Medical Videos ppt and Lecture Notes: Microbiology

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03 May 2009

Microbiology

Microbiology

* The study of organisms too small to be seen without magnification
* Microorganisms include:

o viruses
o protozoa
o helminths (worms)

Branches of Study Within Microbiology

* Public health microbiology and epidemiology
* Food, dairy and aquatic microbiology
* Genetic engineering and recombinant DNA technology

Microbes are Involved in
* Nutrient production and energy flow
* Biotechnology
o production of foods, drugs and vaccines
* Bioremediation

Infectious Diseases
* Nearly 2,000 different microbes cause diseases.
* 10 Billion new infections/year worldwide
* 13 Million deaths from infections/year worldwide

Characteristics of Microbes

* Procaryotes and eukaryotes
o procaryote – microscopic, unicellular organisms, lack nuclei and membrane-bound organelles
o eucaryote – unicellular (microscopic) and multicellular, nucleus and membrane-bound organelles
* Viruses
o acellular, parasitic particles composed of a nucleic acid and protein

Basic cell and virus structures
Microbial Dimensions

* Procaryotes are measured in micrometers.
* Viruses in nanometers
* Helminths are measured in millimeters.

Historical Foundations of Microbiology
* 300 years of contributions by many
* Prominent discoveries include:
o microscopy
o scientific method
o development of medical microbiology
o microbiology techniques

Antonie van Leeuwenhoek

* Dutch linen merchant
* First to observe living microbes
* Single-lens magnified up to 300X

Spontaneous Generation
Early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc)
Scientific Method
* A general approach to explain a natural phenomenon
* Form a hypothesis - a tentative explanation that can be supported or refuted by observation and experimentation
* A lengthy process of experimentation, analysis and testing either supports or refutes the hypothesis.
* Results must be published and repeated by other investigators.
* If hypothesis is supported by a growing body of evidence and survives rigorous scrutiny, it moves to the next level of confidence - it becomes a theory.
* If evidence of a theory is so compelling that the next level of confidence is reached - it becomes a Law or principle.

Discovery of Spores and Sterilization

* John Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes.
o Cohn determined these forms to be
* requires the elimination of all life forms including endospores and

Development of Aseptic Techniques

* Dr. Oliver Wendell – observed that mothers of home births had fewer infections than those who gave birth in hospital
* Dr. Ignaz – correlated infections with physicians coming directly from autopsy room to maternity ward
* Joseph – introduced aseptic techniques reducing microbes in medical settings to prevent infections
o involved disinfection of hands using chemicals prior to surgery
o use of heat for sterilization

Pathogens and Germ Theory of Disease

* Many diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc.
* Two major contributors:

Louis Pasteur
* Showed microbes caused fermentation and spoilage
* Disproved spontaneous generation of microorganisms
* Developed pasteurization
* Demonstrated what is now known as Germ Theory of Disease
* Developed a rabies vaccine

Robert Koch

* Established Koch’s postulates - a sequence of experimental steps that verified the germ theory
* Identified cause of anthrax, TB, and cholera
* Developed pure culture methods

Taxonomy: Organizing, Classifying and Naming Living Things
* Formal system originated by Carl von Linné (1701-1778)

* Concerned with:
o classification – orderly arrangement of organisms into groups
o nomenclature – assigning names
o identification – discovering and recording traits of organisms for placement into taxonomic schemes

Levels of Classification
* Domain - Archaea, Bacteria & Eukarya
* Kingdom - 5
* Phylum or Division
* Class
* Order
* Family
* Genus
* species

Naming Micoorganisms

* Binomial (scientific) nomenclature
* Gives each microbe 2 names:
o Genus - noun, always capitalized
o species - adjective, lowercase
* Both italicized or underlined
o Staphylococcus aureus (S. aureus)
o Bacillus subtilis (B. subtilis)
o Escherichia coli (E. coli)

Evolution - living things change gradually over millions of years

* Changes favoring survival are retained and less beneficial changes are lost.
* All new species originate from preexisting species.
* Closely related organism have similar features because they evolved from common ancestral forms.
* Evolution usually progresses toward greater complexity.

* Bacteria - true bacteria, peptidoglycan
* Archaea - odd bacteria that live in extreme environments, high salt, heat, etc.
* Eukarya- have a nucleus and organelles

Woese-Fox System
Microbiology.ppt

Aseptic techniques for bacteria culture

Aseptic techniques for bacteria culture

Aseptic techniques and media used for bacteria culture

Using sterile techniques

* Bacteria are everywhere
* Media used for bacteria growth - welcoming for many bacteria
* We only want specific ones to grow
* Sterile remain sterile as long as doesn’t touch anything that isn’t sterile
* Also avoid prolonged exposure to air

Sterile techniques: what can you do in the lab?
* Wash your hands
* Keep your bench clean
* Wear gloves
* Flame loop, neck of tube
* Keep cap facing down
* Work quickly albeit efficiently
* Limit talking when opening cultures

Autoclaving

* Apparatus used to sterilize liquid and instrument
* Heating up to 121oC at 15 psi for 15 minutes
* Kill most microbe
* Autoclave tape - chemical reaction - black stripes if autoclaving ok

Culture media
Bacteria colonies
Composition of media

* NA = Nutrient Agar
o peptone, beef extract, salt, agar 1.5%
* TSA = Tryptic soy agar
o Peptone from casein, peptone from soymeal, sodium chloride, agar 1.5%
* Many other medias available. These 2 will be used very often in this lab
* Note: Peptone: enzymatic digest protein

Few notes on agar

* Not degraded by most bacteria
* Is liquified at 100oC and remain liquid until about 40oC
* If added to growth medium - medium becomes solid
* Semi solid media: 0.5% agar
* Broth: no agar
* Solid media: 1.5-3% agar

How to prepare a Petri plate

* Take liquid agar (in the water bath)
* Pour aseptically into the base of the Petri plate (top is larger than the base)
* Wait until solidify (15 minutes) - invert
* ***Plates are kept inverted so condensation does not drip onto the agar

Pouring a plate
Objective : Cultivate bacteria sample from the environment
How to inoculate a plate
Colonial morphology
Description
How to open a tube
How to inoculate a deep
Bacteria motility
Oxygen requirement
Deep observation
How to inoculate a slant
Slant observation
How to inoculate a broth
Broth observation
Uses
Synthesis

* Cultivate a bacterial sample from the environment. Incubate 27o C
* Inoculate the pure culture provided
o Into a broth
o Into a slant
o Into a deep
o Into a Petri plate
o *** Using aseptic techniques ***Put all the above in the 37oC incubator
* Describe colonial morphology from a Petri plate and a slant
* Identify growth pattern in broth and deep

Aseptic techniques for bacteria culture.ppt

02 May 2009

Microbiology and Infectious Diseases video

Microbiology and Infectious Diseases video presentations
from University of Wisconsin

Date		Presentation
03/06/2008		Rhinoviruses, the Old, the New and the UW J. Gern
04/17/2007		Bird Flu: A Virus of Our Own Hatching M. Greger View description Michael Greger, MD, Director of Public Health and Agriculture for the Humane Society of the US, speaks at the Health Sciences Learning Center on his national tour to discuss the theory that modern agricultural practices have played an influential role in the evolution of the H5N1 influenza strain. His theories are controversial because of his outspoken bias against industrialized agriculture and his employment by the nation's largest animal welfare agency; at the same time they are intriguing and well presented in his book on the topic. In addition he has been praised as an excellent and entertaining speaker.
02/08/2006		Tropical Disease: What you will see in Developing Countries R. Anstett View description

Safety in the Microbiology Lab

Safety in the Microbiology Lab

An Introduction to Principles and Practices at Biosafety Levels 1, 2 & 3

Pre-Test

Some Category A agents pose limited to moderate risk to the laboratory worker (BSL-2) while others (BSL-3) pose a greater risk.

o What does this tell you about the:
1. ease or difficulty for bioterrorists to produce BSL-2 and BSL-3 agents?
2. ease or difficulty to control BSL-2 and BSL-3 agents if used for bioterrorism?
* Why is Anthrax (a BSL-2) agent considered a very likely biothreat agent?
* What microbiology clues would implicate tularemia as a bioterror event?
* How do microbiologists protect themselves form accidental exposure to pathogenic microorganisms?

Learning Objectives

* By the end of the lesson the student will understand:
o The need for and use of biosafety designations
o Standard (or Good) Laboratory Practices
o The basic principles and practices for working in Labs designated BSL 1, BSL 2 or BSL 3
o CDC Priority Categories and the Select Agents Act
o Examples of microorganisms designated by their Biosafety Level

Microorganism Categories

* How are microorganisms categorized?
o By genetics to show how they are related
o By tissues they infect to show how they cause disease
o By pathogenicity and communicability (also known as their BioSafety Level)

Guidelines for Microorganism Use

* Besides federal law and regulations other guidelines exist for the use and control of microorganisms:
o CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL)
o WHO (World Health Organization) Biosafety Manual
o USDA (United States Department of Agriculture) protocols

Guidelines for Microorganism Use

* All the afore mentioned agencies use the same system to categorize microorganisms based on the organisms danger to the laboratory worker and other research personnel.

