coryne & rhodoco pt. 1

Actinomycetales

Corynebacterium belongs to the Corynebacteriaceae family of ______ order

Gram-positive rods

• small

• Short

• Pleomorphic ____

• rod

• Coccoid

• Club-shaped

Corynebacterium occurs in

Catalase

Corynebacterium

• ______ positive

Non-acid fast

Corynebacterium

• non-

negative

Corynebacterium

• oxidase-

Facultative anaerobic

Corynebacterium

• usually …..

Non-motile

Corynebacterium

• animal pathogens are

Rhodococcus equi

Previous name: Corynebacterium equi

Present name:

Corynebacterium kutscheri

Previous name: Corynebacterium murium

Present name:

Corynebacterium pseudotuberculosis

Previous name: Corynebacterium ovis

Present name:

Trueperella (Arcanabacterium pyogenes)

Previous name: Actinomyces (Corynebacteium) pyogenes

Present name:

Actinobaculum suis

Previous name: Eubacterium (Corynebacterium) suis

Present name:

Corynebacterium renale

Previous name: Corynebacterium renale type I

Present name:

Corynebacterium pilosum

Previous name: Corynebacterium renale type II

Present name:

Corynebacterium cystitidis

Previous name: Corynebacterium renale type IIi

Present name:

Rhodococcus equi

• belongs to the corynebacteriaceae family of the actinomycetes order

• has oxidative mechanism

• This specieis is the only significant veterinary pathogen in the genus

• It is considered an emerging human opportunistic pathogen in immunocompromised humaan

Rhodococcus equi

• aerobic, gram-positive coccus or rod

• Bacterial cell is capsulated

• Sometimes weakly acid-fast

• Catalase positive CP

• has oxidative mechanims

• skin

• Mucuous membranes (nasopharynx)

• Intstinal pseudotuberculosis

Corynebacterium is found on the:

Corynebacterium pseudotuberculosis

• Can survive for 1-8 days on inanimate surfaces

• Can survive for 7-55 days on particulate fomites (wood

  shavings, hay, straw, and

• Lower temperature extends their survival potential

Soil contaminated with manure from horse and farm animals

Rhodococcus equi - Natural Habitat

• found in….

Volatile fatty acids

Rhodococcus equi - Natural Habitat

• _________ in fecal material promote growth of bacterium

Acidic soils

Rhodococcus equi - Natural Habitat

• lower soil moisture concentration and lower pasture heights

  • Give rise to elevated airborne concentration of virulen

• ________ may contribute to increased proportion of virulent strains with an R. equi population

Corynebacteria

Pyogenic bacteria causing a variety of suppurative conditions

Corynebacteria

______ on abdominal fluid cytology (species unknown). Note the ‘club-shaped’ rods.

Corynebacterium pseudotuberculosis

• causes caseous lymphadenitis

• Forms abscesses in the skin, lymph nodes (external or internal) and organs such as spleen, lungs, liver and kidneys

Caseous lymphadenitis

• chronic contagious disease

• Affects foats and sheep (but can also aff3ct ofher animals)

• Can cause severe economic losses

Corynebacterium pseudotuberculosis

Ceseating, necrotic lymph nodes in a sheed

Corynebacterium pseudotuberculosis

Corynebacterium pseudotuberculosis

Corynebacterium pseudotuberculosis

• can cause lymphadenitis and abscesses with granulomafous necrotizing lesions in humans

• shearing

• Castration

• Skin wounds

• Inhalation and ingestion are also possible

Corynebacterium pseudotuberculosis Is transmitted via

Lymph or the blood

Corynebacterium pseudotuberculosis

• infected phagocytes disseminate the bacteria via the _______ to secondary sites where they cause lesion

Phospholipase D (PLD)

Corynebacterium pseudotuberculosis

• virulence is attributed to

  • ________ an exotoxin

Surface lipid layer adjacent to the cell wall

Corynebacterium pseudotuberculosis

• virulence is attributed to

  • ________ an exotoxin

  • __________________

Expression of fagB C D genes

Corynebacterium pseudotuberculosis

• virulence is attributed to

  • ________ an exotoxin

  • Surface lipid layer adjacent to the cell wall

  • ______ - encode a putative iron uptake aystem

Corynebacterium diptheriae

• had animal reports, but primarily a human pathogen

• Rravel related (more common in developing countries)

