Background: This study aimed to examine the antibacterial effect of Polyamidoamine-G4 dendrimer on Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus.

Materials and Methods: In this experimental study, the antibacterial effects of Polyamidoamine-G4 dendrimer were studied by disc diffusion and micro-dilution method. Different concentrations of Polyamidoamine-G4 inoculated onto blank disks and were placed in Mueller-Hinton agar media. Zone of inhibition was investigated by bacterial inoculation according to the McFarland standard 0.5. Minimum inhibitory concentration and minimum bactericidal concentration of Polyamidoamine-G4 dendrimer were determined by micro-dilution method in nutrient broth culture.

Results: Zone of inhibition in concentration 500 &mug/ml of Polyamidoamine-G4 dendrimers for Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus were 14, 0, 35 and 29mm, respectively. Concerning the Zone of inhibition in gram negative bacteria with gram positive ones was p<0.05 and had significant difference. The minimum inhibitory concentration of Polyamidoamine-G4 dendrimer for Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 1250, 2.5, and 1 &mug/ml, respectively. The minimum bactericidal concentration of Polyamidoamine-G4 dendrimer belonged to Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 2500, 5 and 5 &mug/ml, respectively. Polyamidoamine-G4 dendrimer had not bacteriostatic and bactericidal effects on Enterobacter cloacae.

Conclusion: According to the results, Polyamidoamine-G4 dendrimer can eliminate Escherichia coli, Staphylococcus aureus and Bacillus subtilis effectively. It is suggested in the rest of this study that the probable toxicity of nanostructured compounds examined in drinking water and, economic studies is done for synthesis and their applications in case of prevention of using.

Background: Pseudomonas aeruginosa is one of the major etiologic agents of nosocomial infection among burn patients that has high resistance to antibiotics. Integrons can extend antibiotic resistance genes among bacteria. The aim of this study was to investigate the antibiotic resistance pattern and the prevalence of integron among P. aeruginosa isolates.

Materials and Methods: In this cross-sectional study, a total of 73 P. aeruginosa isolated from burn wound infections among hospitalized patients in Ahvaz Taleghani hospital. Antibiotic resistance pattern of these bacteria was investigated to 9 antibiotics by Disk Agar Diffusion method. Polymerase chain reaction (PCR) method was used to investigate the prevalence of class 1, 2 and 3 integrons. The data were analyzed by Chi-square test. A P-value of <0.05 was considered as a statistical significance level.

Results: The most antibiotic resistance level was seen against ofloxacin (94.5%), aztreonam (94.5%), and ceftazidime (93.6%). Fifteen isolates of P. aeruginosa were resistance to all of the antibiotics. The study of molecular results showed that class 1 integron was detected in 35.6% of isolates, while none of them harbored class 2 and 3 integron.

Conclusion: The rates of antibiotic resistance in pseudomonas aeruginosa to antibiotics such as ceftazidime, oflaxacin, aztreonam, cefepime, and ceftriaxone is very high. Although, class 1 integron were detected in 35.6% of isolates, there was no statistically significant differences between the presence of integron and resistance to a specific antibiotic, that it shows the role of the other antibiotic resistance mechanisms among pseudomonas aeruginosa.

        Background: Dendrimers are a subset of branched structures that have certain structural order. The aim of this study was to investigate the performance of Polypropylenimine-G2 (PPI-G2) dendrimers in removal of Escherichia coli, Proteus mirabilis, Bacillus subtilis and Staphylococcus aureus from aqueous solution .

        Materials and Methods: In this experimental study , initially dilution of 10³ CFU/ml was prepared from each strain of bacteria . Then , different concentrations of dendrimers (0.5, 5, 50 and 500 µg/ml) was added to water . In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 40, 50 and 60 min) and were cultured on nutrient agar medium . Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted .

       Results: By the increasment of dendrimer concentration and contact time , the number of bacteria in aqueous solution decreased. In times of 40 , 50 and 60 minutes, and the concentrations of 50 and 500 µg/ml, all kinds of bacteria in aqueous solution were removed . 0.5 µg/ml of dendrimer concentration had not effect in reducing the number of Escherichia coli and Proteus mirabilis . The effect of dendrimer on gram-negative bacteria was weaker than gram-positive bacteria.

       Conclusion: Results of this study indicated that PP I -G2 dendrimer is able to remove Escherichia coli , Proteus mirabilis , Staphylococcus aureus and Bacillus subtilis in aqueous solution. However, using dendrimers can be considered as a new approach for drinking water disinfection but it requires further wide range studies.

