Contact Details
- Phone
- +64 3 364 0570
- jacqui.keenan@otago.ac.nz
University Links
- Position
- Research Associate Professor
- Department
- Department of Surgery and Critical Care (Christchurch)
- Qualifications
- MApplSc (Linc) PhD (Otgao)
- Research summary
- Gastrointestinal disease
Research
Jacqui is a Research Associate Professor in the department.
Her research is centred on the role of bacteria in the pathogenesis of gastrointestinal disease. She is particularly interested in the ability of outer membrane vesicles shed from the surface of Gram negative bacteria to induce epithelial permeability, inflammation and DNA damage.
Another interest is the influence of diet on bacterial phenotype and host response.
Publications
Waddell, O., Pearson, J., McCombie, A., Marshall, H., Glyn, T., Purcell, R., Keenan, J., & Frizelle, F. (2024). The rising incidence of early onset colorectal cancer in Aotearoa New Zealand: Changing trends from 2000 to 2020. ANZ Journal of Surgery, 94(Suppl. 1), GS003. doi: 10.1111/ans.18951 Conference Contribution - Published proceedings: Abstract
Waddell, O., Pearson, J., McCombie, A., Marshall, H., Purcell, R., Keenan, J., Glyn, T., & Frizelle, F. (2024). The incidence of early onset colorectal cancer in Aotearoa New Zealand: 2000–2020. BMC Cancer, 24, 456. doi: 10.1186/s12885-024-12122-y Journal - Research Article
Pearson, J., Waddell, O., McCombie, A., Marshall, H., Purcell, R., Keenan, J., Glyn, T., & Frizelle, F. (2023, November-December). The incidence of early-onset colorectal cancer in Aotearoa: 2000-2020. Verbal presentation at the International Biometric Society Australasian Region (IBS-AR) and the Statistical Ecology and Environmental Monitoring (SEEM) Joint Conference, Waitangi, New Zealand. Conference Contribution - Verbal presentation and other Conference outputs
Waddell, O., Frizelle, F. A., & Keenan, J. I. (2023). The role of biomarkers to increase the detection of early-onset colorectal cancer. Medical Research Archives, 11(11). doi: 10.18103/mra.v11i11.4690 Journal - Research Article
Vernon-Roberts, A., Premaratne, M., Wright, R., Keenan, J. I., & Day, A. S. (2023). Profile of Helicobacter pylori infections among children in the South Island of New Zealand (2010-2021). Helicobacter, e13037. Advance online publication. doi: 10.1111/hel.13037 Journal - Research Article
2024
Journal - Research Article
Waddell, O., Pearson, J., McCombie, A., Marshall, H., Purcell, R., Keenan, J., Glyn, T., & Frizelle, F. (2024). The incidence of early onset colorectal cancer in Aotearoa New Zealand: 2000–2020. BMC Cancer, 24, 456. doi: 10.1186/s12885-024-12122-y
Conference Contribution - Published proceedings: Abstract
Waddell, O., Pearson, J., McCombie, A., Marshall, H., Glyn, T., Purcell, R., Keenan, J., & Frizelle, F. (2024). The rising incidence of early onset colorectal cancer in Aotearoa New Zealand: Changing trends from 2000 to 2020. ANZ Journal of Surgery, 94(Suppl. 1), GS003. doi: 10.1111/ans.18951
2023
Journal - Research Article
Waddell, O., Frizelle, F. A., & Keenan, J. I. (2023). The role of biomarkers to increase the detection of early-onset colorectal cancer. Medical Research Archives, 11(11). doi: 10.18103/mra.v11i11.4690
Vernon-Roberts, A., Premaratne, M., Wright, R., Keenan, J. I., & Day, A. S. (2023). Profile of Helicobacter pylori infections among children in the South Island of New Zealand (2010-2021). Helicobacter, e13037. Advance online publication. doi: 10.1111/hel.13037
Keenan, J. I., Aitchison, A., Frizelle, F. A., & Hock, B. D. (2023). Detection of chitinase 3-like 1 in symptomatic primary care patient faecal samples is not a reliable biomarker of colonic lesions. Asian Pacific Journal of Cancer Prevention, 24(7), 2289-2293. doi: 10.31557/APJCP.2023.24.7.2289
Ali, H., Douwes, J., Burmanje, J., Gokhale, P., Crane, J., Pattemore, P., Stanley, T., Keenan, J., & Brooks, C. (2023). Sputum inflammatory, neural, and remodeling mediators in eosinophilic and noneosinophilic asthma. Annals of Allergy, Asthma & Immunology, 130, 776-783. doi: 10.1016/j.anai.2023.03.015
Thompson, N., Gatenby, G., Waddell, O., Purcell, R., Keenan, J., Pearson, J. F., Frizelle, F., & Glyn, T. (2023). Early onset colorectal cancer in Canterbury, New Zealand. ANZ Journal of Surgery, 93, 2148-2154. doi: 10.1111/ans.18357
James, S. C., Fraser, K., Cooney, J., Günther, C. S., Young, W., Gearry, R. B., … Keenan, J. I., … Roy, N. C. (2023). Concentrations of plasma amino acids and neurotransmitters in participants with functional gut disorders and healthy controls. Metabolites, 13, 313. doi: 10.3390/metabo13020313
Simon, M. H., Heenan, P. E., Frampton, C., Bayer, S., Keenan, J. I., de Boer, N. K., Roy, N. C., … Gearry, R. B. (2023). Economic living standard and abdominal pain mediate the association between functional gastrointestinal disorders and depression or anxiety. Neurogastroenterology & Motility, 35, e14465. doi: 10.1111/nmo.14465
Journal - Research Other
Li, S., Keenan, J. I., Shaw, I. C., & Frizelle, F. A. (2023). Could microplastics be a driver for early onset colorectal cancer? Cancers, 15, 3323. doi: 10.3390/cancers15133323
Conference Contribution - Verbal presentation and other Conference outputs
Pearson, J., Waddell, O., McCombie, A., Marshall, H., Purcell, R., Keenan, J., Glyn, T., & Frizelle, F. (2023, November-December). The incidence of early-onset colorectal cancer in Aotearoa: 2000-2020. Verbal presentation at the International Biometric Society Australasian Region (IBS-AR) and the Statistical Ecology and Environmental Monitoring (SEEM) Joint Conference, Waitangi, New Zealand.
