scholarly journals Insights on carbapenem-resistant Pseudomonas aeruginosa

2021 ◽  
Vol 65 (1) ◽  
pp. 105-112
Author(s):  
Márió Gajdács ◽  
Krisztina Kárpáti ◽  
Anette Stájer ◽  
Stefania Zanetti ◽  
Matthew Gavino Donadu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Epidemiological Features ◽  
Life Threatening ◽  
Phenotypic Methods ◽  
Disk Test

Pseudomonas aeruginosa (P. aeruginosa) is ubiquitous in nature, and may be a causative agent in severe, life-threatening infections. In >60% of cases, β-lactam antibiotics are used in the therapy of P. aeruginosa infections, therefore the emergence of carbapenem-resistant P. aeruginosa (CRPA) is a significant clinical concern. In this study, phenotypic methods were used to characterize fifty-four (n = 54) P. aeruginosa isolates, which were included based on their suspected non-susceptibility to meropenem. Minimum inhibitory concentrations (MICs) of meropenem, ceftazidime, cefepime, ciprofloxacin, gentamicin, were determined using E-tests, while colistin MICs were determined using broth microdilution. The isolates were subjected to the modified Hodge test (MHT), the modified carbapenem-inactivation method (mCIM) and the imipenem/EDTA combined disk test (CDT). AmpC and efflux pump overexpression was studied using agar plates containing cloxacillin and phenylalanine-arginine β-naphthylamide (PAβN), respectively. Assessment of biofilm-formation was carried out using the crystal violet tube-adherence method. 38.9% of the strains showed meropenem MICs in the resistant range (>8 mg/L). Efflux-pump overexpression and AmpC-hyperproduction was seen in 44.4% and 35.2% of isolates, respectively. 88.8% of the isolates were characterized as strong biofilm-producers. On the other hand, the presence of carbapenemases was suspected in a minority (16.7%) of tested isolates. As safe and effective therapeutic options in carbapenem-resistant Gram-negative infections are severely limited, characterization of these isolates using phenotypic and molecular-based methods is important to provide insights into the epidemiological features of these pathogens.

scholarly journals NDM-5 and OXA-181 Beta-Lactamases, a Significant Threat Continues To Spread in the Americas

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Laura J. Rojas ◽  
Andrea M. Hujer ◽  
Susan D. Rudin ◽  
Meredith S. Wright ◽  
T. Nicholas Domitrovic ◽  
...  
Keyword(s):  
Abdominal Surgery ◽  
Hot Spot ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Beta Lactamases ◽  
Carbapenem Resistant ◽  
Multiple Copies ◽  
Life Threatening

ABSTRACT Among Gram-negative bacteria, carbapenem-resistant infections pose a serious and life-threatening challenge. Here, the CRACKLE network reports a sentinel detection and characterization of a carbapenem-resistant Klebsiella pneumoniae ST147 isolate harboring bla NDM-5 and bla OXA-181 from a young man who underwent abdominal surgery in India. bla NDM-5 was located on an IncFII plasmid of ≈90 kb, whereas bla OXA-181 was chromosomally encoded. Resistome and genome analysis demonstrated multiple copies of the transposable element IS26 and a “hot-spot region” in the IncFII plasmid.

The pel genes of the Pseudomonas aeruginosa PAK strain are involved at early and late stages of biofilm formation

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 985-997 ◽  
Author(s):  
Perrine Vasseur ◽  
Isabelle Vallet-Gely ◽  
Chantal Soscia ◽  
Stéphane Genin ◽  
Alain Filloux
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gene Cluster ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Matrix Material ◽  
Solid Surfaces ◽  
Gram Negative ◽  
Initiation Phase ◽  
Late Stages

Pseudomonas aeruginosa is a Gram-negative bacterium associated with nosocomial infections and cystic fibrosis. Chronic bacterial infections are increasingly associated with the biofilm lifestyle in which microcolonies are embedded in an extracellular matrix. Screening procedures for identifying biofilm-deficient strains have allowed the characterization of several key determinants involved in this process. Biofilm-deficient P. aeruginosa PAK strains affected in a seven-gene cluster called pel were characterized. The pel genes encode proteins with similarity to components involved in polysaccharide biogenesis, of which PelF is a putative glycosyltransferase. PelG was also identified as a putative component of the polysaccharide transporter (PST) family. The pel genes were previously identified in the P. aeruginosa PA14 strain as required for the production of a glucose-rich matrix material involved in the formation of a thick pellicle and resistant biofilm. However, in PA14, the pel mutants have no clear phenotype in the initiation phase of attachment. It was shown that pel mutations in the PAK strain had little influence on biofilm initiation but, as in PA14, appeared to generate the least robust and mature biofilms. Strikingly, by constructing pel mutants in a non-piliated P. aeruginosa PAK strain, an unexpected effect of the pel mutation in the early phase of biofilm formation was discovered, since it was observed that these mutants were severely defective in the attachment process on solid surfaces. The pel gene cluster is conserved in other Gram-negative bacteria, and mutation in a Ralstonia solanacearum pelG homologue, ragG, led to an adherence defect.

