scholarly journals 1278. Testing the Synergistic Effect of Ceftazidime-Avibactam Plus Aztreonam on Metallobetalactamase-Producing Non-Fermenting Gram-negative Bacteria

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S727-S727
Author(s):  
Elena M Crouch ◽  
Sheila Johnson ◽  
Jason Bennett

Abstract Background Metallo-betalactamases (MBL) are rapidly becoming a more widespread form of antimicrobial resistance. MBL are class B betalactamases that use zinc rather than serine in their active site and are only inactivated by monobactams, such as aztreonam. Unfortunately, most MBL-producing organisms also produce aztreonam-inactivating beta-lactamases. Synergy between ceftazidime-avibactam and aztreonam is well documented for MBL-producing Enterobacteriaceae but has not been tested extensively in non-fermenting Gram-negative bacteria. This study evaluates the susceptibilities of non-fermenting Gram-negative bacteria via E-test to this combination in vitro, in order to provide support for use to treat infections from these organisms. Methods The antibiotic combination ceftazidime-avibactam+aztreonam was tested against a total of 33 isolates, including MBL-producing Pseudomonas aeruginosa, Pseudomonas putida, and the intrinsically aztreonam resistant Acinetobacter baumanii using the E-test method. MBL-producing Enterobacteriaceae were included as positive controls. All isolates were also tested against ceftazidime alone, aztreonam alone, and ceftazidime-avibactam. Bacterial isolates were procured from the Multidrug-resistant organism Repository & Surveillance Network at the Walter Reed Army Institute of Research. Antimicrobial resistance genes were previously identified by whole genome sequencing Results Of 13 Pseudomonas spp. isolates tested, 9 were resistant, 3 were intermediate, and 1 was susceptible to aztreonam. Synergistic testing of ceftazidime-avibactam+aztreonam reduced the MIC of 4 Pseudomonas isolates by 1-2 doubling dilutions. While Acinetobacter spp. are usually considered intrinsically resistant to aztreonam, synergistic testing of ceftazidime-avibactam+aztreonam reduced the MIC of all 12 isolates tested by 1 to 3 doubling dilutions. Conclusion The ability of ceftazidime-avibactam+aztreonam to reduce the MICs of Acinetobacter baumanii and MBL-producing Pseudomonas aeruginosa is a potentially promising therapeutic option when faced with growing antimicrobial resistance. Disclosures All Authors: No reported disclosures

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.


2017 ◽  
Vol 07 (04) ◽  
pp. 016-020
Author(s):  
Juliet Roshini Mohan Raj ◽  
Rajeshwari Vittal ◽  
Santosh Kogaluru Shivakumaraswamy ◽  
Vijaya Kumar Deekshit ◽  
Indrani Karunasagar

AbstractDownstream water systems provide for a conducive environment for horizontal gene transfer. The objective of this study was to determine the burden of antimicrobial resistance in waste water effluents from different sources and their impact on human health. Gram negative bacteria were isolated from 30 samples each of industrial, hospital and domestic effluents. The antimicrobial susceptibility of the 367 isolates from 90 effluent samples was determined by disc diffusion test and presence of antimicrobial resistance genes by polymerase chain reaction. Resistance to ampicillin was 62% in hospital effluents and was higher than that recorded for industrial and domestic effluents. While the highest percentage of resistance to tetracycline was observed in isolates from industrial effluents (42%) a low of 9.5% was observed in hospital effluents. Antimicrobial resistance determinants present on mobile genetic elements were observed in a small fraction (~10%) of the resistant isolates. The resistance profile of isolates in effluents reflect the practices of different industries. Resistant isolates in domestic effluents could be a reflection of the indiscriminate use of antibiotics andthat many of the contents of disinfectants and cleaning agents routinely used may contain structural analogs of antimicrobials used in therapy. Though by phenotypic test a higher prevalence of antimicrobial resistance was recorded the genotypic study revealed the prevalence to be low. This could be due to the limited number of antimicrobial resistance genes included in this study.


