[Beta-lactam antibiotic sensitivity in Aeromonas spp. of clinical, animal, and environmental origin]. / Estudio de susceptibilidad a antibióticos beta-lactámicos en Aeromonas spp. de origen clínico, animal y ambiental.

Susceptibility to beta-lactam antibiotics was investigated in Aeromonas spp. Microorganisms were isolated from both, clinical and water creek samples, as well as from processed raw chicken carcasses. Aeromonas like colonies were identified by means of Aerokey II and API 20 E System (Bio-Merieux). A. hydrophila prevailed both of human origin (44%) and water creek samples (41%), while A. caviae ranked first among raw chicken samples (65%). Dilution testing by Agar Method was performed to determine minimum inhibitory concentration (MIC), following NCCLS standards. All tested microorganisms were susceptible to third generation cephalosporin, cefepime, imipenem, aztreonam, and resistant to ampicillin. Only with cefepime and aztreonam exceptions, strains of human origin showed higher values of MIC90 than environmental ones. These results suggest that antibiotic resistance is mainly due to a steady environmental pressure, on account of the widely used above mentioned compounds.

Estudio de susceptibilidad a antibióticos beta-lactßmicos en Aeromonas spp. de origen clínico, animal y ambiental / Beta-lactam antibiotic sensitivity in Aeromonas spp. of clinical, animal, and environmental origin

Susceptibility to beta-lactam antibiotics was investigated in Aeromonas spp. Microorganisms were isolated from both, clinical and water creek samples, as well as from processed raw chicken carcasses. Aeromonas like colonies were identified by means of Aerokey II and API 20 E System (Bio-Merieux). A. hydrophila prevailed both of human origin (44) and water creek samples (41), while A. caviae ranked first among raw chicken samples (65). Dilution testing by Agar Method was performed to determine minimum inhibitory concentration (MIC), following NCCLS standards. All tested microorganisms were susceptible to third generation cephalosporin, cefepime, imipenem, aztreonam, and resistant to ampicillin. Only with cefepime and aztreonam exceptions, strains of human origin showed higher values of MIC90 than environmental ones. These results suggest that antibiotic resistance is mainly due to a steady environmental pressure, on account of the widely used above mentioned compounds.(AU)

Estudio de susceptibilidad a antibióticos beta-lactßmicos en Aeromonas spp. de origen clínico, animal y ambiental / Beta-lactam antibiotic sensitivity in Aeromonas spp. of clinical, animal, and environmental origin

Susceptibility to beta-lactam antibiotics was investigated in Aeromonas spp. Microorganisms were isolated from both, clinical and water creek samples, as well as from processed raw chicken carcasses. Aeromonas like colonies were identified by means of Aerokey II and API 20 E System (Bio-Merieux). A. hydrophila prevailed both of human origin (44) and water creek samples (41), while A. caviae ranked first among raw chicken samples (65). Dilution testing by Agar Method was performed to determine minimum inhibitory concentration (MIC), following NCCLS standards. All tested microorganisms were susceptible to third generation cephalosporin, cefepime, imipenem, aztreonam, and resistant to ampicillin. Only with cefepime and aztreonam exceptions, strains of human origin showed higher values of MIC90 than environmental ones. These results suggest that antibiotic resistance is mainly due to a steady environmental pressure, on account of the widely used above mentioned compounds.

Estudio de susceptibilidad a antibióticos beta-lactámicos en Aeromonas spp. de origen clínico, animal y ambiental. / [Beta-lactam antibiotic sensitivity in Aeromonas spp. of clinical, animal, and environmental origin]

Susceptibility to beta-lactam antibiotics was investigated in Aeromonas spp. Microorganisms were isolated from both, clinical and water creek samples, as well as from processed raw chicken carcasses. Aeromonas like colonies were identified by means of Aerokey II and API 20 E System (Bio-Merieux). A. hydrophila prevailed both of human origin (44

) and water creek samples (41

), while A. caviae ranked first among raw chicken samples (65

). Dilution testing by Agar Method was performed to determine minimum inhibitory concentration (MIC), following NCCLS standards. All tested microorganisms were susceptible to third generation cephalosporin, cefepime, imipenem, aztreonam, and resistant to ampicillin. Only with cefepime and aztreonam exceptions, strains of human origin showed higher values of MIC90 than environmental ones. These results suggest that antibiotic resistance is mainly due to a steady environmental pressure, on account of the widely used above mentioned compounds.

