scholarly journals Problematic clinical isolates of Pseudomonas aeruginosa from the university hospitals in Sofia, Bulgaria: current status of antimicrobial resistance and prevailing resistance mechanisms

2007 ◽  
Vol 56 (7) ◽  
pp. 956-963 ◽  
Author(s):  
Tanya Strateva ◽  
Vessela Ouzounova-Raykova ◽  
Boyka Markova ◽  
Albena Todorova ◽  
Yulia Marteva-Proevska ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Clinical Isolates ◽  
Current Status ◽  
University Hospitals ◽  
Active Efflux ◽  
Genes Encoding

A total of 203 clinical isolates of Pseudomonas aeruginosa was collected during 2001–2006 from five university hospitals in Sofia, Bulgaria, to assess the current levels of antimicrobial susceptibility and to evaluate resistance mechanisms to antipseudomonal antimicrobial agents. The antibiotic resistance rates against the following antimicrobials were: carbenicillin 93.1 %, azlocillin 91.6 %, piperacillin 86.2 %, piperacillin/tazobactam 56.8 %, ceftazidime 45.8 %, cefepime 48.9 %, cefpirome 58.2 %, aztreonam 49.8 %, imipenem 42.3 %, meropenem 45.5 %, amikacin 59.1 %, gentamicin 79.7 %, tobramycin 89.6 %, netilmicin 69.6 % and ciprofloxacin 80.3 %. A total of 101 of the studied P. aeruginosa isolates (49.8 %) were multidrug resistant. Structural genes encoding class A and class D β-lactamases showed the following frequencies: bla VEB-1 33.1 %, bla PSE-1 22.5 %, bla PER-1 0 %, bla OXA-groupI 41.3 % and bla OXA-groupII 8.8 %. IMP- and VIM-type carbapenemases were not detected. In conclusion, the studied clinical strains of P. aeruginosa were problematic nosocomial pathogens. VEB-1 extended-spectrum β-lactamases appear to have a significant presence among clinical P. aeruginosa isolates from Sofia. Carbapenem resistance was related to non-enzymic mechanisms such as a deficiency of OprD proteins and active efflux.

scholarly journals Pathogenicity Genomic Island-Associated CrpP-Like Fluoroquinolone-Modifying Enzymes among Pseudomonas aeruginosa Clinical Isolates in Europe

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
José Manuel Ortiz de la Rosa ◽  
Patrice Nordmann ◽  
Laurent Poirel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genomic Island ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Genomic Islands ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Genes Encoding

ABSTRACT Many transferable quinolone resistance mechanisms have been identified in Gram-negative bacteria. The plasmid-encoded 65-amino-acid-long ciprofloxacin-modifying enzyme CrpP was recently identified in Pseudomonas aeruginosa isolates. We analyzed a collection of 100 clonally unrelated and multidrug-resistant P. aeruginosa clinical isolates, among which 46 were positive for crpP-like genes, encoding five CrpP variants conferring variable levels of reduced susceptibility to fluoroquinolones. These crpP-like genes were chromosomally located as part of pathogenicity genomic islands.

scholarly journals Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil

2015 ◽  
Vol 110 (8) ◽  
pp. 1003-1009 ◽  
Author(s):  
Felipe Lira de Sá Cavalcanti ◽  
Cristina Rodríguez Mirones ◽  
Elena Román Paucar ◽  
Laura Álvarez Montes ◽  
Tereza Cristina Leal-Balbino ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Clinical Isolates

Carbapenem-resistance mechanisms of multidrug-resistant Pseudomonas aeruginosa

2013 ◽  
Vol 62 (9) ◽  
pp. 1317-1325 ◽  
Author(s):  
Ester Fusté ◽  
Lídia López-Jiménez ◽  
Concha Segura ◽  
Eusebio Gainza ◽  
Teresa Vinuesa ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Class 1 Integron ◽  
Carbonyl Cyanide ◽  
Class 1

