scholarly journals Antimicrobial Resistance in Haemophilus influenzae and Moraxella catarrhalis Respiratory Tract Isolates: Results of the Canadian Respiratory Organism Susceptibility Study, 1997 to 2002

2003 ◽  
Vol 47 (6) ◽  
pp. 1875-1881 ◽  
Author(s):  
George G. Zhanel ◽  
Lorraine Palatnick ◽  
Kimberly A. Nichol ◽  
Don E. Low ◽  
Daryl J. Hoban

ABSTRACT A total of 7,566 unique patient isolates of Haemophilus influenzae and 2,314 unique patient isolates of Moraxella catarrhalis were collected between October 1997 and June 2002 from 25 medical centers in 9 of the 10 Canadian provinces. Among the 7,566 H. influenzae isolates, 22.5% produced β-lactamase, while 92.4% of the 2,314 M. catarrhalis isolates produced β-lactamase. The incidence of β-lactamase-producing H. influenzae isolates decreased significantly over the 5-year study period, from 24.2% in 1997-1998 to 18.6% in 2001-2002 (P < 0.01). The incidence of β-lactamase-producing M. catarrhalis isolates did not change over the study period. The overall rates of resistance to amoxicillin and amoxicillin-clavulanate for H. influenzae were 19.3 and 0.1%, respectively. The rank order of cephalosporin activity based on the MICs at which 90% of isolates were inhibited (MIC90s) was cefotaxime > cefixime > cefuroxime > cefprozil > cefaclor. On the basis of the MICs, azithromycin was more active than clarithromycin (14-OH clarithromycin was not tested); however, on the basis of the NCCLS breakpoints, resistance rates were 2.1 and 1.6%, respectively. Rates of resistance to other agents were as follows: doxycycline, 1.5%; trimethoprim-sulfamethoxazole, 14.2%; and chloramphenicol, 0.2%. All fluoroquinolones tested, including the investigational fluoroquinolones BMS284756 (garenoxacin) and ABT-492, displayed potent activities against H. influenzae, with MIC90s of ≤0.03 μg/ml. The MIC90s of the investigational ketolides telithromycin and ABT-773 were 2 and 4 μg/ml, respectively, and the MIC90 of the investigational glycylcycline GAR-936 (tigecycline) was 4 μg/ml. Among the M. catarrhalis isolates tested, the resistance rates derived by using the NCCLS breakpoint criteria for H. influenzae were <1% for all antibiotics tested except trimethoprim-sulfamethoxazole (1.5%). In summary, the incidence of β-lactamase-positive H. influenzae strains in Canada is decreasing (18.6% in 2001-2002), while the incidence of β-lactamase-positive M. catarrhalis strains has remained constant (90.0% in 2001-2002).

2001 ◽  
Vol 45 (5) ◽  
pp. 1463-1466 ◽  
Author(s):  
Ana Gales ◽  
Helio Sader ◽  
Ronald N. Jones

ABSTRACT The antimicrobial activity of BMS 284756, a novel des-F(6)-quinolone, was comparatively evaluated against 257Streptococcus pneumoniae, 198 Haemophilus influenzae, and 88 Moraxella catarrhalis strains isolated in Latin America between July and September of 1999 as part of the SENTRY Antimicrobial Surveillance Program. Nearly 28.0% ofS. pneumoniae strains were nonsusceptible to penicillin. The rank order of quinolone potency versus S. pneumoniaewas BMS 284756 (MIC at which 90% of isolates were inhibited [MIC90], 0.12 μg/ml) > trovafloxacin (MIC90, 0.25 μg/ml) > gatifloxacin (MIC90, 0.5 μg/ml) > levofloxacin and ciprofloxacin (MIC90, 1 to 2 μg/ml). All S. pneumoniaestrains that were not susceptible to other quinolones were inhibited by BMS 284756 at ≤2 μg/ml. The overall prevalence of β-lactamase production was 15.2% in H. influenzae and 98.9% inM. catarrhalis. BMS 284756 showed excellent potency and spectrum against this group of pathogens, inhibiting all isolates at ≤0.12 μg/ml. BMS 284756 exhibited activity similar to those displayed by the new fluoroquinolones, such as levofloxacin, trovafloxacin, or gatifloxacin, and could be a therapeutic option for empirical treatment of community-acquired respiratory tract infections.


2003 ◽  
Vol 47 (6) ◽  
pp. 1867-1874 ◽  
Author(s):  
George G. Zhanel ◽  
Lorraine Palatnick ◽  
Kimberly A. Nichol ◽  
Tracy Bellyou ◽  
Don E. Low ◽  
...  

