Tigecycline in the treatment of multidrug-resistant Acinetobacter baumannii meningitis: Results of the Ege study.

OBJECTIVES: In this study we retrospectively reviewed A. baumannii meningitis cases treated with tigecycline including regimens and evaluated the efficacy of tigecycline in the therapy. PATIENTS AND METHODS: Study was performed in seven tertiary-care educational hospitals from five cities of Turkey and one center from France. We extracted data and outcomes of all adult (aged >18) patients with culture proven A. baumannii meningitis treated with tigecycline including antibiotic therapy until April 2016. RESULTS: A total of 23 patients (15 male and eight female) fulfilled our inclusion criteria. All Acinetobacter strains were carbapenem-resistant and susceptible to tigecycline. Six cases received tigecycline monotherapy while 17 received tigecycline including combination therapy (10 with colistin, 4 with netilmicin, 3 with amikacin, 4 with meropenem). Seven of 23 cases (30%) died during the tigecycline including therapy (1 in monotherapy, 4 in colistin, 2 in netilmicin, 1 amikacin, one case received tigecycline + netilmicin followed by tigecycline + colistin). Hence, overall end of treatment (EOT) success was 70%. However, since further 27% died due to additional nosocomial infections, overall clinical success (relieved symptoms at the EOT and one-month post-therapy survival without any relapse or reinfection) decreased to 43%. CONCLUSION: We conclude that tigecycline may be an alternative in the salvage treatment of nosocomial multidrug-resistant Acinetobacter spp. meningitis. Acinetobacter spp. Meningitis.

Vancomycin versus linezolid in the treatment of methicillin-resistant Staphylococcus aureus meningitis.

BACKGROUND: Vancomycin is the mainstay of treatment for methicillin-resistant Staphylococcus aureus (MRSA) meningitis. However, successful outcomes with linezolid have not been reported in a large series of patients. We conducted a single-center retrospective cohort study to compare vancomycin with linezolid in the treatment of MRSA meningitis. METHODS: We extracted data and outcomes for all adult patients (age >18 years) with culture-proved MRSA meningitis who received vancomycin or linezolid between January 2006 and June 2011. A definite diagnosis of meningitis was based on the isolation of MRSA in at least one cerebrospinal fluid (CSF) culture and findings in CSF that are typical of the infection. Linezolid was given intravenously (IV) at a dosage of 600 mg q12h and vancomycin IV at 500 mg q6h. RESULTS: A total of 8 patients with MRSA meningitis (5 male, 3 female; age [mean±SD] 61.6±13.2 years) received vancomycin and 9 patients (7 male, 2 female; age 59.1±15.6 years) received linezolid. All isolated strains of MRSA were susceptible to both vancomycin and linezolid. The rates of microbiologic success with linezolid or vancomycin, in terms of clearance of MRSA from CSF on day 5, were 7/9 and 2/8 (p=0.044, Fisher exact test). No severe adverse events occurred in either treatment arm of the study. One-month survival of the patients in whom treatment was successful microbiologically was 2/2 in the vancomycin-treated group and 4/7 in the linezolid-treated group. Minimum inhibitory concentration (MIC) data for vancomycin were available for 5/6 treatment failures with vancomycin, and vancomycin MIC values of these five strains were 2 mg/L. CONCLUSION: Analysis of the findings in the limited cohorts in our study suggests that linezolid is superior to vancomycin for treating MRSA meningitis, especially in cases in which there is a high MIC (2 mg/L) for vancomycin. A clinical study involving larger cohorts may increase the evidence available in relation to this question.

Daptomycin versus vancomycin in treatment of methicillin-resistant Staphylococcus aureus meningitis in an experimental rabbit model.

In this study, we aimed to compare the antibacterial activities of daptomycin and vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) meningitis (induced by MRSA strain ATCC 43300) in an experimental rabbit meningitis model. After an 8-h period of treatment, bacterial counts decreased significantly in both treatment groups compared to the control group (P < 0.05). However, there was no statistically significant difference between treatment groups. Our results suggest that the antibacterial activity of daptomycin is similar to vancomycin for treatment in the experimental MRSA meningitis model in rabbits.

Moxifloxacin versus ampicillin + gentamicin in the therapy of experimental Listeria monocytogenes meningitis.

OBJECTIVES: This study aimed to compare the antibacterial activity of moxifloxacin and ampicillin + gentamicin in the treatment of Listeria monocytogenes meningitis in a rabbit meningitis model. METHODS: Meningitis was induced by direct inoculation of a clinical strain isolated from an immunocompromised patient (10(7) cfu/mL) into the cisterna magna of New Zealand rabbits. After 16 h of incubation, rabbits were separated into four groups: moxifloxacin (M), ampicillin + gentamicin (A), ampicillin + gentamicin 2 (A2) and control (C). Group M received 20 mg/kg moxifloxacin at the end of the incubation time and 5 h later by intravenous (i.v.) route. Group A received ampicillin (30 mg/kg/h) and gentamicin (2.5 mg/kg/h) by i.v. route with continuous infusion for 8 h in 36 mL of 0.9% NaCl, group A2 received the same dosage of gentamicin and ampicillin in two different 36 mL 0.9% NaCl solutions and group C did not receive any treatment. Cerebrospinal fluid (CSF) samples (0.1-0.25 mL) were obtained 16 and 24 h after induction of meningitis. RESULTS: At the end of the 16 h of incubation, CSF bacterial counts were similar in all groups (P > 0.05). At the final stage of the study (24 h after induction of meningitis), bacterial counts in all treatment groups were significantly lower than the control group (P < 0.05). When the three treatment groups were compared, bacterial counts were found to be similar (P > 0.05). CONCLUSIONS: These data suggest that antibacterial activity of moxifloxacin is similar to ampicillin + gentamicin in the treatment of experimental L. monocytogenes meningitis of rabbits.