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Background&Objective: Staphylococcus aurues is on important cause of community and hospital- aquired infections. Caused by methicillin or oxacillin- resistant s.aureus (MRSA) are mainly nosocomial and are increasingly from many countries word wide. Many attempt have been made by the reasearchers to find new compounds as a subsitute for this antibiotics. The aim of this study was to investigate the antimicrobial activity of alcoholic extracts of 20 medical plants species of Golestan provience on clinical and standard strains of MRSA and MSSA and comprative and detect the best medical plant. Materials&Methods: In this study the compunds of the plant were extracted by percolation method and the effect of ethanolic extract of 20 Iranian medical plants against methicillin resistant and methicillin sensitve strains were assessed by disc diffusion method and each test were repeated 3 times and mean inhibition zone were recorded and then, the minimum inhibitory concentration (MIC) of the extracts, that show good inhibition zone in disc diffusion method, was determined by the micro broth dilution method. Results: The results of antibacterial activity of the ethanolic extracts of 20 plants revealed that, the ethamlic extracts of 8 plants have the best effect on strains and the maximum mean inhibition zone was 22.4 mm and the lowest MIC of plants was 0.01 mg/ml. Conclusion: The result of this study indicate that, ethanolic extract of Eucalyptus. Global, Peganum.hermla, Punica.granatum, Berberis.vulgaris, Ttamarixaphylla, Nnigella.sativa, Hypericum.perforatum AND, Artemisia. Herbaalba have the best antibacterial effect against MRSA andMSSA. The result obtained from these plants might be considered sufficent for further study.

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Background and Objective: Considering the significant incidence of nosocomial infections in hospitalized patients, this study was done to determine the prevalence of Staphylococcus aureus strains isolated from wound infection and drug sensitivity pattern, Tehran-Iran. Materials and Methods: In this descriptive study, Staphylococcus aureus isolated and identified according to standard procedures from the wound infections of 614 patients referred to Baqiyatallah hospital, Tehran-Iran during 2006-07. The samples were examined and antibiogram was performed by disc diffusion method on Mueller Hinton agar with 12 antibiotics. Results: 100 (16.28%) of wound infection of Staphylococcus aureus was isolated from 614 patients. The infection rate in men was twice compared to women. The highest rate 29 (29%) was observed in people aged 40 to 60 group. Also specimen's patients with immunosuppressive diseases (28 cases), surgical site infection (16 cases) and normal wounds (13 cases) were considered to be most prevalent isolates. Antibiotic sensitivity testing revealed that 96 (96%) of isolates were sensitive to vancomycin, 95 (95%) and 92 (92%) were resistant to penicillin and cotrimoxazole, respectively. Our result showed that 43% of strains were resistant at 11 antibiotics. Conclusion: This study showed that the prevalence of Staphylococcus aureus was 16.28% of samples, with 43% antibiotic resistance. The highest sensitivity was toward to vancomycin.

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Background and Objective: The generated genetic diversity in the microbial pathogens and drug resistant led to a growing interest to use herbal medicine. This study was carried out to determine the in vitro anti-bacterial activity of chloroform, ethyl acetate and hydroalcoholic extracts of Scilla persica Hausskn. Methods: In this laboratory study, chloroform, ethyl acetate and hydroalcoholic extracts were obtained from bulb of Scilla persica. The anti-microbial activity, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the extracts were evaluated on Staphylococcus aureus, Bacillus cereus and Escherichia coli using the disk diffusion (growth inhibition zone) and macro-dilution methods. Dimethyl sulfoxide (DMSO) was used as a negative control while nalidixic acid and ampicillin were used as positive control. Results: The maximum inhibition zone for ethyl acetate extract was 26.3±0.1 milimetre, 23.7±0.3 milimetre and 19.5±0.4 milimetre for Staphylococcus, Escherichia coli and Bacillus, respectively. The maximum inhibition zone of chloroform extract was found to be 16.4±0.2 milimetre and 14.9±0.3 milimetre for Staphylococcus and Bacillus, respectively. Conclusion: Antimicrobial activity of the chloroform and ethyl acetate extracts of bulb of Scilla persica on Escherichia coli, Staphylococcus aureus and Bacillus cereus are more effective compared to nalidixic acid and it is similar to ampicillin in in-vitro condition.

