Phytochemical constituents and biological activities of Salvia macrosiphon Boiss.

Salvia macrosiphon Boiss. is an aromatic perennial herb belonging to the family Lamiaceae. Phytochemical studies and biological activities of this plant have been rarely documented in the literature. The current study aimed to investigate antibacterial and cytotoxic activity of different fractions of aerial parts of S. macrosiphon. Also, we tried to isolate and identify cytotoxic compounds from the plant. In this respect, the hydroalcoholic extract of the corresponding parts of the plant was fractionated into four fractions. Then, antibacterial and cytotoxic activity of each fraction were examined. It was found that the chloroform fraction had a good antibacterial activity against gram-positive and gram-negative bacteria. The most potent cytotoxicity was also obtained by the n-hexane fraction comparing with etoposide as the reference drug which was selected for the study and characterization of secondary metabolites. Accordingly, 13-epi manoyl oxide (1), 6α-hydroxy-13-epimanoyl oxide (2), 5-hydroxy-7,4'-dimethoxyflavone (3), and ß-sitosterol (4) were isolated and evaluated for their cytotoxic activity. Among them, compound 1 revealed significant cytotoxicity against A549, MCF-7, and MDA-MB-231. It merits mentioning that it showed high selectivity index ratio regarding the low cytotoxic effects on Human Dermal Fibroblast which can be considered as a promising anticancer candidate.

Down-regulatory effects of green coffee extract on las I and las R virulence-associated genes in Pseudomonas aeruginosa.

BACKGROUND: Antibiotic resistant strains of Pseudomonas aeruginosa are the cause of Gram negative nosocomial infections especially among the immunosuppressed patients. The bacteria contains las I and las R genes that play very important roles in the pathogenesis and mechanisms of aggression. These genes can be influenced by the quorum sensing (QS) system and such mechanism is becoming clinically important worldwide. This study aimed to investigate the preventive effects of green coffee extract (GCE) on the expression of pathogenesis-related genes, las I and las R in P. aeruginosa. METHODS: A total of fifty four P. aeruginosa strains were isolated out of 100 clinical samples collected from the infectious wards in different hospitals (Tehran province) using conventional microscopic and biochemical methods. Susceptibility of the isolates to different antibiotics, GCE and chlorogenic acid were elucidated. Multiplex polymerase chain reaction (PCR) and real-time PCR were performed to detect and quantify the expression levels of las I and las R genes. The presence of chlorogenic acid in GCE was confirmed by HPLC. RESULTS: Antibiotic susceptibility tests revealed multidrug resistance among the clinical isolates of those 40 strains were resistant to ciprofloxacin (74.07%), 43 to ceftazidime (79.26%), 29 to amikacin (53.7%), 42 to ampicillin (77.77%), 17 to colistin (31.48%), 40 to gentamicin (74.77%), and 50 to piperacillin (92.59%). PCR outcomes exhibited that the frequency of las I and las R genes were 100% in resistant and sensitive strains isolated from clinical and standard strains of P. aeruginosa (ATCC 15449). Real-time PCR analyses revealed that GCE significantly prevented the expression of las I and las R genes in P. aeruginosa. GCE at concentration level as low as 2.5 mg/mL could prevent the expression of lasI and lasR genes in P. aeruginosa clinical isolates. CONCLUSION: The presence and expression levels of las I and las R genes in P. aeruginosa isolates were investigated when the bacteria was exposed to GCE. Our results tend to suggest that genes involved in pathogenesis of:Pseudomonas aeruginosa are down regulated by quorum sensing effect of chlorogenic acid and therefore GCE could be useful as an adjuvant in combating multidrug resistance strains of Pseudomonas aeruginosa.

Improvement of the functionality of pancreatic Langerhans islets via reduction of bacterial contamination and apoptosis using phenolic compounds.

