Mnemonics of Microbiology

Investigations of Typhoid fever

BASU


1st week - Blood culture
2nd week -Agglutination test
3rd week -Stool culture
4th week - Urine culture 

Immunoglobulins -Order of appearance

'IMmunoGlobulin'
IgM appears first in response to antigens followed by IgG.

IgM antibodies appear early in the course of an infection and usually reappear, to a less extent, after further exposure. IgM antibodies cannot pass through human placenta. These two biological properties of IgM make it useful in the diagnosis of infectious diseases. Demonstrating IgM antibodies in a patient's serum indicates recent infection, or in a neonate's serum indicates intrauterine infection (e.g. congenital rubella).

Leprosy: early signs diagnostic criteria

"LEProsy":
Loss of sensation in affected skin/ Loss of function (paralysis)
Enlargement of affected superficial nerves (tender too)
Positive identification of M. leprae under microscope

Catalase positive organims

 SPACE:
Staphylococcus aureus
Pseudomonas
Aspergillus
Candida
Enterobacter

Streptococcus pneumoniae: diseases caused

COMPS:
Conjunctivitis
Otitis media
Meningitis
Pneumonia
Sinusitis

Diphtheria toxin properties

ABCDEF:
A/B-type toxin. Made by
Corynebacterium diphtheriae, which binds to
EF-2 (elongation factor 2).

Syphilis vs. H. ducreyi (chancroid): which ulcer is painful

"In du-crey-i, you do cry (because it is painful)":
In H. ducreyi, the ulcer is painful, in syphilis the ulcer is painless

Meningitis: most common organisms

 NHS:
Neisseria meningitidis
Hemophilus Influenzae
Streptococcus pneumonia
·The cause of the most Severe meningitis is Streptococcus.
· Note: NHS is an acronym for National Health Service in several countries.

Pneumonia: causes: gram negative vs. gram positive

Gram Negatives (eg coliforms) are responsible mainly for Nosocomial pneumonia.
Gram positives (eg strep pneumonia, staph) are thus more responsible for community acquired pneumonia

Capsulated microbes

 "Some Nasty Killers Have Some Capsule Protection":
Streptococcus pneumoniae
Neisseria meningitidis
Klebsiella pnemoniae
Haemophilus influenzae
Salmonella typhi
Cryptococcus neoformans
Pseudomanas aerigenosa

Hepatitis: transmission routes

"Vowels are bowels":
Hepatitis A and E transmitted by fecal-oral route.

Typhus: Epidemic Typhus: etiologic agent, vector

ePidemic typhus:
Etiological agent: Rickettsia Prowazekii.
Vector: Pediculus corporis (human body louse).
· This is in contrast to Endemic typhus.

Tetanus: treatment for infection

 SAD RAT:
Sedation
Antitoxin
Debridement
Relaxant
Antibiotic
Tracheostomy

AIDS pathogens (T-cell suppression) worth knowing

"The Major Pathogens Concerning Complete T-Cell Collapse":
Toxoplasma gondii
M. avium intracellulare
Pneumocystis carinii
Candida albicans
Cryptococcus neoformans
Tuberculosis
CMV
Cryptosporidium parvum

Urease positive organisms

PUNCH:
Proteus (leads to alkaline urine)
Ureaplasma (renal calculi)
Nocardia
Cryptoccocus (the fungus)
Helicobacter pylori

E. coli: major subtypes

key point of each "HIT by E. coli outbreak":
EnteroHemorrhagic:
· HUS from Hamburgers
EnteroInvasive:
· Immune-mediated Inflammation
EnteroToxigenic:
· Traveller's diarrhea

Teratogens: placenta-crossing organisms

ToRCHeS:
Toxoplasma
Rubella
CMV
Herpes simplex, Herpes zoster (varicella), Hepatitis B,C,E
Syphilis

Trypanosoma brucei: disease caused

"I went on a TRYP to AFRICA":
TRYPanosoma brucei causes AFRICAn sleeping sickness

McConkey agar- components

'PLANT'

