[Acute gastroenteritis caused by a Vibrio cholerae non-O1, non-O139 strain harboring a genetic region homologous to the VpaI-7 pathogenicity island]. / Gastroenteritis aguda causada por Vibrio cholerae no-O1, no-O139 que porta una región homologa a la isla de patogenicidad VpaI-7.

Pathogenic Vibrio cholerae isolates, the etiologic agents of cholera, generally express one of two O antigens (O1 or O139). Most environmental isolates are nonpathogenic and are referred to as "non-O1, non-O139". However some V. cholerae non-O1, non-O139 strains are clearly pathogenic and have caused outbreaks or sporadic cases of gastroenteritis and extraintestinal infections in humans. We report a case of acute gastroenteritis by a V. cholerae non-O1, non-O139 harboring a genetic region homologous to a segment of the VpaI-7 V. parahaemolyticus pathogenicity island.

Gastroenteritis aguda causada por Vibrio cholerae no-O1, no-O139 que porta una región homologa a la isla de patogenicidad VpaI-7 / Acute gastroenteritis caused by a Vibrio cholerae non-O1, non-O139 strain harboring a genetic region homologous to the VpaI-7 pathogenicity island

Pathogenic Vibrio cholerae isolates, the etiologic agents of cholera, generally express one of two O antigens (O1 or O139). Most environmental isolates are nonpathogenic and are referred to as "non-O1, non-O139". However some V. cholerae non-O1, non-O139 strains are clearly pathogenic and have caused outbreaks or sporadic cases of gastroenteritis and extraintestinal infections in humans. We report a case of acute gastroenteritis by a V. cholerae non-O1, non-O139 harboring a genetic region homologous to a segment of the VpaI-7 V. parahaemolyticus pathogenicity island.

Cepas patogénicas de Vibrio cholerae, el agente causal del cólera, expresan generalmente uno de dos antígenos O (denominados O1 u O139). La mayoría de las cepas ambientales son no patogénicas y corresponden al tipo denominado "no-O1, no-O139". Sin embargo, algunas cepas de este tipo son claramente patogénas y han causado brotes de gastroenteritis e infecciones extra-intestinales en humanos. Se reporta un caso clínico de gastroenteritis aguda causado por una cepa de V. cholerae no-O1, no-O139 que contiene en su genoma una región homóloga a un segmento de la isla de patogenicidad VpaI-7 descrita previamente en V. parahaemolyticus.

[Bacteremia and endarteritis cases secondary to Campylobacter spp. in a metropolitan hospital: our experience along a quarter of a century]. / Bacteriemias e infección endovascular por Campylobacter spp: nuestra experiencia en un cuarto de siglo de historia.

Six cases of bacteremia and one of endarteritis were identified between 1986 and 2010 in a general hospital in Chile. Five of these cases occurred during the second half of this timeframe, Campylobacter fetus predominated (5 out of 7) and the majority of the infections presented during warmer months. The mean age was 32.4 years (range 19 to 63) all had comorbidities, and main clinical manifestations included fever with diarrhea. Four patients developed hypotension and two septic shock. The latter, associated to C. fetus bacteremia, died before microbiological diagnosis. Six out of 7 patients received antimicrobial therapy. During 2004 and 2010, the rates of Campylobacter spp. positive stool cultures in the same hospital increased 4 times, suggesting an emerging profile. Bacteremia and endarteritis by Campylobacter spp. can develop in vulnerable patients and manifest as fever with or without diarrhea. Finding curved or spiral shaped gram negative rods in blood cultures leads to suspect this pathogen. Species identification is of utmost importance due to antimicrobial resistance especially in C. jejuni. Prognosis is unfavorable due to host characteristics, and case-fatality rate is high.

Bacteriemias e infección endovascular por Campylobacter spp: nuestra experiencia en un cuarto de siglo de historia / Bacteremia and endarteritis cases secondary to Campylobacter spp. in a metropolitan hospital: Our experience along a quarter of a century

Six cases of bacteremia and one of endarteritis were identified between 1986 and 2010 in a general hospital in Chile. Five of these cases occurred during the second half of this timeframe, Campylobacterfetus predominated (5 out of 7) and the majority of the infections presented during warmer months. The mean age was 32.4 years (range 19 to 63) all had comorbidities, and main clinical manifestations included fever with diarrhea. Four patients developed hypotension and two septic shock. The latter, associated to C. fetus bacteremia, died before microbiological diagnosis. Six out of 7 patients received antimicrobial therapy. During 2004 and 2010, the rates of Campylobacter spp. positive stool cultures in the same hospital increased 4 times, suggesting an emerging profile. Bacteremia and endarteritis by Campylobacter spp. can develop in vulnerable patients and manifest as fever with or without diarrhea. Finding curved or spiral shaped gram negative rods in blood cultures leads to suspect this pathogen. Species identification is of utmost importance due to antimicrobial resistance especially in C. jejuni. Prognosis is unfavorable due to host characteristics, and case-fatality rate is high.

