Microbes play an important role in causing infectious diseases. They can enter the body through various portals of entry and cause localized or systemic infections depending on factors like virulence and host defenses. Diseases may be communicable through direct or indirect contact or non-communicable if the agent normally inhabits the body. Microbes have specific biological requirements for oxygen, nutrients, temperature, pH and other factors that influence their ability to cause infection.

1. THE ROLE OF
MICROBES IN DISEASE
PRODUCTION

2. •INFECTION---CONDITION WHERE MICROBES
ENTER THE HUMAN BODY OR ANY PLANT OR
ANIMAL, MULTIPLY IN THE HOST AND
PRODUCES A REACTION
•*CONTAMINATION---REFERS TO THE MERE
PRESENCE OF INFECTIOUS MATERIAL/
CONSTITUTES THE NORMAL FLORA OF THE
BODY

3. •INFECTIOUS DISEASES MAY BE COMMUNICABLE OR
NON-COMMUNICABLE AS BASED ON THE MANNER
IN WHICH THE CAUSATIVE AGENT REACHES THE
BODY OF THE HOST
***COMMUNICABLE---IF THE CAUSATIVE AGENT
IS DIRECTLY OR INDIRECTLY TRANSMITTED FROM
HOST TO HOST
EX. DIPHTHERIA / TUBERCULOSIS

4. •NON-COMMUNICABLE---AGENT NORMALLY
INHABITS THE BODY; PRODUCES THE DISEASE ONLY
WHEN INTRODUCED INTO THE BODY
EX. TETANUS---NOT COMMUNICABLE BUT INFECTIOUS
•CONTAGIOUS---APPLIED TO DISEASES THAT ARE
EASILY SPREAD FROM PERSON TO PERSON

5. •INFECTIOUS DISEASES MAY BE:
1. EXOGENOUS---CAUSATIVE AGENT COMES FROM
OUTSIDE & ENTERS THE BODY THROUGH ONE OF
THE PORTALS OF ENTRY
2. ENDOGENOUS---CAUSED BY ORGANISMS
NORMALLY PRESENT IN THE BODY; OCCURS
WHEN THE DEFENSIVE POWERS OF THE HOST ARE
WEAKENED OR THE VIRULENCE OF THE
ORGANISM IS INCREASED.

6. •PORTALS OF ENTRY:
1. SKIN----STAPHYLOCOCCI / FUNGI
2. RESPIRATORY APPARATUS---PULMONARY
TUBERCULOSIS/ PNEUMONIA/ INFLUENZA/
VIRUSES OF MEASLES/ SMALLPOX/ GERMAN
MEASLES
3. ALIMENTARY TRACT---DYSENTERY
BACILLI/CHOLERA VIBRIOS/ AMOEBAS OF
DYSENTERY

7. ***MOST OFTEN CONTACTED THROUGH
FOOD & DRINKS
4. GENITOURINARY SYSTEM---STDs
• A. GONORRHEA
• B. SYPHILIS
5. PLACENTA
***SPIROCHETE OF SYPHILIS/ VIRUS OF
SMALLPOX

8. •FACTORS INFLUENCING THE OCCURRENCE OF
INFECTION:
1. PORTAL OF ENTRY---ORGANISMS MAY FAIL TO
PRODUCE THE DISEASE WHEN INTRODUCED INTO
THE BODY BY SOME OTHER ROUTE/PATHWAY
**TYPHOID BACILLI---NEED TO BE SWALLOWED TO
CAUSE INFECTION; PRODUCES INFLAMMATION ONLY
WHEN RUBBED ON THE SKIN

9. ** STRETOCOCCI---CAUSES CELLULITIS WHEN
RUBBED ON THE SKIN; NO EFFECT WHEN
SWALLOWED; CAUSES PNEUMONIA WHEN
BREATHED INTO THE LUNGS
2. VIRULENCE OF THE ORGANISM---ABILITY OF THE
MICROBE TO PRODUCE THE DISEASE BY
OVERCOMING THE DEFENSIVE POWERS OF THE
HOST; MICROBES ARE MOST VIRULENT WHEN FRESHLY
DISCHARGED FROM AN AILING PERSON

10. 3. NUMBER OF MICROBES---CRUCIAL TO INFECTION
4. DEFENSIVE POWERS OF THE HOST
***MICROBES CAN CAUSE DISEASE BY:
A. MECHANICAL MEANS---OCCLUSION OF VITAL
ORGANS/ AREAS
B. PRODUCTION OF BIOCHEMICAL EFFECTS LIKE
TOXIN PRODUCTION

11. ***ELECTIVE LOCALIZATION---FAVORED PART OF THE
BODY FOR INFECTION
1. DYSENTERY BACILLI----LARGE BOWEL
2. PNEUMONIA---LUNGS
3. PNEUMOCOCCI---LUNGS
4. MENINGOCOCCI---LEPTOMENINGES

