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

Purpose 1. Determine the prevalence of MRSA carriage among veterinarians, veterinary technicians and others at a Fall 2008 veterinary conference. 2.Determine antibiotic sensitivity patterns of Staphylococcus aureus isolates. 3.Determine the oxacillin MIC for each MRSA sample. 4. Distinguish between HA-MRSA and CA- MRSA based on PCR and gel electrophoresis.

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

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

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

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

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

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)

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

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

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

Kirby Bauer Oxacillin R Oxacillin MIC/ E Strips

Molecular Analysis MECCCR-all ccr type 2 LADDER BA

MSSA and MRSA Carriage Rates #MSSAMRSA Total population (17.4%) 17 (6.2%) Veterinarians142 (51.4%) 27 (19%) 4 (2.8%) Vet techs102 (37%) 13 (12.7%) 11 (10.8%) Other 32 (11.6%) 8 (25%) 2 (6.25%)

Survey Results Average age group was (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

Carriers Based on Gender, Role, and Practice Type

Carriage Based on General Risk Factors

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.

MRSANFMOxRaECCCipP 1RSRSRSRR 2SSRSSSSR 3SSRSSSRR 4RSRSRRRR 5SSRSSSRR 6SRRRRRSR 7RSRSRRRR 8SSRSSSSR 9SSRSSSSR 10RSRSRRRR *11RSRSRSSR *12RSRSRSSR 13RSRSRSSR 14SSRSRSSR 15RSRSRSRR 16RSRSRSRR 17RSRSRRRR

Oxacillin MIC/E Strips MRSAMIC (µg/mL) > > >

Molecular Analysis - HA or CA MRSA? MEC CCR LADDER BA 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

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)

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)

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

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.

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

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