130 results on '"Atterbury, Robert J."'
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2. Exposure to blue light reduces antimicrobial resistant Pseudomonas aeruginosa isolated from dog ear infections.
- Author
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Gigante, Adriano M., Hadis, Mohammad A., Secker, Bailey, Shaw, Stephen C., Cooper, Paul R., Palin, William M., Milward, Michael R., and Atterbury, Robert J.
- Subjects
BLUE light ,EAR infections ,OTITIS externa ,FLUOROQUINOLONES ,DOGS ,DETECTION limit ,PSEUDOMONAS aeruginosa - Abstract
Introduction: Pseudomonas aeruginosa is a leading cause of canine otitis externa. Enrofloxacin is often applied topically to treat this condition, although recalcitrant and recurring infections are common. There is evidence that exposure to blue light (400-470 nm) has a bactericidal effect on P. aeruginosa and other microorganisms. Methods: In the present study, we tested the biocidal effect of blue light (375-450 nm), alone or in combination with enrofloxacin, against six isolates of P. aeruginosa from dogs with otitis externa (5 of which were resistant to enrofloxacin). Results: Treatment of planktonic cell cultures with blue light resulted in significant (p < 0.5) reductions in Colony Forming Units (CFU) for all seven strains tested, in some cases below the limit of detection. The greatest bactericidal effect was observed following exposure to light at 405 nm wavelength (p < 0.05). Exposure to blue light for 20 min usually resulted in a greater reduction in Pseudomonas aeruginosa than enrofloxacin treatment, and combination treatment typically resulted in the largest reductions in CFU. Analysis of the genome sequences of these strains established that enrofloxacin resistance was likely the result of a S466F substitution in GyrB. However, there was no clear association between genotype and susceptibility to blue light treatment. Discussion: These results suggest that blue light treatment, particularly at 405 nm wavelength, and especially in combination with enrofloxacin therapy, could be an effective treatment for otherwise recalcitrant canine otitis externa caused by Pseudomonas aeruginosa. It may also provide a way of extending the usefulness of enrofloxacin therapy which would otherwise be ineffective as a sole therapeutic agent. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Pseudomonas spp. in Canine Otitis Externa
- Author
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Secker, Bailey, primary, Shaw, Stephen, additional, and Atterbury, Robert J., additional
- Published
- 2023
- Full Text
- View/download PDF
4. Efficacy of Different Encapsulation Techniques on the Viability and Stability of Diverse Phage under Simulated Gastric Conditions
- Author
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Dlamini, Sicelo B., primary, Gigante, Adriano M., additional, Hooton, Steven P. T., additional, and Atterbury, Robert J., additional
- Published
- 2023
- Full Text
- View/download PDF
5. Bacteriophage control of Campylobacters in retail poultry
- Author
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Atterbury, Robert J.
- Subjects
664.9397 ,QR Microbiology - Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production. Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro. A series of trials using 'phage therapy' in broiler chickens revealed that Campylobacter colonisation can be reduced by ≥log[subscript]10 8.0 cfu g[superscript]-1 caecal contents by dosing with specific bacteriophage. However, both the timing and extent of the reduction in Campylobacter colonisation showed considerable variation. Additionally, the ability of bacteriophage to infect their host in vitro was not a reliable indicator of their efficacy in vivo. The direct application of bacteriophage to the surface of chicken skin artificially contaminated with Campylobacter led to a significant reduction in the number of recoverable host cells. Host resistance to bacteriophage infection was not detected in either the in vivo trials or when recovering Campylobacter cells from chicken skin treated with phage. The work presented in this thesis demonstrates that bacteriophage have considerable potential in the control of Campylobacter in poultry production. They already appear to constitute a limiting factor in Campylobacter colonisation of the chicken gastrointestinal tract and can be detected with their host on retail products. However, further research is required to fully realise their potential and optimising the timing, level and type of bacteriophage used in dosing will be important for their efficacy in vivo.
- Published
- 2004
6. Veterinary use of bacteriophage therapy in intensively-reared livestock
- Author
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Gigante, Adriano and Atterbury, Robert J
- Published
- 2019
- Full Text
- View/download PDF
7. The Use of Bacteriophages in Veterinary Therapy
- Author
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Atterbury, Robert J., primary and Barrow, Paul A., additional
- Published
- 2019
- Full Text
- View/download PDF
8. Prophylactic Delivery of a Bacteriophage Cocktail in Feed Significantly Reduces Salmonella Colonization in Pigs
- Author
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Thanki, Anisha M., primary, Mignard, Guillaume, additional, Atterbury, Robert J., additional, Barrow, Paul, additional, Millard, Andrew D., additional, and Clokie, Martha R. J., additional
- Published
- 2022
- Full Text
- View/download PDF
9. Bacteriophage Therapy and Campylobacter
- Author
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Connerton, Ian F., primary, Connerton, Phillippa L., additional, Barrow, Paul, additional, Seal, Bruce S., additional, and Atterbury, Robert J., additional
