Propionibacterium acnes: an under-appreciated cause of post-neurosurgical infection

BACKGROUND: Propionibacterium acnes is increasingly recognized as a cause of post-neurosurgical infection. This review of patients with P. acnes neurosurgical infection was carried out in order to determine clinical characteristics and outcomes in relation to duration of antimicrobial treatment. METHODS: We retrospectively reviewed the charts of consecutive patients with P. acnes isolated from neurosurgical specimens from 1 January 1999 to 30 June 2005. We defined P. acnes neurosurgical infection as isolation of P. acnes alone from a sterile neurosurgical site in a patient who clinically improved following treatment with an appropriate antibiotic. RESULTS: We identified 28 patients with definite P. acnes neurosurgical infection; median age 49 years (range 23-77); 15 (54%) male. All patients had prior neurosurgical procedures: 27 (96%) post-craniotomy. The median time from surgery to presentation was 54 days (range 12-1,578). Eighteen out of 28 (64%) patients who met the definition of neurosurgical infection had Gram-positive bacilli seen in at least one surgical specimen compared with only 2/56 (4%) patients who did not meet the definition (P < 0.0001). Intravenous benzyl penicillin +/- oral penicillin VK was the most common treatment. The median duration of antibiotic treatment for intracranial infection was 29 days. Five of nine patients who had extracranial bone-flap-associated infection had 相似文献   

In vitro activities of cefotaxime, vancomycin, quinupristin/dalfopristin, linezolid and other antibiotics alone and in combination against Propionibacterium acnes isolates from central nervous system infections

OBJECTIVES: To evaluate the antibiotic susceptibilities of Propionibacterium acnes isolates from central nervous system (CNS) infections to agents used in current treatment regimens. METHODS: MICs of 16 reference antibiotics were determined by an agar dilution method for 24 consecutive strains of P. acnes isolated from individual patients with intracranial empyema or brain abscess. Bactericidal activities of antibiotics against P. acnes PAN14 were studied at 0.25-2 x MIC using a time-kill method. RESULTS: All of the isolates were resistant to fosfomycin, intermediate or resistant to metronidazole and susceptible to all the other antibiotics tested, except for nine strains, which were intermediate to ofloxacin. Among antibiotics tested alone in time-kill experiments, vancomycin was the most effective drug and exhibited bactericidal activity after 24 h at 1x and 2 x MIC, whereas cefotaxime and ciprofloxacin were bactericidal after 48 h at 2 x MIC. No significant bactericidal activity could be demonstrated with the other antibiotics tested alone. The addition of cefotaxime to vancomycin resulted in bactericidal activity at lower concentrations (0.5 x MIC), whereas synergy was observed between quinupristin/dalfopristin and cefotaxime at 2 x MIC. In contrast, antagonism was observed between cefotaxime and linezolid, and ciprofloxacin and clindamycin. CONCLUSION: Our data suggest that P. acnes isolates causing CNS infections remain highly susceptible to most antibiotics used for the treatment of such infections. Moreover, we showed that cefotaxime, vancomycin and ciprofloxacin possess good bactericidal activities against P. acnes, and that these activities may be enhanced when vancomycin is combined with cefotaxime or when cefotaxime is combined with quinupristin/dalfopristin.     

Antibiotics for the eradication of Propionibacterium acnes biofilms in surgical infection

