Contributions of IMP-10 Metallo-β-Lactamase, the Outer Membrane Barrier and the MexAB-OprM Efflux System to High-Level Carbapenem Resistance in Pseudomonas aeruginosa

Chemotherapy ◽  
2009 ◽  
Vol 55 (3) ◽  
pp. 168-174 ◽  
Author(s):  
Wei-Hua Zhao ◽  
Zhuting Hu ◽  
Gelin Chen ◽  
Ribu Ito ◽  
Zhi-Qing Hu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Carbapenem Resistance ◽  
Beta Lactamase ◽  
Efflux System ◽  
Membrane Barrier ◽  
High Level

scholarly journals Pseudomonas aeruginosa Reveals High Intrinsic Resistance to Penem Antibiotics: Penem Resistance Mechanisms and Their Interplay

2001 ◽  
Vol 45 (7) ◽  
pp. 1964-1971 ◽  
Author(s):  
Kiyomi Okamoto ◽  
Naomasa Gotoh ◽  
Takeshi Nishino
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Laboratory Strain ◽  
Resistance Mechanisms ◽  
Efflux System ◽  
Intrinsic Resistance ◽  
Active Efflux ◽  
Membrane Barrier ◽  
Susceptibility Tests ◽  
Almost All

ABSTRACT Pseudomonas aeruginosa exhibits high intrinsic resistance to penem antibiotics such as faropenem, ritipenem, AMA3176, sulopenem, Sch29482, and Sch34343. To investigate the mechanisms contributing to penem resistance, we used the laboratory strain PAO1 to construct a series of isogenic mutants with an impaired multidrug efflux system MexAB-OprM and/or impaired chromosomal AmpC β-lactamase. The outer membrane barrier of PAO1 was partially eliminated by inducing the expression of the plasmid-encodedEscherichia coli major porin OmpF. Susceptibility tests using the mutants and the OmpF expression plasmid showed that MexAB-OprM and the outer membrane barrier, but not AmpC β-lactamase, are the main mechanisms involved in the high intrinsic penem resistance of PAO1. However, reducing the high intrinsic penem resistance of PAO1 to the same level as that of penem-susceptible gram-negative bacteria such as E. coli required the loss of either both MexAB-OprM and AmpC β-lactamase or both MexAB-OprM and the outer membrane barrier. Competition experiments for penicillin-binding proteins (PBPs) revealed that the affinity of PBP 1b and PBP 2 for faropenem were about 1.8- and 1.5-fold lower, than the respective affinity for imipenem. Loss of the outer membrane barrier, MexAB, and AmpC β-lactamase increased the susceptibility of PAO1 to almost all penems tested compared to the susceptibility of the AmpC-deficient PAO1 mutants to imipenem. Thus, it is suggested that the high intrinsic penem resistance of P. aeruginosa is generated from the interplay among the outer membrane barrier, the active efflux system, and AmpC β-lactamase but not from the lower affinity of PBPs for penems.

scholarly journals Multifocal outbreaks of metallo-beta-lactamase-producing Pseudomonas aeruginosa resistant to broad-spectrum beta-lactams, including carbapenems.

1996 ◽  
Vol 40 (2) ◽  
pp. 349-353 ◽  
Author(s):  
K Senda ◽  
Y Arakawa ◽  
K Nakashima ◽  
H Ito ◽  
S Ichiyama ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Broad Spectrum ◽  
Early Recognition ◽  
Carbapenem Resistance ◽  
Hybridization Analysis ◽  
Beta Lactamase ◽  
Beta Lactams ◽  
Imipenem Resistance ◽  
High Level ◽  
Lactamase Gene

