Comparison of the effectiveness of ceftobiprole and vancomycin in a rabbit model of methicillin-resistant Staphylococcus aureus induced meningitis.

INTRODUCTION: Nosocomial meningitis may occur after procedures affecting the central nervous system or following traumatic injury. The causative infectious organism is commonly Staphylococcus aureus, a gram-positive bacterium. The aim of the present study was to compare the effectiveness of two antibacterial agents, ceftobiprole and vancomycin in an animal model of methicillin-resistant Staphylococcus aureus (MRSA) meningitis. METHOD: The strain of MRSA used was ATCC 43300. The animals were divided into three groups and infected intracisternally with MRSA. Controls received no antibiotherapy while the ceftobiprole group received 25 mg/kg and the vancomycin group received 20 mg/kg intravenously. Blood and cerebrospinal fluid (CSF) samples were collected at three time points. All animals were euthanased at 73 hours after start of treatment. RESULTS: There was a significant difference (p<0.05) between both treatment groups and the control animals at 24 hours (drug trough) and 73 hours (one hour after third dose) after start of treatment in terms of CSF bacterial levels. At 73 hours there was a significant difference in survival between the control group and the two treatment groups but no difference between the treated animal survival rates. CONCLUSION: In conclusion, intravenous treatment with ceftobiprole and vancomycin appears to be equally effective in a rabbit model of MRSA meningitis.

Intrathecal Tigecycline in the Treatment of Hospital-Acquired Meningitis: A Review of Four Cases.

Objectives: Carbapenem-resistant A. baumannii is a common cause of nosocomial meningitis, and it presents a challenge in terms of treatment because of limited therapeutic options. Intravenous tigecycline has been considered a potential salvage therapy against multi-drug-resistant Acinetobacter baumannii. However, its effectiveness is limited by its poor ability to cross the blood-brain barrier. As an alternative treatment option, intrathecal tigecycline has shown promise with its minimal side effects and high concentration in cerebrospinal fluid. Methods: In this report, we present a series of four cases infected with multi-drug-resistant A. baumannii following neurosurgery and treated with intrathecal tigecycline, including antimicrobial therapy. Results: The rate of successful microbiological response was 2 out of 3 cases (66%) in whom microbiological response could be tested anytime during the intrathecal therapy, whereas the 30-day survival rate after treatment completion was » (25%). Conclusion: Although intrathecal tigecycline treatment has shown relative efficacy in achieving microbiological response, its impact on overall survival is still uncertain. Further studies involving larger groups of patients are necessary to evaluate the outcomes of intrathecal tigecycline therapy.

Importance of Source Control in the Subgroup of Intra-Abdominal Infections for Septic Shock Patients: Analysis of 390 Cases.

Background: This study aimed to evaluate the epidemiology of septic shock (SS) associated with intraabdominal infections (IAI) as well as associated mortality and efficacy of early source control in a tertiary-care educational hospital. Methods: Patients who had SS with IAI and consulted by Infectious Diseases consultants between December 2013 and October 2022 during night shifts in our centre were analyzed retrospectively. Results: A total number of 390 patients were included. Overall, 30-day mortality was 42.5% on day 3, while day 14 and 30 mortality rates were 63.3% and 71.3%, respectively. Source control by surgical or percutaneous operation was performed in 123 of 390 cases (31.5%), and the mortality rate was significantly lower in cases that were performed source control at any time during SS (65/123-52.8% vs 213/267-79.8%, p<0.001). In 44 of 123 cases (35.7%), source control was performed during the first 12 hours, and mortality was significantly lower in this group versus others (24/44-54.5% vs 254/346-73.4%, p=0.009). On the other hand, female gender (p<0.001, odds ratio(OR)= 2.943, 95%CI=1.714-5.054), diabetes mellitus (p= 0.014, OR=2.284, 95%CI=1.179-4.424), carbapenem-resistant Gram-negative etiology (p=0.011, OR=4.386, 95%CI=1.398-13.759), SOFA≥10 (p<0.001, OR=3.036, 95%CI=1.802-5.114), lactate >3 mg/dl (p<0.001, OR=2.764, 95%CI=1.562-4.891) and lack of source control (p=0.001, OR=2.796, 95%CI=1.523-5.133) were significantly associated with 30-day mortality in logistic regression analysis. Conclusion: Source control has a vital importance in terms of mortality rates for IAI-related septic shock patients. Our study underscores the need for additional research, as the present analysis indicates that early source control does not manifest as a protective factor in logistic regression.

The first reported catheter-related Brevibacterium casei bloodstream infection in a child with acute leukemia and review of the literature

Brevibacterium spp. are catalase-positive, non-spore-forming, non motile, aerobic Gram- positive rods that were considered apathogenic until a few reports of infections in immunocompromised patients had been published. To the best of our knowledge, this is the first report of B. casei catheter-related bloodstream infection in a child with acute leukemia. We aim to enhance the awareness of pediatric hematology and infectious disease specialists about this pathogen and review of the literature.

In vitro activity of linezolid & quinupristin/dalfopristin against Gram-positive cocci.

BACKGROUND & OBJECTIVES: Since the incidence of vancomycin- and methicillin-resistant Gram-positive infections continue to increase, novel antimicrobials such as linezolid and streptogramin may provide new options to treat patients. The aim of this study was to investigate in vitro susceptibility of Enterococcus faecium resistant to glycopeptides, coagulase negative staphylococci and S. aureus resistant to methicillin isolated mainly from blood and also rectal swab cultures of patients against quinupristin/dalfopristin and linezolid. METHODS: The in vitro susceptibility to linezolid and quinupristin/dalfopristin for a total of 332 isolates of Gram-positive cocci [127 methicillin-resistant Staphylococcus aureus, 109 methicillin-resistant coagulase negative staphylococci (71 S. epidermidis, 38 S. haemolyticus) and 96 vanA genotype vancomycin-resistant Enterococcus faecium] was investigated by E test. RESULTS: All MRSA and MRCoNS isolates were susceptible to linezolid (MICs < 4.0 mg/l). Ninety per cent of VRE isolates were inhibited by linezolid at concentration of 2.0 mg/l and presented similar activities to quinupristin/dalfopristin. MICs for quinupristin/dalfopristin against staphylococci were also low (MIC(90) = 1.0 mg/l for both MRSA and MRCoNS isolates). INTERPRETATION & CONCLUSION: The results of the present study demonstrated that quinupristin/ dalfopristin and linezolid, have good in vitro activity against MRSA, MRCoNS and vancomycin resistant E. faecium in Turkey. These drugs could be promising therapeutic options in an era of rapidly growing antibiotic resistance in all parts of world.