A common Salmonella Enteritidis sequence type from poultry and human gastroenteritis in Ibagué, Colombia / Un tipo de secuencia común de Salmonella Enteritidis de origen aviar y de humano con gastroenteritis en Ibagué, Colombia

Abstract Introduction: Salmonella Enteritidis is a major cause of human salmonellosis in the world, with contaminated eggs and raw chicken meat as the main routes of infection. The main Salmonella spp. serovars circulating in laying hen farms, the surface of eggs, and in raw chicken carcasses have been identified in Ibagué, Colombia. However, it is unknown whether those serovars are responsible for human gastroenteritis. Objective: To evaluate the genetic relationship between gastroenteritis and Salmonella Enteritidis isolates from poultry and humans using multilocus sequence typing (MLST). Materials and methods: Salmonella spp. was isolated from clinical cases of gastroenteritis (n=110). Antibiotic susceptibility tests, followed by serotyping and MLST were conducted and S. Enteritidis was compared to those from laying hen farms and marketed eggs. Results: Ten isolates of Salmonella spp. were obtained from the stools of people with gastroenteritis. The prevalence of Salmonella spp. in human stools was 9.09%, and S. Enteritidis (n=4), S. Typhymurium (n=2), S. Newport (n=1), S. Uganda (n=1), S. Grupensis (n=1), and S. Braenderup (n=1) were the main serotypes. MLST indicated that a common S. Enteritidis sequence type (ST11) was present in all three sources and showed the same antibiotic resistance pattern. Conclusion: Salmonella Enteritidis ST11 constitutes a link between consumption and manipulation of contaminated eggs and human gastroenteritis in Ibagué. Additional studies would be required to establish if other Salmonella serovars isolated from raw chicken meat are also associated with human gastroenteritis.

Resumen Introducción. Salmonella Enteritidis es una de las mayores causas de salmonelosis en el mundo; los huevos contaminados y la carne de pollo cruda son sus principales fuentes de infección. En Ibagué, Colombia, se han identificado los principales serovares que circulan en granjas, superficies de huevos y canales de pollo, pero se desconoce si esos serovares son responsables de la gastroenteritis. Objetivo. Evaluar la relación genética entre los aislamientos de Salmonella Enteritidis de aves de corral y de humanos con la gastroenteritis mediante tipificación de multiloci de secuencias (Multilocus Sequence Typing, MLST). Materiales y métodos. Se aisló Salmonella spp. de casos clínicos de gastroenteritis (n=110). Se hizo la prueba de sensibilidad antibiótica, así como la serotipificación y la tipificación mediante MLST, y se comparó S. Enteritidis de humanos con la hallada en granjas de gallinas ponedoras y en huevo comercializado (n=6). Resultados. Se aislaron 10 cepas de Salmonella spp. a partir de heces de humanos con gastroenteritis. Se obtuvo una prevalencia de Salmonella spp. de 9,09%, y se identificaron los serotipos S. Enteritidis (n=4), S. Typhymurium (n=2), S. Newport (n=1), S. Grupensis (n=1), S. Uganda (n=1) y S. Braenderup presentes en pacientes con gastroenteritis. Mediante la MLST, se comprobó que un tipo de secuencia común (ST11) de S. Enteritidis estuvo presente en todas las tres fuentes y presentó el mismo patrón de resistencia antibiótica. Conclusión. Salmonella Enteritidis ST11 constituye un vínculo entre el consumo y la manipulación de huevos contaminados, y la gastroenteritis en humanos en Ibagué. Se requieren estudios complementarios para conocer si otros serovares de Salmonella aislados de carne de pollo cruda también se asocian con la gastroenteritis en humanos.

Bacteriemia recurrente por Bordetella bronchiseptica en un paciente con trasplante de medula ósea / Bordetella bronchiseptica recurrent bacteraemia in a patient with bone marrow transplantation

Se reporta un caso de bacteriemia recurrente por Bordetella bronchiseptica en un paciente inmunocomprometido con antecedentes de trasplante alogénico de medula ósea por síndrome mielodisplásico, quien ingresó al hospital por síndrome febril. Bordetella bronchiseptica es un agente patógeno veterinario poco común en humanos que afecta principalmente a pacientes inmunocomprometidos y es causa poco frecuente de bacteriemia.

