Genetic characteristics of vancomycin intermediate Staphylococcus aureus isolated from patients in Tehran, Iran: CC/ST8 is a serious threat

Goudarzi, Mehdi and Raigani, Mozhgan and Salehi, Zahra and Navidinia, Masoumeh and Nasiri, Mohammad Javad and Goudarzi, Hossein (2025) Genetic characteristics of vancomycin intermediate Staphylococcus aureus isolated from patients in Tehran, Iran: CC/ST8 is a serious threat. ACTA MICROBIOLOGICA ET IMMUNOLOGICA HUNGARICA, 72 (3). pp. 237-247. ISSN 1217-8950

Text 030-article-p237.pdf - Published Version Restricted to Repository staff only Download (879kB)

Abstract

Vancomycin-intermediate Staphylococcus aureus (VISA) strains represent a serious public health concern. It is crucial to investigate the genetic diversity, biofilm formation, and virulence analysis of VISA isolated from hospitalized patients. During the two-year study period, 42 VISA were obtained from 520 S. aureus isolates collected from various clinical samples, corresponding to a prevalence of 8.1%, as determined by the broth microdilution method. These VISA isolates were further characterized using biofilm formation, antimicrobial susceptibility tests, SCCmec typing, spa typing, multilocus sequence typing (MLST), and PCR analysis for detecting resistance ( erm(B), tet(M), mecC, msr(B), mecA, mupA, vanA, aac(6′)-Ie/aph(2˝), mupB, msr(A), erm(C), erm(A), vanB, ant(4′)-Ia, and aph(3′)-IIIa ), biofilm ( clfA, clfB, fnbA, fnbB, ebp, cna and bap ) and virulence (eta , etb, pvl , and tst ) genes. Our results indicated that the 42 VISA isolates belonged to three clonal complexes, including CC8 (78.6%), CC22 (11.9%), and CC5 (9.5%). The vast majority of S. aureus isolates belonged to CC8/ST239-SCC mec III/t037 (42.9%). Our result revealed that PVL-positive strains belonged to CC/ST5-SCC mec IV/t002 (9.5%), CC/ST8-SCC mec IV/t008 (19%), and CC/ST22-SCC mec IV/t790 (7.1%) while TST-positive isolates belonged to CC8/ST239-SCC mec III/t030 (9.5%) and CC8/ST239-SCC mec III/t037 (35.7%). The majority of HLMUPR isolates belonged to CC8/ST239-SCC mec III/t037 (14.3%), followed by CC/ST8-SCC mec IV/t008 (7.1%), CC8/ST239-SCC mec III/t030 (4.8%), and CC/ST5-SCC mec IV/t002 (2.4%) lineages carrying mupA . The highest frequency of VISA strain with iMLSB phenotype belonged to the CC8/ST239-SCC mec III/t037 (11.9%) clonal lineage. The study highlights that genetic diversity and characteristics of the VISA strains should be closely and continuously monitored. Besides that, importance of measures to prevent the transmission of VISA to treat such infection were urgently needed.

Actions (login required)

Edit Item