A bacteriological study of ants was conducted. The ants were captured in a dairy goat establishment located in Metropolitan Region. 63 samples were obtained and grouped into: 21 control samples aspirated directly on the sterile filter paper, prior to the passing of ants (Control A), 21 ant samples aspirated from the filter paper (Ants Sample), after removal of the ants from the aforementioned filter paper, 21 samples were obtained after the passing of ants (Control B). A microbiological protocol specifically designed for this study was used. The methodology included sowing in nutritious, selective and differential culture media. Subsequently, and depending on the organism biochemical tests or specific tests followed in each case. In this study it was decided to investigate the presence of 6 important pathogenic agents: Staphylococcus aureus, Salmonella spp., Pseudomonas aeruginosa, Escherichia coli, Listeria monocytogenes and Campylobacter jejuni. Four potential pathogens were isolated from the Ants Samples and the Control B Samples:Staphylococcus aureus, Salmonella spp., Pseudomonas aeruginosa and Escherichia coli. Also, other microbial agents were found such as Streptococcus sp., Micrococcus sp., Escherichia vulneris, Hafnia alvei, Serratia marcencens biog.1, Ewingella americana, Providencia rettgeri, Bacillus sp., Enterobacter aglomerans, Stomatococcu ssp., Morganella morganii. Control A samples were negative to microbial growth. Ant cultures were positive in 95.23%, while Control B samples showed bacterial growth in 90.47% of the cases. Linepithema humile, is capable of carrying microbial agents in a dairy goat farm.

Se trata de establecer la acción de la hormiga argentina Linepithema humile, como potencial vector mecánico de microorganismos patógenos. Desde un plantel lechero de cabras ubicado en la comuna de Lampa, Región Metropolitana, Chile, se obtuvieron 63 muestras: 21 muestras Control A aspiradas directamente sobre el papel filtro esterilizado previo al paso de las hormigas, 21 muestras de hormigas aspiradas desde papel filtro y 21 muestras posterior al paso de las hormigas (Control B). La metodología incluyó siembras en medios de cultivos nutritivos, selectivos y diferenciales. Posteriormente y según el microorganismo a seguir se continuó con algunas pruebas bioquímicas específicas correspondientes a cada caso. En el presente estudio se decidió investigar la presencia de seis agentes patógenos importantes por su frecuencia en caso de infección en humanos: Staphylococcus aureus, Salmonella spp., Pseudomona aeruginosa, Escherichia coli, Listeria monocytogenes y Campylobacter jejuni. En los resultados de este estudio se detectaron cuatro potenciales patógenos: S. aureus, Salmonella spp., P. aeruginosa y E. coli. Además se encontraron otros agentes microbianos: Streptococcus spp., Micrococcus spp., Escherichia vulneris, Hafnia alvei, Serratia marcencens biog.1, Ewingella americana, Providencia rettgeri, Bacillus spp., Enterobacter aglomerans, Stomatococcus spp., Morganella morganii. Las muestras Control A resultaron negativas. Las muestras de hormigas fueron positivos en 95,23%, en cambio, las muestras controles B presentaron desarrollo bacteriano en 90,47% de los casos, siendo ambos estadísticamente mayores al control A (P < 0,05). Se logró confirmar que L. humile es capaz de transportar agentes microbianos en una lechería de cabras.

The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.