Antimicrobial susceptibility among Enterococcus isolates from the city of Porto Alegre, RS, Brazil

Abstract

Resistance to several classes of antimicrobial agents is a remarkable characteristic of enterococcal strains increasingly reported worldwide. Information about strains isolated in the southern region of Brazil is still limited. In this study, a total of 455 consecutive enterococcal isolates recovered from patients living in Porto Alegre, Brazil, were identified at species level and evaluated for their antimicrobial susceptibilities by agar diffusion testing. The most frequent species was E. faecalis (92.8%), followed by E. faecium (2.9%), E. gallinarum (1.5%), E. avium (1.1%), E. hirae (0.7%), E. casseliflavus (0.4%), E. durans (0.4%), and E. raffinosus (0.2%). According to the results of disk tests 62.0% of the strains were resistant to tetracycline, 42.6% to erythromycin, 24.8% to chloramphenicol, 22.6% to ciprofloxacin, 22.0% to norfloxacin, 3.5% to ampicillin, 3.5% to nitrofurantoin. High level resistance to aminoglycosides was found in 37.8% of the isolates, with 23.5% being resistant to gentamicin, 14.3% to streptomycin, and 2.8% to both gentamicin and streptomycin. No vancomycin resistant or b-lactamase producing isolates were found. The results indicate that a significant percentage of isolates are resistant to different antimicrobials, pointing out the need for control strategies to avoid dissemination of resistant isolates and for continuous surveillance for the detection of emerging resistance traits.

Antimicrobial resistance profiles of enterococci isolated from poultry meat and pasteurized milk in Rio de Janeiro, Brazil

“…When intermediate results are added, the percentages of isolates with decreased susceptibility to these antimicrobials were 38.3%, 82.0%, and 5.7%, respectively. These percentages of resistance are significant, while lower or occasionally comparable to those previously reported for enterococci recovered from human sources in Brazil (Mondino et al 2003, d'Azevedo et al 2004 ) and other locations (Lopes et al 2003). The observation of concomitant resistance to chloramphenicol, erythromycin, and tetracycline confirms the frequent resistance to multiple antibiotics among enterococcal isolates from humans sources in Brazil (Mondino et al 2003, Vilela et al 2006.…”

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

“…Regarding tetracycline, although the enterococci resistance rate decreased over time, it remained high in 2009 (57%), but was slightly lower than that reported by the SENTRY Program for Latin America (67.2%) 31 and by other Brazilian studies performed with clinical enterococci strains isolated in 1996 and 1997 (62%) 32 and in 2006 and 2007 (66.5%) 8 . Likewise, the resistance rates to erythromycin were very high, despite the significant decrease observed (95% to 80.6%), confirming that resistance to this drug is very common among enterococci 1,8,31,33 .…”

Occurrence of Multidrug-Resistant and Toxic-Metal Tolerant Enterococci in Fresh Feces from Urban Pigeons in Brazil

“…None of the isolated bacteria were resistant to penicillin and vancomycin, in agreement with scientific information available from Europe regarding E. faecalis isolated from pigs, chickens, humans and wild rabbits ( 1 , 2 , 38 , 42 ). However, in Brazil there are few reports of low β-lactam resistance in enterococci isolated from humans and animal products ( 8 , 13 , 16 ). The observed susceptibility to penicillins and glycopeptides might be a good outcome, since between these antimicrobial substances there are several compounds used to treat severe enterococci-related infections ( 8 , 13 ).…”