NEISSERIA GONORRHEA (GONOCOCCUS): Gram-negative reniform Diplococci
SEXUALLY TRANSMITTED
NEISSERIA GONORRHEA (GONOCOCCUS): Gram-negative reniform Diplococci
Name-Derivation:
Epidemiology / At Risk:
Sexual Contact
Fomite (inanimate object) may be means of transmission in prepubescent female, but it is highly unlikely. We must investigate for sexual abuse.
Manifestations:
Gonorrhea
Male: Painful urethritis. Purulent discharge and dysuria.
Female: Vaginitis; 80% are asymptomatic.
UTI symptoms
Vaginal discharge
Vaginitis progresses to PID, leading to sterility
Common to have coinfection with Chlamydia (one predisposes to the other).
Anorectal: From anal sex; rectal discharge and bleeding; usually asymptomatic.
Pharyngitis: From oral sex; usually asymptomatic.
Bacteremia: Can result from failed, incomplete, or inadequate treatment.
Fever, rash, skin lesions. Rash has no bugs in it.
Septic Arthritis: The leading cause of arthritis in people 20-30 years of age!
Neonatal Conjunctivitis: Rapidly invasive. Destroys cornea and leads to blindness.
By law, NaNO3 or Tetracycline eyedrops are given prophylactically to neonates at birth.
Processing:
Specimen: Urethral exudate preferred, or swab.
Stain: Only useful on urerthral exudate. Sensitive for males but not females.
Stain will show lots of variants, but they're from the same isolate. Variation reflects presence or absence of pili.
Culture:
Thayer-Martin Medium is Chocolate Agar, with iron and antibiotics added to supress Gram (-)'s, Gram (+)'s, and Candida. It is usually inoculated at the bedside, because the bugs die very easily.
Vancomycin gets rid of Gram (+)
Colistin gets rid of other Gram (-)'s
Nystatin gets rid of Candida.
Then subculture to Chocolate Agar to speciate (glucose and maltose fermentation)
Identification:
Neisseria: Catalase(+), Oxidase(+) is key factor.
Glucose-fermenting
Non-maltose fermenting (differ from N. Meningiditis).
Virulence:
Cell-Surface:
Pili
Porin Protein:
Protein I (PI): Complexes with PIII to form the Porin protein.
Structure:
Antigenically diverse: N and C termini are within membrane, and central loop sticks out which is highly antigenically diverse.
High Molecular Weight: Associated with disseminated disease and increased serum resistance.
Low Molecular Weight: Associated with localized (UG) disease and decreased serum resistance.
Action: It triggers phagocytosis.
Protein III (PIII): Complexes with PI to form the Porin protein.
Binds IgG and blocks killing mediated by IgG (serum resistance).
Protein II (PII): Adhesin; causes autoagglutination and adherence to epithelium.
H8: Immunogenic antigen. Antibody and complement will bind to this and lyse the bug.
Penicillin-Binding Protein (PBP):
Peptidoglycan:
Lipooligosaccharide (LOS): Not endotoxin. It damages fallopian tube mucosa and is ciliostatic.
Enzymes:
IgA Protease: Degrades IgA antibodies; two types
beta-Lactamase
Intracellular survival: Catalase, Superoxide Dismutase, Peroxidase
Host Immune Response: Antibodies are effective, but not protective because of antigenic diversity.
Vaccine / Prevention: Tetracycline or NaNO3 eyedrops given to babies prophylactically.
Treatment: Completely Penicillin-resistant, due to both beta-Lactamase and altered PBP's.
HEMOPHILUS DUCREYI: Gram-negative Rod
Epidemiology / At Risk:
Manifestations: Chancroid. Looks like a Syphillus chancre, but it isn't.
Painful
Purulent Exudate
Non-indurated
Usually found on genitalia, but can be on lip.
Suppurative lymph nodes found; may develop abscess.
Processing:
Specimen: Purulent exudate
Stain: Gram-negative rods. If you see bugs on the gram stain, then you have established that it is not Syphillus.
