Panton-Valentine leucocidin-positive methicillin-resistant Staphylococcus aureus (MRSA) strains with identical resistance patterns were cultured from recurrent infections of a 51-year-old patient, her healthy husband, son, and dog, and pulsed-field gel electrophoresis showed that all MRSA strains were indistinguishable.
CASE REPORTIn 2002, a 51-year-old female patient with a diabetic foot was admitted to the surgical ward of a Dutch teaching hospital in the province Overijssel. Cultures were taken from the ulcer at admission, and a methicillin-resistant Staphylococcus aureus (MRSA) strain, resistant to fusidic acid and tetracyclines but susceptible to macrolides, trimethoprim-sulfamethoxazole, quinolones, rifampin, and aminoglycosides was cultured, while cultures from nose, throat, and perineum did not grow MRSA. The patient was treated successfully with trimethoprim-sulfamethoxazole. Two months later the patient was screened for the MRSA carrier state, and a sample from her throat was culture positive for an MRSA strain with the same resistance pattern, while nostril, perineum, and wound cultures were MRSA negative. She developed a urinary tract infection with a positive MRSA culture again 4 months after the initial treatment. Therapy with ciprofloxacin and rifampin was started, after which the MRSA infection was eradicated for half a year, based on monthly negative cultures of urine, nostrils, throat, wound, and perineum. However, the final screening for carrier state after this half-year revealed an MRSA strain again in cultures from the nose, throat, and perineum. After these findings a source of the recurrent MRSA carrier state was suspected at her home. Samples were taken from the nose and throat of the patient's husband (57 years old), son (25 years old), and their dog, a German Shepherd, who were all clinically healthy. The samples from the throat of the husband and from the nose of the son and dog were culture positive for MRSA. In a last effort to eradicate the patient's MRSA infection, all family members (including the dog) were treated simultaneously with ciprofloxacin and rifampin. This last treatment eradicated the MRSA carrier state of all persons and the dog. Follow-up cultures of nostrils, throat, and perineum of all persons and the dog were taken for 6 months, and all cultures remained negative.All isolates were sent to the National Institute of Public Health and the Environment (RIVM) for identification and genotyping by pulsed-field gel electrophoresis (PFGE). The staphylococci isolated from the patient (isolates from the ulcer, throat, and urine), her husband and son, and the dog were all identified as S. aureus by conventional methods, Vitek 2 (BioMérieux, Marcy-l'Étoile, France) and Martineau PCR (8). Susceptibility testing was performed using the Vitek 2 assay according to the manufacturer's instructions. All isolates had the same resistance pattern: they were resistant to all beta-lactams, fusidic acid, and tetracycline and were susceptible to aminoglycosides, fluoroquinolones, erythromy...