Staphylococcus

Biochemical characteristics of Staphylococcus: catalase test

- Catalase test - Staphylococci produce catalase - This is tested by addition of hydrogen peroxide to bacteria on a glass slide, and gas bubbles are observed

S. hyicus (coagulase-variable) in pigs causes

- Exudative epidermitis (greasy-pig disease) - Arthritis

Staphylococcus lipase pathogenic effect

breaks down lipids

S. sciuri host

cats, dogs and other animals

S. felis

cats/otitis externa, skin infections

S. xylosus

cattle, sheep/milk, cats, poultry, pigs, horses/skin

S. epidermidis host

cattle/milk; dogs/horses/wound infections

S. chromogenes

cattle/milk; pigs, poultry/skin

Staphylococci in poultry - Bumblefoot diagnosis

clinical signs

Tick pyemia in lambs diagnosis

clinical symptoms & isolation of S. aureus bacteria

Exudative epidermitis / greasy pig disease treatment and control

- early treatment with topical and systemic antibiotics - topical antiseptics - isolate infected pigs - clean and disinfect surfaces - wash sows with antiseptic before farrowing

General characteristics of Staphylococcus spp

- Gram-positive cocci - clusters resembling a bunch of grapes - about 1 um in diameter - most are salt tolerant - resistant to lysozyme - stable in the environment - cause pyogenic infections

Multidrug resistance staphylococcal infections in animals

- MDR to familiar drugs: trimethoprim-sulfonamides, fluoroquinolones, macrolides, tetracyclines, lincosamides (clindamycin) - therefore, vets are left with drugs such as: Rifampin, Chloramphenicol, Aminoglycosides - newer antimicrobial agents: linezolid, ceftaroline, daptomycin and tigecycline have been developed for methicillin-resistant Staphylococcus aureus in humans

Staphylococcal diseases of vet importance - COAGULASE-POSITIVE

- S. aureus - S. pseudintermedius - S. hyicus (coagulase-variable) - S. intermedius - S. schleiferi subsp. coagulans

Note: the Staphylococcus intermedius group consists of:

- S. pseudintermedius - S. intermedius - S. delphini

Otitis externa in dogs

- S. pseudintermedius may be primary or secondary cause - need to treat all contributing factors of the conditions e.g. mites, fungi

Examples of COAGULASE-NEGATIVE staphylococci

- S. sciuri - S. epidermidis - S. xylosus - S. chromogenes - S. caprae - S. equorum - S. felis

Exudative epidermitis / greasy pig disease predisposing factors

- agalactiae in the sow - concurrent infection - weaning

Methicillin-resistance (MR)

- an alternative binding site for Beta-lactam antibiotics (penicillin-binding protein 2A (PBP2A)) is encoded for by mecA/C genes - Mec A/C genes confer resistance to Beta-lactam antibiotics (e.g. penicillin, ampicillin and cephalosporins and others) - MR is used as a marker for resistance to all Beta-lactam antibiotics including penicllins, cephalosporins and carbapenems

Exudative epidermitis / greasy pig disease clinical signs

- anorexia, depression, fever - extensive, exfoliative, non-pruritic dermatitis with a greasy exudate - piglets under 3 weeks of age may die within 24-48 hrs

Bovine staphylococcal mastitis treatment and control

- antimicrobial agents: parenteral antibiotics (IM, SC), intramammary antibiotics, antibiotics - Cephalosporins, cloxacillin, erythromycin, penicillin (if organism is susceptible), penicillin combined with novobiocin, pirlimycin, tetracyclines, tylosin, tilmicosin - Oxytocin: in combination with hand stripping - improve animal husbandry and milking practices - maintain a good milking machine/system

S. aureus in poultry causes

- arthritis and septicemia in turkeys - Bumblefoot - omphalitis

Diagnosis of Staphylococcus: biochemical tests, molecular/genetic testing

- biochemical tests: catalase, coagulase, DNase, latex agglutination tests - molecular/genetic testing - PCR: to detect spa gene codes for Protein A production, to detect MRSA - mecA and mecC gene which encodes an alternative PBP2A binding site; MLST and PFGE, RFLP identify clonal strains; MALDI-TOF

Summary: Staphylococcus spp. can be cultured on

- blood agar plates - common selective and differential media include: MSA, Purple agar

