BACTERIOLOGY PART-2

• Features
• Pink Color = Urease +ve
• Club () il protein () kazhichondirunna aale idich → he cried () → said Noooo ()
• passed stools () & urine ()
• 2 staph ()() came behind us → we escaped in helicopter

• Proteus

• Ureaplasma

• Nocardia

• Cryptococcus

• Helicobacter

• Klebsiella

• CONS
• Staph saprophyticus
• Staph epidermidis

• Clinical Relevance
• Predisposes to struvite (magnesium ammonium phosphate) stones
• Particularly Proteus

Differential Media

• Pink () Monkey ()

• Cled () blue () blood

• Man (Mannitol) is red (when salty experience - angry red)

• Give TC (TCBS) to panchara (sucrose fermenter) & watch blue film (BTB)

MacConkey Agar

• Pink color - Lactose fermentation

• Only Gram-negative organisms grow

• Monkey () on a pretty pink () PLANT eating lactose
• P – Peptone
• L – Lactose - differential media
• A – Agar (Nutrient agar)
• N – Neutral red - indicator media
• T – Taurocholate - selective media

CLED

• Cysteine Lactose Electrolyte Deficient

• Gram-negative, Gram-positive, and Candida grow

• Indicator - Bromothymol Blue

• CLED is better as it allows gram positive and gram negative organisms to grow.

• cled blue blood

• Yellow colonies
• Lactose fermenters (LF)

• Blue colonies
• Non-lactose fermenters (NLF)

• Wayson stain shows safety pin
• Klebsiella granulomatis
• Yersenia

• Safety pin seen in:



• vibrio parahaemolyticus
• Yersinia pestis
• Haemophilus ducreyi
• Burkholderia
• klebsiella granulomatis

• Donovanosis:
• Grand party in Club (Kleb Granulo) mnemonic - refer micro
• Right Don () → aka False Bob (Pseudobuoes)
• Rolls (Rolled edges) in Club (Klebsiella), eat beef (red beefy)
• Has no Pain (Painless), but bleeds (bleed on touch)
• Put bodies → Donovan bodies
• Takes a long day to come
• why right (Wright Giemsa)?
• He kills with safety pin (safety pin appearance) painlessly

• Syphillis
• It was dark (dark field),
• Button hole → Felt
• hard (hard chancre) and rubbery (rubbery LN) d*** → did it Bilaterally (B/L LN)
• But no pain (Ulcer and LN painless)

• LGV
• LGTV → Keep Neat (NAAT) → From Dogs (Doxy)
• Only Painless ulcer with Painful Buboes (U/L)

• Chance with his Wife (Chancroid and Herpes)
• Multiple people (Multiple lesions)
• Painful sex (Painful)
• Cried (H ducreyi) → Soft (Soft chancre)
• HSV → Vesicles

• Black → Bubo

• Ulcer → White/Blue

• Herpes → Red

• Partner Rx
• Urethral and scrotal swelling, ulcer → treat partners
• Cervical d/d → treat partners when symptomatic
• Vaginal d/d → only trichomonas only when symptomatic
• Non herpetic Ulcer → last 3 months partners
• Herpetic Ulcer → no partner Rx
• PID → Rx partner with kit 1 (Patient kit 6)
• Bubo → All partners for last 3 weeks → BAD (Bubo, azithro, Doxy)

Atrophic Rhinitis

• F > M (Starts during puberty).

• Atrophy of all nose structures (nasal/sinus mucosa, olfactory fibers).

• Caused by: Klebsiella ozaenae (Perez bacillus)

• Other causes:
• Hereditary,
• endocrinal,
• nutritional deficiency (Vit D, B12, iron),
• racial, autoimmune.

• Signs:
• Wide roomy nasal cavity.
• Dry nose.
• Crusty nose (greenish, foul smelling).
• Merciful anosmia (patient cannot smell the odor).

Medical Treatment:

• Alkaline nasal douching.
• Parts
• Sodium chloride (2),
• sodium bicarbonate (1),
• sodium biborate (1)
• mixed in 280 ml of water,
• patient is asked to flush the nose with this solution

• Glycerol.

• Glucose in glycerin.

• Kemicetine antiozena solution
• Chloromycetin
• Estradiol
• Placental extracts
• Mnemonic: Kemidennu chloroform manapichitt, estrogen, placental extract edukkum

Surgery (if medical therapy fails):

• Young's operation
• Complete closure of nasal cavity

• Modified Young's surgery.

