Genome Analysis of Multidrug-Resistant Escherichia coli Isolated from Poultry in Nigeria.

Escherichia coli is one of the most common commensal bacteria of the gastrointestinal tract of humans and warm-blooded animals. Contaminated poultry can lead to disease outbreaks in consumers causing massive economic losses in the poultry industry. Additionally, commensal E. coli can harbor antibiotic resistance genes that can be transferred to other bacteria, including pathogens, in a colonized human host. In a previous study on antimicrobial resistance of E. coli from food animals from Nigeria, multidrug-resistant E. coli were detected. Three of those isolates were selected for further study using whole-genome sequencing due to the extensive drug resistance exhibited. All of the isolates carried the extended-spectrum ß-lactamase (ESBL) genes, blaCTX-M15 and blaTEM-1, whereas one isolate harbored an additional ESBL, blaOXA-1. All of the tetracycline-resistant isolates carried tet(A). The genes aac3-IIa and aacA4, conferring resistance to aminoglycosides, were identified in an E. coli isolate resistant to gentamicin and tobramycin. In two E. coli isolates, dfrA14, qnrS1, and sulII, were detected conferring resistance to trimethoprim, fluoroquinolones, and sulfonamides, respectively. The third isolate carried dfrA17, no fluoroquinolone resistance gene, an additional sulI gene, and a chloramphenicol resistance gene, catB3. Mutations in candidate genes conferring resistance to fosfomycin and fluoroquinolones were also detected. Several efflux systems were detected in all the E. coli isolates and virulence-associated genes related to serum resistance, motility, and adhesion. E. coli and non-E. coli origin prophages were also identified in the isolates. The results underline the higher resolution power of whole-genome sequencing for investigation of antimicrobial resistance, virulence, and phage in E. coli.

Genetic Polymorphisms in LTF/EcoRI and TLR4/AluI loci as candidates for milk and reproductive performance assessment in Holstein cattle.

The aim of this study was to explore the genetic polymorphisms in LTF/EcoRI and TLR4/AluI loci and their association with milk and reproductive performance in Holstein cattle. A randomly selected 800 Holstein dairy cows from two dairy farms (400 animals each) in Egypt were used. Based on the two farm records, association between LTF/EcoRI genotypes and milk performance traits (order of lactation, daily milk yield, days in milk, corrected milk at 305 day and dry period) was carried out. Meanwhile, exploring of TLR4/AluI genotypes effect was done on data for reproductive performance (age at first freshening, calving interval, number of services per conception, ovarian rebound and days open). DNA was extracted from blood samples collected from Holstein dairy cows of the both farms and restriction analysis of 301-bp PCR products of LTF gene revealed two genotypes: AA genotype (301 bp) and AB genotype (301, 201 and 100 bp). Meanwhile, restriction analysis of 382-bp PCR products of TLR4 gene digested with AluI yielded two alleles (A and B) and three genotypes (AA, AB and BB). The A allele was indicated by two bands at 300 and 82 bp, and the B allele resulted in three fragments of 160, 140 and 82 bp. There was a significant association (p ≤ 0.05) between LTF genotypes and milk performance traits except for days in milk. The TLR4 genotypes had significant effects (p ≤ 0.05) on age at first freshening, calving interval, number of services per conception, ovarian rebound and days open. Ordinal logistic regression statistical model also revealed that it is possible to calculate high reproductive performance traits and to predict favourable dairy cows based on LTF and TLR4 genotypes. This research reveals the effectiveness of LTF/EcoRI and TLR4/AluI loci as candidates for reproductive performance assessment in Holstein cattle.

Contribution of Healthy Chickens to Antimicrobial-Resistant Escherichia coli Associated with Human Extraintestinal Infections in Egypt.

BACKGROUND: Chickens are considered potential reservoirs for human extraintestinal infections with pathogenic Escherichia coli. However, information about genetic relatedness between E. coli from healthy chickens and human patients is still limited. METHODS AND RESULTS: In this study, clinical samples from patients with extraintestinal infections and healthy broiler chickens were collected from geographically related locations in Egypt during the 2nd half of 2015. The recovered isolates were tested for susceptibility against ß-lactam antimicrobials and screened for the presence of extended-spectrum ß-lactamases (ESBLs) and virulence genes; clonal and phylotypes were also determined. Forty-eight percent (48/100) and 31.3% (50/160) of human and chicken samples were positive for E. coli, respectively. Although only 4% (2/50) of the chicken isolates were resistant to the tested ß-lactams, over 58% of human E. coli isolates (28/48) exhibited resistance to cefotaxime. For ß-lactamases, 52.1%, 33.3%, 20.8%, and 6.25% of human E. coli were positive for blaCTX-M, blaTEM, blaOXA, and blaCMY, while blaTEM, blaOXA, and blaCMY were found in 32%, 4%, and 34% of chicken isolates, respectively. Low frequencies of virulence genes within human and chicken E. coli isolates were detected by PCR. The majority of E. coli isolates harboring ß-lactam resistance genes from human and chicken sources belonged to phylogroup C and B1, respectively. Using pulsed-field gel electrophoresis (PFGE), some E. coli grouped based upon source; however, most clusters contained isolates from both humans and chickens. CONCLUSIONS: The above findings suggest that although no single clone appeared to be circulating among E. coli isolates from human and chicken, some shared characteristics exist among isolates from both sources. Increased study will aid to track the dissemination of ß-lactam-resistant E. coli from healthy chickens to humans for implementation of effective intervention strategies.