1 The ecology of anthrax spores: Tough but not invincible Sonja Brockmüller Seminar presentation based on a paper by Daniel C. Dragon and Robert P. Rennie The Canadian Veterinary Journal Volume 36, May 1995, pgs (A copy of the paper is available in the course folder „Science News“ on OLAT)

2 Short introduction to Anthrax: Biologische Kampfsoffe sind wieder zu beachten Artikel von Marc Deschka in: Die Schwester / Der Pfleger 42, Jahrg 3/03

3 Summary of possible bio-weapons

4 Anthrax (Bacillus anthracis) pulmonary-, cutaneous- and gastrointestinal- anthrax Incubation time: First symptomes after 48 h (2-7 d) Therapie: Antibiotics (Ciprofloxazin, Doxycyclin, Penicilin)

5

6 Cutaneous-anthrax

7 Ecology of anthrax spores Spore integument respon- sible for the spores‘s surface hydrophobicity --> Protect inner spore Inside core less water Spores interact with their surroundings Vegetative cells need a nutrient rich environement --> spore formation and lysis of vegetative cell (See also BBOM 9th ed. Chapter 3.15)

8 Ecology of anthrax spores Vegetative cells need a nutrient rich environement --> spore formation and lysis of vegetative cell Endospore coat component: Dipicolinic acid (DPA) -> ingestion by host macrophage cells is limited

9 Ecology of anthrax spores Vegetative cells need a nutrient rich environement -> spore formation and lysis of vegetative cells Endospore coat component: Dipicolinic acid (DPA) -> ingestion by host macrophage cells is limited Endospores resist even prolonged exposure to chemical disinfectants, desiccation and extremes in pH, temperature, pressure, UV and ionizing radiation.

10 Ecology of anthrax spores Vegetative cells need a nutrient rich environement -> spore formation and lysis of vegetative cells Endospore coat component: Dipicolinic acid (DPA) -> ingestion by host macrophage cells is limited Endospores resist even prolonged exposure to chemical disinfectants, desiccation and extremes in pH, temperature, pressure, UV and ionizing radiation. Global in its geographical distribution and endemic to many parts of Europe, Asia, Africa, North- and South America, Australia

11 The ecology of anthrax spores: Tough but not invincible

12 The ecology of anthrax spores: Tough but not invincible Bison - Mortality in Northern Canada caused by Anthrax

13 The ecology of anthrax spores: Tough but not invincible Dissemination of spores Weather and its consequences Soil quality Epidemiology of Anthrax with respect to Bisons Summary

14 Dissemination of spores Scavengers and carnivores can act as carriers by dispersing ingested spores in their feces over large distances. Insects (mosquitoes, flies) Soil on the coat of wallowing animals (bison) Water and wind

15 The ecology of anthrax spores: Tough but not invincible Dissemination of spores Weather and its consequences Soil quality Epidemiology of Anthrax with respect to Bisons Summary

16 Weather and his consequence Anthrax epidemics generally occur during dry summer months following prolonged periods of heavy rain Water collects and concentrates the spores in „storage“ areas Water evaporates and allows the spores to be dispersed via the air

17 The ecology of anthrax spores: Tough but not invincible Dissemination of spores Weather and its consequences Soil quality Epidemiology of Anthrax with respect to Bisons Summary

18 Soil and its quality Outbreaks were most freqently associated with calcareous soils, rich in Ca 2+ and nutrients High levels of calcium in the soil may buffer the internal supply of anthrax spores and greatly extend their viability “incubator area“ hypothesis: alkaline pH, high soil moisture, organic matter

19 The ecology of anthrax spores: Tough but not invincible Dissemination of spores Weather and its consequences Soil quality Epidemiology of Anthrax with respect to Bisons Summary

20 Epidemiology of anthrax with respect to bison Mortality among sexually mature males is higher than females and immature bisons. High temperatures, breeding activity, high levels of insect harassment, and population size of bisons -> immunity is weak -> low oral doses -> lethal infections Rutting agression-> stamping, wallowing -> dust clouds of aerosolized spores

21 The ecology of anthrax spores: Tough but not invincible Dissemination of spores Weather and its consequences Soil quality Epidemiology of Anthrax with respect to Bisons Summary

22 Summary Long lasting, highly resistant spores Correlation between disease and soil factors (likes calceouros soils) Vegetative cells are unlikely to survive outside a host