• Lautenslager surgery (medialization of lateral wall).
• Submucous teflon injection
• Also in VUR → Sting procedure

• Red diaper syndrome seen in
• Serratia Marcescens
• Lesch Nyhan syndrome

• Blue diaper is seen in
• Hartnup’s disease

Mnemonic:

• for Mycoplasma
• Atypical Walking (walking pneumonia) people (PPLO agar) with CAT (Cold agglutination test) → Eat (Eaton agent) fried egg (fried egg colonies) and Dine (Diens stain) → No walls (cell wall deficient) and take steroids (steroid in cell membrane)

• for Diens
• Diens phenomenon → Proteus
• Diens stain → Mycoplasma

• Etiology: Salmonella typhi (Gram -ve flagellate).

• Typhoid outbreak: Indicates poor sanitation.

• Reservoir: Humans.
• Age group: 5-19 y
• Sex:
• Cases: m > F
• Carriers: F > m.

• Mode of transmission: Feco oral > urine.

• Seasonal variation: Late summers & monsoon.

• Incubation period: 7-14 days (up to 4 weeks).

• Wilson/Salmonella → climbed with a Longitudinal (Longitudinal ulcers in GIT) Ladder (Step ladder pattern fever) → to drink pea soup (Pea soup diarrhea) → fell on a Spot with Rose flowers (Rose spots) with pressure (fade on pressure) → swelling in belly (Soft palpable spleen, liver) → he was then carried in a Sac (Sach's Buffered glycerol Saline)

• Clinical Features
• Enteric fever
• Step ladder pattern fever
• Longitudinal ulcers in GIT
• Pea soup diarrhea
• Fever with bradycardia - Faget's sign
• Soft palpable spleen, liver
• Rose spots
• 2nd /3rd week
• fade on pressure

• Transport – Sach's Buffered glycerol Saline

• Culture media
• Wilson blair media - jet black colonies
• (Only for salmonella, not shigella)

• Treatment - Ciprofloxacin

Diagnosis (mnemonic: BASU)

• Typhoid BASU prob (Probenecid with cholecystectomy)

• If started on antibiotics - most sensitive
• Bone marrow culture

Widal Test Table

• O (1st appears) – H (2nd to appears) – O (disappears 1st) – H (disappears last)

• Most immunogenic and earliest and highest Antibody appears - H

Slide Widal test

• Non specific test so serial testing needed

• Dot → Agglutination test occurred

New test

• Typhidot

• Dot blot

• Wayson stain shows safety pin
• Klebsiella granulomatis
• Yersenia

• Safety pin seen in:



• vibrio parahaemolyticus
• Yersinia pestis
• Haemophilus ducreyi
• Burkholderia
• klebsiella granulomatis

• TAD GH

• CADherins (A → Adherans, D → Desmosomes)

Vibrio Classification by Salt Requirement

V. Cholera classification - Classical vs. EL TOR

• Vibrio cholerae (Gram -ve comma shaped, motile bacilli).

• m/c type: O1 (serogroup) → El tor (biotype) → Ogawa (serotype)
• O → OG → group
• Ogawa → OGT

C/f: 

• Mostly asymptomatic.

• Fever → Uncommon

• Clinical history: Rice water stools (↑↑ cAMP)

Important Information

• Increased cAMP:
• Cholera
• Anthrax
• ETEC (liable)
• Pertussis

cAMP vs cGMP Mechanism

Important Information

• Vibrio cholera targets small intestine

• Cholera toxin increases cAMP

• Vibrio cholera disrupts zona occludens (Tight junction)

Epidemiology

• Cholera outbreak: 
• Indicates lack of social development.
• Note: lack of sanitation - typhoid

• Force of infection: 



• After controlling the source of outbreak
• the incidence of cholera cases still remains a plateu
• called force of infection / tail of outbreak
• D/t carrier stages.
• So no need for vaccination or any other interventions as half of people are carriers

• Reservoir of infection: Humans.

• Transmission: Water borne.

• Period of communicability:

Source	Period of communicability
Cases	7-10 days
Convalescent carriers	2-3 weeks
Chronic carriers	Weeks-months

Stool Collection & Transportation

• Container: McCartney bottle

• Transport media:
• Venkataraman Ramakrishna (VR) media
• Rectal swabs:
• Alkaline peptone water
• Cary Blair media
• Mnemonic: Venkata Raman Ramakrishnan () → Namamde Appi water (Alkaline peptone water) carry (Cary blair) cheyyum → Cartil (McCartney bottle)

• Culture media:
• TCBS (Thiosulphate citrate bile salt sucrose)
• Bromothymol blue (BTB) is the indicator.