We report a case of recurrent bacteraemia caused by Bordetella bronchiseptica in an immunocompromised patient with a history of allogenic bone marrow transplantation for myelodysplastic syndrome, who was admitted to hospital with febrile syndrome. Bordetella bronchiseptica is an uncommon human pathogen which mainly affects immunocompromised patients, being a rare cause of bacteraemia.

Gastroenteritis por Salmonella spp. en tres lactantes asociada a contacto con tortugas acuáticas / Salmonella spp. gastroenteritis associated to pet turtles in three infants

Non-typhoidal salmonellosis is an important cause of acute diarrhea in children. Generally they are acquired by consumption of contaminated food, but contact with reptiles is an increasing cause of this zoonoses. We describe three pediatric cases of gastroenteritis by Salmonella (Montevideo, Newport and Pomona), related to having turtles as pets. In two cases, the bacteria were isolated from the patient’s stools and the turtle’s droppings. The same genetic subtype by PFGE was obtained in both isolates. All the children recovered. Information and public health measures should be undertaken to control this zoonoses which affects young children.

Las infecciones por Salmonella no tíficas, son una importante causa de diarrea aguda en niños. Generalmente adquiridas por alimentos contaminados, el contacto con animales, especialmente reptiles, también es responsable de esta zoonosis. Describimos tres casos de lactantes con gastroenteritis por Salmonella (S. Montevideo, S. Newport y S. Pomona), relacionados a contacto con tortugas mascotas. En dos de los casos se aisló Salmonella en las deposiciones de los niños y de las tortugas. En todos hubo proximidad entre los niños y los acuarios y/o tortugas, siendo probable la contaminación en la preparación de alimentos. El estudio de clonalidad por electroforesis de campo pulsado demostró el mismo subtipo genético en el aislado correspondiente al paciente y en el procedente de la mascota, lo cual confirmó la fuente zoonótica de los casos. Esta zoonosis debe ser abordada por las autoridades de salud y las sociedades científicas, ya que representa un importante riesgo para la salud, especialmente de niños pequeños.

Distribution of non-LEE-encoded type 3 secretion system dependent effectors in enteropathogenic Escherichia coli

Enteropathogenic Escherichia coli (EPEC) are important human gastroenteritis agents. The prevalence of six non-LEE genes encoding type 3 translocated effectors was investigated. The nleC, cif and nleB genes were more prevalent in typical than in atypical EPEC, although a higher diversity of genes combinations was observed in atypical EPEC.

Utilidad clínica de la procalcitonina en gastroenteritis aguda / Use of procalcitonin as diagnostic marker in acute gastroenteritis

Introducción: No hay ningún marcador hematológico que diferencie con seguridad entre gastroenteritis aguda (GEA) bacteriana y no bacteriana. Nuestro objetivo fue evaluar la procalcitonina (PCT) como marcador de GEA de origen bacteriano y analizar su correlación con el ingreso hospitalario. Pacientes y Método: Estudio prospectivo de niños diagnosticados de GEA en el departamento de Urgencias durante un período de 7 meses que requirieron de analítica sanguínea y muestras de heces. Se analizaron variables epidemiológicas, clínicas y analíticas. Se excluyeron pacientes con enfermedad digestiva crónica, diarrea prolongada, inmunodeficiencia o tratamiento antibiótico previo. El estudio fue aprobado por el Comité de Ética y se solicitó consentimiento informado. Resultados: Se analizaron 45 pacientes. Los niños con GEA bacteriana tenían mayor edad (p = 0,027), mayor mediana de PCT y proteína C reactiva (PCR) (p = 0,001). Los valores de PCT y PCR que mejor discriminaron la etiología bacteriana fueron PCT > 0,5 mg/L (sensibilidad: 64,3 por ciento, especificidad: 83,9 por ciento, cociente de probabilidad positivo (CPP): 4) y PCR > 3 mg/dL (sensibilidad: 78,6 por ciento, especificidad: 90,3 por ciento, CPP: 8). No se encontró asociación entre la elevación de dichos marcadores y una mayor probabilidad de hospitalización. Conclusión: La procalcitonina, al igual que la PCR, se eleva en gastroenteritis bacterianas (p = 0,001), no siendo estos marcadores predictores de hospitalización.

