2012年12月2日 訊 /生物谷BIOON/ --近日,，一項來自錫耶納大學等處研究者的研究揭示了其在意大利分離出的綠膿桿菌菌株中發(fā)現(xiàn)的一種新型的細菌獲得性的金屬β內酰胺酶類,，名為FIM-1,，相關研究成果“FIM-1， a new acquired metallo-β-lactamase from a Pseudomonas aeruginosa clinical isolate from Italy”刊登于國際雜志Antimicrobial Agents and Chemotherapy上,。
綠膿桿菌是一種革蘭氏陰性機會致病菌,，其是醫(yī)院內常見的引發(fā)慢性感染和急性感染的致病菌，嚴重者可引發(fā)患者肺部功能衰竭以及纖維化囊腫,。獲得性的金屬β-內酰胺酶類（MBLs）是增加革蘭氏陰性致病菌耐藥性的主要決定因素,，其通常含有一個廣譜的β內酰胺類抗生素抗性，包括碳青霉烯類抗生素,。
這項研究中,，研究者發(fā)現(xiàn)了一種新型的MBL，名為FIM-1,。研究者從意大利一位血管移植感染病人機體中分離到了一株臨床的綠膿桿菌菌株,。FIM-1酶獲得性的MBLs家族中亞家族B1的一個成員，其與NDM酶類具有高度的相似性,。
研究者Gian Maria Rossolini說,，我們可以使用兩種色譜法從大腸桿菌中純化出蛋白質FIM-1，通過對純化出的蛋白質進行動力學參數(shù)分析,，可以揭示,，F(xiàn)IM-1具有廣譜的底物特異性，而且其更易于分解青霉素類以及碳青霉烯類抗生素,。但是不會對氨曲南進行分解,。
綠膿桿菌臨床菌株中分離出的新型MBL對于研究者了解細菌耐藥性、耐藥性的多樣性及日益增加的耐藥性可以提供幫助,，而且開發(fā)新型地抵御耐藥細菌的療法也提供了希望和研究基礎。（生物谷Bioon.com）
doi:10.1128/AAC.01953-12
PMC:
PMID:
FIM-1, a new acquired metallo-β-lactamase from a Pseudomonas aeruginosa clinical isolate from Italy
Simona Pollinia, Simona Maradeia, Patrizia Pecileb, Giuseppe Olivoc, Francesco Luzzarod, Jean-Denis Docquiera and Gian Maria Rossolinia,e,#
Acquired metallo-β-lactamases (MBLs) are resistance determinants of increasing clinical importance in Gram-negative bacterial pathogens, which confer a broad-spectrum β-lactam resistance including carbapenems. Several such enzymes have been described since the 1990s. In this work a novel acquired MBL, named FIM-1, was identified and characterized. The blaFIM-1 gene was cloned from a multidrug-resistant Pseudomonas aeruginosa clinical isolate (FI-14/157) cultured from a patient with a vascular graft infection in Florence, Italy. The isolate belonged in the sequence type 235 epidemic clonal lineage. The FIM-1 enzyme is a member of subclass B1 and, among acquired MBLs, exhibited the highest similarity (around 40% amino acid identity) with NDM-type enzymes. In P. aeruginosa FI-14/157 the blaFIM-1 gene was apparently inserted into the chromosome and associated with ISCR19-like elements that were likely involved in the capture and mobilization of this MBL gene. Transfer experiments of the blaFIM-1 gene to an Escherichia coli or another P. aeruginosa strain by conjugation or electrotransformation were not successful. The FIM-1 protein was produced in Escherichia coli and purified by two chromatography steps. Analysis of the kinetic parameters, carried out with the purified enzyme, revealed that FIM-1 has a broad substrate specificity, with preference for penicillins (except the 6α-methoxy derivative temocillin) and carbapenems. Aztreonam was not hydrolyzed. Detection of this novel type of acquired MBL in a P. aeruginosa clinical isolate underscores the increasing diversity of such enzymes that can be encountered in the clinical setting.
