Association of the 'secretor state' with the presence and recurrence of urinary infections in pregnant women

The correlation between non-O blood group type and recurrent catheter-associated urinary tract infections in critically ill patients: A retrospective study

Objective

To investigate the correlation between the ABO blood group and the risk of recurrent catheter-associated urinary tract infections (CA-UTI) and multi-drug resistant (MDR) organism reinfection in the critically ill.

Methods

This retrospective cohort study enrolled adult patients admitted to the intensive care unit (ICU) with confirmed CA-UTI to investigate the correlation between ABO type and the susceptibility to recurrent, reinfection and MDR reinfection. Patients were classified into two groups based on ABO type (O blood group versus non-O blood group).

Results

A total of 81 patients were included in the study: 37 in the O blood group and 44 in the non-O blood group. Patients in the O blood group were associated with significantly lower odds of recurrent CA-UTI (adjusted odds ratio 0.28; 95% confidence interval 0.08, 0.95), a shorter ICU length of stay (LOS) (estimate [SE] –0.24 [0.05]), hospital LOS (estimate [SE] –0.15 [0.03]) and mechanical ventilation duration (estimate [SE] –0.41 [0.07]) compared with the non-O blood group type.

Conclusion

Non-O blood group type might be a risk factor for recurrent CA-UTI and infection with MDR organism.

Maternal H-antigen secretor status is an early biomarker for potential preterm delivery

OBJECTIVE

Pre-pregnancy or first trimester biomarkers predicting preterm delivery are lacking. The purpose of this study was to determine whether maternal H-antigen (secretor status) is a potential biomarker for preterm delivery.

METHODS

This cohort study examined maternal saliva samples and birth data gathered by the National Children's Study Vanguard pilot phase (2009-2014) and included 300 women who were ≥18 years old and provided birth data and saliva samples. The maternal secretor status phenotype was determined by quantifying H-antigen in saliva using enzyme-linked immunoassay. Mothers were stratified by secretor status and multivariable analysis estimated adjusted associations with preterm delivery.

RESULTS

Maternal lack of H-antigen production was an independent risk factor for preterm delivery after adjusting for known confounders (aOR 4.53; 95% CI: 1.74, 11.81; P = 0.002).

CONCLUSIONS

Maternal H-antigen may be a biomarker identifying women at-risk for preterm delivery. Prospective cohort studies validating these findings are needed.

Human Milk Oligosaccharides Modulate the Risk for Preterm Birth in a Microbiome-Dependent and -Independent Manner

The causes for preterm birth (PTB) often remain elusive. We investigated whether circulating human milk oligosaccharides (HMOs) might be involved in modulating urinary and vaginal microbiome promoting or preventing PTB. We identified here HMOs and key microbial taxa associated with indicators of PTB. Based on our results, we propose two models for how HMOs might modulate risk for PTB: (i) by changes in HMOs associated with sterile inflammation (microbiome-independent) and (ii) by HMO-driven shifts in microbiome (microbiome-dependent). Our findings will guide current efforts to better predict the risk for PTB in seemingly healthy pregnant women and also provide appropriate preventive strategies.

Preterm birth (PTB) is one of the leading causes of neonatal mortality. The causes for spontaneous PTB are multifactorial and often remain unknown. In this study, we tested the hypothesis that human milk oligosaccharides (HMOs) in blood and urine modulate the maternal urinary and vaginal microbiome and influence the risk for PTB. We analyzed the vaginal and urinary microbiome of a cross-sectional cohort of women with or without preterm labor and correlated our findings with measurements of metabolites and HMOs in urine and blood. We identified several microbial signatures, such as Lactobacillus jensenii, L. gasseri, Ureaplasma sp., and Gardnerella sp., associated with a short cervix, PTB, and/or preterm contractions. In addition, we observed associations between sialylated HMOs, in particular 3′-sialyllactose, with PTB, short cervix, and increased inflammation and confirmed an influence of HMOs on the microbiome profile. Since they identify serum and urinary HMOs and several key microorganisms associated with PTB, our findings point at two distinct processes modulating the risk for PTB. One process seems to be driven by sterile inflammation, characterized by increased concentrations of sialylated HMOs in serum. Another process might be microbiome mediated and potentially associated with specific HMO signatures in urine. Our results support current efforts to improve diagnostics and therapeutic strategies in PTB.

IMPORTANCE The causes for preterm birth (PTB) often remain elusive. We investigated whether circulating human milk oligosaccharides (HMOs) might be involved in modulating urinary and vaginal microbiome promoting or preventing PTB. We identified here HMOs and key microbial taxa associated with indicators of PTB. Based on our results, we propose two models for how HMOs might modulate risk for PTB: (i) by changes in HMOs associated with sterile inflammation (microbiome-independent) and (ii) by HMO-driven shifts in microbiome (microbiome-dependent). Our findings will guide current efforts to better predict the risk for PTB in seemingly healthy pregnant women and also provide appropriate preventive strategies.

