Escherichia Coli
Also written as ETEC.
Group B streptococcus and Escherichia coli are the leading causes of early neonatal sepsis and meningitis.
What our notes say
- Group B streptococcus and Escherichia coli are the leading causes of early neonatal sepsis and meningitis. (Paediatrics end of first trimester exam (MBPE 4300): 27 November 2018, 49 of 50 )
- He is taken to the operating room for surgery, and postsurgical cultures reveal Escherichia coli and Bacteroides fragilis, susceptibilities pending. (MBPL3822 Chemotherapy CAT 1 MCQs)
- Discuss how intestinal tract infections are caused by Escherichia coli. (Medical Microbiology Q&A Guide)
- A) Lipopolysaccharide is part of the cell wall of *Escherichia coli* (Medical Bacteriology and Entomology MCQs)
- Lipopolysaccharide is part of the cell wall of *Escherichia coli (Medical Bacteriology and Entomology MCQs)
- Organisms (early-onset): group B streptococcus, *Escherichia coli,* *Klebsiella* and *Listeria.* Late-onset: *Staphylococcus aureus,* coagulase-negative staphylococci, *Klebsiella,* *Pseudomonas* and *Candida.* (Integrated case paper: Medicine, Surgery, Gynaecology and Paediatrics (160 marks)
Study material on Escherichia Coli
- Medical Bacteriology and Entomology MCQs
- Medical Bacteriology and Entomology
- Medical Microbiology Q&A Guide
- Bacteriology and Entomology Supplementary Exam
- Medical Bacteriology Examination MCQs
- Mbmm3311 – Medical Bacteriology
- Bacteriology and Entomology Main Exam
- Medical Bacteriology MCQs: ETEC, Pseudomonas, Salmonella & More
- Male Reproductive & Urinary Tract Pathology MCQs | MKU Year 3 Medicine
- MBPL3822 Chemotherapy CAT 1 MCQs
- Weekly Year 2: Microbiology Exam - May 15, 2026 (Section A: MCQs)
- Weekly Year 2: Microbiology Exam - April 17, 2026 (Section A: MCQs)
Practice questions on Escherichia Coli
A 23-year-old man presents with acute appendicitis that ruptures shortly after admission. He is taken to the operating room for surgery, and postsurgical cultures reveal Escherichia coli and Bacteroides fragilis, susceptibilities pending. Which of the following provides adequate empiric coverage of these two pathogens?
- Cefepime
- Aztreonam
- Piperacillin/tazobactam
- Ceftaroline
- Reduced by routine feedback control
Answer: C. Piperacillin/tazobactam is a β-lactam/β-lactamase inhibitor combination that provides excellent coverage against both gram-negative aerobes (E. coli) and anaerobes (Bacteroides fragilis). While the other agents cover E. coli, only piperacillin/tazobactam provides adequate coverage against Bacteroides species, which are common in intra-abdominal infections. ---
The heat-labile toxin of Enterotoxigenic Escherichia coli (ETEC) acts through which mechanism?
- Inhibition of protein synthesis by ADP-ribosylation of elongation factor 2
- Activation of adenylate cyclase, leading to increased intracellular cAMP
- Cleavage of the 60S ribosomal subunit
- Formation of ion channels in the intestinal epithelium
Answer: B. The heat-labile toxin (LT) of ETEC is an enterotoxin that activates adenylate cyclase in intestinal epithelial cells, leading to increased cyclic AMP (cAMP) levels, which in turn causes fluid and electrolyte secretion.
The heat-labile toxin (LT) of Enterotoxigenic Escherichia coli (ETEC) acts through which mechanism?
- Increases intracellular cAMP
- Increases intracellular cGMP
- Direct damage to the cell membrane
- Inhibition of protein synthesis
Answer: A. LT increases cAMP by activating adenylate cyclase, while the heat-stable toxin (ST) increases cGMP.