Severe Necrotizing Tracheobronchitis From Panton-Valentine Leukocidin-positive MRSA Pneumonia Complicating Influenza A-H1N1-09.

In the human lower respiratory tract, influenza A (INFA) can activate an inflammatory response that interferes with the innate immune response to bacterial pathogens, increasing the probability of subsequent infection by opportunistic organisms such as methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA).1,2 Some hypervirulent strains of communityacquired and hospital-acquired MSSA and MRSA can express Panton-Valentine Leukocidin (PVL), which is a 2-component pore-forming cytotoxin that primarily destroys neutrophils in both healthy and immunocompromised patients.3 As a result of white blood cell destruction by PVL-positive MSSA/MRSA pathogens