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Showing 5 results for Efflux Pump
Prevalence of norA and norB efflux pump genes in clinical isolates of Staphylococcus aureus and their contribution in ciprofloxacin resistance
Mohadeseh Alsadat Haddadi Zahmatkesh, Mohadeseh Laripoor, Amir Mirzaie, Fatemeh Ashrafi,
year 10, Issue 5 (12-2016)
Abstract

Background and Aim: Recently, ciprofloxacin resistance in Staphylococcus aureus strains due to efflux pumps has become a significant challenge. This study was performed to evaluate the frequency of norA and norB efflux pump genes and their roles in resistance to ciprofloxacin in clinical isolates of S. aureus.

Materials and Methods: A total of 250 clinical samples were collected from different hospitals Tehran-Iran during 2015-2016 and S. aureus isolates were identified by standard microbiological tests. Antimicrobial susceptibility patterns were determined by disk diffusion method using CLSI guideline. Subsequently, the presence of norA and norB efflux pump genes in ciprofloxacin isolates were detected using PCR method. Finally, active efflux pumps were evaluated using ciprofloxacin and ethidium bromide MICs.

Results: Among 250 clinical samples, 50 S. aureus isolates were recovered and the results of antibiotic susceptibility tests showed the 34 out of 50 S. aureus isolates (68%) were resistant to methicillin (MRSA) and from the 34 MRSA, 12 isolates (24%) were resistant to ciprofloxacin. Moreover, the norA and norB genes were found in 100% and 83% of ciprofloxacin resistant isolates, respectively.

Conclusions: The results of this study show the potential role played by norA and norB efflux pumps in the development of resistance to ciprofloxacin in clinical isolates of S. aureus and the detection of these genes could be important for the suggestion of an effective treatment model for the S. aureus infections.


Investigation of Association Between adeA, adeB ,adeI Genes and Phenotypic Activity of Efflux Pump in Multiple Drug Resistant Acinetobacter baumannii Isolates
Negin Sedighian Kashi, Dr Sahar Honarmand, Dr Fahimeh Baghbani Arani,
year 12, Issue 5 (12-2018)
Abstract
Background and Aims: Acinetobacter baumannii  is a major cause of nosocomial infections and is resistant to many antibiotics. Over expression of AdeABC and AdeIJK efflux pumps in Acinetobacter causes resistance to aminoglycosides and decreases the sensitivity of fluoroquinolones. The aim of this study was to investigate the phenotypic activity of the Acinetobacter baumanni  isolates associated with  presence of adeA, adeB, and adeI genes.
Materials and Methods: The study was performed on 55 strains of A. baumannii isolated collected from specimens of patients hospitalized in Milad Hospital , Tehran. The isolates were diagnosed using biochemical tests and antibiotic susceptibility testing was done by disk diffusion method based on CLSI guidelines. Cartwheel method was used to study phenotypic activity of efflux pump. Multiplex PCR was used to determine the presence of genes.
Results: The prevalence of multiple drug resistant isolates was 98%. In terms of efflux pump activity 3.63% isolates were strong, 67.27% moderate and 29.09% were non-active.  The frequency of adeA, adeB, adeI genes was 87.2%, 85.4% and 94.5%, respectively. There was significant association between adeA and adeB genes among isolates with actively and non-actively efflux pump.
 Conclusions: Determination of actively phenotype of efflux pump can determine the multiple drug resistance among A. baumannii isolates. The results confirms the role of main genes encoding AdeABC operon,adeA and adeB  in activity of A. baumannii efflux pump.

Effect of Artemisia ciniformis Extract on Expression of NorA Efflux Pump Gene in Ciprofloxacin Resistant Staphylococcus aureus by Real Time PCR
Zeynab Ghomi, Farzaneh Tafvizi, Vahid Naseh, Iman Akbarzadeh,
year 14, Issue 1 (3-2020)
Abstract
Background: Activity of norA efflux pump is one of the antibiotic resistance mechanisms in ciprofloxacin resistant Staphylococcus aureus. In this study, the effect of Artemisia ciniformis extract on reducing the expression of norA efflux pumps gene in ciprofloxacin-resistant Staphylococcus aureus isolates was studied.
Materials and Methods: Ciprofloxacin resistant S. aureus isolates, were treated by different concentration of A. ciniformis extract. After extracting RNA and synthesizing cDNA, norA efflux pump expression was evaluated by Real Time PCR. 
Results: There was significant decrease of norA efflux pump expression in ciprofloxacin-resistant S. aureus isolates treated by A. ciniformis extract (P<0.05). Also, a different expression of norA efflux pump gene was reported.
Conclusion: It seems A. ciniformis extract as a natural inhibitor, had potential for suppression of norA efflux pump activity.


