---

🐔 AVIAN MYCOPLASMOSIS

Exam-Oriented Complete Notes | Vet Medicine | Hindi-English Mix

---

📌 INTRODUCTION (परिचय)

⭐ Exam Key Point: Mycoplasma class Mollicutes ka member hai - इसकी सबसे बड़ी खासियत है कि इसमें cell wall ABSENT होती है। इसीलिए Penicillin काम नहीं करती।

---

🦠 ETIOLOGY (कारण / जीवाणु की पहचान)

• Organism: Family Mycoplasmataceae, Class Mollicutes
• Shape: Pleomorphic (बदलती हुई shape)
• Size: Smallest self-replicating prokaryotes (सबसे छोटे self-replicating bacteria)
• Special Feature: NO cell wall → Beta-lactam antibiotics ineffective
• Gram stain: Gram-negative appearance लेकिन true gram staining नहीं होती
• MG is the MOST pathogenic of all avian mycoplasmas
• Considerable strain variability exists - कुछ strains ज्यादा virulent, कुछ कम

---

🌍 EPIDEMIOLOGY (महामारी विज्ञान)

• Chickens (मुर्गी) - primary host
• Turkeys (टर्की) - more susceptible, severe disease
• Game birds (तीतर, बटेर)
• Finches and other pet birds

• Transovarian (egg transmission) - infected hen के अंडे से chick में जाता है
• यही वजह है कि बीमारी पीढ़ी दर पीढ़ी चलती है

• Aerosols (हवा में सांस के साथ)
• Respiratory secretions (नाक-मुंह का स्राव)
• Fomites - infected shoes, equipment, clothes (इंसानों के जूते, कपड़े, उपकरण)
• Direct contact

⭐ Exam Tip: "Once infected, birds remain infected FOR LIFE" - ये carrier बन जाते हैं!

• Stress (overcrowding, nutritional deficiency)
• Concurrent infections: Newcastle Disease Virus, Infectious Bronchitis Virus, E. coli
• Poor ventilation
• Young age

---

🔬 PATHOGENESIS (बीमारी कैसे होती है)

Mycoplasma enters via respiratory tract
         ↓
Attaches to respiratory epithelium (ciliated cells)
(Specialized organelle helps attachment)
         ↓
Prevents ciliary clearance (cilia काम करना बंद)
         ↓
Produces H₂O₂ and superoxide radicals
         ↓
Oxidative damage to host cells
         ↓
Innate immune system activation → cytokines release
         ↓
Inflammation of trachea, air sacs, sinuses, lungs
         ↓
CRD (MG) / Synovitis (MS)

• MG alone ज्यादा नुकसान नहीं करता
• जब E. coli + NDV + IBV साथ आते हैं → बहुत severe disease
• Turkeys में avian metapneumovirus के साथ synergism होता है

---

🤒 CLINICAL SIGNS (लक्षण)

MG - Chronic Respiratory Disease (CRD)

• Nasal discharge (नाक से पानी/mucus)
• Rales (गले में घड़घड़ाहट) - mild to marked
• Coughing, Sneezing (खांसी, छींक)
• Conjunctivitis with frothy eyes (आंख में झाग)
• Decreased feed efficiency and weight gain
• Egg production में कमी (layers/breeders में)

• Swelling of infraorbital sinuses ⭐ (आंख के नीचे सूजन) - Pathognomonic in turkeys
• Eyelids may close due to swelling
• Wing feathers soiled (आंख से exudate पोंछने की कोशिश में)
• Conjunctivitis with frothy discharge

MS - Infectious Synovitis

• Subclinical mostly (mild rales, subclinical infection)
• Similar to MG but milder

• Lameness (लंगड़ापन) - first sign
• Pale-bluish head/comb (कलगी नीली-फीकी)
• Birds sit near feeders/drinkers (खाने-पानी के पास बैठे रहते)
• Swollen hocks and footpads ⭐ (टखने और पंजे सूजे हुए)
• Sternal bursitis (breast blisters) (सीने पर छाले)
• Depression, reduced growth
• Egg shell abnormalities (MS में)

---

🏥 LESIONS (पोस्टमॉर्टम में क्या दिखता है)

• Mucoid/catarrhal/caseous exudate in nasal passages, sinuses
• Airsacculitis - air sacs cloudy, thickened with caseous material
• Tracheitis (mild mucoid initially → caseous later)
• "Pearls" - amorphous masses in air sacs (turkeys)