12. ***TISSUE AFFINITY --- specific body part affected
1. TOXINS OF TETANUS --- act on the CNS
2. TOXINS OF DIPHTHERIA --- affect the
CNS & heart
*** LOCAL EFFECTS:
1. INFLAMMATION --- body’s answer to
injury; designed to halt the invasion
2. REDDENING
3. WATER RETENTION

13. ***GENERAL EFFECTS
1. Fever
2. Tachycardia
3. Increased metabolic rate
4. Signs of Toxicity
5. Anemia --- results from prolonged and severe
infections
 INFECTIONS---LEUKOCYTOSIS—INCREASED WBCs OR
LEUKOPENIA---DECREASED WBCs

14. PORTALS OF
EXIT

15. 1. FECES --- Salmonella / Vibrio cholerae / Amoeba /
Shigella / Viruses of Poliomyelitis & Type A hepatitis
2. URINE --- Causes Pyelonephritis, TB of the Genitourinary
Tract / Undulant Fever
3. DISCHARGES FROM THE MOUTH, NOSE & RESPIRATORY
PASSAGES --- Tuberculosis / Whooping Cough /
Pneumonia / Scarlet Fever / Epidemic Meningitis / Viruses
of Measles / Smallpox / Mumps / Polio / Influenza &
Epidemic Encephalitis

16. 4. SALIVA --- Viruses of Rabies
5. BLOOD --- Protozoa of Malaria / Bacteria of
Tularemia / Rickettsias of Typhoid fever / Virus of
Yellow Fever

17. PATTERNS OF INFECTION
1. INCUBATION PERIOD --- infection is received to the
appearance of the disease
Affected by the following factors:
a. Nature of the agent
b. Virulence of the agent
c. Resistance of the
d. Distance from the site of entrance to the focus of action
e. Number of infectious agents invading the body

18. 2. PRODROMAL PERIOD --- short interval that follows the
period of incubation with headache and malaise
3. INVASION PERIOD --- disease reaching its full
development and maximum intensity --- characterized
by rigors & chills, fever, pale &dry skin, decreased heat
loss
4. FASTIGIUM OR ACME --- disease at its high/peak

19. 5. DEFERVESCENCE OR DECLINE
--- phase where manifestations of the disease
subsides
--- characterized by profuse sweating
--- heat loss exceeds heat production

20. TYPES OF INFECTION:
1. LOCALIZED---MICROBES REMAIN CONFINED TO A
PARTICULAR PART OF THE BODY
EX. BOILS/ ABSCESSES
2. GENERALIZED---MICROORGANISMS & THEIR
PRODUCTS ARE SPREAD GENERALLY OVER THE
BODY BY THE BLOOD OR LYMPHATICS
3. MIXED---CAUSED BY 2 OR MORE ORGANISMS (
PRIMARY INFECTION PLUS SECONDARY INFECTION)

21. 4. FOCAL--- INFECTION IS CONFINED TO A RESTRICTED
AREA FROM WHICH INFECTIOUS MATERIAL
SPREADS TO OTHER PARTS OF THE BODY---EX.:
INFECTIONS OF THE TEETH, SINUSES & PROSTATE
GLANDS
5. INAPPARENT OR SUBCLINICAL---DOES NOT CAUSE
ANY DELECTABLE MANIFESTATIONS

22. 6. LATENT INFECTION---INFECTION IS HELD IN CHECK BY
THE DEFENSIVE FORCE OF THE BODY; ACTIVATED
WHEN THE BODY’S RESISTANCE IS REDUCED
7. INOCULATION INFECTION--- AN INFECTION CAUSED
BY ACCIDENTAL OR SURGICAL PENETRATION OF
THE SKIN OR MUCOUS MEMBRANES

23. 8. BACTEREMIA---BACTERIA ENTER THE BLOOD BUT DO
NOT MULTIPLY
9. SEPTICEMIA---BACTERIA ENTER THE BLOOD BUT DO
NOT MULTIPLY; CAUSES BLOOD POISONING
10. PYEMIA---PYOGENIC BACTERIA(PUS FORMERS) IN
THE BLOOD SPREADS TO THE DIFFERENT PARTS OF
THE BODY & SETS UP A NEW FOCUS OF DISEASE

24. 11. TOXEMIA---TOXINS LIBERATED BY BACTERIA ENTER
THE BLOODSTREAM TO CAUSE A DISEASE.
EX. DIPHTHERIA
12. SAPREMIA--- SAPROPHYTIC BACTERIA MAY GROW
ON DEAD TISSUE & PRODUCE POISONS WHICH
ARE ABSORBED BY THE BODY
13. TERMINAL---CHRONIC WASTING DISEASES

25. 14. SPORADIC---INFECTION OCCURING
OCCASIONALLY IN A COMMUNITY
15. ENDEMIC---INFECTION IS CONSTANTLY PRESENT IN A
COMMUNITY
16. EPIDEMIC---DISEASE ATTACKING A LARGE NO. OF
PEOPLE IN THE COMMUNITY IN A SHORT TIME

26. SPREAD OF INFECTION:
1. DIRECT CONTACT--- DROPLET INFECTION/ PLACENTAL
TRANSMISSION/ BODILY CONTACT (STDs TRANSMISSION)/
BLOOD TRANSFUSIONS/ FROM PERSON TO PERSON IN
CLOSE ASSOCIATION
2. INDIRECT CONTACT---SPREAD BY CONVEYORS LIKE MILK,
FOOD, WATER, AIR, CONTAMINATED HANDS,
INANIMATE OBJECTS OR FOMITES/ FILTH/INSECTS
EITHER MECHANICALLY THROUGH ITS FEET OR
BIOLOGICALLY THROUGH INSECT BITES.

