lect 27-36 Flashcards

Question

potomac horse fever cause and clinical

Answer 1

-caused by neorickettsia risticii * Clinical signs: * Mild colic * Fever * Diarrhea – watery * Abortion in pregnant mares -think trematode vector (snails with metacercaria) -case fatality is 5-30%

Answer 2

* Treatment * Oxytetracycline! * Supportive care * Possibly NSAIDS * Fluid therapy * Control * Inactivated vaccines are available

Answer 3

* R. akari – Rickettisalpox * House mouse reservoir * Zoonotic via mites * Urban areas * R. felis – cat flea typhus * Opossums identified as one reservoir * Worldwide distribution * Zoonotic via cat flea

Answer 4

* Potential biological weapon due to: * Non-specific initial presentations * High morbidity and mortality rate * Ability to aerosolize * Requires specialized laboratory to diagnose * Not notifiable diseases in Canada * R. prowazekii was weaponized by the US, Japan and the Soviet Union * Therapy generally relies upon the tetracyclines * In people macrolides, penicillins and aminoglycosides NOT effective

Answer 5

* Obligate intracellular parasites * Doesn’t stain using the Gram-stain * Worldwide distribution EXCEPT New Zealand -borrelia: * Large spirochetes * Small linear chromosome * Bartonella * Small Gram-negative coccobacilli * Biocontainment level 2 – Borrelia, Bartonella spp. * Biocontainment level 3 – Coxiella burnetii * Coxiella requires specialized conditions to cultivate in vitro

Answer 6

- Coxiella: * Obligate parasite * Infects wide variety of species * Shed in milk, urine, feces and amniotic fluids -* Borrelia * Obligate parasites – host associated * Associated with reservoir hosts and arthropod vectors(tick bites) -* Bartonella * Facultative intracellular parasite * Erythrocyte and endothelial cell pathogens -spread through vectors (cat fleas)

Answer 7

* Outer surface proteins (Osp) – attachment in tick host, allows organism to persist in gut between meals * Surface lipoproteins – stimulating inflammation, persistence in ticks * Porin-like proteins – adhesion * Flagella – motility

Answer 8

* Type 4 secretion systems * Bartonella effector proteins (BEPS), secreted into host cells and modulate physiology in favour of bacteria * Induction of phagocytosis by host cells (entry) * Prevention of apoptosis (keep host cells alive)

Answer 9

* Generalist parasite of eukaryotic cells * Found in arthropods, reptiles, birds and mammals * Agent of Q fever * Short for ‘query’ fever * When present, high concentrations in placenta and fetal tissues * Animals frequently eat these tissues after birth * Passes through GIT * Excreted in feces -aerosolized in dust gets into lungs and replicated and disseminates throughout the body.

Answer 10

* Most often, infections in domestic animals are mild or non-apparent * Clinical signs related to sites of localization * Reproductive tract and mammary tract – abortions/shedding in milk. -placentitis, hepatitis, myocardial. * Control: * Segregation of parturient ruminants * Careful disposal of tissues (abortuses and placentas) * Vaccination * Inactivated vaccines available

Answer 11

* Most common subclinical * In affected dogs splenomegaly is the most common * In affected cats abortion has occurred * Has been associated with human outbreaks * See fever, lethargy, anorexia 2 days following experimental infection

Answer 12

-caused by coxiella borrelia -can have lab aquired infections/ fatal * Incubation period is up to 3 weeks * 50% of infected people asymptomatic * Acute febrile illness (flu like) * Typically, mild disease but serious complications occur * Pneumonia * Granulomatous hepatitis * Myocarditis * Abortion * Case fatality rate <2% of hospitalized patients -neatherlands large outbreaks from living DOWNWIND of infected dairy/ goat farm. -vaccination, manure management, culling.

Answer 13

* Acquired as occupational disease * Farmers * Abattoir workers * Veterinarians * Laboratory workers * Foodborne * Unpasteurized products (goat cheese) * Rarely associated with cats * Treatment - doxycycline * Prevention - vaccine for high risk workers

Answer 14

-caused by borrelia burgorferi * Ticks are the only competent vectors * In North America: * Ixodes scapularis * Ixodes pacificus -most cases NE USA * Ticks primarily infected by biting reservoir host * Transmission of the organism isn’t instantaneous * Can take up to 24 hours for transmission to occur, co-infections common