• Peptone
• Lactose
• Agar
• Neutral red
• Taurocholate

DiGeorge Syndrome: features

'DiGeorge's  T's':

• Third and 4th pharyngeal pouch absent.
• Chromosome Twenty-Two
• T-cells absent
• Tetany: hypocalcemia

Chlamydia: elementary vs. initial body location

 Elementary: Extracellular
Initial: Intracellular

Toxoplasma gondii: manifestations

"My Cat Eats Mice":
Mononucleosis-like illness
Chorioretinits/ Congenital infection
Encephalitis
Myocarditis

Psedomonas aeruginosa:

 features AERUGINOSA:
Aerobic
Exotoxin A
Rod/ Resistance
UTIs, burns, injuries
Green-blue dressings
Iron-containing lesions
Negative gram
Odor of grapes
Slime capsule sometimes (in CF pt)
Adherin pili

Non bile stained eggs

The parsites producing non bile stained eggs are
' NEHA'

• Necator americanus
• Enterobius vermicularis    (Pinworm)
• Hymenolepis nana        (Dwarf tapeworm)
• Ancylostoma duodenale   (Hookworm)

Hymenolepis nana or Dwarf tapeworm is the smallest and most common tapeworm found in human intestine.

Hypersensitivity reactions

'ACID' 

• Type I:  Anaphylaxis
• Type II:  Cytotoxic-mediated
• Type III:  Immune-complex
• Type IV:  Delayed hypersensitivity.

As per Goombs classification.

Influenza infection: clinical manifestations

 "Having Flu Symptoms Can Make Moaning Children A Nightmare":
Headache
Fever
Sore throat
Chills
Myalgias
Malaise
Cough
Anorexia
Nasal congestion

Hepatitis viruses: Families

'Physically Handicapped Friend Danced Happily'

• Hepatitis A  : Picornavirus
• Hepatitis B  : Hepadnavirus
• Hepatitis C : Flavivirus
• Hepatitis D : Delta virus
• Hepatitis E : Hepevirus

Meningitis: risk factors

 "Can Induce Severe Attacks Of Head PAINS":
Cancer
Immunocompromised state
Sinusitis
Age extremes
Otitis
Head trauma
Parameningeal infection
Alcoholism
Infections (systemic, esp. respiratory)
Neurosurgical procedures
Splenectomy

Endocarditis: indications for surgery

PUS RIVER:
Prosthetic valve endocarditis (most cases)
Uncontrolled infection
Supporative local complications with conduction abnormalities
Resection of mycotic aneurysm
Ineffective antimicrobial therapy (eg Vs fungi)
Valvular damage (significant)
Embolization (repeated systemic)
Refractory congestive heart failure

Klebsiella: Morphology & Infections

You can tell the patient: "Fat Alcoholics Never Get UPSet"
Morphology:
Fat prominent capsule
Alcoholics are at increased risk of infection
Motility:
"Never Get up" : non-motile (non-flagellated)
Infections:
UTI (Urinary tract infection)
Pneumonia
Sepsis

Endocarditis: causes of culture negative endocarditis

"With Negative Tests, Investigators Should Focus Attention Somewhere Meaningful":
Wrong diagnosis
Noninfectious endocarditis
Timing (cultures drawn at end of chronic course)
obligate Intracellular organisms
Slow growing fastidious organisms
Fungal infection
Antibiotic used previously
Subacute right-sided endocarditis
Mural endocarditis

Endocarditis: lab results suggesting it

"High Tech Lab Results Point At Endocarditis":
Hematuria
Thrombocytopenia
Leukocytosis, -penia
Red blood cell casta
Proteinuria
Anemia
Elevated ESR

Obligate anaerobes

' ABC '

• Actinomyces
• Bacteroids
• Clostridium

Neisseria: fermentation of N. gonorrhoeae vs. N. meningitidis

Gonorrhoeae: Glucose fermenter only.
MeninGitidis: Maltose and Glucose fermenter.
· Maltose fermentation is a useful property to know, since it's the classic test to distinguish the Neisseria types.