Se presentan seis casos de bacteriemia y uno de infección vascular por Campylobacter spp, observados en 25 años, con el fin de describir sus características clínicas. Cinco de ellos se registraron en la segunda mitad del período, en concomitancia con el incremento de este agente en el porcentaje de coprocultivos, lo que sugiere un perfil emergente. Las infecciones fueron más frecuentes en los meses cálidos, asociadas principalmente a C. fetus (5 de 7) y a co-morbilidad. La edad promedio de los pacientes fue de 32,4 años (rango 19 a 63 años) y todos tenían comorbilidades. Las manifestaciones clínicas más frecuentes fueron diarrea y fiebre (5 de 7 casos) y dos pacientes cursaron con shock séptico (28,6 por ciento). La evolución fue favorable en cinco pacientes pero los dos que presentaron shock asociado a C. fetus fallecieron (28,6 por ciento). Las bacteriemias o infecciones vasculares por Campylobacter spp., aunque infrecuentes, pueden presentarse en pacientes vulnerables y debutar como cuadros febriles, en presencia o ausencia de diarrea. La identificación de la especie involucrada es de suma importancia debido a la escasa actividad terapéutica de cefalosporinas de tercera generación y quinolonas. El pronóstico de estas bacteriemias es grave debido a las características del hospedero y a su elevada letalidad.

[Vibrio parahaemolyticus bacteremia: case report and literature review]. / Bacteriemia por Vibrio parahaemolyticus: Reporte de caso y revisión de la literatura.

Vibrio parahaemolyticus is a facultative anaerobic gram negative rod responsible of sea food-associated diarrhoea. Although less common, it also causes wound infections and bacteraemia. We present a case of bacteraemia by this agent and a review of the literature.

[Risk factors associated to vancomycin-resistant enterococccus colonization in the Army Hospital in Santiago]. / Estudio de factores de riesgo para colonización por enterococo resistente a vancomicina en el Hospital Militar de Santiago.

Since the appearance of Vancomicin-resistant enterococci (VRE) in our country, the Chilean Ministry of Health recommended the surveillance of intestinal colonization in patients in critical wards. We report the results of surveillance in ICU and onco-hematological wards from 2002 to 2008, with analysis of possible risk factors: demographical data, use and type of antibiotic, days of hospitalization prior to sampling, and year of hospitalization. Colonization rate increased from 0.03 cases per 1000 bed-days in 2003 to 0.18 cases during 2008. Univariate analysis identified 7 risk factors associated with ERV colonization: hospitalization in ICU, use of antibiotics, use of 3 or more compounds, use of imipenem or colistin, >10 days of hospitalization prior to the study and year of hospitalization (before 2007 or after). Multivariate analysis by logistic binary regression showed that only the last two: >10 days of hospitalization prior to the study and year of hospitalization (before 2007 or after), were significantly associated to colonization by ERV.

Bacteriemia por Vibrio parahaemolyticus: reporte de caso y revisión de la literatura / Vibrio parahaemolyticus bacteremia: case report and literature review

Vibrio parahaemolyticus is a facultative anaerobio gram negative rod responsible of sea food-associated diarr-hoea. Although less common, it also causes wound infections and bacteraemia. We present a case of bacteraemia by this agent and a review of the literature.

Vibrio parahaemolyticus es un bacilo gram negativo, anaerobio facultativo, responsable de brotes de síndrome diarreico agudo por ingestión de mariscos crudos o mal cocidos contaminados. Ocasionalmente. se ha reportado asociado a infección de heridas y sepsis. Se reporta un caso clínico de bacteriemia por este microorganismo y se realiza una revisión de la literatura.

Estudio de factores de riesgo para colonización por enterococo resistente a vancomicina en el Hospital Militar de Santiago / Risk factors associated to vancomycin-resistant enterococccus colonization in the Army Hospital in Santiago

Since the appearance of Vancomicin-resistant enterococci (VRE) in our country, the Chilean Ministry of Health recommended the surveillance of intestinal colonization in patients in critical wards. We report the results of surveillance in ICU and onco-hematological wards from 2002 to 2008, with analysis of possible risk factors: demographical data, use and type of antibiotic, days of hospitalization prior to sampling, and year of hospitaliza-tion. Colonization rate increased from 0.03 cases per lOOObed-days in2003 to 0.18 cases during2008. Univariate analysis identified 7 risk factors associated with ERV colonization: hospitalization in ICU, use of antibiotics, use of 3 or more compounds, use of imipenem or colistin, > 10 days of hospitalization prior to the study and year of hospitalization ( before 2007 or after). Multivariate analysis by logistic binary regression showed that only the last two: >10 days of hospitalization prior to the study and year of hospitalization (before 2007 or after), were significantly associated to colonization by ERV.