Investigación de Estreptococos fecales en aguas del arroyo Zaimán / Isolation of fecal streptococci in Zaiman creek waters

Se investigó la presencia de las distintas especies y biovariedades de estreptococos fecales en aguas del arroyo Zaimán, cuya cuenca hídrica comprende importantes zonas de la ciudad de Posada, Misiones. Las muestras fueron extraídas en zonas aledañas cercanas a un establecimiento de la industria de la carne, que vierte sus efluentes en el citado cruso de aguas. Se efectuaron 18 operaciones de muestreo en puntos geográficos representativos. La metodología seguida para la detección y caracterización de las especies presentes consistió en una etapa de enriquecimiento en caldo azida dextrosa, con posteriores repiques en placas de agar KF y agar kanamicina-esculina-azida. El estudio bioquímico de las colonias desarrolladas en medio agar cerebro corazón, se llevó a cabo de acuerdo a normas de estándares americanos de aguas. Las especies de mayor frecuencia de aislamiento resultaron ser: S. faecalis V. liquefaciens (48%), S. faecalis (20%), y S. durans (14%). La distribución de estreptococos fecales por puntos de muestreo indica que la contaminación proviene no sólo del vertido de efluentes, sino tambíen del asentamiento poblacional cercano al curso de aguas (AU)

Investigación de Estreptococos fecales en aguas del arroyo Zaimán / Isolation of fecal streptococci in Zaiman creek waters

Se investigó la presencia de las distintas especies y biovariedades de estreptococos fecales en aguas del arroyo Zaimán, cuya cuenca hídrica comprende importantes zonas de la ciudad de Posada, Misiones. Las muestras fueron extraídas en zonas aledañas cercanas a un establecimiento de la industria de la carne, que vierte sus efluentes en el citado cruso de aguas. Se efectuaron 18 operaciones de muestreo en puntos geográficos representativos. La metodología seguida para la detección y caracterización de las especies presentes consistió en una etapa de enriquecimiento en caldo azida dextrosa, con posteriores repiques en placas de agar KF y agar kanamicina-esculina-azida. El estudio bioquímico de las colonias desarrolladas en medio agar cerebro corazón, se llevó a cabo de acuerdo a normas de estándares americanos de aguas. Las especies de mayor frecuencia de aislamiento resultaron ser: S. faecalis V. liquefaciens (48%), S. faecalis (20%), y S. durans (14%). La distribución de estreptococos fecales por puntos de muestreo indica que la contaminación proviene no sólo del vertido de efluentes, sino tambíen del asentamiento poblacional cercano al curso de aguas

[Fecal Streptococci in the waters of the Zaiman stream]. / Investigación de estreptococos fecales en aguas del arroyo Zaimán.

The investigation was focused on the occurrence of different species and biovarieties of fecal streptococci in Zaiman creek waters, the basin of which comprises important zones of Posadas, Misiones. The samples were collected from points near a meat-packing industrial establishment which pours its effluents in the above mentioned water course. So far, 18 sampling operations have been carried out in representative geographic locations. The methodology followed for detecting and characterizing the present species consisted in an enrichment procedure performed by incubating samples in Azida Dextrose broth at 35 degrees C during 24-48 h. Further streaks were made on KF Agar and Kanamycin Agar plates. The biochemical study of the colonies developed in Brain Heart Agar media was the one described in the American Water Standards (APHA and EPA). The isolation frequency of the different species of fecal streptococci is shown. (Table 2). The efficiency of both culture media KF Agar and Kanamycin Aesculin Azide Agar proved to be similar. (Table 1). The distribution of fecal streptococci by sampling points shows that the pollution comes not only from the pourings of effluents but also from the population settlement near the water course.

Investigación de estreptococos fecales en aguas del arroyo Zaimán. / [Fecal Streptococci in the waters of the Zaiman stream]

The investigation was focused on the occurrence of different species and biovarieties of fecal streptococci in Zaiman creek waters, the basin of which comprises important zones of Posadas, Misiones. The samples were collected from points near a meat-packing industrial establishment which pours its effluents in the above mentioned water course. So far, 18 sampling operations have been carried out in representative geographic locations. The methodology followed for detecting and characterizing the present species consisted in an enrichment procedure performed by incubating samples in Azida Dextrose broth at 35 degrees C during 24-48 h. Further streaks were made on KF Agar and Kanamycin Agar plates. The biochemical study of the colonies developed in Brain Heart Agar media was the one described in the American Water Standards (APHA and EPA). The isolation frequency of the different species of fecal streptococci is shown. (Table 2). The efficiency of both culture media KF Agar and Kanamycin Aesculin Azide Agar proved to be similar. (Table 1). The distribution of fecal streptococci by sampling points shows that the pollution comes not only from the pourings of effluents but also from the population settlement near the water course.

[Isolation of new serovars of Salmonella in streams of water]. / Aislamiento de nuevas serovariedades de Salmonella en cursos de aguas.

The present work is the final stage of a research to determine the causes and degree of pollution of the Zaiman creek waters, which flow through the Capital District of Misiones, Argentina. The research was focused on the presence of Salmonella serovars in samples collected from 2 stream sites equidistant from a cold storage plant and slaughterhouse, one downstream, and the other before the source of pollution. Elevated temperature technique for the isolation of Salmonella was applied. The methodology consisted in applying an enrichment procedure for waterborne pathogens, performed by incubating after a convenient exposure period, gauze swabs in Dulcitol Selenite and Tetrationate (with the addition of 0,001% brilliant green) broths. Salmonella organisms were recovered by streaking duplicate plates of E.M.B Agar (Eosin Methylene Blue), B.P.L.S Agar (Brilliant Green Agar) and Bismuth Sulphite Agar. Best results were obtained when Bulcitol Selenite broth and Bismuth Sulphite Agar were used. (Tables 1, 2, 3). Suspected colonies were classified by 10 biochemical reactions, and further verified by serological identification. So far, 716 suspected colonies have been studied. Salmonella was isolated from 76% of the samples and 22 serovars were identified (Table 3). Isolating frequency of serovars during 1981-1984 is shown (Table 4). S. saphra prevailed among the studied samples, while both S. anatum and S. newport ranked second.(ABSTRACT TRUNCATED AT 250 WORDS)

Aislamiento de nuevas serovariedades de Salmonella en cursos de aguas / Isolation of new serum varieties of Salmonella in water streams

Se continuaron las investigaciones tendientes a determinar las causas y grado de contaminación de las aguas del arroyo Zaimán, del distrito Capital de la provincia de Misiones. Se investigó la presencia de serovars del género Salmonella, en muestras extraídas de 2 puntos equidistantes de un establecimiento frigorífico y matadero, en ambos sentidos de la corriente. Se aplicaron técnicas de incubación de alta temperatura, con plaqueos sucesivos efectuados a distintos tiempos de incubación. Como medios de enriquecimiento se emplearon Caldo-Dulcitol Selenito y Caldo-Tetrationato con Verde Brilhante al 0,001%. Para el aislamiento de colonias se utilizaron Agar Eosina-Azul de metileno, Agar Verde Brilhante con Sacarosa y Agar Sulfito de Bismuto. La mejor combinación resultó ser: Caldo Dulcitol Selenito-Agar Sulfito de bismuto. Se caracterizaron las cepas por medio de 10 reacciones bioquímicas y por serología. Se realizaron 34 operaciones de muestreo, hallando Salmonella en un 76% de las muestras analizadas, describiéndose un total de 22 serovariedades. Se señala a S. saphra como la serovar de mayor abundancia, ocupando S. anatum y S. newport el segundo lugar en forma compartida. La mayor parte de los aislamientos y serovars confirmados, provinieron del punto de muestreo ubicado aguas abajo del establecimento industrial, lo que demuestra la influencia de vertido de efluentes en el grado de contaminación de las aguas del arroyo Zaimán, considerándose que el nivel de Salmonella hallado constituye un riesgo potencial significativo para los probladores ribereños que utilizan estas aguas, principalmente con fines de recreación. Se destaca la detección de una nueva seroviedad en el orden mundial, designada como S. zaimán y la presencia de los primeros aislamientos en la Argentina de las serovars S. jos, S. madelia y S. belem, todas pertenecientes a la sub-especie I y la S. IV (HARMELEN) que corresponde a la sub-especie IV del género Salmonella (AU)

