General features and principles
Epidemiology
Structure and function
Pathogenesis
| Bacterial Goal | Host Obstacle | Bacterial Solution |
| Extraintestinalattachment | Flow of urine, mucociliary escalator | Multiple adhesins (e.g., type 1, S, and F1C fimbriae; Ppili) |
| Nutrient acquisitionfor growth | Nutrient sequestration (e.g., iron via intracellular storageand extracellular scavenging via lactoferrin andtransferrin) | Cellular lysis (e.g., hemolysin), multiple mechanisms forcompeting for iron (e.g., siderophores) and othernutrients |
| Initial avoidance ofhost bactericidalactivity | Complement, phagocytic cells, antimicrobial peptides | Capsular polysaccharide, lipopolysaccharide |
| Dissemination (withinhost and betweenhosts) | Intact tissue barriers | Irritant tissue damage resulting in increased excretion(e.g., toxins such as hemolysin), invasion of brainendothelium |
| Late avoidance of hostbactericidal activity | Acquired immunity (e.g., specific antibodies), treatmentwith antibiotics | Cell entry, acquisition of antimicrobial resistance |
Infectious syndromes
Diagnosis
Treatment
Prevention
Escherichia coli infections
Commensal strains
Extraintestinal pathogenic strains
| Pathotype | Epidemiology | ClinicalSyndromea | Defining Molecular Trait | Responsible GeneticElementb |
| STEC/EHEC/ST-EAEC | Food, water, person-to- person; allages, industrialized countries | Hemorrhagiccolitis, hemolytic-uremic syndrome | Shiga toxin | Lambda-like Stx1- or Stx2-encoding bacteriophage |
| ETEC | Food, water; young children in andtravelers to developing countries | Traveler’s diarrhea | Heat-stable and labileenterotoxins, colonizationfactors | Virulence plasmid(s) |
| EPEC | Person-to-person; young childrenand neonates in developingcountries | Watery diarrhea, persistent diarrhea | Localized adherence,attaching and ewacing lesionon intestinal epithelium | EPEC adherence factor plasmidpathogenicity island (locus forenterocyte ewacement [LEE]) |
| EIEC | Food, water; children in andtravelers to developing countries | Watery diarrhea, occasionally dysentery | Invasion of colonic epithelialcells, intracellularmultiplication, cell- to-cellspread | Multiple genes containedprimarily in a large virulenceplasmid |
| EAEC | ?Food, water; children in and travelers to developing countries; all ages, industrialized countries | Traveler’s diarrhea,acute diarrhea,persistent diarrhea | Aggregative/diwuseadherence, virulence factorsregulated by AggR | Chromosomal or plasmid-associated adherence and toxingenes |
Diagnosis
Treatment
Intestinal pathogenic strains
Pathotypes
Diagnosis
Treatment
Klebsiella infections
Alcoholism (2/3), DM
Infectious syndromes
Pneumonia
- Hospital acquired pneumonia? m/c
- Red currant jelly like sputum (necrotizing pneumonia)
- CXR: bulging fissure (??? ??? ??? ?? ? minor fissure? ??), ??? ?? ??
UTI
Abdominal infection
- Liver abscess
- Metastatic spread to distant sites
- Eyes: endophthalmitis
- CNS: meningitis
Other infections
Bacteremia
Diagnosis
Treatment
- ESBL: carbapenem
- Quinolone
- 3rd cepha
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