The authors would like to thank Ms. A. De Paoli and Ms. Georgie Wray-McCann for technical assistance. The authors acknowledge use of the facilities and technical assistance of Monash Histology Platform, Department of Anatomy and Developmental Biology, Monash University. The laboratory is supported by funding from the National Health and Medical Research Council (NHMRC) to RLF (APP1079930, APP1107930). RLF is supported by a Senior Research Fellowship from the NHMRC (APP1079904). KD and MC are both supported by Monash Graduate Scholarships. KD is also supported by the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, while MC has an International Postgraduate Scholarship from the Faculty of Medicine, Nursing and Health Sciences, Monash University. Research at the Hudson Institute of Medical Research is supported by the Victorian Government&#8217;s Operational Infrastructure Support Program.

<ol>
	<li>Goh, K. L., Chan, W. K., Shiota, S., Yamaoka, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+Helicobacter+pylori+infection+and+public+health+implications.">Epidemiology of Helicobacter pylori infection and public health implications.</a> Helicobacter. 16, 1-9 (2011).</li><li>Montecucco, C., Rappuoli, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Living+dangerously:+how+Helicobacter+pylori+survives+in+the+human+stomach.">Living dangerously: how Helicobacter pylori survives in the human stomach.</a> Nature Reviews Molecular Cell Biology. 2 (6), 457-466 (2001).</li><li>Akopyants, N. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analyses+of+the+cag+pathogenicity+island+of+Helicobacter+pylori.">Analyses of the cag pathogenicity island of Helicobacter pylori.</a> Molecular Microbiology. 28 (1), 37-53 (1998).</li><li>Censini, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=cag,+a+pathogenicity+island+of+Helicobacter+pylori,+encodes+type+I-specific+and+disease-associated+virulence+factors.">cag, a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factors.</a> Proceedings of the National Academy of Sciences of the United States of America. 93 (25), 14648-14653 (1996).</li><li>Peek, R. M., Fiske, C., Wilson, K. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+innate+immunity+in+Helicobacter+pylori-induced+gastric+malignancy.">Role of innate immunity in Helicobacter pylori-induced gastric malignancy.</a> Physiological Reviews. 90 (3), 831-858 (2010).</li><li>O'Rourke, J. L., Lee, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+Helicobacter+pylori+infection+and+disease.">Animal models of Helicobacter pylori infection and disease.</a> Microbes and Infection. 5 (8), 741-748 (2003).</li><li>Sakagami, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atrophic+gastric+changes+in+both+Helicobacter+felis+and+Helicobacter+pylori+infected+mice+are+host+dependent+and+separate+from+antral+gastritis.">Atrophic gastric changes in both Helicobacter felis and Helicobacter pylori infected mice are host dependent and separate from antral gastritis.</a> Gut. 39 (5), 639-648 (1996).</li><li>Correa, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helicobacter+pylori+and+gastric+carcinogenesis.">Helicobacter pylori and gastric carcinogenesis.</a> The American Journal of Surgical Pathology. 19, S37-S43 (1995).</li><li>Enno, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MALToma-like+lesions+in+the+murine+gastric+mucosa+after+long-term+infection+with+Helicobacter+felis.+A+mouse+model+of+Helicobacter+pylori-induced+gastric+lymphoma.">MALToma-like lesions in the murine gastric mucosa after long-term infection with Helicobacter felis. A mouse model of Helicobacter pylori-induced gastric lymphoma.</a> The American Journal of Pathology. 147 (1), 217-222 (1995).</li><li>Lee, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+standardized+mouse+model+of+Helicobacter+pylori+infection:+introducing+the+Sydney+strain.">A standardized mouse model of Helicobacter pylori infection: introducing the Sydney strain.</a> Gastroenterology. 112 (4), 1386-1397 (1997).</li><li>Crabtree, J. E., Ferrero, R. L., Kusters, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mouse+colonizing+Helicobacter+pylori+strain+SS1+may+lack+a+functional+cag+pathogenicity+island.">The mouse colonizing Helicobacter pylori strain SS1 may lack a functional cag pathogenicity island.</a> Helicobacter. 7 (2), 139-140 (2002).</li><li>Israel, D. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helicobacter+pylori+strain-specific+differences+in+genetic+content,+identified+by+microarray,+influence+host+inflammatory+responses.">Helicobacter pylori strain-specific differences in genetic content, identified by microarray, influence host inflammatory responses.</a> Journal of Clinical Investigation. 107 (5), 611-620 (2001).</li><li>Fox, J. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helicobacter+pylori-induced+gastritis+in+the+domestic+cat.">Helicobacter pylori-induced gastritis in the domestic cat.</a> Infection and Immunity. 63 (7), 2674-2681 (1995).</li><li>Lee, A., Hazell, S. L., O'Rourke, J., Kouprach, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+a+spiral-shaped+bacterium+from+the+cat+stomach.">Isolation of a spiral-shaped bacterium from the cat stomach.</a> Infection and Immunity. 56 (11), 2843-2850 (1988).</li><li>Ferrero, R. L., Wilson, J. E., Sutton, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+Helicobacter-induced+gastric+cancer:+use+of+cocarcinogens.">Mouse models of Helicobacter-induced gastric cancer: use of cocarcinogens.