slide1
Download
Skip this Video
Download Presentation
REVIEW OF MEDICAL MICROBIOLOGY

Loading in 2 Seconds...

play fullscreen
1 / 87

REVIEW OF MEDICAL MICROBIOLOGY - PowerPoint PPT Presentation


  • 142 Views
  • Uploaded on

REVIEW OF MEDICAL MICROBIOLOGY. Infections of Respiratory tract Cardiovascular system Gastrointestinal tract Skin and soft tissue Central nervous system Genitourinary tract. THE RESPIRATORY TRACT. Upper Respiratory Tract Pharyngitis (mostly 2 years through adolescence)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'REVIEW OF MEDICAL MICROBIOLOGY' - melva


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

REVIEW OF MEDICAL MICROBIOLOGY

Infections of

Respiratory tract

Cardiovascular system

Gastrointestinal tract

Skin and soft tissue

Central nervous system

Genitourinary tract

slide2

THE RESPIRATORY TRACT

Upper Respiratory Tract

Pharyngitis (mostly 2 years through adolescence)

Adenoviruses

Group A Streptococci (S. pyogenes)

Potential for rheumatic fever

Chlamydophila pneumoniae

Neisseria gonorrhoeae

Corynebacterium diphtheriae

Mycoplasma pneumoniae

slide3

THE RESPIRATORY TRACT

Otitis media (infants and young children)

Streptococcus pneumoniae

Haemophilus influenzae

Staphylococcus aureus

Group A streptococcus

Moraxella catarrhalis

Formerly “Branhamella”

Gram-negative cocci

Opportunistic pathogen

slide4

THE RESPIRATORY TRACT

Otitis externa

Staphylococcus aureus

Pseudomonas aeruginosa

Group A Streptococcus

Malignant otitis externa

• In diabetics, elderly & immunocompromised

• Can lead to osteomyelitis and meningitis

slide5

THE RESPIRATORY TRACT

Sinusitis

Streptococcus pneumoniae

Haemophilus influenzae

Staphylococcus aureus

Chlamydophila pneumoniae

Moraxella catarrhalis

Group A Streptococcus

Pseudomonas aeruginosa

Viruses

Oral anaerobic bacteria

slide6

THE RESPIRATORY TRACT

Conjunctivitis

Streptococcus pneumoniae

Group B Streptococcus

Viridans Streptococcus

Staphylococcus aureus

Haemophilus influenzae

Moraxella catarrhalis

slide7

THE RESPIRATORY TRACT

Conjunctivitis (contd)

Pseudomonas aeruginosa

Corynebacterium species

Francisella tularensis

Adenoviruses

Chlamydia trachomatis

slide8

THE RESPIRATORY TRACT

Rhinocerebral mucormycosis

• Life-threatening

• Most common in diabetics

• The fungi Mucor and Rhizopus invade blood

vessels, resulting in necrosis of bone and

thrombosis of the cavernous sinus and internal

carotid artery

slide9

THE RESPIRATORY TRACT

Bacterial epiglottitis

Life-threatening

Haemophilus influenzae type b

Streptococcus pneumoniae

Staphylococcus aureus

slide10

THE RESPIRATORY TRACT

Diphtheria

Corynebacterium diphtheriae

Whooping cough

Bordetella pertussis

slide11

THE RESPIRATORY TRACT

“Common colds”

Rhinoviruses

Adenoviruses

Influenza C

Coronaviruses

Coxsackie viruses

slide12

THE RESPIRATORY TRACT

“Croup”

Respiratory syncytial virus

Influenza virus

Parainfluenza virus

slide13

THE RESPIRATORY TRACT

Lower Respiratory Tract

Community acquired infections

Streptococcus pneumoniae (elderly)

Klebsiella pneumoniae (alcoholics)

Mycoplasma pneumoniae (school-age children)

Mycobacterium tuberculosis

RSV (infants and young children)