2022
Journal - Research Article
Aitchison, A., Pearson, J. F., Purcell, R. V., Frizelle, F. A., & Keenan, J. I. (2022). Detection of Fusobacterium nucleatum DNA in primary care patient stool samples does not predict progression of colorectal neoplasia. PLoS ONE, 17(6), e0269541. doi: 10.1371/journal.pone.0269541
Purcell, R. V., Permain, J., & Keenan, J. I. (2022). Enterotoxigenic Bacteroides fragilis activates IL-8 expression through Stat3 in colorectal cancer cells. Gut Pathogens, 14, 16. doi: 10.1186/s13099-022-00489-x
Ho, S. S. C., Hall, S., Keenan, J. I., & Day, A. S. (2022). Australasian pediatric gastroenterologists' perspectives and practices of Celiac disease diagnosis and management. Digestive Diseases & Sciences, 67, 1744-1752. doi: 10.1007/s10620-021-06988-2
Journal - Research Other
Waddell, O., Keenan, J., & Frizelle, F. (2022). Early-onset colorectal cancer: Never too young. New Zealand Medical Journal, 135(1563), 7-11. Retrieved from https://journal.nzma.org.nz/
Ho, S. S. C., Keenan, J. I., & Day, A. S. (2022). Urinary chitinase 3-like 1 and intestinal fatty-acid binding proteins are not elevated in children with inflammatory bowel disease. Intestinal Research, 20(4), 509-513. doi: 10.5217/ir.2022.00064
Permain, J., Appleton, L., Ho, S. S. C., Coffey, M., Ooi, C. Y., Keenan, J. I., & Day, A. S. (2022). Children with cystic fibrosis have elevated levels of fecal chitinase-3-like-1. Journal of Pediatric Gastroenterology & Nutrition, 75(1), 48-51. doi: 10.1097/mpg.0000000000003477
Keenan, J. I., & Frizelle, F. A. (2022). Biomarkers to detect early-stage colorectal cancer. Biomedicines, 10(2), 255. doi: 10.3390/biomedicines10020255
Conference Contribution - Published proceedings: Abstract
Thompson, N., Gatenby, G., Waddell, O., Keenan, J., Frizelle, F., & Glyn, T. (2022). Characteristics of early-onset colorectal cancer in the Canterbury population. ANZ Journal of Surgery, 92(Suppl. 1), (pp. 34). doi: 10.1111/ans.17609
2021
Journal - Research Article
James, S. C., Fraser, K., Young, W., Heenan, P. E., Gearry, R. B., Keenan, J. I., … Roy, N. C. (2021). Concentrations of fecal bile acids in participants with functional gut disorders and healthy controls. Metabolites, 11, 612.
Edwards, T. S., Dawson, K. L., Keenan, J. I., & Day, A. S. (2021). A simple method to generate β-casomorphin-7 by in vitro digestion of casein from bovine milk. Journal of Functional Foods, 85, 104631. doi: 10.1016/j.jff.2021.104631
Ho, S. S. C., Keenan, J. I., & Day, A. S. (2021). Parent Perspectives of Diagnostic and Monitoring Tests Undertaken by Their Child with Inflammatory Bowel Disease. Pediatric Gastroenterology, Hepatology & Nutrition, 24(1), 19-29. doi: 10.5223/pghn.2021.24.1.19
Conference Contribution - Published proceedings: Abstract
Ho, S. S., Keenan, J., & Day, A. (2021). Chitinase-3-like protein 1 levels in feces but not urine as an emerging biomarker of pediatric inflammatory bowel disease. Journal of Gastroenterology & Hepatology, 36(Suppl. 3), (pp. 164). doi: 10.1111/jgh.15617
2020
Journal - Research Article
Ho, S. S. C., Ross, M., Keenan, J. I., & Day, A. S. (2020). Fecal calprotectin in combination with standard blood tests in the diagnosis of inflammatory bowel disease in children. Frontiers in Pediatrics, 8, 609279. doi: 10.3389/fped.2020.609279
Aitchison, A., Hakkaart, C., Day, R. C., Morrin, H. R., Frizelle, F. A., & Keenan, J. I. (2020). APC mutations are not confined to hotspot regions in early-onset colorectal cancer. Cancers, 12, 3829. doi: 10.3390/cancers12123829
Ho, S. S., Wall, C., Gearry, R. B., Keenan, J., & Day, A. S. (2020). A pilot study evaluating novel urinary biomarkers for Crohn's disease. Inflammatory Intestinal Diseases, 5(4), 212-220. doi: 10.1159/000510682
Heenan, P., Creemers, R. H., Sharma, S., Keenan, J., Bayer, S., Young, W., … Skidmore, P. M., … Roy, N., Gearry, R. B., & COMFORT Cohort Collaborators. (2020). Cohort profile: The Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT). Inflammatory Intestinal Diseases, 5(3), 132-143. doi: 10.1159/000508160
Ho, S. S. C., Keenan, J. I., & Day, A. S. (2020). Role of serological tests in the diagnosis of coeliac disease in children in New Zealand. Journal of Paediatrics & Child Health, 56, 1906-1911. doi: 10.1111/jpc.15076
