BB Ch3 80-93 KD Flashcards
- Which of the following agents is a gram negative, pleomorphic bacterium lacking a cell wall?
Mycoplasma pulmonis
- Differential diagnoses for weight loss, piloerection, chattering, dyspnea, and torticollis include infection with , , , , .
CAR bacillus, Sendai virus, Pneumonia virus of mice, Corynebacteria kutscheri, Pneumocystis carnii
- T/F Ooprhoritis, salpingitis, and metritis are seen in natural infections of Mycoplasma pulmonis.
False: has only been seen in experimental infection with this agent.
- M. pulmonis can be found in approximately what percentage of conventional mouse colonies?
a. 10%
b. 15%
c. 20%
d. 25%
b. 15%
- M. pulmonis is spread
a. Fecal-oral
b. Fomites
c. Aerogenically
c. Aerogenically
- T/F M. pulmonis can be transmitted in utero in mice
False– demonstration of in utero tramsmission has only been seen in rats
- T/F Mice infected with other pathogens are at increased risk of developing MRM
True–mice infected with Sendai or Mouse Coronavirus are at increased risk of developing MRM.
- M. pulmonis has not been isolated from which of the following ?
a. Rat
b. Hamster
c. Gerbil
d. Guinea pig
e. Rabbit
c. Gerbil
- T/F M. pulmonis in an intracellular organism.
False–extracellular
- Where does M. pulmonis colonize?
Colonizes in the apical cell membranes of the respiratory epithelium anywhere between the anterior nasal passages to alveoli
- M. pulmonis may injure host cells via which mechanism?
a. Competition for metabolites (carbohydrates and metabolites)
b. Release of toxic substances (such as peroxides)
c. Neither
d. Both
d. both
M. pulmonis causes ciliostasis, which leads to distrupted mucociliary transport.
True
- How many M. pulmonis CFU are required to produce acute, lethal pneumonia?
a. <10
b. 100-1000
c. 1000-10,000
d. >10,000
d. >10,000
- T/F Arthritis a significant feature of natural M. pulmonis infection
d. False
- Which of the following strains are resistant to pathogenic infection by M. pulmonis?
a. BALB/c
b. C3H
c. DBA/2
d. SWR
e. AKR
f. CBA
g. SJL
h. C57BL/6
h. C57BL/6
- T/F Lymphoid infiltration of the submucosa in the trachea can persist for weeks after initial infection with M. pulmonis.
True
- The initial lesion of MRM (murine respiratory mycoplasmosis) is
a. Suppurative rhinitis
b. transient hyperplasia of submucosal glands
c. suppurative otitis media
d. chronic laryngotracheitis with mucosal hyperplasia
e. suppurative bronchitis, bronchiolitis, alveolitis
a. Suppurative rhinitis
- T/F Squamous metaplasia is a feature of MRM.
True
- Pulmonary lesions in MRM are typified by .
bronchopneumonia spreading from the hilus
- The typical inflammatory lesions seen in MRM pneumonia include
a. Neutrophils in the parenchyma
b. Lymphoid and plasma cells in the bronchial lumena
c. Lymphoid and plasma cells around the bronchi with neutrophils in the bronchial lumena
c.Lymphoid and plasma cells around the bronchi with neutrophils in the bronchial lumena
- The predominant lesions seen in chronic MRM include:
a. Suppurative bronchitis, bronchiolitis, and alveolitis
b. Lymphocytic bronchitis, bronchiolitis, and alveolitis
c. Histiocytic bronchitis, bronchiolitis, and alveolitis
a. Suppurative bronchitis, bronchiolitis, and alveolitis
- Serologic tests do not differentiate between which species of mycoplasmosis
a. M. arthriditis and M. collis
b. M. arthriditis and M. neurolyticum
c. M. arthriditis and M. pulmonis
d. M. collis and M. neurolyticum
e. M. collis and M. pulmonis
f. M. neuroltyicum and M. pulmonis
c. M. arthriditis and M. pulmonis
- T/F The media of choice for collecting samples for culture of M. pulmonis is TSB.
