RESUMEN
A fatal case of Erysipelothrix rhusiopathiae mitral valve endocarditis is described in a 45 years old male, with a history of chronic alcohol abuse and without animals contact. He presented intermittent fever, polyarthralgia, weight loss, and low back pain. In blood cultures (2 bottles), gram-positive pleomorphic rods grew after 48 hours of incubation. The subculture on blood agar media showed a small, alpha-hemolytic colony, catalase and oxidase negative, PYR and LAP positive and the production of H2S in triple sugar iron agar, was demonstrated. The isolate was initially identified as E. rhusiopathiae, and confirmed by API Coryne (BioMérieux). On the basis of these findings and a transthoracic echocardiogram, an endocarditis was confirmed. Intravenous ampicillin and gentamicin treatment was initiated. The patient became afever, nevertheless he died on day 19 after admission as a consequence of acute pulmonary edema. Susceptibility testing by E-test showed that the microorganism was resistant to vancomycin and gentamicin, and susceptible to penicillin and cefotaxime. We emphasize the importance to consider the isolates of gram-positive pleomorphic rods, catalase and oxidase negative, and the addition of H2S production test in TSI medium. Vancomycin-resistance helps in the identification, and to establish the correct antimicrobial therapy. Although E. rhusiopathiae is usually reported as an occupational pathogen, the contact with pigs and other farm animals may be underestimated.
Asunto(s)
Endocarditis Bacteriana/microbiología , Infecciones por Erysipelothrix/microbiología , Erysipelothrix/aislamiento & purificación , Válvula Mitral/microbiología , Alcoholismo/complicaciones , Ampicilina/uso terapéutico , Sordera/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Farmacorresistencia Bacteriana Múltiple , Quimioterapia Combinada , Endocarditis Bacteriana/diagnóstico , Endocarditis Bacteriana/diagnóstico por imagen , Endocarditis Bacteriana/tratamiento farmacológico , Erysipelothrix/efectos de los fármacos , Infecciones por Erysipelothrix/diagnóstico , Infecciones por Erysipelothrix/tratamiento farmacológico , Resultado Fatal , Gentamicinas/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Edema Pulmonar/etiología , UltrasonografíaRESUMEN
Two monthly studies on the prevalence of penicillin and erythromycin susceptibility of Streptococcus pyogenes were performed in May and October of 1994 in Argentina. A total of 58 centers from 27 cities participated in these studies. A total of 1072 isolates were tested by a diffusion method, although 595 isolates were tested both by the diffusion and an agar dilution method (n = 1767 isolates). No penicillin-resistant streptococci were found in our study (MIC100 = 0.03 microgram/ml). Only four isolates were confirmed as erythromycin resistant S. pyogenes (prevalence 0.14 and 0.28% in May and October 1994, respectively). Resistance in three isolates was due to an inducible mechanism, although in one strain a different phenotype was observed.
Asunto(s)
Antibacterianos/farmacología , Eritromicina/farmacología , Penicilinas/farmacología , Streptococcus pyogenes/efectos de los fármacos , Argentina , Farmacorresistencia Microbiana , Pruebas de Sensibilidad Microbiana , Resistencia a las Penicilinas , Streptococcus pyogenes/metabolismoRESUMEN
Penicillin resistance has not yet been detected in Streptococcus pyogenes. However macrolide-resistant streptococci have emerged in several countries. Only low rates of erythromycin-resistant S. pyogenes were reported in Argentina, with the exception of a 11.1% observed in Mendoza. The aim of the present study was to determine the susceptibility to penicillin and to erythromycin of 251 consecutive clinically-significant isolates of S. pyogenes obtained from four centers of Cipolletti and Neuquén during the period April-December 1998. The double disk test with erythromycin and clindamycin disks was employed as a screening method to detect ERY-resistant streptococci and to determine the phenotype of macrolide resistance. Disk diffusion was also employed for determining penicillin susceptibility. Macrolide-resistant isolates were also tested for penicillin, ceftriaxone, erythromycin, clindamycin and azithromycin susceptibility by the agar dilution method. Additionally they were also tested for erythromycin susceptibility by E-test (AB Biodisk, Solna, Sweden). All streptococci studied were susceptible to penicillin and thirty of them (12.0%) were resistant to erythromycin. All these resistant isolates were also resistant to azithromycin but susceptible to ceftriaxone and clindamycin. They showed the phenotype M (probably efflux-mediated mechanism) and the MICs of erythromycin ranged between 8 and 16 micrograms/ml. According to these results we conclude that in spite of universal susceptibility to penicillin in S. pyogenes, macrolide resistance is a matter of concern in Neuquén and Cipolletti. At least in those cities it appears to be necessary to routinely perform macrolide susceptibility tests in beta-hemolytic streptococci.