Aitchison, A., Hakkaart, C., Whitehead, M., Khan, S., Siddique, S., Ahmed, R., Frizelle, F. A., & Keenan, J. I. (2020). CDH1 gene mutation in early-onset, colorectal signet-ring cell carcinoma. Pathology: Research & Practice, 216, 152912. doi: 10.1016/j.prp.2020.152912
Journal - Research Other
Day, A. S., Keenan, J. I., & Tannock, G. W. (2020). The intestinal microbiota in health and disease. Journal of the Royal Society of New Zealand, 50(3), 367-370. doi: 10.1080/03036758.2020.1760896
Heenan, P. E., Keenan, J. I., Bayer, S., Simon, M., & Gearry, R. B. (2020). Irritable bowel syndrome and the gut microbiota. Journal of the Royal Society of New Zealand, 50(3), 470-490. doi: 10.1080/03036758.2019.1695635
Keenan, J. I., & Frizelle, F. A. (2020). Toxigenic gut bacteria, diet and colon carcinogenesis. Journal of the Royal Society of New Zealand, 50(3), 418-433. doi: 10.1080/03036758.2019.1695636
Ho, S. S. C., Keenan, J. I., & Day, A. S. (2020). The role of gastrointestinal-related fatty acid-binding proteins as biomarkers in gastrointestinal diseases. Digestive Diseases & Sciences, 65, 376-390. doi: 10.1007/s10620-019-05841-x
Conference Contribution - Published proceedings: Abstract
Heenan, P., Frampton, C., Young, W., Roy, N., Keenan, J., Wall, C., … Gearry, R. (2020). Gastrointestinal and mental health symptoms group participants in an irritable bowel syndrome cohort. Journal of Gastroenterology & Hepatology, 35, (pp. 173). doi: 10.1111/jgh.15273
Ho, S. S., Keenan, J., & Day, A. (2020). Patient perceptions of current and potential inflammatory bowel disease diagnostic and monitoring tests. Journal of Gastroenterology & Hepatology, 35(Suppl. 1), (pp. 109-110). doi: 10.1111/jgh.15271
Roy, N., Heenan, P., Wall, C., Young, W., Carco, C., Keenan, J., … Gearry, R. (2020). Association of habitual dietary fiber intake and fecal microbiome gene abundance with gastrointestinal symptoms in an irritable bowel syndrome cohort. Current Developments in Nutrition, 4(Suppl. 2), (pp. 1581). doi: 10.1093/cdn/nzaa062_038
2019
Journal - Research Article
Keenan, J., Aitchison, A., Leaman, J., Pearson, J., & Frizelle, F. (2019). Faecal biomarkers do not always identify pre-cancerous lesions in patients who present in primary care with bowel symptoms. New Zealand Medical Journal, 132(1501), 48-56. Retrieved from https://www.nzma.org.nz/journal
Journal - Research Other
Keenan, J. I., Aitchison, A., Pearson, J. F., Frizelle, F. A., & Munday, J. S. (2019). Detection of the Bacteroides fragilis toxin gene in sheep with and without small intestinal adenocarcinoma. New Zealand Veterinary Journal, 67(6), 329-332. doi: 10.1080/00480169.2019.1651233
Conference Contribution - Published proceedings: Abstract
Ho, S., Ross, M., Keenan, J., & Day, A. (2019). The role of fecal calprotectin in the diagnosis of inflammatory bowel disease in children. Journal of Gastroenterology & Hepatology, 34(Suppl. 2), (pp. 206). doi: 10.1111/jgh.14795
Ho, S., Keenan, J., & Day, A. (2019). The role of combination serological tests in the diagnosis of celiac disease in children. Journal of Gastroenterology & Hepatology, 34(Suppl. 2), (pp. 206). doi: 10.1111/jgh.14795
2018
Journal - Research Article
Purcell, R. V., Kaakoush, N. O., Mitchell, H. M., Pearson, J. F., & Keenan, J. I. (2018). Gastrointestinal pathobionts in pediatric Crohn's disease patients. International Journal of Microbiology, 2018, 9203908. doi: 10.1155/2018/9203908
Conference Contribution - Published proceedings: Abstract
Aitchison, A., Hakkaart, C., Kahn, S., Whitehead, M., Frizelle, F., & Keenan, J. (2018). E-cadherin in early-onset colorectal signet-ring cell carcinoma. Proceedings of the New Zealand Society for Oncology (NZSO) Conference. Retrieved from http://www.nzsoncology.org.nz/
Conference Contribution - Poster Presentation (not in published proceedings)
Swan, J., Aitchison, A., Hampton, M., & Keenan, J. (2018, September). Asprin's role in preventing e-cadherin cleavage by the carcinogenic Bacteroides Fragilis toxin. Poster session presented at the Otago Spotlight Symposium on Infectious Disease, Wellington, New Zealand.
