Professor John Tagg’s first significant encounter with Streptococcus pyogenes – the bacteria that causes a strep sore throat – was as a 12-year-old boy living in Melbourne, Australia.
A series of sore throats culminated in him developing rheumatic fever, for which he then had to consume penicillin tablets daily over the following decade to help prevent any follow-up attacks of the disease. Fortunately, due to this antibiotic regime, he did not suffer any of the residual heart damage that can occur from recurrent episodes of rheumatic fever.
Despite this, it just seemed to young John that there must be a better way to defend against streptococcal sore throats – an accessible way to prevent, instead of merely treat with antibiotics after and infection had already settled in.
In the third year of his Microbiology degree at Melbourne University, John became influenced by the teachings of Dr Rose Mushin concerning the potential applications of bacterial interference as a targeted and natural means of preventing infection.
Dr Mushin was a devotee of an old-world strategy for infectious disease control, the origins of which pre-date the discovery of antibiotics and can be traced back to the studies of Louis Pasteur – the father of all vaccines.
Dr Mushin managed to convince the entire microbiology class to consume milk that had been seeded with “friendly” Escherichia coli. These bacteria were equipped with a bacteriocin armament that would enable them to kill any vulnerable salmonellae (illness-causing bacteria) that happened to pass close by.
As John listened to Dr Mushin it occurred to him that perhaps a similar strategy could be applied in the human oral cavity to gain some relatively specific protection against S. pyogenes infections – the same recurring infection he has suffered from as a child.
This insight provided him with an irresistible challenge – he now knew what he wanted to do.
The Good Fight
John believed that in order to prevent S. pyogenes from assaulting its human host, it would be important to strengthen the territorially defensive capabilities of the non-virulent streptococcal component of our indigenous microbiota. Or, in layman’s terms, he needed to find a way to arm and strengthen the defences of the good guys in the fight against the bad.
A eureka moment, it occurred to John that over the course of their co-evolution with humans, the indigenous oral streptococcal populations (i.e., good guys) would surely have developed the most effective weaponry to counter competition for their space by rapidly multiplying virulent streptococci (bad guys).
John then undertook PhD research at Monash University – the overarching theme of those studies being an exploration of the relationship between S. pyogenes infections and the induction of the autoimmune manifestations of rheumatic fever.
On September 1, 1969, John discovered that number 22 in this series produced bacteriocin-like inhibitory activity against some other S. pyogenes strains when tested in a deferred antagonism assay.
The inhibitory agent, later given the name streptococcin A-FF22, was the first of the streptococcal bacteriocins to be isolated and characterised.
The commercial outcome of these laboratory discoveries was the launching of the Dunedin-based company Blis Technologies Ltd in August, 2000.
Two years later the first oral probiotic product, BLIS K12™ ThroatGuard, appeared on the shelves of New Zealand pharmacies. A wide variety of BLIS K12™ and BLIS M18™ (our 2nd commercial strain) products in powder, lozenge, chewing gum and ice cream formulations have subsequently been developed and many are available internationally.
As for Professor Tagg, he continues his important work with BLIS Technologies in our Dunedin laboratory. He has isolated more than 2000 strains of bacteria during his studies and research, and his role now is to continue looking at how those strains can be used to further benefit human health.
In 2021, BLIS Technologies is proud to manufacture and sell a variety of science-lead and backed oral probiotics with specific focuses, which you can find in our shop.