ABSTRACT A total of 6,991 unique patient isolates of Streptococcus pneumoniae were collected from October 1997 to June 2002 from 25 medical centers in 9 of the 10 Canadian provinces. Among these isolates, 20.2% were penicillin nonsusceptible, with 14.6% being penicillin intermediate (MIC, 0.12 to 1 μg/ml) and 5.6% being penicillin resistant (MIC, ≥2 μg/ml). The proportion of high-level penicillin-resistant S. pneumoniae isolates increased from 2.4 to 13.8% over the last 3 years of the study, and the proportion of multidrug-resistant S. pneumoniae isolates increased from 2.7 to 8.8% over the 5-year period. Resistant rates (intermediate and resistant) among non-β-lactam agents were as follows: macrolides, 9.6 to 9.9%; clindamycin, 3.8%; doxycycline, 5.5%; chloramphenicol, 3.9%; and trimethoprim-sulfamethoxazole, 19.0%. Rates of resistance to non-β-lactam agents were higher among penicillin-resistant strains than among penicillin-susceptible strains. No resistance to vancomycin or linezolid was observed; however, 0.1% intermediate resistance to quinupristin-dalfopristin was observed. The rate of macrolide resistance (intermediate and resistant) increased from 7.9 to 11.1% over the 5 years. For the fluoroquinolones, the order of activity based on the MICs at which 50% of isolates are inhibited (MIC50s) and the MIC90s was gemifloxacin > clinafloxacin > trovafloxacin > moxifloxacin > grepafloxacin > gatifloxacin > levofloxacin > ciprofloxacin. The investigational compounds ABT-773 (MIC90, 0.008 μg/ml), ABT-492 (MIC90, 0.015 μg/ml), GAR-936 (tigecycline; MIC90, 0.06 μg/ml), and BMS284756 (garenoxacin; MIC90, 0.06 μg/ml) displayed excellent activities. Despite decreases in the rates of antibiotic consumption in Canada over the 5-year period, the rates of both high-level penicillin-resistant and multidrug-resistant S. pneumoniae isolates are increasing in Canada.


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%).


2007 ◽  
Vol 1 (03) ◽  
pp. 296-302 ◽  
Author(s):  
Abiola Senok ◽  
Mansour Al-Zarouni ◽  
Jalila Al-Najjar ◽  
Abeer Nublusi ◽  
Debadatta Panigrahi

Background: Streptococcus pneumoniae and Haemophilus influenzae represent key aetiological agents in respiratory tract infections showing an increasing trend of antimicrobial resistance. We present the first report on the antimicrobial resistance in S. pneumoniae and H. influenzae isolated from patients in the United Arab Emirates. Methods: One hundred S. pneumoniae and 102 H. influenzae strains were isolated from patients with community acquired respiratory tract infections during the study period (October 2004-March 2006). Susceptibility testing to a panel of antibiotics was conducted using disc diffusion and E test. Minimum inhibitory concentrations were interpreted using CLSI and Pharmacokineticpharmacodynamic (PK/PD) breakpoints. Results: For S. pneumoniae isolates, 57% were penicillin susceptible while 98% were susceptible to amoxicillin/clavulanate with both interpretative criteria. Cefaclor was the least effective cephalosporin with only 57% and 43% of isolates showing susceptibility with CLSI and PK/PD breakpoints respectively. Thirty-six isolates were ofloxacin non-susceptible (intermediate and resistant); three resistant isolates were associated with high ciprofloxacin MICs (>8mg/L). There was elevated macrolide resistance with associated high levels of erythromycin/clindamycin cross-resistance (n=22/30) suggesting predominant erm(B)-mediated resistance and 21% of isolates demonstrated multidrug resistance. For H. influenzae, 18% were beta-lactamase producers. Reduction in cefaclor and cefprozil susceptibility with PK/PD breakpoints (94.1% to 41.2% and 62.7% respectively) was seen and only 1% remained azithromycin and clarithomycin susceptible. For both pathogens, lowest susceptibility was with co-trimoxazole. Conclusion: These findings indicate a high level of penicillin resistance and continued usefulness of amoxicillin/clavulanate. Elevated macrolide and fluoroquinolone resistance and the occurrence of multidrug resistance indicate a need for continued surveillance.


2002 ◽  
Vol 59 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Claudine Zellweger ◽  
M. G. Täuber

Die Resistenzentwicklung unter den Pathogenen des Respirationstraktes hat in den letzten 10–20 Jahren weltweit stark zugenommen. Der weitverbreitete Einsatz von Antibiotika in der ambulanten Medizin hat wesentlich zur Ausbreitung der Antibiotikaresistenzen unter den wichtigsten Erregern von Atemwegsinfekten, nämlich Streptococcus pneumoniae, Haemophilus influenzae und Moraxella catarrhalis, beigetragen. Die Pneumokokken haben gegen die meisten für ihre Behandlung eingesetzten Antibiotika Resistenzen entwickelt. Dies betrifft neben den beta-Laktamen auch die Makrolide, die Lincosamide, Trimethoprim/Sulfamethoxazol sowie die Tetrazykline. Resistenzen gegen mehr als nur eine Antibiotikaklasse sind dabei häufig. Bei Haemophilus influenzae und Moraxella catarrhalis steht die beta-Laktamresistenz im Vordergrund. Nach Prüfung der Indikation zur antibiotischen Therapie einer Atemwegsinfektion ist die Kenntnis der lokalen Resistenzlage unabdingbare Voraussetzung für die Wahl einer sinnvollen und wirksamen empirischen Antibiotikatherapie.