27. BIOLOGIC REQUIREMENTS
OF THE BACTERIAL CELL

28. I. ATMOSPHERIC REQUIREMENTS---USEFUL IN
IDENTIFYING BACTERIA:
A. RELATIONSHIP TO OXYGEN:
1. OBLIGATE AEROBES---REQUIRE OXYGEN
CONCENTRATIONS COMPARABLE TO THAT FOUND
IN ROOM AIR (20-21% O2)
* Mycobacteria
* certain fungi

29. 2. MICROAEROPHILES---REQUIRE OXYGEN
CONCENTRATION LOWER THAN THAT AT ROOM TEMP.
FOR MULTIPLICATION( 5% O2)
* Neiserria gonorrheae
*Campylobacter
3. ANAEROBES---DO NOT REQUIRE OXYGEN FOR LIFE
AND REPRODUCTION; MAY VARY IN THEIR
SENSITIVITY TO OXYGEN

30. A. OBLIGATE ANAEROBE---CAN GROW IN AN
ENVIRONMENT CONTAINING NO OXYGEN
B. AEROTOLERANT ANAEROBE---DOES NOT REQUIRE
OXYGEN, GROWS BETTER IN THE ABSENCE OF
OXYGEN BUT CAN SURVIVE IN ATMOSPHERES
CONTAINING MOLECULAR OXYGEN (AIR/ CO2
INCUBATOR)
C. FACULTATIVE ANAEROBES---CAPABLE OF
SURVIVING IN EITHER THE PRESENCE OR ABSENCE OF
OXYGEN (0 % O2 TO 20 TO 21% O2)

31. ***MEMBERS OF ENTEROBACTERIACEAE/
STREPTOCOCCI/ STAPHYLOCOCCI
D. CAPNOPHILES---GROW BETTER IN THE PRESENCE
OF INCREASED CONCENTRATIONS OF CO2
EX. ANAEROBES---BACTEROIDES/FUSOBACTERIUM
AEROBES----NEISSERIA/CAMPYLOBACTER/
HAEMOPHILUS

32. II. NUTRITIONAL REQUIREMENTS
* PROTEINS---COMPRISES 50% OF THE BACTERIAL CELL
***CARBON/HYDROGEN/OXYGEN/SULFUR/PHOSPHOR
US/NITROGEN
***POTASSIUM/CALCIUM/IRON/MANGANESE/MAGNES
IUM/COBALT/COPPER/ZINC/URANIUM ( SPECIAL
ELEMENTS REQUIRED BY BACTERIA)
***FASTIDIOUS----ORGANISMS WITH SPECIALLY
DEMANDING NUTRITIONAL REQUIREMENTS

33. * GROWTH FACTORS
* SOURCES OF ENERGY
***ALL BACTERIA DERIVE THEIR CARBON AND
NITROGEN FROM ORGANIC MATTER, EXCEPT THE
SAPROPHYTES
KINDS OF ORGANISMS ACCDG. TO WHERE
NOURISHMENT IS OBTAINED:
1. SAPROPHYTES---FROM NON-LIVING ORGANIC
MATTER

34. *** PARASITES---DEPEND ON LIVING MATTER FOR
SUSTENANCE
*** FACULTATIVE SAPROPHYTES---USUALLY OBTAIN
NOURISHMENT FROM LIVING MATTER BUT MAY OBTAIN
IT FROM THE DEAD ORGANIC MATTER.
***FACULTATIVE PARASITES---USUALLY OBTAIN THEIR
NOURISHMENT FROM DEAD ORGANIC MATTER BUT
MAY OBTAIN IT FROM LIVING MATTER.

35. ***HETEROTROPHS/ ORGANOTROPHS--- OBTAIN THEIR
NUTRIENTS BY BREAKING DOWN ORGANIC MATTER
INTO SIMPLER INORGANIC SUBSTANCES.
MOISTURE___75-80 % OF BACTERIAL CELL IS WATER;
NEEDED TO DISSOLVE FOOD MATERIALS IN THE
ENVIRONMENT
DRYING---DETRIMENTAL TO BACTERIA GROWTH

36. •TEMPERATURE:
•*** OPTIMUM TEMP----BEST TEMP FOR GROWTH
•*** MINIMUM TEMP---LOWEST TEMP. AT WHICH SPORES
WILL GROW.
•***MAXIMUM TEMP--- HIGHEST TEMP AT WHICH
GROWTH IS POSSIBLE.

