Microstructural and Mechanical Characteristics of Alkali-Activated Binders Composed of Milled Fly Ash and Granulated Blast Furnace Slag with µ-Limestone Addition.

Concrete is the most used construction material, needing large quantities of Portland cement. Unfortunately, Ordinary Portland Cement production is one of the main generators of CO2, which pollutes the atmosphere. Today, geopolymers are an emerging building material generated by the chemical activity of inorganic molecules without the Portland Cement addition. The most common alternative cementitious agents used in the cement industry are blast-furnace slag and fly ash. In the present work, the effect of 5 wt.% µ-limestone in mixtures of granulated blast-furnace slag and fly ash activated with sodium hydroxide (NaOH) at different concentrations was studied to evaluate the physical properties in the fresh and hardened states. The effect of µ-limestone was explored through XRD, SEM-EDS, atomic absorption, etc. The addition of µ-limestone increased the compressive strength reported values from 20 to 45 MPa at 28 days. It was found by atomic absorption that the CaCO3 of the µ-limestone dissolved in NaOH, precipitating Ca(OH)2 as the reaction product. SEM-EDS analysis showed a chemical interaction between C-A-S-H- and N-A-S-H-type gels with Ca(OH)2, forming (N, C)A-S-H- and C-(N)-A-S-H-type gels, improving mechanical performance and microstructural properties. The addition of µ-limestone appeared like a promising and cheap alternative for enhancing the properties of low-molarity alkaline cement since it helped exceed the 20 MPa strength recommended by current regulations for conventional cement.

[Pneumocystis jiroveci pneumonia: comparative study of cases in HIV-infected patients and immunocompromised non-HIV-infected patients]. / Características clínicas, diagnósticas y pronosticas de pacientes con neumonía por Pneumocystis jiroveci en individuos infectados por virus de inmunodeficiencia humana e individuos inmunocomprometidos por otra etiología: comparative study of cases in HIV-infected patients and immunocompromised non-HIV-infected patients.

BACKGROUND: Although P. jiroveci pneumonia affects immunocompromised (IC) patients of any etiology, clinical features and prognostic outcomes are different depending if they are patients with HIV infection or other causes of IC. OBJECTIVES: To compare clinical and laboratory features as well as outcomes of P. jiroveci pneumonia in HIV versus non-HIV patients. METHODS: Retrospective review of clinical records of HIV and non-HIV patients with P. jiroveci pneumonia managed at the Hospital Clínico Universidad Católica in Santiago, Chile, between 2005 and 2007. RESULTS: We included 28 HIV and 45 non-HIV patients with confirmed P. jiroveci pneumonia. The non-HIV population was older (65 vs 36,2 years, p < 0,01), had shorter duration of symptoms (7 [1-21] vs 14 [2-45] days, p < 0,01), required more invasive techniques (60 vs 21%, p < 0,01) and RT-PCR to confirm the diagnosis (93 vs 68%, p < 0,01), were more frequently treated at intensive care units (58 vs. 25%, p < 0,01) requiring artificial ventilation (56 vs 11%, p < 0,01), and had a higher attributable mortality (33% vs 0%, p < 0,01). CONCLUSIONS: Our study confirmed that P. jiroveci pneumonia in non-HIV IC patients is more severe, more difficult to diagnose and has higher mortality that in HIV patients. Therefore, it is mandatory to optimize diagnostic and therapeutic strategies for this patients group.

Características clínicas, diagnósticas y pronosticas de pacientes con neumonía por Pneumocystis jiroveci en individuos infectados por virus de inmunodeficiencia humana e individuos inmunocomprometidos por otra etiología: comparative study of cases in HIV-infected patients and immunocompromised non-HIV-infected patients / Pneumocystis jiroveci pneumonia

