Microbiome, normal flora, and antimicrobial stewardship
Learning goals Explain virulence and how it relates to benign versus pathogenic microorganisms Name common bacterial species that are considered normal human flora for each of the following locations: skin, mouth, colon, and vagina, and describe how these organisms enhance host immunity Explain the impact of a distorted microbiome, related to antibiotic exposure or hospitalization, […]
Key zoonoses
Naturally transmitted from animals to humans. Arthropod-borne bacteria and parasites Ticks Rickettsia (e.g. RMSF/R. rickettsii), African Tick-borne Fever/Rickettsia, Lyme Disease/Borrelia burgdorferi, Relapsing Fever/Borrelia, Babesia, Anaplasma, Ehrlichia Mites/Chiggers Scrub typhus/Orientia tsutsugamushi, Scabies, Hair follicle mite/Demodex Mosquitos Malaria/Plasmodium, lymphatic filariasis/e.g. Wuchereria (many ARBO viruses as above) Fleas Endemic typhus/murine typhus/Rickettsia typhi, epidemic typhus/Rickettsia prowazekii, Tunga penetrans Flies […]
Notable bacterial toxins and mechanisms
These are exemplars of the most notable toxins and their mechanisms. Organisms such as Clostridia perfringens, Staphyloccoccus aureus, and Pseudomonas have a variety of toxins, some of which use similar mechanisms. Anthrax A/B toxin with three-protein components. Cell binding component is called protective antigen. There are two enzyme components: Edema factor Acts as adenylate cyclase […]
Infections based on predominant disease location (tropism)
Healthy Organisms associated with a healthy microbiome Bacteroides (GI tract) Lactobacillus (Vagina) Staphylococcus epidermidis (Skin) Head Central Nervous System (CNS) Meningitis: Differentiate by age (newborn, adult, elderly) and by “septic” (culture +) vs “aseptic” (culture negative – usually virus, prior antibiotics, or drug-induced). Bacteria: Neonate: E. coli, Group B Strep, Listeria Infant: Neisseria meningitidis, Strep […]
Outline of parasitic diseases and organisms according to site/specimen
Blood Plasmodium, Babesia, Trypanosoma, Microfilaria (Leishmania and Toxoplasma can be blood-bourne, but are not usually seen on the peripheral blood smear.). CSF Trypanosoma brucei, Naegleria, Angiostrongylus (eosinophilic meningitis). Brain Neurocysticercosis (Tinea solium), Toxoplasma. Eye Acanthamoeba, Toxoplasmosis, Onchocerciasis, Loa loa, visceral larva migrans (Toxocariasis). Mouth/Throat Ascaris. Sputum/Lung Ascaris, Strongyloides, Pneumocystis, Paragonimus. Abdomen/Ascites Echinococcal cysts, Entamoeba histolytica […]
Pharmacology: Introduction to antimicrobial therapy
Learning goals Describe the five basic mechanisms of action of antimicrobials against bacterial cells (inhibition of cell wall synthesis, inhibition of protein synthesis, alteration of cell membranes, inhibition of nucleic acid synthesis, and antimetabolite activity) Define empiric versus directed antimicrobial therapy and describe the basic principles behind selecting an empiric antimicrobial regimen Discuss the pharmacokinetic […]
Principles of laboratory diagnosis
Learning goals Describe considerations used to select microbiologic diagnostic tests Compare and contrast direct examination, culture, serologic, and molecular laboratory methods for identifying microorganisms in terms of the benefits and limitations of each Compare and contrast laboratory methods used to identify and characterize bacteria versus viruses Study materials These materials are not required; they are […]
Current Events
All Mental Health Vector Borne Disease Heat Impact Extreme Weather Water/Food Borne Illness Degraded Air Quality The Impact of Hurricane Katrina on the Mental and Physical Health of Low-Income Parents in New Orleans 9/11/2025 “Long-term health and mental health services are needed for low-income disaster survivors, especially those who experience disaster-related stressors and loss.” The […]
Ectoparasites
Scabies/Sarcoptes Human-to-human spread. Clinical: intensely itchy papular rash (hands, wrists, elbows, webbing between fingers, penis, scrotum), or occasionally diffuse non-pruritic rash in immune suppressed patients (crusted scabies). Secondary bacterial infection is common. Dx: Skin scraping or adhesive tape (look for mites, eggs or feces). Rx: Lindane, etc. Lice/Pediculosis Three types: Head louse Body louse Pubic […]
Trematodes
check yourself Fill in these summary tables to check your learning. Flukes Non-segmented flat worms. Schistosomiasis (Blood fluke) A very common parasitic disease with significant morbidity and mortality. Human reservoir (or animal reservoir for some species) with snails in life cycle. Infection occurs when humans are in water and schistosomal cercariae (from snails) penetrate human […]