37. *** 42-45 DEGREES CELCIUS IS THE HIGHEST TEMP
WHERE BACTERIA CAN STILL MULTIPLY; 20 DEGREES
CELCIUS---LOWEST TEMP AT WHICH THEY CAN
MULTIPLY
***THERMOPHILES---HEAT-LOVING SPECIES; CAN
GROW ABOVE 45 DEGREES CELCIUS TEMP.

38. ***PSYCHROPHILES/CRYOPHILES---COLD-LOVING
SPECIES;CAN GROW AT TEMP JUST ABOVE THE
FREEZING POINT
***COLD RETARDS OR STOPS BACTERIAL GROWTH THUS
EMPLOYED IN THE PROCESS OF REFRIGERATION IN
ORDER TO PROLONG THE SPOILAGE OF FOOD

39. PH---REFERS TO THE
ACIDITY/ALKALINITY OF THE MEDIUM
•***PREFERRED PH IS BETWEEN 6-8
•**BEST PH FOR PATHOGENS IS PH 7 (NEUTRAL)
•OXYGEN REQUIREMENT:
•***AEROBES--- GROW IN THE PRESENCE OF FREE
ATMOSPHERIC OXYGEN

40. •OBLIGATE AEROBES---CANNOT DEVELOP IN THE
ABSENCE OF FREE OXYGEN
•* ANAEROBES---OBTAAIN THEIR OXYGEN FROM
OXYGEN CONTAINING COMPOUNDS LIKE
INORGANIC SULFATES, NITRATES, CARBONATES OR
FROM ORGANIC COMPOUNDS
•* OBLIGATE ANAEROBES---ORGNISMS WHOSE
ENZYME SYSTEMS ARE INACTIVATED BY ATMOSPHERIC
OXYGEN

41. •* FACULTATIVE ORGANISMS---ADAPTABLE EITHER TO
THE PRESENCE OR ABSENCE OF ATMOSPHERIC
OXYGEN
•* MICROAEROPHILES---ORGANISMS THAT CAN GROW
EVEN IIN LOWERED OXYGEN CONTENT IN THE AIR
•* CAPNOPHILES---NEED 3-10 % INCREASE IN CARBON
DIOXIDE CONTENT IN THE AIR TO INITIATE
DEVELOPMENT

42. LIGHT REQUIREMENTS:
•RED/ YELLOW----LITTLE BACTERICIDAL EFFECT
•*GREEN---HAVE LESS KILLING ACTION
•*VIOLE/ULTRAVIOLET/ BLUE---LIGHT WAVELENGTHS
THAT ARE HIGHLY DESTRUCTIVE TO THE BACTERIAL
CELL
•** SOME SAPROPHYTIC SPECIES USE LIGHT FOR
AUTOTROPHIC ACTIVITY

43. BY-PRODUCTS OF BACTERIAL
GROWTH
•BACTERIAL METABOLISM---DEPLETES FOOD SUPPLY &
RELEASE PRODUCTS THAT INHIBIT FURTHER BACTERIAL
GROWTH
•EX. PRODUCTION OF ORGANIC ACIDS & OTHER
PRODUCTS
•***ELECTRICITY & RADIANT ENERGY---INHIBIT
BACTERIAL GROWTH

44. •**CHEMICALS---DESTROY & INHIBIT THE GROWTH OF
BACTERIA
•CHEMOTAXIS---RESPONSES TO CHEMICALS; POSITIVE
OR NEGATIVE RESPONSES
•**OSMOTIC PRESSURE----MOST BACTERIA RESIST SMALL
CHANGES IN OSMOTIOC PRESSURE

45. •** BACTERIA CAN BE KILLED BY HIGH
CONCENTRATIONS OF SALT OR SUGAR THUS
EMPLOYED IN FOOD PRESERVATION
•***OSMOPHILES----PREFER HIGH SALT
CONCENTRATIONS; CLASSIFIED AS HALOPHILES OR
SALT LOVERS WHERE THEY CAN TOLERATE HIGH
CONCETRATIONS OF SALT

46. BACTERIAL INTER- RELATIONS
•SYMBIOSIS---BACTERIA GROWING WELL TOGETHER;
BOTH PARTIES ARE BENEFITTED
•1. SYNGERGISTIC RELATIONSHIP BETWEEN
STAPHYLOCOCCI & THE INFLUENZA BACILLI
•2. LEGUMES & THE NITROGEN-FIXING BACTERIA---
NITROSOMONAS/ NITROBACTER
•***ANTAGONISM---PRESENCE OF 1 ORGNAISM
INHIBITS THE OTHER DUE TO SUBSTANCES THAT ARE
SECRETED

47. MAJOR METABOLIC ACTIVITIES
•ENZYMES----PLAY AN IMPT ROLE IN THE METABOLLIC
ACTIVITIES OF BACTERIA
•2,000-3,000 ENZYMES IN THE BACTERIAL CELL UNDER
THE CONTROL OF THE DNA APPARATUS
•CHEMOSYNTHESIS---PROCESSING OF ENERGY FROM
THE CHEMICAL ALTERATION OF SUBSTANCES AT HAND