Introduction: There is no hematological marker that reliably differentiates between bacterial and nonbacterial acute gastroenteritis (AGE). The objective of this study is to evaluate procalcitonin (PCT) as a marker for bacterial AGE and analyze its relationship with hospital admission. Patients and Method: A prospective study of children diagnosed with AGE was conducted at the emergency room during a period of seven months, which required blood and stool samples. Epidemiological, clinical and analytical variables were analyzed. Patients with chronic digestive disease, prolonged diarrhea, immunodeficiency or prior antibiotic treatment were excluded. The study was approved by the Ethics Committee and an informed consent was requested. Results: 45 patients were analyzed. Children with bacterial GEA were older (p = 0.027) and presented higher median PCT and C-reactive protein concentrations (CRP) (p = 0.001). The PCT and CRP values that best discriminated bacterial infection were PCT > 0.05 mg/L (sensibility 64.3 percent specificity 83.9 percent, positive probability coefficient (PPC): 4), and CRP > 3mg/dL (sensibility 78.6 percent, specificity 90.3 percent, PPC: 8). No association between the elevation of these markers and higher hospitalization probability was found. Conclusion: Procalcitonin, like CRP, is elevated in bacterial gastroenteritis (p = 0.001), but these markers are not a predictor of hospitalization.

Diarreia aguda / Acute diarrhea

Diarreia aguda é a passagem de quantidade acima do normal de fezes amolecidas associada ao aumento do número de evacuações. No diagnóstico diferencial das diarreias agudas devem ser enfocados as infecções, as alergias alimentares, a intoxicação alimentar, o uso de medicações e a apresentação inicial de diarreia crônica. Dentre estas possíveis etiologias, especialmente em nosso meio, as causas infecciosas devem sempre vir à mente e constituir uma das primeiras opções na investigação diagnóstica. As infecções intestinais associadas a quadros diarreicos são a segunda causa de mortes de origem infecciosa em todo o mundo, com prevalência estimada de 3 a 5 bilhões de casos/ano. Os autores atualizam as novidades e peculiaridades a respeito do diagnóstico e dos tratamentos — geral e/ou específico — dos diferentes agentes associados à diarreia aguda infecciosa.

Acute diarrhea is the passage of above normal quantities of soft faeces also associated with increased bowel movements. Differential diagnosis of acute diarrhea should be focused on infections, food allergies, food poisoning, use of medications and the initial presentation of chronic diarrhea. Among these possible etiologies, given the environment we live in, infectious causes should always be taken into account and be one of the first options in diagnostic investigation. Intestinal infections associated with diarrheal frames are the second leading cause of infectious deaths worldwide, with an estimated to 3-5 billion cases/per year. In this review, the authors intend to review the new features and aspects concerning diagnosis and treatment — general and/or specific — of the different agents associated with acute infectious diarrhea.