Clonal dissemination of multidrug-resistant Pseudomonas aeruginosa (MDRPA) is a major concern worldwide. The aim of this study was to explore the mechanisms leading to the carbapenem resistance of an MDRPA clone. Isolates were obtained from a surgical wound, sputum, urine and a blood culture. Pulsed-field gel electrophoresis (PFGE) showed high genomic homogeneity of these isolates and confirmed the circulation of an endemic clone belonging to serotype O4. Outer membrane protein (OMP) bands were visualized by SDS-PAGE, meropenem accumulation was measured in a bioassay and integrons were detected by PCR. Efflux pumps were studied for several antimicrobial agents and synergic combinations thereof in the presence or absence of both carbonyl cyanide m-chlorophenylhydrazone (CCCP) and Phe-Arg-β-naphthylamide (PAβN) at final concentrations of 10 and 40 mg l−1, respectively. On OMP electrophoretic profiles, MDRPA showed a reduction of outer membrane porin D (OprD) and PCR demonstrated the presence of a class 1 integron with a cassette encoding aminoglycoside adenyltransferase B (aadB). Meropenem accumulation was slightly higher in bacilli than in the filamentous cells that formed in the presence of antibiotics. Overexpression of the efflux pump MexAB-OprM and a functional MexXY-OprM were detected in all isolates.

scholarly journals Phenotypic Antimicrobial Susceptibility and Genotypic Characterization of Clinical Ureaplasma Isolates Circulating in Shanghai, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Hongxia Ma ◽  
Xuemei Zhang ◽  
Xiaoxing Shi ◽  
Jun Zhang ◽  
Yunheng Zhou
Keyword(s):  
Antimicrobial Susceptibility ◽  
Ribosomal Proteins ◽  
Antimicrobial Agents ◽  
Ureaplasma Urealyticum ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Ureaplasma Parvum ◽  
Genes Encoding

There is a growing global concern regarding the rise of antimicrobial resistance among Ureaplasma spp. isolates. However, studies on the antimicrobial susceptibility profiles, resistance mechanisms, and clonality of Ureaplasma spp. clinical isolates are still limited and cover only some geographic regions. Firstly, Ureaplasma species from the urogenital tracts of patients in Shanghai, China, were isolated by using the culture medium (A8 and 10B broth), and identified the genotype by polymerase chain reaction (PCR). Secondly, the antimicrobial susceptibility tests were determined by using broth microdilution assay. Then, the resistance genetic determinants to fluoroquinolones (FQs), macrolides, and tetracyclines were investigated through PCR/DNA sequencing. Finally, the molecular epidemiology of Ureaplasma species was studied by multilocus sequence typing (MLST). Among 258 isolates, Ureaplasma parvum (UPA) and Ureaplasma urealyticum (UUR) were found in 226 (87.60%) and 32 (12.40%) isolates, respectively. The minimum inhibitory concentrations (MICs) of 258 Ureaplasma spp. strains ranged from 0.015 to 64μg/ml for all 11 kinds of antimicrobials. Regardless of species, the isolates were most sensitive to AZI (1.94%), JOS (3.49%), and CLA (4.23%). Among them, there were 39 (15.12%) multidrug-resistant (MDR) strains, including 32 UPA isolates. The resistance rates of UPA to CIP (91.59%), and ROX (36.28%) were significantly higher than those of UUR. Twenty six FQ-resistant isolates had amino acid substitutions in gyrA and in parC (Ser83Leu). Mutations were detected in genes encoding ribosomal proteins L4 (Thr84Ile) and L22 (Ser81Pro) in macrolide-resistant isolates. Tet(M) was found in four UPA isolates. These mutations were mainly found in UPA isolates. Sequence type 1 (ST1) was the predominant ST, which contained 18 isolates. In conclusion, this study showed a higher resistance rate (especially to ROX and CIP), higher substitution rate, and higher MDR rate among UPA strains. The most active antimicrobial agents were AZI, JOS, and CLA. Identifying UPA or UUR in clinical isolates could help clinicians to choose appropriate drugs for treatment. The main resistance mechanisms may involve gene substitution of Ser83Leu in parC and Ser81Pro in L22. ST1 was the predominant ST of Ureaplasma isolates with MDR to FQs and macrolides in Shanghai, China.

