Antibiotic Treatment of Vertebral Osteomyelitis caused by Methicillin-Susceptible Staphylococcus aureus: A Focus on the Use of Oral β-lactams

Abstract

BackgroundVertebral osteomyelitis (VO) is a rare but serious condition, and a potentially significant cause of morbidity. Methicillin-susceptible Staphylococcus aureus (MSSA) is the most common microorganism in native VO. Long-term administration of parenteral and oral antibiotics with good bioavailability and bone penetration is required for therapy. Use of oral β-lactams against staphylococcal bone and joint infections in adults is not generally recommended, but some experts recommend oral switching with β-lactams. This study aimed to describe the current status of antibiotic therapy and treatment outcomes of oral switching with β-lactams in patients with MSSA VO, and to assess risk factors for treatment failure.Materials and MethodsThis retrospective study included adult patients with MSSA VO treated at nine university hospitals in Korea between 2005 and 2014. Treatment failure was defined as infection-related death, microbiological relapse, neurologic deficits, or unplanned surgical procedures. Clinical characteristics and antibiotic therapy in the treatment success and treatment failure groups were compared. Risk factors for treatment failure were identified using the Cox proportional hazards model.ResultsA total of 100 patients with MSSA VO were included. All patients were treated, initially or during antibiotic therapy, with one or more parenteral antibiotics. Sixty-nine patients received one or more oral antibiotics. Antibiotic regimens were diverse and durations of parenteral and oral therapy differed, depending on the patient and the hospital. Forty-two patients were treated with parenteral and/or oral β-lactams for a total duration of more than 2 weeks. Compared with patients receiving parenteral β-lactams only, no significant difference in success rates was observed in patients who received oral β-lactams for a relatively long period. Sixteen patients had treatment failure. Old age (adjusted hazard ratio [HR] 5.600, 95% confidence interval [CI] 1.402 – 22.372, P = 0.015) and failure to improve C-reactive protein levels at follow-up (adjusted HR 3.388, 95% CI 1.168 – 9.829, P = 0.025) were independent risk factors for treatment failure.ConclusionIn the study hospitals, diverse combinations of antibiotics and differing durations of parenteral and oral therapy were used. Based on the findings of this study, we think that switching to oral β-lactams may be safe in certain adult patients with MSSA VO. Since limited data are available on the efficacy of oral antibiotics for treatment of staphylococcal VO in adults, further evaluation of the role of oral switch therapy with β-lactams is needed.

The Cefazolin Inoculum Effect and the Presence of type A blaZ Gene according to agr Genotype in Methicillin-Susceptible Staphylococcus aureus Bacteremia

“…Hence, the use of cefazolin for treating severe infections or large burden infections caused by CIE positive MSSA can lead to treatment failure [13456]. Cefazolin is frequently used as the antibiotic of choice for severe MSSA infections such as osteomyelitis and septic arthritis, due to its high tolerability and favorable dosing schedule [78].…”

Is There a Difference in Clinical Features, Microbiological Epidemiology and Effective Empiric Antimicrobial Therapy Comparing Healthcare-Associated and Community-Acquired Vertebral Osteomyelitis?

“…Antibiotic therapy is essential for the treatment of VO. However, guidelines targeting antibiotic treatment strategies are scarce and only limited data are available on the efficacy of antibiotics [ 26 , 27 ]. For the selection of an appropriate empiric antibiotic regime, the local antibiogram profiles should be respected.…”

Implementation of a consensus protocol for antibiotic use for bone and joint infection to reduce unnecessary outpatient parenteral antimicrobial therapy: A quality improvement initiative

“…First, based on available literature, we created a draft table for possible oral antibiotic regimens for BJI caused by specific organisms: Staphylococcus aureus, coagulase-negative Staphylococcus, Streptococcus spp, Enterococcus spp, enteric gram-negative rod organisms, Pseudomonas aeruginosa, or unknown organisms. 7,10,[13][14][15][16][17][18] Next, a survey questionnaire was distributed using REDCap among ID physicians and ID pharmacists at the University of Iowa Hospitals and Clinics (UIHC) and ICVAHCS. The questionnaire asked how frequently the provider recommends the specific oral antibiotic (1 "almost never" to 5 "very frequently") in the setting where there is no contraindication for choosing oral antibiotics and the patient does not have a condition for which IV therapy is preferred, such as an undrained abscess or epidural abscess.…”