scholarly journals Investigation of Ciprofloxacin Resistance and Its Mechanisms in Clinical Pseudomonas aeruginosa Isolates

ANKEM Dergisi ◽  
2021 ◽  
Author(s):  
Nilüfer Uzunbayır Akel ◽  
Yamaç Tekintaş ◽  
Fethiye Ferda Yılmaz ◽  
İsmail Öztürk ◽  
Mustafa Ökeer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Regulatory Genes ◽  
Quinolone Resistance ◽  
University Hospital ◽  
Clinical Samples ◽  
Genetic Groups ◽  
Ciprofloxacin Resistance ◽  
Polymerase Chain

Pseudomonas aeruginosa is one of the most important causes of hospital infections. Although different antibiotic groups are used for the treatment of P.aeruginosa infections, quinolone groups are distinguished by the advantages of oral administration. However, in recent years, resistance against members of this group has made treatment more difficult. The aim of this study was to investigate the epidemiological relationship and possible mechanisms of resistance in ciprofloxacin resistant P. aeruginosa isolates from Ege University Hospital. The identification of P.aeruginosa bacteria isolated from clinical samples in Ege University Medical Faculty Medical Microbiology Laboratory was determined by VITEK MS automated systems by VITEK compact, antimicrobial susceptibility. The epidemiological relationships of the ciprofloxacin resistant isolates were determined by Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The presence of qnrA, qnrB, qnrS, qepA genes, the quinolone resistance genes and nfxB, mexR, the regulatory genes of the efflux pump, was determined by PCR. The phenylalanine-arginine β-naphthylamide (PAβN) assay was used to determine the activation of the efflux pump. Twenty-two isolates (26.5 %) were found resistant to ciprofloxacin. According to the ERIC-PCR results, 11 unrelated clones were detected. Ciprofloxacin minimum inhibitory concentration (MIC) values were decreased 2-64 times in 10 isolates in the presence of PAIN. No ciprofloxacin MIC change was detected in one isolate. The presence of pump regulatory genes was determined in 10 of the 11 representative isolates, while only qnrB of the genes associated with quinolone resistance was detected in seven representative isolates. qnrA, qnrS, qepA genes were not detected in any isolate. Ciprofloxacin resistant P.aeruginosa isolates are isolated from our hospital. It is noteworthy that the isolates belonging to different genetic groups are in circulation in clinics. Basic resistance mechanisms are thought to be efflux pumps and qnrB genes.

scholarly journals Parallel evolution and local differentiation in quinolone resistance in Pseudomonas aeruginosa

Microbiology ◽  
2011 ◽  
Vol 157 (4) ◽  
pp. 937-944 ◽  
Author(s):  
Alex Wong ◽  
Rees Kassen
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Parallel Evolution ◽  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Clinical Samples ◽  
Resistance Mutations ◽  
Topoisomerase Iv ◽  
Therapeutic Implications ◽  
Local Differentiation

The emergence and spread of antibiotic resistance in pathogens is a major impediment to the control of microbial disease. Here, we review mechanisms of quinolone resistance in Pseudomonas aeruginosa, an important nosocomial pathogen and a major cause of morbidity in cystic fibrosis (CF) patients. In this quantitative literature review, we find that mutations in DNA gyrase A, the primary target of quinolones in Gram-negative bacteria, are the most common resistance mutations identified in clinical samples of all origins, in keeping with previous observations. However, the identities of non-gyrase resistance mutations vary systematically between samples isolated from CF patients and those isolated from acute infections. CF-derived strains tend to harbour mutations in the efflux pump regulator nfxB, while non-CF strains tend to bear mutations in the efflux regulator mexR or in parC, which encodes one of two subunits of DNA topoisomerase IV. We suggest that differences in resistance mechanisms between CF and non-CF strains result either from local adaptation to different sites of infection or from differences in mutational processes between different environments. We further discuss the therapeutic implications of local differentiation in resistance mechanisms to a common antibiotic.

