Distribution, quantitative load and characterization of Salmonella associated with swine farms in upper-northern Thailand

This study was conducted to analyze the prevalence and quantitative loads of Salmonella spp. on pig farms in Chiang Mai, Lamphun, Thailand to assess loading levels before slaughtering. The serotype diversity, antimicrobial-resistance pattern and pulse-field type of Salmonella spp. were also characterized to assess the dynamic propagation of the pathogen. The Salmonella-positive prevalence was 246/805 (30.56%), and the quantitative loads varied from 1.48~4.04 Log10MPN/g, with a mean +/- standard deviation of 2.11 +/- 0.57. AMP/S/TE (ampicillin/streptomycin/tetracycline) was the highest frequency antimicrobial resistance pattern found in this study. In addition, Salmonella Rissen was the primary serotype in this region. PFGE results indicated the occurrence of infection by cross contamination among pig farms. Our study showed that pork is easily contaminated with this pathogen. Farm control programs must be based on strict biosecurity and hygienic measures, which could further reduce the contamination pressure at slaughterhouses or retail shops.

Bacterial infection of mudfish Clarias gariepinus (Siluriformes: Clariidae) fingerlings in tropical nursery ponds

Bacterial infection among the most common cultured mudfish Clarias gariepinus in Africa, has become a cause of concern, because it constitutes the largest economic loss in fish farms. In order to provide useful biological data of the pathogens for good management practices, samples were collected monthly between January 2008 and December 2009 in three monoculture nursery ponds, located in three different positions: upriver (A, grassland), mid-river (B, mixed forest and grassland) and downriver (C, rainforest) along 200km length of Cross River floodplains, Nigeria. A total of 720 fingerlings between 15.1 and 20.7g were analyzed to determine the degree of infection. The bacterial pathogens were taken from their external surfaces, and were isolated and identified by standard methods. The caudal fins of fingerlings from pond A had the highest bacterial load (5.8x10³cfu/g), while the least counts (1.2x103cfu/g) were identified on the head of fish from pond C, with Flexibacter columnaris as the major etiological agent. Pseudomonas fluorescens, Aeromonas hydrophila, Escherichia coli, Staphylococcus aureus and Micrococcus luteus were identified as co-isolates with P. fluorescens as dominant (0.7x10²cfu/mL) co-isolates in pond water. Clinical signs of five white spots with red periphery appeared on the external surface of infected fish. All the fish sampled, died after 4 to 9 days. There was no significant difference in the bacterial counts between different ponds, but the difference between fish organs/parts examined was significant. Fish from these ponds are therefore potentially dangerous to consumers and highly devalued, with the economic impact to producers. Preventive methods to avoid these infections are recommended. Rev. Biol. Trop. 59 (2): 751-759. Epub 2011 June 01.

Las infeccines bacterianas son comunes en el pez de cultivo Clarias gariepinus, el cual es el más cultivado en Africa y se han convertido en una causa de preocupación, ya que constituye la mayor pérdida económica en las granjas piscícolas. Se proporcionan datos biológicos de los agentes patógenos con el fin de proporcionar información útil para buenas prácticas de gestión en las granjas. Las muestras fueron recolectadas mensualmente entre Enero 2008 y Diciembre 2009 en tres viveros de estanques de monocultivo, situados en tres posiciones diferentes: río arriba (A, pastizales), mitad del río (B, bosque mixto y pastos) y aguas abajo (C, bosque) a lo largo de 200km de longitud en las llanuras de inundación del río Cross, Nigeria. Un total de 720 alevines de entre 15.1 y 20.7g fueron analizados para determinar el grado de infección. Los patógenos bacteriales fueron tomados de las superficies externas, y fueron aislados e identificados por métodos estándar. Las aletas caudales de los alevines del estanque A tuvieron la mayor carga bacteriana (5.8x10³cfu/g), mientras el menor conteo de bacterias (1.2x103cfu/g) fue identificado en la cabeza de los peces del estanque C, con Flexibacter columnaris como el agente etiológico más importante. Pseudomonas fluorescens, Aeromonas hydrophila, Escherichia coli, Staphylococcus aureus y Micrococcus luteus se identificaron como co-aislamientos con P. fluorescens, como dominantes (0.7x102cfu/mL) co-aislados en el agua del estanque. Los signos clínicos fueron cinco puntos blancos con la periferia roja y aparecieron en la superficie externa de los peces infectados. Todos los peces de la muestra, murieron después de 4 a 9 días. No hubo diferencia significativa en los recuentos bacterianos entre los diferentes estanques, pero la diferencia entre los órganos y las partes de los peces examinados fue significativa. Los peces de estos estanques son potencialmente peligrosos para los consumidores y con alta devaluación, ...

