#Antimicrobial #Activity of #Ceftazidime-Avibactam When Tested against Gram-negative Bacteria Isolated from Patients Hospitalized with #Pneumonia in #US Medical Centers (2011-2015) (AAC, abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Antimicrobial Activity of Ceftazidime-Avibactam When Tested against Gram-negative Bacteria Isolated from Patients Hospitalized with Pneumonia in United States Medical Centers (2011-2015)

Helio S. Sader⇑, Mariana Castanheira and Robert K. Flamm

Author Affiliations: JMI Laboratories, North Liberty, Iowa, USA

 

ABSTRACT

Bacterial isolates were collected from patients hospitalized with pneumonia (PHP), including ventilator-associated (VAP), from 76 USA medical centers in 2011-2015. The Gram-negative organisms (n=11,185; including 1,097 from VAP) were tested for susceptibility against ceftazidime-avibactam and comparators by broth microdilution method. β-lactamase-encoding genes were screened using a microarray based assay on selected isolates. Pseudomonas aeruginosa and Klebsiella spp. were the most common Gram-negatives isolated from PHP and VAP. Ceftazidime-avibactam was very active against P. aeruginosa (n=3,402; MIC50/90, 2/4 μg/mL; 96.6% susceptible), including isolates non-susceptible to meropenem (86.3% susceptible to ceftazidime-avibactam), piperacillin-tazobactam (85.6% susceptible) or ceftazidime (80.6% susceptible). Ceftazidime-avibactam was also highly active against Enterobacteriaceae (MIC50/90, 0.12/0.5 μg/mL; 99.9% susceptible), including carbapenem-resistant (CRE, n=189; MIC50/90, 0.5/2 μg/mL; 98.0% susceptible), multidrug-resistant (MDR; n=674; MIC50/90, 0.25/1 μg/mL; 98.8% susceptible) and extensively drug-resistant Enterobacteriaceae (XDR; n=156; MIC50/90, 0.5/2 μg/mL; 98.1% susceptible) isolates, as well as Klebsiella spp. isolates showing an ESBL screening-positive phenotype (n=433; MIC50/90, 0.25/1 μg/mL; 99.5% susceptible). Among Enterobacter spp. (24.8% ceftazidime-non-susceptible), 99.8% of isolates, including 99.4% of ceftazidime-non-susceptible isolates, were susceptible to ceftazidime-avibactam. The most common β-lactamases detected among K. pneumoniae and E. coli were KPC-like and CTX-M-15, respectively. Only eight of 6,209 Enterobacteriaceae isolates (0.1%) were ceftazidime-avibactam-non-susceptible, three NDM-1 producing strains with ceftazidime-avibactam MIC values of >32 μg/mL and five isolates with ceftazidime-avibactam MIC values of 16 μg/mL and negative results for all β-lactamases tested. Susceptibility rates among isolates from VAP were generally similar or slightly higher compared to those from all PHP.

 

FOOTNOTES

Contact Information: Helio S. Sader, MD, PhD, JMI Laboratories, 345 Beaver Kreek Ctr, Ste A, North Liberty, Iowa, 52317, USA, Phone: 319-665-3370, Fax: 319-665-3371, helio-sader@jmilabs.com

Copyright © 2017 American Society for Microbiology.

Keywords: Pneumonia; Antibiotics; Drugs Resistance; Avibactam.

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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.