False: lavage with buffered saline or mycoplasma broth
- Speciation of Mycoplasma species can be accomplished using which of the following techniques
a. Immunofluorescence
b. Immunoperoxidasse staining
c. ELISA
d. Growth inhibition
e. PCR
a. immunofluorescence
b. Immunoperoxidase Staining
d. Growth inhibition
e. PCR
- T/F Treatment with tetracyclines is an effective means to eradicate M. pulmonis
False
- Match the organism with the research complication (will be more than one answer)
- Provokes strong Th1 proinflammatory response,
which may perturb other immunological responses - Mitogenic for T and B lymphocytes
- Increases sensitivity of colonic mucosa to chemical carcinogens
- Decreases latent period between administration of carcinogen
and appearance of focal atypical cell growth - Contaminates cells lines and transplantable tumors
- Cofactor or promoter in development of hepatic neoplasia in
A/JCr and B6C3F1 mice - Causes fatal septicemia in immunodeficient mice
- Causes elevations in selected cytokines
- Can increase natural killer cell activity
a. M. pulmonis: 2, 9, 5
b. C. piliforme: 8
c. Citrobacter rodentium: 3, 4
d. Pseudomonas: 7.
e. Helicobacter hepaticus: 1, 6
- T/F Natural infection by M. arthriditis can lead to arthritis.
False: nonpathogenic during natural infection
Match the organism to the clinical signs seen wtih natural infection:
Cilia-associated respiratory bacillus (CAR bacillus)
Clostridium piliforme
M. arthriditis
M. collis
M. pulmonis
CAR bacillus = chronic respiratory disease (rare)
Clostridium piliforme = diarrhea and inactivity and sudden death
M. arthriditis = nonpathogenic
M. collis = nonpathogenic
M. pulmonis = chattering, dyspnea, torticollis
Match the organism to the clinical signs seen wtih experimentally induced disease:
M. arthriditis
M. neurolyticum
M. pulmonis
M. arthriditis = arthritis
M. neurolyticum = spasmodic hyperextension of the head and rasigin of one foreleg followed by intermittent rolling on the long axis of the body
M. pulmonis = oophoritis, salpingitis, metritis
- The etiologic agent of “rolling disease” is .
Mycobacterium neurolyticum
- What is the gram morphology of cilia-associated respiratory bacillus?
Slender, gram negative rod
- T/F CAR-bacillus is a primary/opportunistic pathogen of mice
True: evidence suggests opportunistic, naturally occurring disease in mice
- Diagnosis of infection with CAR-bacillus can be done using which of the following techniques:
a. ELISA for serological detection of infection
b. Histologically by staining with Warthin-Starry stain
c. Immunoperoxidase staining
d. PCR
e. Radioimmunoassay
a. ELISA for serological detection of infection
b. Histologically by staining with Warthrin-Starry stain
c. Immunoperoxidase staining
d. PCR
- A histologic section of lung was stained with a Warthin-Starry stain. Argyrophilic bacilli were adherent to the apical membranes of bronchial respiratory epithelium. The most likely etiologic agent is .
CAR bacillus
- Sulfamerazine (500mg/liter) in drinking water may be effective in eradicating which organism
a. CAR bacilis
b. C. piliforme
c. Helicobacter hepaticus
d. M. pulmonis
a. CAR bacillus
- The etiologic agent of Tyzzer’s disease is .
Clostridium piliforme
- Clostridium piliforme was formerly named .
Bacillus piliformis
- The gram morphology of Clostridium piliforme is .
long, thin, gram negative, spore-forming bacterium
- Tyzzer’s disease is named for .
Ernest Tyzzer, first described in a colony of Japanese Waltzing mice
- T/F C. piliforme can be successfully grown on cell-free media.
False
- C. piliforme can be grown successfully by inoculation of :
a. cell free media
b. hepatocyte cultures from mice
c. susceptible vertebrates
d. yolk sac of embryonated eggs
c. susceptible vertebrates
d. yolk sac of embryonated eggs
b. hepatocytes cultures from mice
(pg. 84)
- T/F Outbreaks of C. piliforme are not usually explosive and have low mortality.