* The microbes are placed into 4 categories called : Biosafety Levels (BSL 1-4)

BSL Labs

* Microbiology Laboratories are set up and maintained to meet a specific containment level. The designated level conveys information about infection potential and engineering controls implemented to protect workers.

Dangerous/exotic agents which pose high risk of life-threatening disease, aerosol-transmitted lab infections; or related agents with unknown risk of transmission Indigenous or exotic agents with potential for aerosol transmission; disease may have serious or lethal consequences

Associated with human disease, hazard = percutaneous injury, ingestion, mucous membrane exposure
Not known to consistently cause disease in healthy adults
Biosafety Levels for Infectious Agents
BSL = Containment
BSL-3 practices plus: Clothing change before entering, Shower on exit, All material decontaminated on exit from facility
BSL-2 practice plus: Controlled access, Decontamination of all waste, Decontamination of lab clothing before laundering,
Baseline serum antibody analysis
BSL-1 practice plus: Limited access, Biohazard warning signs, "Sharps" precautions, Biosafety manual defining any needed waste decontamination or medical surveillance policies
Standard Microbiological Practices
Engineering Controls by Biosafety Level
CDC Categories of Diseases/Agents
Select Agents Act
Biological Agent
Toxin
What are the Select Agents?

* Abrin
* Bacillus anthracis
* Cercopithecine herpesvirus 1 (Herpes B virus)
* Coccidioides posadasii
* Conotoxins
* Crimean-Congo haemorrhagic fever virus
* Diacetoxyscirpenol
* Ebola viruses
* Lassa fever virus
* Marburg virus
* Monkeypox virus
* Ricin
* Rickettsia prowazekii
* Rickettsia rickettsii
* Saxitoxin
* Shiga-like ribosome inactivating proteins
* South American Haemorrhagic Fever viruses
* Tetrodotoxin
* Tick-borne encephalitis complex viruses
* Variola major virus (Smallpox virus)
* Variola minor virus
* Yersinia pestis

Bioterrorism Agents: Laboratory Risk
High-priority agents include organisms that pose a risk to national security because they:

o can be easily disseminated or transmitted from person to person;
o result in high mortality rates and have the potential for major public health impact;
o might cause public panic and social disruption; and
o require special action for public health preparedness.

Category A Definition
Category A Disease/Agents

* Anthrax (Bacillus anthracis)
* Botulism (Clostridium botulinum toxin)
* Plague (Yersinia pestis)
* Smallpox (Variola major)
* Tularemia (Francisella tularensis)
* Viral hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo])
Category B Definition
Category B Disease/Agents

* Brucellosis (Brucella species)
* Epsilon toxin of Clostridium perfringens
* Food safety threats (e.g., Salmonella species, Escherichia coli O157:H7, Shigella)
* Glanders (Burkholderia mallei)
* Melioidosis (Burkholderia pseudomallei)
* Psittacosis (Chlamydia psittaci)
* Q fever (Coxiella burnetii)
* Ricin toxin from Ricinus communis (castor beans)
* Staphylococcal enterotoxin B
* Typhus fever (Rickettsia prowazekii)
* Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis])
* Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)

Category C Definition
Category C Disease/Agents

Safety in the Microbiology Lab.ppt

Food Safety & Microbiology

Food Safety & Microbiology
Presentation lecture by:Dr. Hirsch
Department of Food Science

Food Processing
Food Safety and Microbiology
* Defining Food Illness
* Bad and Good Microorganisms
o Pathogens and Outbreaks
o Spoilage
o Probiotics
* Outbreaks
* Food Safety: Safe food storage and preservation

Food Safety: Foodborne Illness

o Infectious agents
+ Bacteria
+ Viruses
+ Parasites
o A toxin or chemical
+ Bacterial toxin
+ Pesticides
+ Heavy metals
+ Other chemical contaminants

Illness occurring as a result of ingesting food or water contaminated with:
Food Processing
Bad and Good of Microorganisms
Harmful effects:
Beneficial effects:

* Fermentation
o Cheese
o Yogurt
o Fermented sausages
o Wine
o Beer
o Pickles
o Sour kraut
* Probiotics

