scholarly journals Prevalence of multi-drug resistant (MDR) and extensively drug-resistant (XDR) phenotypes of Pseudomonas aeruginosa and Acinetobacter baumannii isolated in clinical samples from Northeast of Iran

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Bahman Mirzaei ◽  
Zahra Norouzi Bazgir ◽  
Hamid Reza Goli ◽  
Fatemeh Iranpour ◽  
Fatemeh Mohammadi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Clinical Samples ◽  
Drug Resistant ◽  
Extensively Drug Resistant

scholarly journals Potentiation of antimicrobial activity of colistin with antibiotics of different groups against multidrug- and extensively drug-resistant strains of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa

2020 ◽  
Vol 22 (2) ◽  
pp. 128-136
Author(s):  
Dmitry V. Tapalskiy ◽  
T.A. Petrovskaya ◽  
A.I. Kozlova ◽  
Mikhail V. Edelstein
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Bactericidal Activity ◽  
Drug Resistant ◽  
Extensively Drug Resistant ◽  
Potentiation Effect ◽  
Resistant Strains ◽  
Drug Resistant Strains

Objective. To reveal antibiotics being capable of potentiating the antimicrobial activity of colistin against multidrug- and extensively drug-resistant strains of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. Materials and Methods. The minimum inhibitory concentrations (MIC) of colistin alone and in combination with fixed concentrations of antibiotics of different groups were determined for 272 multidrug- and extensively drug-resistant strains of K. pneumoniae, A. baumannii and P. aeruginosa. Bactericidal activity of colistin, carbapenems, clarithromycin and their combinations were also determined at fixed PK/PD breakpoint concentrations of antibiotics. Results. Potentiation of colistin antibacterial activity in the presence of fixed concentration of rifampicin (0.5 mg/L) was observed as a 4–16-fold MIC decrease for K. pneumoniae and A. baumannii. In the presence of fixed concentrations of azithromycin (2 mg/L) or clarithromycin (1 mg/L), the colistin MICs decreased 64–512 times for K. pneumoniae, 4–32 times for A. baumannii, 16–64 times for P. aeruginosa. Two- or more-fold reduction of MIC of colistin in the presence of 1 mg/L clarithromycin was observed for 85.2% of K. pneumoniae, 86.3% of A. baumannii and 60.2% of P. aeruginosa strains. In the presence of 1 mg/L clarithromycin and 8 mg/L meropenem, the potentiation effect was enhanced and was observed for an even larger percent of isolates: 96.1% K. pneumoniae, 98.0% A. baumannii and 61.3% P. aeruginosa. Colistin-based combinations with clarithromycin-meropenem and clarithromycin-doripenem were bactericidal against most isolates of A. baumannii and P. aeruginosa (91.4–100%), and against colistin-sensitive K. pneumoniae (95.3%) and colistin-resistant K. pneumoniae (79.1%). Conclusions. The ability of macrolides to significantly potentiate the colistin antimicrobial activity against both colistin-sensitive and colistin-resistant strains of K. pneumoniae, A. baumannii and P. aeruginosa was shown. This potentiation effect was enhanced in the presence of carbapenems. The most potent bactericidal activity was revealed with dual and triple combinations of colistin-clarithromycin and colistinclarithromycin-carbapenems.

scholarly journals Polymyxin B in Combination with Antimicrobials LackingIn VitroActivity versus Polymyxin B in Monotherapy in Critically Ill Patients with Acinetobacter baumannii or Pseudomonas aeruginosa Infections

2015 ◽  
Vol 59 (10) ◽  
pp. 6575-6580 ◽  
Author(s):  
Maria Helena Rigatto ◽  
Fabiane J. Vieira ◽  
Laura C. Antochevis ◽  
Tainá F. Behle ◽  
Natane T. Lopes ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Combination Therapy ◽  
Acinetobacter Baumannii ◽  
Protective Factor ◽  
Polymyxin B ◽  
Apache Ii Score ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Tract Infections