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Background and Objective: Methicillin-resistant Staphylococcus aureus is a common pathogen responsible for health-care-related infections. This study was done to determine the prevalence of Meticilin - resistant Staphylococcus isolated from hand and nasal of hospital health worker. Methods: This descriptive study was conducted on 148 health workers in teaching hospitals in Sari, northern Iran during 2011-12. Samples were collected from fingers and noses and were cultured on mannitol salt agar immediately. Suspected colonies were identified using Gram staining, catalase and coagulase tests. Susceptibility testing was performed by disk diffusion method. Methicillin resistant strains were determined using micro dilution broth method. Results: Staphylococcus aureus was observed in 24 (16.2%) of individuals. 9.5% of population was resistant to Methicillin. The high portions of Staphylococcus aureus carreier were in the operation room, angiography and internal pediatric ward health worker. Methicillin Staphylococcus aureus resistanat were more common in nasal samples of the operation room personal and angiography ward health worker. All strains were sensitive to Vancomycin and Chloramphenicol and resistant to Penicillin and Amoxicillin. Conclusion: In this study the prevalence of the Staphylococcus.aureus in teaching hospitals health worker was low while Staphylococcus aureus resistant to methicillin was higher than other reports in Iran.

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Background and Objective: Resistance of Staphylococcus aureus to antibiotics is one of the major global health problems in human societies. Thus, evaluation of pattern of antibiotic resistance in its different strains is very important. This study was carried out to evaluate the antibiotic resistance in Staphylococcus aureus isolated from clinical samples by disk diffusion and PCR methods.

Methods: In this laboratory- descriptive study, 50 isolates of Staphylococcus aureus to be identified from clinical specimens. Methicillin resistance was examined using PCR and antibiotic susceptibility of isolates was tested by disk diffusion method.

Results: 50 isolates were resistant to methicillin, ampicillin and penicillin. The resistance of isolates to erythromycin, Gentamicin, Clindamycin and Ciprofloxacin were 48%, 34%, 34%, 34%, respectively. The PCR method showed that 98% of Methicillin Resistance of Staphylococcus aureus isolates carried the methicillin resistant gene.

Conclusion: This study indicated that 98% isolates harbor mecA genes and more resistant to methicillin related mecA genes.

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Background and Objective: The rise of antibiotic resistance particulary Methicillin resistance in pathogenic bacteria such as Staphylococcus aureus is found to be an emerging threat to human health especially in hospitals. Heavy metal nanoparticles such as Ag used for inhibition of this bacterium. This study was done to determine of minimum inhibitory concentration (MIC) Ag nanoparticle against Staphylococcus aureus which isolated in Gorgan, north of Iran and its relation with Methicillin resistance and source of bacteria.

Methods: In this descriptive – analytical study, the MIC Ag nanoparticle in 183 isolates of Staphylococcus aureus by microdilution method was determined. 30 isolates, based on mecA gene was considered as MRSA. Samples were collected from patients, nose of healthy carriers and foods. Compare the MIC of isolates based on Methicillin resistance, source of the bacteria and resistance to other antibiotics were assessed.

Results: Out of 183 samples MIC was varied from 1 to 16 µg/ml, and mean±std was 2.9±1.89 µg/ml. MIC mean of silver nanoparticles in isolated from foods were 2±0.7, isolared from healthy carriers were 4.1±2.4 and from patients were 3.4±2.1 µg/ml and were statically significant (P<0.05). MIC mean of silver nanoparticles in MSSA isolates are 3.9±2.3 and in MRSA isolates are 2.4±1.4 µg/ml that were statically significant (P<0.05). MIC mean of gentamycin resistant isolate were lower than sensitive one. But between MIC of silver nanoparticles and other antibiotics resistance was not significant statistically.

