{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T10:39:30Z","timestamp":1773311970589,"version":"3.50.1"},"reference-count":26,"publisher":"BMJ","issue":"3","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,1,30]]},"published-print":{"date-parts":[[2026,3]]},"abstract":"<jats:p>\n                    We report the case of a man in his 70s who presented with constitutional symptoms and intermittent confusion, ultimately diagnosed with a large, complex retroperitoneal and extraperitoneal abscess. He had a background of recurrent urinary tract infections over the preceding year. Initial imaging revealed a multi-loculated collection. Surgical incision and drainage yielded 1000\u2009mL of pus, and cultures identified multiple strains of\n                    <jats:italic>Escherichia coli<\/jats:italic>\n                    required tailored antibiotic therapy. Interval imaging revealed a residual collection requiring a second surgical intervention. Further inpatient investigations also raised suspicion for underlying prostate carcinoma. The patient made a full recovery and demonstrated complete resolution of inflammatory markers.\n                  <\/jats:p>\n                  <jats:p>This case illustrates the diagnostic complexity of deep-seated polymicrobial infections presenting with non-specific constitutional symptoms and underscores the need to consider multistrain pathogens and underlying urological pathology in patients with a history of recurrent urinary tract infections. It also underscores the value of holistic assessment and management during and after hospital admission.<\/jats:p>","DOI":"10.1136\/bcr-2025-268894","type":"journal-article","created":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T16:10:14Z","timestamp":1773245414000},"page":"e268894","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Complex intra-abdominal abscess involving retroperitoneal and extraperitoneal compartments with multiple\n                    <i>E. coli<\/i>\n                    strains"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-0278-8141","authenticated-orcid":false,"given":"Sue Pwint","family":"Phyu","sequence":"first","affiliation":[{"name":"Acute & General Medicine, Borders General Hospital, Melrose, Scotland, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-4624-6013","authenticated-orcid":false,"given":"Husni Mubarak","family":"Zainal","sequence":"additional","affiliation":[{"name":"Acute & General Medicine, Borders General Hospital, Melrose, Scotland, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3741-5902","authenticated-orcid":false,"given":"Ahlain","family":"Mar","sequence":"additional","affiliation":[{"name":"Acute & General Medicine, Borders General Hospital, Melrose, Scotland, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jamie","family":"Young","sequence":"additional","affiliation":[{"name":"General Surgery, Borders General Hospital, Melrose, Scotland, 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