Background Acquired zoonotic infections with Pasteurella bacterial species have a wide clinical spectrum of disease from invasive infections to localised bite-wound infections. Methods This study reviewed the spectrum of the demographic, clinical, temporal, and microbiological trends of laboratory confirmed Pasteurella species infections presenting to a single-centre tropical tertiary hospital over a twenty-year period. Results 195 episodes from 190 patients were included. 51.3% patients were female, and 20.5% Aboriginal or Torres Strait Islander peoples. Crude incidence of Pasteurella spp. infections increased from 1.5 per 100,000 population in 2000, to 11.4 per 100,000 population in 2021. There were 22 (11.3%) bloodstream infections, 22 (11.3%) invasive, 34 (17.4%) deep local, 98 (50.2%) superficial infections, and 19 (9.7%) other or unknown. Adults over 65 years of age accounted for the majority of bacteraemias (63.7%). More severe infections, including bacteraemia, invasive and deep local infections, were more common in lower limb infections and in those with underlying comorbidities. Animal contact with cats was more common in bloodstream infections (36.4%), but dog bites more common in invasive, deep local and superficial infections. 30-day all-cause mortality was low at 1.0%. Pasteurella multocida was most commonly identified (61.1%), but P. canis, P. dagmatis, and other Pasteurella infections were also noted. 67.7% of specimens were polymicrobial, with other significant organisms being Staphylococcus aureus, Streptococcus pyogenes, Group G Streptococcus and Pseudomonas aeruginosa. Conclusion Pasteurella species remain clinically important pathogens, with the ability to cause severe and invasive infections with associated morbidity. Presentations to hospital are becoming more common, and the polymicrobial nature of bites wounds has implications for empiric antibiotic guidelines.

A previously well, immunocompetent 8-year-old Aboriginal girl from Darwin presented with a 6-week history of non-healing ulceration 5 cm proximal to the left lateral malleolus, with associated bony tenderness and pain on weight-bearing. She was systemically well, but the ulcer had evolved from a small papule to a 2.5 Â 1.5 cm wound with undermined edges and surrounding erythema (Fig. 1a). Her general practitioner had prescribed a short course of oral trimethoprim-sulfamethoxazole with minimal improvement.She was commenced on empirical intravenous clindamycin and promptly underwent surgical debridement. Pre-operative swab and intra-operative tissue cultures were positive for non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA), Pseudomonas aeruginosa, group G Streptococcus and mixed cutaneous and enteric flora; and so ceftazidime was added to clindamycin. Histopathology