scholarly journals Discrepancy between VITEK2 and Etest aminoglycoside susceptibility testing for multidrug-resistant Acinetobacter baumannii

Pathology ◽  
2021 ◽  
Author(s):  
John Vardanega ◽  
Raquel Maggacis ◽  
Naomi Runnegar ◽  
Patrick N.A. Harris ◽  
Marjoree M. Sehu
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Multidrug Resistant

scholarly journals Tetracycline Susceptibility Testing and Resistance Genes in Isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus Complex from a U.S. Military Hospital

2009 ◽  
Vol 53 (6) ◽  
pp. 2693-2695 ◽  
Author(s):  
Kevin S. Akers ◽  
Katrin Mende ◽  
Heather C. Yun ◽  
Duane R. Hospenthal ◽  
Miriam L. Beckius ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Tetracycline Resistance ◽  
Acinetobacter Calcoaceticus ◽  
Multidrug Resistant ◽  
Military Hospital ◽  
Tetracycline Resistance Genes ◽  
Testing Method

ABSTRACT Infections with multidrug-resistant Acinetobacter baumannii-Acinetobacter calcoaceticus complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes tetA, tetB, and tetA(39) were present in the isolates.

scholarly journals Tigecycline susceptibility of multidrug-resistant Acinetobacter baumannii from intensive care units in the western Balkans

2020 ◽  
Vol 67 (3) ◽  
pp. 176-181
Author(s):  
Ina Gajic ◽  
Lazar Ranin ◽  
Dusan Kekic ◽  
Natasa Opavski ◽  
Aleksandra Smitran ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Inappropriate Therapy ◽  
Antibiotic Susceptibility Testing ◽  
Broth Microdilution ◽  
Western Balkans ◽  
Colistin Resistance ◽  
European Committee ◽  
Carbapenem Resistant

AbstractTigecycline can be effective to treat infections of carbapenem-resistant Acinetobacter baumannii (CRAB) however, no interpretive criteria have been approved so far. The objectives of this study were to evaluate the proportion of CRAB isolates and to compare gradient test with a broth microdilution (BMD) method for tigecycline susceptibility testing of A. baumannii.This study included 349 multidrug-resistant (MDR) Acinetobacter spp. collected from Serbia, Montenegro, Bosnia and Herzegovina in 2016 and 2017. Antibiotic susceptibility testing was performed by disk diffusion, VITEK2, gradient, ComASP Colistin. Tigecycline susceptibilities were interpreted according to breakpoints of European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Food and Drug Administration (FDA).Majority of the tested isolates were CRAB (92.8%). Tigecycline MIC50/MIC90 values were 4/8 μg/mL by BMD and 0.5/4 μg/mL by gradient test. Essential agreement for BMD and gradient test amounted to 65.1%. With EUCAST breakpoints, categorical agreement (CA) was achieved in 38% isolates. Major discordance (MD-false susceptibility/resistance) and minor discordance (mD-false categorization involving intermediate results) were observed in 10% and 57% A. baumannii, respectively. With FDA breakpoints, CA, MD and mD were observed in 44%, 16% and 47% isolates, respectively. Colistin resistance was 2.1%.The study highlights a high proportion of CRAB and several discordances between BMD and gradient test which may lead to inappropriate therapy.

scholarly journals The Innovative Method for Vaccine Preparation Against Multidrug Resistant and Virulence Acinetobacter baumannii Iraqi Isolates

2017 ◽  
Vol 14 (4) ◽  
pp. 717-726
Author(s):  
Baghdad Science Journal
Keyword(s):  
Acinetobacter Baumannii ◽  
Virulence Factors ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Mouse Serum ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Important Variation ◽  
Innovative Method ◽  
Toll Like Receptor 2

The expanding of the medically important diseases created by multidrug-resistant Acinetobacter baumannii warrants the evolve a new methodology for prevention includes vaccination and treatment. Totally of forty-five clinical isolates identified as A.baumannii were obtained from hospitalized patients from three hospital in Baghdad City during the period from February 2016 to August 2016. Followed by diagnosing using different methods. Every strain was tested for susceptibility testing also some important virulence factorswere detected. Two isolates were chosen for the immunization and vaccine model, the first one remittent for most antibiotics except one are too virulence (strong) and the second is less virulent and resistance (weak).Enzyme-linked immunosorbent assaywas used for assessments of Toll like receptor 4,and Toll like receptor 2 concentrations in mouse serum at 14, 21 and 28 days of immunization. Results proved that the strong isolate showed resistance to all antibiotics except one and positive to all virulence factors except one, while the weak isolate resistance to Ceftriaxone, Cefotaxime, positive to tow virulence factors. Mice were intramuscular inoculated with strong and weak isolate. There are high significant differences when using strong A.baumannii strong in the level of TLR4 and there was not an important variation among the use of strong and weak isolation in the level of TLR2.Finaly,the yield refers to the TLR4 plays a key role in innate sensing with multidrug resistance isolate immunization, whereas TLR 2 shows it gives the same level of stimulation during immunization with both strains but lesser concentration than TLR4, so the inactivated with MDR isolate has a potential for development as a candidate vaccine for strong protection against MDR isolate infections.

scholarly journals In Vitro Antibacterial Activity of Cefiderocol against Multidrug-Resistant Acinetobacter baumannii