48. •1. BACTERIAL DIGESTION---MAKES USE OF
HYDROLASES (ENZYMES) & HYDROLYSIS---PROCESS
INVOLVING THE ADDITION OF WATER
•2. ABSORPTION---VIA DIFFUSION & ACTIVE TRANSPORT
OF MOLECULES
•3. OXIDATION---PREPARATION OF MOLECULES FOR A
POSSIBLE BONDING OR CHEMICAL COMBINATION

49. •---STARTS WITH PHOSPHORYLATION
• INVOLVES
OXIDASES/DEHYDROGENASES/COENZYMES OF THE
CYTOCHROME SYSTEM
• INVOLVES TRANSFER OF ELECTRONS RESULTING IN AN
OXIDIZED OR REDUCED PRODUCT WHERE ENERGY IS
LIBERATED OR TRAPPED

50. CLASSES OF BIOLOGIC
OXIDATION:
•A. AEROBIC---ULTIMATE HYDROGEN ACCEPTOR IS
MOLECULAR OXYGEN
•B. ANAEROBIC---HYDROGEN ACCEPTOR IS
INORGANIOC NITRATE, SULFATE OR CARBONATE
•FERMENTATION---HYDROGEN ACCEPTOR IS AN
ORGANIC COMPOUND; USES ORGNANIC
COMPOUNDS BOTH AS DONORS & ELECTRON
ACCEPTORS

51. MEDICALLY RELATED ACTIVITIES:
•***TOXIGENICITY---TOXIN PRODUCTION
•***TOXICITY---POTENCY OF THE TOXINS
•A. EXOTOXINS---PROTEINS IN NATURE
•------ANTIGENIC; PRODUCES ANTITOXIN
•-----SPECIFIC---CAUSES 1 DISEASE & NOTHING ELSE
•ANATOXINS/ TOXOIDS---MODIFIED TOXINS THAT CAN
NO LONGER CAUSE DISEASE BUT CAN STILL PRODUCE
IMMUNITY TO THE DISEASE

52. •B. ENDOTOXINS---MADE UP OF COMPLEX
LIPOPOLYSACCHARIDES
•---DO NOT PROMOTE ANTITOXIN FORMATION
•---NON-SPECIFIC
•---CANNOT BE CONVERTED INTO TOXOIDS
•EX. SALMONELLA TYPHI
•NEISSERIA MENINGITIDES

53. HARMFUL METABOLLIC PRODUCTS
•---MAY NOT BE DIRECTLY TOXIC BUT RELATED
SIGNIFICANTLY TO DISEASE
•1. HEMOLYSINS---CAUSE LYSIS OF THE RED BLOOD
CELLS
•2 TYPES OF BACTERIAL HEMOLYSINS:
•A. FILTRABLE
•B. THOSE THAT ARE DEMONSTRATED ABOUT THE
BACTERIAL COLONY ON A CULTURE MEDIUM
CONTAINING RBCs

54. • & HEMOLYSINS ---- NAMED AFTER THE BACTERIA THAT
GIVES RISE TO THEM
•EX. STAPHYLOLYSIN
•STREPTOLYSINS
•2. LEUKOCIDINS---DESTROY POLYMORPHONUCLEAR
NEUTROPHILIC LEUKOCYTES
•***FORMED BY PNEUMOCOCCI,STREPTOCOCCI &
STAPHYLOCOCCI

55. •3. COAGULASE---ACCELERATE COAGULATION OF
BLOOD
•EX. STAPHYLOCOCCI
•COAGULASE TEST---USED TO DIFFERENTIATE
PATHOGENIC FROM NON-PATHOGENIC BACTERIA
•4. BACTERIAL KINASES---ACT ON CERTAIN
COMPONENTS OF THE BLOOD TO LIQUIFY FIBRIN;
INTERFERE WITH BLOOD COAGULATION

56. •EX. STREPTOKINASE/FIBRINOLYSIS---PRODUCED BY
MANY HENOLYTIC STREPTOCOCCI, STAPHYLOCOCCI
& OTHER BACTERIA
•---USED TO DISSOLVE BLOOD CLOTS & TO PREVENT
THE FORMATION OF ADHESIONS THAT WOULD BE LAID
DOWN ON THE FIBRIN PRECIPITATED IN THE BODY
CAVITIES

57. •-5. HYALURONIDASE---MAKE TISSUES MORE
PERMEABLE TO THE BACTERIA ELABORATING IT
EX. PNEUMOCOCCI & STREPTOCOCCI
•6. BACTERIOCINS---BACTERIAL PROTEIN OR
POLYPEPTIDE SUSBTANCES PRODUCED BY STRAINS OF
A FAMILY OF MICROBES

58. •7. COLICINS----PRODUCED BY THE FAMILY
ENTEROBACTERIACEAE; WILL ACT ON THE BACTERIAL
MEMBRANE
•OTHER EFFECTS:
•1. PIGMENT PRODUCTION---IMPT. IN THE
IDENTIFICATION OF ORGANISMS BUT NOT RELATED TO
DISEASE PRODUCTION

