Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Eur J Pediatr ; 177(2): 181-192, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29285648

RESUMEN

This cross-sectional study assessed the prevalence of bacteria isolated from Spanish children with suspected chronic lower respiratory tract infection (LRTI) for whom bronchoalveolar lavage (BAL) was indicated. BAL fluid (BALF) was collected from 191 children (aged ≥ 6 months to < 6 years, with persistent or recurrent respiratory symptoms, non-responders to usual treatment) and cultured. Nasopharyngeal swabs (NPSs) were also obtained and cultured to assess concordance of BALF and NPS findings in the same patient. Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis were identified from BALF with a bacterial load indicative of infection (> 104 colony-forming units/mL) in 10.5, 8.9, and 6.3% of children, respectively. Clinical characteristics were similar among participants, regardless of positivity status for any of the bacteria. Approximately 26% of pneumococcal isolates were PCV13 serotypes, and 96% of H. influenzae isolates were non-typeable (NTHi). Concordance between BALF and NPS isolates was 51.0% for S. pneumoniae, 52.1% for H. influenzae, and 22.0% for M. catarrhalis. CONCLUSION: S. pneumoniae, NTHi, and M. catarrhalis were the main bacteria detected in BALF and NPS. Children with suspected chronic LRTI may benefit from a vaccine protecting against NTHi. What is Known: • Chronic lower respiratory tract infection (LRTI) in children can cause high morbidity and is a major use of healthcare resources worldwide. Despite this, their etiology or potential preventive measures are poorly assessed. • Bronchoalveolar lavage can be used to determine bacterial etiology of chronic LRTI. What is New: • We used conventional and molecular techniques to show that Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis were present in the LRT of Spanish children with suspected chronic LRTI • Concordance between isolates from bronchoalveolar lavage fluid and nasopharyngeal swabs was low, suggesting that samples from the upper respiratory tract could not reliably predict the bacterial etiology of suspected chronic LRTI.


Asunto(s)
Líquido del Lavado Bronquioalveolar/microbiología , Infecciones por Haemophilus/diagnóstico , Haemophilus influenzae/aislamiento & purificación , Moraxella catarrhalis/aislamiento & purificación , Infecciones por Moraxellaceae/diagnóstico , Infecciones Neumocócicas/diagnóstico , Neumonía Bacteriana/diagnóstico , Lavado Broncoalveolar , Niño , Preescolar , Enfermedad Crónica , Estudios Transversales , Femenino , Infecciones por Haemophilus/epidemiología , Humanos , Lactante , Masculino , Infecciones por Moraxellaceae/epidemiología , Infecciones Neumocócicas/epidemiología , Neumonía Bacteriana/epidemiología , Neumonía Neumocócica/diagnóstico , Neumonía Neumocócica/epidemiología , España/epidemiología
2.
Sci Adv ; 3(4): e1600582, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28439534

RESUMEN

The subtropical ocean gyres are recognized as great marine accummulation zones of floating plastic debris; however, the possibility of plastic accumulation at polar latitudes has been overlooked because of the lack of nearby pollution sources. In the present study, the Arctic Ocean was extensively sampled for floating plastic debris from the Tara Oceans circumpolar expedition. Although plastic debris was scarce or absent in most of the Arctic waters, it reached high concentrations (hundreds of thousands of pieces per square kilometer) in the northernmost and easternmost areas of the Greenland and Barents seas. The fragmentation and typology of the plastic suggested an abundant presence of aged debris that originated from distant sources. This hypothesis was corroborated by the relatively high ratios of marine surface plastic to local pollution sources. Surface circulation models and field data showed that the poleward branch of the Thermohaline Circulation transfers floating debris from the North Atlantic to the Greenland and Barents seas, which would be a dead end for this plastic conveyor belt. Given the limited surface transport of the plastic that accumulated here and the mechanisms acting for the downward transport, the seafloor beneath this Arctic sector is hypothesized as an important sink of plastic debris.

3.
Vaccine ; 34(8): 1109-14, 2016 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-26718690

RESUMEN

INTRODUCTION: This multi-center, hospital-based observational study determined the seroprevalence of pertussis antibodies amongst healthcare professionals from three different hospitals in Spain to ascertain the health status of professionals attending to susceptible groups who are at risk of contracting and transmitting pertussis. METHODS: Medical professionals from three hospitals in Spain were recruited for this study (NCT01706224). Serum samples from subjects were assessed for anti-pertussis antibodies by ELISA. The percentage of subjects positive for anti-pertussis antibodies were determined by age-strata, gender, vaccination status, professional level (physicians, nurses, ancillary nurses and midwives), hospital department, number of working years, numbers of hours spent with the patient as well as number of children in the household. RESULTS: Overall, 31.2% of subjects were seropositive; 3.3% of these healthcare professionals had ELISA values indicative of current or recent infection. There were no significant differences in terms of pertussis prevalence with respect to age, gender, hospital department, profession, number of working years and number of hours spent with patients. These levels of seronegativity amongst healthcare workers further strengthen the rationale for vaccination amongst this specific population against pertussis.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Personal de Hospital , Tos Ferina/epidemiología , Adulto , Anciano , Ensayo de Inmunoadsorción Enzimática , Femenino , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Seroepidemiológicos , España/epidemiología , Adulto Joven
4.
Vaccine ; 33(6): 789-95, 2015 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-25555381

RESUMEN

Zostavax(®) is a live, attenuated varicella zoster virus (VZV) vaccine developed specifically for the prevention of HZ and PHN in individuals aged ≥50 years. During the clinical development of Zostavax, which was mainly in the US, the vaccine was administrated by the subcutaneous (SC) route. In Europe, many healthcare professionals prefer administering vaccines by the intramuscular (IM) route. This was an open-label, randomised trial conducted in 354 subjects aged ≥50 years. The primary objectives were to demonstrate that IM administration is both non-inferior to SC administration in terms of 4-week post-vaccination geometric mean titres (GMTs), and elicits an acceptable geometric mean fold-rise (GMFR) of antibody titres measured by glycoprotein enzyme-linked immunosorbent assay. Pre-specified non-inferiority was set as the lower bound of the 95% confidence interval (CI) of the GMT ratio (IM/SC) being >0.67. An acceptable GMFR for the IM route was pre-specified as the lower bound of its 95% CI being >1.4. Description of the VZV immune response using the interferon-gamma enzyme-linked immunospot (IFN-γ ELISPOT) assay and of the safety were secondary objectives. Participants were randomised to IM or SC administration (1:1). The baseline demographics were comparable between groups; mean age: 62.6 years (range: 50.0-90.5). The primary immunogenicity objectives were met (per protocol analysis): GMT ratio (IM/SC): 1.05 (95% CI: 0.93-1.18); GMFR: 2.7 (2.4-3.0). VZV immune response using IFN-γ ELISPOT were comparable between groups. Frequencies of systemic adverse events were comparable between groups. Injection-site reactions were less frequent with IM than SC route: erythema (15.9% versus 52.5%), pain (25.6% versus 39.5%) and swelling (13.6% versus 37.3%), respectively. In adults aged ≥50 years, IM administration of Zostavax elicited similar immune responses to SC administration and was well tolerated, with fewer injection-site reactions than with SC administration.


Asunto(s)
Anticuerpos Antivirales/sangre , Vacuna contra el Herpes Zóster/administración & dosificación , Herpes Zóster/sangre , Herpes Zóster/prevención & control , Herpesvirus Humano 3/inmunología , Anciano , Anciano de 80 o más Años , Edema/etiología , Edema/fisiopatología , Ensayo de Immunospot Ligado a Enzimas , Eritema/etiología , Eritema/fisiopatología , Femenino , Herpes Zóster/inmunología , Vacuna contra el Herpes Zóster/efectos adversos , Vacuna contra el Herpes Zóster/inmunología , Humanos , Inyecciones Intramusculares , Inyecciones Subcutáneas , Interferón gamma/sangre , Masculino , Persona de Mediana Edad , Dolor/etiología , Dolor/fisiopatología , Vacunación , Vacunas Atenuadas
5.
PLoS One ; 9(11): e112294, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25392931

