Prevalence, associated risk factors, and antimicrobial resistance profiles of non-typhoidal Salmonella in large scale swine production in Córdoba, Argentina.

Non-typhoidal Salmonella is considered a major public health concern. The growing relevance of pigs as reservoir of Salmonella spp. has prompted several countries to set up surveillance and control programs to fight Salmonella infection in swine and reduce public health risk. In the last decade, pork production in Córdoba increased significantly to become one of the most important pig production provinces in Argentina. The aim of this study was to estimate Salmonella spp. prevalence and associated risk factors in large scale-farms in this province. Mesenteric lymph nodes (MLN) of 580 pigs from 20 finishing large-scale farms were collected between 2014 and 2015 to estimate Salmonella infection. A prevalence of 41.5% (95%CI: 37.6-45.6%) was observed. Two major risk factors were significantly associated with Salmonella infection, both related to the pre-slaughter period (distance from the farm to the slaughterhouse and lairage time), highlighting the need to pay special attention to pre-slaughter practices in the province. Shortening transport times and complying with national regulations for lairage time at slaughter may help to reduce the prevalence of infection. Sixteen different serovars were identified, being S. Anatum and S. Typhimurium the most prevalent ones. Moreover, two isolate of the monophasic variant of Salmonella Typhimurium (I 4,5,12:i:-) resistant to enrofloxacin and which also displayed multidrug resistance was isolated for first time from pigs in Córdoba. The moderate to high levels of antimicrobial resistance detected for antibiotics commonly used in the pig sector suggested the need for implementing a plan to limit their use in the province.

Genotypic diversity of Salmonella ser. Abortusequi isolates from Argentina.

BACKGROUND: Salmonella enterica subsp. enterica serovar Abortusequi (S. Abortusequi) is a serotype restricted to equines, which produces abortion outbreaks. Nowadays the disease is being reported in different countries including Argentina thus generating an important impact in the equine industry. Molecular characterization of the 95 kb virulence plasmid and the spvC gene of S. Abortusequi demonstrated their importance in the pathogenicity of the serotype. In the last decades, high clonality of S. Abortusequi was identified in Japan, Mongolia and Croatia. OBJECTIVES: The aim of this work was to characterize S. Abortusequi isolates obtained in Argentina between 2011 and 2016 by virulence-gene profiling and pulsed-field gel electrophoresis. STUDY DESIGN: Case report. METHODS: S. Abortusequi isolates were studied by virulence-gene profiling and pulsed-field gel electrophoresis. RESULTS: Four virulence profiles and nine pulsed-field gel electrophoresis pulsotypes were identified among the 27 isolates included in the study. Different strains were found in the same outbreak and/or farm suggesting the presence of different sources of infection or mutation of isolates. MAIN LIMITATIONS: The number of related and nonrelated strains. More isolates may be necessary for a more intensive study. CONCLUSIONS: Most strains presented the same virulence profile, being positive for all the studied genes except gipA and sopE1, which are involved in intestinal virulence. Only few isolates showed different results in the same outbreak or farm. Unlike other studies, our results demonstrate a considerable diversity of S. Abortusequi pulsed-field gel electrophoresis pulsotypes, which suggests that different sources of infection may be involved within the same outbreak.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella spp. in free-ranging waterfowl from Entre Rios, Argentina.

The present study was conducted to estimate the apparent prevalence of Salmonella spp. in free-ranging waterfowl that inhabitant Entre Ríos, Argentina, determine the antimicrobial resistance of the isolated, and compare the performance of two selective plating media used for Salmonella isolation. Five hundred ninety nine free-living waterfowl were sampled one time by cloacal swab from April 2014 to July 2016. Only 6 samples from waterfowl belonged to all counties sampled were positive to Salmonella spp., so the apparent prevalence was 1%. Four serovars were isolated (Salmonella ser. Typhimurium, S. ser. Schwarzengrund, S. enterica subsp. I [4,12: i: -], S. enterica subsp. IIIb [60: r: e, n, x, z15]), which were susceptible to 15 antibiotics tested and resistant to erythromycin. Furthermore, some strains showed an intermediate resistant to neomycin, ciprofloxacin and/or streptomycin. The multiple antibiotic resistances index was 0.05. For Hektoen enteric agar and Salmonella Shigella agar, the relative accuracy, sensitivity, specificity, positive predictive value, and negative predictive value did not show any difference between them. The agreement was good between these two plating-media and the difference between these plating-media was not statistically significant. The low prevalence of Salmonella spp. in waterfowl in Entre Rios should not be discounted, since Salmonella ser. Typhimurium was the most prevalent serovar and some free-ranging waterfowl species studied can migrate from/to different countries, increasing the possibility to cross-contaminated Salmonella to resident or other migrant birds.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella in backyard chickens from Entre Rios, Argentina.

