Invasive group B Streptococcus strains and clinical characteristics in Danish infants from 1999 to 2009.

Background: Group B Streptococcus (GBS) infection in infants may result in both respiratory, cardiovascular, and neurological dysfunction and ultimately death of the infant. Surveillance of GBS strains in infants and their clinical characteristics guide development of effective vaccines and other potential treatments and may have implications for future prognostics and infant care. Therefore, we aimed to study GBS serotypes and clonal complexes (CC) in Danish infants with early onset infection (EOD) (0-6 days of life) and late-onset infection (LOD) (7-89 days of life) and to estimate the association between GBS strain and different clinical outcomes. Methods: We included Danish infants less than 3 months of age with GBS isolates from blood or cerebrospinal fluid between 1999 and 2009. GBS isolates were analyzed by serotyping and multilocus sequence typing with classification of isolates into clonal complexes. Clinical characteristics were obtained by questionnaires completed by tending pediatrician including gestational age, Apgar scores, age at onset, meningitis, symptom severity, treatment duration, and mortality. Symptom severities were reported within neurological symptoms, need for respiratory or circulatory support, and treatment of disseminated intravascular coagulation. Results: A total of 212 GBS isolates were collected with 129 from EOD and 83 from LOD. The dominating GBS strains were III/CC17 (41%), Ia/CC23 (17%), III/CC19 (15%), Ib/CC8-10 (7%), and V/CC1 (6%). Strain Ia/CC23 was mostly found in EOD, while III/CC17 was widespread in LOD, though being the most common in both EOD and LOD. Strain III/CC17 and Ia/CC23 had highest percentage of samples from cerebrospinal fluid (26%), while III/CC19 had the least (8%). Strain III/CC19 had highest mortality with about one fifth of infected infants dying (22%) followed by Ia/CC23 (16%), Ib/CC8-10 (9%), and then III/CC17 (6%). The symptom severity varied between strains, but with no strain consistently resulting in more severe symptoms. Conclusion: Some potential differences in disease severity were observed between the different strains. These findings emphasize the continuous need for multimodal surveillance of infant GBS strains and their clinical characteristics to optimize development of GBS vaccines and other potential treatments.

The effect of early probiotic exposure on the preterm infant gut microbiome development.

Premature birth, especially if born before week 32 of gestation, is associated with increased risk of neonatal morbidity and mortality. Prophylactic use of probiotics has been suggested to protect preterm infants via supporting a healthy gut microbiota (GM) development, but the suggested strains and doses vary between studies. In this study, we profiled the GM of 5, 10 and 30-day fecal samples from two cohorts of preterm neonates (born <30 weeks of gestation) recruited in the same neonatal intensive care unit. One cohort (n = 165) was recruited from September 2006 to January 2009 before probiotics were introduced in the clinic. The second cohort (n = 87) was recruited from May 2010 to October 2011 after introducing Lacticaseibacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12 supplementation policy. Through V3-V4 region 16S rRNA gene amplicon sequencing, a distinct increase of L. rhamnosus and B. animalis was found in the fecal samples of neonates supplemented with probiotics. During the first 30 days of life, the preterm GM went through similarly patterned progression of bacterial populations. Staphylococcus and Weissella dominated in early samples, but was gradually overtaken by Veillonella, Enterococcus and Enterobacteriaceae. Probiotic supplementation was associated with pronounced reduction of Weissella, Veillonella spp. and the opportunistic pathogen Klebsiella. Potential nosocomial pathogens Citrobacter and Chryseobacterium species also gradually phased out. In conclusion, probiotic supplementation to preterm neonates affected gut colonization by certain bacteria, but did not change the overall longitudinal bacterial progression in the neonatal period.Abbreviations: GM: Gut microbiota; ASV: Amplicon sequence variant; NEC: Necrotizing enterocolitis; DOL: Days of life; NICU: Neonatal intensive care unit; ESPGHAN: European Society for Pediatric Gastroenterology, Hepatology and Nutrition; Db-RDA: Distance-based redundancy analysis; PERMANOVA: Permutational multivariate analysis of variance; ANCOM: Analysis of compositions of microbiomes; LGG: Lacticaseibacillus (former Lactobacillus) rhamnosus GG; BB-12: Bifidobacterium animalis ssp. lactis BB-12; DGGE: Denaturing Gradient Gel Electrophoresis.

Prevalence of SARS-CoV-2-Antibodies in Danish Children and Adults.

In Denmark, severe acute respiratory syndrome coronavirus 2 antibodies were assessed in a cross-sectional study among 1033 children visiting pediatric departments and 750 blood donors in June 2020, using a point-of-care test. Antibodies were detected in 17 children (1.6%) and 15 blood donors (2.0%) (P = 0.58). In conclusion, children and adults were infected to a similar low degree.

