Tracing and strains causing septicemia in extremely preterm infants to the skin, mouth, and gut microbiota.

Unlabelled: Coagulase-negative staphylococci (CoNS) comprise about 50 species, some of which cause septicemia in preterm neonates. CoNS establish early on the skin and in the oral and gut microbiota, from where they may spread to the bloodstream. The colonization pattern preceding septicemia is not well-defined.

Gut microbiota markers in early childhood are linked to farm living, pets in household and allergy.

Background: Children growing up on farms or with pets have a lower risk of developing allergy, which may be linked to their gut microbiota development during infancy.

Methods: Children from the FARMFLORA birth cohort (N = 65), of whom 28 (43%) lived on a dairy farm and 40 (62%) had pets, provided fecal samples at intervals from 3 days to 18 months of age. Gut microbiota composition was characterized using quantitative microbial culture of various typical anaerobic and facultatively anaerobic bacteria, with colonization rate and population counts of bacterial groups determined at the genus or species level.

Staphylococcus aureus sequence type (ST) 45, ST30, and ST15 in the gut microbiota of healthy infants - persistence and population counts in relation to ST and virulence gene carriage.

Staphylococcus aureus colonizes the anterior nares, and also the gut, particularly in infants. S. aureus is divided into lineages, termed clonal complexes (CCs), which comprise closely related sequence types (STs).

Bacterial Carriage of Genes Encoding Fibronectin-Binding Proteins Is Associated with Long-Term Persistence of Staphylococcus aureus in the Nasal and Gut Microbiota of Infants.

Staphylococcus aureus can colonize both the anterior nares and the gastrointestinal tract. However, colonization at these sites in the same individuals has not been studied, and the traits that facilitate colonization and persistence at these sites have not been compared. Samples from the nostrils and feces collected on 9 occasions from 3 days to 3 years of age in 65 infants were cultured; 54 samples yielded S.

Escherichia coli B2 Phylogenetic Subgroups in the Infant Gut Microbiota: Predominance of Uropathogenic Lineages in Swedish Infants and Enteropathogenic Lineages in Pakistani Infants.

segregates into phylogenetic groups, with group B2 containing both extraintestinal pathogenic (ExPEC) and enteropathogenic (EPEC) strains. Ten main B2 subgroups (subgroups I to X)/sequence type complexes (STcs), as well as EPEC lineages, have been identified. In the current study, we characterized ExPEC and EPEC strains of B2 phylogenetic subgroups/STcs that colonize Swedish and Pakistani infants.

Candida species as commensal gut colonizers: A study of 133 longitudinally followed Swedish infants.

The gut microbiota harbor a wide range of bacterial species, but also yeasts may be part of this ecosystem. Infants who are being treated in intensive care units are often colonized by Candida species. However, little is known regarding commensal yeast colonization of healthy infants and young children.

Neonatal gut colonization by Staphylococcus aureus strains with certain adhesins and superantigens is negatively associated with subsequent development of atopic eczema.

Background: Insufficient early immune stimulation may predispose to atopic disease. Staphylococcus aureus, a skin and gut colonizer, produces the B-cell mitogen protein A and T-cell-activating superantigens. Early gut colonization by S.

Superantigens and adhesins of infant gut commensal Staphylococcus aureus strains and association with subsequent development of atopic eczema.

Background: According to the hygiene hypothesis, insufficient immune activation by microbes increases the risk of allergy development. Staphylococcus aureus, which is part of the skin and gut microbiota of infants in Western countries, produces a variety of T-cell-activating enterotoxins, called superantigens.

Objectives: To investigate whether early (0-2 months of age) gut colonization by S.

Impacts of enterotoxin gene cluster-encoded superantigens on local and systemic experimental Staphylococcus aureus infections.

Staphylococcus aureus is both a component of the normal skin flora and an important pathogen. It expresses a range of recognized and putative virulence factors, such as enterotoxins with superantigenic properties. Several superantigen genes, i.

Different phylogenetic profile and reduced mannose-sensitive adherence capacity characterize commensal Escherichia coli in IgA deficient individuals.

In IgA deficiency, secretory IgA (S-IgA) is absent from intestinal secretions. S-IgA carbohydrate chains act as receptors for the mannose specific (MS) adhesin fim of Escherichia coli. In IgA deficient (IgAd) individuals, commensal E.

Comparison between terminal-restriction fragment length polymorphism (T-RFLP) and quantitative culture for analysis of infants' gut microbiota.

The infantile intestinal microbiota is a major stimulus for immune maturation. Both culture and DNA-based methods can be used for microbiota characterization, but few studies have systematically compared their performance for analysis of the gut microbiota. Here, we examined fecal samples obtained on six occasions between one week and 12 months of age from six vaginally delivered infants.

Virulence gene typing of methicillin-resistant Staphylococcus aureus as a complement in epidemiological typing.

Methicillin-resistant Staphylococcus aureus (MRSA) has widely spread to all parts of the world. For surveillance and effective infection control molecular typing is required. We have evaluated the utility of virulence gene determination as a complementary tool for epidemiological typing of MRSA in relation to spa-typing and pulsed-field gel electrophoresis (PFGE).

Escherichia coli strains with the capacity for long-term persistence in the bowel microbiota carry the potentially genotoxic pks island.