Desde la emergencia de Enterococcus resistente a vancomicina (ERV) en Chile, el Ministerio de Salud recomendó la vigilancia de colonización intestinal por ERV en pacientes hospitalizados en unidades de pacientes críticos. Describimos los resultados de vigilancia en UCI y Unidad de Aislamiento de Pacientes Hemato-oncológicos desde 2002 a 2008, analizando probables factores de riesgo: datos demográficos, uso y tipo de antimicrobiano, días de hospitalización previo a la toma de muestra y año de hospitalización. La tasa de colonización aumentó de 0,03 casos por 1000 días cama en 2003 a 0,18 durante 2008. El análisis univariado permitió identificar siete factores asociados al riesgo de colonización por ERV: hospitalización en UCI, uso previo o actual de antimicrobianos, haber recibido tres o más antibióticos, terapia con imipenem o colistin, más de 10 días de hospitalización y el año de hospitalización. El análisis multivariado mediante regresión logística binaria, señaló la duración de la hospitalización hasta el momento del estudio (> 10 días) y el año de hospitalización (2007 o después) como factores significativamente asociados al riesgo de colonización por ERV.

[Multicenter study on the monitoring of in vitro susceptibility to tigeeyeline in Santiago, Chile]. / Estudio multicéntrico de la vigilancia de la susceptibilidad in vitro a tigeciclina en Santiago de Chile.

The objective of this multicenter study was to determine tigecycline susceptibility rates, measured by agar diffusion, in nine hospitals in Santiago and to compare these rates with other antimicrobials. Each center studied 20 strains per month. All intermediate and fully resistant strains as well as 10% of susceptibile strains were also studied by the broth microdilution method. Overall, 2301 strains were studied displaying the following susceptibility rates for tigecycline: 100% for Streptococcus sp, Enterococcus sp, and E. coli respectively, 99.8% for Staphylococcus sp, 93% for Klebsiella and 80% for Acinetobacter baumarmii. For Proteus, Providencia and Morganella the susceptibility rates were 4%. For cefotaxime-resistant Klebsiella and imipenem-resistant A. baumarmii susceptibility rates were 95% and 80% respectively. The agar diffusion and broth dilution method were 100% concordant for tigecycline susceptible strains but only 27% for resistant or intermediate strains represented mostly by Acinetobacter baumannii. The majority of these strains (57/59) proved to be susceptible after retesting. The great majority (96,6%) of strains tested from nine Chilean hospitals proved to be susceptible to tigecycline with exception for Proteus, Providencia and Morganella (66% resistance). Using the agar diffusion method for measuring tigecycline susceptibility to A. baumannii may be misleading.

Estudio multicéntrico de la vigilancia de la susceptibilidad in vitro a tigeciclina en Santiago de Chile / Multicenter study on the monitoring of in vitro susceptibility to tigeeyeline in Santiago, Chile

The objective of this multicenter study was to determine tigeeyeline susceptibility rates, measured by agar diffusion, in nine hospitals in Santiago and to compare these rates with other antimicrobials. Each center studied 20 strains per month. All intermedíate and fully resistant strains as well as 10 percent of susceptibile strains were also studied by the broth microdilution method. Overall, 2301 strains were studied displaying the foliowing susceptibility rates for tigeeyeline: 100 percent for Streptococcus sp, Enterococcus sp, and E. coli respectively, 99.8 percent for Staphylococcus sp, 93 percent for Klebsiella and 80 percent for Acinetobacter baumarmii. For Proteus, Providencia and Morganella the susceptibility rates were 4 percent. For cefotaxime-resistant Klebsiella and imipenem-resistant A. baumarmii susceptibility rates were 95 percent and 80 percent respectively. The agar diffusion and broth dilution method were 100 percent concordant for tigeeyeline susceptible strains but only 27 percent for resistant or intermedíate strains represented mostly by Acinetobacter baumannii. The majority of these strains (57/59) proved to be susceptible after retesting. The great majority (96,6 percent) of strains tested from nine Chilean hospitals proved to be susceptible to tigeeyeline with exception for Proteus, Providencia and Morganella (66 percent resistance). Using the agar diffusion method for measuring tigeeyeline susceptibility to A. baumannii may be misleading.