Salmonelloses in the State of Rio Grande do Sul, southern Brazil, 2002 to 2004

Salmonella has been identified as the main aetiological agent responsible for foodborne diseases in several countries worldwide, including Brazil. In the State of Rio Grande do Sul (RS), southern Brazil, previews studies analysed official foodborne illnesses data, identifying Salmonella as the main bacterial agent of foodborne diseases during the period of 1997 to 2001. The present study aimed to analyse the official epidemiological data on salmonelloses occurred in the State of RS, during the period of 2002 to 2004. Even though data on recent salmonelloses were available, only data concerning the period comprising in 2002 to 2004 were analysed because the official worksheet records presented more consistent information about the salmonellosis outbreaks. Results indicated that, among the 624 foodborne outbreaks officially investigated, 202 (32.37%) were confirmed as salmonellosis. Among them 23,725 people were involved, 4,148 became sick, 1,878 were hospitalized and one person died. The season with the highest incidence of salmonelloses was spring, and the most affected age group was composed of people aged between 20 to 49 years old (56.66%). Animal origin foods -especially eggs and meat products -were very often involved with the outbreaks, however homemade mayonnaise was identified as the main food vehicle for salmonelloses (53.51%). The majority of the cases occurred inside private homes (55.81%) and food services (12.1%), and the main factors contributing to the occurrence of the outbreaks were the consumption of products without sanitary inspection (26.7%) and exposure of food at room temperature for more than two hours (18.58%). Similarly to what was previously reported for the period of 1997 to 2001, Salmonella spp. was the most prevalent foodborne disease agent in the State of RS during the years of 2002 to 2004.

Diarreia aguda / Acute diarrhea

Diarreia aguda é a passagem de quantidade acima do normal de fezes amolecidas associada ao aumento do número de evacuações. No diagnóstico diferencial das diarreias agudas devem ser enfocados as infecções, as alergias alimentares, a intoxicação alimentar, o uso de medicações e a apresentação inicial de diarreia crônica. Dentre estas possíveis etiologias, especialmente em nosso meio, as causas infecciosas devem sempre vir à mente e constituir uma das primeiras opções na investigação diagnóstica. As infecções intestinais associadas a quadros diarreicos são a segunda causa de mortes de origem infecciosa em todo o mundo, com prevalência estimada de 3 a 5 bilhões de casos/ano. Os autores atualizam as novidades e peculiaridades a respeito do diagnóstico e dos tratamentos - geral e/ou específico - dos diferentes agentes associados à diarreia aguda infecciosa

Acute diarrhea is the passage of above normal quantities of soft faeces also associated with increased bowel movements. Differential diagnosis of acute diarrhea should be focused on infections, food allergies, food poisoning, use of medications and the initial presentation of chronic diarrhea. Among these possible etiologies, given the environment we live in, infectious causes should always be taken into account and be one of the first options in dignostic investigation. Intestinal infections associated with diarrheal frames are the second leading cause of infectious deaths worldwide, with an estimated to 3-5 billion cases/per year. In this review, the authors inted to review the new features and aspects concerning diagnosis and treatment - general and/or specific - of the different agents associated with acute infectious diarrhea

A case of myopericarditis associated to Campylobacter jejuni infection in the southern hemisphere

Myopericarditis is an infrequent complication of acute diarrheal illness due to Campylobacter jejuni, and it has been mainly reported in developed nations. The first case detected in Chile - an upper-middle income country -, that is coincidental with the increasing importance of acute gastroenteritis associated to this pathogen, is described. Recognition of this agent in stools requires special laboratory techniques not widely available, and it was suspected when a young patient presented with acute diarrhea, fever, and chest pain combined with electrocardiogram (EKG) abnormalities and elevated myocardial enzymes. C. jejuni myopericarditis can easily be suspected but its detection requires dedicated laboratory techniques.

Molecular characterization of Salmonella strains in individuals with acute diarrhea syndrome in the State of Sucre, Venezuela / Caracterização molecular de cepas de Salmonella em indivíduos com síndrome da diarreia aguda no Estado de Sucre, Venezuela

