Biochemical characterization of PER-2 and genetic environment of blaPER-2.
PER-2 was the first detected and the second most prevalent extended-spectrum beta-lactamase in clinical pathogens isolated in Argentina and was also reported only in other South American countries. Citrobacter freundii 33587 was isolated in 1999 in Buenos Aires and was resistant to all tested beta-lactams except cephamycins and carbapenems. The strain produced both plasmid-borne TEM-1 and PER-2 (pI 5.4), which could be transferred by conjugation. By PCR screening, thermal asymmetric interlaced PCR, and DNA sequencing, we detected an ISPa12/IS1387a insertion sequence upstream of bla(PER-2), previously reported as also being associated with bla(PER-1). The presence of similar structures upstream of bla(PER-1) and bla(PER-2) suggests a common origin and mobilization. Compared to bla(PER-1) genes, an additional putative promoter for bla(PER-2) was found. PER-2 kinetic analysis showed its high hydrolysis efficiencies toward both CTX and CAZ (k(cat)/K(m), 0.76 and 0.43 microM(-1).s(-1), respectively).
Power
Pablo
P
Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Di Conza
José
J
Rodríguez
María Margarita
MM
Ghiglione
Bárbara
B
Ayala
Juan A
JA
Casellas
José María
JM
Radice
Marcela
M
Gutkind
Gabriel
G
D000595:Amino Acid Sequence; D001483:Base Sequence; D002384:Catalysis; D016971:Citrobacter freundii / Q000235:genetics / Q000302:isolation & purification; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004274:DNA, Recombinant; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000302:isolation & purification; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D006868:Hydrolysis; D007525:Isoelectric Focusing; D007700:Kinetics; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D021382:Protein Sorting Signals; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D004269:DNA, Bacterial; D004274:DNA, Recombinant; D021382:Protein Sorting Signals; C509814:beta-lactamase PER-2, Enterobacteriaceae; D001618:beta-Lactamases