New variant of TEM-10 beta-lactamase gene produced by a clinical isolate of proteus mirabilis

Abstract

A clinical isolate of Proteus mirabilis was found to produce a new variant of the TEM-10 ␤-lactamase gene. This is the first report of TEM-10 production by P. mirabilis and the first report of extended-spectrum ␤-lactamase production by an isolate of this species recovered in the United States.The plasmid-mediated extended-spectrum ␤-lactamases (ESBLs) found among isolates of the family Enterobacteriaceae are recent derivatives of TEM-1, TEM-2, and SHV-1 ␤-lactamases. These enzymes have been reported to cause failures during treatment with extended-spectrum cephalosporins and aztreonam (3). Because ESBLs are most frequently produced by Klebsiella pneumoniae and Escherichia coli (3, 6, 7), it may seem to be cost-effective for laboratories to confine ESBL screening tests to these two species. This report concerns the production of a novel gene encoding the TEM-10 ␤-lactamase in an isolate of Proteus mirabilis from a patient at a hospital in which an ESBL-producing K. pneumoniae strain had been detected previously. Our findings suggest that other species of the family Enterobacteriaceae should also be considered as possible producers of ESBLs, even when ESBL-producing K. pneumoniae and E. coli have not been commonly encountered in an institution.P. mirabilis 177 was cultured from the urine (10 4 CFU/ml) and sputum of a 48-year-old female in the medical intensive care unit of the St. Louis University Health Sciences Center, St. Louis, Mo., on 27 February 1994. Antibiotic susceptibility tests with the Vitek GNS card (Biomérieux Vitek, Inc., St. Louis, Mo.) and Microscan MKD MIC microdilution test (Baxter Microscan, West Sacramento, Calif.) performed at the center indicated resistance to multiple antibiotics, including gentamicin, tobramycin, fluoroquinolones, trimethoprim-sulfamethoxazole, and, possibly, ceftazidime and aztreonam (Table 1). The isolate was susceptible to ceftazidime and aztreonam in the Vitek GNS card test but resistant by microdilution testing. However, the microdilution MICs were very difficult to ascertain because of the trailing endpoints. Thus, there was uncertainty about the accuracy of these results.ESBL screening tests were equivocal (three-dimensional test) or positive (double-disk test and Vitek experimental ESBL card) (4, 13, 16). A crude cell sonicate was analyzed for ␤-lactamase activity by isoelectric focusing and a spectrophotometric assay (17). Isoelectric focusing indicated production of a ␤-lactamase of pI 5.58 which cofocused with TEM-10 and TEM-26 and a second ␤-lactamase of pI 8.1 which was only detected when the sonicate was concentrated threefold. TEM-10, TEM-26, and the pI 5.58 enzyme hydrolyzed cefotaxime in a cefotaxime-isoelectric focusing overlay technique (17). In the spectrophotometric hydrolysis assay, the crude sonicate from P. mirabilis 177 hydrolyzed ceftazidime more rapidly than cefotaxime.On the assumption that the strain contained bla TEM , PCR was performed with primers that are complementary to nucleotides 165 to 182 and 1077 to 1092 (Sutcliffe numbering) (15)....

Extended-Spectrum β-Lactamases in the 21st Century: Characterization, Epidemiology, and Detection of This Important Resistance Threat

“…TEM-type ESBLs have been reported in genera of Enterobacteriaceae such as Enterobacter aerogenes, Morganella morganii, Proteus mirabilis, Proteus rettgeri, and Salmonella spp. (19,91,101,120,128,166). Furthermore, TEM-type ESBLs have been found in non-Enterobacteriaceae gram-negative bacteria.…”

Emerging Extended-Spectrum β-Lactamases in Proteus mirabilis

“…However, a progressive increase of ␤-lactam resistance, mediated by the production of acquired ␤-lactamases, has occurred in this species (5,7,9,10). Recently, extended-spectrum ␤-lactamases (ESBLs) active on expanded-spectrum cephalosporins have also started spreading in P. mirabilis, including most frequently TEM-type derivatives (3,5,6,11,13,19,(21)(22)(23) but also other enzymes of group 2be (2,4).…”

“…However, a progressive increase of ␤-lactam resistance, mediated by the production of acquired ␤-lactamases, has occurred in this species (5,7,9,10). Recently, extended-spectrum ␤-lactamases (ESBLs) active on expanded-spectrum cephalosporins have also started spreading in P. mirabilis, including most frequently TEM-type derivatives (3,5,6,11,13,19,(21)(22)(23) but also other enzymes of group 2be (2, 4).In this work a survey was carried out on ESBL production by P. mirabilis clinical isolates from an Italian hospital where increased resistance rates to expanded-spectrum cephalosporins, mediated by similar enzymes, were recently observed among other Enterobacteriaceae (18).␤-Lactam susceptibility and ␤-lactamase production in P. mirabilis isolates. During a 1-year period (February 1997 to January 1998), 282 consecutive nonduplicate P. mirabilis isolates were collected from inpatients at the S. Matteo I.R.C.C.S.…”

TEM-187, a New Extended-Spectrum β-Lactamase with Weak Activity in a Proteus mirabilis Clinical Strain

“…They emerged from the parental penicillinases TEM-1 and TEM-2 (1). Since the 1990s, different enzymes that combine novel substitutions leading to an ESBL pattern in Proteus mirabilis isolates such as TEM-10, TEM-24, TEM-52, TEM-72, TEM-87, and TEM-92 have been reported (2)(3)(4)(5)(6).…”