RESUMEN

BACKGROUND: Most evidence of the effectiveness of influenza vaccines comes from studies conducted in primary care, but less is known about their effectiveness in preventing serious complications. Here, we examined the influenza vaccine effectiveness (IVE) against hospitalization with PCR-confirmed influenza in the predominant A(H3N2) 2011-2012 influenza season. METHODS: A hospital-based, test-negative study was conducted in nine hospitals in Valencia, Spain. All emergency admissions with a predefined subset of symptoms were eligible. We enrolled consenting adults age 18 and over, targeted for influenza vaccination because of comorbidity, with symptoms of influenza-like-illness within seven days of admission. We estimated IVE as (1-adjusted vaccination odds ratio)*100 after accounting for major confounders, calendar time and recruitment hospital. RESULTS: The subjects included 544 positive for influenza A(H3N2) and 1,370 negative for influenza admissions. Age was an IVE modifying factor. Regardless of vaccine administration, IVE was 72% (38 to 88%) in subjects aged under 65 and 21% (-5% to 40%) in subjects aged 65 and over. By type of vaccine, the IVE of classical intramuscular split-influenza vaccine, used in subjects 18 to 64, was 68% (12% to 88%). The IVE for intradermal and virosomal influenza vaccines, used in subjects aged 65 and over, was 39% (11% to 58%) and 16% (-39% to 49%), respectively. CONCLUSIONS: The split-influenza vaccine was effective in preventing influenza-associated hospitalizations in adults aged under 65. The intradermal vaccine was moderately effective in those aged 65 and over.


Asunto(s)
Subtipo H3N2 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza , Gripe Humana/prevención & control , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Investigación sobre la Eficacia Comparativa , Femenino , Hospitalización , Humanos , Vacunas contra la Influenza/administración & dosificación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , España , Adulto Joven
6.
Proc Natl Acad Sci U S A ; 111(28): 10239-44, 2014 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-24982135

RESUMEN

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.


Asunto(s)
Océanos y Mares , Plásticos/efectos adversos , Contaminantes del Agua/efectos adversos , Contaminación del Agua/efectos adversos
7.
Clin J Am Soc Nephrol ; 6(9): 2208-14, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21852661

RESUMEN

BACKGROUND AND OBJECTIVES: Data are needed to assess safety and efficacy of the 2009 pandemic influenza A H1N1 vaccine in renal patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We prospectively evaluated seroconversion, predictors of response, and vaccine safety in renal patients. Hemagglutination inhibition tests to detect serum antibodies against a new influenza A-H1N1 virus were performed in 79 transplant patients, 48 hemodialysis patients, and 15 healthy workers before and 1 month after vaccination. Healthy controls and 88 of 127 renal patients were vaccinated. Seroconversion was defined as at least 2 dilutions increase in titer. RESULTS: We excluded 19 individuals seroprotected (≥1/40) against the novel H1N1 in the initial sample. Efficacy rate in the 96 vaccinated individuals was 43.7% (42 of 96 seroconverted versus four of 27 nonvaccinated patients, P = 0.007). For vaccinated subgroups, efficacy was 41.8% in transplant patients (P = 0.039 versus nonvaccinated), 33.3% in hemodialysis patients (P = 0.450), and 81.8% in controls. Healthy controls showed better response to vaccine than transplant (P = 0.021) and dialysis (P = 0.012) patients. For the transplant subgroup, longer time after transplantation (P = 0.028) was associated with seroconversion, but no influence was found for age, gender, renal function, or immunosuppression. In the hemodialysis subgroup, younger age was associated with response (55.7 ± 20.8 versus 71.6 ± 10.1 years, P = 0.042), but other specific variables, including Kt/V or time on dialysis, were not. No serious adverse events were reported, and kidney function was stable. CONCLUSION: The novel influenza A 2009 H1N1 vaccine was safe in renal patients, although administration of a single dose of adjuvanted vaccine induced a poor response in these patients.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Trasplante de Riñón , Diálisis Renal , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Vacunación
9.
Antimicrob Agents Chemother ; 54(7): 2953-9, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20439616

RESUMEN

A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of > or = 2 microg/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a beta-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLS(B)) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), beta-lactamase production (from 25.7% to 15.7%), and beta-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLS(B) was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes.


