Susceptibility to several β-lactams and β-lactamase production was investigated in a collection of 20 strains of Pseudomonas otitidis, a new Pseudomonas species that has been recently recognized in association with otic infections in humans. All strains appeared to be susceptible to piperacillin, cefotaxime, ceftazidime, and aztreonam, while resistance or decreased susceptibility to carbapenems was occasionally observed. All strains were found to express metallo-β-lactamase (MBL) activity and to carry a new subclass B3 MBL gene, named bla(POM), that appeared to be highly conserved in this species. P. otitidis, therefore, is the first example of a pathogenic Pseudomonas species endowed with a resident MBL. The POM-1 protein from P. otitidis type strain MCC10330 exhibits the closest similarity (60 to 64%) to the L1 MBL of Stenotrophomonas maltophilia. Expression in Escherichia coli and Pseudomonas aeruginosa revealed that, similar to L1 and other subclass B3 MBLs, POM-1 confers decreased susceptibility or resistance to carbapenems, penicillins, and cephalosporins but not to aztreonam. Expression of the POM MBL in P. otitidis is apparently constitutive and, in most strains, does not confer a carbapenem-resistant phenotype. However, a strong inoculum size effect was observed for carbapenem MICs, and carbapenem-resistant mutants could be readily selected upon exposure to imipenem, suggesting that carbapenem-based regimens should be considered with caution for P. otitidis infections.

Thaller, M.c., Borgianni, L., DI LALLO, G., Chong, Y., Lee, K., Dajcs, J., et al. (2011). Metallo-beta-lactamase production by Pseudomonas otitidis: a species-related trait. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 55(1), 118-123 [10.1128/AAC.01062-10].

Metallo-beta-lactamase production by Pseudomonas otitidis: a species-related trait

THALLER, MARIA CRISTINA;DI LALLO, GUSTAVO;
2011-01-01

Abstract

Susceptibility to several β-lactams and β-lactamase production was investigated in a collection of 20 strains of Pseudomonas otitidis, a new Pseudomonas species that has been recently recognized in association with otic infections in humans. All strains appeared to be susceptible to piperacillin, cefotaxime, ceftazidime, and aztreonam, while resistance or decreased susceptibility to carbapenems was occasionally observed. All strains were found to express metallo-β-lactamase (MBL) activity and to carry a new subclass B3 MBL gene, named bla(POM), that appeared to be highly conserved in this species. P. otitidis, therefore, is the first example of a pathogenic Pseudomonas species endowed with a resident MBL. The POM-1 protein from P. otitidis type strain MCC10330 exhibits the closest similarity (60 to 64%) to the L1 MBL of Stenotrophomonas maltophilia. Expression in Escherichia coli and Pseudomonas aeruginosa revealed that, similar to L1 and other subclass B3 MBLs, POM-1 confers decreased susceptibility or resistance to carbapenems, penicillins, and cephalosporins but not to aztreonam. Expression of the POM MBL in P. otitidis is apparently constitutive and, in most strains, does not confer a carbapenem-resistant phenotype. However, a strong inoculum size effect was observed for carbapenem MICs, and carbapenem-resistant mutants could be readily selected upon exposure to imipenem, suggesting that carbapenem-based regimens should be considered with caution for P. otitidis infections.
gen-2011
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore MED/07 - MICROBIOLOGIA E MICROBIOLOGIA CLINICA
Settore BIO/19 - MICROBIOLOGIA GENERALE
English
Con Impact Factor ISI
Pseudomonas; beta-Lactamases; Phylogeny; Microbial Sensitivity Tests; Sequence Homology, Amino Acid; Molecular Sequence Data; Bacterial Proteins; Carbapenems; Amino Acid Sequence; Anti-Bacterial Agents; Drug Resistance, Bacterial
Thaller, M.c., Borgianni, L., DI LALLO, G., Chong, Y., Lee, K., Dajcs, J., et al. (2011). Metallo-beta-lactamase production by Pseudomonas otitidis: a species-related trait. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 55(1), 118-123 [10.1128/AAC.01062-10].
Thaller, Mc; Borgianni, L; DI LALLO, G; Chong, Y; Lee, K; Dajcs, J; Stroman, D; Rossolini, G
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/9736
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