sa1983 characterization of mucosally - adherent escherichia coli in pediatric inflammatory bowel...
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four patients (30.7%) had a BMI <5th percentile at the time of surgery. Short-term (<30days) post-operative events occurred in two patients with recurrent perianal disease. Bothhad normal BMI: one was on IM and one on biologics peri-operatively. Long-term (30-180days) post-operative events included repeat surgery (1/13, on steroids/biologics), and rectalbleeding requiring readmission (1/13, on biologis); both had normal BMI. One patient hadan anastomotic stricture requiring repeat surgery, however this was at >2 years. Of note, 9/13 (69%) were seen by our practice as a second opinion. Conclusions: Immunosuppressionis more common than malnutrition in pediatric patients with Crohn's disease who havepost-operative events.Pre-Operative Nutritional Status and Immunosuppression as Predictors of Post-OperativeEvents in Pediatric Crohn's Disease Patients
Sa1981
Pre-Operative Nutritional Status and Immunosuppression as Predictors ofPost-Operative Events in Pediatric Ulcerative Colitis PatientsMelissa Rose, Vesta Salehi, Robbyn E. Sockolow, Aliza B. Solomon
Objective: To evaluate the frequency of post-operative events in children with ulcerativecolitis (UC) in relation to nutritional status and use of immunosuppressive medications priorto surgery. Patients/Methods: A case series was conducted of 9 pediatric patients with UCwho underwent surgical intervention between 2007 and 2011. Age of diagnosis, age of firstsurgical intervention, type(s) of surgical intervention(s), pre-operative immunosuppressivemedication use and nutritional status (BMI <5th percentile) were reviewed and evaluatedin the context of post-operative events. Results: The average age of diagnosis was 10.74years (median 11.16). The average age at first surgical intervention was 13.92 years (median12.5), with the average time from diagnosis to first surgical intervention being 3.22 years(median 2.83). Procedures included four (44.4%) two-stage ileal-pouch anal anastomosis(IPAA), three (33.3%) three-stage IPAA, and two total abdominal colectomy with ileostomywith plans to complete a three-stage IPAA (22.2%). One patient had four subsequent surgicalpouch revisions, one had a small bowel resection at stage 3 of her IPAA, and one had pouchfailure requiring end ileostomy placement. Five patients had elective procedures and fourhad emergent procedures. Reasons for emergent surgery included acute failure of medicaltherapy (3/9) and acute toxic colitis (1/9). Five patients (55.5%) were on immunosuppressivemedications at the time of initial surgery; two were on steroids/biologics, one on an immuno-modulator (IM) and two on steroids alone. The four remaining patients had been off ofimmunosuppression for 4-8 weeks pre-operatively. Pre-operative BMI percentile ranged from0.19-97.83% (median 51.69%) and two patients (22.2%) had a BMI <5th percentile. Short-term (<30 days) post-operative events occurred in four patients and included readmissionfor pain, wound infection (both with normal BMI and on steroids/biologics); prolongedsmall bowel edema delaying second stage (normal BMI, on IM); and pouchitis with sinustract formation (low BMI, on no immunosuppression peri-operatively). Long-term (30-180 days) post-operative events occurred in two patients, one with recurrent pouchitis,anastomotic leak and stricture, abscess, sinus tract formation and infection (initial surgeryoccurred at another hospital, patient was on biologics at time of surgery and BMI wasnormal) and one with an incisional hernia after her initial surgery (on steroids, normal BMI)and later pouch failure at 6 months (on no immunosuppression, BMI 6%). All patientsexcept for one (88.8%) were seen by our practice as a second opinion. Conclusions: Immunos-uppression is more common than malnutrition in pediatric patients with ulcerative colitiswho have post-operative events, however malnutrition also likely plays a role in outcomes.Pre-Operative Nutritional Status and Immunosuppression as Predictors of Post-OperativeEvents in Pediatric Ulcerative Colitis Patients
Sa1982
Detecting Enterotoxigenic Bacteroides Fragilis Carriage in PediatricInflammatory Bowel DiseaseLea Ann Chen, Shervin Rabizadeh, Sankar Chirumamilla, Shehzad A. Saeed, EmiliaAlbesiano, Andrew Goodwin, Shaoguang Wu, Charles O. Elson, Maria Oliva-Hemker,Cynthia L. Sears
Enterotoxigenic Bacteroides fragilis (ETBF) causes asymptomatic, chronic colitis in C57BL/6mice and increased colon tumorigenesis in multiple intestinal neoplasia (MinApc/+) mice viaits primary virulence factor the B. fragilis toxin (BFT). Studies suggest an association betweenETBF infection and active inflammatory bowel disease (IBD), but only small studies inhumans are available. Our study aims to develop a sensitive diagnostic touchdown PCRprotocol for bft detection and to apply this protocol to determine ETBF carriage rates inpediatric IBD patients. We spiked known quantities of a serially diluted laboratory ETBFstrain into sham mouse stool. ETBF detection limits range from 2.3 x 103 to 4.6 x 105 CFU/mL for pure ETBF culture and 4.1 x 105 to 4.6 x 106 CFU/gm stool for spiked sham stool.To test for ETBF carriage in humans, we prospectively enrolled pediatric patients withulcerative colitis or Crohn's disease from two academic IBD centers. Control samples weresimilarly collected from confirmed non-IBD patients presenting to the pediatric GI clinicsat the same institutions. Extracted stool DNA from 25 IBD patients and 25 controls weretested by our touchdown PCR protocol for bft with no positive results. Next frozen fecal
S-373 AGA Abstracts
samples from 8 IBD and 3 control patients were thawed and cultured on selective BacteroidesBile Esculin (BBE) agar to help select for Bacteroides spp. Sixteen isolates were collectedfrom each of the 4 IBD and 2 control samples that grew on BBE. Touchdown PCR performedon boiled water preps of each isolate were positive for bft in 2 of the 4 IBD patients (4 of16 isolates and 5 of 16 isolates, respectively) and both controls (1 of 16 and 6 of 16,respectively). Our stool DNA results suggest that the ETBF quantity, if present in our IBDand control samples, is less than ~105CFU/gm stool, though ETBF spiking experimentsusing these bft-negative human stools are needed to account for possible fecal PCR inhibitorsthat may affect our assay sensitivity. Second, our data suggests that testing of bacterialisolates is a more sensitive method to detect bft+ Bacteroides. Testing of more samples isneeded to distinguish if there is a statistically significant difference in the percentage of IBDpatients vs. controls who carry ETBF or in the quantity of ETBF they carry. We are in theprocess of testing for human stool inhibitors, as well as testing other IBD and control samplesfor bft. We will analyze associated clinical data to determine if BFT carriage correlates withclinical manifestations of IBD, such as disease location, severity, or timing of flares.
