Quantitative Bacteriological Analysis of Amniotic Fluid

Abstract

Quantitative bacteriological analysis of amniotic fluid (AF) was performed on 60 fluid samples collected by catheter from 50 selected labor patients regarded as liable to infection. AF cultures were positive in 52 cases. The bacterial colony counts ranged from less than 102 colony-forming units (CFU) per milliliter to 10⁹ CFU/ml. Pathogenic bacteria in neonates such as group B Streptococcus, Escherichia coli, and Listeria monocytogenes were encountered with numerations equal to or greater than 10⁷ CFU/ml in groups with clinical findings. An excellent correlation was noted between bacterial counts in AF and clinical data (p < 0.00006). The results confirm that the quantitative bacteria analysis of the AF is a useful tool for evaluation of an infection risk for neonates.

Rapid in vitro Replication of Group B Streptococcus in Term Human Amniotic Fluid

“…In the present study GBS-878 grew rapidly in AF, achieving large numbers in only 4 h, despite Pj/Zn ratios less than 200 in 8 of 9 specimens examined. GBS numbers exceeded the num bers of E. coli in each AF often by 10-fold to 100-fold in only 4 h. These GBS growth curves are similar to the in vitro curves reported by Edvaldson and Nord [12]; they are consistent with the numbers of GBS re covered from AF by Courcol et al [3] from high-risk women in labor and closely resem ble the in vivo growth curves observed when the same GBS strain (878) was injected percutaneously into the AF of term pregnant rhesus monkeys [1].…”

“…Despite a substantial body of work on microbiology and epidemiology little is presently known about how the neonate with early-onset disease becomes infected with GBS during perinatal life. The striking obser vations of Courcol et al [3] suggest that GBS finding access to AF may proliferate to achieve extremely large numbers of organ isms in a short period of time, offering a for midable bacterial challenge to the unborn in fant. That challenge likely explains the high incidence of congenital pneumonia observed in infants with early-onset GBS disease [2,16], While a substantial literature explores various factors in AF which impede bacterial growth, little is known about the influence of these factors on the prevention of the growth of GBS.…”

“…GBS infec tion of chorioamniotic membranes and AF may be responsible for cases of neonatal early-onset GBS infections including congenital pneumonia, bacteremia and even intrauter ine death [1][2][3][4], AF contains properties reported to im pede the in vitro growth of several bacterial species commonly resident in the human vagina [5][6][7][8][9][10], The literature is contradictory as to whether AF inhibits or supports the growth of GBS [11,12]. This study examined the short-term (4-hour) growth curves of a type III GBS strain and an 06 Escherichia coli strain in normal, term human AF specimens with Pj/Zn ratios in the range purported to inhibit bacterial growth.…”

“…Group B streptococci (GBS) which gain in vivo access to amniotic fluid (AF) of rhesus monkeys [1,2] or humans [3] may rapidly proliferate, thereby exposing the unborn in fant to numbers of bacteria sometimes ex ceeding 1 X 106 organisms/ml. GBS infec tion of chorioamniotic membranes and AF may be responsible for cases of neonatal early-onset GBS infections including congenital pneumonia, bacteremia and even intrauter ine death [1][2][3][4], AF contains properties reported to im pede the in vitro growth of several bacterial species commonly resident in the human vagina [5][6][7][8][9][10], The literature is contradictory as to whether AF inhibits or supports the growth of GBS [11,12].…”

Intrauterine bacterial growth at birth and risk of asthma and allergic sensitization among offspring at the age of 15 to 17 years

“…After rupture of the membranes, up to 70% to 90% of amniotic fluid becomes colonized with microbes, even during normal delivery. [1][2][3][4] Intrauterine bacterial infection or inflammation in the gestational tissues is commonly thought to be the cause of the onset of preterm labor, even when the membranes are intact. 5 Several studies have focused on the effect of maternal infections and antibiotic administrations during pregnancy and at delivery on the development of asthma among offspring.…”