List of Top 10 Bacterial Pathogens
Table of Contents
A list of the Top 10 Bacterial Pathogens is summarized as follows-
- Escherichia coli (E. coli)
- Staphylococcus aureus
- Streptococcus pneumoniae
- Mycobacterium tuberculosis
- Salmonella spp.
- Clostridium difficile (C. difficile)
- Neisseria meningitidis
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
- Helicobacter pylori
Top 10 Bacterial Pathogens Short Descriptions
- Escherichia coli (E. coli):
- A Gram-negative bacterium found in the gut, some strains cause foodborne illnesses, urinary tract infections, and hemolytic uremic syndrome.
- Staphylococcus aureus:
- A Gram-positive bacterium causing skin infections, food poisoning, and toxic shock syndrome. Methicillin-resistant strains (MRSA) are a major concern.
- Streptococcus pneumoniae:
- A Gram-positive bacterium is responsible for pneumonia, meningitis, and ear infections. It is a leading cause of community-acquired infections.
- Mycobacterium tuberculosis:
- A slow-growing, acid-fast bacterium causing tuberculosis (TB). It primarily affects the lungs and can be drug-resistant.
- Salmonella spp.:
- A Gram-negative bacterium causing foodborne illnesses, typhoid fever, and gastroenteritis. It spreads via contaminated food or water.
- Clostridium difficile (C. difficile):
- A Gram-positive, spore-forming bacterium causing antibiotic-associated diarrhea and pseudomembranous colitis, especially in hospitalized patients.
- Neisseria meningitidis:
- A Gram-negative bacterium causing meningitis and septicemia. It spreads rapidly, leading to outbreaks in crowded settings.
- Klebsiella pneumoniae:
- A Gram-negative bacterium causes pneumonia, urinary tract infections, and bloodstream infections. It is known for antibiotic resistance.
- Pseudomonas aeruginosa:
- A Gram-negative opportunistic pathogen causing infections in immunocompromised patients, including wound infections, pneumonia, and biofilm-associated infections.
- Helicobacter pylori:
- A Gram-negative bacterium associated with gastric ulcers, chronic gastritis, and stomach cancer, often acquired during childhood.
Footages
Escherichia coli lactose fermenting colony on CLED agar of urine culture

Beta-haemolytic colonies of Staphylococcus aureus on 5% sheep blood agar

Draughtsman colony of Streptococcus pneumonia

Rough, bough and tough colony of Mycobacterium tuberculosis on L-J medium

Salmonella Typhi (black colony) and Salmonella Paratyphi colony morphology on XLD agar

Clostridium species colony morphology on blood agar

Neisseria meningitidis antimicrobial susceptibility testing (AST) result

Klebsiella pneumoniae mucoid lactose-fermenting colony (MLF) on MacConkey agar

Non-lactose fermenting (NLF) colony of Pseudomonas aeruginosa on CLED agar of urine culture

Helicobacter pylori in gastric biopsy Giemsa stained smear microscopic examination
