Characterization of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates from the community in Morocco

Abstract

Of 803 community Escherichia coli (n5767) and Klebsiella pneumoniae (n536) isolates collected from patients with urinary tract infections in three Moroccan cities, 10 E. coli (1.3%) and 2 K. pneumoniae (5.6 %) isolates were shown to produce extended-spectrum b-lactamases (ESBLs). PFGE revealed that the E. coli isolates comprised seven distinct genotypes. The presence of plasmids in the 12 isolates was revealed by conjugation experiments of plasmids from these Enterobacteriaceae strains with E. coli K 12 J 5 , with further isolation of the plasmids in the transconjugants. Subsequent nucleotide sequencing indicated that the plasmids encoded the bla CTX-M , bla OXA , bla TEM and bla SHV genes, including genes for CTX-M-15 (n511), OXA-1 (n511), TEM-1b (n54), SHV-5 (n51) and SHV-1 (n52). Identification of plasmid-mediated quinolone-resistance genes was performed by PCR. The aac(69)Ib-cr variant was detected in all strains, and two strains co-expressed qnrS1, bla CTX-M-15 and bla OXA-1 genes. The presence of ESBLs in the Enterobacteriaceae strains studied was probably due to the dissemination of resistance plasmids with the predominant genotype of bla CTX-M-15.

PCR-Based Detection of Extended-Spectrum β-Lactamases (bla CTX-M-1 and bla TEM ) in Escherichia coli, Salmonella spp. and Klebsiella pneumoniae Isolated from Pigs in North Eastern India (Mizoram)

“…CTX-M may be increased due to wide use of third generation cephalosporins, especially ceftriaxone and cefotaxime or may be associated with high mobilization of the encoding genes [26]. Barlow et al [27] reported that the bla CTX-M genes have been mobilized to plasmid almost 10 times more frequently than other class A b-lactamases.…”

Study on Phenotypic Detection of Esbl in Gram Negative Bacterial Isolates in a Tertiary Care Hospital in Bangalore

“…Other newly emerged β-lactamase enzymes are CTX-M, PER, VEB and GES [1,2]. So far about 400 different types of ESBL's have been recognized around the world [3]. They belong to Ambler molecular class A and Bush-Jacoby functional group 2be [4].…”

Genetic Determinants of Antibiotic Resistance in Hospital and Community Isolates of Klebsiella pneumoniae and Escherichia coli

“…In Iran, the rate of resistance to third generation cephalosporins amongst ESBL producing K. pneumoniae was between (55%, ceftriaxone), to (67.4%, cefexime) (26). Although these enzymes are not effective on carbapenems, since the cephalosporin resistance results in the use of carbapenem in the treatment of infections, these isolates might be exposed to carbapenem and became resistance (27).…”

“…A polish study revealed that Most of the ESBL-producing isolates (75.7 %) had a bla CTX-M gene (29). Some studies have indicated that CTX-M-producing E. coli and K. pneumoniae have been imported from community acquired urinary tract infections into the hospital setting (27).…”