INTRODUCTION:In Venezuela, acute diarrheic syndrome (ADS) is a primary cause of morbi-mortality, often involving the Salmonella genus. Salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat. METHODS: Conventional and molecular methods were used to detect Salmonella strains from 330 fecal samples from individuals of different ages and both sexes with ADS. Polymerase chain reaction (PCR) was used for the molecular characterization of Salmonella, using invA, sefA, and fliC genes for the identification of this genus and the serotypes Enteritidis and Typhimurium, respectively. RESULTS: The highest frequency of individuals with ADS was found in children 0-2 years old (39.4%), and the overall frequency of positive coprocultures was 76.9%. A total of 14 (4.2%) strains were biochemically and immunologically identified as Salmonella enterica subsp. enterica, of which 7 were classified as belonging to the Enteritidis serotype, 4 to the Typhimurium serotype, and 3 to other serotypes. The S. enterica strains were distributed more frequently in the age groups 3-4 and 9-10 years old. CONCLUSIONS: The molecular characterization method used proved to be highly specific for the typing of S. enterica strains using DNA extracted from both the isolated colonies and selective enrichment broths directly inoculated with fecal samples, thus representing a complementary tool for the detection and identification of ADS-causing bacteria.

INTRODUÇÃO: Na Venezuela, síndrome da diarreia aguda (SDA) é a principal causa de mórbi-mortalidade, muitas vezes envolvem o gênero Salmonella. Infecções por Salmonella são associadas com gastroenterite aguda, uma das mais comuns intoxicações alimentares causada pelo consumo de água e alimentos contaminados, principalmente carne. MÉTODOS: Métodos convencionais e moleculares foram usados para detectar cepas de Salmonella em 330 amostras de fezes de indivíduos com SDA de diferentes idades e ambos os sexos. A reação em cadeia da polimerase (PCR) foi utilizada para a caracterização molecular de genes Salmonella invA, sefA e fliC para identificar o gênero e os sorotipos Enteritidis e Typhimurium, respectivamente. RESULTADOS: A maior frequência de indivíduos com SDA foi encontrada em crianças de 0-2 (39,4%) anos, e a frequência total de culturas de fezes positiva foi de 76,9%. Um total de 14 (4,2%) cepas foram bioquímica e imunologicamente identificados como Salmonella enterica subsp. enterica, dos quais 7 foram classificados como pertencentes ao sorotipo Enteritidis, Typhimurium sorotipo 4 e 3 para outros sorotipos. Cepas S. enterica foram distribuídas mais frequentemente em grupos de 3-4 e 9-10 anos de idade. CONCLUSÕES: O método de caracterização molecular usada provou ser altamente específico para tipificar as estirpes dos S. enterica usando tanto DNA extraído de colônias isoladas e direta e caldos de enriquecimento seletivo inoculados com amostras fecais, o que representa uma ferramenta complementar para a detecção e identificação de bactérias que causam a SDA.

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.

Infecciones por Yersinia / Yersinia infections

La Yersinia enterocolitica o la Yersinia pseudotuberculosis pueden tener diferentes formas de presentación entre las que están la enteritis o enterocolitis, la adenitis mesentérica asociada a ileitis distal, la septicemia, infecciones localizadas o manifestaciones extraintestinales. Es responsable de hasta 7 por ciento de los cuadros de gastroenteritis infecciosas y se asocia a una elevada mortalidad post-infección a corto y largo plazo, de 2 a 3 veces mayor. Esta infección bacteriana se adquiere mediante la ingesta oral de productos contaminados y/o inadecuadamente preparados. El aislamiento de Yersinia en las deposiciones es el examen más específico y siempre debe ser solicitado. Debido a su baja sensibilidad los estudios serológicos pueden ser útiles para el diagnóstico, y la reacción de polimerasa en cadena (PCR) puede constituirse próximamente en el examen de elección para el diagnóstico de esta infección. Los antibióticos útiles para su tratamiento son los aminoglicósidos, cefalosporinas de tercera generación, cloranfenicol, quinolonas, tetraciclinas y trimetoprim-sulfametoxazol.