Answer 15

-ususally No signs * In affected dogs can see: * Intermittent recurrent lameness – polyarthritis is best documented syndrome * Fever * Anorexia -maybe renal failure. * Treatment * Early: Doxycycline, amoxicillin, azithromycin * Control: * Acaricides * Removing ticks promptly * Vaccination

Answer 16

* Symptoms 3-30 days post infection * Fever, chills, swollen lymph nodes * Characteristic erythema migrans rash (target) * Chronic signs occurring days to months later * Severe headache, arthritis, facial palsy, pain, heart palpitations -in western CAD BC and MB, highest in ON, NS

Answer 17

* Endocarditis * Seen with B. vinsonii and other species * Hepatitis * Seen with B. henselae * Flea and tick prevention is important * If clinical signs, treat with long duration antimicrobials * Enrofloxacin, doxycycline

Answer 18

* Important zoonoses, people infected following cat scratches * Symptoms develop 1-3 weeks post exposure * Fever * Papule or pustule at site of scratch * Enlarged, painful lymph nodes * Can see bacillary angiomatosis * Angiogenesis, and lesions in the skin

Answer 19

* Bartonella quintana * Cause of trench fever, name comes from effects on soldiers in WW1 * Bacteremia, localized tissue infection, endocarditis * Reemerging in people affected by extreme poverty in developing countries and in the homeless (developed countries) * Vectored by human body louse * Humans only confirmed reservoir

Answer 20

* Cause of Carrion’s disease * Hemolytic anemia, localized tissue infection, angiomatosis * Biphasic disease * First phase is erythrocyte infection, anemia and transient immunosuppression * In the second phase nodular dermal eruptions occur as a result of vascular proliferation * Transmitted by sandflies in Andes Mountains

Answer 21

* Susceptibility testing impossible! * C. burnetii Treatment: * Doxycycline!, PCR * Borrelia: serology * Doxycycline, β-lactams * Bartonella spp: PCR * treat doxycycline

Answer 22

* Smallest self-replicating prokaryotes * Lack cell wall, only have a cellular membrane * Don’t stain well with Gram-stains * Round, pear shaped or filamentous * Example of genome reduction, heavy reliance on host cells -Colonies often have “fried egg” appearance * Some species slow growing * Biocontainment level 2 * M. bovis, heaemofelis * Biocontainment level 3 * M. capricolum, mycoides

Answer 23

* Host associated * Found on the mucous membranes * Upper respiratory tract * Genital tract * Intestinal tract

Answer 24

* Variable surface proteins (Vsps) - antibody evasion, immune modulation * Adhesins - some species express protein adhesins * Lipoproteins - adhesion, stimulate release of proinflammatory cytokines * Capsule - persistence and dissemination * Biofilm - some species do this, although interesting classical biofilm-associated genes are lacking

Answer 25

* Contagious bovine pleuropneumonia * Very old disease, syndrome first described in 1550! * Three major eradication efforts globally * Currently notifiable disease to OIE * Control in Canada would be about STAMPING OUT! Call CFIA

Answer 26

-caused by m. mycoides * Disease characterized by severe fibrinous pneumonia -classic "marbeling" appearance on lung lobules. * High morbidity (up to 70%) and mortality (up to 50%) * Major production losses * Acute disease * High fever, severe respiratory distress * Sub-acute - chronic disease * Incubation period 3 weeks - 6 months * Transmission through prolonged contact with carriers

Answer 27

* Contagious caprine pleuropneumonia -mouth breathing and saliva * High morbidity (100%), mortality (60-100%) in affected herds * Disease characterized by * Cough, hyperpnea, pyrexia -transmitted via aerosols up to 50m. in africa, middle east -CFIA in canda

Answer 28

* Variety of clinical syndromes associated with this organism * Arthritis * Pneumonia - caseonecrotic pneumonia - often polymicrobial * Genital infections/abortion * Mastitis * Once inside host, M. bovis disseminates hematogenously * Organism maintained by carriers * Sub-clinical disease, recovered, identified in colostrum and semen -can be intracellular infections (hard to treat) control: isolate, treat with antimicrobials.

