Antimicrobial Resistance among Gram-Positive Bacteria Isolated in Latin American Hospitals

Abstract

Antimicrobial resistance patterns of the most frequently isolated Gram-positive bacteria in selected Latin American hospitals were evaluated under the auspices of the SENTRY Antimicrobial Surveillance Program. The strains were consecutively collected (one per patient) between January 2003 and December 2008 and tested by reference broth microdilution methods at the monitoring central laboratory (JMI Laboratories, North Liberty, Iowa, USA). A total of 12,324 Gram-positive cocci were analyzed. The organisms were isolated from bloodstream (53.2%) and skin and skin structure infections (16.4%). Resistance to oxacillin (MRSA) was observed in 40.0% of Staphylococcus aureus, varying from 32.7% in Brazil to 49.7% in Chile. Resistance to erythromycin (90.1%), clindamycin (84.4%), and levofloxacin (86.8%) was very high in MRSA. Vancomycin, linezolid and daptomycin were all very active against S. aureus strains tested (>99.9-100.0% susceptible), but daptomycin (MIC(50/90), 0.25/0.5 microg/ml) was four- to eight-fold more potent than three comparators. Vancomycin resistance increased from 5.0% in 2003 to 15.5% in 2008 among enterococci (VRE); the most significant increase occurred among isolates from Brazilian medical centers (from 6.9 to 31.1%). Daptomycin was the most active antimicrobial tested against enterococci in general (MIC(50/90) microg/ml; 100.0% susceptible), followed by linezolid (MIC(50/90), 1/2 microg/ml; 99.9% susceptible), teicoplanin (MIC(50 )and MIC(90 )of <2 microg/ml; 91.3% susceptible), vancomycin (MIC(50/90), 1/8 microg/ml; 89.6% susceptible). In summary, daptomycin and linezolid showed excellent in vitro activity against Gram-positive organisms (12,324) collected in Latin American hospitals, including MRSA, VRE and other multidrug-resistant organisms.

Current Trends of Emergence and Spread of Vancomycin-Resistant Enterococci

“…Results of a recent SENTRY study revealed a recognizable change of vancomycin resistance rates among clinical enterococcal isolates from participating Latin American countries/hospitals increasing from 5 to 15.5% within 6 years (between 2003 and 2008). The most significant increase was demonstrated for Brazil with VRE rates rising from 7 to 31% (Sader et al, 2009). Considering that the majority of enterococcal isolates is E. faecalis which mainly remained susceptible to vancomycin, the increase of vancomycin resistance among E. faecium isolates seems even more dramatic based on the numbers specified.…”

Trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital: a 4-year study

“…However, the authors did not identify the VRE species or genotypes 19 . According to more recent data from the SENTRY Program, the percentage of VRE in Brazil increased from 6.9% in 2003 to 31.1% in 2008 and the majority (68.5%) of these isolates were E. faecium 20 . These VRE rates are much higher than that observed in other Latin America countries and in our hospital.…”

Antibiotic Resistance in Staphylococcus aureus Strains Isolated from Blood Cultures

“…ARMed çalışmasında en düşük MRSA oranları Lübnan (% 12), Tunus (% 18) ve Fas'da (% 19); en yüksek MRSA oranları Ürdün (% 56), Kıbrıs (% 55) ve Mısır'da (% 52) saptanmış, Türkiye'deki direnç % 39 olarak bildirilmiştir (2) . SENTRY antimikrobial sürveyans çalışmasında 12,324 Gram pozitif suşun % 53'ü kan kültürün-den izole edilmiş ve metisilin direnci % 40 oranında gözlenmiştir (14) . Gales ve ark.…”

“…Sader ve ark. (14) MRSA izolatlarında eritromisin ve klindamisin direncini sırasıyla % 90 ve % 84 oranlarında saptamışdır.…”

“…Sader ve ark. (14) MRSA izolatlarında kinolon direncini % 87 olarak gözlemiştir. Çalışmamızda siprofloksasin direnci MRSA suş-larında % 81, MSSA suşlarında % 4 oranında saptanmıştır.…”