Yersinia enterocolitica or yersinia pseudotuberculosis may have different presentation forms: among those are enteritis or enterocholitis, mesenteric adenitis associated with distal ileitis, septicemia, localized infections or extra-intestinal manifestations. It is responsible for up to 7 percent of infectious gastroenteritis and is associated with high post-infection mortality in the short and long term, which is 2 to 3 times higher. This bacterial infection is acquired through oral consumption of contaminated and/or inappropriately prepared products. Isolation of Yersinia in stool samples is the more specific exam and it should always be performed. Due to its low sensibility, serological studies may be useful for the diagnosis, and the polymerase chain reaction (PCR) may become the elective exam for the diagnosis of this infection in the future. Antibiotics that are useful for its treatment are aminoglycoside, third-generation cephalosporins, chloramphenicol, quinolones, tetracyclines, and Trimetoprim-sulfametoxasol.

Mecanismos moleculares utilizados por Salmonella para causar infecciones del tracto digestivo / Molecular mechanisms used by Salmonella to cause infections in the digestive tract

Salmonella enterica es uno de los principales causantes de gastroenteritis infecciosa en el mundo, debido al consumo de alimentos y aguas contaminadas con esta bacteria. Este grupo de bacterias Gram negativas se caracteriza por tener la capacidad de invadir células eucariontes y sobrevivir en el interior de ellas, evento fundamental para que la bacteria cause una enfermedad tanto localizada como sistémica. Las proteínas de virulencia que este agente utiliza para invadir y sobrevivir en células eucariontes son codificadas por genes presentes en islas de patogenicidad, que corresponden a grandes bloques de material genético integrados en el cromosoma bacteriano y que fueron posiblemente adquiridos a través de transferencia lateral de genes desde otros microorganismos. Estudios recientes han permitido identificar el rol que poseen estas proteínas de virulencia en el proceso infectivo de Salmonella y su impacto en el funcionamiento de la célula eucarionte. De este modo, ha sido posible entender de mejor manera los mecanismos moleculares utilizados para infectar a su hospedero y se han identificado posibles blancos terapéuticos para el tratamiento de los cuadros infecciosos causados por este patógeno.

Salmonella enterica is one of the main ethiological agents of infectious gastroenteritis in the world, due the consumption of food and water contaminated with these bacteria. This group of Gram negative bacterials characterized by its capacity to invade eukaryotic cells and survive inside them, an event that is fundamental for the bacteria to cause a localized as well as a systemic disease. The virulence proteins that this bacterium uses to invade and survive within eukaryotic cells are encoded by genes found in pathogenicity islands, big blocks of genetic material integrated in the bacterial chromosome, that were probably acquired through lateral gene transfer from other microorganisms. Recent studies have identified the role that these virulence proteins play in the infective process of Salmonella, and their impact in the function of the eukaryotic cell. This way, it has been possible to better understand the molecular mechanisms used by Salmonella to infect their hosts, and potential therapeutic targets have been identified to improve the treatment of the infection caused by this pathogen.

Extended-spectrum B-lactamase-producing Salmonella enterica serovar Oranienburg (CTX-M-2 group) in a pediatric hospital in Tucumán, Argentina / Salmonella enterica serovar Oranienburg produtora de B-lactamase de espectro extendido (grupo CTX-M-2) em um hospital pediátrico de Tucumán, Argentina

INTRODUCTION: Salmonella sp infections have been reported over recent years in hospitals in Argentina and other countries due to multiresistant strains. The aim of this study was to characterize the extended-spectrum β-lactamases in third-generation cephalosporin-resistant strains of Salmonella enterica serovar Oranienburg. METHODS: We studied 60 strains isolated from children with gastroenteritis and/or extraintestinal complications. The antibiotic susceptibility patterns of the isolates were analyzed and the β-lactamases were characterized using phenotyping and genotyping methods. RESULTS: All the strains were resistant to ampicillin, cefotaxime, cefepime and aztreonam and partially susceptible to ceftazidime, thus corresponding well with the resistance phenotype conferred by CTX-M-type β-lactamases. An isoelectric point enzyme (pI = 7.9) was detected in all of the strains, and this was confirmed by PCR as a member of the CTX-M-2 group. CONCLUSIONS: This is the first report of Salmonella enterica serovar Oranienburg producing β-lactamases of the CTX-M-2 group in a pediatric hospital in Tucumán, Argentina.

