scholarly journals 1609. Epidemiology and Susceptibility to Imipenem/Relebactam of Gram-Negative Pathogens from Patients with Lower Respiratory Tract Infections – SMART United States 2017-2018

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S799-S799
Author(s):  
Sibylle Lob ◽  
Meredith Hackel ◽  
Katherine Young ◽  
Mary Motyl ◽  
Daniel F Sahm

Abstract Background Relebactam (REL) inhibits class A and C β-lactamases and was approved in the US combined with imipenem (IMI) and cilastatin for complicated urinary tract and intraabdominal infections. Using isolates collected as part of the global SMART surveillance program in the US, we evaluated the activity of IMI/REL against gram-negative pathogens (GNP) from patients with lower respiratory tract infections (LRTI), including a comparison of isolates from ICU and non-ICU wards. Methods In 2017-2018, 27 US hospitals each collected up to 100 consecutive aerobic or facultative GNP from LRTI patients per year. MICs were determined using CLSI broth microdilution and breakpoints. Results Among 3878 GNP isolates from LRTI, the most common species collected were P. aeruginosa (Psa, 33.3%), K. pneumoniae (10.9%), E. coli (10.4%), and S. marcescens (6.9%). Susceptibility of GNP is shown in the table. IMI/REL inhibited 93% of Psa and Enterobacterales, which included 174 isolates of Morganellaceae that are not expected to be susceptible to IMI or IMI/REL. S. marcescens also showed low susceptibility to IMI, with improved but still reduced activity upon addition of REL. IMI/REL inhibited 83% of all GNP combined, 7-18 percentage points higher than the comparator β-lactams. Of the tested comparators, only amikacin exceeded the activity of IMI/REL. Only Psa showed substantial differences in susceptibility between isolates from ICU (n=486) and non-ICU wards (n=611), with 63.4% and 70.2%, respectively, susceptible to IMI, 71.6/78.7% to cefepime, and 64.2/73.3% to piperacillin/tazobactam (P/T). Susceptibility to IMI/REL was high in both settings (91.4/93.6%). Among Enterobacterales, susceptibility was generally similar in ICU and non-ICU wards (IMI/REL, 92.5% in both settings; IMI, 86.3 and 87.1%, respectively; cefepime, 89.9/89.0%; P/T, 88.7/87.4%). Table Conclusion Although resistance rates have frequently been reported to be higher in ICU than non-ICU wards, this pattern was seen in the current study only among Psa isolates. IMI/REL showed activity >90% against both Enterobacterales and Psa from both ward types. These in vitro data suggest that IMI/REL could provide an important treatment option for patients with LRTI in the US, including those in ICUs. Disclosures Sibylle Lob, PhD, IHMA (Employee)Pfizer, Inc. (Consultant) Katherine Young, MS, Merck & Co., Inc. (Employee, Shareholder)Merck & Co., Inc. (Employee, Shareholder) Mary Motyl, PhD, Merck & Co, Inc (Employee, Shareholder) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Consultant)Shionogi & Co., Ltd. (Independent Contractor)

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S790-S791
Author(s):  
Sibylle Lob ◽  
Meredith Hackel ◽  
Daryl DePestel ◽  
Katherine Young ◽  
Mary Motyl ◽  
...  

Abstract Background Ceftolozane/tazobactam (C/T) is an antipseudomonal cephalosporin combined with a β-lactamase inhibitor. C/T has been approved by the FDA and EMA for complicated urinary tract infections, complicated intraabdominal infections, and hospital-acquired and ventilator-associated bacterial pneumonia. Using isolates collected in the United States as part of the global SMART surveillance program, we evaluated the activity of C/T and comparators against gram-negative pathogens collected from patients with lower respiratory tract infections (LRTI). Methods In 2018, 24 hospitals in the US each collected up to 100 consecutive aerobic or facultative gram-negative bacilli (GNB) from LRTI for a total of 1773 isolates. MICs were determined using CLSI broth microdilution and breakpoints. C/T-nonsusceptible (NS) Enterobacterales and P. aeruginosa isolates were screened by PCR and sequencing for genes encoding β-lactamases. Results The 3 most common species collected from LRTI were P. aeruginosa (35.0% of all collected GNB), K. pneumoniae (10.4%), and E. coli (9.6%). Enterobacterales and P. aeruginosa combined comprised 86.3% of all collected LRTI GNB. The activity of C/T and comparators against GNB from LRTI is shown in the table. C/T was active against 93% of Enterobacterales isolates from LRTI (activity only exceeded by meropenem and amikacin), as well as against 97% of P. aeruginosa and 94% of all Enterobacterales and P. aeruginosa combined (activity only exceeded by amikacin). C/T maintained activity against 69-83% of β-lactam-NS subsets of Enterobacterales and P. aeruginosa combined. Among 67 molecularly characterized C/T-NS Enterobacterales isolates, 19.4% carried KPC, 1.5% acquired AmpC, and 16.4% only extended-spectrum β-lactamases. No acquired β-lactamases were detected in the remaining 62.7% of isolates, of which 92.9% were species with intrinsic AmpC. Among 21 molecularly characterized C/T-NS P. aeruginosa, one isolate carried an IMP-type metallo-β-lactamase, and in the remaining isolates no acquired β-lactamases were detected. Table Conclusion With its broad coverage of Enterobacterales and P. aeruginosa, C/T can provide an important empiric therapy option for patients with LRTI in the US. Disclosures Sibylle Lob, PhD, IHMA (Employee)Pfizer, Inc. (Consultant) Daryl DePestel, PharmD, BCPS-ID, Merck & Co, Inc (Employee) Katherine Young, MS, Merck & Co., Inc. (Employee, Shareholder)Merck & Co., Inc. (Employee, Shareholder) Mary Motyl, PhD, Merck & Co, Inc (Employee, Shareholder) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Consultant)Shionogi & Co., Ltd. (Independent Contractor)


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S705-S705
Author(s):  
Sibylle Lob ◽  
Krystyna Kazmierczak ◽  
Francis Arhin ◽  
Daniel F Sahm

Abstract Background β-lactamase-producing Enterobacterales (Ebact) frequently co-carry resistance to antimicrobials from other classes, limiting treatment options. Avibactam (AVI) inhibits class A, class C, and some class D serine β-lactamases, while aztreonam (ATM) is refractory to hydrolysis by class B metallo-β-lactamases (MBLs). ATM-AVI is being developed for use against drug-resistant isolates of Ebact, especially those co-producing MBLs and serine β-lactamases. This study evaluated the in vitro activity of ATM-AVI and comparators against Ebact collected in 2017-2019 from patients with lower respiratory tract infections (LRTI) as part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program. Methods Non-duplicate clinical isolates were collected in 52 countries in Europe, Latin America, Asia/Pacific (excluding mainland China and India), and Middle East/Africa. Susceptibility testing was performed by CLSI broth microdilution and interpreted using CLSI 2021 and FDA (tigecycline) breakpoints. ATM-AVI was tested at a fixed concentration of 4 µg/mL AVI. MDR was defined as resistant (R) to ≥3 of 7 sentinel drugs: amikacin, aztreonam, cefepime, colistin, levofloxacin, meropenem, and piperacillin-tazobactam. PCR and sequencing were used to determine the β-lactamase genes present in all isolates with meropenem MIC >1 µg/mL, and Escherichia coli, Klebsiella spp. and Proteus mirabilis with ATM or ceftazidime MIC >1 µg/mL. Results ATM-AVI was active in vitro against Ebact isolates from LRTI (MIC90, 0.25 µg/mL), with 99.97% of isolates inhibited by ≤8 µg/mL of ATM-AVI, including 100% of isolates that produced MBLs. ATM-AVI tested with MIC90 values of 0.5 µg/mL against subsets of cefepime-nonsusceptible (NS), meropenem-NS, amikacin-NS, colistin-resistant, and MBL-positive Ebact (Table). The tested β-lactam comparators showed susceptibility of < 78% against these subsets of resistant isolates. Results Table Conclusion Based on MIC90 values, ATM-AVI was the most potent agent tested against drug-resistant and MBL-positive subsets of Ebact collected from LRTI. The promising in vitro activity of ATM-AVI warrants further development of this combination for treatment of LRTI caused by drug-resistant Ebact. Disclosures Sibylle Lob, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Krystyna Kazmierczak, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Francis Arhin, PhD, Pfizer, Inc. (Employee) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor)


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S255-S255
Author(s):  
Sibylle Lob ◽  
Krystyna Kazmierczak ◽  
Daryl Hoban ◽  
Meredith Hackel ◽  
Katherine Young ◽  
...  