Distribution of carbapenem resistance mechanisms in clinical isolates of XDR Pseudomonas aeruginosa

2019 ◽  
Vol 38 (8) ◽  
pp. 1547-1552 ◽  
Author(s):  
Annalisa De Rosa ◽  
Nico T. Mutters ◽  
Claudio M. Mastroianni ◽  
Stefan J. Kaiser ◽  
Frank Günther
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Clinical Isolates

scholarly journals Pseudomonas aeruginosa Clinical Isolates in Nepal Coproducing Metallo-β-Lactamases and 16S rRNA Methyltransferases

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Tatsuya Tada ◽  
Kayo Shimada ◽  
Kazuhito Satou ◽  
Takashi Hirano ◽  
Bharat M. Pokhrel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
16S Rrna ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Content Type ◽  
First Report ◽  
Genes Encoding

ABSTRACT A total of 11 multidrug-resistant Pseudomonas aeruginosa clinical isolates were obtained in Nepal. Four of these isolates harbored genes encoding one or more carbapenemases (DIM-1, NDM-1, and/or VIM-2), and five harbored genes encoding a 16S rRNA methyltransferase (RmtB4 or RmtF2). A novel RmtF variant, RmtF2, had a substitution (K65E) compared with the same gene in RmtF. To our knowledge, this is the first report describing carbapenemase- and 16S rRNA methyltransferase-coproducing P. aeruginosa clinical isolates in Nepal.

scholarly journals Molecular Epidemiology and Mechanisms of Carbapenem Resistance in Pseudomonas aeruginosa

2009 ◽  
Vol 53 (11) ◽  
pp. 4783-4788 ◽  
Author(s):  
José-Manuel Rodríguez-Martínez ◽  
Laurent Poirel ◽  
Patrice Nordmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Protein ◽  
Molecular Epidemiology ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Mechanisms Of Resistance ◽  
Genes Encoding ◽  
Imipenem Resistance

ABSTRACT The contributions of different mechanisms of resistance to carbapenems among a collection of imipenem- and meropenem-nonsusceptible Pseudomonas aeruginosa isolates were investigated. This screening included the recently reported extended-spectrum cephalosporinases (ESACs) weakly hydrolyzing carbapenems. Eighty-seven percent of the studied isolates were resistant to imipenem. Genes encoding metallo-β-lactamases or carbapenem-hydrolyzing oxacillinases were not identified. The main mechanism associated with imipenem resistance was the loss of outer membrane protein OprD. Identification of overexpressed ESACs and loss of OprD were observed for 65% of the isolates, all being fully resistant to imipenem. Resistance to meropenem was observed in 78% of the isolates, with all but one also being resistant to imipenem. Overexpression of the MexAB-OprM, MexXY-OprM, or MexCD-OprJ efflux systems was observed in 60% of the isolates, suggesting the contribution of efflux mechanisms in resistance to meropenem. The loss of porin OprD and the overproduction of ESACs were observed in 100% and 92% of the meropenem-resistant isolates, respectively. P. aeruginosa can very often accumulate different resistance mechanisms, including ESAC production, leading to carbapenem resistance.

