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.