A belated Happy New Year to all Microbioloblog’s readers!
We grew a bacterium in the lab recently which was identified as Pasteurella multocida. Without looking at the patient’s specimen I could tell with confidence that it would be a swab from an infected animal bite, mostly likely a cat or a dog. This is because this bacterium is mostly likely to be found living in the mouths of these (and other) animals. When they bite, it is introduced into the skin or deeper tissues of the victim and can then go on to cause infection.
It turned out that our patient had been bitten by her cat but as there was hardly anything to see, she had merely cleaned the wound as best she could with an antiseptic. A few days later, however, her hand had begun to swell and it became really painful. A visit to our Casualty Department (Emergency Room) for treatment and a prescription for an antibiotic called co-amoxiclav resolved the problem.
One of the reasons why cat bites are much more likely to become infected than those inflicted by man’s best friend is that dog bites often result in crushing or tearing of the skin. As well as being painful, crushed or torn skin looks pretty bad and patients often visit the Casualty Department shortly after being bitten for attention. This means that the wound is cleaned up at an early stage and a preventative (prophylactic) course of antibiotics can be given.
Infected cat bite cause by Pasteurella multocida (Credit Pediatric Supersite)
Patients often tend not to seek medical attention after a cat bite. Why? This because cats’ teeth are thin and sharp, so when they bite they tend to cause “in and out” puncture wounds. There is often very little to see and patients think that there is little need to have the bite looked at by a doctor or nurse, so they don’t receive prophylactic antibiotics and infection is free to develop.