Background: Although P. jiroveci pneumonia affects immunocompromised (IC) patients of any etiology, clinical features and prognostic outcomes are different depending if they are patients with HIV infection or other causes of IC. Objectives: To compare clinical and laboratory features as well as outcomes of P. jiroveci pneumonia in HIV versus non-HIV patients. Methods: Retrospective review of clinical records of HIV and non-HIV patients with P. jiroveci pneumonia managed at the Hospital Clínico Universidad Católica in Santiago, Chile, between 2005 and 2007. Results: We included 28 HIV and 45 non-HIV patients with confirmed P. jiroveci pneumonia. The non-HIV population was older (65 vs 36,2 years, p < 0,01), had shorter duration of symptoms (7 [1-21] vs 14 [2-45] days, p < 0,01), required more invasive techniques (60 vs 21%, p < 0,01) and RT-PCR to confirm the diagnosis (93 vs 68%, p < 0,01), were more frequently treated at intensive care units (58 vs. 25%, p < 0,01) requiring artificial ventilation (56 vs 11%, p < 0,01), and had a higher attributable mortality (33% vs 0%, p < 0,01). Conclusions: Our study confirmed that P. jiroveci pneumonia in non-HIV IC patients is more severe, more difficult to diagnose and has higher mortality that in HIV patients. Therefore, it is mandatory to optimize diagnostic and therapeutic strategies for this patients group.

Introducción: Pneumocystis jiroveci puede causar neumonía en pacientes inmunocomprometidos de cualquier etiología, pero las diferencias clínicas y pronósticas entre inmunocomprometidos por VIH y por otras causas han sido poco exploradas. Objetivo: Comparar las características clínicas, de laboratorio y pronóstico de neumonía por P. jiroveci en pacientes inmunocomprometidos por infección VIH versus no infectados por VIH. Métodos: Análisis retrospectivo de casos confirmados de neumonía por P. jiroveci en adultos con infección por VIH y no infectados, entre los años 2005 y 2007. Resultados: Se incluyeron 28 pacientes infectados por VIH y 45 no infectados, con neumonía por P. jiroveci confirmada. La población no infectada por VIH presentaba mayor edad (65 vs 36,2 años, p < 0,01), menor duración de síntomas previos a la consulta (7 [121] vs 14 [2-45] días, p < 0,01), mayor requerimiento de técnica invasora (60 vs 21%, p < 0,01) y estudio molecular (93 vs 68%, p < 0,01) para confirmación diagnóstica, mayor requerimiento de camas críticas (58 vs 25%, p < 0,01), y ventilación mecánica (56 vs 11%, p < 0,01), con mayor mortalidad atribuible (33 vs 0%, p < 0,01). Conclusiones: La neumonía por P. jiroveci en pacientes inmunocomprometidos no infectados por VIH ofrece más dificultades diagnósticas y presenta mayor gravedad y mortalidad que en pacientes con infección por VIH; por esto, es mandatario optimizar los procesos diagnóstico y terapéutico en esta población.

Chronic oral or intraarticular administration of docosahexaenoic acid reduces nociception and knee edema and improves functional outcomes in a mouse model of Complete Freund's Adjuvant-induced knee arthritis.

INTRODUCTION: Clinical and preclinical studies have shown that supplementation with ω-3 polyunsaturated fatty acids (ω-3 PUFAs) reduce joint destruction and inflammation present in rheumatoid arthritis (RA). However, the effects of individual ω-3 PUFAs on chronic arthritic pain have not been evaluated to date. Thus, our aim in this study was to examine whether purified docosahexaenoic acid (DHA, an ω-3 PUFA) reduces spontaneous pain-related behavior and knee edema and improves functional outcomes in a mouse model of knee arthritis. METHODS: Unilateral arthritis was induced by multiple injections of Complete Freund's Adjuvant (CFA) into the right knee joints of male ICR adult mice. Mice that received CFA injections were then chronically treated from day 15 until day 25 post-initial CFA injection with oral DHA (10, 30 and 100 mg/kg daily) or intraarticular DHA (25 and 50 µg/joint twice weekly). Spontaneous flinching of the injected extremity (considered as spontaneous pain-related behavior), vertical rearing and horizontal exploratory activity (considered as functional outcomes) and knee edema were assessed. To determine whether an endogenous opioid mechanism was involved in the therapeutic effect of DHA, naloxone (NLX, an opioid receptor antagonist, 3 mg/kg subcutaneously) was administered in arthritic mice chronically treated with DHA (30 mg/kg by mouth) at day 25 post-CFA injection. RESULTS: The intraarticular CFA injections resulted in increasing spontaneous flinching and knee edema of the ipsilateral extremity as well as worsening functional outcomes as time progressed. Chronic administration of DHA, given either orally or intraarticularly, significantly improved horizontal exploratory activity and reduced flinching behavior and knee edema in a dose-dependent manner. Administration of NLX did not reverse the antinociceptive effect of DHA. CONCLUSIONS: To the best of our knowledge, this report is the first to demonstrate DHA's antinociceptive and anti-inflammatory effects as individual ω-3 PUFAs following sustained systemic and intraarticular administration in a mouse model of CFA-induced knee arthritis. The results suggest that DHA treatment may offer a new therapeutic approach to alleviate inflammation as well as a beneficial effect on pain-related functional disabilities in RA patients.

