scholarly journals Relationship between the Biofilm-Forming Capacity and Antimicrobial Resistance in Clinical Acinetobacter baumannii Isolates: Results from a Laboratory-Based In Vitro Study

2021 ◽  
Vol 9 (11) ◽  
pp. 2384
Author(s):  
Matthew Gavino Donadu ◽  
Vittorio Mazzarello ◽  
Piero Cappuccinelli ◽  
Stefania Zanetti ◽  
Melinda Madléna ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
In Vitro Study ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
Antibiotic Resistant ◽  
Significant Difference ◽  
Two Factors ◽  
Resistance Rates ◽  
The Relationship

The relationship between the multidrug-resistant (MDR) phenotype and biofilm-forming capacity has been a topic of extensive interest among biomedical scientists, as these two factors may have significant influence on the outcomes of infections. The aim of the present study was to establish a possible relationship between biofilm-forming capacity and the antibiotic-resistant phenotype in clinical Acinetobacter baumannii (A. baumannii) isolates. A total of n = 309 isolates were included in this study. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out. The capacity of isolates to produce biofilms was assessed using a crystal violet microtiter-plate-based method. Resistance rates were highest for ciprofloxacin (71.19%; n = 220), levofloxacin (n = 68.61%; n = 212), and trimethoprim-sulfamethoxazole (n = 66.02%; n = 209); 42.72% (n = 132) of isolates were classified as MDR; 22.65% (n = 70) of tested isolates were positive in the modified Hodge-test; the overexpression of efflux pumps had significant effects on the susceptibilities of meropenem, gentamicin, and ciprofloxacin in 14.24% (n = 44), 6.05% (n = 19), and 27.51% (n = 85), respectively; 9.39% (n = 29), 12.29% (n = 38), 22.97% (n = 71), and 55.35% (n = 170) of isolates were non-biofilm-producing and weak, moderate, and strong biofilm producers, respectively. A numerical, but statistically not significant, difference was identified between the MDR and non-MDR isolates regarding their biofilm-forming capacity (MDR: 0.495 ± 0.309 vs. non-MDR: 0.545 ± 0.283; p = 0.072), and no association was seen between resistance to individual antibiotics and biofilm formation. Based on numerical trends, MER-resistant isolates were the strongest biofilm producers (p = 0.067). Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of A. baumannii infections.

scholarly journals 694. In vitro Antibacterial Activity of Sulbactam–Durlobactam (ETX2514SUL) Against 121 Recent Acinetobacter baumannii Isolated from Patients in India

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S314-S314
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Tarun Mathur ◽  
Ian Morrissey
Keyword(s):  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Package Insert ◽  
Multidrug Resistant ◽  
Antibiotic Resistant ◽  
Carbapenem Resistant ◽  
In Vitro Antibacterial Activity ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

Abstract Background The incidence of infections caused by multidrug-resistant Acinetobacter baumannii is increasing at an alarming rate in Southeast Asia and other parts of the world. Sulbactam (SUL) has intrinsic antibacterial activity against A. baumannii; however, the prevalence of β-lactamases in this species has limited its therapeutic use. Durlobactam (ETX2514, DUR) is a novel β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C and D β-lactamases. DUR restores SUL in vitro activity against multidrug-resistant A. baumannii. Against >3,600 globally diverse, clinical isolates from 2012–2017, addition of 4 mg/L DUR reduced the SUL MIC90 from >32 to 2 mg/L. SUL-DUR is currently in Phase 3 clinical development for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.The goal of this study was to determine the activity of SUL-DUR and comparator antibiotics (amikacin (AMK), ampicillin-sulbactam (AMP-SUL), cefoperazone-sulbactam (CFP-SUL) and meropenem (MEM)) against A. baumannii isolated from hospitalized patients in India. Methods A total of 121 clinical A. baumannii isolates from multiple hospital settings and infection sources were collected between 2016–2019 from six geographically diverse hospitals in India. Species identification was performed by MALDI-TOF. Susceptibility of these isolates to SUL-DUR (10µg/10µg) and comparator antibiotics was determined by disk diffusion using CLSI methodology and interpretive criteria, except for CFP-SUL, for which resistance was defined using breakpoints from the CFP-SUL package insert. Results As shown in Table 1, resistance of this collection of isolates to marketed agents was extremely high. In contrast, based on preliminary breakpoint criteria, only 11.5% of isolates were resistant to SUL-DUR. Conclusion The in vitro antibacterial activity of SUL-DUR was significantly more potent than comparator agents against multidrug-resistant A. baumannii isolates collected from diverse sites in India. These data support the continued development of SUL-DUR for the treatment of antibiotic-resistant infections caused by A. baumannii. Disclosures All authors: No reported disclosures.