</a> Methods in Molecular Biology. 921, 157-173 (2012).</li><li>Ferrero, R. L., Thiberge, J. M., Huerre, M., Labigne, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+responses+of+specific-pathogen-free+mice+to+chronic+Helicobacter+pylori+(strain+SS1)+infection.">Immune responses of specific-pathogen-free mice to chronic Helicobacter pylori (strain SS1) infection.</a> Infection and Immunity. 66 (4), 1349-1355 (1998).</li><li>Blanchard, T. G., Nedrud, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laboratory+maintenance+of+Helicobacter+species.">Laboratory maintenance of Helicobacter species.</a> Current Protocols in Microbiology. , (2012).</li><li>Kim, J. S., Chang, J. H., Chung, S. I., Yum, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Importance+of+the+host+genetic+background+on+immune+responses+to+Helicobacter+pylori+infection+and+therapeutic+vaccine+efficacy.">Importance of the host genetic background on immune responses to Helicobacter pylori infection and therapeutic vaccine efficacy.</a> FEMS Immunology and Medical Microbiology. 31 (1), 41-46 (2001).</li><li>Nedrud, J. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lack+of+genetic+influence+on+the+innate+inflammatory+response+to+helicobacter+infection+of+the+gastric+mucosa.">Lack of genetic influence on the innate inflammatory response to helicobacter infection of the gastric mucosa.</a> Frontiers in Immunology. 3, 181 (2012).</li><li>Cai, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helicobacter+felis+eradication+restores+normal+architecture+and+inhibits+gastric+cancer+progression+in+C57BL/6+mice.">Helicobacter felis eradication restores normal architecture and inhibits gastric cancer progression in C57BL/6 mice.</a> Gastroenterology. 128 (7), 1937-1952 (2005).</li><li>Ferrero, R. L., Labigne, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning,+expression+and+sequencing+of+Helicobacter+felis+urease+genes.">Cloning, expression and sequencing of Helicobacter felis urease genes.</a> Molecular Microbiology. 9 (2), 323-333 (1993).</li><li>Stevenson, T. H., Castillo, A., Lucia, L. M., Acuff, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+Helicobacter+pylori+in+various+liquid+and+plating+media.">Growth of Helicobacter pylori in various liquid and plating media.</a> Letters in Applied Microbiology. 30 (3), 192-196 (2000).</li><li>Uotani, T., Graham, D. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnosis+of+Helicobacter+pylori+using+the+rapid+urease+test.">Diagnosis of Helicobacter pylori using the rapid urease test.</a> Annals of Translational Medicine. 3 (1), 9 (2015).</li><li>Riley, L. K., Franklin, C. L., Hook, R. R., Besch-Williford, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+murine+helicobacters+by+PCR+and+restriction+enzyme+analyses.">Identification of murine helicobacters by PCR and restriction enzyme analyses.</a> Journal of Clinical Microbiology. 34 (4), 942-946 (1996).</li><li>Chaouche-Drider, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+commensal+Helicobacter+sp.+of+the+rodent+intestinal+flora+activates+TLR2+and+NOD1+responses+in+epithelial+cells.">A commensal Helicobacter sp. of the rodent intestinal flora activates TLR2 and NOD1 responses in epithelial cells.</a> PLoS One. 4 (4), e5396 (2009).</li><li>Fox, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helicobacter+bilis:+bacterial+provocateur+orchestrates+host+immune+responses+to+commensal+flora+in+a+model+of+inflammatory+bowel+disease.">Helicobacter bilis: bacterial provocateur orchestrates host immune responses to commensal flora in a model of inflammatory bowel disease.</a> Gut. 56 (7), 898-900 (2007).</li><li>McGee, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholesterol+enhances+Helicobacter+pylori+resistance+to+antibiotics+and+LL-37.">Cholesterol enhances Helicobacter pylori resistance to antibiotics and LL-37.</a> Antimicrobial Agents and Chemotherapy. 55 (6), 2897-2904 (2011).</li><li>Viala, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nod1+responds+to+peptidoglycan+delivered+by+the+Helicobacter+pylori+cag+pathogenicity+island.">Nod1 responds to peptidoglycan delivered by the Helicobacter pylori cag pathogenicity island.</a> Nature Immunology. 5 (11), 1166-1174 (2004).</li><li>Kong, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+sensitive+and+specific+PCR+method+to+detect+Helicobacter+felis+in+a+conventional+mouse+model.">A sensitive and specific PCR method to detect Helicobacter felis in a conventional mouse model.</a> Clinical and Vaccine Immunology. 3 (1), 73-78 (1996).</li><li>Ng, G., Every, A., McGuckin, M., Sutton, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+Helicobacter+felis+colonization+in+male+129/Sv+mice+fails+to+suppress+gastritis.">Increased Helicobacter felis colonization in male 129/Sv mice fails to suppress gastritis.</a> Gut Microbes. 2 (6), 358-360 (2011).</li><li>Ferrero, R. L., Ave, P., Radcliff, F. J., Labigne, A., Huerre, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outbred+mice+with+long-term+Helicobacter+felis+infection+develop+both+gastric+lymphoid+tissue+and+glandular+hyperplastic+lesions.">Outbred mice with long-term Helicobacter felis infection develop both gastric lymphoid tissue and glandular hyperplastic lesions.</a> The Journal of Pathology. 191 (3), 333-340 (2000).</li></ol>

