scholarly journals In vitro activity of colistin against multidrug-resistant Acinetobacter baumannii isolates harboring blaOXA-23-like and blaOXA-24-like genes: A multicenter based study

2020 ◽  
Vol 67 (3) ◽  
pp. 182-186
Author(s):  
Susan Khanjani ◽  
Hadi Sedigh Ebrahim-Saraie ◽  
Mohammad Shenagari ◽  
Ali Ashraf ◽  
Ali Mojtahedi ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Cross Sectional ◽  
The North ◽  
North Of Iran

AbstractThis study was aimed to evaluate occurrence of antibiotic resistance and the presence of resistance determinants among clinical isolates of Acinetobacter baumannii. This cross-sectional study from January to September 2018 was performed on 59 A. baumannii strains isolated from clinical samples in the north of Iran. Isolates were identified by standard microbiologic tests and molecular method. Antimicrobial susceptibility testing was carried out by disk diffusion and broth microdilution methods. The presence of carbapenem resistance genes was detected by PCR method. All isolates were resistant to cefepime, meropenem, imipenem and ceftazidime. The lowest resistance rate was observed against doxycycline with 33.9%. Minimum inhibitory concentration (MIC) results showed that all carbapenem-resistant A. baumannii (CRAB) isolates were susceptible to colistin with MIC50 and MIC90 values of 1/2 µg/mL. Among 59 CRAB, blaOXA-23-like was the most prevalent gene (86.4%) followed by blaOXA-24-like (69.5%). Meanwhile, none of the clinical isolates harbored blaOXA-58-like gene. We found a high prevalence of CRAB strains harboring OXA-type carbapenemases in the north of Iran. Our results suggests that the presence of OXA-type genes was not directly correlated with the increase of imipenem MIC level, but can be clinically important as they contribute to the selection of CRAB strains.

scholarly journals 1280. In-Vitro Activity of Cefiderocol, Imipenem/Relebactam, & Ceftazidime/Avibactam in Ceftolozane/Tazobactam Resistant Strains of Multidrug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander
Keyword(s):  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Resistance Testing ◽  
Clinical Samples ◽  
In Vitro Activity ◽  
Carbapenemase Gene ◽  
Resistant Strains

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures

scholarly journals 1293. Sulbactam-durlobactam is active against recent, multi-drug resistant Acinetobacter baumannii clinical isolates from the Middle East

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S662-S662
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Samir Moussa ◽  
Meredith Hackel
Keyword(s):  
Antibacterial Activity ◽  
Middle East ◽  
Acinetobacter Baumannii ◽  
United Arab Emirates ◽  
Blood Stream ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Surveillance Systems ◽  
Spectrum Activity

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)

scholarly journals In Vitro Activity of Sulbactam-Durlobactam against Acinetobacter baumannii-calcoaceticus Complex Isolates Collected Globally in 2016 and 2017

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Sarah M. McLeod ◽  
Samir H. Moussa ◽  
Meredith A. Hackel ◽  
Alita A. Miller
Keyword(s):  
Acinetobacter Baumannii ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Single Amino Acid ◽  
Content Type ◽  
Level Of Activity ◽  
Severe Infections ◽  
Sources Of Infection

ABSTRACT Acinetobacter baumannii-calcoaceticus complex (ABC) organisms cause severe infections that are difficult to treat due to preexisting antibiotic resistance. Sulbactam-durlobactam (formerly sulbactam-ETX2514) (SUL-DUR) is a β-lactam–β-lactamase inhibitor combination antibiotic designed to treat serious infections caused by ABC organisms, including multidrug-resistant (MDR) strains. The in vitro antibacterial activities of SUL-DUR and comparator agents were determined by broth microdilution against 1,722 clinical isolates of ABC organisms collected in 2016 and 2017 from 31 countries across Asia/South Pacific, Europe, Latin America, the Middle East, and North America. Over 50% of these isolates were resistant to carbapenems. Against this collection of global isolates, SUL-DUR had a MIC50/MIC90 of 1/2 μg/ml compared to a MIC50/MIC90 of 8/64 μg/ml for sulbactam alone. This level of activity was found to be consistent across organisms, regions, sources of infection, and subsets of resistance phenotypes, including MDR and extensively drug-resistant isolates. The SUL-DUR activity was superior to those of the tested comparators, with only colistin having similar potency. Whole-genome sequencing of the 39 isolates (2.3%) with a SUL-DUR MIC of >4 μg/ml revealed that these strains encoded either the metallo-β-lactamase NDM-1, which durlobactam does not inhibit, or single amino acid substitutions near the active site of penicillin binding protein 3 (PBP3), the primary target of sulbactam. In summary, SUL-DUR demonstrated potent antibacterial activity against recent, geographically diverse clinical isolates of ABC organisms, including MDR isolates.

scholarly journals Role of Aminoglycoside-Modifying Enzymes (AMEs) in Resistance to Aminoglycosides among Clinical Isolates of Pseudomonas aeruginosa in the North of Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Leila Ahmadian ◽  
Zahra Norouzi Bazgir ◽  
Mohammad Ahanjan ◽  
Reza Valadan ◽  
Hamid Reza Goli
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Resistance Pattern ◽  
Dilution Method ◽  
The North ◽  
Agar Diffusion Test ◽  
North Of Iran ◽  
Encoding Genes

