Clinical isolates of Acinetobacter baumannii from a Portuguese hospital: PFGE characterization, antibiotic susceptibility and biofilm-forming ability

Author(s):  
Andreia Duarte ◽  
Susana Ferreira ◽  
Sofia Almeida ◽  
Fernanda C. Domingues
2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
E. Dahdouh ◽  
S. H. Shoucair ◽  
S. E. Salem ◽  
Z. Daoud

The aim of this study was to determine the usefulness of the MPC of carbapenems against clinical isolates ofPseudomonasspp.andAcinetobacterspp. and to assess its possible relationship with mechanisms of resistance. Detection of the mechanisms of resistance was performed using Antibiotic Susceptibility Testing, Double Disk Synergy, disk antagonism, addition of NaCl to the medium, addition of PBA or EDTA to Carbapenem disks, addition of PBA to Cefoxitin disks, and CCCP test for 10Pseudomonasspp. andAcinetobacter baumanniistrains. The MIC and MPC were determined using the broth macrodilution and plate dilution methods, respectively. FourAcinetobacter baumanniistrains produced MBL. Two of them produced Oxacillinase and one produced ESBL. TwoPseudomonasspp. isolates produced both KPC and MBL. The resistantAcinetobacterspp. andPseudomonasspp. strains had higher MPC values than susceptible ones. However, the Mutant Selection Window was found to be dependent on the degree of resistance but not on a particular mechanism of resistance. The usefulness of the MPC was found to be dependent on its value. Based on our data, we recommend determining the MPC for each isolate before using it during treatment. Furthermore, the use of T>MSW instead of T>MIC is suggested.


2021 ◽  
Vol 30 (2) ◽  
pp. 35-42
Author(s):  
Roshdan M. Arafa ◽  
Abeer A.Aboelazm ◽  
Mona M. Saleh ◽  
Hasnaa S. Abd Elhameed

Background: The evolution of nosocomial infections by multidrug resisitance (MDR) and extensive drug resistance (XDR) Acinetobacter baumannii and klebsiella pneumoniae are considered a major health problem owing to the relatively limited treatment options. Colistin and tigecycline are increasingly used as a last choice for treatment of these infections. The most accurate antibiotic susceptibility methods for colistin and tigecycline are still challenging. Objectives: The aim of the current study was to detect colistin and tigecycline antibiotic susceptibility of K. pneumoniae and A. baumanii and evaluate disk diffusion (DD), E- test and VITEK 2 automated system compared to broth dilution (BD) test. Methodology: This study was performed on 35 K. pneumoniae and 15 A. baumanii clinical isolates collected from patients admitted to Benha University Hospitals. The isolated strains were identified by the standard laboratory technique with subspecies identification by VITEK 2 automated system. Colistin and tigecycline antibiotic susceptibility for K. pneumoniae and A. baumanii were evaluated by E-test, disk diffusion and VITEK 2 compared to BD as the reference method. Results: Through the study of the studied k. pneumoniae and A. baumanii strains, The essential and categorical agreements of colistin suscebtibility were (82% & 80 %) for E-test, (92% & 98%) for VITEK 2 and categorical agreement for DD was 54%. The essential and categorical agreements of tigecycline suscebtibility were (96% & 98%) for E-test, (88% &78%) for VITEK 2 and categorical agreement for DD was 74%. Conclusion: For colistin, VITEK 2 is considered a reliable method to detect colistin susceptibility while E-test and disk diffusion showed a poor performance. For tigecycline, E-test showed the best performance compared to the gold standard test while shortcomings of automated VITEK 2 and manual DD were observed.


2020 ◽  
Vol 13 (2) ◽  
pp. 327
Author(s):  
R Bawazeer ◽  
M Algoribi ◽  
T Abujamel ◽  
L Okdah ◽  
M Alzayer ◽  
...  

