Bohomolets Microbiology Lecture #22
-
Upload
dr-rubz -
Category
Health & Medicine
-
view
938 -
download
8
description
Transcript of Bohomolets Microbiology Lecture #22
Curviform bacteriaCurviform bacteria
The spirochetesThe spirochetes
Campylobacter Campylobacter
Helicobacter Helicobacter
Curviform bacteria that are Curviform bacteria that are pathogenic for humanpathogenic for human
VibrioVibrioCampylobacter Campylobacter Helicobacter Helicobacter SpirillumSpirillumSpirochetae Spirochetae
““Sodoku” diseaseSodoku” disease
Spirillum minor causes rat-bite fever Spirillum minor causes rat-bite fever (“sodoku”)(“sodoku”)
CampilobacterCampilobacter
Curved, gram-negative, Curved, gram-negative, motile rods either comma- motile rods either comma- or S-shapedor S-shaped
MicroaerophilsMicroaerophils
Urease-neganive Urease-neganive
C.jejuni cause C.jejuni cause enterocolitis and watery enterocolitis and watery or bloody diarrheaor bloody diarrhea
Transmission is fecal-oralTransmission is fecal-oral
Diagnosed by Diagnosed by bacteriologic methodbacteriologic method
Treatment - antibioticsTreatment - antibiotics
Scanning micrograph Scanning micrograph of Campylibacter jejuniof Campylibacter jejuni
Helicobacter pyloriHelicobacter pyloriCurved, gram-negative, motile Curved, gram-negative, motile rod rod Microaerophil, grows in Microaerophil, grows in presence 5-10% COpresence 5-10% CO22
Urease-positiveUrease-positiveRequires special laboratory Requires special laboratory mediamediaCauses gastritis and peptic Causes gastritis and peptic ulcerulcerDiagnosis: Diagnosis:
bacteriological methodbacteriological methodimmunoenzyme test for finding of immunoenzyme test for finding of Helicobacter antigen in fecesHelicobacter antigen in fecesPCR testPCR test
Helicobacter morphologyHelicobacter morphology
Diagnosis, Diagnosis, treatmenttreatment
Helicobacter pylori in Helicobacter pylori in the gastric mucosathe gastric mucosa
Diagnosis: Diagnosis: microscopy of Gram-stained microscopy of Gram-stained
smears of biopsy specimens of smears of biopsy specimens of the gastric mucosathe gastric mucosa
bacteriological methodbacteriological method immunoenzyme test for immunoenzyme test for
finding of Helicobacter antigen finding of Helicobacter antigen in fecesin feces
PCR testPCR test “ “Urease breath” testUrease breath” test
TreatmentTreatment – antibiotics – antibiotics (amoxicillin and (amoxicillin and metronidazole)metronidazole)
Classification of spirochetesClassification of spirochetes
Order – SpirochaetalesOrder – SpirochaetalesFamily – SpirochaetaceaeFamily – Spirochaetaceae
Genus: Genus:
LeptonemaLeptonema
CristispiraCristispira
BrachispiraBrachispira
TreponemaTreponema
BorreliaBorrelia
Family – LeptospiraceaeFamily – LeptospiraceaeGenus - Genus - LeptospiraLeptospira
Free-living saprobes
Human pathogens
Properties of spirochetesProperties of spirochetes Prokaryotes Prokaryotes Helically-coiled rod-shaped bacteriaHelically-coiled rod-shaped bacteriaHave Gram-negative cell wallHave Gram-negative cell wallMotileMotileHave endoflagella (or periplasmic flagella) located Have endoflagella (or periplasmic flagella) located within well-developed periplasmic spacewithin well-developed periplasmic spaceThin cells with diameter 0,06 to 0,8 Thin cells with diameter 0,06 to 0,8 m and length 6-m and length 6-30 30 mmDoes not stain with the usual bacteriological methods Does not stain with the usual bacteriological methods (eg, Gram staining)(eg, Gram staining)Dark-field and phase-contrast microscopy are used for Dark-field and phase-contrast microscopy are used for spirochetes investigation spirochetes investigation Useful staining methods are Romanowsky-Giemsa, Useful staining methods are Romanowsky-Giemsa, Morozov’sMorozov’s ( (silver impregnation)silver impregnation)
Dark-field photomicrograph of Dark-field photomicrograph of spirochetesspirochetes
Structure of spirochete Structure of spirochete
Structure of spirochete cellStructure of spirochete cell
