[Minimum inhibitory concentration of silver nanoparticle against Staphylococcus aureus and its relation with Methicillin resistance and bacterial source of isolation]

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 micro g/ml, and mean +/- std was 2.9 +/- 1.89 micro g/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 micro g/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 micro g/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

Detection of staphylococcus aureus enterotoxin genes A-E

The main cause of spreading staphylococcal infections among patients is the healthy carriers working in hospitals. With the secretion of different sorts of toxins such as entrotoxin, this bacteria can provide the conditions for attacking on the host. The main objective of this study is identification of the characteristics and differences in the Staphylococcus aureus isolated from healthy carriers and from the patients on the basis of enterotoxin genes [sea-see]. One hundred and twenty of the patients and 80 of healthy carriers worked in health centers of Gorgan, north of Iran, were investigated for S. aureus isolate. The isolates were evaluated by PCR for Enterotoxin Genes A-E [SEA to SEE]. Enterotoxin genes [SEA to SEE] was found in 87.5% of the total isolates and the most frequent one was enterotoxin gene sea [N= 124]. The prevalence of these isolates in healthy carriers was significantly higher than those of the patients. Based on the results, the high percentage of S. aureus isolated from clinical samples contains enterotoxin genes. Therefore, Human as the source and carrier of S. aureus is paramount importance, which is due to significant relationship between being toxigenic strains and the source of isolation

Effects of aqueous Echinacea purpurea extract on immunogenicity of DNA vaccine encoding M2 gene of Influenza virus

Continuous antigenic variation of Influenza a viruses causes a major concern to develop Influenza vaccine. Conserved antigens are suitable candidates for vaccine production due to its non-requirement to match the designed strains with circulating strains. The M2 gene is conserved among Influenza a viruses and has potential to be considered as a universal vaccine. This study was designed to evaluate the effects of aqueous Echinacea purpurea extract on immunogenicity of DNA vaccine encoding M2 gene of Influenza virus. This interventional study was carried out on female BALB/c mice with 3-4 week age [250-300 gr]. Plasmid DNA encoding M2 gene [pcDNA-M2] of Influenza virus A/New Caledonia/20/99 [H1N1] was transformed into E.coli top10 f' and cultured in LB broth media. Large scale plasmid preparation was done and the concentration was measured by spectrophotometric method. Mice were divided into eight groups and immunized three times with fifteen days apart. Vaccine groups received inactivated Influenza virus or pcDNA-M2, alone or in combination with Echinacea extract. Control groups were injected pcDNA, Echinacea extract, and phosphate buffer. All animals were left to bleed before immunization and at 21 days after the last vaccination and specific anti-M2 antibodies were measured by indirect ELISA. Then the mice were intranasally challenged under an aesthesia with mouse-adapted PR8 Influenza virus and monitored for 3 weeks to evaluate the vaccine regimen efficacy in reduction of mortality rate compared to control groups. Data were analyzed using SPSS-16, One-way ANOVA and Kaplan-Meier tests. The highest specific immune response was obtained in mice received inactivated virus plus extract [P<0.05]. Immune responses in mice inoculated with pcDNA-M2 were significantly higher compared to all control groups mice [P<0.05]. In addition the specific immune responses in group inoculated with pcDNA-M2 and aqueous extract was higher compared to the group receiving only pcDNA-M2 [P<0.001]. The highest survival rate was observed in mice injected with inactivated virus or pcDNA-M2 plus extract. This study showed that pcDNA-M2 induced specific immunity and protected mice against lethal challenge with PR8 Influenza virus. Furthermore, application of Echinacea extract with M2 gene vaccine increased vaccine efficacy

Drug- resistance- associated mutations and HIV sub-type determination in drug-naive and HIV-positive patients under treatment with antiretroviral drugs

Resistance to antiretroviral agents is a significant concern in clinical management of HlV-infected individuals. Resistance is the result of mutations that develops in the viral protein targeted by antiretroviral agents. In this cross-sectional study, the blood samples of 40 HI.V-positive patients were collected. Twenty of them were drug-naive and the rest were under treatment for at least one year by antiretroviral agents. Virus genome was extracted from patient's plasma with high-pure-viral-nucleie-acid kit. Then, by means of reverse-transcriptase and specific primers of protease genes were amplified and sequenced. Sequences of genes, drug- antiretroviral-resistant mutations and subtypes were determined using Stanford University's HI Vdrugresistance databases. Drug-naive patients show 15% resistance to nucleoside-reverse-transcriptase inhibitor [NRTI] and 20% resistance to non-nucleoside-reverse-transcriptase inhibitor [NNRTI]. Anti-protease resistance is not observed in any patients. In under treatment patients, drug resistance to NNRTI [25%] is more than drug resistance to NRTI [20%] and the rate of drug resistance to protease inhibitor is 5%.Our findings show a high prevalence of drug-resistant mutations in Itanian-drug-naiVe-HIV-infected patients. But in under treatment individuals, the rate of drug resistance is less than previous studies