P867 Carbapenem resistance mechanisms in Norwegian clinical isolates of Pseudomonas aeruginosa

2007 ◽  
Vol 29 ◽  
pp. S223-S224
Author(s):  
Ø. Samuelsen ◽  
L. Buarø ◽  
B. Aasnæs ◽  
C.G. Giske ◽  
B. Haldorsen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Clinical Isolates

scholarly journals Antimicrobial Susceptibility and Characterization of Resistance Mechanisms of Corynebacterium urealyticum Clinical Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 404
Author(s):  
Itziar Chapartegui-González ◽  
Marta Fernández-Martínez ◽  
Ana Rodríguez-Fernández ◽  
Danilo J. P. Rocha ◽  
Eric R. G. R. Aguiar ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Point Mutations ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Tract Infections ◽  
Corynebacterium Urealyticum

Corynebacterium urealyticum is a non-diphtherial urease-producing clinically relevant corynebacterial, most frequently involved in urinary tract infections. Most of the C. urealyticum clinical isolates are frequently resistant to several antibiotics. We investigated the susceptibility of 40 C. urealyticum isolated in our institution during the period 2005–2017 to eight compounds representative of the main clinically relevant classes of antimicrobial agents. Antimicrobial susceptibility was determined by the Epsilometer test. Resistance genes were searched by PCR. All strains were susceptible to vancomycin whereas linezolid and rifampicin also showed good activity (MICs90 = 1 and 0.4 mg/L, respectively). Almost all isolates (39/40, 97.5%) were multidrug resistant. The highest resistance rate was observed for ampicillin (100%), followed by erythromycin (95%) and levofloxacin (95%). Ampicillin resistance was associated with the presence of the blaA gene, encoding a class A β-lactamase. The two rifampicin-resistant strains showed point mutations driving amino acid replacements in conserved residues of RNA polymerase subunit β (RpoB). Tetracycline resistance was due to an efflux-mediated mechanism. Thirty-nine PFGE patterns were identified among the 40 C. urealyticum, indicating that they were not clonally related, but producing sporadic infections. These findings raise the need of maintaining surveillance strategies among this multidrug resistant pathogen.

Geographic Patterns of Carbapenem-resistant Pseudomonas aeruginosa in the Asia-Pacific Region: Results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program, 2015–2019

2021 ◽  
Author(s):  
Yu-Lin Lee ◽  
Wen-Chien Ko ◽  
Po-Ren Hsueh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Asia Pacific ◽  
Pacific Region ◽  
Asia Pacific Region ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method ◽  
Resistance Patterns

Pseudomonas aeruginosa is a common pathogen that is associated with multidrug-resistant (MDR) and carbapenem-resistant (CR) phenotypes; therefore, we investigated its resistance patterns and mechanisms by using data from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program in the Asia-Pacific region during 2015–2019. MICs were determined using the broth microdilution method. Genes encoding major extended-spectrum β-lactamases and carbapenemases were investigated by multiplex PCR assays. Susceptibility was interpreted using the Clinical and Laboratory Standards Institute (CLSI) breakpoints. A total of 6,349 P. aeruginosa isolates were collected in the ATLAS program between 2015 and 2019 from 14 countries. According to the CLSI definitions, the numbers (and rates) of CR and MDR P. aeruginosa were 1,198 (18.9%) and 1,303 (20.5%), respectively. For 747 of the CR P. aeruginosa strains that were available for gene screening, 253 β-lactamases genes were detected in 245 (32.8%) isolates. The most common gene was bla VIM (29.0, 71/245), followed by bla NDM (24.9%, 61/245) and bla VEB (20.8%, 51/245). The resistance patterns and associated genes varied significantly between the countries in the Asia-Pacific region. India had the highest rates of carbapenem resistance (29.3%, 154/525) and gene detection (17.7%, 93/525). Compared to those harboring either class A or B β-lactamase genes, the CR P. aeruginosa without detected β-lactamase genes had lower MICs for most of the antimicrobial agents, including ceftazidime/avibactam and ceftolozane/tazobactam. In conclusion, MDR and CR P. aeruginosa infections pose a major threat, particularly those with detected carbapenemase genes. Continuous surveillance is important for improving antimicrobial stewardship and antibiotic prescriptions.

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