Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen that causes severe and lethal infections in immunocompromised individuals. This bacterium possesses a single polar flagellum. Flagellum and its subunit Flagellin play important roles in the pathogenesis of P. aeruginosa. Flagellin induces immune responses by interaction of its N-terminal domain with TLR-5. Our main aims of this study were cloning and expression of N-terminal domains of flagellin and evaluation of antibodies raised against it on motility inhibition of P. aeruginosa.Material and Methods: The DNA sequence coding for the first 161 amino acids of flagellin was PCR amplified and cloned into a pET-28a expression vector. Recombinant protein was over expressed in BL-21(DE3), and purified by Ni-NTA resin. The immune reactivity of recombinant truncated flagellin was evaluated by Western blotting. The recombinant protein was injected into a rabbit and antibodies raised against it were evaluated for the cell motility inhibition of P. aeruginosa 8821M.Results: The N-terminal domain of Flagellin was successfully overexpressed in Escherichia coli BL-21(DE3) host strain. Anti-native and anti-N-terminal flagellin antibodies reacted with the recombinant protein. Motility inhibition assay demonstrated that polyclonal antiserum against N-teminal flagellin is able to inhibit the motility of P. aeruginosa 8821M.Conclusion: The N-terminal domain of flagellin may be used for development of a new recombinant vaccine against P. aeruginosa infections.

Background & Aims: Cystic Fibrosis is one of the most prevalent fatal autosomal recessive diseases among white children. Mutation in CFTR gene cause ion imbalance of membranes and reduce the fluid in the face of main pulmonary airways which in turn provide proper medium for opportunistic bacteria specially pseudomonasaeroginosa and may lead to lung dysfunction. The aim of this study was to state antibiogram and genotype of pseudomonasaeroginosa in cystic fibrosis patients.Material & Methods: In this cross sectional study, we obtained specimen of sputum or deep pharyngeal swaps from 46 patients for determining the bacterial species. We used standard lineage P. aeruginosa ATCC27853 for antibiotic susceptibility test and one type of B. cepacia for standardization and comparison. We also used 11 antibiotic discs for antibiogram. The method for determination of genetic lineage was RAPD-PCR.Results: from the total of 46patients with fibrous cystic 58. 7% were male and 48. 3% were female. There were 20 patients (74. 1%) in the male group and 11 patients (57. 9%) in the female group with pseudomonasaeroginosa colonization and there was not B. cepacia colonization. There were 9 patients with staphylococcus aureous, 7 with Klebsiela, 11 with Candida albicans, and 1 with Serachia marsensis colonization. The pseudomonas aeroginosa was detected in 31 patients (67. 4%) which had three lineages: mucoid (15 patients), non-mucoid (12 patients), and mucoid & non-mucoid (4 patients). Antibiogram shows the sensitivity to Tobramycin and Ciprofloxacin in all patients; there was also sensitivity to Amikacin (7. 8%), Piperacilin (93. 3%), Gentamicin (91. 1%), Ticarcilin (86. 75), Colicitin (80%), Carbenicilin (48. 9%), Cefotaxim (26. 7%), Imipenem (26. 7%), and Ceftazidim (11. 1%). There was hemogenocity in genetic phenotyping with RAPD-PCR method.Conclusion: This study showed high resistant to Imipenem and Cephalosporins in pseudomonaslineages. There was not any relation between genotype and antibiogram and demographic characteristics of patients (sex and age). In addition, there was no difference among species according to potency and transmission properties.

Background and objectives: Pseudomonas aeruginosa is important opportunistic pathogen and to produce widespread infection by numerous virulence factors. Drug delivery system that reduces the drugs toxicity while increasing their therapeutic index is a great interest and liposomes can provide the benefits. Liposomes are colloidal vesicules ranging from a few nanometers to several micrometers in diameter. The present in vitro study was designated to evaluate the antimicrobial activity of free and liposomal amikacin against Pseudomonas aeruginosa (ATCC 27853).Materials and methods: The minimal inhibitory concentrations (MICs) of free and liposomal amikacin for Pseudomonas aeruginosa (ATCC 27853) were determined by broth macro-dilution technique as recommended by CLSI (Clinical and laboratory standards institute). We therefore, encapsulated this drug in to liposome prepared by sonication. Change of number of bacteria in equal minimal inhibitory concentration of liposomal amikacin was compared with the change of number of bacteria in the present of various concentrations of free amikacin.Results: The results showed that of liposomal amikacin had antimicrobial effect and MIC of liposomal amikacin were equal of 4mg/ml however minimal inhibitory concentration of free amikacin was 2mg/ml. Comparison of change of number of bacteria had shown that the effect of liposomal amikacin (4mg/ml) after 8h is equal of 6mg/ml free amikacin after 4h.Conclusion: According to the results we can probably to use of liposomal amikacin for Pseudomonas infections, but we need more study and research

