Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis associated with renal disease in four beef cattle

BACKGROUND: Renal disease caused by Corynebacterium cystitidis in beef cattle may be misclassified as Corynebacterium renale, and limited information about C. cystitidis infections in beef cattle currently is available. OBJECTIVE: To describe clinical presentation, diagnosis, minimum inhibitory concentrations (MICs), and outcome of renal disease caused by C. cystitidis in beef cattle. METHODS: Retrospective case series. ANIMALS: Four client‐owned beef cattle. RESULTS: All affected cattle had anorexia as a primary complaint. Of the 3 that had ante‐mortem diagnostic tests performed, all had pyelonephritis based on azotemia in combination with urinalysis and ultrasonographic findings. Cultures yielded C. cystitidis which was identified by biochemical testing, 16S RNA sequencing, and mass spectrometry. All affected cattle deteriorated despite aggressive treatment, indicating that C. cystitidis infections in beef cattle may carry a poor prognosis. Bacterial isolates collected from the 4 cattle showed similarities in MICs for ampicillin, florfenicol, gentamicin, neomycin, sulfadimethoxine, trimethoprim sulfonamide, and tylosin. CONCLUSIONS AND CLINICAL IMPORTANCE: Corynebacterium cystitidis should be considered in the differential diagnosis of cattle with renal disease. Definitive diagnosis of C. cystitidis as compared to C. renale may be challenging.