List of contents Microbiology

NO. Subject Page No.

Introduction

Section I – Microbiology

1. Sterilization and Disinfection

2. Selection of antibiotics

3. Gram-positive bacilli Aerobic non-spore forming bacilli

4. Gram positive cocci Genus Staphylococci

5. Genus Streptococcus

6. Genus campylobacter

7. Haemophilus

8. Sexually transmitted diseases (STD) Genus Neisseria

9. Legionella

10. Bordetella

11. (Part – one )Anaerobic Bacteriology

(Part – Two) Spore-forming gram-positive Bacilli: Bacillus and

Clostridium Species

12. Spore-forming gram-positive Bacilli: Bacillus and Clostridium

Species

13. Mycobacterium

14. Central Nervous System Diagnostic Microbiology

15. Gastrointestinal Tract Diagnostic Microbiology

16. Diagnostic Microbiology /Urinary tract infections (UTIs)

Arranged by Sarah Mohssen

 List of contents Microbiology

17. Eye Diagnostic Microbiology

Section II - Virology

18. General structure and classification of viruses

19. Virological Tests

20. Herpesviruses

21. paramyxoviruse virus

22. Hepatitis B Virus

23. Enteroviruses

24. Adenoviruses

25. Human Immunodeficiency Virus

26. Human Cancer Viruses

27. What is a vaccine

Section III – Parasitology

Section IV - Medical Mycology

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Section I– Microbiology Introductory By Dr. Mohammed Ayad

Introductory Lecture-Part One

Microorganisms can be found in every ecosystem and in close association with every type of multicellular

organism.

They populate the healthy human body by the billions as benign passengers (normal flora) and even as

participants in bodily functions. Those relatively few species of microorganisms that are harmful to

humans, either by production of toxic compounds or by direct infection, are characterized as pathogens.

Most infectious disease is initiated by colonization (the establishment of proliferating microorganisms on

the skin or mucous membranes). The major exceptions are diseases caused by introduction of organisms

directly into the bloodstream or internal organs.

Microbial colonization may result in:

1- elimination of the microorganism without affecting the host

2- infection in which the organisms multiply and cause the host to react by making an immune or other

type of response

3- Transient or prolonged carrier state.

Infectious disease occurs when the organism causes tissue damage and impairment of body function.

All prokaryotic organisms are classified as bacteria, whereas eukaryotic organisms include fungi,

protozoa, and helminths as well as humans.

Prokaryotic organisms are divided into two major groups: the eubacteria, which include all bacteria of

medical importance, and the archaebacteria, a collection of evolutionarily distinct organisms.

Most bacteria have shapes that can be described as a rod, sphere, or corkscrew. Prokaryotic cells are

smaller than eukaryotic cells. Nearly all bacteria, with the exception of the Mycoplasma, have a rigid cell

wall surrounding the cell membrane that determines the shape of the organism.

The cell wall also determines whether the bacterium is classified as gram positive or gram negative.

External to the cell wall may be flagella, pili, capsule.

Bacterial cells divide by binary fission. However, many bacteria exchange genetic information carried on

plasmids (small, specialized genetic elements capable of self-replication) including the information

necessary for establishment of antibiotic resistance.

Atypical bacteria include groups of organisms such as Mycoplasma, Chlamydia, and Rickettsiae that,

although prokaryotic, lack significant characteristic structural components or metabolic capabilities that

separate them from the larger group of typical bacteria.

Fungi are nonphotosynthetic, generally saprophytic, eukaryotic organisms. Some fungi are filamentous

and are commonly called molds, whereas others (that is, the yeasts) are unicellular.

Fungal reproduction may be asexual, sexual, or both, and all fungi produce spores. Pathogenic fungi can

cause diseases, ranging from skin infections (superficial mycoses) to serious, systemic infections (deep

mycoses).

Protozoa are single-celled, nonphotosynthetic, eukaryotic organisms that come in various shapes and

sizes. Many protozoa are free living, but others are among the most clinically important parasites of

humans. Members of this group infect all major tissues and organs of the body.

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Arranged by Sarah Mohssen

Section I– Microbiology Introductory By Dr. Mohammed Ayad

They can be intracellular parasites, or extracellular parasites in the blood, urogenital region, or intestine.

Transmission is generally by ingestion of an infective stage of the parasite or by insect bite.

Helminths are groups of worms that live as parasites. They are multicellular, eukaryotic organisms with

complex body organization. They are divided into three main groups: tapeworms (Cestodes), flukes

(Trematodes), and roundworms (Nematodes).

Helminths are parasitic, receiving nutrients by ingesting or absorbing digestive contents or ingesting or

absorbing body fluids or tissues. Almost any organ in the body can be parasitized.

Viruses are obligate intracellular parasites that do not have a cellular structure. Rather, a virus consists of

molecule(s) of DNA (DNA virus) or RNA (RNA virus), but not both, surrounded by a protein coat.

A virus may also have an envelope derived from the plasma membrane of the host cell from which the

virus is released. Viruses contain the genetic information necessary for directing their own replication but

require the host’s cellular structures and enzymatic machinery to complete the process of their own

reproduction.

The fate of the host cell following viral infection ranges from rapid lysis and release of many progeny

virions to gradual prolonged release of viral particles.

The human body is continuously inhabited by many different microorganisms (mostly bacteria, but also

fungi and other microorganisms), which, under normal circumstances in a healthy individual, are harmless

and may even be beneficial.

These microorganisms are termed “normal flora.” The normal flora is also termed commensals, which

literally means “organisms that dine together.” Except for occasional transient invaders, the internal

organs and systems are sterile, including the spleen, pancreas, liver, bladder, central nervous system, and

blood.