Culture: Chocolate agar, but it is very difficult to grow.
Identification:
It stains on the gram-stain.
Virulence:
Pili: Adhesin
beta-Lactamase
Treatment: Penicillin-resistant. Use erythromycin or bactram.
TREPONEMA PALLIDUM: Spirochete
Name-Derivation: Treponema - turning thread
Epidemiology / At Risk: Syphillus
PRIMARY SYPHILLUS: Chancre
Painless
Serous Exudate
Indurated (hard)
Lymph nodes are slightly enlarged but not tender.
Between primary and secondary phases, there is an asymptomatic spirochetemia, during which the bugs replicate.
SECONDARY SYPHILLUS: Rash all over, including palms and soles.
Rashes are also loaded with bugs and highly infectious.
Not painful.
Lymph nodes enlarged but not too painful.
Latency:
Early Latency: Lots of antibodies and symptoms present.
Headache, achiness, lethergy, tenderness of lymph nodes.
Late Latency: Asymptomatic
TERTIARY SYPHILLUS: Not infectious, due to immune response.
Gumma: Cell-mediated hypersensitivity with tremendous necrosis and Giant-cells.
Skin: patchy loss of hair.
Neurosyphillus: Tabes Dorsalis, dementia, seizures, paresis.
Presence of symptoms depends on penetration of blood-brain barrier.
To determine likelihood of these symptoms, look for antibodies in the CSF.
Cardiovascular: Dissecting Aortic Aneurysm
Congenital Syphillus:
Symptoms: Stillbirth, abortion, or structural (but not intellectual) defects if the baby is born.
The fetus is protected during the first 16 weeks of pregnancy. Langerhorn cells of placenta act as barrier.
Manifestations:
Processing:
Specimen: Serous exudate.
Stain: Dark-field microscopy shows tiny spirochetes.
Culture: Cannot be grown on agar. Koch's postulates not fulfilled.
Identification:
Non-Specific Tests: Used for screening
Wasserman: Old complement-fixation test looking for IgG against Cardiolipin (found in mitochondria) + lecithin + cholesterol
This IgG is termed Reagin for historical reasons.
Venereal Diseases Research Laboratory (VDRL): Has been superseded by RPR
Rapid Plasma Reagin (RPR): Rapid card that tests for Reagin in the blood, i.e. IgG against Cardiolipin, lecithin, and cholesterol.
Test is highly sensitive but not specific. If you get positive here, than go on and do one of the specific tests such as the FTA.
False positives occur with SLE, aging, and other cross-reactions.
Specific Tests
Treponema Pallidin Immobilization (TPI): Expensive and difficult. It is limited to people with SLE or for research. Immobilize the bug to make it visible on darkfield microscopy.
Fluorescent Treponema Antibody (FTA):
Antigen: A uniform strain of the bug itself grown up in rabbits.
Antibody: Potentially the patient's serum, if the test is positive.
Procedure: Run an indirect FA, using antihuman IgG with a fluorescein tag.
FTA-Absorbed: Improved specificity from the FTA test. DEFINITIVE TEST.
Eliminate (absorb and centrifuge off) cross-reacting antibodies with the Reiter Strain, which are periodontal spirochetes in the mouth.
This gives the test higher specificity.
A positive result with this test is an absolute positive for Syphillus.
Microhemmaglutination Assay: Similar to Absorbed FTA. Less expensive, more rapid, but not as sensitive.
IgM-FTA-Absorbed: Just as reliable as the IgG test if it is positive, but false negatives occur. Thus it is even more specific but not sensitive enough.
Interpretation:
Virulence: Little is known because it hasn't been cultured.
Hyaluronidase: invasion
Host Immune Response:
Antibody is not protective.
Cell-mediated response is essential.
CMI is slow to be activated. T-Supressor cells are involved.
Treatment:
Treatment is most effective in secondary phase.
Jarisch-Herxheimer Reaction: Systemic illness resulting from Penicillin treatment given to a patient that wasn't manifesting symptoms. They think it is due to the bug being lysed and killed.