INTRODUÇÃO: Em recentes anos foram informadas infecções por Salmonella sp em hospitais da Argentina e outros países devido as cepas multiresistentes. O objetivo deste estudo era caracterizar as β-lactamasas de espectro extendido em cepas de Salmonella enterica serovar Oranienburg resistentes às cefalosporinas de terceira geração. MÉTODOS: Nós estudamos 60 cepas obtidas de pacientes com gastroenterites e com complicações extraintestinais. Os padrões de susceptibilidade antibiotica foram estudados em os isolamentos, as β-lactamasas foram caracterizadas por métodos fenotípicos e genotípicos. RESULTADOS: Todas as cepas eram resistentes a ampicillin, cefotaxime, cefepime e aztreonam e parcialmente suscetível a ceftazidime que corresponde bem com o fenótipo de resistência conferido por as β-lactamasas tipo CTX-M. Na totalidade das cepas, se detectou uma enzima de ponto isoelétrico (pI) 7,9, confirmada por PCR como pertencente ao grupo CTX-M2. CONCLUSÕES: Este é o primeiro reporte de Salmonella enterica serovar Oranienburg produtora de β-lactamasa grupo CTX-M2 em um hospital pediátrico de Tucuman, Argentina.

Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea / Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

La infección por Vibrio cholerae, el agente causal del cólera, se trasmite al hombre por ingestión de agua y alimentos contaminados. Aunque son los serogrupos O1 y O139 los que habitualmente se asocian al cólera epidémico, los aislamientos de otros serogrupos también son causales de gastroenteritis e infecciones extra-intestinales. Durante el período 2003-2005, se investigó la presencia de V. cholerae en la materia fecal de niños con diarrea atendidos en el Hospital del Niño Jesús, Tucumán. Se recuperaron 34 aislamientos de V. cholerae no-O1, no-O139. Se determinaron sus perfiles de virulencia por PCR, la sensibilidad a los antimicrobianos y la diversidad genética por electroforesis en campo pulsado. Se obtuvieron ocho perfiles de virulencia, aunque ningún aislamiento fue positivo para la toxina colérica ni para la toxina termoestable. Cuatro aislamientos fueron positivos para el sistema de secreción de tipo tres. El 17,6% de los aislamientos fueron resistentes o de sensibilidad intermedia a ampicilina y el 5,9% fueron resistentes a trimetoprima-sulfametoxazol. Los aislamientos resultaron muy diversos: se hallaron 27 patrones distintos en 29 aislamientos tipificables por electroforesis en campo pulsado. A pesar de su baja incidencia, V. cholerae continúa siendo un agente causal de diarrea en niños, los que se ven afectados por una amplia variedad de cepas circulantes.

Vibrio cholerae, etiologic agent of cholera, is transmitted to humans by ingestion of contaminated food or water. Even though serogroups O1 and O139 are the ones usually associated to epidemic cholera, isolates from other serogroups also cause gastroenteritis and extraintestinal infections. During the period 2003-2005, presence of V. cholerae in stools was investigated in children with diarrhea that seaked assistance at the Niño Jesús Hospital in Tucumán. Thirty four isolates of V. cholerae non-O1, non-O139 were recovered. We characterized the isolates studying its virulence factors by PCR, antimicrobial susceptibility patterns and genetic diversity by pulsed-field gel electrophoresis. Eight virulence patterns were obtained although no isolate was positive for the cholera toxin or the thermostable toxin. Four isolates were positive for the type three secretion system. The 17.6% of the isolates were resistant or intermediate to ampicillin and 5.9% were resistant to trimethoprim-sulfamethoxazole. By SfiI-PFGE, all isolates were genetically very diverse, as 27 different patterns were identified in 29 typeable isolates by pulsed-field gel electrophoresis. Although it has a low incidence, V. cholerae continues to be a causative agent of diarrhea in children, who are affected by a variety of circulating strains of V. cholerae non-O1, non-O139.

