Microbiology – Flashcards
Unlock all answers in this set
Unlock answersquestion
| Epidemiology |
answer
| The study of the occurance and spread of disease |
question
| Symbiosis |
answer
| to live together |
question
| Three types of symbiotic relationships |
answer
Mutualism Commensalism Parasitism |
question
| Mutualism |
answer
| Both members benifit |
question
| Commensalism |
answer
| One member benifits without significantly affecting the other member. |
question
| Staphylococcus epidermidis is an example of? |
answer
Commensalism, This bacteria may inhibit pathogenic mocrobes from colonizing on our skin. |
question
| Parasitism |
answer
| The parasite benifits from the host while harming it. |
question
| Tuberculosis is an example of? |
answer
Parasitism which lives in the human lungs |
question
| A parasite that causes a disease is called |
answer
| pathogen |
question
| Axenic |
answer
| an environment that is free of microbes |
question
| How many bacteria live in the large intestine |
answer
| 400 - 1000 bacteria |
question
| Normal microbiota |
answer
| Microbes that colonize the body without causing disease |
question
| Normal microbiota is sometimes called |
answer
| normal flora |
question
| Two types of normal microbiota |
answer
Resident microbiota Transient microbiota |
question
| Resident microbiota |
answer
| remain part of the normal microbiota of a person throught life |
question
| Most resident microbiota are ? |
answer
| commensal, they feed on excreted cellular waste and dead cells without causing harm. |
question
| Transient microbiota |
answer
| remain in the body for only a few hours, day or months before disappearing. |
question
| An example of an axenic environment |
answer
| mother's uterus |
question
| Most resident microbiota are established during |
answer
| the first months of life |
question
Describe three conditions that create opportunities for normal microbiota to cause disease |
answer
| 1. Immune suppression 2. Changes in the normal microbiota (changes in relative abundance of normal microbiota may allow opportunity for a member to thrive and cause disease) 3. Introduction of normal microbiota into sterile area of body (axenic environment) |
question
| Opportunistic pathogens |
answer
| Is when microbes may become harmful if the opportunity arises. |
question
| Immune supression |
answer
anything that supresses the body's immune system disease, malnutrition, stress |
question
| microbial antagonsim |
answer
| is microbial competition, when a new pathogen has to compete against resident pathogens |
question
| Three types of reservoirs of infection in humans? |
answer
Animal reservoirs Human carriers Nonliving reservoirs |
question
| A reservoir of infection is |
answer
| the site where pathogens are maintained as a source of infection |
question
| sylvatic animal |
answer
| wild animal |
question
| Diseases that spread naturally from thier usual animal host to humans are called |
answer
| zoonoses |
question
| Yellow fever, anthrax, bubonic plague and rabies are examples of |
answer
| zoonoses |
question
| zoonoses infect humans by |
answer
animal waste eating animals bloodsucking arthropods |
question
| Typical dead end host for zoonotic pathogen |
answer
| Humans |
question
| Example of nonliving reservoir |
answer
soil water food |
question
| Contamination |
answer
| the presense of microbes in or on the body |
question
| Infection |
answer
| A successful invasion of the body by a pathogen. An infection may or may not cause disease |
question
| Three portals of entry |
answer
Skin Mucous membranes Placenta |
question
| Parenteral |
answer
| not a true portal of entry, step on nail, bug bite |
question
| Hair follicles, sweat glands, and burrowing are examples of |
answer
| Skin portal |
question
| The main portal of entry for pathogen is? |
answer
| Muscous membrane, these line all body cavities that are open to the outside world |
question
| Conjunctiva |
answer
| thin membrane covering the surface of the eyeball |
question
| Adhesion |
answer
| The process by which microorganisms attache themselves to cells. |
question
| Adhesion factors |
answer
| specialized structures and attachment proteins |
question
| Adhesion disk in protozoa and suckers and hooks in helminths are examples of |
answer
| adhesion factors |
question
| Ligands |
answer
| adhesion factors such as surface lipoproteins and glycoprotein molecules |
question
| Ligands bind to ? |
answer
| complementary receptors on host cells |
question
| Adhesin is? |
answer
| A ligand on bacteria |
question
| Attachement protein on a virus is called |
answer
| Ligand |
question
| Adhesins are found on? |
answer
| fimbriae, flagella and glycocalyces of many pathogenic bacteria |
question
| What determines specificity of pathogens |
answer
| interaction of adhesins and receptors with chemicals on host cells |
question
| A pathogen can evade the body's immune system and attack more than one type of cell by? |
answer
| changing their adhesins, Plasmodium the cause of malaria can do this |
question
| Avirulent |
answer
| A bacteria or virus that has lost the ability to produce ligands and becomes harmless. |
question
| Disease |
answer
| Also known as mirbidity, is when a pathogen becomes so harmful it interferes with the normal function of the body. |
question
| Infection is? |
answer
| infection is the invasion by a pathogen |
question
| Symptoms |
answer
| are characteristics of a disease than can be felt by the patient only |
question
| Signs |
answer
| signs are objective manifistations of disease that can be observed. |
question
| Syndrome |
answer
| A syndrome is a group of symptoms and signs |
question
| Congenital disease |
answer
| Congenital diseases are diseases that are present at brith, regardless of cause (hereditary, environmental, or infectious) |
question
| Etiology |
answer
| The study of the cause of a disease |
question
| Germ theory of disease |
answer
| states that disease is caused by infections of pathogenic microorganisms |
question
| Koch's postulates |
answer