scholarly journals Development of in vitro resistance to fluoroquinolones in Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Lei Zhao ◽  
Shiqi Wang ◽  
Xiaobing Li ◽  
Xiaojing He ◽  
Lingyan Jian
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Target Genes ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance ◽  
Relative Quantitation ◽  
Evolutionary Trajectories ◽  
Polymerase Chain ◽  
Quantitation Method

Abstract Fluoroquinolone resistance in Pseudomonas aeruginosa typically arises through site-specific mutations and overexpression of efflux pumps. In this study, we investigated the dynamics of different resistance mechanisms in P. aeruginosa populations that have evolved under fluoroquinolone pressure, as well as the interactions between these mechanisms in evolutionary trajectories. Bacteria of strain ATCC27853 were selected under different concentrations of ciprofloxacin and levofloxacin for six parallel lineages, followed by amplification of four target genes in the quinolone-resistance determining region (QRDR) and Sanger sequencing to identify the mutations. The expression of four efflux pump proteins was evaluated by real-time polymerase chain reaction using the relative quantitation method, with the ATCC27853 strain used as a control. We found that ciprofloxacin killed P. aeruginosa sooner than did levofloxacin. Further, we identified five different mutations in three subunits of QRDRs, with gyrA as the main mutated gene associated with conferring fluoroquinolone resistance. Additionally, we found a larger number of mutations appearing at 2 mg/L and 4 mg/L of ciprofloxacin and levofloxacin, respectively. Moreover, we identified the main efflux pump being expressed as MexCD-OprJ, with initial overexpression observed at 0.25 mg/L and 0.5 mg/L of ciprofloxacin and levofloxacin, respectively. These results demonstrated gyrA83 mutation and MexCD-OprJ overexpression as the primary mechanism conferring ciprofloxacin and levofloxacin resistance in P. aeruginosa. In addition, we also show that ciprofloxacin exhibited a stronger ability to kill the bacteria while potentially rendering it more susceptible to resistance.

Involvement of the AcrAB efflux pump in ciprofloxacin resistance in clinical Klebsiella pneumoniae isolates

2020 ◽  
Vol 20 ◽  
Author(s):  
Saeed Khoshnood ◽  
Mohsen Heidary ◽  
Ali Hashemi ◽  
Fatemeh Shahi ◽  
Morteza Saki ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bacterial Infections ◽  
Efflux Pump ◽  
Quinolone Resistance ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
Disk Diffusion Method ◽  
Rapd Pcr ◽  
Ciprofloxacin Resistance

Background: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. Objective: We aimed in this study to investigate the role of AcrAB, qepA efflux pump, and AAC(6′)-Ib-cr enzyme in ciprofloxacin resistance and to detect the RAPD-PCR fingerprint of K. pneumoniae isolates. Methods: In total, 117 K. pneumoniae isolates were collected from hospitalized patients in three hospitals in Tehran, Iran from August 2013 to March 2014. Antimicrobial susceptibility tests were performed by the disk diffusion method. Molecular identification and expression level of encoding quinolone resistance genes, acrA, acrB, qepA, and aac(6')-Ib-cr, was per-formed by PCR and real-time PCR assays, respectively. All the K. pneumoniae isolates containing these genes was used simultaneously for RAPD-PCR typing. Results: Colistin and carbapenems were the most efficient antibiotics against the clinical isolates of K. pneumoniae. PCR assay demonstrated that among the 117 isolates, 110 (94%) and 102 (87%) were positive for acrA and acrB gene, and for qepA and aac(6′)-Ib-cr genes, 5 (4%) and 100 (85%) isolates were detected, respectively. Determination of AcrAB pump expression in 21% of strains demonstrated an increased expression, and the mean increase expression for acrB genes was 0.5-81. The results of RAPD-PCR reflected that in 95% CI, all isolates belong to a clone. Conclusion: A high prevalence of genes encoding quinolone resistance in K. pneumoniae was detected in clinical samples. Therefore, control of infection and prevention of drug-resistant bacteria spread need careful management of medication and identification of resistant isolates.

scholarly journals Resistance Mechanisms of Multiresistant Pseudomonas aeruginosa Strains from Germany and Correlation with Hypermutation

2007 ◽  
Vol 51 (11) ◽  
pp. 4062-4070 ◽  
Author(s):  
B. Henrichfreise ◽  
I. Wiegand ◽  
W. Pfister ◽  
B. Wiedemann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Type Ii ◽  
Mechanisms Of Resistance ◽  
Resistance Determinants ◽  
Class 1 ◽  
Mutator Strains ◽  
Multiresistant Strains

ABSTRACT In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different Pseudomonas aeruginosa strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in P. aeruginosa. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant P. aeruginosa.

