ABSTRACT
This study examined whey protein's impact on insulin resistance in a high-fat diet-induced pediatric obesity mouse model. Pregnant mice were fed high-fat diets, and male pups continued this diet until 8 weeks old, then were split into high-fat, whey, and casein diet groups. At 12 weeks old, their body weight, fasting blood glucose (FBG), blood insulin level (IRI), homeostatic model assessment for insulin resistance (HOMA-IR), liver lipid metabolism gene expression, and liver metabolites were compared. The whey group showed significantly lower body weight than the casein group at 12 weeks old (p = 0.034). FBG was lower in the whey group compared to the high-fat diet group (p < 0.01) and casein group (p = 0.058); IRI and HOMA-IR were reduced in the whey group compared to the casein group (p = 0.02, p < 0.01, p < 0.01, respectively). The levels of peroxisome proliferator-activated receptor α and hormone-sensitive lipase were upregulated in the whey group compared to the casein group (p < 0.01, p = 0.03). Metabolomic analysis revealed that the levels of taurine and glycine, both known for their anti-inflammatory and antioxidant properties, were upregulated in the whey group in the liver tissue (p < 0.01, p < 0.01). The intake of whey protein was found to improve insulin resistance in a high-fat diet-induced pediatric obesity mouse model.
Subject(s)
Diet, High-Fat , Insulin Resistance , Pediatric Obesity , Whey Proteins , Animals , Female , Male , Mice , Pregnancy , Blood Glucose/metabolism , Diet, High-Fat/adverse effects , Disease Models, Animal , Insulin/blood , Lipid Metabolism/drug effects , Liver/metabolism , Liver/drug effects , Mice, Inbred C57BL , Pediatric Obesity/metabolism , Whey Proteins/pharmacologyABSTRACT
We examined whether the administration of growth hormone (GH) improves insulin resistance in females of a non-obese hyperglycemic mouse model after birth with low birth weight (LBW), given that GH is known to increase muscle mass. The intrauterine Ischemia group underwent uterine artery occlusion for 15 min on day 16.5 of gestation. At 4 weeks of age, female mice in the Ischemia group were divided into the GH-treated (Ischemia-GH) and non-GH-treated (Ischemia) groups. At 8 weeks of age, the glucose metabolism, muscle pathology, and metabolome of liver were assessed. The insulin resistance index improved in the Ischemia-GH group compared with the Ischemia group (p = 0.034). The percentage of type 1 muscle fibers was higher in the Ischemia-GH group than the Ischemia group (p < 0.001); the muscle fiber type was altered by GH. In the liver, oxidative stress factors were reduced, and ATP production was increased in the Ischemia-GH group compared to the Ischemia group (p = 0.014), indicating the improved mitochondrial function of liver. GH administration is effective in improving insulin resistance by increasing the content of type 1 muscle fibers and improving mitochondrial function of liver in our non-obese hyperglycemic mouse model after birth with LBW.
Subject(s)
Disease Models, Animal , Hyperglycemia , Insulin Resistance , Liver , Animals , Female , Humans , Mice , Pregnancy , Human Growth Hormone/pharmacology , Human Growth Hormone/administration & dosage , Hyperglycemia/drug therapy , Hyperglycemia/metabolism , Liver/metabolism , Liver/drug effects , Oxidative Stress/drug effects , Recombinant Proteins/pharmacologyABSTRACT
We aimed to characterize the metabolomic profiles in preterm small-for-gestational age (SGA) infants using cord blood. We conducted a gestational age (GA)-matched case-control study that included 30 preterm infants who were categorized into two groups: SGA infants, with a birth weight (BW) < 10th percentile for GA (n = 15) and non-SGA infants, with BW ≥ 10th percentile for GA (n = 15). SGA infants with chromosomal or genetic abnormalities were excluded. At birth, the umbilicus was double-clamped, and the cord blood was sampled from the umbilical vein. Metabolomic analyses were performed using capillary electrophoresis time-of-flight mass spectrometry. The median GA at birth was not significantly different between the two groups [SGA, 32 (26-36) weeks; non-SGA, 32 (25-35) weeks; p = 0.661)]. Of the 255 metabolites analyzed, 19 (7.5%) showed significant differences between SGA and non-SGA infants. There were significant reductions in the carnosine, hypotaurine, and S-methylcysteine levels in SGA infants as compared to non-SGA infants (p < 0.05). Carnosine was correlated with gestational age, BMI before pregnancy, body weight gain during pregnancy (p = 0.002, p = 0.023, and p = 0.020, respectively). In conclusion, preterm SGA infants have low levels of cord blood antioxidative- and antiglycation-related metabolites, making them vulnerable to oxidative stress.