scholarly journals Incidence of carbapenem-resistant Enterobacteriaceae in the multidisciplinary pediatric hospital

2020 ◽  
Vol 3 (4) ◽  
pp. 295-301
Author(s):  
L.G. Boronina ◽  
◽  
E.V. Samatova ◽  
S.M. Blinova ◽  
M.P. Kukushkina ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Pediatric Hospital ◽  
Mechanisms Of Resistance ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Phenotypic Methods ◽  
Carbapenem Resistant Enterobacteriaceae

Aim: to define the incidence of carbapenem-resistant Enterobacteriaceae in the bioassay of hospitalized children. Patients and Methods: From January to December 2019, 940 strains of gram-negative bacteria were isolated from clinical material of 900 patients. Antibiotic susceptibility testing was conducted using the disk diffusion method; SENSITITRE and Phoenix M50 analyzers used «CHROMagarTM KPC» medium. Also, Carbapenem Inactivation Method was used to detect the carbapenemase activity. Results: the species composition of carbapenem-resistant Enterobacteriaceae included: Pseudomonas aeruginosa (n=55), Acinnetobacter baumannii (n=22), Escherichia coli (n=2), Klebsiella pneumoniae (n=40), Klebsiella oxytoca (n=1), Enterobacter cloacae (n=7), Serratia marcescens (n=2), Proteus mirabilis (n=2), Pseudomonas putida (n=1). 12.1% of all Enterobacterales isolates and 29.4% Klebsiella pneumoniae strains were resistant to ertapenem; 17.2% of Enterobacteriaceae and 20% of K. pneumoniae strains were resistant to imipenem and meropenem. 50.9% of Pseudomonas aeruginosa strains were resistant to meropenem and imipenem, and 45% — to doripenem. Acinetobacter baumannii strains resistant to meropenem — 66.6%, imipenem — 63.6%, doripenem — 83.3%. In 30.4% of P. aeruginosa and A. baumannii strains, carbapenemase activity was not detected, which indicated other mechanisms of resistance to carbapenem. Conclusion: in most cases, phenotypic methods only allow to suspect the presence of certain mechanisms of acquired resistance. However, since the main, most common mechanism is the production of hydrolytic enzymes, the identification of mechanisms of resistance to carbapenems should be precisely directed at this. At present, in addition to phenotypic methods, it is optimal to use molecular methods, in particular, realtime PCR, to effectively monitor the distribution of carbapenemase producers. KEYWORDS: Enterobacterales, non-fermenting gram-negative bacteria, carbapenemases, children, infection. FOR CITATION: Boronina L.G., Samatova E.V., Blinova S.M. et al. Incidence of carbapenem-resistant Enterobacteriaceae in the multidisciplinary pediatric hospital. Russian Journal of Woman and Child Health. 2020;3(4):295–301. DOI: 10.32364/2618-8430-2020-3-4-295-301.

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

scholarly journals Correlation between the Antibiotic Resistance Genes and Susceptibility to Antibiotics among the Carbapenem-Resistant Gram-Negative Pathogens

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 255
Author(s):  
Salma M. Abdelaziz ◽  
Khaled M. Aboshanab ◽  
Ibrahim S. Yahia ◽  
Mahmoud A. Yassien ◽  
Nadia A. Hassouna
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multiple Drug ◽  
P Value ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Gram Negative ◽  
Carbapenem Resistant

In this study, the correlation between the antibiotic resistance genes and antibiotic susceptibility among the carbapenem-resistant Gram-negative pathogens (CRGNPs) recovered from patients diagnosed with acute pneumonia in Egypt was found. A total of 194 isolates including Klebsiella pneumoniae (89; 46%), Escherichia coli (47; 24%) and Pseudomonas aeruginosa (58; 30%) were recovered. Of these, 34 (18%) isolates were multiple drug resistant (MDR) and carbapenem resistant. For the K. pneumoniae MDR isolates (n = 22), blaNDM (14; 64%) was the most prevalent carbapenemase, followed by blaOXA-48 (11; 50%) and blaVIM (4; 18%). A significant association (p value < 0.05) was observed between the multidrug efflux pump (AcrA) and resistance to β-lactams and the aminoglycoside acetyl transferase gene (aac-6’-Ib) gene and resistance to ciprofloxacin, azithromycin and β-lactams (except for aztreonam). For P. aeruginosa, a significant association was noticed between the presence of the blaSHV gene and the multidrug efflux pump (MexA) and resistance to fluoroquinolones, amikacin, tobramycin, co-trimoxazole and β-lactams and between the aac-6’-Ib gene and resistance to aminoglycosides. All P. aeruginosa isolates (100%) harbored the MexAB-OprM multidrug efflux pump while 86% of the K. pneumoniae isolates harbored the AcrAB-TolC pump. Our results are of great medical importance for the guidance of healthcare practitioners for effective antibiotic prescription.

scholarly journals Molecular characterization of carbapenem-resistant Gram-negative bacilli clinical isolates in Algeria

