Staphylococcus Aureus, a Gram-Positive Coccus Occurring in Clusters (Grapes Like)

STAPHYLOCOCCOSIS, STREPTOCOCCOSIS & CAMPYLOBACTERIOSIS DEFINITION Staphylococcosis is acute systemic or chronic disease of birds characterized most frequently by purulent arthritis and tenosynovitis. OCCURRENCE • Staphylococcal infections of poultry occur worldwide and affect all classes of birds. • Outbreaks are most important in turkeys and broilers. • The organisms are common in the environment and are especially associated with the skin (normal inhabitant). • Most diseases produced by Staphylococcus sp. are associated with ahistory of break in the skin or beak (trauma, beak trimming, toe trimming, foot pad burns etc.). OCCURRENCE • Avian infections tend to be caused by types occurring in birds rather than human strains. • Isolates pathogenic for one class of poultry are usually pathogenic for other classes of birds. • Toxigenic strains capable of causing food poisoning can contaminate the skin of processed poultry (zoonotic importance). • The source of these strains at present is in debate. • Bio-typing indicates processing plant worker origin while plasmid profile indicates poultry origin. HISTORICAL INFORMATION • Staphylococci were first discovered to be a cause of arthritis in geese in 1892. • Since that time they have been identified as the cause of a variety of localized and systemic diseases in many different avian species and in most areas of the world. • The disease was more common in turkeys when they were raised on range than it is now. ETIOLOGY • 1. Most staphylococci isolates have been identified as Staphylococcus aureus, a Gram-positive coccus occurring in clusters (grapes like). Pathogenic isolates are usually coagulase positive. 2. Organisms are moderately resistant to common disinfectants. • Chlorine-containing disinfectants are efficacious in the absence of organic material. 3. Toxins produced by staphylococci can increase both the virulence and pathogenicity of a particular strain. Clinico-pathological picture • General signs of illness. • Fever and reduced appetite. • Foot abscess (bumblefoot). • Lameness and arthritis. • Birds unable to move. • Omphalitis in newly hatched chicks. • Reduced fertility and hatchability in breeders. LESIONS Diseases produced by staphylococcus infections include: 1. Omphalitis. 7. Discospondylitis (spondylitis). 2. Gangrenous dermatitis. 8. Osteomyelitis. 3. Cellulitis. 9. Endocarditis. 4. Abscesses (bumble foot). 10. Green liver-osteomyelitis complex in turkey. 5. Septicemia. Sternal bursitis. 6. Arthritis/periarthritis/synovitis. 11. 1. Omphalitis • Although infections of the yolk sac occur, they are less common than omphalitis caused by other bacteria as (Aerobacter, Proteus, Klebsiella, Pseudomonas, Salmonella, Bacillus, enteric Streptococcus, E. coli, …etc.). • Sources of the bacterium include the breeder flock, hatchery environment, and hatchery workers. 2. Gangrenous dermatitis • Affected areas of the skin are dark red, moist, crepitation sound, thickened, and clearly demarcated from adjacent normal skin. • Usually traumatic lesions such as punctures or scratches are present. • The serosanguinous fluid seen in clostridial infections is minimal or absent. Staphylococcal gangrenous dermatitis is typically secondary to immunosuppression caused by infectious bursal disease or chicken infectious anemia virus. • Immune suppression (CIA, IBD, MD, Reo)+ Staph + Cl. Septicum ↓ Gangarenous dermatitis (blue wing disease) 3. Cellulitis • A purulent inflammation is present in subcutaneous tissues. • Traumatic lesions may or may not be present. • The overlying skin tends to be dry and discolored. 4. Abscesses • There are localized purulent lesions in the skin. • The plantar surface of the foot is a common site and results in bumble foot. • Abscesses result from puncture wounds. 5. Septicemia • There is an acute increase in mortality with congestion of the internal organs, hyperaemia, enlargement, sub –capsular hemorrahge and various- degree coagulative necrosis in the liver or the spleen are observed. • It is usually associated with a processing event of the bird such as beak trimming or some other trauma to the skin. • As staphylococci are ubiquitous, their presence could not be prevented . • The measures should be directed toward minimizing the possibilities for traumas of skin, respiratory and intestinal mucosa. 6. Arthritis/periarthritis/synovitis • Any joint, tendon sheath, or synovial bursa can be affected. • Arthritis/periarthritis/synovitis is seen clinically as swollen, hot joints, especially hock joints. • It occurs as a sequel to septicemia and can be experimentally reproduced by intravenous injection of pathogenic strains. • Initially, affected tissues are acutely inflamed and contain white to yellow soft fibrinopurulent exudate. Later, the exudate becomes caseous. • Fibrosis of affected tissues occurs late. • Affected birds often have bile stasis of the liver. • High numbers of large mononuclear cells are seen in blood smears. 