Bacteriology and Mycology Flashcards

Question

Mycoplasma epidemiology and properties

Answer 1

– Very fragile – easily inactivated – Most spread by close contact – Contagious – Aerosols * Piggeries, poultry sheds – Vertical transmission * Auto-immune disease

Answer 2

– Host and environmental factors may predispose to disease caused by mycoplasmas – Stress (eg. transport and overcrowding – Husbandry practices – Age (eg. young most susceptible) – Immunity – Concurrent disease – Mycoplasmas often exacerbate disease initiated by other pathogens and vice versa – This is particularly true in the respiratory tract.

Answer 3

M. mycoides subsp. mycoides small colony type Contagious bovine pleuropneumonia

Answer 4

– Obligate parasite of the respiratory tract of pigs – Upper and lungs – Associated with cilia and causes ciliostasis and extensive loss of cilia – The continuous nature of pig production ensures a self perpetuating cycle of infections from older to younger pigs – Recovered pigs protected against re-infection – Breakdown in EPP-free herds usually occurs following the introduction of infected animals, although windborne transmission is also suspected – Wild boars ?

Answer 5

– Respiratory tract of chickens, turkeys and other birds – Nasal sinuses and tracheas – Reproductive tract – Causes respiratory disease – Many factors influence the onset and severity of disease – Subclinical to severe in complicated disease – Exacerbated by: * Concurrent infections (ILT and E. coli) * Environmental factors which lower the resistance in the bird Sinusitis – Immune birds may remain carriers and can transmit the disease horizontally (aerosols) or vertically (egg) Live attenuated vaccine

Answer 6

– Haemophilic mycoplasma - cats * Diagnosis by DiffQuik of blood smears – Short rods or cocci which stain deep purple – Associated with RBC – Intravascular haemolysis resulting in anaemia and ill-thrift – Feline Infectious Anaemia – Fleas play a role as vectors – Ectoparasite control is important !!!

Answer 7

vaccination live attenuation eradicate through serological tsting and culling Pathogen free herds and flocks – General management factors can help reduce severity and spread – Stress, stocking density, nutrition and concurrent disease – Can’t use penicillin (no cell wall), drug of choice is tetracycline (not reliant on cell wall synthesis for its activity) – Water medication in pigs and poultry common when endemic to control spread – Ectoparasite control for the haemophilic mycoplasma important

Answer 8

– Obligate intracellular parasite – Small pleomorphic rods – Non motile endotoxins From cattle, sheep and goats - relativly resistant in the environment

Answer 9

Transmission – Shed in birth fluid of cattle, sheep and goats – Found in milk, urine and faeces – Aerosol and ingestion result in human infections Prevention and control – Occupation hazard – Protective clothing and masks – Vaccine available for humans – single shot * Live attenuate vaccine grown in eggs * YOU ALL SHOULD BE VACCINATED AGAINST THIS – Preventative tick treatment of pets and livestock – Prophylactic treatment of pregnant or lactating animals ?? * Minimise exposure ?? * Infectious dose may be as low as 1 cell per humans ?? Treatment – Long term tetracyclines – Acidic intracellular environment reduces antimicrobial efficiency ?

Answer 10

– Large Gram + rods – Facultative anaerobes – Catalase + – Endospore forming – Aerobic condition – Centrally located – Free – living in the environment – Saprophyte – 2 species of importance – B. cereus * Acute mastitis and food poisoning in humans – B. anthracis * Anthrax

Answer 11

– *Protective antigen (PA)* channel forming protein * Required for activity of other toxins – *Oedema factor (EF)* calmodulin-dependent adenylate cyclase * Increase cAMP → electrolytic and fluid loss – *Lethal factor (LF)* metalloprotease cleaves MAPK (mitogen activated protein kinase) * Disruption of signalling pathways of macrophages * Massive IL-1 release from macrophages * Inflammatory cascade – LF together with PA form lethal toxin – EF together with PA form oedema toxin

