A man bitten by a stray cat in the U.K. developed an infection from a bacterial species that wasn't present in any DNA database, researchers reported in a case study published in the August edition of Emerging Infectious Diseases.
According to the report, a 48-year old man presented to the emergency department in 2020 with painful bilateral hand swelling eight hours after being bitten several times by a stray cat. After initial treatment — which included antibiotics and a booster dose of the tetanus vaccine — he was discharged. The man returned to the ED a day later with cellulitis in both forearms and swollen fingers.
Researchers obtained tissue samples and found the infection was caused by an unknown bacterial species. Gene sequence data "did not match any named species in the GenBank database," researchers said. They conducted whole-genome sequencing on the sample and found its most closely related cluster was Globicatella sulfidifaciens. There was still about a 20 percent divergence between the bacteria sample and its closest relative, "suggesting a distinct and previously undescribed species," researchers said.
Human infections from G. sulfidifaciens had not been previously described, researchers said. The patient made a full recovery after physicians removed damaged tissue around the wounds and treatment with intravenous vancomycin, ciprofloxacin and metronidazole.
"This report highlights the role of cats as reservoirs of as yet undiscovered bacterial species that have human pathogenic potential," researchers said. "Currently recommended antimicrobial drug regimens for treating cat bites can be expected to include the Globicatella species described."
Access the full case study here.