Drug Resistance; Pneumonia; Respiratory Tract Infections; Infection Control; Pulmonary Disease, Chronic Obstructive
Status of Women in Medicine Committee (SWIM)
Professor Pettigrew's research focuses on pathobionts of the respiratory tract (e.g., Streptococcus pneumoniae and Haemophilus influenzae) and the growing public health threat of antibiotic resistance. Her current work utilizes a combined approach involving microbiology and infectious disease epidemiology to identify factors that influence whether pathobionts asymptomatically colonize or cause diseases such as pneumonia and exacerbations of chronic obstructive pulmonary disease (COPD). Additional projects focus on how disruptions of homeostasis in the respiratory and gastrointestinal microbiota influence colonization resistance, development of antibiotic resistance, and risk of hospital-acquired infections.
Extensive Research Description
My research focuses on Streptococcus pneumoniae and non-typeable Haemophilus influenzae. The bacteria that I study asymptomatically colonize the respiratory tract of 10-50% of healthy individuals. While asymptomatic colonization is far more common than disease, S. pneumoniae and H. influenzae are important causes of bacterial infections in children and adults (e.g., otitis media, pneumonia, and exacerbations of chronic obstructive pulmonary disease (COPD)). Moreover, these infections are frequently, and controversially, treated with antibiotics. We use state-of-the-art methods that integrate clinical epidemiologic, and laboratory studies to elucidate factors that tip the balance between asymptomatic bacterial colonization and disease.
Additional projects focus on how disruptions of homeostasis in the respiratory and gastrointestinal microbiota influence colonization resistance, development of antibiotic resistance, and risk of hospital-acquired infections. We use data and specimens from clinical epidemiologic studies and next-generation sequencing methods to address several key questions including: 1) How does the duration of antibiotic use impact the prevalence of antibiotic resistance genes in the respiratory and gastrointestinal microbiota? 2) How do antibiotic induced changes in the composition and diversity of the gastrointestinal microbiota contribute to antibiotic-associated diarrhea? and 3) How does the diversity and composition of the microbiota relate to risk of colonization, expansion, and infection due to antibiotic-resistant pathogens? Over the long-term, our research will help identify new methods to exploit protective mechanisms provided by an intact microbiota and lead to new interventions to prevent development of antibiotic resistance and hospital-acquired infections.
Haemophilus influenzae genome evolution during persistence in the human airways in chronic obstructive pulmonary disease
Pettigrew MM, Ahearn CP Gent JF, Kong Y, Gallo MC, Munro JB, D'Mello A, Sethi S, Tettelin H, Murphy TF. Proc Natl Acad Sci U S A. 2018;115(14):E3256-E3265.
Effect of fluoroquinolones and macrolides on eradication of Haemophilus influenzae and development of antibiotic resistance in chronic obstructive. pulmonary disease
Pettigrew, M.M., Tsuji, B, Gent, J. F., Jones, M. M., Sethi, S., Kong, Y., and Murphy, T.M. Antimicrobial Agents and Chemotherapy. 2016; 60:4151-8.
The human microbiota: novel targets for hospital acquired infections and antibiotic resistance.
Pettigrew, M.M., Johnson, J.K. and Harris, A.D. Annals of Epidemiology. 2016; 26:342-7.
Innovating in health care management education: Development of an accelerated MBA/MPH degree program at Yale.
Pettigrew, M.M., Forman, H.P., Pistell, A.F., and Nembhard, I.M. American Journal of Public Health. 2015; 105:S68-S72.
Changes in the pneumococcal transcriptome during transition from biofilm formation to invasive disease upon influenza A virus infection.
Pettigrew, M.M., Marks, L.R., Kong, Y., Gent, J. F. and Hakansson. Infection and Immunity. A.P. 2014; 82:4607-19.
Upper respiratory tract microbial communities, acute otitis media pathogens and antibiotic use in healthy and sick children.
Pettigrew, M.M., Laufer, A.S., Gent, J.F., Fennie, K.P., Kong, Y. and Metlay, J.P. Applied and Environmental Microbiology. 2012; 78:6262-70.