Fatal Fulminant Pneumonia Caused by Methicillin-Sensitive Staphylococcus aureus Negative for Major High-Virulence Factors Following Influenza B Virus Infection

Abstract

Patient: Male, 32Final Diagnosis: MSSA pneumoniaSymptoms: Cough • dyspnea • feverMedication: Meropenem • levofloxacin • vancomycin • peramivirClinical Procedure: Diagnosed based on CT images • sputum culture • PCRSpecialty: Infectious DiseasesObjective:Rare diseaseBackground:Increasing evidence has indicated that Staphylococcus aureus pneumonia complicated with influenza virus infection is often fatal. In these cases, disease severity is typically determined by susceptibility to antimicrobial agents and the presence of high-virulence factors that are produced by Staphylococcus aureus, such as Panton-Valentine leukocidin (PVL).Case Report:We describe a rare case of fatal community-acquired pneumonia caused by methicillin-sensitive Staphylococcus aureus (MSSA), which did not secrete major high-virulence factors and coexisted with influenza type B infection. The 32-year-old previously healthy male patient presented with dyspnea, high fever, and cough. His roommate had been diagnosed with influenza B virus infection 3 days earlier. Gram-positive clusters of cocci were detected in the patient’s sputum; therefore, he was diagnosed with severe pneumonia and septic shock, and was admitted to the intensive care unit. Despite intensive antibiotic and antiviral treatment, he died of multiple organ failure 5 days after admission. His blood culture from the admission was positive for MSSA, and further analysis revealed that the strain was negative for major high-virulence factors, including PVL and enterotoxins, although influenza B virus RNA was detected by PCR.Conclusions:Physicians should pay special attention to patients with pneumonia following influenza and Staphylococcus aureus infection, as it may be fatal, even if the Staphylococcus aureus strain is PVL-negative and sensitive to antimicrobial agents.

Two Cases of Influenza B Virus-Related Fatal Fulminant Pneumonia Complicated With Staphylococcus aureus Infection in China Diagnosed Using Next-Generation Sequencing (2018)

“…Co-infection with the influenza B virus and bacterial pneumonia has been reported worldwide (3,4). But to our knowledge, this is the first report of fatal fulminant pneumonia and septicemia in China in which co-incident infection with both influenza B and PVL-positive MSSA was laboratory confirmed.…”

“…But to our knowledge, this is the first report of fatal fulminant pneumonia and septicemia in China in which co-incident infection with both influenza B and PVL-positive MSSA was laboratory confirmed. Several reports indicated that influenza virus infection results in epithelial cell injury and facilitates the occurrence of secondary bacterial infection through multiple mechanisms of immunological injury (3,(6)(7)(8)(9). The hypothesis of immunological injury caused by the influenza virus B in the host includes decreased bacterial phagocytosis among alveolar macrophages, downregulated expression of toll-like receptors, and functional inhibition of neutrophil recruitment by type I interferon initiated by the viral infection (10).…”

“…The hypothesis of immunological injury caused by the influenza virus B in the host includes decreased bacterial phagocytosis among alveolar macrophages, downregulated expression of toll-like receptors, and functional inhibition of neutrophil recruitment by type I interferon initiated by the viral infection (10). Moreover, hyperactive immune cell (T cells)-mediated cell immunity may aggravate the acute lung injury caused by influenza B virus infection and facilitate the occurrence of the secondary bacterial invasion (3,10,11).…”

“…Moreover, NGS identified 2,037 sequence reads (8.40934%) uniquely corresponding to the S. aureus genome; the identified S. aureus was a positive carrier of the PVL genes ( Figure S6) (the virulence factors of S. aureus identified via NGS are shown in Table S2). The PVL genes were also amplified through PCR using the blood sample of this patient as previously described (3). In contrast, the commonly used bacterial culture methods were negative for the blood sample and tracheal secretion.…”

“…The influenza virus poses a health threat to human health worldwide and often predisposes individuals to person-to-person transmission (1). Co-infection with influenza virus and bacteria, most frequently Streptococcus pneumonia and Staphylococcus aureus (S. aureus), often worsen disease progression and prognosis (2)(3)(4). In recent years, co-infections with the influenza virus and S. aureus pneumonia have been increasingly reported worldwide (e.g., USA, Australia, Thailand, Hong Kong, and Taiwan) (5).…”