OBJECTIVES: During type-1 diabetes treating by pancreatic islet transplantation, increasing oxidative stress and microbial contaminations are the main reasons of transplantation failure. In this study, we evaluated anti-apoptotic, antioxidant and antimicrobial potentials of phenolic compounds called ellagic acid (EA) and silybin on rat pancreatic islets. MATERIALS AND METHODS: By doing MTT assay, effective concentrations of EA and silybin were determined as 1500 and 2100 µM, respectively. Then, ELISA methods, flow cytometry and MIC were done to investigate antioxidant, anti-apoptotic and antibacterial effects of those compounds, respectively. RESULTS: Results of FITC Annexin-V and PI staining via flow cytometry, and also caspase-3 and -9 activities performed that EA has anti-apoptotic effects on pancreatic cells. Both compounds significantly diminished reactive oxygen species, and enhanced antioxidant power and insulin secretion. Furthermore, the minimum inhibitory concentration test indicated that these two have antibacterial effects on both Gram-positive and Gram-negative bacteria which usually contaminate the pancreatic islets. CONCLUSION: These findings support that use of EA and silybin can improve the function of islets which are used in transplantation, along with decreasing islets bacterial contamination.

Burn Wound Healing Activity of Lythrum salicaria L. and Hypericum scabrum L.

OBJECTIVE: Burns are complicated traumatic injuries caused by several physical or chemical factors. Plants with a wide range of secondary metabolites, with valuable properties like antioxidant and anti-inflammatory activities, can be a promising source of wound healing agents. MATERIALS AND METHODS: Effects of hydromethanolic extracts of Lythrum salicaria and Hypericum scabrum, individually and in combination, were assessed in second-degree burn wounds in rats in comparison to a white oleaginous base (negative control) and silver sulfadiazine (positive control). Histological assessments as well as total thiol molecules, lipid peroxidation, and total antioxidant power were evaluated in skin tissue samples. Total phenol, flavonoids, and tannins along with the antioxidant and antimicrobial activities of the extracts were also as- sessed. RESULTS: Total phenol, total flavonoid, and total tannin amounts for L. salicaria and H. scabrum were 331 ± 3.7 and 308.1 ± 5.2 µg gallic acid/mg extract, 5.8 ± 0.4 and 4.3 ± 0.3 µg quercetin/mg extract, and 430 ± 2.33 and 13.4 ± 0.5 µg tannic acid/mg extract, respectively. H. scabrum significantly inhibited S. aureus and L. salicaria moderately suppressed Staphylococcus aureus and Candida albicans growth. Wound contraction percentage with L. salicaria and H. scabrum was 89.5 ± 3.7 and 77.6 ± 4.1, respectively. A well-organized epidermal layer and normal appearance in dermis layer were more observable in the L. salicaria group. Moreover, L. salicaria ointment individually displayed better influence on tissue oxidative stress parameters than H. scabrum and the negative control (P < 0.05). CONCLUSION: Results of this study clearly confirm the effectiveness of L. salicaria topical ointment as a wound healing agent, possibly due to the considerable polyphenolic content and antioxidant properties.

Phytochemical analysis, antimicrobial, antioxidant activities and total phenols of Ferulago carduchorum in two vegetative stages (flower and fruit).

Ferulago carduchorum (Apiaceae family) is an endemic plant of Iran. The crude extract and four fractions of aerial parts of F. carduchorum in two vegetative stages (flower and fruit) were studied for their total phenolic contents, antimicrobial and antioxidant activities using folin-ciocalteu assay, micro dilution method and DPPH assay, respectively. The results indicated that the best antioxidant activity was determined in flower crude extract (IC50=0.44 mg/mL). The flower ethyl acetate fraction (FLE) showed better antimicrobial and antifungal activities than other fractions. So, FLE was selected for phytochemical investigations, resulting in isolation of a flavonoid (hesperetin). Hesperetin showed antimicrobial activity. The results showed that the antimicrobial and antioxidant effects during the flowering are obviously more than the fruit season.

Comparison of essential oil composition and antimicrobial activity of Coriandrum sativum L. extracted by hydrodistillation and microwave-assisted hydrodistillation.