Pathogens
Harmful: Food Infection vs. Food Poisoning

Food infection

* Live cells delivered by contaminated food; organism multiply once food is ingested
o Salmonella; E. coli

Food poisoning (intoxication)

* Caused by preformed toxin in the food; organism may or may not be alive and growing
o Clostridium botulinum; Staphylococcus aureus

Harmful: Pathogens of Public Health Concern

* Clostridium botulinum
* Escherichia coli
* Listeria monocytogenes
* Salmonella
* Staphylococcus aureus
* Aeromonas hydrophila
* Bacillus cereus
* Campylobacter jejuni
* Clostridium perfringens
* Shigella
* pathogenic Vibrio spp.
* Yersinia enterocolitica

Specific Product Concerns

* Produce
* Imported foods
* Juice
* Eggs

Peanut Salmonella Recall More than 31 million pounds 125 items affected in salmonella probe
2006 Nationwide Outbreak of E. coli
Food Processing
Timeline of Foodborne Illness
Preventive measures
Spoilage Microorganisms: NOT Harmful
Food Spoilage Microorganisms bacteria, yeasts, molds
Microbial Food Spoilage = Changes in Food Quality
The Good Microorganisms: Probiotics

Human probiotics: where?

• Gastro-intestinal
• Skin
• Scalp
• Oral cavity
• Underarm and feet
• Urogenital
including vaginal

Expected Benefits with Consumption

• Increased tolerance to infections
• Control of diarrhea
• Reduction of blood pressure
• Cholesterol reduction
• Allergy control
• Immunomodulation
• Cancer reduction
Probiotics species
Prevention of Deleterious Microbes
Knowledge and Action
Food Handling and Food Processing
Safe Food Storage and Preparation
Major Risk Factors of Food Safety
A day in the life of…fresh Produce
Washing produce would not have prevented the E-coli spinach outbreak
Proper food storage starts at the store
Food Processing
Guidelines for Leftovers

Food Safety & Microbiology.ppt

01 May 2009

Diagnostic Testing in the Microbiology Laboratory

Diagnostic Testing in the Microbiology Laboratory
Presentation by: Jane Wong
Public Health Microbiologist

Topics

* Some basic principles of microbiology testing
* A crash course in microbiology
* Follow a specimen through the lab
* Laboratory staffing issues

Media and Culture

* Media: Nutrients (agar, pH indicators, proteins and carbohydrates) used to grow organisms outside of their natural habitats
* Culture: The propagation of microorganisms using various media

Direct and Indirect Testing

* Direct: Demonstration of the presence of an infectious agent
o Culture
o Microscopy
o Molecular methods such as PCR
* Indirect: Demonstration of presence of antibodies to a particular infectious agent
o Serology

Sterile versus Non-sterile Body Sites

* Sterile body sites:
o These sites normally do not contain any bacteria, so any bacteria found there are significant
+ Blood
+ Spinal fluid
* Non-sterile body sites:
o These sites are open to the external environment and normally contain bacteria
+ Throat
+ Feces

Specimens from Sterile Sites
Specimens from Non-Sterile Sites
Sensitivity
Specificity
Documentation
Specimen

* Appropriateness
* Collection
* Transport to lab
* Inoculation of media
* Culture and isolation
* Confirmation
* Report
Appropriate Specimen
Collection
Transport to Laboratory
Inoculation of Media
Culture media

* Used to grow bacteria
* Can be used to:
o Enrich the numbers of bacteria
o Select for certain bacteria and suppress others
o Differentiate among different kinds of bacteria

Microbiological Culture Media
Isolation of Individual Bacteria
Growth of Colonies
Mixed Culture of Soil Organisms Containing Bacillus anthracis
Colony “Picking”
Colonies of Bacteria in Pure Culture
Pure Culture of Francisella tularensis
Colonies After 72 hours Growth
Pure Culture of Yersinia pestis
Colonies on Blood Agar After 48 hours of Growth
Yersinia pestis Colonial Morphology Viewed With Transmitted Light

Confirmation

* Now we have a pure culture of bacteria
* Testing is now done to confirm the identification of the bacteria culture
o Stains
o Biochemical tests
o Serological tests (using known antibodies)
o Molecular tests (nucleic acid probes)

Gram Stain of Streptococcus sp.
Yersinia pestis
Gram stain
Gram stain of Brucella sp.
B. anthracis Gram stain showing spores
Gram stain of B. anthracis from broth culture