A total of 3,700 Pseudomonas aeruginosa isolates were collected from 17 general hospitals in Japan from 1992 to 1994. Of these isolates, 132 carbapenem-resistant strains were subjected to DNA hybridization analysis with the metallo-beta-lactamase gene (blaIMP)-specific probe. Fifteen strains carrying the metallo-beta-lactamase gene were identified in five hospitals in different geographical areas. Three strains of P. aeruginosa demonstrated high-level imipenem resistance (MIC, > or = 128 micrograms/ml), two strains exhibited low-level imipenem resistance (MIC, < or = 4 micrograms/ml), and the rest of the strains were in between. These results revealed that the acquisition of a metallo-beta-lactamase gene alone does not necessarily confer elevated resistance to carbapenems. In several strains, the metallo-beta-lactamase gene was carried by large plasmids, and carbapenem resistance was transferred from P. aeruginosa to Escherichia coli by electroporation in association with the acquisition of the large plasmid. Southern hybridization analysis and genomic DNA fingerprinting profiles revealed different genetic backgrounds for these 15 isolates, although considerable similarity was observed for the strains isolated from the same hospital. These findings suggest that the metallo-beta-lactamase-producing P. aeruginosa strains are not confined to a unique clonal lineage but proliferated multifocally by plasmid-mediated dissemination of the metallo-beta-lactamase gene in strains of different genetic backgrounds. Thus, further proliferation of metallo-beta-lactamase-producing strains with resistance to various beta-lactams may well be inevitable in the future, which emphasizes the need for early recognition of metallo-beta-lactamase-producing strains, rigorous infection control, and restricted clinical use of broad-spectrum beta-lactams including carbapenems.

scholarly journals Extrusion of Penem Antibiotics by Multicomponent Efflux Systems MexAB-OprM, MexCD-OprJ, and MexXY-OprM of Pseudomonas aeruginosa

2002 ◽  
Vol 46 (8) ◽  
pp. 2696-2699 ◽  
Author(s):  
Kiyomi Okamoto ◽  
Naomasa Gotoh ◽  
Takeshi Nishino
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Efflux System ◽  
Cell Interior ◽  
Active Efflux ◽  
Membrane Barrier

ABSTRACT The high intrinsic penem resistance of Pseudomonas aeruginosa is due to the interplay among the outer membrane barrier, the active efflux system MexAB-OprM, and AmpC β-lactamase. We studied the roles of two other efflux systems, MexCD-OprJ and MexXY-OprM, in penem resistance by overexpressing each system in an AmpC- and MexAB-OprM-deficient background and found that MexAB-OprM is the most important among the three efflux systems for extrusion of penems from the cell interior.

scholarly journals Resistance to β-Lactam Antibiotics inPseudomonas aeruginosa Due to Interplay between the MexAB-OprM Efflux Pump and β-Lactamase

1999 ◽  
Vol 43 (5) ◽  
pp. 1301-1303 ◽  
Author(s):  
Taiji Nakae ◽  
Akira Nakajima ◽  
Toshihisa Ono ◽  
Kohjiro Saito ◽  
Hiroshi Yoneyama
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Efflux System ◽  
High Level

ABSTRACT We evaluated the roles of the MexAB-OprM efflux pump and β-lactamase in β-lactam resistance in Pseudomonas aeruginosa by constructing OprM-deficient, OprM basal level, and OprM fully expressed mutants from β-lactamase-negative, -inducible, and -overexpressed strains. We conclude that, with the notable exception of imipenem, the MexAB-OprM pump contributes significantly to β-lactam resistance in both β-lactamase-negative and β-lactamase-inducible strains, while the contribution of the MexAB-OprM efflux system is negligible in strains with overexpressed β-lactamase. Overexpression of the efflux pump alone contributes to the high level of β-lactam resistance in the absence of β-lactamase.

scholarly journals Investigation of Metallo-Beta-Lactamases in Carbapenem Resistant Pseudomonas aeruginosa Strains by Phenotypic and Genotypic Methods

2020 ◽  
Vol 25 (3) ◽  
pp. 301-307
Author(s):  
M. Duygu Aksoy ◽  
H. Murat Tuğrul
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylenediaminetetraacetic Acid ◽  
Carbapenem Resistance ◽  
Beta Lactamase ◽  
Bacterial Strains ◽  
Beta Lactamases ◽  
Carbapenem Resistant ◽  
Synergy Test ◽  
Phenotypic Tests ◽  
Positive Controls