Answer 12

Acute septicaemia vaccination is effective in preventing disease

Answer 13

– Transmission to human – Ingestion * Intestinal – Inhalation * Pulmonary – Contact * Cutaneous form – Spores germinate  Toxin  Disease – Pulmonary and Intestinal form most serious * 95% and 50% mortality respectively

Answer 14

Saprophytes - soil - anthrax belt - endospores highly resistant - formed when CO2 pressure drops *dead animals = environmental contamination --> burn them – Spores brought to the surface – Flood, industrial effluent from rending plants, tanniers, carpet mills or wherever carcasses are salvaged can be a source of contamination – Spores germinate and bacteria multiple when exposed to high temperatures, moist conditions and when there is a lack of other soil-living bacteria – Alkaline soil – Heavy rain following drought – Decaying vegetative matter * Spore survival, germination and sporulation * Increase environmental contamination * Increases likelihood of an outbreak

Answer 15

Inhilation Ingestion of spores scratches or wounds invade mucous membranes/ skin through breaks *germinate in host

Answer 16

– Disease occurs when and where ?? – “Anthrax belt” – Ideal soil condition – Warm humid/wet weather – Recent floods * Watering holes – Drought – Stalky feed – Windy ?? – HOW DO YOU CONTROL and PREVENT IT?? – In the anthrax belt !! * Vaccination ?? * Penicillin prophylaxis ?? * Timing ?? – Heavy rains after a period of drought  – Supplement feed in drought – Removing soil ?? – Infected animals and material should be burned (source of contamination) * Stop environmental seeding

Answer 17

Neurotoxic (paralysis or stiffness) Histotoxic (local disease) Enterotoxic (GI disease) Invasive

Answer 18

– C. tetani → tetanus – C. botulinum → botulism

Answer 19

spores found in soil cross strain protection

Answer 20

unable to inhibit muscle contraction specific neurotoxin for neurones toxi destroyed in intestine

Answer 21

Local infection of wound by spores ↓ Other bacteria and necrosis lowers redox potential allowing germination and growth ↓ Exotoxin produced and either binds to local nerve endings or enters circulation and binds to nerve endings distant from site of replication ↓ Toxin internalised and transported up the axon to the cell body ↓ Cleavage event and translocation to hydrolyse ‘docking’ proteins of inhibitory synapses ↓ Block of GABA and glycine release ↓ Tetanic spasm due to failure to control muscular contraction ↓ Respiratory paralysis and death

Answer 22

*Host* – Bruising * Germination and toxin production – Horses most susceptible * Then pigs, ruminants and carnivores *Environment* – Invasions of spores through wounds * Nail wounds to foot * Tail docking * Castration *Immunity* – Toxoid made from the neurotoxin * Inactivated toxin * Antibodies against the toxin – Passive acquire antibodies protective – Anti-toxin can be use but will not remove bound toxin

Answer 23

Treatment – Sensitive to penicillin but unlikely to be affective * Necrotic tissue  – Anti-toxin treatment in early cases Preventions – Vaccination and minimise chance of abrasions or wounds * Vaccinate mother to increase passive transfer * Vaccinate prior to castration or tail docking * Good procedures and clean yards help. Control – Usually sporadic cases – Environmental and minimising host factors

Answer 24

– Spores very resistant and essentially ubiquitous – Germinates when environment suits – Toxin ingestion – Intoxication – Environment or the animal source – Toxin can be inactivated by heat – Toxico-infectious

Answer 25

7/8 neurotoxic – Protection against one type DOES NOT confer protection against the others – Not all types of botulinum toxin produce intoxication in all species – INACTIVE PROTOXIN is release on cell lysis – Requires activation by enzymes

Answer 26

– FLACCID paralysis of skeletal muscle – Respiratory paralysis and death

Answer 27

Organism multiplies under suitable conditions in feed ↓ Toxin released by lysis of cells ↓ Toxin ingested, activated by trypsin cleavage and absorbed (resistant to gastrointestinal conditions) ↓ Toxin binds to gangliosides at the neuromuscular junction ↓ Active component enters nerve and blocks acetylcholine release ↓ Flaccid paralysis due to inability to initiate muscle contraction ↓ Respiratory paralysis and death

