The EREN network received information on the 2021 spring meeting from the German authority on Staphylococcus saprophyticus, based on a publication published in February 2021. The study found epidemiological and genomic evidence that the meat industry is a potential major source of S. saprophyticus, which causes human urinary tract infections (UTIs).

S. saprophyticus is a Gram-positive bacterium that is a common cause of urinary tract infections, especially in young women. S. saprophyticus was thought to be essentially endogenous, found in the human intestinal tract, where it often colonises, causing UTIs. Urinary tract infections caused by S. saprophyticus have a higher rate of successful treatment than, for example, UTI caused by Escherichia coli, but a higher incidence of recurrent infections. A rare complication of S. saprophyticus UTI may be acute pyelonephritis, nephrolithiasis and endocarditis.

S. saprophyticus is also found in the intestinal tract of living animals, but studies to date have found no evidence of a link between S. saprophyticus in animals and S. saprophyticus in humans, although it should be noted that these studies have used small sample sizes.

Lawel et al. (2021) performed a phylogenomic analysis of hundreds of S. saprophyticus isolates from human urinary tract infections collected worldwide. Human isolates were collected between 1997 and 2017, supplemented by a collection during 2016-2017 from the pig-processing chain in a confined region (Portugal). Epidemiological and genomic evidence was found that the meat production chain is a major source of S. saprophyticus causing human urinary tract infections, with human microbiota as another possible source. The pathogenic S. saprophyticus belonged to 2 genetic lineages with distinct genetic features that are globally and locally disseminated. Pangenome-wide approaches have identified a strong association between pathogenicity and antimicrobial resistance, phages, platelet-binding proteins and an increased recombination rate. This research provides insights into the origin, transmission and population structure of pathogenic S. saprophyticus and identifies putative new virulence factors.

In view of this, it would be appropriate for food safety authorities to investigate the presence of S. saprophyticus in the meat production chain, and meat products should also be considered as a possible source of infection in human disease investigations.