2018 ◽  
Vol Volume 11 ◽  
pp. 735-742 ◽  
Author(s):  
Nadjette Bourafa ◽  
Wafaa Chaalal ◽  
Sofiane Bakour ◽  
Rym Lalaoui ◽  
Nafissa Boutefnouchet ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Carbapenem Resistant

scholarly journals Antimicrobial Activity of Ceftolozane–Tazobactam Tested against Contemporary (2012–2016) Enterobacteriaceae and Pseudomonas aeruginosa Isolates by US Census Division

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S371-S372
Author(s):  
Dee Shortridge ◽  
Leonard R Duncan ◽  
Michael A Pfaller ◽  
Robert K Flamm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
The United States ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Tract Infections ◽  
Abdominal Infections ◽  
Us Census ◽  
Phenotype Screen ◽  
Lactamase Inhibitor ◽  
Research Grant

Abstract Background Ceftolozane-tazobactam (C-T) is a combination of a novel antipseudomonal cephalosporin and a well-described β-lactamase inhibitor. C-T was approved by the United States (US) Food and Drug Administration in 2014 for complicated urinary tract infections, including acute pyelonephritis and complicated intra-abdominal infections. C-T is currently in clinical trials for the treatment of nosocomial pneumonia. The Program to Assess Ceftolozane-Tazobactam Susceptibility (PACTS) monitors C-T resistance to gram-negative (GN) isolates worldwide. In this study, the activities of C-T and comparators vs. GN isolates from each of the 9 US Census divisions were compared. Methods A total of 18,856 Enterobacteriaceae (ENT) and 4,735 Pseudomonas aeruginosa (PSA) isolates were collected from 32 US hospitals in 2012–2016. Isolates were tested for susceptibility (S) to C-T and comparators by CLSI broth microdilution methodology in a central monitoring laboratory. Other antibiotics tested included amikacin (AMK), ceftazidime (CAZ), colistin (COL), meropenem (MER), and piperacillin-tazobactam (TZP). The following resistant phenotypes were analyzed for ENT: carbapenem resistant (CRE); extended-spectrum β-lactamase phenotype screen-positive (ESBL); and ESBL, nonCRE. or PSA, MER-nonsusceptible (NS), TZP-NS, and CAZ-NS isolates were analyzed. CLSI (2017) interpretive criteria were used. Results For all ENT, 94.2% were S to C-T, 91.5% were S to TZP, 98.0% were S to MER, and 98.8% were S to AMK; 1,697 (9.0%) were ESBL, nonCRE and 356 (1.9%) were CRE. For all PSA isolates, 97.4% were S to C-T, 99.3% were S to COL, 96.9% were S to AMK, and 81.2% were S to MER. The % C-T S for each division (DIV) are shown in the table. The % C-T S for ENT ranged from 98.1% (DIV 4) to 87.4% (DIV 2) and % C-T S for ESBL, nonCRE ranged from 93.8% in DIV 4 to 79.8% in DIV 7. For PSA, the % C-T S ranged from 99.6% in DIV 4 to 94.9% in DIV 9. Activity of C-T against PSA NS to MER, CAZ or TZP varied by division and was &gt;80% for all except DIV 9. Conclusion Against PSA, only COL was more active than C-T. C-T demonstrated potent activity against PSA NS to other β-lactams. For ENT, overall activity was good. For both PSA and ENT, C-T varied by DIV. Disclosures D. Shortridge, Merck: Research Contractor, Research grant; L. R. Duncan, Merck: Research Contractor, Research grant; M. A. Pfaller, Merck: Research Contractor, Research grant; R. K. Flamm, Merck: Research Contractor, Research grant

First Detection of OXA-10 Extended-Spectrum Beta-Lactamases and the Occurrence of mexR and nfxB in Clinical Isolates of Pseudomonas aeruginosa from Nigeria

Chemotherapy ◽  
2015 ◽  
Vol 61 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Bamidele T. Odumosu ◽  
Bola A. Adeniyi ◽  
Ram Chandra
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Clinical Isolates ◽  
Beta Lactamases ◽  
First Report ◽  
Extended Spectrum ◽  
Pcr Rflp ◽  
Extended Spectrum Beta Lactamases ◽  
Regulator Genes

Background: The characterization of β-lactamase production in Pseudomonasaeruginosa is rarely reported in Nigeria. The objective of this study was to investigate the occurrence and characterize the different β-lactamases as well as mechanisms of fluoroquinolones resistance among P. aeruginosa isolated from various clinical sources from Nigeria. Materials and Method: Isolates were investigated using PCR, RFLP and sequencing for the detection of various β-lactamases and efflux pump regulator genes. Result: The prevalence of OXA-10, AmpC, CTX-M and SHV in P. aeruginosa was 80, 70, 5 and 5%, respectively. The coexistence of blaOXA-10 with blaAmpC, blaSHV and blaCTX-M was reported in 40, 5 and 5% of isolates, respectively. The efflux pump regulator genes mexR and nfxB were both amplified in 45% of the OXA-10-positive isolates. Conclusion: This is the first report of the characterization of OXA-10 extended-spectrum β-lactamases and occurrence of mexR and nfxB efflux regulator genes in clinical isolates of P. aeruginosa in Nigeria.

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