In recent years, the prevalence of resistance to aminoglycosides among clinical isolates of Pseudomonas aeruginosa is increasing. The aim of this study was to investigate the role of aminoglycoside-modifying enzymes (AMEs) in resistance to aminoglycosides in clinical isolates of P. aeruginosa. The clinical isolates were collected from different hospitals. Disk agar diffusion test was used to determine the antimicrobial resistance pattern of the clinical isolates, and the minimum inhibitory concentration of aminoglycosides was detected by microbroth dilution method. The PCR was performed for discovery of aminoglycoside-modifying enzyme-encoding genes. Among 100 screened isolates, 43 (43%) isolates were resistant to at least one tested aminoglycosides. However, 13 (13%) isolates were resistant to all tested aminoglycosides and 37 isolates were detected as multidrug resistant (MDR). The resistance rates of P. aeruginosa isolates against tested antibiotics were as follows: ciprofloxacin (41%), piperacillin-tazobactam (12%), cefepime (32%), piperacillin (26%), and imipenem (31%). However, according to the MIC method, 13%, 32%, 33%, and 37% of the isolates were resistant to amikacin, gentamicin, tobramycin, and netilmicin, respectively. The PCR results showed that AAC(6 ′ )-Ib was the most commonly (26/43, 60.4%) identified AME-encoding gene followed by AAC(6 ′ )-IIa (41.86%), APH(3 ′ )-IIb (34.8%), ANT(3 ″ )-Ia (18.6), ANT(2 ″ )-Ia (13.95%), and APH(3 ″ )-Ib (2.32%). However, APH(3 ′ )-Ib was not found in any of the studied isolates. The high prevalence of AME-encoding genes among aminoglycoside-resistant P. aeruginosa isolates in this area indicated the important role of AMEs in resistance to these antibiotics similar to most studies worldwide. Due to the transmission possibility of these genes between the Gram-negative bacteria, we need to control the prescription of aminoglycosides in hospitals.

scholarly journals In VitroActivities of Combinations of Rifampin with Other Antimicrobials against Multidrug-Resistant Acinetobacter baumannii

2014 ◽  
Vol 59 (3) ◽  
pp. 1466-1471 ◽  
Author(s):  
Yan Bai ◽  
Bin Liu ◽  
Tianlin Wang ◽  
Yun Cai ◽  
Beibei Liang ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Antimicrobial Treatment ◽  
Clinical Isolates ◽  
Content Type ◽  
Synergistic Interactions ◽  
Therapeutic Alternatives ◽  
Concentration Indices

ABSTRACTThe antimicrobial treatment of multidrug-resistant (MDR)Acinetobacter baumanniiinfections has become a great challenge for medical staff all over the world. Increasing numbers of MDRA. baumanniiinfections have been identified and reported, but effective clinical treatments for them are decreasing. The objective of this study was to investigate thein vitroactivities of combinations of rifampin (an established antimicrobial) and other antimicrobials, including biapenem, colistin, and tigecycline, against 73 clinical isolates of MDRA. baumannii. In total, 73 clinical isolates of MDRA. baumanniiwere collected from two A-level general hospitals in Beijing, and the MICs of rifampin, biapenem, colistin, and tigecycline were determined. The checkerboard method was used to determine the fractional inhibitory concentration indices (FICIs), that is, whether the combinations acted synergistically against these isolates. The MIC50, MIC90, and MICrangeof rifampin combined with biapenem, colistin, and tigecycline against the isolates were clearly lower than those for four antimicrobials (rifampin, biapenem, colistin, and tigecycline) that were used alone. Combinations of rifampin with biapenem, colistin, and tigecycline individually demonstrated the following interactions: synergistic interactions (FICI ≤ 0.5) for 31.51%, 34.25%, and 31.51% of the isolates, partially synergistic interactions (0.5 < FICI < 1) for 49.31%, 43.83%, and 47.94% of the isolates, and additive interactions (FICI = 1) for 19.18%, 21.92%, and 20.55% of the isolates, respectively. There were no indifferent (1 < FICI < 4) or antagonistic (FICI ≥ 4) interactions. Therefore, combinations of rifampin with biapenem, colistin, or tigecycline may be future therapeutic alternatives for the treatment of MDRA. baumanniiinfections.

scholarly journals Detection of NDM and OXA-48 Resistant Genes in Acinetobacter Baumannii Isolated FromIntensive Care Units’ Patients Clinical Samples in Khartoum State

2021 ◽  
Author(s):  
Ghaida EL-Makki Ali El-Makki ◽  
Abdelhakam H. Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Lemya Abdelgadier Kaddam
Keyword(s):  
Acinetobacter Baumannii ◽  
Acquired Resistance ◽  
Bacterial Pathogen ◽  
Control Measures ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Cross Sectional ◽  
Infection Control Measures ◽  
Resistant Genes ◽  
Low Prevalence

Abstract Background: Acinetobacter baumannii is an opportunistic bacterial pathogen with intrinsic and acquired resistance to many antibiotics causing high rates of morbidity and mortality. This study was aimed to detect MDR Acinetobacter baumannii and its resistant genes (blaNDM, blaOXA48) from clinical isolates in Khartoum state. Method: A cross sectional hospital-based study was done during the period fromApril to July 2019. A total of 50 clinical isolates were obtained from samples of patients in intensive care units (ICUs) for the purpose of molecular confirming of A. baumannii and detecting NDM and OXA-48 resistance genes by usingconventional PCR. Results: Out of 50 isolates investigated PCR was confirmed 47 (94%) as A. baumannii isolates , while 3(6%) isolates were appeared to be other species. Moreover,the 47 A. baumannii isolates were examined for the presences of resistant genes and the result showed that NDM gene was detected in 2 isolates (4.3%) and OXA-48 gene was detected in only one isolate (2.1%). Conclusion: There is low prevalence of NDM and OXA-48 Resistant Genes among ICUs A. baumannii isolates. However, continuous regional antimicrobial resistance surveillance and improved infection control measures are required in Khartoum hospitals ICUs to prevent further dissemination.

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.

Sign in / Sign up

Export Citation Format

Share Document