococcus agalactiae is a major contagious pathogen causing bovine sub-clinical mastitis. The present investigation was carried out to determine some phenotypic characteristics of the S. agalactiae strains isolated from bovine mastitis cases in dairy cows of Shahrekord in the west-center of Iran. One hundred eighty California mastitis test (CMT) positive milk samples were bacteriologically studied. A total of 31 (17.2%) S. agalactiae isolated. Twenty eight (90.3%) of the isolates were biofilm producers. This finding may indicate the high potential of pathogenicity in isolated strains. Sixteen (51.6%) isolates were α hemolysin producers. Only 19.3%, 22.5% and 29.0% of the isolates were sensitive to streptomycin, flumequine and kanamycin, respectively. None of these three agents is recommended for treatment of mastitis cases.
- انتشار مقاله: 12-11-1390
- نویسندگان: Azizollah Ebrahimi,Azar Moatamedi,Sharareh Lotfalian,Pejhman Mirshokraei
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pharmaceutical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Antibiotics,Biofilm,Pseudomonas,Enterococcus,Staphylococcus,Acinetobacter,Silver nano particles
- چکیده:
- چکیده انگلیسی: Nowadays silver nanoparticles (AgNPs) are used as antimicrobial due to its well known physical, chemical, and biological properties. A large collection of bacterial cells adhering to a surface is called bacterial biofilm. Exposure to silver nano particles (AgNPs) may prevent colonization of new bacteria onto the biofilm.
In the present work, we have investigated whether the biofilm formation of some hospital isolates of pathogenic bacteria can be influenced by AgNPs. Also we examined the susceptibility of the isolates to some antibiotics in combination with AgNPs.
Standard strains of Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis and Staphylococcus aureus, in addition to nine hospital isolates for each species were used. Tube double serial dilution method for determination of MIC of AgNPs against isolates was performed. Biofilm formation was evaluated by end smooth 96 cells micro titer plates. A disc diffusion method was used to assay the various antibiotics and combinations for bactericidal activity against the isolates.
Mean MICs of AgNPs for Ps. aeruginosa, A. baumannii, E. faecalis and S. aureus were 3.125, 6.25, 6.25 and 12.5 ug/mL. respectively. AgNPs exhibited more than % 90 inhibitory effect on biofilm formation of the examined species. The results showed that AgNPs have strong anti bacterial and anti biofilm activity against the examined pathogens. Synergistic effects of AgNPs in combination with gentamicin, kanamycine, cephalosporin and penicillin were observed in different cases.
Ps. aeruginosa and S. aureus showed more sensitivity (increase in fold) to examined antibiotics plus AgNPs compared to A. baumannii and E. faecalis. Our results demonstrated that AgNPs showing promising anti biofilm activity on hospital isolates of Ps. aeruginosa, A. baumannii, E. faecalis and S. aureus. The study also showed a possible combination of examined antibiotics with AgNPs which concluded as synergism.- انتشار مقاله: 06-09-1395
- نویسندگان: Azizollah Ebrahimi,Hosein Jafferi,Saied Habibian,Sharareh Lotfalian
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pharmaceutical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Biosurfactant,Emulsification,Oil spreading,Ruminant skin
- چکیده:
- چکیده انگلیسی: Biosurfactants are surface-active compounds produced by microorganisms. In this study, we collected 60 inguinal area and ear canal samples from cows, sheep, and goats (each, 10 animals) and screened for biosurfactant-producing bacteria. We also determined the genera of culturing strains. Fifty six hemolytic bacterial strains (27, 22 and 7, from cows, sheep and goats, respectively) were isolated. Oil spreading test and bioemulsifying activities were measured for all isolates. The cows’ samples had higher population of positive strains than other animals, so that 5 isolates from inguinal area and 4 from ear canal samples (16.1%) were positive for all tests. For sheep, the numbers were 6 and one (12.5%) while for goats one and two (5.3%), respectively. Totally, 19 isolates (33.9%) were positive for all examinations out of them 12 were gram positives. The microorganisms isolated in this study could well be sources of novel biosurfactants. Further investigation into the composition of the biosurfactants and phylogenetic determination of biosurfactant producing bacteria is suggested.