Conclusion: There is a relation between silver nanoparticle MIC, source of sample isolation, Methicillin and gentamycin resistance. Since MIC of silver nanoparticles on isolates of Methicillin resistant is low, the possibility of its use in the control of MRSA in hospital infections can be considered as a prime attention the Gentamycine.

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Background and Objective: Probiotc bacteria have benefical effect on consumer health. This study was done to investigate the antimicrobial effect of several probiotic in combinations with different prebiotics against food patoghenic bacteria including Staphylococcus aureus and Listeria monocytogenes.

Methods: In this descriptive - analytical study, probiotics including Lactobacillus plantarum, L. acidophilus, L. fermntum, L. casei and L. rhamnosus with prebiotics (1%) including raffinose, lactulose, inulin and trehalose were cultured in MRS broth for 24 hours at 30ºC in anaerobic conditions. Antimicrobial property of them was determined with well diffusion plate's method.

Results: Probiotics in the presence of prebiotics indicated the higher antimicrobial effect compared to probiotics alone (P<0.05). The application of prebiotics such as L. casei with raffinose showed higher antimicrobial property against Listeria monocytogenes than the free prebiotics consumption. The diameter of inhibitory growth zone in the presence of raffinose as a prebiotics was 14.66 mm and its absence reduced to 11.75 mm.

Conclusion: Antimicrobial effect of probiotics in combination with prebiotics against Staphylococcus aureus and Listeria monocytogenes was higher than probiotics consumption alone.

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Background and Objective: The adoption of methods for increasing the shelf life of dairy products by using natural preservatives is necessary. This study was done to determine the antimicrobial activity of aqueous extract of orange peel and its effect on the shelf life of flavored milks.

Methods: In this descriptive –analytical studty the antimicrobial activity of aqueous extract of orange peel was investigated by using disk diffusion method and minimum inhibitory concentration (MIC) by successive dilution of culture broth and then its impact on the shelf life of milk.

Results: In disk diffusion method and MIC the antimicrobial effect of aqueous extract of orange peel was more effective against Staphylococcus aureus and Candida albicans and less effective on Escherichia coli. The growth diameter of disk diffusion method in aqueous extract of orange peel was 7.11, 29.06 and 50 mm for Staphylococcus aureus, Escherichia coli and Candida albicans, respectively. The inhibitory concentration in the aqueous extract of orange peel was 15, 2 and 2 mg/ml, respectively. Also 0.17 g/ml of aqueous extract of orange peel in milk reduced the growth of microorganisms at the time of 6, 12, 24, 48 and 72 hours. Temperature affected the growth of Candida albicans in the milk, so that the growth of microorganisms reduced with decreasing temperature (P<0.05). The growth inhibitory activity of the aqueous extract of orange peel on Staphylococcus aureus was significantly more than on Escherichia coli (P<0.05).

Conclusion: This study showed that the antimicrobial activity of aqueous extract of orange peel on Staphylococcus aureus, Escherichia coli and Candida albicans in vitro and in the milk.

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Background and Objective: Nowadays, microorganisms have high resistance to antibiotics due to indiscriminate and unnecessary consumption. Treatment of infections caused by resistant bacteria has become difficult and expensive. Galls wild rose created by wasp's species Diplolepis mayri. This study was done to evaluate antibacterial activity of methanol, acetone and aqueous extracts of Wild Rose gall against Staphylococcus aureus and Enterococcus faecalis.
Methods: In this experimental laboratory study, the methanol, acetone and aqueous extracts of wild rose galls in 15.6, 31.3, 62.5, 125, 250 and 500 mg/dl were prepared by Soxhlet apparatus. Antibacterial activity of extracts was determined using well diffusion. MIC and MBC were determined by microdilution method. The active compounds of gall were evaluated by GC-MS.
Results: The inhibition zone of 500 mg/ml methanol, acetone and aqueous extracts of wild rose gall were 27.3, 26.7 and 20.0, respectively. The inhibition zone of wild rose gall was similar to imipenem (antibiotics). The extract concentration was related with antibacterial activity. The gall rose methanol extract showed the highest antibacterial effect. The MIC and MBC of methanol extract against Staphylococcus aureus and Enterococcus faecalis was 62.5, 31.3 mg/ml, respectively.
Conclusion: This study showed that aqueous, methanol and acetone extracts of wild rose galls have strong antibacterial activity.

