Review of Factors Affecting Microbial Survival in Groundwater

Abstract

This review quantitatively examines a number of published studies that evaluated survival and inactivation of public-health-related microorganisms in groundwater. Information from reviewed literature is used to express microbial inactivation in terms of log10 decline per day for comparison to other studies and organisms. The geometric mean value for inactivation rates for coliphage, poliovirus, echovirus, coliform bacteria, enterococci, and Salmonella spp. were similar at approximately 0.07−0.1 log10 day-1, while geometric mean inactivation rates for hepatitis A virus, coxsackievirus, and phage PRD-1 were somewhat less at 0.02−0.04 log10 day-1. Viruses show a temperature dependency with greater inactivation at greater temperatures; however this occurs largely at temperatures greater than 20 °C. Coliform bacteria dieoff in groundwater does not show the temperature dependency that viruses show, likely indicating a complex interplay of inactivation and reproduction subject to influences from native groundwater organisms, temperature, and water chemistry. The presence of native microorganisms seems to negatively impact E. coli survival more so than viruses, but in most cases, nonsterile conditions led to a greater inactivation for viruses also. The effect of attachment to solid surfaces appears to be virus-type-dependent, with PRD-1 more rapidly inactivated as a result of attachment and hepatitis A and poliovirus survival prolonged when attached.

Polioviruses and other Enteroviruses

“…The persistence and survival of human enteric viruses, including EVs and other picornaviruses, in the extracellular environment (e.g., water, soil, food, aerosols, and environmental surfaces or fomites), the combination of factors that influence survival (i.e., temperature and seasonal variation, pH, salinity, relative humidity, sunlight irradiation and UV light penetration, wet weather flows, viral aggregation, viral adsorption to suspended solids or surfaces, microbial biome and microbial predation), the risks for transmission of EV infections through environmental exposures (water, foods, aerosols, and fomites), and prevention strategies to reduce this risk have been extensively documented by peer-reviewed scientific research and reviewed in detail by several authors (Bertrand et al, 2012;Bosch et al, 2006;de Roda Husman et al, 2009;Gerba, , 2007Gerba et al, 2013;John and Rose, 2005;Rzezutka and Cook, 2004;Vasickova and Kovarcik, 2013;Vasickova et al, 2010;Xagoraraki et al, 2014;Yates and Yates, 1988) EV virions can survive outside the body for months under favorable environmental conditions (Bosch et al, 2006;Dowdle and Birmingham, 1997;Mattle et al, 2011;National Research Council, 2004;Pallansch et al, 2013;Templeton et al, 2004;Templeton et al, 2008;Young and Sharp, 1977). These conditions include neutral pH, moisture, low temperature: 4 -10°C), and association with particles in untreated or partly treated waste waters that protects against inactivation by natural or artificial processes, including enzymatic (i.e., proteolytic bacterial enzymes) or UV degradation and chemical disinfection (discussed further in Section 3.2).…”

“…Persistence of EVs in groundwater can be inferred from temperature-based inactivation studies (John and Rose, 2005;Schijven and Hassanizadeh, 2000). As above, variations in inactivation times for the same enterovirus or other members within the Picornaviridae family have been reported: The mean inactivation rate of PV was to 0.02 log 10 per day (range 0.005 -0.05 log 10 per day ) between 0 and 10°C and 0.4 log 10 per day (range 0.006 -1.4 log 10 per day) at 26-30°C; the mean inactivation rate for echovirus was 0.1 log 10 per day (range 0.05 -0.2 log 10 per day) at temperatures between 11 and 15°C, and 0.2 log 10 per day-1 (range 0.06 -0.6 log 10 per day) at temperatures between 21 and 25°C; and the mean inactivation rate for coxsackieviruses was 0.06 log 10 per day-1 (range 0.002 -0.2 log 10 per day) at temperatures between 0 and 20°C and 0.1 log 10 per day at temperatures between 25 and 30°C.…”

Addition of a magnetite layer onto a polysulfone water treatment membrane to enhance virus removal

“…In natural aquatic environments viruses are charged biocolloidal particles with the ability to adsorb to solid surfaces, which influences viral fate and transport. The factors controlling the adhesion kinetics of viruses including the type of viruses and the associated surface properties are pH, ionic strength, degree of water saturation in soil, and the presence or absence of interfering substances such as natural organic matter (NOM), which may either adsorb the viruses or compete with them for adsorption sites on a surface (Bitton et al , 1976;Chu et al, 2003;Hurst et al, 1980;John and Rose, 2005;Schijven and Hassanizadeh, 2000).…”

Heterogeneous Composites on the Basis of Microbial Cells and Nanostructured Carbonized Sorbents

“…It would be adequate to name just a few notorious examples on microbial colonization of contact lenses, ship hulls, petroleum pipelines, rocks in streams and all kinds of biomedical implants. The propensity of microorganisms to become surface-bound is so profound and ubiquitous that it vindicates the advantages for attached forms over their free-ranging counterparts [2]. Indeed, from ecological and evolutionary standpoints, for many microorganisms the surface-bound state means dwelling in nutritionally favorable, non-hostile environments [3].…”