• Viscous, creamy-grey synovial fluid in joints
• Thickened synovium
• Sternal bursa distended

• Lymphocytic and heterophilic infiltration of synovium
• Respiratory epithelial damage, loss of cilia

---

🔍 DIAGNOSIS (रोग की पहचान)

Step 1 - Sample Collection

• Tracheal swabs, choanal swabs (for respiratory)
• Joint aspirates (for synovitis)
• Infraorbital sinus aspirate
• Egg yolk / embryo samples

Step 2 - Laboratory Tests

⭐ Exam Trap: SPA is SCREENING test; HI is CONFIRMATORY test. False agglutination can occur after oil-emulsion vaccines or MS co-infection.

---

💊 TREATMENT (इलाज)

⭐ Remember: Mycoplasma में cell wall नहीं है, इसलिए:

• Penicillin, Cephalosporins, Ampicillin - USELESS ❌
• Beta-lactam antibiotics काम नहीं करते

⭐ Key Limitations:

• Antibiotics decrease clinical signs लेकिन infection eliminate नहीं करते
• Can reduce egg transmission if given to breeders
• Established synovitis cases में antibiotics कम effective

---

🛡️ PREVENTION & CONTROL (रोकथाम)

1. Eradication (उन्मूलन) - BEST method

• Source birds from MG/MS-free breeder flocks
• National Poultry Improvement Plan (NPIP) - US में control program
• Regular serological monitoring of breeder flocks

2. Biosecurity (जैव सुरक्षा)

• All-in, all-out management
• Disinfection of fomites (shoes, equipment)
• Visitor control

3. Vaccination (टीकाकरण)

• Live attenuated vaccines available for MG
  • F-strain (mild virulence)
  • ts-11 (temperature sensitive mutant)
  • 6/85 strain
• Vaccines used in high-challenge situations - reduce clinical signs and economic losses
• Killed/inactivated oil-emulsion vaccines also available

4. Egg Treatment

• Dipping/injecting hatching eggs in antibiotic solution to reduce vertical transmission

---

📊 MG vs MS - Quick Comparison Table ⭐

---

⚡ ECONOMIC IMPORTANCE (आर्थिक नुकसान)

• Reduced egg production and hatchability
• Decreased feed efficiency and weight gain
• Condemnation of carcasses at processing (MG in broilers)
• Treatment costs
• WOAH-listed disease (international significance)
• India में poultry industry को करोड़ों का नुकसान

---

🎯 HIGH-YIELD EXAM POINTS (याद रखने वाली बातें)

1. No cell wall → Penicillin ineffective ❌
2. "Fried egg" colonies on PPLO media ⭐
3. MG = Most pathogenic avian mycoplasma
4. Transovarian transmission = vertical spread through eggs
5. Turkeys show infraorbital sinus swelling (MG)
6. MS causes infectious synovitis = swollen hocks + footpads
7. SPA = Screening; HI = Confirmatory ⭐
8. Real-time PCR = most sensitive/specific current test
9. Drug of choice = Tylosin (Macrolide)
10. Antibiotics treat but never eliminate infection
11. Polymicrobial disease with E. coli + NDV + IBV = severe CRD
12. Birds infected for LIFE = lifelong carriers

---

🔑 ONE-LINERS FOR QUICK REVISION

• "Mycoplasma = Mollicutes = No cell wall = No penicillin"
• "MG = Sinusitis in Turkey, CRD in Chicken"
• "MS = Synovitis = Lame bird with swollen hocks"
• "Fried egg colony on PPLO = Mycoplasma ka pehchaan"
• "Tylosin is your go-to drug"
• "SPA screen karo, HI se confirm karo"

---

---

🐣 PULLORUM DISEASE

Exam-Oriented Complete Notes | Vet Medicine | Hindi-English Mix

---

📌 INTRODUCTION (परिचय)

⭐ Other Names (परीक्षा में पूछा जाता है):

• Bacillary White Diarrhea (BWD) - सबसे classic नाम
• Salmonella Pullorum infection
• White Diarrhea of Chicks

---

🦠 ETIOLOGY (कारण)

