-
Julio Cesar Medina-Presentado,
Verónica Seija,
Rafael Vignoli,
Julio Pontet,
Luciana Robino,
Nicolás F Cordeiro, Inés Bado,
Virginia García-Fulgueiras,
Maximiliano Berro,
Cristina Bazet,
Eduardo Savio,
Gloria Rieppi
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: To identify the mechanisms responsible for respiratory infections by Acinetobacter baumannii in intubated patients and risk factors for digestive colonization and infection by A. baumannii. METHODS: We conducted a prospective study in an intensive care unit (ICU) between May 2005 and November 2006, including 175 consecutive patients at the beginning of invasive ventilation (day 1). We performed pharyngeal and rectal swabs on days 1, 4, 7, 10, 13, and 16. Respiratory samples were taken on days 1 and 7, or on suspicion of ventilator-associated pneumonia (VAP). RESULTS: We detected 62 patients with A. baumannii digestive colonization and 20 cases of A. baumannii lower respiratory infection (14 VAP and six purulent tracheobronchitis (PTB)). Digestive colonization by A. baumannii was an independent risk factor for lower respiratory tract infections with that microorganism (p<0.0001; relative risk 8.71, 95% confidence interval 2.73-27.77). Respiratory and rectal A. baumannii isolates from the same patients were compared by enterobacterial repetitive intergenic consensus (ERIC)-PCR; in 9/11 cases (eight VAP and one PTB) results suggested events of exogenous pneumonia with previous colonization, whereas the remaining two cases (two PTB) were suggestive of exogenous infection without previous colonization. CONCLUSIONS: In our unit the pathogenesis of VAP by A. baumannii is mixed, most cases corresponding to exogenous pneumonia with previous colonization.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 02/2013; · 2.17 Impact Factor
-
Inés Bado,
Virginia García-Fulgueiras,
Nicolás F Cordeiro,
Laura Betancor,
Leticia Caiata,
Verónica Seija,
Luciana Robino,
Gabriela Algorta,
José A Chabalgoity,
Juan A Ayala,
Gabriel O Gutkind,
Rafael Vignoli
[show abstract]
[hide abstract]
ABSTRACT: We studied a clinical isolate of Salmonella enterica serotype Enteritidis showing resistance to oxyiminocephalosporins. PCR analysis confirmed the presence of bla(CTX-M-14) linked to IS903 in a 95-kb IncI1 conjugative plasmid. Such a plasmid is maintained on account of the presence of a pndAC addiction system. Multilocus sequence typing (MLST) analysis indicated that the strain belongs to ST11. This is the first report of bla(CTX-M-14) in Salmonella Enteritidis of human origin in South America.
Antimicrobial Agents and Chemotherapy 01/2012; 56(4):2132-4. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To analyse the prevalence of resistance to β-lactams and plasmid-mediated quinolone resistance in Enterobacteriaceae in the paediatric hospital of Uruguay.
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.
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.
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.
Journal of Antimicrobial Chemotherapy 06/2011; 66(8):1725-9. · 5.07 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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 bla(CTX-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 bla(CTX-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.
International journal of antimicrobial agents 11/2010; 36(5):453-8. · 3.03 Impact Factor
-
Marina Macedo-Viñas,
Nicolás F Cordeiro, Inés Bado,
Silvia Herrera-Leon,
Magdalena Vola,
Luciana Robino,
Ruben Gonzalez-Sanz,
Soledad Mateos,
Felipe Schelotto,
Gabriela Algorta,
Juan A Ayala,
Aurora Echeita,
Rafael Vignoli
[show abstract]
[hide abstract]
ABSTRACT: To study the evolution of antibiotic resistance in isolates of Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) obtained in Uruguay between the years 1976 and 2000, and to determine the incidence of class 1 and 2 integrons in the multi-resistant isolates.
We studied 258 strains of Salmonella Typhimurium from various sources, isolated between 1976 and 2000. We determined the evolution of antibiotic resistance and the distribution of class 1 and 2 integrons in all isolates by means of disk diffusion assays and PCR.
During the period 1989-2000 resistance to streptomycin was 56.8%, tetracycline 13.6%, sulfonamides 11.2%, and ampicillin 7.2%. Resistance to gentamicin, kanamycin, chloramphenicol, and nalidixic acid were lower than 5%; no resistance was detected to fluoroquinolones, oxyiminocephalosporins, and amikacin. These results show a dramatic decrease with respect to values found in the period 1976-1988. In this period, resistance to streptomycin was 63.2%, tetracycline 36.8%, sulfonamides 32.3%, and ampicillin 27.8%. Throughout the two periods, 29 multi-resistant Salmonella Typhimurium strains were isolated harboring some class of integron: 15 strains had only intI2, 11 strains presented both intI1 and intI2, and three isolates only intI1.
Our results show a marked decrease in resistance throughout these years, along with a correlation between resistance to different antibiotics and the presence of integrons.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 11/2008; 13(3):342-8. · 2.17 Impact Factor
-
Nicolás F Cordeiro,
Luciana Robino,
Julio Medina,
Verónica Seija, Inés Bado,
Virginia García,
Maximiliano Berro,
Julio Pontet,
Lucía López,
Cristina Bazet,
Gloria Rieppi,
Gabriel Gutkind,
Juan A Ayala,
Rafael Vignoli
Antimicrobial Agents and Chemotherapy 03/2008; 52(2):806-7. · 4.84 Impact Factor
