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

Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species

Extended-spectrum β-lactamases and plasmid-mediated quinolone resistance in enterobacterial clinical isolates in the paediatric hospital of Uruguay

Objectives To analyse the prevalence of resistance to β-lactams and plasmid-mediated quinolone resistance in Enterobacteriaceae in the paediatric hospital of Uruguay. Methods A total of 368 enterobacterial isolates collected between 1 May and 30 November 2009 were studied for the presence of extended-spectrum β-lactamases (ESBLs), qnr alleles and aac(6′)Ib by phenotypic and molecular methods. The genomic context and transferability of β-lactamase and qnr genes were examined by PCR and conjugation, respectively. Results The proportion of inpatients having an infection caused by ESBL-producing enterobacteria was 0.23% (16/7073) in paediatrics wards, 0.64‰ (3/4696) in the neonatology department and 0.03‰ (1/32 557) in the emergency department. ESBL-carrying enterobacteria constituted a total of 21.6% (16/74), 13% (3/23) and 0.37% (1/271) when samples were obtained from paediatrics wards, the neonatology department and the emergency department, respectively. Overall, CTX-M-2 (n = 7), CTX-M-9 (n = 3), CTX-M-8 (n = 2), CTX-M-15 (n = 1), SHV-5 (n = 5) and SHV-2 (n = 2) β-lactamases were detected. Thirteen out of 20 ESBL-producing isolates also carried the aac(6′)Ib gene, and the cr variant was detected in one of them. qnr alleles were detected in four isolates comprising two qnrA1 genes, a qnrB8-like variant and a new qnrB gene showing 26 amino acid differences from QnrB1. Conclusions The proportion of ESBL-producing enterobacteria in Uruguay's paediatric hospital during the study period was 2.3 per 1000 hospitalized patients. The number of different microorganisms detected, as well as the various EBSLs, suggests the occurrence of sporadic episodes instead of nosocomial outbreaks. Nevertheless, the presence of new resistance genes reinforces the necessity for permanent surveillance programmes.Fil: García Fulgueiras, Virginia. Universidad de la Republica; UruguayFil: Bado, Inés. Universidad de la Republica; UruguayFil: Mota, María Inés. Universidad de la Republica; Uruguay. Uruguay. Ministerio de Salud Pública; UruguayFil: Robino, Luciana. Universidad de la Republica; UruguayFil: Cordeiro, Nicolás F.. Universidad de la Republica; UruguayFil: Varela, Adriana. Uruguay. Ministerio de Salud Pública; UruguayFil: Algorta, Gabriela. Universidad de la Republica; Uruguay. Uruguay. Ministerio de Salud Pública; 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: Ayala, Juan A.. Universidad Autónoma de Madrid; España. Consejo Superior de Investigaciones Cientificas; 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

Identification of the first blaCMY-2 gene in Salmonella enterica serovar Typhimurium isolates obtained from cases of paediatric diarrhoea illness detected in South America

The objectives of this study were to investigate clinical isolates of Salmonella enterica serovar Typhimurium resistant to β-lactam antibiotics, to characterise their mechanisms of antibiotic resistance and to evaluate the possible biological cost of expressing resistance genes. Two oxyimino-cephalosporin-resistant Salmonella isolates obtained from children with diarrhoea were characterised. The occurrence of plasmid-encoded bla CMY-2 genes was confirmed by molecular methods and conjugation assays; transcription levels were determined by quantitative real-time PCR (qRT-PCR). The genomic context of the β-lactamases, replicon type and addiction systems were analysed by PCR. Genomic relatedness of both isolates was studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) assays. Growth curves, motility and invasiveness assays in Caco-2 cells were performed to analyse the bacterial fitness of both isolates. Both isolates carried a blaCMY-2-like allele in an IncI plasmid and belonged to the same MLST sequence type (ST19); nevertheless, they showed extensive differences in their PFGE profiles and virulotypes. Isolate STM709 appeared to lack the Salmonella virulence plasmid and displayed less motility and invasiveness in cultured cells than isolate STM910. qRT-PCR showed that isolate STM709 had higher blaCMY-2 mRNA levels compared with STM910. Altogether, the results suggest that a plasmid carrying blaCMY-2 could be disseminating among different clones of S. Typhimurium. Different levels of blaCMY-2 mRNA could have an effect on the fitness of this micro-organism, resulting in lower invasiveness and motility. © 2013 International Society for Chemotherapy of Infection and Cancer.Comisión Sectorial de Investigación Científica (CSIC, Uruguay)Peer Reviewe