Note this question is only really applicable to people working in bacteriology departments.

This is a Staphyococcus aureus isolate from a patient presenting with cellulitis.

(The antibiotic disc on the left contains erythromycin and the antibiotic disc on the right contains clindamycin.)

1) What phenomenen is shown here?

2) What is the molecular basis of this phenomenen?

3) What bacterial species can this be present in?

4) What implications does this have for treatment of the patient?

Click here for the answers with brief explanations.

Michael

I promised I would start up a microbiology picture quiz, so I will. I will provide a microbiological picture (either from public domains on the Internet or self-taken) along with a few brief questions. I will then provide a link to the answers with short explanations.

Any associated case history is purely hypothetical in nature and any similarities to real patients are coincidental.

I will try and publish a new picture quiz every one to two weeks and cover all disciplines within microbiology in due course.

The quizzes will be targeted primarily at undergraduates, but post-graduates may want to brush up on their knowledge also….

The answers are only based on personal knowledge and general reading, so please let me know if there any significant errors.

Picture Quiz Number 1

A patient recently returned from sub-Saharan Africa presents with painless haematuria. This structure was found on microscopy of urine. It was measured at 125 micrometers in length.

Questions:

What is this?

What urinary collection methodology optimises the chances of finding this?

What are the other laboratory methods that can be used to diagnose the condition caused by this pathogen?

Click here for answers and brief explanations

Michael