Answer 28

Host - shaker foal syndrome - GI environment Immunity - anti toxin can be used bu won't remove boud toxin Environment - related to poor quality feed pica in cattle ingestion of exposed rotting aquatic veg material (waterfowl)

Answer 29

– Freshly made feed – Clean feed troughs – Cook thoroughly – Place feed away for contaminated area – Discourage waterfowl from feeding near waterways with exposed decaying material – Exclusion zone, netting, sirens ?? – Maintain nutritional balance in diet – Prevents pica – Vaccination – Remove dead carcasses – MANAGE THE ENVIRONMENT and the ANIMAL to reduce the chance of bacterial proliferation and toxin ingestion – Difficult especially with wildlife – Difficult to control environment and animal habits – Treatment → Specific antitoxin if seen early

Answer 30

– C. novyi type A → malignant oedema – C. novyi type B → Blacks disease – C. chauvoei → Black leg

Answer 31

– Motile, very fastidious anaerobe – 3 types based on toxins produced – A and B are pathogenic – Type A → malignant oedema “big head” – Gas gangrene – Young rams fighting and head butting – Alpha, Gamma, Delta and Epsilon toxins – Type B → Black disease – Infectious necrotic hepatitis – Alpha, beta, zeta and eta toxins – Alpha toxin is phage mediated – Lethal and increases capillary permeability and causes oedema. – Vaccination ✓

Answer 32

– Malignant oedema = Blackleg – Rancid odour and gas bubbles – Form short chains or occur singly – Produce a range of toxins with systemic and local effects (alpha to delta)

Answer 33

Ingested and replicates in the intestine ↓ Spores lodge in muscle, presumably reaching there via the circulation ↓ Muscle damage (eg. bruising particularly in young animals on a high plane of nutrition) allows germination and replication ↓ Toxins cause local damage but also enter circulation ↓ Lameness, fever, depression and eventually death

Answer 34

– Minimise muscle damage – Avoid overtly high nutritional feed – Especially young animals – Bacterin (not just toxoid) necessary to produce protective antibody as antibody needed against cell wall as well as toxins – Some antigenic variation between isolates from different geographic regions which may necessitate a local derived vaccine strain

Answer 35

-C. perfringens types A, B, C – Dysentery/enteritis – C. perfringens type D – “Pulpy kidney” – C. perfringens type E – “Enterotoxaemia” in calves and lambs

Answer 36

– Non-motile – Types A – E based on possession of four major lethal toxins (alpha, beta, epsilon and Iota) – Also can cause malignant oedema

Answer 37

*Alpha (a)* – Phospholipase C which splits lecithin-protein complexes in cell membranes – Types A - E *Beta (b)* – Causes inflammation of intestine and loss of mucosa – Causes damage only in the presence of trypsin inhibitors as is destroyed by trypsin – Type B and C *Epsilon (e)* – Activated by trypsin and pepsin and also by the exotoxins Kappa and Lambda – Lethal systemic affects – Type B and D *Iota (i)* – Activated by cleavage – Composed of two components – Type E

Answer 38

– Overeating, sudden change in diet or continued feeding on rich feed a post mortem change due to rapid autolysis

Answer 39

– Immunity – Toxoids prepared from types C and D induce protection against types A-D – Protection depends on the neutralisation of the toxin * Antibody – Prevention of enteric disease = antibody in the intestinal lumen * Colostrum

Answer 40

*P. aerguinosa* – Variety of opportunistic diseases * Skin, ears, mastitis and others – Many host species *P. fluorescens* – Tail/fin rot and septicaemia – Occasionally seen in other species *B. mallei* – Glanders * Skin and respiratory disease * Equidae, Carnivores *B. pseudomallei* – Melioidosis * Chronic suppurative lesions * Many species

