40 research outputs found
SURVIVAL CAPACITY OF Arcobacter butzleri INOCULATED IN POULTRY MEAT AT TWO DIFFERENT REFRIGERATION TEMPERATURES
Arcobacter spp. are emerging enteropathogens and potential zoonotic agents that can be transmitted by food and water, being considered a public health risk. The high isolation rate of these bacteria from poultry products suggests that it may be a major source of human infections. One hallmark for differentiating the genus Arcobacter fromCampylobacter includes their growing capacity at low temperatures (15-30 掳C) under aerobic conditions. However, little is known about the population density variation of these bacteria at different refrigeration temperatures. The aim of this study was to determine the survival behavior of two different Arcobacter butzleri concentrations (104 CFU/mL and 107 CFU/mL) inoculated on chicken legs and held at two different refrigeration temperatures (4 and 10 掳C) throughout storage time. Results have shown that A. butzleri had growing capacity both at 4 and 10 掳C. No statistical difference between the survival trends was found for both bacterial concentrations and temperatures tested. This study shows that A. butzleri is a robust species with regard to storage temperature, and represents a potential health risk for poultry meat consumers
First isolation report of Arcobacter cryaerophilus from a human diarrhea sample in Costa Rica
Arcobacter cryaerophilus is an emerging enteropathogen and potential zoonotic agent transmitted by food and water. In Costa Rica, this bacterium has not been associated with cases of human gastroenteritis, even though it has been isolated from farm animals, especially poultry. This paper reports the first isolation of A. cryaerophilus from a human case of bloody watery diarrhea and the virulence genes associated with this isolate
First isolation report of Arcobacter cryaerophilus from a human diarrhea sample in Costa Rica
Survival of the bacterium Listeria monocytogenes (Listeriaceae) after addition of lemon juice or sodium hypochlorite
Comparaci贸n de m茅todos para el an谩lisis de coliformes totales y fecales en muestras de agua mediante la t茅cnica de N煤mero M谩s Probable (NMP)
The basic microbiological analysis of water includes the determination of total and fecal coliforms. The presence or abscense of fecal coliforms in water defines its potability. The main objective of this work was to design and execute a comparison scheme of two techniques for the determination of coliforms in water, applying modifications to the reference technique of the Most Probable Number, derived from the Standard Methods for the Examination of Water and Wastewater. The modifications included the type of media used for the presumptive phase and the use of an air incubator instead of a water bath for the confirmatory phase. At the same time, the effect of using calibrated automatic pipettes and calibrated glass pipettes was also compared. Artificial water samples, elaborated with standard laboratory material and inoculated with Escherichia coli ATCC 25922 and environmental samples, were used. The alternative methodology shows a superior performance only when inoculation is low. There was no difference between the two volumetric systems.KEY WORDSTotal coliforms, fecal coliforms, water, Most Probable Number.El an谩lisis microbiol贸gico b谩sico del agua comprende la determinaci贸n de coliformes totales y fecales. La ausencia o presencia de los coliformes fecales en el agua define su potabilidad. El objetivo del presente estudio consisti贸 en el dise帽o y ejecuci贸n de un esquema de comparaci贸n de dos t茅cnicas para la determinaci贸n de coliformes en aguas, a partir de modificaciones aplicadas sobre la t茅cnica de referencia de N煤mero M谩s Probable (NMP) derivada del Standard Methods for the Examination of Water and Wastewater. Espec铆ficamente, las modificaciones incluyeron el tipo de medio utilizado en la fase presuntiva de la t茅cnica y el uso de incubadora de aire, alternativo al ba帽o de mar铆a en la fase confirmatoria. Simult谩neamente, se compar贸 el efecto del uso de equipo volum茅trico tipo micropipeta autom谩tica calibrada o pipetas de vidrio est茅riles calibradas. Para tal efecto, se utilizaron muestras de agua artificiales, elaboradas con material del laboratorio e inoculadas con una cepa de Escherichia coli ATCC 25922 as铆 como muestras ambientales. La metodolog铆a alternativa tiene un rendimiento superior solamente cuando el nivel de in贸culo en las muestras es bajo. No se determin贸 ninguna diferencia estad铆sticamente significativa entre los dos sistemas de medici贸n volum茅trica.PALABRAS CLAVEcoliformes totales, coliformes fecales, agua, N煤mero M谩s Probable
Calidad microbiol贸gica de la materia prima y el producto final del ceviche de tilapia y de camar贸n expendidos en el 脕rea Metropolitana de San Jos茅, Costa Rica
