Genetic background of novel sequence types of CTX-M-8- and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae from public wastewater treatment plants in São Paulo, Brazil.

The release of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae to the environment is a public health issue worldwide. The aim of this study was to investigate the genetic background of genes encoding ESBLs in wastewater treatment plants (WWTPs) in São Paulo, southeastern Brazil. In 2009, during a local surveillance study, seven ESBL-producing Enterobacteriaceae strains were recovered from five WWTPs and screened for ESBL genes and mobile genetic elements.

Complex class 1 integrons harboring CTX-M-2-encoding genes in clinical Enterobacteriaceae from a hospital in Brazil.

Introduction: CTX-M enzymes are the most prevalent extended-spectrum beta-lactamases (ESBLs) in Brazil and around the world. The spread of CTX-M lies in their ability to be mobilized by insertion sequences and integrons. This study aimed to identify the mobile genetic structures associated with bla(CTX-M) genes from clinical Enterobacteriaceae strains.

Molecular and biochemical characterization of CTX-M-131, a natural Asp240Gly variant derived from CTX-M-2, produced by a Providencia rettgeri clinical strain in São Paulo, Brazil.

CTX-M-131 is a natural Asp240Gly variant from the CTX-M-2 group detected in a Providencia rettgeri clinical strain from Brazil. Molecular analysis showed that blaCTX-M-131 was inserted in a complex class 1 integron harbored by a 112-kb plasmid, which has not been previously described as a platform for CTX-M-encoding genes with the Asp240Gly mutation. Steady-state kinetic parameters showed that the enzyme has a typical cefotaximase catalytic profile and an enhanced activity against ceftazidime.

Presence of bla TEM-116 Gene in Environmental Isolates of Aeromonas Hydrophila and Aeromonas Jandaei from Brazil.

It is known that Aeromonas spp. possess different chromosomal β-lactamase genes. Presence and phenotypic expression of bla TEM, bla SHV, and bla CTX-M ESBL-encoding genes were investigated in environmental water isolates of Aeromonas hydrophila and Aeromonas jandaei.

Extended-spectrum beta-lactamases among Enterobacteriaceae isolated in a public hospital in Brazil.

Extended-spectrum beta-lactamases (ESBL) in enterobacteria are recognized worldwide as a great hospital problem. In this study, 127 ESBL-producing Enterobacteriaceae isolated in one year from inpatients and outpatients at a public teaching hospital at São Paulo, Brazil, were submitted to analysis by PCR with specific primers for bla SHV, bla TEM and bla CTX-M genes. From the 127 isolates, 96 (75.