The Role of Faecalibacterium, Roseburia, and Butyrate in Inflammatory Bowel Disease.

Faecalibacterium and Roseburia are major producers of butyrate in the intestine. A reduced abundance of the organisms and a concurrent reduction in butyrate levels are associated with inflammatory bowel disease.

Interactions of bile acids and the gut microbiota: learning from the differences in Clostridium difficile infection between children and adults.

Bile acids and microbiota differ significantly in the gut of children and adults. In the first 3 yr of life, intestinal bile consists mostly of two primary bile acids, cholic acid (CA) and chenodeoxycholic acid (CDCA); however, in adults, primary bile acids are transformed into the secondary bile acids, deoxycholic acid (DCA) and lithocholic acid. This difference has a major impact on the gut microbiome, especially on anaerobic spore-forming bacteria. CA augments germination of spores in the terminal ileum. On the other hand, DCA curtails the number of germinated anaerobes entering the cecum from the terminal ileum. The control mechanism that exists in the adult cecum is absent in the young child and results in unrestrained proliferation of anaerobes, such as Clostridium difficile, in the cecum. A similar situation may develop during antibiotic therapy when an antibiotic eradicates the anaerobic population capable of converting primary bile acids into secondary bile acids.

Trimethoprim-Sulfamethoxazole Therapy Reduces Failure and Recurrence in Methicillin-Resistant Staphylococcus aureus Skin Abscesses after Surgical Drainage.

OBJECTIVE: To determine whether a 3-day vs 10-day course of antibiotics after surgical drainage of skin abscesses is associated with different failure and recurrence rates. STUDY DESIGN: Patients age 3 months to 17 years seeking care at a pediatric emergency department with an uncomplicated skin abscess that required surgical drainage were randomized to receive 3 or 10 days of oral trimethoprim-sulfamethoxazole therapy. Patients were evaluated 10-14 days later to assess clinical outcome. Patients were followed for 6 months to determine the cumulative rate of recurrent skin infections. RESULTS: Among the 249 patients who were enrolled, 87% of wound cultures grew Staphylococcus aureus (S aureus) (55% methicillin-resistant S aureus [MRSA], 32% methicillin-sensitive S aureus), 11% other organisms, and 2% no growth. Thirteen patients experienced treatment failure. Among all patients, no significant difference in failure rates between the 3- and 10-day treatment groups was found. After we stratified patients by the infecting organism, only patients with MRSA infection were more likely to experience treatment failure in the 3-day group than the 10-day group (P = .03, rate difference 10.1%, 95% CI 2.1%-18.2%) Recurrent infection within 1 month of surgical drainage was more likely in patients infected with MRSA who received 3 days of antibiotics. (P = .046, rate difference 10.3%, 95% CI 0.8%-19.9%). CONCLUSION: Patients with MRSA skin abscesses are more likely to experience treatment failure and recurrent skin infection if given 3 rather than 10 days of trimethoprim-sulfamethoxazole after surgical drainage. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02024867.

Development of the Anaerobic Microbiome in the Infant Gut.

Ninety-five percent of gut microbiota are anaerobes and vary according to age and diet. Complex carbohydrates in human milk enhance the growth of Bifidobacterium and Bacteroides in the first year. Complex carbohydrates in solid foods enhance the growth of Bacteroides and Clostridium in the second year. Short-chain fatty acids produced by Akkermansia and Faecalibacterium may reduce obesity, diabetes and IBD.

Genomic comparisons of USA300 Staphylococcus aureus colonizating the nose and rectum of children with skin abscesses.

USA300 Staphylococcus aureus is responsible for the current outbreak of skin abscesses in the United States. Unlike other USA types, USA300 colonizes the rectum at rates higher than the nose. The reason for the difference in colonization site preference may be related to specific adherence or attachment factors contained in the genome of these strains. Additional knowledge in this field may help design novel prophylactic and therapeutic strategies to combat staphylococcal infections. Strains of USA300 MSSA and MRSA colonizing the nose and/or rectum from children with staphylococcal skin abscesses were compared by whole genome array technology to identify bacterial genetic determinants associated with site-specific colonization. Strains isolated from different colonization sites were indistinguishable by genomic content. Site-specific colonization traits were not detected in the colonizing bacteria by this array. Either host characteristics associated with staphylococcal carriage or under represented bacterial genomic constructions need to be examined to determine the etiology of this site-specific colonization.

Review and Commentary on the Importance of Bile Acids in the Life Cycle of Clostridioides difficile in Children and Adults.

Clostridioides difficile, a spore-forming anaerobe, resides in the intestine. The life cycle of C. difficile illustrates an interdependent relationship between bile acids, commensal microbiota, and C. difficile. Primary bile acids are critical for the germination of C. difficile spores in the small intestine, while secondary bile acids serve as a counterbalance to inhibit the growth of the organism in the colon. Many commensal bacteria especially Clostridium spp. are responsible for transforming primary bile acids into secondary bile acids. Antibiotics eliminate bacteria that convert primary bile acids into secondary bile acids and, thus, allow C. difficile to flourish and cause diarrhea. In children younger than 2 years of age, who normally only produce primary bile acids, colonization with toxin-producing C. difficile is exceedingly common. The reason for the absence of C. difficile diarrhea in the children remains unexplained.