OBJECTIVES: Propionibacterium acnes is increasingly recognized as a cause of delayed infection after spinal instrumentation or shunting for hydrocephalus. Biofilm development by this organism has recently been demonstrated. We therefore investigated the effect of two different courses of three antibiotics (penicillin, rifampicin and linezolid) on mature P. acnes biofilms in vitro. Outcomes were eradication or regrowth after withdrawal of antibiotics, simulating successful treatment and relapse. METHODS: P. acnes biofilms were grown on titanium discs for 6 days until mature, then exposed to the antibiotics for either 7 or 14 days before sonication and culture. Further, discs were similarly exposed, but after each course, they were reincubated for a further 9 days to check for regrowth. RESULTS: Penicillin, linezolid and linezolid plus rifampicin eradicated P. acnes biofilms after 14 days, but only penicillin had this effect after 7 days. 'Relapse' was prevented only by 14 day courses of penicillin or linezolid plus rifampicin, but not by linezolid alone. CONCLUSIONS: For P. acnes spinal instrumentation infections, either penicillin or linezolid plus rifampicin might be equally effective. For shunt infections, as penicillin does not give therapeutic cerebrospinal fluid concentrations, rifampicin plus linezolid might be the treatment of choice. Linezolid alone appears not to be as effective as penicillin against P. acnes biofilms.     

Central nervous system infections due to Abiotrophia and Granulicatella species: an emerging challenge?

Although Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci, were initially identified over 40 years ago, isolation of these pathogens from the central nervous system (CNS) was first noted only recently. Recognition of CNS involvement with these organisms is of great concern given the association of Abiotrophia/Granulicatella infections with increased morbidity and mortality as well as greater bacteriologic failure and relapse rates. We describe A. defectiva and G. adiacens CNS infections in two patients and review the existing literature of CNS involvement with these bacteria. The clinical presentation and initial cerebrospinal fluid analysis has varied substantially across reported patients. While most infections have been characterized primarily by a localized infection (e.g., abscess), evidence of meningitis has usually also been present. Furthermore, nearly all cases have followed neurosurgical procedures suggesting possible introduction of the organism into the CNS at the time of surgery. Given the significant negative clinical impact of Abiotrophia/Granulicatella infections, elucidation of the emerging epidemiology of CNS infections with these bacteria is warranted.     

Cerebral and spinal nocardia infection. A case report]

We report a case of multiple cerebral and spinal abscesses due to Nocardia asteroides in a non-immunocompromised patient. The initial central nervous system manifestation was a sterile meningitis, with secondary development of multiple cerebral and spinal abscesses. Since the location of the abscesses did not allow neurosurgical exploration and the cultures remained negative, the diagnosis was finally established by raised antibody titres to Nocardia asteroides. After specific antibiotic therapy, resolution of the spinal and cerebral abscesses was documented on the basis of serial magnetic resonance tomography and computed tomography controls.     

Propionibacterium acnes: infection beyond the skin

Propionibacterium acnes is a Gram-positive bacterium that forms part of the normal flora of the skin, oral cavity, large intestine, the conjunctiva and the external ear canal. Although primarily recognized for its role in acne, P. acnes is an opportunistic pathogen, causing a range of postoperative and device-related infections. These include infections of the bones and joints, mouth, eye and brain. Device-related infections include those of joint prostheses, shunts and prosthetic heart valves. P. acnes may play a role in other conditions, including inflammation of the prostate leading to cancer, SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, sarcoidosis and sciatica. If an active role in these conditions is established there are major implications for diagnosis, treatment and protection. Genome sequencing of the organism has provided an insight into the pathogenic potential and virulence of P. acnes.     

Therapy of Penicillin- and Cephalosporin-resistant Pneumococcal Infections

Streptococcus pneumoniae has recently developed resistance to almost every agent that has been used for therapy, including the extended-spectrum cephalosporins. The empiric therapy of penicillin-resistant pneumococcal meningitis should include cefotaximine or ceftriaxone plus vancomycin pending cephalosporin susceptibility results. Intermediate penicillin-resistant pneumococcal infections outside the central nervous system will usually respond to high dose intravenous β-lactam antibiotic therapy. Highly penicillin-resistant pneumococcal infections may not respond to penicillin therapy, in which case therapy with vancomycin, imipenem or a macrolide (if susceptible) can be considered. Pneumococcal resistance to commonly used oral agents varies geographically and the efficacy of a particular agent can only be assured once the infecting strain is known to be susceptible. It is imperative to determine the susceptibility of every pneumococcal isolate to the agent(s) being used for therapy, particularly in cases of meningitis and to document rapid sterilization of infected body sites or fluids.     