Answer 41

– Colony morphology * Blue-green * Beaten copper appearance – Odour * Old socks – Saprophyte – Soil – Freshwater – Marine * Absolute require for MOISTURE (biofilm) * Minimal nutrient requirement – Isolated from skin, mucous membranes and intestine – Reflects exposure and TRANSIENT colonisation – Environmental organism – Resistant to chemical * DISINFECTANTS * ANTIMICROBIALS *unpredictable antimicrobial sensitivity*

Answer 42

Opportunistic Fleece rot Corneal ulcers

Answer 43

Adhesions Slime layer Capsule polysacceride siderophores pigment - blue-reen - fluorescent green yellow

Answer 44

– Causing tissue damage, oedema and haemorrhage Exotoxin A

Answer 45

– Stress – Changes in feed – Antimicrobial usage – Concurrent disease * Allergies – Immunosuppression burns Breeds obesity floppy ears

Answer 46

needs moisture aquatic enviro and moist soils biofilms - rocks - feedig, water troughs and dips

Answer 47

Enviro organism | Opportunistic PAth | compromised individual | infection | disease

Answer 48

FLEECE ROT – Plunge dipping  Pour-on ✓ – Shearing prior to rainy season * Shearing wounds  * Saturated rain post-shearing  * After March in winter rainfall districts  – Susceptibility greatest when 4-6 months of wool – Shearing timing and genetics ? * Low wax content, irregular fibre size and wrinkling  OTITIS EXTERNA – Floppy ears !! – Dry out ears or limit swims – Clean ears * Cotton swabs – Hairy ears ?? – Allergies ?? – Foreign bodies / wounds – Ear mites

Answer 49

Obligate parasite respitory and skin nasal cutaneous facultative intracellular parasite - saphroyte killed by chilling and freeezing Pathology - nasal discahrge - nodules - inhailation - skin abrasion - zoonotic * host fitness important

Answer 50

Endemic - ELIZA cull pos isolate cases quarantine and test imports - at least 2 weeks

Answer 51

Chlamyda – C. trachomatis → genital, ocular and respiratory pathogen of humans – C. suis → enteritis and conjunctivitis in pigs – C. muriadum → pneumonia in mice Chlamydophila – C. pneumoniae → pneumonia in humans, ocular, respiratory and urogenital tract disease in Koala and possible respiratory disease in horses – C. psittaci → systemic disease in birds and zoonotic

Answer 52

local necrosis chronic inflam immune-mediated damage persistant and latent infections Suppression but not elimination

Answer 53

– Antibody against the Major Outer Membrane Protein (MOMP) is thought to play some role in protective immunity – MOMPS are adhesins and are distinct in different species and serovars – Useful diagnostic - killed vaccines used in sheep and cats

Answer 54

– TWAR, Koala, Equine – TWAR causes pneumonia in humans

Answer 55

Wild bird resovior - parrots wild birds --> parrots – Shed in discharge * Ocular * Nasal * Faecal – Resistant in environmental condition Zoonotic Gardening close contact with bird secretions Treated by antibiotics Control: Biosecurity and wild game meat PPE when gardening

Answer 56

– M. ovis → pinkeye sheep – M. equi → pinkeye horse – Non haemolytic – M. catarrhalis → pinkeye and respiratory disease in humans – M. bovis → PINKEYE – Mucous membrane – Carriers – Nasopharynx – Conjunctiva – Vagina – Highly contagious – Avoid predisposing factors * Minimise risk of irritants – Fly repellents – Shelter – Irrigation of yards – Clovers rather than tall stalky grass

Answer 57

B. arbortus → Cattle (horses) – abortion / orchitis B. melitensis → Goats and sheep – abortion / orchitis / arthritis B. ovis☺* → Sheep – abortion / epididymitis B. suis* → Pigs (cattle) – abortion / orchitis / arthritis / spondylitis ▪Transmission ▪Ingestion (milk)* ▪Venereal ▪Exposure to mucosal surfaces ▪Abortion / Parturition / Vaginal discharge ZOONOTIC Test and cull bulls

