Showing 14 results for Pseudomonas Aeruginosa
Mana Shojapour, Laleh Shariati, Ali Karimi, Behnam Zamanzad,
Volume 14, Issue 1 (3-2011)
Abstract
Background: Existence of extended spectrum B-lactamase (ESBL) genes plays an important role in spreading B-lactam antibiotic resistance in the producing strains of these enzymes. The resistance of gram-negative bacteria, such as Pseudomonas aeruginosa, to different antimicrobial agents, especially B-lactam and carbapenem, has increasingly been reported. This study was conducted to determine the prevalence of TEM-1 beta-lactamases in Pseudomonas aeruginosa isolates through Duplex PCR. Materials and Methods: In this descriptive-analytic study, 175 Pseudomonas aeruginosa isolates collected from burn patients were subjected to bacteriological tests. The samples were cultured and identified according to standard methods. Then the frequency of ESBL producing strains was determined via the combined disk method. Using boiling method, DNA was extracted and examined for the existence of TEM-1 gene by Duplex PCR. Results: Out of the 175 Pseudomonas aeruginosa isolates, 66 (37.7%) were ESBL positive, 15.15% of which were positive for TEM-1 B-lactamases resistance gene. Conclusion: Noticing the increasing rate of the ESBLs producing strains, using the appropriate treatment protocol based on the antibiogram pattern of the strains is highly recommended.
Ali Hashemi, Saeed Shams, Mohammad Barati, Azizeh Samedani,
Volume 14, Issue 4 (9-2011)
Abstract
Background: Pseudomonas aeruginosa is one of the most important causes of nosocomial infection which due to extended spectrum-beta lactamases (ESBLs) and metallo-beta lactamase (MBL) producing strains is resistant to a wide range of antibiotics. The aim of this study was to detect ESBL and MBL producing P.aeruginosa isolated from patients and investigate the effects of methanol extracts of Zataria multiflora, Myrtus communis, and Peganum harmala on them.
Materials and Methods: In this experimental study, samples were obtained from 245 patients, referring to Shafa Hospital, Kerman, Iran. ESBLs producing strains were detected by double disk synergy test and phenotypic confirmatory test. In addition, E-test strips were used for MBL detection. P.aeruginosa MIC was determined for cefotaxime, ceftazidime, azteronam, imipenem, and meropenem. Methanol extracts of Zataria multiflora, Peganum harmala, and Myrtus communis plants were prepared by Agar perculation method.
Results: Out of 245 patients referring to the burn unit, 120 P.aeruginosa isolates were detected from which 41 contained ESBL but they lacked MBL. 60% of isolates were resistant to cefotaxime, 66% to ceftazidime, 42% to azteronam, 3% to imipenem, and 5% to meropenem. Among the extracts, Zataria multiflora had the highest antibacterial effect on standard strains of P.aeruginosa in comparison with Peganum harmala and Myrtus communis.
Conclusion: The prevalence of ESBL producing P.aeruginosa strains is high. In addition, noticing their high antibiotic resistance, utilization of herbs, such as Zataria multiflora may be considered an appropriate alternative for treatment however, more investigations are needed.
Mohammadbagher Salehi, Mojtaba Saadati, Babak Barati, Mahdi Saberi, Gholamreza Olaad, Aliasghar Rahimi,
Volume 14, Issue 6 (1-2012)
Abstract
Background: The major aim of this study was synthesis and assay of antimicrobial activity of peptide D28 and its new analogues derivatives as dimeric peptides.
Materials and Methods: Three antimicrobial peptides known as D28, Di-D28-Lys,Di-Cys-D28 including 20, 41, 42 residues were synthesized respectively. For peptide synthesis, solid phase peptide synthesis method using blocked amino acids with flourenyl methoxy carbonyl group and for peptide purification HPLC were used. Peptides compositions were confirmed by amino acid analysis and SDS-PAGE electrophoresis. Antimicrobial tests against Staphylococcus aureus and Pseudomonas aeruginosa were performed as disk and well diffusion on plate and by adding to liquid broth culture (Broth macrodilution) in different concentrations.
Results: Three required peptides (D28, Di-D28-Lys, Di-Cys-D28) successfully were synthesized. All three peptides were effective against S. aureus, but Di-Cys-D28 on the contrary to two other ones, showed no antimicrobial activity against P. aeruginosa. The inhibitory activity of Di-D28-Lys against P. aeruginosa was more than that of D28 peptide.
