Question

If I needed to determine if a pneumonia was bacterial, fungal, or viral. Would it be correct to hypothesize that:If the microbe causing the patient’s pneumonia is a bacteria, then a gram stain of the specimen slide will reveal an organism with a cell wall, lacking a nucleus? Expert Answer Anonymous answered this Was this answer helpful? 0 1 665 answers No, this is not true. If the microbe causing the patient’s pneumonia is a bactera then it should have a nucleus. Streptococcus pneumoniae is the most common bacterial cause of pneumonia, and it is a gram positive bacteria. So, their cell wall will be clearly visible with purple color, and they have the nucleus. In addition, several gram negative bacteria can cause pneumonia such as Haemophilus influenzae, Klebsiella pneumoniae, but they are less frequent. Bacteria always posses nucleus, and can be clearly visible after gram staining (under microscope). The original question is at the top I don't think the answer was correct

Answer 1

Yes, the answer provided is wrong

Correct answer : yes the hypothesis is true that if the slide would show cell wall with lacking a nucleus. Bacteria are prokaryotes and so would lack a nucleus. Also, most bacteria have a cell wall composed of peptidoglycan ( cross-linked polymer of NAM and NAG). Those having a thick layer of it get stained by primary Gram stain crystal violet and so are called gram positive bacteria while those having a thinner layer would be counter stained by safranin or fuchsin. Streptococcus pneumoniae ( a common pneumonia causing microbe) is a Gram positive bacteria and so would appear as violet cell wall without a nucleus.

Fungi and virus both lack peptidoglycan.