Examples of Biochemical Tests
Left: API 50 Test
Above: Antimicrobial Sensitivity Test
Yersinia pestis E-Test (Antimicrobial Sensitivity Test)
Nitrate and Urea Reactions
Reactions on MacConkey Agar
Triple Sugar Iron (TSI) Test
Blood Bottles Incubated
18 Hours of Incubation
Microbiologist Suspects Bacillus anthracis
India Ink Preparation
Growth on a Blood Agar Plate (Petri Dish) After 18-24 Hours
Gram stain of B. anthracis from broth culture
Motility
Laboratory Cannot Rule Out Bacillus anthracis
* Refers the culture to a reference laboratory that is part of the Laboratory Response Network (LRN)
Report
Molecular Tests
The Flip Side!
Other Factors in Personnel Shortage
Licensing Applications/Year For Clinical Laboratory Scientist Certification

Diagnostic Testing in the Microbiology Laboratory

The Microbiology of Wounds

The Microbiology of Wounds
Presentation by:Neal R. Chamberlain, Ph.D.,
Department of Microbiology/Immunology
KCOM

Microbes and Chronic Wounds

* All chronic wounds are contaminated by bacteria.
* Wound healing occurs in the presence of bacteria.
* Certain bacteria appear to aid wound healing.
* It is not the presence of organisms but their interaction with the patient that determines their influence on wound healing.

Definitions

* Wound contamination: the presence of non-replicating organisms in the wound.
* All chronic wounds are contaminated.
* These contaminants come from the indigenous microflora and/or the environment.
* Most contaminating organisms are not able to multiply in a wound. (Ex. Most organisms in the soil won’t grow in a wound).
* Wound colonization: the presence of replicating microorganisms adherent to the wound in the absence of injury to the host.
* This is also very common.
* Most of these organisms are normal skin flora.
* Staphylococcus epidermidis, other coagulase negative Staph., Corynebacterium sp., Brevibacterium sp., Proprionibacterium acnes, Pityrosporum sp..
* Wound Infection: the presence of replicating microorganisms within a wound that cause host injury.
* Primarily pathogens are of concern here.
* Examples include; Staphylococcus aureus, Beta-hemolytic Streptococcus (S. pyogenes, S. agalactiae), E. coli, Proteus, Klebsiella, anaerobes, Pseudomonas, Acinetobacter, Stenotrophomonas (Xanthomonas).

Microbiology of Wounds

* The microbial flora in wounds appear to change over time.
* Early acute wound; Normal skin flora predominate.
* S. aureus, and Beta-hemolytic Streptococcus soon follow. (Group B Streptococcus and S. aureus are common organisms found in diabetic foot ulcers)
* After about 4 weeks
o Facultative anaerobic gram negative rods will colonize the wound.
o Most common ones= Proteus, E. coli, and Klebsiella.
* As the wound deteriorates deeper structures are affected. Anaerobes become more common. Oftentimes infections are polymicrobial (4-5).
* Long-term chronic wounds oftentimes contain more anaerobes than aerobes.
* Aerobic gram-negative rods also infect wounds late in the course of chronic wound degeneration. Usually acquired from exogenous sources; bath and foot water
* Ex. Pseudomonas, Acinetobacter, Stenotrophomonas (Xanthomonas).
* Organisms like Pseudomonas are not very invasive unless the patient is highly compromised (ex. Ecthyma gangrenosum in neutropenic patients).
* These organisms are associated with marked wound deterioration due to endotoxin, enzymes, and exotoxins.

* As the wounds go deeper and become more complex they can infect the underlying muscles and bone causing osteomyelitis.
* Coliforms and anaerobes are associated with osteomyelitis in these patients. You also see Staphylococcus aureus.
* Enterococcus and Candida are often isolated from wounds.
* Treating a patient for these organisms is only indicated if there are no other pathogens present and the organisms are present in high concentrations (106 CFU’s per gram of tissue)

From Colonization to Infection?
Dose of Bacteria
Bacterial Problems to Consider
Virulence
Host Resistance
Wound Depth can Result in Different Diseases
How do you know when a wound is infected?

* This can be very difficult.
* A continuum exists between when pathogens colonize the wound and then start to cause damage.
* There is no absolutely foolproof laboratory test that will aid in this diagnosis.
* One feature is common to all infected chronic wounds;
* The failure of the wound to heal and progressive deterioration of the wound.
* Unfortunately, wound infections are not the only reasons for poor wound healing.
* The typical features of wound infections:
* increased exudate
* increased swelling
* increased erythema
* increased pain
* increased local temperature
* Periwound cellulitis, ascending infection, change in appearance of granulation tissue (discoloration, prone to bleed, highly friable).

