OPTO435

Microbiology II

Gamal El-Hiti

Introduction to OPTO435

Lecture One

OPTO435

Lecture Notes

http://fac.ksu.edu.sa/gelhiti/home

http://fac.ksu.edu.sa/gelhiti/home

http://fac.ksu.edu.sa/gelhiti/home

OPTO435

Handbooks

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OPTO435

Course Calendar

Week 01

06/01/2019

L01

Week 02

13/01/2019

L02

Week 03

20/01/2019

L03

Week 04

27/01/2019

L04

Week 05

03/02/2019

L05

Week 06

10/02/2019

1st Mid-term exam

Week 07

17/02/2019

L06

Week 08

24/02/2019

L07

Week 09

03/03/2019

L08

Week 10

10/03/2019

L09

Week 11

17/03/2019

2nd Mid-term exam

Week 12

24/03/2019

L10

Week 13

31/03/2018

L11

Week 14

07/04/2019

Revision

Week 16

21/04/2019

Final Exam

All the best for your exams

Course Calendar Course Calendar

OPTO435

Learning Outcomes

Ou

tco

mes

To provide the basic concepts of antibiotics

To acquire the basic understanding of bacteria infectious diseases

To provide the basic knowledge of infectious diseases caused by fungi

To provide the basic knowledge of infectious diseases caused by Protozoa

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Learning Outcomes

Ou

tco

mes

To provide the basic knowledge about the

types of viruses

To provide the basic concepts of non-enveloped DNA viruses

To provide the basic concepts and causes for the red eye infection

To provide the basic knowledge about the diagnostic methods in microbiology

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Learning Outcomes

OPTO435

Weekly Plan

Antimicrobial Drugs

Lecture Two

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Antibiotics

Antibiotics are of biological origin and produced by microbes to inhibit others. It is difficult to treat Gram-negative bacteria in comparison to Gram-positive bacteria. Natural and semisynthetic penicillins contain β-lactam ring. Penicillins are still widely used today, but many bacteria have now become resistant. Semisynthetic penicillins can be made in the laboratory.

Antibiotics mode of action

Different antibiotics have different modes of action depending on their structure and degree of affinity to certain target sites within bacterial cells.

Inhibitors of cell wall synthesis

Inhibitors of cell membrane function

Inhibitors of protein synthesis

Inhibitors of nucleic acid synthesis

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Antibiotics

Penicillin (-lactams)

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Action of Antibiotics

A variety of mutations can lead to antibiotic resistance.

Mechanisms of antibiotic resistance

1) Enzymatic destruction of drug

2) Prevention of penetration of drug

3) Alteration of drug's target site

4) Rapid ejection of the drug

A single regimen of antibiotics (i.e. ca. 10 days) makes a person 3 to 4 times more likely to get another infection.

Antibiotic Resistance

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Antifungal drugs are pharmaceutical fungicide used to treat fungi. Antiparasitic drugs are medications that can be used to treat parasitic diseases by killing the worms. Antiviral drugs are medications used specifically for treating viral infections.

Other Drugs

Gram-Positive Bacteria

Staphylococci

Lecture Three

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Bacteria

Staphylococci have remarkable ability to resist antibiotics.

Generally stain darkly Gram positive.

They are facultative anaerobe organisms (can grow with or without oxygen).

They make ATP by aerobic respiration if oxygen is present, but use fermentation or anaerobic respiration if oxygen is absent.

They produce catalase that breaks hydrogen peroxide into water and oxygen.

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Staphylococci

S. aureus diseases may be the result of:

Invasive infection to overcome host defense.

Production of toxins.

A combination of invasive infection and intoxication.

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Staphylococcus aureus

Staphylococcus aureus

S. aureus produce toxins and causes diseases by infecting tissues through:

1 Localized skin infections

2 Deep and localized infections

3 Acute endocarditis

4 Septicemia

5 Pneumonia

6 Nosocomial infections

7 Toxinoses

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Staphylococcus aureus

Treatment: Serious S. aureus infections require aggressive treatment, including incision and drainage of localized lesions, as well as systemic antibiotics. Choice of antibiotics is complicated by the frequent presence of acquired antibiotic resistance determinants. S. aureus infections are now resistant to penicillin G. β-Lactamase resistant penicillins, such as methicillin, can be used.

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Staphylococcus aureus

PVL = Panton–Valentine leukocidin

Gram-Positive Bacteria

Streptococci

Lecture Four

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Streptococci Streptococci are Gram + and catalase negative bacteria and Streptococci pyogenes is the most important type. α-Hemolytic streptococci cause a chemical change in hemoglobin. -Hemolytic streptococci cause a complete lysis of red cells. -Hemolytic streptococci cause no color change or lysis of red blood cells.

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Streptococci

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Streptococcus pneumoniae Streptococci pneumoniae (-Hemolytic) are Gram-positive, non-motile, encapsulated cocci. S. pneumoniae is the most common cause of community acquired pneumonia and adult bacterial meningitis. The risk of disease is highest among young children, older adults, smokers and persons with certain chronic illnesses.

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The bacterial capsule of S. pneumoniae is the most important virulence factor. Two types of vaccine can be used to immunize against Streptococcus pneumoniae. Pneumococcal polysaccharide vaccine (PPV; 1983): 2 years. Pneumococcal conjugate vaccine (PCV13; 2010): It is effective in infants and toddlers (ages 6 weeks to 5 years).

