Legionella spp. is an environmental bacterium that can survive in a wide range of physicochemical conditions and may colonize distribution systems of drinking water and storage tanks. Legionella pneumophila is the major waterborne pathogen that can cause 90% of Legionnaires' disease cases. The aim of this study was to detect the presence of Legionella spp. in household drinking water tanks in the city of Resistencia, Chaco. The detection of Legionella in water samples was performed by culture methods as set out in ISO 11731:1998. Thirty two water samples were analyzed and Legionella spp. was recovered in 12 (37.5%) of them. The monitoring of this microorganism in drinking water is the first step towards addressing the control of its spread to susceptible hosts.

In order to determine the occurrence of antimicrobial-resistant Enterobacteriaceae, 506 samples of drinking water, surface water, and ground water were studied in the province of Chaco, Argentina. One hundred and ninety one isolates of Enterobacteriaceae Family members were obtained. The most frequent specie was Escherichia coli and it showed the highest rate of acquired resistance, being the β-lactams the most affected antibiotics. The findings of the present work suggest that the occurrence of antimicrobial-resistant bacteria in aquatic ecosystems of Chaco may contribute to the environmental dissemination of antibiotic resistance.

The aim of this work was to detect the presence of Salmonella spp. in recreational aquatic environments in the Northeast of Argentina and to relate it with water and environmental parameters. Sixty eight samples of water from recreational aquatic environments in the provinces of Chaco and Corrientes, Argentina, were studied. Salmonellae were detected in 6 samples (8.8%). Salmonella spp. isolates belonged to the following species and serovars: S. enterica serovar Give, S. enterica subespecie IV, S. enterica ser. Bredeney, S. enterica ser. Rubislaw, and S. enterica ser. Enteritidis (two isolates). None of the isolates were resistant to tested antimicrobials. There were no significant differences among sampling sites as a reservoir of bacteria Salmonella spp. and the other variables. The presence of Salmonella spp. in our recreational aquatic environments reaffirms the need for monitoring in order to minimize the risks of infection to exposed persons

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Legionella, siendo la especie pneumophila el principal agente etiológico de esta patología. Esta bacteria se describió por primera vez en 1977 como causa de un brote de neumonía grave registrado en 1976 en un centro de convenciones en los Estados Unidos de América. La enfermedad se presenta como una neumonía atípica, responsable del 1 al 15 % de los casos de neumonías adquiridas en la comunidad (NAC), del 5 al 10% de neumonías del adulto y del 1% en menores de 15 años. Los miembros de la familia Legionellaceae son bacilos aeróbicos gramnegativos que crecen lentamente y se encuentran ampliamente distribuidos en cuerpos de agua. La forma más común de transmisión de Legionella spp es la inhalación de aerosoles contaminados generados a partir de fuentes de agua artificiales.  Se asocian con la aparición de brotes esporádicos y epidémicos en la comunidad y en infecciones nosocomiales. Las especies pertenecientes al género Legionella se consideran patógenos emergentes transmitidos por el agua.  El objetivo de este trabajo es realizar una revisión sobre las manifestaciones y presentaciones clínicas de la infección causada por L. pneumophila, en virtud de que es considerado mundialmente un patógeno emergente y por existir evidencias de su presencia en sistemas de almacenamiento de agua tratada en la región Nordeste de la República Argentina, razón primordial para alertar y actualizar conocimientos al respecto.

Groundwater is an important source of drinking water for many communities in Northern Argentina; particularly, in the province of Chaco, where about 14% of households use this natural resource. Enteroaggregative Escherichia coli is an emerging pathogen whose global importance in public health has increased in recent years. Despite the significant risk of disease linked to contaminated water exposure, the prevalence of E. coli pathotypes in aquatic environments is still not so well defined. The aim of the present study was to detect the presence of typical enteroaggregative E. coli through the recognition of its virulence factors aap, AA probe and aggR by molecular techniques. A total of 93 water samples from different small communities of Chaco were analyzed. E. coli was identified in 36 (38.7%) of the tested samples. Six strains isolated from different samples harbored the studied genes. Of these 6 isolates, 3 carried the aap gene, 2 the AA probe and the last one the combination of aap/aggR genes. The prevalence of E. coli isolates harboring enteroaggregative virulence genes in groundwater sources was 6.4%. This work represents the first contribution to the study of the presence and distribution of virulence genes of EAEC in groundwater sources in this region of Argentina.

El objetivo fue detectar la resistencia frente a fosfomicina (FOS), colistina (COL) y tigeciclina (TGC) en enterobacterias recuperadas de fuentes superficiales y profundas de agua del Chaco (Argentina). Se incluyeron aislamientos provenientes de muestras de agua de ríos, lagunas y pozos. Se analizaron 70 muestras de agua (40 de origen superficial y 30 subterráneas). Se obtuvieron 106 aislamientos de enterobacterias (68 en fuentes superficiales y 38 en fuentes subterráneas). En aguas superficiales se encontraron 10 (14,7%) aislamientos resistentes a alguno de los antimicrobianos estudiados mientras que en aguas subterráneas resultaron resistentes 3 (7,9%) aislamientos; en total: FOS (8), TGC (1), COL (1), FOS+TGC (2) y FOS+COL (1). El presente es el primer trabajo realizado en nuestro país cuyo foco es la detección de enterobacterias resistentes a FOS, COL y TGC en ambientes acuáticos. El número de aislamientos resistentes encontrados es bajo pero su sola presencia debe alertar sobre el posible pasaje de este tipo de bacterias desde el ambiente al hombre, considerando al agua como un reservorio y medio de transmisión.