Specimen Collection and Culture Techniques.

* There is a good deal of controversy concerning specimen collection.
* The gold standard collection method is to do a tissue biopsy or needle aspirate of the leading edge of the wound after debridement.
* >105 CFU/gm of tissue= greater likelihood of sepsis developing.
* Indicate the specific anatomic site the biopsy is collected from.
* Indicate whether this is a surface or deep wound. Ask for a smear and gram stain of the tissue.
* Surface wounds are NOT cultured for anaerobes.
* Deep wounds are cultured for anaerobes.
* If a tissue biopsy is not possible;
* cleanse the wound with sterile saline
* vigorously swab the base of the lesion
* Surface wounds place the swab in a sterile container for transport.
* Deep wounds place the swab in a sterile anaerobic container for transport.

The Microbiology of Wounds.ppt

Microbiology, Infections, and Antibiotic Therapy

Microbiology, Infections, and Antibiotic Therapy
Presentation by: Elizabeth J. Rosen, MD
Francis B. Quinn, MD

Basic Bacteriology
Shape
Arrangement
Gram Staining
Cell Wall Characteristics

* Gram Positive
* Gram Negative

Bacterial Growth

* Binary Fission = Exponential Growth
* Four Phases of Growth

Normal Bacterial Flora
Host Defense Mechanisms

* Nonspecific Immunity
o barriers
o inflammatory response
* Specific Immunity
o Passive
o Active
+ humoral
+ cell-mediated

Clinical Microbiology

* Gram Positive Cocci
* Gram Positive Bacilli
* Gram Negative Cocci
* Gram Negative Bacilli
* Anaerobes
* Spirochetes
* Mycobacteria

Gram Positive Cocci

* Staphylococcus
* Streptococcus

Staphylococcus

* S. aureus, S. epidermidis, S. saprophyticus
* S. aureus

Streptococcus

* S. viridans
o oral flora
o infective endocarditis
S. pyogenes

* Group A, beta hemolytic strep
* pharyngitis, cellulitis
* rheumatic fever
+ fever
+ migrating polyarthritis
+ carditis
+ immunologic cross reactivity
* acute glomerulonephritis
+ edema, hypertension, hematuria
+ antigen-antibody complex deposition
S. pneumoniae

Gram Negative Cocci

* Neisseria
o meningitidis
o gonorrhea
* Moraxella catarrhalis

Gram Positive Bacilli

* Clostridium
* Bacillus
* Corynebacterium
* Listeria
* Actinomyces
* Nocardia

C. tetani
C. botulinum

* Descending weakness-->paralysis
* diplopia, dysphagia-->respiratory failure

C. perfringens
C. diphtheriae

* Fever, pharyngitis, cervical LAD
* thick, gray, adherent membrane
* sequelae-->airway obstruction, myocarditis
* colony morphology
L. monocytogenes
Actinomyces

* Part of normal oral cavity flora
* 50% of infections occur in face & neck
* forms abscesses with sulfur granules
* draining sinus tracts

Nocardia
Gram Negative Bacilli

* Facultative Anaerobes
o Respiratory
# Haemophilus
# Bordetella
# Legionella
o Zoonotic
# Yersinia
# Francisella
# Pastuerella
o Enteric
# Klebsiella
# Serratia
# Proteus
# Enterobacter

* Strict Aerobes
o Pseudomonas
* Anaerobes
o Bacteroides

Enterobacteriaceae
K. rhinoscleromatis
* Catarrhal
o purulent rhinorrhea
* Granulomatous
o mucosal nodules
* Cicatricial
o fibrosis
o stenosis

H. influenzae
Legionella

* Community and Nosocomial pneumonia
* contaminated water sources
B. pertussis
Zoonotic Gram Negative Rods

* Yersinia
o plague
* Franciscella
o tularemia
* Pasturella
o dog/cat bites

Pseudomonas
Anaerobic Bacteria

* Bacteroides
* Fusobacterium
* Peptostreptococcus
* Actinomyces
* Prevotella

Spirochetes

* Treponema
* Borrelia

Manifestations of Syphilis
Lyme Disease

* Cutaneous lesions
o erythema chronicum migrans
* Nonspecific symptoms
o malaise, fatigue, headache, fevers, chills, myalgias, arthralgias, lymphadenopathy
* Late manifestations
o neurologic
o cardiac

M. tuberculosis

* Pulmonary disease (82%)
* Extrapulmonary disease (18%)