Para conocer la susceptibilidad a tigeciclina por difusión en agar en nueve hospitales de Santiago y comparar la susceptibilidad con otros antimicrobianos, se diseñó este estudio multicéntrico. Cada centro estudió 20 cepas mensualmente. Las intermedias, resistentes y 10 por cientoo de las susceptibles se re-testearon y estudiaron por microdilución en caldo. Se incluyeron 2.304 cepas. Fueron susceptibles a tigeciclina Strep-tococcus sp (100 por cientoo), Enterococcus sp (100 por ciento), E. coli (100 por cientoo), Staphylococcus sp (99,8 por ciento), Klebsiella pneumoniae (93 por ciento) y Acinetobacter baumannii (80 por ciento). En Proteus, Providencia y Morganella la susceptibilidad fue 4 por cientoo. Klebsiella resistente a cefotaxima y Acinetobacter resistente a imipenem, 95 por cientoo y 80 por cientoo fueron susceptibles a tigeciclina, respectivamente. La concordancia en cepas susceptibles y en las enviadas como resistentes o intermedias (A. baumannii) fue 100 por cientoo y 27 por cientoo respectivamente. El re-testeo confirmó que la mayoría eran susceptibles. Los patrones de susceptibilidad bacteriana muestran muy buena actividad in vitro a tigeciclina. La resistencia in vitro de A. baumannii por difusión en agar debe interpretarse con precaución.

[Presence of metallo beta-lactamases in imipenem-resistant Pseudomonas aeruginosa]. / Presencia de metalo-beta-lactamasas en Pseudomonas aeruginosa resistente a imipenem.

BACKGROUND: Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. AIM: To detect the presence of MBL in imipenem resistant Psae strains. MATERIAL AND METHODS: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains were studied by pulse field gel electrophoresis. RESULTS: The presence of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. All the strains were also multiresistant. CONCLUSIONS: The presence of MBL was detected in 19% of imipenem resistant Psae strains.

Presencia de metalo-ß-lactamasas en Pseudomonas aeruginosa resistente a imipenem / Presence of metal lo ß-lactamases in imipenem-resistant Pseudomonas aeruginosa

Background: Metallo-ß-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. Aim: To detect the presence of MBL in imipenem resistant Psae strains. Material and methods: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains, were studied by pulse field gel electrophoresis. Results: The presente of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. AH the strains were also multiresistant. Conclusions: The presence of MBL was detected in 19 percent of imipenem resistant Psae strains.

Consenso: manejo racional del paciente con cáncer, neutropenia y fiebre / Consensus: rational approach towards the patient with cancer, fever and neutropenia

La intensidad y duración de la neutropenia post quimioterapia fueron identificadas en la década del 60 como los factores de mayor relevancia predisponentes a infecciones en pacientes con cáncer. A inicios de la década del 70 se estableció un manejo estandarizado para todos los episodios de neutropenia febril (NF), consistente en hospitalización y terapia antimicrobiana intravenosa empírica, de amplio espectro, lo que se tradujo en una importante disminución de la mortalidad por infecciones bacterianas en estos pacientes. En los últimos 10 a 15 años, distintos grupos de investigadores han considerado poco beneficiosas estas estrategias estandarizadas, que proporcionan un manejo uniforme a todos los pacientes con episodios de NF, independiente de la gravedad de estos. Así, se acuñaron en la década pasada los conceptos de NF de alto y bajo riesgo, lo que ha permitido implementar estrategias terapéuticas diferenciadas según el riesgo que entrañe el episodio para cada paciente en particular. La Sociedad Chilena de Infectología ha tenido la iniciativa de proponer, en un trabajo conjunto con dos programas gubernamentales: Programa Infantil de Drogas Antineoplásicas y Programa Adulto de Drogas Antineoplásicas y la Sociedad Chilena de Hematología, un consenso de diagnóstico, manejo terapéutico y prevención de NF en adultos y niños con cáncer, considerando básicamente dos aspectos: el cambio de enfoque que esta patología ha tenido en la última década, lo que obliga a una revisión sistematizada del tema, y en segundo lugar, una población creciente de pacientes oncológicos, cada vez con mejores expectativas terapéuticas para su patología de base, lo que exige ofrecer en forma acorde un muy buen manejo de esta complicación. Entregamos este documento con una completa revisión de la literatura médica sobre epidemiología, exploración de laboratorio, categorización de riesgo, enfoque terapéutico y quimioprofilaxis, con la mayor cantidad de datos nacionales disponibles, para ofrecer al equipo de salud que atiende a estos pacientes recomendaciones basadas en evidencias, y acotadas a nuestra realidad nacional.

Estudio microbiológico del tracto respiratorio superior / Microbiological procedures for diagnosis of upper respiratory tract infections

Las infecciones del tracto respiratorio superior son muy comunes, particularmente en niños. Se describen las bacterias que producen faringitis, otitis media aguda y sinusitis aguda y los procedimientos microbiológicos empleados en su identificación.