⭐ Exam Trap: S. Pullorum is NON-MOTILE - यह इसे अन्य Salmonella से अलग बनाता है (ज़्यादातर Salmonella motile होते हैं)।

• S. Pullorum और S. Gallinarum (Fowl Typhoid) दोनों same serogroup D1 में हैं
• इसीलिए दोनों का antigen cross-react करता है - एक test से दोनों detect हो सकते हैं

---

🌍 EPIDEMIOLOGY (महामारी विज्ञान)

• Chickens - primary host (most susceptible)
• Turkeys - second most affected
• Quail, pheasants, guinea fowl, ducks, pigeons, canaries
• Mammals भी: pigs, cattle, cats, dogs, foxes, mink (कभी-कभी)
• Zoonotic potential - humans में भी infection reported

• Most severe: < 3-4 weeks old chicks/poults ⭐
• Semi-mature and mature birds → usually subclinical carriers
• Infected flock में newly hatched chicks सबसे ज़्यादा die करते हैं

• Infected hen → egg → chick
• Infected carrier hen अपने 1/3 अंडों (33%) में bacteria transfer करती है
• Hatchery contamination से disease rapidly spread होती है
• Egg/hatchery se infected chicks → पहले कुछ दिनों से 2-3 हफ्ते में मरते हैं

• Bird-to-bird direct contact
• Fecal contamination of feed, water, litter
• Cannibalism of infected carcasses
• Wild birds, rodents, insects, flies
• Contaminated equipment, shoes (fomites)
• Farm-to-farm: poor biosecurity से

---

🔬 PATHOGENESIS (बीमारी कैसे होती है)

S. Pullorum enters via:
  ↓
Egg (Vertical) OR Ingestion/Inhalation (Horizontal)
  ↓
Intestinal colonization → Mucosal invasion
  ↓
Bacteremia / Septicemia (blood में bacteria)
  ↓
Localization in organs:
Liver, Spleen, Lungs, Cecum, Joints, Ovary
  ↓
CHICKS (< 3 weeks): Acute fatal septicemia
ADULTS: Chronic carrier state (ovary/testicles)
  ↓
Adult carriers → Transovarian transmission
(cycle continues)

• Chicks में immune system immature होती है → septicemia और high mortality
• Adults में bacteria ovary में persist करते हैं → lifelong carrier
• Recovered birds = permanent carriers → इसीलिए treatment useless है

---

🤒 CLINICAL SIGNS (लक्षण)

CHICKS (< 3-4 weeks) - ACUTE FORM ⭐

⭐ "Chicks huddle near heat source + white pasted vent = Pullorum Disease"

Signs पहले 5-10 दिनों तक नहीं दिखते, फिर 7-10 दिन में बढ़ते हैं, 2nd-3rd week में peak mortality

ADULT BIRDS - CHRONIC/SUBCLINICAL FORM

• Usually asymptomatic carriers (कोई लक्षण नहीं)
• Decreased egg production
• Poor hatchability
• Occasional: diarrhea, depression, dehydration

---

🏥 POST-MORTEM LESIONS (मृत्यु के बाद क्या दिखता है)

Chicks (Acute):

⭐ Pathognomonic Lesion Combination: Liver necrotic foci + Grey lung nodules + Cecal caseous cores = Pullorum Disease

Adult Carriers:

⭐ Exam Point: "Atrophic, caseous ovarian follicles" = Pullorum in adult hens

---

🔍 DIAGNOSIS (रोग की पहचान)

1. Clinical Diagnosis (field पर)

• History: young chicks dying in 2nd-3rd week
• White diarrhea, pasted vent, huddling
• Post-mortem: liver necrosis, lung nodules, cecal cores

2. Serological Tests (Blood Tests) ⭐

⭐ WBPA (Whole Blood Plate Agglutination) = field diagnosis ka gold standard

• Antigen (stained S. Pullorum antigen) + blood drop → agglutination = positive
• 2 negative tests, 21 days apart = flock declared clean

⭐ Cross-reaction: S. Pullorum और S. Gallinarum का common antigen है → एक test दोनों detect करता है (Pullorum-Typhoid test)

3. Definitive/Confirmatory Diagnosis

• Bacterial isolation and identification
• Culture on Blood agar, MacConkey agar, Brilliant Green agar
• Biochemical tests + Serotyping
• PCR (now NPIP-approved)

4. Samples for Isolation

• Liver, spleen, cecal cores
• Yolk sac (dead-in-shell)
• Tracheal/cloacal swabs
• Ovarian follicles (adults)

---

💊 TREATMENT (इलाज)

⭐⭐ MOST IMPORTANT EXAM POINT: "Treatment is NOT RECOMMENDED" - यह pullorum disease की सबसे बड़ी खासियत है!

