Bacterial Endospores

Bacterial endospores exist solely to help low G and C Gram-positive organisms, such as Bacillus, Clostridium, and Staphylococcus species, survive through the most extreme environmental conditions (Ahmad et al, 1999; Cornell University, 2019).

Designed with a uniquely formidable cellular structure, bacterial endospores arise during the absence of key nutrients in their environment and play a significant role in protecting the starving bacteria (Pommerville, 2014). Over several hours, endospores are created by the asymmetrical cell division of a vegetative cell to form a mother cell and forespore that unite as one to build the endospore before releasing it into the environment (Cornell University, 2019).

According to Sonenshein (2000), spore-forming bacteria is characterised by dormancy, refractility and extreme resistance. Consequently, the highly resistant nature of endospores makes it difficult to destroy by heat, dehydration, radiation and chemicals. For example, contaminated medical equipment must be heated to 121°C for a minimum of 15 minutes to ensure complete sterilisation is achieved (Acharya, 2016).

Once favourable environmental conditions return, dormant endospores revert back to vegetative cells which contain pathogenic bacteria. This recurring cycle of germination makes the task of removing bacterial endospores in highly populated healthcare settings particularly challenging.

Bacterial endospores, such as Clostridioides difficile (C. diff), are an infection control nightmare, one that can run endlessly if not managed carefully by infection control managers. During a prevalence study across 175 hospitals in Queensland, 58.3% of patients presented with onset symptoms of C. diff pathogen once hospitalised (Huber et al, 2014).

Сurrent and future trends in australia

More recent research shows that national multi-centre studies estimate 4,902 C. diff infections occur annually in Australia (Mitchell et al, 2017). The rate of severe C. diff infection cases (currently 113 annually) is expected to increase, however the mortality rate will not be affected (Australian Commission on Safety and Quality in Health Care, 2018b).

Infection control challenges

Preventing the spread of C. diff infection requires compliance on all fronts within the healthcare environment, with patients, visitors and staff members all responsible for minimising the risk of infection. The primary challenges that impact the effectiveness of C. diff management includes:

Infection control prevention methods

The Australian Commission on Safety and Quality in Health Care (2018b) confirmed that the best approaches to the future management of C. diff involves continuous national monitoring of CDI prevalence at quarterly intervals and a combination of local and severity surveillance.

Administrative and traditional HAI surveillance covering the incidence of C. diff infections is critical for adequate infection prevention and control responses across each Australian state and territory. According to Australian Commission on Safety and Quality in Health Care (2018b), the recommended method for capturing enhanced surveillance is to focus on severity, instead of exposure classification, as it can lead to better management of local cases and allocation of resources. Currently in Australia, state wide monitoring of severe CDI only occurs in Victoria (Australian Commission on Safety and Quality in Health Care, 2018b).

In the case of Clostridioides difficile management for infection control managers across hospitals and aged care facilities in Australia, sharing findings from local and severity surveillance, and working together to better manage resource allocation will make a big difference in the long-term.

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References

1. Acharya, T 2016, Bacterial Spores: Structure, Importance and examples of spore forming bacteria, Microbeonline, viewed 16 August 2019, <https://microbeonline.com/bacterial-spores-structure-importance-and-examples-of-spore-forming-bacteria/>
2. Ahmad, S, Selvapandiyan, A & Bhatnagar, RK 1999, ‘A protein-based phylogenetic tree for gram-positive bacteria derived from hrcA, a unique heat-shock regulatory gene’, International Journal of Systematic Bacteriology, 49, no. 4, pp. 1387-1394, viewed 13 September 2019, Academic Search Complete database, PubMed, PMID: 10555317
3. Australian Commission on Safety and Quality in Health Care 2018a, Clostridium difficile infection. A model to improve the management and control of Clostridium difficile in Australia, viewed 3 September 2019, <https://www.safetyandquality.gov.au/publications-and-resources/resource-library/clostridium-difficile-infection-model-improve-management-and-control-clostridium-difficile-australia>
4. Australian Commission on Safety and Quality in Health Care 2018b, Clostridium difficile infection. Monitoring the national burden of Clostridium difficile, viewed 28 August 2019, <https://www.safetyandquality.gov.au/publications-and-resources/resource-library/clostridium-difficile-infection-monitoring-national-burden-clostridium-difficile>
5. Centers for Disease Control and Prevention 2019, Your Risk of C. diff, viewed 29 August 2019, <https://www.cdc.gov/cdiff/risk.html>
6. Clostridium difficile colonies 1965, image, Centers for Disease Control and Prevention ‘s Public Health Image Library, viewed 18 September 2019, <https://phil.cdc.gov/details.aspx?pid=3647>
7. ‘Clostridium difficile’ 2018, NHS, viewed 29 August 2019, <https://www.nhs.uk/conditions/c-difficile/#>
8. Cornell University 2019, Bacterial Endospores, viewed 16 August 2019, <https://micro.cornell.edu/research/epulopiscium/bacterial-endospores/>
9. Fernando, SA, Gray, TJ & Gottlieb, T 2017, ‘Healthcare‐acquired infections: prevention strategies’, Internal Medical Journal, vol. 47, no. 12, pp. 1341-1351, viewed 3 September 2019, Academic Search Complete database, Wiley Online Library, doi:10.1111/imj.13642
10. Huber, CA, Hall, L, Foster, NF, Gray, M, Allen, M, Richardson, LJ et al. 2014, ‘Surveillance snapshot of Clostridium difficile infection in hospitals across Queensland detects binary toxin producing ribotype UK 244’, Communicable Diseases Intelligence, vol. 38, no. 4, pp. 279-284, viewed 4 September 2019, Academic Search Complete database, PubMed, PMID: 25631588
11. Mitchell, BG, Shaban, RZ, Macbeth, D, Wood, C & Russo, PL 2017, ‘The burden of healthcare-associated infection in Australian hospitals: A systematic review of the literature’, Infection, Disease & Health, 22, no. 3, pp. 117-128, viewed 28 August 2019, Academic Search Complete database, ScienceDirect, doi:10.1016/j.idh.2017.07.001
12. Pommerville, J 2014, ‘Microbial Growth and Nutrition’ in Fundamentals of Microbiology, Jones & Bartlett Learning, Burlington, MA, pp. 133-143
13. Sonenshein, A 2000, ‘Chapter 6: Endospore-Forming Bacteria: an Overview’, in Y Brun and L Shimkets (ed.), Prokaryotic Development, ASM Press, Washington, DC, pp. 133-150, viewed 4 September 2019, <https://www.asmscience.org/content/book/10.1128/9781555818166.chap6>
14. Worth, LJ, Spelman, T, Bull, AL, Brett, JA & Richards, MJ 2016, ‘Epidemiology of Clostridium difficile infections in Australia: enhanced surveillance to evaluate time trends and severity of illness in Victoria, 2010-2014’, The Journal of Hospital Infection, 93, no. 3, pp. 280-285, viewed 28 August 2019, Academic Search Complete database, ScienceDirect, doi:10.1016/j.jhin.2016.03.014