Author(s):  
Sotianingsih Sotianingsih ◽  
Samsirun H. ◽  
Lipinwati Lipinwati

Pneumonia is defined as an inflammation of the lungs caused by microorganisms (bacteria, viruses, fungi, parasites). This research aimed to determine the pneumonia-causing bacteria along with the sensitivity and the antibiotic resistance test. This research was a descriptive study with samples of ICU pneumonia patients at Raden Mattaher Regional Hospital during the study period. All samples were consecutively selected. Samples for blood culture were incubated in the BactAlert device, whereas the sensitivity test was then performed using Vitex instruments. Sputum was previously enriched with BHI media and then cultured on culture media, and sensitivity test with the Vitex instruments was carried out. Of the 354 ICU patients during the study period, 30 patients (11.8%) had pneumonia, but only 19 patients could undergo sputum culture. Five of 19 patients were infected with Gram-positive bacteria, and 14 patients were infected with Gram-negative bacteria. The most commonly found bacteria were Klebsiella pneumonia (36.84%), followed by Acinetobacter baumanii (21.05%) and Pseudomonas aeruginosa (10.53%). Gram-negative bacteria obtained from sputum culture in this study were resistant to almost all antibiotic groups, especially penicillin, cephalosporin, quinolone, and tetracycline groups. Gram-positive bacteria obtained from sputum culture in this study were resistant to the penicillin antibiotic. The most commonly found bacteria were Klebsiella pneumonia (36.84%), followed by Acinetobacter baumanii (21.05%) and Pseudomonas aeruginosa (10.53%). The bacteria cultured from the sputum showed multidrug resistance mainly to the penicillin and cephalosporin antibiotic. This research data can be used to consider the treatment of pneumonia patients to decide more appropriate therapy.


2007 ◽  
Vol 73 (20) ◽  
pp. 6686-6690 ◽  
Author(s):  
Ashraf M. Ahmed ◽  
Yusuke Motoi ◽  
Maiko Sato ◽  
Akito Maruyama ◽  
Hitoshi Watanabe ◽  
...  

ABSTRACT A total of 232 isolates of gram-negative bacteria were recovered from mammals, reptiles, and birds housed at Asa Zoological Park, Hiroshima prefecture, Japan. Forty-nine isolates (21.1%) showed multidrug resistance phenotypes and harbored at least one antimicrobial resistance gene. PCR and DNA sequencing identified class 1 and class 2 integrons and many β-lactamase-encoding genes, in addition to a novel AmpC β-lactamase gene, bla CMY-26. Furthermore, the plasmid-mediated quinolone resistance genes qnr and aac(6′)-Ib-cr were also identified.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 474
Author(s):  
Luca Gregorio Giaccari ◽  
Maria Caterina Pace ◽  
Maria Beatrice Passavanti ◽  
Francesca Gargano ◽  
Caterina Aurilio ◽  
...  

Background: Ceftolozane/tazobactam (C/T) is a β-lactam/β-lactamase inhibitor combination that mainly targets Gram-negative bacteria. The current international guidelines recommend including C/T treatment in the empirical therapy for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Pseudomonas aeruginosa (PA) is one of the most challenging Gram-negative bacteria. We conducted a systematic review of all cases reported in the literature to summarize the existing evidence. Methods: The main electronic databases were screened to identify case reports of patients with drug-resistant PA respiratory infections treated with C/T. Results: A total of 22 publications were included for a total of 84 infective episodes. The clinical success rate was 72.6% across a wide range of comorbidities. The 45.8% of patients treated with C/T presented colonization by PA. C/T was well tolerated. Only six patients presented adverse events, but none had to stop treatment. The most common therapeutic regimens were 1.5 g every 8 h and 3 g every 8 h. Conclusion: C/T may be a valid therapeutic option to treat multidrug-resistant (MDR), extensively drug-resistant (XDR), pandrug-resistant (PDR), and carbapenem-resistant (CR) PA infections. However, further data are necessary to define the optimal treatment dosage and duration.


2009 ◽  
Vol 54 (1) ◽  
pp. 346-352 ◽  
Author(s):  
Ørjan Samuelsen ◽  
Mark A. Toleman ◽  
Arnfinn Sundsfjord ◽  
Johan Rydberg ◽  
Truls M. Leegaard ◽  
...  