Reduced renovascular resistance by clonidine.

The antihypertensive effect of clonidine has been attributed to acute inhibition of sympathetic outflow from the central nervous system. This conclusion is derived from experiments with single doses of clonidine. The mechanism of the long-term blood pressure-lowering effect of clonidine has been less well characterized. Antihypertensive therapy may alter renal hemodynamics and these changes may ultimately affect systemic blood pressure. We studied the effect of long-term clonidine therapy on intrarenal hemodynamics, the renin-angiotensin system, and selected indices of sympathetic nervous system activity in 13 patients with essential hypertension to further elucidate its action. Long-term clonidine therapy resulted in decreased MAP and RVR associated with the suppression of supine but not upright PRA. RPF, RBF, FF, and WBV did not change. UKA, on index of the the putative vasodilating renal kallikrein-kinin system, was also not changed. Our findings suggest a role for PRA in modulating RVR during long-term clonidine therapy. This was associated with the reduction observed in MAP.     

Adjunctive rifampin therapy for central nervous system staphylococcal infections.

OBJECTIVE: To review the published clinical data assessing the role of adjunctive rifampin therapy for the treatment of staphylococcal central nervous system (CNS) infections. DATA SOURCES: A MEDLINE search (January 1966-March 2000) of English-language literature pertaining to CNS staphylococcal infections and rifampin was performed; tertiary sources were also used. DATA EXTRACTION: Human data and case reports were included, as no clinical trials have been published. DATA SYNTHESIS: Retrospective reviews of rifampin used in combination with other antibiotics for serious bacterial infections show conflicting results. Few case reports have described clinical successes with adjunctive rifampin therapy for CNS infections. CONCLUSIONS: The routine use of adjunctive rifampin for CNS infections cannot be justified.     

The permeability of the blood-cerebrospinal fluid barrier in the first 24 hours after cranio-cerebral injury]

The permeability of the blood-liquor barrier (BLB) for blood proteins was studied in 30 patients within 24 hours after craniocerebral injuries of various severity and 21 patients whose condition was critical within 24 hours after different neurosurgical interventions. BLB permeability was assessed from the ratio of albumin/IgG in the cerebrospinal fluid and blood. A direct though not always statistically significant relationship between BLB permeability and the severity of injury was revealed. The authors suppose that this methodological approach, combined with other methods of investigation, may be useful in assessing the course of brain edema. Local IgG synthesis in the central nervous system was detected in half of the injured patients and in half of those in the critical condition. Local immune humoral reaction of the central nervous system appears to be largely related to the trauma severity and not influencing the outcome. This phenomenon is to be verified by specific immunologic methods.     

Successful clearance of catheter-related bloodstream infection by antibiotic lock therapy using ampicillin

OBJECTIVE: To report a case in which ampicillin was used successfully as lock therapy for a central venous intravascular catheter and to discuss the implications of ampicillin used in this modality. CASE SUMMARY: A 14-month-old girl with a long-term central venous catheter acquired a polymicrobial (Escherichia coli and Enterococcus durans) bloodstream infection. The central venous catheter was suspected as the source for the bacteremia based on the timing and number of positive blood cultures in relation to therapy with antibiotics. Antibiotic sensitivity testing revealed ampicillin monotherapy to be an ideal choice to treat both organisms. A combination of systemic therapy via a temporary catheter and antibiotic lock therapy of the central venous catheter was then instituted using ampicillin without anticoagulants. The patient tolerated this therapy without complications, and follow-up cultures demonstrated effective clearance of the bacteria. DISCUSSION: Antibiotic lock therapy has been shown to be useful in the treatment of catheter-related bloodstream infections. However, many antibiotics have yet to be tested with this modality. Ampicillin, which is frequently used in the treatment of Enterococcus and E. coli infections, has not previously been reported as a single agent for lock therapy. CONCLUSIONS: Ampicillin may be a useful agent with the relatively new modality of lock therapy for central venous catheters. Further studies are needed to demonstrate possible compatibility of this agent with anticoagulants, such as heparin, as well as its efficacy in treating catheter-related bloodstream infections.     