Bacterial flagella
Electron micrographs of Electron micrographs of spirochetesspirochetes
Treponema
Borrelia Leptospira
Phase contrast photomicrograph Phase contrast photomicrograph of free-living spirocheteof free-living spirochete
Spirochetes morphologySpirochetes morphology
Treponema
Leptospira
Borrelia
Members of genus TreponemaMembers of genus Treponema
Tr. pallidum pallidum causes syphilisTr. pallidum pallidum causes syphilis
Tr. pallidum endemicus causes bejelTr. pallidum endemicus causes bejel
Tr. pallidum pentenue causes yawsTr. pallidum pentenue causes yaws
Tr. carateum causes pintaTr. carateum causes pinta
Treponema propertiesTreponema properties Thin flexible, spiral rodsThin flexible, spiral rodsCell length is approximately 20 Cell length is approximately 20 m, diameter is m, diameter is 0,1-0,2 0,1-0,2 mmTreponema has 8-20 coilsTreponema has 8-20 coilsStrict anaerobes or microaerophilsStrict anaerobes or microaerophilsCan live in the oral cavity, intestinal tract, and Can live in the oral cavity, intestinal tract, and perigenital regions of human and animals (not perigenital regions of human and animals (not Tr.pallidum)Tr.pallidum)Tr.pallidum pallidum causes venereal and Tr.pallidum pallidum causes venereal and congenital syphiliscongenital syphilisTr.pallidum Tr.pallidum has not been grownhas not been grown on bacteriologic on bacteriologic media or in cell culture. media or in cell culture. Tr.pallidum can be cultivated in the testicles of Tr.pallidum can be cultivated in the testicles of laboratory rabbits.laboratory rabbits.
Treponemes in the specimen Treponemes in the specimen from a patient with syphilisfrom a patient with syphilis
Pathogenesis and forms of syphilisPathogenesis and forms of syphilis
The human is the sole The human is the sole host and sourcehost and source of Tr.pallidum of Tr.pallidumTransmissionTransmission::
by intimate (sexual or oral) contactby intimate (sexual or oral) contactFrom pregnant woman to the fetusFrom pregnant woman to the fetusThrough blood transfusion (rare)Through blood transfusion (rare)
Forms Forms of syphilis:of syphilis:venereal syphilisvenereal syphilisvongenital syphilisvongenital syphilis
Stages Stages of syphilis:of syphilis:Primary Primary Secondary Secondary Tertiary Tertiary
Pathogenesis of syphilis.Pathogenesis of syphilis.Primary syphilis
Hard chancre on external male genitalia
Incubation period – 10-90 daysIncubation period – 10-90 days
Duration – 2-6 weeksDuration – 2-6 weeks
After inoculation trepomenes After inoculation trepomenes multiply in a localized area of the multiply in a localized area of the genitalia, spreading from there to the genitalia, spreading from there to the lymph nodes and blood stream. lymph nodes and blood stream.
First sign is the appearance of a First sign is the appearance of a hard chancrehard chancre at the site of infection at the site of infection (chancre is a painless, red ulcer with a (chancre is a painless, red ulcer with a hard rim)hard rim)
The ulcer heals spontaneously in 3-6 The ulcer heals spontaneously in 3-6 weeksweeks
Treponemes spread widely in tissueTreponemes spread widely in tissue
Electron micrograph of the Tr.pallidum attached to cells
.
Tip of spirochete Host cell
Pathogenesis of syphilis.Pathogenesis of syphilis.Secondary syphilisSecondary syphilis
About 3 weeks to 6 months (average About 3 weeks to 6 months (average is 6 weeks) after the chancre heals, is 6 weeks) after the chancre heals, the secondary stage appears. the secondary stage appears.
Signs: fever, headache, sore throat, Signs: fever, headache, sore throat, red rash on the body, the palms and red rash on the body, the palms and the soles (lesion contain the soles (lesion contain treponemes), that disappear treponemes), that disappear spontaneously spontaneously
In most individuals, the symptoms of In most individuals, the symptoms of secondary syphilis disappear in a few secondary syphilis disappear in a few weeks. weeks.
