The specific and sensitive detection of bacterial pathogens within 4 h using bacteriophage amplification

• Published in: Journal of applied microbiology Vol. 84; no. 5; pp. 777 - 783
• Main Authors: STEWART, G. S. A. B, JASSIM, S. A. A, DENYER, S. P, NEWBY, P, LINLEY, K, DHIR, V. K
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-05-1998; Blackwell Science
• Subjects: Bacteriological methods and techniques used in bacteriology; Bacteriological Techniques; Bacteriology; Bacteriophages - genetics; Bacteriophages - growth & development; Biological and medical sciences; Ferrous Compounds - pharmacology; Fundamental and applied biological sciences. Psychology; Humans; Microbiology; Neutralization Tests; Plant Extracts - pharmacology; Pseudomonas aeruginosa; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - isolation & purification; Pseudomonas aeruginosa - virology; Pseudomonas Phages - genetics; Pseudomonas Phages - growth & development; Salmonella Phages - genetics; Salmonella Phages - growth & development; Salmonella typhimurium; Salmonella typhimurium - growth & development; Salmonella typhimurium - isolation & purification; Salmonella typhimurium - virology; Sensitivity and Specificity; Staphylococcus aureus; Staphylococcus aureus - growth & development; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - virology; Staphylococcus Phages - genetics; Staphylococcus Phages - growth & development; Viral Plaque Assay; Pseudomonadales; Identification; Method; Salmonella typhimurium; Virus; Amplification; Specificity; Pathogenic; Bacteria; Micrococcales; Pseudomonadaceae; Pseudomonas aeruginosa; Micrococcaceae; Detection; Staphylococcus aureus; Enterobacteriaceae; Phage
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.1998.00408.x

This paper describes a novel approach, termed the ‘phage amplification assay’, for the rapid detection and identification of specific bacteria. The technique is based on the phage lytic cycle with plaque formation as the assay end‐point. It is highly sensitive, quantitative and gives results typically within 4 h. The assay comprises four main stages : (1) phage infection of target bacterium ; (2) destruction of exogenous phage ; (3) amplification of phage within infected host and (4) plaque formation from infected host with the aid of helper bacteria. A key component of this assay is a potent virucidal agent derived from natural plant extracts, pomegranate rind extract (PRE). In combination with ferrous sulphate PRE can bring about an 11 log‐cycle reduction in phage titre within 3 min. This is achieved without any injury to the infected target bacteria. Subsequently, any resulting plaques are derived only from infected target organisms. Data are presented for a range of bacterial hosts including Pseudomonas aeruginosa, Salmonella typhimurium and Staphylococcus aureus. The detection limit for Ps. aeruginosa was 40 bacteria ml−1 in a time of 4 h and 600 bacteria m−1 for Salm. typhimurium. Application of the principles of this technology to other bacterial genera is discussed.