Asunto(s)
Antibacterianos/farmacología , Eritromicina/farmacología , Penicilinas/farmacología , Streptococcus pyogenes/efectos de los fármacos , Argentina , Farmacorresistencia Microbiana , Resistencia a las PenicilinasRESUMEN
Son ampliamente conocidos por los pediatras los procedimientos a seguir ante las heridas inflingidas a un niño por perros, gatos o por otros seres humanos. En esta actualización se detallan los microorganismos causales de infecciones posteriores a mordeduras, enfatizando aquellos vinculados a agresiones de otros animales. En casos de mordeduras por animales de granja, salvajes (en especial reptiles) y acuáticos es necesario considerar la inclusión, en el esquema profiláctico empírico inicial, antibióticos activos frente a enterobacterias, Aeromonas, Vibrio y Pseudomonas. En el caso de mordeduras de monos se debe tener en cuenta la posibilidad de infecciones virales potencialmente fatales, en las provocadas por roedores, la esporotricosis y en las producidas por animales acuáticos, las micobacterias atípicas como Mycobacterium marinum o Mycobacterium haemophilum, dado que desarrollan en medios para micobacterias pero a 30ºC (AU)
The adequate procedures to follow in children with bite wounds inflicted by dogs, cats, or by other human beings are well known by pediatricians. This update describes microorganisms that may cause infections in bite wounds, with a focus on those caused by other animals. In bite injuries caused by farm, wild (especially reptiles), and aquatic animals, antibiotics effective against Enterobacteriaceae, Aeromonas, Vibrio, and Pseudomonas should be included in the initial empirical prophylactic treatment scheme. In case of bite injuries caused by monkeys, the possibility of potentially fatal viral infections should be taken into account, in the case of bites by rodents the possibility of sporotricosis should be considered, and in bite wounds inflicted by aquatic animals atypical mycobacteria, such as Mycobacterium marinum or Mycobacterium haemophilum, should be taken into account as they develop in an environment for mycobacteria, but at 30ºC (AU)
Asunto(s)
Humanos , Antibacterianos/uso terapéutico , Mordeduras y Picaduras/epidemiología , Mordeduras y Picaduras/microbiología , Mordeduras y Picaduras/mortalidad , Mordeduras HumanasRESUMEN
Kingella kingae es un agente causal de infecciones osteoarticulares especialmente en niños menores de 4 años. En este trabajo se ha realizado un estudio comparativo entre un método molecular [reacción en cadena de la polimerasa (PCR) en tiempo real y dos métodos microbiológicos habitualmente empleados para el estudio de las infecciones osteoarticulares. Sólo se obtuvo resultado positivo para K. kingae por el método de PCR en 3 de las 60 muestras analizadas. Los pacientes evolucionaron sin secuelas aparentes con tratamiento antibiótico. Es importante destacar, como ya lo han hecho otros autores, que adicionando métodos moleculares se puede aumentar sensiblemente la recuperación de este patógeno.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Artritis Infecciosa/diagnóstico , Artritis Infecciosa/etiología , Diagnóstico , Discitis/diagnóstico , Discitis/etiología , Kingella kingae , Técnicas de Diagnóstico Molecular , Reacción en Cadena de la Polimerasa , ArgentinaRESUMEN
Susceptibility to penicillin, vancomycin, imipenem, streptomycin, kanamycin and gentamicin was tested in 130 clinical isolates of Enterococcus spp. by an agar dilution method. Penicillin resistance (MIC > 8 mg/l) was only observed among strains of Enterococcus faecium and Enterococcus raffinosus. Thirty-nine percent of the penicillin-resistant enterococci showed low-level resistance to at least one of the three aminoglycosides tested (gentamicin, kanamycin and streptomycin). Six Enterococcus strains (5 E. faecium and 1 E. raffinosus) with low-level resistance to gentamicin and different MICs for penicillin were tested for antibiotic synergy using time-killing curves. When penicillin concentrations equal to or higher than the MICs were used, synergism was established, even when highly penicillin-resistant strains (MIC > 200 mg/l) were tested. No synergy was observed when penicillin concentrations were below the MICs.
