Analysis of the results of bacteriological study of wounds in patients with implant-associated spinal infection

Abstract

Introduction Results of bacteriological study of the pathological material taken from sinus exits and surgical wounds in 105 patients with implantassociated spinal infection (IAI) who were surgically treated at the bone infection clinic of the RISC for RTO in the period from 2011 to 2017 were analyzed. Purpose Identify the main pathogens of the IAI of the spine. Materials and methods Patients were divided into three groups: group 1 had fistulous forms of peri-implant infection: paravertebral and epidural abscesses and phlegmon (n = 18, subgroup 1); suppuration of soft tissues around metal structures (n = 20, subgroup 2); spondylitis / discitis / osteomyelitis (n = 26, subgroup 3), infectious complications associated with postoperative liquorrhea (n = 5, subgroup 4); group 2 suffered peri-implant infection that developed due to postoperative instability of the metal structure (n = 26); group 3 had infection that developed after implantation of the systems for chronic electrical stimulation (n = 10). Identification of the isolated bacterial cultures was carried out both by the traditional method and by using panels for gram-positive (PBBCS 20) and gram-negative microorganisms (NBC 44) on the WalkAway-40 Plus bacteriological analyzer (Siemens). Results and discussion According to the analysis of the bacteriological results, gram-positive microorganisms (65.7 %) significantly prevailed among the pathogens of implant-associated spinal infection, of which the major ones were staphylococci (52.9 %). Isolation of S. aureus was 34.8 %. Among the methicillin-resistant strains, S. epidermidis was dominant. Among gram-negative microorganisms, both non-fermentative (16.8 %) and enterobacteria (20.9 %) were found. Most frequently identified non-fermenting bacteria were P. aeruginosa and A. baumannii. Enterobacteria were mainly represented by strains of K. pneumoniae and E. coli. Mixed cultures, consisting of two or more microorganisms, were significant. Conclusion Difficulties in the treatment of IAI of the spine require the development of methods for predicting these complications and measures to reduce them. Microbiological monitoring is an integral part of infection control in hospitals, where patients with IAI of the spine are treated. Timely identification of infection pathogens enables to choose correct antibiotic therapy and arrest the infection process in a short time.

Keywords

• implant-associated spinal infection
• microbial panel
• associations of microorganisms
• biofilms