ABSTRACT
This study investigated the mechanism of reducing body fat via whey protein diet. Pregnant mice were fed whey or casein, and their offspring were fed by birth mothers. After weaning at 4 weeks, male pups received the diets administered to their birth mothers (n = 6 per group). At 12 weeks of age, body weight, fat mass, fasting blood glucose (FBG), insulin (IRI), homeostatic model assessment of insulin resistance (HOMA-IR), cholesterol (Cho), triglyceride (TG), the expression levels of lipid metabolism-related genes in liver tissues and metabolomic data of fat tissues were measured and compared between the groups. The birth weights of pups born were similar in the two groups. Compared to the pups in the casein group, at 12 weeks of age, pups in the whey group weighed less, had significantly lower fat mass, HOMA-IR and TG levels (p < 0.01, p = 0.02, p = 0.01, respectively), and significantly higher levels of the antioxidant glutathione and the anti-inflammatory 1-methylnicotinamide in fat tissues (p < 0.01, p = 0.04, respectively). No differences were observed in FBG, IRI, Cho levels (p = 0.75, p = 0.07, p = 0.63, respectively) and expression levels of lipid metabolism-related genes. Whey protein has more antioxidant and anti-inflammatory properties than casein protein, which may be its mechanism for reducing body fat.
Subject(s)
Insulin Resistance , Whey , Pregnancy , Female , Animals , Mice , Male , Whey Proteins , Whey/metabolism , Caseins , Antioxidants , Adipose Tissue/metabolism , Diet, High-Fat/adverse effects , Body Weight , Blood Glucose/metabolismABSTRACT
BACKGROUND: The association between umbilical cord blood insulin-like growth factor 1 (IGF-1) levels and retinopathy of prematurity (ROP) remains unclear. This study aimed to investigate whether umbilical cord blood IGF-1 levels can predict the development of severe ROP in extremely preterm infants. METHODS: This hospital-based retrospective cohort study included infants born at <37 weeks gestational age (GA) between 2019 and 2021 and then classified them into the two GA groups: extremely preterm, <28 weeks and preterm infants, 28-36 weeks. Extremely preterm infants were further subclassified into two groups according to the laser treatment as follows: the severe ROP (ROP-Tx) and ROP (No ROP-Tx) groups. Median umbilical cord blood IGF-1 values were compared between the groups. Perinatal risk factors were identified by univariate and multivariate analyses. Finally, umbilical cord IGF-1 cut-off values requiring ROP treatment with laser were determined by receiver operating characteristic (ROC) curve analyses. RESULTS: A total of 205 infants were enrolled, with 32 being extremely preterm (ROP-Tx: n = 11; No ROP-Tx: n = 21) and 173 being preterm. IGF-1 levels were significantly lower in extremely preterm (13.5 ng/mL) than preterm infants (36 ng/mL, p < 0.001). In extremely preterm infants, IGF-1 levels were significantly lower in the ROP-Tx group than the No ROP-Tx group (10 vs. 19 ng/mL, respectively, p = 0.024). Only GA, umbilical cord blood IGF-1 levels, birth head circumference, and birth chest circumference were identified as risk factors by univariate analysis (p < 0.05). Multivariate analysis showed that only umbilical cord blood IGF-1 was an independent risk factor (odds ratio: 1.26, p = 0.021). ROC curves revealed an IGF-1 cut-off value of 14 ng/mL. CONCLUSION: The need of laser treatment for ROP was found to be associated with low umbilical cord blood IGF-1 levels in extremely preterm infants. Umbilical cord blood IGF-1 can be used as a biomarker for the risk of developing severe ROP.