- Published
- 2014
- Full Text
- View/download PDF
10. Predatory bacteria as living antibiotics – where are we now?
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Atterbury, Robert J., primary and Tyson, Jess, additional
- Published
- 2021
- Full Text
- View/download PDF
11. Antibacterial and Antivirulence Activity of Manuka Honey against Genetically Diverse Staphylococcus pseudintermedius Strains
- Author
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Brown, Helen L., primary, Metters, Georgie, additional, Hitchings, Matthew D., additional, Wilkinson, Thomas S., additional, Sousa, Luis, additional, Cooper, Jenna, additional, Dance, Harry, additional, Atterbury, Robert J., additional, and Jenkins, Rowena, additional
- Published
- 2020
- Full Text
- View/download PDF
12. Dual Predation by Bacteriophage and Bdellovibrio bacteriovorus Can Eradicate Escherichia coli Prey in Situations where Single Predation Cannot
- Author
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Hobley, Laura, primary, Summers, J. Kimberley, additional, Till, Rob, additional, Milner, David S., additional, Atterbury, Robert J., additional, Stroud, Amy, additional, Capeness, Michael J., additional, Gray, Stephanie, additional, Leidenroth, Andreas, additional, Lambert, Carey, additional, Connerton, Ian, additional, Twycross, Jamie, additional, Baker, Michelle, additional, Tyson, Jess, additional, Kreft, Jan-Ulrich, additional, and Sockett, R. Elizabeth, additional
- Published
- 2020
- Full Text
- View/download PDF
13. Genome analysis of a simultaneously predatory and prey-independent, novel Bdellovibrio bacteriovorus from the River Tiber, supports in silico predictions of both ancient and recent lateral gene transfer from diverse bacteria
- Author
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Hobley Laura, Lerner Thomas R, Williams Laura E, Lambert Carey, Till Rob, Milner David S, Basford Sarah M, Capeness Michael J, Fenton Andrew K, Atterbury Robert J, Harris Maximilian ATS, and Sockett R Elizabeth
- Subjects
Evolutionary genetics of bacteria ,Lateral gene transfer ,Predatory Bdellovibrio ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Evolution equipped Bdellovibrio bacteriovorus predatory bacteria to invade other bacteria, digesting and replicating, sealed within them thus preventing nutrient-sharing with organisms in the surrounding environment. Bdellovibrio were previously described as “obligate predators” because only by mutations, often in gene bd0108, are 1 in ~1x107 of predatory lab strains of Bdellovibrio converted to prey-independent growth. A previous genomic analysis of B. bacteriovorus strain HD100 suggested that predatory consumption of prey DNA by lytic enzymes made Bdellovibrio less likely than other bacteria to acquire DNA by lateral gene transfer (LGT). However the Doolittle and Pan groups predicted, in silico, both ancient and recent lateral gene transfer into the B. bacteriovorus HD100 genome. Results To test these predictions, we isolated a predatory bacterium from the River Tiber- a good potential source of LGT as it is rich in diverse bacteria and organic pollutants- by enrichment culturing with E. coli prey cells. The isolate was identified as B. bacteriovorus and named as strain Tiberius. Unusually, this Tiberius strain showed simultaneous prey-independent growth on organic nutrients and predatory growth on live prey. Despite the prey-independent growth, the homolog of bd0108 did not have typical prey-independent-type mutations. The dual growth mode may reflect the high carbon content of the river, and gives B. bacteriovorus Tiberius extended non-predatory contact with the other bacteria present. The HD100 and Tiberius genomes were extensively syntenic despite their different cultured-terrestrial/freshly-isolated aquatic histories; but there were significant differences in gene content indicative of genomic flux and LGT. Gene content comparisons support previously published in silico predictions for LGT in strain HD100 with substantial conservation of genes predicted to have ancient LGT origins but little conservation of AT-rich genes predicted to be recently acquired. Conclusions The natural niche and dual predatory, and prey-independent growth of the B. bacteriovorus Tiberius strain afforded it extensive non-predatory contact with other marine and freshwater bacteria from which LGT is evident in its genome. Thus despite their arsenal of DNA-lytic enzymes; Bdellovibrio are not always predatory in natural niches and their genomes are shaped by acquiring whole genes from other bacteria.
- Published
- 2012
- Full Text
- View/download PDF
14. Reviving Phage Therapy for the Treatment of Cholera
- Author
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Bhandare, Sudhakar, primary, Colom, Joan, additional, Baig, Abiyad, additional, Ritchie, Jenny M, additional, Bukhari, Habib, additional, Shah, Muhammad A, additional, Sarkar, Banwarilal L, additional, Su, Jingliang, additional, Wren, Brendan, additional, Barrow, Paul, additional, and Atterbury, Robert J, additional
- Published
- 2018
- Full Text
- View/download PDF
15. Complete Genome Sequences of Seven Vibrio cholerae Phages Isolated in China
- Author
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Bhandare, Sudhakar G., primary, Warry, Andrew, additional, Emes, Richard D., additional, Su, Jingliang, additional, Barrow, Paul A., additional, and Atterbury, Robert J., additional
- Published
- 2017
- Full Text
- View/download PDF
16. Complete Genome Sequences of Vibrio cholerae-Specific Bacteriophages 24 and X29
- Author
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Bhandare, Sudhakar G., primary, Warry, Andrew, additional, Emes, Richard D., additional, Hooton, Steven P. T., additional, Barrow, Paul A., additional, and Atterbury, Robert J., additional
- Published
- 2017
- Full Text
- View/download PDF
17. Application of host-specific bacteriophages to the surface of chicken skin leads to a reduction in recovery of Campylobacter jejuni
- Author
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Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., rees, Catherine E.D., and Connerton, Ian F.
- Subjects
Statistics ,Bacteriophages -- Usage ,Food contamination -- Prevention ,Chickens -- Contamination ,Biological sciences - Abstract
Research shows that human campylobacteriosis can be contained by the application of the Campylobacter jejuni NCTC 12662 phage type 14 to the surface of chicken skin, which reduces the number of recoverable C. jejuni cells from broiler carcasses in abattoir.
- Published
- 2003
18. Isolation and characterization of Campylobacter bacteriophages from retail poultry
- Author
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Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E. R., Rees, Catherine E. D., and Connerton, Ian F.
