E . coli ST131 and ST405 and multidrug-resistant IncFII plasmids may determine spread of this lactamase.

Salmonellosis remains one of the most frequent food-borne zoonoses, constituting a worldwide major public health concern. Currently, at a global level, the main sources of infection for humans include meat products, including the consumption of contaminated poultry meat, in spite of the success of Salmonella control measures implemented in food-animal production of industrialized countries. In recent years, a shift in Salmonella serotypes related to poultry and poultry production has been reported in diverse geographical regions, being particularly associated with the spread of certain well-adapted clones. Moreover, antimicrobial resistance in non-typhoidal Salmonella is considered one of the major public health threats related with food-animal production, including the poultry production chain and poultry meat, which is an additional concern in the management of salmonellosis. The circulation of the same multidrug-resistant Salmonella clones and/or identical mobile genetic elements encoding antibiotic resistance genes from poultry to humans highlights this scenario. The purpose of this review was to provide an overview of the role of poultry meat on salmonellosis at a global scale and the main problems that could hinder the success of Salmonella control measures at animal production level. With the increasing globalization of foodstuffs like poultry meat, new problems and challenges might arise regarding salmonellosis control, making new integrated intervention strategies necessary along the food chain.

Extended-spectrum beta-lactamases (ESBLs) represent a major threat among resistant bacterial isolates. The first types described were derivatives of the TEM-1, TEM-2 and SHV-1 enzymes during the 1980s in Europe, mainly in Klebsiella pneumoniae associated with nosocomial outbreaks. Nowadays, they are mostly found among Escherichia coli isolates in community-acquired infections, with an increasing occurrence of CTX-M enzymes. The prevalence of ESBLs in Europe is higher than in the USA but lower than in Asia and South America. However, important differences among European countries have been observed. Spread of mobile genetic elements, mainly epidemic plasmids, and the dispersion of specific clones have been responsible for the increase in ESBL-producing isolates, such as those with TEM-4, TEM-24, TEM-52, SHV-12, CTX-M-9, CTX-M-14, CTX-M-3, CTX-M-15 and CTX-M-32 enzymes.

Acquired carbapenemases are emerging resistance determinants in Gram-negative pathogens, including Enterobacteriaceae, Pseudomonas aeruginosa and other Gram-negative non-fermenters. A consistent number of acquired carbapenemases have been identified during the past few years, belonging to either molecular class B (metallo-beta-lactamases) or molecular classes A and D (serine carbapenemases), and genes encoding these enzymes are associated with mobile genetic elements that allow their rapid dissemination in the clinical setting. Therefore, detection and surveillance of carbapenemase-producing organisms have become matters of major importance for the selection of appropriate therapeutic schemes and the implementation of infection control measures. As carbapenemase production cannot be simply inferred from the resistance profile, criteria must be established for which isolates should be suspected and screened for carbapenemase production, and for which tests (phenotypic and/or genotypic) should be adopted for confirmation of the resistance mechanism. Moreover, strategies should be devised for surveillance of carbapenemase producers in order to enable the implementation of effective surveillance programmes. The above issues are addressed in this article, as a follow-up to an expert meeting on acquired carbapenemases that was recently organized by the ESCMID Study Group for Antibiotic Resistance Surveillance.