Answer 58

– Foot rot is contagious – Prevention and control ✓ – Parasitic properties – Variation in breed susceptibility – Spread occurs in warm, wet condition ◼ D. nodosus survive away from the host for less than a week or two – Formalin or zinc sulphate footbaths – Foot paring/trimming segregation, quarantine

Answer 59

– Actinobacillus – Haemophilus – Avibacterium – Mannheimia – Pasteurella – Most are commensals – Extensive taxonomic change – Haemophilus / Avibacterium – Pasteurella / Mannheimia

Answer 60

– A. lignieresii → ‘wooden tongue’ in cattle – A. equuli → ‘sleepy foal disease’ – A. pleuropneumoniae → pneumonia in pigs and horses – A. suis→ septicaemia in young pigs EXOTOXINS

Answer 61

– “Wooden tongue – Endogenous origin * Commensal of the oral cavity – Special initiating circumstances are required * Wounds in the mouth * Rough feed * Foreign body injuries – Avoid these circumstance = prevention – Produce small grey-white granules in pus – “Club colonies”

Answer 62

– Serious, obligate parasite of pigs – Fibrinohaemorrhagic pneumonia – Lung lesions covered with pleuritic adhesions *prevention through eradication* – Predominantly a pathogen of pigs < 6 months of age – Geographical localisation of serovars – Recently introduced animal – Spread of infection is facilitated under intensive conditions. – Autumn/winter – Stress (poor ventilation, cold) and concurrent infection increase severity of disease. – Strict biosecurity to reduce introduction and spread in non- endemic herds – Quarantine (cases and in-coming) – Screening new breeding stocks etc.. – All-in/All-out✓

Answer 63

– 19 recognised species – P. multocida ✓ – M. haemolytica ✓ – Septicaemia – cattle (haemorrhagic septicaemia), pigs, birds (fowl cholera) and rabbits – Bronchopneumonia – cattle, sheep, goats, horses, pigs and rabbits (usually secondary to respiratory virus and/or Mycoplasma infection) – Rhinitis – piglets and rabbits – Wound infections – Other occasional opportunistic infections – Prevention and control – Environmental and husbandry – Stress minimisation – Avoid overcrowding – Health management and concurrent disease – Host and environmental factors

Answer 64

“Shipping fever complex” in cattle and sheep

Answer 65

– S. Abortus-equi → abortion and septicaemia in horses – S. Abortus-ovis → abortion and septicaemia in sheep – S. Choleraesuis → pigs – S. Dublin → Cattle – S. Gallinarium and S. Pullorum → poultry – S. Typhi → humans – Faecal contamination of feed/pasture – Ingestion of Salmonella (dose received is critical) – Excreted in faeces and survives in the environment – Carriers !!! – High stocking rates and other stresses predispose to disease both by lowering host resistance and increasing environmental contamination – Test, detect carriers and eliminating ✓ – Biosecurity ✓ – Both humoral and cell mediated immunity ✓ – Test and cull positive

Answer 66

– Y. pestis → Bubonic plaque in humans – Y. pseudotuberculosis → Systemic disease in mammals and birds, enteritis in lambs and calves – Localised inflammation and water loss = enteritis Hosts: fleas, rats – Control and prevent – Minimise faecal contamination – Wild reservoirs and carriers

Answer 67

– O antigen – Somatic H, K and F antigens E.coli S.enteritis Y.psuedotuberculosis

Answer 68

– Lactose fermenter – Pili, Flagella, Capsule and O-antigen – Toxins – Nature of pathogenesis – What type of toxins? – Is the bacteria invasive or not? – Host and environmental factors – Hygiene, age, other predisposing factors – Concentration – Control and prevention – Treatment of infections ?? – Based on pathogenesis – Invasive and cytotoxic versus non-invasive and cytotonic