ABSTRACTThere is no clinical evidence supporting the use of polymyxin B in combination with another antimicrobial for infections caused by extensively drug-resistantAcinetobacter baumanniiorPseudomonas aeruginosaisolates. We developed a cohort study of patients in two intensive care units from teaching hospitals to evaluate treatment with intravenous polymyxin B for ≥48 h for severeA. baumanniiorP. aeruginosainfections. Covariates potentially associated with 30-day mortality were evaluated in a Cox proportional hazards model. A total of 101 patients were included; 33 (32.7%) were treated with polymyxin B in combination with an antimicrobial lackingin vitroactivity and 68 (67.3%) with polymyxin B in monotherapy. The overall 30-day mortality was 59.4% (60 patients), comprising 42.4% (14 of 33) and 67.6% (46 of 68) in combination and monotherapy groups, respectively (P= 0.03). The mortality rates were 18.5/1,000 patient days and 36.4/1,000 patient days in the combination and monotherapy groups, respectively (P= 0.02). Combination therapy was independently associated with lower 30-day mortality (hazard ratio, 0.33; 95% confidence interval, 0.17 to 0.64;P= 0.001). Creatinine clearance of ≥60 ml/min was also a protective factor, while a higher acute physiology and chronic health evaluation (APACHE II) score and polymicrobial infection were associated with increased mortality. The results did not change after adding a propensity score for prescribing combination therapy into the model. The protective effect remained when only combination with β-lactam or carbapenem was considered and in both subgroups of patients: those withA. baumanniiinfection and those with lower respiratory tract infections. To our knowledge, this is the first clinical study to show a benefit of combination over monotherapy with polymyxin B for severe extensively drug-resistantA. baumanniiorP. aeruginosainfections.

scholarly journals Draft Genome Sequences of Two Extensively Drug-Resistant Strains of Acinetobacter baumannii Isolated from Clinical Samples in Pakistan

2020 ◽  
Vol 9 (20) ◽  
Author(s):  
Sara Lomonaco ◽  
Matthew A. Crawford ◽  
Christine Lascols ◽  
Debra J. Fisher ◽  
Kevin Anderson ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Draft Genome ◽  
Clinical Samples ◽  
Drug Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Health Care Associated Infections ◽  
Genome Assemblies ◽  
Drug Resistant Strains

Infections in immunocompromised patients that are caused by extensively drug-resistant (XDR) Acinetobacter baumannii strains have been increasingly reported worldwide. In particular, carbapenem-resistant A. baumannii strains are a prominent cause of health care-associated infections. Here, we report draft genome assemblies for two clinical XDR A. baumannii isolates obtained from hospitalized patients in Pakistan.

scholarly journals Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii strains in Belgian acute-care hospitals

2021 ◽  
Author(s):  
Adam Valcek ◽  
Pierre Bogaerts ◽  
Olivier Denis ◽  
Te-Din Huang ◽  
Charles Van der Henst
Keyword(s):  
Acinetobacter Baumannii ◽  
Acute Care ◽  
De Novo ◽  
Acquired Resistance ◽  
Acute Care Hospitals ◽  
Clinical Samples ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Pcr Targeting

Objectives: To describe the genotypic epidemiological distribution and the antibiotic resistance mechanisms of recent carbapenem-resistant Acinetobacter baumannii (CRAb) strains recovered from clinical samples in Belgium. Methods: A total of 40 clinical isolates of CRAb collected by the national reference center from 19 acute-care hospitals through national microbiological surveillance in 2014 and 2017 were analysed in this study. The isolates were tested for antimicrobial susceptibility by broth microdilution and determined for carbapenemase-encoding genes by multiplex PCR targeting major carbapenemases families. Isolates were subjected to whole-genome sequencing (WGS) with Illumina technology and the complete chromosomal sequences were de novo assembled. Genome analysis was performed to identify intrinsic and acquired resistance determinants and to characterize clonal lineage according to the sequence type (ST). Results: All 40 isolates were resistant to carbapenems and exhibited extensively drug-resistant phenotype with blaOXA-23 (n=29) being the most abundant detected acquired AMR gene with 38 isolates encoding at least two different types of OXA enzymes. The majority of the isolates were globally disseminated clones of ST2 (n=25) while less frequent sequence types such as ST636 (n=6), ST1 (n=3), ST85 (n=2) and per one isolate from ST604, ST215, ST158 and ST78 were also detected. Conclusions: We have detected extensively drug-resistant globally occurring clones of A. baumannii ST1 and ST2 throughout Belgium as well as other sporadic ST including ST636 causing local outbreaks. Our results show the presence of high-risk clones of A. baumannii with common travel importation and the crucial need of constant surveillance.

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