title: International external quality assurance for laboratory identification and typing of Streptococcus agalactiae (Group B streptococci).
abstract: We report the results from the first international multicenter external quality assessment (EQA) studies for molecular and serological typing of group B streptococcus (GBS) strains as part of DEVANI (Design of a Vaccine against Neonatal Infections), a pan-European program. A questionnaire-based surveillance was undertaken among eight laboratories participating in DEVANI and six laboratories not participating in DEVANI from 13 countries in order to assess their current microbiological procedures for GBS screening, diagnosis, and typing. GBS strains from three EQA distributions were characterized using molecular and serological methods based on GBS capsular polysaccharide typing. Participants were asked to test the first distribution using their current serotyping and genotyping methods. The Strep-B-Latex agglutination method was the most widely used method, with a typeability value of >90%. A multiplex PCR assay for GBS capsular gene typing was also used by 2 of 14 centers, which achieved a typeability value of 93%; this assay detected only 9 of 10 GBS capsular polysaccharide genes. From the second and third EQA studies, standardized protocols were prepared for serological and molecular typing of GBS strains based on the Strep-B-Latex agglutination method and a novel multiplex PCR assay that detected all 10 GBS capsular types (Ia to IX). These standardized protocols are being used by many European laboratories, and as the use of these methods increases, it is imperative to continuously improve and assess laboratory performance and offer training to any laboratories that have technical difficulties.
authors.affiliation: Streptococcus and Diphtheria Reference Unit, Respiratory and Systemic Infection Laboratory, Health Protection Agency, Microbiology Services Division, 61 Colindale Avenue, London NW9 5EQ, United Kingdom. Baharak.Afshar@hpa.org.uk
authors.forename: Baharak
authors.initials: B
authors.lastname: Afshar
authors.forename: Karen
authors.initials: K
authors.lastname: Broughton
authors.forename: Roberta
authors.initials: R
authors.lastname: Creti
authors.forename: Antoaneta
authors.initials: A
authors.lastname: Decheva
authors.forename: Markus
authors.initials: M
authors.lastname: Hufnagel
authors.forename: Paula
authors.initials: P
authors.lastname: Kriz
authors.forename: Lotte
authors.initials: L
authors.lastname: Lambertsen
authors.forename: Marguerite
authors.initials: M
authors.lastname: Lovgren
authors.forename: Pierrette
authors.initials: P
authors.lastname: Melin
authors.forename: Graziella
authors.initials: G
authors.lastname: Orefici
authors.forename: Claire
authors.initials: C
authors.lastname: Poyart
authors.forename: Andreas
authors.initials: A
authors.lastname: Radtke
authors.forename: Javier
authors.initials: J
authors.lastname: Rodriguez-Granger
authors.forename: Uffe B Skov
authors.initials: UB
authors.lastname: Sørensen
authors.forename: John
authors.initials: J
authors.lastname: Telford
authors.forename: Lea
authors.initials: L
authors.lastname: Valinsky
authors.forename: Levantia
authors.initials: L
authors.lastname: Zachariadou
authors.forename: Androulla
authors.initials: A
authors.lastname: Efstratiou
mesh_terms: D015373:Bacterial Typing Techniques; D001431:Bacteriological Techniques / Q000592:standards*; D005060:Europe; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007391:International Cooperation; D008297:Male; D058889:Molecular Typing; D011247:Pregnancy; D011785:Quality Assurance, Health Care; D012703:Serotyping; D013290:Streptococcal Infections / Q000175:diagnosis*; D013292:Streptococcus agalactiae / Q000145:classification* / Q000302:isolation & purification*