Ulett et al. Journal of Medical Case Reports 2012, 6:237 http://www.jmedicalcasereports.com/content/6/1/237 Introduction Streptococcus agalactiae, or group B streptococcus (GBS), is a leading cause of infection in newborns, preg- nant women, and older persons with chronic medical ill- ness [1]. In addition to maternal cervicovaginal colonization and neonatal infection, GBS causes invasive infections in adults including urinary tract infections (UTI). The incidence of neonatal disease has decreased due to improvements in screening and prophylaxis [1-3], and the changing spectrum of disease in adults has been noted [4]. Over 60% of cases of invasive GBS disease in the United States of America (USA) now occur in adults and most are unrelated to pregnancy [5]. A rare form of invasive GBS infection in adults is secondary abscess, which characteristically presents as a subcutaneous, retroperitoneal psoas, thoracic, aortic, or myocardial ab- scess secondary to an often-occult source of infection. GBS is a notable urinary pathogen in adults [6] and reports on the incidence of genitourinary infections due to GBS have increased in the past decade [4,7-11]. The spectrum of GBS UTI includes asymptomatic bacteri- uria, cystitis, pyelonephritis and urosepsis with risk fac- tors of neurogenic bladder [12] and prior UTI [8] having been described. GBS is cultured from urine in approxi- mately 2% of all clinically suspected cases of UTI [6,8,13]. Particularly high prevalence rates of GBS bac- teriuria have been reported among elderly adults [1,14,15]. Here, we report the first case of an adult pa- tient with an unusual, massive GBS abdominopelvic ab- scess that occurred secondary to cystitis, and we review prior cases of secondary GBS abscesses to describe their etiology and clinical characteristics. Case presentation A 46-year-old African-American woman presented to the University Emergency Department complaining of severe abdominal pain. On presentation, she reported experiencing dysuria, urinary frequency and urgency, as well as incontinence and abdominal fullness for several weeks. Her medical history was unremarkable with no history of sexually transmitted diseases and no current medications. Her heart rate was 98, blood pressure 124/59mmHg, and her temperature was 37.6°C. Phys- ical examination revealed increased tenderness in her right and left lower quadrants. Urine analysis revealed proteinuria, hematuria, pyuria (>50 white blood cells per high-power field), and positive urinary leukocyte es- terase. A culture of the patient’s urine, which was tur- bid, yielded pure growth of S. agalactiae at 108 colony forming units per liter. The patient had a hematocrit of 17%, a white blood cell count of 15.4 × 109/L, glucose of 816mg/100mL, serum creatinine of 1.2mg/100mL, and HbA1C of 10.6. Page 2 of 4 A transvaginal ultrasound revealed a fibroid uterus and a heterogeneous fluid collection in the patient’s pel- vis. Examination by computed tomography (CT) showed a massive peripherally enhancing, low-attenuating fluid collection measuring approximately 17.4cm by 10.4cm within her pelvis extending to the right adnexa (Figure 1). A second smaller collection was noted within the pouch of Douglas; the two fluid collections did not appear to communicate. There were several reactive inguinal, mes- enteric, and retroperitoneal lymph nodes as well as sub- tle areas of right renal cortical non-enhancement suggestive of pyelonephritis. The bladder wall was mark- edly thickened with surrounding soft tissue stranding. The patient was given one dose of ceftriaxone empiric- ally. Her antibiotic regimen was then changed to vanco- mycin and piperacillin/tazobactam for broad empiric coverage and she was admitted for management of her abdominopelvic abscess and UTI. She was also newly diagnosed with diabetes and placed on sliding scale insu- lin to manage her hyperglycemia. Her anemia was attrib- uted to iron deficiency due to uterine leiomyomas. A pigtail drainage catheter was placed using ultrasound and fluoroscopic guidance in order to drain the patient’s abdominopelvic abscess and this yielded a septic aspirate that was culture positive for abundant S. agalactiae. Antibiotic-susceptibility testing showed the isolate was re- sistant to tetracycline, intermediate to clindamycin and erythromycin, and sensitive to penicillin and vancomycin. A day after abscess drainage, a CT scan showed near complete interval resolution of the large pelvic fluid collec- tion (Figure 1). The patient subsequently developed acute kidney insufficiency (creatinine 5.0mg/100mL), leucocyt- osis, and fever. Bacteremia was suspected, however, blood cultures taken at this time were negative. Urine analysis revealed persistent cystitis with pyuria and leukocyte ester- ase. Her renal failure was attributed to multifactorial acute tubular necrosis due to sepsis and vancomycin toxicity. After 4 days of vancomycin and piperacillin/tazobactam, the patient was switched to intravenous ceftriaxone (2g intravenous/24 hours) and 2 days later her fever and ab- dominal pain were resolved. The results of a repeat urine test were culture-negative. The patient was discharged on outpatient intravenous ceftriaxone and the pelvic drain was removed 2 weeks later. Metformin and insulin glar- gine treatment was commenced for diabetes management. She remained afebrile and was well on subsequent out- patient visits. Her acute kidney insufficiency resolved within 7 days of discharge (creatinine 1.5mg/100mL). An outpatient hysterectomy was planned for management of the patient’s anemia due to uterine leiomyomas. Discussion GBS is a recognized cause of fatal puerperal sepsis in adults and rare invasive infections including unusual