Abstract The modified Carba NP test presented here may be a valuable tool for laboratories interested in investigating a large number of carbapenemase-producing bacteria in a less-costly way. The test was evaluated against 48 carbapenemase-producing and carbapenemase-non-producing gram-negative bacteria. No false–positive results were obtained, but false-negative results were observed with OXA-23- and GES-carbapenemase-producing isolates. Aeromonas sp. are not testable by Modified Carba NP.

This study provides the first description of healthcare-associated infections with Escherichia coli clonal group A (CgA) isolates in Latin America. Isolates were typed by enterobacterial repetitive intergenic consensus-PCR, pulsed-field gel electrophoresis, E. coli phylogenetic grouping, multilocus sequence typing and fimH single nucleotide polymorphism analysis. Out of 42 E. coli hospital isolates studied, three belonged to E. coli phylogenetic group D and ST69 and had fimH sequences identical to that of the CgA reference strain ATCC BAA-457. E. coli CgA is another potential source of resistant infections in hospitals.

Previous analysis of Pseudomonas aeruginosa class-1 integrons from Rio de Janeiro, Brazil, revealed the blaGES gene in one isolate. We screened isolates of two widespread PFGE genotypes, A and B, at a public hospital in Rio, for the presence of blaGES. The gene was detected in all seven P. aeruginosa isolates belonging to genotype B. Three of the seven genotype-B isolates were resistant to amikacin, aztreonam, ceftazidime, cefepime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin-tazobactam and ticarcillin-clavulanic acid. The other four isolates were resistant to all these agents, except gentamicin, imipenem, meropenem and piperacillin-tazobactam. A synergistic effect between ceftazidime and imipenem or clavulanic acid suggested the production of GES-type ESBL.