OBJECTIVES: To characterize the naturally occurring β-lactamase gene identified from a clinical isolate belonging to a novel enterobacterial species that is closely related to Rahnella spp. and Ewingella spp. METHODS: Shotgun cloning and expression in Escherichia coli were performed in order to characterize this resistance determinant. Enzymatic activities were measured by UV spectrophotometry after an ion-exchange chromatography purification procedure. RESULTS: A chromosomal gene coding for the extended-spectrum β-lactamase (ESBL) SMO-1 was identified from a novel enterobacterial species that is taxonomically related to Rahnella aquatilis and Ewingella americana. The β-lactamase efficiently hydrolysed penicillins and cefotaxime, and shared 75% amino acid identity with the plasmid-mediated β-lactamase SFO-1 from Serratia fonticola, 74% amino acid identity with the plasmid-mediated ESBL CTX-M-2 originating from Kluyvera spp. and 72% amino acid identity with the chromosomally encoded and intrinsic RAHN-1 from R. aquatilis. CONCLUSIONS: We have identified a novel enterobacterial species recovered from a clinical specimen, constituting another potential source of acquired ESBL. The ESBL shared significant similarities with the CTX-M-type enzymes.
OBJECTIVES: To characterize the naturally occurring β-lactamase gene identified from a clinical isolate belonging to a novel enterobacterial species that is closely related to Rahnella spp. and Ewingella spp. METHODS: Shotgun cloning and expression in Escherichia coli were performed in order to characterize this resistance determinant. Enzymatic activities were measured by UV spectrophotometry after an ion-exchange chromatography purification procedure. RESULTS: A chromosomal gene coding for the extended-spectrum β-lactamase (ESBL) SMO-1 was identified from a novel enterobacterial species that is taxonomically related to Rahnella aquatilis and Ewingella americana. The β-lactamase efficiently hydrolysed penicillins and cefotaxime, and shared 75% amino acid identity with the plasmid-mediated β-lactamase SFO-1 from Serratia fonticola, 74% amino acid identity with the plasmid-mediated ESBL CTX-M-2 originating from Kluyvera spp. and 72% amino acid identity with the chromosomally encoded and intrinsic RAHN-1 from R. aquatilis. CONCLUSIONS: We have identified a novel enterobacterial species recovered from a clinical specimen, constituting another potential source of acquired ESBL. The ESBL shared significant similarities with the CTX-M-type enzymes.
Authors: Sebastián Klinke; Pablo Power; Barbara Ghiglione; María Margarita Rodríguez; Florencia Brunetti; Krisztina M Papp-Wallace; Ayumi Yoshizumi; Yoshikazu Ishii; Robert A Bonomo; Gabriel Gutkind Journal: Antimicrob Agents Chemother Date: 2021-03-18 Impact factor: 5.191
Authors: Windy D Tanner; James A VanDerslice; Ramesh K Goel; Molly K Leecaster; Mark A Fisher; Jeremy Olstadt; Catherine M Gurley; Anderson G Morris; Kathryn A Seely; Leslie Chapman; Michelle Korando; Kalifa-Amira Shabazz; Andrea Stadsholt; Janice VanDeVelde; Ellen Braun-Howland; Christine Minihane; Pamela J Higgins; Michelle Deras; Othman Jaber; Dee Jette; Adi V Gundlapalli Journal: Sci Rep Date: 2019-03-08 Impact factor: 4.379