• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.260-264
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• 2019

An 84-year-old woman presented to the emergency department with a chief complaint of pressure sores of the anus. She had a urine catheter when she showed pyuria three times but had no fever. A microscopic examination revealed many grapevine-like Gram positive strains and neutrophils. After 24 hours of urine culture on blood agar, non-hemolytic mucous colonies were found and further enlarged after 48 hours of culture. The capsules were identified after India ink stain. The catalase was positive, but the tube coagulase and latex coagulase were both negative. The S. aureus was identified by Vitek-2 and mass spectrometer Vitek MS V-3 IVD. The strain was confirmed by 16S rRNA gene sequencing and multilocus sequence typing (MLST). The phenotypically atypical MRSA found in the tube coagulase and latex coagulase were both negative. MRSA often show no beta hemolysis as in this case but are rarely latex coagulase-negative. We report a woman whose urine culture showed non-hemolytic, tube coagulase-negative, and latex coagulase-negative MRSA.