Persistent extended-spectrum β-lactamase-positive Escherichia coli chronic prostatitis successfully treated with a combination of fosfomycin and doxycycline.

For chronic bacterial prostatitis, there are few oral antibiotics available that are active against common uropathogens and are able to penetrate the non-inflamed prostate at therapeutic concentrations. Oral options to treat chronic prostatitis due to Gram-negative bacillary multidrug-resistant organisms are even more limited. We report a case of persistent extended-spectrum β-lactamase (ESBL)-positive Escherichia coli chronic prostatitis refractory to antibiotic therapy. Prolonged courses of fosfomycin failed to eradicate the infection. Re-treatment with high-dose fosfomycin again failed to clear the infection. After repeated courses of fosfomycin, the ESBL-positive E. coli remained susceptible to fosfomycin. Transrectal ultrasound revealed prostatic calcifications that were thought to be the reason for antibiotic failure. Following transurethral resection of the prostate (TURP) to remove the prostatic calcifications, the prostatic calcifications remained and the infection persisted. Although the patient's ESBL-positive E. coli was resistant to doxycycline, he was treated with a combination of fosfomycin plus doxycycline. Treatment with fosfomycin and doxycycline rapidly cured his chronic prostatitis.