ANAEROBIC SPORE FORMING

THE GENUS CLOSTRIDIUM MORPHOLOGY Gram + rod, club shape oxidase - spore forming, anaerobe catalase - most motile

soil intestinal tract of man and animals most are saprophytic organisms HABITAT

1. Neurotoxic Clostridia 2. Histotoxic Clostridia 3. Enteropathogenic - producing Clostridia Enterotoxaemia - producing Clostridia DISEASE PRODUCING CLOSTRIDIUM

PATHOGENESIS 1. Neurotoxic disease (non-invasive) C. tetani C. botulinum (botulism)

2. Histotoxic disease (invasive, gas gangrene) trauma of deep muscle tissue inflamme, edema, necrosis degenerative capillaries C. chauvoei (Black leg) C. septicum (Malignant edema) etc. C. perfringens type A (Gas gangrene) PATHOGENESIS

3. Enteropathogenic & Enterotoxaemia C. perfringens (C. welchii) type A, B, C, D, E

TRANSMISSION Ingestion, Botulism C. botulinum Wound, Gas gangrene C. chauvoei C. septicum C. perfringens etc.

C. chauvoei Black leg in cattle * ingestion is the most probable route * skeletal muscles seeded with spore (local muscle anoxia, overexercise, insect) * damage to muscle provide spore germination * subsequent multification & toxin production tissue necrosis, gas gangrene, toxaemia PATHOGENICITY 2. Histotoxic disease

Toxins released :  α - hemolysin, necrotizing  β - deoxyribonuclease (DNase)  γ - hyaluronidase  δ - hemolysin

myositis

Myocarditis (blackleg)

C. septicum Malignant edema in horse cattle swine  wound (exogenous infection)  edema, gas in soft tissue  hemorrhage, edema and necrosis “Braxy” in sheep (winter in Europe) ingest frozen harbage may cause wound in abomasum, gangrene, edema at gastrointestinal wall, toxemia Toxin released as the same as C. chauvoei

Ovine abomastitis ( Braxy, C. septicum)

C. septicum in cook meat media.

C. novyi (C. oedematiens) Type A : Gas gangrene wound, inflammation man, cattle, sheep mix organisms (C. chauvoei, C. septicum) “big head” in ram toxin α - necrotizing (typeA & B)

Type B Black disease (Infectious Necrotic Hepatitis) sheep in U.S.A. (cattle, horse, pig rarely) - dormant spore germinate in liver tissue often damaged by fluke migration - systemic effects – death - follow dissermination of – α toxin hepatic efffects produce edema, necrosis

Black disease caused by C. novyi (type B) Dark skin caused by marked subcutaneous venous congestion

C. novyi

C. haemolyticum (C. novyi type D) Bacillary Hemoglobinuria Ruminant : cattle, lamb  deposition of type D spores or vegetative cells in the digestive tract & liver follow digestion  immature liver fluke migrate through the liver resulting in tissue damaged  spore germinate & toxigenesis  hemoglobinuria caused by extensive RBC destruction  death caused by anoxia hemoglobinuria “Red water”

Toxin released : β - hemolysin, necrotizing Lecithinase - act on lecithroprotein of RBC surface hemolysis

Toxin released C. perfringens (C. welchii) myonecrosis and gas gangrene types A  α - hemolytic, necrotizing, lecithinase, lethal

Gas gangrene C. perfringens type A

Gas gangrene following leg amputation C. perfringens type A

Gangrenous dermatitis

Species Toxin name biological activity C. chauvoei C. septicum C. novyi type A C. perfringens typeA     4 toxins  Lethal, hemolytic, necrotizing Deoxyribonucleus Hyaluronidase Oxygen-labile haemolysis Same as C. chauvoei toxins Necrotizing, lethal Haemolytic, necrotizing, lethal, lecithinase Histotoxic clostridia

SpeciesToxin name biological activity C. sordellii C. novyi type B C. haemolyticum     Lecithinase Edema-producing lethal factor Necrotizing, lethal Necrotizing, haemolytic lethal, lecithinase Necrotizing, haemolytic, lethal, lecithinase

3. Enteropathogenic & Enterotoxaemia C. perfringens (C. welchii) - 5 types A B C D E Major toxin released :  α - hemolytic, necrotizing, lecithinase, lethal  β - necrotizing, lethal  ε - protoxin (convert to toxin by trypsin, pepsin)  ι - protoxin

Other toxin released :  Theta - A B C D E, lethal, hemotytic necrotizing  Lamda - B E D, proteolytic enzyme  Mu - hydrolyzing hyaluronic  Enterotoxin - A, C, cytotoxin