Abstract Background Relebactam (REL), formerly MK-7655, is a β-lactamase inhibitor of class A and C β-lactamases that is in clinical development in combination with imipenem (IMI). In this study, we evaluated the activity of IMI/REL against Gram-negative bacilli and resistant phenotypes collected in the United States as part of the SMART surveillance program from patients with lower respiratory tract infections (RTI) in ICUs, where antimicrobial resistance is typically higher than in non-ICU wards. Methods In 2015–2017, 26 hospitals in the United States each collected up to 100 consecutive Gram-negative pathogens from RTI per year. Antimicrobial susceptibility was determined for 1,298 non-Proteeae Enterobacteriaceae (NPE) and 638 P. aeruginosaisolates collected in ICUs, using CLSI broth microdilution and breakpoints; for comparison purposes, the IMI susceptible breakpoint was applied to IMI/REL. Proteeae were excluded due to intrinsic nonsusceptibility to IMI. Susceptibility was calculated for the 4 United States census regions and overall. Results Susceptibility of NPE was lowest in the Midwest to ceftazidime (81%) and cefepime (87%) and highest in the Northeast (88% and 94%, respectively); susceptibility to imipenem (89–93%) and piperacillin–tazobactam (86–90%) showed less variability across regions. Susceptibility of P. aeruginosa to the four agents was lowest in the West region (57–65%) and highest in the Northeast (68–76%). Susceptibilities to IMI/REL of NPE and P. aeruginosa as well as of phenotypes nonsusceptible (NS) to β-lactams are shown below. Conclusion The studied β-lactams showed some variability in activity against pathogens from RTI patients in ICUs across census regions, whereas IMI/REL maintained activity in all regions against NPE (>96%) and P. aeruginosa (90–95%). IMI/REL remained active against ≥98% of resistant phenotypes of NPE, except the imipenem-NS subset (67.5% susceptible), which was composed mainly of Serratia spp., and remained active against 77–82% of resistant phenotypes of P. aeruginosa, including 77.2% of imipenem-NS isolates. IMI/REL may provide a valuable therapeutic option for the treatment of ICU patients with respiratory tract infections caused by organisms resistant to commonly used β-lactams. Disclosures S. Lob, IHMA, Inc.: Employee, Salary. Merck: Consultant, Consulting fee. K. Kazmierczak, Merck: Consultant, Consulting fee. IHMA, Inc.: Employee, Salary. D. Hoban, IHMA, Inc.: Employee, Salary. Merck: Consultant, Consulting fee. M. Hackel, IHMA, Inc.: Employee, Salary. Merck: Consultant, Consulting fee. K. Young, Merck: Employee and Shareholder, Dividends and Salary. M. Motyl, Merck: Employee and Shareholder, Dividends and Salary. D. Sahm, IHMA, Inc.: Employee, Salary. Merck: Consultant, Consulting fee.


2018 ◽  
Vol 159 (1) ◽  
pp. 23-30
Author(s):  
Emese Juhász ◽  
Miklós Iván ◽  
Júlia Pongrácz ◽  
Katalin Kristóf

Abstract: Introduction: Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet. Aim: The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options. Method: Lower respiratory tract samples of 3589 patients collected in a four-year period (2013–2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method. Results: Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also. Conclusions: Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23–30.


2021 ◽  
Vol 71 (2) ◽  
pp. 211-218
Author(s):  
Herica Makino ◽  
Alessandra Tammy Hayakawa Ito De Sousa ◽  
Lucas Avelino Dandolini Pavelegini ◽  
Yolanda Paim Arruda Trevisan ◽  
Edson Moleta Colodel ◽  
...  

Abstract Neisseria sp. is a Gram-negative diplococcus bacterium usually present on the mucosal surfaces of animals without causing an obvious pathology. The objective of this study was to report the isolation of Neisseria sp. from severe cases of pyogranulomatous pneumonia with the formation of a Splendore-Hoeppli structure in two cats treated at a veterinary hospital. This paper suggests that the Neisseria genus members may be involved in lower respiratory tract infections in cats, with the molecular diagnosis being a necessary method for the correct identification of this bacteria in animals.


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