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Background and Objective: Mupirocin is a secreted antibiotic inhibitor of Isoleucine-tRNA, a bacterial synthetase that is used against yellow wounds from Streptococcus pyogenic and Staphylococcus aureus. This study was carried out to determine the plasmid resistance of mupirocin in Staphylococcus aureus strains isolated from clinical specimens of the skin of hospital employees and hospitalized patients.
Methods: This descriptive study was performed on 150 strains of Staphylococcus aureus isolated from clinical specimens of the skin of patients and employees of three hospitals in Qom, Iran during
2014-15. In order to confirm the identity of Staphylococcus aureus isolates, conventional biochemical methods were used. Also, PCR of srRNA16 was used for molecular confirmation of isolates. The presence of mupA (iles-2) and mupB plasmid genes was investigated using PCR method and AluI enzyme digestion plan was performed for them. Disc diffusion method was used to demonstrate resistance to mupirocin.
Results: Seven isolated samples (4.66%) were resistant to mupirocin. All Mupirocin-resistant isolates possessed PCR-positive mupacysin mupirocidal genes (iles-2) and mupB, and all plasmid genes were resistant to all resistant specimens. Genotyping of mupB gene was able to isolate samples from patients and staff as well as male and female.
Conclusion: The prevalence of mupirocin-resistant Staphylococcus aureus isolated from skin specimens was low.

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Background and Objective: Staphylococcus aureus (S. aureus) is the most common cause of nosocomial infections. Treatment of Staphylococcal infections has become more complicated due to the emergence of methicillin-resistant S.aureus (MRSA) strains. This study was done to determine the frequency of methicillin resistance encoding gene (mecA) and β-lactamase resistance encoding gene (blaZ) in S. aureus isolates from clinical samples using Polymerase Chain Reaction (PCR) method.
Methods: This descriptive-analytic study was carried out on 59 S. aureus isolates from clinical samples in Gorgan hospitals from January-February 2017 to June-July 2017. All the isolates were identified using gram staining, catalase test, tube coagulase test, growth on Mannitol salt agar medium and the DNase test in the Microbiology Laboratory .Antibiotic resistance was evaluated using the standard disk diffusion.  Iodometric method was used to detect β-lactamase production / activity in this bacterium. PCR test was done to detect mecA and blaZ genes.
Results: All S. aureus isolates (100%) clinical samples possessed blaZ gene, followed by 27 isolates (45.8%) possessed mecA gene (MRSA), which these isolates possessed mecA gene were concurrently positive for blaZ gene. 5% of oxacillin-resistant strains and 3% of cefoxitin-resistant strains possessed mecA gene and 47 isolates (79.4%) carrying blaZ gene were β-lactamase-positive in phenotypic method.
Conclusion: This study showed that in all clinical samples isolated S. aureus isolates which these isolates possessed mecA gene were concurrently positive for blaZ gene.

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Background and Objective: Binding of antibiotics to nanoparticles increases the antibacterial potential of nanoparticles and antibiotics. This study was performed to determine the antibacterial and hemolytic effect of zinc / ferrite / cellulose nanocomposite (ZnFe2O4 @ Cell) (single nanoparticle), zinc / ferrite / cellulose nanocomposite was aminated with 3-aminopropyltriethoxysilane (APTES) with the name of ZnFe2O4@Cell@APTES (Coated nanocomposite) and ZnFe2O4@Cell@APTES@Van nanocomposite (coated nanocomposite bound to vancomycin) against gram-negative bacteria Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) and gram-positive bacterium Staphylococcus aureus (S. aureus).
Methods: In this descriptive study, antibacterial-activity was evaluated by broth macro dilution method. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MBC) were determined for E. coli, S. aurous and P. aeruginosa. The hemolytic activity of nanoparticles was investigated by colorimetric method.
Results: Nanoparticles did not have hemolytic activity. ZnFe2O4@Cell and ZnFe2O4@Cell@APTES@Van did not have a significant antibacterial effect against gram-positive and gram-negative bacteria, and vancomycin binding resulted in antibacterial-activity. ZnFe2O4@Cell@APTES@Van inhibited the growth of Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. The growth of E. coli was reduced to 85% at a concentration of 0.4 mg/ml and a concentration of 0.1 mg nanoparticles completely prevented the growth of P. aeruginosa. The growth of gram-positive S. aureus bacteria at a concentration of 0.3 mg/ml nanoparticles was completely stopped.
Conclusion: Vancomycin-modified nanocomposite has antibacterial-activity against both gram-positive and gram-negative bacteria and has the potential to overcome the antibiotic resistance of bacteria.