This study was conducted to estimate the apparent prevalence of Salmonella spp. in birds kept under backyard system in Entre Ríos, Argentina, and determine the performance of two selective plating media used for Salmonella isolation, and the antimicrobial resistance of the isolated. Also, the association of farms characteristics with Salmonella presence was evaluated. A total of 657 backyard chickens and 15 gooses were sampled one time by cloacal swab, belonging to 51 and one family farms, respectively, and four counties in Entre Rios state from April 2014 to May 2015. Only four samples from backyard chickens belonged to three family farms from Uruguay County were positive to Salmonella spp., so the apparent prevalence was 0.6% for this kind of chicken. Four serovars were isolated (Salmonella ser. Lille, S. ser. Newport, S. ser. Enteritidis and S. ser. Rissen), which were susceptible to all antibiotics tested with the exception of erythromycin. For Hektoen enteric agar and brilliant green agar, relative specificity and positive predictive value were 1, and the relative sensitivity and negative predictive value did not show any difference between them. The agreement was very good between these two plating media. None of the variables studied could be selected to calculate the risk factors associated with Salmonella isolation because p > .15. Although the prevalence of Salmonella spp. is low in backyard birds in Entre Rios, the presence of S. ser. Enteritidis should not be discounted, because it is found in the county that concentrates a large population of intensive poultry production in the state.

[Serovars of Salmonella enterica subspecies enterica and its antimicrobial resistance in slaughterhouse pigs]. / Serovariedades de Salmonella enterica subespecie enterica en porcinos de faena y su resistencia a los antimicrobianos.

A study was carried out in order to determine the prevalence of Salmonella and its serovars among porcine slaughterhouses, to evaluate the antimicrobial resistance profiles and to know the presence of class 1 integrons as possible reservoir of resistance. From a total of 386 samples from four porcine slaughterhouses of Buenos Aires and Santa Fe Provinces (Argentina), 93 (24.1%) Salmonella enterica subspecies enterica strains were identified, 52 (55.9%) from cecal contents and 41 (44.1%) from ileocecal lymph nodes. Thirteen serovars of S. enterica were found, the most prevalent were: S. Schwarzengrund, S. Heidelberg, S. subspecie I 6,8:e,h:-, S. Derby and S. Bredeney. Fifteen antimicrobials by the agar dilution method were tested: amikacin, gentamicin, ciprofloxacin, cephalotin, cefotaxime, enrofloxacin, fosfomycin, polimixin-B, tetracycline, chloramphenicol, streptomycin, trimethoprim-sulfamethoxazole, ampicillin, nitrofurantoin, and nalidixic acid. According to the CIM determination, 73% Salmonella enterica subspecies enterica strains were sensible to all the antimicrobials tested. Antimicrobial resistance was observed to tetracycline in 24 (25.8%) of 93 strains, to chloramphenicol in 22 (23.7%), to streptomycin in 22 (23.7%), to trimethoprim-sulfamethoxazole in 20 (21.5%), to ampicillin in 18 (19.4%), to nitrofurantoin in 3 (3.2%) and to nalidixic acid in 3 (3.2%). Some isolates of S. Typhimurium, S. Heidelberg, S. Derby, S. Orion showed multidrug resistance and carried the class 1 integrase gene. The highest percentage of resistance corresponded to the antimicrobials currently used in veterinary and porcine farms.

