NDM-1 廣泛抗藥性腸道菌介紹

Introduction to New Delhi Metallo-β- lactamase 1 (NDM-1)

「NDM-1超級細菌」因媒體大幅報導引起國人重視，其實NDM-1並非指某特定細菌，而是一種廣泛性抗藥基因，擁有該抗藥性基因的細菌對包含carbapenem在內的所有beta-lactam抗生素都有抗藥性，一旦感染，可以選擇的治療藥物有限，所以不管對醫療照護或是公共衛生都有重大影響。NDM-1位於細菌質體上，它可以在不同細菌間藉由接合傳遞，目前主要帶有NDM-1的致病菌仍以革蘭氏陰性腸道桿菌為主。在印度與巴基斯坦等NDM-1高度流行區域的醫療院所，甚至在環境中如公共飲用水，都已發現有NDM-1抗藥細菌存在，此抗藥基因也已證實由此區域散佈至世界多個國家。在臨床實務上，當患者檢出對carbapenem抗藥的腸道桿菌時，必須詢問是否有該區域的旅行史，高度警覺細菌攜帶NDM-1的可能性，即時採取適當的感控措施並通報衛生主管機關。在平時也必須養成正確使用抗生素的習慣，降低抗生素篩選壓力以減少抗藥性細菌產生。

The report of New Delhi Metallo-β-lactamase 1 (NDM-1) in a medical journal raised great public concern of a “superbug” with multiple drug resistance. NDM-1 does not refer to a single bacterial species, but rather a transmissible genetic element that encodes resistance to nearly all beta-lactam antibiotics, including carbapenem. Therefore, limited therapeutic choices are available for the management of infections caused by NDM-1 strains. NDM-1 can be carried on plasmids in bacteria, and are transmissible between different bacterial species via conjugation. India and Pakistan are the most prevalent areas for NDM-1 strains. The emerging strains not only exist in health care facilities, but also widely spread throughout the community in these areas. Identification of strains carrying NDM-1 has also been reported in several other countries. It is crucial for clinicians dealing with carbapenem-resistant Enterobacteriaceae infections to obtain travel history to endemic areas. Prompt recognition of the NDM-1 strains and adequate control measures will be the keys to successful control of these frightening bacteria. In addition, judicious use of antibiotics to reduce selection pressure remains one of the most effective ways to prevent the emergence of resistant bacteria.