Adsorption ofMycobacterium aviumsubsp.paratuberculosisto Soil Particles

Abstract

Attachment of Mycobacterium avium subsp. paratuberculosis to soil particles could increase their availability to farm animals, as well as influence the transportation of M. avium subsp. paratuberculosis to water sources. To investigate the possibility of such attachment, we passed a known quantity of M. avium subsp. paratuberculosis through chromatography columns packed with clay soil, sandy soil, pure silica, clay-silica mixture, or clay-silica complexes and measured the organisms recovered in the eluent using culture or quantitative PCR. Experiments were repeated using buffer at a range of pH levels with pure silica to investigate the effect of pH on M. avium subsp. paratuberculosis attachment. Linear mixed-model analyses were conducted to compare the proportional recovery of M. avium subsp. paratuberculosis in the eluent between different substrates and pH levels. Of the organisms added to the columns, 83 to 100% were estimated to be retained in the columns after adjustment for those retained in empty control columns. The proportions recovered were significantly different across different substrates, with the retention being significantly greater (P < 0.05) in pure substrates (silica and clay-silica complexes) than in soil substrates (clay soil and sandy soil). However, there were no significant differences in the retention of M. avium subsp. paratuberculosis between silica and clay-silica complexes or between clay soil and sandy soil. The proportion retained decreased with increasing pH in one of the experiments, indicating greater adsorption of M. avium subsp. paratuberculosis to soil particles at an acidic pH (P < 0.05). The results suggest that under experimental conditions M. avium subsp. paratuberculosis adsorbs to a range of soil particles, and this attachment is influenced by soil pH.

Fate ofMycobacterium aviumsubsp.paratuberculosisafter Application of Contaminated Dairy Cattle Manure to Agricultural Soils

“…A recent study (4) demonstrated that M. paratuberculosis has negatively charged, hydrophobic walls, and that its transport through positively charged soil particles is slow. A low degree of M. paratuberculosis recovery in loamy (volcanic ash) soil has been explained by a high adsorption rate due to electrostatic and van der Waal's forces and by cell surface hydrophobicity (6). These forces increase at acidic pHs and at a high electrolyte concentrations (24,45).…”

“…Intact soil core samples that maintained undisturbed soil and plant structures, texture, hydraulic conductivity, and porosity were more accurate in predicting pathogen movement under natural soil conditions (43,49). Two recent studies investigated the passage of M. paratuberculosis through a saturated aquifer and the adsorption of the bacteria to soil particles (4,6). In both studies, factors affecting organism movement and attachment were analyzed in columns containing specific soil types artificially composed in a lysimeter.…”

“ Mycobacterium avium subsp. hominissuis ” in Neck Lymph Nodes of Children and their Environment Examined by Culture and Triplex Quantitative Real-Time PCR

“…Furthermore, mycobacteria present in soil samples are easily outgrown by other, faster-growing microorganisms (15). Their strong adherence to soil particles and their viability can also present difficulties in their isolation by culture (4,8). Due to these obstacles, the use of molecular methods for detection and identification of mycobacteria in the environment is favorable.…”

Effect of Soil Slope on the Appearance of Mycobacterium avium subsp. paratuberculosis in Water Running off Grassland Soil after Application of Contaminated Slurry

“…There are major differences in the cell wall structure of mycobacteria and Gram-negative bacteria. These differences likely affect adsorption to soil particles mediated by van der Waals electrostatic forces or by hydrophobic interactions with the cell surface (19,20). Adsorption to soil would also be affected by soil pH (20).…”

“…These differences likely affect adsorption to soil particles mediated by van der Waals electrostatic forces or by hydrophobic interactions with the cell surface (19,20). Adsorption to soil would also be affected by soil pH (20). In southern Chile, acidic soils are frequent, with pH values normally ranging from 5.1 to 6.0.…”