Aeromonas hydrophila
Jenna Tune


The organism presented is gram negative, rod-shaped bacterium, found in water and food world-wide, resistant to penicillin and ampicillin, resistant to chlorine, has the ability to grow 25-37 oC. A. hydrophila is a heterotrophic, opportunistic pathogen that ferments glucose, digest gelatin, hemoglobin, and elastin.


The content of this report will focus on the organism A. hydrophila in its relation to public health, specifically drinking water contamination. A. hydrophilia is largely aquatic and has been associated with diarrheal-type diseases, though yet to be determined as the causative agent. It is important to recognize this as a potential threat to public health world-wide. According to a 2002 study in Iran, A. hydrophila displayed the highest sensitivity to chlorine when compared to Escherichia coli, Enterococcus faecalis, and Salmonella typhi. It was inactived in < 100 minutes at chlorine levels of 0.11 mg/L to 0.90 mg/L. A study in Brazil (2005) pulled several drinking water samples from several sources and concluded that the concentration of A. hydrophila was not directly associated with fecal coliforms. In the same year, a group from Italy studied the behavior of this bacteria in river water, spring water, brackish water, mineral water, and chlorinated drinking water, which had different physical and chemical characteristics. Their method involved many of the conventional plate count techniques and well as a flow cytometric analysis. Unfortunately, the results of this study indicates that viable strains of A. hydrophila are present at concentrations undetectable using the traditional plate techniques. The results of the previously mentioned studies do pose a problem to researchers trying to determine the effectiveness of drinking water treatment facilities in the field, when materials are limited.


Fuzihara, Terumi Oyama; Pisani, Beatriz; Simoes, Marise; Brigido, Berenice Mandel; Leopoldo E Silva, Christina; Vannucci, Lucia; Arioshi, Kioka. The Occurrence of Aeromonas spp in Drinking Water. Revista do Instituto Adolfo Lutz. 64(1). 2005.

Pianetti, Anna; Falcioni, Tania; Bruscolini, Francesca; Sabatini, Luigio; Sisti, Elivio; Papa, Stefano. Determination of the Viability of Aeromonas hydrophila in Different Types of Water by F low Cytometry, and Comparison with Classical Methods. Applied & Environmental Microbiology. 71(12). DEC 2005. 7948-7954.

Tavakoli, A.; Yazdani, R.; Shahmansouri, M. R.; Isfahani, B. N. Chlorine Residual Efficiency in Inactivating Bacteria From Secondary Contamination in Isfahan, 2002. Eastern Mediterranean Health Journal. 11(3). MAY 2005. 425-434.

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.


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