False
- Which of the following clinical signs can be attributed to infection with C. piliforme?
a. diarrhea
b. emesis
c. inactivity
d. No signs evident - subclinical infection
a. diarrhea
c. inactivity
d. subclinical infection
- Which of the following has not been shown to predispose mice to Tyzzer’s disease
a. Overcrowding
b. High humidity
c. High temperature
d. Host genotype
e. Immunosuppression
f. Moist food
None: they have all been shown to cause susceptibility. Page 84
- Which mouse is more resistant to Tyzzers, C57BL/6 or DBA/2?
C57BL/6
- Mice deficient in which of the following cell types are more susceptible to Tyzzer’s disease
a. B lymphocytes
b. Eosinophils
c. Monocytes
d. Neutrophils
e. Natural killer cells
d. neutrophils
e. natural killer cells
b. B lymphcytes
The reservoir of Tyzzer’s disease is the rabbit
False: it is unknown
- T/F Strains of C. piliforme are always host specific.
False, some strains can infect multiple hosts (mice, rats, hamsters)
- Spores of C. piliforme can remain viable in the environment at room temperature for
a. 2-3 weeks
b. 2 months
c. 6 months
d. 12 months
d. 12 months
- Which form (vegetative or spore) of C. piloforme should be considered the primary means of spread.
Spore form
- The most likely source of environmental contamination of Tyzzer’s disease is .
Feces contaminated food and soiled bedding
- The mode of transmission of C. piliforme is .
Fecal-oral
- Infection with C. piliforme begins in the _______and spreads to the ____________ .
Intestines and spreads to the liver and heart
- Lesions caused by C. piliforme are characterized by
a. Chronic inflammation in the intestines, liver, heart
b. Hemorrhage in the heart and mesenteric lymph nodes
c. Necrosis in the intestines, liver, and heart
d. Necrosis in the intestines, liver, heart, and mesenteric lymph nodes
d. Necrosis in the intestines, liver, heart, and mesenteric lymph nodes
- During the necropsy of a mouse, it is noted that segments of the ileum, cecum, and colon are red and dilated, and contain watery, fetid contents. The liver contains gray-white foci. Based on these findings, differential diagnoses include
a. Helicobacteriosis
b. Rotavirus (EDIM)
c. Salmonellosis
d. Transmissible Murine Colonic Hyperplasia
e. Tyzzer’s Disease
c. Salmonellosis
e. Tyzzer’s Disease
- Inflammation found in cases of Tyzzer’s disease is generally
a. Granulomatous
b. Histiocytic
c. Lymphocytic
d. Neutrophilic
c. Lymphocytic
d. Neutrophilic
- T/F Bundles of long slender rods in the nucleus of dead cells bordering necrotic foci in the liver are diagnostic for Tyzzer’s disease.
False–they are in the cytoplasm
- The stains most useful for diagnosing Tyzzer’s disease are .
Silver Stains (Warthin-Starry)
Giemsa
Periodic-Acid-Schiff
- T/F Asymptomatic infections caused by Tyzzer’s disease can be detected by ELISA.
True; also by PCR
- The causative agent of Transmissible Murine colonic Hyperplasia is .
Citrobacter rodentium
- Citrobacter rodentium was formerly named .
Citrobacter freundii strain 4280
- The gram morphology of C. rodentium is .
Gram negative rod
- C. rodentium can/cannot ferment lactose.
C. rodentium can ferment lactose
- C. rodentium can/cannot utilize citriate.
