Rickettsiaceae Chlamydiaceae Mycoplasmas 송명기 ( 발표 ) 김석진 ( 발표 ) 최재국 (PPT) 전범찬 (PPT)

Contents -Family Rickettsiaceae -Specific Rickettsioses -Emerging Rickettsioses -Other Vector-Borne Pathogens : Coxiella & Bartonella -Other Obligate Parasitic Bacteria : The Chlamydiaceae -Biological characteristics of the Mycoplasmas -Bacteria that have lost their cell wall -Bacteria in Dental Disease

Rickettsiaceae & Rickettsioses

Family Rickettsiaceae

G- cell wall, Binary fission the smallest cell Nonmotile pleomorphic rods, coccobacilli metabolic pathway (some Obligate parasitism : inability to metaboilize AMP) sensitive to environmental exposure (except. R. typhi ) Morphology distinction of Rickettsia

Family Rickettsiaceae Arthropod vector : 8 tick genera, 2 fleas, 1 louse Most vectors harbor rickettsias with no ill effect Ticks : directly inoculate the skin lesion Fleas & lice : defecate or are smashed → releasing the rickettsias into a wound Distribution and Ecology of Rickettsial Diseases

Family Rickettsiaceae common target : endothelial lining of blood vessels → necrosis, vasculitis, vascular leakage, thrombosis skin rash, edema, hypotension, gangrene, high fever intravascular clotting in the brain → stuporous suitable live medium : yolk sacs, chick embryo cell cultures, mice & guinea pig General Factors in Rickettsial Pathology

Specific Rickettsioses The typhus group Epidemic Typhus by Rickettsia prowazekii -louse-borne typhus : war, poverty, famine -human : the only reservoir of R. prowazekii -by defecating into its bite wound -crowding, infrequently changing clothing

Rickettsia prowazekii

Specific Rickettsioses Disease Manifestations& Immune Response entering the circulation → intracellular infection → high fever, chills, muscular pain → rash → extremities → hypotension, gangrene mortality rate : 40-60% in patients over 50 years milder recurring form of the typhus : Brill-Zinsser disease

Specific Rickettsioses Treatment Tetracycline, chloramphenicol, ciflafloxacine Prevention exterminating the vector : antilouse shampoo or ointment

Specific Rickettsioses The typhus group Endemic Typhus by Rickettsia typhi (R. mooseri ) -murine typhus, flea-borne typhus -Reserviors : rodents -Fever, headache, malaise, skin rash -Tetracycline, chloramphenicol -Pesticides for vectors & rodent control

Specific Rickettsioses The typhus group Scrub Typhus by Orientia tsutsugamushi -Mite-borne typhus -Reserviors : rodents -Endemic to South Asia, Australia, Pacific Islands -black scab → fever, muscle aches → rash → mental confusion, pneumoniae → mortality rate 50%

Specific Rickettsioses Rocky Mountain spotted fever(RMSF) Epidemiology & Pathology Rickettsia rickettsii : transmitted by ticks (hard, dog, wood) the tick passes R.rickettsia to its offspring (transovarial passage) : continual source children living in rural and mountain areas in spring, summer

Specific Rickettsioses Rocky Mountain spotted fever(RMSF) Pathogenesis & Clinical Manifestation incubation → fever, chills, muscular pain → spotted rash → slightly mottled → macular, maculopapular, petechial hemorrhage → necrotic, gangrene cardiovascular disruption restlessness, delirium, convulsions, tremor, coma

Specific Rickettsioses

Rocky Mountain spotted fever(RMSF) Diagnosis : clinical observation, patient history 1.Cluster of symptoms : sudden fever, headache, rash 2.Recent contact with ticks and dogs 3.Occupational or recreational exposure in spring & summer Isolating rickettsias → specially qualified facilities → PCR assay

Specific Rickettsioses Treatment Tetracycline(doxycycline), chloramphenicol Prevention Vaccine Wearing protective clothing Using insect sprays, fastidiously removing ticks

Emerging Rickettsioses Ehrlichia & Ehrlichosis Strict parasitic existence in host cells Human monocytic erhlichosis(HME) by Lone Star ticks Human granulocytic erhlichosis(HGE) by Ixodes scapularis ticks PCR test, Indirect flourescent antibody test Doxycycline

Coxiella & Bartonella

Other Vector-Borne Pathogens : Coxiella & Bartonella Q fever by Coxiella burnetii intracellular parasite(similar to rickettsias ), endospore Ticks: transmission between wild and domestric animals Human infection by airborne particle from infected animal Fever, chills, muscle ache → hepatitis, endocarditis Tetracycline

Trench fever by Bartonella quintana Small G- rods, fastidious, Not obligate parasites louse vector (like epidemic typhus) Not multiply intracellularly, Not kill the louse vector quintana fever, headache, muscle aches, macular rash Other Vector-Borne Pathogens : Coxiella & Bartonella

Cat-scratch disease(CSD) by Bartonella henselae Cat scratch or bite Small papules at the site of inoculation lymph nodes swell and pus-filled Tetracycline, erythromycin, rifampin Bacillary angiomatosus in AIDS patients Cutaneous & systemic infection Other Vector-Borne Pathogens : Coxiella & Bartonella

Chlamydiaceae & Chlamydial Disease

Other Obligate Parasitic Bacteria : The Chlamydiaceae Chlamydia Obligate intracellular parasites (like Rickettsias) G- cell wall, small size, pleomorphic morphology Chlamydia trachomatis : sexually transmitted pathogen Chlamydia pneumoniae : atypical pneumoniae Chlamydia psittaci : zoonosis of birds & mammals, ornithosis in human

The Biology of Chlamydia : Two distinct stages Elementary body(EB) -A small, metabolically inactive, infectious form -survive outside the host cell (envelope) Reticulate body(RB) -A larger, noninfectious, thin cell walls -Grows within the host cell vacuoles -Energy parasites (lacking enzyme systems for ATP) Other Obligate Parasitic Bacteria : The Chlamydiaceae

Disease by Chlamydia trachomatis reservior : human body Elementary bodies(EB) : transmitted in infectious secretions Two human strains 1.Trachoma strain : attacks the squamous or columnar cells of the eyes, genitourinary tract, lungs 2.Lymphogranuloma venereum(LGV) strain : invades the lymphatic tissues of the genitalia Other Obligate Parasitic Bacteria : The Chlamydiaceae

Chlamydial Disease of the Eye (1) ocular trachoma - Infection : epithelial cells of the eye → blindness - Transmission : by contaminated fingers, fomites, flies & hot, dry climate

Chlamydial Disease of the Eye - Symptom : mild exudate & inflammation of conjunctiva → marked infiltration of lymphocytes and macrophages → pebbled appearance → pannus - Chronic & Secondary infection : can lead to corneal damage, impaired vision - Treatment : tetracycline, sulfa drugs

Chlamydial Disease of the Eye (2) inclusion conjunctivitis - Transmission : through contact with secretions of an infected genitourinary tract - Infantile conjunctivitis : develop 5~12 days after a baby has passed through infected birth canal

Chlamydial Disease of the Eye - Symptom : conjunctival irritation profuse adherent exudate, redness, swelling - Prevention : erythromycin, tetracycline

Sexually Transmitted Chlamydial Disease - by C. trachomatis - 10% of infected males : no symptom 70% of infected women : asymptomatic - chlamydiosis : the 2nd most prevalent STD (1) nongonococcal urethritis - Symptom : inflammation of the urethra (male) cervicitis, endometritis, salpingitis (female)

Sexually Transmitted Chlamydial Disease (2) lymphogranuloma venereum - Infection : enter through tiny nicks, breaks in the perigenital skin or mucous memb. → form vesicular lesion - Symptom : headache, fever, muscle aches

Chlamydiosis (1) identification - specimen sampling, genital samples - culture in chicken embryo, mice, cell line - immunofluorescence, PCR-based probe - Giemsa, iodine stains (inclusion conjunctivitis) (2) treatment & prevention - tetracycline, azithromycin (act intracellularly) - sexual partner : drug therapy, condom

Chlamydophila - new genus of obligate pathogens (1) C. pneumoniae - strict human pathogen - respiratory illness : pharyngitis, bronchitis, pneumonitis - mild illness in young adult, but severe reaction in asthmatic patients - chronic infection of arteries → heart disease

Chlamydophila (2) C. psittaci - psittacosis, ornithosis : worldwide zoonosis (by contaminated feces, discharges that become airborne) - symptom : mimic influenza & pneumococcal pneumonia fever, chills, headache, muscle aches (early) → coughing, lung consolidation (later) - treatment : tetracycline, erythromycin

the Class Mollicutes Genus Mycoplasma

the Class Mollicutes - mycoplasmas : smallest self-replicating microorganisms lack a cell wall parasites of animals and plants - Mycoplasma & Ureaplasma : M. pneumoniae → respiratory tract disease M. hominis & U. urealyticum → urogenital tract infection

Mycoplasma (1) characteristic - without cell wall → pleomorphic & small, flexible cells - not strict parasites, can grow in cell-free media, - generate metabolic energy, synthesize proteins with their own enzymes - fastidious, require complex media - membrane parasite - chronic infection & difficult to eliminate

membrane parasite

Mycoplasma (2) M. pneumoniae - human parasite, primary atypical pneumonia (PAP) - atypical pneumonia : by rickettsias, chlamydias, respiratory syncytial viruses, adenoviruses - walking pneumonia

Mycoplasma - infection : bind to specific receptors of the epithelial cells of the respiratory tract → gradual spread → disrupt the cilia & damage the respiratory epithelium - symptom : fever, malaise, sore throat, headache → nasal symptom, chest pain, earache

Mycoplasma - diagnosis : stain of sputum, leukocyte counting, X-ray, serological test - treatment : tetracycline, erythromycin - prevention : control contamination of fomite, avoid droplet nuclei

Mycoplasma (3) other Mycoplasmas - M. hominis : vaginitis, PID - U. urealyticum : NGU, prostatitis, opportunistic infections of fetus & fetal memb. - weak reproductive pathogen samples from urethra, vagina, cervix - M. fermentens : isolated from the spleen, liver cofactor for rapid deterioration

Mycoplasma (4) wall deficient bacteria - L forms : exposure to drugs or enzymes not related to mycoplasmas - Formation process antimicrobiotic therapy → become L- form → resist → remain therapy ends → reacquire wall → resume pathogenic - chronic pyelonephritis, endocarditis, Crohn’s disease (chronic intestinal syndrome)

Bacteria in Dental Disease

The Structure of Teeth and Associated Tissues

Hard-tissue disease - Dental caries : gradually destroy the enamel → destruction of deeper tissue

Plague Formation thin, mucous coating(adhesive salivary proteins) → Acquired pellicle cariogenic genera : Streptococcus, Actinomyces → cling to the tooth surfaces → dense, whitish mass ’paluge’ S. mutans, S. gordonii : ’primary invaders’ Lactobacillus, Neisseria : ‘secondary invaders’

Acid Formation and Localization and Etching of the Enamel -the role of plaque in caries development + streptococci & lactobacilli → produce acid → below pH 5 → dissolve the calcium phosphate of the enamel : ‘first-degree caries -deterioration reach the level of the dentin : ‘second- degree caries’ -exposure of the pulp : ‘third-degree caries’, severe tenderness and toothache

Soft-tissue & Periodontal disease - gingivitis : swelling, loss of normal contour, patches of redness, increased bleeding of the gingiva - periodontitis : more serious disease periodontal memb. and cementum - ANUG (acute necrotizing ulcerative gingivitis)

Factos in Dental Disease -nutrition, eating sugar, without brushing -Anatomical, physiological, -Vaccine -Preventive dentistry