Invasive potential of biofilm-forming Staphylococci bovine subclinical mastitis isolates

Staphylococcus (S.) aureus is a common infectious agent of bovine chronic mastitis, a disease that is difficult to eradicate. The abilities of Staphylococci to be internalized and form a biofilm can contribute to host immunological defence evasion that subsequently impairs antimicrobial therapy. The invasive capability of six S. aureus field isolates with different biofilm-forming profiles was compared in vitro using a bovine mammary epithelial cell line. This was further confirmed in primary cell cultures using fluorescent rRNA probes against S. aureus. The results suggest that S. aureus invasion levels are not related to biofilm formation.

A simplified PCR assay for fast and easy mycoplasma mastitis screening in dairy cattle

A simplified polymerase chain reaction (PCR) assay was developed for fast and easy screening of mycoplasma mastitis in dairy cattle. Species of major mycoplasma strains [Mycoplasma (M.) bovis, M. arginini, M. bovigenitalium, M. californicum, M. bovirhinis, M. alkalescens and M. canadense] in cultured milk samples were detected by this simplified PCR-based method as well as a standard PCR technique. The minimum concentration limit for detecting mycoplasma by the simplified PCR was estimated to be about 2.5 x 10(3) cfu/mL and was similar to that of the standard PCR. We compared the specificity and sensitivity of the simplified PCR to those of a culture method. Out of 1,685 milk samples cultured in mycoplasma broth, the simplified PCR detected Mycoplasma DNA in 152 that were also positive according to the culture assay. The sensitivity and specificity of the simplified PCR were 98.7% and 99.7%, respectively, for detecting mycoplasma in those cultures. The results obtained by the simplified PCR were consistent with ones from standard PCR. This newly developed simplified PCR, which does not require DNA purification, can analyze about 300 cultured samples within 3 h. The results from our study suggest that the simplified PCR can be used for mycoplasma mastitis screening in large-scale dairy farms.

Salmonella sp. em avicultura industrial: diagnóstico imunológico e molecular / Salmonella sp. in poultry industry: immunological and molecular diagnostics

Os sorotipos de salmonelas paratifóides, tais como, Salmonella enteritidis e Salmonella typhimurium acometem diversas espécies de animais e possuem significado em saúde pública, como agentes etiológicos da salmonelose humana.A indústria avícola atende a uma série de exigências para o controle higiênico-sanitário dos plantéis e produtos avícolas. A legislação inclui procedimentos de campo, de abate e de processamento, rotulagem, diagnóstico laboratorial e certificação de produtos, a fim de evitar a transmissão de Salmonella sp. para outros animais e seres humanos. As tecnologias de diagnóstico de Salmonella sp. confiáveis e rápidas são essenciais para que a indústria avícola atenda às exigências legais e comerciais e diminua o tempo de estocagem dos produtos em câmaras e contêineres frigoríficos. Esta revisão objetiva abordar os principais assuntos relacionados ao diagnóstico imunológico e molecular de Salmonella sp. e destacar a importância do diagnóstico rápido deste patógeno para a indústria avícola nacional.

Contagem bacteriana da superfície de tetas de vacas submetidas a diferentes processos de higienizaçäo, incluindo a ordenha manual com participaçäo do bezerro para estimular a descida do leite / Bacterial counts on the surface of the teats of cows milked and different methods of udder preparation, including cows milked by hand and stimulated by suckling a calf

