Abstract The mechanisms involved in the uncommon resistance phenotype, carbapenem resistance and broad-spectrum cephalosporin susceptibility, were investigated in 25 Pseudomonas aeruginosa clinical isolates that exhibited this phenotype, which were recovered from three different hospitals located in São Paulo, Brazil. The antimicrobial susceptibility profile was determined by CLSI broth microdilution. β-lactamase-encoding genes were investigated by PCR followed by DNA sequencing. Carbapenem hydrolysis activity was investigated by spectrophotometer and MALDI-TOF assays. The mRNA transcription level of oprD was assessed by qRT-PCR and the outer membrane proteins profile was evaluated by SDS-PAGE. Genetic relationship among P. aeruginosa isolates was assessed by PFGE. Carbapenems hydrolysis was not detected by carbapenemase assay in the carbapenem-resistant and cephalosporin-susceptible P. aueruginosa clinical isolates. OprD decreased expression was observed in all P. aeruginosa isolates by qRT-PCR. The outer membrane protein profile by SDS-PAGE suggested a change in the expression of the 46 kDa porin that could correspond to OprD porin. The isolates were clustered into 17 genotypes without predominance of a specific PFGE pattern. These results emphasize the involvement of multiple chromosomal mechanisms in carbapenem-resistance among clinical isolates of P. aeruginosa, alert for adaptation of P. aeruginosa clinical isolates under antimicrobial selective pressure and make aware of the emergence of an uncommon phenotype among P. aeruginosa clinical isolates.

Infections due to multidrug-resistant organisms continue to increase, and therapeutic options remain scarce. Given this challenge, it has become necessary to use older antimicrobials for treatment of these pathogens. We report three patients with lower urinary tract infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae who were successfully treated with a seven-day course of oral fosfomycin monotherapy.

Non cholera Vibrio may cause conjunctivitis, wound infection, gastroenteritis and serious sepsis. Transmission to men is through contact with skin, mucosa or wounds exposed to marine water, and consumption of certain barely cooked or raw seafood, more frequently in the summer. This is one of the first cases of severe infection related to Vibrio vulnificus described in Brazil. The patient was an old man, who ingested seafood in Guarujá, a seashore city near São Paulo, 3 days before hospitalization. He was admitted to the emergency room in an ill state with septic shock. On 2 sets of blood culture a highly virulent microorganism was isolated, Vibrio vulnificus, which leads to sepsis and frequently to death in susceptible patients. The objective of this report was to use this case to discuss clinical aspects, microbiological diagnosis and treatment of the infection caused by this agent, besides the review of epidemiology, associated risk factors and prevention before consuming or getting in contact with seafood, especially in patients with greater susceptibility to this kind of infection.