No abstract

The continuing rise of infections caused by multi-drug resistant bacteria has led to a renewed interest in bacteriophage therapy. Here we characterize phage vB_AbaM-KARL-1 with lytic activity against multi-drug resistant clinical isolates of Acinetobacter baumannii (AB). Besides genomic and phenotypic phage analysis, the objective of our study was to investigate the antibacterial outcome when the phage acts in concert with distinct antibiotics. KARL-1 belongs to the family of Myoviridae and is able to lyse 8 of 20 (40%) tested clinical isolates. Its double-stranded DNA genome consists of 166,560 bp encoding for 253 open reading frames. Genome wide comparison suggests that KARL-1 is a novel species within the subfamily Tevenvirinae, sharing 77% nucleotide identity (coverage 58%) with phage ZZ1. The antibacterial efficacy at various multiplicities of infection (MOI) was monitored either alone or in combination with meropenem, ciprofloxacin, and colistin. A complete clearance of liquid cultures was achieved with KARL-1 at an MOI of 10 and meropenem (>128 mg/l). KARL-1 was still effective at an MOI of 10, but antibacterial activity was significantly augmented with meropenem. While ciprofloxacin did generally not support phage activity, the application of KARL-1 at an MOI of 10 and therapeutic doses of colistin significantly elevated bacterial suppression. Hence, KARL-1 represents a novel candidate for use against multi-drug resistant AB and the therapeutic outcome may be positively influenced by the addition of traditional antibiotics.

Objectives: There are currently no data available on drain associated infection occurrence related to the number of drainage days (DD), and thus drain associated infection rates. Therefore, a prospective surveillance study was conducted to determine drain associated infection rates and DD of hospital acquired external ventricular drain (EVD) and lumbar drain (LD) associated meningitis/ ventriculitis in a neurosurgery and a neurological intensive care unit. Methods: All patients admitted in 2005 and 2006 were documented. Data on age, admitting diagnosis, type and duration of drain, duration of hospital stay and occurrence of meningitis were recorded and analysed statistically. Results: A total of 1333 patients were included, amounting to 3023 DD. After exclusion of 15 contaminations, a total of 26 cases of meningitis were reported accounting for an overall device associated meningitis rate of 8.6 infections/1000 DD. Infections associated with LD seemed to occur more frequently (19.9/1000 DD) compared with EVD (6.3/1000 DD). The presence of intraventricular blood and previous trauma were significant risk factors for infection (p = 0.003; p = 0.04). Finally, length of stay was significantly longer in meningitis patients (p = 0.0003). Coagulase negative staphylococci were the main pathogen (56%) causing meningitis, followed by Staphylococcus aureus (25%). Conclusions: To the best of the authors' knowledge, this study represents the first to provide data on EVD as well as LD associated meningitis rates calculated per 1000 DD; a parameter that is well established for other invasive devices such as central venous and urinary tract catheters. However, further prospective studies are needed to investigate the possible risk factors for meningitis.Nosocomial infection rates mainly correspond with the severity of illness and exposure to invasive devices.1 External ventricular drains (EVD) and lumbar drains (LD) are commonly used to control hydrocephalus and to monitor and decrease intracranial pressure. Ventriculostomy related infections are a serious problem in up to 40% of patients. [2][3][4][5]

To the best of our knowledge, this study is the first to provide data on time dependency of EVD- and LD-associated MV-IR based on drainage-days. However, because of the limited scale of our study, it would be desirable to confirm these results in a more powerful larger study. In conclusion, we recommend that future efforts should be made to better identify preventable risk factors as well as to define time periods of higher risk for the difficult-to-diagnose MV infection as a first step in profiling high risk patients.