Answer 29

* This is the most pathogenic Mycoplasma species in birds * Turkeys more severely affected than chickens * Turkeys - infectious sinusitis - mucopurulent sinusitis and airsacculitis * Broilers - chronic respiratory infections * Layers - usually subclinical, reductions in number of eggs * Transmitted vertically (within eggs) and horizontally (aerosols) * Control - good biosecurity * Treatment - tetracyclines and macrolides

Answer 30

-causes enzoonotic pneumonia * Chronic, mild disease * Endemic pneumonia * Persistent dry cough * Reduced feed efficiency/growth rate * Flare ups of disease seen with poor management * Such as poor ventilation aerosol transmission -lung lesions at slaughter control: vaccintaes treat: macrolides and tetracyclines

Answer 31

* Member of upper respiratory microbial community or conjunctivitis * Can find in healthy cats and in association with disease * Lower respiratory tract disease * If you find M. felis it is probably clinically significant * Pneumonia in kittens * Tetracyclines, macrolides,

Answer 32

* Parasitizes erythrocytes * Several species in cats, although M. haemofelis most common * Anemia is a hallmark of infection, immune-mediated process which can be fatal. Characterized by: * Lethargy, weakness, depression * Tachycardia, dyspnea * Hepatosplenomegaly, lymphadenopathy * Incubation period of 2-30 days -transmission via biting (vertical) from queens. or fleas. -control: keep cats inside, no fighting -treat: tetra/ fluro

Answer 33

* Intrinsically β-lactam resistant * Tetracyclines and fluoroquinolones generally good choices

Answer 34

* Nucleated * Fungal hyphae * Cell walls composed of chitin * Cell membranes * Contain ergosterol as the primary sterol * Visualization: KOH wet prep

Answer 35

* Aerobic * Most fungi grow at low temperatures * 20-30⁰C * Tolerant of high pressures and low pH * Capable of growing in a wide variety of environments * Play a very important function in the carbon cycle * Very good at degrading polymers * Fungi have been found at the Chernobyl site which utilize radiation as an energy source

Answer 36

-food, don't let you dog eat (mushroom poisoning) -make antimicrobials

Answer 37

-tissue invasion (ex guttural pouch mycosis) -mycotoxicosis: toxic production * Aflatoxicosis – aflatoxins in feed affect poultry * Fusariotoxicosis – zearalenone is non-toxic for poultry but causes disease in pigs * Ergotism – alkaloids produced by fungi growing on cereals -hypersensitivities: ect moulds in damp buildings, makes asthma worse.

Answer 38

-not many are pathogenic -oppertunistics * Dermatophytes both common and contagious * Common cause of disease in ectotherms * Plants, insects, fish and amphibian -grow best below the body temp

Answer 39

* In mammals, fungi are typically considered * Commensal/host-associated * Candida, Malassezia * Disease happens in states of immunosuppression * Environmentally acquired * Many of the dimorphic fungi (Blastomyces etc.) * Disease typically follows exposure to large inoculum

Answer 40

* White nose syndrome in North American bats from - Pseudogymnoascus destructans, in eastern USA * Chytridiomycosis in amphibians – threatening amphibians on every continent caused by Batrachochytrium dendrobatidis * Snake fungal disease – emerging disease in US * Ophidiomyces ophiodiicola

Answer 41

* Most commonly infections associated with identifiable risk factors: * Immunosuppression * Organ transplant recipients * SLE (Lupus), vascular diseases, diabetes mellitus, alcoholics or IV drug users * Iatrogenic factors including prolonged antimicrobial, steroid or cytotoxic therapy * AIDS – oral candidiasis is an AIDS defining condition

Answer 42

* Septate fungi * Microsporum – boat shaped macroconidia * Trichophyton – cigar shaped macroconidia * Utilize keratin for growth * Relatively slow growing -BCL 2

Answer 43

* Can be described as geophilic or zoophilic * Geophiles – free living saprophytes in the soil * M. gypsum * Zoophiles – adapted to survival in host skin * Microsporum canis - cats * Trichophyton verrucosum – cattle

Answer 44

* Depending on species, transmission can be: * animal → animal * animal → human * human → human * Direct contact with infected hair, or contaminated environment * Fleas from infected animals can serve as mechanical vectors * Infectious dose is unknown, but thought to be ≥100 spores

Answer 45

1. Infective arthrospores germinate following adherence to keratinized structure 2. Trauma, moisture and maceration of the skin facilitates infection 3. Keratin hydrolyzing ability allows invasion of skin, hair and feathers 4. Incubation period is 1-3 weeks 5. Host inflammatory response leads to lesions * Classical round lesion “ringworm” * Alopecic 6. Clinical disease more common in warm humid climates

Answer 46

-caused by dermatophytes fungi * Clinical signs are not pathognomonic, lesions are typically: * Foci of alopecia * Follicular papules * Scales, crusts * Lesions may have central area of pigmentation -puritis -generalized lesions or focal