Picornavirus: features

PICORNAvirus:
Positive sense
ICOsahedral
RNA virus

Common cold: viral causes

"Common cold (acute infectious rhinitis, coryza) is PRIMArily caused by":
Paramyxoviruses
Rhinoviruses
Influenza viruses
Myxoviruses
Adenoviruses

Spore forming bacteria

' BSC.Chemistry '

• Bacillus anthracis and Bacillus subtilis
• Sporosarcina
• Clostridium species
• Coxiella burnetti

Gram positive stain

Gram Positives
Stain Purple (violet-blue)
because of their thick Peptidoglycan layer

Streptococcus pyogenes: virulence factors

SMASHED:
Streptolysins
M protein
Anti-C5a peptidase
Streptokinase
Hyaluronidase
Exotoxin
DNAses

DNA viruses: morphology rule of thumb DNA:

Double-stranded
Nuclear replication
'Anhedral symmetry
· Rule breakers: pox (cytoplasmic), parvo (single-stranded).

IgA protease-producing bacteria

 "Nice Strip of Ham":
Neisseria
Streptococcus pneumonia
Haemophilus influenza

Meningococci and gonococci: Fermentation properties

MeninGococci and Gonococci '

• Meninigococci ferments both Maltose and Glucose; whereas              
• Gonococci ferments only Glucose

B19 virus: at-risk groups

 B19 affects 3 B's:
Babies (5th disease, infectiousum erythematosa)
Black Bleeders (sickle cell anemics - anaplastic anemic crisis)
Bearing Babies [pregnant women] (hydrops fetalis)

Food poisoning: bugs inducing

"Eating Contaminated Stuff Causes Very Big Smelly Vomit":
E. coli O157-H7 [undercooked meat, esp. hamburgers]
Clostridium botulinum [canned foods]
Salmonella [poultry, meat, eggs]
Vibrio parahaemolyticus [seafood]
Bacillus cereus [reheated rice]
Staphylococcus aureus [meats, mayo, custard]
Clostridium perfringens [reheated meat]
Vibrio vulnificus [seafood]

Nematodes: ones spreading by egg ingestion

"ATE eggs":
Ascaris Lumbricoides
Trichuris trichuira
Enterobius vermicularis
spread by ingestion of eggs (vs skin invasion or insect bite)

Vibrio cholerae: reactions

" COINS "
The biochemical reactions which help to differentiate vibrio cholera are

• Catalase +ve
• Oxidase +ve
• Indole +ve
• Nitrates reduced to nitrites and
• Sucrose fermentation

Vibrio cholerae causes the acute diarrhoeal disease called cholera.

Trichomaniasis: features

· 5 F's:
Flagella
Frothy discharge
Fishy odor (sometimes)
Fornication (STD)
Flagyl (metronidazole) Rx

Enteric fever: lab diagnosis

' BASU '

• Blood culture- 1st week
• Antibody detection- 2nd week
• Stool culture- 3rd week
• Urine culture- 4th week

HIV infection: high-risk groups

HIV:
Homosexuals/ Hemophiliacs
IV drug abusers

Gram staining: mechanism

"Murein gets the red out" [Allusion to an old eye-wash slogan]:
Peptidoglycan (aka murein) remains purple during Gram staining. The Gram negatives, devoid of murein, are red.
Thus, murein prevents redness and are purple (positive).

Staphylococcus aureus: diseases caused

 SOFT PAINS:
Skin infections
Osteomyelitis
Food poisoning
Toxic shock syndrome
Pneumonia
Acute endocarditis
Infective arthritis
Necrotizing fasciitis
Sepsis

Streptococcus pyogenes: antibody

 SPAM:
Streptococcus Pyogenes: Antibody to M protein.

E. coli: diseases caused in presence of virulence factors

DUNG:
Diarrhea
UTI
Neonatal meningitis
Gram negative sepsis
· Dung, since contract E. coli from dung-contaminated water.

Streptococci: Quellung reaction:

 positive sign, Strep type confirmed "Quell-lung":
Quell: Capsules swell [+ve test].
Lung: S. pnuemonia [type confirmed].
· You get pneumonia in your lung.