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Background and Objective: Trametes versicolor is important for its medicinal rather than nutritional value. Given the various pharmacological activities of this plant, this study aimed to investigate the antioxidant and antimicrobial potential of the aqueous extract of T. versicolor.
Methods: In this descriptive-analytical study, an aqueous extract of T. versicolor was prepared. Antioxidant activity, flavonoid content and total phenol were measured by diphenyl picryl hydrazyl (DPPH) and reducing power (RP) methods, aluminum chloride (AlCl3), and Folin-Ciocalteu assays. The antibacterial and antifungal activity of the aqueous extract of T. versicolor on Staphylococcus aureus, Escherichia coli and Fusarium thapsinum was determined by the disk diffusion method. Butylated hydroxytoluene (BHT), ciprofloxacin and amphotericin-B were used as positive controls for antioxidant activity and bacterial and fungal strains, respectively.
Results: Total phenolic content was 27.6±0.38 (mg GAE/g), and total flavonoid content was 4.2±0.04 (mg QE/g). Based on DPPH radical scavenging activity, the extract of T. versicolor showed strong scavenging activity (93.8±1.2 %) with IC50 of 103.9±0.8 μg/mL when compared with the standard BHT (IC50 of 30.0±0.6 μg/mL). In addition, it was observed that increasing the concentration of aqueous extract of turkey tail increased the reducing power of iron. The zone of inhibition around the extract ranged from 13.0±0.65 mm (in F. thapsinum at 75 mg/ml) to 21±0.73 mm (in S. aureus at 300 mg/ml) (P<0.05).
Conclusion: The aqueous extract of  T. versicolor contains a significant amount of phenolic compounds and also has strong antimicrobial and antioxidant properties.
 

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Background and Objective: Staphylococcus aureus is one of the most common causes of bacterial keratitis and conjunctivitis. This study was done to determine the efficacy of fluoroquinolones on Methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from external ocular infections.
Methods: This descriptive-analytical study was conducted on 187 pateiants (2 months to 61 years old) with symptoms of conjunctivitis and keratitis who were hospitalized or referred to the emergency department of hospitals in Golestan and Mazandaran provinces, Iran during 2020-22. The samples were taken from the external infection of the patients’ eyes. Methicillin-resistant Staphylococcus aureus isolates were identified by standard phenotypic microbiological and molecular detection (PCR) methods. The broth microdilution method determined sensitivity to quinolones and the minimum inhibitory concentration (MIC) in the 0.06-64 μg/ml range.
Results: The frequency of ocular MRSA isolates (n=52) was significantly higher in spring, females and patients aged 1-30 years (P<0.05). Among the MRSA isolates causing conjunctivitis, the highest rates of resistance were observed against ciprofloxacin (n=18, 48.64%), enoxacin (n=17, 45.95 %), and ofloxacin (n=17, 45.95%). The MIC of gemifloxacin that inhibited the growth of 90% of MRSA isolates from conjunctivitis (MIC90=0.25 μg/ml) was 32-fold lower than that of ciprofloxacin.
Conclusion: Depending on the season and age, staphylococcus aureus may be the most common cause of bacterial conjunctivitis and keratitis. Considering the in vitro antibacterial potential of gemifloxacin, this antibiotic can be used to treat the bacterial external eye infections.