Investigating the Antibiotic Resistance Prevalence and Phenotypic and Genotypic Evaluation of AcrAB-OprM Efflux Pump in Multidrug-resistant in Clinical Isolates of Moraxella catarrhalis in Kazerun City, Iran
Parvin Mohammad Shafiei, Majid Baserisalehi, Sina Mobasherizade,
year 14, Issue 5 (9-2020)
Abstract
Background and Objective: Moraxella catarrhalis a gram-negative bacterium, is a significant cause of lower and upper respiratory infections. The RND family efflux pumps lead to multidrug resistance in gram-negative bacteria. One of the well-known pumps in M. catarrhalis is AcrAB-OprM system. This study aimed to investigate the antibiotic resistance in M. catarrhalis and to determine its antibiotic resistance dependence on the efflux pump.
Methods: In this study, 137 different clinical samples were collected. M. catarrhalis isolates were confirmed by biochemical assays and PCR. The antibiotic susceptibility pattern was investigated by disc diffusion method according to CLSI. Phenotypic study of the efflux pumps activity was done using cartwheel method. Study of the acra, acrb, and oprm genes were performed by, PCR. In addition, the association of efflux pump with antibiotic resistance was investigated using phenylalanine-arginine β-naphthylamide.
Results: Of 10 isolated M. catarrhalis, 70% (7 isolates) showed multiple antibiotic resistance. The resistance to cefazolin, ceftazidime, tetracycline, chloramphenicol, and ciprofloxacin antibiotics was also dependent on the efflux pump.
Conclusion: The results showed that multiple antibiotic resistance has increased in Moraxella catarrhalis. The 70% presence of acra, acrb, oprm efflux genes of the efflux pumps in this bacterium and antibiotic resistance reduction in the presence of efflux pump inhibitor shows the importance of examining these genes’ presence to suggest a suitable treatment model for the patients infected with M. catarrhalis.

A molecular New Update on the Biofilm Production and Carbapenem Resistance Mechanisms in Clinical Pseudomonas aeruginosa Isolates
Raziyeh Ramazani, Rabeeh Izadi Amoli, Mojtaba Taghizadeh Armaki, Abazar Pournajaf, Hami Kaboosi,
year 16, Issue 6 (10-2022)
Abstract

Background and Aim: Carbapenem resistant- Pseudomonas aeruginosa (CRPA) is one of the most important causes of severe and persistent infections. The contributions of different resistance mechanisms to Carbapenems and biofilm formation among a collection of imipenem susceptible and non-susceptible P. aeruginosa isolates were investigated.
Materials and Methods: In this cross-sectional study, a total of 117 P. aeruginosa isolates were collected. The disc diffusion method assessed the susceptibility of isolates to various antimicrobials. The Carbazole method was used for the detection of alginate producers. Multiplex-PCRs were performed for the detection of biofilm and resistance genes. The expression mRNA levels of efflux pumps were assessed by phenotypic and genotypic (Quantitative Real-time PCR) approaches.
Results: The highest resistance rate was related to ceftazidime, chloramphenicol, ceftriaxone, tetracycline, and levofloxacin. MDR phenotype was observed in 8.4% of strains. The frequency of carbapenem resistance was also 24.7%. The Carbazole test was positive at 53.8%. In general, 62.4% of isolates were able to form a biofilm, 28.8% of which were resistant to carbapenem. The distribution of algD and algU genes were 41.8% and 26.5%, respectively. The frequency of MBL-encoded genes was as follows; blaIMP (62.1%), blaVIM (31.0%), and blaNDM (6.8%). The relative levels of MexX, MexC, MexB and MexA mRNA in CRPA strains with active efflux pump were 81.8%, 63.6%, 54.5%, and 36.4%, respectively.
Conclusion: The existence of different resistant mechanisms in P. aeruginosa can cause cross antibiotic resistance, lead to the appearance of resistant strains, and make the treatment difficult. Biofilm production is directly related to antibiotic resistance. Efflux pumps are actively expressed in carbapenem-resistant strains.


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