1999 ◽  
Vol 43 (10) ◽  
pp. 2504-2509 ◽  
Author(s):  
George G. Zhanel ◽  
James A. Karlowsky ◽  
Lorraine Palatnick ◽  
Laverne Vercaigne ◽  
Donald E. Low ◽  
...  

ABSTRACT From October 1997 to November 1998, 1,180 respiratory tract isolates of Streptococcus pneumoniae were collected from 18 medical centers in 9 of the 10 Canadian provinces. Penicillin-intermediate and -resistant isolates occurred at rates of 14.8 and 6.4%, respectively, and these rates varied considerably by geographic region. Trimethoprim-sulfamethoxazole, tetracycline, and macrolide rates of nonsusceptibility were 12.2, 10.6, and 8.0 to 9.3%, respectively. The most potent agents studied were newer fluoroquinolones.


1996 ◽  
Vol 40 (4) ◽  
pp. 891-894 ◽  
Author(s):  
G V Doern ◽  
M J Ferraro ◽  
A B Brueggemann ◽  
K L Ruoff

Three hundred fifty-two blood culture isolates of viridans group streptococci obtained from 43 U.S. medical centers during 1993 and 1994 were characterized. Included were 48 isolates of "Streptococcus milleri," 219 S. mitis isolates, 29 S. salivarius isolates, and 56 S. sanguis isolates. High-level penicillin resistance (MIC, > or = 4.0 micrograms/ml) was noted among 13.4% of the strains; for 42.9% of the strains, penicillin MICs were 0.25 to 2.0 micrograms/ml (i.e., intermediate resistance). In general, amoxicillin was slightly more active than penicillin. The rank order of activity for five cephalosporins versus viridans group streptococci was cefpodoxime = ceftriaxone > cefprozil = cefuroxime > cephalexin. The percentages of isolates resistant (MIC, > or = 2 micrograms/ml) to these agents were 15, 17, 18, 20, and 96, respectively. The rates of resistance to erythromycin, tetracycline, and trimethoprim-sulfamethoxazole were 12 to 38%. Resistance to either chloramphenicol or ofloxacin was uncommon (i.e., < 1%). In general, among the four species, S. mitis was the most resistant and "S. milleri" was the most susceptible.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S577-S578
Author(s):  
Dee Shortridge ◽  
Jennifer M Streit ◽  
Michael D Huband ◽  
Robert K Flamm

Abstract Background Delafloxacin (DLX) is an anionic fluoroquinolone (FQ) antimicrobial that was approved in 2017 by the United States (US) Food and Drug Administration for the treatment of acute bacterial skin and skin structure infections. DLX recently successfully completed a clinical trial for the treatment of community-acquired bacterial pneumonia (CABP). In the present study, in vitro susceptibility (S) results for DLX and comparator agents were determined for CABP pathogens including Streptococcus pneumoniae (SPN), Haemophilus influenzae (HI), H. parainfluenzae (HP) and Moraxella catarrhalis (MC) clinical isolates from US hospitals participating in the SENTRY Program during 2014–2018. Methods A total of 1,975 SPN, 1,128 HI, 684 MC, and 43 HP isolates were collected from community-acquired respiratory tract infections (CARTI) during 2014–2018 from US hospitals. Sites included only 1 isolate/patient/infection episode. Isolate identifications were confirmed at JMI Laboratories. Susceptibility testing was performed according to CLSI broth microdilution methodology, and CLSI (2019) breakpoints were applied where applicable. Other antimicrobials tested included levofloxacin (LEV) and moxifloxacin (MOX; not tested in 2015). Multidrug-resistant (MDR) SPN isolates were categorized as being nonsusceptible (NS) to amoxicillin-clavulanate, erythromycin, and tetracycline; other SPN phenotypes were LEV-NS or penicillin (PEN)-NS. β-Lactamase (BL) presence was determined for HI, HP, and MC. Results The activities of the 3 FQs are shown in the table. The most active agent against SPN was DLX, with the lowest MIC50/90 values of 0.015/0.03 mg/L. DLX activities were similar when tested against the MDR or PEN-NS for SPN phenotypes. LEV-NS isolates had DLX MIC50/90 results of 0.12/0.25 mg/L. DLX was the most active FQ against HI, HP, and MC. BL presence did not affect FQ MIC values for HI or MC; only 2 HP isolates were BL-positive. Conclusion DLX demonstrated potent in vitro antibacterial activity against SPN, HI, HP, and MC. DLX was active against MDR SPN that were NS to the agents commonly used as treatments for CABP. DLX had excellent activity against LEV-NS SPN. These data support the continued study of DLX as a potential treatment for CABP. Disclosures All authors: No reported disclosures.


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