Tetanus is caused by Clostridium tetani bacteria. The spores can enter the body through breaks in the skin and wounds. The bacteria releases toxins that cause painful muscle spasms. There are four main types - generalized tetanus affects many muscles, neonatal tetanus affects newborns, local tetanus affects the injury area, and cephalic tetanus affects the head region. The toxins block inhibitory neurotransmitters in the spinal cord, causing uncontrolled muscle contractions. Proper wound care and vaccination can help prevent tetanus infections.

1. Tetanus
 Tetanus (to stretch) also called Lockjaw disease Trismus.
 Its bacterial infection characterized by muscle spasms (Involuntary
action) & autonomic nervous system disturbance.
 Its caused by Closteridium tetani, an anaerobic, Gram +ve, bacilli,
with terminal endospore forming (drum stick appearance).
 Tetanus has been known since ancient time; causative organism was
isolated later by Kitasato (1889).
 The spores of Closteridium tetani are commonly found in hospitals,
environment, in soil/mostly in soils with high organic manure, many
farm animals .

2.  Tetanus occurs in all parts of the world but is most frequently found
in hot and wet climatic areas, where the soil contains lot of organic
matter.
 Manure treated soil is major resource of endospores, and they are
distributed in feces of many animals like sheep, goats, houses, dogs,
cats, chickens.
Transmission & symptoms
 Animal bites can transmit tetanus infection.
 Tetanus bacilli enter through Injury (superficial abrasions,
punctured wounds, road traffic accidents).
 Surgery done without proper aseptic conditions.

3.  Neonates- following abortion/ delivery, due to unhygienic practices.
 It is non-infectious- there is no person-to-person spread.
 In most cases spasms begins in jaw and then proceed into other
parts of body.
 Spasms usually lasts for few minutes, and occur frequently for 3-4
weeks may cause bone fracture.
 Tetanus is international health problem as spores of C. tetani are
ubiquitous in nature.
 Being anaerobic in nature they colonise in wounds where oxygen is
lacking.
 In 2015, about 2,09000 infection and 59000 deaths globally.

4.  Transmission to humans is assisted with skin wounds, any break in
the skin that allows spores to enter.
 Cut or puncture wound by a contaminated object can cause
infection.
 The spores are also present on skin surface of heroin injection users.
 If injury site is away from CNS then it take time for incubation and if
close to CNS then incubation occurs in lesser period.
NeonataI tetanus (bodily rigidity); Lockjaw and the facial spasms

5. Symptoms
 Fever, sweating, headache, high blood pressure, and fast heartbeat,
loss of stool control, burning sensation during urination.
 Symptoms start after 3-21 days of infection and recovery may take
months.
 Its incubation period may be in months but usually 10days.
 The spasms can also affect the facial muscles resulting in an
appearance called Risus Sardonicus.
 Back muscle spasms often cause arching called Opisthotonos.
 Sometimes spasms affects the muscles that help in breathing, which
can lead to breathing problems.

6.  A neuron (also called neurone or nerve cell) is a
cell that carries electrical impulses.
 Every neuron is made of a cell body (also called
soma or cyton), dendrites and an axon.
 Dendrites and axons are nerve fibers. There are
about 86 billion neurons in the human brain,
which comprises roughly 10% of all brain cells.
 In nervous system there is a structure called
Synapse that permits neuron to pass an signal
chemical/electrical) to other nerve cell.
 Synapse is a microscopic voids between cells,
where chemicals (signals) are released by
terminal of axon of one cell to specialized
chemical receptors on the dendrite of the
receiving cell.
 Transferred via neuro-transmitters in Synaptic
vesicle from Pre- Synaptic neuron (sends signal)
to post- Synaptic neuron (receives signal).
 Motor neuron carries signal from CNS to muscles

7. Virulence Factors - Exotoxins
 C. tetani produces two exotoxins- Tetano-lysin and Tetano-spasmin.
 These toxin interfere with normal muscle interactions.
 Cause tension, cramping and twisting in skeletal muscles surrounding the
wound and tightness of jaw muscles.
 If the oxygen tension is low enough the spores germinate and release the
neurotoxin namely Tetano-spasmin (Tetanus toxin).
 It is oxygen stable but heat labile.
 Toxin is produced as a single polypeptide chain, that is cleaved to produce
heavy two chains joined by a di-sulfide bond.
 It is an endo-peptidase, that selectively cleaves the synaptic vesicle
membrane.

8.  Synaptic vesicle: that contains neurotransmitters (Signals)
 Tetanus toxin prevents release of inhibitory neurotransmitters
(Amino-butyric acid and Glycine) at synapses (Junction between two
neurons) within the spinal cord motor nerve.
 Which is required to check the nervous impulses.
 Motor neuron carries signal from CNS to muscles.
 The result is uncontrolled stimulation of skeletal muscles (Spastic
paralysis).
 Other toxin namely Tetano-lysin, is a hemolysin that aids in tissue
destruction.
 Its heat labile, oxygen labile it plays no role in pathogenesis of
tetanus.

