Bacterial Growth in Amniotic Fluid Is Dependent on the Iron-Availability and the Activity of Bacterial Iron-Uptake System

Ahn, Young‐Joon; Park, Sang-Kee; Oh, Jae-Wook; Sun, Hui; Shin, Sung‐Heui

doi:10.3346/jkms.2004.19.3.333

Cited by 9 publications

(5 citation statements)

References 25 publications

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“…Thus, the higher the iron-saturation of transferrin, the easier bacteria can capture iron from transferrin. Similarly, Ahn et al37 reported that antibacterial activity of amniotic fluid is closely related with low iron-availability.…”

Section: Commentmentioning

confidence: 92%

Total hemoglobin concentration in amniotic fluid is increased in intraamniotic infection/inflammation

Vaisbuch

Romero

Erez

et al. 2008

American Journal of Obstetrics and Gynecology

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Objective-Discolored amniotic fluid (AF) has been associated with intra-amniotic infection/ inflammation (IAI) in patients with preterm labor (PTL). The presence of hemoglobin and its catabolic products have been implicated as a cause for AF discoloration. The aim of this study was to determine whether there is an association between total hemoglobin concentration in AF and gestational age, spontaneous labor (term and preterm) and the presence or absence of IAI.Study design-This cross-sectional study included patients in the following groups: 1) midtrimester (n=65); 2) term not in labor (n=22); 3) term in labor (n=47); 4) spontaneous PTL who delivered at term (n=92); 5) PTL without IAI who delivered preterm (n=76); 6) PTL with IAI (n=81); 7) preterm prelabor rupture of the membranes (PPROM) with IAI (n=48); and 8) PPROM without IAI (n=49). Total hemoglobin concentrations in amniotic fluid were determined by an enzyme-linked immunoassay. Non-parametric statistics were used for analysis. Results-1)Hemoglobin was detected in all AF samples (n=480); 2) The median AF total hemoglobin concentration at term was significantly higher than in mid-trimester [520.6 ng/mL, interquartile range (IQR) 271.2-1549.2 vs. 58.5 ng/mL, IQR 26. 1-200.8; p<0.001]; 3) Among patients with PTL, the median AF total hemoglobin concentration was significantly higher in patients with IAI than in those without IAI (4671.8 ng/mL, IQR 1294.2-8620.7 vs. 2013.6 ng/mL, IQR 629.2-5420.4; p=0.01) or women who delivered at term (1143.4 ng/mL, IQR 451.8-4037.9; p=0.001); 4) Similarly, among patients with PPROM, the median AF total hemoglobin concentration was significantly higher in patients with IAI than in those without IAI (10753.7 ng/mL, IQR 2053.9-56026.6 vs. 2281 ng/mL, IQR 938.2-9191.7; p=0.02); 5) Women at term in labor had a higher median hemoglobin concentration than those not in labor (1952.6 ng/mL, IQR 709.6-6289.2 vs. 520.6 ng/ mL, IQR 271.1-1549.2; p=0.003).

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Section: Commentmentioning

confidence: 92%

Total hemoglobin concentration in amniotic fluid is increased in intraamniotic infection/inflammation

Vaisbuch

Romero

Erez

et al. 2008

American Journal of Obstetrics and Gynecology

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“…Iron is one of the most important macronutrient required for microbial growth in diverse environments . In microorganisms it acts as a global regulator for many cellular, metabolic and biosynthetic processes including: i) DNA synthesis ii) electron transport system iii) formation of heme iv) cofactor for enzymes v) oxygen transport vi) synthesis of ATP and vii) nitrite reduction in nitrogen cycle.…”

Section: Need For Ironmentioning

confidence: 99%

Microbial siderophores: a mini review

et al. 2012

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Iron is one of the major limiting factors and essential nutrients of microbial life. Since in nature it is not readily available in the preferred form, microorganisms produce small high affinity chelating molecules called siderophores for its acquisition. Microorganisms produce a wide variety of siderophores controlled at the molecular level by different genes to accumulate, mobilize and transport iron for metabolism. Siderophores also play a critical role in the expression of virulence and development of biofilms by different microbes. Apart from maintaining microbial life, siderophores can be harnessed for the sustainability of human, animals and plants. With the advent of modern molecular tools, a major breakthrough is taking place in the understanding of the multifaceted role of siderophores in nature. This mini review is intended to provide a general overview on siderophore along with its role and applications.

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“…In general, samples from early stage pregnancies are less bacteriostatic than samples from late stage pregnancies [27] . In addition, bacteriostatic properties of AF also depend on the presence of meconium and iron availability [28] . Often the presence of meconium in AF is used to predict the likelihood of the mother developing a postpartum or intrapartum bacterial infection [29] .…”

Section: Resultsmentioning

confidence: 99%

Adaptation of Group A Streptococcus to Human Amniotic Fluid

et al. 2010

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BackgroundFor more than 100 years, group A Streptococcus has been identified as a cause of severe and, in many cases, fatal infections of the female urogenital tract. Due to advances in hospital hygiene and the advent of antibiotics, this type of infection has been virtually eradicated. However, within the last three decades there has been an increase in severe intra- and post-partum infections attributed to GAS.MethodologyWe hypothesized that GAS alters its transcriptome to survive in human amniotic fluid (AF) and cause disease. To identify genes that were up or down regulated in response to growth in AF, GAS was grown in human AF or standard laboratory media (THY) and samples for expression microarray analysis were collected during mid-logarithmic, late-logarithmic, and stationary growth phases. Microarray analysis was performed using a custom Affymetrix chip and normalized hybridization values derived from three biological replicates were collected at each growth point. Ratios of AF/THY above a 2-fold change and P-value <0.05 were considered significant.Principal FindingsThe majority of changes in the GAS transcriptome involved down regulation of multiple adhesins and virulence factors and activation of the stress response. We observed significant changes in genes involved in the arginine deiminase pathway and in the nucleotide de novo synthesis pathway.Conclusions/SignificanceOur work provides new insight into how pathogenic bacteria respond to their environment to establish infection and cause disease.

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Bacterial Growth in Amniotic Fluid Is Dependent on the Iron-Availability and the Activity of Bacterial Iron-Uptake System

Cited by 9 publications

References 25 publications

Total hemoglobin concentration in amniotic fluid is increased in intraamniotic infection/inflammation

Total hemoglobin concentration in amniotic fluid is increased in intraamniotic infection/inflammation

Microbial siderophores: a mini review

Adaptation of Group A Streptococcus to Human Amniotic Fluid

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