Aislamiento de nuevas serovariedades de Salmonella en cursos de aguas. / [Isolation of new serovars of Salmonella in streams of water]

The present work is the final stage of a research to determine the causes and degree of pollution of the Zaiman creek waters, which flow through the Capital District of Misiones, Argentina. The research was focused on the presence of Salmonella serovars in samples collected from 2 stream sites equidistant from a cold storage plant and slaughterhouse, one downstream, and the other before the source of pollution. Elevated temperature technique for the isolation of Salmonella was applied. The methodology consisted in applying an enrichment procedure for waterborne pathogens, performed by incubating after a convenient exposure period, gauze swabs in Dulcitol Selenite and Tetrationate (with the addition of 0,001

brilliant green) broths. Salmonella organisms were recovered by streaking duplicate plates of E.M.B Agar (Eosin Methylene Blue), B.P.L.S Agar (Brilliant Green Agar) and Bismuth Sulphite Agar. Best results were obtained when Bulcitol Selenite broth and Bismuth Sulphite Agar were used. (Tables 1, 2, 3). Suspected colonies were classified by 10 biochemical reactions, and further verified by serological identification. So far, 716 suspected colonies have been studied. Salmonella was isolated from 76

of the samples and 22 serovars were identified (Table 3). Isolating frequency of serovars during 1981-1984 is shown (Table 4). S. saphra prevailed among the studied samples, while both S. anatum and S. newport ranked second.(ABSTRACT TRUNCATED AT 250 WORDS)

Aislamiento de nuevas serovariedades de Salmonella en cursos de aguas / Isolation of new serum varieties of Salmonella in water streams

Se continuaron las investigaciones tendientes a determinar las causas y grado de contaminación de las aguas del arroyo Zaimán, del distrito Capital de la provincia de Misiones. Se investigó la presencia de serovars del género Salmonella, en muestras extraídas de 2 puntos equidistantes de un establecimiento frigorífico y matadero, en ambos sentidos de la corriente. Se aplicaron técnicas de incubación de alta temperatura, con plaqueos sucesivos efectuados a distintos tiempos de incubación. Como medios de enriquecimiento se emplearon Caldo-Dulcitol Selenito y Caldo-Tetrationato con Verde Brilhante al 0,001%. Para el aislamiento de colonias se utilizaron Agar Eosina-Azul de metileno, Agar Verde Brilhante con Sacarosa y Agar Sulfito de Bismuto. La mejor combinación resultó ser: Caldo Dulcitol Selenito-Agar Sulfito de bismuto. Se caracterizaron las cepas por medio de 10 reacciones bioquímicas y por serología. Se realizaron 34 operaciones de muestreo, hallando Salmonella en un 76% de las muestras analizadas, describiéndose un total de 22 serovariedades. Se señala a S. saphra como la serovar de mayor abundancia, ocupando S. anatum y S. newport el segundo lugar en forma compartida. La mayor parte de los aislamientos y serovars confirmados, provinieron del punto de muestreo ubicado aguas abajo del establecimento industrial, lo que demuestra la influencia de vertido de efluentes en el grado de contaminación de las aguas del arroyo Zaimán, considerándose que el nivel de Salmonella hallado constituye un riesgo potencial significativo para los probladores ribereños que utilizan estas aguas, principalmente con fines de recreación. Se destaca la detección de una nueva seroviedad en el orden mundial, designada como S. zaimán y la presencia de los primeros aislamientos en la Argentina de las serovars S. jos, S. madelia y S. belem, todas pertenecientes a la sub-especie I y la S. IV (HARMELEN) que corresponde a la sub-especie IV del género Salmonella

[Acetobutylic fermentation: strains and regional raw materials]. / Fermentación acetobutílica: cepas y materias primas regionales.