Coriander (Coriandrum sativum L.), is an annual herb in the Apiaceae family which disperses in Mediterranean and Middle Eastern regions. The Coriander essential oil has been used in food products, perfumes, cosmetics and pharmaceutical industries for its flavor and odor. In Iran, fruits of Coriander used in pickle, curry powders, sausages, cakes, pastries, biscuits and buns. The aim of this study was to investigate microwave radiation effects on quality, quantity and antimicrobial activity of essential oil of Coriander fruits. The essential oils were obtained from the Coriander fruits by hydrodistillation (HD) and Microwave-assisted hydrodistillation (MAHD) then, the oils were analyzed by GC and GC-MS. Antimicrobial activities of essential oils were evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans by microdilution method. The results indicated that the HD and MAHD essential oils (EO) were dominated by monoterpenoids such as linalool, geranyl acetate and γ-terpinene. The major compound in both EO was linalool which its amount in HD and MAHD was 63 % and 66 %, respectively. The total amount of monoterpenes hydrocarbons in HD EO differ significantly with the amount in MAHD EO (12.56 % compare to 1.82 %). HD EO showed greater activity against Staphylococcus aureus and Candida albicans than MAHD EO. Moreover, their activities against Ecoli and P. aeruginosa were the same with Minimum Inhibitory Concentration (MIC) 0.781 and 6.25 µL mL(-1), respectively. By using MAHD method, it was superior in terms of saving energy and extraction time, although the oil yield and total composition decrease by using this method.

Bioactive Terpenoids and Flavonoids from Daucus littoralis Smith subsp. hyrcanicus Rech.f, an Endemic Species of Iran.

BACKGROUND: Daucus littoralis Smith subsp. hyrcanicus Rech.f. (Apiaceae) is an endemic species in northern parts of Iran where it is commonly named Caspian carrot. The fruits have been used as condiment. METHODS: In a series of in vitro assays, antioxidant (DPPH and FRAP assays), cytotoxic and antimicrobial activities of different extracts of roots and fruits were evaluated for the first time. The separation and purification of the compounds were carried out on the most potent extracts using various chromatographic methods and identified by spectroscopic data (1H and 13C NMR). RESULTS: The results showed that among the extracts only fruit methanol extract (FME) has significant antioxidant activity (IC50 = 145.93 µg.ml-1 in DPPH assay and 358 ± 0.02 mmol FeII/g dry extract in FRAP assay). The radical scavenging activity of FME at 400 µg.ml-1 was comparable with α-tocopherol (40 µg.ml-1) and with BHA (100 µg.ml-1) (p > 0.05). FME did not show any toxicity against cancerous and normal cell lines. Fruit ethyl acetate extract (FEE) had cytotoxic activity against breast carcinoma and hepatocellular carcinoma cells (IC50 168.4 and 185 µg.ml-1, respectively), while it did not possess antioxidant activity in comparison with α-tocopherol and BHA as standard compounds. Ethyl acetate and methanol extract of fruits showed antimicrobial activity against Staphylococcus aureus (MIC: 3.75 mg.ml-1) and Candida albicans (MIC: 15.6 and 7.8 mg.ml-1, respectively). Four terpenoids were isolated form FEE including: ß-sitosterol (1), stigmasterol (2), caryophyllene oxide (3), ß-amyrin (4). Also, three flavonoids namely quercetin 3-O-ß-glucoside (5), quercetin 3-O-ß-galactoside (6) and luteolin (7) were isolated from FME. CONCLUSION: This study showed that FEE and FME of D. littoralis Smith subsp. hyrcanicus Rech.f. had the highest biological activities which may be correlated with in vitro cytotoxic, antimicrobial and antioxidant activities of terpenoids and flavonoids components of the extracts.

Bacterial contamination of single- and multiple-dose vials after multiple use and intravenous admixtures in three different hospitals in iran.