NEISSERIA GONORRHEA (GONOCOCCUS): Gram-negative reniform Diplococci
Name-Derivation:
Epidemiology / At Risk:
Sexual Contact
Fomite (inanimate object) may be means of transmission in prepubescent female, but it is highly unlikely. We must investigate for sexual abuse.
Manifestations:
Gonorrhea
Male: Painful urethritis. Purulent discharge and dysuria.
Female: Vaginitis; 80% are asymptomatic.
UTI symptoms
Vaginal discharge
Vaginitis progresses to PID, leading to sterility
Common to have coinfection with Chlamydia (one predisposes to the other).
Anorectal: From anal sex; rectal discharge and bleeding; usually asymptomatic.
Pharyngitis: From oral sex; usually asymptomatic.
Bacteremia: Can result from failed, incomplete, or inadequate treatment.
Fever, rash, skin lesions. Rash has no bugs in it.
Septic Arthritis: The leading cause of arthritis in people 20-30 years of age!
Neonatal Conjunctivitis: Rapidly invasive. Destroys cornea and leads to blindness.
By law, NaNO3 or Tetracycline eyedrops are given prophylactically to neonates at birth.
Processing:
Specimen: Urethral exudate preferred, or swab.
Stain: Only useful on urerthral exudate. Sensitive for males but not females.
Stain will show lots of variants, but they're from the same isolate. Variation reflects presence or absence of pili.
Culture:
Thayer-Martin Medium is Chocolate Agar, with iron and antibiotics added to supress Gram (-)'s, Gram (+)'s, and Candida. It is usually inoculated at the bedside, because the bugs die very easily.
Vancomycin gets rid of Gram (+)
Colistin gets rid of other Gram (-)'s
Nystatin gets rid of Candida.
Then subculture to Chocolate Agar to speciate (glucose and maltose fermentation)
Identification:
Neisseria: Catalase(+), Oxidase(+) is key factor.
Glucose-fermenting
Non-maltose fermenting (differ from N. Meningiditis).
Virulence:
Cell-Surface:
Pili
Porin Protein:
Protein I (PI): Complexes with PIII to form the Porin protein.
Structure:
Antigenically diverse: N and C termini are within membrane, and central loop sticks out which is highly antigenically diverse.
High Molecular Weight: Associated with disseminated disease and increased serum resistance.
Low Molecular Weight: Associated with localized (UG) disease and decreased serum resistance.
Action: It triggers phagocytosis.
Protein III (PIII): Complexes with PI to form the Porin protein.
Binds IgG and blocks killing mediated by IgG (serum resistance).
Protein II (PII): Adhesin; causes autoagglutination and adherence to epithelium.
H8: Immunogenic antigen. Antibody and complement will bind to this and lyse the bug.
Penicillin-Binding Protein (PBP):
Peptidoglycan:
Lipooligosaccharide (LOS): Not endotoxin. It damages fallopian tube mucosa and is ciliostatic.
Enzymes:
IgA Protease: Degrades IgA antibodies; two types
beta-Lactamase
Intracellular survival: Catalase, Superoxide Dismutase, Peroxidase
Host Immune Response: Antibodies are effective, but not protective because of antigenic diversity.
Vaccine / Prevention: Tetracycline or NaNO3 eyedrops given to babies prophylactically.
Treatment: Completely Penicillin-resistant, due to both beta-Lactamase and altered PBP's.
HEMOPHILUS DUCREYI: Gram-negative Rod
Epidemiology / At Risk:
Manifestations: Chancroid. Looks like a Syphillus chancre, but it isn't.
Painful
Purulent Exudate
Non-indurated
Usually found on genitalia, but can be on lip.
Suppurative lymph nodes found; may develop abscess.
Processing:
Specimen: Purulent exudate
Stain: Gram-negative rods. If you see bugs on the gram stain, then you have established that it is not Syphillus.
Culture: Chocolate agar, but it is very difficult to grow.
Identification:
It stains on the gram-stain.
Virulence:
Pili: Adhesin
beta-Lactamase
Treatment: Penicillin-resistant. Use erythromycin or bactram.
TREPONEMA PALLIDUM: Spirochete
Name-Derivation: Treponema - turning thread
Epidemiology / At Risk: Syphillus
PRIMARY SYPHILLUS: Chancre
Painless
Serous Exudate
Indurated (hard)
Lymph nodes are slightly enlarged but not tender.
Between primary and secondary phases, there is an asymptomatic spirochetemia, during which the bugs replicate.
SECONDARY SYPHILLUS: Rash all over, including palms and soles.
Rashes are also loaded with bugs and highly infectious.
Not painful.
Lymph nodes enlarged but not too painful.
Latency:
Early Latency: Lots of antibodies and symptoms present.
Headache, achiness, lethergy, tenderness of lymph nodes.
Late Latency: Asymptomatic
TERTIARY SYPHILLUS: Not infectious, due to immune response.
Gumma: Cell-mediated hypersensitivity with tremendous necrosis and Giant-cells.
Skin: patchy loss of hair.
Neurosyphillus: Tabes Dorsalis, dementia, seizures, paresis.
Presence of symptoms depends on penetration of blood-brain barrier.
To determine likelihood of these symptoms, look for antibodies in the CSF.
Cardiovascular: Dissecting Aortic Aneurysm
Congenital Syphillus:
Symptoms: Stillbirth, abortion, or structural (but not intellectual) defects if the baby is born.
The fetus is protected during the first 16 weeks of pregnancy. Langerhorn cells of placenta act as barrier.
Manifestations:
Processing:
Specimen: Serous exudate.
Stain: Dark-field microscopy shows tiny spirochetes.
Culture: Cannot be grown on agar. Koch's postulates not fulfilled.
Identification:
Non-Specific Tests: Used for screening
Wasserman: Old complement-fixation test looking for IgG against Cardiolipin (found in mitochondria) + lecithin + cholesterol
This IgG is termed Reagin for historical reasons.
Venereal Diseases Research Laboratory (VDRL): Has been superseded by RPR
Rapid Plasma Reagin (RPR): Rapid card that tests for Reagin in the blood, i.e. IgG against Cardiolipin, lecithin, and cholesterol.
Test is highly sensitive but not specific. If you get positive here, than go on and do one of the specific tests such as the FTA.
False positives occur with SLE, aging, and other cross-reactions.
Specific Tests
Treponema Pallidin Immobilization (TPI): Expensive and difficult. It is limited to people with SLE or for research. Immobilize the bug to make it visible on darkfield microscopy.
Fluorescent Treponema Antibody (FTA):
Antigen: A uniform strain of the bug itself grown up in rabbits.
Antibody: Potentially the patient's serum, if the test is positive.
Procedure: Run an indirect FA, using antihuman IgG with a fluorescein tag.
FTA-Absorbed: Improved specificity from the FTA test. DEFINITIVE TEST.
Eliminate (absorb and centrifuge off) cross-reacting antibodies with the Reiter Strain, which are periodontal spirochetes in the mouth.
This gives the test higher specificity.
A positive result with this test is an absolute positive for Syphillus.
Microhemmaglutination Assay: Similar to Absorbed FTA. Less expensive, more rapid, but not as sensitive.
IgM-FTA-Absorbed: Just as reliable as the IgG test if it is positive, but false negatives occur. Thus it is even more specific but not sensitive enough.
Interpretation:
Virulence: Little is known because it hasn't been cultured.
Hyaluronidase: invasion
Host Immune Response:
Antibody is not protective.
Cell-mediated response is essential.
CMI is slow to be activated. T-Supressor cells are involved.
Treatment:
Treatment is most effective in secondary phase.
Jarisch-Herxheimer Reaction: Systemic illness resulting from Penicillin treatment given to a patient that wasn't manifesting symptoms. They think it is due to the bug being lysed and killed.