Answer 47

-wide spectrum clinically: * Inapparent, silent infection * Lesions may be focal or multi focal * May or may not have scaling * May or may not be pruritic * Erythema and scaling of outer pinna are common presentations * In kittens may see erythema and scaling * Muzzle, ears, face and forelegs are most common sites * Granulomatous dermatitis also possible (poor prognosis) * Ulcerated nodules

Answer 48

* Generally self-limited infection * Clipping the hair coat is key * Prevents additional contamination of environment * Topical therapy is possible * Whole body shampooing * Systemic therapy * Decontaminating the environment is key * Can persist in the environment for long period

Answer 49

-caused by dermatophytes * Trichophyton equinum is the most common species * Infections typically superficial * Lesions most commonly occur on the axilla or rump * Lesions begin as reddened, raised areas * After ~7 days hair falls out * Becomes scabby and crusty * Hair re-growth begins in 24-30 days -dermatophysis

Answer 50

* Trichophyton verrucosum is the most common species * Lesions are most commonly on the head/neck * There are heavy grey crusts over the lesions * Alopecic spots develop * Not typically pruritic Bovine dermatophytosis

Answer 51

* Ringworm is very common * Presentation depends on site of infection * Can occur at variety of body sites * Risk factors include: * Use of public showers * Contact sports (wrestling) * Tight shoes * Excessive sweating * Some animal contact control: clean dry skin, dont use public lockers, towels, clean hands after animals.

Answer 52

* PLUCK hair from lesions * Fungi are more likely to be in base of hair * Preferentially pluck damaged looking hair * Scabs from the edge of the lesion * Brushings * Collect using a toothbrush -KOH of wet hairs, nails, scabs -woods lamp test 50% will glow under UV. -treat: usually self limiting, dogs and cats all 3: environmental decon, topical therapy, systemic (azoles) -horses: shampoos -cattle and rumiants: enticonazole rinses

Answer 53

* Ringworm should always be considered zoonotic * 3.5% of human dermatophytes caused by M. canis * Patients at risk of more severe disease * Children, elderly, transplant and cancer patients * Estimated that 50% of people living in household with infected cats develop lesions * Cats have been shown to carry T. rubrum, the agent of athlete’s foot -between cats and ag animals

Answer 54

* Enterococcus faecium * Staphylococcus aureus (pseudintermedius) * Klebsiella pneumoniae * Acinetobacter baumannii * Pseudomonas aeruginosa * Enterobacter spp

Answer 55

* Decreased permeability * Active Efflux * Enzymatic Degradation/Alteration * Target Modification * Alternate Pathways * Resistance by Absence -Bacteria can deploy these strategies intrinsically or after gaining genetic competence

Answer 56

* Phenotypic susceptibility tests * Categorical * Quantitative * Molecular* * Look for the resistance gene * Other phenotypic tests* * Look for gene products

Answer 57

* “Resistance” has a very specific meaning * Designed to predict clinical outcomes * Predicated on certain assumptions: * Species * Achievable drug concentration in target tissue * Intrinsic resistance is constitutive for an organism * Acquired resistance is not inherent to the organism, it is a decrease in susceptibility compared to the wild typ

Answer 58

* A good grasp of normal allows lab data to be interpreted * What do all of those “R’s” really mean? * Intrinsic resistance is independent of antibiotic exposure * “Wild-type” phenotype * Mycoplasma spp. intrinsically resistant to penicillin * They lack a cell wall and therefore don’t have the drug target

Answer 59

* SPICE organisms * Serratia * Providentia * Indole positive Proteae* * Citrobacter * Enterobacter * Produce AmpC β-lactamases * Can become de-repressed (over-produced) with therapy * Intrinsic 3 rd generation cephalosporin resistance * In a veterinary context I would recommend avoiding all β- lactams

Answer 60

-many intrinsic resistances to many drugs

Answer 61

enterococcus: resistant to all cephlosporins and some to vacomycin

Answer 62

* Natural phenomenon - resistance is often a byproduct of something else: * Soil organisms survive in an environment that contains antimicrobial compounds * Enteric organisms need to survive in the presence of bile acids -resiatance for all drugs is already out there, make sure using drug is worth it. -bacteria adept very quick.

Answer 63

-mutation -conjugation -transduction -transformation B lactamalses- degradation enzymes which dont let the drug work.