Influenza virus

slide14

THE RESPIRATORY TRACT

Lower Respiratory Tract

Community acquired infections

Bronchitis or pneumonia secondary to viral pneumonia

Streptococcus pneumoniae

Haemophilus influenzae

Staphylococcus aureus

Moraxella cararrhalis

slide15

THE RESPIRATORY TRACT

Lower Respiratory Tract

Nosocomial infections

Mycobacterium tuberculosis

RSV in pediatric patients

Methicillin-resistant S. aureus (pneumonia)

Pseudomonas aeruginosa

Legionella spp.

slide16

THE RESPIRATORY TRACT

Lower Respiratory Tract

Patients with underlying lung infections

Chronic obstructive pulmonary disease

P. aeruginosa

S. pneumoniae

H. influenzae

Moraxella cararrhalis

Allergic bronchopulmonary aspergillosis

slide17

THE RESPIRATORY TRACT

Lower Respiratory Tract

Patients with underlying lung infections

Cystic fibrosis

S. aureus

P. aeruginosa

Allergic bronchopulmonary aspergillosis

slide18

THE RESPIRATORY TRACT

Lower Respiratory Tract

Patients with underlying lung infections

Cavitary lung disease (due to prior MTB infection)

Aspergillus spp (Aspergilloma or fungus ball)

slide19

THE RESPIRATORY TRACT

Lower Respiratory Tract

Immunocompromised individuals

At risk for all recognized respiratory tract pathogens

AIDS patients

Pneumocystis carinii

S. pneumoniae

MDR M. tuberculosis

slide20

THE RESPIRATORY TRACT

Lower Respiratory Tract

Immunocompromised individuals

Neutropenic patients

Invasive aspergillosis

Mucormycosis

slide21

THE RESPIRATORY TRACT

Lower Respiratory Tract

Immunocompromised individuals

Transplant patients

Invasive fungi

CMV

HSV

Legionella spp.

Pneumocystis carinii

slide22

A 40-year-old male with multisystem failure secondary to bilateral pneumonia was transferred to our hospital via helicopter.

He had presented to his local physician 3 days previously complaining of fever, malaise, and vague respiratory symptoms.

He was given amantadine for suspected influenza. His condition became progressively worse, with shortness of breath and a fever to 40.5˚C.

From: “Cases in Medical Microbiology and Infectious Disease”

slide23

He was admitted to an outside hospital 24 h prior to transfer.

A laboratory examination revealed abnormal liver and kidney function.

Therapy with Timentin (ticarcillin-clavulanic acid) and trimethoprim-sulfamethoxazole was begun.

He underwent pronchoscopic examination which revealed mildly inflamed airways containing thin, watery secretions.

slide24

A Gram-stain of bronchial washings and culture results are shown in the figure.

Based on these findings, he was begun on appropriate antimicrobial therapy.

slide26

Streptococcus pneumoniae

Haemophilus influenzae

Mycoplasma pneumoniae

Staphylococcus aureus

(frequently following an influenza infection)

Klebsiella pneumoniae

(elderly & alcoholics)

Legionella pneumophila

Chlamydophila pneumoniae

slide27

On the basis of the Gram-stain of bronchial washings, and the patient’s presentation, what is the most likely cause of this patient’s catastrophic infection?

Why must the laboratory be notified if this organism is considered in the differential diagnosis?

slide28

The patient has Legionella pneumophila.

Renal and hepatic dysfunction and thin watery secretions are characteristic of this infection.

Patients with bacterial pneumonia due to most other bacterial agents have thick, purulent secretions.

The laboratory needs to be informed because the organism requires a specific growth medium, buffered charcoal yeast extract (BCYE) agar.

slide31

What is the appropriate antimicrobial agent for the treatment of this infection?

