NCLEX-PN

Bacteria's reactions to laboratory testing can vary. Gram-positive bacteria respond to gram staining due to their thick walls containing peptidoglycan and teichoic acid. Gram-negative bacteria, which are more common, lack such a reaction because of their thin walls, which comprise a lipid membrane with endotoxins like lipoproteins and lipopolysaccharides. Bacteria can also be categorized based on their ability to resist color changes during staining procedures. Acid-fast bacteria resist decolorization when stained with Ziehl-Neelsen or Kinyoun stain. The four phases of bacterial growth are as follows: ●​ Lag Phase : Bacteria acclimate to the environment, mature without division, and undergo RNA synthesis to prepare for rapid growth. ●​ Log Phase : Rapid and continuous growth occurs until nutrients are depleted. ●​ Stationary Phase : Depletion of necessary nutrients leads to growth cessation and reduced metabolic activity. ●​ Death Phase : The bacteria's life cycle ends.

Viruses: Are composed of RNA, DNA, and proteins with an outer lipid-protein coat . They are smaller than bacteria and possess varying host ranges. Some viruses impact multiple species, while others affect only a specific species.

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