Evaluation of liquid biphasic Granada medium and instant liquid biphasic Granada medium for group B streptococcus detection.
BACKGROUND
Group B streptococci (GBS) are transmitted from the mother to the newborn. Prevention of neonatal infection is achieved by intrapartum prophylaxis given to mothers colonized with GBS at 35 to 37 weeks of pregnancy.


METHODS
Liquid biphasic Granada medium (LB) and instant liquid biphasic Granada medium (ILB) were evaluated for GBS detection. Vaginal swabs obtained from 300 women were inoculated onto LB or ILB, or onto Todd-Hewitt broth and analyzed with the ATB system (comparison method).


RESULTS
Prevalence of GBS was 20% (61/300). LB and Todd-Hewitt with ATB detected GBS in 20% of women, and ILB in 19% of women. No growth was observed at four hours in any of the media studied. At 10 h and 14 h, identification of GBS was possible in 43/300 (14%) and 53/300 (18%) of ILB cultures, respectively, and in 32/300 (11%) and 46/300 (15%) of LB cultures.


CONCLUSIONS
All the media used are suitable for GBS detection. The majority of GBS were identified in ILB and LB cultures at 10 h and 14 h.
Martinho
Filipa
F
Sexually Transmitted Diseases Unit, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal.
Prieto
Emília
E
Pinto
Dulce
D
Castro
Rita Maria
RM
Morais
Ana Maria
AM
Salgado
Luísa
L
Exposto
Filomena da Luz
Fda L
D000328:Adult; D003470:Culture Media / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D012007:Rectum / Q000382:microbiology; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control / Q000635:transmission; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology
D003470:Culture Media