ENT Manifestations of TB

* Scrofula
o matted lymphadenopathy: posterior triangle
* Laryngeal TB
o edema, ulcers, polypoid changes: arytenoids
* Oral TB
o painless ulcers: tongue
* Aural TB
o thickened TM-->hyperemia-->multiple perfs
o thin, watery otorrhea-->thick, cheesy d/c
M. leprae

Antibiotic Therapy

* Identify infecting organism
* Evaluate drug sensitivity
* Target site of infection
* Drug safety/side effect profile
* Patient factors
* Cost

Classification of Antibiotics

* Bacteriostatic
* Bactericidal
* Chemical Structure
* Spectrum of Activity
* Mechanism of Action

Mechanism of Action
Inhibitors of Cell Wall Synthesis
Beta Lactam Antibiotics

* Penicillins
* Cephalosporins
* Carbapenems
* Monobactams
Penicllins

* Derived from the fungus Penicillium
* Therapeutic concentration in most tissues
* Poor CSF penetration
* Renal excretion
* Side effects: hypersensitivity, nephritis, neruotoxicity, platelet dysfunction

Natural Penicillins

* Penicillin G, Penicillin V

Antistaphylococcal Penicillins
Aminopenicillins
Antipseudomonal Penicillins
Cephalosporins
Generations of Cephalosporins
Monobactams
Carbapenems
Vancomycin
Protein Synthesis Inhibitors
Tetracyclines
Aminoglycosides
Macrolides
Erythromycin
Alternate Macrolides
Chloramphenicol
Clindamycin
Inhibitors of Metabolism
Sulfonamides
Trimethoprim
Co-Trimoxazole (TMP/SMX)
Inhibitors of Nucleic Acid Function/Synthesis
Fluoroquinolones
Antimycobacterial Therapy
First-Line Agents
Antimycobacterials for Leprosy
Antibiotic Prophylaxis
Classification of Wounds
Classification of Wounds
Prophylactic Antibiotics
Effective Prophylactic Regimens
Topical Antibiotic Prophylaxis
Indications for Antibiotic Prophylaxis in ENT Surgery

Microbiology, Infections, and Antibiotic Therapy.ppt

Microbiology in a Nutshell

Microbiology in a Nutshell
Presentation from nebo.edu

Yes, you will need to know this
Microbes
Viruses

* Microscopic (can’t see with the naked eye)
* nonliving particle
* Invades and reproduces inside a host.
* Contains DNA or RNA

Virus Multiplication

* Active
o Become sick within hours or days
* Hidden
o Illness can be delayed for weeks, months, or years
o Triggered by environment?

Bacteria

* Microscopic
* Prokaryotes (means they don’t have a nucleus)
* Living
* Contains DNA

Shapes of bacteria

* Spherical
* Rodlike
* Spiralshaped
* They can also be in chains
o Spherical chain

Bacteria Multiplication

* Sexual reproduction
o Two parents
o Conjugation (transfer of genetic material through bridge)
* Asexual reproduction
o Binary Fission-Simply splitting in two

Growth in Action

* Rapid, as fast as once every 20 minutes
* Continues until they run out of the basics
o Food
o Air
o Space

Parasites

* Organisms that live on or in a host and cause harm.
* Examples: Viruses, Bacteria, and tapeworms.
* Can a bacteria be a host?

How many can there be?

* These bubble-headed creatures are called bacteriophages, viruses that target bacteria. The head holds DNA and the tail acts as a needle attaching to a specific site on the bacterial cell wall, the virus squirts DNA through the tail into the bacterium. Ouch! They are among the smallest of organisms. You could fit about 680,000 of these creatures on the head of a pin.

What can you do?

* Get Vaccines
* Personal Hygiene
* Use Disinfectants
* Lines of Defense
o Skin
o Mucus barriers
o Immune System

Vaccines

Existing flu shots are 70 percent to 90 percent effective at preventing flu in healthy young people

* 50 percent effective in the elderly, (And even if the vaccines don't prevent the flu, they do tend to reduce symptoms and serious complications).

High Risk Groups

* aged 65 and older
* with chronic diseases affecting the heart, lung or kidneys
* with diabetes, immunosuppression, or severe anemia
* people in contact with doctors, nurses and nursing-home staff

Prevention

* "The current U.S. plan in the event of a pandemic is to vaccinate virtually the entire population," says epidemiologist Nancy Arden.
* Despite its advantages, less than 60 percent of the high-risk population gets the flu shot each year.

