A Retrospective National Study on Colonization Rate and Antimicrobial Susceptibility of Streptococcus agalactiae in Pregnant Korean Women, 2018–2020

Abstract

Purpose The prevalence of Group B Streptococcus (GBS) colonization in pregnant Korean women is increasing; however, nationwide studies are lacking. Therefore, we aimed to analyze regional colonization rates and antimicrobial susceptibility for GBS in pregnant Korean women through a nationwide survey. Materials and Methods From January 2018 to December 2020, data from the Seoul Clinical Laboratories on vaginal swab cultures were retrospectively analyzed to detect maternal GBS carriers. Each swab specimen was inoculated onto a 5% blood agar plate and incubated at 35℃–37℃ in a 5% CO 2 incubator for 24 h. GBS isolates were identified using a Microflex MALDI Biotyper. Antimicrobial susceptibility tests were performed using the Vitek 2 automated system. Results The overall nationwide GBS colonization rate in pregnant Korean women was found to be 10.6% (3578/33721). The maternal GBS colonization rates ranged from 10.5%–10.8% over the 3-year study period. The GBS colonization rates by province, in descending order, were as follows: Jeolla-do, 13.2%; Gangwon-do, 12.0%; Chungcheong-do, 11.8%; Gyeonggi-do, 11.3%; Seoul, 10.2%; and Gyeongsang-do, 9.6%. During the study period, the resistance rates against chloramphenicol, levofloxacin, clindamycin, erythromycin, and tetracycline were 2.6%–2.7%, 18.2%–19.6%, 33.4%–35.7%, 35.6%–36.8%, and 50.5%–53.3%, respectively. Conclusion In pregnant Korean women, GBS colonization rates were in the range of 9.6%–13.2%, with Gyeongsang-do being the lowest and Jeolla-do the highest. The resistance rate against clindamycin was high (33.4%–35.7%). GBS colonization rates during pregnancy should be studied nationwide according to the Centers for Disease Control and Prevention-recommended guidelines with periodic antimicrobial resistance monitoring.

An Overview of Macrolide Resistance in Streptococci: Prevalence, Mobile Elements and Dynamics

“…Worldwide, macrolide resistant rates are also high in S. agalactiae. As occurred with other streptococci, Asian countries have the highest resistance prevalence, up to 70% in China in 2015 and 36% in Korea between 2018 and 2021 [86,87]. Nevertheless, high resistance rates were reported in the USA (55% of MR in the last decade) and some European countries with rates ranging from 17.5% in Denmark (2018) to 20-35% in Spain, Portugal, France and Belgium in 2019, and up to 48% in Italy in 2019 (Table 1) [88][89][90][91][92][93][94][95].…”

“…Nevertheless, high resistance rates were reported in the USA (55% of MR in the last decade) and some European countries with rates ranging from 17.5% in Denmark (2018) to 20-35% in Spain, Portugal, France and Belgium in 2019, and up to 48% in Italy in 2019 (Table 1) [88][89][90][91][92][93][94][95]. These MR rates are associated with a dominance of the MLS B phenotype related to both erm(B) and erm(TR) and associated with serotypes III, V, Ib and Ia (Table 2) [86][87][88][89][92][93][94][95][96][97]. Recently, an increase of macrolide resistance has been described in Portugal with rates of up to 35% [94] linked with the spread of a recombinant lineage of clonal complex (CC) 1 expressing type Ib serotype.…”

Current research update on group B streptococcal infection related to obstetrics and gynecology

“…Du et al (Du et al, 2021) found that in Vietnamese pregnant women, the multidrug-resistance rate was 59.19%, with 8.46% of isolates resistant to six to seven antibiotics. Similarly, Bae et al (Bae et al, 2022) reported a nationwide GBS colonization rate of 10.6% in pregnant Korean women. Furthermore, Du et al (Van Du et al, 2021) highlighted the importance of considering the high rates of erythromycin, clindamycin, and multidrug resistance in GBS as a risk factor for neonates.…”

Designing phage cocktails to combat the emergence of bacteriophage-resistant mutants in multidrug-resistant Klebsiella pneumoniae

“…However, this approach has been unsuccessful owing to a decrease in investment in the development of new antibiotics and the depletion of novel antibiotic candidates ( 3 ). Furthermore, antibiotic resistance rates among bacteria are increasing annually ( 4 – 6 ). The World Health Organization (WHO) declared that we are entering a post-antibiotic era where no antibiotics can treat MDR bacterial infections ( 7 , 8 ).…”