Working Group 3 (WG3)

Working Group 3 (WG3)
Working Groups

Working Group 3: Clinical applications of microbial responses to low pH


Microbial infections are a serious source of global morbidity and mortality and increasing AMR to antibiotics and antifungals is a severe health risk. Antibiotics and antifungals are poorly effective against biofilm growth, such as in wounds and on medical devices like catheters; these thus pose a risk particularly to ageing populations. A small amount of clinical use of organic acids (principally acetic and citric) against bacteria and fungi is being reported in the medical literature.

The low pH of the vaginal epithelium, established by the native lactic acid-producing microflora, helps prevent colonisation by pathogenic fungi, and the use of lactobacilli as probiotics against thrush is starting to receive attention14,15. However, although organic acids as agents to reduce microbial spoilage in food have a long history, this work has barely translated into clinical usage. Understanding microbial responses to low pH is also relevant to tacking organisms that have to traverse human or animal GI tracts where exposure to varying pH and organic acid concentrations occurs, such as in Brucellosis, so there are also potential applications in animal husbandry and veterinary medicine.


(1) evaluate the potential of organic acids as anti-microbial and anti-fungal agents through transfer of existing methods from food microbiology to clinical pathogens;

(2) develop new approaches to studying the cellular consequences of acid (including organic acid) stress, from individual cells to populations and biofilms. An area of particular relevance to both WG3 and WG4 is the use of new methods for investigating the states of individual cells in populations.