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S662-S662
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Samir Moussa ◽  
Meredith Hackel

Abstract Background The incidence of infections caused by multidrug-resistant (MDR) Acinetobacter baumannii (Ab) is increasing at an alarming rate in certain regions of the world, including the Middle East. Sulbactam (SUL) has intrinsic antibacterial activity against Ab; however, the prevalence of β-lactamases in Ab has limited its therapeutic utility. Durlobactam (DUR, formerly ETX2514) is a diazabicyclooctenone β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C and D β-lactamases that restores SUL activity in vitro against MDR Ab. SUL-DUR is an antibiotic designed to treat serious infections caused by Acinetobacter, including multidrug-resistant strains, that is currently in Phase 3 clinical development. In global surveillance studies of >3600 isolates from 2012-2017, the MIC90 of SUL-DUR was 2 mg/L. Although surveillance systems to monitor MDR infections in the Middle East are currently being established, quantitative, prevalence-based data are not yet available. Therefore, the potency of SUL-DUR was determined against 190 recent, diverse Ab clinical isolates from this region. Methods 190 Ab isolates were collected between 2016 - 2018 from medical centers located in Israel (N = 47), Jordan (N = 36), Qatar (N = 13), Kuwait (N = 42), Lebanon (N = 8), Saudi Arabia (N = 24) and United Arab Emirates (N = 20). Seventy-five percent and 20.5% of these isolates were from respiratory and blood stream infections, respectively. Susceptibility to SUL-DUR and comparator agents was performed according to CLSI guidelines, and data analysis was performed using CLSI and EUCAST breakpoint criteria where available. Results This collection of isolates was 86% carbapenem-resistant and 90% sulbactam-resistant (based on a breakpoint of 4 mg/L). The addition of SUL-DUR (fixed at 4 mg/L) decreased the sulbactam MIC90 from 64 mg/L to 4 mg/L. Only 3 isolates (1.6%) had SUL-DUR MIC values of > 4 mg/L. This potency was consistent across countries, sources of infection and subsets of resistance phenotypes. Conclusion SUL-DUR demonstrated potent antibacterial activity against recent clinical isolates of Ab from the Middle East, including MDR isolates. These data support the global development of SUL-DUR for the treatment of MDR Ab infections. Disclosures Alita Miller, PhD, Entasis Therapeutics (Employee) Sarah McLeod, PhD, Entasis Therapeutics (Employee) Samir Moussa, PhD, Entasis Therapeutics (Employee)


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Amit Gaurav ◽  
Varsha Gupta ◽  
Sandeep K. Shrivastava ◽  
Ranjana Pathania

AbstractThe increasing prevalence of antimicrobial resistance has become a global health problem. Acinetobacter baumannii is an important nosocomial pathogen due to its capacity to persist in the hospital environment. It has a high mortality rate and few treatment options. Antibiotic combinations can help to fight multi-drug resistant (MDR) bacterial infections, but they are rarely used in the clinics and mostly unexplored. The interaction between bacteriostatic and bactericidal antibiotics are mostly reported as antagonism based on the results obtained in the susceptible model laboratory strain Escherichia coli. However, in the present study, we report a synergistic interaction between nalidixic acid and tetracycline against clinical multi-drug resistant A. baumannii and E. coli. Here we provide mechanistic insight into this dichotomy. The synergistic combination was studied by checkerboard assay and time-kill curve analysis. We also elucidate the mechanism behind this synergy using several techniques such as fluorescence spectroscopy, flow cytometry, fluorescence microscopy, morphometric analysis, and real-time polymerase chain reaction. Nalidixic acid and tetracycline combination displayed synergy against most of the MDR clinical isolates of A. baumannii and E. coli but not against susceptible isolates. Finally, we demonstrate that this combination is also effective in vivo in an A. baumannii/Caenorhabditis elegans infection model (p < 0.001)


2020 ◽  
Vol 9 (40) ◽  
Author(s):  
Peechanika Chopjitt ◽  
Thidathip Wongsurawat ◽  
Piroon Jenjaroenpun ◽  
Parichart Boueroy ◽  
Rujirat Hatrongjit ◽  
...  

ABSTRACT Here, we report the complete genome sequences of four clinical isolates of extensively drug-resistant Acinetobacter baumannii (XDRAB), isolated in Thailand. These results revealed multiple antimicrobial-resistant genes, each involving two sequence type 16 (ST16) isolates, ST2, and a novel sequence type isolate, ST1479.


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