1. The suspected agent must be present in every case of the disease. 2. The agent must be isolated and grown in pure culture. 3. The cultured agent must cause the disease when it is inoculated into a healthy host. 4. The same agent must be reisolated from the diseased experimental host. |
question
| Pathogenicity |
answer
| the ability of a microorganism to cause disease |
question
| Virulence |
answer
| The degree of pathogenicity to cause disease |
question
| Virulence factors |
answer
| ability of the pathogen to enter a host, adhere to host cells, gain access to nutrients, and escape detection or removal by the immune system. |
question
| ectracellular enzymes, toxins, and antiphagocytic factors are? |
answer
| Virulence factors |
question
| Pathogenic extracellular enzymes |
answer
Hyaluraonidase digest hyaluronic acid the glue that holds animal cells together. Collagenase breaks down collagen the body's chief structural protein. Coagulase causes blood proteins to clot Kinase digest blood clots |
question
| Toxins |
answer
| Are chemicals that either harm tissue or trigger host immune responses that cause damage. |
question
| Two types of toxins |
answer
| exotoxins and endotoxins |
question
| Exotoxins |
answer
| exotoxins destroy host cells or interfere with host metabolism |
question
Cytotoxin- kill host cells Neurotoxins - interfere with nerve cell function Enterotoxins - affect cell lining are examples of |
answer
| Exotoxins |
question
| The body protects itself against exotoxins with |
answer
| antitoxins |
question
| Antitoxins are |
answer
| protective molecules called antibodies that bind and neutralize specific toxins |
question
| Toxoid |
answer
| are toxins that have been chemically treated to make them  non toxic. |
question
| Endotoxin is called |
answer
| Lipid A |
question
| When a gram negative bacteria divides, dies naturally, or digested by phagocytic cell it releases? |
answer
| endotoxin |
question
| Lipid A releases a chemical that causes |
answer
| fever, inflamation, diarrhea, hemorrhaging, shock, and blood coagulation |
question
| Macrophage? |
answer
| Is a phagocytic white blood cell |
question
| Capsules |
answer
| are compsed of chemicals naturally found in the body, as a result they do not tritrigger the immune system. |
question
| Some bacteria produce a chemical that prevents the fusion of lysosomes with phagocytic cells known as? |
answer
| Antiphagocytic chemicals |
question
| Leukocidins |
answer
| are chemicals that are capable of destroying phagocytic white blood cells |
question
| Five stages after infection |
answer
incubation period prodromal period illness decline convalescence |
question
| Incubation period |
answer
| time between infection and the first symptoms |
question
| Prodromal period |
answer
| short time of mild symptoms |
question
| Illness stage |
answer
| most severe stage of disease, signs and symptoms are most evident in this stage |
question
| Decline period |
answer
| the body gradually returns to normal, antibodies are peak during this stage |
question
| Convalescence stage |
answer
| pateint recovers and tissues are repaired |
question
| Earwax, tears, nasal secretions, and saliva are examples of |
answer
| Portals of exit |
question
| Transmission of disease can occur by? |
answer
contact transmission vehicle transmission vector transmission |
question
| Contact transmission |
answer
| is the spread of pathogens by direct contact, indirect contact, or respiratory droplets. |
question
| Indirect contact transmission |
answer
| is when pathogens are spread by fomites (inanimate objects) |
question
| Contact transmission includes? |
answer
Direct contact Indirect contact Droplet transmission |
question
| Droplet transmission |
answer
| Pathogen exits by exhaling, coughing, or sneezing. if the pathogen travels more than 1 meter it is respiratory tansmission |
question
| Vehicle transmission |
answer
| is by air, drinking water, food and body fluids |
question
| Airborne transmission |
answer
| is by respiratory mucous membranes more than 1 meter, sneezing, coughing, AC, sweeping |
question
| Vehicle transmissions include |
answer
Airborne Waterborne Foodborne |
question
| Vector tranmssion |
answer
| are animals that transmit disease, either biological or mechanical |
question
| Bitting anthropods are ...... vectors |
answer
| biological vectors |
question
| House flies and cockroaches are |
answer
| Mechanical vectors, pathogens passively carried |
question
| Acute disease |
answer
| A disease that develops rapidly but last a short time |
question
| Chornic disease |
answer
| A disease that develops slowy and last a long time |
question
| Latent disease |
answer
| Pathogen remains inactive for a long period |
question
| Communicable disease |
answer
| a disease that cones from another infected host |
question
| Incidence |
answer
| number of NEW cases in a population |
question
| Prevalence |
answer
| total number of cases |
question
| Endemic |
answer
| a stable incidence in a given population |
question
| Sporadic |
answer
| a few scattered cases |
question
| Epidemic |
answer
| A disease occurs more than usual |
question
| Pandemic |
answer
| An epidemic disease on more than one continent |
question
| Descriptive epidemiology |
answer
| careful tabulation of disease |
question
| Analytical epidemiology |
answer
| investigates a disease in detail, probable cause, and mode of transmission |
question
| Experimental epidemiology |
answer
| testing a hypothesis concerning disease |
question
| Noscomial infections |
answer
| Are aquired by patients while in health care facility |
question
| Exogenous |
answer
| a pathogen aquired from a health care facility |
question
| Endogenous |
answer
| noscomial infection caused by normal microbiota |
question
| Iatrogenic infection |
answer
| a noscomial infection caused by a medical procedure |
question
| Factors influencing noscomial infections |
answer
1. pathogens present in health care facility 2. weakened immune system 3. transmission of pathogens from other patients |
