Allovahlkampfia spelaea is a Potential Environmental Host for Pathogenic Bacteria

Abstract

Allovahlkampfia spelaea was identified for the first time in 2009. As a free living amoeba, it has been suggested to be a protective host for some bacterial pathogens against harsh environmental conditions and can transmit them to vulnerable hosts. We aimed in this study to test the interactions between Allovahlkampfia spelaea and some waterborne and foodborne bacteria and unravel if the tested bacteria can survive and multiply inside amoeba. We used a keratitis isolate of Allovahlkampfia spelaea grown in PYG medium containing proteose peptone, yeast extracts, and glucose. We examined amoeba interactions with Methicillin resistant Staphylococcus aureus, Escherichia coli 1, Klebsiella pneumoniae, Enterobacter aerogenes, Citrobacter cloaca, Proteus mirabilis, Raoultella terrigena, Raoultella ornitholytica, Aeromonas hydrophila and Pseudomonas aeruginosa using the co-culture assays. Amoebal survival rate with different bacterial strains were determined. With the exception of Proteus mirabilis that showed decreased survival rates inside amoebal cells, other bacterial isolates could survive and multiply inside Allovahlkampfia spelaea that was associated with decreased survival rates of the amoeba. Particularly, Pseudomonas aeruginosa, Aeromonas hydrophila and MRSA exhibited significantly increased multiplication rates inside amoeba. Our study demonstrated that Allovahlkampfia spelaea may act as a replicative host for pathogenic bacteria with environmental and clinical implications.

The cooling tower water microbiota: Seasonal dynamics and co-occurrence of bacterial and protist phylotypes

“…Echinamoeba is a known host for Pseudomonas aeruginosa (Michel et al., 1995). In addition, Allovahlkampfia which have been suggested to act as hosts for pathogenic bacteria (Mohamed and Huseein, 2016), were also represented in our networks. In this respect, we have recently isolated from the water sample of the tower CT-1 the first testate amoeba, Cochliopodium minus, containing a bacterial symbiont (Tsao et al., 2017).…”

Evolution of the Arsenal of Legionella pneumophila Effectors To Modulate Protist Hosts

“…One recently identified amoeba that consumes L. pneumophila is Solumitrus palustris , a percolozoan most closely related to Allovahlkampfia spelaea , which may be able to harbor pathogenic bacteria ( 132 , 136 , 137 ). Legionella steelei induces “food poisoning” in S. palustris , causing the death of the host without intracellular replication, under conditions of high bacterium-to-protist ratios ( 132 ).…”

Amoebicidal effect of Allium cepa against Allovahlkampfia spelaea: A keratitis model

“…In the form of a vegetative trophozoite and a cyst, A. spelaea exists in nature and propagates by forming cysts with single cell wall and single nucleus which can survive for many years in the environment ( Walochnik and Mulec, 2009 ). It has been molecularly confirmed as a causative agent of amoebic human keratitis ( Tolba et al, 2016 ) and acts as a vehicle of other pathogenic microbes ( Mohamed and Huseein, 2016 ), making it worthy of study.…”