| Congresso Brasileiro de Microbiologia 2023 | Resumo: 352-1 | ||||
Resumo:Streptococcus agalactiae (Group B Streptococcus; GBS) can be found in gastrointestinal and genitourinary tracts of healthy humans, being an important pathogen in infants and adults. Little is known about the association of GBS with epididymitis and prostatitis, since strains from the male genitourinary tract are not well characterized in the literature. Therefore, the aim of this study was to characterize GBS strains isolated from semen samples between 2017 and 2022. Strain identification was confirmed by CAMP factor production, hippurate hydrolysis, and MALDI-TOF MS. Capsular type was determined by latex agglutination (Immulex Strep-B kit, SSI Diagnostica, Denmark), and antimicrobial susceptibility was determined using the disk diffusion method, according to CLSI guidelines. Strains were whole genome sequenced (WGS) and important genes related to virulence and resistance were predicted. All strains were found to be gram-positive cocci, positive for CAMP factor production and for hippurate hydrolysis. Also, all strains were identified as GBS with a reliability score (≥ 2.0) by MALDI-TOF MS. Serotype V was the most frequent (40%), followed by serotypes Ia (21.8%), III (10%), Ib (10%), IV (8.2%), II (7.3%), and 2.7% were non-typable (NT). All strains were susceptible to penicillin and vancomycin, while resistance to tetracycline, erythromycin, levofloxacin and clindamycin was observed in 90%, 33.7%, 9.1% 5.5% of the strains, respectively. Of note, 14% of GBS strains showed resistance to 3 different classes of antimicrobials, being considered multidrug resistant strains. In addition, 62 strains were sequenced and genome analysis revealed that strains were distributed in 5 clonal complexes (CCs) (CC1, CC17, CC19, CC144 and CC498) and 6 singletons (ST10, ST26, ST103, ST196, ST2111 and 2112), being ST1 and ST144 the most frequent sequence types (STs). An association between serotype Ia and CC144, as well as between serotype V and CC1, was observed. Furthermore, virulence determinants, such as fbsB, srr-1, lmb, hylB, sip, scpA and pili (PI-1, PI-2a or PI-2b), were present in more than 90% of the stains each, suggesting that these proteins would be interesting targets for vaccines. Also, the most common resistance gene was tetM(85.2%), followed by msrD(11.4%), mefA(11.4%), tetO(8.1%), ermB(6%) and ermA(6%). These results provide support to the literature, as it is a work with unpublished data regarding characterization of GBS strains recovered from semen circulating in Brazil. The actual impact of these findings is not yet known, reinforcing the need for additional studies.
Palavras-chave: Antimicrobial resistance, Prostate, Semen, Streptococcus agalactiae, Virulence Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. | |||||