We describe a case of Pasteurella multocida bacteremia in a patient that was dependent on a tunnelled catheter for dialysis and document the successful treatment with line retention and 2 weeks of intravenous antibiotics administered with dialysis.
P. multocida infection is common in particular after cat bite due to the depth of puncture caused by cats’ teeth. Infection can result in a number of complications including necrotising fasciitis, septic arthritis, osteomyelitis and less commonly septic shock, endocarditis and meningitis. The bacteria have several potential virulence factors including capsular lipopolysaccharide, a cytotoxin, hemagglutin, adhesins and iron acquisition proteins [3]. More severe disease has been documented in infants, pregnant women, patients on steroids, people living with HIV and immunocompromised patients [4]. In general, the organism is very sensitive to penicillin though some β-lactamase-producing isolates have been reported and empiric treatment is recommended with β–lactam/β–lactamase combinations such as ampicillin/sulbactam or amoxicillin/clavulanic [5]. Alternatives that have shown good activity against P multocida include second and third generation cephalosporins, tetracyclines, co-trimoxazole and fluoroquinolones.
Infection of prosthetic material with P. multocida following animal bites or licks is rare but has been described for prosthetic joints, aortic endografts and peritoneal catheters [6,7,8]. One retrospective study in France identified six P. multocida cases among 4686 prosthetic joint infections. All patients underwent surgery with prosthesis retention in three. Long-term antibiotics were used for all patients (range 6–18 months) without relapse at least 3 years after end of treatment [6]. The authors reviewed the literature identifying an additional 26 cases of P. multocida prosthetic joint infection. About half of these were treated with prosthesis retention (with or without debridement) with only four requiring subsequent prosthesis removal and staged replacement. An earlier study described aortic endovascular graft infection following rabbit bite and reviewed another two cases of endograft infection. The authors concluded in these cases that operative management is optimal with removal of infected material [7].
Perhaps most relevant to our case is a study of P. multocida peritonitis associated with peritoneal dialysis catheters [8]. The study reviewed seven local cases and 30 previously published reports with the authors concluding that although most patients were treated with catheter retention (89%), relapse occurred in only one patient. Despite significant heterogeneity in treatment the authors suggested that a 14-day course of intraperitoneal antibiotics was most likely adequate. They recommended use of penicillin or ampicillin-based regimens for non-β-lactamase producing isolates. Alternatives included third generation cephalosporins, ceftazidime and oral fluoroquinolones. One of three patients treated with intraperitoneal aminoglycosides had recurrence of infection thus the authors recommend against monotherapy with aminoglycosides.
In our patient, the infection route was via direct inoculation and line replacement was performed for punctured tubing. Bacteraemia ensued but was successfully treated without relapse, despite line retention, with a 14-day course of susceptible antibiotics intravenously and with catheter locks. Our case suggests that in cases of P. multocida infection with bacteremia, individuals can be considered for a trial of treatment with IV antibiotics, catheter locks and line retention. This is supported by the literature of successful treatment with prosthesis retention for prosthetic joint infections and peritoneal catheter associated infections. Given the discussed evidence for treatment failure of intraperitoneal aminoglycosides, the authors recommend catheter lock with either ampicillin or a cephalosporin such as ceftazidime depending on isolate sensitivities. In the case of purulent line infection, we believe it would be prudent to advocate for line replacement as recommended in Infectious Diseases Society of America (IDSA) guidelines [2].
To our knowledge this is the first description of a line associated Pasteurella multocida infection and provides management guidance for clinicians managing similar infections. Clearly recommendations are limited by the paucity of evidence; however, we believe that such infections are likely more common than reported in the literature and clinicians will benefit from our experience.