Summarixes

1. By: YASSER, MOHAMMAD MOSLIM, AHMED QADRI,

2. Biological weapons bacteria

3. Biological Weapons: A Microbiological Perspective
• Biological weapons are microorganisms or toxins intentionally used to cause disease
or death in humans, animals, or plants. These agents exploit natural microbial
characteristics such as replication, infectivity, virulence, and transmission. Because
they rely on living organisms, biological weapons are difficult to detect, easy to
disseminate, and capable of causing large-scale outbreaks. Understanding their
microbiological properties is essential for recognizing, preventing, and responding to
bioterrorism threats.

4. What Are Biological Weapons?
• Biological weapons consist of pathogenic bacteria, viruses, fungi, or microbial toxins that
are manipulated or deployed to cause harm. Effective biological agents typically have:
• High infectivity — a small infectious dose can cause disease.
• Environmental stability — spores or resistant viral particles can survive harsh
conditions.
• Ease of production — many microbes can be cultured using basic laboratory
equipment.
• Silent spread — incubation periods allow undetected transmission.
• From a microbiology standpoint, biological weapons take advantage of microbial
growth, host invasion mechanisms, and efficient modes of transmission such as aerosols,
contaminated food/water, or vectors.

5. Historical Use of Biological Agents
• Biological warfare has been documented throughout history. In 1346, attacking
armies catapulted plague-infected corpses over city walls during the siege of
Kaffa, contributing to outbreaks. During World War II, Unit 731 in Japan
conducted large-scale field tests using anthrax and plague. In 1979, an
accidental release of aerosolized Bacillus anthracis spores from a Soviet facility
in Sverdlovsk caused dozens of deaths. In 2001, letters containing anthrax
spores were mailed in the United States, demonstrating that biological
weapons can be used on a small scale by individuals as well as by governments.

6. Major Biological Agents
• 1. Bacillus anthracis (Anthrax)
A Gram-positive, spore-forming rod. Its spores survive for decades in soil and can be aerosolized. Inhalation
anthrax causes severe respiratory distress, sepsis, and has a high fatality rate.
• 2. Variola virus (Smallpox)
A double-stranded DNA virus from the Orthopoxvirus family. It spreads by respiratory droplets and has a
high mortality rate. Because natural smallpox has been eradicated, population immunity is extremely low,
increasing its danger if released intentionally.
• 3. Yersinia pestis (Plague)
A Gram-negative coccobacillus transmitted naturally by fleas, but it can be weaponized as an aerosol to cause
pneumonic plague, which is highly infectious and rapidly fatal without treatment.
• 4. Botulinum toxin
Produced by Clostridium botulinum, this toxin is the most potent biological substance known. It blocks
neuromuscular transmission, causing flaccid paralysis and respiratory failure. Even tiny amounts can be
lethal.

7. Microbiological Mechanisms of Biological Weapons
• Biological agents cause harm through several microbiological mechanisms.
Infectious organisms invade host tissues, replicate rapidly, and evade the
immune system using capsules, enzymes, or intracellular residence. Toxin-
producing bacteria release potent exotoxins that disrupt cellular processes—
such as botulinum toxin blocking acetylcholine release or anthrax toxin
impairing immune signaling. Some pathogens form resistant structures, like
anthrax spores, allowing long-term environmental survival. Aerosolized
particles sized 1–5 µm can lodge deep in the lungs, enabling efficient airborne
infection and rapid spread.

8. Detection, Prevention & Control
• Detection relies on microbiological techniques such as PCR for genetic
identification, culture methods for isolating pathogens, and ELISA tests for
detecting microbial toxins. Environmental biosensors and rapid diagnostic
platforms are increasingly used for early warning. Prevention includes vaccines
such as the anthrax vaccine and stored smallpox vaccines, antimicrobial
treatments, and public health measures like isolation and contact tracing.
Decontamination uses heat, ultraviolet light, chlorine, or autoclaving to destroy
microbial agents. Microbiology laboratories play a critical role in confirming
cases, sequencing pathogens, and guiding outbreak response.

9. Ethical, Legal & Public Health Implications
• The development and use of biological weapons are prohibited under the
Biological Weapons Convention, but concerns remain due to dual-use
research, where the same microbial techniques used for vaccines and
treatments can also be misused for weaponization. Advances in genetic
engineering and synthetic biology raise the risk of modified or more virulent
agents. Public health systems must maintain strong surveillance, preparedness
plans, and laboratory capacity to detect and control biological threats.
Microbiology is essential not only for understanding these agents but also for
preventing misuse and protecting global health.

10. Clostridium
Botulinum

11. What is clostridium
Botulinum?
Clostridium botulinum is a tiny germ that can grow with no air and makes a very
strong poison that can stop nerve signals, weaken the body, and cause serious
sickness, because its spores live in soil, water, and unsafe canned food, and even a
very small amount of this poison can harm babies, wounds, or anyone who eats food
kept in a wrong way.
High dose dangerous and may be used as a biological weapon.
→
Low dose safe for medical and cosmetic use, known as Botox.
→

12. Food botulism
A person eats food with toxin made before eating.
• Seen in canned food or food kept with no air.
• Signs: two-way sight, no easy eating, weak move going down the
body.
01
02 Infant botulism
• Tiny spore gets into the gut of a baby and starts to grow.
• Signs: soft body, weak cry, no easy poo (soft-baby state).
• Honey can have spore, so no honey for babies.
03
Wound botulism
Spore gets into a cut and makes toxin in a spot with no air.
• Signs look the same as food botulism.
Infections
Mechanism of pathogenesis
• The toxin stops the send-off of body nerve signal at
the join of nerve and muscle.
• This makes the body soft and unable to move with
power.
• The toxin can act in the whole body, but the germ
stays in one spot.

13. Staphylococcus

14. Staphylococcus, from Ancient Greek σταφυλή, meaning "bunch of grapes", and
κόκκος, meaning "kernel" or "Kermes", is a genus of Gram-positive bacteria
Staphylococci:
-Occur in grape like clusters - They are non motile and
non sporing.
-A few strains possess capsules - Produce pigments
Cultural Characteristics:
i) On nutrient agar- The colonies are large, circular,
convex, smooth, shiny, opaque . Most strains
produce golden yellow pigments.

15. Infections
Mechanism of pathogenesis:
* Cocci gain access to damaged skin, mucosal or tissue site
* Colonize by adhering to cells or extracellular matrix
* Evade the host defense mechanisms and multiply
* Cause tissue damage
Common Staphylococcal infections are:
1) Skin and soft tissue: Folliculitis, furuncle (boil),
carbuncle, styes, abscess, wound infections,
impetigo, and less often cellulitis.
Folliculitis