ABSTRACT Scandinavia is considered a region with a low prevalence of antimicrobial resistance. However, the number of multidrug-resistant (MDR) Gram-negative bacteria is increasing, including metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa. In this study MBL-producing P. aeruginosa isolates identified in Norway (n = 4) and Sweden (n = 9) from 1999 to 2007 were characterized. Two international clonal complexes (CC), CC111 (n = 8) and CC235 (n = 2), previously associated with MBL-producing isolates, were dominant. CC111 isolates (ST111/229; serotype O12; bla VIM-2) included clonally related isolates identified in Skåne County, Sweden (n = 6), and two isolates associated with importation from Greece and Denmark. In all CC111 isolates, bla VIM-2 was located in integron In59.2 or In59 variants. The two CC235 isolates (ST235/ST230; serotype O11; bla VIM-4) were imported from Greece and Cyprus, were possibly clonally related, and carried bla VIM-4 in two different integron structures. Three isolates imported from Ghana (ST233; serotype O6; bla VIM-2), Tunisia (ST654; serotype O11; bla VIM-2), and Thailand (ST260; serotype O6; bla IMP-14) were clonally unrelated. ST233 was part of a new CC (CC233) that included other MBL-producing isolates, while ST654 could also be part of a new CC associated with MBL producers. In the isolates imported from Ghana and Tunisia, bla VIM-2 was part of unusual integron structures lacking the 3′ conserved segment and associated with transposons. The bla VIM gene was found to be located on the chromosome in all isolates. Known risk factors for acquisition of MBL were reported for all patients except one. The findings suggest that both import of successful international clones and local clonal expansion contribute to the emergence of MBL-producing P. aeruginosa in Scandinavia.


Author(s):  
Bratko Filipič ◽  
Lidija Gradišnik ◽  
Adriana Pereyra ◽  
Hrvoje Mazija

ABSTRACT. The immunotherapies, as a modern therapeutic approach, get an attention because of theirs’ promise to treat a large number of different medical disorders. Immunomodulation effects of low titres (10 HA/ml) of NDV (Newcastle Disease Virus) ZG1999HDS or La Sota were tested on TLT (Human macrophage cell line) bound to PBMC (Peripheral Blood Mononuclear Cells). During the immunomodulation, the amount of NO, H2O2, lysozym and induced antibacterial activity against Gram - positive bacteria (Staphylococcus aureus, MRSA, Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus mutants) and against Gram - negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and Acinetobacter baumanii) were analysed. In addition, the cytokine secretion, IL-1α, IL-2, IL-4, GM-CSF, TNF-α, IFN-α and IFN-α were evaluated. Firstly, the TLT cells are activated through the NDV ZG1999HDS or La Sota binding, followed by the NO “burst” and H2O2 and lysozyme level increase. Secondly, after the binding to the TLT cells and interaction with the PBMCs, the decrease of GM-CSF, and an increase of TNF – α and IFN – γ were found. Simultaneously, the decrease of pro – inflammatory cytokine IFN-α and the differentially increase of IL-1α, IL-2 and IL-4 were recorded. During the induction of the antibacterial response, against Gram - positive bacteria (Staphylococcus aureus, MRSA, Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus mutants) the effect was one third higher with NDV ZG1999HDS compared to La Sota. Antibacterial response against Gram - negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and Acinetobacter baumanii) was not so clear. In general, NDV ZG1999HDS or La Sota activated TLT cells, further bound to PBMC; the ZG1999HDS is stronger immunomodulator than La Sota.


Author(s):  
Tingting Wang ◽  
Yongxiang Zheng ◽  
Jiami Dai ◽  
Junxiu Zhou ◽  
Rong Yu ◽  
...  

Antimicrobial resistance (AMR) is a major issue to global health, particularly the multidrug-resistant (MDR) Gram-negative infections, which pose great challenges. Even new antibiotics research is ongoing, antibiotics used to treat Gram-negative bacteria in the clinical are limited in a small set of molecular scaffolds, and biomolecular categories of antibiotics are urgently needed.


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