The influence of probiotics for preterm neonates on the incidence of atopic dermatitis-results from a historically controlled cohort study.

Probiotic supplementation is a promising preventive strategy for atopic dermatitis (AD). To help clarifying the significance of timing with respect to prevention of AD, we here evaluate the benefit of prophylactic use of probiotic supplementation in neonates younger than 30 weeks of gestation. Preterm children from the Department of Neonatology, Rigshospitalet, Denmark from two different admission periods were included in a historically controlled cohort study. Neonates from January 2007 to February 2010, not treated with and neonates from March 2010 to February 2013 treated with probiotic were enrolled. Main outcome was prevalence of AD, and secondary outcomes were use of topical corticosteroids, and number of skin-related visits to GPs and dermatologists. 527 preterm neonates were included in the study, 249 treated and 278 not treated with probiotics. Response rate for the two cohorts was 76.7 and 77.7% respectively. The prevalence of AD was similar in the two groups (20.9% in the probiotic treated group versus 17.1% in the not treated group, p = 0.33). No significant differences were found between the groups with respect to treatment with topical corticosteroids, or visits at GPs or dermatologist. We found no indication that probiotics may prevent AD when administered to neonates <30 gestation weeks from birth until discharge home. Factors influencing the early maturation of the immune system have been assumed to be of particular importance in atopic dermatitis, and hence, our unique cohorts contribute information on how probiotic supplementation may affect the extremely immature immune systems of preterm infants.

[The first case of cap polyposis in Denmark].

Cap polyposis (CP) is characterized by the presence of inflammatory polyps mainly involving the rectosigmoid. It primarily causes mucous to bloody diarrhoea and is often misdiagnosed initially. We report the first case in Denmark with multiple polyps in the rectosigmoid causing constipation in between periods of mucous and bloody diarrhoea. He was initially misdiagnosed as having ulcerative colitis with pseudopolyps. Due to insufficient effect of medical treatment biopsies from the polyps were obtained. They showed typical histological signs of CP. He was successfully treated by rectosigmoid resection.

Intestinal proteome changes during infant necrotizing enterocolitis.

BACKGROUND: Changes in the intestinal and colonic proteome in patients with necrotizing enterocolitis (NEC) may help to characterize the disease pathology and identify new biomarkers and treatment targets for NEC. METHODS: Using gel-based proteomics, proteins in NEC-affected intestinal and colonic sections were compared with those in adjacent, near-normal tissue sections within the same patients. Western blot and immunohistochemistry were applied to crossvalidate proteomic data and histological location of some selected proteins. RESULTS: Thirty proteins were identified with differential expression between necrotic and vital small-intestine sections and 23 proteins were identified for colon sections. Five proteins were similarly affected in the small intestine and colon: histamine receptors (HRs), actins, globins, immunoglobulin, and antitrypsin. Two heat shock proteins (HSPs) were affected in the small intestine. Furthermore, proteins involved in antioxidation, angiogenesis, cytoskeleton formation, and metabolism were affected. Finally, secretory proteins such as antitrypsin, fatty-acid binding protein 5, and haptoglobin differed between NEC-affected and vital tissues. CONCLUSION: NEC progression affects different pathways in the small intestine and colon. HSPs may play an important role, especially in the small intestine. The identified secretory proteins should be investigated as possible circulating markers of NEC progression in different gut regions.

[Prophylactic probiotics for preterm infants reduces mortality]. / Profylaktiske probiotika til præmature børn reducerer dødelighed.

Meta-analyses indicate that prophylactic probiotics for preterm infants reduces mortality and necrotising enterocolitis significantly. Despite the robust evidence clinicians are reluctant to implement probiotics because the beneficial mechanism is not clearly understood and due to concerns about the safety, the long-term effects, and the optimal treatment regimen. Hence, only few countries and only two-thirds of the Danish neonatal departments use probiotics. Currently three large randomised trials on probiotics vs. placebo are ongoing and it is an ethical dilemma whether to proceed or terminate the trials.

Investigation of the early intestinal microflora in premature infants with/without necrotizing enterocolitis using two different methods.