Serovariedades de Salmonella enterica subespecie enterica en porcinos de faena y su resistencia a los antimicrobianos / Serovars of Salmonella enterica subspecies enterica and its antimicrobial resistance in slaughterhouse pigs

Se realizó un estudio para determinar la prevalencia de Salmonella y sus serovariedades en cerdos de faena, para evaluar sus perfiles de resistencia a los antimicrobianos y para conocer la presencia de integrones de clase 1 como posibles reservorios de resistencia. A partir de un total de 386 muestras de porcinos provenientes de cuatro frigoríficos de las provincias de Buenos Aires y de Santa Fe (Argentina), se identificaron 93 (24,1%) cepas de Salmonella enterica subespecie enterica, 52 (55,9%) de contenido cecal y 41 (44,1%) de nódulo linfático ileocecal. Se hallaron 13 serovariedades de S. enterica, las más prevalentes fueron S. Schwarzengrund, S. Heidelberg, S. subespecie I 6,8:e,h:-, S. Derby y S. Bredeney. Se probaron 15 antimicrobianos por el método de dilución en agar: amikacina, gentamicina, ciprofloxacina, cefalotina, cefotaxima, enrofloxacina, fosfomicina, polimixina-B, tetraciclina, cloranfenicol, estreptomicina, trimetoprima-sulfametoxazol, ampicilina, nitrofurantoína y ácido nalidíxico. Según se estableció mediante la determinación de la CIM, el 73% de las cepas de S. enterica subespecie enterica fueron sensibles a todos los antimicrobianos probados. Se observó resistencia a tetraciclina en 24 (25,8%) de las 93 cepas, a cloranfenicol en 22 (23,7%), a estreptomicina en 22 (23,7%) a trimetoprima-sulfametoxazol en 20 (21,5%), a ampicilina en 18 (19,4%), a nitrofurantoína en 3 (3,2%) y a ácido nalidíxico en 3 (3,2%). Algunos aislamientos de S. Typhimurium, S. Heildelberg, S. Derby y S. Orion presentaron multirresistencia y portaban el gen de la integrasa clase 1. Los mayores porcentajes de resistencia correspondieron a los antimicrobianos habitualmente utilizados en veterinaria y en las explotaciones porcinas.

A study was carried out in order to determine the prevalence of Salmonella and its serovars among porcine slaughterhouses, to evaluate the antimicrobial resistance profiles and to know the presence of class 1 integrons as possible reservoir of resistance. From a total of 386 samples from four porcine slaughterhouses of Buenos Aires and Santa Fe Provinces (Argentina), 93 (24,1%) Salmonella enterica subspecies enterica strains were identified, 52 (55,9%) from cecal contents and 41 (44,1%) from ileocecal lymph nodes. Thirteen serovars of S. enterica were found, the most prevalent were: S. Schwarzengrund, S. Heidelberg, S. subspecie I 6,8:e,h:-, S. Derby and S. Bredeney. Fifteen antimicrobials by the agar dilution method were tested: amikacin, gentamicin, ciprofloxacin, cephalotin, cefotaxime, enrofloxacin, fosfomycin, polimixin-B, tetracycline, chloramphenicol, streptomycin, trimethoprim-sulfamethoxazole, ampicillin, nitrofurantoin, and nalidixic acid. According to the CIM determination, 73% Salmonella enterica subspecies enterica strains were sensible to all the antimicrobials tested. Antimicrobial resistance was observed to tetracycline in 24 (25,8%) of 93 strains, to chloramphenicol in 22 (23,7%), to streptomycin in 22 (23,7%), to trimethoprim-sulfamethoxazole in 20 (21,5%), to ampicillin in 18 (19,4%), to nitrofurantoin in 3 (3,2%) and to nalidixic acid in 3 (3,2%). Some isolates of S. Typhimurium, S. Heidelberg, S. Derby, S. Orion showed multidrug resistance and carried the class 1 integrase gene. The highest percentage of resistance corresponded to the antimicrobials currently used in veterinary and porcine farms.

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

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 Sfil-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.

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.

Environment and virulence factors of Vibrio cholerae strains isolated in Argentina.

