Prevalencia y factores de riesgo para infecciones del tracto urinario de inicio en la comunidad causadas por Escherichia coliproductor de betalactamasas de espectro extendido en Colombia / Prevalence and risk factors for extended-spectrum Beta-lactamase-producing Escherichia coli causing community-onset urinary tract infections in Colombia

INTRODUCCIÓN: Las infecciones del tracto urinario (ITU) son frecuentes en la comunidad. Sin embargo, la información de aislamientos resistentes en este contexto es limitada en Latinoamérica. Este estudio tiene como objetivo determinar la prevalencia y los factores de riesgo asociados con ITU de inicio en la comunidad (ITU-IC) causadas por Escherichia coli productor de betalactamasas de espectro extendido (BLEE) en Colombia. MATERIALES Y MÉTODOS: Entre agosto y diciembre de 2011 se realizó un estudio de casos y controles en 3 instituciones de salud de tercer nivel en Colombia. Se invitó a participar a todos los pacientes admitidos a urgencias con diagnóstico probable de ITU-IC, y se les pidió una muestra de orina. En los aislamientos de E.coli se realizaron pruebas confirmatorias para BLEE, susceptibilidad antibiótica, caracterización molecular (PCR en tiempo real para genes bla, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] y factores de virulencia por PCR). Se obtuvo información clínica y epidemiológica, y posteriormente se realizó el análisis estadístico. RESULTADOS: De los 2.124 pacientes seleccionados, 629 tuvieron un urocultivo positivo, en 431 de estos se aisló E.coli, 54 fueron positivos para BLEE y 29 correspondieron a CTX-M-15. La mayoría de los aislamientos de E.coli productor de BLEE fueron sensibles a ertapenem, fosfomicina y amikacina. La ITU complicada se asoció fuertemente con infecciones por E.coliproductor de BLEE (OR=3,89; IC95%: 1,10-13,89; p = 0,03). E.coli productor de CTX-M-15 mostró 10 electroferotipos diferentes; de estos, el 65% correspondieron al ST131. La mayoría de estos aislamientos tuvieron 8 de los 9 factores de virulencia analizados. DISCUSIÓN: E.coli portador del gen blaCTX-M-15 asociado al ST131 sigue siendo frecuente en Colombia. La presencia de ITU-IC complicada aumenta el riesgo de tener E.coli productor de BLEE, lo cual debe tenerse en cuenta para ofrecer una terapia empírica adecuada

INTRODUCTION: Urinary tract infections (UTI) are common in the community. However, information of resistant isolates in this context is limited in Latin America. This study aims to determine the prevalence and risk factors associated with community-onset UTI (CO-UTI) caused by extended-spectrum β-lactamase (ESBL)-Producing Escherichia coli in Colombia. MATERIALS AND METHODS: A case-control study was conducted between August and December of 2011 in three Colombian tertiary-care institutions. All patients who were admitted to the Emergency Department with a probable diagnosis of CO-UTI were invited to participate. All participating patients were asked for a urine sample. ESBL confirmatory test, antibiotic susceptibility, and molecular epidemiology were performed in these E.coli isolates (Real Time-PCR for blagenes, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] and virulence factors by PCR). Clinical and epidemiological information was recorded, and a statistical analysis was performed. RESULTS: Of the 2124 recruited patients, 629 had a positive urine culture, 431 of which grew E.coli; 54 were positive for ESBL, of which 29 were CTX-M-15. The majority of ESBL isolates were susceptible to ertapenem, phosphomycin and amikacin. Complicated UTI was strongly associated with ESBL-producing E.coli infections (OR=3.89; 95%CI: 1.10-13.89; P=.03). CTX-M-15-producing E.coli showed 10 different pulsotypes, 65% were PT1 or PT4, and corresponded to ST131. Most of these isolates had 8 out of the 9 analysed virulence factors. DISCUSSION: E.coli harbouring blaCTX-M-15 associated with ST131 is still frequent in Colombia. The presence of complicated CO-UTI increases the risk of ESBL-producing E.coli, and must be taken into account in order to provide an adequate empirical therapy

[Prevalence and risk factors for extended-spectrum ß-lactamase-producing Escherichia coli causing community-onset urinary tract infections in Colombia]. / Prevalencia y factores de riesgo para infecciones del tracto urinario de inicio en la comunidad causadas por Escherichia coli productor de betalactamasas de espectro extendido en Colombia.