Sa1983
Characterization of Mucosally - Adherent Escherichia coli in PediatricInflammatory Bowel Disease PatientsRebecca Flint, Ward Jarvis, Matthew Overton, Robert Baldassano, Sandra C. Kim
Background: Children with inflammatory bowel disease (IBD) have unique characteristicsnot seen in adult patients, including growth and nutritional deficiencies and aggressivedisease. Thus, a better understanding of factors that potentially perpetuate disease is crucial.Prior studies have shown that both adults and children with IBD, particularly Crohn's disease(CD), have increasedmucosally - adherent Escherichia coli. However, the relationship betweenE. coli in pediatric IBD patients and bacterial - associated virulence genes has not beenclearly delineated. Aim: Determine whether mucosally - associated E. coli isolated frompediatric CD patients is found in greater numbers and express more virulence genes comparedto children with ulcerative colitis (UC) and healthy controls. Methods: Mucosal biopsysamples (2 - 3 per section) were obtained from the ileum (IL), cecum (CEC), and distalcolon (DC) of pediatric pts undergoing routine procedures. Samples were processed usingestablished lab protocols for culture (plated on MacConkey) and quantification. Individualcolonies were selected from bacterial cultures and incubated. PCR was used to confirm thepresence of E. coli and to test for E. coli - associated virulence genes (Table 1) from bacterialDNA extracted from the cultures. Bacterial DNA was extracted from biopsies for E. coliquantification by real time PCR (qPCR). Results: Mucosal biopsy samples were analyzed (n=42 pts; 50% M, 50% F; 10-23 yrs, mean: 16.2 ± 3.0 yrs). There were 34 CD (15.9±2.9yrs), 4 UC (18.3±3.4 yrs), 2 healthy control, and 2 indeterminate colitis (IC) pts. Therewere no statistically significant differences in E. coli-associated virulence genes between CDand UC pts or between different regions (IL/CEC/DC) within disease subsets, but sometrends were seen. Virulence genes kpsmII and fliC were expressed in CD but not UC pts,and all IBD pt, but no control, samples expressed fimA and hcp. In the E. coli quantificationdata, we group samples by quartile. 100% of IL and DC and 66.7% of CEC samples in theupper quartiles were from CD pts. In the lower quartiles, only 55.6% of IL, 22.2% of CEC,and 55.6% of DC samples were from CD pts. Conclusion: E. coli adherence virulence genesmay be necessary to induce and maintain the dysregulated response in IBD. Differences invirulence genes may affect E. coli mucosal adherence in different pediatric IBD pt subsets.Ongoing studies are focused on sample size expansion, antimicrobial resistance and correlat-ing patient risk alleles associated with impaired bacterial sensing/processing to E. coli quanti-fication/characteristics. A better understanding of the relationship between E. coli, in pediatricIBD patients, and antimicrobials may lead to targeted therapies including less toxic therapieswhich modulate specific components of the intestinal microbiota.Table 1: Virulence genes
Sa1984
Quantification and Characterization of Klebsiella pneumoniae in PediatricPatients With Inflammatory Bowel DiseaseMatthew Overton, Ward Jarvis, Rebecca Flint, Robert Baldassano, Sandra C. Kim
Background: Inflammatory Bowel Diseases (IBD), including Crohn's disease (CD) and ulcerat-ive colitis (UC), are chronic relapsing diseases resulting from a dysregulated host immuneresponse against normal commensal bacteria. Members of the Enterobacteriaceae family,including Klebsiella spp, are known to be increased in IBD patients. Previous studies haveshown an association between increased anti-Klebsiella antibodies in patients with Crohn'sand ankylosing spondylitis. Furthermore, studies in rodent IBD models have shown acorrelation between increased intestinal Klebsiella pneumoniae and the development of colitis.
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