Spinal infections, including spondylodiscitis, are rare but serious clinical conditions that necessitate prompt diagnosis and appropriate treatment to prevent severe complications such as neurological deficits or even death[6, 7]. Among the causative pathogens, Klebsiella pneumoniae is a gram-negative bacterium often associated with nosocomial infections, including pneumonia, urinary tract infections, and bloodstream infections. Compared to other Enterobacteriaceae bacteria, Klebsiella bacteria are more likely to cause septic shock or even death in patients[8]. Klebsiella pneumoniae particularly virulent due to for its polysaccharide capsule, siderophores, and fimbriae,which enable it to evade host immune defenses and establish infections in various tissues[5]. Although the occurrence of Klebsiella. pneumoniae in the spine is rare, it is often associated with immunocompromised states or pre-existing conditions such as diabetes mellitus (DM)[8]. Additionally, researchers suggested that alcoholism, intravenous drug users (IVDU), and compromised immune status are significant risk factors for Klebsiella pneumoniae infection leading to spinal epidural abscesses[9].
The rarity of Klebsiella pneumoniae as a cause of spinal infections, including spondylodiscitis, is well-documented in the literature, with only a few case reports published to date[5, 8, 9]. A review of the literature reveals that most reported cases of Klebsiella pneumoniae spondylodiscitis involve the lumbar spine[2], as observed in this case. The clinical presentation of spinal K. pneumoniae infection is often nonspecific, including symptoms such as back pain, fever, and neurological deficits, which can lead to misdiagnosis. For instance, in our case, the initial diagnosis was tuberculosis, a common misdiagnosis that can delay appropriate treatment and worsen outcomes. This issue is particularly problematic in regions where tuberculosis is endemic, and the threshold for initiating anti-tuberculosis treatment is low[10].
Diagnosing K. pneumoniae spinal infection is challenging due to its nonspecific symptoms and the rarity of the condition. In the case of Fatal Cervical Spinal Epidural Abscess (SEA) and Spondylodiscitis Complicated With Rhombencephalitis caused by Klebsiella pneumoniae reported by Nitinai et al.[11], the first report of hypervirulent K. pneumoniae (hvKP) infection caused by community-acquired Klebsiella pneumoniae, early metastatic spread and led to multiple organ involvement, including the central system and the eye. This case underscores the importance of early diagnosis and prompt allied medical and surgical treatment. Enhanced imaging techniques such as contrast-enhanced MRI and computed tomography (CT) are crucial for diagnosing of spinal infections, as they help identify vertebral involvement, abscess formation, and the extent of soft tissue involvement[12]. However, radiographic findings alone cannot distinguish between different pathogens. Advanced diagnostic tools such as metagenomic next-generation sequencing (mNGS) can aid in the early identification of this pathogen, facilitating timely and effective treatment[13]. While MRI is the gold standard for detecting spinal infections due to its ability to visualize soft tissues, bone marrow edema, and abscesses, it's crucial to use imaging as a tool for ongoing evaluation throughout the treatment. In the case presented, core needle biopsy (CNB) under local anesthesia provided definitive microbiological confirmation of Klebsiella pneumoniae as the causative pathogen, emphasizing the importance of tissue sampling and culture in establishing a precise diagnosis.
The treatment of K. pneumoniae spinal infections typically involves prolonged antibiotic therapy tailored to the pathogen's resistance profile[14]. Surgical intervention may be necessary in cases of abscess formation, impaired spinal nerve function, or structural damage to the spine[15]. In the presented case, the organism was sensitive to ceftriaxone, levofloxacin, and imipenem, which are commonly used antibiotics for treating gram-negative infections. Initially, rifampicin was used empirically, likely influenced by the suspicion of tuberculosis. However, subsequent adjustment to antibiotics targeted against Klebsiella pneumoniae led to complete resolution of symptoms and infection. This underscores the importance of obtaining culture results before initiating long-term antibiotic therapy to avoid unnecessary use of anti-tuberculosis drugs, which carry significant toxicity. Furthermore, multidrug-resistant (MDR) Klebsiella pneumoniae poses a significant treatment challenge, as increasing resistance to antibiotics such as carbapenems and extended-spectrum beta-lactams (ESBLs) complicates therapy. It is essential to consider the possibility of MDR strains when selecting empirical antibiotic treatment, especially in regions with high rates of resistance. Non-compliance can lead to treatment failure, persistent infection, and potentially, the emergence of antibiotic resistance, all of which significantly increase the risk of relapse.
Current literature suggests that the prognosis for patients with spinal K. pneumoniae infections depends on the timeliness and appropriateness of the treatment[16]. Early diagnosis and targeted therapy can lead to excellent outcomes, as evidenced by our case where the patient remained symptom-free during follow-up. Most cases respond well to appropriate antibiotics, with surgical intervention rarely required unless there is significant abscess formation or neurological compromise. Delayed treatment, however, can result in complications such as chronic pain, neurological deficits, and even mortality[17].
Despite the increasing recognition of Klebsiella pneumoniae as a pathogen in spinal infections, there are still significant gaps in the literature regarding its epidemiology, risk factors, and optimal management strategies[18]. Most available studies are limited to case reports or small case series, making it difficult to draw robust conclusions about the best therapeutic approach, especially regarding the duration of antibiotic therapy and the role of adjunctive therapies. Therefore, confirmed cases often require a multidisciplinary approach, along with a consistent assessment of antibiotic use, including the selection of drugs, dosage, duration of therapy, route of administration, and de-escalation strategies[19, 20].
Spinal infections such as spondylodiscitis require long-term follow-up to monitor for recurrence, especially in cases of K. pneumoniae, which can have delayed or insidious recurrence[21]. Recurrence can occur due to incomplete eradication of the pathogen or biofilm formation within the spine, which makes the infection more resistant to antibiotics. The literature indicates that early and aggressive treatment is associated with better long-term outcomes, but recurrent infections can still develop even after appropriate therapy. Therefore, clinical follow-up combined with imaging is critical for ensuring the infection has been fully eradicated. MRI remains a cornerstone in the long-term surveillance of spondylodiscitis. A study by Sobottke et al. emphasizes that follow-up MRI scans are essential after antibiotic therapy to ensure the complete resolution of infection and to rule out the need for further interventions, such as surgery, in cases where structural damage or abscess formation persists[22]. Given the challenges of treating infections deep within vertebral bone tissue, MRI’s high resolution allows clinicians to observe the reconstitution of normal bone marrow and the absorption of inflammatory infiltrates, which is crucial in assessing the success of long-term antibiotic therapy. In a retrospective analysis of bacterial spondylodiscitis cases, Cheung et al. found that a substantial proportion of patients with gram-negative infections, including Klebsiella pneumoniae, required extended treatment durations beyond the typical 6–12 weeks due to the risk of recurrence [23]. The study highlighted that early discontinuation of therapy or incomplete treatment courses was associated with higher relapse rates and more severe long-term complications, such as chronic pain and neurological deficits.
This case report contributes to the limited but growing body of literature on primary Klebsiella pneumoniae infections in the spine. It emphasizes the importance of considering Klebsiella pneumoniae as a differential diagnosis in cases of suspected spinal tuberculosis, especially when radiological findings are equivocal. CNB remains essential for definitive diagnosis, and early, targeted antimicrobial therapy can lead to successful outcomes without the need for surgical intervention. Further research is needed to develop standardized diagnostic and treatment guidelines for this rare but serious condition.