- Subjects
Microbial contamination -- Physiological aspects ,Microbial contamination -- Prevention ,Campylobacter -- Genetic aspects ,Campylobacter -- Environmental aspects ,Campylobacter -- Physiological aspects ,Bacteriophages -- Genetic aspects ,Bacteriophages -- Environmental aspects ,Bacteriophages -- Physiological aspects ,Microbial populations -- Environmental aspects ,Microbial populations -- Genetic aspects ,Microbial populations -- Physiological aspects ,Microbiology -- Research ,Microbiology -- Environmental aspects ,Biological sciences - Abstract
The authors discuss the study of Campylobacter bacteriophages. They demonstrate that these bacteriophages can survive on retail chicken under commercial storage conditions, and that the phages have a wide range of recovery rates from chicken skin stored at 4 degrees Celsius.
- Published
- 2003
19. Reviving Phage Therapy for the Treatment of Cholera.
- Author
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Bhandare, Sudhakar, Colom, Joan, Baig, Abiyad, Ritchie, Jenny M, Bukhari, Habib, Shah, Muhammad A, Sarkar, Banwarilal L, Su, Jingliang, Wren, Brendan, Barrow, Paul, and Atterbury, Robert J
- Subjects
CHOLERA ,VIBRIO cholerae ,CHOLERA treatment ,THERAPEUTIC use of bacteriophages ,SYMPTOMS - Abstract
Cholera remains a major risk in developing countries, particularly after natural or man-made disasters. Vibrio cholerae El Tor is the most important cause of these outbreaks, and is becoming increasingly resistant to antibiotics, so alternative therapies are urgently needed. In this study, a single bacteriophage, Phi_1, was used to control cholera prophylactically and therapeutically in an infant rabbit model. In both cases, phage-treated animals showed no clinical signs of disease, compared with 69% of untreated control animals. Bacterial counts in the intestines of phage-treated animals were reduced by up to 4 log
10 colony-forming units/g. There was evidence of phage multiplication only in animals that received a V. cholerae challenge. No phage-resistant bacterial mutants were isolated from the animals, despite extensive searching. This is the first evidence that a single phage could be effective in the treatment of cholera, without detectable levels of resistance. Clinical trials in human patients should be considered. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
20. Correlation of Campylobacter bacteriophage with reduced presence of hosts in broiler chicken ceca
- Author
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Atterbury, Robert J., Dillon, E., Swift, C., Connerton, Phillippa L., Frost, J.A., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
Campylobacter jejuni and Campylobacter-specific bacteriophage were enumerated from broiler chicken ceca selected from 90 United Kingdom flocks (n = 205). C. jejuni counts in the presence of bacteriophage (mean log10 5.1 CFU/g) were associated with a significant (P < 0.001) reduction compared to samples with Campylobacter alone (mean log10 6.9 CFU/g).
- Published
- 2005
21. Application of a bacteriophage cocktail to reduce Salmonella Typhimurium U288 contamination on pig skin
- Author
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Hooton, Steven P.T., primary, Atterbury, Robert J., additional, and Connerton, Ian F., additional
- Published
- 2011
- Full Text
- View/download PDF
22. Effects of Orally Administered Bdellovibrio bacteriovorus on the Well-Being and Salmonella Colonization of Young Chicks
- Author
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Atterbury, Robert J., primary, Hobley, Laura, additional, Till, Robert, additional, Lambert, Carey, additional, Capeness, Michael J., additional, Lerner, Thomas R., additional, Fenton, Andrew K., additional, Barrow, Paul, additional, and Sockett, R. Elizabeth, additional
- Published
- 2011
- Full Text
- View/download PDF
23. VI. FOOD SAFETY AND INTERVENTION: Chapter 38: Bacteriophage Therapy and Campylobacter.
- Author
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CONNERTON, IAN F., CONNERTON, PHILLIPPA L., BARROW, PAUL, SEAL, BRUCE S., and ATTERBURY, ROBERT J.
- Published
- 2008
24. Bacteriophage control of Campylobacters in retail poultry
- Author
-
Atterbury, Robert J.
- Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production.\ud \ud Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro.\ud \ud A series of trials using 'phage therapy' in broiler chickens revealed that Campylobacter colonisation can be reduced by ≥log[subscript]10 8.0 cfu g[superscript]-1 caecal contents by dosing with specific bacteriophage. However, both the timing and extent of the reduction in Campylobacter colonisation showed considerable variation. Additionally, the ability of bacteriophage to infect their host in vitro was not a reliable indicator of their efficacy in vivo. The direct application of bacteriophage to the surface of chicken skin artificially contaminated with Campylobacter led to a significant reduction in the number of recoverable host cells. Host resistance to bacteriophage infection was not detected in either the in vivo trials or when recovering Campylobacter cells from chicken skin treated with phage.\ud \ud The work presented in this thesis demonstrates that bacteriophage have considerable potential in the control of Campylobacter in poultry production. They already appear to constitute a limiting factor in Campylobacter colonisation of the chicken gastrointestinal tract and can be detected with their host on retail products. However, further research is required to fully realise their potential and optimising the timing, level and type of bacteriophage used in dosing will be important for their efficacy in vivo.
25. Complete genome sequences of Vibrio cholera: specific bacteriophages 24 and X29
- Author
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Bhandare, Sudhakar Ganapati, Warry, Andrew, Emes, Richard D., Hooton, Steven P.T., Barrow, Paul A., Atterbury, Robert J., Bhandare, Sudhakar Ganapati, Warry, Andrew, Emes, Richard D., Hooton, Steven P.T., Barrow, Paul A., and Atterbury, Robert J.
- Abstract
The complete genomes of two Vibrio cholerae bacteriophages of potential interest for cholera bacteriophage (phage) therapy were sequenced and annotated. The genome size of phage 24 is 44,395 bp encoding 71 putative proteins, and that of phage X29 is 41,569 bp encoding 68 putative proteins.