2017
Journal - Research Article
Flores, S. E., Aitchison, A., Day, A. S., & Keenan, J. I. (2017). Helicobacter pylori infection perturbs iron homeostasis in gastric epithelial cells. PLoS ONE, 12(9), e0184026. doi: 10.1371/journal.pone.0184026
Purcell, R. V., Pearson, J., Aitchison, A., Dixon, L., Frizelle, F. A., & Keenan, J. I. (2017). Colonization with enterotoxigenic Bacteroides fragilis is associated with early-stage colorectal neoplasia. PLoS ONE, 12(2), e0171602. doi: 10.1371/journal.pone.0171602
Budd, G. R., Aitchison, A., Day, A. S., & Keenan, J. I. (2017). The effect of polymeric formula on enterocyte differentiation. Innate Immunity, 23(3), 240-248. doi: 10.1177/1753425916689333
Chae, A., Aitchison, A., Day, A. S., & Keenan, J. I. (2017). Bovine colostrum demonstrates anti-inflammatory and antibacterial activity in in vitro models of intestinal inflammation and infection. Journal of Functional Foods, 28, 293-298. doi: 10.1016/j.jff.2016.11.016
Journal - Research Other
Keenan, J., Aitchison, A., & Frizelle, F. (2017). Are young people eating their way to bowel cancer? New Zealand Medical Journal, 130(1460), 90-92. Retrieved from https://www.nzma.org.nz/journal
Hock, B. D., McKenzie, J. L., & Keenan, J. I. (2017). Helicobacter pylori outer membrane vesicles inhibit human T cell responses via induction of monocyte COX-2 expression [Short communication]. Pathogens & Disease, 75(4), ftx034. doi: 10.1093/femspd/ftx034
Conference Contribution - Published proceedings: Abstract
Sharma, S., Heenan, P., Keenan, J., Willington, A., & Gearry, R. (2017). The association between smoking and belly pain in participants from the Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT). Proceedings of the New Zealand Society of Gastroenterology and the NZNO Gastroenterology Nurses' College Annual Scientific Meeting. 67. Retrieved from http://gastro2017.co.nz
Heenan, P., Sharma, S., Keenan, J., Willington, A., & Gearry, R. (2017). Anxiety and depression are associated with irritable bowel syndrome: Preliminary results from Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT) study. Proceedings of the New Zealand Society of Gastroenterology and the NZNO Gastroenterology Nurses' College Annual Scientific Meeting. 22. Retrieved from http://gastro2017.co.nz
2016
Journal - Research Article
Wakeman, C., Keenan, J., Eteuati, J., Hollington, P., Eglinton, T., & Frizelle, F. (2016). Chemoprevention of colorectal neoplasia. ANZ Journal of Surgery, 87(12), E228-E232. doi: 10.1111/ans.13392
Purcell, R. V., Pearson, J., Frizelle, F. A., & Keenan, J. I. (2016). Comparison of standard, quantitative and digital PCR in the detection of enterotoxigenic Bacteroides fragilis. Scientific Reports, 6, 34554. doi: 10.1038/srep34554
Keenan, J. I., Aitchison, A., Purcell, R. V., Greenlees, R., Pearson, J. F., & Frizelle, F. A. (2016). Screening for enterotoxigenic Bacteroides fragilis in stool samples. Anaerobe, 40, 50-53. doi: 10.1016/j.anaerobe.2016.05.004
Wright, E. K., Kamm, M. A., De Cruz, P., Hamilton, A. L., Ritchie, K. J., Keenan, J. I., … Burgess, L., Aitchison, A., … Day, A. S., & Gearry, R. B. (2016). Comparison of fecal inflammatory markers in Crohn's disease. Inflammatory Bowel Diseases, 22(5), 1086-1094. doi: 10.1097/mib.0000000000000671
Aitchison, A., Frizelle, F. A., & Keenan, J. I. (2016). PCR detection of the Bacteroides fragilis enterotoxin gene relies on robust primer design. Journal of Clinical Microbiology, 54(1), 239-240. doi: 10.1128/jcm.02785-15
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J. (2016, September). Bugs and bowel cancer. Verbal presentation at the Colorectal Surgical Society of Australia and New Zealand (CSSANZ) and the Colon & Rectal Surgery Section, Royal Australasian College of Surgeons (RACS) Spring Colorectal Meeting, Queenstown, New Zealand.
Purcell, R., Pearson, J., Keenan, J., Schmeier, S., & Frizelle, F. (2016, August-September). Bacterial dysbiosis and the development of colorectal cancer. Verbal presentation at the Queenstown Molecular Biology (QMB) Meetings, Nelson, New Zealand.
2015
Journal - Research Article
Flores, S. E., Day, A. S., & Keenan, J. I. (2015). Measurement of total iron in Helicobacter pylori-infected gastric epithelial cells. Biometals, 28, 143-150. doi: 10.1007/s10534-014-9810-z
Conference Contribution - Poster Presentation (not in published proceedings)
Hock, B. D., McKenzie, J. L., & Keenan, J. I. (2015, November). Helicobacter pylori outer membrane vesicles modulate human immune responses. Poster session presented at the 18th International Conference on Campylobacter, Helicobacter, and Related Organisms (CHRO), Rotorua, New Zealand.
2014
Journal - Research Article
Tyrer, P. C., Frizelle, F. A., & Keenan, J. I. (2014). Escherichia coli-derived outer membrane vesicles are genotoxic to human enterocyte-like cells. Infectious Agents & Cancer, 9, 2. doi: 10.1186/1750-9378-9-2
Keenan, J. I., Hooper, E. M., Tyrer, P. C., & Day, A. S. (2014). Influences of enteral nutrition upon CEACAM6 expression by intestinal epithelial cells. Innate Immunity, 20(8), 848-856. doi: 10.1177/1753425913513309
Meijer, B., Hoskin, T., Ashcroft, A., Burgess, L., Keenan, J. I., Falvey, J., Gearry, R. B., & Day, A. S. (2014). Total soluble and endogenous secretory receptor for advanced glycation endproducts (RAGE) in IBD. Journal of Crohn's & Colitis, 8(6), 513-520. doi: 10.1016/j.crohns.2013.11.004
Journal - Research Other
Keenan, J. I., & Frizelle, F. A. (2014). Bacteria flying under the radar: Linking a bacterial infection to colon carcinogenesis. Infectious Agents & Cancer, 9, 31. doi: 10.1186/1750-9378-9-31
Keenan, J. I., Leaman, J. D., Greenlees, R., & Day, A. S. (2014). Is Campylobacter consisus an unrecognised cause of diarrhoea in New Zealand? New Zealand Medical Journal, 127(1391). Retrieved from http://www.nzma.org.nz/journal
Conference Contribution - Published proceedings: Abstract
Keenan, J., Aitchison, A., Greenlees, R., & Frizelle, F. (2014). Are toxin-producing strains of Bacteroides fragilis involved in colorectal cancer? ANZ Journal of Surgery, 84(Suppl. 1), (pp. 36). doi: 10.1111/ans.12609
Wright, E. K., De Cruz, P., Kamm, M. A., Hamilton, A. L., Ritchie, K. J., Krejany, S., … Keenan, J. I., … Day, A. S., Gearry, R. B., & Desmond, P. V. (2014). Faecal calprotectin is superior to faecal lactoferrin and S100A12 as a surrogate marker for post-operative Crohn's disease endoscopic recurrence: Prospective longitudinal endoscopic validation: Results from the POCER Study. Gastroenterology, 146(5, Suppl. 1), (pp. S-174). doi: 10.1016/S0016-5085(14)60617-X
Conference Contribution - Poster Presentation (not in published proceedings)
Braun, J., Keenan, J., Schultz, M., & Butt, G. (2014, November). Polarization of Caco2 cells impedes uptake of outer membrane vesicles. Poster session presented at the New Zealand Society of Gastroenterology & New Zealand Nurses Organisation Gastroenterology Section Annual Scientific Meeting, Auckland, New Zealand.
