Major Canine & Feline Pathogens Flashcards
1
Q
Gram negative bacteria stain what color?
A
Red
2
Q
Gram positive bacteria stain what color? Why?
A
Blue; due to their thick peptidoglycan walls
3
Q
Why do Mycoplasma stain red? What is their bacterial classification?
A
- Because they lack a cell wall and pick up the last stain they’re hit with
- acid fast (evolved Gram +)
4
Q
Why is there limitations for antimicrobial that target fungi?
A
Because their cellular makeup is so similar to that of their hosts (ie. Us and animals)
5
Q
What are some methods for detection of microbial pathogens?
A
Classical culture, molecular PCR, antigen detection agents
6
Q
What are examples of viral diagnostic procedures?
A
- Detection of viral antigens
- detection of viral-specific RNA/DNA
- antibody response
**these are only helpful if you know what you’re looking for**
7
Q
What are some potential problems with classical bacterial cultures?
A
- Slow growing or fastidious microbes
**new molecular techniques are faster to overcome these problems
8
Q
What is the basis for PCR diagnostics?
A
To detect infectious agents and discriminate non-pathogenic from pathogenic strains
9
Q
What are the 4 different types of PCR assays?
A
- Standard PCR (DNA)
- reverse transcription PCR (RNA)
- quantitative real time PCR
- Pan16S/Microbiome
10
Q
What is so special about the Pan16S gene?
A
It has several conserved, non variable sequences
11
Q
What are the advantages to PCR diagnostics?
A
- Fast and amenable to high throughput
- can use target gene or “generic” primers followed by sequencing
- permits ID of non-cultivatable or slow-growing microbes (e.g. mycobacterium, anaerobes, viruses)
12
Q
What are some disadvantages of PCR?
A
- You do not get clinical isolates, so you cannot perform sensitivity testing
- high risk of contamination so requires rigorous quality control
13
Q
What are four methods of detecting an immune response?
A
- ELISA
- fluorescent antibody test (FA)
- complement fixation (CF)
- hemagglutination direct and indirect (HA)
14
Q
What are three methods of detecting lesions or microbes associated with lesions?
A
- Histology/immunohistology
- molecular probes
- electron microscopy
15
Q
What is the time interval for seroconversion?
A
Paired sera and 4 fold rise
16
Q
How do you differentiate acute vs. chronic immune responses using serology?
A
- Acute: IgM
- Chronic: IgG
17
Q
Serology is a good screening tool for what?
A
Negative status of a group of animals and vaccine efficacy
18
Q
Define sensitivity
A
The percentage of true positives among those truly infected
- TP/TP + FN
19
Q
Define specificity
A
The percentage of true negatives among the non-infected
- TN/TN + FP
20
Q
Define prevalence
A
Total positives out of all tested
- TP + FN/total # tested
21
Q
Define accuracy
A
Total true results out of all tested
- TP + TN/ total # tested
22
Q
Define positive predictive value
A
Total amount of positives out of all positives
- TP/TP + FP
23
Q
Define negative predictive value
A
Total amount of negatives out of all negatives
- TN/TN + FN
24
Q
What is the diagnostic uncertainty range?
A
20% prevalence (more sensitive/TN) < x < 60% prevalence (more specific/TP)
- if there is < 20% prevalence, don’t believe a positive result
- if there is >60% prevalence, don’t believe a negative result
25
Sampling sites without normal microflora include:
* Blood
* CSF
* joint fluid
* urine from the bladder
* SQ
* surgically prepped sites
26
Sampling sites with normal microflora include:
* Skin
* mucosal sites (minimize contamination)
27
What are sampling protocols for viral samples?
* Use viral transport medium (keep at 4\*C)
* **buffered** at physiological pH (protein buffer like BSA) with **antibiotics** to inhibit bacterial overgrowth
28
Why should swabs be used with caution for viral sample submission?
Some inhibit PCR
29
What is the sampling protocol for organism isolation, PCR, or Ag detection?
* specimens = tissue, excretions, secretions
* Aseptic, store cold - DO NOT freeze or fix (some can be frozen at -80 or in liquid nitrogen)
30
What are the sampling specimen types and collection protocols for serology?
* Specimens: serum, CSF, synovial fluid
* collection: aseptic, handle gently to prevent hemolysis, remove needle before dispensing, clot at RT and centrifuge, remove serum
* shipping: refrigerate in MANUAL DEFROST (not frost free!) freezers - double bag and ice pack
31
What are the sampling specimen types and collection protocols for histology?
* Specimens: tissue
* Collection: aseptic, 5 mm thick, fix in 10% formalin @ 10x volume
* shipping: double bag and leak proof container
32
What are the sampling specimen types and collection protocols for direct FA?
