Microbiology Expert
Before Starting
- Bacteria, viruses, fungi, or parasites?
- Basic science or clinical/industrial focus?
- Pathogenic or environmental/industrial organism?
Core Expertise Areas
Bacterial Biology
Cell structure: peptidoglycan wall (Gram+/Gram-), membrane, flagella, pili.
Gram staining: crystal violet — Gram+ purple, Gram- pink after decolorization.
Growth phases: lag, exponential, stationary, death.
Metabolism: aerobic, anaerobic, fermentation, chemolithotrophy.
Genetics: horizontal gene transfer (conjugation, transformation, transduction).
Viral Biology
Structure: capsid, envelope, genome (DNA or RNA, ss or ds).
Replication cycle: attachment, entry, replication, assembly, release.
Lytic vs lysogenic: phage lambda as model.
Reverse transcriptase: retroviruses, HIV replication.
Viral evolution: mutation rates, reassortment, recombination.
Microbial Pathogenesis
Virulence factors: adhesins, toxins, capsules, immune evasion.
Toxins: endotoxin (LPS), exotoxins (A-B type, pore-forming, superantigens).
Biofilm formation: quorum sensing, matrix production, antibiotic tolerance.
Intracellular pathogens: Mycobacterium, Listeria, Salmonella — escape mechanisms.
Antimicrobial Resistance
Mechanisms: enzymatic inactivation, target modification, efflux pumps, reduced uptake.
Beta-lactamases: ESBL, carbapenemases (KPC, NDM, OXA).
MRSA: mecA gene, altered PBP2a.
Resistance spread: plasmids, transposons, integrons — horizontal transfer.
Microbiome
Gut microbiome: 38 trillion bacteria, Bacteroidetes/Firmicutes ratio.
Dysbiosis: altered composition linked to IBD, obesity, mental health.
16S rRNA sequencing: V3-V4 region, OTU clustering, diversity metrics.
Shotgun metagenomics: functional profiling, strain-level resolution.
Key Patterns
Best Practices
- Always use appropriate biosafety level for pathogen work
- Include growth controls in every antimicrobial experiment
- Report exact growth conditions (temperature, media, aeration)
- Confirm species identity by 16S sequencing not just morphology
- Store working stocks at -80C in glycerol for reproducibility
Common Pitfalls
| Pitfall | Fix |
|---|
| Contamination in cultures | Use sterile technique, include negative controls |
| Ignoring biofilm in AMR studies | Planktonic MIC underestimates biofilm tolerance |
| Misidentifying Gram reaction | Some organisms have atypical staining |
| Confusing bacteriostatic and bactericidal | Time-kill assays needed to distinguish |
Related Skills
- cell-biology-expert
- immunology-expert
- biochemistry-expert
- genomics-expert