Eurosurveillance - Volume 27, Issue 49, 08 December 2022

Since 2008, Danish national surveillance of Clostridioides difficile has focused on binary toxin-positive strains in order to monitor epidemic types such as PCR ribotype (RT) 027 and 078. Additional surveillance is needed to provide a more unbiased representation of all strains from the clinical reservoir.

Setting up a new sentinel surveillance scheme for an improved understanding of type distribution relative to time, geography and epidemiology, here presenting data from 2016 to 2019.

For 2─4 weeks in spring and autumn each year between 2016 and 2019, all 10 Danish Departments of Clinical Microbiology collected faecal samples containing toxigenic C. difficile. Isolates were typed at the national reference laboratory at Statens Serum Institut. The typing method in 2016–17 used tandem-repeat-sequence typing, while the typing method in 2018–19 was whole genome sequencing.

During the study period, the sentinel surveillance scheme included ca 14–15% of all Danish cases of C. difficile infections. Binary toxin-negative strains accounted for 75% and 16 of the 20 most prevalent types. The most common sequence types (ST) were ST2/13 (RT014/020) (19.5%), ST1 (RT027) (10.8%), ST11 (RT078) (6.7%), ST8 (RT002) (6.6%) and ST6 (RT005/117) (5.1%). The data also highlighted geographical differences, mostly related to ST1 and temporal decline of ST1 (p = 0.0008) and the increase of ST103 (p = 0.002), ST17 (p = 0.004) and ST37 (p = 0.003), the latter three binary toxin-negative.

Sentinel surveillance allowed nationwide monitoring of geographical differences and temporal changes in C. difficile infections in Denmark, including emerging types, regardless of binary toxin status.

Meat can be a vehicle for food-borne transmission of antimicrobial resistant bacteria and antimicrobial resistance genes. The occurrence of extended‐spectrum beta‐lactamase (ESBL) producing Enterobacterales has been observed in meat from livestock production but has not been well studied in meat from wild game.

We aimed to investigate, particularly in central Europe, to what extent ESBL-producing Enterobacterales may be present in wild game meat.

A total of 111 samples of different types of game meat supplied by butchers, hunters, retail stores and a large game-processing establishment in Europe were screened for ESBL-producing Enterobacterales using a selective culture medium. Isolates were genotypically and phenotypically characterised.

Thirty-nine samples (35% of the total) yielded ESBL-producing Enterobacterales, with most (35/39) supplied by the game-processing establishment. Isolates included 32 Moellerella wisconsensis, 18 Escherichia coli and one Escherichia marmotae. PCR screening identified blaCTX-M-1 (n = 31), blaCTX-M-32 (n = 8), blaCTX-M-65 (n = 4), blaCTX-M-15 (n = 3), blaCTX-M-8 (n = 1), blaCTX-M-14 (n = 1), blaCTX-M-55 (n = 1), and blaSHV-12 (n = 2). Most E. coli belonged to phylogenetic group A (n = 7) or B1 (n = 9), but several isolates belonged to extraintestinal pathogenic E. coli (ExPEC) sequence types (ST)58 (n = 4), ST68 (n = 1) and ST540 (n = 1). Whole genome sequencing of six selected isolates localised blaCTX-M-1 on megaplasmids in four M. wisconsensis and blaCTX-M-32 on IncN_1 plasmids in one M. wisconsensis and one E. marmotae. Forty-eight isolates (94%) exhibited a multidrug-resistance phenotype.

We found a high occurrence of ESBL-producing Enterobacterales in wild game meat, suggesting wildlife habitat pollution and possible microbial contamination events occurring during skinning or cutting carcasses.