Clostridium perfringens types in animal diseases MAJOR TOXIN PRESENT Type Alpha Beta Epsilon Iota A B C D E* Enterotoxin all types * Type E strain often present in cattle and sheep intestine. Rarely implicated in enterotoxemia

Types of C. perfringens and their major toxins C.perfringens Toxin name biological activity Type A Type B Type C  * Enterotoxin   *    * Enterotoxin Lecithinase Cytotoxin Lecithinase Lethal, necrotizing increase intestinal and capillary permeability, lethal Lecithinase Lethal, necrotizing Cytotoxin

Types of C. perfringens and their major toxins C.perfringens Toxin name biological activity Type D Type E * ι* * ι* Lecithinase increase intestinal and capillary permeability, lethal Lecithinase Lethal * Major toxin

A - necrotic enteritis in chicken, pig, dog B - lamb dysentery, hemorrhagic enteritis in calves and foals C - necrotic enteritis in chicken, hemorrhagic enteritis in piglets D - pulpy kidney in sheep, enterotoxemia in calves and goats E - hemorrhagic enteritis in calves enteritis in rabbits

C. perfringens

C. tetani (tetanus) Man, horse are most susceptible Swine & ruminant moderate susceptible Carnivores are comparative resistant Poultry are not susceptible * wound from docking, dehorning castrating, umbilical infection 1. Neurotoxic Clostridia

C. tetani.

Toxin released : 1. Hemolysin (tetanolysin) released during replicated in the tissue 2. Neurotoxin (tetanospasmin) harmless if administered by mouth highly toxic when injected parenterally

Pathogenesis of C. tetani Tetanospasmin produced at wound site peripheral nerve & blood vessel motor nerve terminal vesicle, travel inside axon nerve cell body and its dendritic process in CNS terminal of inhibitory neurones suppress of release inhibitory neurotransmitter from signaling relaxation (glycine) clonic or tonic spasm (spastic paralysis)

Ascending tetanus * typical of animals not susceptible to toxin e.g. dogs and cats * only nerve trunk near toxigenic site absorb sufficient toxin to produce signs, localized tetanus Descending tetanus * typical of animals highly susceptible (horse, humans) * toxin disseminated via vascular channels to nerve endings in areas remote from that site * toxin enter CNS producing, generalized tetanus

Tetanus in cat

Muscle spasm can break bone

C. Botulinum (7 types) neurotoxin A, B, (soil) C, D, E, F, G (wet environment) intoxication ingestion spoiled food, animal carcasses contain toxin toxico-infection (uncommon) spore germinate in intestine, wound toxin producing by vegetative cell “infant botulism” – honey, dust muscle weakness, breathing problem

Most commonly in waterfowl, cattle, horse, sheep, poultry (C, D) Pig and dog are relative resistant Rare in domestic cat

 toxin (absorbed from gastrointestinal tract) transferred to neurone via blood stream to peripheral nerves act at neuromuscular junction  inhibit release of acetylcholine synapse degenerate and flaccid paralysis  death from circulartory failure of respiratory paralysis Pathogenesis of C. botulinum

Avian botulism (type C)

Paralysed inner eyelid Avian botulism

Limberneck (advanced stage)

C. botulinum

OTHER CLOSTRIDIA C. piliforme (Bacillus piliforme) Tyzzer’s disease * severe hepatic necrosis * originally described in mice & lab animals * sporadically in foals, rarely in calves, dogs and cats C. difficile * chronic diarrhea in dogs * haemorrhagic enterocolitis in new born foals

C. difficile

C. colinum * implicated in enteritis in quails, chickens, turkeys, pheasants and geese * morbidity may approach 100% in quail * < 10% in chickens C. spiroforme * implicated in spontaneous and antibiotic-induced enteritis in rabbits

IMMUNITY antibacterial C. chauvoei antitoxin C. tetani, C. botulinum toxoid

ISOLATION AND IDENTIFICATION Anaerobic bacteria N 2 85%, CO 2 5%, H 2 10 % Gas gangrene C. chauvoei, C. septicum etc. 1.1 Tissue suspension inoculated in guinea pig, die within 48 hrs 1.2 Fluorescent antibody technique (FA) 1.3 Biochemical test Detect organisms :

C. septicum in spleen smear of mouse.

FA test to differentiate between C. septicum from C. chauvoei.

1. Enterotoxemia ISOLATION AND IDENTIFICATION Detect toxin : C. perfringens 1.1 Caecal content (fresh) inoculate in mice, die within 10 hrs 1.2 Toxin (serum) neutralization test Type-specific toxin reacts with homologous antitoxin

2. Botulism C. botulinum 1.1 mouse inoculation, food, urine, serum 1.2 toxin ( serum) neutralization test