Modic Changes and Disc Degeneration Caused by Inoculation ofPropionibacterium acnesinside Intervertebral Discs of Rabbits: A Pilot Study

Abstract

Purpose. To investigate whether P. acnes could induce disc degeneration and Modic changes when inoculated into the discs of rabbits. Method. A wild-type strain of P. acnes isolated from a patient associated with Modic change and disc degeneration was inoculated into the intervertebral discs of rabbits. Meanwhile, S. aureus was injected into the discs to establish a model of discitis as the comparison and a standard strain of P. acnes was inoculated as the control. MRI and histological change were observed. Results. Both the P. acnes-inoculated and S. aureus-inoculated rabbits showed hyperintense signals at endplates and hypointense signals at nucleus pulposus on T2WI. However, P. acnes only resulted in moderate disc degeneration and endplates rupture in histological examination, which was different from the pathological change of discitis caused by S. aureus. In addition, higher death rates (2/3 versus 0/5) were observed in S. aureus-inoculated rabbits. Conclusion. Compared to S. aureus, the pathological change caused by P. acnes would be considered as Modic-I change and disc degeneration rather than a discitis.

The NLRP3/Caspase-1/Interleukin-1β Axis Is Active in Human Lumbar Cartilaginous Endplate Degeneration

“…Qin et al [36] reported that Propionibacterium acnes-induced human monocytes secrete mature IL-1b via the NLRP3-mediated pathway. Chen et al [7] showed that Propionibacterium acnes could induce Modic changes when inoculated into the discs of rabbits. Nevertheless, additional studies are required to explore the origin of cartilaginous endplate degeneration.…”

Lumbar Disc Herniation

“…Aghazadeh et al also found a high prevalence of P. acnes DNA and correlated it to vertebral edema as seen on preoperative MRI [27]. Chen et al found that the bacterium was able to induce disc degeneration outright in rabbit models [28]. Furthermore, long-term antibiotics targeting anaerobes may improve lower back pain in those with disc herniation and vertebral edema [22].…”

10 Years of Research: From Ignoring Modic Changes to Considerations Regarding Treatment and Prevention of Low-Grade Disc Infections

“…0-3-4-5) [4]. Low or high virulent infections may take place depending upon the bacterial species or subtype [10]. Anaerobic P. acnes bacteria are often present in the herniated mass following an acute disc herniation [4].…”

“…In some cases, the invading bacteria may have a nonskin origination, for example, from the oral cavity, as shown by Rollason et al . in a phylogenetic study [20];The most commonly found bacteria in the disc and herniated discal tissue are different subtypes of P. acnes [20–22];Bacteria with sufficiently virulent characteristics are able to colonize intradiscally [10];This is followed by inflammation and accelerated degeneration that in turn leads to end plate damage and MC changes as seen on MRI scans [10,23,24];Disc-related inflammation will lead to back pain and the injection of anti-inflammatory agents has demonstrated short-term pain reduction in several studies [23,25];A long-term antibiotic regimen results in a 50% reduction of pain in 50% of patients with low back pain following a disc herniation and Modic changes type 1 [12,13]. …”

“…This is followed by inflammation and accelerated degeneration that in turn leads to end plate damage and MC changes as seen on MRI scans [10,23,24];…”