Answer 64

* Efflux: * Common in Gram positive and negative * Resistance not necessarily across class... * Ribosomal protection * S. pseudintermedius (tetM) * Conformational change in tetracycline binding site on 30S subunit of ribosome * Ribosomal mutations, enzymatic inactivation also occur

Answer 65

* Enzymatic inactivation * Aminoglycoside modifying enzymes * Most common mechanism of resistance * Decreased permeability * Cross resistance to other antimicrobials

Answer 66

* Target Modification * Ribosomal methylases * erm gene family * Be aware of inducible resistance * Active Efflux * Enzymatic Inactivation

Answer 67

* Target mutations (Gram positive and negative) * gyrA and parC particularly * Step-wise resistance * Can see MIC creep * Efflux * mar operon * multidrug resistance * Plasmid mediated (target protection)

Answer 68

* Hyper-production of PABA * Altered enzymes * dfr genes (trimethoprim resistance) * Gram positive and negative * sul genes (sulfa resistance) * Gram negative bacteria

Answer 69

* Treating a diagnosis rather than a syndrome * Concatenating laboratory evidence and your clinical exam into a diagnosis * Asking questions when you need more information * Using evidence-based empiric therapy * Likely pathogens, local resistance epidemiology * Applying your knowledge of * Intrinsic resistance * Drug mechanisms of action and spectrum of activity * Mechanisms of resistance * Recognizing the evolving world of infectious diseases * Resistance is emerging * Be nimble enough to adapt * Lifelong learning - sounds cliché but: * Professional duty * If you’re not up to date you’re out of date * Utilizing recognized therapeutic guidelines

Answer 70

* Pathogen identified (or likely pathogen) * Susceptibility of organism: Knowledge of local resistance epidemiology * Animal species * Signalment * Site/type of infection * Co-morbidities * Route of administration

Answer 71

-cost -complience -label indication -withdrawl time -business factors -fear factors -habitual practice factors -pharmaceutical factors

Answer 72

-rapidly growing fungi -blue colonies look like dandi lions but with conidiophores unbranched. very small -natural habitat in decomposing matter -respiratory or hypersensitivity reactions

Answer 73

Brooder pneumonia in young chickens * Seen in young chicks exposed to large number of spores *granulatamous Nodules in lungs and air sacs * Associated with dirty environments -in mature birds: emaciation, lung nodules. **penguins very suseptible

Answer 74

-causes guttural pouch mycosis -aspirgillus fumigatus -clinically: epistaxis, dysphagia, laryngeal nerve paralysis, horners syndrome -fungus invades neuro structures -diagnosis based on endoscope -case fatality 1/3 -treatment: poor, debridegment, topical antimicrobials (eniconazole or miconazole) * Iatrogenic thrombosis and embolization of carotid= Prevents bleeding following debridement

Answer 75

-cause mycotic abortion -sporadic disease -6-8 months in preg, with poor feed quality. -reach placenta hematogenously -ringworm like lesions on abortuses -thickened placenta with necrotis cotyledons

Answer 76

* A. fumigatus nasal disease * Clinical signs include * Mucopurulent nasal discharge, epistaxis * Sneezing * Nasal discomfort * A. fumigatus can produce osteolytic toxins * Destruction of the turbinates * Erosion of the cribriform plate -can see on rhinoscopic exam, physical

Answer 77

* Treatment * Systemic therapy does not have a good success rate, ~40-60% -debride fungal plaques * Topical antifungal therapy * Enilconazole or clotrimazole * Trephination of sinus * Fill with clotrimazole cream * Close hole with bone wax * Be sure the cribriform is intact

Answer 78

* Most commonly affect respiratory system * A. fumigatus or flavus 1. Allergic bronchopulmonary aspergillosis * Similar signs to asthma 2 aspergilloma: cough, hemoptysis 3. invasive aspergillosis: fever, chest pain * Very high mortality rates * 94% mortality in bone marrow transplant patients * Aspergillus has an affinity for invading blood vessels

Answer 79

-koh of tissues -culture - Galactomannan is a component of the cell wall of Aspergillus spp. * In people a quantitative galactomannan ELISA is used to monitor response to therapy * If levels decreasing this indicates successful clinical strategy

Answer 80

-not much transmission, more in environment * Possible occupational exposure * Waste management workers who work with organic waste * Large number of Aspergillus spores in degrading plant material * Susceptible to developing allergic bronchopulmonary aspergillosis

Answer 81

* Azoles drugs are the treatment of choice systemically * Itraconazole, voriconazole * NOT fluconazole Other filamentous fungi (Mucor and Rhizopus spp.) intrinsically voriconazole resistant

lect 27-36 Flashcards

(105 cards)