Extended-Spectrum β-Lactamases in Enterobacteriaceae in Buenos Aires, Argentina, Public Hospitals

Abstract

Resistance to extended-spectrum cephalosporins is often associated with plasmid encoded extended spectrum ␤-lactamases (ESBL). In order to evaluate the prevalence and diversity of ESBLs in enterobacteria in our city, a 1-month-period survey was carried out from April to May 2000. Extended-spectrum-cephalosporinresistant strains, isolated from inpatient clinical specimens other than stools, were collected among 17 participating hospitals. From a total of 427 enterobacterial strains that were collected during this period, 39 were extended-spectrum cephalosporin resistant. The National Committee for Clinical Laboratory Standards' Screening and Confirmatory Tests for ESBL production were performed using cefotaxime and ceftazidime; cefepime and cefepime-clavulanic acid-containing disks were included. ␤-Lactamases were characterized by isoelectric focusing and PCR amplification using specific primers. Three different ESBLs were detected: SHV-related (4 isolates), PER-2-type (9 isolates), and CTX-M-2-related (26 isolates). Sequencing of the corresponding genes confirmed CTX-M-2 in 19 of 21 and CTX-M-31 (an allelic variant) in the remaining 2 of 21. CTX-M-2 (or its variant) was detected in all Escherichia coli, Enterobacter aerogenes, Serratia marcescens, Proteus mirabilis, and Providencia stuartii strains, while PER-2 was detected in Enterobacter cloacae, E. aerogenes, and Klebsiella pneumoniae; SHV-related ESBL were found only in K. pneumoniae. These results clearly show that CTX-M-2 is the most prevalent ESBL produced by enterobacterial species isolated from public hospitals in Buenos Aires.

382 CTX-M-15 extended-spectrum β-lactamases in Enterobacteriaceae in the intensive care unit of Tlemcen Hospital, Algeria

“…The presence of CTX-M-15 enzyme in the west of Algeria indicates a countrywide spread of the CTX-M β-lactamases. This situation is comparable to those reported in numerous countries, such as Argentina, Poland and Lebanon where CTX-M-producing Enterobacteriaceae have been described to be endemic [15][16][17][18].…”

Regional outbreak of CTX-M-2 β-lactamase-producing Proteus mirabilis in Japan

“…Non-TEM-derived ESBLs such as VEB-1 (Kim et al, 2004), CTX-M b-lactamases (CTX-M-1, CTX-M-2, CTX-M-13 and CTX-M-31) (Ho et al, 2005;Karapavlidou et al, 2005) and plasmid-borne AmpC blactamases (CMY-2 and CMY-4) (Verdet et al, 1998;Park et al, 2006) have also been reported infrequently. The prevalence of ESBL-positive strains has been reported at 6.9 % in France , 7.0 % in Argentina (Quinteros et al, 2003), 8.8 % in Italy (Luzzaro et al, 2001) and 9.5 % in the US (Saurina et al, 2000). An outbreak of ESBL-producing P. mirabilis has been reported as a nosocomial infection caused by clonal spread (Nagano et al, 2003;Kim et al, 2004).…”

The continuing challenge of ESBLs

“…These are now considered the most prevalent ESBLs worldwide [11][12][13]. PER-and OXAtype enzymes are more common in P. aeruginosa and Acinetobacter spp., but there have been sporadic reports of PER type ESBLs in Enterobacteriacea originating from France, Argentina and Italy [14][15][16]. Of tremendous import because of their ability to inactivate carbapenems, plasmid-borne KPC enzymes are emerging among K. pneumoniae and other enterobacteria in the Eastern seabord and the heartland of the U.S. and internationally [17].…”