The authors have nothing to disclose.

This protocol describes the use of an in vivo mouse model for Helicobacter infection. The critical steps of the procedure are the: 1) preparation of Helicobacter inocula containing viable and motile bacteria; 2) delivery of the appropriate numbers of bacteria to the mouse via intragastric gavage; 3) detection of bacterial infection by colony counting and/or PCR; and 4) processing of gastric tissues to enable the assessment of histopathology in infected stomachs. Further suggestions for modifica...

Helicobacter pylori is a spiral-shaped, Gram-negative, human gastric pathogen present in all populations across the world, with infection rates in developing countries estimated to be in the order of 80%1. Although most H. pylori-infected individuals are asymptomatic, some develop more severe diseases, ranging from peptic ulceration to gastric cancer2. H. pylori-associated cancers are broadly characterized either by malignant changes in epithelial cells (GECs) or by the formation of extra-nodal lymphoid tissues in the stomach, resulting in gastric adenocarcinoma or mucosa-associated lymphoid tissue (MALT) lymphoma, respectively. H. pylori is highly adapted to survive in the harsh ecological niche of the stomach due to the presence of various virulence factors and mechanisms facilitating its adherence, growth and metabolism in this niche. In particular, virulent strains of H. pylori possess the 40 kb cag Pathogenicity Island (cagPAI) that encodes approximately 30 genes required for the production of a Type 4 secretion system (T4SS)3,4. cagPAI-positive H. pylori strains are associated with the induction of higher levels of chronic inflammation in the host, which has been implicated as an essential precursor of gastric adenocarcinoma5.
In vivo animal models, particularly mice, have been highly informative by allowing researchers to investigate the relative contributions of host, bacterial and environmental factors on H. pylori infection and disease outcome6. Studies have previously demonstrated that prolonged H. pylori infection of mice on the C57BL/6 genetic background results in the development of chronic gastritis and gland atrophy, both hallmarks of H. pylori infection7. Furthermore, infection with the related feline/canine bacterial species, H. felis, has been shown to induce MALT formation in mice with similar pathology and disease progression as seen in human MALT lymphoma8,9. The most commonly used H. pylori isolate in mouse colonization studies is the &#8220;Sydney Strain 1&#8221; (SS1) strain10, which is cagPAI+ but has a non-functional T4SS (T4SS&#8722;)11. Other widely used strains include H. pylori B128 7.13 (cagPAI+/T4SS+)12 and X47-2AL (cagPAI-/T4SS&#8722;)13. For H. felis infections, the strain CS1 (&#8220;Cat Spiral 1&#8221;, cagPAI-/T4SS&#8722;) is generally used14.
Herein, we provide a protocol describing the preparation of Helicobacter inocula for in vivo infection, the procedure for intragastric gavage of mice, as well as methods for the processing of tissues for the study of histopathological changes in the stomach. In particular, this article will focus on the histological methods used to visualize bacterial colonization and assess histopathological changes, including MALT formation, in the gastric mucosa of infected mice. Some of the methods described here may be adapted to the study of other gut pathogens such as S. Typhimurium or C. rodentium.