It does not really utilize citrate or does so marginally. (page 85)
- Clinical infection with Citrobacter rodentium is characterized by
a. Diarrhea
b. Explosive mortality
c. Rectal prolapse
d. Soft feces
c. rectal prolapse
d. soft feces
- Which of the following groups is more likely to develop Transmissible Murine Colonic Hyperplasia?
a. Suckling or recently weaned mice
b. Mice 8-12 weeks of age
c. Mice > 6 months of age
a. Suckling or recently weaned mice
- T/F Citrobacter rodentium can be found in the GI flora of normal mice
False
- C. rodentium can be spread by
a. Aerosol
b. Contact
c. Fecal-oral transmission
b. Contact
c. Fecal-oral transmission
- Which strain(s) of mice is(are) relatively resistant to infection with C. rodentium
a. C3H/HeJ
b. C57BL
c. DBA
d. NIH Swiss
C. DBA
B. C57BL
D. NIH Swiss
- T/F Diet has no effect on infection by C. rodentium.
False; however, no specific dietary factor has been identified
- T/F C. rodentium attaches to the mucosa of the ileum.
False; it attaches to the descending colon
- The characteristic gross finding seen in Transmissible Murine Colonic Hyperplasia is
a. Dark mesenteric lymph nodes
b. Flaccid, gas filled colon
c. Red, distended intestines
d. Severe thickening of the descending colon
d. Severe thickening of the descending colon
- Lesions caused by C. rodentium persist
a. For a few weeks
b. For a few months
c. For at least a year
a. For a few weeks
- The agar of choice for identifying C. rodentium in culture is .
MacConkey’s agar
- What is the gram morphology of Pseudomonas aerugenosa?
Motile gram negative rod
- Which of the following is not a clinical sign of infection with Pseudomonas aeruginosa
a. Conjunctivitis
b. Edema of the head
c. Edema of the hind limbs
d. Equilibrium imbalance
e. Serosanguinous nasal discharge
c. edema of the hind limbs
- The most common clinical sign seen in immunocompetent mice infected with Pseudomonas aeruginosa is
a. Conjunctivitis
b. Infection of the head
c. None (infection is subclinical)
d. Weight loss
c. None, infection is subclinical
- T/F Pseudomonas aeruginosa is part of the normal flora
False
- Once established in a mouse, Pseudomonas aeruginosa can be cultured from all but one of the following sites:
a. GI tract
b. Nasopharynx
c. Oropharynx
d. Reproductive tract
d. reproductive tract
T/F Pathogenic infection with Pseudomonas aeruginosa is most common in immunocompetent mice
False
- Put the following into order of occurrence when an immunodeficient mouse is infected with Pseudomonas aeruginosa:
a. Bacteremia
b. Enter the squamocolumnar junction of upper respiratory tract or periodontal gingival
c. necrosis of liver, spleen, or other tissues
b. enters URT or gingiva
a. creates a bacteremia
c. Necrosis of liver, spleen, or other tissues
- On necropsy of an immunosuppressed mouse with clinical signs of weight loss, conjunctivitis, serosanguinous nasal discharge, and otitis media, you observe the following clinical signs: the bowel is distended with fluid, gastrointestinal ulceration is present, and the tympanic bulla contain green suppurative exudate. What is the most likely etiologic agent?
a. Clostridium piliforme
b. Pasteurella pneumotropica
c. Pseudomonas aeruginosa
d. Salmonella enteriditis
c. Pseudomonas aeruginosa
Pseudomonas aeruginosa carrier mice can be identified by either nasal culture or by placing bottles of sterile, nonacidified, nonchlorinaged water on cages for 24-48 hours and then culturing the sipper tubes.
True
Acidification or hyperchlorination of the drinking water will eliminate established infection with Pseudomonas aeruginosa.
False
- T/F Pasteurella pneumotropica is a long, gram positive rod.
False
- The gram morphology of Pasteurella pneumotripica is .
a short gram negative rod
T/F Pasteurella pneumotripica is most properly viewed as an opportunistic pathogen.
True
T/F Studies of experimental infections with Pasteurella pneumotropica suggest that it does not complicate pneumonias due to M. pulmonis and Sendai virus.
False, studies have shown that P. pneumotropica may complicate pneumonias due to M. pulmonis and Sendai virus
- Pasteurella pneumotripica is a ubiquitous inhabitant of which of the following sites in the mouse:
a. Gastrointestinal tract
b. Lower respiratory tract
c. Nasolacrimal ducts
d. Skin
e. Upper respiratory tract
f. Urogenital tract
a. GI tract
d. Skin
e. Upper respiratory tract
- How soon after birth can litters from dams infected with Pasteurella pneumotropica can become infected?
during the first week after birth
- Which of the following has not been attributed to infection by P. pneumotropica
a. Conjunctivitis
b. Dacryoadenitis
c. Dermatitis
d. Hepatitis
e. Infections of the bulbourethral glands
f. Mastitis
g. Panopthalmitis
d. heptatis
- T/F Cutaneous lesions caused by P. pneumotropica are always associated with systemic disease.
False, cutaneous lesions can occur without systemic disease
- Lesions caused by P. pneumotropica are most often in nature.
a. Caseous
b. Liquefactive
c. Necrotizing
d. Suppurative
d. suppurative
- T/F Infection with P. pneumotropica can be detected by ELISA
True
- List 6 bacteria that can cause suppurative lesions in mice.
Pastuerella pneumotropica
Staphylococcus
Streptococcus
Corynebacterium
Klebsiella
Mycoplasma
- What is the gram morphology of Helicobacter?
gram negative, curved to spiral shaped
- T/F Helicobacter can be grown in culture
True
- Describe the environmental conditions under which Helicobacter can be grown in culture.
microaerobic atmosphere (5% cO2, 90% N2, 5% H2)
- 2 types of media on which Helicobacter can be grown are , .
freshly prepared antibiotic impregnated blood agar
broth supplemented with fetal bovine serum
- Helicobacter species isolated from mice include (hint, there are 6).
H. bilis
H. hepaticus
H. muridarum
H. rappini
H. rodentium
H. typhlonius
- Helicobacter organisms are most commonly urease (positive, negative), catalase (positive, negative), and oxidase (positive, negative).
urease negative
catalase negative
oxidase positive
- List 2 species of Helicobacter that are urease negative.
H. rodentium and H. typhlonicus are urease negative
- T/F Infection of adult immunocompetent mice with Helicobacter hepaticus usually causes inflammatory bowel disease.
False: infection in immunocompetent mice is usually asymptomatic
- H. hepaticus may cause an elevation in liver enzymes in which of the following strains of mice
a. A/JCr
b. BALB/c
c. C3H/HeNCr
d. C57BL/6
A/JCr
- Transmission of Helicobacter hepaticus occurs primarily by which route
a. Aerogenically
b. Fecal-oral
c. By fomite contamination
fecal-oral
- T/F H. hepaticus cannot persist in the GI tract (cecum and colon).
False: H. hepaticus CAN persist in the GI tract, in particular the cecum and the colon. This implies that carrier mice can spread infection in enzootically infected colonies.
- T/F Proliferative typhlitis caused by H. hepaticus is always associated with liver lesions.
False: proliferative typhlitis, colitis, and proctitis can occur without coincident hepatitis
- T/F Inflammation in the livers of mice infected with H. hepaticus originates in the central lobular areas of the liver and spreads to the portal triads.
False: inflammation orginates in the portal triads and spreads to the hepatic parenchyma
- Histologically, liver lesions caused by H. hepaticus are characterized as
a. Angiocentric nonsuppurative hepatitis and hepatic necrosis
b. Coagulative or caseous necrosis bordered by intense neutrophilic infiltration
c. Foci of coagulative necrosis that are generally distributed along branches of the portal vein
d. Granulomatous lesions with thrombosis from septic venous embolism
e. Necrosis with syncytia cell formation
a. Angiocentri nonsuppurative hepatits and hepatic necrosis = H. hepaticus
b. Coagulative or caseious necrosis bordered by intense neutrophilic infiltration = C. kutscheri
c. Foci of coagulative necrosis that are generally distribued along brances of the portal vein is seen with Tyzzer’s
d. Granulomatous lesions with thrombosis from septic venous embolism = Salmonellosis
e. Necrosis with syncytial cell formation = MHV
T/F H. hepaticus may cause necrosis in the liver of susceptible mice
True
- Which strains of mice are susceptible to developing age-related hepatomas and hepatocellular carcinomas caused by H. hepaticus?
A/JCr and B6C3F1
- Which strain of mice is resistant to hepatitis caused by H. hepaticus?
a. A/JCr
b. C3h/HeNCr
c. C57BL/6
d. SJL/NCr
C57BL6
- In which strain of mice infected with H. hepaticus is there an increased incidence of hepatic haemangiosarcoma?
B6C3F1
- What is the pattern of inheritance for susceptibility to H. hepaticus-induced neoplasia?
dominant pattern of inheritance
- T/F PCR can differentiate between H. hepaticus, H. bilis, H. ‘typhlonicus’, H muridarum and H. rappini.
False: PCR cannot differentiate between species; however, molecular speciation can be accomplished by restriction fragment length polymorphism analysis of the PCR product
- T/F Helicobacters grow rapidly in culture, and no growth after 4 days is long enough to deem the culture “negative”.
False: Helicobacters require prolonged incubation (up to 3 weeks) in culture before it can be deemed negative.
- H. bilis has been isolated from the livers and intestines of aged mice.
True (page 90)
- H. bilis induces disease in SCID mice.
Inflammatory Bowel Disease
- Match the bacteria with the disease (some answers will be used more than once):
a. H. bilis 1. gastritis under certain conditions
b. H. bilis and H. rodentium 2. IBD in SCID
c. H. muridarum 3. may be component of normal flora
d. H. “rappini” 4. natural outbreak of IBD in immunocompromised mice
e. H. rodentium 5. no clinical signs associated with isolation
f. H. typhlonicus
a. H. bilis = 2. IBD in SCID
b. H. bilis and H. rodentium = 4. natural outbreak of IBD in immunocompromised mice
c. H. muridarum = 1. gastritis under certain circumstances
d. H. rappini = 5. no clinical signs associated with isolation
e. H. rodentium = 3. may be component of normal flora
f. H. typhlonicus = 2. IBD in SCID
- Match the bacteria with the site of isolation (some will have more than one answer)
a. H. bilis cecum
b. H. muridarum colon
c. H. “rappini” feces
d. H. rodentium ileum
intestine
intestine
liver
stomach
a. H. bilis = liver and intestine
b. H. muridarum = ileum, cecum, colon, stomach
c. H. rappini = feces
d. H. rodentium = intestine
The combination of antibiotics most effective in treating infections with Helicobacter is . This treatment works best when the antibiotics are given via which method?
Triple therapy, daily gavage:
amoxicillin, metronidazole, bismuth
- What is the gram morphology of Corynebacterium bovis?
Short, gram postive rods
- The etiologic agent of pseudotuberculosis in mice is .
Corynebacterium kutcheri
- T/F Corynebacterium kutscheri infection is often symptomatic in otherwise healthy mice
False–usually asymptomatic in otherwise healthy mice
- T/F Active disease caused by C. kutscheri is precipitated by immunosuppression or environmental stress.
True
- T/F Active disease caused by C. kutscheri is expressed as an acute illness with low mortality or a chronic syndrome with high mortality.
False: Active disease caused by C. kutscheri is expressed as an acute illness with HIGH mortality or a chronic syndrome with LOW mortality
- Infection with C. bovis causes
a. Pustules
b. Cutaneous abscesses
c. Cutaneous ulceration
d. Hyperkeratitic dermatitis
Hyperkeratitic dermatitis
- T/F Rats are susceptible to infection with C. kutscheri
True
- Which of the following lesions is not likely to be seen in a mouse infected with C. kutscheri
a. Suppurative rhinitis
b. Cervical lymphadenopathy
c. Grey-white nodules in the kidney
d. Arthritis of the carpometacarpal and tarsometatarsal joints
a. Suppurative rhinitis
- Which of the following agents does not cause septicemic bacterial infections
a. Corynebacterium kutscheri
b. Mycoplasma pulmonis
c. Staphylococcus species
d. Streptococcus species
c. Staphylococcus species
- T/F Corynebacterium kutscheris is a primary skin pathogen
False: skin ulcers or fistulas follow bacterial embolization and infarcation of dermal vessels
- Skin scaliness and alopecia is characterized by infection with which organism
Corynebacterium bovis
- Nodular, caseous lesions are observed in the lung of a mouse. Which of the following stains should be done to differentiate the etiologic agents?
a. silver stain
b. acid-fast stain
c. gram stain
Acid fast to rule out Mycobacterium avium and gram stain to rule out Corynebacterium kutscheri
- T/F Scaly skin in glabrous mice can be caused by low humidity.
True
- The gram morphology of Streptobacillus moniliformis is .
nonmotile, gram negative, pleomorphic rod
- Which of the following is the virulent form of Streptobacillus moniliformis
a. L phase variant
b. Bacillus form
b. Bacillus form
- T/F Streptobacillosis has an acute phase with high mortality, followed by a subacute phase, and finally a chronic phase that may persist for months.
True
- Which of the following is not a sign of acute disease caused by Streptobacillus moniliformis
a. Anemia
b. cyanosis
c. Diarrhea
d. Dull, damp hair coat
e. Gangrenous amputation
f. Keratoconjunctivitis
Gangrenous amputation: this is a sign of chronic disease
- T/F Infection with Streptobacillus moniliformis can cause abortions and stillbirths.
True
- The most likely source of dissemination of Streptobacillus moniliformis to mice in a laboratory animal setting is
a. Asymptomatic persistently infected hamsters
b. Asymptomatic persistently infected humans
c. Asymptomatic persistently infected rats
d. Asymptomatic persistently infected rabbits
c. Asymptomatic persistently infected rats
- The etiologic agent of rat bite fever in humans is .
Streptobacillus moniliformis
- T/F Streptobacillus moniliformis has been isolated from joint fluid as long as 26 months after infection.
True
- T/F Culture of Streptobacillus moniliformis from chronic lesions does not require special medium.
False, requires serum-enriched medium
- Which antibiotics are an effective means to control of Streptobacillus moniliformis?
None; antibiotics are not effective in controlling S. moniliformis
- There are approximately 2400 known serotypes of Salmonella . The most frequent isolates from mice are Salmonella and Salmonella .
Salmonella enteritidis and Salmonella typhimurium
- The gram morphology of Salmonella enteritidis is .
gram negative rod
- T/F Salmonella enteritidis rarely ferments lactose
True
- Acute infection with Salmonella enteritidis is not characterized by
a. Anorexia
b. Conjunctivitis
c. Hepatomegaly
d. Lethargy
e. Weight loss
Hepatomegaly
- T/F Chronic infection with Salmonella enteritidis can produce distended abdomens from hepatomegaly and splenomegaly.
False: subacute infection can produce distended abdomens from hepatomegaly and splenomegaly
- Which of the following clinical signs are suggestive of infection of Salmonella enteritidis in a breeding colony
a. Alternating periods of quiescence and high mortality
b. Anorexia
c. Diarrhea
d. Reduced production
e. Weight loss
ALL are clinical signs
- Which of the following is not a potential source of Salmonella infection
a. Birds
b. Cats
c. Dogs
d. Feral rodents
e. Human carriers
f. Nonhuman primates
g. Vermin
h. None of the above
h. none of the above
- T/F Murine salmonellosis does not present a zoonotic hazard to humans.
False
- T/F Adult mice are more susceptible to infection with Salmonella than weanling mice.
FAlse: suckling and weanling mice are more susceptible than mature mice.
- Which of the following can decrease the severity of disease caused by Salmonella
a. Abnormal ambient temperatures
b. Exposure to heavy metal
c. Immune deficiency
d. Nutritional iron deficiency
nutritional iron deficiency attentuate salmonella infection
- Put the following in order of occurrence during infection with Salmonella
a. Bacteremia
b. Enter Peyer’s patches
c. Penetrate intestinal wall
d. Spread to mesenteric lymph nodes
e. Spread to spleen and liver
- Penetrates intestinal wall
- Enters Peyer’s patches
- SPread to mesenteric lymph nodes
- Bacteremia
- Spread to spleen and liver
- T/F Salmonella enterititis infection has not been associated with chronic arthritis.
False: it has been associated with arthrtitis
- Mice infected with Salmonella that survive for several weeks may have which of the following gross lesions:
a. Distended and reddened intestines
b. Hepatomegaly
c. Splenomegaly
d. Yellow-gray necrotic foci of liver and spleen
e. Enlarged, red, and focally necrotic lymph nodes
All the lesions can occur
- T/F Thrombosis from septic arterial embolism (esp. in the liver) may occur during infection with Salmonella.
False
- Which of the following is particularly characteristic of chronic infection with Salmonella
a. Granulomatous lesions, esp. in the liver
b. Histiocytic inflammation in the lungs
c. Necrotic lesions in the heart
d. Necrosuppurative inflammation in the spleen
e. Suppurative inflammation in the spleen
Granulomatous lesions, esp. in the liver
- T/F During acute Salmonellosis, bacteria cannot be isolated from the blood.
False, during acute stages, bacteria can be isolated in the blood.
- Which is a more reliable site for culturing Salmonella from asymptomatic mice
a. Feces
b. Mesenteric lymph nodes
b. MLN as fecal shedding can be intermittent
- T/F The use of agglutination tests is a reliable way to identify antibodies to Salmonella in the serum of infected mice.
False, serological cross-reactivity is common
- Infectious differential diagnoses for Salmonellosis include (list 8) .
- Tyzzer’s dz
- Pseudomoniasis
- Corynebacteriosis
- Murine colonic hyperplasia
- Pasteurellosis
- Coronavirus
- Ectromelia virus
- Reovirus
- A noninfectious differential diagnosis for Salmonellosis is .
Mesenteric lymphadenopathy
- T/F Infection with Salmonella can be controlled by treating with sulfa antibiotics.
False: there is no evidence that treating with any antibiotic is beneficial
A colony of SCID mice has a 6-month history of low mortality. Mice develop inappetance, become emaciated, have a hunched posture and a rough hair coat. Some mice develop hyperpnea, an ocular discharge, cutaneous ulcerations, and arthritis. At necropsy, gray-white nodules can be seen in the liver and lung. Histologic lesions are characterized by coagulative or caseous necrosis bordered by intense neutrophilic infiltration. Colonies of gram-positive organisms are sometimes visible in caseous lesions. The most likely diagnosis is infection with .
Corynebacterium kutscheri
- A mouse develops a dull, damp hair coat, keratoconjunctivitis, and cyanosis. Over time it becomes emaciated and develops cutaneous ulcers, arthritis, and gangrenous amputation. Histologic findings include purulent polyarthritis. A gram stain of joint fluid shows gram-negative, pleomorphic rods. The most likely etiologic agent is .
Streptobacillus moniliformis
- A nude mouse develops scaly skin. Histologic findings of the skin include acanthosis and moderate hyperkeratosis. There is mild, nonsuppurative inflammation. Gram-positive organisms are visible in the hyperkeratotic layers. The most likely etiologic agent is .
Corynebacterium bovis
- A weanling mouse presents with anorexia, weight loss, lethargy, dull coat, humped posture and conjunctivitis. Feces is formed. During necropsy, visceral hyperemia, a pale liver, and catarrhal enteritis is observed. Histologically, necrotic foci are found in the intestine, mesenteric lymph nodes, liver, and spleen. Neutrophilic leukocytes and histiocytes are observed in the lymphoid tissues. Culture of the mesenteric lymph nodes yields gram negative rods. The most likely etiologic agent is .
Salmonella enteritis (acute disease)
- A SCID mouse presents with a rectal prolapse. During necropsy, it is found that the cecum and large bowel are thickened. Proliferative typhlitis, colitis, and proctitis are present. No lesions are found in the liver. A silver stain of the crypts of the lower bowel shows spiral and curved organisms. The most likely etiologic agent is .
Helicobacter hepaticus or H. bilis