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J., Aitchison, A., Greenlees, R., Pearson, J., & Frizelle, F. (2014, October). Are toxin-producing strains of Bacteroides fragilis involved in colorectal cancer? Verbal presentation at the New Zealand Society for Oncology (NZSO) Conference, Tauranga, New Zealand.
Keenan, J. (2014, August). The role of gut bacteria. Workshop presentation at the South General Practice Conference & Medical Exhibition (GP CME), Dunedin, New Zealand.
2013
Journal - Research Article
Keenan, J. I., Salm, N., Pearson, J. F., Gearry, R. B., & Day, A. S. (2013). Campylobacter seroreactivity in adults with recent onset of Crohn’s disease. Journal of Gastroenterology & Hepatology Research, 2(3), 468-472. doi: 10.6051/j.issn.2224-3992.2013.02.228
Journal - Research Other
Keenan, J. I., & Day, A. S. (2013). Risks for celiac disease: Bacteria make it three. Digestive Diseases & Sciences, 58(11), 3066-3067. doi: 10.1007/s10620-013-2839-y
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J. (2013, August). Gut bacteria and colorectal cancer. Verbal presentation at the National Rectal Cancer Summit, Wellington, New Zealand.
Keenan, J. (2013, February). Unravelling gastrointestinal disease. Verbal presentation at the Christchurch Medical School 40th Anniversary Celebrations, Christchurch, New Zealand.
2012
Journal - Research Article
Keown, D. A., Collings, D. A., & Keenan, J. I. (2012). Uptake and persistence of Mycobacterium avium subsp. paratuberculosis in human monocytes. Infection & Immunity, 80(11), 3768-3775. doi: 10.1128/iai.00534-12
Bentley, R. W., Keown, D. A., Gearry, R. B., Cameron, V. A., Keenan, J., Roberts, R. L., & Day, A. S. (2012). Vitamin D receptor polymorphisms in colorectal cancer in New Zealand: An association study. New Zealand Medical Journal, 125(1356). Retrieved from http://www.nzma.org.nz/journal
Keenan, J. I., Salm, N., Wallace, A. J., & Hampton, M. B. (2012). Using food to reduce H. pylori-associated inflammation. Phytotherapy Research, 26(11), 1620-1625. doi: 10.1002/ptr.4618
Coray, D. S., Heinemann, J. A., Tyrer, P. C., & Keenan, J. I. (2012). Human lactoferrin increases Helicobacter pylori internalisation into AGS cells. World Journal of Microbiology & Biotechnology, 28(5), 1871-1880. doi: 10.1007/s11274-011-0984-z
Parker, H., & Keenan, J. I. (2012). Composition and function of Helicobacter pylori outer membrane vesicles. Microbes & Infection, 14(1), 9-16. doi: 10.1016/j.micinf.2011.08.007
Journal - Professional & Other Non-Research Articles
Keenan, J. (2012). Laboratory mice: Are you getting more than you paid for? ANZCCART News, 25(2), 5-6.
Conference Contribution - Published proceedings: Abstract
Falvey, J. D., Munday, J. S., Keenan, J. I., Dyer, A. E., Gearry, R. B., & Hampton, M. B. (2012). Clinical assessment of murine Dextran Sodium Sulphate (DSS) colitis: Prospective validation of a novel scoring tool. New Zealand Medical Journal, 125(1367). Retrieved from http://www.nzma.org.nz/journal
Conference Contribution - Poster Presentation (not in published proceedings)
Keown, D. A., Collings, D. A., & Keenan, J. I. (2012, June). Mycobacterium avium subspecies paratuberculosis impairs phagosome trafficking in human monocytes. Poster session presented at the American Society for Microbiolgoy (ASM) 112th General Meeting, San Francisco, USA.
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J. (2012, May). Gut bacteria: A cause of cancer? Verbal presentation at the New Zealand Society for Oncology (NZSO) Conference, Wellington, New Zealand.