Microbiological quality of raw material and final product of tilapia and shrimp ceviche expended in the Metropolitan Area of San Jos茅, Costa Rica. Ceviche is a common use dish from Latin American countries, made up of raw fish or seafood marinated with lemon or lime juice, and several seasoning ingredients. It includes the normal flora coming from raw product and flora acquired from handling and additional ingredients. The product is consumed raw, representing a risk for Public Health. The aim of this work was to determine the microbiological quality of tilapia fish ceviche and shrimp ceviche sold at the Metropolitan Area of San Jos茅, Costa Rica, as well as the raw material used in its elaboration. A total of 25 samples of tilapia ceviche and 27 samples of shrimp ceviche were analyzed; the same number of raw material was analyzed. The behavior of some of the spoilage populations was analyzed in 25 samples of shrimp and same number of tilapia ceviche during its storage at 4oC. Even though the ceviche includes manipulation plus an important bacterial contamination in raw material, there is an important reduction in the bacterial charge of the final product, especially referring to total aerobic psychrofilic plate count and total coliforms; but not to fecal coliforms. Escherichia coli was isolated from 15% of the tilapia鈥檚 ceviche and 4% from shrimp鈥檚 ceviche, 3 strains of Listeria monocytogenes were isolated from tilapia, one from shrimp, 3 strains of V. parahaermolyticus were isolated from shrimp and 2 from its ceviche. Salmonella spp. was not isolated. The pH of ceviche plates stored at 4oC for one week showed a trend towards stability or a slight increase of this parameter. The concentration of spoilage microorganisms suffered slight variations, nevertheless, the low number of Pseudomonas spp. present in tilapia鈥檚 ceviche is an outstanding result considering that this population is associated to spoilage of the product.KEY WORDSCeviche, tilapia, shrimp, spoilage.El ceviche es un platillo formulado a base de pescado de agua salada o dulce, o mariscos frescos y diversos ali帽os. Su elaboraci贸n acarrea no solo la flora normal y adquirida de la materia prima a utilizar, sino que tambi茅n la flora que se agregue durante su procesamiento y a partir de ingredientes adicionales. Adem谩s, es un producto que se consume marinado, representando un riego para la salud p煤blica. El objetivo de este trabajo fue determinar la calidad microbiol贸gica del ceviche de tilapia y del ceviche de camar贸n que se vende en el 脕rea Metropolitana de San Jos茅, Costa Rica, as铆 como de la materia prima utilizada en su respectiva elaboraci贸n. Para tal efecto, se analizaron 25 muestras de ceviche de tilapia y 27 de camar贸n, analizando igual n煤mero de muestras de materia prima. De la misma manera, se analiz贸 el comportamiento de las poblaciones de algunos microorganismos de deterioro a partir de 25 muestras de ceviche de camar贸n y 25 muestras de ceviche de tilapia durante su almacenaje a 4oC. A pesar de la contaminaci贸n bacteriol贸gica presente en la materia prima, y de que el ceviche es un producto que incluye mucha manipulaci贸n, existe una disminuci贸n importante en las cargas bacterianas en el producto final, especialmente en lo que respecta a recuento total de aerobios psicr贸filo y coliformes totales, no as铆 los coliformes fecales. Se aisl贸 Escherichia coli a partir de 15% de ceviches de tilapia y 4% de los ceviches de camar贸n, 3 cepas de Listeria monocytogenes a partir de tilapia, 1 a partir de camar贸n, y 3 cepas de V. parahaermolyticus a partir de camar贸n y 2 a partir de su ceviche. No se aisl贸 Salmonella spp. En cuanto a los ceviches almacenados a 4oC por una semana, cabe destacar que el pH mostr贸 una tendencia hacia la estabilidad o de aumento muy ligero. De la misma manera, la concentraci贸n de microorganismos de deterioro sufri贸 pocas variaciones, no obstante, llama la atenci贸n el bajo n煤mero de Pseudomonas spp. presentes en los ceviches de tilapia.PALABRAS CLAVECeviche, tilapia, camar贸n, deterioro
Calidad microbiol贸gica y actividad antimicrobiana de la miel de abejas sin aguij贸n
Introduction. Honey has been recognized for
its anti-infl ammatory and antibacterial properties
since ancient times. The growing appearance of
antibiotics resistant bacterial strains has promoted
honey's analysis for the alternative treatment of
ulcers, wounds and burns. There are two major
groups of honey producing bees, those that sting
(Apis melliphera) and stingless (Meliponini).
The chemical composition of each of these two group's honey is not identical, and these chemical
differences may affect the honey's effects on
microorganisms.
Objective. The aim of this work was to evaluate
the microbiological charge present in stingless bee
honey and their potential antimicrobial effects, in
order to evaluate its use in the therapeutic treatment
of wounds, ulcers, burns, etc.
Materials and Methods. The microbiological
quality and potential presence of Clostridium botulinum
was evaluated in 30 samples coming from
different geographic zones of Costa Rica. Also,
antimicrobial activity against Staphylococcus aureus
(ATCC 25923), Staphylococcus epidermidis
(UCR 2902), Pseudomonas aeruginosa (ATCC
9027), Escherichia coli (ATCC 25922), E. coli
O157:H7, Salmonella enteritidis (ATCC 13076)
and Listeria monocytogenes (ATCC 19116) was
evaluated.
