Anaphylaxis-induced premature uterine contractions: a case report and literature review.

BACKGROUND: Preterm labor is caused by multiple etiologies, including intra-amniotic infection and/or intra-amniotic inflammation, vascular disorders, cervical disease, decidual senescence, and breakdown of maternal-fetal tolerance. Accumulating evidence in vivo and in vitro has shown that an allergic reaction, including anaphylaxis, can induce preterm uterine contractions. This report describes a case of a pregnant woman who developed anaphylaxis and regular uterine contractions after the ingestion of a strawberry-coated biscuit. We also review the mechanism of allergic reaction (hypersensitivity)-induced preterm labor. Case presentation A 31-year-old woman (gravida 1, para 0) at 30+2 weeks of gestation was admitted to the labor and delivery unit with regular uterine contractions and anaphylactic symptoms after she ingested a strawberry-coated biscuit as a snack. The uterine contractions resolved after the treatment of anaphylaxis by administering antihistamines and epinephrine. The patient subsequently delivered at 39+3 weeks of gestation. The amniotic fluid profile showed no infection or inflammation. A postpartum skin-prick test confirmed a positive type 1 hypersensitivity reaction to the strawberry-coated biscuit. CONCLUSIONS: We report a case of anaphylaxis-induced uterine contractility in which uterine contractions subsided after the treatment of anaphylaxis. The absence of intra-amniotic infection and/or intra-amniotic inflammation and the cause of the anaphylaxis were confirmed. Our findings indicate that maternal allergic reactions may be one of the mechanisms of preterm labor.

Genomic analysis of Enterococcus faecium strain RAOG174 associated with acute chorioamnionitis carried antibiotic resistance gene: is it time for precise microbiological identification for appropriate antibiotic use?

BACKGROUND: Preterm labor syndrome is associated with high perinatal morbidity and mortality, and intra-amniotic infection is a cause of preterm labor. The standard identification of causative microorganisms is based on the use of biochemical phenotypes, together with broth dilution-based antibiotic susceptibility from organisms grown in culture. However, such methods could not provide an accurate epidemiological aspect and a genetic basis of antimicrobial resistance leading to an inappropriate antibiotic administration. Hybrid genome assembly is a combination of short- and long-read sequencing, which provides better genomic resolution and completeness for genotypic identification and characterization. Herein, we performed a hybrid whole genome assembly sequencing of a pathogen associated with acute histologic chorioamnionitis in women presenting with PPROM. RESULTS: We identified Enterococcus faecium, namely E. faecium strain RAOG174, with several antibiotic resistance genes, including vancomycin and aminoglycoside. Virulence-associated genes and potential bacteriophage were also identified in this genome. CONCLUSION: We report herein the first study demonstrating the use of hybrid genome assembly and genomic analysis to identify E. faecium ST17 as a pathogen associated with acute histologic chorioamnionitis. The analysis provided several antibiotic resistance-associated genes/mutations and mobile genetic elements. The occurrence of E. faecium ST17 raised the awareness of the colonization of clinically relevant E. faecium and the carrying of antibiotic resistance. This finding has brought the advantages of genomic approach in the identification of the bacterial species and antibiotic resistance gene for E. faecium for appropriate antibiotic use to improve maternal and neonatal care.

Rapid diagnosis of intra-amniotic infection using nanopore-based sequencing.

OBJECTIVES: Early diagnosis and treatment of intra-amniotic infection is crucial. Rapid pathogen identification allows for a definite diagnosis and enables proper management. We determined whether the 16S amplicon sequencing performed by a nanopore sequencing technique make possible rapid bacterial identification at the species level in intra-amniotic infection. METHODS: Five cases of confirmed intra-amniotic infection, determined by either cultivation or 16S rDNA polymerase chain reaction (PCR) Sanger sequencing, and 10 cases of women who underwent mid-trimester genetic amniocentesis were included. DNA was extracted from amniotic fluid and PCR was performed on the full-length 16S rDNA. Nanopore sequencing was performed. The results derived from nanopore sequencing were compared with those derived from cultivation and Sanger sequencing methods. RESULTS: Bacteria were successfully detected from amniotic fluid using nanopore sequencing in all cases of intra-amniotic infection. Nanopore sequencing identified additional bacterial species and polymicrobial infections. All patients who underwent a mid-trimester amniocentesis had negative cultures, negative 16S PCR Sanger sequencing and nanopore sequencing. Identification of the microorganisms using nanopore sequencing technique at the bacterial species level was achieved within 5-9 h from DNA extraction. CONCLUSIONS: This is the first study demonstrating that the nanopore sequencing technique is capable of rapid diagnosis of intra-amniotic infection using fresh amniotic fluid samples.