9. Four Types Of Tetanus - On Basis Of Clinical Observation
Generalized Tetanus:
 Common type of Tetanus in about 80% of cases.
 Its symptoms occurs in descending order (from major symptoms to
lighter ones) like Trismus / jawlock, facial spasms, stiffness of neck.
 Other symptoms blood pressure, rapid heart beat, high temperature.
 Here in this case, spasms (involuntary actions) occur frequently and
persist for few minutes.
Neonatal tetanus:
 Occurs in new-borns, usually present in those new-borns, who's
mothers are not been vaccinated during pregnancy.
 It often occurs unsterilized instruments used for cutting of umbilical
stump/cord.
Local tetanus:
 It an uncommon form of tetanus, in which people have persistent
muscle contraction.

10.  In the area of injury, the contraction may persist for many weeks till
it ends.
 Its about 1% fatal.
 It may lead to symptoms of Generalized Tetanus if not treated.
Cephalic Tetanus:
 It rarest form of tetanus 0.9-3% of causes.
 Its limited to muscles and nerves of head.
 It usually occurs after trauma to the head area, including skull
fracture, laceration, eye injury, dental extraction etc.
 It is observed from injuries to other parts of body.
 It may cause frequent paralysis of facial nerves leading to lockjaw,
facial palsy.
 It may cause sever symptoms like in Generalized Tetanus, and
patients are not properly diagnosed.

11. Pathogenicity & virulence
 C tetani is not an invasive organism.
 The infection remains strictly localized in the area of devitalized
tissue (wound, burn, injury, umbilical stump, surgical suture) into
which the spores have been introduced.
 Toxin released from vegetative cells reaches the central nervous
system and rapidly becomes fixed to receptors of nerves (in the
spinal cord and brainstem).
 Tetanus toxin (Tetanospasmin) initially binds with peripheral nerve
terminals. It binds with receptors present on motor nerve terminals
which results in toxin internalization.

12.  Then transported to synaptic junctions until it reaches the CNS.
 In CNS, toxin rapidly fixes with ganglosides (molecules of
polysaccharides present on cell membrane/surfaces mostly in
Nervous system) at the pre-synaptic inhibitory motor nerve endings
and is taken into axon by endocytosis.
 The toxin block the release of inhibitory neuro-transmitters, glycine
and gamma-amino-butyric-acid (GABA) across the synaptic cleft,
which is required to check the nervous impulses.
 If nervous impulses cant be checked by normal inhibitory
mechanism, the general muscle spams are produced by tetanus.

13. Diagnosis
• Currently no blood examination test for diagnosis of tetanus.
• Gram staining reveals gram-positive bacilli with terminal and round
spores (drum slick appearance).
• Lab identification of C. tetani is done by only production of
tetanospasmin in mice.
• Anaerobic culture is more reliable than microscopy.
• Robertson cooked meat broth- C. tetani, being proteolytic turns the
meat particles black and produces foul odor.
• Blood agar with polymyxin B- these plates are incubated at 37°C for 24-
48 hours under anaerobic condition.
• Active immunization with toxoids; proper care of wounds contaminated
with soil; prophylactic use of Antitoxin; administration of penicillin.

15. Pneumonia
• Among different lower reparatory track infection Pneumonia is one
of the serious infection.
• Pneumonia is an inflammatory condition of lungs (Pneumonitis)
affecting primarily the small air sacs called alveoli.
• Pneumonia can be Community Acquired Pneumonia or Nosocomial
Pneumonia.
• In both cases multiple agents are responsible for infection
bacteria/viruses less commonly by fungi and protozoa.
• Nosocomial Pneumonia occurs approximately 48 hours after
admitting of patient and is usually caused by Staphylococcus aureus,
or with G-ve bacteria like P. aeruginosa.
• If the infection is caused by Staphylococcus sp, then its difficult to
deal with antibiotic as they are being resistant to drugs MDRS.
• While as Community Acquired Pneumonia is usually lobar
pneumonia (Bacterial infection of lungs; showing inflammation of
an entire lobe) accompanied by fever, chest pain.

16.  Atypical pneumonia can be caused by Mycoplasma pneumoniae;
Chlamydia pneumoniae; Chlamydia psittaci; Legionella
pneumoniae.
 Pneumonia causes infection to 450 million people globally and
leads to death of 4million people /year.
 Risk factors include cystic fibrosis, chronic obstructive pulmonary
disease COPD, asthma, diabetes, heart failure, week immune
system, smoking.
Types of Pneumonia:
Community Acquired Pneumonia
Nosocomial Pneumonia or hospital acquired Pneumonia.
Mycoplasma Pneumonia
Chlamydial Pneumonia

18. Symptoms
 Productive cough, fever with chills, shortness of breath, chest pain.
 In children below 5 years have fever, cough, fast or difficult
breathing.
 Children below 2 months don’t show cough symptoms.
 Some sever symptoms in children are blue-tinged skin, vomiting,
high body temperature, decreased level of consciousness.
• There can be some cases having cough with out sputum, its called
Atypical pneumonia.
• Pneumonia cased by Legionella, cause abdominal pain, diarrhea
and confusion.
• Pneumonia cased by Streptococcus pneumonia shows rusty color
sputum.
• Pneumonia cased by Klebsiella sp shows bloody sputum.

