Under a microscope, a stained slide of Clostridium tetani resembles a__________________?
Show answer Hide answer
Answer: C. Drum stick
Explanation
Terminal spores formed by Clostridium tetani bacilli give them a characteristic morphology resembling a drumstick. Microscopic examination of stained smears reveals swollen spore-bearing bacilli that match this classic appearance. This distinctive cellular morphology aids clinical microbiologists in making a rapid presumptive microscopic identification. Clostridium tetani is an anaerobic, spore-forming gram-positive rod responsible for causing tetanus disease. The spherical endospore forms at the extreme pole of the bacterial cell, causing the characteristic distension. Tetanus spores survive indefinitely in soil environments until introduced into devitalized human wound tissues.
Puncture wounds contaminated with soil can introduce tetanus spores into hypoxic tissue environments favorable for germination. Tetanus toxoid vaccination provides robust protective immunity against the potent neurotoxin produced by these bacteria. Recognizing microscopic morphology assists laboratory workers in identifying suspicious anaerobic cultures during investigations. Bunch of grapes describes the typical microscopic clustering arrangement of Staphylococcus species rather than clostridial bacilli. Chain of beads describes streptococcal cellular arrangements, differing completely from drumstick-like clostridial spores. Safety pin appearance is characteristic of bipolar staining seen in Yersinia pestis organisms rather than Clostridium tetani.
Related questions
Q1. Which of the following represents a specific treponemal test for diagnosing syphilis? _____________?
Show answer Hide answer
Answer: A. FTAB
Fluorescent Treponemal Antibody Absorption is a specific treponemal test for diagnosing syphilis. Detecting antibodies directed against Treponema pallidum confirms active or past infection. Option A correctly identifies...
Q2. The majority of clinically important human fungi belong to the group__________________?
Show answer Hide answer
Answer: D. Deuteromycetes
The vast majority of clinically significant fungi that cause human disease lack a known sexual cycle. Mycologists historically classified these asexual forms into a temporary grouping known as fungi imperfecti. Modern ta...
Q3. Which of the following is an agglutination assay utilized in diagnosing typhoid fever? ___________?
Show answer Hide answer
Answer: A. Widal test
The Widal test detects specific antibodies against Salmonella typhi antigens using standard agglutination laboratory methods. Patients suffering from typhoid fever develop measurable agglutinating antibodies that react d...
Q4. Bacterial multi-drug resistance is primarily governed by which of the following mechanisms? _______________?
Show answer Hide answer
Answer: A. Resistance transfer factor (RTF)
Resistance transfer factors are specialized plasmid segments that facilitate conjugative transfer among bacteria. This process allows multiple drug resistance genes to spread rapidly through microbial populations. These...
Q5. Negative staining procedures are typically employed to visualize________________?
Show answer Hide answer
Answer: D. Bacterial fimbriae
Negative staining techniques employ dark stains like India ink to outline transparent microbial structures. Bacterial capsules and fimbriae exclude the surrounding dye, creating a clear halo against a dark background. Th...
Q6. What standard method is used to sterilize hospital operating theaters? _____________?
Show answer Hide answer
Answer: C. Formaldehyde fumigation
Hospital operating theaters require thorough sterilization to eliminate all pathogenic microorganisms and prevent postoperative infections. Formaldehyde gas fumigation effectively penetrates complex surgical environments...