[Anonymous]

The best kept secret has arrived! Greetings, I am Helicobacter pylori (previously known as Campylobacter pylordis because I appeared to be similar to Campylobacter, but in 1989 I got my own genus!). I saw an ad for a room in a human stomach, which looks super comfy to live in and wanted to let you know that I’m interested in moving in. Hopefully we’ll be great roommates. I am a gram negative epsilon proteobacterium, so I don’t mind if you are mean or rude because I have a “thick skin”. It’ll be difficult to penetrate my outer membrane, which contains lipopolysaccharides, or my thin peptidoglycan layer, periplasmic space, and cell membrane layer. In the past, it was pretty difficult to find locations that I liked to live in but I definitely prefer ones with a low concentration of oxygen as I am a microaerophile. I have hydrogenase which can also be used to obtain energy. There are a lot of misunderstandings about my oxygen and carbon dioxide requirements, but don’t you fret, I always have a spare oxygen tank just in case. I do not use complex carbohydrates as an energy source, but rather glucose which is metabolized via the Entner Douderoff pathway.

In your ad, you mentioned that you wanted to know where I lived previously. My whole life I’ve lived in contaminated food and water, but a lot of my family (shout out to Helicobacter!) have found cozy places in human and animal stomachs and in duodenums (the first part of the small intestine) so I thought this was a great opportunity to try a new environment. My family often creates biofilms so they all live right next to each other which have been very beneficial in staying safe and acquiring nutrients. In fact, my relatives inhabit 2/3 of the world’s population (majority of them in developing countries) and these silly humans don’t even know it because 40% of them do not develop ulcers as we are a slow growing bacterium. We would’ve remained unknown if Barry Marshall and Robin Warren didn’t identify us in 1982. Humans think they know how my relatives have gotten into their stomachs. Some have mentioned oral transmission from person to person, or fecal oral contact, but they don’t really know, and we’d like to keep it that way.

As you may know, I am a human pathogen. My helical shape allows me to penetrate into the mucous lining of the stomach. I’m very motile and have lophotrichous flagella so if we ever need to get somewhere quickly I’m the one you want! Both of these characteristics allow me to survive well in an acidic stomach. I can cause infection in the stomach, damage duodenal tissue, cause inflammation and peptic ulcers. I also do this thing where I produce the enzyme urease which neutralizes the stomach’s acid which weakens the stomach’s protective mucous, making it more susceptible to being damaged ie sores and ulcers. Unfortunately, this can also lead to stomach and gastric cancer, gastritis, nausea, vomiting, and black stool. But don’t worry sometimes I randomly trigger the stomach to produce acid. These are all due to my virulence factors: lipopolysaccharide, urease, cytotoxin, outer membrane inflammatory protein, and cagA – a duodenal ulcer promoting gene. I’m a pretty social person, my closest friends are Campylobacter! But I also am friends with other proteobacteria. I hope this is detailed enough, and let me know when you’re available so I can come see the room. Thanks! I included some pictures of me. I’ll be a handsome roommate.

Images:
http://bioweb.uwlax.edu/bio203/s2008/pluym_evan/pictures/h_pylori%20scott%20smith.gif
http://ilovebacteria.com/Images/helicobacter.png
http://www.sciencepicturecompany.com/images/4721/Helicobacter-pylori.html

Resources:
http://www.ncbi.nlm.nih.gov/pubmed/16220040
http://onlinelibrary.wiley.com/doi/10.1111/j.1523-5378.2006.00413.x/abstract
http://medicalcenter.osu.edu/patientcare/healthcare_services/digestive_disorders/h_pylori/Pages/index.aspx
http://en.wikipedia.org/wiki/Helicobacter_pylori