2021 ◽  
Author(s):  
Jacinda C. Abdul-Mutakabbir ◽  
Logan Nguyen ◽  
Philip T. Maassen ◽  
Kyle C. Stamper ◽  
Razieh Kebriaei ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Synergistic Activity ◽  
Strong Activity ◽  
Gram Negative ◽  
In Vitro Antibacterial Activity ◽  
Time Kill

Cefiderocol (CFDC), a novel siderophore cephalosporin, demonstrates strong activity against multidrug-resistant (MDR) Acinetobacter baumannii. Limited studies have evaluated CFDC alone and in combination with other Gram-negative antibiotics against MDR A. baumannii isolates. Susceptibility testing revealed lower CFDC minimum inhibitory concentration (MIC) values than the comparator Gram-negative agents (87% of MICs ≤ 4mg/L). Six isolates, with elevated CFDC MICs (16-32 mg/L), were selected for further experiments. Time-kill analyses presented with synergistic activity and beta-lactamase inhibitors increased CFDC susceptibility in each of the isolates.

scholarly journals Antibiogram, Prevalence of OXA Carbapenemase Encoding Genes, and RAPD-Genotyping of Multidrug-Resistant Acinetobacter baumannii Incriminated in Hidden Community-Acquired Infections

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 603
Author(s):  
Waleed El-Kazzaz ◽  
Lobna Metwally ◽  
Reham Yahia ◽  
Najwa Al-Harbi ◽  
Ayat El-Taher ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Extensively Drug Resistant ◽  
Rapd Pcr ◽  
High Prevalence ◽  
Acinetobacter Spp ◽  
Encoding Genes

Acinetobacter spp. has gained fame from their ability to resist difficult conditions and their constant development of antimicrobial resistance. This study aimed to investigate the prevalence, susceptibility testing, OXA carbapenemase-encoding genes, and RAPD-genotyping of multidrug resistant Acinetobacter baumannii incriminated in hidden community-acquired infections in Egypt. The antimicrobial susceptibility testing was assessed phenotypically using Kirby–Bauer disk diffusion method. Also, Modified-Hodge test (MHT) was carried out to detect the carbapenemases production. Multiplex-PCR was used to detect the carbapenemase-encoding genes. Furthermore, the genetic relationship among the isolated strains was investigated using RAPD fingerprinting. The bacteriological examination revealed that, out of 200 Gram-negative non-fermentative isolates, 44 (22%) were identified phenotypically and biochemically as Acinetobacter spp. and 23 (11.5%) were molecularly confirmed as A.baumannii. The retrieved A.baumannii strains were isolated from urine (69%), sputum (22%), and cerebrospinal fluid (csf) (9%). The isolated A. baumannii strains exhibited multidrug resistance and the production rates of carbapenemases were 56.5, 60.9, and 78.3% with meropenem, imipenem, and ertapenem disks, respectively. The blaOXA-24-like genes were the most predominant among the tested strains (65.2%), followed by blaOXA-23 (30.4%) and blaOXA-58 (17.4%), in addition, the examined strains are harbored IMP, VIM, and NDM genes with prevalence of 60.9, 43.5, and 13%, respectively, while KPC and GES genes were not detected. RAPD-PCR revealed that the examined strains are clustered into 11 different genotypes at ≥90% similarity. Briefly, to the best of our knowledge, this study is the first report concerning community-associated A. baumannii infections in Egypt. The high prevalence of hidden multidrug-resistant (MDR) and extensively drug-resistant (XDR) A.baumannii strains associated with non-hospitalized patients raises an alarm for healthcare authorities to set strict standards to control the spread of such pathogens with high rates of morbidity and mortality.

scholarly journals First Occurrence of OXA-72-Producing Acinetobacter baumannii in Serbia

2016 ◽  
Vol 60 (10) ◽  
pp. 5724-5730 ◽  
Author(s):  
Laurent Dortet ◽  
Rémy A. Bonnin ◽  
Sandrine Bernabeu ◽  
Lélia Escaut ◽  
Daniel Vittecoq ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Pcr Analysis ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
A Genome ◽  
16S Rna ◽  
Genes Encoding ◽  
First Occurrence

ABSTRACTHere, we characterized the first OXA-72-producingAcinetobacter baumanniiisolate (designated MAL) recovered from a urine sample from a Serbian patient. Antimicrobial susceptibility testing, plasmid analysis, and whole-genome sequencing (WGS) were performed to fully characterize the resistome of theA. baumanniiMAL clinical isolate. The isolate was multidrug resistant and remained susceptible only to colistin and tigecycline. PCR analysis revealed the presence of the carbapenemase OXA-72, an OXA-40 variant. Extraction by the Kieser method revealed the presence of two plasmids, and one of these, a ca. 10-kb plasmid, harbored theblaOXA-72gene. WGS revealed 206 contigs corresponding to a genome of 3.9 Mbp in size with a G+C content of 38.8%. The isolate belonged to sequence type 492 and to worldwide clone II (WWCII). Naturally occurring β-lactamase-encoding genes (blaADC-25andblaOXA-66) were also identified. Aminoglycoside resistance genes encoding one aminoglycoside adenyltransferase (aadA2), three aminoglycoside phosphatases (strA,strB,aphA6), and one 16S RNA methylase (armA) conferring resistance to all aminoglycosides were identified. Resistance to fluoroquinolones was likely due to mutations ingyrA,parC, andparE. Of note, the resistome matched perfectly with the antibiotic susceptibility testing results.

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