59. •***PRODUCED BY BOTH PARASITIC & SAPROPHYTIC
BACTERIA
•EX. STAPHYLOCOCCUS AUREUS---GOLD COLOR
•PSEUDOMONAS AERUGINOSA---PRODUCES THE BLUE-
GREEN PIGMENT
•HALOBACTERIUM HALOBIUM---PRODUCES RED
PIGMENT
•SERRATIA MARCESCENS---RED PIGMENT

60. •2. HEAT PRODUCTION----RESULTS IN THE HEATING OF
DAMP HAY
•3. LIGHT PRODUCTION
•EX. BIOLUMINESCENCE---EXHIBITED BY BACTERIA THAT
LIVE IN SALT WATER; EMITS LIGHT AS THEY OPEN THEIR
MOUTHS; LIGHT PRODUCERS ARE GENERALLY NON-
PATHOGENIC

61. •4. PRODUCTION OF ODORS---DUE TO
DECOMPOSITION OF THE MATERIAL WHERE THE
BACTERIA IS GROWING

62. CULTIVATION OF BACTERIA

63. • CULTURE
---REFERS TO THE GROWTH OF MICROBES
• CULTURING
---PROCESS OF ALLOWING MICROBES TO GROW ON
ARTIFICIAL MEDIUM
• CULTURE MEDIUM
---NUTRIENT SUBSTANCE WHERE MICROBES ARE GROWN

64. GENERAL CONSIDERATIONS WHEN
CULTURING ON ARTIFICIAL LAB. MEDIA:
1. PROPER TEMPERATURE
2. RIGHT AMOUNT OF MOISTURE
3. REQUIRED OXYGEN TENSION
4. PROPER pH
5. NUTRIENTS & GROWTH-PROMOTING FACTORS
6. STERILECONDITION/FREE FROM CONTAMINANTS

65. • BASIC TYPES OF CULTURE
MEDIA:
1. LIQUID
2. SOLID THAT CAN BE LIQUIFIED BY HEATING
3. SOLID THAT CANNOT BE LIQUIFIED

66. AGAR---COMMONLY USED
CULTURE MEDIUM
USES OF AGAR AS A MEDIUM:
1. MELTS AT BOILING TEMPERATURE
2. SOLIDIFIES WHEN COOLED DOWN TO 40
DEGREES CELCIUS
3. NO EFFECT ON BACTERIAL GROWTH
4. IS NOT ATTACKED BY THE BACTERIA
GROWING ON IT

67. ENRICHING MATERIALS
• 1. CARBOHYDRATES (CHO)---ADDED TO
INCREASE THE NUTRITIVE VALUE OF THE
MEDIUM
• 2. SERUM---USED TO INDICATE THE GROWTH
OF LESS HARDY ORGANISMS
EX. WHOLE BLOOD/ ASCITIC FLUID

68. 3. DYES---USED AS INDICATORS TO DETECTACID
FORMATION
EX. PHENOL RED---INDICATOR DYE
---USED AS INHIBITORS OF CERTAIN
BACTERIA
EX. GENTIAN VIOLET---INHIBITORY DYE (
MOST GRAM POSITIVE BACTERIA)

69. CLASSIFICATION OF CULTURE
MEDIA
1. DIFFERENTIAL---WHEN THE INGREDIENTS OF THE
MEDIUM IS USED TO DISTINGUISH ORGANISMS
GROWING TOGETHER.
EX. A. EMB (EOSIN METHYLENE BLUE) AGAR
B. MAC CONKEY AGAR---USED IN THE DIFFERENTIATION
OF GRAM (-) BACTERIA OF THE INTESTINAL TRACT
C. LACTOSE---SEPARATES ORGANISMS THAT

70. •FERMENT THE LACTOSE SUGAR FROM THOSE WHO DO
NOT USE THE SUGAR
•A. LACTOSE FERMENTERS---PRODUCES DEEPLY
COLORED RED COLONIES WITH A METALLIC SHEEN
•B. NON-FERMENTERS----PRODUCES COLORLESS
COLONIES

71. 2. SELECTIVE MEDIUM---PROMOTES THE GROWTH OF 1
ORGANISM & RETARD THE GROWTH OF OTHERS
A. DEOXYCHOLATE-CITRATE AGAR
---INHIBITS THE GROWTH OF MOST COLIFORMS
INCLUDING MANY STRAINS OF PROTEUS BUT
FAVORS THE ISOLATION OF INTESTINAL
PATHOGENS LIKE SALMONELLA & SHIGELLA

72. B. LOWENSTEIN-JENSEN MEDIUM
---PROMOTES THE GROWTH OF TUBERCLE BACILLI
BUT RETARDS THE GROWTH OF OTHER ORGANISMS
C. EMB AGAR/ MAC CONKEY AGAR
---DISPLAY SELECTIVE FUNCTION IN THAT THEY
ALLOW THE GROWTH OF GRAM-NEGATIVE
BACTERIA BUT PREVENTS THE GROWTH OF GRAM-
POSITIVE ONES

73. • SELECTIVE & DIFFERENTIAL MEDIA ---ARE OF
•GREAT VALUE IN THE DIAGNOSIS OF INFECTIONS AS
VARIOUS PATHOGENS TEND TO BE MIXED WITH MANY
OTHER ORGANISMS.