- Full Text
- View/download PDF
26. Application of a bacteriophage cocktail to reduce Salmonella Typhimurium U288 contamination on pig skin
- Author
-
Hooton, Steven P.T., Atterbury, Robert J., Connerton, Ian F., Hooton, Steven P.T., Atterbury, Robert J., and Connerton, Ian F.
- Abstract
Multidrug-resistant Salmonella Typhimurium U288 is a significant pathogen of pigs, accounting for over half of all outbreaks on UK pig production premises. The potential of this serovar, and other salmonellae, to enter the food chain during the slaughtering process requires that efforts be made to reduce the prevalence of these bacteria at both the pre- and post-harvest stages of production. A bacteriophage cocktail (PC1) capable of lysing various Salmonella enterica serovars was designed using the broad host-range phage Felix 01, and three phages isolated from sewage. PC1 applied to pig skin experimentally-contaminated with U288 achieved significant reductions (P < 0.05) in Salmonella counts when stored at 4 °C over 96 h. Reductions of > 1 log10 unit were observed when the ratio of phage applied was in excess of the bacterial concentration. The treatment was found to be effective at a multiplicity of infection (MOI) of 10 or above, with no significant reductions taking place when the MOI was less than 10. Under these conditions U288 counts of log10 4.1–4.3 CFU were reduced to undetectable levels following the application of PC1 to pig skin (> 99% reduction). These data suggest phage cocktails could be employed post-slaughter as a means to reduce Salmonella contamination of pig carcasses.
- Full Text
- View/download PDF
27. Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens
- Author
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Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., Connerton, Ian F., Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., and Connerton, Ian F.
- Abstract
Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.
- Full Text
- View/download PDF
28. Isolation and characterization of Campylobacter bacteriophages from retail poultry
- Author
-
Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
The ability of phages to survive processing is an important aspect of their potential use in the biocontrol of Campylobacter in poultry production. To this end, we have developed a procedure to recover Campylobacter bacteriophages from chilled and frozen retail poultry and have validated the sensitivity of the method by using a characterized Campylobacter phage (i.e., NCTC 12674). By using this method, we have shown that Campylobacter phages can survive on retail chicken under commercial storage conditions. Retail chicken portions purchased in the United Kingdom were screened for the presence of endogenous Campylobacter phages. Thirty-four Campylobacter bacteriophages were isolated from 300 chilled retail chicken portions, but none could be recovered from 150 frozen chicken portions. The phage isolates were characterized according to their lytic profiles, morphology, and genome size. The free-range products were significantly more likely to harbor phages (P < 0.001 by single-factor analysis of variance) than were standard or economy products. This study demonstrates that Campylobacter bacteriophages, along with their hosts, can survive commercial poultry processing procedures and that the phages exhibited a wide range of recovery rates from chicken skin stored at 4°C.
- Full Text
- View/download PDF
29. Correlation of Campylobacter bacteriophage with reduced presence of hosts in broiler chicken ceca
- Author
-
Atterbury, Robert J., Dillon, E., Swift, C., Connerton, Phillippa L., Frost, J.A., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Dillon, E., Swift, C., Connerton, Phillippa L., Frost, J.A., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
Campylobacter jejuni and Campylobacter-specific bacteriophage were enumerated from broiler chicken ceca selected from 90 United Kingdom flocks (n = 205). C. jejuni counts in the presence of bacteriophage (mean log10 5.1 CFU/g) were associated with a significant (P < 0.001) reduction compared to samples with Campylobacter alone (mean log10 6.9 CFU/g).
- Full Text
- View/download PDF
30. Bacteriophage control of Campylobacters in retail poultry
- Author
-
Atterbury, Robert J. and Atterbury, Robert J.
- Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production. Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro. A series of trials using 'phage therapy' in broiler chickens revealed that
31. Genome analysis of a simultaneously predatory and prey-independent, novel Bdellovibrio bacteriovorus from the River Tiber, supports in silico predictions of both ancient and recent lateral gene transfer from diverse bacteria
- Author
-
Hobley, Laura, Lerner, Thomas R., Williams, Laura E., Lambert, Carey, Till, Rob, Milner, David S., Basford, Sarah M., Capeness, Michael J., Fenton, Andrew K., Atterbury, Robert J., Harris, Maximilian A.T.S., Sockett, R. Elizabeth, Hobley, Laura, Lerner, Thomas R., Williams, Laura E., Lambert, Carey, Till, Rob, Milner, David S., Basford, Sarah M., Capeness, Michael J., Fenton, Andrew K., Atterbury, Robert J., Harris, Maximilian A.T.S., and Sockett, R. Elizabeth
- Abstract
Background: Evolution equipped Bdellovibrio bacteriovorus predatory bacteria to invade other bacteria, digesting and replicating, sealed within them thus preventing nutrient-sharing with organisms in the surrounding environment. Bdellovibrio were previously described as “obligate predators” because only by mutations, often in gene bd0108, are 1 in ~1x107 of predatory lab strains of Bdellovibrio converted to prey-independent growth. A previous genomic analysis of B. bacteriovorus strain HD100 suggested that predatory consumption of prey DNA by lytic enzymes made Bdellovibrio less likely than other bacteria to acquire DNA by lateral gene transfer (LGT). However the Doolittle and Pan groups predicted, in silico, both ancient and recent lateral gene transfer into the B. bacteriovorus HD100 genome. Results: To test these predictions, we isolated a predatory bacterium from the River Tiber- a good potential source of LGT as it is rich in diverse bacteria and organic pollutants- by enrichment culturing with E. coli prey cells. The isolate was identified as B. bacteriovorus and named as strain Tiberius. Unusually, this Tiberius strain showed simultaneous prey-independent growth on organic nutrients and predatory growth on live prey. Despite the prey-independent growth, the homolog of bd0108 did not have typical prey-independent-type mutations. The dual growth mode may reflect the high carbon content of the river, and gives B. bacteriovorus Tiberius extended non-predatory contact with the other bacteria present. The HD100 and Tiberius genomes were extensively syntenic despite their different cultured-terrestrial/freshly-isolated aquatic histories; but there were significant differences in gene content indicative of genomic flux and LGT. Gene content comparisons support previously published in silico predictions for LGT in strain HD100 with substantial conservation of genes predicted to have ancient LGT origins but little conservation of AT-rich genes predicted to be recently
- Full Text
- View/download PDF
32. Complete genome sequences of seven Vibrio cholerae phages isolated in China
- Author
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Bhandare, Sudhakar G., Warry, Andrew, Emes, Richard D., Su, Jingliang, Barrow, Paul A., Atterbury, Robert J., Bhandare, Sudhakar G., Warry, Andrew, Emes, Richard D., Su, Jingliang, Barrow, Paul A., and Atterbury, Robert J.