Subject(s)
Infant, Extremely Premature , Retinopathy of Prematurity , Infant , Infant, Newborn , Humans , Insulin-Like Growth Factor I/analysis , Retrospective Studies , Gestational Age , Retinopathy of Prematurity/diagnosis , Risk FactorsABSTRACT
BACKGROUND: There is insufficient research on cholesterol uptake capacity (CUC) in preterm infants; therefore, the relationship between CUC and cholesterol transport in preterm infants is unclear. This study aimed to clarify the relationship between CUC and anthropometric measurements, high-density lipoprotein cholesterol (HDL-C) levels, and HDL-C subclasses in preterm infants. METHODS: Fifty-eight preterm infants were divided into small-for-gestational age (n = 20) (SGA) and appropriate-for-gestational age (AGA) (n = 38). CUC was measured using a fully automated immunoassay system, HI-1000. HDL-C subclasses were measured using high-performance liquid chromatography. RESULTS: SGA showed significantly lower HDL-C and CUC levels than AGA. We found a positive correlation between CUC and birth weight, birth height, and birth head circumference in preterm infants. Moreover, CUC had a strong relationship with HDL-C and very large, large, and medium HDL-C in preterm infants. CONCLUSIONS: In preterm infants, CUC is associated with normal growth and may indicate the ability to transport cholesterol forward by large-or medium-size HDL.
Subject(s)
Fetal Blood , Infant, Premature , Cholesterol , Cholesterol, HDL , Female , Humans , Infant , Infant, Newborn , Infant, Small for Gestational AgeABSTRACT
The number of low birthweight (LBW) infants weighing below 2500 g has not decreased in Japan. This study aimed to develop an adult non-obese hyperglycemic mouse model born with LBW to study the pathogenesis. At 16.5 days of gestation, transient intrauterine ischemia (blocked blood flow in both uterine arteries for 15 min) was performed in a subgroup of pregnant mice (group I). Non-occluded dams were used as sham controls (group C). After birth, female pups in each group were weaned at 4 weeks of age and reared on the normal diet until 8 weeks of age (n = 7). Fasting blood glucose levels, serum immunoreactive insulin (IRI), and body composition were then measured. Metabolite analyses was performed on the liver tissues. Birthweight was significantly lower in group I compared with group C. Pups from group I remained underweight with low fat-free mass and showed hyperglycemia with high serum IRI and homeostasis model assessment of insulin resistance levels, indicating insulin resistance. Metabolite analyses showed significantly reduced adenosine triphosphate and nicotinamide adenine dinucleotide production and increased lactic acid in group I. The pathogenesis of our non-obese hyperglycemic mouse model may be due to increased myogenic insulin resistance based on mitochondrial dysfunction and reduced lean body mass.
ABSTRACT
[This corrects the article DOI: 10.3389/fmicb.2017.01877.].
ABSTRACT
A standard treatment for disseminated intravascular coagulation in neonates has not yet been established. We analyzed the outcomes of 23 neonates who developed disseminated intravascular coagulation due to infection or asphyxia between 2004 and 2017. The overall survival rate was 95.7% on day 28 after anticoagulant therapy. In contrast, the bleeding-free survival rate was 69.6% (95% confidence interval, 53.1%-91.2%). Of the 6 neonates with intracranial bleeding, 2 developed neurological sequelae. The current study showed that intracranial bleeding remained a major problem in the early 2000s, despite the introduction of a new anticoagulant drug, recombinant thrombomodulin, at our institution since 2009.