Asunto(s)
Antibacterianos/farmacología , Haemophilus influenzae/efectos de los fármacos , Infecciones del Sistema Respiratorio/microbiología , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pyogenes/efectos de los fármacos , Ampicilina/farmacología , Cefotaxima/farmacología , Eritromicina/farmacología , Haemophilus influenzae/patogenicidad , Lincosamidas/farmacología , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Penicilinas/farmacología , España , Streptococcus pneumoniae/patogenicidad , Streptococcus pyogenes/patogenicidad , Estreptogramina B/farmacología
10.
J Antimicrob Chemother ; 61(3): 603-11, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18218647

RESUMEN

OBJECTIVES: To assess changes in macrolide and ketolide resistance among Streptococcus pyogenes in Europe and to examine the relationship of resistance to antimicrobial usage. METHODS: Clinical S. pyogenes isolates were collected from Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Spain, Sweden, UK, Croatia, Hungary, Poland, Slovak Republic and Slovenia during 2002-03 (n = 2165) and 2004-05 (n = 2333). Resistance to telithromycin (MIC > or = 2) and erythromycin (MIC > or = 0.5) was determined by CLSI broth microdilution. Changes in resistance over time and the relationship of resistance to antimicrobial use (European Surveillance of Antimicrobial Consumption data) were assessed. Telithromycin-resistant isolates were characterized by PFGE to determine genetic relatedness and by PCR to detect mef(A), erm(A) and erm(B). RESULTS: The erythromycin resistance rate during 2004-05 (11.6%) was similar to 2002-03 (10.4%). The proportion of macrolide-resistant isolates with the constitutive MLS(B) phenotype increased from 29.3% (2002-03) to 45.7% (2004-05). Telithromycin resistance increased from 1.8% in 2002-03 to 5.2% in 2004-05. For Western Europe, associations of telithromycin and erythromycin resistance, respectively, were found with azithromycin use (R2 = 0.52 and 0.60), clarithromycin use (R2 = 0.76 and 0.85) and total macrolide/lincosamide use (R2 = 0.75 and 0.69). For Eastern Europe, associations of antimicrobial use with resistance were not apparent. The 162 telithromycin-resistant isolates comprised 42 PFGE patterns with 68.5% in eight major PFGE groups. The erm(B) gene was detected in 155 of the 162 telithromycin-resistant isolates. CONCLUSIONS: Significant increases in telithromycin resistance occurred from 2002-03 to 2004-05 in Europe. Macrolide use appears to be a factor in the emergence of ketolide resistance among S. pyogenes in Western Europe.


Asunto(s)
Farmacorresistencia Bacteriana/efectos de los fármacos , Cetólidos/farmacología , Inhibidores de la Síntesis de la Proteína/farmacología , ARN Ribosómico 23S , Streptococcus pyogenes/efectos de los fármacos , Farmacorresistencia Bacteriana/fisiología , Europa (Continente)/epidemiología , Humanos , Cetólidos/metabolismo , Inhibidores de la Síntesis de la Proteína/metabolismo , ARN Ribosómico 23S/metabolismo , Streptococcus pyogenes/aislamiento & purificación
11.
Water Res ; 41(14): 3121-31, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17524444

RESUMEN

The role of the nitrate-reducing, sulfide-oxidising bacteria (NR-SOB) in the nitrate-mediated inhibition of sulfide net production by anaerobic wastewater biofilms was analyzed in two experimental bioreactors, continuously fed with the primary effluent of a wastewater treatment plant, one used as control (BRC) and the other one supplemented with nitrate (BRN). This study integrated information from H(2)S and pH microelectrodes, RNA-based molecular techniques, and the time course of biofilm growth and bioreactors water phase. Biofilms were a net source of sulfide for the water phase (2.01 micromol S(2-)(tot)m(-2)s(-1)) in the absence of nitrate dosing. Nitrate addition effectively led to the cessation of sulfide release from biofilms despite which a low rate of net sulfate reduction activity (0.26 micromol S(2-)(tot)m(-2)s(-1)) persisted at a deep layer within the biofilm. Indigenous NR-SOB including Thiomicrospira denitrificans, Arcobacter sp., and Thiobacillus denitrificans were stimulated by nitrate addition resulting in the elimination of most sulfide from the biofilms. Active sulfate reducing bacteria (SRB) represented comparable fractions of total metabolically active bacteria in the libraries obtained from BRN and BRC. However, we detected changes in the taxonomic composition of the SRB community suggesting its adaptation to a higher level of NR-SOB activity in the presence of nitrate.