74. CULTURE METHODS
•A. PREPARATION OF CULTURE MEDIUM:
•1. DETERMINE ORGANISM TO BE CULTURED AND USE
THE REQUIRED /SPECIFIC MEDIUM
•2. STERILIZATION OF ALL INSTRUMENTS NEEDED
INCLUDING THE CULTURE MEDIUM BY AUTOCLAVING-
---MOST COMMONLY USED STERILIZATION
PROCEDURE IN THE LAB.

75. * **121-123 DEGREES CELCIUS TEMPERATURE
***15-17 PSI PRESSURE
***NOT USED IN THE STERILIZATION OF MATERIALS THAT
ARE DESTROYED BY TOO MUCH HEAT.
B. INOCULATION---INTRODUCTION OF THE SOURCE OF
THE ORGANISM

76. SOURCES OF INNOCULUM
1. SPUTUM
2. URINE
3. BLOOD
4. PUS
5. RESPIRATORY OR UROGENITAL SECRETIONS
*** THESE INNOCULUM MAY BE ADDED TO A FLUID
MEDIUM OR RUBBED GENTLY OVER THE SURFACE
OF A SOLID MEDIUM USING A COTTON SWAB OR A
WIRE LOOP

77. C. ROUTINE INCUBATION PERIOD IS WITHIN 24 TO 48
HOURS WITH A TEMPERATURE OF ABOUT 0.5 EGREES
CELCIUS & KEPT CONSTANT FROM DAY TO DAY
***INSPECTION / STUDY OF CULTURES:
1. LIQUID MEDIA LIKE NUTRIENT BROTH---TO OBSERVE
FOR TURBIDITY, GAS PRODUCTION & COLOR CHANGE;
PROCEED TO GRAM STAINING

78. 2. SOLID MEDIUM----BACTERIA TEND TO CLING
TOGETHER TO FORM A COLONY WHICH HAS
CHARACTERISTICS LIKE TEXTURE, SIZE, SHAPE,
COLOR, ELEVATION, ETC THAT ARE FAIRLY
CONSTANT FOR EACH SPECIE
D. DISCARDING CULTURES--VIA AUTOCLAVING OR
INCINERATION

79. CULTIVATION OF BACTERIA
IN THE LABORATORY
1. ALL INSTRUMENTS/EQUIPMENTS ARE STERILIZED FOR
THE STUDENTS
2. FOR SOLID MEDIUM, USE EITHER AGAR PLATE OR
AGAR SLANT
3. OBTAIN INOCULUM FROM EITHER THE COIN OF ANY
DENOMINATION, FROM THE TABLE TOP[,BALLPEN, HEM
OF PANTS OR SKIRT, IN BETWEEN TOES, ARMPITS & FRUIT
PEELINGS

80. 4. DO SERIAL DILUTION----MAKES BACTERIAL PLATE
COUNT MORE ACCURATE WITH THE PREMISE THAT
EVERY BACTERIUM PRESENT IN AN INOCULUM
DEVELOPS INTO A COLONY
5. PROCEED TO POUR PLATING OR STREAK PLATING
TECHNIQUES
6. BACTERIAL PLATE COUNT USING THE QUEBEC
COLONY COUNTER

81. •QUANTIFICATION----HELPS TO INDICATE WHETHER
BACTERIA RECOVERED FROM A SAMPLE (URINE) ARE
PATHOGENIC OR JUST PLAIN CONTAMINANTS ( LESS
THAN 10,000 COLONIES PER ML REPRESENT NORMAL
FLORA OR JUST CONTAMINANTS)

82. CASE STUDY
82

83. HISTORY: ROBERT FORBES
• 33-year-old male who presents to his doctor reporting a
purulent urethral discharge and dysuria for 3 days
• Lives in Dallas with history of travel to Hawaii 3 weeks ago
• New female sex partner (Laura) for 2 months. They have
unprotected vaginal intercourse 4 times/week, the last time
being 2 days ago. No oral or rectal sex.
• Also had a one-time sexual encounter with a woman he
met in Hawaii 3 weeks ago (Monica)
• No history of urethral discharge or STDs, no sore throat or
rectal discomfort. Negative HIV test 1 year ago.
83
Case Study

84. PHYSICAL EXAM
• Vital signs: blood pressure 98/72, pulse 68, respiration
14, temperature 37.2° C
• Cooperative, good historian
• Chest, heart, musculoskeletal, and abdominal
exams within normal limits
• No flank pain on percussion, normal rectal exam, no
sores or rashes
• The genital exam reveals a reddened urethral
meatus with a purulent discharge, without lesions or
lymphadenopathy.
84
Case Study

