Cytomegalovirus reactivation enhances the virulence of Staphylococcus aureus pneumonia in a mouse model. (January 2017)

• Record Type: Journal Article
• Authors: Hraiech, S.; Bordes, J.; Mège, J.L.; de Lamballerie, X.; Charrel, R.; Bechah, Y.; Pastorino, B.; Guervilly, C.; Forel, J.M.; Adda, M.; Rolain, J.M.; Lepidi, H.; Raoult, D.; Lehingue, S.; Papazian, L.
• Is Part Of: Clinical microbiology and infection. Volume 23:Number 1(2017)
• Page Start: 38
• Page End: 45
• Publication Date: 2017-01
• Subjects: Cytomegalovirus reactivation -- Intensive care unit -- Lung abscesses -- Murine model -- Pneumonia -- Staphylococcus aureus; Medical microbiology -- Periodicals; Diagnostic microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.01
• DOI: 10.1016/j.cmi.2016.09.025
• Languages: English
• ISSNs: 1198-743X

Abstract

Abstract: Objectives: Cytomegalovirus (CMV) reactivation in intensive care unit patients may increase mortality and favour bacterial pneumonia. We developed a murine model to compare the severity of staphylococcal pneumonia after CMV reactivation and in CMV-negative mice. Methods: Balb/c mice were primo-infected with murine cytomegalovirus (MCMV n = 90) or received saline (control n = 90). After latency, all mice underwent caecal ligation and puncture to trigger MCMV reactivation in MCMV primary-infected mice. Surviving animals received an intra-nasal inoculation with methicillin-susceptible Staphylococcus aureus (MSSA) to induce pneumonia. Mortality, lung bacterial count, histology and interferon-alpha and gamma serum levels were compared in MCMV reactivated and control mice 2, 5 and 15 days after pneumonia. Results: After MSSA pneumonia, MCMV mice showed a trend towards a higher mortality (9.4% versus 0%; p 0.09) and a higher weight loss (2.2 (0.6–4.1 g) versus 0.7 (–0.3 to 1.3 g); p 0.005). The lung bacterial count was higher in MCMV mice 2 days (5 × 10 3 (10 3 to 3 × 10 5 ) versus 10 2 (0 to 4 × 10 2 ) CFU/lung; p 0.007) and 5 days (2.5 × 10 4 (1.6 × 10 4 to 6.5 × 10 5 ) versus 15 (10–40) CFU/lung; p 0.005) after MSSA pneumonia. 8/40 (20%) MCMV mice developed lung abscesses compared to 0% in control (p 0.011). Interferon-alpha serum levels 2 days after staphylococcal pneumonia were higher in MCMV mice. Conclusions: MCMV reactivation decreased lung bacterial clearance and favoured the development of staphylococcal abscessing pneumonia. CMV reactivation may be responsible for a higher susceptibility to bacterial sepsis.