NEW Non fermenter gram -ve part 3

Lawsonia intracellularis Gram stain

Slender curved Gram-negative rod

Oxygen requirement of Lawsonia intracellularis

Microaerophilic

Lifestyle of Lawsonia intracellularis

Obligate intracellular bacterium

Lawsonia intracellularis can only be grown in

Cell culture

Lawsonia intracellularis causes

Proliferative enteropathy

Primary host of Lawsonia intracellularis

Pigs

Most susceptible pigs

Post-weaning and young growing pigs

Primary site of infection

Terminal ileum

Lawsonia intracellularis infects

Crypt epithelial cells

Effect of Lawsonia infection on crypt cells

Hyperplasia (proliferation)

Characteristic intestinal lesion

Thickened intestinal mucosa

Clinical signs of proliferative enteropathy

Diarrhea dehydration abdominal pain and poor growth

Proliferative hemorrhagic enteropathy occurs in

Older pigs

Characteristic lesion of proliferative hemorrhagic enteropathy

Thickened intestinal wall with hemorrhage into the lumen

Mortality of proliferative hemorrhagic enteropathy

Approximately 50%

Porcine intestinal adenomatosis occurs in

Pigs younger than 12 weeks

Lesions of porcine intestinal adenomatosis

Thickened terminal ileum and proximal large intestine

Clinical signs of porcine intestinal adenomatosis

Anorexia wasting and poor growth

Necrotic enteritis caused by Lawsonia intracellularis is characterized by

Necrosis of proliferative intestinal mucosa

Clinical outcome of necrotic enteritis

Sudden death

Regional ileitis is also called

Hosepipe gut

Why is regional ileitis called hosepipe gut?

Marked muscular hypertrophy causes a rigid thick intestine

Major complication of regional ileitis

Intestinal rupture and peritonitis

Outcome of intestinal rupture

Sudden death

Best clue for Lawsonia intracellularis

Intracellular curved Gram-negative rod causing proliferative enteropathy in post-weaning pigs

Francisella tularensis Gram stain

Small Gram-negative coccobacillus

Francisella tularensis causes

Tularemia

Other names for tularemia

Rabbit fever and Deer fly fever

Francisella tularensis subsp. tularensis

Type A

Type A strain is found mainly in

North America

Reservoir of Type A strain

Land mammals

Virulence of Type A strain

Highly virulent

Francisella tularensis subsp. holarctica

Type B

Type B strain is found in

North America Europe and Asia

Reservoir of Type B strain

Aquatic mammals

Virulence of Type B strain

Less virulent

Primary hosts of Francisella tularensis

Wild rabbits rodents and beavers

Other susceptible hosts

Humans dogs cats and ruminants

Transmission of tularemia

Tick bites deer fly bites skin contact inhalation and ingestion

Important arthropod vectors

Rabbit ticks wood ticks deer flies and black flies

Pathogenesis of tularemia

Septicemia and lymphadenitis

Characteristic lesions of tularemia

Pyogranulomatous lesions in multiple organs

Most common form of human tularemia

Ulceroglandular

Other forms of human tularemia

Pneumonic typhoidal and oropharyngeal

Characteristic lesion in cats with tularemia

Enlarged spleen with multiple white necrotic foci

Characteristic liver lesion in rabbits

Multifocal necrotizing hepatitis

Characteristic intestinal lesion in rabbits

Pyogranulomatous enteritis

Characteristic lesion in beavers

Granulomatous enteritis with peritonitis

Diagnosis of tularemia

Serology showing a fourfold rise in antibody titer

Treatment of tularemia

Gentamicin or doxycycline

Vaccine for tularemia

Live attenuated vaccine

How can tularemia be prevented?

Avoid handling or eating undercooked wild rabbits

Best clue for Francisella tularensis

Rabbit fever transmitted by ticks and deer flies causing pyogranulomatous lesions

Lawsonia intracellularis is intracellular or extracellular?

Obligate intracellular

Francisella tularensis is zoonotic?

Yes

Major disease caused by Lawsonia intracellularis

Proliferative enteropathy

Major disease caused by Francisella tularensis

Tularemia

Characteristic lesion of Lawsonia intracellularis

Thickened terminal ileum due to crypt hyperplasia

Characteristic lesion of Francisella tularensis

Pyogranulomatous lesions in multiple organs