* Specimens: tissue, tissue impression
* Collection: make impression on clean slide and air dry, fix in alcohol for cytology or acetone for direct FA
* Shipping: tissue pack on ice and ship as would for microbial isolation, slides can be unrefrigerated
33
What are the sampling specimen types and collection protocols for electron microscopy (usually viral)?
* Specimens: tissue
* Collection: aseptic, 1x2 mm thick, fix in 2-4% glutaraldehyde at 10x volume
34
What are the sampling collection and shipping protocols for feces or body fluids?
* Collection: Aseptic, fresh, do no freeze or fix
* Shipping: double bag and wet ice sufficient for 48-72 hr
35
What are the sampling specimen types and collection protocols for aspirates ?
* Sites: joint fluid (may need to collect in syringe w/ small amount of sterile heparin), CSF, abscesses
* Collection: into syringe, cap tightly, refrigerate, transport on ice
36
What are the sampling specimen types and collection protocols for swabs?
* Sites: EENT, skin; aspirates and biopsies almost **ALWAYS** **preferable** to swabs
* clean and disinfect surface prior to collection
* general purpose cotton swabs contain substances that inhibitory for some bacteria, PCR rxns, and are NOT SUITABLE for specimen transport
* Transport: Amies semi-solid transport medium for Mycoplasma and anaerobes, crush ampule to moisten swab
37
What are the sampling specimen types and collection protocols for TTW and BAL?
* Recovery rate for fastidious organisms higher than w/ oropharyngeal or nasal swabs
* transport and lab set-up ASAP as saline not good preservative
* refrigerate and use transport medium if mailing
38
What are the sampling specimen types and collection protocols for urine?
* Need to notify when and how urine was collected, collect into sterile container, preferable via cysto or catheter
* refrigerate \<1 hr of collection and process by lab \<72 hrs from collection
39
What are the sampling specimen types and collection protocols for blood?
* May need to take multiple samples over time
* animals not receiving antimicrobials at time of collection —\> mix blood collection transport bottle and may hold at room temp for up to 8 hours
* IF receiving antimicrobials at time of collection —\> transport on ice to lab immediately and note usage
40
What are the sampling specimen types and collection protocols for feces?
* Submit 5-10 grams in sterile screw cap container, avoid use of swabs, don’t always contain sufficient numbers of organisms
* does not protect anaerobic/microaerophilic organisms well, refrigerate
41
What are the sampling methods of choice for anaerobes?
Biopsy or needle aspirates
42
Describe necropsy sample submission protocols
* If uncontaminated, survival of pathogens usually good —\> use freshest tissues possible (\>6 hours after death freq. heavily contaminated)
* ideal specimen size = 2-4 cm^3 of parenchyma tissue, centered on margin of lesion
* send ligated intestinal loop 8-10 cm long, **NOT contents for culture and list DDX**
43
Why are spleen, heart, blood, or bone marrow preferred over liver to detect septicemic infections?
Livers are often contaminated by retrograde spread of intestinal flora from from the bile duct
44
What necropsy sites are best for Mycoplasma isolation?
Airways
45
What tissues are usually most rewarding for lung cultures?
Tissue just ahead of the advancing lesion
46
Mycoplasmas and Ureaplasmas are typically extracellular except for which ones?
Hemotrophic mycoplasmas
47
Adenoviridae are what kind of virus? What is an example of this?
* DS linear, non-enveloped, DNA virus
e. g. Canine adenovirus (Infectious canine hepatitis)
48
Herpesviridae are what kind of virus? Give examples of this.
* DS linear, enveloped, DNA virus
E.g. Canine herpes virus 1 & 2 (hemorrhagic puppy disease); feline viral rhinotracheitis (FHV1)
49
Name some examples of DNA viruses
* Adenoviridae
* Herpesviridae
* Parvoviridae
* Poxviridae
50
Name a few examples of RNA viruses
* Arenaviridae
* Astroviridae
* Bunyaviridae
* Caliciviridae
* Paramyxoviridae
* Retroviridae
* Coronoviridae
* Rhabdoviridae
51
Describe characteristics of Parvoviridae. What are some examples of these?
* SS linear, non-enveloped, DNA virus
e. g. Canine parvovirus 1 & 2, feline panleukopenia virus
52
Describe characteristics of Poxviridae. What are some examples of this?
* DS linear, enveloped, DNA virus
e. g. Feline pox virus, contagious ecthyma/orf/contagious pustular dermatitis (dog, caprine, cervine)
53
Which viruses include Foreign Animal disease agents?
Poxviridae, Bunyaviridae, and Paramyxoviridae
54
Describe characteristics of Arenaviridae. What is an example of one?
