#corynebacteria

[bmedizinischa]

Bacteriology

Genus: Corynebacterium

Microscopy: gram-positive, mostly club-shaped rods

Culture: grows on blood-infused media,some strains grow better with some kind of lipid (like Tween 80), grows in small grayish colonies 

It’s the microscopy that is specific, the culture really isn’t helping with identification. This bacterium is very rarely detected in humans, and even less often clinically relevant. 

One species, C. diphtheriae, can cause diphtheria, which is a serious diagnosis and requires a therapy not only with antibiotica, but also an antitoxin. The toxin-gen however is transmitted via a bacteriophage and therefore not every strain of bacteria is toxin positive. If there is any chance that you actually found C.diphtheriae you have to let a specialized labratory handle it from there on. In a normal lab you can NOT test whether or not the strain is toxin positiv. The identification is usually done via MALDI TOF (a biochemical method). There are a few characteristics to help you in addition to that. The selective-media Tinsdale (which contains Fosfomycin), catalase positive, not mobile, partially acid-fast and reverse Camp-Test positiv.

The cell-wall structure of Corynebacteria contain a certain protein that prevent S.aureus from building a hemolysis. Since it’s a prohibition is the reverse Camp-test. The usual Camp-test would be used to confirm a kind of streptococcus, which would lead to a double hemolysis.

[fraise-impossible]

I'm sorry, I just googled this and this, this is the kind of answer I want from the internet ALWAYS

"I work in a biological research institute. As two of us have Tevas and both have the same problem we set about finding out why. The smell is caused by bacteria which live in and feed on the sweat and skin cells which accumulate on the sandals. This is by no means unusual and most forms of footwear are susceptible to the problem, but we wanted to find out why the problem seems worse with Tevas than other types of footwear. The smell is actually caused by the waste excreted by the bacteria as they feed. Through taking swabs from the Tevas and growing the bacteria found on agar we were able to isolate the strains of bacteria present. Although several strains were found, the predominant strain was Corynebacteria. This bacterium is known to thrive only in acid conditions, and a simple litmus test confirmed the Tevas to be slightly acidic with a pH of 5.5. In further tests we discovered the acidity had been absorbed by the thick skin on the soles of the feet and the Corynebacteria were also present there.  It seems the materials used in Tevas are slightly acidic and so encourage the Corynebacteria bacteria to live on them, which in turn causes the Teva smell. There are many ways to reduce acidity, but most of the methods we use in the laboratory would not be suitable for use on footwear and feet. After trying several ways of tackling the problem we decided to try Marmite, yes I do mean the stuff you put on your toast. Marmite is slightly alkaline with a pH of around 8 but also acts an antiseptic due to the high salt content. Marmite is just alkaline enough to neutralize the acidity present in Tevas, and the mild antiseptic effect is all that is needed to kill the Corynebacteria bacteria. After treating both the sandals and soles of the feet by coating with Marmite for about ten minutes then rinsing in water we found the problem of the smell was completely gone. Tests by taking further swabs from the sandals confirmed the Corynebacteria bacteria were no longer present. The pH of the sandals was found to have shifted to almost 7 which should prevent the Corynebacteria bacteria from returning. It's too early to tell how long this treatment will work for, but our best guess is about three months before needing to be done again."

http://www.thriftyfun.com/tf30271271.tip.html