GBRU: reference and diagnostic services

GBRU is the national reference laboratory for gastrointestinal pathogens and provides specialist testing of clinical, food, water and environmental samples.

Gastrointestinal bacteria reference unit (GBRU) is part of Public Health England’s (PHE’s) bacteria reference department (BRD).

GBRU is made up of 3 sections:

  • foodborne pathogens reference services
  • gastrointestinal infections reference service
  • salmonella reference services

GBRU services

GBRU provides national reference facilities for many gastrointestinal associated bacteria, including:

  • Bacillus
  • Clostridium botulinum
  • Clostridium perfringens
  • Clostridium tetani
  • Listeria
  • Staphylococcal enterotoxin detection
  • Campylobacter
  • Helicobacter pylori
  • Escherichia coli
  • Shigella, Vibrio and Yersinia species
  • Salmonella

Reference laboratory services during coronavirus (COVID-19) pandemic

During the coronavirus (COVID-19) pandemic, the following critical services will continue:

  1. Detection of Shiga toxin-producing E. coli (STEC) from stool specimens and isolates using PCR.

  2. Detection of Clostridium botulinum and botulinum toxin from food, stool, serum and tissues.

  3. Confirmation of identity and typing of Salmonella, Shigella, STEC and Listeria using whole genome sequencing.

Clinicians and laboratories are therefore advised to keep sending isolates and appropriate clinical samples to the GBRU for testing, identification and typing of bacterial pathogens.

All other activities related to identification and typing of other gastrointestinal pathogens which include Bacillus, Clostridium perfringens, Clostridium tetani, Campylobacter, Helicobacter pylori, Vibrio and Yersinia have been temporarily suspended until further notice, but will be considered if there is an outbreak. Customers are advised not to send gastric biopsies for culture and antibiotic susceptibility testing for Helicobacter pylori, as retrieval of this organism after prolonged freezing of specimens is extremely difficult. All other referred pathogen isolates belonging to the suspended services will be stored appropriately and tested once services are restored.

Important service update

To enable Public Health England (PHE) reference and specialist laboratories to continue to provide critical support to the enhanced COVID-19 incident, some service delivery changes have been made with immediate effect.

The situation will be regularly reviewed. For the most current information, contact the relevant department using the contact details provided in the BRD user manual.

Research and Training

GBRU undertakes research into the genetic diversity of pathogens and the development of improved detection and characterisation techniques for food, water and environmentally-borne diseases.

GBRU is also able to offer expert advice, education and training on public health aspects of food microbiology and safety.

For more information on GBRU services and contact details refer to the BRD user manual.

Guidance and forms

BRD manual

Gastrointestinal bacteria culture request form: L4

Gastrointestinal bacteria clinical request form: L5

Gastrointestinal bacteria food and environmental sample form: L7

Gastrointestinal pathogens: specimen acceptance criteria

Gastrointestinal pathogens: interpreting PCR assays guidance

Implementing pathogen genomics: a case study



Public Health England
61 Colindale Avenue

Published 1 July 2014
Last updated 14 May 2020 + show all updates
  1. Added notification of service delivery changes made to PHE reference and specialist laboratories to provide critical support to the COVID-19 incident.

  2. Added guidance about GBRU reference and diagnostic services during the COVID-19 pandemic.

  3. Added 'Implementing pathogen genomics: a case study'.

  4. First published.