Conclusion: Improvement of antimicrobial peptides activity through dimerization depends on the methods of dimerization and the strain of bacterium. Di-D28-Lys peptide in comparison with D28 and Di-Cys-D28 showed wide range and more antimicrobial activity. Therefore, Di-D28-Lys peptide could be a suitable antibiotic candidate for future studies.
Bahare Rahimi, Mana Shojapour, Abdorrahim Sadeghi, Ahmad Ali Pourbabayi,
Volume 15, Issue 3 (8-2012)
Abstract
Background: Pseudomonas aeruginosa is a human opportunistic pathogen which is considered one of the agents causing nosocamial infection. Recent studies have reported increased resistance of Pseudomonas aeruginosa to imipenem. The aim of this study was to determine resistance to antipseudomonal antibiotics including imipenem in Pseudomonas aeruginosa strains. Materials and Methods: In this cross-sectional study, 100 Pseudomonas aeruginosa strains obtained from clinical samples of patients in hospitals in Arak, Iran, were identified and isolated through microbiological methods, including Gram staining, oxidase test, Indol test, and oxidative-fermentative test. Then antibiotic susceptibility test was performed for imipenem, meropenem, gentamicin, amikacin, ciprofloxacin, and ceftazidime by disk diffusion method according to NCCLS (National Committee for Clinical Laboratory Standards) .Minimum inhibitory concentration (MIC) was done for determining imipenem-resistant strains Results: Antibiotic susceptibility test showed that resistance rates to imipenem, meropenem, gentamicin, amikacin, ciprofloxacin, and ceftazidime were 35%, 35%, 14%, 9%, 23% and 15%, respectively. Also, MIC test showed that 30 strains were resistant to imipenem, 27 to ceftazidime, 35 to cefepime, and 35 to ciprofloxacin. Conclusion: The results of this study indicated a high rate of antibiotics resistant of Pseudomonas aeroginosa strains to different antibiotic groups. Therefore, new and more effective methods should be found for controlling Pseudomonas infections and preventing the outbreak of its antibiotic-resistant strains.
Salman Ahmady Asbchin1, Moein Safari, Hosein Moradi, Vahid Sayadi,
Volume 16, Issue 6 (9-2013)
Abstract
Background: The most important pathogen in nosocomial infections are microorganisms in the patient's body. 90 percent of nosocomial infections caused by bacteria. Medlar is an medicinal plant that its therapeutic effects has historically been emphasized. The aim of this study was to evaluate the antibacterial effect of methanolic and ethanolic leaf extract of medlar against bacteria isolated from hospital environment.
Materials and Methods: In this experimental study, the Nosocomial bacteria were obtained from Shahid Mostafa Khomeini hospital, Ilam, Iran. Soxhlet extraction method was used for medlar leaf extract. Disk diffusion method was used to study the effect of antimicrobial and broth microdilution method were used to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC).
Results: Two strains of Pseudomonas aeruginosa, three strain of Staphylococcus aureus and five strains of Escherichia coli were isolated from hospital. The results showed that the methanolic extract of Medlar leaf inhibited the growth of all strains of pseudomonas aeruginosa and four strain of Staphylococcus aureus and also inhibits the growth of all strains of Escherichia coli strains except E4 strain. The maximum antimicrobial activity was against E2 strain that zone diameter around it was 19/67 Millimeters. Quantities of minimum inhibitory concentration for all three strains P1, P2 and P3 and E2, E3, E5, S1, S2 and S3 strains was equals with 125 mg/ml.
Conclusion: Medlar leaf methanolic extract possesses significant antibacterial activity against bacteria causing nosocomial infections and so this extract can be considered in the control of infectious diseases.
Mohammad Reza Arabestani, Mojtaba Rajabpour, Rasoul Yousefi Mashouf, Mohammad Yusef Alikhani, Seyed Masoud Mousavi,
Volume 17, Issue 11 (2-2015)
Abstract
Background: Pseudomonas aeruginosa is one of the most common nosocomial pathogens with high mortality rates. OprD is the major resistance mechanism to carbapeneme antibiotics. The aim of this study was to determine the expression of the genes encoding these efflux pumps using qRT-PCR.
