Antimicrobial resistance of Streptococcus pneumoniae and Haemophilus influenzae in Sao Paulo, Brazil from 1996 to 2000.

This study was undertaken to assess the in vitro activity of several antimicrobial agents against Brazilian isolates of Streptococcus pneumoniae and Haemophilus influenzae from 1996 to 2000. The antibiotics used were penicillin, amoxicillin/clavulanic acid (A/C), ampicillin, amoxicillin, cefaclor, cefdinir, cefixime, cefprozil, ceftriaxone, cefuroxime, azithromycin, clarithromycin, erythromycin, ciprofloxacin, levofloxacin, ofloxacin, chloramphenicol, clindamycin, doxycycline and trimethoprim/sulphamethoxazole (T/S). MICs were determined by the National Committee for Clinical Laboratory Standards (NCCLS) method and interpreted using NCCLS and PK/PD breakpoints. For S. pneumoniae 80.0% were penicillin susceptible, 18.3% intermediate, 1.7% resistant; most active agents were amoxicillin, A/C, ceftriaxone and levofloxacin; T/S was the least active agent. Beta-lactamase was produced by 13.7% of H. influenzae. All were susceptible to A/C, cefdinir, cefixime, ceftriaxone and quinolones. The least active agents were T/S and macrolides.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000).

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000)

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1 percent) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3 percent) were penicillin-resistant and 79 (15.3 percent) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5 percent) and erythromycin (31.2 percent) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9 percent) produced b-lactamase, ranging from 11 percent (Brazil) to 24.5 percent (Mexico). Among M. catarrhalis isolates, 138 (98.6 percent) produced b-lactamase. Twenty-four (8.7 percent) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5 percent of the S. aureus isolates (Argentina 15 percent; Mexico 20 percent; Brazil 31.3 percent). Telithromycin was effective against 97.7 percent of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy