Case Study
Pathogenic Bacteriology
2009
Case #7, 34, 64
Evelyn Loi
Hien Dang
Jose Cervantes Jr.
Case Summary


8:00am

65-year-old woman bitten by her cat on
dorsal aspect of the right middle finger.
4:00pm

swelling and pain the finger and dorsum
of the right hand.

pain in the axilla, red streaking up the
forearm, and chills.

Body temperature: 38oC

Lab

Aspiration of abscess sent for culture
Operating room

Incision and drainage of abscess

Key Information Pointing to Diagnosis

Age

Body temperature
 38oC

Arm
 Red streaking
 Pain in axilla

Hand
 Erythema
 Swelling
 Warmth
 Tenderness of finger

Elevated WBC
 12,000 /microliter
Classification,Gram Stain Results, and Microscopic
Appearance of Pathogen
1. Which organism was isolated on culture of the abscess?

Family: Pasteurellacaea

Genus: Pasteurella

Species: multocida

Gram –

Coccobacilli

Bipolar staining

Fermentative

Non-motile

Facultative anaerobe
Diagnosis/Isolation/Identification/ of Pathogen

Media

No growth on Mac plate

Growth on Chocolate and Blood Agar

Biochemical testing

Oxidase +

Indole +

Catalase+

Nitrate +

Urease -
Diseases and Pathogenesis of Disease Caused by P.
multocida

Virulence Factor

Endotoxin

Capsule
What is the reservoir of this organism? How do humans most commonly become
infected by this organism?

Upper respiratory tract of pets and farm animals as NF

Bites or scratches inflicted by dogs and cats
Diseases caused by Pasteurella


Soft tissue inflammation

Purulent wounds, cellulitis, abscesses
Deep soft-tissue inflammation

Tenosynovitis

Septic arthritis

Osteomyelitis
Which other clinical syndromes can be caused by this organism?

Systemic infection (rare)

Endocarditis

Meningitis

Eyes

Conjunctivitis

Corneal ulcer

Respiratory

Pharangitis

Pneumonia (patients with underlying pulmonary disease)
Therapy and Prognosis of Patient Infected with P.
multocida



Cat bites are worse than dog bites because of their small, sharp and penetrative
teeth.
Aggressive organism

Symptoms appear within 24 hours

Sensitive to antibiotics
Antibiotics

Highly sensitive to Penicillin

Chloramphenicol

Tetracyclin

Ciprofloxins
How can infection with this organism be prevented?






Young infants should avoid contact with the
saliva of dogs and cats
Inform immunocompromised patients and
children about Pasteurella infection and
animal exposure
Don’t pet strange animals
Never bother an animal that is eating or
sleeping
Be sure household pets are up to date on
their vaccinations
Seek medical advice if there is redness,
swelling, or pain if you suffer an animal
bite.
Primary Research Article Contributing to the
Understanding of the Disease caused by Pasteurella
multocida

Freshwater, A. (2008). Why Your Housecat’s Trite Little Bite Could Cause You Quite a Fright: A Study of Domestic
Felines on the Occurrence and Antibiotic Susceptibility of Pasteurella multocida. Zoonoses and Public Health. 55:507513.

Purpose



Identify potential antibiotic resistance
Examine carriage rate
Materials and Methods

Specimen collection



Culture and ID of specimens


CBA, MacConkey
Antibiotic susceptibility testing


409 veterinary clinics, humane shelters, private residence
Cats’s gingival margins
Penicillin and Penicillin derivatives
G-tests

Age, breed, food type, gingival scale, lifestyle and sex
Results & Discussion



G test

No significant relationship between individual factors and the presence of
P. multocida

Carriage rate is 90%
Susceptibility testing

Penicillin (Penicillin derivatives) is still the suitable method to treat cat
bite wounds
Canine bites far outnumber cat bites
Biochemical test
production

20-80% of all cat bite wounds become infectedCatalase
Glucose acidification
reduction

3-18% of dog bite wounds become infected Nitrate
Indole production
Antimicrobials
Benzylpenicillin
Amoxicillinclavulanate
Cefazolin
Azithromycin
Susceptibility
100%
100%
98.37%
94.02%
Table 1 % Susceptibility in 409 isolates of
Pasteurella multocida
Mannitol fermentation
MacConkey agar
Arginine dihydrolase production
B-Galactosidase production
Esculin production
Glucose fermentation
Protease production (gelatin hydrolysis)
Urease production
Table 2 Characterization of Pasteurella
multocida
Result
+
+
+
+
+
-
Take Home Message







Pasteurella multocida
Diseases usually involves domestic animals such as cats and dogs
Typical symptoms

abscess and cellulitis at local wounds

Fever

Elevated white blood cells
Diagnostics

Antimicrobial susceptibility testing
Pasteurella can be aggressive (symptoms within 24 hours) however it can be
treated easily.

Penicillin
Prevention

Inform children and immunocompromised individuals about Pasteurella
infection and animal exposure.
Transmission

animal bite, scratches, licks, and inhalation
References







Freshwater, A. (2008). Why Your Housecat’s Trite Little Bite Could Cause You Quite a
Fright: A Study of Domestic Felines on the Occurrence and Antibiotic Susceptibility of
Pasteurella multocida. Zoonoses and Public Health. 55:507-513.
Bryant, Barbara J. et al. (2007). Pasteurella multocida bacteremia in asymptomatic
plateletpheresis donors: a tale of two cats. Transfusion. 47: 1984-1989.
Green, Bryant T. et al. (2001). Pasteurella multocida Meningitis: Case Review of the last
11 Y. Scand J Infect Dis. 34:213-217
Loiez, Caroline et al. (2002). Pasteurella multocida and Intrauterine Device: A Woman and
her Pets. Scand J Infect Dis. 34:473-474
Wade, T. et al. (1999). Pasteurella multocida meningitis in infancy- (a lick may be as bad
as a bite). Eur J Pediatr 158: 875-878
Kimura, Ryosuke et al. (2004) Pasteurella multocida septicemia caused by close contact
with a domestic cat: case report and literature review. J Infect Chemoter. 10: 250-252
McQueen, Nancy. Winter 2009. Pasteurellacaea.