Microbiology in a Nutshell.ppt

28 April 2009

Mycobacterium

Mycobacterium

Mycobacterium tuberculosis
Mycobacterium leprae (uncommon)
Mycobacterium avium-intracellulaire Complex (MAC) or (M. avium)
Important Human Pathogens
Lipid-Rich Cell Wall of Mycobacterium
Mycolic acids
CMN Group: Unusual cell wall lipids (mycolic acids,etc.)
(Purified Protein Derivative)
Acid-Fast (Kinyoun) Stain of Mycobacterium
Photochromogenic Mycobacterium kansasii on Middlebrook Agar
Improved Mycobacterial Isolation Medium
Eight Week Growth of Mycobacterium tuberculosis on Lowenstein-Jensen Agar
Pathogenic Mycobacterium spp.
BCG
AIDS patients
Mycobacterial Clinical Syndromes
Diagram of a Granuloma
Laboratory Diagnosis of Mycobacterial Disease
Nucleic acid probes
Nucleic acid sequencing
Differential Characteristics of Commonly Isolated Mycobacterium spp.
Mycobacterium tuberculosis
Mycobacterium tuberculosis Infections
Incidence of Tuberculosis in USA
BCG (bacille Calmette-Guerin) = attenuated M. bovis
Positive PPD + Chest X-Ray +
MDR-TB a serious global health threat
Typical Progression of Pulmonary Tuberculosis
PPD Tuberculosis Skin Test Criteria
PPD = Purified Protein Derivative from M. tuberculosis
Chest X-Ray of Patient with Active Pulmonary Tuberculosis
Mycobacterium Tuberculosis Stained with Fluorescent Dye
Mycobacterium leprae
Mycobacterium leprae Infections
Tuberculoid vs. Lepromatous Leprosy
Clinical Manifestations and Immunogenicity
Lepromatous vs. Tuberculoid Leprosy
Lepromatous Leprosy (Early/Late Stages)
Lepromatous Leprosy Pre- and Post-Treatment
Clinical Progression of Leprosy
Effect of Cell-Mediated Immunity on Leprosy Clinical Outcome
Mycobacterium avium-intracellulaire Complex (MAC)
Mycobacterium avium-intracellulaire Infections
M. avium-intracellulaire Complex (MAC) Progression vs. CD4 Count in AIDS Patients
Mycobacterium avium-intracellulaire in Tissue Specimens
Important Human Pathogens
Lipid-Rich Cell Wall of Mycobacterium
Mycolic acids
CMN Group: Unusual cell wall lipids (mycolic acids,etc.)
Mycobacterial Clinical Syndromes

Mycobacterium.ppt

26 April 2009

The Changing Face of Viral Hepatitis

The Changing Face of Viral Hepatitis
Presentation by:D. Robert Dufour, MD, FACB, FCAP
Consultant Pathologist
Attending, Liver Clinic
VAMC, Washington DC
Emeritus Professor of Pathology

SIGNIFICANCE
HEPATITIS A
HEPATITIS E
HEV DIAGNOSIS
HEPATITIS B
HBV BIOLOGY
HBV Replication
Circulating HBV
Infection
Reservoir
Replication
HBV
mRNA
Reverse
Transcriptase
RNA-DNA Hybrid
Partially ds-DNA
Pre-S
Free HBsAg
DNA Polymerase
Partially ds-DNA
HBV BIOLOGY
OUTCOME
Loss of HBsAg
HBV SEROLOGIC TESTS
HBsAg
ISOLATED ANTI-HBc
HBeAg
ANTI-HBe
HBV DNA
HBV OUTCOMES & SEROLOGY
Immune control
Immune active
Immune tolerance
Acute hepatitis
HBV REACTIVATION
Anti-HBc pos
HBsAg neg
HEPATITIS C
HCV BIOLOGY
ANTI-HCV
RIBA for anti-HCV
Screening test for Anti-HCV
HCV RIBA
TREATMENT OF CHRONIC HBV AND HCV
ACUTE HEPATITIS
CHRONIC HEPATITIS B
TREATMENT INDICATIONS
TREATMENT BENEFITS
MONITORING Rx

* In HBeAg + with loss HBV DNA, serial monitoring of HBeAg status prognostic; if HBeAg lost (and anti-HBe develops), treatment can be D/C after 6-12 mo with 80% success
* In HBeAg – (or HBeAg + who do not convert), D/C treatment leads to rapid reactivation of HBV replication; treatment usually long-term in these patients

CHRONIC HEPATITIS C
RECENT ARTICLES

The Changing Face of Viral Hepatitis.ppt