AIMS: To determine the presence of Vibrio cholerae in different areas of Argentina in three sample types, to determine the composition of planktonic communities in areas at which this pathogen was detected and to characterize the virulence properties and antimicrobial resistance of the recovered environmental isolates. METHODS AND RESULTS: Water and plankton samples were collected in marine, brackish and freshwater environments. Vibrio cholerae non-O1, non-O139 was isolated in 36.1% of the samples analysed. The micro-organism was detected in freshwater but not in marine or brackish samples. No relationship was found between isolation of V. cholerae and presence of any species of plankton. All the isolates presented very similar virulence profiles by PCR, lacking ctxA and tcpA El Tor and containing hlyA (98.7%), rtxA (99.0%), toxR (98.7%) and stn-sto (1.9%). Resistance to ampicillin was found in both Tucumán (21%) and Buenos Aires isolates (45%). CONCLUSIONS: We identified two geographic areas in Argentina where V. cholerae was present: freshwaters of the rivers from Tucumán and the Río de la Plata. SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of V. cholerae strains in the environment, carrying both virulence factors and resistance to antimicrobial agents, highlight the need for a continuous and active surveillance of this pathogen.

Serotipos, perfil plasmídico y antibiotipos de cepas de Shigella flexneri aisladas de niños menores de 5 años con diarrea sanguinolenta usuarios de los servicios de Salud Pública / Serotypes, serum profile and anti-biotypes of Shigella flexneri cultures isolated from infants under 5 years with diarrhea sanguinolenta users of Public Health Services

Introducción: en niños menores de 5 años con diarrea sanguinolenta, Shigella flexneri es el agente bacteriano más frecuentemente recuperado en nuestro medio. La shigellosis es una de las enfermedades infecciosas en las cuales el tratamiento con antimicrobianos es efectivo. La elección empírica del antimicrobiano adecuado es problemática debido a la resistencia de Shigella a diversos antibióticos. Esta situación estimuló el interés en el desarrollo de vacunas para el control de esta enfermedad. Debido a que algunas vacunas están orientadas a promover la respuesta inmune serotipo específica, es importante establecer la distribución de los serotipos prevalentes en la población que interesa inmunizar. El objetivo de este estudio fue caracterizar 50 cepas de Shigella flexneri aisladas a partir de niños con diarrea sanguinolenta, recuperadas en 4 encuestas etiológicas de gastroenteritis. Método: a cada una se le realizó: serotipificación, estudio del patrón de lipopolisacárido, perfil plasmídico y estudio de sensibilidad a diferentes antimicrobianos. Resultados: los seroptipos prevalentes fueron 2a, 3c, 4, 6, y 1. Se identificaron 10 antibotipos diferentes. En los cultivos del serotipo 2a se hallaron 3 patrones plasmídicos; el 5 fue el más frecuente, seguido por el 6 y el 7. El análisis de la evolución de los antibiotipos circulantes mostró una tendencia hacia la aparición de tipos con mayor espectro de resistencia. Conclusiones: vista esta evolución, y de acuerdo a los resultados obtenidos, resulta de interés ensayar un inmunógeno que incluya los determinantes "O" específicos de los serotipor 2a, 1, 3c, 4, 6 y el de Shigella sonnei.

[Serotypes of Salmonella isolated from the Luján River, Argentina]. / Serotipos de Salmonella aislados del Río Luján, Argentina.

In this work, the serotypes of Salmonella genus polluting the waters of Lujan River, situated in the north east of the province of Buenos Aires, Argentina, were studied. A total of 690 samples of water were collected and analysed from February 1988 through December 1989, at three different sites. They were obtained according to the Moore technique and then preenriched in buffered peptone water and enriched in Rappaport-Vassiliadis Soya peptone broth was carried out. The isolations were realised in brilliant green-desoxycholate agar and bismuth sulphite agar and the presumptive colonies to be Salmonella were tested by the standard biochemical identification. Salmonella spp. was isolated in 434 samples (62.9%). The predominant serotype was S. Anatum, followed in a decreasing order by S. Montevideo, S. Newport and S. Bredeney. A large amount of serotypes that are isolated with very low frequency and very rarely in other hidric courses in the country were: S. Westhampton, S. Poona and S. Saintpaul were found.