Secretors of HBGA and Susceptibility to Norovirus and Rotavirus Diarrhea.

Histo-blood group antigen contains oligosaccharides that serve as receptors for norovirus (NoV) and rotavirus (RV). The receptors are only present on the surface of intestinal mucosal epithelial cells of secretors; therefore, secretors are susceptible to NoV and RV diarrhea and nonsecretors are resistant. The prevalence of secretors in different countries varies between 50% and 90%. Secretor rates evolved in response to environmental pressures such as infectious diseases.

Comparison of midturbinate flocked-swab specimens with nasopharyngeal aspirates for detection of respiratory viruses in children by the direct fluorescent antibody technique.

Paired nasopharyngeal aspirate (NPA) and midturbinate flocked-swab specimens from 153 children with respiratory symptoms were examined by the direct fluorescent antibody (DFA) technique. Seventy-four infants (49%) had a viral infection documented by DFA. The flocked-swab specimens had 93% sensitivity and 96.7% agreement with the NPA specimens, with a kappa coefficient of 93.4% (95% confidence interval, 0.877, 0.991).

Pseudo-outbreak of adenovirus infection in a neonatal intensive care unit due to a false-positive antigen detection test.

Twenty-eight of 56 infants in a neonatal intensive care unit had stools positive for adenovirus by the Sure-Vue adenovirus test. Virus cultures of conventionally processed and chloroform-extracted stool samples, as well as conventional and real-time PCR tests, were negative for adenovirus. The cause for the 50% false-positive rate with the antigen test was not determined.

The Response of the Gut Microbiota to Dietary Changes in the First Two Years of Life.

The infant gut microbiota undergoes significant changes in the first two years of life in response to changes in the diet. The discontinuation of the milk-based diet of the first year and the introduction of solid foods in the second year of life results in a decline in bifidobacterium, a shift from infant strains of bifidobacterium to adult strains which preferentially metabolize oligosaccharides derived from plants rather than from milk, a surge in short chain fatty acids such as acetic, propionic and butyric acid from newly acquired commensal clostridium, and the transformation of primary bile acids into secondary bile acids by a limited number of newly acquired and highly specialized Clostridium spp. By 3 years of age, diet and gut microbiota closely resemble those of adults. Gut bacteria required for the production of SCFAs and secondary BAs are potential targets for the intervention of microbiome-related diseases.

The high rate of adverse drug events in children receiving prolonged outpatient parenteral antibiotic therapy for osteomyelitis.

Forty-five children treated with 82 courses of 15 different antibiotics over 344 weeks during outpatient parenteral antibiotic therapy were evaluated for adverse drug events (ADE). Fifty-one percent of the courses had an associated ADE and 32.5% of the antibiotic courses were discontinued because of ADE. Vancomycin had the highest ADE rate at 85.7% and ceftriaxone had the highest ADE-related discontinuation rate at 66.7%. Cefazolin had the lowest rate of ADE and ADE-related discontinuation rates at 0% for both.

Nontypeable Haemophilus influenzae as a pathogen in children.

Nontypeable Haemophilus influenzae is a significant pathogen in children, causing otitis media, sinusitis, conjunctivitis, pneumonia, and occasionally invasive infections. H. influenzae type b conjugate vaccines have no effect on infections caused by nontypeable strains because nontypeable strains are nonencapsulated. Approximately, one-third of episodes of otitis media are caused by nontypeable H. influenzae and the bacterium is the most common cause of recurrent otitis media. Recent progress in elucidating molecular mechanisms of pathogenesis, understanding the role of biofilms in otitis media and an increasing understanding of immune responses have potential for development of novel strategies to improve prevention and treatment of otitis media caused by nontypeable H. influenzae. Feasibility of vaccination for prevention of otitis media due to nontypeable H. influenzae was recently demonstrated in a clinical trial with a vaccine that included the surface virulence factor, protein D.

The milk-based diet of infancy and the gut microbiome.

The composition and the diversity of the gut microbiome play a major role in the health and well-being of humans beginning at birth. The impact of the diet on the structure and the function of the gut microbiome is evident by the changes in the gut microbiome concurrent with the transition from human milk to solid food. Complex oligosaccharides contained in milk are essential nutrients for commensal microbes in the infant gut. The most important commensal bacterium in the infant gut, bifidobacterium, requires α1, 2 fucosylated oligosaccharides for growth. Because not all humans are able to secrete α1, 2 fucosylated oligosaccharides into milk, the gut microbiome of infants and bifidobacteria, in particular, vary considerably between 'secretors' and 'non-secretors'. A paucity of α1, 2 fucosylated oligosaccharides and bifidobacteria in the gut of infants may be associated with poor health.

Clinical and molecular characteristics of staphylococcal skin abscesses in children.

