Name: mouse models of helicobacter infection and gastric pathologies
Uploaded: 2018-10-18T13:00:00
Description: Watch this Scientific Journal Video about Mouse Models Of Helicobacter Infection And Gastric Pathologies at JoVE.com

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.

1. Growth and Preparation of Bacterial Inocula
<ol>
	<li>Thaw glycerol stocks of H. pylori or H. felis15 from -80 &#176;C and subculture on horse blood agar (HBA) plates comprising: Blood Agar Base No.2 (see Table of Materials); a modified &#8220;Skirrow&#8217;s antibiotic selective supplement&#8221; (consisting of vancomycin, 10 &#956;g/mL; polymyxin B, 25 ng/mL; trimethoprim, 5 &#181;g/mL; amphotericin B, 2.5 &#956;g/mL); and 5&#8211;10% (v/v) horse blood<sup...

<ol>
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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. 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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>

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 ...

This method can help answer key questions in the gastroenterology field about the impact of members of the microbiota, specifically those of the genus Helicobacter, on inflammation and cancer. The main advantage of this technique is that it allows the study of Helicobacter infection and its impact on the stomach under physiological conditions. The implications of this technique extend toward the development of therapies for the prevention or elimination of Helicobacter infection or its consequences, including antibiotics, drugs, or vaccines.These methods provide insight specific to the pathogenesis of Helicobacter infection. However, several of the techniques may be adapted to the study of other gastrointestinal pathogens. Generally, individuals new to this method will struggle with the preparation of a bacterial inoculum capable of establishing an infection in mice.It is imperative that the Helicobacter isolates are known mouse-colonizing strains that have not undergone extensive subculture in vitro. In addition, the number of in vitro subcultures for these strains should be recorded. Add bacterial suspensions to 15-milliliter polystyrene tubes, and use a plastic loop to transfer one 10-to 20-microliter droplet from each culture onto individual glass microscope slides.Then, assess the viability and motility of the bacteria under phase-contrast microscopy at a 100 times magnification. Only use the H.pylori inocula if the majority of the bacteria have a bacillary shape. H.felis inocula should primarily contain helical-shaped bacteria.And load the inocula into individual, disposable, one-milliliter syringes. Equip each syringe with a 23-gauge needle, and use plastic paraffin film to attach a disposable polyethylene catheter to each needle. Next, manually restrain a six-to eight-week-old specific-pathogen-free and Helicobacter-free mouse by the scruff of the neck and tail, and insert one catheter into the center of the open jaw.Guide the catheter in a caudal toward the esophagus, extending the neck of the mouse to allow ease of access to the stomach through the esophagus and away from the trachea until most or all of the catheter is no longer visible and a resistance is felt. Then, deliver at least one times 10 to the fifth bacteria to ensure an optimal colonization and disease pathology. At the end of the experiment, use fine, curved scissors to open the abdominal cavity for excision of the stomach.Cut the stomach along the greater curvature, and gently wash the organ two times in one 50-milliliter tube of fresh PBS per wash to remove any residual food. After the second wash, place the tissue into a tared, six-centimeter, plastic Petri dish to record the wet weight. After flattening the stomach, bisect the sample sagittally into two equal tissue fragments comprising the antrum, body, and non-glandular forestomach regions.Remove the non-glandular region, and weigh one half of each stomach before storing the piece of tissue in the appropriate solution for the planned downstream analysis. Add the other half of stomach tissue to a 15-milliliter conical tube containing 10%formalin, flattening the tissues against the top sides of the tubes after 10 seconds. When the tissues have become affixed to the tube walls, re-immerse the samples in the formalin for at least 24 hours.To count the number of viable H.pylori in the stomach post-infection, homogenize stomach samples stored in BHI, and perform duplicate serial dilutions of the resulting gastric homogenates in fresh, sterile broth. Divide pre-dried horse blood agar, or HBA, plates supplemented with additional antibiotics into three or four segments, and, using an adaptation of the Miles and Misra technique, add 10 to 100 microliters of each stomach homogenate dilution onto a segment of each agar plate. Spread the homogenates with sterile, plastic loops, and allow the plates to dry.Then, place the plates in an inverted position in anaerobe gas jars containing a Petri dish of water and a gas pack. Then, incubate the jars at 37 degrees Celsius for four to seven days. When colonies can be observed, enumerate the segments containing between 10 and 100 isolated colonies.Following euthanasia, the stomach is harvested from the animals and weighed. The non-glandular region is removed, and the stomach is divided into two equal halves comprising the antrum and body. Successful colonization is typically confirmed by performing viable counting and subsequent enumeration of individual colonies from gastric homogenates streaked onto HBA plates.Note that the presence of contaminating bacteria from the mouse gastric microbiota or large numbers of H.pylori colonies can complicate the enumeration of H.pylori CFUs. Alternatively, PCR can be employed to verify infection using specific validated primers directed at a 325-base pair region of the H.felis and H.pylori ureB genes. In this representative experiment, wild-type C57 Black-6 mice displayed moderate signs of inflammation, including hyperplasia and gland atrophy at six months post-infection with H.felis, as well as cellular infiltration of the submucosa.More severe inflammation is observed in knockout mice at the same time point, with the additional presence of lymphoid follicles observed in close proximity to the cellular infiltrates. H.felis bacteria can also be visualized in Giemsa-stained sections of infected mouse stomach tissue. Following this procedure, other methods like quantitative PCR, immunohistochemistry, or immunofluorescence can be performed to answer additional questions about the types of host responses induced during Helicobacter infection.After its development, this technique paved the way for researchers in the field of microbiology and gastroenterology to explore the causative role of Helicobacter pylori in stomach disease in humans. After watching this video, you should have a good understanding of how to reproducibly infect mice with Helicobacter species and to study the pathology associated with the infection. Don't forget that the Helicobacter strains used in this protocol are infectious, and therefore standard biosafety procedures should always be followed while working with these bacteria.

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