Growth and Bacteriolytic Activity of a Soil Amoeba,
            <i>Hartmannella glebae</i>

Upadhyay, J.

doi:10.1128/jb.95.3.771-774.1968

Cited by 19 publications

(10 citation statements)

References 13 publications

(8 reference statements)

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“…Studies addressing amoeba-bacteria relationships can be rather complex. Amoebae have the ability to produce antimicrobial compounds that lyse bacteria [59]; amoebae can also engulf bacteria, resulting in either degradation in lysosomes, or the bacteria may begin intracellular replication. After bacteria are phagocytized, the amoebae may thus serve as a potential reservoir [60,61].…”

Section: Discussionmentioning

confidence: 99%

Busting biofilms: free-living amoebae disrupt preformed methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis biofilms

et al. 2020

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Biofilm-associated infections are difficult to eradicate because of their ability to tolerate antibiotics and evade host immune responses. Amoebae and/or their secreted products may provide alternative strategies to inhibit and disperse biofilms on biotic and abiotic surfaces. We evaluated the potential of five predatory amoebae – Acanthamoeba castellanii, Acanthamoeba lenticulata, Acanthamoeba polyphaga, Vermamoeba vermiformis and Dictyostelium discoideum – and their cell-free secretions to disrupt biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis . The biofilm biomass produced by MRSA and M. bovis was significantly reduced when co-incubated with A. castellanii, A. lenticulata and A. polyphaga, and their corresponding cell-free supernatants (CFS). Acanthamoeba spp. generally produced CFS that mediated biofilm dispersal rather than directly killing the bacteria; however, A. polyphaga CFS demonstrated active killing of MRSA planktonic cells when the bacteria were present at low concentrations. The active component(s) of the A. polyphaga CFS is resistant to freezing, but can be inactivated to differing degrees by mechanical disruption and exposure to heat. D. discoideum and its CFS also reduced preformed M. bovis biofilms, whereas V. vermiformis only decreased M. bovis biofilm biomass when amoebae were added. These results highlight the potential of using select amoebae species or their CFS to disrupt preformed bacterial biofilms.

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Section: Discussionmentioning

confidence: 99%

Busting biofilms: free-living amoebae disrupt preformed methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis biofilms

et al. 2020

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“…A wide variety of microorganisms (gram-positive and gram-negative bacteria, actinomycetes, myxobacteria, and molds), bacteriophages, plants, and animals have been shown to contain bacteriolytic enzymes (4,16,17). Since 1968, they have also been reported in amoebae (3,9,12,18,19). In bacteria, these enzymes seem to be involved in cell biosynthesis, regulation, and in permeation of large molecules.…”

Section: Discussionmentioning

confidence: 99%

“…The extracellular bacteriolytic enzymes produced by myxobacteria enable them to feed on other soil bacteria, a substrate which seems to be a major food source in their natural habitat (5,6). In amoebae, however, they seem to be endoenzymes, and thus the amoebae get their nutrients from the bacteria they engulf (3,18).…”

Section: Discussionmentioning

confidence: 99%

Specificity of bacteriolytic enzyme II from a soil amoeba, Hartmannella glebae

Hemelt¹,

Mares²,

Upadhyay³

1979

Appl Environ Microbiol

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Two bacteriolytic enzymes were produced when Hartmanella glebae was grown in the presence of both Enterobacter aerogenes and Alcaligenes faecalis. The identification of enzyme I as N-acetylmuramidase was reported earlier. Enzyme II was purified further by gel filtration on a Bio-Gel A column. A recovery of 68.76% with 72.3-fold purification was obtained. It was found that 5 and 10 mM MgCl2 significantly increased the bacteriolytic activity. It is a basic protein. The cell walls of Micrococcus lysodeikticus were lysed by the enzyme, and the products of digestion were purified by Amberlite CG-120 and Sephadex G-15 chromatography to facilitate the detection of amino sugars. After reduction of the oligosaccharides with sodium borohydride and acid hydrolysis, the amino sugars were identified by paper chromatography. It was found that enzyme II cleaved the glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine of the peptidoglycan moiety of the cell walls. Thus, the enzyme was identified as endo-,8-N-acetylmuramidase.

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“…The presence of bacteriolytic activity in a soil amoeba, H. glebae, was first reported in 1968 (11). Since then, several bacteriolytic enzymes in amoebae have been described in the literature (1-3, 5, 8, and 12).…”

Section: Discussionmentioning

confidence: 99%

Purification and specificity of bacteriolytic enzyme I from Hartmannella glebae

Upadhyay¹,

Mares²,

Hemelt³

et al. 1977

Appl Environ Microbiol

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A soil amoeba (Hartmannella glebae), when grown in conjunction with Enterobacter aerogenes and Alcaligenes faecalis, produced two enzymes. Enzyme I was purified by gel filtration on Sephadex G-100 and chromatography on diethylaminoethyl-cellulose. It is a basic protein. The analysis of the enzymic digest of the cell walls of Micrococcus lysodeikticus after reduction and acid hydrolysis showed that the enzyme cleaved the glycosidic bond between acetylmuramic acid and acetylglucosamine of the peptidoglycan moiety of the cell walls. The enzyme is identified as endo-/3-N-acetylmuramidase.

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Growth and Bacteriolytic Activity of a Soil Amoeba, Hartmannella glebae

Cited by 19 publications

References 13 publications

Busting biofilms: free-living amoebae disrupt preformed methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis biofilms

Busting biofilms: free-living amoebae disrupt preformed methicillin-resistant Staphylococcus aureus (MRSA) and Mycobacterium bovis biofilms

Specificity of bacteriolytic enzyme II from a soil amoeba, Hartmannella glebae

Purification and specificity of bacteriolytic enzyme I from Hartmannella glebae

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