• Culture Methods
• Hanging drop preparation:
• Shows scintillating (darting) motility
• Darkfield microscopy:
• "Darting/Shooting stars in dark sky" appearance
• Mnemonic: VR →
• appi thuukki idum (hanging drop) → apo aadum (dartling motility) OR
• Ratriyil starsine nokki eriyum ( Dark field → shooting star)

• Gelatin Stab:
• Turnip/Napiform Liquefaction

Biochemical tests:

• CCOINSS
• Cholera red reaction (nitroso indole compound)
• Catalase +ve
• Oxidase +ve
• Indole test +ve
• Nitrate reduction +ve
• Sucrose lysis +ve
• String test

• String test positive:
• Vibrio cholera
• Klebsiella
• Giardia lamblia
• when kleb ile guard vibe anel

• Oxidase positive
• Features
• vighnesh pseudo nyc vibe on camp helicopter micropenis
• Pseudomonas
• Vibrio cholera
• Neisseria
• Campylobacter
• Helicobacter

A child is brought to the PHC with acute diarrhoea. The doctor, based on history, suspects that the child may be suffering from an infection due to Shigella over cholera and proceeds to give ciprofloxacin as the antibiotic. Which of the following points on history, apart from bloody stools, favour the doctor’s suspicion?

Notification & isolation:

• Typhoid → Till 3 negative stool cultures.

• Diphtheria → 2 culture negative

• Cholera → Isolate patient until 2–3 negative stool cultures

Diagnosis

Treatment

• Isolation:
• Isolate patient until 2–3 negative stool cultures

• Rehydration:
• ORS + Zinc

• Antibiotics:
• Adults: Doxycycline
• Children: Erythromycin
• Pregnant women: Erythromycin or Azithromycin

Chemoprophylaxis

• Drug of choice: Tetracycline

• No use

Chemoprophylaxis cases isolation ??

• 3 days after starting Tetracycline till 48 hours of antibiotics

Disinfection

• Disinfectant: 5% cresol

Cholera Outbreak Management

1. Notifiable
• Single case is not notifiable
• Outbreak → Within 24 hours
• To WHO and Government of India

2. Most effective prophylactic measure:
• Health education

3. No use of chemoprophylaxis, vaccination in cholera
• Except for healthcare workers → vaccines given

4. Verification of diagnosis.

5. Early case finding.

6. Treatment

7. Epidemiological investigation.

8. Sanitation, health education.

Vaccines for healthcare workers :

• Lens users in Ophthal
• Acanthameba
• Contact lens misuse
• Dirty contact lens
• Pseudomonas
• M/c/c of corneal ulcer in contact lens users
• Giant Papillary conjunctivitis

• Hot Tub Folliculitis:
• Cause: Pseudomonas
• History: Jacuzzi or public pool exposure
• Presentation: Monomorphic papules (especially trunk)

• Ecthyma Gangrenosum:
• Cause: Pseudomonas
• Ek (one) thyma - monas (mono)
• Erythema progressing to skin necrosis
• leading to necrotic crust/eschar
• Affected: Immunocompromised (e.g., HIV, hospitalized)
• Deep infection, leads to scar

General Treatment of Bacterial Infections

• Mild: Topical antibiotics
• Examples: Fusidic acid, Mupirocin, Bacitracin, Retapamulin

• Severe: Oral antibiotics
• Examples: Cloxacillin, Cephalosporins, Erythromycins, Amoxicillin
• (+ Clavulanic acid preferred)

Eschar seen in

• E: Ecthyma Gangrenosum

• S: Scrub typhus, Spider bite

• C: Cutaneous anthrax

NOTE: Ecthyma Types (Distinction):

• Ecthyma Contagiosum: Virus (Parapox → Orf virus)

• Ecthyma Infectiosum: Bacteria (Streptococcus)

• Ecthyma Gangrenosum: Bacteria (Pseudomonas)

• Does not grow in simple blood agar

• Need
• Chocolate agar
• Heating blood at 70 degree C → appear like chocolate → releases Factor V and X needed by H influenza for growth
• Blood agar + Staph Aureus
• Blood → Contains Factor X (Hematin)
• Staph aureus → Release Factor V (NAD) by hemolysis
• Satellitism Positive
• H. influenzae growth near the staph streak.

 

• Mnemonic: Ooi Oii → Cry → Baby
• Hint thannitt mullum (Muller hinton)
• Schoolil (school of fish) povum,
• railway trackil (rail road track) kuda nadakum,
• chocolate thinnond horse (chocolate horse blood) ride cheyyum

Ulcer Characteristics:

• Soft chancre

• painful soft genital ulcers.

• Non-indurated base.

• Floor with yellow necrotic tissue

• Undermined edges.

• Bleeds on touch.