Introduction: Carbapenem resistant Pseudomonas aeruginosa strains cause serious problems in treatment. A large number of identified metallo-beta-lactamase (MBL) enzymes produced by P. aeruginosa are one of the most important mechanisms in resistance to carbapenems. MBL genes are located on the chromosome or plasmid, and they can easily spread between different bacterial strains. The activities of these enzymes are zinc-dependent, and they are inhibited by ethylenediaminetetraacetic acid (EDTA). Therefore, this advantage is used in MBL identification tests. In this study, it was aimed to determine MBL among P. aeruginosa strains. Materials and Methods: MBL existence was investigated in 35 P. aeruginosa strains accepted to be mildly susceptible/resistant to any of the carbapenem group of antibiotics through phenotypic and genotypic methods. Phenotypic tests were performed as double disk synergy test (DDST), combined disk diffusion tests (CDDT) by using 0.1 M and 0.5 M EDTA, MBL E-test, and modified Hodge test (MHT). blaIMP, blaVIM, blaGIM, blaSIM, blaSPM genes and blaNDM gene were investigated by multiplex polimerase chain reaction (PCR) and PCR, respectively. Escherichia coli ATCC 25922 and P. aeruginosa ATCC 27853 standard bacteria were used in tests. VIM-1, VIM-2, IMP-13, SPM-1, NDM-1 type MBL-producing P. aeruginosa strains were used as positive controls. Results: Among the carbapenems resistant P. aeruginosa isolates, positivity of MBL was found as 54.2% by MBL E-test, 42.8% by DDST, 94.2% and 37.1% by CDDT method using 0.5 M and 0.1 M EDTA, respectively. Modified Hodge test and genotypic method did not detect MBL. Conclusion: In order to correctly evaluate the results of the phenotypic method, the investigation of resistance genes by molecular methods is also required. The most common metallo-beta-lactamase enzymes responsible for resistance to carbapenem in Pseudomonas were not observed. It was thought that different mechanisms might be responsible for the identified carbapenem resistance.

scholarly journals A TEM-derived extended-spectrum beta-lactamase in Pseudomonas aeruginosa.

1996 ◽  
Vol 40 (11) ◽  
pp. 2488-2493 ◽  
Author(s):  
P Mugnier ◽  
P Dubrous ◽  
I Casin ◽  
G Arlet ◽  
E Collatz
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Strain ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Aminoglycoside Resistance ◽  
Double Mutation ◽  
Extended Spectrum Beta Lactamase ◽  
Beta Lactam Antibiotics ◽  
Extended Spectrum ◽  
High Level

A clinical strain of Pseudomonas aeruginosa, PAe1100, was found to be resistant to all antipseudomonal beta-lactam antibiotics and to aminoglycosides, including gentamicin, amikacin, and isepamicin. PAe1100 produced two beta-lactamases, TEM-2 (pI 5.6) and a novel, TEM-derived extended-spectrum beta-lactamase called TEM-42 (pI 5.8), susceptible to inhibition by clavulanate, sulbactam, and tazobactam. Both enzymes, as well as the aminoglycoside resistance which resulted from AAC(3)-IIa and AAC(6')-I production, were encoded by an 18-kb nonconjugative plasmid, pLRM1, that could be transferred to Escherichia coli by transformation. The gene coding for TEM-42 had four mutations that led to as many amino acid substitutions with respect to TEM-2: Val for Ala at position 42 (Ala42), Ser for Gly238, Lys for Glu240, and Met for Thr265 (Ambler numbering). The double mutation Ser for Gly238 and Lys for Glu240, which has so far only been described in SHV-type but not TEM-type enzymes, conferred concomitant high-level resistance to cefotaxime and ceftazidime. The novel, TEM-derived extended-spectrum beta-lactamase appears to be the first of its class to be described in P. aeruginosa.

scholarly journals A Screen for Antibiotic Resistance Determinants Reveals a Fitness Cost of the Flagellum in Pseudomonas aeruginosa

2019 ◽  
Vol 202 (6) ◽  
Author(s):  
E. A. Rundell ◽  
N. Commodore ◽  
A. L. Goodman ◽  
B. I. Kazmierczak
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Critical Role ◽  
Fitness Cost ◽  
Intrinsic Resistance ◽  
Content Type ◽  
Fitness Advantage ◽  
Membrane Barrier ◽  
Flagellar Assembly ◽  
Cell Envelopes

