case_images: PMC3892063_01
case_images: Clinical course of the patient. Abbreviations: CLDM, clindamycin; CPFX, ciprofloxacin; DIV, drip infusion; LZD, linezolide; MEPM, meropenem; MRSA, methicillin-resistant Staphylococcus aureus; MZN, metronidazole; TEIC, teicoplanin; VCM, vancomycin.
case_images: 1756-0500-7-21-1.jpg
case_images: PMC3892063_01_1756-0500-7-21-1.jpg
case_images: F1
case_images: However, acute watery diarrhea amounting to 4 L/day (determined by inserting a rectal tube) together with pyrexia (38 C) was evident on day 19 (Figure  1). Although stool specimens were negative for Clostridium difficile toxins A and B, pseudomembranous colitis was considered and metronidazole (1 g/day) was started via a nasogastric tube (Figure  1). Intermittent pain in the right hip joint started on day 71 after he started rehabilitation for walking (Figure  1).
case_images: Gram staining findings of stool cultures. Fecal leukocytes are abundant.
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case_images: PMC3892063_01_1756-0500-7-21-2.jpg
case_images: F2
case_images: However, the watery diarrhea was refractory to metronidazole, and Gram staining stool samples revealed abundant fecal leukocytes (Figure  2), suggesting colonic membranous damage.
case_images: Magnetic resonance imaging of right hip joint. T2-weighted image (T2WI) of hip joint shows high-intensity area surrounding head of right femur, indicating fluid collection (A). Fat saturated T2WI shows high-intensity area on right obturator externus or adducent muscles (B) that appears as a hotspot on gallium scintigram (C). Synovial fluid contains abundant leukocytes that are phagocytically engulfed by gram-positive cocci (D).
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case_images: PMC3892063_01_1756-0500-7-21-3.jpg
case_images: F3
case_images: We explored the source of the fever and right hip joint pain using magnetic resonance imaging (MRI) (Figure  3A and B) and 67gallium scintigraphy of the hip joint. T2-weighted MRI (T2WI) revealed an area of high intensity around the head of the right femur indicating fluid collection (Figure  3A). Fat-saturated T2-weighted images (T2WI) revealed another area of high intensity on the right obturator externus or adducent muscles (Figure  3B), suggesting right hip arthritis that 67gallium scintigraphy confirmed as a hotspot (Figure  3C). Joint drainage fluid collected on day 100 showed abundant leukocytes enclosed by phagocytic gram-positive cocci (Figure  3D) that were later identified as MRSA.
case_images: Analysis of identified methicillin-resistant Staphylococcus aureus strains on pulsed-field gel electrophoresis. M, marker; 1, sputum (day 10); 2, stool (day 19); 3, intravenous hyperalimentation catheter (day 20); 4, blood (day 30); 5, sputum (day 44); 6, hip joint synovial fluid (day 100); C, control (Staphylococcus aureus, strain NCTC 8325).
case_images: 1756-0500-7-21-4.jpg
case_images: PMC3892063_01_1756-0500-7-21-4.jpg
case_images: F4
case_images: Pulsed-field gel electrophoresis (PFGE) showed that the MRSA strains in the samples isolated from stool (day 19), blood (day 30) and synovial fluid (day 100) were identical (Figure  4), suggesting a hematological spread of MRSA originating from the colonic membrane damaged by MRSA enterocolitis.