<table>
	<tbody>
		<tr>
			<td>Bacteriological reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Oxoid Blood Agar Base No.2</td>
			<td>Thermo Fischer Scientific</td>
			<td>CM0271B</td>
			<td>Dissolve in deinonized water prior to sterilization</td>
		</tr>
		<tr>
			<td>Premium Defibrinated Horse blood</td>
			<td>Australian Ethical Biologicals</td>
			<td>PDHB100</td>
			<td></td>
		</tr>
		<tr>
			<td>Bacto Brain Heart Infusion Broth</td>
			<td>BD Bioscience</td>
			<td>237500</td>
			<td>Dissolve in deinonized water prior to sterilization</td>
		</tr>
		<tr>
			<td>CampyGen gas packs</td>
			<td>Thermo Fischer Scientific</td>
			<td>CN0035A/CN0025A</td>
			<td></td>
		</tr>
		<tr>
			<td>Histological reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Formalin, neutral buffered, 10%</td>
			<td>Sigma Aldrich</td>
			<td>HT501128</td>
			<td></td>
		</tr>
		<tr>
			<td>Absolute alcohol, 100% Denatured</td>
			<td>ChemSupply</td>
			<td>AL048-20L-P</td>
			<td></td>
		</tr>
		<tr>
			<td>Isopropanol (2-propanol)</td>
			<td>Merck</td>
			<td>100995</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene (sulphur free)</td>
			<td>ChemSupply</td>
			<td>XT003-20L</td>
			<td></td>
		</tr>
		<tr>
			<td>Mayer&#39;s Haematoxylin</td>
			<td>Amber Scientific</td>
			<td>&#160;MH-1L</td>
			<td>Filter before use</td>
		</tr>
		<tr>
			<td>Eosin, Aqueous Stain</td>
			<td>Amber Scientific</td>
			<td>EOCA-1L</td>
			<td>Filter before use</td>
		</tr>
		<tr>
			<td>Wright-Giemsa Stain, modified</td>
			<td>Sigma Aldrich</td>
			<td>WG80-2.5L</td>
			<td>Dilute before use (20% Giemsa, 80% deionized water)</td>
		</tr>
		<tr>
			<td>Histolene</td>
			<td>Grale Scientific</td>
			<td>11031/5</td>
			<td></td>
		</tr>
		<tr>
			<td>DPX mounting medium</td>
			<td>VWR</td>
			<td>1.00579.0500</td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular biology reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit dsDNA BR Assay Kit</td>
			<td>Thermo Fischer Scientific</td>
			<td>Q32850</td>
			<td></td>
		</tr>
		<tr>
			<td>Oligonucleotides</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td>The annealing temperature of ureB primers used in this study is 61&#176;C</td>
		</tr>
		<tr>
			<td>GoTaq Flexi DNA Polymerase</td>
			<td>Promega</td>
			<td>&#160;M8291</td>
			<td>Kit includes 10X PCR buffer and Magnesium Chloride</td>
		</tr>
		<tr>
			<td>dNTPs</td>
			<td>Bioline</td>
			<td>BIO-39028</td>
			<td>Dilute to 10mM in sterile nuclease free water before use</td>
		</tr>
		<tr>
			<td>Molecular Grade Agarose</td>
			<td>Bioline</td>
			<td>BIO-41025</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Hydrogen Carbonate</td>
			<td>Univar (Ajax Fine Chemicals)</td>
			<td>A475-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium Sulphate Heptahydrate</td>
			<td>Chem-Supply</td>
			<td>MA048-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Antibiotics</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vancomycin</td>
			<td>Sigma Aldrich</td>
			<td>V2002-1G</td>
			<td>Dissolve in deionized water</td>
		</tr>
		<tr>
			<td>Polymyxin B</td>
			<td>Sigma Aldrich</td>
			<td>P4932-5MU</td>
			<td>Dissolve in deionized water</td>
		</tr>
		<tr>
			<td>Trimethoprim (&#8805;98% HPLC)</td>
			<td>Sigma Aldrich</td>
			<td>T7883</td>