Background: Dendrimers are macromolecules with regular three-dimensional structure that have many branches. The aim of this study was to investigate the fficiency of Nano Polyamidoamine–G5 (NPAMAM-G5) dendrimers in removal of Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.

Materials and Methods: In this experimental study, initially, dilution of 10³ CFU/ml was prepared from each strain of bacteria. Then, different concentrations of dendrimers (0.025, 0.25, 2.5 and 25 µg/ml) in the ambient temperature (23-25°C) was added to water. In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 50 and 60 min) and were cultured on nutrient agar medium. Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted.

Results: There is a direct relation between antibacterial properties of dendrimers in aqueous solution and increasing the dendrimer concentration and contact time. At a concentration of 25 μg/ml and 60 minutes, all kinds of bacteria except Staphylococcus aureus, and at 30 minutes, E. coli and Klebsiella bacteria, were removed by 100% The concentration of 2.5 μg/ml at 60 minutes of  bacteria, Escherichia coli, Klebsiella and Proteus mirabilis, 100% Were removed. All concentrations of dendrimer at different times were reduced bacteria.

Conclusion: Results of this study indicated that NPAMAM–G5 dendrimer is able to remove Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus from aqueous solution.

Background: because of the side effects of chemical drugs, using plant drugs was considered during recent decades. Based on previous studies, various concentrations of plant extracts can reduce ileum contraction caused by KCl and carbachol. Therefore, in this study, the role of muscarinic receptors in anti-spasmolytic activity of hydroalcohlic extract of parsley(petroselinum crispum)seed in adult male rat's ileum was investigated.

Materials and Methods: The distal part of Wistar rat’s ileum was separated and its contractions were recorded under 1 gr stretching and 37^oC temperature in the bathroom containing the solution of Tyrode by Isotonic method. The ileum tissue was inserted in separately in first group affected by KCl and parsley seed, in the second group affected by KCl and carbachol with concentration 10^-2 mg/ml and after that parsley seed, the third group affected by carbachol with concentration 10^-2 mg/ml and then the extraction of parsley seed and the fourth group affected by scopolamine with concentration 10^-3 M and after that KCl and then the extraction of parsley seed.

Results: Non-cumulative concentrations of extract reduced the ileum contraction caused by KCl (60mM) in a concentration-dependent form (p<0.001). There was a significant difference between the effect of extract in the presence of carbachol and extract concentration 0.2 mg/ml (p<0.01). There was no significant difference between the effect of extract in the presence of carbachol without stimulating tissue by KCl (60mM) with extract concentration 0.2mg/ml (p<0.05). There was no significant difference between the effect of extract in the presence of scopolamine with extract concentration 0.2mg/ml(p<0.05).

Conclusion: This study showed that the hydroalcholic of parsley seed extract has a relaxatory effect on rat’s ileum. Carbachol with KCl has a synergistic effect on smooth muscle contraction of the ileum wall and muscarinic receptors do not involve in the inhibitory function of parsley seed extract.

Abstract

Background: Parsley is one of the medicinal herbs used for gastrointestinal disorders. However, spasmolytic activity of Petroselinum crispum (parsley) extract has been reported, there is a lack of information to support the mechanism of this antispasmodic activity. Taking this into account, the purpose of the present work was to investigate the role of GABA_A receptor on antispasmodic activity of the hydroalcoholic extract of parsley seed in isolated rat ileum.

Materials and Methods: In this study, terminal portion of ileum (2 cm) was dissected out and mounted in an organ bath containing air bubbled Tyrode solution (37^οC, pH=7.4). Under 1gr resting tension, ileal contraction was induced by KCl (60 mM) and recorded isotonically. The effects of non-cumulative (0.1-0.5 mg/ml) concentrations of extract on KCl-induced contractions were examined.  After evaluating the effect of agonist and antagonist GABA_A receptor, the effect of parsley extract was assessed in the presence of muscimol (25 µM) and bicuculline (10 µM) as agonist and antagonist of GABA_A, respectively. 

Results: Parsley seed extract reduced the KCl-induced ileal contraction in a concentration-dependent manner (n=7, p<0.001). Both muscimol and bicuculline exerted relaxant effect on ileal contraction (n=7, p<0.05, p<0.01, respectively). Surprisingly, agonist and antagonist of GABA_A both potentiated the spasmolytic effect of extract (0.2 mg/ml). Altogether, spasmolytic effect of extract was not attenuated in the presence of GABA_A antagonist.

Conclusion: It seems that GABA_A receptor is not involved in the antispasmodic effect of parsley seeds extract in rat ileum.