- Abstract
The complete genome sequences of seven closely related Vibrio cholerae phages isolated from environmental sites in southeastern China are reported here. Phages QH, CJY, H1, H2, H3, J2, and J3 are members of the Podoviridae family and are highly similar to the previously sequenced Vibrio phages VP2, VP5, and phiVC8.
- Full Text
- View/download PDF
33. Complete genome sequences of Vibrio cholera: specific bacteriophages 24 and X29
- Author
-
Bhandare, Sudhakar Ganapati, Warry, Andrew, Emes, Richard D., Hooton, Steven P.T., Barrow, Paul A., Atterbury, Robert J., Bhandare, Sudhakar Ganapati, Warry, Andrew, Emes, Richard D., Hooton, Steven P.T., Barrow, Paul A., and Atterbury, Robert J.
- Abstract
The complete genomes of two Vibrio cholerae bacteriophages of potential interest for cholera bacteriophage (phage) therapy were sequenced and annotated. The genome size of phage 24 is 44,395 bp encoding 71 putative proteins, and that of phage X29 is 41,569 bp encoding 68 putative proteins.
- Full Text
- View/download PDF
34. Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens
- Author
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Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., Connerton, Ian F., Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., and Connerton, Ian F.
- Abstract
Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.
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35. Biology and genomics of an historic therapeutic Escherichia coli bacteriophage collection
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Baig, Abiyad, Colom, Joan, Barrow, Paul, Schouler, Catherine, Moodley, Arshnee, Lavigne, Rob, Atterbury, Robert J., Baig, Abiyad, Colom, Joan, Barrow, Paul, Schouler, Catherine, Moodley, Arshnee, Lavigne, Rob, and Atterbury, Robert J.
- Abstract
We have performed microbiological and genomic characterization of an historic collection of nine bacteriophages, specifically infecting a K1 E. coli O18:K1:H7 ColV+ strain. These phages were isolated from sewage and tested for their efficacy in vivo for the treatment of systemic E. coli infection in a mouse infection model by Smith and Huggins (1982). The aim of the study was to identify common microbiological and genomic characteristics, which co-relate to the performance of these phages in in vivo study. These features will allow an informed selection of phages for use as therapeutic agents. Transmission electron microscopy showed that six of the nine phages were Podoviridae and the remaining three were Siphoviridae. The four best performing phages in vivo belonged to the Podoviridae family. In vitro, these phages exhibited very short latent and rise periods in our study. In agreement with their microbiological profiles, characterization by genome sequencing showed that all six podoviruses belong to the Autographivirinae subfamily. Of these, four were isolates of the same species (99% identity), whereas two had divergent genomes compared to other podoviruses. The Siphoviridae phages, which were moderate to poor performers in vivo, exhibited longer latent and rise periods in vitro. Two of the three siphoviruses were closely related to each other (99% identity), but all can be associated with the Guernseyvirinae subfamily. Genome sequence comparison of both types of phages showed that a gene encoding for DNA-dependent RNA polymerase was only present in phages with faster replication cycle, which may account for their better performance in vivo. These data define a combination of microbiological, genomic and in vivo characteristics which allow a more rational evaluation of the original in vivo data and pave the way for the selection of phages for future phage therapy trails.
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36. Application of a bacteriophage cocktail to reduce Salmonella Typhimurium U288 contamination on pig skin
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Hooton, Steven P.T., Atterbury, Robert J., Connerton, Ian F., Hooton, Steven P.T., Atterbury, Robert J., and Connerton, Ian F.
- Abstract
Multidrug-resistant Salmonella Typhimurium U288 is a significant pathogen of pigs, accounting for over half of all outbreaks on UK pig production premises. The potential of this serovar, and other salmonellae, to enter the food chain during the slaughtering process requires that efforts be made to reduce the prevalence of these bacteria at both the pre- and post-harvest stages of production. A bacteriophage cocktail (PC1) capable of lysing various Salmonella enterica serovars was designed using the broad host-range phage Felix 01, and three phages isolated from sewage. PC1 applied to pig skin experimentally-contaminated with U288 achieved significant reductions (P < 0.05) in Salmonella counts when stored at 4 °C over 96 h. Reductions of > 1 log10 unit were observed when the ratio of phage applied was in excess of the bacterial concentration. The treatment was found to be effective at a multiplicity of infection (MOI) of 10 or above, with no significant reductions taking place when the MOI was less than 10. Under these conditions U288 counts of log10 4.1–4.3 CFU were reduced to undetectable levels following the application of PC1 to pig skin (> 99% reduction). These data suggest phage cocktails could be employed post-slaughter as a means to reduce Salmonella contamination of pig carcasses.