Asunto(s)
Antibacterianos/farmacología , Enterococcus/efectos de los fármacos , Resistencia a las Penicilinas , Penicilinas/farmacología , Aminoglicósidos , Sinergismo Farmacológico , Enterococcus/clasificación , Humanos , Pruebas de Sensibilidad Microbiana , Especificidad de la Especie , Vancomicina/farmacologíaRESUMEN
Four strains that were moderately susceptible to penicillin and/or ampicillin were found among 54 consecutive isolates of meningococci recovered from patients in one pediatric hospital in Argentina from October 1991 to December 1992. Disk diffusion tests performed with 2 U of penicillin failed to detect one strain. These findings suggest that attention should be paid to changes in the susceptibility patterns of meningococci in order to anticipate therapeutic failures in the future.
Asunto(s)
Ampicilina/farmacología , Neisseria meningitidis/efectos de los fármacos , Neisseria meningitidis/aislamiento & purificación , Penicilinas/farmacología , Argentina , Humanos , Meningitis Meningocócica/sangre , Meningitis Meningocócica/líquido cefalorraquídeo , Pruebas de Sensibilidad MicrobianaRESUMEN
Six beta-lactamase-producing (Bla+) isolates of Enterococcus faecalis recovered over a 17-month period from an Argentinian pediatric hospital were found to have identical or almost identical chromosomal restriction patterns by pulsed-field gel electrophoresis, although the plasmid patterns were different. These isolates, like Bla+ enterococci in the United States, hybridized to a staphylococcal Bla gene probe. The presence of a single strain was somewhat surprising, since all isolates transferred Bla by conjugation.
Asunto(s)
Enterococcus faecalis/aislamiento & purificación , Gentamicinas/farmacología , Hospitales Pediátricos , beta-Lactamasas/metabolismo , Argentina , Farmacorresistencia Microbiana , Enterococcus faecalis/enzimología , Enterococcus faecalis/genética , Genoma Bacteriano , Humanos , Hibridación Genética , PlásmidosRESUMEN
Beta-lactamase-producing (Bla+) enterococci have been reported in three state and two countries. Pulsed-field gel electrophoresis was used to compare 14 Bla+ Enterococcus (Streptococcus) faecalis isolated from hospitalized patients in seven states and three continents. The restriction endonuclease digestion patterns of isolates from Connecticut, Massachusetts, Lebanon, and Argentina were all markedly different, indicating that these were different strains. However, isolates from Delaware, Texas, Pennsylvania (Philadelphia and Pittsburgh), Florida, and Virginia were similar, indicating that these isolates were derivatives of a single strain. This conclusion was supported by hybridization using individual fragments as probes. Spread of Bla+ enterococci within the hospital setting was also demonstrated. These findings illustrate the value of pulsed-field gel electrophoresis for epidemiologic analyses and support the importance of identifying and containing organisms with new resistance properties in an effort to decrease their transmission to and from, as well as within, hospitals.