Brote de enfermedad alimentaria en la localidad de El Huecú, provincia de Neuquén / Foodborne disease outbreak in El Huecú community, province of Neuquén

En febrero de 2006 ocurrió un brote epidémico de gastroenteritis aguda de origen alimentario, en ocasión de un festejo popular en una pequeña localidad de la provincia de Neuquén, Argentina. Aproximadamente 800 personas participaron de un almuerzo en las instalaciones del Gimnasio Municipal, y unas tres horas después de finalizado, cerca de 150 asistentes consultaron al hospital local, afectados por síndrome gastroentérico agudo. Se realizó una investigación epidemiológica caso-control a través de un muestreo representativo no probabilístico. Los resultados epidemiológicos establecieron un brote de ETA a fuente común, con una relación caso-control de 1:1,8. Los principales síntomas fueron cólicos abdominales (88%), vómitos (73,5%) y diarrea (60%). La torta que se sirvió en ese evento fue identificada como el alimento causal (OR 9,79; IC 95%; 2,66-36,00; valor p = 0,0001), sujeto a condiciones higiénico-sanitarias insatisfactorias en los diferentes procesos de elaboración, conservación y manipulación. De una porción de la torta se aisló una cepa de Staphylococcus aureus subespecie aureus, coagulasa positiva, enterotoxigénica, con un recuento de 2,4x10(6) UFC/g, y también se aisló este microorganismo de tres muestras de manos y narinas de personas involucradas en la preparación y el servicio. Las cepas aisladas de un operador y de la torta portaron el gen sea y presentaron el mismo patrón de SmaI-PFGE. Se atribuyó el brote de ETA a la contaminación durante el proceso de preparación de la torta consumida durante ese almuerzo popular, lo que podría estar relacionado con deficiencias en aspectos higiénicos y con la falta de refrigeración y de mantenimiento de la cadena de frío.

In the summer of 2006, an epidemic outbreak of acute gastrointestinal illness related to food consumption occurred in a small town in the province of Neuquén, Argentina. During a popular feast, approximately 800 local residents attended lunch held in the facilities of the Municipal Gymnasium. About three hours later, nearly 150 attendees sought medical assistance at the local hospital due to acute gastroenteritis. A case-control epidemiological investigation was conducted using representative non-probability sampling. The epidemiological investigation showed a common-source foodborne disease outbreak with a case-control ratio of 1:1.8. The main symptoms were abdominal cramps (88%), vomiting (73.5%) and diarrhea (60%). The cake was identified as the source of infection (OR 9.79; IC 95%, 2.66-36.00; p = 0.0001), and unsatisfactory hygienic conditions in food production, conservation and handling steps were identified. Coagulase positive, enterotoxigenic Staphylococcus aureus, subspecies aureus was detected in a piece of cake, with a count of 2.4x10(6) CFU/g, and in samples from the hands and nostrils of three people involved in food preparation and service. The strains isolated from both the cake and one of the food handlers carried the sea gene, and presented the same SmaI-PFGE pattern. The foodborne disease outbreak was considered to be due to contamination in the preparation process of the cake consumed at the feast, which was related to inadequate hygienic conditions, lack of refrigeration and cold chain disruption.

Gastroenteriris / Gastroenteritis

Las gastroenteritis agudas son autolimitadas; su duración oscila generalmente entre 3 y 5 días; su pronóstico es benigno salvo en los niños y ancianos deshidratados; en los pacientes inmunodeprimidos y ocasionalmente en los viajeros. En estos últimos se trata de diarrea acuosa, secretora, sin sangre, habitualmente afebril, acompañada inicialmente por vómitos que cesan rápidamente. Su agente etiológico habitual es la Escherichia coli enterotóxica en la mayorías de los casos. Dada la corta y rápida del cuadro no procede realizar estudio microbiológicos ni administrar antibióticos (Ciprofloxacino o trimetoprim sulfamidazol) salvo si el cuadro es febril y se prolonga por más de 5 días. Cuando hay indicación, se puede administrar ciprofloxacino o trimetoprim sulfamidazol.