Boris Zavizion

Inactivation of protozoan parasites in red blood cells using INACTINE PEN110 chemistry.

BACKGROUND: The transmission of parasites, including Babesia, plasmodia, and Trypanosoma cruzi, via transfusions is an important public health concern. INACTINE technology is a pathogen‐reduction process that utilizes PEN110, an electrophilic agent that inac‐tivates a wide range of pathogens by disrupting nucleic acid replication. The present study investigated the effect of PEN110 treatment on the viability of protozoa in RBCs.

Prevention of Yersinia enterocolitica, Pseudomonas fluorescens, and Pseudomonas putida outgrowth in deliberately inoculated blood by a novel pathogen‐reduction process

BACKGROUND : Yersinia enterocolitica, Pseudomonas fluorescens, and P. putida are responsible for a significant amount of the bacterial sepsis cases attributed to RBC transfusions. INACTINE is a pathogen‐reduction process for RBCs, which consists of incubation of RBCs with PEN110 (proprietary compound) followed by automated washing of the RBCs. INACTINE is an electrophilic agent, which inactivates a wide range of viruses and WBCs by disruption of nucleic acid replication. The present study investigated the effect of the PEN110 process on Y. enterocolitica, P. fluorescens, and P. putida.

Inactivation of mycoplasma species in blood by INACTINE PEN110 process

BACKGROUND: Mycoplasmas have been associated with multiple acute and chronic diseases. Mycoplasma genome is found in the blood of 10 to 15 percent of subjectively healthy individuals. If blood borne and viable in donated blood, mycoplasmas could potentially be transfusion transmissible. The INACTINE PEN110 technology is a pathogen reduction process that is in Phase 3 clinical studies. The present study investigated the ability of this process to eradicate mycoplasmas in human blood.

Direct detection of the bacterial stress response in intact samples of platelets by differential impedance

BACKGROUND: We have previously described a new rapid approach that relies on monitoring intentionally stressed bacteria in contaminated platelet concentrates (PCs). This earlier work included human cell lysis with Triton X‐100 and filtration as steps in the sample preparation. This study was undertaken to develop an improved and time‐saving protocol that enables direct bacterial detection in PCs without lysis and filtration.

Monitoring the physiologic stress response: a novel biophysical approach for the rapid detection of bacteria in platelet concentrate

BACKGROUND: Currently approved culture‐based methods for the bacterial testing of platelet concentrates (PCs) require an extended period of time to obtain results. A new approach based on the monitoring of the bacterial response to physiologic stress is presented. Because the stress response is independent of the growth rate, decisive results can be obtained in near real time.

Rapid microbiological testing: monitoring the development of bacterial stress.

The ability to respond to adverse environments effectively along with the ability to reproduce are sine qua non conditions for all sustainable cellular forms of life. Given the availability of an appropriate sensing modality, the ubiquity and immediacy of the stress response could form the basis for a new approach for rapid biological testing. We have found that measuring the dielectric permittivity of a cellular suspension, an easily measurable electronic property, is an effective way to monitor the response of bacterial cells to adverse conditions continuously. The dielectric permittivity of susceptible and resistant strains of Escherichia coli and Staphylococcus aureus, treated with gentamicin and vancomycin, were measured directly using differential impedance sensing methods and expressed as the Normalized Impedance Response (NIR). These same strains were also heat-shocked and chemically stressed with Triton X-100 or H2O2. The NIR profiles obtained for antibiotic-treated susceptible organisms showed a strong and continuous decrease in value. In addition, the intensity of the NIR value decrease for susceptible cells varied in proportion to the amount of antibiotic added. Qualitatively similar profiles were found for the chemically treated and heat-shocked bacteria. In contrast, antibiotic-resistant cells showed no change in the NIR values in the presence of the drug to which it is resistant. The data presented here show that changes in the dielectric permittivity of a cell suspension are directly correlated with the development of a stress response as well as bacterial recovery from stressful conditions. The availability of a practical sensing modality capable of monitoring changes in the dielectric properties of stressed cells could have wide applications in areas ranging from the detection of bacterial infections in clinical specimens to antibiotic susceptibility testing and drug discovery.

New Approach for Drug Susceptibility Testing: Monitoring the Stress Response of Mycobacteria

ABSTRACT Methods currently used for in vitro drug susceptibility testing are based on the assessment of bacterial growth-related processes. This reliance on cellular reproduction leads to prolonged incubation times, particularly for slowly growing organisms such as mycobacteria. A new rapid phenotypic method for the drug susceptibility testing of mycobacteria is described. The method is based on the detection of the physiological stress developed by susceptible mycobacterial cells in the presence of an antimicrobial compound. The induced stress was quantified by differential monitoring of the dielectric properties of the bacterial suspension, an easily measurable electronic property. The data presented here characterize the stress developed by Mycobacterium tuberculosis cells treated with rifampin (rifampicin), isoniazid, ethambutol, and pyrazinamide. Changes in the dielectric-based profiles of the drug-treated bacteria revealed the respective susceptibilities in near real time, and the susceptibilities were well correlated with conventional susceptibility test data.