* SS linear **segments**, enveloped, RNA virus
e. g. Canine lymphocytic choriomenigitis virus
55
Describe characteristics of Astroviridae. Give an example of one.
* SS linear, non-enveloped, RNA virus
e. g. Feline astrovirus (gastroenteritis)
56
Describe characteristics of Bunyaviridae. Give an example of one.
* SS linear **segments**, enveloped, RNA virus
e. g. Rift Valley fever virus, Hantavirus (zoonotic)
57
Describe characteristics of Caliciviridae. Give an example of one.
* SS linear, non-enveloped, RNA virus
e. g. Feline calicivirus (URT), canine calicivirus
58
Describe characteristics of Paramyxoviridae. Give an example.
* SS linear, enveloped, RNA virus
e. g. Canine distemper, canine parainfluenza virus
59
Describe characteristics of Retroviridae. Give an example of one.
* 2 copies SS linear, enveloped, RNA virus
e. g. FIV, FeLV
60
Describe characteristics of Coronaviridae. Give an example of one.
* SS linear, enveloped, RNA virus
e. g. Feline enteric coronavirus, FIP, canine coronavirus
61
Describe characteristics of Rhabdoviridae. Give an example of one.
* SS linear, enveloped, RNA virus
e. g. RABIES
62
What are some airborne diseases that dogs and cats can both contract?
* Anthrax
* Aspergillus
* Bordetella bronchiseptica
* Canine parvovirus 2
* Cocciodes immitis
* Cryptococcus neoformans
* Glanders
* Histoplasma
* Meliodiosis
* Nipah virus
* Plague virus
* Pneumocystis carinii
* Q fever
* Tuberculosis
63
Name some airborne diseases that only cats get?
* Chlamydophila
* Hendra virus
* FRV
* Calicivirus
* Panleuk
* FIP
64
Name some airborne diseases only dogs get?
* Tularemia
* Blastomyces
* Parvo
* Infectious canine hepatitis (CAV-2)
* Canine distemper virus
65
Which vector-borne diseases are transmitted by only ticks?
* Babesia spp.
* Cytauxzoon felis
* Erhlichia spp.
* Lyme disease
* Q fever (Coxiella)
* Haemobartonella canis
* Rocky Mountain Spotted Fever (Rickettsia)
* Tularemia (Francisella)
66
Which vector-borne diseases are transmitted by flies and ticks?
* Bartonella
* Tularemia
67
Which vector-borne diseases are transmitted by only fleas?
* Haemobartonella
* Plague (Yersinia)
68
Which vector-borne diseases are transmitted by only fly larvae?
* Screwworm myiasis
69
Which vector-borne disease is transmitted by only sandflies?
* Leishmaniasis
70
Which vector-borne disease is transmitted by the Triatomine bug?
* Chagas’ disease
71
Which vector-borne diseases are transmitted by only mosquitoes?
* West Nile
* Rift Valley Fever
72
Name some examples of enveloped viruses
* Herpesviridae
* Poxviridae
* Paramyxoviridae
* Arenaviridae
* Bunyaviridae
* Retroviridae
* Coronaviridae
* Rhabdoviridae
73
Name some examples of non-enveloped viruses
* Adenoviridae
* Parvoviridae
* Astroviridae
* Caliciviridae
74
Name the gram positive cocci
* Enterococcus
* Micrococcus
* Staphylococcus
* Streptococcus
75
Name the Gram positive rods
* Actinomycetes
* Bacillus
* Coryneform
* Erysipelothrix
* Listeria
* Mycobacterium (Acid fast)
* Nocardia
* Rhodococcus
* Streptomyces
76
What are the Gram negative aerobic bacteria we focused on?
* Actinobacillus
* Bordetella
* Brucella
* Enterobacter/Enterobacteriaceae
* Escherchia
* Haemophilus
* Klebsiella
* Pasteurella
* Proteus
* Pseudomonas
* Salmonella
* Shigella
* Yersinia
77
What are some examples of Gram negative rods that are curved/spiral-shaped?
* Borrelia
* Campylobacter
* Helicobacter
* Leptonema
* Leptospira
* Treponema
78
What are some examples of obligate intracellular bacteria (gram negative)?
* Chlamydia
* Coxiella
* Ehrlichia
* Mycoplasma\*
* Rickettsia
* Ureaplasma\*
\*Mycoplasmas and Ureaplasmas are generally extracellular EXCEPT for hemotrophic mycoplasmas
79
Which bacteria are anaerobes?
* Actinomyces - GP
* Bacteroides - GN
* Clostridium - GP
* Fusobacterium - GN
* Lactobacillus - GP
GP = Gram +
GN = Gran -