[Agglutination of hen egg-yolk immunoglobulins (IgY) against Salmonella enterica, serovar enteritidis]. / Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad enteritidis.

Two groups of 6 laying hens were used to produce IgY. In the vaccinated group (V), hens were injected by intramuscular route with two doses of a Salmonella enterica serovar Enteritidis bacterin at 20-day interval. In the control group (T) hens remained unvaccinated. Four IgY extractions were performed on the egg production of both groups. The first two extractions were carried out using the yolks obtained from the eggs produced during the 4th and 5th post-vaccination week (extracts 1V and 1T) and the other two using the ones from the 6th, 7th and 8th week (2V and 2T). Starting from the extracts 1V and 1T other products were obtained by freezing-thawing (1V-A and 1T-A) and simple (1V-B and 1T-B) or double (1V-C and 1T-C) flow capillary dialysis concentration. All these products were compared using an ELISA test specific for the detection of chicken antibodies against flagellar antigens of S. Enteritidis. In this test, V extracts were positive whereas T extracts were negative. The extract 1V was more positive than the extract 2V. The extract 1V-C was the most positive and was therefore selected to be used as an antiserum in the agglutination tests. This extract contained 1.9 g/dl of total proteins, 0.028 g/dl of triglycerides and 0.012 g/dl of cholesterol and showed an electrophoretic pattern characteristic of IgY. The 1T-C extract was used as a negative control in the agglutination tests. Slide somatic and tube flagellar agglutination tests were simultaneously carried out using both IgY extracts and a standard rabbit anti-Salmonella (IgG) sera. Overall 367 strains from the Enterobacteriaceae family were tested together with two other strains belonging to the Vibrionaceae family. The 1V-C extract specifically agglutinated S. Enteritidis strains in the same way as the rabbit sera. This extract also agglutinated other Salmonella strains antigenically related to S. Enteritidis. Salmonella which did not share somatic or flagellar antigens with S. Enteritidis, other different species of the Enterobacteriaceae family and the two strains of the Vibrionaceae family were all negative. None of the strains tested was agglutinated by the 1T-C extract. This paper show that it is possible to use specific IgY to identify S. enterica serovars. The more extended use of IgY for diagnostic purposes may be a convenient way to complement the current use of mammal polyclonal antibodies.

Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad Enteritidis / Agglutination of chicken egg yolk immunoglobulins (IgY) against Salmonella enterica serovar Enteriditis

Para producir extractos de IgY se emplearon dos lotes de 6 gallinas ponedoras cada uno. En el lote vacunado (V) las aves se inocularon por vía intramuscular con dos dosis de una bacterina contra Salmonella enterica serovariedad Enteritidis. En el lote testigo (T) las aves no se vacunaron. Con las yemas de ambos lotes se efectuaron 4 extracciones de IgY. Las dos primeras se realizaron con las yemas de los huevos producidos durante la 4§ y 5§ semana post-vacunación (extractos 1V y 1T) y las otras dos con las de la 6§, 7§ y 8§ semana (2V y 2T). Los extractos 1V y 1T se congelaton y descongelaron (1V-A y 1T-A) y se concentraron por diálisis simple (1V-B y 1T-B) o doble (1V-C y 1T-C). Mediante una prueba de ELISA para detectar antígenos flagelares de S. Enteritidis, los extractos V fueron positivos y los T negativos. El extracto 1V-C fue el más positivo y se seleccionó para realizar las aglutinaciones. Este extracto contenía 1,9 g/dl de proteínas totales y presentó bandas electroforéticas características de IgY. El extracto 1T-C fue usado como control negativo de aglutinación. Emplenado ambos extractos IgY y antisueros policlonales de conejo (IgG) se efectuaron aglutinaciones somáticas en placa y flagelares en tubo. Se estudiaron 357 cepas de S. enterica, 10 cepas de diferentes especies de la familia Enterobacteriaceae y dos cepas de la familia Vibrionaceae. El extracto 1V-C aglutinó a distintas cepas de Salmonella con estructura antigénica somática o flagelar relacionada con la cepa vacunal, mientras que las salmonelas con antígenos diferentes y otras especies de la familia Enterobacteriaceae y Vibrionaceae fueron negativas. Este trabajo demuestra que es posible emplear las IgY para identificar serovariedades de S. enterica