scholarly journals Pharmacokinetics and Pharmacodynamics of Minocycline against Acinetobacter baumannii in a Neutropenic Murine Pneumonia Model

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Jian Zhou ◽  
Kimberly R. Ledesma ◽  
Kai-Tai Chang ◽  
Henrietta Abodakpi ◽  
Song Gao ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Time Curve ◽  
Content Type ◽  
Concentration Time ◽  
Dose Linearity ◽  
Unit Reduction ◽  
The Relationship

ABSTRACT Multidrug-resistant (MDR) Acinetobacter baumannii is increasingly more prevalent in nosocomial infections. Although in vitro susceptibility of A. baumannii to minocycline is promising, the in vivo efficacy of minocycline has not been well established. In this study, the in vivo activity of minocycline was evaluated in a neutropenic murine pneumonia model. Specifically, we investigated the relationship between minocycline exposure and bactericidal activity using five A. baumannii isolates with a broad range of susceptibility (MIC ranged from 0.25 mg/liter to 16 mg/liter). The pharmacokinetics of minocycline (single dose of 25 mg/kg of body weight, 50 mg/kg, 100 mg/kg, and a humanized regimen, given intraperitoneally) in serum and epithelial lining fluid (ELF) were characterized. Dose linearity was observed for doses up to 50 mg/kg and pulmonary penetration ratios (area under the concentration-time curve in ELF from 0 to 24 h [AUCELF,0–24]/area under the concentration time curve in serum from 0 to 24 h [AUCserum,0–24]) ranged from 2.5 to 2.8. Pharmacokinetic-pharmacodynamics (PK-PD) index values in ELF for various dose regimens against different A. baumannii isolates were calculated. The maximum efficacy at 24 h was approximately 1.5-log-unit reduction of pulmonary bacterial burdens from baseline. The AUC/MIC ratio was the PK-PD index most closely correlating to the bacterial burden (r 2 = 0.81). The required AUCELF,0–24/MIC for maintaining stasis and achieving 1-log-unit reduction were 140 and 410, respectively. These findings could guide the treatment of infections caused by A. baumannii using minocycline in the future. Additional studies to examine resistance development during therapy are warranted.

scholarly journals Combination Inhibition Activity of Chlorhexidine and Antibiotics on Multidrug-Resistant Acinetobacter Baumannii in Vitro

2021 ◽  
Author(s):  
Fei Lin ◽  
Bin Yu ◽  
Qinghui Wang ◽  
Mingyong Yuan ◽  
Baodong Ling
Keyword(s):  
Acinetobacter Baumannii ◽  
Inhibitory Concentration ◽  
Anaerobic Bacteria ◽  
Hospital Setting ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Antibiotic Resistant ◽  
A New Technique ◽  
And Control