Forty-nine children with skin abscesses (36 methicillin-resistant Staphylococcus aureus and 13 methicillin-susceptible S. aureus) exhibited similar disease severity. Both pathogen groups were pulse field type USA300, multilocus sequence type 8, and possessed Panton-Valentine leukocidin genes. Related microbial genetic architecture may account for similarities in disease severity despite differences in antibiotic susceptibility.

Morbidity and mortality of Staphylococcal bacteremia in children.

BACKGROUND: Staphylococcal aureus bacteremia (SAB) is a major problem in adult patients with a significant mortality. Less is known about SAB in children. The present study was designed to review a 5-year experience with SAB in a children's hospital. METHODS: We conducted a retrospective chart review from 2000-2004. RESULTS: Thirty-six children experienced 42 episodes of SAB and ranged in age from 1 week to 16.7 years with a mean age of 30.5 months. Thirty-two (89%) of the 36 children had preexisting medical conditions. Thirty-six (86%) of 42 episodes of SAB were due to hospital-acquired infections, and 22 (61%) of these 36 episodes occurred in premature infants in the neonatal intensive care unit. Only 3 episodes (7%) of endocarditis were identified, and 2 were community-acquired infections. Fourteen (39%) episodes of SAB were due to methicillin-resistant strains. There were only 3 (8%) deaths, and all were unrelated to SAB. CONCLUSION: SAB occurred most often as a hospital-acquired infection in the neonatal intensive care unit, and methicillin-resistant Staphylococcal aureus accounted for one third of the episodes. Complications such as endocarditis or other metastatic infections and death because of SAB were infrequent.

Infections Associated With Streptococcus Constellatus in Children.

Streptococcus constellatus is a viridans Streptococcus belonging to the Anginosus group. It was associated with abscesses in 37 children, 80% of whom had acute appendicitis with perforation and abscess formation in 50%. None of the children was <3 years of age.

Pitfalls in the diagnosis of enteroviral infection in young children.

BACKGROUND: Three infants with enteroviral infections were admitted to a neonatal intensive care unit (NICU). Investigation into the possible nosocomial spread of enterovirus identified 31 other infected infants. Only 1 of the 31 was truly positive; 30 were false-positive results. METHODS: This was a retrospective observational study. Investigational laboratory studies were conducted to identify problems in diagnostic procedures. RESULTS: Stool cultures were used to identify asymptomatic infections. Investigation identified several problems in the procedures in identification of enterovirus: (1) stool specimens were not properly filtered, (2) insufficient number of tissue culture cell types were used, (3) nonspecific toxicity due to stool and the presence of Clostridia difficile toxin was responsible for cytopathic effects in tissue culture, (4) the failure to block nonspecific fluorescent staining led to misidentification of enteroviruses. CONCLUSIONS: The use of stool cultures to identify asymptomatic enteroviral infections in infants in an NICU can be fraught with problems because of high frequency of C. difficile toxin and the nonspecific toxic effects of stool on tissue culture cells. These problems can be rectified when proper procedures are followed.

The dramatic change in the epidemiology of pediatric epiglottitis.

OBJECTIVE: To review the epidemiology of epiglottitis in a large children's hospital from 1995-2003 and to compare the findings with a previous report published 27 years previously from the same hospital. METHODS: Chart review. RESULTS: Two cases identified. Both children were 18 years old. Group F and group A streptococci were causative agents. CONCLUSIONS: Over the past 27 years, the admission rate for acute epiglottitis declined ten fold. Streptococci are becoming major pathogens in acute epiglottitis.

Management of primary herpetic gingivostomatitis in young children.

OBJECTIVE: To review the treatment of primary herpetic gingivostomatitis at a children's hospital. METHODS: A review of charts from 1999 to 2003. RESULTS: Forty-eight cases were identified. They ranged in age from 8 months to 12 years, with a median age of 2 years 7 months. All children were treated with fluids and analgesics; 11 children were treated with fluids and analgesics exclusively. Thirty-five children were treated with a mixture of Maalox and diphenhydramine, 8 with acyclovir, and 7 with viscous lidocaine; 11 children were treated with 2 or more of these regimens. Both the Maalox and diphenhydramine mixture and the viscous lidocaine were administered as swish and swallow, swish and spit, or by application with a swab as frequently as every hour or as infrequently as every 8 hours. CONCLUSIONS: Topical therapy with Maalox and diphenhydramine or viscous lidocaine was administered to 73% and 15% of the patients, respectively, whereas acyclovir was administered to only 17%. Dosing and administration of topical agents in the treatment of primary herpetic gingivostomatitis in preschoolers were problematic. Acyclovir was not being used as often as it could have been.

Infections Associated with Streptococcus intermedius in Children.

Streptococcus intermedius is a viridans Streptococcus belonging to the Anginosus group. In the past 7 years, it has been associated with abscesses in 48 children, 40% of whom had complicated and/or life-threatening illness. It was the sole pathogen in 35 cases. Seventy-five percent of the infections occurred in winter and spring. None occurred in infants younger than 1 year.