1. 2010-2011
2nd Term 2nd Semester

2. Haemophilus Spp (Blood-loving bacteria)
 H. Influenzae
 Does not cause influenza, Why named so?
 mistakenly considered the cause of influenza 1890 Pandemic.
 Gram negative coccobacilli
 Obligate parasites of man
 Cause hidden disease because:
 Does not cause a specific disease
 Responding first with antibiotics may mask Hib's
 Difficult to isolate
 Fastidious, require X (hemine) and V (NAD or NADP) factors
in chocolate agar
 A "Rapid Assessment Tool" has been developed by WHO and CDC
to make sensible estimates of Hib
 H. Ducreyi : STD (soft chancroid) not common
 Opportunistic Haemophilus pathogens are rare

3. H. Influenza have no
specific syndrome but
can cause:
meningitis, conjunctivitis,
sinusitis, cellulitis, otitis,
epiglottitis, pneumonia,
Health Canada and www.cdc.gov/vaccines/pubs

4. One of the most transformable genomes
 H. Influenza was the first free living organism to have the
complete genome sequenced in 1995
 The genome consists of 1.8 MB of DNA in a single circular
chromosome of which 1.7 code for proteins.
 How does it become highly-specific to humans?.
 Mutations,Transformable by many ways,
 Phase variation by DNA repeats

5. Diagnosis
 Microscopy to detect in CSF, synovial fluids,
 Culturing, difficult, may be not sensitive
 latex particle agglutination test (LAT)
 PCR
H.Influenza Gram stain H.Influenza Choclate agar

6. Treatment and prophylaxis
 cefotaxime , ceftriaxone, ampicillin and sulbactam,
cephalosporins of the second and third generation, or
fluoroquinolones are preferred.
 Hib conjugate vaccine
 Hib is preventable, but there are two problems:
 A shortage of information : difficult to diagnose, it
causes death without being recognized
 Expensive: Hib vaccine is expensive

7. Vibrio
V. cholerae, and V. parahaemolyticus are human pathogens
V. cholerae: cause cholera. Comma shaped rods , with Two
circular chromosomes
 What is Cholera? Cholera toxin activates adenyl cyclase causing
increased cAMP level and hypersecretion of fluids and electrolytes
 Extensive watery diarrhea (15-20 liters/day) called Rice-Water Stool:
Colorless
Odorless
No protein
Speckled with mucus
 Source contaminated waters and food
 Caused 8 cholera pandemics, example of Pandemic strain is El
Tor
Treatment and prevention
Rehydration & supportive therapy
Water purification, sanitation & sewage treatment
Vaccines

8. Sack, David, et al. 2004. Seminar: Cholera. The Lancet. 363: 223-233.

9. Diagnosis
 Rapid tests
 Dark-field microscopy
 Rapid immunoassays
 Molecular methods – PCR & DNA probes
 Selective/differential culture medium -
Thiosulfate Citrate Bile salts Sucrose (TCBS) agar
 V. cholerae grow as yellow colonies
 Biochemical and serological tests

10. Helicobacter
H. pylori = gastritis, peptic ulcer
disease(PUD)
 Helical (spiral or curved) corkscrew shape and
lophotrichous (tuft at one pole)flagella helps in
penetration and colonization of mucosal lining of stomach
& duodenum
 Acid-inhibitory protein
 Hydrolyzes urea and inhibits acids in gastrics
• Most gastric cancers are preceded by an infection with
H. pylori
 Microaerophilic: Change chape to coccoid when exposed to
oxygen or upon prolonged culture

11.  Diagnostic aspects
 Detected in endoscopic antral gastric biopsy material
 Culture media containing whole or lysed blood
 Microaerophilic
 does not ferment or oxidize carbohydrates
 Triple Chemotherapy (synergism):
 Proton pump inhibitor (e.g., omeprazole = Prilosec(R))
 One or more antibiotics (e.g., clarithromycin;
amoxicillin; metronidazole)
 Bismuth compound

12. Mycobacterium tuberclosis: Tuberclosis 1/3RD of World has it, a
global Emergency.
TB what it is, and how it spreads?
Outside body Inside body:
Spreads through the air when a
person with TB:  bacilli go to lungs and infect alveoli
 Coughs  Macrophages attack bacteria, but some
survive
 Speaks  Infected macrophages form tubercles
 Dead cells form granulomas
 Laughs
 Sneezes
 Sings
http://www.cpmc.columbia.edu/resources/tbcpp/abouttb.html.

13. Symptoms for Pulmonary TB:
There are many types of Tuberclosis, pulmonary
is most important
 Perpetual Cough
 Fever
 Weight loss
 Night sweats Types of TB bacteria include:
Mycobacterium tuberculosis
 Loss of appetite
Mycobacterium leprae
 Fatigue
Mycobacterium avium
 Swollen glands
 Chills
 Pain while breathing

14. Some diagnostics
 Acid fast staining, and Lowenstein-Jensen Agar
 Skin test- Mantoux test
 Purified Protein Derivative PPD injected in forearm and
examined 2-3 days later
 Red welt around injection indicates infection
 Examine medical history, x-rays, and sputum

15. Treatment and prevention
 Take antibiotics for 6-12 months
 Preventative drug to destroy dormant bacteria
 For active TB, 4 medications: isoniazid, rifampin,
ethambutol, and pyrazinamide
 Vaccines (relatively ineffective today)
 Check with X-ray

16. Mycobacterium leprae, Leprosy (uncommon)

17. Spirochetes:
Treponema, Borrelia, & Leptospira
 Spirochete means “coiled hair” Greek. They are
tightly coiled like telephone cord, only a fraction of
a micron in diameter but hundred of microns long
 Twisting Motility by periplasmic flagella (axial
fibrils or endoflagella) is a major difference
between this and other bacteria

18. Spirochaetes: Genus Treponema
 Genus: Treponema: Treponema pallidum, causes syphilis
(sexually, or congenitally transmitted), delicate obligate parasite
 Stages of Syphilis:
 1. Primary Chancre lesion is the main sign
 2. Secondary rash
 3. Latent , no sign but bacteria present
 4.Tertiary, very complicated systemic
 Treponema pertenue, causes yaws
skin lesion

19. Spirochetes
 Genus: Borrelia
 Borrelia burgdorferi,
 Causes a zoonotic vector borne disease called Lyme disease
 Transmitted by ticks
 Linear chromosome
 Borrelia recurrentis, causes relapsing fever
 Genus: Leptospira
 Leptospira species, causes leptospirosis
 Main Diagnostic tests for Spirochetes:
 Darkfield microscopy
 Fluorescent antibody staining
 VDRL
 Wasserman Test
 Hemagglutination tests

20. Treatment and control
 Penicillin remains drug of choice
• WHO monitors treatment recommendations
• 7-10 days continuously for early stage
• At least 21 days continuously beyond the early
stage
 Prevention of Mother-child transfer by
barrier methods (e.g., condoms)
 Prophylactic treatment of contacts identified
through epidemiological tracing
 Cautiousness, and morals play significant
roles

21. Rickettsial Diseases
Transmitted by Arthropod Vectors
 Fastidious, obligate intracellular bacteria that grow only on
cells, eggs, and tissue cultures
 Transmitted by Arthropod Vectors
 They are pleomorphic & coccobacillary
 Do not show on Gram stain, but can be seen with either
Gimenez or Giemsa stains
Gimenez stain of tissue culture cells
infected with Rickettsia rickettsii

22. Rickettsial Diseases
1. Spotted Fever Group
 Mediterranean spotted fever
 Rocky Mountain spotted fever
 – Rickettsia conorii
 – Rickettsia rickettsii
 Siberian tick typhus
 Rickettsial pox
 – Rickettsia siberica
 – Rickettsia akari
 Queensland tick typhus
 Canadian typhus
 – Rickettsia australis
 – Rickettsia canada

23. 2. Typhus Group
 Murine typhus
 – Rickettsia mooseri (typhi)
 Epidemic typhus
 – Rickettsia prowazekii
 Scrub typhus
 – Rickettsia tsutsugamushi

24. 3. Others
 Q Fever
 – Coxiella burnetii
 • Ehrlichiosis
 – Ehrlichia canis
 – Ehrlichia equi
 – Ehrlichia chafeensis
 – Several others now identified

25. Pathogenesis and Clinical Symptoms
 Pathogenesis for all these infections is very similar regardless
of species. A vasculitis (inflammation of blood vessel wall) is
caused by the invasion and multiplication of the organism in
the endothelial and smooth muscle cells of the blood vessels.
Clinical symtoms
 Thrombosis, occlusion, and necrosis of blood vessel walls
 Thrombocytopenia with hemorrhage
 – occurs primarily as a result of platelet consumption as
opposed to true (DIC)disseminated intravascular coagulation
 Massive capillary leakage, edema, hypotension, and
respiratory distress, encephalitis, myocarditis, & nephritis

26. Four Prototype Diseases
 1. Rocky Mountain spotted fever… by Rickettsia rickettsii
 Fever, heache, rash…
 2. Murine typhus…by Rickettsia typhi
 3. Epidemic typhus …by Rickettsia prowazekii
 4. Q fever…by Coxiella burnetii
 Occurs in veterinarians, ranchers, and animal researchers
from infected placenta of sheep, cattle, or goats (no
arthropod vector for C. burnetii). Pneumonia is common

27. Weil-Felix Reaction
and the bit of a history
 Historical known that Proteus antibodis cross-reactive
with several of the rickettsiae. Today, Weil-Felix test is not
confirmed for rickettsial infection.
 In Poland during World War II, two physicians cleverly
used killed Proteus bacteria to vaccinate the men of a
small town, to induce a positive Weil-Felix reaction.
 The occupying Germans feared typhus epidemic and Due
the vaccination reaction, the village was saved of a certain
destruction. The men were not forced into the army, and
the women and children were not forced into the camps.

28. Diagnosis and treatment
Specific & sensitive tests:
 Indirect immunofluorescent antibody (IFA)
 Indirect hemagglutination antibody (IHA)
 Complement fixation (CF)
Treatment
 In life-threatening rickettsial infections, early antibiotic
intervention is recommended to prevent endothelial damage
 Doxycycline, tetracycline, and chloramphenicol are the drugs
of choice
Prevention (transmitted by vectors so avoid them)
 Use of repellents & protective clothing in endemic areas
 Inspection & removal of ticks
 Vaccine for RMSF is available for risk groups
 Weekly doxycycline