scholarly journals Decreasing Prevalence of β-Lactamase Production among Respiratory Tract Isolates of Haemophilus influenzae in the United States

2005 ◽  
Vol 49 (6) ◽  
pp. 2561-2564 ◽  
Author(s):  
Kris P. Heilmann ◽  
Cassie L. Rice ◽  
Ashley L. Miller ◽  
Norma J. Miller ◽  
Susan E. Beekmann ◽  
...  

ABSTRACT A total of 986 isolates of Haemophilus influenzae from patients with respiratory tract infections in 45 United States medical centers were characterized during the winter of 2002-2003. β-Lactamase production was noted with 26.2% of isolates; 14.6% were resistant to trimethoprim-sulfamethoxazole. Resistance to other relevant antimicrobial agents was extremely uncommon. In comparison to the results of four previous national surveys conducted since 1994, the prevalence of β-lactamase production with this pathogen appears to be decreasing.

1999 ◽  
Vol 43 (2) ◽  
pp. 385-389 ◽  
Author(s):  
Gary V. Doern ◽  
Ronald N. Jones ◽  
Michael A. Pfaller ◽  
Kari Kugler ◽  

Between February and June of 1997, a large number of community-acquired respiratory tract isolates of Haemophilus influenzae (n = 1,077) and Moraxella catarrhalis (n = 503) from 27 U.S. and 7 Canadian medical centers were characterized as part of the SENTRY Antimicrobial Surveillance Program. Overall prevalences of β-lactamase production were 33.5% in H. influenzae and 92.2% in M. catarrhalis with no differences noted between isolates recovered in the United States and those from Canada. Among a total of 21 different antimicrobial agents tested, including six cephalosporins, a β-lactamase inhibitor combination, three macrolides, tetracycline, trimethoprim-sulfamethoxazole (TMP-SMX), rifampin, chloramphenicol, five fluoroquinolones, and quinupristin-dalfopristin, resistance rates of >5% with H. influenzae were observed only with cefaclor (12.8%) and TMP-SMX (16.2%).


1998 ◽  
Vol 42 (12) ◽  
pp. 3313-3314 ◽  
Author(s):  
Patricia A. Hogan ◽  
Daniel J. Sheehan

ABSTRACT In 1996 and 1997, 68 hospital laboratories throughout the United States determined the β-lactamase production and susceptibility to macrolides of 1,998 isolates of Haemophilus influenzaeobtained from patients with community-acquired respiratory tract infections. The MICs at which 90% of the isolates are inhibited of azithromycin, erythromycin, and clarithromycin were 4, 8, and 16 μg/ml, respectively. By National Committee for Clinical Laboratory Standards interpretive criteria, 99 and 78% of the isolates were susceptible to azithromycin and clarithromycin, respectively. The prevalence of β-lactamase production was 32%.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S323-S323
Author(s):  
Sibylle Lob ◽  
Krystyna Kazmierczak ◽  
Janet Raddatz ◽  
Daryl DePestel ◽  
Katherine Young ◽  
...  

Abstract Background Ceftolozane–tazobactam (C/T) is an antipseudomonal cephalosporin combined with a β-lactamase inhibitor. The combination was cleared by FDA and EMA and is approved in the United States and over 60 countries worldwide. Using clinical isolates collected in the United States and Canada as part of the global SMART surveillance program, we compared the activity of C/T and ceftazidime–avibactam (CAZ/AVI) against P. aeruginosa isolates and subsets nonsusceptible (NS) to selected antimicrobial agents. Methods In 2018, 31 clinical laboratories from United States and Canada collected up to 250 consecutive, aerobic or facultatively anaerobic, Gram-negative pathogens (GNP) from blood, intra-abdominal, urinary, and lower respiratory tract infections. A total of 6,178 GNP were collected, of which 1,138 (18.4%) were P. aeruginosa. MICs were determined using CLSI broth microdilution and interpreted with CLSI 2019 breakpoints. Results The MIC distributions of C/T and CAZ/AVI against 1,138 P. aeruginosa are shown below. The modal MIC value for C/T was ≥2 doubling dilutions lower than that for CAZ/AVI, and it was ≥3 dilutions lower than the C/T CLSI susceptible breakpoint, whereas the modal MIC value for CAZ/AVI was 2 dilutions lower than its susceptible breakpoint. Among all P. aeruginosa isolates, percentages of susceptibility were 96.0% (C/T), 93.8% (CAZ/AVI), 76.6% (CAZ and cefepime), 67.0% (imipenem [IMI]), 74.0% (meropenem [MEM]), 71.5% (piperacillin–tazobactam [TZP]), and 64.9% (aztreonam). Among subsets of nonsusceptible isolates, susceptibilities to C/T and CAZ/AVI were 83.5% and 74.4%, respectively (CAZ-NS subset, n = 266), 91.0% and 85.1% (IMI-NS, n = 376), 87.5% and 80.1% (MEM-NS, n = 296), 87.0% and 79.6% (TZP-NS, n = 324), and 72.4% and 57.8% among isolates nonsusceptible to all tested β-lactams (n = 116). Conclusion The activity of C/T exceeded that of CAZ/AVI and other tested comparators against a recent collection of clinical isolates of P. aeruginosa, including subsets of isolates nonsusceptible to other β-lactams. Susceptibilities to C/T were 6–14 percentage points higher than observed for CAZ/AVI among β-lactam-NS subsets. C/T promises to be an important treatment option for patients with antimicrobial-resistant P. aeruginosa infections. Disclosures All authors: No reported disclosures.


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)


2002 ◽  
Vol 46 (2) ◽  
pp. 550-555 ◽  
Author(s):  
Ian A. Critchley ◽  
James A. Karlowsky ◽  
Deborah C. Draghi ◽  
Mark E. Jones ◽  
Clyde Thornsberry ◽  
...  

ABSTRACT The in vitro activities of faropenem and other antimicrobial agents were determined against 4,725 Streptococcus pneumoniae isolates, 2,614 Haemophilus influenzae isolates, and 1,193 Moraxella catarrhalis isolates collected from 273 U.S. laboratories during 1999. Faropenem MICs at which 90% of isolates are inhibited were 0.008, 0.25, and 1 μg/ml for penicillin-susceptible, -intermediate, and -resistant S. pneumoniae strains, respectively; 0.5 and 1 μg/ml for β-lactamase-positive and -negative H. influenzae strains, respectively; and 0.12 and 0.5 μg/ml for β-lactamase-negative and -positive M. catarrhalis strains, respectively. Faropenem holds promise as an oral therapy for community-acquired respiratory tract infections.


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