Materials and Methods: This study examined 100 strains of Pseudomonas aeruginosa isolated from patients admitted to various hospitals in the Hamedan. Conventional phenotypic tests were used for identifying the 100 collected samples, then 31 samples were selected based on type of collected specimen and antibiotic susceptibility test i.e. antibiotic disk diffusion method performed for aminoglycoside, quinolone and carbapenem antibiotics. Furthermore, MIC method was performed for imipenem. Finally, RNA was extracted and converted to cDNA for determining the efflux pump genes expression using qRT-PCR.
Results: Among 8 selected antibiotics, the greatest resistance was for levofloxacin (61.2%, n=19) and the lowest one for imipenem (9.6%, n=3). The results of MIC were to imipenem 12 samples (38.7%) resistant, 13 samples (41.93%) intermediate, and 6 samples (19.35%) sensitive. The OprD gene was present in all strains but different expression has been observed. The strains with over expression of OprD gene showed high sensitivity towards carbapenems family antibiotics especially imipenem.
Conclusion: Identifying of bacterial resistance mechanisms is very complicated and extensive due to different mechanisms involved for similar antibiotics. OprD is main cause of attachment to the carbapenems family antibiotics. The more expression of OprD shows the more antibiotic sensitivity.
Seyyed Sajjad Khorramrooz, Farzaneh Gharibpour, Najmeh Parhizgari, Mahboobeh Yazdanpanah, Reza Mohammadi , Nasim Rahbari,
Volume 18, Issue 3 (6-2015)
Abstract
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.
Bahador Behrouz, Nour Amirmozafari, Mohammad Mehdi Fizabadi, Nima Khoramabadi, Mahboobeh Bahroudi, Mehdi Mahdavi,
Volume 18, Issue 5 (8-2015)
Abstract
Background: Pathogenic Pseudomonas aeruginosa strains produce a polar flagellum that required for motility, adhesion, invasion and secretion of virulence factors. The aim of this study was to evaluate the effect of prevention and treatment with anti-recombinant type B flagellin antibody in a burned mouse model.
Materials and Methods: One hundred twenty six mice were divided into 16 groups injected with different regimen of anti-recombinant type B flagellin antibody. Infections were caused by sub-dermal injection of P. aeruginosa PAO1 and PAK strains at the burn site. Groups were monitored for mortality for one week. Additionally, functional activity of this antibody was assessed by motility inhibition and opsonophagocytosis assays.
Results: Immunotherapy with rabbit antisera substantially increased (85.71%) survival rate of mice challenged with a homologous strain PAO1 compared with the control PBS. The mortality rate in mice infected by the heterologous strain PAK was only 28.57%. This antibody increased phagocytosis killing of the homologous strain but it only had a slight effect on the heterologous strain.
Conclusion: Passive immunotherapy protected burned mice challenged with the homologous strain but showed lower efficacy against the heterologous strain.
Yasamin Abdanankord, Hossein Dabiri, Hossein Goodarzi,
Volume 18, Issue 6 (9-2015)
Abstract
Background: Pseudomonas aeruginosa is one of the important causes of hospital infections septicemia, in patients hospitalized in burn ward and those with cystic fibrosis. Considering the PAPI-2 important role in bacteria pathogenesis, the aim of this study is to investigate the frequency of the encoding genes exoU and xerC as markers of PAPI-2 from isolated environmental and clinical samples.
Materials and Methods: In this descriptive study, 40 isolates from sewage of burn wound hospital and 30 from patients hospitalized in burn ward of the hospital covered by shahid Beheshti University, respectively. The frequency of PAPI-2 in both environmental and clinical strains was detected by using PCR and the primers exou and xerc.
Results: Of 40 studied environmental pseudominas aeruginosa strains that their genus and species were confirmed by chemical tests, 30 samples (75%) consisted of exoU gene and 32(80%) included xerC gene. Also, of 30 isolated strains of burn patients, 23 isolates(76.7%) contained both exoU and xerC gene. The results revealed a high prevalence of PAPI-2 (90%) between clincial and environmental samples of pseudomonas aeruginosa.
Conclusion: With due attention to the results, information reveal that the importance and prevalence of pathogenicity island type 2 were high in Iranian clinical and environmental Pseudomonas aeruginosa isolates. Also, considering all environmental isolates have at least one of genes, we should care about the risk of transporting pathogenic strains and find solutions to control it.