Lymphadenopathy: 

• Unilateral and tender

• Suppurative LN → Buboes

Gram Stain: 

• Gram negative bacilli in chains
• "School of Fish"
• "Rail Road Track”

Investigation of Choice: 

• Culture
• Mueller Hinton Agar + chocolate horse blood
• supplemented with isovitalex and fetal calf serum

Treatment:

• Single Dose T. Azithromycin 1 gram.

• If unavailable: 
• Ceftriaxone 250 mg IM.

Important Information

• In syphilis - hard – painless chancre

For a 3-week-old baby suffering from a cough and sore throat, where the mother states that the baby experiences a sudden bout of coughing followed by temporary cessation of breathing, with a total leukocyte count exceeding 50,000 cells per microliter, which medication would you recommend for this patient?

• Bordetella pertussis (also known as the 100-day cough)

• Toxin - PT (↑↑ CAMP)

• Disease: Whooping cough/pertussis

• Common in: Infants, especially unvaccinated

Phases of Whooping Cough

Diagnostic Criteria

• Suspect if cough ≥14 days with no other cause + any of:
• Paroxysmal cough
• Worse at night, after feeding
• Inspiratory whoop
• Post-tussive vomiting
• Central cyanosis
• Undiagnosed apnoeic attacks (infants)
• May cause syncope/seizures from anoxia

• Marked lymphocytosis also seen

Investigations

• PCR (1st line):
• Best in first 3 weeks
• Fast and sensitive

• Swab type:
• Pernasal → infants/young children
• Nasopharyngeal → older children/adults

Characteristics

• Bordet - Gengou medium/ Regan Lowe
• Bisected pearls/mercury drops
• Aluminum paint appearance (confluent)

• M/E: thumb print appearance

• Boarderil gengiwar→ camp ketti→ 100 days war → they used mercury and aluminium paint for war

• Board il mercury drops- fuse to form aluminium paint- make thumb print out of it

• Drug of Choice:
• Macrolides (within 21 days of onset):
• Erythromycin > Azithromycin > Clarithromycin
• Admit infants <6 months

• Prevention: Acellular vaccine
• FHA, PT, AGG, PERT
• No complication

Complications

• Subconjunctival hemorrhage

• Pneumonia

• Bronchiectasis

• Seizures

Do not stain with Gram Stain

• Mycoplasma

• Rickettsia

• Chlamydia

• Spirochetes

• T. Pallidium

• Venereal syphilis: STD

• Incubation period: 9 - 90 days

Syphilis Stages and Diagnosis

Guidelines for Follow-up

• Follow-up at 6, 12 and 24 months

Investigations:

Dark field microscope

• Cannot be stained with Geimsa

• Most sensitive and specific (for primary stage, chancre/lymph node).

• Spiral, slender, wavy organisms (spirochetes).

• Reflect the light transmitted by organism

Silver impregnation:

• Fontana Stain - fluid/films

• Levaditi stain: tissue

• silver pyrates live near fountain

Serological Diagnosis

Reagin Tests (Non-Treponemal Tests) (Non-specific)

• Become positive later

• Become negative → Helps in monitoring

• Includes
• Wasserman test (Complement Fixation Test)
• Kahn test
• VDRL
• RPR
• TRUST
• UST
• RST

VDRL

• Purified lipid extract of beef heart + lecithin + cholesterol

• Use all samples - blood as well as CSF

• IOC for Neurosyphilis → CSF sample

Treponemal Tests (Specific)

• Become positive first

• Do not help in monitoring

• Most Specific blood test: 
• FTA-ABS > TPPA

• Earliest Positive: 
• IgM Capita > FTA-ABS

• Most Sensitive: 
• IgM Capita > FTA-ABS

• Screening: 
• VDRL or RPR (RPR cards for field).

• IOC
• Primary Syphilis: DGM.
• Secondary Syphilis: FTA-ABS.
• Tertiary Syphilis: Enzyme Immunoassay.
• Neurosyphilis: CSF Examination.

• Monitoring Activity: VDRL

Treatment:

• Standard: Injection Benzathine Penicillin.
• Adult Dose:
• 2.4 million units IM single dose (1.2M each buttock).
• Duration:
• Single dose: Primary, Secondary, Early Latent.
• Three doses (weekly): Late Latent, CVS, Benign Tertiary.
• Child Dose: 
• 50,000 units/kg IM
• up to adult dose

• Special Cases (Cannot cross barriers):
• Neurosyphilis, Congenital Syphilis:
• Drug of Choice: Aqueous Crystalline Penicillin IV.
• Alternative: Procaine Penicillin + Probenecid.

