title: Dissemination and diversity of metallo-beta-lactamases in Latin America: report from the SENTRY Antimicrobial Surveillance Program.
abstract: Carbapenem resistance among Pseudomonas aeruginosa and Acinetobacter spp. is becoming a critical therapeutic problem worldwide. The SENTRY Antimicrobial Surveillance Program monitors pathogen frequency and antimicrobial resistance patterns of nosocomial and community-acquired infections through sentinel hospitals on five continents. Pseudomonas spp. and Acinetobacter spp. strains resistant to imipenem (MIC, >/=16 mg/l), meropenem (MIC, >/=16 mg/l), and ceftazidime (MIC, >/=32 mg/l) collected from January 2001 to December 2003 were routinely screened for antimicrobial resistance genes. Resistant isolates were initially tested for metallo-beta-lactamase (MbetaL) production by phenotypic tests (disk approximation or MbetaL Etest strip) and then characterization of the MbetaL (hydrolysis assays, PCR for bla(IMP), bla(VIM), bla(SPM), gene sequencing). Eighty-nine isolates (33 Acinetobacter spp., 54 Pseudomonas aeruginosa, and 2 P. fluorescens) had positive phenotypic screening tests. Among those, 34 isolates producing MbetaL were identified, including 7 Acinetobacter spp., 25 P. aeruginosa and 2 P. fluorescens. The MbetaLs identified were IMP-1, VIM-2 and two newly described enzymes: SPM-1 and IMP-16. The greatest concentration of MbetaL strains was in Brazil, where imipenem-resistant P. aeruginosa increased significantly in the time period evaluated by the SENTRY Program. MbetaL-producing P. aeruginosa was detected in São Paulo (SPM-1) and Brasilia (SPM-1 and IMP-16), Brazil and Caracas, Venezuela (VIM-2); while MbetaL-producing Acinetobacter spp. isolates were detected in São Paulo, Brazil (IMP-1). P. fluorescens isolates producing IMP-1 and VIM-2 were detected in São Paulo, Brazil and Santiago, Chile, respectively. The emergence and dissemination of mobile MbetaL-producing isolates represent an alarming factor for increasing resistance to carbapenems in several medical centres evaluated by the SENTRY Program in Latin America.
authors.affiliation: The JONES Group/JMI Laboratories, 345 Beaver Kreek Centre, Suite A, North Liberty, IA, USA. helio-sader@jmilabs.com
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.forename: Mariana
authors.initials: M
authors.lastname: Castanheira
authors.forename: Rodrigo E
authors.initials: RE
authors.lastname: Mendes
authors.forename: Mark
authors.initials: M
authors.lastname: Toleman
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Walsh
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000201:enzymology; D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007843:Latin America / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000201:enzymology; D021521:Ribotyping; D018571:Sentinel Surveillance; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000145:classification* / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D015378:Imipenem; D001618:beta-Lactamases