THE EFFECTS OF ALCOHOL ON MRSA PNEUMONIA
Document Type
Presentation
Start Date
22-10-2010 10:45 AM
End Date
22-10-2010 12:00 PM
Description
Despite great advances in antibiotics, lower respiratory infections continue to be the third leading cause of death worldwide. Bacterial pneumonia is a significant component to this problem causing much morbidity and mortality. Excessive alcohol consumption leads to increased susceptibility to pulmonary infections, partly due to compromised host immune defenses. With the advent of methicillin resistant Staphylococcus aureus (MRSA), outbreaks of communityassociated MRSA (CA-MRSA) leading to necrotizing pneumonia have emerged in healthy individuals and are associated with high mortality rates. In the United States, CA-MRSA USA300 is the predominant strain that cause necrotizing pneumonia which can lead to bronchiectasis and destruction of lung function. We used a mouse model of USA300 pneumonia to determine the effects of alcohol on immune responses to this pathogen.
With acute alcohol, there was a significant increase in pulmonary USA300 burden. Mice were given 4.0 g/kg of EtOH (20% v/v) intraperitoneally and challenged with 1x1 OAS CFU of USA300 one hour later. Bacterial burden was measured at 20 hours after infection. Despite increased levels of pro-inflammatory cytokines, IL-1 ~. IL-6, and TNFa alcohol mice were more susceptible to SA. Acute alcohol also increases the levels of interleukin (IL)-17 and IL-22 during USA300 pneumonia. Th17 cytokines, IL-17 and IL-22, are important in neutrophil development and recruitment in host defense against some pulmonary pathogens. Moreover we see the importance of these cytokines in host defense against SA, especially with respect to MRSA. Conversely mRNA levels of Regenerating islet-derived protein 3 gamma (Reg3g) was decreased with alcohol. Reg3 is a recently described family of C-type lectins shown to have antimicrobial activity. Furthermore, we see that recombinant Reg3g protein is able to kill USA300 by in vitro killing assay. With further mechanistic studies, Reg3g can potentially be developed to supplement antibiotics in the treatment strategy of alcoholic MRSA pneumonia.
Recommended Citation
Choi, Sun Mi; McAleer, Jeremy; Chen, Kong; and Zheng, Mingquan, "THE EFFECTS OF ALCOHOL ON MRSA PNEUMONIA" (2010). Dr. Joseph M. Moerschbaecher, III Graduate Research Day. 8.
https://digitalscholar.lsuhsc.edu/grad_rs/2010/poster1/8
THE EFFECTS OF ALCOHOL ON MRSA PNEUMONIA
Despite great advances in antibiotics, lower respiratory infections continue to be the third leading cause of death worldwide. Bacterial pneumonia is a significant component to this problem causing much morbidity and mortality. Excessive alcohol consumption leads to increased susceptibility to pulmonary infections, partly due to compromised host immune defenses. With the advent of methicillin resistant Staphylococcus aureus (MRSA), outbreaks of communityassociated MRSA (CA-MRSA) leading to necrotizing pneumonia have emerged in healthy individuals and are associated with high mortality rates. In the United States, CA-MRSA USA300 is the predominant strain that cause necrotizing pneumonia which can lead to bronchiectasis and destruction of lung function. We used a mouse model of USA300 pneumonia to determine the effects of alcohol on immune responses to this pathogen.
With acute alcohol, there was a significant increase in pulmonary USA300 burden. Mice were given 4.0 g/kg of EtOH (20% v/v) intraperitoneally and challenged with 1x1 OAS CFU of USA300 one hour later. Bacterial burden was measured at 20 hours after infection. Despite increased levels of pro-inflammatory cytokines, IL-1 ~. IL-6, and TNFa alcohol mice were more susceptible to SA. Acute alcohol also increases the levels of interleukin (IL)-17 and IL-22 during USA300 pneumonia. Th17 cytokines, IL-17 and IL-22, are important in neutrophil development and recruitment in host defense against some pulmonary pathogens. Moreover we see the importance of these cytokines in host defense against SA, especially with respect to MRSA. Conversely mRNA levels of Regenerating islet-derived protein 3 gamma (Reg3g) was decreased with alcohol. Reg3 is a recently described family of C-type lectins shown to have antimicrobial activity. Furthermore, we see that recombinant Reg3g protein is able to kill USA300 by in vitro killing assay. With further mechanistic studies, Reg3g can potentially be developed to supplement antibiotics in the treatment strategy of alcoholic MRSA pneumonia.