Microbiology Pathogens

# Microbiology Pathogens

## 1. Bacterial Pathogens
### GNR (Enterobacteriaceae)
* **E. coli**: Major cause of UTI, neonatal meningitis. VF: Pili, endotoxin (LPS).
* **Salmonella**: Typhoid/Enterocolitis. Intracellular survival in macrophages.
### GPC
* **S. aureus**: Skin infections, abscesses, toxic shock. VF: Protein A, coagulase.
* **S. pyogenes**: Pharyngitis, rheumatic fever. VF: M protein.

## 2. Viral Pathogens
### DNAv
* **Herpesviridae**: Latency in sensory ganglia. Mechanisms of immune evasion.
### RNAv
* **Influenza**: Segmented genome allows antigenic shift/drift.
* **HIV**: Retroviral integration into host CD4+ T-cell genome.

## 3. Fungal Pathogens
* **Candida albicans**: Dimorphism (yeast to hyphae transition). Opportunistic infections in immunocompromised hosts.
* **Cryptococcus neoformans**: Polysaccharide capsule prevents phagocytosis.

## 4. Clinical Correlation
* **ABX Resistance**: Mechanisms include efflux pumps, beta-lactamase production, and target site modification.
* **Pathogenesis**: Colonization -> Invasion -> Evasion of host immunity -> Damage.