The spherical shaped bacteria present in chains are?

Appeared in: UPRVUNL - 2021

Explanation

Streptococci are spherical bacteria (cocci) that grow in chains because they divide along a single axis and do not separate after division.
The name itself provides a clue: 'Strepto-' is a prefix meaning chain, and 'cocci' refers to a spherical or berry-like shape.
This chain-like arrangement is a key characteristic used for the microscopic identification of this genus of bacteria, which includes significant pathogens like Streptococcus pyogenes.

Option B: This term describes bacteria that are rod-shaped (bacilli), not spherical.
Option C: Spirochetes are spiral or corkscrew-shaped bacteria, which is morphologically distinct from spherical cocci.
Option D: While staphylococci are also spherical, they are arranged in grape-like clusters, not chains. This is because they divide in multiple planes.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Bacterial Morphology and Arrangement as background academic context rather than a clinical decision trigger.
Identifying bacterial shape and arrangement via Gram staining is a fundamental first step in microbiology for diagnosing infections and guiding the selection of appropriate antibiotic treatment.
For example, Streptococcus pyogenes (Group A Strep), which causes strep throat, is identified by its characteristic chains of gram-positive cocci from a throat swab.
What if? If a Gram stain of a wound sample showed grape-like clusters of gram-positive cocci, the likely pathogen would be Staphylococcus aureus, not Streptococcus, leading to a different antibiotic choice, possibly considering methicillin-resistant strains (MRSA).

How to Approach the Question

First, break down the question into its key descriptive terms: 'spherical shaped' and 'in chains'.
Recall or deduce the meaning of the prefixes and suffixes commonly used in bacteriology.
The term 'cocci' (or coccus) refers to a spherical shape.
The prefix 'Strepto-' refers to a chain-like arrangement.
Combine these two parts: 'Strepto-' + 'cocci' = Streptococci.
Evaluate the other options to confirm your choice: 'bacilli' means rod-shaped, 'staphylo-' means cluster, and 'spirochetes' are spiral-shaped.

Concept Tested & Keywords

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E6 Microbiology Applied AnjuDhir 3e Part 1 p. 54-56

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 367-369

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