7. Discospondylitis (spondylitis) • The joints of articulating thoracolumbar vertebrae are affected. • The process spreads to affect adjacent vertebrae. • Lesions may become so extensive that pressure on the spinal cord will develop causing paresis and paralysis . 8. Osteomyelitis(fumer head necrosis) • This is a sequel to septicemia. • Organisms localize in metaphyseal vessels invading the cartilage of the growth plate of actively growing bones. • Initially, pale yellow, friable bone is seen in affected areas adjacent to the growth plate, especially in the proximal tibia and metatarsus. • Necrotic areas, abscesses, and sequestra are seen later. 9. Endocarditis • This is an uncommon sequel to septicemia. • There are vegetations on the mitral and/or aortic valves. • Emboli from valve lesions cause infarcts in the brain, liver, and spleen. 10. Green liver-osteomyelitis complex in turkey • This is a condition observed at slaughter. • Normal-appearing processed turkey carcasses present green discoloration of the liver and associated arthritis/synovitis, soft- tissue abscesses, and osteomyelitis of the proximal tibia. • Staphylococcus aureus is most commonly isolated from these lesions but other opportunistic bacteria such as Escherichia coli have also been isolated. Green liver-osteomyelitis complex Other local form of Staphylococcosis is Sternal bursitis. • The sternal bursa is enlarged at a various extent because of gathering of purulent substance. • Sometimes, the covering skin is necrotized. • The microorganism is widely distributed in the environment and mainly on the skin. • Most of Staphylococcus aureus-induced lesions are associated with skin injuries, debeaking, finger cuts. • All categories of birds are affected. Diagnosis 1- field diagnosis: • Flock history • Clinical signs • PM lesions 2- Lab. diagnosis. DIAGNOSIS 1. Gross lesions are suggestive. A rapid, presumptive diagnosis can be made by identifying direct smear stained with Gram stain is showing the typical cocci in smears from lesions. 2. Organisms can be readily cultured and identified from lesions and often from the livers of affected birds. On mannitol salt agar appear as golden yellow colonies. On blood agar appear as rounded colonies with Beta hemolysis. DIAGNOSIS • Biochemical identification. • Molecular identification. CONTROL 1. Because staphylococci are ubiquitous in the environment their presence cannot be prevented. When an outbreak is associated with a particular environment, the source should be sought and eliminated. 2. Protect broilers from infectious bursal disease with an appropriate vaccination program. 3. Take measures to reduce the occurrence of traumatic skin lesions and foot pad burns, as well as any enteric disease which would damage the integrity of the intestinal mucosa. CONTROL 4. The respiratory tract has also been identified as an important portal of entry for pathogenic staphylococci in turkeys. Exposing chickens or turkeys to a live avirulent vaccine, namely strain 115 of Staphylococcus epidermidis, by aerosol at 10 days and again at 4-6 weeks substantially reduced the incidence of staphylococcosis and improves overall flock livability. 5. Avoid overly severe feed restriction in breeder replacements which has been associated with an increased incidence of staphylococcosis. TREATMENT 1. Broad spectrum antibiotics are effective against staphylococci if given early in the course of the disease. 2. Resistance to antibiotics is common and isolates should be tested for sensitivity. 3. Usually treatment is not cost effective and preventive programs should be relied on. 4. Treatment: based on sensitivity testing; Penicillin, streptomycin, tetracyclines, erythromycin, novobiocin and sulfa drugs INTRODUCTION Streptococcosis in avian species is worldwide in distribution, occurring as both acute septicemic and chronic infections with mortality ranging from 0.5%–50%. HISTORY • Acute streptococcal infections of poultry were first described in chickens in 1902 and 1908 as a septicemia. • Chronic streptococcosis caused 50% mortality in a flock over a 4- month period and was identified as the cause of mortality due to salpingitis and peritonitis in chickens. • Streptococcosis in turkeys was reported as early as 1932. • Bacterial or vegetative endocarditis associated with streptococci was first reported in 1927 and again in 1947. ETIOLOGY •The genus Streptococcus is composed of Gram-positive, non-motile, non-spore forming, facultative anaerobes, spherical bacteria occurring in singles, pairs, and short chains. ETIOLOGY oStreptococcus spp., isolated from avian

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