Which other Gram-negative respiratory pathogen is treated with this antibiotic?

slide32

Erythromycin

Can penetrate into white blood cells

Legionella multiplies in macrophages

Bordetella pertussis

slide33

THE CARDIOVASCULAR SYSTEM

Septicemia: Predisposing factors and agents

Abdominal sepsis

Enterobacteria

Bacteroides fragilis

Enterococcus faecalis

Enterococcus faecium

Infected wounds

Staphylococcus aureus

Streptococcus pyogenes

Enterobacteria

slide34

THE CARDIOVASCULAR SYSTEM

Septicemia: Predisposing factors and agents

Osteomyelitis

Staphylococcus aureus

Pneumonia

Streptococcus pyogenes

Food poisoning

Salmonella spp.

Campylobacter spp.

slide35

THE CARDIOVASCULAR SYSTEM

Septicemia: Predisposing factors and agents

Intravascular devices

Staphylococcus aureus

Staphylococcus epidermidis

Enterobacteria

Meningitis

Streptococcus pneumoniae

Neisseria meningitidis

Haemophilus influenzae

slide36

THE CARDIOVASCULAR SYSTEM

Septicemia: Predisposing factors and agents

Immunocompromised patients

Staphylococcus aureus

Enterobacteria

slide37

THE CARDIOVASCULAR SYSTEM

Infective endocarditis

> 80% of cases caused by streptococci

or staphylococci

Total streptococci 60%

Viridans group 35%

anginosus group

mitis group

mutans group

salivarius group

slide38

THE CARDIOVASCULAR SYSTEM

Infective endocarditis

Total streptococci 60%

Total staphylococci 25%

S. aureus 20%

S. epidermidis 5%

slide39

THE CARDIOVASCULAR SYSTEM

Myocarditis

Corynebacterium diphtheriae

Clostridium perfringens

Group A Streptococcus

Borrelia burgdorferi

Neisseria meningitidis

Staphylocccus aureus

slide40

The patient was a 4-month-old female who was admitted to the hospital in March with sever respiratory distress.

Five days prior to admission she had developed a cough and rhinitis.

Two days later she began wheezing and was noted to have a fever.

She was brought to the emergency room when she became lethargic.

From: “Cases in Medical Microbiology and Infectious Disease”

slide41

One sibling was reported to be coughing, and her father had a “cold”.

On examination she had

a fever of 38.9˚C

tachycardia with a pulse of 220/min

tachypnea with respirations of 80/min

Her throat was clear.

slide42

A chest X-ray revealed interstitial infiltrates.

She was put in respiratory isolation in the pediatric intensive care unit, and was subsequently intubated.

Blood and nasopharyngeal cultures were sent to the bacteriology and virology laboratories.

A rapid diagnostic test was positive and specific antiviral therapy was begun.

slide43

She was also given a bronchodilator (aminophylline) to treat the bronchospasm which was resulting in her wheezing.

She was extubated 5 days later and discharged home on day 8.

1. What are the possible causes for this patient’s pneumonia?

slide44

Parainfluenza virus

Influenza A and B

Respiratory syncytial virus

Mycoplasma pneumoniae

Bordetella pertussis

slide47

Direct Fluorescence Antibody

“Shell Vial Assay”

Fibroblasts grown on coverslips in a shell vial

Clinical specimens a centrifuged onto the cell monolayer

Incubation for 1-2 days

The monolayer is stained with a fluorescent monoclonal antibody specific for an RSV antigen

slide49

RSV is spread by large droplets and on fomites

Can be spread via contaminated hands

Occurs primarily in winter months

slide51

RSV is tropic for bronchial epithelium

Edema and necrosis can lead to collapse and obstruction of a child’s small bronchioles

slide53

Only one antiviral agent is available for treatment of RSV in infants

Aerosolized ribavirin

(oral administration can result in hepatic or bone marrow toxicity)

The American Academy of Pediatrics recommends its use in children with congenital heart disease, cystic fibrosis, immunodeficiency or severe illness.

slide55

Patients should be put on respiratory isolation

Gowns and gloves should be used during contact

slide57

Inactivated RSV vaccine did not work and exacerbated the disease

Immune globulin can be used in children at greatest risk

slide58

THE GASTROINTESTINAL SYSTEM

Two basic mechanisms of diarrheal disease:

Enterotoxin-induced fluid loss

Cholera toxin

Direct damage to the intestinal epithelium

Cytotoxin

Entamoeba histolytica

Invasion of epithelium

Salmonella spp.