85. LABORATORY
Results of laboratory tests:
• Urethral culture: showed growth of a Gram-
negative diplococcus that was oxidase-positive.
Biochemical and Fluorescent Antibody conjugate
testing confirmed this isolate to be N. gonorrhoeae.
• DNA probe for chlamydia: negative
• RPR: nonreactive
• HIV antibody test: negative
85
Case Study

86. QUESTIONS
•What should be included in the differential
diagnosis?
•Which laboratory tests are appropriate to
order or perform?
86
Case Study

87. GONORRHEA
87
Neisseria gonorrhoeae

88. I. Pathogenesis
II. Clinical manifestations
III. Diagnosis
88

89. RISK FACTORS
• sex partners or inconsistent condom use
• Urban residence
• Adolescents
• Lower socio-economic status
• Use of drugs
• Exchange of sex
89
Epidemiology

90. TRANSMISSION
• Efficiently transmitted by:
–Male to female
–Female to male urethra
–Rectal intercourse
–Fellatio
–Perinatal transmission
• Gonorrhea associated with increased transmission
of and susceptibility to HIV infection
90
Epidemiology

91. PATHOGENESIS
91

92. MICROBIOLOGY
• Etiologic agent: Neisseria gonorrhoeae
• Gram-negative intracellular diplococcus
• Infects mucus-secreting epithelial cells
92
Pathogenesis

93. GONORRHEA: GRAM STAIN OF
URETHRAL DISCHARGE
93
Pathogenesis

94. CLINICAL MANIFESTATIONS
94

95. GENITAL INFECTION IN MEN
• Urethritis – Inflammation of urethra
• Epididymitis – Inflammation of the epididymis
95
Clinical Manifestations

96. MALE URETHRITIS
• Symptoms
–Typically purulent or mucopurulent urethral
discharge
–Often accompanied by dysuria
–Discharge may be clear or cloudy
• Asymptomatic in 10% of cases
• Incubation period: usually 1-14 days for symptomatic
disease, but may be longer
96
Clinical Manifestations

97. GONOCOCCAL
URETHRITIS:
PURULENT DISCHARGE
97
Clinical Manifestations

98. EPIDIDYMITIS
• Symptoms: unilateral testicular pain and swelling
• Infrequent, but most common local complication in
males
• Usually associated with overt or subclinical urethritis
98
Clinical Manifestations

99. SWOLLEN OR
TENDER TESTICLES
(EPIDIDYMITIS)
99
Clinical Manifestations

100. GENITAL INFECTION IN WOMEN
• Most infections are asymptomatic
• Cervicitis – inflammation of the cervix
• Urethritis – inflammation of the urethra
100
Clinical Manifestations

101. CERVICITIS
• Non-specific symptoms: abnormal vaginal
discharge, intermenstrual bleeding, dysuria, lower
abdominal pain, or dyspareunia
• Clinical findings: mucopurulent or purulent cervical
discharge, easily induced cervical bleeding
• 50% of women with clinical cervicitis have no
symptoms
• Incubation period unclear, but symptoms may
occur within 10 days of infection
101
Clinical Manifestations

102. GONOCOCCAL
CERVICITIS
102
Clinical Manifestations

103. URETHRITIS
• Symptoms: dysuria, however, most women are
asymptomatic
• 40%-60% of women with cervical gonococcal
infection may have urethral infection
103
Clinical Manifestations

104. COMPLICATIONS IN WOMEN
• Accessory gland infection
–Bartholin’s glands
–Skene’s glands
• Pelvic Inflammatory Disease (PID)
• Fitz-Hugh-Curtis Syndrome
–Perihepatitis
104
Clinical Manifestations

105. BARTHOLIN’S ABSCESS
105
Clinical Manifestations

106. SYNDROMES IN MEN AND WOMEN
• Anorectal infection
• Pharyngeal infection
• Conjunctivitis
• Disseminated gonococcal infection (DGI)
106
Clinical Manifestations

107. GONOCOCCAL
OPHTHALMIA
107
Clinical Manifestations

108. DISSEMINATED GONORRHEA—
SKIN LESION
108
Clinical Manifestations

109. GONORRHEA INFECTION IN
CHILDREN
• Perinatal:
conjunctiva infection
pharynx infection
respiratory tract infection
• Older children (>1 year): considered possible
evidence of sexual abuse
109
Clinical Manifestations

110. DIAGNOSIS
110

111. DIAGNOSTIC METHODS
• Culture tests
111
Diagnosis

112. Non-culture tests
Amplified tests (NAATs)
• Polymerase chain reaction (PCR) (Roche Amplicor)
• Transcription-mediated amplification (TMA) (Gen-
Probe Aptima)
• Strand displacement amplification (SDA)
(Becton-Dickinson BD ProbeTec ET)
112
Diagnosis

113. Non-amplified tests
• DNA probe (Gen-Probe PACE 2, Digene Hybrid
Capture II)
• Gram stain