Glucocorticoid therapy in neurologic critical care

BACKGROUND: The pivotal role of inflammation and edema across the spectrum of central nervous system injury has driven extensive investigation into the therapeutic potential of glucocorticoids. OBJECTIVE: To review the experimental and clinical data relating to the efficacy and adverse effects of glucocorticoids in conditions encountered in critical neurologic and neurosurgical illness. DATA SOURCE: Search of MEDLINE and Cochrane databases, manual review of article bibliographies. DATA SYNTHESIS AND CONCLUSIONS: The efficacy of glucocorticoids is well established in ameliorating edema associated with brain tumors and in improving outcome in subsets of patients with bacterial meningitis. Despite frequently encouraging experimental results, clinical trials of glucocorticoids in ischemic stroke, intracerebral hemorrhage, aneurysmal subarachnoid hemorrhage, and traumatic brain injury have not shown a definite therapeutic effect. The evidence supporting glucocorticoid therapy for spinal cord injury is controversial; however methylprednisolone continues to be widely employed in this setting.     

Spinal epidural hematoma complicating thrombolytic therapy with tissue plasminogen activator--a case report

Patients who receive thrombolytic therapy are at risk of central nervous system (CNS) hemorrhage, and this diagnosis must be sought in any patient who develops neurologic complaints after thrombolysis and anticoagulation. Early imaging and neurosurgical consultation are essential to improve outcome after hemorrhage occurs. We describe a patient who developed spinal epidural hematoma (SEH) after thrombolysis and anticoagulation for acute myocardial infarction. Delay in diagnosis and management may have contributed to a poor outcome. The literature on SEH is reviewed, and approaches to improve the prognosis of patients suffering CNS hemorrhage after thrombolysis are discussed.     

Pharmacokinetic model for tobramycin in acinetobacter meningitis

OBJECTIVE: To report a case of acinetobacter meningitis treated with a once-daily intravenous dose of tobramycin and to propose a pharmacokinetic model for the drug disposition. CASE SUMMARY: A 28-year-old man with chronic hydrocephalus was admitted with a diagnosis of intracranial hypertension. Acinetobacter spp. was detected in the cerebrospinal fluid (CSF); it was sensitive to tobramycin, ampicillin/sulbactam, and colistin. Based on the culture report, multiple daily-dose therapy with tobramycin was started. As the infectious symptoms remained, once-daily therapy was recommended; the optimal dose was calculated with nonlinear regression by least-squares analysis and a Bayesian method, using plasma and CSF samples. The infection was resolved, tobramycin therapy was discontinued, and the patient was discharged from the intensive care unit. DISCUSSION: We use once-daily intravenous tobramycin therapy because, although the intrathecal administration of drugs is generally well tolerated, the presence of preservatives may be a source of central nervous system adverse effects. Pharmacokinetic parameters were calculated with plasma and CSF concentration values obtained during the first once-daily dose by using a compartment-effect model which allows fitting of simultaneous plasma and CSF concentrations. The prediction level was determined by the estimation of drug concentrations during the fourth once-daily dose. CSF concentrations of drug were enough to eradicate the clinical signs of infection. CONCLUSIONS: Therapy using once-daily intravenous administration of tobramycin may be an adequate alternative for acinetobacter infections in neurosurgical patients when an intrathecal route is initially not recommended. The development of a compartment-effect model can be useful to predict drug concentrations.     

