Related Experiment Video
Updated: Jun 29, 2026
Experimental Endocarditis Model of Methicillin Resistant Staphylococcus aureus (MRSA) in Rat
Published on: June 4, 2012
Clinically overt infections with methicillin-resistant Staphylococcus aureus in animals in New Zealand: a pilot study
A Grinberg1, D D Kingsbury, I R Gibson
1Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand. a.grinberg@massey.ac.nz
Aim:
To describe clinically overt infections with methicillin resistant Staphylococcus aureus (MRSA) in animals in New Zealand, characterise clinical isolates, and track their sources.
Methods:
MRSA isolates identified in 2005 and 2006 by a veterinary diagnostic laboratory were referred to Massey University for confirmation and characterisation. Clinical information was extracted from the laboratory records or obtained from referring clinicians.
Results:
Seven MRSA isolates from animals and contact persons were characterised. All the isolates belonged to the British epidemic MRSA 15 strain (EMRSA-15). Three EMRSA-15 were isolated from post-operative infections in two dogs. An EMRSA-15 indistinguishable from the isolate recovered from one dog was isolated from the anterior nares of a healthy hospital staff member involved in the care of the animal, suggesting nosocomial transmission. Other EMRSA-15 isolates of uncertain clinical significance were isolated from the femoral head of a cat, and from a sample of cow's milk. AlleMRSA-15 isolates were resistant to ciprofloxacin, and four were resistant to erythromycin; the latter four isolates also exhibited inducible resistance to clindamycin.
Conclusions:
MRSA can cause clinically overt and difficult-to-treat infections in animals in New Zealand. The rapid emergence of EMRSA-15 as the dominant MRSA strain in humans has resulted in infection spill over to animals.
Clinical Relevance:
Little is known about the incidence of clinically overt infections with MRSA in animals. The cases described here illustrate the complexities involved in the pharmacological management of EMRSA-15 infections, which is compounded by the universal resistance to beta-lactams, and by the strain's fluoroquinolone resistance and frequent inducible resistance to clindamycin. Such complexities indicate there is a need to develop specific empirical antimicrobial treatment strategies and antibiotic susceptibility testing protocols in countries where EMRSA-15 is dominant.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) infections, specifically the EMRSA-15 strain, are emerging in New Zealand animals. This highlights potential transmission from humans and challenges in treatment due to antibiotic resistance.
Area of Science:
- Veterinary Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in human healthcare.
- The emergence and spread of specific MRSA strains, like EMRSA-15, in animal populations is a growing concern.
- Limited data exists on clinically apparent MRSA infections in New Zealand animals.
Purpose of the Study:
- To document MRSA infections in animals within New Zealand.
- To characterize the genetic profile and antibiotic susceptibility of clinical MRSA isolates from animals.
- To investigate potential sources and transmission routes of MRSA in animal cases.
Main Methods:
- MRSA isolates from 2005-2006 were collected from a veterinary diagnostic laboratory.
- Isolates were confirmed and characterized at Massey University.
- Clinical data was obtained from laboratory records and referring veterinarians.
Main Results:
- Seven MRSA isolates were analyzed, all identified as the British epidemic strain (EMRSA-15).
- EMRSA-15 caused post-operative infections in two dogs, with one case linked to a hospital staff member, suggesting nosocomial spread.
- Resistances included ciprofloxacin (all isolates) and erythromycin (four isolates), with inducible clindamycin resistance in the latter.
Conclusions:
- Clinically apparent MRSA infections, particularly EMRSA-15, can occur in New Zealand animals.
- The dominance of EMRSA-15 in human populations may facilitate spillover infections into animals.
- Complex resistance patterns necessitate tailored antimicrobial strategies and susceptibility testing for EMRSA-15.
Related Concept Videos
01:25Clinical Significance of Antibiotic Resistance
01:25Mechanism of Antibiotic Resistance in MRSA