title: Virulence factors, antimicrobial susceptibility and molecular characterization of Streptococcus agalactiae isolated from pregnant women.
abstract: Forty-one Streptococcus agalactiae isolates collected from pregnant women at 35-37 weeks of gestation were analysed for their capsular types, antimicrobial resistance determinants, distribution of virulence factors and genetic relatedness using PCR and multiplex PCR. Capsular type III was predominant (65.8%), followed by capsular type II (14.6%), Ib (7.3%), and V(4.9%). All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline, erythromycin and clindamycin were found in 97.6%, 24.4%, and 14.6% of isolates, respectively. The most common antimicrobial resistance gene was tetM found in 97.6% of the isolates followed by ermTR and ermB found in 12% and 7.3% of isolates, respectively. The most common virulence gene was hly (100%), followed by scpB (97.6%), bca (97.6%), rib (53.65%) and bac (4.9%). The insertion sequence IS1548 was found in 63.4% of isolates. By multi locus variable number of tandem repeat analysis (MLVA) typing, 30 different allelic profiles or MLVA types (MTs) were identified. The most frequent was the MT1 (5/41, 12.2%) and followed by MT2 (4/41, 9.75%). Our data revealed that population structure of these isolates is highly diverse and indicates different MLVA types.
authors.affiliation: Tehran University of Medical Sciences Department of Microbiology, School of Medicine Tehran Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Beigverdi
authors.affiliation: Tehran University of Medical Sciences Department of Microbiology, School of Medicine Tehran Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Jabalameli
authors.affiliation: Tehran University of Medical Sciences Department of Microbiology, School of Medicine Tehran Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Mirsalehian
authors.affiliation: Tehran University of Medical Sciences Maternal, Fetal and Neonatal Research Center, Vali-asr Hospital Tehran Iran.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Hantoushzadeh
authors.affiliation: Pars Hospital Department of Microbiology Tehran Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Boroumandi
authors.affiliation: Ilam University of Medical Sciences Clinical Microbiology Research Center Ilam Iran.
authors.forename: Morovat
authors.initials: M
authors.lastname: Taherikalani
authors.affiliation: Tehran University of Medical Sciences Department of Microbiology, School of Medicine Tehran Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Emaneini
mesh_terms: D024881:Drug Resistance, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D013292:Streptococcus agalactiae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D037521:Virulence Factors / Q000032:analysis* / Q000235:genetics
chemical_list: D037521:Virulence Factors
keywords: MLVA type; Streptococcus agalactiae; antimicrobial resistance; virulence factors