Extended-spectrum cephalosporins (ESCs) are critically important antibiotics for humans and their use in animals poses a potential threat for public health. Chicken represents an increasing part of the human diet and has also been regarded as a source of ESC-resistant Enterobacteriaceae because of the worldwide off-label use of ceftiofur, a broad-spectrum cephalosporin. Thus, numerous studies pointed out chicken as a reservoir of ESBL/pAmpC genes, plasmids and/or clones at risk for humans. In France, late 2011, strong political pressure led to a drastic reduction of ceftiofur use and all other antibiotics in chicken production. Here, we ascertained the potential impact of those efforts on the prevalence of ESC-resistant E. coli in retail chicken. From October 2015 to January 2016, of 48 unrelated pieces of meat (chicken legs) belonging to four different brands, 44 (91.7%) were positive for ESC-resistant E. coli. The bla gene was highly prevalent (68/74, 91.9%), mostly located on IncI1/ST3 plasmids (65/68, 95.6%). Other ESBL/pAmpC genes (bla, bla, bla) were carried by IncX1, IncI1/ST36, IncI1/ST95, IncA/C or IncK plasmids. The positive isolates were non-clonal, suggesting a horizontal spread of the ESBL/pAmpC genes. Obviously, the strong decrease of antimicrobial use in chicken farms had no impact yet on the ESBL/pAmpC prevalence in retail chicken meat in France. A human source of these ESBL/pAmpC genes is unlikely as bla IncI1/ST3 plasmids are dominant in animals and rare in humans. Our data question the real impact of the decrease of antimicrobial use in chicken production on ESBL contamination of chicken meat and point out the risk of ESBL/AmpCs human transfer through the food chain.

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BackgroundNosocomial infections caused by Pseudomonas aeruginosa presenting resistance to beta-lactam drugs are one of the most challenging targets for antimicrobial therapy, leading to substantial increase in mortality rates in hospitals worldwide. In this context, P. aeruginosa harboring acquired mechanisms of resistance, such as production of metallo-beta-lactamase (MBLs) and extended-spectrum beta-lactamases (ESBLs) have the highest clinical impact. Hence, this study was designed to investigate the presence of genes codifying for MBLs and ESBLs among carbapenem resistant P. aeruginosa isolated in a Brazilian 720-bed teaching tertiary care hospital.MethodsFifty-six carbapenem-resistant P. aeruginosa strains were evaluated for the presence of MBL and ESBL genes. Strains presenting MBL and/or ESBL genes were submitted to pulsed-field gel electrophoresis for genetic similarity evaluation.ResultsDespite the carbapenem resistance, genes for MBLs (blaSPM-1 or blaIMP-1) were detected in only 26.7% of isolates. Genes encoding ESBLs were detected in 23.2% of isolates. The blaCTX-M-2 was the most prevalent ESBL gene (19.6%), followed by blaGES-1 and blaGES-5 detected in one isolate each. In all isolates presenting MBL phenotype by double-disc synergy test (DDST), the blaSPM-1 or blaIMP-1 genes were detected. In addition, blaIMP-1 was also detected in three isolates which did not display any MBL phenotype. These isolates also presented the blaCTX-M-2 gene. The co-existence of blaCTX-M-2 with blaIMP-1 is presently reported for the first time, as like as co-existence of blaGES-1 with blaIMP-1.ConclusionsIn this study MBLs production was not the major mechanism of resistance to carbapenems, suggesting the occurrence of multidrug efflux pumps, reduction in porin channels and production of other beta-lactamases. The detection of blaCTX-M-2,blaGES-1 and blaGES-5 reflects the recent emergence of ESBLs among antimicrobial resistant P. aeruginosa and the extraordinary ability presented by this pathogen to acquire multiple resistance mechanisms. These findings raise the concern about the future of antimicrobial therapy and the capability of clinical laboratories to detect resistant strains, since simultaneous production of MBLs and ESBLs is known to promote further complexity in phenotypic detection. Occurrence of intra-hospital clonal dissemination enhances the necessity of better observance of infection control practices.

The survival of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella was studied in apple, orange, pineapple, and white grape juice concentrates and banana puree. Pouches of juice concentrate or puree were inoculated with pathogens at a level > or = 10(3) CFU/g and stored at -23 degrees C (-10 degrees F). Pathogen survival was monitored at 6 and 24 h, once a week for four consecutive weeks, and biweekly thereafter until 12 weeks. When pathogens were not detectable by direct plating, samples were enriched in universal preenrichment broth for 72 h and plated on selective media. Results showed that E. coli O157:H7, L. monocytogenes, and Salmonella were recoverable from all five concentrates through 12 weeks of storage at -23 degrees C.

RNA interference (RNAi) is a process that is induced by double stranded RNA and involves the degradation of specific sequences of mRNA in the cytoplasm of the eukaryotic cells. It has been used as an antiviral tool against many viruses, including flaviviruses. The genus Flavivirus contains the most important arboviruses in the world, i.e., dengue (DENV) and yellow fever (YFV). In our study, we investigated the in vitro and in vivo effect of RNAi against YFV. Using stable cell lines that expressed RNAi against YFV, the cell lines were able to inhibit as much as 97% of the viral replication. Two constructions (one against NS1 and the other against E region of YFV genome) were able to protect the adult Balb/c mice against YFV challenge. The histopathologic analysis demonstrated an important protection of the central nervous system by RNAi after 10 days of viral challenge. Our data suggests that RNAi is a potential viable therapeutic weapon against yellow fever.