Neutrophil percentages in bronchoalveolar lavage fluid: Implications for diagnosing bacterial pneumonia in patients with immunocompromise and neutropenia.

Rationale: Pneumonia is the most common infection in ICU patients and a leading cause for death. Assessment of bronchoalveolar lavage fluid (BALF) cellularity can aid in pneumonia diagnosis. Low percentages (<50%) of BALF neutrophils have a high negative predictive value for bacterial pneumonia in a general medical ICU population.

Staphylococcus aureus Preferentially Liberates Inorganic Phosphate from Organophosphates in Environments where This Nutrient Is Limiting.

Phosphate is an essential nutrient that and other pathogens must acquire from the host during infection. While inorganic monophosphate (P) is the preferred source of this nutrient, bacteria can also obtain it from phosphate-containing organic molecules. The P-responsive regulator PhoPR is necessary for to cause infection, suggesting that P is not freely available during infection and that this nutrient must be obtained from other sources.