Intracytoplasmic inclusion bodies

" BiG  HeN "

• Bollinger bodies- Fowlpox [image:744 align=right width=200]
• Guarineri bodies- Vaccinia/ variola
• Henderson patterson bodies- Molluscum contagiosum
• Negri bodies- Rabies

In rabies, Negri bodies occur in neurons of the brain stem, particularly those in the hippocampus, and in the Purkinje cells of the cerebellum. Their presence is pathognomic for rabies and is an important diagnostic finding.

Streptococci: classification by hemolytic ability

Gamma: Garbage (no hemolytic activity).
Alpha: Almost (almost lyse, but incomplete).
Beta: Best (complete lysis)

Acute post-streptococcal glomerulonephritis: classic presentation

" Throat,  bloat,  coke":
Sore throat: 1 week ago
Face bloat: facial edema
Pi$$ coke: coke-coloured urine

Filamentous fungi

" MR. PAD "

• Mucor
• Rhizopus
• Penicillium
• Aspergillus
• Dermatophytes

Listeria: motility

Istanbul sounds like Listambul = list + tumble.
Listeria has tumbling motility.

Skin-invasive Nematodes

 "ANS"
(Think: Autonomic nervous sysytem)

• Ancylostoma duodenale
• Necator americanus
• Strongyloides stercoralis

Types of Vaccines

"STARK"

• Subunit
• Toxoid
• Attenuated (live)
• Recombinant
• Killed (inactivated)

Vibrio: motility

 "Vibrio Vibrates":
Vibrio is a genus of actively motile bacteria.

Mycobacterium tuberculosis: culture identification

"Rough, Tough, Buff":
Rough: colony isn't smooth but rough like breadcrumbs.
Tough: colony stuck to plate well, and tough to remove.
Buff: buff is a color, a cream/coffee shade.

Endotoxin features

ENDOTOXIN:
Endothelial cells/ Edema
Negative (gram- bacteria)
DIC/ Death
Outer membrane
TNF
O-antigen
X-tremely heat stable
IL-1
Nitric oxide/ Neutrophil chemotaxis

Microorganisms causing UTI

"KEEPS"

• Klebsiella pneumoniae
• E.coli
• Enterococcus faecalis/ Enterobacter cloacae
• Pseudomonas aeruginosa/ Proteus mirabilis
• Staphylococcus saprophyticus/ Serratia marcescens

Kidney transplant virus

"Borrowed Kidney":
BK virus is associated with kidney transplants

Picorna virus: Features

"PICORNA"

• Positive sense
• ICOsahedral
• RNA virus

Lymphogranuloma venereum

 "A, B, C, D.........G"

• Asymptomatic lesion
• Bubo
• Chlamydia Trachomatis (causative agent)
• Doxycycline (drug of choice)
• Esthiomene
• Frei's test
• Groove sign

Esthiomene refers to vaginal and rectal stricture and elephantiasis of vulva.

Frei test is an immunological test in which reaction to antigens injected intradermally were read after 1-2days. The test is no longer used to detect LGV.

The 'groove' in the Groove sign refers to the depression that separates the enlarged inguinal and femoral nodes. The groove overlies the inguinal ligament which separates the two groups of nodes.

Pneumonia: acute pneumonia infiltrates from different causes

"Pyogenic=PMN, Miscellaneous=Mononuclear":
Acute pneumonia caused by Pyogenic bacteria: PMN infiltrate.
Acute pneumonia caused by Miscellaneous microbes: Mononuclear infiltrate.

Entameoba histolytica: disease caused, action

EntAmoeba causes Amoebic dysEntery.
Action: histo (cell) lytic (burst), so it bursts cells.

Lactose formers:

' CEEK '

C ~ Citrobacter
E ~ Enterobacter
E ~ E.coli ( K-1 capsule more important )
K ~ Klebsiella

Endotoxin features

ENDOTOXIN:

Endothelial cells/ Edema
Negative (gram- bacteria)
DIC/ Death
Outer membrane
TNF
O-antigen
X-tremely heat stable
IL-1
Nitric oxide/ Neutrophil chemotaxis