Aglutinación de inmunoglobulinas de yema de huevo de gallina (IgY) contra Salmonella enterica serovariedad Enteritidis / Agglutination of chicken egg yolk immunoglobulins (IgY) against Salmonella enterica serovar Enteriditis

Para producir extractos de IgY se emplearon dos lotes de 6 gallinas ponedoras cada uno. En el lote vacunado (V) las aves se inocularon por vía intramuscular con dos dosis de una bacterina contra Salmonella enterica serovariedad Enteritidis. En el lote testigo (T) las aves no se vacunaron. Con las yemas de ambos lotes se efectuaron 4 extracciones de IgY. Las dos primeras se realizaron con las yemas de los huevos producidos durante la 4º y 5º semana post-vacunación (extractos 1V y 1T) y las otras dos con las de la 6º, 7º y 8º semana (2V y 2T). Los extractos 1V y 1T se congelaton y descongelaron (1V-A y 1T-A) y se concentraron por diálisis simple (1V-B y 1T-B) o doble (1V-C y 1T-C). Media

Casos de gastroenteritis asociados a Vibrio cholerae no O1 en Orán, Salta / Non- O group 1 Vibrio cholerae gastroenteritis in Oran, Salta

Entre febrero de 1992 y 1995 se detectaron 41 casos de gastroenteritis asociada a Vibrio cholerae no O1 en Orán, Salta. La frecuencia de aislamiento fue del 0,9 o/o, entre los casos de diarrea. El 51,2 o/o de los casos correspondió a mayores de 15 años y el 60,9, al sexo masculino. Todos los pacientes tuvieron diarrea, en 24 (58,5 o/o) fue líquida y en 6 (14,5 o/o) con aspecto coleriforme. Diez (24,4 o/o) de los pacientes presentaron vómitos y 12 (29,3 o/o) deshidratación leve o moderada. Seis pacientes pediátricos, desnutridos de 2§ y 3§ grado, que presentaron diarrea de más de una semana de evolución y deshidratación moderada, requirieron hospitalización durante 7 días. Durante el primer brote, en un paciente se aisló simultáneamente V. cholerae no O1 y Shigella flexneri y en el cuarto brote en otro se detectó la asociación V. cholerae no O1 y Salmonella subespecie IV 50: b:-. Una mujer de 72 años falleció durante el segundo brote. El cuadro clínico estuvo caracterizado por diarrea líquida, vómitos, fiebre y deshidratación moderada. De su coprocultivo se recuperó V. cholerae O5 negativo para los siguientes factores de virulencia: toxina de cólera (CT), enterotoxina termoestable, hemolisina (El Tor) y hemaglutinina asociadas a células resistentes a D-manosa y L-fucosa. La caracterización bioquímica de los 41 aislamientos correspondió a V. cholerae con serología negativa para los serogrupos O1 y O139. Ningún aislamiento produjo CT. El 19,5 o/o presentó resistencia a la ampiclina y 4,9 o/o, a trimetoprimasulfametoxazol. La vigilancia activa de las diarreas en Orán, ha demostrado que V. cholerae no O1 no es un agente causal importante de las mismas

Casos de gastroenteritis asociados a Vibrio cholerae no O1 en Orán, Salta / Non- O group 1 Vibrio cholerae gastroenteritis in Oran, Salta

Entre febrero de 1992 y 1995 se detectaron 41 casos de gastroenteritis asociada a Vibrio cholerae no O1 en Orán, Salta. La frecuencia de aislamiento fue del 0,9 o/o, entre los casos de diarrea. El 51,2 o/o de los casos correspondió a mayores de 15 años y el 60,9, al sexo masculino. Todos los pacientes tuvieron diarrea, en 24 (58,5 o/o) fue líquida y en 6 (14,5 o/o) con aspecto coleriforme. Diez (24,4 o/o) de los pacientes presentaron vómitos y 12 (29,3 o/o) deshidratación leve o moderada. Seis pacientes pediátricos, desnutridos de 2º y 3º grado, que presentaron diarrea de más de una semana de evolución y deshidratación moderada, requirieron hospitalización durante 7 días. Durante el primer brote, en un paciente se aisló simultáneamente V. cholerae no O1 y Shigella flexneri y en el cu

