To evaluate the potential probiotic properties ofLactobacillus strains isolated from feces of infants and also to determine their antimicrobial activity against some enteropathogenic bacteria. The Fecal samples were prepared from 120 infants aged less than 24 months. In total,105 Lactobacillus strains were identified by phenotypic tests. Thirty isolates were randomly selected to study their potential probiotic properties. These isolates were examined for resistance to acid (pH: 2.5, 2 h) and bile (oxgall 0.3%, 8 h), adhesion to HT-29 cells, antibiotic susceptibility, and antimicrobial activities. On basis of 16S rRNA sequencing, 30 isolates identified as Lactobacillus fermentum (n = 11; 36.7%), Lactobacillus plantarum (n = 9; 30%), Lactobacillus rhamnosus (n = 6; 20%), and Lactobacillus paracasei (n = 4; 13.3%). All tested strains survived at acid and bile conditions. Six Lactobacillus strains revealed high adherence to HT-29 cells. Three strains including the L. fermentum (N2, N7), and the L. plantarum (N20) showed good probiotic potential and inhibited the growth of Yersinia enterocolitica ATCC 23715, Shigella flexneri ATCC 12022, Salmonella enterica ATCC 9270, and enteropathogenic Escherichia coli (EPEC) ATCC 43887. The antibiotic resistance test showed that all the isolates were susceptible to tetracycline, and chloramphenicol. Lactobacillus strains like L. fermentum (N2, N7), and the L. plantarum (N20), could be potential probiotic, but further in vitro and in vivo studies on these probiotic strains are still required.

Introduction: Enteroaggregative Escherichia coli (EAEC) has been implicated as an emerging cause of traveler’s diarrhea, persistent diarrhea among children, and immunocompromised patients. The present study aimed to investigate the prevalence of antibiotic resistance, extended-spectrum β-lactamase (ESBL) production, and virulence factors of EAEC isolates obtained from Iranian children suffered from diarrhea. Materials and methods: In this cross-sectional study, from March 2015 to February 2016, 32 EAEC isolates were collected from fecal samples of children aged <12 years with diarrhea in southwest of Iran. All EAEC isolates identified using phenotypic and molecular methods and the cell line adhesion assay. Antimicrobial susceptibility testing was determined using disk diffusion method. The presence of virulence factors and ESBL resistance genes were determined by polymerase chain reaction. Results: Overall, 28.1% (9/32) of the isolates were positive for at least one of virulence genes. The most frequent gene was aap with a frequency of 96.9%. Neither aafA nor aggA gene was detected among all of the EAEC isolates. Antimicrobial susceptibility testing revealed the highest resistance rate to ampicillin (100%) and co-trimoxazole (100%), followed by ceftriaxone (81.3%). Further analysis revealed that the rate of ESBLs-producing isolates was 71.9% (23/32). Polymerase chain reaction screening revealed that 87.5% and 65.5% of EAEC isolates were positive for bla_TEM and bla_CTX-M genes, respectively, and 17 (53.1%) of isolates contained both bla_TEM and bla_CTX-M genes. Conclusion: The high detection rate of ESBL-producing EAEC isolates accompanied with virulence genes highlights a need to restrict infection control policies in order to prevent further dissemination of the resistant and virulent EAEC strains.

Background: Functional constipation is a common and annoying gastrointestinal disorder among children worldwide in which the intestinal microbiota composition plays a fundamental role. This study aimed to compare the quantity of main intestinal Lactobacillus species in constipated children and healthy controls. Materials and Methods: Fecal samples were collected from 40 children fulfilling Rome IV criteria for functional constipation and 40 healthy volunteers. Quantitative real-time polymerase chain reaction (qPCR) method with species-specific primers was used to investigate seven main Lactobacillus species in fecal samples. Results: Lactobacillus strains of the patient group were different from the healthy controls, main differences being noticeable decrease in the population quantity of Lactobacillus reuteri (mean 10^2.61 CFU/gram feces) and lower abundance of Lactobacillus fermentum (p< 0.0001). Conclusion: Lactobacillus species might be quantitatively altered in childhood functional constipation. Our findings on the different species of Lactobacillus population showed significantly decreased quantity in the patient group compared with the healthy subjects.

Background: Hirschsprung's disease is the most common cause of pediatric intestinal obstruction. Contrast enema is used for evaluation of the patients with its diagnosis. Aim: To evaluate sensitivity, specificity, positive predictive value, and negative predictive value of radiologic findings for diagnosis of Hirschsprung in patients underwent barium enema. Methods: This cross sectional study was carried out in Imam Khomeini Hospital for one year starting from 2012, April. Sixty patients were enrolled. Inclusion criteria were: neonates with failure to pass meconium, abdominal distention, and refractory constipation who failed to respond with medical treatment. Transitional zone, delay in barium evacuation after 24 h, rectosigmoid index (maximum with of the rectum divided by maximum with of the sigmoid; abnormal if <1), and irregularity of mucosa (jejunization) were evaluated in barium enema. Biopsy was obtained at three locations apart above dentate line. PPV, NPV, specificity , and sensitivity was calculated for each finding. Results: Mean age of the cases with Hirschsprung's disease and without was 17.90±18.29 months and 17.8±18.34 months respectively (p=0.983). It was confirmed in 30 (M=20, F=10) of cases. Failure to pass meconium was found in 21(70%) cases. Sensitivity, specificity, PPV, and NPV were 90%, 80%, 81.8% and 88.8% respectively for transitional zone in barium enema. Sensitivity, specificity, PPV, and NPV were 76.7%, 83.3%, 78.1% and 82.1% respectively for rectosigmoid index .Sensitivity, specificity, PPV, and NPV were 46.7%, 100%, 100% and 65.2% respectively for irregular contraction detected in barium enema. Sensitivity, specificity, PPV, and NPV were 23.3%, 100%, 100% and 56.6% respectively for mucosal irregularity in barium enema. Conclusion: The most sensitive finding was transitional zone. The most specific findings were irregular contraction, mucosal irregularity, and followed by cobblestone appearance.

BACKGROUND: Ultrasonography has shown to be useful in the diagnosis of constipation. OBJECTIVE: The aim of this study was to compare the rectal diameter and rectal wall thickness in children with and without constipation. METHODS: Children with the diagnosis of constipation according to Rome III criteria were included in the study. The children underwent transabdominal sonography for the evaluation of rectal diameter and rectal wall thickness. Ultrasonography was performed with a full bladder. Children without constipation who underwent abdominal sonography were assigned to the control group. RESULTS: The rectal diameter was larger in children with constipation than in children without constipation (31.72±9.63 mm vs 19.85±4.37 mm; P=0.001). The rectal wall was thinner in children with constipation than in children without constipation (1.75±0.33 mm vs 1.90±0.22 mm; P=0.032). There was no significant difference between boys and girls with constipation in terms of rectal diameter (31.02±8.57 mm 32.77±11.35 mm; P=0.63). CONCLUSION: Transabdominal rectal diameter measurement may be useful in the diagnosis of constipation.