Subject(s)
Disseminated Intravascular Coagulation , Thrombomodulin , Anticoagulants/therapeutic use , Disseminated Intravascular Coagulation/drug therapy , Disseminated Intravascular Coagulation/etiology , Hemorrhage/drug therapy , Humans , Infant, Newborn , Intracranial Hemorrhages/chemically induced , Intracranial Hemorrhages/drug therapy , Recombinant Proteins/adverse effects , Thrombomodulin/therapeutic useABSTRACT
INTRODUCTION: A simple and rapid diagnosis of Ureaplasma spp. is required for the choice of the appropriate antibiotic. However, an ideal detection method has not been available. This study examines the efficacy of the loop-mediated isothermal amplification (LAMP) assay, which provides rapid and sensitive results, to detect Ureaplasma spp. in respiratory tract samples of preterm infants. METHODS: The study included preterm infants born before 32 weeks of gestation admitted Kagoshima City Hospital from June 2018 to March 2020. Nasopharyngeal swabs and/or tracheal aspirates were obtained in the first seven postnatal days. One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were analyzed by LAMP, culture, and quantitative real-time polymerase chain reaction. RESULTS: All 167 infants had a median (range) gestational age of 28.7 weeks (22.3-30.9) and birthweight 1030g (322-1828). One hundred sixty-seven nasopharyngeal swabs and 101 tracheal aspirates were obtained. In the results of nasopharyngeal swabs, the sensitivity and specificity of LAMP were 73.9% (17/23) and 97.2% (140/144), whereas those of quantitative real-time polymerase chain reaction were 73.9% (17/23) and 95.8% (138/144), compared to culture. In the results of tracheal aspirates, the sensitivity and specificity of LAMP were 89.5% (17/19) and 92.7% (76/82), whereas those of quantitative real-time polymerase chain reaction were 89.5% (17/19) and 93.9% (77/82), compared to culture. CONCLUSIONS: The LAMP assay showed similar sensitivity and specificity with quantitative real-time polymerase chain reaction in the respiratory tracts of preterm infants including extremely preterm infants during the immediate postnatal period. Therefore, the LAMP is a practical alternative for the early detection so that appropriate antibiotics can be administered for preventing BPD.
Subject(s)
Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Ureaplasma Infections/diagnosis , Ureaplasma/genetics , Bacterial Proteins/genetics , Female , Gestational Age , Humans , Infant, Newborn , Infant, Premature , Male , Nasopharynx/microbiology , Reproducibility of Results , Respiratory System/microbiology , Sensitivity and Specificity , Species Specificity , Ureaplasma/classification , Ureaplasma/physiology , Ureaplasma Infections/microbiologyABSTRACT
BACKGROUND: Bacterial infections and some antibiotics show displacer effects on bilirubin-albumin binding and increase unbound bilirubin (UB) but not total bilirubin (TB) in serum. METHODS: A case study was conducted to show a successful treatment of hyperbilirubinemia by monitoring UB. RESULTS: In an extremely preterm infant with bloodstream bacterial infection caused by methicillin-resistant coagulase-negative staphylococci, 2 days after high-dose ampicillin and regular-dose amikacin were initiated, UB markedly increased, but TB did not. After vancomycin was substituted, UB decreased immediately with phototherapy and intravenous albumin infusion. CONCLUSIONS: When using antibiotics, the clinicians should be mindful regarding the displacer effect on bilirubin-albumin binding.
Subject(s)
Bacterial Infections , Infant, Extremely Premature , Bilirubin , Humans , Hyperbilirubinemia/therapy , Infant , Infant, Newborn , PhototherapyABSTRACT
OBJECTIVE: Delayed cord clamping (DCC) is recommended for healthy term infants. However, the effectiveness of umbilical cord milking (UCM) in term infants remains unknown. The study aimed to compare the effects of UCM versus DCC on term infants. STUDY DESIGN: A systematic review and meta-analysis were conducted which included individual and clustered RCTs comparing UCM with DCC for infants born at ≥37 weeks of gestation. RESULTS: Three trials (650 term infants) were included. Compared with DCC, UCM was associated with higher hemoglobin levels at 6 weeks after birth [infants, 621; mean difference, 0.17; 95% confidence interval, 0.05-0.29] and had no statistical differences in hemoglobin levels at birth, serum bilirubin levels at 48 h after birth, or hematocrit levels at 48 h after birth. CONCLUSION: This study suggested that UCM might be as beneficial as DCC in term infants, however, further RCTs are required to accurately assess the outcomes.