Asunto(s)
ADN Bacteriano/análisis , Enterococcus faecalis/clasificación , Infecciones Estreptocócicas/microbiología , beta-Lactamasas/biosíntesis , Argentina , Boston , Connecticut , Delaware , Electroforesis en Gel de Agar , Enterococcus faecalis/enzimología , Enterococcus faecalis/genética , Florida , Humanos , Líbano , Hibridación de Ácido Nucleico , Pennsylvania , Philadelphia , Plásmidos , Mapeo Restrictivo , Infecciones Estreptocócicas/transmisión , Texas , VirginiaAsunto(s)
Cefuroxima/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Streptococcus pneumoniae/efectos de los fármacos , Resistencia a las Cefalosporinas , Niño , Interpretación Estadística de Datos , Errores Diagnósticos , Estudios de Evaluación como Asunto , Humanos , Pruebas de Sensibilidad Microbiana/estadística & datos numéricos , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/microbiología , Streptococcus pneumoniae/aislamiento & purificaciónRESUMEN
Erythromycin (ERY) resistance in Streptococcus pyogenes has recently emerged as a problem of growing concern all through the world. We are presenting the comparison of results of the continuous surveillance of erythromycin resistance in S. pyogenes performed since 1989 in the Hospital de Pediatría J.P.Garrahan of Buenos Aires City, with independently observed rates in other five centers of Buenos Aires and seven centers of six other Argentinian cities, obtained between 1999 and 2001. A significant increase of erythromycin resistance was observed among S. pyogenes isolated in the Hospital Garrahan (6.6% in 1998-1999 to 9.9% in 2000). Similar trends were also detected in other centers of other Argentinian cities when recent data were compared to results of a multicenter study performed in 1995. However, lower rates of resistance were recorded in Mendoza, Cipolletti and Neuquén in comparison with data of 1995, 1998 and 1998 respectively. The reason of such decreasing resistance rates deserves to be investigated. The average of ERY-resistance rates obtained in the surveyed centers was 6.7% (range 0.5-14.1%). Control of antimicrobial use should be performed to warrant the future effectiveness of macrolide antibiotics regarding the positive association between use and resistance. These results also suggest that susceptibility tests for macrolides should be performed whenever S. pyogenes is isolated in Argentina.
La resistencia a la eritromicina en Streptococcus pyogenes ha emergido en los últimos tiempos como un problema creciente en todo el mundo. En este trabajo se presenta la comparación de los resultados de la vigilancia continua de la resistencia a la eritromicina que se viene realizando en el Hospital de Pediatría J.P.Garrahan de Buenos Aires desde 1989, con resultados independientes de otros cinco centros de la ciudad de Buenos Aires y siete de otras seis ciudades argentinas, obtenidos entre 1999 y 2001. Se observó un aumento significativo en el Hospital Garrahan (6.6% en1998-1999 a 9.9% en el año 2000) y una tendencia similar en otros centros de diversas ciudades argentinas si secomparan estos datos con los de un estudio multicéntrico realizado en 1995. No obstante, se registraron menoresporcentajes de resistencia en Mendoza, Neuquén y Cipolletti, en relación a lo hallado en 1995, 1998 y 1998respectivamente. La razón de esta disminución merece ser investigada. El porcentaje promedio de resistencia aeritromicina obtenido en los distintos centros participantes de este estudio fue de 6.7% (rango 0.5-14.1%). Debeefectuarse un control en el uso de estos antibióticos para garantizar la efectividad futura de los macrólidos, teniendo en cuenta la asociación estrecha entre uso y resistencia. Estos resultados sugieren que deberían realizarse pruebas de sensibilidad a los macrólidos para todos los aislamientos de S. pyogenes en la Argentina.