How Fucose of Blood Group Glycotopes Programs Human Gut Microbiota

Formation of appropriate gut microbiota is essential for human health. The first two years of life is the critical period for this process. Selection of mutualistic microorganisms of the intestinal microbiota is controlled by the FUT2 and FUT3 genes that encode fucosyltransferases, enzymes responsible for the synthesis of fucosylated glycan structures of mucins and milk oligosaccharides. In this review, the mechanisms of the selection and maintenance of intestinal microorganisms that involve fucosylated oligosaccharides of breast milk and mucins of the newborn's intestine are described. Possible reasons for the use of fucose, and not sialic acid, as the major biological signal for the selection are also discussed.

Secretor Status Is Strongly Associated with Microbial Alterations Observed during Pregnancy

During pregnancy there are significant changes in gut microbiota composition and activity. The impact of secretor status as determined by genotyping FUT2 (fucosyltransferase 2) gene was taken as one of the confounding factors associated with faecal microbiota changes during pregnancy. In this prospective study, we followed women during pregnancy (total = 123 of which secretors = 108, non-secretors = 15) and characterised their gut microbiota by quantitative polymerase chain reaction (qPCR), Fluorescence In situ Hybridisation (FISH), Denaturing Gradient Gel Electrophoresis (DGGE) and pyrosequencing. qPCR revealed that C. coccoides group counts decreased significantly in non-secretors in comparison to secretors (p = 0.02). Similar tendency was found by FISH analysis in Clostridium histolyticum and Lactobacillus-Enterococcus groups between the secretor and the non-secretor pregnant women. DGGE analysis showed significant decrease in richness of Clostridium sp. between secretor and non-secretor mothers during pregnancy. Pyrosequencing based analysis at phyla level showed that there is greater increase in Actinobacteria in secretors in comparison to non-secretors, whereas Proteobacteria showed more increase in non-secretors. Change in relative abundance of Clostridiaceae family from first to third trimester were significantly associated with secretor status of pregnant women (p = 0.05). Polyphasic approach for microbiota analysis points out that the host secretor status (FUT2 genotype) affects the gut microbiota during pregnancy. This may lead to altered infant gut microbiota colonization.

Blood Groups in Infection and Host Susceptibility

Blood group antigens represent polymorphic traits inherited among individuals and populations. At present, there are 34 recognized human blood groups and hundreds of individual blood group antigens and alleles. Differences in blood group antigen expression can increase or decrease host susceptibility to many infections. Blood groups can play a direct role in infection by serving as receptors and/or coreceptors for microorganisms, parasites, and viruses. In addition, many blood group antigens facilitate intracellular uptake, signal transduction, or adhesion through the organization of membrane microdomains. Several blood groups can modify the innate immune response to infection. Several distinct phenotypes associated with increased host resistance to malaria are overrepresented in populations living in areas where malaria is endemic, as a result of evolutionary pressures. Microorganisms can also stimulate antibodies against blood group antigens, including ABO, T, and Kell. Finally, there is a symbiotic relationship between blood group expression and maturation of the gastrointestinal microbiome.

Systematic sequence analysis of the human fucosyltransferase 2 (FUT2) gene identifies novel sequence variations and alleles

BACKGROUND

The FUT2 gene regulates the expression of ABH antigens in body secretions and hence controls the secretor status. It is highly polymorphic.

STUDY DESIGN AND METHODS

Healthy Chinese (n = 79) and Caucasian (n = 20) subjects were recruited for this study. Lewis blood group and secretor status were determined. The entire FUT2 coding region was amplified and screened for sequence variations by single-strand conformation polymorphism analysis under four different conditions to ensure comprehensive detection, and representative samples with distinct banding patterns were characterized by DNA sequencing. The haplotypes of novel alleles were determined by sequencing of cloned inserts.

RESULTS

Seventeen single-nucleotide polymorphisms and one 3-base duplicating insertion were identified. Six novel FUT2 alleles each found in a heterozygous individual were defined by six novel sequence variations: 210A>G (T70T), 380G>A (R127H), 572G>A (R191Q), 748_750dupGTG (V250dup), 853G>A (A285T), and 855A>C (A285A). The three most common alleles were Se, Se(357), and Se(357,385) in Chinese persons (total frequency, 94%) and se(428), Se(357), and Se in Caucasian persons (total frequency, 85%). The FUT2 genotypes correlated with Lewis phenotypes and secretor status.

CONCLUSION

This study identified 18 sequence variations in the FUT2 gene, and 6 were novel. The frequencies of alleles and genotypes were also determined in Chinese and Caucasian persons.