Streptococcus pneumoniae

Gram-Negative Bacteria

Lecture Five

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Gram Negative Cocci The genus Neisseria consists of Gram-negative, aerobic cocci. Neisseria gonorrhoeae is a Gram-negative diplococcus that causes gonorrhea infectious disease.

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Neisseria gonorrhoeae N. gonorrhoeae does not produce exotoxins but has many virulence factors.

Pili

Lipooligosaccharide

Porin proteins

IgA Protease

Capsules

It cause conjunctivitis in newborns.

More than 20% of N. gonorrhoeae isolates are resistant to penicillin.

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Moraxella

Treatment is via the use of either subconjunctival injection of a tetracycline.

Gram Negative Rods

What are enteric bacteria?

Enteric bacteria are Gram-negative rod bacteria.

They are bacteria of the intestines that are associated with gastrointestinal flora (Gut flora) or disease.

The taxonomic family is Enterobacteriaceae.

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Escherichia coli

Most E. coli strains, Gram-negative rods, are harmless, but some serotypes can cause serious food poisoning in their hosts. E. coli can get into meat, raw milk or dairy products during processing. E. coli spread from one person to another.

Gram Negative Rods

What are nonenteric bacteria?

They are Gram-negative Bacilli.

They do not ferment sugars.

They resist antibiotics.

Can cultured in the lab.

e.g. Pseudomonas aeruginosa.

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Pseudomonas aeruginosa is a Gram negative rods found in soil, water, plants and animals.

It may colonize healthy humans without causing disease (opportunistic pathogen).

It is a major cause of nosocomial infections.

It produces numerous toxins.

It causes localized and systemic illness.

It is difficult to treat with antibiotics and aggressive antimicrobial therapy is required.

Pseudomonas aeruginosa

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H. influenzae is a Gram negative rod and resident upper respiratory tract in human. H. influenzae was a leading cause of meningitis (infants and young children). A conjugated vaccine can be used. Rifampin, antibiotic can be used. Brazilian purpuric fever (BPF) is a fatal illness of children caused by H. influenzae. H. influenzae causes conjunctivitis and may be associated with respiratory and sore throat infections.

Haemophilus influenzae

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OPTO435 Microbiology II

1st Midterm Exam L02—L05

Chlamydia trachomatis and Mycobacterium tuberculosis

Lecture Six

Chlamydia trachomatis

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Chlamydiaceae consists of small bacteria that are obligate intracellular parasites, depending on the host cell for energy in the forms of adenosine triphosphate (ATP). The family has three important human pathogens: Chlamydia trachomatis, Chlamydophila psittaci and Chlamydophila pneumoniae.

Treponema pallidum

Secondary lesions may be accompanied by systemic involvement, such as syphilitic hepatitis, meningitis, nephritis and chorioretinitis.

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Mycobacterium tuberculosis

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Mycobacteria are slender rods with lipid-rich cell walls that are resistant to penetration by chemical dyes such as those used in the Gram stain. Mycobacterium tuberculosis causes tuberculosis in humans that cause worldwide of death from infection.

Mycobacterium tuberculosis Tuberculin reaction: It is the tuberculin reaction test is a manifestation of delayed hypersensitivity to protein antigens of M. tuberculosis.

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Fungi

Lecture Seven

Fungi

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Human fungal diseases (mycoses) are classified by the location on or in the body where the infection occurs.

They are called cutaneous when limited to the epidermis, subcutaneous when the infection penetrates significantly beneath the skin.

Fungi

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Candida albicans

Candida albicans is a yeast that is part of the normal body flora, which can be found in the skin, mouth, vagina and intestines.

It is the causal agent of opportunistic oral and genital infections in humans.

It grows as yeast and filamentous cells.

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Aspergillus is a genus consisting of a few hundred mould species.

Aspergilli are ubiquitous, growing only as filamentous molds.

Aspergillus

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Fungal Eye Infection

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Protozoa

Lecture Eight

Protozoa

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Protozoa

Life cycle of Toxoplasma gondii

Protozoa

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Nonenveloped DNA Viruses

Lecture Nine

Nonenveloped DNA Viruses

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Nonenveloped DNA Viruses

Adenoviruses are members of the family Adenoviridae.

They are medium sized (90–100 nm), nonenveloped viruses with an icosahedral nucleocapsid containing a double stranded DNA genome.

Their name derives from their initial isolation from human adenoids in 1953.

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Nonenveloped DNA Viruses

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Nonenveloped DNA Viruses

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OPTO435 Microbiology II

2nd Midterm Exam L06—L09

Enveloped DNA Viruses

Lecture Ten

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Enveloped DNA Viruses

Herpesviridae is a large family of DNA viruses that cause diseases in humans.

Herpesviridae is more complex than nonenveloped DNA viruses.

Members of this family also known as herpesviruses.

Eight human herpesviruses species are known.

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Herpesvirus

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Uveitis They often cause blindness if left untreated.

Symptoms of uveitis

Redness of the eye

Blurred vision

Eye pain

Headaches

Photophobia or sensitivity to light

Floaters, which are dark spots that float in the visual field

Diagnostic Methods in Microbiology

Lecture Eleven

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Diagnostic Immunology

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Sample antigens are attached to a surface. A specific antibody is then applied over the surface so it can bind to the antigen. This antibody is linked to an enzyme, and, in the final step, a substance containing the enzyme's substrate is added. The subsequent reaction produces a color change in the substrate.

ELISA

Immunofluorescence Staining

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PCR is used to amplify a single copy or pieces of DNA generating thousands to millions of copies of a particular DNA.

Polymerase Chain Reaction

OPTO435

Revision Week

OPTO435

Final Exam