Bacterial Infection PDF

Infection & Immune Dysfunction N111 Pathopharmacology Samuel Merritt University Infection  Definitions Pathogenicity Microorganism’s ability to infect and cause disease in the host Microbial Ability of a microorganis...

Infection & Immune Dysfunction N111 Pathopharmacology Samuel Merritt University Infection  Definitions Pathogenicity Microorganism’s ability to infect and cause disease in the host Microbial Ability of a microorganism to latch onto and gain Adherence entrance into its host Invasion Mechanism by which the microorganism invades/enters the host Communicability Ability to spread the disease from one individual to another Virulence Microorganism’s ability to cause severe disease or harm to the host  More Definitions Immunogenicity Ability of pathogens to induce an immune response Infectivity Ability of pathogen to invade and multiply in the host Bacteremia (presence) or septicemia (growth) in blood  Infection Portal of entry Route by which a pathogenic microorganism infects the host Direct contact Inhalation Ingestion Bites of an animal or insect  Risk Factors Environmental Host Sanitation Malnutrition Air quality Age Living conditions Chronic illness Climate Stress Immunosuppression Recent antibiotic use Bacterial Infection  Etiology: Bacteria Inhibit phagocytosis Oxygen requirement Produce toxins Aerobic Single celled Anaerobic Cocci Gram stain reaction Bacilli Gram + Vibrio Gram – Spirilla Acid-fast Bacterial Infection mediators Toxins Exotoxins Endotoxins Enzymes Endospores Anti-phagocytic factors Mobile appendages Antimicrobial resistance Bacterial Infection Pathogenesis Penetrate Multiply & Inflammatory initial defenses create colony response Overwhelm Stimulate Move in body lymph nodes, immune via fluid blood system response Bacteremia, SIRS, & Sepsis  Pathogenesis & Clinical Manifestations Streptococcus Streptococcus Staphylococcus pneumoniae pyogenes aureus  Pathogenesis & Clinical Manifestations Gram negative Haemophilus bacilli influenzae Clostridium dificile Salmonella Shigella  Treatment Implications Antibiotics Complications Antimicrobial resistance Destruction of vaginal and GI flora Side effect profile sometimes include anaphylactic shock Stimulate immune response: Vaccines  Antimicrobial Resistance Causes: Sub-therapeutic dosing Excessive antibiotic use Resistance mechanisms Enzymes that inactivate antibiotic Created target that is no longer susceptible to antibiotic Prevent entry into cell Actively pump antibiotic out of cell  Antimicrobial resistance pathogenesis Chance Proliferation Survive Examples: mutation in of mutated antibiotic VRE & the bacteria bacteria exposure MRSA