ABSTRACT The aim of this study was to evaluate three processes for the removal of organic matter and inactivation of Salmonella spp re inoculated in water from pig farms. Specific water samples were obtained to perform physical, chemical and microbiological characterization. Next, the operating conditions that favored the photolysis process were selected through a 2x2 factorial design. Finally, inactivation/removal kinetics were carried out, assessing UV254 nm photolysis, UV254 nm photolysis with hydrogen peroxide H2O2at 15 ppm and hydrogen peroxide H2O2at 15 ppm. The inactivation of Salmonella spp was favored by using an aeration of 1 L/min and with a concentration of Salmonella spp of 1x104 UFC/ml obtaining an inactivation of 97.3±1.9% after 10 minutes of treatment. On the other hand, for the inactivation kinetics it was established that the best treatments were photolysis and photolysis/H2O2, without significant differences. At 30 seconds of exposure, the inactivation of Salmonella was 99.9±2.4% in T1, with a removal of chemical oxygen demand (COD), NO3 and NO2 of 30±2, 27±3, 83±4, 41±1.0 and 99±5% for T1 and T2 respectively. The bacteria recovered in T2 and T3 and the treatments had no residual effect, determining that the final populations were 8 CFU/ml and 3x103 CFU/ml, respectively.

RESUMEN El objetivo del presente trabajo fue evaluar tres procesos para la remoción de materia orgánica e inactivación de Salmonella spp re inoculada en agua proveniente de granjas porcícolas. Se hicieron muestreos puntuales del agua para realizar la caracterización física, química y microbiológica. A continuación, se seleccionaron las condiciones de operación que favorecieran el proceso de fotólisis a través de un diseño factorial 2x2. Finalmente se realizaron cinéticas de inactivación/remoción valorando fotólisis UV254 nm, fotólisis UV254nm con peróxido de hidrógeno H2O2a 15 ppm y peróxido de hidrógeno H2O2a 15 ppm. La inactivación de Salmonella spp se favoreció al emplear una aireación de 1 L/min y con una concentración de Salmonella spp de 1x104 UFCml-1 obteniendo una inactivación de 97.3±1.9% a los 10 minutos de tratamiento. Por otro lado, para las cinéticas de inactivación se estableció que los mejores tratamientos fueron fotólisis y fotólisis/ H2O2, sin que hubiera diferencias significativas. A los 30 segundos de exposición la inactivación de Salmonella fue del 99.9±2.4% en T1, con una remoción de la demanda química de oxígeno (DQO), NO3 y NO2 del 30±2, 27±3, 83±4, 41±1,0 y99±5% para T1 yT2 respectivamente. La bacteria se recuperó en T2 y T3 y los tratamientos no tuvieron efecto residual, determinando que las poblaciones finales fueran de 8 UFC/ml y 3x103 UFC/ml, respectivamente.

RESUMO: Para determinar Salmonellaspp. prevalência/soroprevalência, padrões de resistência antimicrobiana e identificação de fatores de risco associados à sua presença em granjas suínas colombianas. Foram obtidas 504 amostras (fezes, zaragatoas e amostras do ambiente) de 21 fazendas distribuídas em quatro regiões geográficas da Colômbia. Salmonella spp., a detecção microbiológica e molecular foi determinada por 2 Salmonella spp. Ensaios MDS3M™ e MALDI-TOF MS, respectivamente. Além disso, para avaliação sorológica, foram analisadas 231 amostras de soro empregando ELISA Salmonella Pigtype® - Salmonella Ab (QUIAGEN®). Além disso, 41 isolados foram testados quanto à suscetibilidade antimicrobiana usando a técnica de microdiluição em caldo (Painel B1016-180 Beckman Coulter NC72®) e verificados com o software WHONET 2016. Os fatores de risco foram avaliados em uma pesquisa e analisados quanto à significância estatística pelo teste U Mann-Whitney. Foram determinadas prevalências de 8,9% (n=45) e 38,1% (n=88). Todos os isolados apresentaram 100% de suscetibilidade antimicrobiana à amicacina. No entanto, resistência à penicilina, tetraciclina, cefuroxima e trimetoprim/sulfametoxazol estava presente em mais de 50% das cepas avaliadas. Fatores de risco associados à Salmonella spp., presença de uso de água de superfície, superfície áspera no chão, presença de tremonhas como alimentadores e botas de trabalho. Bactérias estavam presentes em animais e amostras ambientais de fazendas avaliadas. O contato animal e/ou a exposição ao microrganismo também foram evidentes na resposta sorológica obtida. A presença de bactérias dependia de práticas de manejo e infraestrutura, assim como o uso de antibióticos suplementados na dieta pode ter induzido um aumento de Salmonella spp. resistência antimicrobiana.