INTRODUCTION: The pathophysiology of necrotizing enterocolitis (NEC) is multifactorial, and gastrointestinal bacteria are thought to play an important role. In this study, the role of microflora in the gastrointestinal tract of neonates with NEC was assessed by comparing cases with controls. RESULTS: Of the 163 neonates, 21 developed NEC. The risk of NEC decreased by 8% with each additional day of gestational age. DISCUSSION: Typically, very few bacterial species could be cultured from the fecal specimens obtained. Gram-positive (G(+)) bacteria dominated the samples in the NEC group, whereas in the control group mixed flora of G(+) and Gram-negative (G(-)) bacteria were isolated. Surprisingly, molecular analysis using PCR-DGGE profiles did not confirm these differences. Our data suggest that G(+) bacteria in the intestine may play a role in the development of NEC in premature infants. METHODS: One hundred and sixty three neonates born at <30 weeks of gestation were enrolled. Fecal samples taken during the first month of life were subjected to culture and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). A total of 482 fecal samples were examined.

Reduced diversity of the intestinal microbiota during infancy is associated with increased risk of allergic disease at school age.

BACKGROUND: Changes in the human microbiome have been suggested as a risk factor for a number of lifestyle-related disorders, such as atopic diseases, possibly through a modifying influence on immune maturation in infancy. OBJECTIVES: We aimed to explore the association between neonatal fecal flora and the development of atopic disorders until age 6 years, hypothesizing that the diversity of the intestinal microbiota influences disease development. METHODS: We studied the intestinal microbiota in infants in the Copenhagen Prospective Study on Asthma in Childhood, a clinical study of a birth cohort of 411 high-risk children followed for 6 years by clinical assessments at 6-month intervals, as well as at acute symptom exacerbations. Bacterial flora was analyzed at 1 and 12 months of age by using molecular techniques based on 16S rRNA PCR combined with denaturing gradient gel electrophoresis, as well as conventional culturing. The main outcome measures were the development of allergic sensitization (skin test and specific serum IgE), allergic rhinitis, peripheral blood eosinophil counts, asthma, and atopic dermatitis during the first 6 years of life. RESULTS: We found that bacterial diversity in the early intestinal flora 1 and 12 months after birth was inversely associated with the risk of allergic sensitization (serum specific IgE P = .003; skin prick test P = .017), peripheral blood eosinophils (P = .034), and allergic rhinitis (P = .007). There was no association with the development of asthma or atopic dermatitis. CONCLUSIONS: Reduced bacterial diversity of the infant's intestinal flora was associated with increased risk of allergic sensitization, allergic rhinitis, and peripheral blood eosinophilia, but not asthma or atopic dermatitis, in the first 6 years of life. These results support the general hypothesis that an imbalance in the intestinal microbiome is influencing the development of lifestyle-related disorders, such as allergic disease.

Optimising bacterial DNA extraction from faecal samples: comparison of three methods.

Culture independent methods are used widely in diagnostic laboratories for infectious disease Isolation of genomic DNA from clinical samples is the first and important step in the procedure. Several procedures for extracting DNA from faecal samples have been described, including different mechanical cell disruptors. To our knowledge, the use of TissueLyser as a mechanical disruptor on faecal samples before DNA extraction has not been previously described. The purpose of the study was to implement a method for preparing faecal samples for optimal DNA extraction. Thus, three different procedures for extracting DNA from human faeces were compared. This was done either by using the mechanical disrupter by Mini BeadBeater 8, or the TissueLyser both followed by DNA purification using QIAamp DNA stool MiniKit, in comparison with DNA extractions using QIAamp DNA stool MiniKit without any prior mechanical disruption, according to manufacturer's instructions. The obtained DNA from the three procedures was analysed by DGGE, and the number of bands was compared between each procedure. There was no significant difference between the numbers of bacterial bands obtained from DGGE when using a TissueLyser or Mini BeadBeater 8, so the two different mechanical cell disruptors can be used comparably when isolating bacterial DNA from faecal samples. The QIAamp DNA stool MiniKit alone resulted in a reduced number of bands compared to the two mechanical disruption methods.

