A Longitudinal Study of Dominant E. coli Lineages and Antimicrobial Resistance in the Gut of Children Living in an Upper Middle-income Country

The gastrointestinal tract constitutes a complex and diverse ecosystem. Escherichia coli is one of the most frequently studied and characterized species in the gut ecosystem, nevertheless, there has been little research to determine their diversity and population dynamics in the intestines of children over time. In this prospective study, a fresh fecal sample was obtained from children longitudinally over one year (30 fecal samples at sampling period 1 and 22 fecal samples at sampling periods 2 and 3). From each stool sample, five E. coli colonies were randomly selected (n = 405 E. coli isolates total) in order to characterize the genotype and phenotypic antimicrobial resistance patterns. We found that all numerically dominant E. coli lineages in children's intestines were transient colonizers, and antimicrobial resistance phenotypes of these strains varied significantly over time without any apparent selective force. Whole-genome sequencing of 3 isolates belonging to ST131 found in one child during the sampling period I and II indicated that isolates were three different ST 131 clones that carried extended-spectrum β-lactamase (ESBL) genes.

A longitudinal study of E. coli lineages and antimicrobial resistance in Ecuadorian children

ABSTRACTThe gastrointestinal tract (GIT) constitutes a complex and diverse ecosystem. Escherichia coli is one of the most frequently studied and characterized species in the gut ecosystem. Nevertheless, there has been little research to determine their diversity and population dynamics in the intestines of children over time. Many intestinal E. coli lineages carry antimicrobial resistance and virulence genes, which have implications in disease and public health. In this one-year prospective study, a fresh fecal sample was obtained from 30 children longitudinally for one year (n = 82 fecal samples). From each stool sample, five Escherichia coli colonies were randomly selected to characterize their genotype and phenotypic antimicrobial resistance pattern (n = 405 E. coli isolates). We found that the most numerically dominant E. coli lineages in children’s intestines were transient colonizers, and phenotypic antimicrobial resistance varied significantly over time, however, ST131 a multi-drug resistant pathogen, and 3 additional STs persisted in a child’s intestine for 3 months or more.IMPORTANCEThe length of residency and numeric dominance of antimicrobial-resistant E. coli may affect the extent to which an isolate contributes to the dissemination of antimicrobial resistance. We studied the persistence of numerically dominant and antimicrobial-resistant lineages of E. coli in the human intestine and found that E. coli lineages in the gut of children change rapidly over time.

Prevalence of Geohelminth Parasites of Horses in Dutsinma Metropolis, Katsina State Nigeria

This study was carried out to investigate the prevalence of geohelminth parasites of horses in Dutsinma metropolis between May to August, 2016. Fresh fecal sample were obtained from the rectum of 48 randomly selected horses. A floatation technique was used for the lab work experiment. From the result, out of the total sample collected 6 (12.50%) were positive with eggs of two parasites Strongyles and Oxyuris spp with the prevalence of (6.25%) for each. Among the three points of sample collection, the highest prevalence was recorded at Kadangaru (20.00%) followed by Unguwa Yandaka (18.18%) and no case recorded at Hayingada. X2 cal = 36.84 at P=0.05 and 2df. The highest prevalence was recorded among the males (18.52%) while only 1 female was affected with the prevalence of (4.76%) X2 cal = 36.57 at P=0.05 and 2df. Prevalence was recorded in adult of 14.29% while young horses recorded a prevalence of 10.00%, X2 cal = 36.84 at P=0.05 Strongyles and Oxyuris spp were recognized as important geohelminth parasites in Horses in Dutsinma Local Goverment Area of Katsina State with various rates of infection (12.50%). Managerial control tools should be integrated to improve prevention of geohelminth parasites by communication, information and health education.

Investigating the Strongyle Populations, with Emphasis on Strongylus vulgaris (Nematoda: Strongylidae) in Romanian Horses, Based on Larval Cultures

This study aimed to investigate the presence of Strongylus vulgaris on different horse establishments in Romania. A total number of 380 horses were enrolled in the study, representing: three stud farms (n=156); four sport/recreational establishments (n=75); and working horses (n=149). Overall, 106 premises/yards from 17 localities in 9 counties from North-Eastern, Center and Southern Romania were visited. Fresh fecal sample were collected from individual horses and were analyzed by a modified McMaster method for fecal strongyle egg per gram counting. Further, larval cultures were performed for morphological identification of S. vulgaris third stage larvae. Overall, of the investigated horses from studs, sport/recreational units, and working horses, 84.60%, 44.0%, and 79.20%, respectively were positive for strongyle. On coprocultures, cyathostomin-larvae were the most prevalent in all horse-establishment types, while S. vulgaris larvae were found only in working horses (12.1%; n=18). Other strongylin species have been identified, namely S. equinus, S. edentatus, Oesophagodontus robustus, and Triodontophorus spp. all in working horses, and Craterostomum acuticaudatum, in both working horses and horses for sport units. However, further studies are planned by using more sensitive technique for monitoring of S. vulgaris in Romanian horse farms.