Xpert GBS Assay for Rapid Detection of Group B Streptococcus in Gastric Fluid Samples from Newborns

Abstract

eThe Xpert GBS real-time PCR assay was applied to gastric fluid samples from 143 newborns, and it detected group B streptococcus (GBS) within 1 h for 16 (11.2%) cases, while microscopic examination detected only 2 cases. The sensitivity and specificity of the Xpert GBS were 80% and 100%, respectively, with regard to 20 cases of GBS colonization or infection. Concordance of Xpert GBS results versus culture was 92.3%. This test detects in a timely manner newborns at risk for invasive GBS disease. Early-onset group B streptococcus (GBS) neonatal disease is a serious and frequent complication of birth in developed countries. GBS causes more than one-third of the materno-fetal infections (MFI) of term infants, followed by Escherichia coli and other Streptococcus spp., as well as species now classified in the Enterococcus genus (1). GBS colonizes the maternal genitourinary tract (at reported frequencies from 4 to 36%) during pregnancy in Europe and the United States (2) and may cause an ascending infection after the onset of labor or the preterm rupture of membranes. Neonates may become colonized (in 40 to 70% of the cases [3]) during passage through the birth canal at the time of delivery. Two strategies have significantly reduced the rate of early neonatal GBS colonization and infection (4): (i) late antenatal GBS screening of pregnant women and (ii) intrapartum chemoprophylaxis for colonized women to reduce vertical transmission of GBS. Despite international guidelines, the worldwide incidence rate of GBS neonatal diseases is still 0.23 to 1.22‰ of births (5, 6).Because early detection of infected newborns is clinically difficult and the newborn's health can worsen rapidly, GBS detection for newborns is one of the emergencies in clinical microbiology. Gastric fluid is the usual relevant specimen for GBS detection (7). Its microscopic examination is so far the only bacteriological finding rapidly available for clinicians who suspect an early MFI. GBS microbiological diagnosis is delayed, since it is based on an 18-h culture. Since microscopic examination has a low sensitivity (27.5%) (8), a rapid method of GBS detection that is reasonably sensitive and specific would be valuable in stratifying the risk of MFI among neonates.The Xpert GBS assay (Cepheid) is a marketed real-time PCR for screening maternal carriage by detecting GBS DNA in vaginal or rectal specimens. Recently, two studies have shown its utility when it is performed on vaginal swabs during intrapartum instead of antenatal screening, at 35 to 37 weeks of gestation (9), and on amniotic fluids collected from pregnant women with premature rupture of membranes (10). Our study aimed to evaluate the test's performance when applied to gastric fluid specimens collected from newborns. Our aim was to shorten the time to detect GBScolonized infants and thus help in the diagnosis of invasive GBS materno-fetal infections.We conducted a prospective study at Lariboisière University Hospital (Paris, France), where 2,500 deliveries are processed per year in an IIA matern...

Newborn colonization and antibiotic susceptibility patterns of Streptococcus agalactiae at the University of Gondar Referral Hospital, Northwest Ethiopia

“…Our study showed that 62 (16.1%; 95% CI: 12.2-20.0) of the newborns participated in the study were colonized with GBS, which could be the possible causes to the high morbidity and mortality of neonates in the study area. This prevalence of colonization was in agreement with different studies conducted worldwide such as: France (13.9%) [ 26 ], Turkey (17.3%) [ 27 ]), South Africa (15.8%) [ 14 ] and Gambia (12.0%) [ 28 ]. Contrary to our study, other studies showed the lower prevalence of newborn colonization with GBS and some of these were Iran (1.7% to 5.5%) [ 29 – 31 ], Saudi Arabia (1.0%) [ 32 ], Turkey (1.6% to 8.0%) [ 12 , 33 ], Pakistan (6.0%) [ 13 ], China (4.9%) [ 34 ], India (1.3% to 3.2%) [ 35 , 36 ], Korea (1.5%) [ 37 ], Bangladesh (6.3% to 7.4%; in which, the finding from umbilicus is in agreement with ours) [ 38 , 39 ], Lithuania (6.4%; where 5.3% GBS were isolated from the ear swab of the newborns as it was observed in our study and 4.6% from the throat) [ 40 ], Greek (2.4%) [ 41 ], Nigeria (6.8%) [ 42 ], Tanzania (8.9%) [ 43 ] and Ethiopia (5%) [ 19 ].…”

Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

“…46 However, it was lower compared to studies from Gondar (16.1%) in Ethiopia, 47 Gambia (24.8%), 41 Turkey (17.3%) 48 and France (11.2%). 49 But it was higher in comparison to findings from India (1.0% and 3.2%). 21 , 50 The discrepancies between the studies might be due to variation in the sampled body surface, provision of IAP, geography and prevalence of maternal GBS colonization.…”

Risk of infection in neonates born in accidental out-of-hospital deliveries

“…Several studies have proposed that gastric aspirates are related to amniotic fluid leaks and neonatal infection [26][27][28][29]. The neonatal gastrointestinal tract is considered sterile, but diverse microbiota flora is present soon after birth [30,31]. Preterm neonates are more susceptible to colonization by potentially pathogenic bacteria, resulting in an increased risk of necrotizing enterocolitis [32][33][34].…”