  • Respiratory diptheria

  • Cutaneous diptheria

Respirwtory diptheria

Corynebacterium diptheriae

• fever, soree throat, malaise, croup-like cough

• Pseudomembranous pharyngitis

  • Gry or bluish white membrane on soft palate, tonsils or back of the throat (bleeds easily)

• Severe cervical lymphadenopathy

  • Bull neck

Cutaenous diptheria

Corynebacterium diptheriae

• ulcerative lseions or cellulitis

• Can occur independently of respiratory diltheria

Corynebacterium diptheriae

Respiratory droplets

Transmission of corynebacterium diptheriae

Diptheria toxin

Corynebacterium diptheriae peoduces ______

DTap vaccine

• vaccine against diptheria, tetanus and perrussi

• Completed by 4-6 age

Tdap vaccine

• booster vaccine at 11-12 yo

• Should be given to pregnant morher

Td vaccine

• tetanus and diptheria toxoid vaccine

Corynebacterium ulcerans

• rare cause of mild to severe bovine mastitis

• Loss of affected quarter

• Carry a phage that encodes for the diptheria toxin

  • Human diptheria has been reported after consumption of raw milk

• Occasionally associated with disease in cats and dogs

  • Transmission from pets to humans can occur

Corynebacterium ulcerans

Phospholipase D (PLD)

Corynebacterium ulcerans

• virulence is attributedd to

• ______- genetically fesembles the one produced by C. pseudotuberculosis

Corynebacterium bovis

• rarely cause clinical mastitis

• Considered a commensal of bovine mammary gland

• May protect the gland from infection with more virulent pathogens

corynebacterium kutscheri

• commensal of the upper respiratory and intestinal tracts of laboratory rodents

• Infection is usually subclinical in mice and rats

• When immunosuppressed, a pseudotuberculosis with high morbidity and mortality can appear in these animals

Corynebacterium kutscheri

• c. Renale

• C. cystitidis

• C. pilosum

• commensals of the bovine epeoductive tract

• Opportunistic pathogens

• Cause simple or c9mplicated ascending urinary tract infections

C. Renale

most common cause of

• cystitis,

• ureteritis, and

• pyelonephritis

C. pilosum

• milder pathfoen often resulting to uncomplicated cystitis

• Virulence is attributed to

  • pili,

  • urease, and

  • renalin

Pili

Meditate adhesion to epithelial cells of the bladder

Urease

Hydrolyzes urea and releases nitrogen

renalin

Play a role in lysis of host cells (manily C. renale)

C. renale

Rhodococcus equi

• In immunocompromised humans

• Necrotizing pneumonia

• Can also cause wound infections and subcutaneous abscess

Necrotizing pneumonia

Rhodococcus equi

• ____ common form of infection

Suppurative bronchopneumonia

• can multiple in soil enriches with equine feces

• may be commensal in the intestine of horses

• Cause of ______ in foals

  • Increases in prevalence wher high stocking rates occur

  • Usually seen in foals of 4-12 weeks of age

  • Due to decline in maternal antibody at about 6 weeks of age.

Rhodococcus equi

Severe pyogranulomatous pneumonia in a horse

Inhalation

Rhodococcus equi main route of infection is

Ulcerative colitis and mesenteric lymphadenitis

Rhodococcus equi

• heavily infected sputum may be swallowed by the affected foal leading to

Alveolar macrophages

Rhodococcus equi

• bacteria multiplies in adn destroys ________ while neutrophils remain bactericidal

R. equi

80-90 kb plasmid

R. equi is associated with _____

• includes pathogenicity islands containing the virulence-associated protein (vap) gene family

9

R. equi has _ chromosomal genes that were significantly induced in its cells

• choD

• fadD13

• fbpB

involv3d in fatty acid and lipid bolism

hemE

Heme biosynthesis

mbtF

Iron utilixation

• clpB

• groEL

heat schock resistance and gene encoding chaperones

sigK

Sigma factor

moxR

transcriptional regularor