Results. Results obtained show that 87% of the
samples had bacterial and spore counts equal or
lower than 1.0 x 101 CFU/g, none presented fecal
or total coliforms, and none were positive for the
detection of C. botulinum. All the honeys analyzed
exhibited some kind of inhibitory effect over at
least one of the microorganisms evaluated, either
in pure form or diluted.
Conclusions. Results obtained conclude that
stingless bee honey shows good microbiological
quality and adequate inhibitory effect over the
growth of several microorganisms, so, its potential
therapeutic use is promising.Introducci贸n. Desde la antig眉edad, la miel de
abeja ha sido reconocida por sus propiedades
antiinfl amatorias y antibacterianas. La creciente
aparici贸n de cepas bacterianas resistentes contra
los antibi贸ticos ha motivado que se analice, de
nuevo, el uso de tratamientos alternativos, como la
miel de abeja, sobre 煤lceras, quemadas y heridas.
Existen dos grandes grupos de abejas productoras
de miel: con aguij贸n (Apis melliphera) y sin
aguij贸n (Meliponini). La composici贸n de la miel
de estos dos grupos no es id茅ntica, lo cual puede
marcar una diferencia en el efecto que puedan
presentar sobre diferentes microorganismos.
Objetivo. Se pretende con este trabajo evaluar la
carga microbiol贸gica presente en miel proveniente
de abejas sin aguij贸n, as铆 como su posible efecto
antimicrobiano, con el fi n de valorar su utilizaci贸n
a nivel de tratamiento de heridas, 煤lceras, quemaduras,
etc.
Materiales y M茅todos. Se analiz贸 la calidad
microbiol贸gica de 30 muestras provenientes de
diversas zonas geogr谩fi cas de Costa Rica, as铆 como
la potencial presencia de Clostridium botulinum y
la actividad antimicrobiana contra Staphylococcus
aureus (ATCC 25923), Staphylococcus epidermidis
(UCR 2902), Pseudomonas aeruginosa (ATCC
9027), Escherichia coli (ATCC 25922), E. coli
O157:H7, Salmonella enteritidis (ATCC 13076)
y Listeria monocytogenes (ATCC 19116).
Resultados. Los resultados obtenidos muestran
que el 87% de las muestras ten铆a recuentos bacterianos y de esporas iguales o menores a 1.0x101
UFC/g, ninguna muestra present贸 coliformes
totales ni fecales y no se obtuvo ning煤n resultado
positivo en la determinaci贸n de la presencia de C.
botulinum. Todas las mieles analizadas exhibieron
alg煤n efecto inhibitorio sobre, al menos, uno de
los microorganismos evaluados, tanto de forma
pura como diluida.
Conclusiones. Los resultados obtenidos permiten
concluir que la miel de abejas sin aguij贸n muestra
una buena calidad microbiol贸gica y un adecuado
efecto inhibitorio sobre el crecimiento de varios
microorganismos, por lo que su potencial uso
terap茅utico es muy prometedor
Synthesis and preliminary determination of antibacterial activity of some 1,3-enynes
The synthesis of five 1,3-enynes was performed and its activity against Gram-positive and Gram-negative bacteria was determined.Universidad de Costa Rica//UCR/Costa RicaUCR::Vicerrector铆a de Docencia::Ciencias B谩sicas::Facultad de Ciencias::Escuela de Qu铆micaUCR::Vicerrector铆a de Investigaci贸n::Unidades de Investigaci贸n::Ciencias de la Salud::Centro de Investigaci贸n en Enfermedades Tropicales (CIET
Design and synthesis of n-[3-(3-oxoprop-1-yn-1-yl) phenyl] benzene sulfonamide: a highly active antimicrobial compound
The synthesis of the highly active compound N-[3-(3-oxoprop-1-yn-1-yl)phenyl] benzene sulfonamide was performed and its activity against Gram (+), Gram (-), mold and yeast was determined.Universidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrector铆a de Docencia::Ciencias B谩sicas::Facultad de Ciencias::Escuela de Qu铆micaUCR::Vicerrector铆a de Docencia::Salud::Facultad de Microbiolog铆aUCR::Vicerrector铆a de Investigaci贸n::Unidades de Investigaci贸n::Ciencias de la Salud::Centro de Investigaci贸n en Enfermedades Tropicales (CIET
Synthesis of N-[3-(prop-1-yn-1-yl)phenyl] benzene sulfonamide and Determination of its Antibacterial Activity
The synthesis of N-[3-(prop-1-yn-1-yl)phenyl] benzenesulfonamide was performed and its antibacterial activity against Staphylococcus aureus and Escherichia coli was determined. Minimalinhibitory concentrations (MIC) of 12.5 碌g/mL and 25.0 碌g/mL were obtained respectively.Escuela de Qu铆mica, Universidad de Costa Rica/ /UCR/Costa RicaUCR::Vicerrector铆a de Docencia::Ciencias B谩sicas::Facultad de Ciencias::Escuela de Qu铆micaUCR::Vicerrector铆a de Investigaci贸n::Unidades de Investigaci贸n::Ciencias de la Salud::Centro de Investigaci贸n en Enfermedades Tropicales (CIET