Antibacterials

Abstract

Intraabdominal abscess and Entamoeba histolytica amoebiasis secondary to change in intestinal flora: case report A 62-year-old man developed intraabdominal abscess and Entamoeba histolytica amoebiasis secondary to change in intestinal flora following antibiotic treatment with ampicillin/sulbactam, cefmetazole and piperacillin/tazobactam for spontaneous bacterial peritonitis (SBP). The man was hospitalised with pleural effusion, ascites and elevated C-reactive protein (CRP) level. He was diagnosed with SBP and was treated with cefmetazole, ampicillin/sulbactam [sulbactam/ampicillin] and piperacillin/tazobactam [tazobactam/ piperacillin] for 5 weeks [routes and dosages not stated]. After two months of hospitalization, he was discharged following improvement in CRP level. Immediately after discharge, his CRP level was found to have increased. He was advised to attend an outpatient clinic once a month. Four months after discharge, he was re-hospitalised with alcoholic cirrhosis. Upon admission, no complaints of fever or abdominal tenderness were noted. His CRP level was 10.10 mg/dL. Dynamic CT demonstrated ant’s nest-like encapsulated bulky abdominal cystic cavities around the stomach to the pelvis, with each cavity connected by a narrow bypass. Abdominal ultrasound echo revealed that the wall of the cystic lesions was thick, with no echo inside, but rather fine floating echoes, indicating that the contents were likely to be mucus. The continuity between the cystic lesions and the intestinal tract was not clear. Blood cultures were negative. An intraabdominal abscess was suspected. A drainage tube was placed 6 days after admission. The aspirated pus was reddish-brown and highly viscous (with unmeasurable WBC and protein total 3.0 g/dL). A bacterial culture was negative and cytological examination demonstrated no malignant cells. Following placement of drainage tube, the pus was aspirated every day. On the 13th day after admission, the drainage tube was changed. Microscopic examination revealed that the aspirated pus contained cystic types of amoeba. Whole-body CT revealed no evidence of amoeba infection other than intraabdominal abscesses. He was diagnosed with Entamoeba histolytica amoebiasis suspected to be due to change in intestinal flora following antibiotic treatment with ampicillin/sulbactam, cefmetazole and piperacillin/tazobactam [time to reaction onsets not clearly stated]. The man was initiated on metronidazole 16 days after admission. Thereafter, the abscess cavity shrank markedly and the CRP level decreased. Microscopic examination of the puncture fluid confirmed that the amoeba had disappeared. Therefore the drainage tube was removed. He was treated with paromomycin for 10 days, to prevent recurrence of the abscess. Upon follow-up, no recurrence of amoebiasis was noted.