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37. Isolation and characterization of Campylobacter bacteriophages from retail poultry
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Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
The ability of phages to survive processing is an important aspect of their potential use in the biocontrol of Campylobacter in poultry production. To this end, we have developed a procedure to recover Campylobacter bacteriophages from chilled and frozen retail poultry and have validated the sensitivity of the method by using a characterized Campylobacter phage (i.e., NCTC 12674). By using this method, we have shown that Campylobacter phages can survive on retail chicken under commercial storage conditions. Retail chicken portions purchased in the United Kingdom were screened for the presence of endogenous Campylobacter phages. Thirty-four Campylobacter bacteriophages were isolated from 300 chilled retail chicken portions, but none could be recovered from 150 frozen chicken portions. The phage isolates were characterized according to their lytic profiles, morphology, and genome size. The free-range products were significantly more likely to harbor phages (P < 0.001 by single-factor analysis of variance) than were standard or economy products. This study demonstrates that Campylobacter bacteriophages, along with their hosts, can survive commercial poultry processing procedures and that the phages exhibited a wide range of recovery rates from chicken skin stored at 4°C.
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38. Fleas and smaller fleas: virotherapy for parasite infections
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Hyman, Paul, Atterbury, Robert J., Barrow, Paul, Hyman, Paul, Atterbury, Robert J., and Barrow, Paul
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Bacteriophages are viruses of bacteria that are used for controlling bacterial food-borne pathogens and have been proposed for more extensive usage in infection control. Protists are now recognised to harbour viruses and virus-like particles. We propose that investigation of their prevalence in parasites be intensified. We also propose that such viruses might be considered for virotherapy to control certain parasite infections of man and animals.
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39. Application of host-specific bacteriophages to the surface of chicken skin leads to a reduction in recovery of Campylobacter jejuni
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Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
Retail poultry products are widely purported as the major infection vehicle for human campylobacteriosis. Numerous intervention strategies have sought to reduce Campylobacter contamination on broiler carcasses in the abattoir. This study reports the efficacy of bacteriophage in reducing the number of recoverable Campylobacter jejuni cells on artificially contaminated chicken skin.
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40. Correlation of Campylobacter bacteriophage with reduced presence of hosts in broiler chicken ceca
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Atterbury, Robert J., Dillon, E., Swift, C., Connerton, Phillippa L., Frost, J.A., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Dillon, E., Swift, C., Connerton, Phillippa L., Frost, J.A., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
Campylobacter jejuni and Campylobacter-specific bacteriophage were enumerated from broiler chicken ceca selected from 90 United Kingdom flocks (n = 205). C. jejuni counts in the presence of bacteriophage (mean log10 5.1 CFU/g) were associated with a significant (P < 0.001) reduction compared to samples with Campylobacter alone (mean log10 6.9 CFU/g).
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41. Molecular epidemiology of nontyphoidal Salmonella in poultry and poultry products in India: implications for human health
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Saravanan, Sellappan, Purushothaman, Venketaraman, Murthy, Thippichettypalayam Ramasamy Gopala, Sukumar, Kuppannan, Srinivasan, Palani, Gowthaman, Vasudevan, Balusamy, Mohan, Atterbury, Robert J., Kuchipudi, Suresh V., Saravanan, Sellappan, Purushothaman, Venketaraman, Murthy, Thippichettypalayam Ramasamy Gopala, Sukumar, Kuppannan, Srinivasan, Palani, Gowthaman, Vasudevan, Balusamy, Mohan, Atterbury, Robert J., and Kuchipudi, Suresh V.
- Abstract
Human infections with non-typhoidal Salmonella (NTS) serovars are increasingly becoming a threat to human health globally. While all motile Salmonellae have zoonotic potential, Salmonella Enteritidis and Salmonella Typhimurium are most commonly associated with human disease, for which poultry are a major source. Despite the increasing number of human NTS infections, the epidemiology of NTS in poultry in India has not been fully understood. Hence, as a first step, we carried out epidemiological analysis to establish the incidence of NTS in poultry to evaluate the risk to human health. A total of 1215 samples (including poultry meat, tissues, egg and environmental samples) were collected from 154 commercial layer farms from southern India and screened for NTS. Following identification by cultural and biochemical methods, Salmonella isolates were further characterized by multiplex PCR, allele-specific PCR, enterobacterial repetitive intergenic consensus (ERIC) PCR and pulse field gel electrophoresis (PFGE). In the present study, 21/1215 (1.73 %) samples tested positive for NTS. We found 12/392 (3.06 %) of tissue samples, 7/460 (1.52 %) of poultry products, and 2/363 (0.55 %) of environmental samples tested positive for NTS. All the Salmonella isolates were resistant to oxytetracycline, which is routinely used as poultry feed additive. The multiplex PCR results allowed 16/21 isolates to be classified as S. Typhimurium, and five isolates as S. Enteritidis. Of the five S. Enteritidis isolates, four were identified as group D Salmonella by allele-specific PCR. All of the isolates produced different banding patterns in ERIC PCR. Of the thirteen macro restriction profiles (MRPs) obtained by PFGE, MRP 6 was predominant which included 6 (21 %) isolates. In conclusion, the findings of the study revealed higher incidence of contamination of NTS Salmonella in poultry tissue and animal protein sources used for poultry. The results of the study warrants further investigation on dif
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42. Bacteriophage therapy to reduce Salmonella colonization of broiler chickens
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Atterbury, Robert J., Van Bergen, M.A.P., Ortiz, F., Lovell, M.A., Harris, J.A., De Boer, A., Wagenaar, J.A., Allen, V.M., Barrow, P.A., Atterbury, Robert J., Van Bergen, M.A.P., Ortiz, F., Lovell, M.A., Harris, J.A., De Boer, A., Wagenaar, J.A., Allen, V.M., and Barrow, P.A.
