Mycobacterium bovis infection of an aortobifemoral bypass graft with Streptococcus intermedius superinfection after intravesical bacillus Calmette-Guérin immunotherapy for bladder cancer.

BACKGROUND: The Bacillus Calmette-Guerin (BCG) is a life-attenuated form of Mycobacterium bovis widely used as immunotherapy for localized bladder cancer. Adverse reactions to intravesical BCG instillations are rare. CASE: We describe a 70-year-old man with a history of an aortobifemoral bypass graft, placement of a synthetic mesh for treatment of a ventral hernia and, most recently, superficial bladder cancer treated with BCG therapy. Ten months after his final intravesical BCG instillation, he complained of fever and asthenia. After 12 months of investigation, he was diagnosed with Mycobacterium bovis infection of his aortobifemoral bypass graft and abdominal mesh, with Streptococcus intermedius superinfection. The bypass graft was excised and replaced with an in situ arterial allograft, the abdominal mesh was removed, and treatment started with amoxicillin, isoniazid, rifampicin and ethambutol. Several additional vascular interventions were needed for allograft degradation, but 12 months after the final procedure, outcome was good. DISCUSSION AND CONCLUSIONS: Among 35 cases of mycotic aneurysm reported after BCG therapy in the last 10 years, only one involved a vascular prosthesis. Surgical repair of such aneurysms using prosthetic grafts is commonly performed, associated with anti-mycobacterial treatment. Prognosis is poor with mortality of 14% (4/35) and a 26% rate of aneurysm recurrence under treatment (9/35).

Successful 6-Week Antibiotic Treatment for Early Surgical-site Infections in Spinal Surgery.

BACKGROUND: The incidence of spinal surgical site infections (SSIs) remains stable at less than 10%. Surgical reinterventions may be hampered by decubitus, treatment-related adverse events, and cost. In the context of emergence of bacterial resistance, a short duration of antimicrobial treatment is of critical importance. If the duration of treatment for SSI is currently 12 weeks, the aim of our study was to assess the efficacy of an antimicrobial treatment shortened to 6 weeks. METHODS: This prospective study was carried out from November 2014 to July 2016 in an 827-bed teaching hospital. After surgical management of SSIs, patients received broad-spectrum antibiotics intravenously for 10 days and orally for the remainder, for a total of 6 weeks. Success was defined as absence of relapse, superinfection, or surgical failure at the end of treatment and at 1-year follow-up. RESULTS: Eighty-five patients were included in this study. The median delay between initial surgery and diagnosis of SSI was 16 days. In 65 cases (76.4%), SSIs were monomicrobial; among these, Staphylococcus aureus was found in 30 cases (46%). Failure was observed in 7 cases (8.2%), with more than half caused by anaerobic bacteria. CONCLUSIONS: Surgical management of SSI followed by a 6-week antibiotic treatment is associated with favorable outcome. Anaerobic bacteria seem to play a role in the occurrence of relapses. A 6-week reduction in antibiotic treatment leads to reduction in cost and, likely, also to reduction in the emergence and spread of resistant microorganisms.

Use of specific agar plates for early detection of anaerobic bacteria in surgical site infections after spinal surgery: a prospective single centre study.

To determine if additional agar plates could allow earlier detection of anaerobes in spinal surgical site infections (SSIs), we performed a prospective study (November 2017-January 2019) of patients with early spinal SSIs. In addition to routine 14-day cultures, surgical samples were inoculated onto three additional plates (CDC anaerobe agar with 5% sheep blood [CDC], CDC anaerobe laked sheep blood agar with kanamycin/vancomycin [BBL], and Bacteroides bile esculin [BBE] agar with amikacin (BD, USA)) incubated under anaerobic conditions (72 h, 37°C). The primary endpoint was detection of anaerobes by these methods, as compared to routine culture. Anaerobes were identified in 7/61 patients (11%) using the routine procedure and in one extra case with additional plates (overall detection rate 8/61, 13%). Sensitivity was greater for the CDC plate than for the BBL and BBE plates. When routine culture was positive, the CDC plate was always positive, and in three cases showed at least one additional anaerobe. Using additional agar plates, anaerobes were identified in early spinal SSI in 13% of patients. Within 3 days, CDC agar plate enabled detection of anaerobes in one extra case and at least one additional anaerobe in three other cases, compared to routine 14-day culture.

Comparative evaluation of the QMAC-dRAST V2.0 system for rapid antibiotic susceptibility testing of Gram-negative blood culture isolates.

To comparatively evaluate the performance of the rapid antimicrobial susceptibility testing (AST) system QMAC-dRAST V2.0 and of standard disk diffusion in agar, AST was performed directly from 100 positive blood culture bottles with Gram-negative bacilli. AST results provided by QMAC-dRAST showed 92.9% agreement with disk diffusion method results. Discrepancies observed between results obtained with QMAC-dRAST and disk diffusion method conducted to 10 very major errors (0.8%, S with QMAC-dRAST vs R with disk diffusion method), 40 major errors (3.2%, R vs S, respectively), 15 minor errors (1.2%, S vs I or I vs R, respectively) and 23 very minors errors (1.8%, I vs S or R vs I, respectively). For very major and major errors, in only 36% of the cases did the repeat QMAC-dRAST confirm the initial result, whereas a repeat AST using disk diffusion method confirmed the initial result in 92% of cases. AST results obtained using microdilution in liquid medium confirmed those obtained with QMAC-dRAST and disk diffusion method in 4% and 89%, respectively. Repeatability and reproducibility tests performed on QMAC-dRAST using reference strains showed 94% to 100% of R/S/I categorical agreement.