Overview
EN ISO 10705-1:2001 (ISO 10705-1:1995) specifies a microbiological method for the detection and enumeration of F-specific RNA bacteriophages in water, sediments, sludges and shellfish extracts. The standard defines a host‑based plaque assay: samples are incubated with an appropriate host strain, plated on nutrient media and scored for visible plaques. Results are reported as plaque‑forming particles per unit volume and the presence of F‑specific RNA bacteriophages is interpreted as an indicator of wastewater faecal contamination from human or animal sources.
Key topics and technical requirements
- Principle: incubation of sample with an F‑pilus host strain and enumeration of plaques on a bacterial lawn.
- Applicability: all kinds of water, sediments, sludges and shellfish extracts; preconcentration recommended when phage numbers are low.
- Confirmation: differential counts using RNase (typical inhibitory concentrations noted in the standard) to confirm F‑specific RNA phages.
- Quality control: maintenance and QC of host strains (e.g., Salmonella typhimurium WG49), turbidity calibration, susceptibility testing and plate‑count performance checks.
- Safety: management of host cultures (low‑pathogenic host strains) and prevention of cross‑contamination; work with high‑titre materials in appropriate containment (biosafety cabinet or dedicated area).
- Reagents & media: use analytical‑grade chemicals and specified diluents/media; reference to ISO laboratory water and media preparation standards.
- Results: expressed as concentration of plaque‑forming particles (cpfp or pfu) per unit volume.
- Normative references: cross‑references to ISO 3696 (laboratory water), ISO 5667 series (sampling), ISO 6887, ISO 8199 and related microbiological standards.
Applications and users
- Environmental and public‑health laboratories performing microbiological water quality monitoring.
- Water and wastewater utilities assessing faecal pollution and treatment performance.
- Shellfish monitoring programmes evaluating virus concentration/retention in shellfish.
- Regulatory agencies and consultants requiring standardized methods for enteric virus surrogate monitoring.
- Academic and applied researchers studying virus fate, transport and removal in environmental systems.
Related standards
- ISO 10705‑2 (somatic coliphages) - companion part for other bacteriophage groups.
- ISO 5667 series - guidance on sampling of water bodies.
- ISO 3696, ISO 6887, ISO 8199 - laboratory water quality, dilution preparation and microbial enumeration guidance.
Keywords: water quality, F-specific RNA bacteriophages, detection and enumeration, ISO 10705-1, bacteriophage plaque assay, faecal contamination indicator, environmental microbiology.