National Surveillance of Tetracycline, Erythromycin, and Clindamycin Resistance in Invasive : A Retrospective Study of the Situation in Spain, 2007-2020.

BACKGROUND

This work reports on antimicrobial resistance data for invasive in Spain, collected by the 'Surveillance Program for Invasive Group A ', in 2007-2020.

METHODS

typing was determined by sequencing. Susceptibility to penicillin, tetracycline, erythromycin, and clindamycin was detined via the E-test. M, O, D, A, B, TR, and T were sought by PCR. Macrolide-resistant phenotypes (M, cMLSB, and iMLSB) were detected using the erythromycin-clindamycin double-disk test. Resistant clones were identified via their type, multilocus sequence type (ST), resistance genotype, and macrolide resistance phenotype.

RESULTS

Penicillin susceptibility was universal. Tetracycline resistance was recorded for 237/1983 isolates (12.0%) (152 carried only M, 48 carried only O, and 33 carried both). Erythromycin resistance was detected in 172/1983 isolates (8.7%); B was present in 83, A in 58, D in 51, TR in 46, and T in 36. Clindamycin resistance (methylase-mediated) was present in 78/1983 isolates (3.9%). Eight main resistant clones were identified: two that were tetracycline-resistant only (22/ST46/M and 77/ST63/O), three that were erythromycin-resistant only (4/ST39/A-D/M, 12/ST36/A-D/M, and 28/ST52/B/cMLSB), and three that were tetracycline-erythromycin co-resistant (11/ST403/M-B/cMLSB, 77/ST63/O-TR/iMLSB, and 77/ST63/M-O-TR/iMLSB).

CONCLUSIONS

Tetracycline, erythromycin, and clindamycin resistance rates declined between 2007 and 2020. Temporal variations in the proportion of resistant clones detined the change in resistance rates.