- Abstract
Acute enteric infections caused by salmonellas remain a major public health burden worldwide. Poultry, particularly chickens, are known to be the main reservoir for this zoonotic pathogen. Although some progress has been made in reducing Salmonella colonization of broiler chickens by using biosecurity and antimicrobials, it still remains a considerable problem. The use of host-specific bacteriophages as a biocontrol is one possible intervention by which Salmonella colonization could be reduced. A total of 232 Salmonella bacteriophages were isolated from poultry farms, abattoirs, and wastewater in 2004 and 2005. Three phages exhibiting the broadest host ranges against Salmonella enterica serotypes Enteritidis, Hadar, and Typhimurium were characterized further by determining their morphology and lytic activity in vitro. These phages were then administered in antacid suspension to birds experimentally colonized with specific Salmonella host strains. The first phage reduced S. enterica serotype Enteritidis cecal colonization by ≥4.2 log10 CFU within 24 h compared with controls. Administration of the second phage reduced S. enterica serotype Typhimurium by ≥2.19 log10 CFU within 24 h. The third bacteriophage was ineffective at reducing S. enterica serotype Hadar colonization. Bacteriophage resistance occurred at a frequency commensurate with the titer of phage being administered, with larger phage titers resulting in a greater proportion of resistant salmonellas. The selection of appropriate bacteriophages and optimization of both the timing and method of phage delivery are key factors in the successful phage-mediated control of salmonellas in broiler chickens.
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43. Effect of delivery method on the efficacy of Salmonella vaccination in chickens
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Atterbury, Robert J., Morris, V., Harrison, D., Tucker, V., Allen, V.M., Davies, R.H., Carrique-Mas, J.J., Atterbury, Robert J., Morris, V., Harrison, D., Tucker, V., Allen, V.M., Davies, R.H., and Carrique-Mas, J.J.
- Abstract
To investigate whether the efficacy of live vaccines is influenced by the mode of vaccine delivery, a widely-used UK live commercial Salmonella Enteritidis vaccine was delivered to pullet chicks either by spray, in drinking water, or in combination with a bivalent vaccine containing inactivated Salmonella Enteritidis and Salmonella Typhimurium. The birds were subsequently challenged with 102 or 108 colony-forming units (cfu) of Salmonella Enteritidis through drinking water at either six or 20 weeks of age. Ten days after the challenge, the birds were euthanased and their caecal contents cultured for Salmonella. All of the vaccinated groups contained fewer Salmonella Enteritidis-positive birds than the unvaccinated groups. The ‘spray-vaccinated’ group contained significantly fewer Salmonella Enteritidis-positive birds than the ‘water-vaccinated’ group after challenge with 108 cfu at 20 weeks. However, there was little or no difference at the other challenge time points between the groups that received vaccine through different modes of delivery.
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44. Investigation into the animal species contents of popular wet pet foods
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Maine, Isabella R., Atterbury, Robert J., Chang, Kin-Chow, Maine, Isabella R., Atterbury, Robert J., and Chang, Kin-Chow
- Abstract
Background: The use of the generic term “meat and animal derivatives” in declared ingredient lists of pet foods in the European Union is virtually universal. In the wake of the 2013 “horse meat scandal” in the human food chain, we examined the presence and authenticity of animal sources (cow, chicken, pig and horse) of proteins in a range of popular wet pet foods in the United Kingdom. Findings: Seventeen leading dog and cat foods were sampled for the relative presence of DNA from each of the four animal species by quantitative real-time polymerase chain reaction. No horse DNA was detected. However, there was detection at substantial levels of unspecified animal species in most products tested. In 14 out of 17 samples, bovine, porcine and chicken DNA were found in various proportions and combinations but were not explicitly identified on the product labels. Of the 7 products with prominent headline descriptions containing the term “with beef”, only 2 were found to contain more bovine DNA (>50%) than pig and chicken DNA combined. Conclusions: There is a need for the pet food industry to show greater transparency to customers in the disclosure of the types of animal proteins (animal species and tissue types) in their products. Full disclosure of animal contents will (a) allow more informed choices to be made on purchases which are particularly important for pets with food allergies, (b) reduce the risk of product misinterpretation by shoppers, and (c) avoid potential religious concerns.
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45. Bacteriophage therapy to reduce Campylobacter jejuni colonization of broiler chickens
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Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., Connerton, Ian F., Loc Carrillo, C., Atterbury, Robert J., El-Shibiny, A., Connerton, Phillippa L., Dillon, E., Scott, A., and Connerton, Ian F.
- Abstract
Colonization of broiler chickens by the enteric pathogen Campylobacter jejuni is widespread and difficult to prevent. Bacteriophage therapy is one possible means by which this colonization could be controlled, thus limiting the entry of campylobacters into the human food chain. Prior to evaluating the efficacy of phage therapy, experimental models of Campylobacter colonization of broiler chickens were established by using low-passage C. jejuni isolates HPC5 and GIIC8 from United Kingdom broiler flocks. The screening of 53 lytic bacteriophage isolates against a panel of 50 Campylobacter isolates from broiler chickens and 80 strains isolated after human infection identified two phage candidates with broad host lysis. These phages, CP8 and CP34, were orally administered in antacid suspension, at different dosages, to 25-day-old broiler chickens experimentally colonized with the C. jejuni broiler isolates. Phage treatment of C. jejuni-colonized birds resulted in Campylobacter counts falling between 0.5 and 5 log10 CFU/g of cecal contents compared to untreated controls over a 5-day period postadministration. These reductions were dependent on the phage-Campylobacter combination, the dose of phage applied, and the time elapsed after administration. Campylobacters resistant to bacteriophage infection were recovered from phage-treated chickens at a frequency of <4%. These resistant types were compromised in their ability to colonize experimental chickens and rapidly reverted to a phage-sensitive phenotype in vivo. The selection of appropriate phage and their dose optimization are key elements for the success of phage therapy to reduce campylobacters in broiler chickens.