ABSTRACT The intrinsic resistance of Pseudomonas aeruginosa to many antibiotics limits treatment options for pseudomonal infections. P. aeruginosa’s outer membrane is highly impermeable and decreases antibiotic entry into the cell. We used an unbiased high-throughput approach to examine mechanisms underlying outer membrane-mediated antibiotic exclusion. Insertion sequencing (INSeq) identified genes that altered fitness in the presence of linezolid, rifampin, and vancomycin, antibiotics to which P. aeruginosa is intrinsically resistant. We reasoned that resistance to at least one of these antibiotics would depend on outer membrane barrier function, as previously demonstrated in Escherichia coli and Vibrio cholerae. This approach demonstrated a critical role of the outer membrane barrier in vancomycin fitness, while efflux pumps were primary contributors to fitness in the presence of linezolid and rifampin. Disruption of flagellar assembly or function was sufficient to confer a fitness advantage to bacteria exposed to vancomycin. These findings clearly show that loss of flagellar function alone can confer a fitness advantage in the presence of an antibiotic. IMPORTANCE The cell envelopes of Gram-negative bacteria render them intrinsically resistant to many classes of antibiotics. We used insertion sequencing to identify genes whose disruption altered the fitness of a highly antibiotic-resistant pathogen, Pseudomonas aeruginosa, in the presence of antibiotics usually excluded by the cell envelope. This screen identified gene products involved in outer membrane biogenesis and homeostasis, respiration, and efflux as important contributors to fitness. An unanticipated fitness cost of flagellar assembly and function in the presence of the glycopeptide antibiotic vancomycin was further characterized. These findings have clinical relevance for individuals with cystic fibrosis who are infected with P. aeruginosa and undergo treatment with vancomycin for a concurrent Staphylococcus aureus infection.

scholarly journals Detection of VIM and NDM-1 metallo-beta-lactamase genes in carbapenem-resistant Pseudomonas aeruginosa clinical strains in Bahrain

2019 ◽  
Vol 11 (02) ◽  
pp. 138-143 ◽  
Author(s):  
Ronni Mol Joji ◽  
Nouf Al-Rashed ◽  
Nermin Kamal Saeed ◽  
Khalid Mubarak Bindayna
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multiple Drug Resistance ◽  
Infectious Agent ◽  
Carbapenem Resistance ◽  
Conventional Polymerase Chain Reaction ◽  
Control Measures ◽  
Multiple Drug ◽  
Beta Lactamase ◽  
Infection Control Measures ◽  
Carbapenem Resistant

Abstract INTRODUCTION: Carbapenem-resistant Pseudomonas aeruginosa has emerged as a life-threatening infectious agent worldwide. Carbapenemase genes are reported to be some of the most common mechanisms for carbapenem resistance in P. aeruginosa. No reports are available from the Kingdom of Bahrain about carbapenem resistance and the underlying cause. In this study, we determined to study the presence of the metallo-beta-lactamase (M β L) genes of VIM family and NDM-1 in carbapenem-resistant P. aeruginosa strains. METHODOLOGY: Fifty carbapenem-resistant P. aeruginosa isolates were obtained from three main hospitals of Bahrain. They were subjected to antimicrobial susceptibility testing by disc diffusion test. Subsequently, MβL was detected by imipenem-ethylene diamine tetraacetic acid (EDTA) combined disc test and conventional polymerase chain reaction. RESULTS: Among 50 P. aeruginosa strains, 40 (80%) were imipenem resistant. Among the 40 imipenem-resistant strains, 35 (87.5%) strains were positive for the imipenem-EDTA combined disc test, and 21 (52%) were carrying MβL genes. Nineteen (47.5%) strains were positive for the VIM gene; one (2.5%) strain was carrying the NDM-1 gene, while one strain was carrying both the VIM and NDM-1 genes. None of the imipenem sensitive strains carried the VIM or NDM-1 gene. CONCLUSION: This is the first study to report the presence of the VIM family gene and NDM-1 genes in imipenem-resistant P. aeruginosa isolates in the Kingdom of Bahrain. The study also confirms the multiple drug resistance by the MβL strains, attention should therefore from now on, be focused on prevention of further spread of such isolates by firm infection control measures, and to reduce its threat to public health.

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