S. aureus in pigs causes

- botryomycosis of mammary glands - impetigo on mammary glands

Summary: Staphylococcus also causes

- bovine mastitis - tick pyemia in lambs - botryomycosis in horses and sows - exudative epidermitis/greasy pig disease - bumblefoot in chickens - in humans: similar to to those for dogs and cats; food poisoning

Staphylococcus cell-associated virulence factors

- capsule - protein A - adhesins

Staphylococcus exoenzymes virulence factors

- catalase - coagulase - lipase - elastase - DNase - hyaluronidase - staphylokinase

Exudative epidermitis / greasy pig disease diagnosis

- clinical signs: exudative dermatitis - isolation and ID of S. hyicus

Biochemical characteristics of Staphylococcus: coagulase

- coagulase - a major virulence factor - observing for agglutination when rabbit plasma is combined with a pure colony - Prothrombin - (Coagulase) -> Thrombin - Fibrinogen - (Thrombin) -> Fibrin

Pyoderma in dogs clinical signs

- dermatitis and folliculitis (rarely systemic) - starts as papular lesions -> pustules and small intradermal abscesses - deep skin lesions (furuncles/large haemorrhagic bullae) may rupture -> fistulous tracts with pus

Staphylococcus selective and differential plates: Purple agar

- differentiates S. aureus from S. pseudintermedius - contains: Bromocresol purple as an indicator, 1% maltose

Staphylococcus selective and differential plates: Mannitol Salt Agar (MSA)

- differentiates staphylococci from coliforms and streptococci: aids in diagnosis in mastitis - differentiates between S. aureus/S. pseudintermedius (pathogenic) and non-pathogenic

Summary: Methicillin-resistant staphylococcal infections are

- difficult to treat - may display multidrug resistance

Bovine staphylococcal mastitis diagnosis

- direct microscopic examination of the milk - culture

Pyoderma in dogs treatment

- drain abscesses - depends on whether lesions are deep or superficial - topical antiseptics - topical and/or systemic antibiotics - staphage lysate

Summary: Methicillin resistance is encoded by the mec A/C gene

- encodes for penicillin-binding protein (PBP2A) which is an alternative binding site for Beta-lactam antibiotics - used as an indicator of resistance to Beta-lactams

Staphylococcus exotoxins virulence factors

- enterotoxins - toxic shock syndrome toxin - exfoliative toxin - hemolysins - leukocidin

Staphylococcal diseases in humans

- food poisoning - transmission: readily transferred to food by carriers handling food - foods implicated: rich foods - custard and cream-filled baked goods, puddings, and creamy salad dressings; salads prepared with mayo-based dressings e.g. potato and egg salads; salty foods, ham - risk is increased by: temperature abuse: food at room temp for too long and poor hygiene e.g. poor hand washing, etc. - exfoliating or Scalded Skin syndrome

Cultural characteristics of Staphylococcus

- grow on non-enriched media (non-fastidious) - facultative anaerobes, non-motile - oxidase-negative - non-spore forming - rapid growth in 18-24 hrs at 37 C - moderately sized - some are pigmented (yellowish/golden especially for some S. aureus)

Exudative epidermitis / greasy pig disease transmission

- highly contagious - a commensal of the vaginal mucosa and skin of healthy sows - enter skin through abrasions

Botryomycosis in horses and sows diagnosis

- history, epidemiology and clinical signs - lesion consists of fibrous tissue with foci of pus and sinus tracts

S. intermedius in horses and pigeons causes

- in horses: isolated from the nares - in pigeons: isolated from the upper respiratory tract

Methicillin-resistant staphylococcal (MRS) infections in animals

- initially began as a major problem in hospitals: hospital-associated methicillin-resistant S. aureus (HA-MRSA) - has become a major problem in vet med and animal health: livestock-associated methicillin-resistant S. aureus (LA-MRSA) - transmission between people and pets including vet personnel has been recorded - MR isolates may also be multi-drug resistant (MDR) - MDR isolates are resistant to 3 or more classes of antimicrobial agents

Staphylococci in poultry - Bumblefoot clinical signs

- lameness - decreased food intake and growth rate - economic losses

Staphylococcus general characteristics

- major opportunistic pathogen - associated pyogenic infections - mainly involved in skin and soft tissue infections (SSTI)

Antibiotic sensitivity testing is important due to high occurrence of antimicrobial resistance (AMR):