Shigella spp.

Campylobacter spp.

Yersinia enterocolitica

slide59

THE GASTROINTESTINAL SYSTEM

Infectious doses

Hundreds of thousands to millions

Salmonella spp.

Vibrio cholerae

Less than 100

Shigella spp.

slide60

THE GASTROINTESTINAL SYSTEM

Bacteria

Invasive diarrhea

Campylobacter spp.

Salmonella spp.

Shigella spp.

Yersinia enterocolitica

Large-volume watery diarrhea

Vibrio spp.

slide61

THE GASTROINTESTINAL SYSTEM

Bacteria

Watery diarrhea

Enterotoxigenic E. coli

Yersinia enterocolitica

Typhoid fever

Salmonella spp.

slide62

THE GASTROINTESTINAL SYSTEM

Bacteria

Traveler’s diarrhea

Enterotoxigenic E. coli

Dysentery

Shigella spp.

slide63

THE GASTROINTESTINAL SYSTEM

Bacteria

Antibiotic-associated diarrhea

Pseudomembranous colitis

Clostridium difficile

Food poisoning

Staphylococcus aureus

Clostridium perfringens

Bacillus cereus

Salmonella spp.

slide64

THE GASTROINTESTINAL SYSTEM

Bacteria

Abdominal abscess

Bacteroides fragilis

Gangrenous lesions of bowel or gall bladder

Clostridium perfringens

Enterohemorrhagic colitis

Enterohemorrhagic E. coli

slide65

THE GASTROINTESTINAL SYSTEM

Viruses

Acute, self-limited hepatitis

Hepatitis A

Acute and chronic hepatitis

Hepatitis B

Hepatitis C

slide66

THE GASTROINTESTINAL SYSTEM

Viruses

Diarrhea

Enterovirus

Rotavirus

Norwalk agent (calicivirus)

Vomiting

Rotavirus

Norwalk agent (“24-hour flu”)

slide67

THE GASTROINTESTINAL SYSTEM

Viruses

Infants

Rotavirus A (most common cause)

Adenovirus 40, 41

Coxsackie A24 virus

Infants, children, and adults

Norwalk agent (“24-hour flu”)

Calicivirus

Reovirus

slide68

SKIN AND SOFT TISSUE

Diffuse erythematous macular rash may be a manifestation of systemic disease

Rocky Mountain spotted fever

Meningococcemia

Entereoviral infection

Toxic shock syndrome

Scarlet fever

Measles

German measles

slide69

SKIN AND SOFT TISSUE

Erythema migrans

Lyme diseases

Vesicular skin lesions

Varicella Zoster virus

Macular, papular or pustular, but not vesicular, skin lesions

Secondary syphilis

slide70

SKIN AND SOFT TISSUE

Important to treat superficial skin infections

Folliculitis caused by Staphylococcus aureus

Cellulitis caused by Streptococcus pyogenes

Delay in treatment may result in invasion of the deeper structures (e.g necrotizing fasciitis)

slide71

SKIN AND SOFT TISSUE

Cat scratch disease, bacillary angiomatosis

Bartonella henselae

Lyme disease

Borrelia burgdorferi

Gas gangrene

Clostridium perfringens

Tetanus

Clostridium tetani

slide72

SKIN AND SOFT TISSUE

Diphtheria and wound diphtheria

Corynebacterium diphtheriae

Cellulitis

Group A streptococci (S. pyogenes)

Group B streptococci (S. agalactiae)

Pasteurella multocida

Staphylococcus aureus

Cryptococcus neoformans

slide73

SKIN AND SOFT TISSUE

Skin infection in burn patients

Pseudomonas aeruginosa

Thrush

Candida albicans

Candida spp.