Subject(s)
Infant, Premature , Umbilical Cord , Constriction , Humans , Infant , Infant, NewbornABSTRACT
BACKGROUND: The objective of the present study was to verify the speed and accuracy of fetal ultrasonic Doppler (fetal Doppler) in measuring heart rate of newborns at rest, including preterm, low-birthweight infants, and its efficacy during neonatal resuscitation, including cases of neonatal asphyxia. METHODS: A three-lead electrocardiogram and fetal Doppler were used to measure resting heart rates in 100 newborns, including 48 preterm, low-birthweight infants, at 0 to 72 h after birth. Times to display heart rate were compared between electrocardiogram and fetal Doppler by the Bland-Altman analysis and Wilcoxon signed-rank test. The time required for the fetal Doppler to measure heart rate during neonatal resuscitation was also assessed. RESULTS: In 100 newborns, the mean error of the resting heart rate in 1,293 measurement points was 0.07 beats/min. To display the heart rate, the fetal Doppler required a median time of 5 s, and electrocardiogram required a median time of 10 s (P < 0.001). During neonatal resuscitation, the heart rate was measured within 10 s in 18 of 21 cases (86%) and displayed with a median time of 5 s; this was measured in all neonatal asphyxia cases (9/9, 100%). CONCLUSIONS: Fetal Doppler can measure heart rate in newborns accurately and rapidly and is useful for evaluating heart rate not only at rest but also during neonatal resuscitation, especially in asphyxia.
Subject(s)
Asphyxia Neonatorum/therapy , Electrocardiography/methods , Heart Rate , Resuscitation/methods , Ultrasonography, Doppler/methods , Female , Humans , Infant, Low Birth Weight , Infant, Newborn , Infant, Premature , Male , Ultrasonography, Prenatal/methodsABSTRACT
BACKGROUND: Preterm infants sometimes have transient late-onset hemolytic jaundice; however, the etiology has yet to be determined. CASE PRESENTATION: In our case, fetal hemoglobin (HbF) level increased significantly to 100% at 23 days of age. Levels of methemoglobin and carboxyhemoglobin also increased to 2.9% and 3.5%, respectively, following the elevated HbF level. At 26 days, hemolytic jaundice developed. No abnormality of red blood cell membranes and enzyme activities was found. CONCLUSIONS: The etiology of late-onset hemolytic jaundice in preterm infants may associate with an impaired switching from HbF to adult hemoglobin (HbA) or reverse switching from HbA to HbF.
Subject(s)
Fetal Hemoglobin/analysis , Infant, Extremely Low Birth Weight , Jaundice , Erythrocytes/pathology , Humans , Infant, Newborn , Male , Methemoglobin/analysisABSTRACT
We previously reported that triglyceride (TG) levels in small-for-gestational age (SGA) newborns were significantly higher than those in appropriate-for-gestational age (AGA) newborns. Stearoyl-CoA desaturase (SCD) activity is required for TG synthesis, while lipoprotein lipase mass (LPLm) facilitates TG clearance. The purpose of this study is to reveal whether SCD activity or LPLm is the cause of high TG levels in SGA newborns. Fifty-five newborns were classified as AGA (nâ¯=â¯42) and SGA (nâ¯=â¯13). Serum LPLm, TG and fatty acids in umbilical cord blood were analyzed. Then, [16:1 (n-7)]/ [16:0] and [18:1 (n-9)]/ [18:0] were calculated as SCD16 and SCD18 activities, respectively. The SGA group showed significantly higher TG levels and significantly lower LPLm levels than the AGA group. However, SCD16 and 18 activities were lower in SGA newborns than in AGA newborns. In conclusion, LPLm, rather than SCD activity may be involved in the increased TG levels in SGA newborns.
