Microbiology Essentials: Infection Control and Common Pathogens

Published: 2025-12-25T00:00:00.000Z

Healthcare-associated infections remain a leading cause of preventable harm. Prevention combines basic microbiology principles with consistent infection prevention measures and stewardship of antimicrobial use. This practical guide outlines what clinicians must prioritise at the bedside and points to authoritative references for policy and further reading.

Standard precautions everyone must apply

Start with hand hygiene, correct glove use, respiratory hygiene, and safe sharps handling. These steps reduce transmission risk across a wide range of pathogens. Refer to national guidance for protocols: CDC Infection Control and the WHO infection prevention programme provide up-to-date recommendations.

When to add transmission-based precautions

• Contact precautions: For organisms like MRSA and C. difficile—use gown and gloves and dedicate equipment.
• Droplet precautions: For respiratory pathogens transmitted by large droplets (eg influenza)—mask within close distance.
• Airborne precautions: For TB, measles and similar agents—use respirators and, if possible, negative-pressure rooms.

Clinical practice tips

• Perform hand hygiene before and after patient contact; use soap and water when hands are visibly soiled.
• Follow device-care bundles for central lines and urinary catheters to prevent device-associated infections.
• Clean and disinfect high-touch surfaces and shared equipment between patients.
• Collect appropriate cultures before starting antibiotics when infection is suspected.

Common pathogens and settings

Be familiar with organism‑specific risks: Staphylococcus aureus for skin/soft tissue and device infection, Gram-negative bacilli for urinary and intra-abdominal infections, Candida species in ICU patients with central lines, and seasonal respiratory viruses in wards and clinics. Local antibiograms should guide empirical therapy; consult our Pharmacology Guide for prescribing considerations.

Antimicrobial stewardship

Good stewardship reduces resistance and improves outcomes. Key actions: give the right antibiotic at the right dose and duration, stop or de-escalate therapy when cultures allow, and avoid unnecessary broad-spectrum agents. Education, audit, and feedback are effective system measures.

Learning and systems

Prevention is organisational: training, clear protocols, surveillance and rapid reporting of outbreaks. For case-based practice, visit our Question Bank and use CDC/WHO resources for policy updates.