- انتشار مقاله: 13-11-1389
- نویسندگان: Azizollah Ebrahimi,Najmeh Tashi,Saeid Karimi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pharmaceutical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Antimicrobial activity,Iran,Medicinal plants,Endophytes
- چکیده:
- چکیده انگلیسی: Random samples from asymptomatic leaves and branches of five native medicinal plants: Stachys lavandulifolia, Rumex pulcher, Hypericum scabrum, Starja bachteriarica and Achillea kellalensis were collected from Chaharmahal province of Iran and examined for the presence of endophytic bacteria and fungi with biological activity. From 8 isolated endophytic fungi, all displayed considerable activity against at least one indicator fungi. Fungal isolates from R. pulcher leaves and branches showed activity against Aspergillus niger, Penicillium spp, Alternaria spp and S. aureus. Five Bacillus spp strains were isolated from R. pulcher leaves and branches, four (80%) showed activity against S. aureus, and two strains were active against all indicator fungi. Bacillus spp strain isolated from leaves of H. scabrum was active against S. aureus and all 3 indicator fungi. None of the isolated endophytes showed antibacterial activity against E- coli.
- انتشار مقاله: 14-11-1388
- نویسندگان: Azizollah Ebrahimi,Shirin Asgharian,Saied Habibian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advanced Herbal Medicine
- نوع مقاله: Journal Article
- کلمات کلیدی: Antibacterial activities,Gram-negative bacteria,Melissa officinalis,Efflux pumps
- چکیده:
- چکیده انگلیسی: Background and aims: In bacteria using inhibitors of efflux pumps (EPIs) is one of several strategies to combat with bacterial resistance. It is well documented that most medicinal plants especially those with antimicrobial properties composed of elements (EPIs) that disturb the efflux pumps of bacteria.
The current work was designed to evaluate antibacterial activities of ethanol and chlorophorm extracts of Melissa officinalis and also synergistic effects of the extracts with ciprofloxacin against some gram negative pathogenic bacteria. We also examined the inhibitory effects of the extracts on efflux pumps.
Methods: Minimum inhibitory concentrations (MICs) of the extracts alone or in association with ciprofloxacin or phenylalanine arginine β- naphtylamide (PAβN) were determined using broth micro dilution method. Effects of the extracts on efflux pumps of the examined bacteria detected by using ethidium bromide in well diffusion assays.
Results: The extracts from M. officinalis showed antibacterial activities against all examined bacteria in a range of 3125 to 25000 μg/mL as determined by MIC determination.
The extracts from M. officinalis showed synergistic effects with ciprofloxacin on Salmonella enteritidis and Escherichia coli. In Pseudomonas aeruginosa and Acinetobacter baumannii PAβN had no effect on MIC of ciprofloxacin but the association of extracts decreased it. In S. enertidis and E Coli both extracts of M. officinalis increased the amount of ethidium bromide accumulation (i.e. reduced efflux).
Conclusion: The overall results show that associations of fluoroquinolones with extracts of M. officinalis may potentiate the antibacterial effects of fluoroquinolones.- انتشار مقاله: 10-07-1397
- نویسندگان: Azizollah Ebrahimi,Maryam Shahrokhi,Saied Habibian,Sharareh Lotfalian
- مشاهده
- جایگاه : پژوهشی
- مجله: Advanced Herbal Medicine
- نوع مقاله: Journal Article
- کلمات کلیدی: Antibacterial activities,Berberis vulgaris L,Gram-negative bacteria
- چکیده:
- چکیده انگلیسی: Background and aims: Some medicinal plants particularly those with antimicrobial properties contain compounds that potentiate the activity of antimicrobials against pathogenic bacteria. This study was planned to search the antibacterial activities of the hydro alcoholic and chloroform extracts of Berberis vulgaris L.root and their synergistic effects with ciprofloxacin against some gram-negative pathogenic bacteria.
Methods: After grinding, powder of Berberis vulgaris L. roots were extracted with ethanol 85% and chloroform by maceration method. Broth micro dilution method was used for determination of minimum inhibitory concentrations (MICs) of the extracts alone or in association with ciprofloxacin and Phenylalanine-Arginine β- Naphtylamide (PAβN) as a positive control and efflux pumps inhibitor (EPI).
Results: MIC determination indicated that the hydro alcoholic and chloroform extracts from Berberis vulgaris L. rootwere able to inhibit the growth of all the studied bacteria within a concentration range of 25000 to 75000 and 1562 to 6250 µg/mL, respectively. Synergistic effects were noted between the extracts from Berberis vulgaris L.root extracts and ciprofloxacin on all tested bacteria.
Conclusion: Berberis vulgaris L. root extracts act as an antibacterial agent and potentiate ciprofloxacin effects on examined pathogenic bacteria. The present investigation brings about primary information’s for the possible use of these extracts in association with fluoroquinolones.- انتشار مقاله: 06-02-1395
- نویسندگان: Azizollah Ebrahimi,Bahareh Moazami,Mohamad Reza Mahzoonieh,Sharareh Lotfalian
- مشاهده