Subject(s)
Fetal Blood/enzymology , Infant, Small for Gestational Age/blood , Lipoprotein Lipase/blood , Stearoyl-CoA Desaturase/blood , Adult , Female , Gestational Age , Humans , Infant, Newborn , MaleABSTRACT
In children, the incidence of pneumococcal meningitis has decreased since the introduction of pneumococcal conjugate vaccine (PCV7 and PCV13). However, since the introduction of the vaccine, developed countries have seen the emergence of non-PCV13 serotypes. However, invasive pneumococcal disease (IPD) caused by PCV13-targeted serotypes still represents an important public health problem in resource-limited countries. To develop a rapid, simple, and cost-effective assay to detect serotypes of Streptococcus pneumoniae, we developed a novel loop-mediated isothermal amplification (LAMP) assay based on the sequences available for the 13 capsular types that are included in PCV13: 1, 3, 4, 5, 6 A, 6B, 7 F, 9 V, 14, 18 C, 19 A, 19 F, and 23 F. We evaluated test reactivity, specificity, sensitivity and performance, and compared the results between established LAMP and conventional PCR assays. To support its clinical use, the detection limits of the LAMP assay were evaluated using bacterial genomic DNA-spiked cerebrospinal fluid (CSF) and blood specimens. We confirmed the specificity of the LAMP assay using 41 serotypes of pneumococcal strains. The sensitivity of the LAMP assay was 10 to 100 copies per reaction, compared to 10 to 104 copies per reaction for PCR assays. The detection limits of the LAMP assay were comparable when using DNA-spiked CSF and blood specimens, as compared to using purified DNA as the template. In conclusion, a rapid and simple LAMP-based pneumococcal serotyping method has been developed. This is the first report of a LAMP method for a PCV13 serotype-specific identification assay, which could be a promising step to facilitate epidemiological studies of pneumococcal serotyping.
Subject(s)
DNA, Bacterial/genetics , Nucleic Acid Amplification Techniques/methods , Pneumonia, Pneumococcal/diagnosis , Streptococcus pneumoniae/genetics , Bacterial Capsules/classification , Bacterial Capsules/genetics , Base Sequence , Child, Preschool , Female , Humans , Infant , Male , Pneumonia, Pneumococcal/microbiology , Sensitivity and Specificity , Serogroup , Serotyping/methods , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/physiologyABSTRACT
OBJECTIVE: To clarify clinical and genetic features of Japanese children with congenital chloride diarrhea (CCD). STUDY DESIGN: This was a multi-institutional, retrospective survey of 616 pediatric centers in Japan with identified patients with CCD between 2014 and 2018. Mutations involving SLC26A3 were detected by Sanger sequencing. RESULTS: Thirteen patients met all entry criteria including mutations in SLC26A3, and 14 patients satisfied clinical diagnostic criteria. Homozygous or compound heterozygous mutations in SLC26A3, including 6 novel mutations, were identified in 13 of these 14 patients (93%). The most common (detected in 7 of 13) was c.2063-1g>t. Median age at diagnosis was 1 day. Nine of the patients meeting all criteria were diagnosed as neonates (69%). Median follow-up duration was 10 years. When studied, 8 patients had <5 stools daily (62%), and all had fewer than in infancy. Only 1 patient had nephrocalcinosis, and 3 (23%) had mild chronic kidney disease. Neurodevelopment was generally good; only 1 patient required special education. Five patients (38%) received long-term sodium, potassium, and chloride supplementation. CONCLUSIONS: Early fetal ultrasound diagnosis and prompt long-term sodium, potassium, and chloride supplementation were common management features. Genetic analysis of SLC26A3 provided definitive diagnosis of CCD. In contrast with previously reported localities, c.2063-1g>t might be a founder mutation in East Asia.