Maternal septicemia caused by Streptococcus mitis: a possible link between intra-amniotic infection and periodontitis. Case report and literature review.

BACKGROUND: Intra-amniotic infection has a strong causal association with spontaneous preterm birth and preterm prelabor rupture of membranes (PPROM). The most common route of intra-amniotic infection is the ascending pathway in which microorganisms from the vagina gain access to the amniotic cavity. Distant microorganisms such as those from the oral cavity have been reported in intra-amniotic infection through hematogenous spreading. CASE PRESENTATION: A 31-year-old gravida 1, para 0 Thai woman at 33+6 weeks' gestation presented with leakage of vaginal fluid and irregular uterine contraction. She developed fever at 4 h after admission and was later diagnosed with acute chorioamnionitis. A Cesarean section was performed to terminate pregnancy. In addition to a blood culture, the cultures of amniotic fluid, vaginal and chorioamniotic membrane swabs were positive for Streptococcus mitis with identical susceptibility profiles. After the delivery and antibiotic prescription, oral examination showed dental caries and chronic periodontitis. CONCLUSIONS: This is the first case report demonstrating maternal septicemia and intra-amniotic infection caused by S. mitis which might be attributed to periodontitis in women presenting with preterm PROM. We highlighted the association of periodontal disease and preterm labor/PROM syndrome. Oral cavity examination should be included in the prenatal care to ensure good dental hygiene.

Comprehensive Analysis of Imipenemase (IMP)-Type Metallo-ß-Lactamase: A Global Distribution Threatening Asia.

Antibiotic resistance, particularly beta-lactam resistance, is a major problem worldwide. Imipenemase or IMP-type metallo-ß-lactamase (MBL) has become a more prominent enzyme, especially in Asia, since it was discovered in the 1990s in Japan. There are currently 88 variants of IMP-type enzymes. The most commonly identified variant of IMP-type enzymes is IMP-1 variant. IMP-type MBLs have been detected in more than ten species in Enterobacterales. Pseudomonas aeruginosa is the most frequent carrier of IMP-type enzymes worldwide. In Asia, IMP-type MBLs have been distributed in many countries. This work investigated a variety of currently available IMP-type MBLs at both a global level and a regional level. Out of 88 variants of IMP-type MBLs reported worldwide, only 32 variants were found to have susceptibility profiles. Most of the bacterial isolates carrying IMP-type MBLs were resistant to Carbapenems, especially Imipenem and Meropenem, followed by the 3rd-generation cephalosporins, and interestingly, monobactams. Our results comprehensively indicated the distribution of IMP-type MBLs in Asia and raised the awareness of the situation of antimicrobial resistance in the region.

Alternative Sigma Factor B in Bovine Mastitis-Causing Staphylococcus aureus: Characterization of Its Role in Biofilm Formation, Resistance to Hydrogen Peroxide Stress, Regulon Members.

This study examines treatments of the bacterial pathogen Staphylococcus aureus, namely, in the context of its being a major cause of subclinical bovine mastitis. Such infections caused by S. aureus among dairy cows are difficult to detect and can easily become chronic, leading to reduced productivity and large losses for dairy manufacturers. In this study, the role of alternative sigma factor B (σB), which has been shown to be a global regulator for S. aureus infections, was explored in a mastitis-causing S. aureus strain, RF122. For comparison with the wild-type strain, a sigB null (ΔsigB) mutant was constructed and analyzed for its phenotypes and transcriptome. Our study found that σB is essential for biofilm formation as the ΔsigB mutant strain produced significantly less biofilm than did the wild-type strain at 48 h. σB is involved in response to H2O2 stress. However, σB plays a minor or no role in resistance to antiseptics (e.g., povidone-iodine and chlorhexidine), resistance to tested antibiotics, hemolysin activity, and invasion ability. RNA sequencing identified 225 σB-dependent genes, of which 171 are positively regulated and 54 are negatively regulated. The identified genes are involved in stress response, pathogenesis, and metabolic mechanisms. Quantitative TaqMan RT-PCR was performed to verify the RNA sequencing results; i.e., σB is a positive regulator for asp23, sarA, katA, yabJ, sodA, SAB2006c, and nrdD expressions. In the RF122 strain, σB plays a role in biofilm formation, general stress response (e.g., H2O2), and regulation of virulence factors and virulence-associated genes.