The influence of adipocytes’ secretome and immune response on bacterial growth

• Autor(a) principal: Aveiro, Alexandra Gouveia
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/36407
• topic: Obesity; Chronic inflammation; Antimicrobial resistance; Secretome; Macrophages

Obesity is characterized by excessive fat in adipose tissue and continues to be described as a public health problem. In addition, it is associated with the development and worsening of comorbidities such as type II diabetes, cardiovascular diseases, hypertension and metabolic syndrome. Another public health problem focuses on antimicrobial resistance (AMR). Over time, they have been gaining alarming proportions worldwide, due to the ability to acquire new mechanisms of resistance threatening the treatment of infections acquired in the community and in hospitals, resulting in a prolonged illness, disability, and death. The state of obesity entails an imbalance in the production of proinflammatory and anti-inflammatory factors that contributes to infections’ susceptibility. This susceptibility translates into respiratory and skin barrier impairment, obesity-related comorbidities, slower healing and inefficient antimicrobial therapy. Bacteria’s alarming ability to gain resistance has raised concerning obstacles in antimicrobial therapies in patients with chronic inflammation, such as obese individuals. This study aimed to understand the influence of an inflammatory obesity-mimicking environment in the growth of Staphylococcus aureus, Mycobacterium smegmatis, Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa strains with different antibiotic resistance. For this, the cell lines Raw 264.7 (macrophages) and 3T3-L1 (adipocytes) were collected to serve as a conditioned medium for bacterial growth. All strains were exposed to a variety of conditioned media (DMEM, DMEM enriched with 10% and 50% adipocyte secretome (SA), macrophage secretome (SM) and macrophage secretome enriched with 10% and 50% SA). Results showed Methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae Carbapenem/ESBL are of greater risk factor in a SM environment. On the other hand, S.aureus, M. smegmatis, wild-type K.pneumoniae, K.pneumoniae ESBL, K.pneumoniae Carbapenem, E. coli and P. aeruginosa only seems to depend more on SA environment. Additionally, bacterial strains with AmpC resistance showed high risk to bacterial growth in environment enriched with SA. Overall, this study demonstrates that the kind of resistance and the environment in which each bacteria strain is present can contribute to the state of chronic inflammation.