Fatemeh Hakimi, Najmeh Ranji, Mohammad Faezi Ghasemi,
Volume 19, Issue 7 (10-2016)
Abstract
Background: Pseudomonas aeruginosa is a major nosocomial pathogen that due to its intrinsic and acquired resistance to a wide spectrum of antibiotics poses a threat in clinical settings. One of the drug resistance mechanisms in P. aeruginosa is mutation in negative regulators of efflux pump systems such as nalC. The aim of this study was investigation of nalC mutations in P. aeruginosa isolates from some Rasht hospitals and Lahijan laboratories.
Materials and Methods: In this cross-sectional study, forty-five P. aeruginosa strains was isolated from several Rasht hospitals and Lahijan laboratories between 2013 to 2014 and identified by biochemical tests. The antibiotic resistance and susceptibility of isolates was determined by Kirby Bauer method and microdilution method. Then PCR-sequencing was carried out to assess nalC mutations in ciprofloxacin resistant isolates.
Results: In this study, the most P. aeruginosa strains was isolated from urine sample (53%), followed by burned strains (31%). The most resistance was seen to erythromycin (100%) and the lowest resistance was seen to ciprofloxacin (~31 %). The highest MIC of ciprofloxacin was determined in some strains >512 μg/ml. Sequencing results showed that 12 ciprofloxacin resistant isolates had one or several missense mutations G71E, S209R and E153Q in nalC gene.
Conclusion: Given that mutation was defined in most isolates in this study, it seems that mutation in nalC gene plays an important role in ciprofloxacin resistance of nosocomial P. aeruginosa isolates in Guilan province.
Aref Mohammadipour, Najmeh Ranji, Leila Asadpour,
Volume 20, Issue 5 (8-2017)
Abstract
Abstract
Background: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen that using several classes of antibiotics to treat has been led to the emergence of multiple drug resistance. One of the drug resistance mechanisms in Pseudomonas aeruginosa is overexpression of mexXY-oprM efflux pump system. Silybin as main flavonolignan of silymarin extracted from Silybum marianum is a hepatoprotective agent that its anti-bacterial properties was studied, recently. In this study, the effect of combination of silybin and ciprofloxacin on oprM gene expression in clinical isolates of Pseudomonas aeruginosa was evaluated.
Materials and Methods: In this study, seven ciprofloxacin resistant isolates of Pseudomonas aeruginosa were treated by ciprofloxacin (1/2MIC) only (control sample) and in the combination with silybin-encapsulated micelle (nanoparticles) (test sample). After 24h, RNA extraction and cDNA synthesis were performed in silybin treated and un-treated cells and oprM gene expression was quantitatively investigated by realtime PCR method.
Results: Results of this study showed that a silybin encapsulated in nanoparticles (400µg/ml) induces death up to 50% in resistant isolates treated by ciprofloxacin (1/2MIC) during 24h. Also, quantitative Real-Time PCR analysis revealed that silybin encapsulated in nanoparticles decreases the expression of oprM gene compared to silybin untreated cells.
Conclusion: It seems that Decrease of oprM expression in resistant isolates lead to decrease of mexAB-oprM and mexXY-oprM in cell surface, subsequently decrease of antibiotic withdrawal to extracellular environment and increase of sensitivity to antibiotics.
Bozorgmehr Imani Pirsaraei, Najmeh Ranji, Leila Asadpour,
Volume 21, Issue 2 (5-2018)
Abstract
Abstract
Background: Pseudomonas aeruginosa is an opportunistic gram-negative bacterium that is a major cause of nosocomial infections such as severe burns. Curcumin is the main component of turmeric (Curcuma longa) that has anti-cancer and anti-inflammatory effects. The aim of this study was to evaluate antibacterial effect of curcumin in ciprofloxacin resistant isolates of Pseudomonas aeruginosa through mexC and mexD gene expression.
Materials and Methods: In this descriptive-analytical study, Pseudomonas aeruginosa strains were obtained from hospitals and laboratories in Guilan province. After disc difusion and MIC tests, four ciprofloxacin resistant strains of Pseudomonas aeruginosa were treated by ciprofloxacin (1/2MIC) only (control sample) and in the combination with curcumin encapsulated in micelle nanoparticles (test sample). After 24h, RNA extraction and cDNA synthesis was performed. Then, the expression of mexC and mexD genes was evaluated quantitatively by Real-time PCR method in curcumin treated and un-treated cells
Results: This study showed that combination of ciprofloxacin (1/2 MIC) with curcumin encapsulated in micelle nanoparticles led to approximately 50% of growth inhibition in Pseudomonas aeruginosa. In treated cells with curcumin and ciprofloxacin compared to treated cells with ciprofloxacin alone, mexC and mexD genes were significantly (p<0.05) downregulated >0.65 fold in three isolates and >0.1 fold in four isolates, respectively.
