Title |
Evaluation of a lytic bacteriophage, Φ st1, for biocontrol of Salmonella enterica serovar Typhimurium in chickens
|
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Published in |
International Journal of Food Microbiology, December 2013
|
DOI | 10.1016/j.ijfoodmicro.2013.11.034 |
Pubmed ID | |
Authors |
Chuan Loo Wong, Chin Chin Sieo, Wen Siang Tan, Norhani Abdullah, Mohd. Hair-Bejo, Jalila Abu, Yin Wan Ho |
Abstract |
In this study, a Salmonella Typhimurium lytic bacteriophage, Φ st1, which was isolated from chicken faecal material, was evaluated as a candidate for biocontrol of Salmonella in chickens. The morphology of Φ st1 showed strong resemblance to members of the Siphoviridae family. Φ st1 was observed to be a DNA phage with an estimated genome size of 121 kbp. It was found to be able to infect S. Typhimurium and S. Hadar, with a stronger lytic activity against the former. Subsequent characterisation of Φ st1 against S. Typhimurium showed that Φ st1 has a latent period of 40 min with an average burst size of 22 particles per infective centre. Approximately 86.1% of the phage adsorbed to the host cells within the initial 5 min of infection. At the optimum multiplicity of infection (MOI) (0.1), the highest reduction rate of S. Typhimurium (6.6 log₁₀ CFU/ml) and increment in phage titre (3.8 log₁₀ PFU/ml) was observed. Φ st1 produced adsorption rates of 88.4-92.2% at pH7-9 and demonstrated the highest bacteria reduction (6.6 log₁₀ CFU/ml) at pH9. Φ st1 also showed an insignificant different (P>0.05) reduction rate of host cells at 37 °C (6.4 log₁₀ CFU/ml) and 42 °C (6.0 log₁₀ CFU/ml). The in vivo study using Φ st1 showed that intracloacal inoculation of ~10¹² PFU/ml of the phage in the chickens challenged with ~10¹⁰ CFU/ml of S. Typhimurium was able to reduce (P<0.05) the S. Typhimurium more rapidly than the untreated group. The Salmonella count reduced to 2.9 log₁₀ CFU/ml within 6h of post-challenge and S. Typhimurium was not detected at and after 24h of post-challenge. Reduction of Salmonella count in visceral organs was also observed at 6h post-challenge. Approximately 1.6 log₁₀ FU/ml Φ st1 was found to persist in the caecal wall of the chicks at 72 h of post-challenge. The present study indicated that Φ st1 may serve as a potential biocontrol agent to reduce the Salmonella count in caecal content of chickens. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
United Kingdom | 1 | <1% |
Italy | 1 | <1% |
South Africa | 1 | <1% |
Switzerland | 1 | <1% |
Unknown | 145 | 97% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Bachelor | 22 | 15% |
Student > Ph. D. Student | 20 | 13% |
Researcher | 20 | 13% |
Student > Master | 14 | 9% |
Student > Doctoral Student | 8 | 5% |
Other | 26 | 17% |
Unknown | 39 | 26% |
Readers by discipline | Count | As % |
---|---|---|
Agricultural and Biological Sciences | 48 | 32% |
Immunology and Microbiology | 20 | 13% |
Biochemistry, Genetics and Molecular Biology | 11 | 7% |
Veterinary Science and Veterinary Medicine | 11 | 7% |
Medicine and Dentistry | 7 | 5% |
Other | 7 | 5% |
Unknown | 45 | 30% |