2011
Journal - Research Article
Glubb, D. M., Gearry, R. B., Barclay, M. L., Roberts, R. L., Pearson, J., Keenan, J. I., McKenzie, J., & Bentley, R. W. (2011). NOD2 and ATG16L1 polymorphisms affect monocyte responses in Crohn's disease. World Journal of Gastroenterology, 17(23), 2829-2837. doi: 10.3748/wjg.v17.i23.2829
Day, A. S., & Keenan, J. (2011). Probiotic-mediated modulation of host inflammation. Expert Review of Gastroenterology & Hepatology, 5(3), 319-321. doi: 10.1586/egh.11.34
Journal - Research Other
Keenan, J. I., Mitchell, H. M., & Day, A. S. (2011). Interactions between gastric and enteric infections: Clues to the pathogenesis of inflammatory bowel disease? [Viewpoint]. New Zealand Medical Journal, 124(1332). Retrieved from http://journal.nzma.org.nz/journal/124-1332/4606/content.pdf
Conference Contribution - Published proceedings: Abstract
Braun, J. H., Butt, A. G., Keenan, J. I., & Schultz, M. (2011). Outer membrane vesicles (OMV) from intestinal bacteria as means of communication: Comparison of the effects of OMV from three different Escherichia coli strains on intestinal epithelial cells in vitro. New Zealand Medical Journal, 124(1347). Retrieved from http://journal.nzma.org.nz/journal/124-1347/5015/content.pdf
Falvey, J. D., Munday, J. S., Keenan, J. I., Gearry, R. B., & Hampton, M. B. (2011). Assessing the efficacy of isothiocyanates in experimental colitis. New Zealand Medical Journal, 124(1347). Retrieved from http://journal.nzma.org.nz/journal/124-1347/5015/content.pdf
2010
Journal - Research Article
Parker, H., Chitcholtan, K., Hampton, M. B., & Keenan, J. I. (2010). Uptake of Helicobacter pylori outer membrane vesicles by gastric epithelial cells. Infection & Immunity, 78(12), 5054-5061. doi: 10.1128/IAI.00299-10
Keenan, J. I., Salm, N., Hampton, M. B., & Wallace, A. J. (2010). Individual and combined effects of foods on Helicobacter pylori growth. Phytotherapy Research, 24(8), 1229-1233. doi: 10.1002/ptr.3167
Keenan, J. I., Beaugie, C. R., Jasmann, B., Potter, H. C., Collett, J. A., & Frizelle, F. A. (2010). Helicobacter species in the human colon. Colorectal Disease, 12(1), 48-53. doi: 10.1111/j.1463-1318.2008.01672.x
2009
Journal - Research Article
Munday, J. S., Keenan, J. I., Beaugie, C. R., & Sugiarto, H. (2009). Ovine small intestinal adenocarcinomas are not associated with infection by herpesviruses, Helicobacter species or Mycobacterium avium subspecies paratuberculosis. Journal of Comparative Pathology, 140(2-3), 177-181. doi: 10.1016/j.jcpa.2008.11.005
2008
Journal - Research Article
Chitcholtan, K., Hampton, M. B., & Keenan, J. I. (2008). Outer membrane vesicles enhance the carcinogenic potential of Helicobacter pylori. Carcinogenesis, 29(12), 2400-2405. doi: 10.1093/carcin/bgn218
Piuhola, J., Kerkelä, R., Keenan, J. I., Hampton, M. B., Richards, A. M., & Pemberton, C. J. (2008). Direct cardiac actions of erythropoietin (EPO): Effects on cardiac contractility, BNP secretion and ischaemia/reperfusion injury. Clinical Science, 114(4), 293-304. doi: 10.1042/CS20070229
Bentley, R. W., Keenan, J. I., Gearry, R. B., Kennedy, M. A., Barclay, M. L., & Roberts, R. L. (2008). Incidence of Mycobacterium avium subspecies paratuberculosis in a population-based cohort of patients with Crohn's disease and control subjects. American Journal of Gastroenterology, 103(5), 1168-1172. doi: 10.1111/j.1572-0241.2007.01742.x
Keenan, J. I., Davis, K. A., Beaugie, C. R., McGovern, J. J., & Moran, A. P. (2008). Alterations in Helicobacter pylori outer membrane and outer membrane vesicle-associated lipopolysaccharides under iron-limiting growth conditions. Innate Immunity, 14(5), 279-290. doi: 10.1177/1753425908096857
Conference Contribution - Published proceedings: Abstract
Chitcholtan, K., Hampton, M., & Keenan, J. (2008). Outer membrane vesicles (OMVs) of Helicobacter pylori alter cellular signalling pathways in human gastric epithelial cells. New Zealand Medical Journal, 121(1271). Retrieved from http://journal.nzma.org.nz/journal/121-1271/2990/content.pdf
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J., Stebbings, S., Bentley, R., Roberts, R., Lindstroem, A., Woods, P., Duncan, A., … and others. (2008, November). 2nd Workshop on Intestinal Permeability. Verbal presentation at the Satellite Symposium, Medical Sciences Congress, Queenstown, New Zealand.
Piuhola, J., Kerkelä, R., Keenan, J. I., Hampton, M. B., Richards, A. M., & Pemberton, C. (2008, November). Direct cardiac actions of erythropoietin (EPO): Effects on cardiac contractility, BNP secretion and ischemia-reperfusion injury. Verbal presentation at the Medical Sciences Congress, Queenstown, New Zealand.
Bentley, R., Glubb, D. M., Keenan, J. I., Gearry, R. B., Barclay, M. L., & Roberts, R. L. (2008, November). Mycobacterium Avium subsp. Paratuberculosis associated with Crohn's disease in New Zealand. Verbal presentation at the Medical Sciences Congress, Queenstown, New Zealand.
Keenan, J. (2008, November). Bacterial outer membrane vesicles. Verbal presentation at the Medical Sciences Congress, Queenstown, New Zealand.
2007
Conference Contribution - Published proceedings: Abstract
Bentley, R. W., Gearry, R. B., Keenan, J. I., Aitken, J. M., Kennedy, M. A., Barclay, M. L., & Roberts, R. L. (2007). Relative incidence of Mycobacterium avium subsp. paratuberculosis in a population-based cohort of Crohn's disease patients. Gut. 56(Suppl. III), (pp. A127). [Abstract]
Bentley, R. W., Gearry, R. B., Keenan, J. I., Aitken, J. M., Kennedy, M. A., Barclay, M. L., & Roberts, R. L. (2007). Relative incidence of Mycobacterium avium subsp. paratuberculosis in a population-based cohort of Crohn's disease patients. Journal of Gastroenterology and Hepatology. 22(Suppl. 3), (pp. A317). [Abstract]
Chitcholtan, K., Hampton, M., & Keenan, J. (2007). H. pylori outer membrane vesicles induce DNA damage in gastric epithelial cells. Zoonoses and Public Health. 54(Suppl. 1), (pp. 155). [Abstract]
Salm, N., Hampton, M., Wallace, A. J., & Keenan, J. (2007). Broccoli sprouts inhibit the release of interleukin-8 from AGS cells co-cultured with Helicobacter pylori. Zoonoses and Public Health. 54(Suppl. 1), (pp. 97-98). [Abstract]
Davis, K. A., Chitcholtan, K., Hampton, M., & Keenan, J. I. (2007). Helicobacter pylori outer membrane vesicles induce cytoskeletal rearrangements and cell signaling events in gastric epithelial cells. Zoonoses and Public Health. 54(Suppl. 1), (pp. 151). [Abstract]
Conference Contribution - Verbal presentation and other Conference outputs
Bentley, R. W., Roberts, R. L., Gearry, R. B., Keenan, J. I., Kennedy, M. A., & Barclay, M. L. (2007, November). Relative incidence of Mycobacterium avium subsp. paratuberculosis in a New Zealand population-based cohort of patients with Crohn's disease. Verbal presentation at the New Zealand Society of Gastroenterology & NZNO Gastroenterology Nurses Section Annual Scientific Meeting combined with the RACP and IMSANZ, Christchurch, New Zealand.
2006
Journal - Research Article
Mandhan, P., Qi, B. Q., Keenan, J. I., Ismail, S., Beasley, S. W., & Sullivan, M. J. (2006). Counterstaining improves visualization of the myenteric plexus in immunolabelled whole-mount preparations. Journal of Fluorescence, 16, 655-658.
2005
Journal - Research Article
Keenan, J. I., Peterson, II, R. A., & Hampton, M. B. (2005). NADPH oxidase involvement in the pathology of Helicobacter pylori infection. Free Radical Biology & Medicine, 38, 1188-1196.
Hynes, S. O., Keenan, J. I., Ferris, J. A., Annuk, H., & Moran, A. P. (2005). Lewis epitopes on outer membrane vesicles of relevance to Helicobacter pylori pathogenesis. Helicobacter, 10(2), 146-156.
Journal - Research Other
Gearry, R. B., Aitken, J. M., Roberts, R. L., Ismail, S. L., Keenan, J., & Barclay, M. L. (2005). Gastrointestinal: Mycobacterium avium paratuberculosis and Crohn's disease. Journal of Gastroenterology & Hepatology, 20(12), 1943. doi: 10.1111/j.1440-1746.2005.04187.x
Conference Contribution - Published proceedings: Abstract
Ismail, S., Jasmann, B., Potter, H., & Keenan, J. (2005). Extragastric Helicobacter species in patients presenting for colonoscopy. In V. Korolik, A. Lee, H. Mitchell, G. Mendz, B. Fry & P. Coloe (Eds.), Proceedings of the 13th International Workshop on Campylobacter, Helicobacter and Related Organisms. (pp. 58). [Abstract]
Parker, H., Ismail, S., Neal, S., Hampton, M., & Keenan, J. (2005). Association of Helicobacter pylori outer membrane vesicles with gastric epithelial cells. In V. Korolik, A. Lee, H. Mitchell, G. Mendz, B. Fry & P. Coloe (Eds.), Proceedings of the 13th International Workshop on Campylobacter, Helicobacter and Related Organisms. (pp. 72). [Abstract]
Conference Contribution - Verbal presentation and other Conference outputs
Keenan, J., Peterson, R., Ismail, S., Hock, B., Frampton, C., & Hampton, M. (2005, September). Host iron deficiency alters the outcome of infection in Helicobacter pylori-infected mice. Verbal presentation at the 13th International Workshop on Campylobacter, Helicobacter and Related Organisms, Gold Coast, Australia.
2004
Journal - Research Article
Keenan, J. I., Peterson, R. A., Fraser, R., Frampton, C. M., Walmsley, T. A., Allardyce, R. A., & Roake, J. A. (2004). The effect of Helicobacter pylori infection and dietary iron deficiency on host iron homeostasis: A study in mice. Helicobacter, 9(6), 643-650.
Arsic, D., Cameron, V., Ellmers, L., Quan, Q. B., Keenan, J., & Beasley, S. (2004). Adriamycin disruption of the Shh-Gli pathway is associated with abnormalities of foregut development. Journal of Pediatric Surgery, 39(12), 1747-1753.
Bland, M. V., Ismail, S., Heinemann, J. A., & Keenan, J. I. (2004). The action of bismuth against Helicobacter pylori mimics but is not caused by intracellular iron deprivation. Antimicrobial Agents & Chemotherapy, 48(6), 1983-1988.
Conference Contribution - Published proceedings: Abstract
Keenan, J. I., Peterson, R. A., & Hampton, M. B. (2004). Role of neutrophil oxidants in the gastric pathology associated with Helicobacter pylori infection. Helicobacter. 9(5), (pp. 591-592). [Abstract]
Keenan, J. I., Ismail, S., McGovern, J. J., & Moran, A. P. (2004). Iron availability influences lipopolysaccharide expression on Helicobacter pylori bacteria and outer membrane vesicles. Helicobacter. 9(5), (pp. 500). [Abstract]
Mandhan, P. L., Beasley, S. W., Quan, Q. B., Keenan, J., Ismail, S., & Sullivan, M. (2004). Counterstaining improves visualization of the myenteric plexus in immunolabelled whole-mount preparations. Australian & New Zealand Journal of Surgery, 74(Suppl.), (pp. A87-A88). [Abstract]
2003
Journal - Research Article
Arsic, D., Keenan, J. I., Quan, Q., & Beasley, S. W. (2003). Differences in the levels of Sonic hedgehog protein during early foregut development caused by exposure to Adriamycin give clues to the role of the Shh gene in oesophageal atresia. Pediatric Surgery International, 19, 463-466.
Keenan, J. I., Rijpkema, S., Durrani, Z., & Roake, J. A. (2003). Differences in immunogenicity and protection in mice and guinea pigs following intranasal immunization with Helicoba pylori outer membrane antigens. FEMS Immunology & Medical Microbiology, 36(3), 199-205.
Ismail, S., Hampton, M. B., & Keenan, J. I. (2003). Helicobacter pylori outer membrane vesicles modulate proliferation and interleukin-8 production by gastric epithelial cells. Infection & Immunity, 71(10), 5670-5675.
