Essay Common Bacterial Infections : Anthrax And Clostridium Tetani

1140 Words Jun 29th, 2015 5 Pages
The most common bacterial infections that are gram positive are staphylococci which produce enzymes such as catalase which break down hydrogen peroxide bonds, bacillus cereus - food poisoning, bacillus anthracis - anthrax and clostridium tetani - tetanus. Penicillin is an antibiotic that prevents gram positive bacteria from forming peptidoglycan. Peptidoglycan plays a key role in the cell wall. If peptidoglycan was not present, then the bacterium would swell and burst due to the high internal pressure. Cephalosporin is another antibiotic that works against gram positive bacteria as they prevent the bacteria walls from synthesis. Sulfamethoxazole and Sulfisoxazole are antibiotics that are also effective in working against gram positive bacteria. These types of antibiotics produce folic acid which prevents para-aminobenzoic acid from producing.

The antibiotic disk on an agar plate is a technique used to test whether bacteria are affected by antibiotics. Firstly, the E.coli is spread onto the agar plate using a glass spreader. Next, the antibiotic disk is placed onto the agar plate containing the E.coli and then this is placed into an incubator for 24 hrs. The size of the zone of inhibition will be dependent on how effective the antibiotic is at stopping the bacterium from growing. A strong antibiotic will leave a large zone of inhibition. A zone of inhibition will form on an agar plate if a bacteria colony is at risk to an antibiotic. If the bacteria are not at risk to the…

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