The significance of group B streptococci in neonatal pneumonia

Abstract

Thirty-eight infants admitted to a neonatal intensive care unit because of pneumonia (14 patients) and pulmonary maladaption syndrome (PMA) (24 patients) were included in the study. Samples of potentially pathogenic, facultatively anaerobic bacteria were taken from the external ear, blood, throat, nasopharynx, umbilicus and gastric aspirates of the children, and from urethra and cervix of the mothers. Group B streptococci (GBS) and Escherichia coli were the only potentially pathogenic bacteria isolated from the infants. Out of 14 infants with pneumonia 11 (79%) harboured one of these bacteria, in contrast to 3 out of 24 (13%) with PMA (P less than 0.001). GBS was found in 8/14 infants with pneumonia and in 1/24 infants with PMA (P less than 0.001). The respective frequencies for Escherichia coli were 3/14 and 2/24 (not significant). The infant and/or the mother in 10/14 pneumonia cases harboured GBS, in contrast to 4/24 pairs in the PMA group (P less than 0.001). The levels of antibodies against GBS in sera of mothers to infants with pneumonia did not differ from the antibody levels in control sera (parturient GBS-carriers giving birth to healthy infants). The results gave evidence for an important manifestation of neonatal GBS-infection: pneumonia without septicemia. The incidence of the disease is estimated to be 1:25 parturient GBS-carriers. Finally, maternal fever, gestational age above 42 weeks, more severe respiratory difficulties and the occurrence of severe changes in fetal heart rate during the first stage of labour were found to be typical characteristics of pneumonia, as compared to PMA.

Human IgG Antibodies to Carbohydrate and Protein Antigens in Mouse Protection Tests with Group B Streptococci

“…These sera represented "low" (L) and "high" (H) levels for all GBS-type antigens, as judged by tests on sera from pregnant GBS camers giving birth to healthy infants (6,8).…”

“…GBS are a major cause of systemic infections in newborn infants, with a case fatality rate of 20-50% and a frequency of neurologic sequelae of about 30% in infants with meningitis (6,10,14,17). The disease seems to be correlated with a relative deficiency of maternal antibodies to GBS-type antigens (2,5,16,25,37).…”

Increased Frequency of High Serum IgM among Mothers of Infants with Neonatal Group-B Streptococcal Septicemia

“…Group-B streptococci (GBS) are a major cause of serious infections in newborns [1,7,9], Low levels of type-specific antibodies against GBS in maternal serum are associated with an increased risk of GBS infection in the neonate [3,5]. Antibodies against the carbohydrate-type antigens are particularly import ant for protection [2,4], although antibodies to pro tein antigens might also be crucial [13].…”

“…Mothers of GBS-infected infants are not only defi cient in IgG antibodies against GBS, but also against other bacterial carbohydrate antigens, including pneumococcal and Gram-negative bacterial antigens [8], A divergent IgG-allotype distribution among these women indicated a genetic base for the dimin ished anti-carbohydrate IgG production [11], In contrast to the IgG, serum IgM levels against bacterial carbohydrate antigens seem to be elevated [7,8]. We found it therefore interesting to study the total IgM serum levels in mothers of infants with GBS-septicemia.…”

“…All infants had growth of GBS in the blood and/or liquor. Strains from 57 patients were available for serotyping, performed as previ ously described [7], and 10 were type-la, 6 type-lb, 6 type-II and 34 type-III GBS.…”