Abstract Background: Chlorhexidine is a widely used disinfectant in clinical settings and a broad-spectrum antimicrobial agent effective against aerobic and anaerobic bacteria. However, disinfectant resistant or non-susceptible bacteria, including antibiotic-resistant Acinetobacter baumannii, have been found. This study aimed to develop a new technique to prevent and control A. baumannii infection in the hospital setting. Methods: Chlorhexidine combined with minocycline, doxycycline, meropenem, imipenem, levofloxacin and ciprofloxacin were tested against the 30 multidrug-resistant and extremely drug-resistant A. baumannii clinical isolates. The checkerboard test was used to calculate the fractional inhibitory concentration index according to the minimum inhibitory concentration value for chlorhexidine combined with antibiotics. Results: The combination of chlorhexidine with minocycline, doxycycline, meropenem, or ciprofloxacin showed synergistic responses in all clinical isolates, and more than 50% of isolates showed FICI ≤ 0.5. However, chlorhexidine together with imipenem or levofloxacin showed indifferent responses in 10% and 3.33% clinical isolates, respectively. In all tests, combinations of chlorhexidine with each of the above six antibiotics showed synergistic and additive effects, and inhibited the clinical isolates.Conclusions: We concluded that, chlorhexidine combined with antibiotics could be used to control the risk of infection with A. baumannii.

scholarly journals In Vitro Study On The Potential Fungicidal Effects of Atorvastatin In Combination With Some Azole Drugs Against Multidrug Resistant Candida Albicans

2021 ◽  
Author(s):  
Dina Ezzat Mahmoud Mahmoud ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Wael Mohamed Abu El-Wafa
Keyword(s):  
Candida Albicans ◽  
In Vitro Study ◽  
Docking Study ◽  
Multidrug Resistant ◽  
Global Challenge ◽  
Inhibition Zones ◽  
Resistance Rates ◽  
Time Kill ◽  
Fungistatic Effect

Abstract The resistance of Candida albicans to azole drugs represents the great global challenge. This study investigates the potential fungicidal effects of atorvastatin (ATO) combinations with fluconazole (FLU), itraconazole (ITR), ketoconazole (KET) and voriconazole (VOR) against thirty-four multidrug-resistant (MDR) C. albicans using checkerboard and time-kill methods. Results showed that 94.12% of these isolates were MDR to ≥ two azole drugs, whereas 5.88% of them were susceptible to azole drugs. The tested isolates exhibited high resistance rates to FLU (58.82%), ITR (52.94%), VOR (47.06 %) and KET (35.29 %), whereas only three representative (8.82%) isolates were resistant to all tested azoles. Remarkably, the inhibition zones of these isolates were increased at least two-fold with the presence of ATO, which interacted in a synergistic (FIC index ≤ 0.5) manner with tested azoles. In silico docking study of ATO and the four azole drugs were performed against the Lanosterol 14-alpha demethylase enzyme (ERG11) of C. albicans. Results showed that the mechanism of action of ATO against C. albicans is similar to that of azole compounds, with docking score (-4.901) lower than azole drugs (> - 5.0) due to the formation a single H-bond with Asp 225 and a pi-pi interaction with Thr 229. Importantly, ATO combinations with ITR, VOR and KET achieved fungicidal effects (≥ 3 Log10 cfu/ml reduction) against the representative isolates, whereas a fungistatic effect (≤ 3 Log10 cfu/ml reduction) was observed with FLU combination. Thus, the combination of ATO with azole drugs could be promising options for treating C. albicans infection.

scholarly journals Combination inhibition activity of chlorhexidine and antibiotics on multidrug-resistant Acinetobacter baumannii in vitro

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fei Lin ◽  
Bin Yu ◽  
Qinghui Wang ◽  
Mingyong Yuan ◽  
Baodong Ling
Keyword(s):  
Acinetobacter Baumannii ◽  
Inhibitory Concentration ◽  
Anaerobic Bacteria ◽  
Hospital Setting ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Antibiotic Resistant ◽  
A New Technique ◽  
And Control

