Molecular determination, serotyping, antibiotic profile and virulence factors of group B Streptococcus isolated from invasive patients at Arabcare Hospital Laboratory, Palestine

Background: Streptococcus agalactiae (group B Streptococcus) is beta-hemolytic, catalase negative, gram -posi-tive cocci, recognized as main bacterial pathogen causing infections in newborns, infants, adults, and elderly people around the world. The aim of this study is to investigate group B Streptococcus samples recovered from invasive patients and determine serotype, virulent genes, and antibiotic-resistant profile of Streptococ-cus agalactiae in Palestine.Methods: A total of 95 group B Streptococcus strains were isolated from neonates, infants, pregnant and non -pregnant women and males at Arabcare Hospital Laboratory, Palestine, between the period of June 2018 and September 2020. Species identification was carried out through cultivation and conventional biochemical tests. A conventional Polymerase Chain Reaction (cPCR) was used to determine the 5 serotypes and virulent genes of the Streptococcus agalactiae strains. The antibiotic resistance test of group B Streptococcus was evalu-ated using Kirby-Bauer disk susceptibility. Sequencing and BLAST analysis were used to determine the rela-tionship of the isolates in this study to worldwide isolates.Results: Serotype III (35%) was the major group B Streptococcus strains serotype causing invasive infections in neonates, infants, pregnant and nonpregnant women, and males, followed by serotypes V (19%), Ia, and II (15%), Ib (6%), respectively. All our isolates encoding for surface protein virulent factors, including a highly virulent gene (HvgA) were mostly found in strains isolated from pregnant women (12%). These group B Strep-tococcus strains exhibited a high rate of resistance to clindamycin (26%). The overall percentage of levofloxa-cin resistance was 11%, while vancomycin and ampicillin showed higher resistance, at 14.7 and 16% respectively. In addition, the phylogenetic relationship dendrogram illustrates that Streptococcus agalactiae isolated from an invasive patient (newborn) in Palestine was similar to strains found in China and Japan.Conclusions: The outcomes of this study demonstrate that resistant group B Streptococcus strains are common in Palestine, therefore, evidence-based infection prevention and antibiotic stewardship efforts are necessary.(c) 2022 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Automated summary

This study investigated group B Streptococcus samples recovered from invasive patients in Palestine, identifying serotype III as the major cause of invasive infections. The study also found that highly virulent genes were mainly present in strains isolated from pregnant women. Furthermore, the research revealed the resistance patterns of group B Streptococcus to various antibiotics in the region, as well as the genetic relationship among the isolates.