Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2022

Geographical variation in antimicrobial resistance patterns of bacteria isolated from canine skin and ear samples in Queensland (82536)

Sara Horsman 1 , Erika Meler 1 , Deirdre Mikkelsen 2 , Justine Gibson 1 , Ricardo Soares Magalhaes 1 3
  1. School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia
  2. School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD, Australia
  3. Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, QLD, Australia

Introduction

Dogs with skin and ear conditions often require antimicrobial treatment, with the risk of antimicrobial resistance likely to be geographically variable due to the local epidemiology of infections and prescribing patterns. We investigated the geographical variation of antimicrobial resistance patterns of bacteria cultured from skin and ear swabs from canines residing in Queensland.

Methods

Bacterial culture and antimicrobial susceptibility data from canine skin and ear swabs, from January 2016 to August 2018 in Queensland, were extracted from a commercial laboratory database. After removing intrinsic resistances, bacterial isolates were identified as multidrug resistant (MDR) and resistant to critically important antimicrobial categories1. We investigated the presence of geographical clustering in the percentages of antimicrobial resistance patterns per South-East Queensland postcodes, using Moran’s I and Local Indicators of Spatial Autocorrelation statistics.

Results

A total of 3,804 isolates were included in the analysis. MDR was found in 9.4% (359/3,804) of all isolates, with 98.9% (355/359) resistant to at least one critically important antimicrobial. Fifteen percent (180/1,235) of skin isolates and 6.9% (179/2,569) of ear isolates were classified as MDR.

Escherichia coli isolates were found with the highest proportion of MDR [23% (62/269)], followed by Staphylococcus spp. [17% (180/1,056)], Streptococcus spp. [8.7% (33/378)], Proteus spp. [3.7% (18/482)] and Pseudomonas aeruginosa [1.8% (23/1,280)].

Our results indicate a higher number of all isolates [N=3,804] and P. aeruginosa [N=1,280] isolates cultured in January to March compared to other months. Additionally, we found significant geographical MDR hot-spots (i.e., postcodes with a high proportion of isolates with MDR susceptibility patterns) for all isolates and Staphylococcus spp. isolates only, across South-East Queensland.

Conclusion

Our study indicates high rates of MDR isolations from canine skin and ear patient samples geographically circumscribed to a small set of postcodes in Queensland. The seasonality patterns found in all isolates may indicate local environmental risk factors which exacerbate infection risk and create an opportunity for temporally targeted antimicrobial stewardship programs.

 

  1. World Health Organisation 2019, Critically important antimicrobials for human medicine, 6th revision, Geneva, Switzerland.