- many genes associated with antimicrobial resistance - major problem in vet med - S. aureus (MRSA), S. pseudintermedius (MRSP) and some CoNS (MRCoNS) can display methicillin-resistance

S. aureus in goats causes

- mastitis - dermatitis

S. aureus in sheep causes

- mastitis - tick pyemia in lambs - benign folliculitis in lambs - dermatitis

Bovine staphylococcal mastitis pathogenesis

- neutrophils and macrophages are impaired - chronic inflammation - occasionally gangrenous

Staphylococcus: Hemolysis on blood agar variable, depending on species:

- non-hemolytic (S. hyicus) - single hemolysis - double hemolysis

Botryomycosis transmission

- post-surgery - trauma with contamination

Tick pyemia in lambs treatment

- prophylactic antibiotics e.g. long-acting tetracycline given to lambs starting at 1 week of age - tick-control measures

Summary: Staphylococcus common clinical conditions in dogs and cats

- pyoderma - otitis externa - mastitis - endometritis - cystitis - osteomyelitis - wound infections

Staphylococcal infections in dogs and cats: Staphylococcus pseudintermedius is associated with

- pyoderma - otitis externa - other suppurative conditions: mastitis, endometritis, cystitis, osteomyelitis, wound infections

Botryomycosis in horses and sows lab diagnosis

- samples - pus, skin biopsy - culture and microscopy

Botryomycosis in horses

- schirrhous cord a few weeks post castration - commonly located in the limbs near the point of the elbow

Biochemical characteristics of staphylococcus: slide vs tube coagulase test

- slide test for BOUND coagulase - tube test for UNBOUND coagulase

Staphylococci in poultry - Bumblefoot treatment

- soaks - scab removal - antibiotic ointments - dressings

Staphylococcal species

- species: >50 species of Staphylococcus described to date - most important species in vet med include: S. aureus - coagulate-positive; S. pseudintermedius - coagulate-positive; S. hyicus - coagulase-variable

Diagnosis of Staphylococcus: specimens, direct microscopy, culture

- specimens: pus, milk or other suitable specimens - direct microscopy: observation of Gram-positive cocci - culture: Blood agar (BAP): observe for colony morphology, hemolysis; Selective media: mannitol salt agar (MSA), purple agar, Baird Parker agar (BPA), Chromogenic agars: CHROMagar MRSA, Brilliance MSRA

Botryomycosis in horses and sows treatment and control

- surgical excision - prolonged systemic antibiotics after sensitivity testing - good hygiene

Pathogenic Streptococcus spp

- tend to be species-adapted - mastitis, metritis, polyarthritis, meningitis, pneumonia

Staphylococcus transmission and predisposing factors

- transmission: endogenous; exogenous - predisposing factors: compromise in the integrity of skin or mucous membranes; impairment in some other host defense; presence of a foreign body - e.g. catheter, suture, prosthesis

Staphylococcus habitat

- worldwide in distribution - occur as commensals/normal flora: skin; mucous membranes; upper respiratory (nares) and lower urogenital tract; transient flora of the GI tract - some are opportunistic pathogens causing pyogenic infections - primary or secondary infections

Staphylococcus exfoliative toxin pathogenic effect

causes blistering, responsible for desquamation

Staphylococcus class

Bacili

Only coagulase-positive staphylococci are pathogenic

False

Staphylococci are catalase-negative

False

Staphylococcus aureus and Staphylococcus pseudintermedius are non-hemolytic

False

Staphylococcus aureus is responsible for greasy pig disease/exudative epidermitis

False

Staphylococcus phylum

Firmicutes

Exudative epidermitis / greasy pig disease aetiology

S. hyicus - causes 'greasy pig disease' - worldwide in distribution - occurs in sucklers and weaned pigs up to 3 months of age

Pyoderma in dogs caused by

S. pseudintermedius

Staphylococcus order

Lactobacillales

S. aureus in horses causes

Scirrhous cord (botryomycosis of the spermatic cord)

S. pseudintermedius in dogs causes

Pyoderma, endometritis, cystitis, otitis externa and other suppurative conditions

Tick pyemia in lambs: aetiological agent:

