Proficiency in detecting vancomycin resistance in enterococci among clinical laboratories in Santiago, Chile.
To the Editor: Vancomycin-resistant enterococci enterococci
bacteria in the genus Enterococcus. (VRE VRE
VRE Vancomycin-resistent enterococcus, see there ) can be difficult to detect because of limitations in the susceptibility testing methods commonly used in clinical laboratories. Although VRE have not been reported in Chile, clinical isolates have been reported in Argentina (1) and Brazil (2). It is important to detect vancomycin vancomycin (văn'kōmī`sĭn), antibiotic resembling penicillin in the way it acts. It is derived from the bacterium Streptomyces orientalis, which was isolated from soil of India and Indonesia. resistance as early as possible, so infection control preventive measures can be instituted when they have their greatest impact. The microbiology laboratory is the first line of defense against VRE, as it plays a critical role in its recognition. In Chi]e, most laboratories follow the National Committee for Clinical Laboratory Standards recommendations for antimicrobial susceptibility testing and use disk-diffusion methods (3); however, these methods have limitations in detecting low levels of resistance to vancomycin in enterococci.
We evaluated the ability of referral microbiology laboratories in Chile to detect vancomycin resistance in five Enteroccocus spp. isolates with different susceptibility patterns for vancomycin, penicillin, and ampicillin ampicillin (ăm'pĭsĭl`ĭn), a penicillin-type antibiotic that is effective against both gram-negative microorganisms and gram-positive microorganisms such as Escherichia coli. . Of six referral laboratories that agreed to participate, four used the disk-diffusion method to evaluate antimicrobial susceptibility. Two used an agar dilution minimum inhibitory concentration minimum inhibitory concentration Lab medicine The minimum antibiotic concentration needed to inhibit bacterial growth from a clinical isolate–eg, a bloodborne infection, which is a form of antimicrobial susceptibility testing. Cf Minimum bactericidal concentration. (MIC) method, one as the only susceptibility testing method and the other in addition to disk diffusion. The participants correctly evaluated vancomycin susceptibility in 17 (57%) of 30 isolates.
The accuracy of detecting vancomycin resistance varied according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. the level of resistance. Isolate 1, which had a high level of resistance (Van A phenotype, MIC 256 [micro]g/ml), was evaluated correctly in 5 (83%) of 6 laboratories. Isolate 2, with a lower level of resistance (Van B, MIC 64 [micro]g/ml), was evaluated correctly in 4 (67%) of 6 laboratories. Isolates 3 and 4, both with intermediate resistance (Van B, MIC 16-32 [micro]g/ml, and Van C, MIC 8 [micro]g/ml, respectively), were evaluated correctly by one laboratory each. Isolate 5 (vancomycin susceptible) was evaluated correctly by all laboratories. Susceptibility to penicillin and ampicillin was correctly identified in 53 (96.4%) of 55 isolates. Although laboratories correctly identified E. faecium and E. faecalis to the species level, most (4 of 5) did not correctly identify E. gallinarum (three misidentified it as E. casseliflavus and one as E. faecalis).
The results of this study are consistent with those of previous studies in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. (4,5), South America South America, fourth largest continent (1991 est. pop. 299,150,000), c.6,880,000 sq mi (17,819,000 sq km), the southern of the two continents of the Western Hemisphere. (6), Spain (7), and Mexico (8). Although in countries like Chile, disk diffusion is practical and reliable for most susceptibility testing, detecting low-level vancomycin resistance in enterocci is difficult without supplementary testing. In Chile, as in other countries, strategies should be implemented to improve detection of these strains, including improvement of phenotypical and genotypical methods for VRE detection and species identification. Documentation of proficiency in detecting VRE is important for improving laboratory performance, detecting clinical isolates, and accurate and reliable reporting to local, national, and international surveillance systems.
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(7.) Alonso-Echanove J, Robles Robles is a common surname in the Spanish language meaning oaks, and may refer to:
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Jaime A. Labarca,(*) L. Clifford McDonald,([dagger]) Maria Eugenia Pinto,([double dagger]) Elizabeth Palavecino,(*)([double dagger]) Patricia Gonzalez,([double dagger]) Erna Cona,([double dagger]) Alejandra Fernandez,([double dagger]) Maria Soledad Giglio,([double dagger]) and William R. Jarvis([dagger])
(*) P. Universidad Catolica de Chile, Santiago, Chile; ([dagger]) Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. , Atlanta, Georgia, USA; and ([double dagger]) Chilean Society for Infectious Diseases, Santiago, Chile