			<td>Dissolve in 100% (absolute) Ethanol</td>
		</tr>
		<tr>
			<td>Amphotericin</td>
			<td>Amresco (Astral Scientific)</td>
			<td>E437-100MG</td>
			<td>Dissolve in deionized water</td>
		</tr>
		<tr>
			<td>Bacitracin from Bacillus licheniformis</td>
			<td>Sigma Aldrich</td>
			<td>B0125</td>
			<td>Dissolve in deionized water</td>
		</tr>
		<tr>
			<td>Naladixic acid</td>
			<td>Sigma Aldrich</td>
			<td>N8878</td>
			<td>Dissolve in deionized water</td>
		</tr>
		<tr>
			<td>Other reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Methoxyflurane (Pentrhox)</td>
			<td>Medical Developments International</td>
			<td>Not applicable</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraffin Wax</td>
			<td>Paraplast Plus, Leica Biosystems</td>
			<td>39601006</td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment and plasticware</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Oxoid Anaerobic Jars</td>
			<td>Thermo Fischer Scientific</td>
			<td>HP0011/HP0031</td>
			<td></td>
		</tr>
		<tr>
			<td>COPAN Pasteur Pipettes</td>
			<td>Interpath Services</td>
			<td>200CS01</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf 5810R centrifuge</td>
			<td></td>
			<td></td>
			<td>Collect bacterial pellets by centrifugation at 2,200 rpm for 10 mins at 4&#176;C</td>
		</tr>
		<tr>
			<td>23g precision glide needle</td>
			<td>BD Bioscience</td>
			<td>301805</td>
			<td></td>
		</tr>
		<tr>
			<td>Parafilm M</td>
			<td>Bemis, VWR</td>
			<td>PM996</td>
			<td></td>
		</tr>
		<tr>
			<td>Portex fine bore polythene tubing</td>
			<td>Smiths Medical</td>
			<td>800/100/200</td>
			<td></td>
		</tr>
		<tr>
			<td>Plastic feeding catheters</td>
			<td>Instech&#160; Laboratories</td>
			<td>FTP20-30</td>
			<td></td>
		</tr>
		<tr>
			<td>1 ml tuberculin luer slip disposable syringes</td>
			<td>BD Bioscience</td>
			<td>302100</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf micropestle for 1.2 - 2 mL tubes</td>
			<td>Sigma Aldrich</td>
			<td>Z317314</td>
			<td>Autoclavable polypropylene pestles used for stomach homogenization</td>
		</tr>
		<tr>
			<td>GentleMACs Dissociator</td>
			<td>Miltenyi Biotec</td>
			<td>130-093-235</td>
			<td>Use a pre-set gentleMACS Programs for mouse stomach tissue</td>
		</tr>
		<tr>
			<td>M Tubes (orange cap)</td>
			<td>Miltenyi Biotec</td>
			<td>30-093-236</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Qubit Fluorometer</td>
			<td>Thermo Fischer Scientific</td>
			<td>Q33216</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile plastic loop</td>
			<td>LabServ</td>
			<td>LBSLP7202</td>
			<td></td>
		</tr>
		<tr>
			<td>Cold Plate, Leica EG1160 Embedding System</td>
			<td>Leica Biosystems</td>
			<td>Not applicable</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue-Tek Base Mould System, Base Mold 38 x 25 x 6</td>
			<td>Sakura, Alphen aan den Rijn</td>
			<td>4124</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue-Tek III Uni-Casette System</td>
			<td>Sakura, Alphen aan den Rijn</td>
			<td>4170</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome, Leica RM2235</td>
			<td>Leica Biosystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Charged SuperFrost Plus glass slides</td>
			<td>Menzel Glaser, Thermo Fischer Scientific</td>
			<td>4951PLUS4</td>
			<td></td>
		</tr>
	</tbody>
</table>