Community analysis of bacteria colonizing intestinal tissue of neonates with necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in newborn neonates. Bacteria are believed to be important in the pathogenesis of NEC but bacterial characterization has only been done on human faecal samples and experimental animal studies. The aim of this study was to investigate the microbial composition and the relative number of bacteria in inflamed intestinal tissue surgically removed from neonates diagnosed with NEC (n=24). The bacterial populations in the specimens were characterized by laser capture microdissection and subsequent sequencing combined with fluorescent in situ hybridization (FISH), using bacterial rRNA-targeting oligonucleotide probes. RESULTS: Bacteria were detected in 22 of the 24 specimens, 71% had moderate to high densities of bacteria. The phyla detected by 16S rRNA gene sequencing were: Proteobacteria (49.0%), Firmicutes (30.4%), Actinobacteria (17.1%) and Bacteroidetes (3.6%). A major detected class of the phylum Proteobacteria belonged to δ-proteobacteria. Surprisingly, Clostridium species were only detected in 4 of the specimens by FISH, but two of these specimens exhibited histological pneumatosis intestinalis and both specimens had a moderate to a high density of C. butyricum and C. parputrificum detected by using species specific FISH probes. A 16S rRNA gene sequence tag similar to Ralstonia species was detected in most of the neonatal tissues and members of this genus have been reported to be opportunistic pathogens but their role in NEC has still to be clarified. CONCLUSION: In this study, in situ identification and community analysis of bacteria found in tissue specimens from neonates with NEC, were analysed for the first time. Although a large variability of bacteria was found in most of the analyzed specimens, no single or combination of known potential pathogenic bacteria species was dominating the samples suggestive NEC as non-infectious syndrome. However there was a significant correlation between the presence of C. butyricum & C. parputrificum and histological pneumatosis intestinalis. Finally this study emphasizes the possibility to examine the microbial composition directly on excised human tissues to avoid biases from faecal samples or culturing.

[A case of tularemia in a Danish hunter]. / Harepest hos jaeger.

"Rabbit fever" (Francisella Tularensis) is a rare infection in Denmark. It was first described in Denmark in 1987. It is most likely to affect people who come into close contact with infected animals or ticks, such as hunters, butchers and veterinarians. The diagnosis should be suspected in such persons presenting with fever, headache, lethargy, lymphadenitis and bite wounds. We present a Danish case describing the diagnosis and treatment of a hunter infected with T. tularensis.

Determination of new cutoff values for indirect immunofluorescence antibody test for Q fever diagnosis in Denmark.

Q fever is a ubiquitous zoonosis caused by Coxiella burnetii. The disease is emerging in many parts of the world, likely because of increased awareness and availability of better diagnostics. The diagnosis is primarily based on serology. Because the prevalence of the disease varies worldwide, the establishment of local cutoff values is needed. A baseline for antibodies against C. burnetii in Denmark was defined by testing sera from healthy Danish volunteers using a commercially available immunofluorescence antibody test. Cross-reactivity was studied on sera obtained from patients experiencing clinically related diseases. The cutoff titers suggested by the manufacturer were found to result in very low specificity of the test. The specificity was, however, effectively increased by using cutoff titers based on the local baseline and equal to immunoglobulin M (IgM) phase I > or =128, IgM phase II > or =256, IgG phase I > or =512, and IgG phase II > or =1024.

Outbreak of non-O157 Shiga toxin-producing Escherichia coli infection from consumption of beef sausage.

We describe an outbreak of Shiga toxin-producing Escherichia coli O26:H11 infection in 20 patients (median age, 2 years). The source of the infection was an organic fermented beef sausage. The source was discovered by using credit card information to obtain and compare customer transaction records from the computer systems of supermarkets.

Listeria monocytogenes: maternal-foetal infections in Denmark 1994-2005.

Maternal-foetal infection by Listeria monocytogenes is a rare complication in pregnancy. In the period 1994-2005, 37 culture-confirmed cases of maternal-foetal Listeria monocytogenes infections were reported in Denmark. We examined 36 patients' files in order to evaluate risk factors, clinical and laboratory findings, response to therapy, and outcome for maternal-foetal listeriosis. Patient data and bacteriological findings were divided into 2 groups for comparison: 1 group with children born alive (n=24) and another group with abortion or stillbirth (n=12). 23 of the 36 children survived the acute infection, as did all the mothers. The mothers were generally only mildly affected by the infection. In contrast, among the children born alive, 15 were diagnosed with bacteraemia/septicaemia, 3 children with pneumonia, 3 with neonatal meningitis, and 3 were unaffected. Despite the high frequency of illness only 1 of the live-born children died from the infection and none of the surviving children showed signs of permanent damage at the time they were discharged from hospital. Listeriosis during pregnancy is a serious threat to the unborn child. One-third of culture-confirmed cases of maternal-foetal infections resulted in abortion or stillbirth; however, the prognosis for live-born children is good, even in severely ill newborns.

[Congenital methaemoglobinaemia: an infrequent cause of neonatal cyanosis]. / Kongenit methaemoglobinaemi: en sjaelden årsag til neonatal cyanose.

We present a case study of a newborn girl with a reduced erythrocytic nicotinamide adenine dinucleotide (NADH)-dependent methaemoglobin reductase level. Within the first days of life she developed cyanosis due to a methaemoglobin level of 21%. The hyperoxia test was characteristic, with normal increases in blood oxygen tension, whereas the oxygen saturation remained constant at 92%. Over the next months the methaemoglobin level decreased to 10%, and the girl did well without treatment.