Risk factors associated with invasive fungal disease in children with cancer and febrile neutropenia: a prospective multicenter evaluation.

BACKGROUND: Empiric antifungal treatment has become standard of care in children with cancer and prolonged fever and febrile neutropenia (FN), with the downside that it leads to significant over treatment. We characterized epidemiologic, clinical, and laboratory features of invasive fungal disease (IFD) in children with cancer and FN with the aim to identify risk factors for IFD that can aid in better selecting children who require antifungal treatment. METHODS: In a prospective, multicenter study, children admitted with FN at high-risk for sepsis, in 6 hospitals in Santiago, Chile were monitored from admission until the end of the FN episode. Monitoring included periodic evaluation of clinical findings, absolute neutrophil count, absolute monocyte count (AMC), serum C-reactive protein (CRP), bacterial cultures, imaging studies, and galactomannan antigen. A diagnosis of proven, probable, and possible IFD was made after episode resolution based on European Organization for Research and Treatment of Cancer classification. RESULTS: A total of 646 high-risk FN episodes were admitted during the study period, of which 604 were enrolled. IFD was diagnosed in 35 episodes (5.8%) of which 7 (1.2%) were proven, 10 (1.6%) probable, and 18 (3.0%) possible. Four variables obtained on day 4 were significantly more common in IFD cases, which were presence of fever, absolute neutrophil count < or =500/mm, AMC < or =100/mm, and CRP > or =90 mg/L. The combination of fever, AMC < or =100/mm, and CRP > or =90 at day 4 provided a RR for IFD of 5.4 (99% CI, 3.2-9.2) with a sensitivity of 75%, specificity of 87%, positive and negative predictive values of 13% and 99%, respectively. CONCLUSIONS: Fever persisting at day 4 of admission, together with AMC < or =100 and CRP > or =90 significantly increased the risk for IFD in children with cancer.

Correlation between Yersinia enterocolitica and type I collagen reactivity in patients with arthropathies.

We investigated the association with Yersinia infection in patients with arthropathies in our region. To assess the reactivity to articular antigens, the correlation of anti-Yersinia with anti-type I and type II collagen antibodies was studied. Sera from 124 patients with musculoskeletal symptoms, and 47 synovial fluids (SF) from patients with rheumatoid arthritis (RA), spondyloarthopathies (SpA) or osteoarthritis (OA) were examined. Immunoglobulins against Yersinia enterocolitica, type I and type II collagens were determined by enzyme-linked immunosorbent assay. Immunoglobulin (Ig) A to Yersinia lipopolysaccharide (LPS) was present in 13/124 sera (10%) and 3/47 SF (6%). By Western blot, IgA to Yersinia outer proteins (Yops) was found in 14/124 sera (11%) and 2/47 SF (4%). Yersinia DNA from SF was not amplified by polymerase chain reaction. We found a significant correlation with anti-collagen type I but not type II antibodies. These results suggest different reactivity to articular collagen in patients with Yersinia antibodies.

Prevalence of some bacteria yeasts and molds in meat foods in San Luis, Argentina.

