Culture-Proven Thorn-Associated Infections in Arizona: 10-Year Experience at Mayo Clinic

BACKGROUND: Thorn injuries are common in the desert Southwest; however, the frequency and microbiology of thorn-associated infections have not been systematically described. Most information comes from case reports describing infections from atypical or environmental microorganisms. Our aim was to summarize the spectrum of thorn-associated infections. METHODS: We conducted a retrospective review of electronic health records for patients presenting to our institution from January 1, 2005 to December 31, 2014 for treatment of thorn-associated injuries and then focused on the patients with cultures. RESULTS: Of 2758 records reviewed, 1327 patients had thorn-associated injuries; however, only 58 (4.4%) had cultures. Of these patients, 37 (64%) had positive findings; 5 had polymicrobial infection. The most commonly identified organisms were Staphylococcus aureus (n = 22, 59.0%) and coagulase-negative Staphylococcus species (n = 8, 21.6%). Other pathogens included Nocardia species (n = 3, 8.1%), Streptococcus species (n = 2, 5.4%), Gram-negative bacteria (n = 2, 5.4%), Aspergillus species (n = 2, 5.4%), Paecilomyces lilacinus (n = 1, 2.7%), and Candida species (n = 1, 2.7%). There were no infections caused by Pantoea agglomerans, Sporothrix schenckii, or Coccidioides spp. CONCLUSIONS: In contrast to most published case reports, we found that typical cutaneous microorganisms, such as Staphylococcus species, caused the majority of culture-positive, thorn-related infections.