- Full Text
- View/download PDF
46. Bacteriophage control of Campylobacters in retail poultry
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Atterbury, Robert J. and Atterbury, Robert J.
- Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production. Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro. A series of trials using 'phage therapy' in broiler chickens revealed that
47. Genome analysis of a simultaneously predatory and prey-independent, novel Bdellovibrio bacteriovorus from the River Tiber, supports in silico predictions of both ancient and recent lateral gene transfer from diverse bacteria
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Hobley, Laura, Lerner, Thomas R., Williams, Laura E., Lambert, Carey, Till, Rob, Milner, David S., Basford, Sarah M., Capeness, Michael J., Fenton, Andrew K., Atterbury, Robert J., Harris, Maximilian A.T.S., Sockett, R. Elizabeth, Hobley, Laura, Lerner, Thomas R., Williams, Laura E., Lambert, Carey, Till, Rob, Milner, David S., Basford, Sarah M., Capeness, Michael J., Fenton, Andrew K., Atterbury, Robert J., Harris, Maximilian A.T.S., and Sockett, R. Elizabeth
- Abstract
Background: Evolution equipped Bdellovibrio bacteriovorus predatory bacteria to invade other bacteria, digesting and replicating, sealed within them thus preventing nutrient-sharing with organisms in the surrounding environment. Bdellovibrio were previously described as “obligate predators” because only by mutations, often in gene bd0108, are 1 in ~1x107 of predatory lab strains of Bdellovibrio converted to prey-independent growth. A previous genomic analysis of B. bacteriovorus strain HD100 suggested that predatory consumption of prey DNA by lytic enzymes made Bdellovibrio less likely than other bacteria to acquire DNA by lateral gene transfer (LGT). However the Doolittle and Pan groups predicted, in silico, both ancient and recent lateral gene transfer into the B. bacteriovorus HD100 genome. Results: To test these predictions, we isolated a predatory bacterium from the River Tiber- a good potential source of LGT as it is rich in diverse bacteria and organic pollutants- by enrichment culturing with E. coli prey cells. The isolate was identified as B. bacteriovorus and named as strain Tiberius. Unusually, this Tiberius strain showed simultaneous prey-independent growth on organic nutrients and predatory growth on live prey. Despite the prey-independent growth, the homolog of bd0108 did not have typical prey-independent-type mutations. The dual growth mode may reflect the high carbon content of the river, and gives B. bacteriovorus Tiberius extended non-predatory contact with the other bacteria present. The HD100 and Tiberius genomes were extensively syntenic despite their different cultured-terrestrial/freshly-isolated aquatic histories; but there were significant differences in gene content indicative of genomic flux and LGT. Gene content comparisons support previously published in silico predictions for LGT in strain HD100 with substantial conservation of genes predicted to have ancient LGT origins but little conservation of AT-rich genes predicted to be recently
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48. Bacteriophage control of Campylobacters in retail poultry
- Author
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Atterbury, Robert J. and Atterbury, Robert J.
- Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production. Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro. A series of trials using 'phage therapy' in broiler chickens revealed that
49. Bacteriophage control of Campylobacters in retail poultry
- Author
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Atterbury, Robert J. and Atterbury, Robert J.
- Abstract
Food-borne disease continues to be a major cause of human morbidity and mortality. During the past few decades, Campylobacter jejuni has ascended to become the greatest cause of bacterial enteric disease worldwide. Anecdotal evidence suggests the majority of human campylobacteriosis in industrialised countries is caused by the consumption of undercooked chicken. Campylobacter continues to frustrate current control strategies throughout the food chain and in 2001 was responsible for over 56, 000 cases of food poisoning in the U.K. alone. The work presented in this thesis examined the potential of host-specific bacteriophage as a novel measure to control the population of Campylobacter in poultry production. Several surveys in this thesis revealed that campylobacters and their bacteriophage permeate the entire poultry meat supply chain, from chickens in the broiler house to packaged retail products. Characterisation of the bacteriophage recovered from such sources showed that retail poultry isolates exhibited greater similarities in host range than those originating from broiler houses, implying poultry processing selected for a subpopulation of phage. Additionally, broiler chickens harbouring bacteriophage in their gastrointestinal tract generally contained fewer campylobacters. All of the phage isolates studied belonged to the Myoviridae virus family as they possessed dsDNA genomes encapsulated in an icosahedral head with a rigid, contractile tail. Fragments of the phage genomes exhibited significant sequence homology with a number of genes involved in DNA replication from phage T4. Studies of the attachment and replication of the phage isolates in vitro suggested that adsorption to the host cell was efficient but the burst size was low (˂10 virions per cell). Campylobacter jejuni was found to produce membrane vesicles but these did not significantly affect bacteriophage replication in vitro. A series of trials using 'phage therapy' in broiler chickens revealed that
50. Application of host-specific bacteriophages to the surface of chicken skin leads to a reduction in recovery of Campylobacter jejuni
- Author
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Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., Connerton, Ian F., Atterbury, Robert J., Connerton, Phillippa L., Dodd, Christine E.R., Rees, Catherine E.D., and Connerton, Ian F.
- Abstract
Retail poultry products are widely purported as the major infection vehicle for human campylobacteriosis. Numerous intervention strategies have sought to reduce Campylobacter contamination on broiler carcasses in the abattoir. This study reports the efficacy of bacteriophage in reducing the number of recoverable Campylobacter jejuni cells on artificially contaminated chicken skin.
- Full Text
- View/download PDF
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