[Cases of gastroenteritis associated to Vibrio cholerae no 01 in Oran, Salta]. / Casos de gastroenteritis asociados a Vibrio cholerae no O1 en Orán, Salta.

Forty-one sporadic cases of non-O group 1 Vibrio cholerae gastroenteritis were detected in Orán, Salta, between February 1992 and February 1995. The frequency of isolation was 0.9% of the diarrhea cases. Out of 41 patients, 21 (51.2%) were older than 15 years and 25 (60.9%) were male. All the patients had diarrhea, 24 (58.5%) had watery stools and 6 (14.6%) cholera-like diarrhea; 10 (24.4%) presented vomiting and 12 (29%) mild dehydration. Six malnourished children who suffered from diarrhea with moderate dehydration for more than a week, were hospitalized. V. cholerae non O1 and Shigella flexneri were isolated from one patient, during the first outbreak and V. cholerae non O1 and Salmonella IV 50:b:- were recovered simultaneously from another patient during the fourth outbreak. A 72 year old woman died during the second cholera outbreak. The symptoms were: watery diarrhea, vomiting, fever and mild dehydration. A strain of V. cholerae O5, that did not produce cholera toxin, heat-stable enterotoxin, Kanagawa-like hemolysin or verocitotoxin was detected. It was positive for El Tor hemolysin and D-mannose and L-fucose resistant cells-associated hemagglutinins. Among the 41 isolates studied, all were oxidase and indole positive, fermented glucose, saccharose and mannitol. They were all motile, produced lysine and ornithine decarboxylases but not arginine dihydrolase or hydrogen sulfide. They were sensitive to O129 vibriostatic compound. None of them belonged to O1 or O139 serogroup and they did not produce cholera troxin. Among the V. cholerae non O1 strains isolated, 9.5% were resistant to ampicillin and 4.9% to trimethoprim-sulfamethoxazole. Active surveillance had shown that V. cholerae non-O1 is not an important agent of diarrhea in Orán, Salta.

Salmonella Freetown: primer aislamiento en Argentina / Salmonella Freetown: first report in Argentina

En el presente trabajo se comunica el primer aislamiento de Salmonella Freetown en Argentina. Se obtuvo a partir de un coprocultivo de una paciente de 1 mes y 7 días, cuya madre consultó por un cuadro de diarrea aguda en el Hospital de Niños Dr. Ricardo Gutiérrez de la ciudad de Santa Fe. Por sus características bioquímicas y su fórmula antigénica, esta nueva serovariedad se ubica dentro de la especie Salmonella enterica subespecie enterica

Salmonella Freetown: primer aislamiento en Argentina / Salmonella Freetown: first report in Argentina

En el presente trabajo se comunica el primer aislamiento de Salmonella Freetown en Argentina. Se obtuvo a partir de un coprocultivo de una paciente de 1 mes y 7 días, cuya madre consultó por un cuadro de diarrea aguda en el Hospital de Niños Dr. Ricardo Gutiérrez de la ciudad de Santa Fe. Por sus características bioquímicas y su fórmula antigénica, esta nueva serovariedad se ubica dentro de la especie Salmonella enterica subespecie enterica (AU)

[Salmonella Freetown: 1st isolation in Argentina]. / Salmonella Freetown: primer aislamiento en Argentina.

In this paper we report the first case of Salmonella Freetown in Argentina. It was isolated from a stool sample of a child of 1 month and 7 days, assisted as outpatient in the Hospital de Niños Dr. Ricardo Gutiérrez of the city of Santa Fe. On the basis of the biochemical characteristics and antigenic formulae, this new serovar belongs to the species Salmonella enterica subspecies enterica.