INTRODUCTION: Urinary tract infections (UTI) are common in the community. However, information of resistant isolates in this context is limited in Latin America. This study aims to determine the prevalence and risk factors associated with community-onset UTI (CO-UTI) caused by extended-spectrum ß-lactamase (ESBL)-Producing Escherichia coli in Colombia. MATERIALS AND METHODS: A case-control study was conducted between August and December of 2011 in three Colombian tertiary-care institutions. All patients who were admitted to the Emergency Department with a probable diagnosis of CO-UTI were invited to participate. All participating patients were asked for a urine sample. ESBL confirmatory test, antibiotic susceptibility, and molecular epidemiology were performed in these E.coli isolates (Real Time-PCR for bla genes, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] and virulence factors by PCR). Clinical and epidemiological information was recorded, and a statistical analysis was performed. RESULTS: Of the 2124 recruited patients, 629 had a positive urine culture, 431 of which grew E.coli; 54 were positive for ESBL, of which 29 were CTX-M-15. The majority of ESBL isolates were susceptible to ertapenem, phosphomycin and amikacin. Complicated UTI was strongly associated with ESBL-producing E.coli infections (OR=3.89; 95%CI: 1.10-13.89; P=.03). CTX-M-15-producing E.coli showed 10 different pulsotypes, 65% were PT1 or PT4, and corresponded to ST131. Most of these isolates had 8 out of the 9 analysed virulence factors. DISCUSSION: E.coli harbouring blaCTX-M-15 associated with ST131 is still frequent in Colombia. The presence of complicated CO-UTI increases the risk of ESBL-producing E.coli, and must be taken into account in order to provide an adequate empirical therapy.

Immediate and long-term follow-up of percutaneous balloon mitral valvuloplasty in pregnant patients with rheumatic mitral stenosis.

Percutaneous mitral balloon valvuloplasty (PMV) can be performed during pregnancy without significant maternal risk or fetal morbidity or mortality. However, little is known about long-term follow-up results after PMV in populations of pregnant women. Thus, the present study was undertaken to determine the immediate and long-term outcomes after PMV in a large cohort of pregnant patients with severe mitral stenosis. The patient population consisted of 71 consecutive pregnant women with severe rheumatic mitral stenosis admitted to the hospital with severe congestive heart failure (New York Heart Association class III and IV) for PMV. All patients underwent clinical and obstetric evaluations, electrocardiography, and 2-dimensional and Doppler echocardiography. PMV was successful in all patients, resulting in a significant increase in mitral valve area from 0.9 +/- 0.2 to 2.0 +/- 0.3 cm2 (p <0.001). At the end of pregnancy, 98% of the patients were in New York Heart Association functional class I or II. At a mean follow-up of 44 +/- 31 months, the total event-free survival rate was 54%. The mean gestational age at delivery time was 38 +/- 1 weeks. Preterm deliveries occurred in 9 patients (13%), including 2 twin pregnancies. The remaining 66 of 75 newborns (88%) had normal weight (mean 2.8 +/- 0.6 kg) at delivery. At long-term follow-up of 44 +/- 31 months after birth, the 66 children exhibited normal growth and development and did not show any clinical abnormalities. In conclusion, PMV is safe and effective, has a low morbidity and mortality rate for the mother and the fetus, and has favorable long-term results in pregnant women with rheumatic mitral stenosis in New York Heart Association functional class III or IV.

Immediate and long-term follow-up of percutaneous balloon mitral valvuloplasty in pregnant patients with rheumatic mitral stenosis

Percutaneous mitral balloon valvuloplasty (PMV) can be performed during pregnancy without significant maternal risk or fetal morbidity or mortality. However, little is known about long-term follow-up results after PMV in populations of pregnant women. Thus, the present study was undertaken to determine the immediate and long-term outcomes after PMV in a large cohort of pregnant patients with severe mitral stenosis. The patient population consisted of 71 consecutive pregnant women with severe rheumatic mitral stenosis admitted to the hospital with severe congestive heart failure (New York Heart Association class III and IV) for PMV. All patients underwent clinical and obstetric evaluations, electrocardiography, and 2-dimensional and Doppler echocardiography. PMV was successful in all patients, resulting in a significant increase in mitral valve area from 0.9 0.2 to 2.0 0.3 cm2 (p <0.001). At the end of pregnancy, 98% of the patients were in New York Heart Association functional class I or II. At a mean follow-up of 44 31 months, the total event-free survival rate was 54%. The mean gestational age at delivery time was 38 1 weeks. Preterm deliveries occurred in 9 patients (13%), including 2 twin pregnancies. The remaining 66 of 75 newborns (88%) had normal weight (mean 2.8 0.6 kg) at delivery. At long-term follow-up of 44 31 months after birth, the 66 children exhibited normal growth and development and did not show any clinical abnormalities. In conclusion, PMV is safe and effective, has a low morbidity and mortality rate for the mother and the fetus, and has favorable long-term results in pregnant women with rheumatic mitral stenosis in New York Heart Association functional class III or IV.

Comparison between sirolimus-eluting stents and intracoronary catheter-based beta radiation for the treatment of in-stent restenosis.

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a beta-Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 +/- 1.1 and 12.1 +/- 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 +/- 0.45 vs 0.34 +/- 0.46 mm, p = 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 +/- 0.13 vs 0.57 +/- 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 +/- 0.32 vs 0.16 +/- 0.42 mm, p = 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.

