Prevalence of extended-spectrum beta-lactamases in South America.

In South American countries, the class A extended-spectrum beta-lactamases (ESBLs) so far recognised belong to the CTX-M, Pseudomonas Extended Resistance (PER), SHV and TEM families. ESBL rates in South America are among the highest in the world, probably due to multiple factors. SHV- and TEM-type ESBLs have been frequently encountered, but CTX-M is endemic and widely dominant. PER-type ESBLs seem to be restricted to the southern 'cone' of South America. Community-acquired ESBLs are starting to appear.