Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Bench-to-bedside review: The role of β-lactamases in antibiotic-resistant Gram-negative infections. | Bush Critical Care 2010 14 224 http content 14 3 224 CRITICAL CARE REVIEW L_ Bench-to-bedside review The role of p-lactamases in antibiotic-resistant Gram-negative infections Karen Bush Abstract Multidrug resistance has been increasing among Gram-negative bacteria and is strongly associated with the production of both chromosomal- and plasmid-encoded p-lactamases whose number now exceeds 890. Many of the newer enzymes exhibit broad-spectrum hydrolytic activity against most classes of p-lactams. The most important plasmid-encoded p-lactamases include a AmpC cephalosporinases produced in high quantities b the expanding families of extended-spectrum p-lactamases such as the CTX-M enzymes that can hydrolyze the advanced-spectrum cephalosporins and monobactams and c carbapenemases from multiple molecular classes that are responsible for resistance to almost all p-lactams including the carbapenems. Important plasmid-encoded carbapenemases include a the KPC p-lactamases originating in Klebsiella pneumoniae isolates and now appearing worldwide in pan-resistant Gram-negative pathogens and b metallo-p-lactamases that are produced in organisms with other deleterious p-lactamases causing resistance to all p-lactams except aztreonam. p-Lactamase genes encoding these enzymes are often carried on plasmids that bear additional resistance determinants for other antibiotic classes. As a result some infections caused by Gramnegative pathogens can now be treated with only a limited number if any antibiotics. Because multidrug resistance in Gram-negative bacteria is observed in both nosocomial and community isolates eradication of these resistant strains is becoming more difficult. Introduction Much has been publicized recently about the expansion of hospital- and community-based infections caused by Correspondence karbush@ Department of Biology Indiana University Jordan Hall A311 Bloomington IN 47405 USA 2 BioMed Central 2010 BioMed Central Ltd .