Duration – for weeks to monthsDuration – for weeks to months
After secondary stage latency occurs After secondary stage latency occurs (duration 0,5-8 or more years).(duration 0,5-8 or more years).
The skin rash in secondary syphilis
Pathogenesis of syphilis.Pathogenesis of syphilis.Tertiary syphilisGummaGumma formation in the liver, skin, formation in the liver, skin, bone (gummas are painful swollen bone (gummas are painful swollen syphilitic granulomas)syphilitic granulomas)
NeurosyphilisNeurosyphilis can involve any part of can involve any part of the nervous system with personality the nervous system with personality change, emotional instability, change, emotional instability, hallucinations, memory loss, speech hallucinations, memory loss, speech abnormalitiesabnormalities
Atrophy fo the optic verve leads to Atrophy fo the optic verve leads to blindnessblindness
Cardiovascular syphilisCardiovascular syphilis results from results from damage to the small arteries and the damage to the small arteries and the aortic walls (death from fatal aortic walls (death from fatal rupture of vessels and heart failure)rupture of vessels and heart failure)
A ring-shaped erosive gumma on the arm in late (tertiary syphilis)
Congenital syphilisCongenital syphilis
A profuse nasal discharge that obstructs breathing
Hutchinson's teeth
Consequences: from mild to the extremes of spontaneous miscarriage or stillbirth
Signs - nasal discharge, skin eruptions and loss, bone deformation, and nervous system abnormalities. In the late form - formation of Hutchinson's teeth
Nonsyphilitic TrepanematosesNonsyphilitic Trepanematoses
Yaws
(frambesia tropica)
Bejel
(endemic syphilis)
Diagnosis Diagnosis Depends on stage and form of diseaseDepends on stage and form of disease
Primary syphilis.Primary syphilis. Investigation of native material Investigation of native material from the chancre from the chancre
Dare-field and phase-contrast microscopyDare-field and phase-contrast microscopy
Immunofluorescence microscopy (express diagnosis)Immunofluorescence microscopy (express diagnosis)
PCRPCR
Secondary syphilis. Secondary syphilis. Dare-field and phase-contrast microscopy material from Dare-field and phase-contrast microscopy material from lesions and lymph nodes lesions and lymph nodes
Immunofluorescence microscopy (express diagnosis)Immunofluorescence microscopy (express diagnosis)
PCR (lesions and blood)PCR (lesions and blood)
Serological method: nonspecific and specific serologic test Serological method: nonspecific and specific serologic test for antitreponemal antibody revealing for antitreponemal antibody revealing
Tertiary, neurosyphilis, congenital syphilis.Tertiary, neurosyphilis, congenital syphilis.Serological method. Serological method.
Immunofluorescence microscopy. Immunofluorescence microscopy. Treponemes in the specimen from a Treponemes in the specimen from a patient with syphilispatient with syphilis
Diagnosis Diagnosis The laboratory The laboratory diagnosis of diagnosis of congenital syphiliscongenital syphilis is is based in the finding that the infant has a higher titer based in the finding that the infant has a higher titer of antibody than has the mother. of antibody than has the mother. Nonspecific serologic test.Nonspecific serologic test. These tests involve the use of These tests involve the use of nontreponemal antigens. Cardiolipin extracts from beef heart nontreponemal antigens. Cardiolipin extracts from beef heart react with antibodies in serum samples from patients with react with antibodies in serum samples from patients with syphilis (Wasserman test). syphilis (Wasserman test).
False-positive reactions occurs in infections such as leprosy, False-positive reactions occurs in infections such as leprosy, hepatitis, and infectious mononucleosis and in autoimmune hepatitis, and infectious mononucleosis and in autoimmune disease. disease.
Specific serologic test.Specific serologic test. These tests involve the use of These tests involve the use of treponemal antigens and therefore are more specific (indirect treponemal antigens and therefore are more specific (indirect hemagglutination assay, immunoenzyme test, immobilization hemagglutination assay, immunoenzyme test, immobilization test)test)
Bacteriological method can not be used.Bacteriological method can not be used.
Treatment and preventionTreatment and prevention
Treatment. Antibiotic – penicillin is effective in all Treatment. Antibiotic – penicillin is effective in all stages of syphilis.stages of syphilis.
There is no vaccine against syphilisThere is no vaccine against syphilis
Properties of BorreliaProperties of Borrelia
Borrelia is Borrelia is comparatively large comparatively large spirochetespirochete with diameter 0,2- with diameter 0,2-0,7 0,7 m and length 10-20 m and length 10-20 mmThey have 3-10 irregularly They have 3-10 irregularly spaced and loose coilsspaced and loose coilsThey contain 30-40 They contain 30-40 periplasmic flagellaperiplasmic flagellaThey can be cultured in They can be cultured in bacteriologic media containing bacteriologic media containing serum or tissue extractsserum or tissue extractsThey are They are transmitted by transmitted by arthropod vectorsarthropod vectors, usually ticks , usually ticks and liceand lice
Scanning electron micrograph Scanning electron micrograph of Borreliaof Borrelia
Diseases caused by BorreliaDiseases caused by BorreliaBorrelia recurrentis causes epidemic (louse-born) Borrelia recurrentis causes epidemic (louse-born) relapsing fever that is transmitted by licerelapsing fever that is transmitted by lice
Borrelia hermsii, caucasica, duttoni, persica cause Borrelia hermsii, caucasica, duttoni, persica cause endemic (tick-born) relapsing fever that is endemic (tick-born) relapsing fever that is transmitted by tickstransmitted by ticks
Borrelia burgdorferi causes Lyme disease that is Borrelia burgdorferi causes Lyme disease that is transmitted by tickstransmitted by ticks
Tick Lice
Pathogenesis of relapsing feverPathogenesis of relapsing feverThe reservoirThe reservoir::
for agents of tick-born relapsing fever are wild rodents, for agents of tick-born relapsing fever are wild rodents, and the human is an accidental hostand the human is an accidental hostfor agent of louse-born relapsing fever is humanfor agent of louse-born relapsing fever is human
VectorsVectors::for agents of tick-born relapsing fever are ticksfor agents of tick-born relapsing fever are ticksfor agent of louse-born relapsing fever are licefor agent of louse-born relapsing fever are lice
The spirochetes mature and persist in the salivary The spirochetes mature and persist in the salivary gland and intestines of the arthropods and are gland and intestines of the arthropods and are transmitted to human by its bytetransmitted to human by its byteThe species of Borrelia are passed The species of Borrelia are passed transovariallytransovarially in the ticksin the ticksThe pathologic manifestation are similar in tick-The pathologic manifestation are similar in tick-born and louse-born relapsing feverborn and louse-born relapsing fever
Pathogenesis of relapsing feverPathogenesis of relapsing fever
The incubation periodThe incubation period – 2 to 15 days – 2 to 15 daysEarly singsEarly sings: high fever, headache, shaking chills, : high fever, headache, shaking chills, and fatigueand fatigueLater featuresLater features: nausea, vomiting, muscle aches, : nausea, vomiting, muscle aches, and abdominal pain. Extensive damage to the and abdominal pain. Extensive damage to the liver, spleen, heart, kidneys, and cranial nerves liver, spleen, heart, kidneys, and cranial nerves occurs in many cases. occurs in many cases. Untreated cases are often lengthy and Untreated cases are often lengthy and debilitating and are attended by debilitating and are attended by 5% to 40% 5% to 40% mortalitymortality. .
1. Primary infection and fever2. Initial antibody response with
concurrent reduction in symptoms3. Reinfection with a new antigenic
type, causing renewed symptoms
4. A second antibody response, producing a second remission5, 6. This pattern can continue for up to four relapses
Diagnosis of relapsing feverDiagnosis of relapsing fever
MicroscopyMicroscopy of stained by Romanowsky-Giemsa of stained by Romanowsky-Giemsa smears of peripheral blood (the most useful smears of peripheral blood (the most useful method and very definitive evidence of relapsing method and very definitive evidence of relapsing fever)fever)
Bacteriological methodBacteriological method (rarely) (rarely)
Serologic methodSerologic method (rarely) (rarely)
Borrelia in blood smearBorrelia in blood smear
Romanowsky-Giemsa staining Romanowsky-Giemsa staining
The main reservoir – small mammalians (mice), upon which the nymphs feed.
Large mammalians (deer), are an obligatory host in the tick’s life cycle but are not an important reservoir of the Borrelia.
There is no human-to-human spread
Pathogenesis of Pathogenesis of Lime diseaseLime disease
The clinical findings have been divided into 3 stages:The clinical findings have been divided into 3 stages:1. A spreading curcular red rash with a clear center at the 1. A spreading curcular red rash with a clear center at the
bite site. Possible “flulike” symptoms, arthralgiasbite site. Possible “flulike” symptoms, arthralgias
2. Myocarditis or pericarditis, accompanied by various forms 2. Myocarditis or pericarditis, accompanied by various forms of heart block, acute (aseptic) meningitis and cranial of heart block, acute (aseptic) meningitis and cranial neuropathies neuropathies
3. Arthritis, usually of the large joints. Chronic progressive 3. Arthritis, usually of the large joints. Chronic progressive central nervous system diseasecentral nervous system disease
Diagnosis, treatment, Diagnosis, treatment, preventionprevention
DiagnosisDiagnosis: : Serological methodSerological method – detection either IgM antibody or – detection either IgM antibody or a rising titer of IgG antibody with ELISA a rising titer of IgG antibody with ELISA (immunoenzyme test) or an indirect (immunoenzyme test) or an indirect immunofluorescence testimmunofluorescence test
PCR testPCR test
Bacteriological methodBacteriological method (rarely) (rarely)
TreatmentTreatment – antibiotics – antibiotics
Prevention Prevention – vaccine is absent – vaccine is absent
Leptospira Leptospira
Leptospires are typical spirochetes with tight, regular Leptospires are typical spirochetes with tight, regular coils with a bend or hook at one or both endscoils with a bend or hook at one or both endsVery thing cells with diameter 0,06-0,09 Very thing cells with diameter 0,06-0,09 mmThey grow in bacteriologic media containing serumThey grow in bacteriologic media containing serumThere are 2 species in the genus:There are 2 species in the genus:
L.interrogansL.interrogans, which causes leptospirosis in humans , which causes leptospirosis in humans and animals. It is divided into nearly 200 serotypes and animals. It is divided into nearly 200 serotypes that occur in different animals and geographic that occur in different animals and geographic locations.locations.L. biflexa, a harmless, free-living saprobe.L. biflexa, a harmless, free-living saprobe.
Leptospira morphology Leptospira morphology
Pathogenesis of Pathogenesis of leptospirosisleptospirosis
ReservoirsReservoirs are rodents, domestic animals (horses, are rodents, domestic animals (horses, dogs, cattle, pigs)dogs, cattle, pigs)TransmissionTransmission. With contaminated water and food.. With contaminated water and food.The illness is The illness is typically “biphasictypically “biphasic”:”:
Early, or leptospiremic, phaseEarly, or leptospiremic, phase, the pathogen appears in , the pathogen appears in the blood and cerebrospinal fluid. Symptoms: high fever, the blood and cerebrospinal fluid. Symptoms: high fever, chills, headache, muscle aches, conjunctivitis, vomiting.chills, headache, muscle aches, conjunctivitis, vomiting.
Second, “immune” phaseSecond, “immune” phase, the leptospiras disappear from , the leptospiras disappear from the blood because of the action of phagocytes, complement, the blood because of the action of phagocytes, complement, and IgM antibodies. Symptoms: milder fever, headache due and IgM antibodies. Symptoms: milder fever, headache due to aseptic meningitis, liver damage (jaundice) and impaired to aseptic meningitis, liver damage (jaundice) and impaired kidney function, anemia, and neurological disturbances. kidney function, anemia, and neurological disturbances.
Diagnosis, treatment, Diagnosis, treatment, preventionprevention
Diagnosis:Diagnosis: Serological methodSerological method – detection antibody titer with – detection antibody titer with macroscopic slide agglutination testmacroscopic slide agglutination testBacteriological methodBacteriological method (rarely). Isolation of (rarely). Isolation of leptospiras from blood and urine by inoculating a leptospiras from blood and urine by inoculating a specimen into special media or laboratory animals.specimen into special media or laboratory animals.Dard-field microscopyDard-field microscopy of specimens of specimens
Treatment Treatment – antibiotics – antibiotics
Prevention Prevention – strain-specific inactivated vaccines are – strain-specific inactivated vaccines are available for humans, dogs, and cattle. available for humans, dogs, and cattle.