• Allergic to penicillin:
• Desensitize the patient
• because Penicillin is the most effective drug ????
• Doxycyline

• In pregnancy

Do not stain with Gram Stain

• Mycoplasma

• Rickettsia

• Chlamydia

• Spirochetes

Culture medium for Chlamydia

• Urethral discharge shows no organism on Gram staining

• McCoy cell culture

• Iodine stained inclusion bodies on microscopy

• “McCoy () Cat Chases (Chlamydia) Iodine () Fish.”Investigation:

• NAAT

• CFT

Chlamydia trachomatis serotypes:

Inclusion Bodies:

• Halberstadter-Prowazeki bodies (HP) are seen in trachoma.

• Levinthal cole lillie body is seen in C. Psittaci.

Trachoma/Egyptian Ophthalmia:

• Agent: Chlamydia Trachomatis (immune type A, B, C)

• IP (Incubation Period): 5-12 days

• Age: 0-10 years (average: 2-5 years)

• Most common cause of preventive blindness in adults.

• DOC (Drug of Choice): Azithromycin 20mg/kg oral single dose.

Stages of Trachoma

• Stage 1: Incipient
• Immature follicles, asymptomatic

• Stage 2: Established
• Typical lesions, no scarring

• Stage 3: Cicatrising
• Scarring + active infection

• Stage 4: Healed
• Only scarring, disease quiet

• Eliminated in 2024, Not eradicated

• Spread: Finger, fly, fomites.

• Signs:
• Sago grain follicles + papillae.
• Arlt’s line:
• Line of cicatrization from concurrent inflammation & healing.
• Herbert’s pits:
• At limbus
• Pannus:
• Vascularization of cornea.

• Mnemonic: Trachoma → Trackil odan Horse power venam (Halb Prow). Odikondirunnapo oru Panni (Pannus) Pit (Herberts Pits) undakki Grains (Sago grains) ittu vachu. But safe (SAFE) ayi line (Arlts) cross cheyth

• Diagnosis: 
• Halberstaedter–Prowazek bodies (cytoplasmic inclusion bodies).

• Treatment (SAFE strategy):
• Surgery → for trichiasis → leading cause of blindness in trachoma
• Antibiotics: Azithromycin 1 gm single dose (Stat).
• Facial cleanliness.
• Environment changes.

• GET strategy

• Complication → Blindness:
• Infections → Inflammation → Scarring of eyelids → Trichiasis → Irritation of cornea by eyelashes → Corneal opacity.

Ophthalmia Neonatorum

• Onset & Cause:

Time of Onset	Cause	Notes
Within first 6 hours	Chemical conjunctivitis	• Due to (silver nitrate) • Rx: Eye lubricant
24–48 hours	Neisseria gonorrhoeae	• Most severe • DOC: Ceftriaxone or cefotaxime
Around 1 week	Chlamydia trachomatis (D–K)	• Most common • DOC: Oral erythromycin

• Prevention:
• Erythromycin eye ointment (first 2 hrs).
• Crede’s method (obsolete; used silver nitrate).

• Ophthalmia Neonatorum Child → (Neisseria Chalmydia)

Lymphogranuloma Venereum (LGV)

• Other Names: 
• "Climatic Bubo," "Lymphogranuloma Inguinale."

• Causative Organism: 
• Chlamydia trachomatis 
• serovars L1, L2 (m/c), L3.

• Incubation: 3-30 days.

• Ulcer Stage: Very transient (hardly seen).

Features

• Mnemonic: ABCDEFG

• Asymptomatic

• Buboes (painful)

• C. trachomatis

• Conjunctivitis

• Urethritis

• Polyarthritis

• Doxycycline - treatment

• Esthiomene (rectal and vulvar strictures)

• Fries test - skin test for LGV

• Complication: Fitz-Hugh-Curtis syndrome

• Groove sign

• curtain in groove

• esthiomene ne fry cheyth door nte adutgh

Presentation:

• Buboes/Enlarged Lymphadenopathy: 
• Usually unilateral
• inflamed, painful, tender (can be bilateral).

• Patients often limp due to pain.

• Lymph nodes are fluctuant, matted, suppurate (leaving multiple sinuses).

Sign: 

• "Groove Sign of Greenblatt"
• taut Poupart's ligament separating femoral and inguinal nodes

Complications:

• Males: "Sexophone Penis."

• Females: "Vulval Elephantiasis"
• Esthiomene - painless due to blocked lymph glands.

Investigation:

• NAAT

• CFT

Treatment: 

• Doxycycline 100 mg twice daily for three weeks.

• Alternative: Erythromycin.