19. Pneumonia
1. Community Acquired Pneumonia (CAP)
 Pneumonia primarily starts in upper respiratory track and progresses
to lower respiratory track.
 Here it shows all the mild to acute symptoms.
 It is mostly caused by Streptococcus pneumonia, isolated from about
50% cases.
 Haemophilus influenzae in 20% cases; Chlamydia pneumoniae in 13%
cases; Mycoplasama pneumoniae in 3% cases.
Pathogenesis:
 This infection usually occurs after the aspiration of pathogens such as
Pneumococcus in huge numbers to overwhelm (engulf) the resident
defences present in the lungs.
 Bacteria residing in throat or nose enter lungs because of small
aspirations of organisms.
 Aspirations: (Sucking of fluid /air) small breaths along sound that
takes pathogens in from upper respiratory track.

20.  Micro-aspiration of contaminated secretion can infect the lower
airways and cause pneumonia.
 The establishment of an infection in the lungs depends not only on
the number of pathogens entering the lungs.
 But also on the competence of the mucociliary escalator to keep
them out.
Pathogenesis of Community Acquired Pneumonia
 Acute congestion occurs where local capillaries become completely
filled with fluid and neutrophils,
 Followed by Red hepatization stage in which RBCs from capillaries
flow into alveolar space.
 Hepatization: When lungs are filled with fluid matter and no longer
capable of passing air.
 Followed by Grey hepatization stage in which large number of dead
and dying neutrophils are present and degenerating red cells as
seen.

21.  In last stage called Resolution the immune system produces
antibodies that controls the infection.
 Minority of bacteria residing in throat like M. tuberculosis and
Legionella pneumophila reaches the lungs via contaminated
airborne droplets.
 Once in lungs bacteria may invade the space between cells and
alveoli.
 Here macrophages and neutrophils try's to inactivate the bacteria.
 Immune system (including neutrophils) release cell signals like
cytokines, which causes activation of immune response.
 That causes fever, chills and fatigue that’s common in pneumonia.
 Bacteria can also spread in blood.
 The neutrophils, bacteria and fluid from surrounding blood vessels
fill the alveoli, resulting in the consolidation.

22. Nosocomial Pneumonia
 As its found that hospitalized patients giving rise to infection are
dangerous.
 Most of acquired infection and pathogens are also becoming
resistant to number of antibiotics, like Enterobacter sp,
Pseudomonas sp, streptococcus sp, staphylococcus aureus MDRS.
 As hospitals are filled with debilitated (immunocompromised)
patients.
 That debilitation causes increase in proteolytic enzyme activity in
saliva of these patients.
 Which directly causes rapid turnover of fibronectin layer, that
covers the epithelium of the pharynx.
 This layer carries normal micro flora, once its lost area become
colonized by opportunistic pathogen.
 That can (aspirated) get into lungs and cause pneumonia.

24. Mycoplasma pneumoniae
 Its mild form of pneumonia accounts about 20% , often called as
Walking pneumonia because for this hospitalization is not needed.
 Mycoplasma pneumoniae is bacteria without cell wall, infection is
transmitted by droplets.
 Needs lest than 100 cells for infection.
 Incubation is between 2-15 days, with fever, cough, headache
followed by respiratory symptoms.
 Infection involves trachea, bronchi, and bronchioles and may go
down to alveoli.
 Primarily Mycoplasma pneumoniae attaches to cilia and microvilli
of cell lining of bronchial epithelium.
 This attachment interfered with the capillary action, that results in
detachment of the mucosal layer and sub-sequent inflammation
and appearance of exudate.
 Inflammatory response is initially composed of lymphocytes,
plasma cells, and macrophages.

25.  Which may infiltrate and thicken the wall of bronchioles and
alveoli.
 The organism may be shed in upper respiratory secretions for 2-
8days.
Chlamydial pneumonia
 Found through out the world, with about 10%.
 Caused by Chlamydia pneumoniae, can spread by person-to-person
contacts. Causes more diseases other than pneumonia.
 This type of pneumonia is reported from both Community Acquired
Pneumonia and Nosocomial Pneumonia or hospital acquired
Pneumonia.
 This can occur mostly in elderly people. Starts from pharyngitis, LRT,
or both.
 Diagnosis: Chest X-ray, complete blood profiling, sputum analysis
and culturing,
 Treatment: Penicillin, amoxicillin-clavunate, erythromycin,
azithromycin, tetracyciline.