高压氧治疗神经外科术后感染

目的:探讨高压氧对神经外科术后感染的治疗作用。方法:70例神经外科术后感染的患者随机分为 高压氧组和对照组各35例,对感染伤口均采用药物、清创及引流等治疗,高压氧组同时接受高压氧治疗。结果:随 访6个月后,高压氧组痊愈率为63%,总有效率94%,且无明显的并发症,明显优于对照组(P<0.01)。结论:高压 氧治疗是一种安全有效的控制神经外科术后感染的辅助疗法。     

Gene therapeutic strategies for neurodegenerative diseases

Gene transfer into the central nervous system by ex vivo or in vivo techniques is a rapidly emerging field in neuroscience. Potential applications of gene therapy for the nervous system include not only congenital single gene disorders, but also brain tumors and acquired chronic diseases. Considerable progress has been made in the understanding of neurodegenerative diseases such as Parkinson's and Alzheimer's disease. As a result, gene therapy for Parkinson's, and possibly Alzheimer's disease could be regarded as a realistic alternative to the limited treatment options currently available. In this review, we highlight the most important developments in gene transfer techniques as well as the newest insights in the mechanisms of some neurodegenerative disorders and put these into the perspective of gene therapeutic strategies for the central nervous system.     

Osteomyelitis and septic arthritis caused by Haemophilus influenzae, type f, in a young girl.

A 4-year-old girl with Legg-Calve Perthes' disease and immunoglobin G1 subclass deficiency developed osteomyelitis of the proximal femur and septic arthritis of the hip secondary to Haemophilus influenzae, type f. This microorganism is a rare cause of invasive infections in children, primarily of the central nervous system (CNS) and respiratory track. It has not previously been associated with bone and joint infections.     

Fulminant community-acquired infectious diseases: diagnostic problems

The processes presented here do not represent an all-inclusive list of fulminant infectious diseases. Some of the more common acute, overwhelming infections of the central nervous system and lungs are covered elsewhere in this issue. We have selected less common, potentially catastrophic syndromes that might be recognized earlier if certain historical clues, physical findings, or laboratory abnormalities are appreciated. Specific and effective therapy is available for most of the diseases we have chosen. Meningitis due to Naegleria fowleri, a free-living ameba that may invade the central nervous system through the cribriform plate in persons swimming in brackish water, and hemorrhagic mediastinitis due to inhalation of Bacillus anthracis, which is acquired in occupational exposure to goat's hair, wool, or an animal with anthrax, are other examples but are lacking in proven effective therapy. Although most physicians quickly consider exotic and overwhelming infections in the severely compromised patient, fewer recognize this risk in the diabetic, cirrhotic, or healthy person with a unique occupational or travel history. During the present epidemic of AIDS, previous exposure to the HTLV-3 virus must be considered in all severely ill patients. The proper use of new diagnostic tests may permit the physician to intercede effectively if these life-threatening diseases are suspected.     

成年患者人型支原体脑膜炎1例并文献复习

目的 分析人型支原体导致成年人中枢神经系统感染的临床特征、诊断及治疗,以期提高对此类感染的认识.方法 总结分析重庆市垫江县中医院收治的1例成年患者神经外科手术后继发人型支原体脑膜炎的诊疗经过,并以"Mycoplasma hominis"和"meningitis"或"encephalitis"或"nervous"或"ne...     

小儿单纯疱疹病毒脑炎的临床分析

目的；通过分子生物学方法了解小儿中枢神经系统单纯疱疹病毒（HSv）感染情况，分析其临床特点。方法：收集150例住院的中枢神经系统病毒感染患儿的脑脊液标本，用套式PCR检测脑脊液中HSV DNA用酶联免疫吸附法检测脑脊液中特异性HSV IgM抗体。结果：150例中有6例脑脊液HSV1 DNA（＋），另1例HSV1 IgM（＋）；病例呈散发性起病，无明显季节、年龄、性别分布特点。与其他病毒感染相比，惊厥持续状态、精神症状发生率高（P〈0．01），意识障碍、病死率无显著差异。结论：单纯疱疹病毒感染占儿童中枢神经系统感染的4．67％。儿童中枢神经系统单纯疱疹病毒感染多为HSVl的原发感染，可导致脑炎、脑干脑炎、急性播散性脊髓膜炎；起病较危重，出现精神症状较多，及时有效的抗病毒治疗能明显改善病情，降低病死率。