The effect of in vivo growth on the cellular and extracellular components of the marine bacterial pathogen Photobacterium damsela subsp. piscicida.

Photobacterium damsela subsp. piscicida, the causative agent of fish pasteurellosis, was grown in vivo. Bacterial cells and extracellular products (ECPs) were analysed via electrophoresis and immunoblot analysis, using specific sea bass antisera. Growth in vivo induced the synthesis of unique bacterial cell proteins at > 206, 206, 21.3, 18, 7.6 and < 7.6 kDa. Sea bass serum raised against live bacterial cells of the pathogen and especially a sea bass serum raised against formalin-inactivated bacterial cells grown in a specific novel medium recognized the novel antigens at > 206 (associated with iron sequestration), 21.3, 7.6 and < 7.6 kDa, suggesting that the latter medium conserves the synthesis of natural bacterial cell proteins in vitro. In vivo growth of the pathogen induced the synthesis of more toxic ECPs in comparison with in vitro growth and an inverse correlation between total protein concentration in the ECPs and toxicity per unit of protein was observed. Substrate-polyacrylamide electrophoresis revealed the presence of in vivo synthesized ECPs of the pathogen (proteases) at 175, 132, < 79 and 48.3 kDa. Histological examination of tissues isolated from fish injected with these ECPs revealed inflammatory and necrotic lesions in the spleen, liver, head kidney, intestine and heart as soon as 48 h post-introduction of the ECPs.

Managing the cost of care: a predictive study to identify critical care patients at risk for nosocomial pneumonia.

Nosocomial infections represent a major health problem and can have a significant impact on the cost of treating a patient. Hospital-acquired pneumonia (HAP) is the second most common nosocomial infection in the United States and the leading cause of death due to a nosocomial infection. The high prevalence of HAP and its significant impact on increased length of stay and incremental treatment costs identify nosocomial pneumonia (NP) as a key component in managing the total cost of care. The study's objective was to develop a predictive tool for identifying those adult patients in critical care (CC) who are at greatest risk of developing NP to better manage the costs of care. The authors also expected to determine the expected probability of a patient developing NP in CC. A prospective study of longer stay critical care unit (CCU) patients was performed in nine U.S. CCUs. There were no interventions in the study. Development was based on variables common to CC and specific patient profile risk factors. Twelve statistically significant and clinically meaningful risk factors were identified and placed in a sequential cascade fashion. The positive predictive value of the sequential decision process and corresponding tool was 87.03 percent.