Application of Lactobacillus gasseri 63 AM supernatant to Pseudomonas aeruginosa-infected wounds prevents sepsis in murine models of thermal injury and dorsal excision.

Introduction. Severely burned patients are susceptible to bacterial infection within their burn wounds, which frequently leads to sepsis, multiple organ failure and death. The opportunistic pathogen Pseudomonas aeruginosa, an organism inherently resistant to multiple antibiotics, is a common cause of sepsis in these patients.Aim. Development of a topical treatment unrelated to conventional antibiotics is essential for prevention of P. aeruginosa infection and sepsis, leading to a role for the direct application of probiotics or their by-products.Methodology. We examined the effectiveness of 20× concentrated supernatant from Lactobacillus gasseri strain 63 AM (LgCS) grown in de Man, Rogosa and Sharpe broth in inhibiting P. aeruginosa biofilms in vitro, as well as in reducing wound bioburden and P. aeruginosa sepsis in vivo.Results. LgCS inhibited the growth of P. aeruginosa strain PAO1, prevented its biofilm development and eliminated partially developed PAO1 biofilms. In the murine model of thermal injury, a single injection of LgCS following injury and PAO1 infection reduced mortality to 0 % and prevented systemic spread (sepsis). Furthermore, a second injection of LgCS 24 h after the first eliminated PAO1 from the wound. In the murine dorsal excision infection model, either LgCS or ceftazidime treatment of the PAO1-infected wound significantly reduced the mortality rate among infected mice, while combining LgCS with ceftazidime eliminated mortality.Conclusion. These results suggest the potential of LgCS in preventing sepsis from P. aeruginosa infection in severely burned and other immunocompromised patients.

Septic abortion presenting as a right lower trapezius abscess secondary to Bacteroides fragilis bacteraemia.

A 43-year-old Japanese woman was evaluated in the outpatient department for right shoulder pain and fever, which began 5 days earlier. MRI of the right shoulder revealed a high-intensity area deep in the right trapezius muscle. Aspiration revealed purulent fluid, and Gram staining of the fluid showed Gram-negative bacilli. The patient was also found to be profoundly anaemic and to have a positive urine pregnancy test. On admission, we initiated intravenous ampicillin-sulbactam and aztreonam. She underwent dilatation and curettage for septic abortion and surgical drainage of the right shoulder abscess. Bacteroides fragilis was isolated from the blood, uterine aspiration and abscess samples. On hospital day 4, a whole-body CT scan revealed no other abscesses, and ampicillin-sulbactam was continued for 28 days. The patient was discharged on hospital day 29. Gram staining is an important tool for evaluating infectious aetiologies.

Metastatic muscle abscesses complicating infected total hip arthroplasty.

A 73-year-old woman with rheumatoid arthritis presented to our institution with infection of her right total hip arthroplasty. On admission, a draining sinus tract over the hip and a palpable mass in the left lower posterior region of the neck were detected. The contrast CT scan showed a large abscess in the trapezius muscle and multiple abscesses involving muscle of the neck and right shoulder. Intraoperative specimens from the muscle abscess were positive for presumably the same methicillin-resistant Staphylococcus aureus that sustained the prosthetic joint infection. Prolonged intravenous daptomycin led to remission of the muscle abscess and control of the prosthetic joint infection. The patient refused revision total hip arthroplasty and oral cotrimoxazole was prescribed for chronic suppression of the infection. Three years after the primary surgery there was stable remission of the prosthetic joint infection. This rare case demonstrates the severity of prosthetic joint infections sustained by multiresistant bacteria in immunocompromised hosts, which may result in their bacteraemic spread.