Extended-spectrum β-lactamases, transferable quinolone resistance, and virulotyping in extra-intestinal E. coli in Uruguay

Introduction: To characterize extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) genes in Escherichia coli isolates obtained from extra-intestinal samples in three Uruguayan hospitals. Methodology: Fifty-five ESBL-producing E. coli isolates were studied. Virulence genes, ESBLs, and PMQR genes were detected by polymerase chain reaction. ESBL-producing isolates were compared by pulsed-field gel electrophoresis. Multi-locus sequence typing was also performed on 13 selected isolates. Results: Thirty-seven isolates harbored blaCTX-M-15 (67.3%), eight blaCTX-M-2 (14.6%), five blaCTX-M-14 (9.1%), three carried both blaCTX-M-2 and blaCTX-M-14, one blaCTX-M-9, and one blaCTX-M-8. Among the CTX-M-15 producers, 92% belonged to sequence types ST131 and ST405, and carried aac(6’)Ib-cr as well. Isolates harboring blaCTX-M-2, blaCTX-M-14, blaCTX-M-9, or blaCTX-M-8 were found to be genetically unrelated. Conclusions: The successful dissemination of CTX-M-15-producing E.coli isolates seems to be linked to the spreading of high-risk clones and horizontal gene transfer. A trade-off between carrying more antibiotic resistance and less virulence-related genes could partially account for the evolutionary advantages featured by successful clones.Fil: Vignoli, Rafael. Universidad de la República; UruguayFil: García Fulgueiras, Virginia. Universidad de la República; UruguayFil: Cordeiro, Nicolás F.. Universidad de la República; UruguayFil: Bado, Inés. Universidad de la República; UruguayFil: Seija, Verónica. Universidad de la República; Uruguay. Hospital Pasteur de Montevideo; UruguayFil: Aguerrebere, Paula. Universidad de la República; UruguayFil: Laguna, Gabriel. Universidad de la República; UruguayFil: Araújo, Lucía. Universidad de la República; UruguayFil: Bazet, Cristina. Universidad de la República; UruguayFil: Gutkind, Gabriel Osvaldo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Chabalgoity Rodríguez, José Alejandro. Universidad de la República; Urugua

Detection of class 1 and 2 integrons, extended-spectrum β-lactamases and qnr alleles in enterobacterial isolates from the digestive tract of Intensive Care Unit inpatients

In this study, we searched for extended-spectrum β-lactamases (ESBLs), class 1 and 2 integrons, and qnrA, qnrB and qnrS genes in 56 oxyimino-cephalosporin and/or ciprofloxacin-resistant enterobacterial isolates obtained from the gastrointestinal tract of patients admitted in an Intensive Care Unit in Uruguay. ESBLs were detected in 11 isolates (6 CTX-M-2, 3 CTX-M-9, 1 CTX-M-15 and 1 PER-2). qnr genes and integrons were detected in 5 and 24 isolates, respectively. Eight different antibiotic resistance gene cassettes were found within six different genetic arrangements. Two types of complex class 1 integrons carrying insertion sequence ISCR1 were found, one showing blaCTX-M-2–orf3 and the other qnrA1–ampR. Ten of the thirteen isolates carrying class 2 integrons presented the element IS5 inserted between intI2 and dfrA1, whereas another class 2 integron lacked the internal stop codon usually present in intI2. This is the first report of the occurrence of qnrA, qnrB and blaCTX-M-9 in Uruguay. Dissemination of the different groups of CTX-M enzymes (i.e. groups 1, 2 and 9) appears to be a recent phenomenon in South America.Fil: Bado, Inés. Universidad de la Republica; UruguayFil: Cordeiro, Nicolás F.. Universidad de la Republica; UruguayFil: Robino, Luciana. Universidad de la Republica; UruguayFil: García Fulgueiras, Virginia. Universidad de la Republica; UruguayFil: Seija, Verónica. Universidad de la Republica; UruguayFil: Bazet, Cristina. Universidad de la Republica; UruguayFil: Gutkind, Gabriel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Ayala, Juan A.. Consejo Superior de Investigaciones Cientificas; España. Universidad Autónoma de Madrid; EspañaFil: Vignoli, Rafael. Universidad de la Republica; Urugua

Ciprofloxacin-Resistant Enterobacteria Harboring the aac(6′)-Ib-cr Variant Isolated from Feces of Inpatients in an Intensive Care Unit in Uruguay▿

The presence of aac(6′)-Ib-cr is associated with decreased susceptibility to aminoglycosides (kanamycin, amikacin, and tobramycin) and to norfloxacin and ciprofloxacin (9). This allelic variant of aac(6′)-Ib was found to be linked to the extended-spectrum β-lactamase (ESBL) gene blaCTX-M-15 in isolates from many countries (4, 6, 7), while association of aac(6′)-Ib with the blaCTX-M-2 ESBL gene has been widely reported in Uruguay and Argentina (3, 11).Fil: Cordeiro, Nicolás F.. Universidad de la República; UruguayFil: Robino, Luciana. Universidad de la República; UruguayFil: Medina, Julio. Hospital de Clinicas Dr. Manuel Quintela; UruguayFil: Seija, Verónica. Universidad de la República; UruguayFil: Bado, Inés. Universidad de la República; UruguayFil: García, Virginia. Universidad de la República; UruguayFil: Berro, Maximiliano. Universidad de la República; UruguayFil: Pontet, Julio. Universidad de la República; UruguayFil: López, Lucía. Universidad de la República; UruguayFil: Bazet, Cristina. Universidad de la República; UruguayFil: Rieppi, Gloria. Universidad de la República; UruguayFil: Gutkind, Gabriel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Ayala, Juan A.. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Vignoli, Rafael. Universidad de la República; Urugua