1. Diane Hartman, DVM Tamarah Adair, PhD Amanda Hartman, BS
A Comparative Study of Methicillin Resistant Staphylococcus aureus Nasal Carriage Rates Between Veterinarians and Veterinary Technicians
Diane Hartman, DVM
Tamarah Adair, PhD
Amanda Hartman, BS

2. Purpose
1. Determine the prevalence of MRSA carriage among veterinarians,
veterinary technicians and others
at a Fall 2008 veterinary conference.
Determine antibiotic sensitivity patterns of Staphylococcus aureus isolates.
Determine the oxacillin MIC for each MRSA sample.
4. Distinguish between HA-MRSA and CA-MRSA based on PCR and gel electrophoresis.

3. Introduction CDC reports
25-30% of the population harbors Staphylococcus aureus in their nasal passages
1-3% carry MRSA. 3

4. Methicillin Resistant Staphylococcus aureus
Emerging opportunist in human and veterinary medicine
skin and soft tissue infections
Transferred by direct contact with carriers or infected individuals
Antibiotic resistance is common
Reverse zoonosis

5. Hospital Associated MRSA or Community Associated MRSA?
Determined by:
source of exposure
patient history
antibiograms
PCR/Pulse field gel electrophoresis

6. Hospital Associated MRSA
Risk Factors
Hospitalization
Dialysis
Prolonged antibiotic use
Long-term care
Multidrug Resistant
Reuters 6

7. Community Associated-MRSA
Cases arise sporadically
At risk groups
prisoners
young children
contact sports participants
Immune compromised
usually susceptible to many different antibiotics
Panton-Valentine leukocidin 7

8. Background
In a study the prevalence of MRSA was 4X greater in a Texas veterinary population than in an undergraduate population
Veterinarian MRSA carriage rate higher than normal population (DVM News 2007)
Canine-Human MRSA transmission (EID2004)
Feline-Human MRSA transmission (NEJM 2008)
Equine-Human transmission of MRSA (EID 2006)

9. Survey and Consent Forms
Surveys
determine possible sources of exposure
recent surgery or hospitalization
volunteer in hospital, day care, nursing home
analyze common risk factors
travel, antibiotic use, recent skin infection, public gym, contact sports
JMP computer program was used to evaluate potential risk factors
Consent forms - required for each participant 9

10. Methods Nasal swabs to mannitol salt agar
Identify Mannitol fermenters that are Gram + cocci
Catalase +
Coagulase +

11. Antibiotic Sensitivity Testing Kirby-Bauer Method
Antibiotics tested:
Amikacin Neomycin
Ciprofloxacin Nitrofurantoin
Clindamycin Oxacillin
Doxycycline Penicillin
Erythromycin Rifampin
Gentamicin Trimethoprim/Sulfa
ATCC Staphylococcus aureus 25923

12. Kirby Bauer Oxacillin R
Oxacillin MIC/ E Strips

13. Molecular Analysis
MEC
CCR-all ccr type 2 B A
LADDER

14. MSSA and MRSA Carriage Rates#
MSSA
MRSA
Total population
276 48
(17.4%) 17
(6.2%)
Veterinarians
142
(51.4%) 27
(19%) 4
(2.8%)
Vet techs
102
(37%) 13
(12.7%) 11
(10.8%)
Other 32
(11.6%) 8
(25%) 2
(6.25%)

15. Survey Results Average age group was 30-39 (32%)
Average time in practice was <10 years (45%)
74 males (26%) and 203 females (74%)
227 (82%) treated mainly small animals or Small animal with exotics
13 (4.7%) treated mainly large animals
15 (5.4%) were in education
21 ( 7.6%) were in the “other” category

16. Carriers Based on Gender, Role, and Practice Type

17. Carriage Based on General Risk Factors

18. Antibiograms
All MRSA isolates were sensitive to Amikacin, Gentamicin, Doxycycline, and Trimethoprim/Sulfamethoxazole.
All MRSA isolates were resistant to oxacillin and penicillin.
MRSA isolates demonstrated 7 antibiogram patterns.

19. MRSA N FM Ox Ra E CC
Cip P 1 R S 2 3 4 5 6 7 8 9 10
*11
*12 13 14 15 16 17

20. Oxacillin MIC/E Strips
MRSA
MIC (µg/mL) 1 64 2 48 3
>256 4 5
128 6 7
192 8 9 32 10 11 12 13 14 15 16 17
Oxacillin MIC/E Strips

21. Molecular Analysis - HA or CA MRSA?
MEC
16 were type 2 ccr.
3 were Class A mec
13 were Class B mec
Class A mec with type 2 ccr are Type II - HA strains
Class B mec with type 2ccr are Type IV -CA strains
CCR B A
LADDER

22. HA or CA MRSA? Samples 4, 10, 16 were HA strains
All 3 Vet Techs
R to 5 or more antibiotics
MIC all 128 µg/ml or greater
13 samples were CA strains
9 R to 4 or fewer antibiotics
MIC µg/ml
1 strain was not typeable with the primers used (vet tech with MIC>256 µg/ml and R to 6 antibiotics)

23. Discussion
None of the survey risk factors were significantly correlated with carriage rates for MSSA or MRSA
Veterinary Technicians are
10 times more likely than the general population and more than 3 times as likely as veterinarians to carry MRSA.
3 technician samples were HA-MRSA (Type II)
6 technician samples were CA-MRSA (Type IV)
1 tech sample was not typed
All 4 vet samples were CA-MRSA (Type IV)
2 “other” were CA-MRSA (Type IV)

24. Discussion Potential Risk Factors for Technicians?
1. Spend more time in the exam room with
clients and pets
2. Spend more time with their face close to the
patient/pet
3. Spend more time face to face with clients in
the exam room and waiting area
4. More likely to interact with client’s children
5. More likely to perform dental prophys on pets
6. More likely to clean cages/kennels
7. More likely to clean ears and/or bathe pets

25. Prevention WASH YOUR HANDS!
Don’t share towels or other personal items.
Cleanse fresh wounds and keep wounds covered.
Wear appropriate PPE for the task,
e.g. dentals - lab coats, gloves, mask/face shield. 25

26. FUNDING
Supported by the Baylor Undergraduate Research and Scholarly Activities Small Grant Program
and the Vice Provost for Research
Department of Biology Baylor University 26

27. STUDENT LAB ASSISTANTS:
Acknowledgements
STUDENT LAB ASSISTANTS:
Amanda Hartman
Ly Nguyen
Trevin Rube
Brooklyn Sandvall
Ayla Farris
Kevin Farquar