mouse models of helicobacter infection and gastric pathologies

Helicobacter pylori is a gastric pathogen that is present in half of the global population and is a significant cause of morbidity and mortality in humans. Several mouse models of gastric Helicobacter infection have been developed to study the molecular and cellular mechanisms whereby H. pylori bacteria colonize the stomach of human hosts and cause disease. Herein, we describe protocols to: 1) prepare bacterial suspensions for the in vivo infection of mice via intragastric gavage; 2) determine bacterial colonization levels in mouse gastric tissues, by polymerase chain reaction (PCR) and viable counting; and 3) assess pathological changes, by histology. To establish Helicobacter infection in mice, specific pathogen-free (SPF) animals are first inoculated with suspensions (containing &#8805;105 colony-forming units, CFUs) of mouse-colonizing strains of either Helicobacter pylori or other gastric Helicobacter spp. from animals, such as Helicobacter felis. At the appropriate time-points post-infection, stomachs are excised and dissected sagittally into two equal tissue fragments, each comprising the antrum and body regions. One of these fragments is then used for either viable counting or DNA extraction, while the other is subjected to histological processing. Bacterial colonization and histopathological changes in the stomach may be assessed routinely in gastric tissue sections stained with Warthin-Starry, Giemsa or Haematoxylin and Eosin (H&#38;E) stains, as appropriate. Additional immunological analyses may also be undertaken by immunohistochemistry or immunofluorescence on mouse gastric tissue sections. The protocols described below are specifically designed to enable the assessment in mice of gastric pathologies resembling those in human-related H. pylori diseases, including inflammation, gland atrophy and lymphoid follicle formation. The inoculum preparation and intragastric gavage protocols may also be adapted to study the pathogenesis of other enteric human pathogens that colonize mice, such as Salmonella Typhimurium or Citrobacter rodentium.

This protocol describes an oral gavage technique to achieve intragastric infection with H. pylori or H. felis in murine mouse models (Figure 1). Following euthanasia, stomachs are removed, weighed and divided into 2 equal halves comprising the antrum, body and non-glandular regions of gastric tissues (Figure 2). The non-glandular region is removed prior to performing any analyses.
Successful colonization of animals i...

Watch this Scientific Journal Video about Mouse Models Of Helicobacter Infection And Gastric Pathologies at JoVE.com

Mouse Models Of Helicobacter Infection And Gastric Pathologies

Mice represent an invaluable in vivo model to study infection and diseases caused by gastrointestinal microorganisms. Here, we describe the methods used to study bacterial colonization and histopathological changes in mouse models of Helicobacter pylori-related disease.

Mouse Models Of Helicobacter Infection And Gastric Pathologies

Helicobacter pylori is a gastric pathogen that is present in half of the global population and is a significant cause of morbidity and mortality in ...

mouse-models-of-helicobacter-infection-and-gastric-pathologies

Research

Education

JoVE Journal

JoVE Core

Anatomy and Physiology

Pharmacology

Immunology and Infection

Unit 1

Digestive System

Drugs for Peptic Ulcer Disease

SCIENTISTS IN ACTION

18.3K Views.  Hudson Institute of Medical Research. Mice represent an invaluable in vivo model to study infection and diseases caused by gastrointestinal microorganisms. Here, we describe the methods used to study bacterial colonization and histopathological changes in mouse models of Helicobacter pylori-related disease.