Asunto(s)
Biopelículas , Nitratos/metabolismo , Sulfuros/metabolismo , Bacterias Reductoras del Azufre/metabolismo , Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos , Anaerobiosis/efectos de los fármacos , Biopelículas/efectos de los fármacos , Biomasa , Reactores Biológicos , Concentración de Iones de Hidrógeno , Nitratos/farmacología , Oxidación-Reducción/efectos de los fármacos , Bacterias Reductoras del Azufre/efectos de los fármacos , Microbiología del Agua
12.
Clin Vaccine Immunol ; 13(6): 665-70, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16760325

RESUMEN

The antibody response to capsular polysaccharides of pneumococcal serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F elicited either naturally or after vaccination with Prevenar was investigated in a cohort of children (n = 163) with underlying chronic or recurrent lung diseases at risk of developing pneumococcal pneumonia and ultimately invasive disease. Serum concentrations of serotype-specific antibodies, as measured by enzyme-linked immunosorbent assay, in unvaccinated children (n = 88) were higher in nasopharyngeal carriers (n = 10) than in noncarriers (n = 78) both at baseline and during follow-up. However, the antibody levels depended on the serotype and age of the children. During the study period, 35% of unvaccinated noncarriers and 60% of unvaccinated carriers displayed serum antibodies to all serotypes above the reported WHO working group putative protective serum concentration against invasive disease (0.2 mug/ml). Overall, children vaccinated with Prevenar before enrollment (n = 61), irrespective of their carrier status, displayed significantly higher serum levels of antibodies to all serotypes than unvaccinated children. More than 85% of the vaccinated children had protective serum antibody concentrations at baseline; although antibody titers tended to decrease over time, the above-mentioned figure remained without change at the end of follow-up. The vaccine Prevenar elicited a significant rise in serum antibody concentrations against all serotypes in 14 children vaccinated at entry. All of these children acquired and maintained serum antibody levels of >0.2 microg/ml throughout the study (a mean of 13 months of follow-up). These data support the systematic use of the vaccine Prevenar in children with underlying chronic or recurrent lung diseases and stress the fact that a percentage of vaccinated children may need to be revaccinated in order to achieve protection against pneumococcal disease.


Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Enfermedades Pulmonares/inmunología , Enfermedades Pulmonares/prevención & control , Vacunas Meningococicas/uso terapéutico , Vacunas Neumococicas/uso terapéutico , Polisacáridos Bacterianos/inmunología , Vacunación/métodos , Adolescente , Anticuerpos Antibacterianos/análisis , Especificidad de Anticuerpos/inmunología , Niño , Preescolar , Enfermedad Crónica , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Estudios de Seguimiento , Vacuna Neumocócica Conjugada Heptavalente , Humanos , Lactante , Masculino , Vacunas Meningococicas/inmunología , Vacunas Neumococicas/inmunología , Estadísticas no Paramétricas
13.
Biotechnol Bioeng ; 93(4): 801-11, 2006 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-16255035

RESUMEN

Biogenic production of sulfide in wastewater treatment plants involves odors, toxicity and corrosion problems. The production of sulfide is a consequence of bacterial activity, mainly sulfate-reducing bacteria (SRB). To prevent this production, the efficiency of nitrate addition to wastewater was tested at plant-scale by dosing concentrated calcium nitrate (Nutriox) in the works inlet. Nutriox dosing resulted in a sharp decrease of sulfide, both in the air and in the bulk water, reaching maximum decreases of 98.7% and 94.7%, respectively. Quantitative molecular microbiology techniques indicated that the involved mechanism is the development of the nitrate-reducing, sulfide-oxidizing bacterium Thiomicrospira denitrificans instead of the direct inhibition of the SRB community. Denitrification rate in primary sedimentation tanks was enhanced by nitrate, being this almost completely consumed. No significant increase of inorganic nitrogen was found in the discharged effluent, thus reducing potential environmental hazards to receiving waters. This study demonstrates the effectiveness of nitrate addition in controlling sulfide generation at plant-scale, provides the mechanism and supports the environmental adequacy of this strategy.