PATTERNS OF ANTIMICROBIAL RESISTANCE AMONG MAJOR BACTERIAL PATHOGENS ISOLATED FROM CLINICAL SAMPLES IN TWO TERTIARY’S HOSPITALS, IN SANA'A, YEMEN

2021 ◽  
Author(s):  
Huda Zaid Al-Shami ◽  
Muhamed Ahmed Al-Haimi ◽  
Omar Ahmed Esma’il Al-dossary ◽  
Abeer Abdulmahmood Mohamed Nasher ◽  
Mohammed Mohammed Ali Al-Najhi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Peer Review ◽  
Bacterial Pathogens ◽  
University Hospital ◽  
Clinical Samples ◽  
Isolation And Identification ◽  
Hemolytic Streptococcus ◽  
Study Results

Background and objectives: At the present time, antimicrobial resistance (AMR) is a major public health hazard, with antimicrobial resistance bacteria increasing exponentially. This study estimates the epidemiological profiles and antimicrobial resistance of Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB)  isolated from clinical samples among patients admitted to two University hospitals in Sana'a city for one year (2019). Methods: This was a retrospective study of clinical samples of patients collected from January 1, 2019 to December 30, 2019. All samples were appraised to determine presence of infectious agents using standard methods for isolation and identification of bacteria and yeasts from clinical samples of patients admitted to Al-Gumhouri University Hospital and Al-Kuwait University Hospital in Sana'a city. Antibiotic resistance was done using Kirby-Bauer disc diffusion methods. Results:  2,931 different pathogenic bacteria were detected from 24,690 different clinical specimens. The samples had an overall detection rate of 11.9% (2931/24,690). Among the bacterial pathogens isolated from clinical samples, 52.4% (n=1536) had GPB and 41.2% (n=1207) had GNB. The predominant GNB isolates were E.coli (22.04%), Klebsiella spp (6.03%), Pseudomonas aeruginosa (7.1%), Acinetobacter baumannii (1.46%), Enterobacter spp. (1.09%), Citrobacter spp. (1.16%), respectively. Among the GPB, S.aureus was the most common (26.3%), Coagulase-negative Staphylococcus (8.1%), Non-hemolytic Streptococcus (9.1%), Other alpha-hemolytic Streptococcus (3.9%), Streptococcus pyogenes (1.9%), and Streptococcus pneumoniae (0.5% ). A high rate of antibiotic resistance was recorded for sulfamethoxazole/trimethoprim (85.5%), ceftazidime (81.07%), ampicillin (70.4%), cefuroxime (66.4%). Conclusions:  The current study results revealed that the rate of resistance between GNB and GPB is associated with the incidence of different infections in patients attending two major tertiary hospitals in Sana'a city is very high. These results indicate ongoing screening and follow-up programs to detect antibiotic resistance, and also suggest the development of antimicrobial stewardship programs in Sana'a, Yemen.                     Peer Review History: Received: 9 September 2021; Revised: 11 October; Accepted: 23 October, Available online: 15 November 2021 Academic Editor:  Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Rima Benatoui, Laboratory of Applied Neuroendocrinology, Department of Biology, Faculty of Science, Badji Mokhtar University Annaba, BP12 E L Hadjar–Algeria, [email protected] Dr. Wadhah Hassan Ali Edrees, Hajja University, Yemen, [email protected] Rola Jadallah, Arab American University, Palestine, [email protected] Similar Articles: PREVALENCE OF PSEUDOMONAS AERUGINOSA (P. AERUGINOSA) AND ANTIMICROBIAL SUSCEPTIBILITY PATTERNS AT A PRIVATE HOSPITAL IN SANA'A, YEMEN EVALUATION OF ANTIBACTERIAL RESISTANCE OF BIOFILM FORMS OF AVIAN SALMONELLA GALLINARUM TO FLUOROQUINOLONES

scholarly journals Phenotypic Variation of Tobramycin and Ofloxacin Resistance of Pseudomonas aeruginosa by Repeated Exhibition

2020 ◽  
pp. 1-9
Author(s):  
Andry Maharo Andrianarivelo ◽  
Christian Emmanuel Mahavy ◽  
Blandine Andrianarisoa ◽  
Tsiry Rasamiravaka
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phenotypic Variation ◽  
Culture Medium ◽  
Wild Strain ◽  
Resistance Mechanisms ◽  
Luria Bertani ◽  
University Hospital ◽  
Buffer System ◽  
Visual Evaluation ◽  
Almost All

Pseudomonas aeruginosa has the ability to resist almost all available antibiotics by rapidly accumulating multiple resistance mechanisms and thus lead to a therapeutic impasse and higher mortality in infected patients. The objective of this study was to assess the phenotypic variation in resistance to tobramycin and ofloxacin from Pseudomonas aeruginosa by repeated exhibition after determination of the minimum inhibitory concentration. This is a prospective and descriptive study carried out in the Laboratory of Microbiology of Fundamental and Applied Biochemistry (Faculty of Sciences, Antananarivo) during the month of January 2020. The strains studied were the virulent wild strain of Pseudomonas aeruginosa PAO1 supplied by the Laboratory and two clinical strains of Pseudomonas aeruginosa from the Microbiology Laboratory of the Joseph Ravoahangy Andrianavalona University Hospital Center, Antananarivo. The strains of P. aeruginosa were cultured in the liquid culture medium (which is Luria Bertani, added with a buffer system of 3- (N-morpholino) propanesulfonic acid (LB-MOPS) which will stabilize the pH and a solid culture medium which is Columbia agar. Repeated exhibition to Tobramycin and Ofloxacin from these strains have been made. The MIC is determined by a visual evaluation of the turbidity of the various wells of the microplate. The MIC value of Pseudomonas aeruginosa with tobramycin and ofloxacin is very variable for the initial MIC until the 5th generation after repeated exhibition. More Pseudomonas aeruginosa is exposed to an antibiotic many times, the more it develops resistance to this antibiotic, even being sensitive at the start. That is to say, clinically, the dose prescribed for the antibiotic has been greatly exceeded if Pseudomonas aeruginosa is repeatedly exposed to the same antibiotic.

Detection of resistance genes from Pseudomonas aeruginosa using immunomagnetic isolation and chemiluminescence

2020 ◽  
Vol 10 (3) ◽  
pp. 412-418
Author(s):  
Fei Xu ◽  
Cheng Chen ◽  
Xing Li ◽  
Bo Zhang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
High Efficiency ◽  
Bacterial Pathogen ◽  
Resistance Mechanisms ◽  
Clinical Samples ◽  
Specific Gene ◽  
Beta Lactamases ◽  
Immunomagnetic Isolation ◽  
Encoding Gene

Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic and nosocomial bacterial pathogen. Various multi-resistance mechanisms present across numerous P. aeruginosa strains counteract conventional antimicrobial therapy, thereby becoming a great challenge. This study aimed to establish the application of immunomagnetic isolation and chemiluminescence to detect the presence of extended spectra of β-lactamases encoding genes: blaTEM and blaVEB; metallo-beta-lactamases encoding gene: blaVIM; aminoglycoside modifying enzymes encoding gene: aac(6)II, ant(3)I; and the specific gene for P. aeruginosa, gyrB. P. aeruginosa was specifically selected using the immunomagnetic nanoparticles (IMNPs) in the six parallel bacterial plates counting, proving that they are reliable. Then, the high efficiency of IMNPs@Probes in targeting the resistance genes of P. aeruginosa was demonstrated using the results of chemiluminescent intensities of blaTEM, blaVEB, blaVIM aac(6)II, ant(3)I, and gyrB (more than 10 times higher than that of the control). Sixty-eight in situ clinical samples were tested for the presence of these resistance genes, and one more blaTEM and three more blaVIM individuals were detected using this method compared to the traditional PCR. Thus, the application of our method in clinical screening is specific, accurate, and reliable, and it could be useful in the administration of appropriate treatment.

scholarly journals Evaluation of different phenotypic tests for detection of metallo-β-lactamases in imipenem-resistant Pseudomonas aeruginosa

2017 ◽  
Vol 9 (04) ◽  
pp. 249-253 ◽  
Author(s):  
Rohit Sachdeva ◽  
Babita Sharma ◽  
Rajni Sharma
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Large Scale ◽  
Wide Spectrum ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Clinical Samples ◽  
Resistant Strains ◽  
Synergy Test ◽  
Phenotypic Tests ◽  
Simple Screening

Abstract PURPOSE: Pseudomonas aeruginosa causes a wide spectrum of infections including bacteremia, pneumonia, urinary tract infection, etc., Metallo-beta-lactamase (MBL) producing P. aeruginosa is an emerging threat and cause of concern as they have emerged as one of the most feared resistance mechanisms. This study was designed to know the prevalence of MBL production in P. aeruginosa and to evaluate the four phenotypic tests for detection of MBL production in imipenem-resistant clinical isolates of P. aeruginosa. METHODS: Totally, 800 isolates of P. aeruginosa isolated from various clinical samples were evaluated for carbapenem resistance and MBL production. All imipenem-resistant strains were tested for carabapenemase production by modified Hodge test. Screening for MBL production was done by double-disc synergy test and combined disc test (CDT). Confirmation of MBL production was done by the E-test (Ab BioDisk, Solna, Sweden). RESULTS: Out of the 800 isolates of P. aeruginosa, 250 isolates were found resistant to imipenem. Based on the results of E-test, 147 (18.37%) isolates of P. aeruginosa were positive for MBL production. The CDT has the highest sensitivity and specificity for the detection of MBL production as compared to other tests. CONCLUSION: The results of this study are indicative that MBL production is an important mechanism of carbapenem resistance among P. aeruginosa. Use of simple screening test like CDT will be crucial step toward large-scale monitoring of these emerging resistant determinants. Phenotypic test for MBL production has to be standardized, and all the isolates should be routinely screened for MBL production.

scholarly journals Differing Effects of Combination Chemotherapy with Meropenem and Tobramycin on Cell Kill and Suppression of Resistance of Wild-Type Pseudomonas aeruginosa PAO1 and Its Isogenic MexAB Efflux Pump-Overexpressed Mutant

2009 ◽  
Vol 53 (6) ◽  
pp. 2266-2273 ◽  
Author(s):  
G. L. Drusano ◽  
Weiguo Liu ◽  
Christine Fregeau ◽  
Robert Kulawy ◽  
Arnold Louie
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Interaction ◽  
Combination Chemotherapy ◽  
Drug Exposure ◽  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Area Under The Curve ◽  
Resistance Mechanisms ◽  
Wild Type ◽  
Resistant Mutants

ABSTRACT The drug interaction terminology (synergy, additivity, antagonism) relates to bacterial kill. The suppression of resistance requires greater drug exposure. We examined the combination of meropenem and tobramycin for kill and resistance suppression (wild-type Pseudomonas aeruginosa PAO1 and its isogenic MexAB-overexpressed mutant). The drug interaction was additive. The introduction of MexAB overexpression significantly altered the 50% inhibitory concentration of meropenem but not that of tobramycin, resulting in the recovery of a marked increase in colony numbers from drug-containing plates. For the wild type, more tobramycin-resistant isolates than meropenem-resistant isolates were present, and the tobramycin-resistant isolates were harder to suppress. MexAB overexpression unexpectedly caused a significant increase in the number of tobramycin-resistant mutants, as indexed to the area under the curve of slices through the inverted U resistance mountain. The differences were significant, except in the absence of meropenem. We hypothesize that the pump resulted in the presence of less meropenem for organism inhibition, allowing more rounds of replication and also affecting the numbers of tobramycin-resistant mutants. When resistance suppression is explored by combination chemotherapy, it is important to examine the impacts of differing resistance mechanisms for both agents.

Sign in / Sign up

Export Citation Format

Share Document