• Antibiotics clinical signs को reduce कर सकते हैं
• लेकिन carrier state को eliminate नहीं करते
• Recovered birds lifelong carriers बन जाते हैं
• Carrier birds अगली generation में disease transmit करते रहते हैं
• इसलिए treatment = waste of time and money

• Sulfonamides (Sulfadimidine)
• Furazolidone ⭐ (traditional drug of choice in India/exam)
• Tetracyclines
• Fluoroquinolones
• Chloramphenicol

⭐ Exam Answer for treatment: "Treatment is NOT recommended. Control is by test-and-slaughter."

---

🛡️ PREVENTION & CONTROL (रोकथाम)

1. TEST AND SLAUGHTER POLICY ⭐⭐ (Most Important)

• यह Pullorum disease का cornerstone of control है
• सभी breeding flocks को routine serological testing
• Reactor birds (positive) को तुरंत slaughter करना
• यही policy US, Europe, Australia में pullorum eradicate करने में काम आई

2. National Poultry Improvement Plan (NPIP) ⭐

• US में 1930s से शुरू हुआ federal-state-industry cooperative program
• Goal: S. Pullorum को commercial flocks से eradicate करना
• इसी की वजह से US में pullorum practically eradicated है
• India में analogous programs exist

3. Clean Flock Program

• Birds only purchase from S. Pullorum-free certified flocks
• Flock को "Pullorum-Typhoid Clean" certify करने के लिए 2 negative tests (21 days apart) चाहिए

4. Hatchery Hygiene

• Hatchery disinfection (Formaldehyde fumigation)
• Infected eggs eliminate करना
• Egg dipping in antibiotic solution (limited use)

5. Biosecurity

• All-in, all-out management
• Rodent and wild bird control
• Fly control
• Visitor and equipment disinfection
• Quarantine of new birds

6. No Vaccine Available ⭐

• Pullorum disease के लिए कोई effective vaccine नहीं है
• Control purely by testing and elimination

---

🔄 PULLORUM vs FOWL TYPHOID - Quick Comparison ⭐

---

⚡ ZOONOTIC IMPORTANCE

• S. Pullorum humans में infection cause कर सकता है
• Particularly immunocompromised individuals में
• Reportable disease - State Veterinarian को 24 hours में report करना mandatory

---

🎯 HIGH-YIELD EXAM POINTS (यह ज़रूर याद करें!)

1. BWD = Bacillary White Diarrhea = Pullorum Disease ⭐
2. Causative agent = S. Pullorum (Gram-negative, NON-MOTILE) ⭐
3. Most affected: Chicks < 3 weeks ⭐
4. Transmission: Transovarian (vertical) = PRIMARY ⭐
5. Classic signs: White pasted vent + huddling near heat ⭐
6. Peak mortality: 2nd-3rd week of life ⭐
7. Liver: necrotic foci | Lungs: grey nodules | Cecum: caseous cores ⭐
8. Adult carriers: caseous ovarian follicles ⭐
9. Diagnosis field test: WBPA (Whole Blood Plate Agglutination) ⭐
10. Treatment NOT recommended (carrier state persist करता है) ⭐⭐
11. Control = Test and Slaughter ⭐⭐
12. No vaccine available ⭐
13. S. Pullorum and S. Gallinarum = same serogroup D1 → cross-react in PT test
14. NPIP = control program (US)
15. Notifiable/Reportable disease ⭐

---

🔑 ONE-LINERS FOR QUICK REVISION

• "White diarrhea in chicks = Pullorum = BWD"
• "S. Pullorum = Gram -ve, Non-motile, Host-adapted"
• "Vertical transmission = primary route"
• "Chicks huddle, white vent paste = Pullorum"
• "Treatment nahi, Test karo aur slaughter karo"
• "WBPA = field test | Isolation = gold standard"
• "Caseous ovary = carrier hen ka sign"
• "Pullorum + Fowl Typhoid = same PT test (common D1 antigen)"

---