Cutaneous infection

Blastomyces dermatitidis

slide74

SKIN AND SOFT TISSUE

Infection of keratinized tissue

Epidermophyton floccosum

Microsporum spp.

Trichophyton spp.

Ulcerative skin lesions

Leishmania tropica

slide75

SKIN AND SOFT TISSUE

Exanthem subitum

Human herpesvirus type 6

Oral infections

Herpes simplex virus

Warts

Human papillomavirus

slide76

CENTRAL NERVOUS SYSTEM

The most frequent infections are

Meningitis

Encephalitis

Abscess

Meningitis

Septic: caused by bacteria

CSF cloudy (>1,000 white blood cells/µl)

Aseptic: Viruses, fungi, MTB

CSF clear (100-500 cells/µl)

slide77

CENTRAL NERVOUS SYSTEM

Neonatal meningitis (newborn - 2 months)

Group B streptococci (most common cause)

Listeria monocytogenes

E. coli

Klebsiella pneumoniae

Citrobacter diversus Citrobacter koseri

Treponema pallidum

slide78

CENTRAL NERVOUS SYSTEM

Meningitis (2 months - 5 years)

Haemophilus influenzae type b

Streptococcus pneumoniae

Neisseria meningitidis (all ages)

Meningitis (Patients with head trauma )

Coagulase-negative staphylococci

Staphylococcus aureus

Pseudomonas aeruginosa

slide79

CENTRAL NERVOUS SYSTEM

Aseptic meningitis

Echovirus

Coxsackievirus

Herpes simplex virus

Fungal meningitis

(primarily in the immunocompromised)

Cryptococcus neoformans (in AIDS patients)

slide80

CENTRAL NERVOUS SYSTEM

Viral encephalitis

Herpes simplex virus (most common)

(necrotizing; necrotizing hemorrhagic)

Eastern equine encephalitis virus

Western equine encephalitis virus

St. Louis encephalitis virus

La Crosse encephalitis virus

slide81

CENTRAL NERVOUS SYSTEM

Encephalitis

Toxoplasma gondii

Taenia solium (“cysticercosis”; from pork)

Meningoencephalitis

Cerebral malaria

Naegleria fowleri (an amoeba)

Citrobacter diversus

slide82

CENTRAL NERVOUS SYSTEM

Brain abscesses

Extension from a contiguous site

Hematogenous spread from another site (endocarditis or lung abscess)

Septic emboli (blood clots containing an infectious agent)

In immunocompetent individuals

S. aureus

viridans streptococci

Actinomyces spp.

Anaerobic bacteria

slide83

CENTRAL NERVOUS SYSTEM

Brain abscesses

In immunocompromised individuals

Aspergillus

Mucor

Rhizopus

Nocardia spp.

In diabetic patients

Rhinocerebral mucormycosis

slide84

GENITOURINARY TRACT

Urinary tract infections

Endogenous infections

Nosocomial (catheterization)

Sexually transmitted diseases

Exogenous infections

slide85

GENITOURINARY TRACT

Urinary tract infections

Enterobacter

Enterococcus

Klebsiella pneumoniae

Proteus mirabilis

Pseudomonas aeruginosa

Staphylococcus saprophyticus

Candida spp.

slide86

GENITOURINARY TRACT

Pelvic inflammatory disease

Chlamydia trachomatis (PID)

Neisseria gonorrhoeae (PID)

Actinomyces spp. (endogenous; IUD usage)

Vaginitis

Candida spp. (endogenous)

Trichomonas vaginalis

slide87

GENITOURINARY TRACT

Sexually transmitted diseases

Chlamydia trachomatis (PID)

Neisseria gonorrhoeae (PID)

Treponema pallidum (fetal loss or perinatal infect.)

Herpes simplex virus (fetal loss or perinatal infect.)

HIV

Human papilloma virus

Trichomonas vaginalis

ad