Subject(s)
Chloride-Bicarbonate Antiporters/genetics , DNA/genetics , Diarrhea/congenital , Forecasting , Metabolism, Inborn Errors/genetics , Mutation , Population Surveillance , Sulfate Transporters/genetics , Chloride-Bicarbonate Antiporters/metabolism , DNA Mutational Analysis , Diarrhea/epidemiology , Diarrhea/genetics , Diarrhea/metabolism , Female , Follow-Up Studies , Genetic Testing , Humans , Incidence , Infant, Newborn , Japan/epidemiology , Male , Metabolism, Inborn Errors/epidemiology , Metabolism, Inborn Errors/metabolism , Retrospective Studies , Sulfate Transporters/metabolism , Survival Rate/trends , Transcription FactorsABSTRACT
PROBLEM: Ureaplasma species occasionally cause chorioamnionitis and premature labor. We developed a novel assay employing a loop-mediated isothermal amplification (LAMP) method to detect Ureaplasma parvum and Ureaplasma urealyticum. METHOD OF STUDY: Loop-mediated isothermal amplification primers were designed to amplify Ureaplasma-specific ureaseB genes. Four U. parvum strains, 5 U. urealyticum strains and 14 reference bacterial species were evaluated. Forty-six vaginal swab samples were analyzed by LAMP, culture, and PCR. RESULTS: Our LAMP primers were specific to each species and had no cross-reaction. Of 46 clinical specimens, the sensitivity, specificity, and positive and negative predictive values of the LAMP method were 100% (12/12), 100% (34/34), 100% (12/12), and 100% (34/34), respectively, whereas those of PCR were 66.7% (8/12), 100% (34/34), 100% (8/8), and 89.5% (34/38), respectively, compared to culture-based detection. CONCLUSION: The LAMP detection method outperformed the culture and PCR methods. Early detection enables appropriate antibiotic selection for improved prenatal outcomes.
Subject(s)
Chorioamnionitis/diagnosis , Nucleic Acid Amplification Techniques/methods , Ureaplasma Infections/diagnosis , Ureaplasma urealyticum/physiology , Ureaplasma/physiology , Vagina/physiology , Cell Culture Techniques , Cells, Cultured , Early Diagnosis , Female , Humans , Polymerase Chain Reaction , Predictive Value of Tests , Pregnancy , Sensitivity and Specificity , Time FactorsABSTRACT
Over the past four decades, the incidence of meningitis caused by Haemophilus influenzae in children has decreased due to widespread vaccination against H. influenzae type b (Hib). The incidence of invasive diseases due to H. influenzae types not included in the vaccines, however, has increased. At present, there are a limited number of diagnostics available to detect non-type b H. influenzae. To address this issue, we developed a rapid, simple, and cost-effective method for detecting serotypes of H. influenzae. We designed LAMP primer sets based on published sequences for H. influenzae capsular types a, c, d, e, and f. The assay was evaluated to determine test reactivity, specificity, and sensitivity. To support its use in patients with suspected meningitis, we evaluated the detection limit of the non-Hib serotype specific LAMP assay using bacterial genomic DNA-spiked cerebrospinal fluid (CSF) specimens. The reactivity and specificity of the LAMP assays were confirmed using six serotypes and non-typeable H. influenzae strains, plus eight strains of other Haemophilus species and non-Haemophilus genera. The detection limits of the LAMP assay for capsular types a, c, d, e, and f were 102, 102, 102, 103, and 10 copies per reaction, while those of the PCR assay were 104, 104, 103, 103, and 104 genome copies per reaction, respectively. Using DNA-spiked CSF specimens, the detection limit of the LAMP assay was equivalent to that using purified DNA as the template. However, the detection limit of the PCR was reduced from 103 to 104 genome copies per reaction for serotype d and from 103 to 105 genome copies per reaction for serotype e. To the best of our knowledge, this is the first report of a serotype-specific identification assay for H. influenzae using the LAMP method. Our results suggest the potential of LAMP methods for patients with suspected meningitis in resource-limited laboratories or public health surveillance systems.