There is possibility of microbial contamination of any single-dose vials (SDVs), multiple-dose vials (MDVs) and admixtures (ADXs) during the preparation and injection to the patients that could be resulted in bloodstream infection. The goal of this study was to investigate the microbial contamination of MDVs and SDVs after multiple use and ADXs prepared by nursing staff in the treatment room versus those prepared by the hospital pharmacist in the clean room. The sterility of 43 opened MDVs and SDVs, 92 prepared ADXs in treatment room and 17 prepared ADXs in clean room were studied by membrane filtration method. Only one of 92 ADXs prepared in treatment room was contaminated with Bacillus subtilis (%1.1) and none of the ADXs prepared in clean room, MDVs and SDVs had microbial contamination. Although good sanitization practices and training of nurses could reduce the risk of microbial contamination in traditional units, using clean room for preparation of parenteral products could be the best strategy.

Probiotic Properties of Lyophilized Cell Free Extract of Lactobacillus casei.

BACKGROUND: In recent years there have been considerable interests in the use of probiotic live cells for nutritional and therapeutic purposes. This strategy can be concomitant with some limitations such as survival of live cell during the GI-transit and their effective delivery to target tissues upon ingestion. Several attempts have been made to overcome these limitations such as their microencapsulation, spray-drying and lyophilization. OBJECTIVES: In this study extract of cultured probiotics without cells was evaluated for its antimicrobial effects, antioxidant activity, and its stability. MATERIALS AND METHODS: In this work the potential of lyophilized-cell-free-probiotic-extract (LPE) as a suitable alternative strategy for the preparation of probiotic-products was investigated. The main aim of this study was to find out the antibacterial and antioxidant activity of LPE and also its stability. LPE was obtained by centrifugation and subsequent lyophilization of the collected supernatant from culture media of Lactobacillus casei. An enzymatic reagent-kit was used for detection of its content of lactic acid. Antibacterial test was performed using agar cup-plat-method, the DPPH scavenging -assay was used to determine its antioxidant activity and during a storage course, LPE was under a long-term stability study. RESULTS: Results showed that, LPE had more antipathogenic effects, antioxidant activity, and stability during storage-time when compared to fresh probiotic-extract. CONCLUSIONS: Employing the LPE as a new approach, gives novel concept of probiotic-products in food and medical marketing.

An evaluation and partial characterization of a bacteriocin produced by Lactococcus lactis subsp lactis ST1 isolated from goat milk

A bacteriocin-like inhibitory substance producing Lactococcus lactis subsp lactis strain, ST1, isolated from goat milk of Iranian origin and with broad spectrum of activity and desirable technical properties was used for evaluating some futures of bacteriocin inhibitory activity. Cell growth and bacteriocin production studies were carried out in MRS medium incubated statically under uncontrolled pH condition. The antibacterial activity presented a primary metabolite pattern and showed a rapid decrease at the stationary phase. Microaerobiosis and capnophily growth conditions resulted in higher bacteriocin production while aerobiosis showed negative effect on both cell growth and bacteriocin production. Bacteriocin production, on the other hand, was favored in MRS broth (pH; 6.5) inoculated with 0.1 ml l-1 fresh culture when incubation was carried out at 30 °C. This indicated that the conditions resulted in higher levels of growth were frequently favoring bacteriocin production by ST1 as well. Decrease in activity, at the stationary growth phase, was much pronounced in favored growth condition. Nutrient depletion, deferent effect of low pH on bacteriocin production and/or protein degradation seemed more responsible for this phenomenon. The study also provided further data on new method for bacteriocin release from the cell wall of producer. It was clearly shown that both heating and ultrasound shock for 5 min at pH 2 could increase bacteriocin activity significantly. The release was more pronounced in the presence of 0.5% Tween80.

Enhanced antibacterial activity of roxithromycin loaded pegylated poly lactide-co-glycolide nanoparticles.

BACKGROUND AND THE PURPOSE OF THE STUDY: The purpose of this study was to prepare pegylated poly lactide-co-glycolide (PEG-PLGA) nanoparticles (NPs) loaded with roxithromycin (RXN) with appropriate physicochemical properties and antibacterial activity. Roxithromycin, a semi-synthetic derivative of erythromycin, is more stable than erythromycin under acidic conditions and exhibits improved clinical effects. METHODS: RXN was loaded in pegylated PLGA NPs in different drug;polymer ratios by solvent evaporation technique and characterized for their size and size distribution, surface charge, surface morphology, drug loading, in vitro drug release profile, and in vitro antibacterial effects on S. aureus, B. subtilis, and S. epidermidis. RESULTS AND CONCLUSION: NPs were spherical with a relatively mono-dispersed size distribution. The particle size of nanoparticles ranged from 150 to 200 nm. NPs with entrapment efficiency of up to 80.0±6.5% and drug loading of up to 13.0±1.0% were prepared. In vitro release study showed an early burst release of about 50.03±0.99% at 6.5 h and then a slow and steady release of RXN was observed after the burst release. In vitro antibacterial effects determined that the minimal inhibitory concentration (MIC) of RXN loaded PEG-PLGA NPs were 9 times lower on S. aureus, 4.5 times lower on B. subtilis, and 4.5 times lower on S. epidermidis compared to RXN solution. In conclusion it was shown that polymeric NPs enhanced the antibacterial efficacy of RXN substantially.

Biochemical and pathological evidences on the benefit of a new biodegradable nanoparticles of probiotic extract in murine colitis.

Efficacy of probiotics in the management of human inflammatory bowel disease (IBD) has been approved in the recent years. In the present work, the efficacy of a new biodegradable nanoparticles (NPs) of encapsulated and lyophilized probiotic extract (LPE) was examined in murine colitis. Colitis was induced by rectal instillation of trinitrobenzen sulfonic acid to male Wistar rats. The safety and effective dose of LPE was determined in a pilot study. To ease delivery into colon, LPE was encapsulated in chitosan-coated-poly (lactide co glycolide acid) NPs. After induction of colitis, animals in different groups received test compound in three doses by gavage for 10 days. Groups of sham, control (saline), and standard (dexamethasone) were also assigned. Colonic pathological examination, tumor necrosis factor alpha, interlukin (IL)-1ß, myeloperoxidase (MPO), and lipid peroxidation (LPO) were performed. LPE at all doses (273, 545, and 1100 mg/kg) had positive effects in reduction of pro-inflammatory cytokines, LPO, and MPO in a dose-dependent manner. The formulated compound containing medium dose of LPE was more efficient in mitigating the experimental colitis in comparison with that of high-dose LPE. It is concluded that LPE and its nanoparticle-encapsulated form are very much effective in control of colitis. Regarding safety of this compound, further studies can be conducted in patients with IBD.

An evaluation and partial characterization of a bacteriocin produced by Lactococcus lactis subsp lactis ST1 isolated from goat milk.

A bacteriocin-like inhibitory substance producing Lactococcus lactis subsp lactis strain, ST1, isolated from goat milk of Iranian origin and with broad spectrum of activity and desirable technical properties was used for evaluating some futures of bacteriocin inhibitory activity. Cell growth and bacteriocin production studies were carried out in MRS medium incubated statically under uncontrolled pH condition. The antibacterial activity presented a primary metabolite pattern and showed a rapid decrease at the stationary phase. Microaerobiosis and capnophily growth conditions resulted in higher bacteriocin production while aerobiosis showed negative effect on both cell growth and bacteriocin production. Bacteriocin production, on the other hand, was favored in MRS broth (pH; 6.5) inoculated with 0.1 ml l(-1) fresh culture when incubation was carried out at 30 °C. This indicated that the conditions resulted in higher levels of growth were frequently favoring bacteriocin production by ST1 as well. Decrease in activity, at the stationary growth phase, was much pronounced in favored growth condition. Nutrient depletion, deferent effect of low pH on bacteriocin production and/or protein degradation seemed more responsible for this phenomenon. The study also provided further data on new method for bacteriocin release from the cell wall of producer. It was clearly shown that both heating and ultrasound shock for 5 min at pH 2 could increase bacteriocin activity significantly. The release was more pronounced in the presence of 0.5% Tween80.

Preparation and characterization of spray dried inhalable powders containing chitosan nanoparticles for pulmonary delivery of isoniazid.

The aim of this study was to prepare spray dried inhalable powders containing isoniazid-loaded chitosan/tripolyphosphate (TPP) nanoparticles for sustained delivery of the drug to the lung. Nanoparticles were prepared by ionic gelation method. In-vitro drug release study indicated that the rate of drug release from nanoparticles was decreased by increasing the amount of chitosan. Entrapment of isoniazid into chitosan/TPP nanoparticles decreased minimum inhibitory concentrations (MIC) of the drug against mycobacterium avium intracellulare. Nanoparticles were spray dried using excipients such as lactose, mannitol and maltodextrin alone or with leucine. Results showed that the obtained powders had different aerosolization property. It was observed that by adding leucine, the particle size of microparticles deceased and the process yield and fine particle fraction (FPF) increased significantly. The in-vitro deposition data indicated that spray drying of isoniazid-loaded nanoparticles with lactose in the presence of leucine resulted in the production of inhalable powders with the highest FPF (45%).

Development of respirable nanomicelle carriers for delivery of amphotericin B by jet nebulization.

The aim of the present work was to prepare and characterize chitosan-stearic acid conjugate nanomicelles for encapsulation of amphotericin B (AmB) and to evaluate the in vitro nebulization of the formulations. Water soluble chitosan was grafted to stearic acid (SA) chains via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide mediated coupling reaction. The chemical structure of depolymerized chitosan (DC)-SA copolymers and degree of amino substitution was determined by (1)H NMR. AmB was loaded in nanomicelles with a maximal encapsulation efficiency of 97%. The physicochemical properties and formation of polymeric micelles were studied by dynamic light scattering and fluorescence spectroscopy method. Nanomicelles possessed positive charges with mean particle sizes of 101-248 nm. AmB-loaded micelles were also characterized for their antifungal activity, aggregation state of the drug, nebulization efficiency and retention of AmB in the micelles after nebulization. The results indicated that encapsulation of AmB in DC-SA micelles could improve the antifungal activity of the drug in some of the cases. The nebulization efficiency was up to 56% and the fine particle fraction (FPF) varied from 40% to 52%. Since there was only a little change in encapsulation of the drug in micelles after nebulization, DC-SA micellar formulations can be a suitable choice for pulmonary delivery of AmB.

A clinical, microbiological and immunological comparison between subgingival irrigation with Dentol and chlorhexidine in advanced periodontitis.

INTRODUCTION: The purpose of this study was to compare the clinical, microbiological and immunological effects of subgingival irrigation with Dentol(™) and 0.2% chlorhexidine in human advanced periodontitis. MATERIAL AND METHODS: Twenty cases of advanced periodontitis patients were randomly treated either with Dentol(™) (as test) or 0.2% chlorhexidine (as control) every other day for 29 days after primary scaling, root planing and oral hygiene instruction. Pocket depth (PD), bleeding on probing (BOP) and plaque index (PI) were considered as clinical parameters. Total counts of aerobic and anaerobic bacteria were measured in subgingival plaque. At the end, concentrations of TNF-α and IL-1ß in gingival crevicular fluid were measured as inflammatory markers. RESULTS: PD and BOP decreased in both groups on the 29(th) day and two weeks afterward. PI did not show any statistical difference either within or among groups (p > 0.05). Results indicate that both chlorhexidine and Dentol(™) diminished total count of subgingival anaerobic bacteria significantly (p < 0.05). Total count of subgingival aerobic bacteria increased in both groups, but the differences between the two groups were statistically significant in favour of Dentol(™) (p < 0.05). The level of IL-1ß in the crevicular fluid was reduced in both groups but it was more significant in the test group (p < 0.05). The TNF-a level decreased in both groups but the statistical difference between the two groups was negligible (p > 0.05). CONCLUSIONS: Subgingivally irrigation with Dentol(™), containing 0.02% carvacrol, every other day for 29 days is equally or more effective than 0.2% chlorhexidine in reducing clinical and immunological inflammatory indices.

Formulation and in vitro evaluation of ciprofloxacin containing niosomes for pulmonary delivery.

In order to develop a niosome-encapsulated ciprofloxacin (CPFX) HCl formulation for pulmonary delivery, the feasibility of encapsulation of CPFX in niosomes, its stability and nebulization capability was evaluated. Various combinations of nonionic surfactants with cholesterol were used to prepare the formulations. The in vitro deposition data of the niosomal formulations were examined using an Andersen cascade impactor. Formulations composed of Span 60 and Tween 60 in combination with 40 mol% of cholesterol exhibited high encapsulation efficacy and stability and also had fine particle fraction and nebulization efficiency of about 61.9% ± 1.0 and 77.9 ± 2.8, respectively. Minimal inhibitory concentration of the niosomal CPFX against some pulmonary pathogens were lower than free CPFX. Using the MTT assay in human lung carcinoma cell line (A549), niosome-entrapped CPFX showed significantly lower cytotoxicity in comparison to the free drug. These results indicate that niosome can be used as a carrier for pulmonary delivery of CPFX via nebulization.

Preparation and in-vitro Antibacterial Evaluation of Electroless Silver Coated Polymers.

Long-term use of indwelling medical catheters has often been hindered by catheter-associated nosocomial infections. In this study the effectiveness of silver coating of polystyrene and polyethylene polymers was investigated. Polymer pieces of 2 cm(2) each were coated with a thin layer of silver using electroless plating technique. Silver-coated polymers were challenged with cultures of four different microorganisms known for their involvement in nosocomial infections in both solid and broth media. The tested bacteria included Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa. Silver release from the coated polymers was 2-5 µg/cm(2) which was confirmed by chemical and biological methods. The silver coating thickness ranged between 20-450 nm. P. aeruginosa and S. aureus were the most adherent bacteria to polystyrene sheets while E. coli showed minimum adherence effect. The survival rate of different bacteria after 80 min in a time course experiment tended to dominate E. coli as the most sensitive bacteria to the effect of silver with zero survival rate while around 4% of P. aeruginosa were detected after same period. Silver coating of indwelling polymers by electroless technique seems promising in combating nosocomial infections due to long-term catheterization.

Efficacy of detergents and fresh produce disinfectants against microorganisms associated with mixed raw vegetables.

Efficacy of commercial detergent and disinfectants to eliminate microorganisms associated with fresh vegetables eaten raw in Iran, including radish, parsley, basil, coriander (cilantro), Allium porrum (leek), and peppermint were studied. The raw vegetables were subjected to a triple wash treatment of washing in tap water for mud removal, washing in water containing a detergent (dishwashing liquid) or disinfectant individually, and rinsing in tap water. The population of total mesophilic microbes on the surface of untreated vegetables ranged from 10(5) to 10(6) CFU/g. Washing in tap water or treatment with detergent (333 ppm for 10 min) or benzalkonium chloride (92 ppm for 15 min) reduced the total microbial count, most probable number (MPN) of coliforms, MPN of fecal coliforms, and MPN of fecal streptococci by about 1.2 to 2.3 log. No significant differences in microbial populations were found on vegetables after decontamination with tap water, detergent, or benzalkonium chloride (P > 0.05). Treatments with peracetic acid (100 ppm for 15 min) and hydrogen peroxide (133 ppm for 30 min) reduced the total mesophilic microbial counts by about 2.8 log. The microbial reductions with calcium hypochlorite (300 ppm for 15 min) and combined hydrogen peroxide and silver ion (133 ppm for 30 min) were significantly higher than those obtained after rinsing in tap water or after detergent or benzalkonium chloride wash (P < 0.05). Pretreatment with detergent slightly enhanced the efficacy of all decontamination treatments, but results were not significantly different from those obtained after individual application of disinfectants.