Abstract Background Chlorhexidine is a widely used disinfectant in clinical settings and a broad-spectrum antimicrobial agent effective against aerobic and anaerobic bacteria. However, disinfectant resistant or non-susceptible bacteria, including antibiotic-resistant Acinetobacter baumannii, have been found. This study aimed to develop a new technique to prevent and control A. baumannii infection in the hospital setting. Methods Chlorhexidine combined with minocycline, doxycycline, meropenem, imipenem, levofloxacin and ciprofloxacin were tested against the 30 multidrug-resistant and extremely drug-resistant A. baumannii clinical isolates. The checkerboard test was used to calculate the fractional inhibitory concentration index according to the minimum inhibitory concentration value for chlorhexidine combined with antibiotics. Results The combination of chlorhexidine with minocycline, doxycycline, meropenem, or ciprofloxacin showed synergistic responses in all clinical isolates, and more than 50% of isolates showed FICI ≤0.5. However, chlorhexidine together with imipenem or levofloxacin showed indifferent responses in 10% and 3.33% clinical isolates, respectively. In all tests, combinations of chlorhexidine with each of the above six antibiotics showed synergistic and additive effects, and inhibited the clinical isolates. Conclusions We concluded that, chlorhexidine combined with antibiotics could be used to control the risk of infection with A. baumannii.

scholarly journals In Vitro Double and Triple Synergistic Activities of Polymyxin B, Imipenem, and Rifampin against Multidrug-Resistant Acinetobacter baumannii

2004 ◽  
Vol 48 (3) ◽  
pp. 753-757 ◽  
Author(s):  
Jimmy Yoon ◽  
Carl Urban ◽  
Christian Terzian ◽  
Noriel Mariano ◽  
James J. Rahal
Keyword(s):  
Acinetobacter Baumannii ◽  
Clinical Studies ◽  
Three Dimensional ◽  
Polymyxin B ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
Lethal Infection ◽  
Effective Option ◽  
Time Kill

ABSTRACT Eight unrelated clinical Acinetobacter baumannii isolates resistant to all commonly used antibiotics were subjected to three-dimensional checkerboard microtiter plate dilution and time-kill studies at one-fourth of their MICs of polymyxin B, imipenem, and rifampin. Synergy was demonstrated with combinations of polymyxin B and imipenem, polymyxin B and rifampin, and polymyxin B, imipenem, and rifampin. Double combinations of polymyxin B and imipenem and of polymyxin B and rifampin were bactericidal for seven of eight isolates, and triple combinations were bactericidal for all isolates within 24 h. Future clinical studies using double and triple therapy with these antibacterials may provide an effective option against potentially lethal infection due to multiresistant Acinetobacter baumannii.

scholarly journals Effect of Immediate and Delayed Postpreparation on the Integrity of the Apical Seal: An in vitro Study

2012 ◽  
Vol 13 (2) ◽  
pp. 153-156
Author(s):  
Abhay Kamra ◽  
Shantanu Choudhari ◽  
Sarvesha Bhondwe ◽  
S Srilatha ◽  
Neha Chhasatia Desai ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Gutta Percha ◽  
Significant Difference ◽  
Relationship Of ◽  
The Relationship ◽  
Apical Leakage ◽  
One Way Anova

ABSTRACT Aim The aim of this in vitro study was to evaluate if there is any significant difference in apical leakage when gutta-percha is removed immediately after obturation for postspace preparation or after a week. Materials and methods Two commonly used sealers AH26 and tubliseal were used in four groups each consisting of 20 teeth each. The tooth was sectioned at the amelocemental junction to leave a root portion of 12 to 14 mm. Canals were checked for patency and prepared to No-55 K file size. Two people, using a stereomicroscope, independently evaluated each tooth-half for the extent of apical leakage. Results The leakage results were analyzed using a one-way ANOVA according to present study, immediate postpreparation is preferable than delayed postpreparation. The relationship of in vitro leakage measurements to the in vivo situation has not been established. Clinical implication Hence, immediate postpreparation is preferable than delayed postpreparation. How to cite this article Bhondwe S, Kamra A, Choudhari S, Srilatha S, Desai NC, Pandit VS. Effect of Immediate and Delayed Postpreparation on the Integrity of the Apical Seal: An in vitro Study. J Contemp Dent Pract 2012;13(2):153-156.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

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