The pks genomic island found in Escherichia coli strains of phylogenetic group B2 encodes colibactin, a polyketide-peptide genotoxin that causes DNA double-strand breaks. We investigated the relationship between carriage of the pks island and the capacity of E. coli strains to persist in the gut microbiota of 130 Swedish infants, who were followed from birth to 18 months of age.

Adhesin and superantigen genes and the capacity of Staphylococcus aureus to colonize the infantile gut.

Staphylococcus aureus is a pathogen and a skin commensal that is today also common in the infant gut flora. We examine the role of S. aureus virulence factors for gut colonization.

Pathogenicity island markers, virulence determinants malX and usp, and the capacity of Escherichia coli to persist in infants' commensal microbiotas.

Virulence-associated genes in bacteria are often located on chromosomal regions, termed pathogenicity islands (PAIs). Several PAIs are found in Escherichia coli strains that cause extraintestinal infections, but their role in commensal bowel colonization is unknown. Resident strains are enriched in adhesins (P fimbriae and type 1 fimbriae), capsular antigens (K1 and K5), hemolysin, and aerobactin and mostly belong to phylogenetic group B2.

Emergence of fluoroquinolone-resistant clonal group A: clonal analysis of Norwegian and Russian E. coli isolates.

We describe a study of urinary tract and intestinal isolates of Escherichia coli from Norway and Russia using automated ribotyping, single nucleotide polymorphism analysis for clonal group A (CgA) supplemented with phylogrouping, virulence gene profiling and resistance profiling. CgA comprised 19% of the Norwegian UTI isolates from 2001. Two highly multiresistant fluoroquinolone-resistant CgA isolates were found.

High cytokine levels in perforated acute otitis media exudates containing live bacteria.

Acute otitis media (AOM) is an inflammatory response to microbes in the middle ear, sometimes associated with rupture of the tympanic membrane. Human leukocytes produce different patterns of inflammatory mediators in vitro when stimulated with Gram-positive and Gram-negative bacteria, respectively. Here, we investigated the cytokine and prostaglandin E2 (PGE2) responses in middle ear fluids (MEFs) from children with spontaneously perforated AOM, and related the mediator levels to the presence of pathogens detected by culture (live) or PCR (live or dead).

Optimization of the detection of microbes in blood from immunocompromised patients with haematological malignancies.

The present study aimed to improve the rate of detection of blood-borne microbes by using PCRs with pan-bacterial and Candida specificity. Seventeen per cent of the blood samples (n=178) collected from 107 febrile patients with haematological malignancies were positive using standard culture (BacT/Alert system). Candida PCR was positive in 12 patients, only one of whom scored culture-positive.

Phylogenetic group B2 Escherichia coli strains from the bowel microbiota of Pakistani infants carry few virulence genes and lack the capacity for long-term persistence.

Escherichia coli strains of phylogenetic group B2 obtained from Western human hosts are enriched in virulence-associated genes and have a superior capacity to persist in the colonic microbiota. Here, E . coli strains from 22 infants born in Pakistan whose rectal flora was sampled regularly over the first 6 months of life were examined.

High frequency of false-positive signals in a real-time PCR-based "Plus/Minus" assay.

Molecular biological methods using real-time polymerase chain reaction (RT-PCR) for detection of bacterial and viral genes in different environments have been developed into assays from different commercial sources. Applied Biosystems include and support two applications with their TaqMan instrument: the "Plus/Minus" and the "Allelic Discrimination" assays. These approaches are RT-PCR based, use short primers and fluorescent-labeled TaqMan probes and include three processes: a pre-read run, a PCR-amplification run, and a post-read run.

Spray bacteriotherapy decreases middle ear fluid in children with secretory otitis media.

Objective: Secretory otitis media (SOM) is characterised by persistent fluid in the middle ear cavity, but the cause is unknown. We investigated the clinical, bacteriological and immunological effects of treatment with probiotic bacteria on SOM.

Design: In this double-blind pilot/preliminary study, 60 children with long-standing SOM (median 6 months) who were scheduled for insertion of tympanostomy tubes were randomised to nasal spray treatment with Streptococcus sanguinis, Lactobacillus rhamnosus or placebo for 10 days before surgery.

Fluoroquinolone-resistant uropathogenic Escherichia coli in Norway: evidence of clonal spread.

Prevalence, resistance profiles, virulence gene complements, and phylogenetic and clonal affinities of fluoroquinolone-resistant Escherichia coli from urinary tract infections (UTIs) in Norway were investigated. Of 7302 E. coli UTI isolates from 2003, 1.

A comparison of phylogenetic group, virulence factors and antibiotic resistance in Russian and Norwegian isolates of Escherichia coli from urinary tract infection.

Isolates of Escherichia coli from 31 Norwegian and 31 Russian females with significant bacteruria who presented with clinical signs of urinary tract infection (UTI) were tested for antimicrobial sensitivity, the presence of virulence genes, phylogroup distribution and clonal affinity. Twenty isolates, representing the full clonal diversity of a collection of 138 intestinal isolates of E. coli from healthy Norwegian females, served as a reference group.

Reduced phase switch capacity and functional adhesin expression of type 1-fimbriated Escherichia coli from immunoglobulin A-deficient individuals.

The mannose-specific adhesin of type 1 fimbriae is the most common adhesin in Escherichia coli. One receptor for this adhesin is the carbohydrate chains of secretory immunoglobulin A (S-IgA), and intestinal E. coli from IgA-deficient individuals has a reduced capacity to adhere to mannose-containing receptors.