In this work we evaluate the microbiological quality and the hygiene degree of meat foods consumed in the city of San Luis. A total of 515 meat food samples (315 from fresh sausages, 100 from hamburgers and 100 from ground beef) were processed, being the most of them non-industrial products. The microbiological quality was determined by counts of total mesophilic bacteria, coliforms, Escherichia coli, molds and yeasts, and Clostridium perfringens. The number of total mesophilic aerobes was within the 10(6) cfu/g limit set by the Argentinaan Alimentary Code (AAC). Two hundred seventy six samples exhibited E. coli levels between 10(1) and 10(3) cfu/g. The 58.26% of the samples with E. coli counts above > 10(1) cfu/g came from hamburgers and fresh sausages exceeding the AAC limits. Counts of molds and yeasts ranged between 10(3) and 10(6) cfu/g. From a total of 515 samples, 126 exhibited C. perfringens, out of which 80 (64.08%) gave counts > 10(2)/g, exceeding the limits set by the AAC. Out of these 80 samples, C. perfringens counts were above 10(5) cfu/g in 12 of them, and E. coli was also detected in 48 samples (38.10%). The samples with counts > 10(5) C. perfringens/g are potentially responsible for alimentary intoxication. The results obtained indicate the need to improve the processing and handling conditions of these products.

[Consensus: Rational approach towards the patient with cancer, fever and neutropenia]. / Consenso: Manejo racional del paciente con cáncer, neutropenia y fiebre.

The severity and duration of post chemotherapy neutropenia were recognized during the 1960s as main predisposing factors for infections in cancer patients. At the beginning of the 70's a standard management approach for all febrile neutropenia (FN) episodes was proposed, based on hospitalization and intravenous empirical broad spectrum antibiotic therapy. Widespread use of this approach resulted in a significant reduction in mortality attributable to bacterial infections. During the last 10 to 15 years, reappraisal of this standard approach has been done by several research groups who question the benefit of treating all FN patients similarly without taking in to consideration differences in severity of the FN episodes. This reappraisal has led during the 1990s to the development of the concept of high and low risk FN episodes that has been the base for the adoption of selective therapies based on the risk categorization of the individual patient. The Chilean Infectious Diseases Society called upon two government National Programs responsible for the appropriate distribution of chemotherapeutic drugs to all pediatric and adults cancer patients within the public health system, and upon the Chilean Hematology Society for the development of a Consensus on Diagnosis, Treatment and Prevention of Infections during FN Episodes in Cancer patients. The need for this Consensus is based on two main aspects: the new approaches proposed during the past year for management of these episodes, and the increasing population of cancer patients receiving improved chemotherapeutic agents that has increased there survival possibilities as well as there possibility to suffer a FN episode. The topics discussed in this document are based on an updated systematic and analytic review of the medical literature including epidemiology, laboratory diagnostics, risk categorization, treatment and prophylaxis. National data was included when available in order to provide the healthcare personnel that take care of these patients with best evidence based recommendations adjusted to the Chilean reality.

Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients.

Saccharomyces cerevisiae is widely used as a probiotic compound. Clinical data suggest that this agent is safe and effective. We report two cases of fungemia caused by S. cerevisiae occurring in immunosuppressed patients treated orally with S. boulardii Molecular typing confirmed clonality in isolate strains from patients and the capsule. Physicians caring for immunosuppressed patients must be aware of this potential serious complication of probiotic use.

Isolation and survival of "Yersinia enterocolitica" in ice cream at different pH values, stored at -18ºC

The presence of "Yersinia enterocolitica" was investigated in 203 samples of industrial (123) and non-industrial ice cream (80). Two "Y. enterocolitica" strains were isolated from non-industrial ice cream, which suggests the possibility of post-manufacturing contamination. One strain was typed as B:1A, O:3,50,51; lis Xz, while the other one was biotyped as B:1A but not serologically typed. Survival of "Y. enterocolitica" was investigated by inoculating nine samples of industrially manufactured ice cream to contain 20 CFU/ml of "Y. enterocolitica" and stored at -18ºC for 480 days. The inoculated samples were classified into three different groups according to their pH (Group 1: pH 4-5; Group 2: pH 5-6 and Group 3: pH 6-7). Viability was determined by a contamination of direct plating and enrichment. In Group 1, "Y. enterocolitica" was not detected after 150 days of storage, while in Groups 2 and 3, this microorganism was isolated until day 480 of storage. These fidings suggest that the survival time of "Y. enterocolitica" in ice cream stored at -18ºC is significantly (p<=0.05) lower at pH values under 5.

Survival of Aeromonas hydrophila in Fresh Tomatoes ( Lycopersicum esculentum Mili) Stored at Different Temperatures and Treated with Chlorine.

This study examines the survival of two Aeromonas hydrophila strains ( A. hydrophila ATCC 7965 [strain A] and A. hydrophila isolated from food [strain B]) on the surface and core tissue of fresh tomatoes stored at different temperatures and the efficacy of chlorine treatment on their survival. Counts of A. hydrophila on the surface of tomatoes stored at 25 and 35 °C were significantly higher between days 1 and 4 for both strains as compared to results obtained at 6°C. Core tissue counts of A. hydrophila cells on tomatoes dipped in a cellular suspension at 25°C and stored at 25°C were significantly higher (P < 0.05) than counts obtained with dip suspensions at 6 or 35°C. In chopped tomatoes stored at 25 and 35°C, populations of aerobic mesophiles showed significant increases after 96 and 70 h, respectively. The populations of both A. hydrophila strains in chopped tomatoes stored at 6°C increased significantly after 96 h, while at 25 and 35°C the counts increased in the first hours of incubation. Viable counts of A. hydrophila on the surface and central tissue of tomatoes significantly decreased (P < 0.05) when the samples were dipped for 2 min in chlorine at a concentration of 50 ppm (50 µg/ml). The results suggest that tomatoes should be kept at low temperatures during storage, shipping, and retail stocking and that chlorine at a concentration of 50 ppm should be used to reduce the levels of A. hydrophila .

Protective immunity induced by a Yersinia enterocolitica serovar 0: 8 cellular extract

The purpose of this study was to investigate the protective power of a cellular extract (CE) from Y. enterocolitica 0:8 grown in condition of expression of chromosomal antigens. Mice were immunized by s.c. route and challenged with: 0 LD50 (1 x 10(4) CFU/ml). Immunoblotting showed that CE-specific serum reacted with several CE antigens. Prominent bands, of molecular weights 60 and 35.5, were present in cytoplasmic and membrane fraction, respectively. The lipopolysaccharide (LPS) was detected in CE. These findings suggest that chromosomally-encoded antigens present in CE may induce protection against Y. enterocolitica infection. Both humoral and cellular immune response contribute to protection in mice.

Protective immunity induced by a Yersinia enterocolitica serovar 0: 8 cellular extract

The purpose of this study was to investigate the protective power of a cellular extract (CE) from Y. enterocolitica 0:8 grown in condition of expression of chromosomal antigens. Mice were immunized by s.c. route and challenged with: 0 LD50 (1 x 10(4) CFU/ml). Immunoblotting showed that CE-specific serum reacted with several CE antigens. Prominent bands, of molecular weights 60 and 35.5, were present in cytoplasmic and membrane fraction, respectively. The lipopolysaccharide (LPS) was detected in CE. These findings suggest that chromosomally-encoded antigens present in CE may induce protection against Y. enterocolitica infection. Both humoral and cellular immune response contribute to protection in mice.(AU)

Prevalence of Yersinia enterocolitica in Hake (Merluccius hubbsi) Fillets.

Yersinia enterocolitica is a human pathogenic bacterium. The prevalence of Y. enterocolitica in refrigerated hake fillets sold for human consumption in retail stores was investigated in order to determine the degree of pathogenicity. Three hundred samples were enriched in 0.067 M phosphate-buffered saline, pH 7.6, with 1% sorbitol and 0.15% biliary salts, postenriched in 0.5% KOH, and isolated in salmonella-shigella agar and MacConkey agar. Twelve strains of Yersinia were isolated from the whole group of samples, 11 (91.6%) of which corresponded to Y. enterocolitica and 1 (8.3%) to Y. intermedia . The Yersinia strains recovered were Y. enterocolitica B1 O:5 Lis Xz (1 strain), Y. enterocolitica B3 O:5 (1 strain), Y. enterocolitica B1 O:6,30-6,31 (1 strain), Y. enterocolitica B1 O:7,8-8-8,19 (1 strain), Y. enterocolitica B1 O:7,8-8-8,19 Lis Xz (7 strains) and Y. intermedia B1 O:40 Lis Xo (1 strain). Of the 12 strains isolated, 8 (66.6%) were recovered by alkaline postenrichment. The first two strains were positive for virulence tests (autoagglutination and calcium dependence for growth at 37°C). The antibiotic susceptibility of the isolated strains was studied by the agar-diffusion method according to Bauer-Kirby, modified by Barry. Some of the isolated strains were potentially pathogenic, representing a risk for human health.

Incidence of Clostridium perfringens in Fresh Sausages in Argentina.

A simple iron-milk medium was used for the isolation and enumeration (MPN) if Clostridium perfringens from fresh sausages. Samples were diluted (log 10) in 0.1% peptone water, aliquots seeded and incubated at 45°C for 16-18 h, and cultures with clots and stormy fermentation were considered positive. Confirmation of C. perfringens was made by subculturing in tryptose-sulfite-neomycin agar under anaerobic conditions. Suspect colonies were identified by standard procedures, including nitrate reduction, gelatin liquefaction, lipase and lecithinase production, starch hydrolysis, hemolysis and reverse CAMP test. From 136 samples studied, 110 were positive. Twenty-six, 48, 25, 7, 3, and 1 samples contained, respectively 10, 102, 103, 104, 105, and 109 C. perfringens per g of food. Three per cent of samples contained enough bacteria to produce food poisoning. The frequency of distribution approximately follows the Poisson equation with a µ=1.793.

Determinación de la calidad higiénico-sanitaria de fideos frescos / Determination of the hygienic-sanitary quality in fresh noodles

Mesófilos aerobios totales (MT), coliformes totales (CT), coliformes fecales (CF), Escherichia coli (EC), hongos y levaduras (HyL) y Salmonella fueron estudiados en 50 muestras de fideos frescos (32 a 35% de agua) preparados con huevo deshidratado o con huevo líquido. Los valores obtenidos fueron: (entre paréntesis el porcentaje de muestras positivas) MT, 10**4 a 10**6 UFC/g (48%); H y L, 10**2 UFC/g (76%); CT, 4 a 100/g (32%) y 460/g (2%); CF, 3 a 10/g (14%) y 21/g (6%). Para EC sólo dos muestras fueron positivas con 4 y 9/g respectivamente. Una sola serovariedad de salmonella (S. oranienburg) fue detectada en el 88% de las muestras

Determinación de la calidad higiénico-sanitaria de fideos frescos / Determination of the hygienic-sanitary quality in fresh noodles

Mesófilos aerobios totales (MT), coliformes totales (CT), coliformes fecales (CF), Escherichia coli (EC), hongos y levaduras (HyL) y Salmonella fueron estudiados en 50 muestras de fideos frescos (32 a 35% de agua) preparados con huevo deshidratado o con huevo líquido. Los valores obtenidos fueron: (entre paréntesis el porcentaje de muestras positivas) MT, 10**4 a 10**6 UFC/g (48%); H y L, 10**2 UFC/g (76%); CT, 4 a 100/g (32%) y 460/g (2%); CF, 3 a 10/g (14%) y 21/g (6%). Para EC sólo dos muestras fueron positivas con 4 y 9/g respectivamente. Una sola serovariedad de salmonella (S. oranienburg) fue detectada en el 88% de las muestras (AU)

Identificación de Clostridium chauvoei por la prueba de coaglutinción / Identification of clostridium chauvoei by coagglutination test