ABSTRACT: To determine Salmonella spp. prevalence/seroprevalence, antimicrobial resistance patterns and risk factor identification associated with its presence in Colombian swine farms. 504 samples (Faeces, swabs and environment samples) were obtained from 21 farms distributed in four geographical regions in Colombia. Salmonella spp. microbiological and molecular detection were determined by two Salmonella spp. MDS3M™ and MALDI-TOF MS assays, respectively. In addition, for serological evaluation 231 serum samples were analyzed employing ELISA Salmonella Pigtype®-Salmonella Ab (QUIAGEN®). Additionally, 41 isolates were tested for antimicrobial susceptibility using broth microdilution technique (Panel B1016-180 Beckman Coulter NC72®) and verified with WHONET 2016 software. Risk factors were assessed from a survey and analyzed for statistical significance by U Mann-Whitney test. An 8.9% prevalence (n=45) and 38.1% (n=88) seroprevalence were determined. All isolates presented 100% antimicrobial susceptibility against amikacin. However, resistance against penicillin, tetracycline, cefuroxime and trimethoprim/sulfamethoxazole was present in more than 50% of evaluated strains. Risk factors associated with Salmonella spp. presence were surface water use, rough-surfaced on floors, presence of hoppers as feeders and worker’s boots. Bacteria were present in animals and environmental samples from evaluated farms. Animal contact and/or exposure with the microorganism were also evident in obtained serological response. Bacteria presence depended on management practices and infrastructure, likewise antibiotic use, supplemented in the diet may have induced an increase in Salmonella spp. antimicrobial resistance.

RESUMEN Objetivo. Determinar la prevalencia de Salmonella spp., en ganglios mesentéricos de porcinos, provenientes de diferentes regiones de Colombia. Materiales y Métodos. Se realizó un muestreo estratificado por fijación proporcional en plantas de beneficio, de cada uno de los 13 departamentos participantes, cuyo volumen de producción de carne de cerdo es representativo a nivel nacional. El muestreo se realizó durante cinco meses, para un total de 457 muestras analizadas. La identificación de Salmonella spp., se realizó mediante el Sistema Molecular MDS, luego los aislamientos fueron confirmados por Maldi-TOF MS. Se determinó la susceptibilidad antimicrobiana de los aislamientos usando el panel B1016-180 y el análisis estadístico se realizó en Whonet 2016, posteriormente algunos de los aisalmientos multi-resistentes fueron serotipificados por el método de Kauffman-White. Resultados. La prevalencia nacional fue 28.2%, con presencia de los serotipos S. Typhimurium, S. Agama, S. London, S. Agona, S. Haifa y S. 1,4,12: i : --. Se encontró resistencia a antibióticos de uso frecuente en humanos (23.6% Trimetoprim/Sulfametoxazol, 2.7% Cefotaxime (CTX), 11.8% Ampicilina (AMP) y 1.8% Ciprofloxacina). Conclusión. La prevalencia de Salmonella en ganglios mesénticos fue del 28.2%, siendo la región del Huila la que más aportó, se recuperaron serotipos atípicos como S. London y S. Haifa.

ABSTRACT Objective. To determine the prevalence of Salmonella spp., in pigs mesenteric ganglion, from different regions of Colombia. Materials and Methods. A stratified sampling by proportional fixation was carried out at benefit plants of each of the 13 participating departments, whose pork production volume is representative at national level. Sampling was performed during five months, for a total of 457 samples analyzed. Salmonella spp., identification was performed by the MDS Molecular System, later isolates were confirmed in Maldi-TOF MS. Antimicrobial susceptibility of the isolates was determined using the B1016-180 panel and statistical analysis was performed in Whonet 2016, some of the multi-resistant isolates were them serotyped by Kauffman-White method. Results. National prevalence was 28.2%, with the presence of S. Typhimurium, S. Agama, S. London, S. Agona, S. Haifa and S. 1,4,12: i: -. Resistance to antibiotics frequently used in human (23.6% Trimethoprim/Sulfamethoxazole, 2.7% Cefotaxime (CTX), 11.8% Ampicillin (AMP) and 1.8% Ciprofloxacin) was found. Conclusion. The prevalence of Salmonella in mesenteric ganglia was 28.2%, being the Huila region the one with the highest prevalence, recovering atypical serotypes such as S. London and S. Haifa.

Se discuten diferentes conceptualizaciones de equidad y desigualdad en salud, concluyendo que inequidad y desigualdad no son sinónimos, y se sugiere la utilización de desigualdad para describir perfiles epidemiológicos y equidad en relación con la distribución y el acceso de los servicios de atención a la salud. Se revisa en más detalle la situación de México, donde existe gran polarización socioeconómica, una reforma sanitaria privatizadora que ha aumentado la inequidad y una ciudadanía incompleta, como obstáculos principales para conseguir una disminución de la inequidad en salud.

The different conceptualisations regarding equity and inequality in health are discussed, concluding that inequity and inequality are not synonyms. It is suggested that inequality should be used for describing epidemiological profiles and equity in relationship to the distribution of and gaining access to health attention services. The situation in México is reviewed in greater detail, as there is great socioeconomic polarisation in this country, a privatising sanitary reform which has increased inequity and incomplete citizenry as the main obstacles for gaining a reduction in inequity in health.

The different conceptualisations regarding equity and inequality in health are discussed, concluding that inequity and inequality are not synonyms. It is suggested that inequality should be used for describing epidemiological profiles and equity in relationship to the distribution of and gaining access to health attention services. The situation in México is reviewed in greater detail, as there is great socioeconomic polarisation in this country, a privatising sanitary reform which has increased inequity and incomplete citizenry as the main obstacles for gaining a reduction in inequity in health.

Se discuten diferentes conceptualizaciones de equidad y desigualdad en salud, concluyendo que inequidad y desigualdad no son sinónimos, y se sugiere la utilización de desigualdad para describir perfiles epidemiológicos y equidad en relación con la distribución y el acceso de los servicios de atención a la salud. Se revisa en más detalle la situación de México, donde existe gran polarización socioeconómica, una reforma sanitaria privatizadora que ha aumentado la inequidad y una ciudadanía incompleta, como obstáculos principales para conseguir una disminución de la inequidad en salud.