Journal - Professional & Other Non-Research Articles
Keenan, J., Neal, S., & Gearry, R. B. (2003). Non-pylori Helicobacter [Medical image]. New Zealand Medical Journal, 116(1179). Retrieved from http://journal.nzma.org.nz/journal/116-1179/546/content.pdf
Conference Contribution - Published proceedings: Abstract
Ismail, S., Parker, H., Hampton, M. B., & Keenan, J. I. (2003). Helicobacter pylori outer membrane vesicles modulate proliferation and IL-8 production by gastric epithelial cells. International Journal of Medical Microbiology, 293(Suppl. 35), (pp. 116). [Abstract]
Conference Contribution - Verbal presentation and other Conference outputs
Beasley, S. W., Arsic, D., Keenan, J. I., & Quan, Q. (2003, May). Disruption of Shh Gli signalling pathway associated with abnormal foregut development. Verbal presentation at the 36th Annual Meeting of the Pacific Association of Pediatri Surgeons with Australasian Association of Paediatric Surgeons, Australia.
2002
Journal - Research Article
Keenan, J. I., Neal, S., Allardyce, R. A., & Roake, J. A. (2002). Serum-derived IgG1-mediated immune exclusion as a mechanism of protection against H.pylori infection. Vaccine, 20, 2981-2988.
Hampton, M. B., Vissers, M. C., Keenan, J. I., & Winterbourn, C. C. (2002). Oxidant-mediated phosphatidylserine exposure and macrophage uptake of activated neutrophils: possible impairment in chronic granulomatous disease. Journal of Leukocyte Biology, 71(5), 775-781.
Conference Contribution - Published proceedings: Abstract
Arsic, D., Keenan, J. I., Beasley, S. W., & Qi, B.-Q. (2002). Expression of SHH protein in the rat foregut varies according to the embryological stage. Australian and New Zealand Journal of Surgery. 72(Suppl.), (pp. A76). [Abstract]
2001
Conference Contribution - Published proceedings: Abstract
Keenan, J. I., Fraser, R., Allardyce, R. A., & Roake, J. A. (2001). H. pylori infection, iron deficiency and disease expression in mice. International Journal of Medical Microbiology. 291(Suppl.31), (pp. 134). [Abstract]
Keenan, J. I., Rijpkema, S., Durrani, Z., & Roake, J. A. (2001). Differences in immunogenicity and protection in mice and guinea pigs following intra-nasal immunization with rLpp20. International Journal of Medical Microbiology. 291(Suppl.31), (pp. 156). [Abstract]
2000
Journal - Research Article
Keenan, J., Oliaro, J., Domigan, N., Potter, H., Aitken, G., Allardyce, R., & Roake, J. (2000). Immune response to an 18-kilodalton outer membrane antigen identifies lipoprotein 20 as a Helicobacter pylori vaccine candidate. Infection & Immunity, 68(6), 3337-3343. doi: 10.1128/IAI.68.6.3337-3343.2000
Keenan, J. I., & Allardyce, R. A. (2000). Iron influences the expression of Helicobacter pylori outer membrane vesicle-associated virulence factors. European Journal of Gastroenterology & Hepatology, 12, 1-7.
Keenan, J. I., Day, T., Neal, S., Cook, B., Perez-Perez, G., Allardyce, R. A., & Bagshaw, P. F. (2000). A role for the bacterial outer membrane in the pathogenesis of Helicobacter pylori infection. FEMS Microbiology Letters, 182, 259-264.
Conference Contribution - Published proceedings: Abstract
Keenan, J. I., Hampton, M. B., & Allardyce, R. A. (2000). H. pylori proteases and the develpoment of gastric cancer. Gut. 47(Suppl. 1), (pp. A27). [Abstract]
Keenan, J. I., & Allardyce, R. A. (2000). IgG1-mediated immune exclusion of H. pylori in vivo. Gut. 47(Suppl. 1), (pp. A61). [Abstract]
1999
Conference Contribution - Published proceedings: Abstract
Keenan, J. I., & Allardyce, R. A. (1999). Iron levels during growth influence the expression of H. pylori virulence factors. 10th International Workshop on Campylobacter, Helicobacter & Related Organisms. HP36, (pp. 154). [Abstract]
1998
Journal - Research Article
Keenan, J. I., Allardyce, R. A., & Bagshaw, P. F. (1998). Lack of protection following immunisation with H-pylori outer membrane vesicles highlights antigenic differences between H-felis and H-pylori. FEMS Microbiology Letters, 161(1), 21-27.
1997
Journal - Research Article
Allardyce, R. A., Chapman, B. A., Tie, A. B., Burt, M. J., Yeo, K. J., Keenan, J. I., & Bagshaw, P. F. (1997). 37 kBq 14C-urea breath test and gastric biopsy analysis of H. pylori infection. Australian & New Zealand Journal of Surgery, 67(1), 31-34. doi: 10.1111/j.1445-2197.1997.tb01890.x
Keenan, J. I., Allardyce, R. A., & Bagshaw, P. F. (1997). Dual silver staining to characterise helicobacter spp. outer membrane components. Journal of Immunological Methods, 209(1), 17-24.
Conference Contribution - Published proceedings: Abstract
Keenan, J. I., Allardyce, R. A., & Bagshaw, P. F. (1997). Identification of a novel H. pylori vaccine candidate. Gut. 41, (pp. 61). [Abstract]
Keenan, J. I., Allardyce, R. A., & Bagshaw, P. F. (1997). A role for the bacterial outer membrane in the pathogenesis of H. pylori infection. Gut. 41, (pp. 18). [Abstract]
1995
Journal - Research Article
Allardyce, R. A., Bagshaw, P. F., & Keenan, J. I. (1995). The outcome of Helicobacter pylori infection. British Journal of Hospital Medicine, 54, 372-377.