Asunto(s)
Compuestos de Calcio/farmacología , Sulfuro de Hidrógeno/metabolismo , Nitratos/farmacología , Piscirickettsiaceae/efectos de los fármacos , Eliminación de Residuos Líquidos , Nitrógeno/metabolismo , Oxidación-Reducción , Piscirickettsiaceae/metabolismo , ARN Bacteriano/análisis , ARN Bacteriano/genética , ARN Ribosómico 16S/análisis , ARN Ribosómico 16S/genética , Thiobacillus/efectos de los fármacos , Thiobacillus/metabolismo
14.
Antimicrob Agents Chemother ; 49(5): 1965-72, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15855520

RESUMEN

A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLS(B) (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events.


Asunto(s)
Antiinfecciosos/uso terapéutico , Farmacorresistencia Bacteriana , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/microbiología , Bacterias/efectos de los fármacos , Bacterias/genética , Farmacorresistencia Bacteriana/genética , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/genética , Humanos , Pruebas de Sensibilidad Microbiana , Fenotipo , Vigilancia de la Población , Serotipificación , España/epidemiología , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/genética
15.
J Clin Microbiol ; 43(3): 1433-6, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15750125

RESUMEN

We conducted a nationwide surveillance of the variable 5' emm-like (M-like protein gene) sequences from 214 pharyngeal group C and group G streptococci. Almost 75% of the isolates exhibited emm or emm-like sequences previously described. We identified six new 5' emm-like regions, and almost 23% of the isolates were nontypeable. Five emm-like sequences accounted for more than 50% of the isolates in group C and group G, suggesting horizontal gene transfer between strains of different species.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Portadoras/genética , Genes Bacterianos , Faringe/microbiología , Streptococcus/genética , Secuencia de Bases , Transferencia de Gen Horizontal , Genotipo , Humanos , Datos de Secuencia Molecular , Streptococcus/clasificación
16.
Int J Antimicrob Agents ; 25(2): 148-56, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15664485

RESUMEN

A multinational surveillance study, GRASP, was conducted between November 2002 and April 2003 with the aim of assessing rates of antimicrobial resistance among 2656 isolates of Streptococcus pneumoniae, 2486 isolates of group A beta-haemolytic streptococci, 1358 isolates of Haemophilus influenzae and 1047 of Moraxella catarrhalis from 20 countries in Europe, eastern Asia and southern Africa. Conspicuous differences between various countries were noted in the S. pneumoniae resistance rates observed for penicillin (0-79.2%) and erythromycin (4-66%), along with other antimicrobials. The percentage of MDR strains was above 25% in 8 of the 20 countries studied. Group A streptococcal macrolide resistance rates ranged from 0% to 35% by country, while rates of beta-lactamase production ranged from 0% to 39% for H. influenzae and 80-100% for M. catarrhalis. Antibiotic resistance in S. pneumoniae remains a significant problem world wide.


Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Haemophilus influenzae/efectos de los fármacos , Moraxella catarrhalis/efectos de los fármacos , Infecciones del Sistema Respiratorio/epidemiología , Streptococcus/efectos de los fármacos , Adulto , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Farmacorresistencia Bacteriana , Humanos , Internacionalidad , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Vigilancia de la Población , Infecciones del Sistema Respiratorio/microbiología , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pyogenes/efectos de los fármacos
17.
J Clin Microbiol ; 42(10): 4853-5, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15472361

RESUMEN

The performance of the Binax NOW immunochromatographic test for detecting Streptococcus pneumoniae antigen in urine specimens from 103 children presenting underlying pulmonary diseases with no recent pneumococcal infection was assessed. Our data indicate that this assay is unlikely to be useful for discriminating between children with and without pneumococcal pneumonia.


Asunto(s)
Antígenos Bacterianos/orina , Enfermedades Pulmonares/complicaciones , Neumonía Neumocócica/diagnóstico , Juego de Reactivos para Diagnóstico , Streptococcus pneumoniae/aislamiento & purificación , Adolescente , Niño , Preescolar , Cromatografía , Femenino , Humanos , Inmunoensayo/métodos , Lactante , Masculino , Infecciones Neumocócicas/microbiología , Neumonía Neumocócica/microbiología , Sensibilidad y Especificidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA