Spirochaetes lecture.pdf

SPIROCHAETALES Treponema, Borrelia and Leptospira Spirochete from Greek speira "a coil" and khaite "hair“ Key Questions What are the unusual characteristics of the spirochaetes? What are the common features of disease caused by spirochaetes? Why is the syphilis spirochaete known as the...

SPIROCHAETALES Treponema, Borrelia and Leptospira Spirochete from Greek speira "a coil" and khaite "hair“ Key Questions What are the unusual characteristics of the spirochaetes? What are the common features of disease caused by spirochaetes? Why is the syphilis spirochaete known as the stealth pathogen? Why don’t YOU want to get Borrelia burgdorferi infection? Why is leptospirosis one of the most neglected diseases? Phylogenetic tree of major lineages of bacteria based on 16S rRNA GC: % of nitrogenous bases in DNA or RNA that are guanine or cytosine SPIROCHAETALES: PHYLOGENY Four clinically important genera Treponema Borrelia Leptospira Brachyspira  Characteristics Gram-negative cell wall Periplasmic flagella (endoflagella) allow motility through highly viscous media (e.g. connective tissue) Differing numbers of periplasmic flagella (endoflagella) according to genus & species Treponemes are not culturable using artificial media Borrellia and Leptospira spp. have been grown on complex media – liquid media is most successful GENERAL SHAPES OF SPIROCHAETALES Treponema https://youtu.be/DsX47fMlkzU?t=8 Leptospira Borrelia  Treponema species Dervied from Greek SYPHILLIS “trypanon”, meaning borer Treponema pallidum sub-species pallidum Worldwide distribution. 7.1 new cases a year. Venereal ~600,000 congenital syphilis cases a year PINTA Treponema pallidum sub-species carateum Mexico and Central and South America A few hundred cases each year YAWS Cranial trepanation Treponema pallidum sub-species pertenue Africa, Asia and Western Pacific Non-venereal ~80 000 – 90 000 cases a year BEJEL Treponema pallidum sub species endemicum Eastern mediteranean and West Africa ~~~100 000 cases a year  Non-venereal treponemal diseases YAWS Common yaws, bejel, and pinta lesions in 2013. A) Papillomatous primary yaws lesion B) Disseminated papilloma of secondary yaws C) Labial mucosal plaques of primary bejel BEJEL D) disfiguring infiltration of the nose, glabella, and forehead in a patient with secondary bejel E) squamous plaque of primary pinta F) Late achromic pinta The individuals photographed for this publication were informed of the purpose of the photograph and they agreed to have their photograph taken and potentially published. PINTA Mitja et al. via Researchgate Sexually transmitted (venereal) syphilis: Treponema pallidum sub sp pallidum A, B - Primary chancre (a and b) after 9-90 days C, D - Secondary syphilis highly infectious mucocutaneous lesions, 4-10 weeks later F - 30% of latent patients will relapse with a benign gumma (f) G, H - 40% of late latent patients progress to late tertiary syphilitic disease 20 years or more after infection e.g. cardiovascular and neuro syphilis (g and h) E - Congenital syphilis Latency: organisms persist (how is a mystery) in the body but asymptomatic  Treponema pallidum subspecies pallidum Sexually transmitted disease of the skin and flesh Transmission: We cannot cultivate T. pallidum subsp pallidum so T. pallidum subsp. Pallidum fragile cells. No how did people study the environmental survival outside of the host disease? Contact between infectious lesions / abraded skin/mucous membranes Most cases transmitted via sexual contact Rare transmission via skin-to-skin contact Mother-to-child transmission (perinatal) Cannot be spread via toilet seats, swimming pools, hot tubs, shared clothing or eating utensils  SYPHILIS: THE TUSKEGEE “to death” STUDY ❑ Began in 1932, a study to record the natural history of syphilis ❑ Involved 600 black men, 399 with syphilis, 201 who did not ❑ Men received free medical exams, free meals, and burial insurance. ❑ NO informed consent ❑ Originally projected to last 6 months, the study actually went on for 40 years UNTIL 1972 ❑ https://www.cdc.gov/tuskegee/timeli ne.html Early treatments for syphilis: fighting fire with fire What does this tell you about the bacteria?  Treponema species SYPHILLIS Treponema pallidum sub-species pallidum Worldwide distribution. 7.1 new cases a year. Venereal ~600,000 congenital syphilis cases a year How do members of PINTA the same species Treponema pallidum sub-species carateum Mexico and Central and South America cause such different A few hundred cases each year diseases? YAWS Treponema pallidum sub-species pertenue Africa, Asia and Western Pacific Non-venereal ~80 000 – 90 000 cases a year BEJEL Treponema pallidum sub species endemicum Eastern mediteranean and West Africa ~~~100 000 cases a year  LYME DISEASE/BORRELIOSIS Transmission By Ixodus ticks 85,000 cases in Europe and 300000 in USA Borrelia burgdorferi sensu lato species complex – Borellia burgdorferi sensu stricto only in North America – Borrelia harinii and Borrelia afzelii also in Europe Occupational risk groups: foresters, game keepers, rangers, farmers, deer handlers Recreational risk groups: hikers, campers, fishers Risk areas linked to tick frequency  LYME DISEASE/BORRELOSIS: Stages of Disease Stage 1 Tick must have been feeding for at least 24h Acute, localized disease at site of inoculation Non-specific flu-like symptoms Erythema migrans 1 to 4 weeks after bite (70-80% people) Without treatment rash clears within 3 to 4 weeks Stage 2 80% patients get subacute, disseminated disease cardiac, neurological, skin lesions, CNS, musculoskeletal systems Stage 3 Latent period of up to 1yr Erythema migrans meaning migrating Arthritis, neurological impairment redness (Bulls eye rash). Very low levels of Even with treatment a subset of patients continue to spirochaetes may be detected in the blood have arthritic symptoms (post infectious antibiotic of some patients refractory arthritis)  Leptospira species Leptospira interrogans (Greek verb = question mark) hooked ends Most common zoonotic infection in the world (1 million cases/60,000 deaths). Easily transmitted from infected animals through their urine, either directly or through infected soil or water. It can cause a self-limiting influenza- like illness or a much more serious Weil disease with multi-organ failure and death. LEPTOSPIRA INTERROGANS: LEPTOSPIROSIS, WEIL’S DISEASE  LEPTOSPIROSIS, WEIL’S DISEASE Mild virus-like syndrome Anicteric leptospirosis systemic with aseptic meningitis Icteric leptospirosis/Weil’s Disease jaundice (5-15% mortality) – Vascular collapse – Thrombocytopenia – Haemorrhage – Hepatic and renal dysfunction  Treatment of spirochaete disease Treponemal diseases respond well to penicillin. Secondary syphilis (weekly injections) are treated with penicillin injections IM Lyme disease is treated with either doxycycline, amoxicillin or cefuroxime for 2-4 weeks. 10-20% Lyme patients continue to suffer persistent symptoms including fatigue, muscle and joint aches, and brain fog that can six months or longer. For Weils Disease no antibiotics in mild cases just fluids and pain and fever control. Antibiotics may include doxycycline, amoxicillin, or ampicillin. Severe cases are treated with IV penicillin G, third-generation cephalosporins, or erythromycin. Patients with icteric leptospirosis need intensive care unit admission