Filamentous Bacteria

Question 1

Filamentous bacteria clinical importance

Answer 1

Filamentous/ diphtheroid rod form
Wrinkled/ fuzzy colonies
Manifestation of Pyogranulomatous inflammation

Question 2

Actinomyces characteristics

Answer 2

Oral flora, GIT and UGT
Strict/ facultative anaerobes
Non-spore forming, gram +, non-acid fast

Question 3

Actinomyces

Answer 3

Require rich media for growth/ capnophilic
Killed by disinfectants, penicillin, fluroquinolones
Endogenous infections caused by commensal/ bites

Question 4

Actinomyces pathogenesis

Answer 4

Triggers suppurative responses in immediate vicinity
Peripheral granulation, mononuclear infiltration, fibrosis
Exudate with yellow sulphur granuales/ rosettes

Question 5

Ruminants infected with Actinomyces

Answer 5

A. bovis and A. israelii
Following trauma → lumpy jaw/ chronic osteomyelitis
Pulmonary infection in cattle

Question 6

Actinomyces CS in ruminants

Answer 6

Porous bone with pus replacing normal bone
Teeth dislodgment, inability to chew, mandible fracture

Question 7

Actinomyces infection in horses

Answer 7

A. bovis and A. denticolens
Isolated from abscesses, corneal swabs and skin pustules
Fistulous withers (saddle sores) and Brucella spp.

Question 8

Actinomyces infection in dogs and cats

Answer 8

A bovis, A. hordeovulneris and A. viscous
Pyogranulomatous infections under the skin and body cavities
Actinomycotic discospondylitis/ foxtail grass

Question 9

Actinomyces infection in swine

Answer 9

A. suis
Mastitis
Recovered from lung lesion and aborted fetuses

Question 10

Diagnosing actinomyces

Answer 10

Aspiration
Granule/ tissue for Gr/AF stain for microscopic smears or culture
Exudate for yellow sulphur granules
qPCR-rRNA uring DNA primers

Question 11

Lumpy jaw

Answer 11

Actinomycosis
Formation of hard tumor-like masses in the tongue
Caused by A. lingnieresii

Question 12

Actinomyces treatment and control

Answer 12

Surgery, drainage and iodine therapy
Penicillin

Question 13

Nocardia characteristics

Answer 13

Gram+, partially acid-fast, saprophytic, nonmotile
Polymorphic rods or cocci
Ubiquitous (soil and water)
Aerobic

Question 14

Where are nocardia found?

Answer 14

Mammals, fish, mollusks, and birds

Question 15

Nocardia transmission

Answer 15

Inhalation, direct contact (trauma) and infection
Bovine mastitis in contaminated equipment

Question 16

Nocardia species

Answer 16

N. asteroides complex (farcinica, nova, transvalensis)- most common
N. brasiliensis
N. otiditiscavarium

Question 17

Important nocardia diseases

Answer 17

Pulmonary nocardiosis and mycetoma

Question 18

Nocardiosis in ruminants

Answer 18

Bovine mastitis
Fistulous tracts discharge, lymphadenopathy

Question 19

Norcardiosis in horses

Answer 19

Mycetoma, pulmonary infection and abortion

Question 20

Nocardiosis in dogs and cats

Answer 20

Pneumonia and suppurative pleuritis with empyema
Co-infection with distemper
Cutaneous and SQ abscess (cats)
High mortality rate

Question 21

Canine nocardiosis

Answer 21

Fluctant masses from otitidiscavarium
Develop mycetomas (tumor like mass of fungal mycelia)
Lyphadenitis

Question 22

Nocardia infection diagnosis

Answer 22

Partial acid-fast/ gram stain

Question 23

Nocardia treatment

Answer 23

Antimicrobial therapy and control
Trimethoprim-sulfonamid therapy
Fluoroquinolones

Question 24

Dermatophilus causes …..

Answer 24

Dermatophilosis
Streptothrichosis in cattle
Lumpy wool, strawberry foot rot in sheep
Rain rot or grease heal in horse

Question 25

Dermatophilosis

Answer 25

Caused by D. congolensis Dense scabs on skin, exudative lesions

Question 26

Dermatophilus characteristics

Answer 26

Gram+, motile flagellate coccoid "zoospore" Facultative anaerobic capnophilic White grey to yellow colonies High hemolytic Obligate parasite CAN'T multiply saprophytically

Question 27

Dermatophilus transmission

Answer 27

Direct physical contact. stinging arthropods (ticks, flies) Moist conditions

Question 28

Dermatophilus risk factors

Answer 28

Ticks of amblyomma genus Tropical regions (cattle most susceptible) Intemperate regions (sheep, horses)

Question 29

Dermatophilus pathogenesis

Answer 29

Invades the epidermis Neutrophils under infected epidermis → scab ↑ PMNs

Question 30

Dermatophilus diagnosis

Answer 30

Gram/ Giemsa stain of scab Florescent Ab in skin debris Culture

Question 31

Treatment of Dermatophilus

Answer 31

Acute cases self limiting Severe: penicillin, streptomycin, tetracycline, chloramphenicol Long acting enrofloxacin*

Question 32

Streptobacillus

Answer 32

Rat-bite fever or haverhill fever Facultative anaerobe Gram-, nonmotile, non-spore, pleomorphic

Question 33

Streptobacillus species

Answer 33

One spp is pathogenic/ zoonotic S. moniliformis (USA) and minus (Asia) Reservoir: rodents pharynx/ rat

Question 34

Streptobacillus transmission

Answer 34

Bite or ingestion of contaminated food or water by rat excrement

Question 35

Streptobacillus patheogenesis

Answer 35

Joint and LN swelling to bronchopneumonia Abscess in liver and septicemia L-form relapses with treatmen

Question 36

Streptobacillus diagnosis

Answer 36

Culture Puffball appearance (gray mucoid colonies) Direct fluorescent Ab test PCR and ELISA

Question 37

Streptobacillus treatment

Answer 37

Penicillin or tetracycline in pen-allergic Resistant to cephalosporins and aminoglycosides