S. aureus - common in UK and Ireland - introduced into the blood stream through minor trauma and tick bites

Bovine staphylococcal mastitis aetiological agent

S. aureus (mainly) - endogenous/contagious mastitis - adapted to the bovine udder colonizing the teat and teat canal

Botryomycosis in horses and sows aetiology

S. aureus (mainly) causing chronic, suppurative, granulomatous condition

Staphylococci in poultry - Bumblefoot aetiology

S. aureus (mainly) causing pododermatitis/dermatitis, osteomyelitis, arthritis, bacteria and septicemia (rarely)

(PAMP) Pathogen-Associated Molecular Pattern

Staphage Lysate (SPL) administered -> Peptidoglycan (PGN) and LP (Lipoprotein) released into immune system -> T helper cells activated -> Cytokines released -> Phagocytes activated -> Staph ingested and lysed by phagocytes -> PGN and LP of lysed bacteria released into immune system -> LP and PGN released into immune system...

Staphylococcus family

Staphylococcaceae

S. aureus in dogs, cats causes

Suppurative conditions like those caused by S. pseudintermedius

Staphylococcus hyicus is non-hemolytic

True

Staphylococcus catalase pathogenic effect

breaks down hydrogen peroxide

Staphylococcus toxic shock syndrome toxin pathogenic effect

a superantigen in humans

Complete haemolysis =

alpha-haemolysin

Staphylococcus capsule pathogenic effect

anti-phagocytic

Staphylococcal infections in dogs and cats: treatment

appropriate antibiotics after sensitivity testing

Tick pyemia in lambs clinical signs

arthritis, ill-thrift, posterior paresis and severe cases septicemia, multi-organ abscesses and death

Staphylococcal infections in dogs and cats: control

aseptic surgical techniques; sanitization of clinics/hospitals

Incomplete haemolysis =

beta-haemolysin

Staphylococcus protein A pathogenic affect

binds IgG in a non-functional orientation to avoid phagocytosis

Staphylococcus adhesins pathogenic effect

binds to host cells, initation of the formation of biofilms

Tick pyemia in lambs: transmission: Ixodes ricinus

bite permits entry of S. aureus + Anaplasma phagocytophilum causing tick fever leading to immune suppression & predisposing to infections

Staphylococcus hyaluronidase pathogenic effect

breaks down connective tissue

Bovine staphylococcal mastitis pathogenesis: infection spreads by milkers, machines, cloths ->

colonization of the apex of the teat, forms microcolonies + minor teat lesions enhance colonization -> enter teat canals, multiply in milk (poor milking machines facilitate entry)

Staphylococcal infections in dogs and cats: diagnosis

culture and microscopy from clinical swabs

Staphylococcus hemolysins pathogenic effect

destroy red blood cells by lysis; alpha-hemolysin/alpha-toxin; Beta-hemolysin/Beta-toxin

Staphylococcus DNase pathogenic effect

digests DNA

Staphylococcus staphylokinase pathogenic effect

dissolves clots

S. pseudintermedius isolated mainly from

dogs and cats

S. delphini isolated from

dolphins, minks, ferrets and badgers

Exudative epidermitis / greasy pig disease MAJOR virulence factor

exfoliative toxin

Staphylococcus enterotoxins pathogenic effect

food poisoning in humans

Staphylococcus =

genus

S. caprae

goats/skin

Summary: antimicrobial sensitivity testing is important due to

high occurrence of resistance

S. equorum

horses/skin

Summary: Both coagulase-positive and coagulase-negative staphylococcus can cause

infections

Some Enterococci are of emerging importance because of

innate resistance to most common antimicrobial drugs

Staphylococcus leukocidin pathogenic effect

kills polymorphonuclear leukocytes

S. aureus in cattle causes

mastitis

Botryomycosis in sows

occurs in mammary tissues

S. schleiferi subsp. coagulans in dogs causes

otitis externa

Staphylococcal infections in dogs and cats: S. schleiferi subsp. coagulans causes

otitis externa in dogs

S. intermedius isolated mainly from

pigeons, dogs, minks, horses

Staphylococcus coagulase pathogenic effect

promotes clotting; may lead to walling off the infection site

Staphylococcus elastase pathogenic effect

protease that breaks down elastin

S. pseudintermedius in cats causes

pyogenic conditions

S. aureus and S. pseudintermedius produce double hemolysis on

sheep blood agar

Staphylococcal infections in dogs and cats: S. aureus occasionally causes

suppurative conditions

Summary: Coagulase activity is only one of many

virulence factors