BS EN ISO 7899-1-1999 (2008) BS 6068-4.3-1999 PDF

Full title and description

STB BS EN ISO 7899-1:1999 (adoption of ISO 7899-1:1998) — Water quality. Detection and enumeration of intestinal enterococci in surface and waste water. Miniaturized method (Most Probable Number) for surface and waste water. Also referenced as BS 6068-4.3:1999. This document specifies a microtitration (miniaturized MPN) procedure for detection and enumeration of major intestinal enterococci in surface and wastewater matrices; it is not intended for drinking water or other waters where guideline counts are expected to be below 15 per 100 ml.

Abstract

This standard defines a miniaturized Most Probable Number (MPN) method using pre‑prepared microtitre plates and selective/enrichment reagents to detect and enumerate intestinal enterococci in surface and waste waters. The method covers sample dilution, inoculation of wells, incubation under controlled temperature, detection of target organisms by enzymatic/fluorescent or colourimetric reactions, interpretation of positive patterns and calculation/reporting of MPN results with associated confidence limits. It includes apparatus and media requirements, sample handling guidance, quality control and limitations of applicability.

General information

• Status: Published / active as the EN/BS adoption of ISO 7899-1 (confirmed by national review processes).
• Publication date: Original ISO edition published November 1998; adopted as BS EN ISO 7899-1:1999 (British publication 1999); BSI confirmation/review referenced 2008.
• Publisher: International Organization for Standardization (ISO) / British Standards Institution (BSI) for the BS/EN adoption.
• ICS / categories: 07.100.20 — Microbiology of water.
• Edition / version: ISO 7899-1:1998 (Edition 2) — published as BS EN ISO 7899-1:1999; cross-referenced with national designation BS 6068-4.3:1999.
• Number of pages: ISO original: 19 pages (ISO publication); BSI-adopted publication listed as 26 pages (BS EN ISO 7899-1:1999 edition).

Scope

This part of ISO 7899 specifies a miniaturized MPN method for the detection and enumeration of intestinal enterococci in surface waters and waste waters, especially those high in suspended solids. The method is intended for environmental and wastewater monitoring and research. It is not suitable for routine analysis of drinking water or other waters where expected enterococci counts are below the stated guideline threshold (typically 15 per 100 ml).

Key topics and requirements

• Principle: serial dilution of samples and inoculation into wells of a microtitre plate containing selective/enrichment medium; incubation and detection of positive wells; MPN calculation from positive/negative patterns.
• Selected media and indicators: provisions for MUD (4‑methylumbelliferyl substrate) or equivalent selective/enrichment formulations and indicators used to detect enterococcal enzymatic activity or characteristic colony reactions in miniaturized format.
• Apparatus and disposables: requirements for non‑fluorescent 96‑well microtitre plates, sterile dispensing systems, calibrated pipettes, incubators capable of ±0.5 °C control at elevated temperatures and UV/fluorescence readout equipment where required.
• Incubation and reading: controlled incubation (typical requirement at around 44 °C with a minimum/maximum incubation window — e.g., a minimum of 36 h and up to 72 h in the microtitre format) and standard procedures for reading fluorescence/colour and declaring positive wells.
• Sampling and sample handling: sampling guidance references (ISO 5667 series) and requirements to minimise changes before analysis (time/temperature limits and dilution practice).
• Result expression: calculation and reporting of MPN per 100 ml with confidence limits, treatment of zero/too numerous results, and required reporting elements in the test report.
• Quality assurance and controls: use of blanks, positive/negative controls, calibration microtitre plates or calibration procedures and recordkeeping; handling of toxic reagents and safety precautions.
• Limitations: explicit statement that the method is not suitable for low‑count potable waters and that alternative methods (e.g., membrane filtration approaches or ISO 7899‑2) may be preferred for drinking water, swimming pools or disinfected waters.

Typical use and users

Environmental and wastewater microbiology laboratories, environmental regulators, water quality consultants, research organisations and treatment plant operators use this standard to detect and enumerate intestinal enterococci in surface waters, effluents and other non‑potable matrices. It is commonly applied in surveillance of recreational waters, effluent compliance testing, pollution investigations and comparative method studies.

Related standards

Standards commonly referenced alongside/encompassing related methods include ISO 7899‑2 (membrane filtration method for intestinal enterococci), the ISO 5667 series (water sampling), ISO 8199 (general guidance for microbiological enumeration), ISO 6222 (enumeration of culturable micro‑organisms by colony counting) and the BS 6068 family of British biological methods for water quality (various parts). National and regional bathing/water quality guidance documents also reference these methods.

Keywords

intestinal enterococci, enterococci, MPN, microtitre, miniaturized method, water quality, wastewater, surface water, BS EN ISO 7899-1, BS 6068-4.3, enumeration, microbiology, sampling, MUD, fluorescence, quality control

FAQ

Q: What is this standard?

A: It is the miniaturized Most Probable Number (MPN) method for detecting and enumerating intestinal enterococci in surface and waste waters (ISO 7899‑1:1998), adopted as BS EN ISO 7899‑1:1999 and referenced by the British designation BS 6068‑4.3:1999.

Q: What does it cover?

A: The standard covers sample dilution, inoculation into microtitre wells containing selective/enrichment medium, incubation and detection (fluorescent or colourimetric) of positive wells, calculation and reporting of MPN results, and required quality control and safety precautions. It specifies limits of applicability (not for low‑count drinking water).

Q: Who typically uses it?

A: Environmental and wastewater testing laboratories, regulatory agencies, consultants and research laboratories for monitoring enterococci levels in surface waters, effluents and other non‑potable water matrices.

Q: Is it current or superseded?

A: The ISO edition referenced here (ISO 7899‑1:1998) was later adopted as BS EN ISO 7899‑1:1999 (BS 6068‑4.3:1999). National review records indicate the document has been subject to confirmation/review processes (BSI review referenced in 2008). Users should check national and international catalogues for any later revisions or replacement parts (for example, ISO 7899‑2 for membrane filtration methods and later updates to the ISO 7899 series) before application.

Q: Is it part of a series?

A: Yes — ISO 7899 is a multipart series addressing detection and enumeration of intestinal enterococci/faecal streptococci. Commonly referenced companion parts include ISO 7899‑2 (membrane filtration method) and later parts or updates in the ISO 7899 series; the method is also used in the context of other microbiological standards (ISO 5667 sampling guidance, ISO 8199 laboratory practice, etc.).

Q: What are the key keywords?

A: intestinal enterococci, MPN, microtitre, water microbiology, wastewater testing, BS EN ISO 7899-1, BS 6068-4.3, enumeration, selective medium, fluorescence.