Under a very high magnification of 25000X, this scanning electron micrograph (SEM) depicted a grouping of Gram-negative Legionella pneumophila bacteria. Please note that youre able to see a number of the flagella emanating from these organisms. Please see PHIL 11092 through 11152 for additional SEMs of these organisms, specifically PHIL 11106 for a colorized version of this image, which better features the flagella.
Youll note that a number of these bacteria seem to display an elongated-rod morphology. L. pneumophila are known to most frequently exhibit this configuration when grown in broth, however, they can also elongate when plate-grown cells age, as it was in this case, especially when theyve been refrigerated. The usual L. pneumophila morphology consists of stout, fat bacilli, which is the case for the vast majority of the organisms depicted here.