The purpose of the present work was to show, as a first stage, that it is possible to characterize autochtohnous strains of Clostridium acetobutilicum of a good solvent producing capacity, specially N-butanol, through the utilization of suitable techniques for isolating anaerobic microorganisms. Cassava roots were employed as raw material using suitable culture media and an anaerobic jar of cold catalyst. The fermentative capacity of the strains thus isolated was evaluated against a control strain of Clostridium acetobutilicum. Even though some of the strains showed a greater solvent producing power, most of them showed lower fermentation capacity than the control strain, which could be increased, by applying successive thermic treatments. As a second stage, and due to the low cost production of cassava in the Province of Misiones, we studied its utilization as an acetone-butanol fermentation substrate. Mashes composed of binary mixtures of cassava flour and variable amounts of integral flour maize or soy were treated with selected "starters" of Clostridium acetobutilicum, being further processed according to standardized techniques in order to obtain the already mentioned solvents. Mashes concentration influence was also studied using culture media the composition of which proved to be excellent in all experiments carried out under "static system" conditions. The highest fermentative yields (maximum value recorded: 26,20 g of total solvents, with respect to dry solids), were recorded for mashes obtained from mixtures containing integral maize flour; these showed a higher degree of nutrients utilization than those prepared with integral soy flour.

[Salmonella: its incidence in waters of the Zaimán arroyo]. / Salmonella: su incidencia en aguas del arroyo Zaimán.

The present work is the initial stage of a project to determine the causes and degree of pollution of the Zaiman creek waters, which flow through wide suburban areas of Posadas, Argentina. The research was focused on the presence of Salmonella serotypes, pathogenic microorganisms probably responsible for most waterborne disease outbreaks. In addition, the N.M.P./100 ml (Most Probable Number) of total coliform organisms was determined in samples collected from points near cold storage plant and slaughterhouse, both to show the pollution effect of industrial discharges. So far, 35 sampling operations have been carried out in representative geographic points. The methodology for Salmonella consisted in applying concentration technics for waterborne pathogens, followed by an enrichment procedure performed by incubating samples in Dulcitol Selenite and Tetrathionate (Muller-Kauffman) broths at 41.5 degrees C during 25 hours. Typical, well-isolated Salmonella-like colonies were obtained by streaking duplicate plates of E.M.B. Agar (Eosin Methylene Blue), Brilliant Green Agar and Bismuth Sulphite Agar. Suspected colonies were classified by 10 biochemical reactions and further verified by serological identification, performed at the National Institute of Microbiology "Carlos Malbrán". The methodology followed for the determination of total coliforms was the one described in the American Water Standards. Salmonella serotypes were isolated in 46% of the examined samples. Isolation efficiency of culture media is shown. First isolations of Salmonella abaetetuba and S. saphra are reported. Most serotypes were isolated from sampling points down-stream from the industrial plant. Zaimán creek waters were classified as No 4 of W.H.O (World Health Organization) stream waters classification, except during heavy rain periods in which they ranked as No 3.

Fermentacion acetobulica: cepas y materias primas regionales. / Acetone-butanol fermentation: strains and regional raw materials

Con el empleo de tecnicas adecuadas para microorganismos anaerobicos, es posible aislar y caracterizar cepas de Clostridium acetobutilicum, buenas productoras de solventes, en especial n-butanol, propanoma y etanol. Se partio de raices de mandioca como materia prima, adoptando el uso de medios de cultivo apropiados y una jarra anaarobica e catalizador frio. Se midio la capacidad fermentativa de las cepas aisladas frente a una cepa testigo de Clostridium acetobutilicum. Si bien algunas de las cepas ensayadas presentaron una mayor produccion de solventes, la mayoria de las mismas exhibieron una menor capacidad fermentativa que el testigo, la que pudo ser incrementada significativamente con el empleo de un numero discreto de tratamientos termicos sucesivos. Se estudio la utilizacion de la mandioca como sustrato en fermentacion acetobutilica. Para ello se trataron mostos formados a partir de mezclas binarias de fecula de mandioca y harinas integrales de maiz y soja, con percultivos de cepas seleccionadas, a fin de obtener solventes de aplicacion industrial: n-butanol y propanona. Los mayores rendimientos fermentativos, hasta 26,20 g en solventes totales, se registraron para mostos suplementativos con harina de maiz.Los medios de cultivo con harina de soja como suplemento proteico mostraron un menor grado de conversion de sustratos en solventes

Fermentación acetobutílica: cepas y materias primas regionales. / [Acetobutylic fermentation: strains and regional raw materials]