El método de Coaglutinación estafilocócica (COA) para la identificación de clostridium chavoei fue estudiado con cuatro inmunosueros obtenidoa a partir de las siguientes preparaciones antigénicas (cultivos de 12h de la cepa 5078 de C. chavoei: a) células tratadas con formol al 0.5% (CF); b) células calentadas a ebullición 2h (CO) (ambas preparaciones con una concentración de 1.05 x 10**9 células/ml); c) extrato de veronal (EV); células lavadas y lisofilizadas se extrajeron con regulador veronal pH 8.50; y d) suspensión flagelar (F): al cultivo lavado dos veces con solución fisiológica se desflageló por agitación manual, se centrifugó a 3.500 x g y 16.000 x g durante 20 min. Los flagelos fueron separados por filtración en membrana filtrante (poro 0.2µm) observándoselos por impregnación argéntica. Lotes de 3 conejos se inocularon con 5 dosis de cada antígeno (0.2; 0.4; 0.8; 1.6 y 3.2ml) por vía IV. Para la preparación de la proteína A se siguió la técnica modificada de Kronvall. La cepa Cowan I de Staphylococcus aureus se estabilizó adiconando 0.1 ml de cada antisuero a 1 ml de suspensión. Como testigo se sensibilizaton estafilococos con suero normal de conejo. La COA se realizó con las cepas de C. chauvoei 5078, Chl y Ch2, con líquidos biológicos de ratones inoculados con la cepa 5078, con las cepas de C. septicum 3606 y S9 y una cepa de C. perfringens. Las lecturas se realizaron entre 2 y 8 min y se informaron de 0 a 4 +. La prueba fue específica para C. chauvoei y no dio reacciones cruzadas con C. spticum ni C. perfringens. La COA fue más efectiva cuando se utilizaron los antisueros obtenidos con EV (los antígenos estarían más purificados) y con F. En este caso se deberían usar los antígenos flagelares f y g, aunque escparían las mutantes inmóviles. El antisuero CF mostró una COS inferior a las anteriores, pero podría emplearse porque la preparación del antígeno es más sencilla. La COA con anti-CO fue menorm dudosa o negativa, el calor destruye componentes antigénicos. La COA puede ser un valioso elemento para el diagnóstico de C. Chauvoei

Investigación de salmonelas en cabritos faenados / Study of Salmonella in slaughtered kids

Se estudió la prevalencia de salmonelas en cabritos recién faenados en un frigorífico de la provincia de San Luis, Argentina. La cría de este ganado es una actividad económica importante en esa zona. Se examinaron 200 muestras de contenido cecal. Todos los aislamientos se obtuvieron únicamente a partir de muestras enriquecidas en caldo nutritivo y seleccionadas en agar verde brillante. Las colonias sospechosas fueron purificadas por reaislamiento y sometidas a identificación por puebas bioquímicas y serológicas. La prevalencia de salmonelas en los animales estudiados fue de 6,5% y el único serotipo aislado fue Salmonella oranienburg. La patogenicidad de las cepas se determinó por vía digestiva y por inoculación intravenosa e intraperitoneal. La sensibilidad a los antibióticos se determinó por el método de Kirby Bauer. Las cepas fueron sensibles a cloramfenicol, kanamicina, fosfomicina, ampicilina, tobramicina, polimixina B, nitrofurantoína mezlocilina, piperacilina, cefalotina, cefotaxima y ala combinación de sulfametoxazol y trimetoprima, y se mostraron resistentes a sisomicina y a sulfisoxazol

Yersinia enterocolitica: primeros aislamentos a partir de alimentos cárnicos en Argentina / Yersinia enterocolitica: first isolations from meat products in Argentina

Se ha investigado la presencia de Yersinia enterocolitica en alimentos frescos de origen animal. Se aislaron 27 cepas a partir de : chorizos, salchichas, lenguas de bovinos, y lenguas y ciegos de porcinos; no se halló en morcillas. Se identificaron los siguientes biotipos (B), serotipos (0) y lisotipos (Lis): en chorizos, B2, 0:9, Lis X3 y B1, 0:7,8, Lis Xo; en salchichas: B1, 0:5, Lis Xz; en lenguas de bovinos: B1, 0:5, Lis Xz y B2, 0:9, Lis X3; en lenguas de cerdos: B1, 0:6, Lis Xz; en ciegos de cerdos: B1, 0:6, Lis Xz y B1, 0:5, Lis Xz. El tipo B2, 0:9, Lis X3 aislado de chorizo y lengua de bovino, ha sido encontrado excepcionalmente fuera del hombre. El tipo B1, 0:6, Lis Xz se aisló de lengua y ciego de un cerdo. Del ciego de un cerdo se aislaron dos tipos: B1, 0:5, Lis Xz y B1, 0:6, Lis Xz. Se considera necesario ampliar los estudios sobre esta bacteria para reconocer su importancia como agente etiológico de la yersiniasis en Argentina