Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-Acquired Infections in Shanghai, China

Abstract

Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA) and hospital-acquired (HA) infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST), serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%), ST23 (16.1%), ST12 (13.8%), and ST1 (12.6%). ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS) isolates. The most frequent serotypes were III (32.2%), Ia (26.4%), V (14.9%), Ib (13.8%), and II (5.7%). Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA) and surface protein genes spb1 and bac, serotype III (HA) and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control.

Characterization of group B Streptococcus colonization in full-term and Late-Preterm neonates in Taiwan

“…25,26 Early-and late-onset disease is particularly attributed to serotypes III (mainly represented by ST19 in Asia and ST17 in Europe) and Ia (mainly represented by ST23 and ST24). 12,27 We found that serotype II isolates (represented by ST1, belonging to CC1) colonized neonates readily and in some cases they persisted in neonates up to 6 months; however, serotype II GBS causing late-onset and very-late-onset disease rarely occurred. 27,28 Another common serotype colonizing neonates was serotype III, as described above, and was the most common serotype to cause late-onset disease in neonates.…”

“…Although the maternal carriage rate in Taiwan is close to that in the entire AsiaePacific region (i.e., 19%), this rate actually varies among regions and countries, such as 8.0% in Korea, 8.2% in Japan, 7.1% in Beijing, China, and 7.1% in Hong Kong. 17e23 Among the 10 serotypes of GBS, the five most common are Ia, Ib, II, III, and V, 12,13,24 accounting for 96 and 88% of invasive GBS isolates from neonates and adults, respectively. 25,26 Early-and late-onset disease is particularly attributed to serotypes III (mainly represented by ST19 in Asia and ST17 in Europe) and Ia (mainly represented by ST23 and ST24).…”

“…PFGE profiling of GBS isolates was conducted according to the PulseNet Standardized Laboratory PFGE Protocol and using SmaI macrorestriction. 12 If SmaI could not digest GBS genomic DNA well, endonuclease XmaI (which recognizes the same nucleotide sequences as SmaI but cuts at different sites) was used instead (New England Biolabs, Ipswich, MA, USA). The PFGE images were analyzed by the software BioNumerics (Applied Maths, Sint-Martens-Latem, Belgium).…”

Multilocus Sequence Typing Analysis of Invasive and Non-Invasive Group B Streptococcus of Hospital Origin in Malaysia

“…Martins et al (12) also showed that ST19 comprised a GBS serotype III that was associated with colonising infection. In addition, a study conducted in China reported the prevalence of ST19 among serotype III isolates that caused community-and hospital-acquired infections (13).…”

Capsular polysaccharide of Streptococcus agalactiae is an essential virulence factor for infection in Nile tilapia (Oreochromis niloticus Linn.)

“…Group B Streptococcus strains are divided into 10 distinct serotypes (Ia, Ib and II–IX), based on their polysaccharide component (Chang et al, ). Among them, capsular serotypes Ⅲ, Ia, Ib and Ⅴ are the most common in humans in China (Jiang et al, ; Wang et al, ). However, in the past decade, GBS strains of the Ia, Ib and III serotypes were shown to predominate in fish infections, and serotype Ia and Ib strains are mainly responsible for tilapia streptococcosis (Barato, Martins, Melo‐Cristino, Iregui, & Ramirez, ; Barony et al, ; Li et al, ).…”