Comparison between sirolimus-eluting stents and intracoronary catheter-based beta radiation for the treatment of in-stent restenosis

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a -Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 1.1 and 12.1 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 0.45 vs 0.34 0.46 mm, p 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 0.13 vs 0.57 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 0.32 vs 0.16 0.42 mm, p 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.

A novel mechanism explaining early lumen loss following balloon angioplasty for the treatment of in-stent restenosis.

We performed serial intravascular ultrasound analysis in patients who underwent balloon dilatation for in-stent restenosis. Early lumen loss was detected by intravascular ultrasound and was associated with minimal changes at the edges and at the external elastic membrane. These results on intravascular ultrasound suggest compression and decompression as the main mechanisms for early lumen loss after dilatation of in-stent restenotic lesions.

A novel mechanism explaining early lumen loss following ballon angioplasty for the treatment of in-stent restenosis

We performed serial intrvascular ultrasound analysis in patients who underwent ballon dilatation for in-stent restenosis.Early lumen loss was detected by intravascular ultrasound and was associated with minimal changes at the edges and at the external elastic membrane. These results on intravascular ultrasound sugest compression and descompression as the main mechanisms for early lumen loss after dilatation of in-stent restenosis...

Angiographic and volumetric intravascular ultrasound comparison between direct sirolimus-eluting stent implantation versus predilation.

Conventional sirolimus-eluting stent (SES) implantation typically follows balloon predilation. The impact of direct SES implantation on in-stent neointimal hyperplasia and the adjacent reference segments has not been evaluated. The aim of this study was to analyze direct and conventional SES implantation techniques by angiography and serial intravascular ultrasound. Fifty-three patients with single de novo coronary lesions underwent successful conventional (n = 26) and direct (n = 27) SES implantation. At 6-month follow-up, similar in-stent late luminal loss and decreased neointimal hyperplasia volume were seen in the 2 groups, preserving the luminal dimensions at the edges of the stents.

Angiographic and volumetric intravascular ultrasound comparison between direct sirolimus-eluting stent implantation versus predilatation

Conventional sirolimus-eluting stent (SES) implantation typically follows ballon predilation.the impact of direct SES implantation on in-stent neointimal hyperplasia and the adjacent refence segments has not been evaluated .The aim of this study was to analyze direct and conventional SES implantation techniques by angiography and serial intravascular ultrasound.Fifty-three patients with single de novo coronary lesions underwent succesful conventional (n=26) and direct (n=27) SES implantation. At 6-month follow-up, similar in-stent late luminal loss and decreased neointimal hyperplasia volume were seen in the 2 groups, preserving the luminal dimensions at the edges of the stents.

Intravascular ultrasound study of effects of overlapping sirolimus-eluting stents.

Drug-eluting stents have been investigated as a treatment option for in-stent restenosis after bare metal stenting. However, it remains unclear whether overlapping drug-eluting stents have a toxic effect on the vessel wall. The aim of this study was to analyze the 1-year intravascular ultrasound findings after 2 overlapping sirolimus-eluting stent implantations in patients with in-stent restenosis lesions. Eight patients required 2 sirolimus-eluting stents, 18 mm in length, for full lesion coverage; these stents were implanted with >1-mm overlap. At 1-year follow-up, there were no significant quantitative changes in intravascular ultrasound measurements within the overlapped segment.

Intravascular ultrasound study of effects of overlapping sirolimus-eluting stents

Drug-eluting stents have been investigated as a treatment opinion for in-stent restenosis after bare metal stenting. However, it remains unclear whether overlapping drug-eluting stents have a toxic effect on the vessel wall. The aim of this study was to analyze the 1-year intravascular ultrasound findings after 2 overlapping sirolimus-eluting stents implantation in patients with in-stents restenosis lesions. Eigth patients required 2 sirolimus-eluting stents , 18mm in length for full lesion coverage ; these stents were implanted with > 1-mm overlap. At 1-year follow-up, there were significant quantitative changes in intravascular ultrasound measurement withn the overlapped segment...

Ultraporous single phase iron oxide-silica nanostructured aerogels from ferrous precursors.

Monoliths of iron oxide-silica aerogel nanocomposites have been synthesized using a novel synthesis route which consists of impregnating silica wet gels with anhydrous iron(II) precursors followed by ethanol supercritical drying of the gels. The process yields aerogels exhibiting high porosity, large surface areas (approximately 900 m2/g), rather low densities (approximately 0.6 g/cm3), and a homogeneous distribution of single-phase maghemite, gamma-Fe2O3, nanoparticles with average sizes in the 7-8 nm range. Remarkably, the gamma-Fe2O3 nanoparticles are obtained in the as-dried state without the need of postannealing. The nanoparticles are mostly superparamagnetic at room temperature but become blocked in a ferrimagnetic state at lower temperatures.