Conclusion: Our results suggested that curcumin encapsulated in micelle nanoparticles combined with 1/2 MIC value of ciprofloxacin inhibits the growth of Pseudomonas aeruginosa through reducing mexC and mexD expression.
Behnoush Sadat Khalili, Javad Hamedi, Setareh Haghighat,
Volume 21, Issue 7 (2-2019)
Abstract
Background and Aim: The widespread use of antibiotics has been led to increased emergence of antibiotic resistant bacteria and high mortality and morbidity rates due to infectious diseases. Pseudomonas aeruginosa is one of the most important causes of nosocomial infections, which shows high resistance to a wide range of antibiotics. So, finding new and effective antimicrobial compounds in order to overcome antibiotic resistant infectious diseases is so critical. Screening of native actinobacteria can be an effective strategy to find novel antimicrobial compounds. The aim of current study was isolation, screening and identification of rare actinobacteria to find the strains which produce antimicrobial compounds against P. aeruginosa.
Material and Methods: Thirty samples of water and sediments were collected from Persian Gulf and Oman Sea and used for isolation of actinobacterial strains. After isolation of actinobacteria, their metabolites were extracted and their anti-P. aeruginosa activities were investigated. Minimum inhibitory concentration (MIC) of the most efficient extract was determined using broth microdilution method. Finally, the most efficient strain was identified.
Ethical Considerations: In this study, all principles of biosafety and bioethics have been considered.
Findngs: Fifty actinobacteria were isolated from water and sediments. Five isolates had considerable antimicrobial activity. MIC value of the most efficient extract against P. aeruginosa was 100 µg/ml. Molecular analysis of 16SrRNA showed that the most effective fermentation broth extract belongs to Micromonospora and has 99.8% similarity to M. chalcea.
Conclusion: The current study revealed that the water of southern Iran and their sediments are promising sources of potent rare Actinobacteria in the production of antimicrobial compounds against P. aeruginosa. |
Ahmad Sahabzamani, Dr. Maryam Sadrnia, Dr. Majid Akbari, Dr. Sasan Saki,
Volume 25, Issue 3 (8-2022)
Abstract
Background and Aim The efflux pump in Pseudomonas aeruginosa inhibits the effect of ciprofloxacin by releasing quinolones out of the cell. It is important to find compounds to inactivate or inhibit its activity to continue using the antibiotics. The present study was done to investigate using sertraline as an efflux pump inhibitor in P. aeruginosa to reduce antibiotic resistance.
Methods & Materials P. aeruginosa strains were isolated from clinical sources and identified by routine microbiological methods. Resistance of the isolates to ciprofloxacin was evaluated by Kirby–Bauer test. Resistance breakdown was investigated by adding sertraline to the Moller Hinton agar medium and determining the zone of inhibition of ciprofloxacin. Minimum inhibitory concentration (MIC) by microplate dilution method and Minimum bactericidal concentration (MBC) by culture and MTT method were done for the isolates and ATCC 27853. The presence of the efflux pump was evaluated by the phenotypic method using sertraline and serial dilution method of the liquid medium in a microplate, on ciprofloxacin-resistant strains. The presence of the producing gene of this pump was determined by the genotyping method in resistant strains by performing PCR. The standard PAO1 strain of P. aeruginosa was used as a positive control.
Ethical Considerations This study was approved by the Ethics Committee of the Faculty of Medical Sciences of Islamic Azad University, Brojerd Branch (Code: IR.IAU.B.REC.1401.011).
Results Based on Kirby–Bauer test results, three strains were considered resistant to ciprofloxacin. MIC of drug-resistant strains was between 32 and 64 mg/ml and MBC was between 16 and 32 mg/ml. By performing electrophoresis on the PCR products, it was determined that the tested strains contained the mexA gene encoding the efflux pump. In the agar medium without sertraline, the zone of inhibition around the ciprofloxacin disc was zero, but after adding sertraline, the diameter of the halo increased to 25 mm. The minimum inhibitory concentration of ciprofloxacin in the isolates before adding 25 µg of sertraline was 128 µg/ml and after adding sertraline, it was 4 µg/ml.
Conclusion It was concluded that sertraline inhibited the efficiency of the efflux pump in resistant P. aeruginosa isolates and reduced ciprofloxacin resistance.
