First Emergence of Resistance to Macrolides and Tetracycline Identified in Mannheimia haemolytica and Pasteurella multocida Isolates from Beef Feedlots in Australia

Tamara Alhamami; Piklu Roy Chowdhury; Nancy Gomes; Mandi Carr; Tania Veltman; Manouchehr Khazandi; Joanne Mollinger; Ania T Deutscher; Conny Turni; Layla Mahdi; Henrietta Venter; Sam Abraham; Steven P Djordjevic; Darren J Trott

doi:10.3390/microorganisms9061322

First Emergence of Resistance to Macrolides and Tetracycline Identified in Mannheimia haemolytica and Pasteurella multocida Isolates from Beef Feedlots in Australia

Microorganisms. 2021 Jun 17;9(6):1322. doi: 10.3390/microorganisms9061322.

Authors

Affiliations

¹ Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy Campus, Roseworthy, SA 5371, Australia.
² The ithree Institute, University of Technology Sydney, City Campus, Ultimo, NSW 2007, Australia.
³ Department of Animal Health and Production, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy Campus, Roseworthy, SA 5371, Australia.
⁴ Biosecurity Sciences Laboratory, Department of Agriculture and Fisheries, Coopers Plains, QLD 4108, Australia.
⁵ NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia.
⁶ Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD 4072, Australia.
⁷ Clinical & Health Sciences, University of South Australia, Adelaide, SA 5000, Australia.
⁸ Antimicrobial Resistance and Infectious Disease Laboratory, Murdoch University, Murdoch, WA 6150, Australia.

Abstract

Bovine respiratory disease (BRD) causes high morbidity and mortality in beef cattle worldwide. Antimicrobial resistance (AMR) monitoring of BRD pathogens is critical to promote appropriate antimicrobial stewardship in veterinary medicine for optimal treatment and control. Here, the susceptibility of Mannheimia haemolytica and Pasteurella multicoda isolates obtained from BRD clinical cases (deep lung swabs at post-mortem) among feedlots in four Australian states (2014-2019) was determined for 19 antimicrobial agents. The M. haemolytica isolates were pan-susceptible to all tested agents apart from a single macrolide-resistant isolate (1/88; 1.1%) from New South Wales (NSW). Much higher frequencies of P. multocida isolates were resistant to tetracycline (18/140; 12.9%), tilmicosin (19/140; 13.6%), tulathromycin/gamithromycin (17/140; 12.1%), and ampicillin/penicillin (6/140; 4.6%). Five P. multocida isolates (3.6%), all obtained from NSW in 2019, exhibited dual resistance to macrolides and tetracycline, and a further two Queensland isolates from 2019 (1.4%) exhibited a multidrug-resistant phenotype to ampicillin/penicillin, tetracycline, and tilmicosin. Random-amplified polymorphic DNA (RAPD) typing identified a high degree of genetic homogeneity among the M. haemolytica isolates, whereas P. multocida isolates were more heterogeneous. Illumina whole genome sequencing identified the genes msr(E) and mph(E)encoding macrolide resistance, tet(R)-tet(H) or tet(Y) encoding tetracycline resistance, and bla_ROB-1 encoding ampicillin/penicillin resistance in all isolates exhibiting a corresponding resistant phenotype. The exception was the tilmicosin-resistant, tulathromycin/gamithromycin-susceptible phenotype identified in two Queensland isolates, the genetic basis of which could not be determined. These results confirm the first emergence of AMR in M. haemolytica and P. multocida from BRD cases in Australia, which should be closely monitored.

Keywords: Mannheimia haemolytica; Pasteurella multocida; antimicrobial susceptibility; bovine respiratory disease.

Grants and funding

na/Meat &Livestock Australia