Asunto(s)
Humanos , Niño , Antibacterianos/uso terapéutico , Eritromicina/uso terapéutico , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus pyogenes/efectos de los fármacos , Argentina , Farmacorresistencia Bacteriana , Hospitales Pediátricos , Pruebas de Sensibilidad Microbiana , Estudios Multicéntricos como AsuntoRESUMEN
A fatal case of Erysipelothrix rhusiopathiae mitral valve endocarditis is described in a 45 years old male, with a history of chronic alcohol abuse and without animals contact. He presented intermittent fever, polyarthralgia, weight loss, and low back pain. In blood cultures (2 bottles), gram-positive pleomorphic rods grew after 48 hours of incubation. The subculture on blood agar media showed a small, alpha-hemolytic colony, catalase and oxidase negative, PYR and LAP positive and the production of H2S in triple sugar iron agar, was demonstrated. The isolate was initially identified as E. rhusiopathiae, and confirmed by API Coryne (BioMérieux). On the basis of these findings and a transthoracic echocardiogram, an endocarditis was confirmed. Intravenous ampicillin and gentamicin treatment was initiated. The patient became afever, nevertheless he died on day 19 after admission as a consequence of acute pulmonary edema. Susceptibility testing by E-test showed that the microorganism was resistant to vancomycin and gentamicin, and susceptible to penicillin and cefotaxime. We emphasize the importance to consider the isolates of gram-positive pleomorphic rods, catalase and oxidase negative, and the addition of H2S production test in TSI medium. Vancomycin-resistance helps in the identification, and to establish the correct antimicrobial therapy. Although E. rhusiopathiae is usually reported as an occupational pathogen, the contact with pigs and other farm animals may be underestimated.
RESUMEN
Dentro del género Capnocytophaga existen dos grupos de bacilos Gram-negativos de dificil crecimiento previamente conocidos como grupos DF-1 y DF-2 del CDC. En ellos se incluye a las especies C. ochracea, C. gingivalis, C. sputigena (ex DF-1), C. canimorsus y C. cynodegmi (ex DF-2 y DF-2 like). Probablemente, en el futuro, se agregue a este género otro grupo de bacterias actualmente conocidas como grupo DF-3 del CDC. Las tres primeras especies se asocian a sepsis en pacientes neutropénicos que reciben quimioterapia, aunque también son capaces de producir infecciones en huéspedes normales. C. canimorsus ha sido reconocida como agente causal de infecciones severas secundarias a contacto previo con animales en pacientes alcohólicos, esplenectomizados o tratados con corticoides. C. cynodegmi ha sido aislada de mordeduras de animales en pacientes normales. Parecería que las bacterias del grupo DF-3 podrían tener que ver con cuadros de diarrea prolongada. Es destacable además el hallazgo de C. cynodegmi en un caso de endoftalmitis en un paciente con transplante de córnea y el informe de algunos casos de infecciones perinatales producidas por bacterias del antiguo grupo DF-1. La sensibilidad de estos microorganismos es bastante amplia. La mayor experiencia clínica es la registrada con penicilina, que parece ser el antibiótico de elección. Sin embargo, es necesario destacar que se han aislado cepas de Capnocytophaga productoras de beta-lactamasas. El aislamiento de estas bacterias a partir de muestras clínicas constituye un desafío para los microbiólogos. Su desarrollo puede lograrse utilizando placas de agar tripteína de soya adicionadas de sangre al 5 por ciento e incubándolas en aero o anaerobiosis en presencia de CO2 al 5 por ciento por espacio de al menos 5 días. Su diferenciación a nivel de especie puede resultar engorrosa por la superposición de resultados en varias pruebas. De todos modos, las pruebas de oxidasa, catalasa, movilidad y arginina separan bien a los antiguos grupos DF-1 y DF-2 entre sí y de otras bacterias similares