Background: The resistance of Pseudomonas aeruginosa strains to broad spectrum cephalosporins may be mediated by extended spectrum b-lactamases (ESBLs). These enzymes are encoded by different genes located either on chromosome or plasmids. In this study, we determined the antimicrobial resistance patterns of P. aeruginosa isolates and screened for ESBL production.Methods: After isolation from burn patients in Tehran Hospital, identification of P. aeruginosa isolates were assessed using biochemical tests. We then performed disk agar diffusion (DAD) according to CLSI guidelines to determine the pattern of antimicrobial resistance. The frequency of ESBLs and prevalence of the OXA-10 and PER-1 genes were determined with combined disk and polymerase chain reaction (PCR) methods, respectively.Results: One hundred strains of P. aeruginosa were isolated. The resistance of these strains to cephpodoxime, aztreonam, ciprofloxacin, ofloxacin, ceftazidime, cefepime, imipenem, meropenem, cefotaxime, levofloxacin, piperacilin- tazobactam and ceftriaxon was 100%, 90%, 83%, 92%, 85%, 88%, 63%, 66%, 98%, 89%, 70% and 91%, respectively. Of these, 40 strains (40%) were ESBL positive, 29 strains (29%) were OXA-10 positive and 18 strains (18%) were PER-1 positive.Conclusion: Our results confirm the need for proper antimicrobial therapy in burn hospitals, considering the resistance pattern and frequency of strains producing ESBLs and the presence of the OXA-10 and PER-1 genes. Since an increase in the prevalence of ESBL in P. aeruginosa strains might lead to the transfer of these ESBL genes to other gram-negative bacteria, we recommend the use of appropriate drugs, especially cephalosporins, in burn hospitals.

Background & aim: Because of emerging multi-drug resistance (MDR) Pseudomonas aeruginosa strains, treatment of burn patients infected by this bacterium is difficult. The aim of this study was to detect antimicrobial profile and molecular epidemiology of metallo-beta-lactamase (MBL) producer strains.Methods: In this cross-sectional investigation 270 Pseudomonas aeruginosa isolates were collected from the burn patients. Carbapenem sresistance strains were detected by phenotypic Etest method. Susceptibility profiles of metallo-b-lactamase (MβL) enzyme producing isolates of this bacterium to 11 antimicrobial drugs were determined by disc diffusion method according Clinical and Laboratory Standards Institute (CLSI) guidelines. The genetic correlations between isolates were determined by Pulsed-Field Gel Electrophoresis (PFGE) method.Results: Among 270 P. aeruginosa isolates, 60 (22.2%) strains showed resistant to meropenem (MEM) and imipenem (IMI) and were considered as metallo-b-lactamase positive. All metallo-β- lactamase positive isolates were resistant to five tested antimcrobial while their sensitivities to the three best effective antibiotics including ciprofloxacin, amikacin and ceftazidime were 1.7%, 6.7 % and 23.3%, respectively. Majority of the isolates (71.6%) showed more than 80% similarity based on the drawn dendrogram.Conclusion: Our results showed, the tested antimicrobials are not safe to prescribe for burn patients. According PFGE pulsotypes, a limited number of P.aeruginosa types are common in the hospital burn units which infect the patients hospitalized in this ward.

BACKGROUND AND OBJECTIVE: Lactoferrin (LF) is an iron-binding glycoprotein that involves a diverse range of biological activities. Lactoferrin is a major component of milk and is present in exocrine secretions such as tears, salvia, bile, and neutrophil granules. Lactoferrin has more potent antimicrobial activities against a wide range of gram negative and positive bacteria as well as antivirus activities. The purpose of this study is to evaluate the effect of this protein on P.aeruginosa growth in patients with burns that show drug resistance.METHODS: In this study, antibacterial activity of Lactoferrin has been scrutinized after isolation and purification of bovine colostrum against pseudomonas aeroginosa. Bacteria samples were isolated from scald patients (Shahid Zare Hospital); then microbial activity was confirmed with biochemical tests like oxidase, catalase and growth on TSI medium. Four concentrations 400, 500, 600 and 700 mg/ml of lactoferrin were assayed. Pseudomonas colonies counted and compared with negative control (without lactoferrin) as well as E.coli (DH5α) as positive control was considered. FINDINGS: Our results showed that 400mg/ml concentration of lactoferrin has the least inhibitory effect with 35% and 29% growth inhibitory and 700mg/ml concentration of lactoferrin has the highest inhibitory effect with 86% and 66% on Pseudomonas and E.coli, respectively. CONCLUSION: Our result showed that all of lactoferrin concentrations have inhibitory activity which in 700μg/ml has the highest inhibition against Pseudomonas aeroginosa and also E.coli.

Background and Objective: Biofilms caused by pathogenic microorganisms that plays an important role against human health. Due to their resistance to detergents and antimicrobial agent, treatment response of affected patients with these bacteria is difficult. This study was done to evaluate the effect of methanol extract of Nasturtium officinale plant on growth and biofilm formation of Pseudomonas aeruginosa.Methods: In this descriptive - laboratory study, the extraction was done by Maceration in 80% methanol and by rotary evaporator. The minimum inhibitory concentration (MIC) of Nasturtium officinale extracts were determined by broth microdilution method. Biofilm formation was investigated using the microtiter plate and stained with crystal violet.Results: The minimum inhibitory concentration of Nasturtium officinale against Pseudomonas aeruginosa was 0.625 mg/ml and the Minimum bactericidal concentration of this extract was 1.25 mg/ml. PAO1 strain and 5 clinical strains were able to biofilm formation. Inhibition of biofilm formation by extract of Nasturtium officinale plant was dependent to concentration. The highest percentage of inhibition of biofilm formation was in the concentration of 7.5 mg/ml and the lowest percentage of inhibition of biofilm formation was in the concentration of 0.11 mg/ml. The mean of Pseudomonas aeruginosa biofilm inhibition by Nasturtium officinale extracts was 72.69±22.27 %. In the concentrations of 7.5, 0.93, 0.46, 0.23 and 0.11 mg/ml, there was a significant difference between clinical strains and PAO1 strain (P<0.05).Conclusion: Methanolic extracts of Nasturtium officinale plant has anti-bacterial and anti-biofilm effect against Pseudomonas aeruginosa.

Background: Pseudomonas aeruginosa is one of the main etiological agents in burn infections which could be life threatening for the infected patients. The aim of the present study was to identify and track source of infections using two molecular typing methods.Materials and Methods: Seventy-four strains of P. aeruginosa were isolated from burn patients and hospital environment in Ghotbadden Burn Hospital, Shiraz, Iran. Isolates were typed by arbitrary primed-polymerase chain reaction (AP-PCR) and plasmid profiling. Similarity and clustering of the strains was assessed using NTSYS-PC software and photo Capt Mw program.Results: Thirty eight plasmid profiles were obtained and classified them into: 2, 3and 5 clusters, based on 50%, 64.7% and 67.5% similarity on the plotted dendrogram, respectively. Drawn dendrogarm categorized AP-PCR products to 47 different types.Conclusion: Based on these results, a limited number of P. aeruginosa types are predominant in the hospitals which infect the burn patients. To control of the infections in patients with antibiotics, resistant isolates, strong disinfection of patients’ bathroom after scrubbing of patients wounds, should be implemented.

Background and aim: Biofilm formation is one of the most notable mechanisms that contributes to antibiotic resistance in P.aeruginosa, The aim of this study was to determine the effects of methanol extrac of Quercus brantii, Pistacia atlantica, Elaeagnus angustifolia Leaves on biofilm formation P. aeruginosa strains.Methods: this study is an experimental study, that extraction with Maceration (powder mixed with 80% methanol) using rotary evaporator method. done. The minimum inhibitory concentration of extracts was determined by broth microdilution. Biofilm formation was investigated using the microtiter plate and stained with crystal violet. Collected data were analyzed using ANOVA and Duncan test.Results: The minimum inhibitory concentration of Quercus brantii, Pistacia atlantica, Elaeagnus angustifoliaextracts against Pseudomonas aeruginosa was 0.625 mg/ml whereas, the Minimum bactericidal concentration ofQuercus brantii jaft was 1.25 mg/ml and for Pistacia atlantica and Elaeagnus angustifoliawere 2.5 mg/ml. The mean percentage of of Pseudomonas aeruginosa biofilm inhibition by extracts of Quercus brantii (jaft), Pistacia atlantica, Elaeagnus angustifolia were 60.24, 57.35, and 72.63 % respectively.Conclusion: Methanolic extracts of medicinal plants Quercus brantii, Pistacia atlantica, Elaeagnus angustifoliahas anti-bacterial and anti-biofilm effect against Pseudomonas aeruginosa. So that Elaeagnus angustifoliaextract had a capability to inhibit biofilm formation and also showed a significant difference compare to Quercus brantii jaft, Pistacia atlantica extract. With further study it can be used of these extracts as a supplement to inhibit bacterial biofilm.

Background and Objectives: Pseudomonas aeruginosais a gram-negative bacterium and an opportunistic pathogen with several virulence factors. This bacterium is one of the common pathogens in nosocomial infections, particularly in patients with cystic fibrosis. Also, one of the important mechanisms of the survival of this pathogen in the pulmonary disease is biofilm formation. This study was conducted with the purpose of determining the sub-MIC concentrations of two antibiotics, ampicillin and gentamicin, along with the form conjugated with gold nanoparticles on the formation of biofilms in mucoid strain of Pseudomonas aeruginosa.Methods: In this study, gold nanoparticles were synthesized using trisodium citrate in a chemical reduction method, then the shape and size of gold nanoparticles were determined by transmission electron microscopy (TEM).Conjugation of gold nanoparticles with ampicillin and gentamicin antibiotics was performed by mixing them together. To test the effect of compound son biofilm formation, micro plate method was performed.Results: In this study, approximate size of nanoparticles was determined to be 10nm. In electronic image (in conjugated form), accumulation of nanoparticles was observed in the image. Also, gold nanoparticles conjugated with the drugs, had better effect on biofilm formation compared to free form of the drugs.Conclusion: According to the results of this study, gold nanoparticles by increasing the concentration of drug around themselves result in better inhibitory effect of drug on the biofilm formation compared to the free form of drug.