The purpose of the present work was to show, as a first stage, that it is possible to characterize autochtohnous strains of Clostridium acetobutilicum of a good solvent producing capacity, specially N-butanol, through the utilization of suitable techniques for isolating anaerobic microorganisms. Cassava roots were employed as raw material using suitable culture media and an anaerobic jar of cold catalyst. The fermentative capacity of the strains thus isolated was evaluated against a control strain of Clostridium acetobutilicum. Even though some of the strains showed a greater solvent producing power, most of them showed lower fermentation capacity than the control strain, which could be increased, by applying successive thermic treatments. As a second stage, and due to the low cost production of cassava in the Province of Misiones, we studied its utilization as an acetone-butanol fermentation substrate. Mashes composed of binary mixtures of cassava flour and variable amounts of integral flour maize or soy were treated with selected [quot ]starters[quot ] of Clostridium acetobutilicum, being further processed according to standardized techniques in order to obtain the already mentioned solvents. Mashes concentration influence was also studied using culture media the composition of which proved to be excellent in all experiments carried out under [quot ]static system[quot ] conditions. The highest fermentative yields (maximum value recorded: 26,20 g of total solvents, with respect to dry solids), were recorded for mashes obtained from mixtures containing integral maize flour; these showed a higher degree of nutrients utilization than those prepared with integral soy flour.

Salmonella: su incidencia en aguas del arroyo Zaimán. / [Salmonella: its incidence in waters of the Zaimán arroyo]

The present work is the initial stage of a project to determine the causes and degree of pollution of the Zaiman creek waters, which flow through wide suburban areas of Posadas, Argentina. The research was focused on the presence of Salmonella serotypes, pathogenic microorganisms probably responsible for most waterborne disease outbreaks. In addition, the N.M.P./100 ml (Most Probable Number) of total coliform organisms was determined in samples collected from points near cold storage plant and slaughterhouse, both to show the pollution effect of industrial discharges. So far, 35 sampling operations have been carried out in representative geographic points. The methodology for Salmonella consisted in applying concentration technics for waterborne pathogens, followed by an enrichment procedure performed by incubating samples in Dulcitol Selenite and Tetrathionate (Muller-Kauffman) broths at 41.5 degrees C during 25 hours. Typical, well-isolated Salmonella-like colonies were obtained by streaking duplicate plates of E.M.B. Agar (Eosin Methylene Blue), Brilliant Green Agar and Bismuth Sulphite Agar. Suspected colonies were classified by 10 biochemical reactions and further verified by serological identification, performed at the National Institute of Microbiology [quot ]Carlos Malbrán[quot ]. The methodology followed for the determination of total coliforms was the one described in the American Water Standards. Salmonella serotypes were isolated in 46

of the examined samples. Isolation efficiency of culture media is shown. First isolations of Salmonella abaetetuba and S. saphra are reported. Most serotypes were isolated from sampling points down-stream from the industrial plant. Zaimán creek waters were classified as No 4 of W.H.O (World Health Organization) stream waters classification, except during heavy rain periods in which they ranked as No 3.

Fermentacion acetobulica: cepas y materias primas regionales. / Acetone-butanol fermentation: strains and regional raw materials

Con el empleo de tecnicas adecuadas para microorganismos anaerobicos, es posible aislar y caracterizar cepas de Clostridium acetobutilicum, buenas productoras de solventes, en especial n-butanol, propanoma y etanol. Se partio de raices de mandioca como materia prima, adoptando el uso de medios de cultivo apropiados y una jarra anaarobica e catalizador frio. Se midio la capacidad fermentativa de las cepas aisladas frente a una cepa testigo de Clostridium acetobutilicum. Si bien algunas de las cepas ensayadas presentaron una mayor produccion de solventes, la mayoria de las mismas exhibieron una menor capacidad fermentativa que el testigo, la que pudo ser incrementada significativamente con el empleo de un numero discreto de tratamientos termicos sucesivos. Se estudio la utilizacion de la mandioca como sustrato en fermentacion acetobutilica. Para ello se trataron mostos formados a partir de mezclas binarias de fecula de mandioca y harinas integrales de maiz y soja, con percultivos de cepas seleccionadas, a fin de obtener solventes de aplicacion industrial: n-butanol y propanona. Los mayores rendimientos fermentativos, hasta 26,20 g en solventes totales, se registraron para mostos suplementativos con harina de maiz.Los medios de cultivo con harina de soja como suplemento proteico mostraron un menor grado de conversion de sustratos en solventes