A pele da teta é uma das principais fontes de contaminaçäo microbiana do leite cru, além de ser uma fonte de infecçäo da glândula mamária. Este estudo comparou diferentes métodos de preparaçäo do úbere, incluindo a participaçäo do bezerro para estimular a descida do leite, em relaçäo à contaminaçäo microbiana da pele da teta. Um experimento com 36 vacas ordenhadas mecanicamente foi conduzido para comparar três procedimentos (A, B, C) de preparaçäo do úbere. Duas tetas de cada vaca foram amostradas para contagem total de bactérias (CTB) e de coliformes, antes e após lavagem com água e secagem com papel toalha descartável (A); procedimento A, mais imersäo das tetas em soluçäo de iodo (4.000ppm) e secagem com papel toalha descartável (B); higienizaçäo com toalha de papel embebida em soluçäo desinfetante contendo clorexidina (C). O segundo experimento incluiu 16 vacas ordenhadas manualmente, na presença do bezerro. Permitiu-se a cada bezerro mamar as quatro tetas por alguns segundos, de acordo com o manejo do rebanho. Amostras para bacteriologia de duas tetas de cada vaca foram coletadas, antes, após a mamada do bezerro, e após higienizaçäo semelhante ao procedimento C, citado acima. Os tratamentos foram analisados usando-se o teste näo-paramétrico de Kruskal-Wallis, considerando-se os dados de tCTB após o uso de um dos métodos de preparaçäo do úbere ou da mamada do bezerro. Usou-se a transformaçäo das contagens bacterianas para a escala logarítmica em base 10, com a fórmula tCTB=log10 (CTB+0,5). Para os grupos A,B e C (primeiro experimento), Os valores médios de diminuiçäo de tCTB foram 1,8, 2,2 e 2,4, respectivamente. No segundo experimento, as CTB's aumentaram significativamente (p<0,05) de 3,2 para 4,3 após a mamada do bezerro, mas houve uma reduçäo (P<0,01) de mais de dez vezes após a aplicaçäo do desinfetante (2,0). Os resultados indicaram que: (a) lavagem das tetas com água seguida de secagem com papel toalha reduz o número de microrganismos da superfície das tetas, mas a reduçäo é muito maior quando se emprega um desinfetante; (b) a mamada do bezerro antes da ordenha aumenta em mais de dez vezes o número de bactérias na superfície das tetas; (c) o número de bactérias na pele das tetas pode ser reduzido em mais de 90 por cento após a mamada do bezerro, se as tetas forem cuidadosamente desinfetadas. Nas condiçöes dos experimentos realizados, a presença de coliformes foi insignificante.

Comparación entre el método estándar sugerido por APHA y los métodos Simplate y Petrifilm, para la identificación del grupo coliforme y de Escherichia coli en tilapia (Oreochromis sp) procedente de piscicultura de agua dulce / Comparison between the standard MPN method recommended by the American Public Health Association and the Simplate and Petrifilm methods for identification of the coliform group and Escherichia coli in tilapia (Oreochromis sp) originating from aquaculture in fresh water

We have compared three methods for the detection and quantification of coliforms and E. coli in fish: the conventional three-tube MNP method (APHA), the Simplate Method and the Petrifilm Method. Thirty samples of the tilapia's external surface (skin, gills and fin) produced in an artificial pond were collected. Samples were processed individually in buffered peptone water 1, then they were diluted and inoculated in Simplate, Petrifilm and LST tubes. Coliforms were isolated from 100 of the samples. The Simplate and 3M Petrifilm results were obtained after 24 h of incubation. The conventional three-tube MNP method showed results only after 96 hours of incubation. Simplate showed better recovery of coliforms and E. coli than 3 M Petrifilm and APHA method (P < 0.05). 3M Petrifilm and APHA were not significantly different for E. coli recovery.

Microbiota conjuntival normal de equinos / Normal conjunctival microflora in horses

O conhecimento da microbiota conjuntival normal de equinos e a realizaçäo de testes de sensibilidade diante de antibióticos e quimioterápicos säo fundamentais para o diagnóstico e tratamento de afecçöes oculares. Colheram-se amostras do saco conjuntival de equinos isentos de afecçöes oculares e/ou sistêmicas que, eventualmente, pudessem levar à alteraçäo ocular. Essas coletas foram realizadas, durante o inverno e o veräo, com animais sob diferentes formas de manejo:; regime de hospitalizaçäo, de estabulaçäo e extensivo. O material coletado foi submetido a exames bacteriológicos e a testes de sensibilidade diante de antibióticos e quimioterápicos. A microbiota conjuntival normal de equinos foi composta por bactérias Gram-positivas, Gram-negativas e leveduras, tais como: Bacillus subtillis, Stafilococcus spp., Streptococcus spp., Enterobactérias, Candida spp.