Seroepidemiology of hepatitis e virus in hemodialysis patients in gorgan-Iran

Hepatitis E virus is one of the most common causes of acute infection in adults. Pregnant and transplant patients are more in risk of REV infection. Fecal-oral is the main route of REV transmission but recently transmission by blood transfusion has been observed. This study was amied to determme tbe prevalence of HEV -Ab in hemodialysis patients in Gorgan, Iran. In this cross-sectional descriptive study, we investigated I 150 hemodialysis patients of Panje Azar hospital in Gorgan. These patients were I evaluated for the presence of HEV total Ab by ELISA method. Of 150, 6 patients [4%] are positive for HEV-Ab. There has been no I significant relation between anti HEV Ab and variables such as age, gender, ethnicity, duration and number of hemodialysis in a week and [P>0.05]. This study, which is the first report from this area, show that the I lower prevalence of anti HEV Ab in hemodialysis patients in comparison with | pregnant and childbearing age women

[Inhibitory effect of green and black teas ethyl acetate extracts on helicobacter pylori the causative agent of peptic ulcers]

Helicobacter pylori is the etiological agent in peptic ulcers and gastric carcinoma. The growing problem of antibiotic resistance by this organism demands the search for novel compounds from plant based sources. Tea is amongst the most popular beverages in Iran. There is no investigation regarding the inhibitory effects of tea extracts on Helicobacter pylori growth or its urease production and function. This study was conducted to evaluate the inhibitory effects of tea ethyl acetate extracts on Helicobacter pylori growth and its urease. This was an experimental study [2008, Science and Research campus] in which the extraction of samples was performed by Soxhelet extractor in methanol/water [1:1] mixture as a solution followed by final re-extraction with ethyl acetate. The minimum inhibitory concentrations of black and green tea extracts were assessed by broth dilution method and examination of urease function performed by Mc Laren method. The urease production was detected on 12% SDS polyacrylamide gel electrophoresis. Both extracts showed inhibitory effects on H. pylori growth, urease function and its production. Urease production was completely inhibited by both black and green tea extracts at concentrations of 3.5mg/ml and 2.5mg/ml, respectively. Also, the growth of H. pylori was inhibited by black tea extract at concentration of 4.5mg/ml and at 3.5mg/ml of green tea extract. Based on inhibitory effects of tea extracts on H. pylori shown in the present study, it seems that both tea extracts in particular the green tea have the potential to reduce the H. pylori population and possibly prevent from chronic gastritis and peptic ulceration

[In vitro reduction in colonization of Streptococcus mutans by honey beeswax ethyl acetate extract]

Dental plaque is composed of bacterial derived extracellular polysaccharide known as glucan which is synthesized by Streptococcus mutans. Natural substances that could inhibit the plaque formation of the bacteria have a significant importance. This investigation has evaluated the honey beeswax extract effect on the Gft production, the key enzyme of S. mutans colonization factor for the first time. In this experimental study extraction of the sample conducted with ethyl acetate and methanol solutions in the Clevenger extractor. The ethyl acetate soluble fraction was separated in the first step and after the evaporation of the first solute, the 70% methanol as inactive solvent was added and the water mixture was used as a second solution, then materials were separated with dH[2]O. Minimum inhibitory concentration [MIC] of the honey beeswax extract was assessed by Broth diffusion method. Examination of cell adherence [Biofilm Inhibitory Concentration, BIC] was calculated by colony counts from surface scratching of glass slides in the bacterial media that supplied with 1% sucrose. Glucosyltransferase expression was detected by 15% SDS poly acrylamide gel electrophoresis. Concentration of 1mg/ml of ethyl acetate honey beeswax extract was inhibited completely biofilm and it was prevented the production of glucosyltransferase enzyme. The concentration of formation 6 mg/ml of the extract had bacteriostatic effect and 30 mg/ml concentration of this extract had bacteridicidal for S. mutans [P<0.01]. Thu sub-bacterial concentration honey beeswax extract was able to block the major enzyme that contributes to S. mutans biofilm formation