scholarly journals Changing Epidemiology of Extended-Spectrum β-Lactamases in Argentina: Emergence of CTX-M-15

2012 ◽  
Vol 56 (11) ◽  
pp. 6003-6005 ◽  
Author(s):  
S. Sennati ◽  
G. Santella ◽  
J. Di Conza ◽  
L. Pallecchi ◽  
M. Pino ◽  
...  

ABSTRACTA multicenter survey, carried out in 2010 in Argentina, showed an increased prevalence of extended-spectrum β-lactamase (ESBL)-producing enterobacteria, with some changes in the molecular epidemiology of circulating ESBLs. While enzymes of the CTX-M-2 group remain endemic, the emergence of CTX-M-15 and of enzymes of the CTX-M-8 and CTX-M-9 groups was observed. The CTX-M-15-positive isolates represented 40% of CTX-M producers and included representatives ofEscherichia coliST131 andKlebsiella pneumoniaeST11.

2012 ◽  
Vol 56 (6) ◽  
pp. 2888-2893 ◽  
Author(s):  
Nan-Yao Lee ◽  
Ching-Chi Lee ◽  
Wei-Han Huang ◽  
Ko-Chung Tsui ◽  
Po-Ren Hsueh ◽  
...  

ABSTRACTA retrospective study was conducted at two medical centers in Taiwan to evaluate the clinical characteristics, outcomes, and risk factors for mortality among patients treated with a carbapenem for bacteremia caused by extended-spectrum-beta-lactamase (ESBL)-producing organisms. A total of 251 patients with bacteremia caused by ESBL-producingEscherichia coliandKlebsiella pneumoniaeisolates treated by a carbapenem were identified. Among these ESBL-producing isolates, rates of susceptibility to ertapenem (MICs ≤ 0.25 μg/ml) were 83.8% and 76.4%, respectively; those to meropenem were 100% and 99.3%, respectively; and those to imipenem were 100% and 97.9%, respectively. There were no significant differences in the critical illness rate (P= 0.1) or sepsis-related mortality rate (P= 0.2) for patients with bacteremia caused by ESBL-producingK. pneumoniae(140 isolates, 55.8%) andE. coli(111 isolates, 44.2%). Multivariate analysis of variables related to sepsis-related mortality revealed that the presence of severe sepsis (odds ratio [OR], 15.9; 95% confidence interval [CI], 5.84 to 43.34;P< 0.001), hospital-onset bacteremia (OR, 4.65; 95% CI, 1.42 to 15.24;P= 0.01), and ertapenem-nonsusceptible isolates (OR, 5.12; 95% CI, 2.04 to 12.88;P= 0.001) were independent risk factors. The patients receiving inappropriate therapy had a higher sepsis-related mortality than those with appropriate therapy (P= 0.002), irrespective of ertapenem, imipenem, or meropenem therapy. Infections due to the ertapenem-susceptible isolates (MICs ≤ 0.25 μg/ml) were associated with a more favorable outcome than those due to ertapenem-nonsusceptible isolates (MICs > 0.25 μg/ml), if treated by a carbapenem. However, the mortality for patients with bacteremic episodes due to isolates with MICs of ≤0.5 μg/ml was similar to the mortality for those whose isolates had MICs of >0.5 μg/ml (P= 0.8). Such a finding supports the rationale of the current CLSI 2011 criteria for carbapenems forEnterobacteriaceae.


2007 ◽  
Vol 52 (2) ◽  
pp. 786-789 ◽  
Author(s):  
Muriel Galas ◽  
Jean-Winoc Decousser ◽  
Nelly Breton ◽  
Thierry Godard ◽  
Pierre Yves Allouch ◽  
...  

ABSTRACT Among 10,872 isolates of Enterobacteriaceae from a nationwide study of 88 French hospitals in 2005, 169 (1.7%) expressed an extended-spectrum β-lactamase. The most prevalent species were Escherichia coli (48.5%), Enterobacter aerogenes (23.7%), and Klebsiella pneumoniae (14.8%). Molecular analysis underlined the polyclonal spread of CTX-M-expressing E. coli, primarily isolates of the CTX-M-1 subgroup.


2012 ◽  
Vol 79 (3) ◽  
pp. 1052-1054 ◽  
Author(s):  
Dixie F. Mollenkopf ◽  
Jennifer M. Mirecki ◽  
Joshua B. Daniels ◽  
Julie A. Funk ◽  
Steven C. Henry ◽  
...  

ABSTRACTWe report the recovery ofEscherichia coliorKlebsiella pneumoniaecontaining the extended-spectrum β-lactamase geneblaCTX-Mfrom 24 of 1,495 (1.6%) swine fecal samples in 8 of 50 (16%) finishing barns located in 5 U.S. states. We did not detect an association between antimicrobial use and recovery ofblaCTX-M.


2012 ◽  
Vol 57 (1) ◽  
pp. 640-642 ◽  
Author(s):  
Pamela R. Tessier ◽  
David P. Nicolau

ABSTRACTProgressively enhanced activity of a humanized tigecycline (TGC) regimen was noted over 3 days against an extended-spectrum-β-lactamase (ESBL)-producingEscherichia coliisolate and an ESBL-producingKlebsiella pneumoniaeisolate. Bacterial density reduction approximated 3 log10approaching bactericidal activity at 72 h. This level of activity has not been previously noted for compounds such as tetracyclines, normally considered bacteriostatic antimicrobials. Extended regimen studiesin vivomay aid in better delineation of antimicrobial effects, producing improved correlation with clinical outcomes.


2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Ghady Haidar ◽  
Cornelius J. Clancy ◽  
Ryan K. Shields ◽  
Binghua Hao ◽  
Shaoji Cheng ◽  
...  

ABSTRACT We identified four bla KPC-3 mutations in ceftazidime-avibactam-resistant clinical Klebsiella pneumoniae isolates, corresponding to D179Y, T243M, D179Y/T243M, and EL165-166 KPC-3 variants. Using site-directed mutagenesis and transforming vectors into Escherichia coli, we conclusively demonstrated that mutant bla KPC-3 encoded enzymes that functioned as extended-spectrum β-lactamases; mutations directly conferred higher MICs of ceftazidime-avibactam and decreased the MICs of carbapenems and other β-lactams. Impact was strongest for the D179Y mutant, highlighting the importance of the KPC Ω-loop.


2012 ◽  
Vol 56 (7) ◽  
pp. 3977-3980 ◽  
Author(s):  
Christopher F. Lowe ◽  
Allison McGeer ◽  
Matthew P. Muller ◽  
Kevin Katz

ABSTRACTRetrospective review from 11 Canadian hospitals showed increasing incidence of extended-spectrum β-lactamase (ESBL)-producingEscherichia coliandKlebsiella pneumoniaefrom 0.12 per 1,000 inpatient days during 2005 to 0.47 per 1,000 inpatient days during 2009. By 2009, susceptibility rates of ESBL-positiveE. coli/K. pneumoniaewere as follows: ciprofloxacin, 12.8%/9.0%; TMP/SMX, 32.9%/12.2%; and nitrofurantoin, 83.8%/10.3%. Nosocomial and nonnosocomial ESBL-producingE. coliisolates had similar susceptibility profiles, while nonnosocomial ESBL-producingK. pneumoniaewas associated with decreased ciprofloxacin (P= 0.03) and nitrofurantoin (P< 0.001) susceptibilities.


Sign in / Sign up

Export Citation Format

Share Document