Genotyping and antimicrobial resistance in Escherichia coli from pig carcasses

ESBL-Producing Enterobacterales at the Human-Domestic Animal-Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil

The use, misuse, and overuse of antimicrobials is one of the main public health threats of the 21st century. We investigated the risk factor of the presence of extended-spectrum, cephalosporin-resistant Enterobacterales in feces of non-domestic and domestic birds and other domestic animals in Piauí State, northeast Brazil. We collected a total of 387 cloacal and rectal swab samples of free-living birds, domestic birds, and domestic mammals in five municipalities: Amarante, Água Branca, Lagoa Alegre, Parnaíba, and Teresina. A total of 59/387 (15.2%) of these samples harbored extended spectrum beta-lactamase (ESBL)-producing Enterobacterales. Using the MALDI-TOF technique, we identified fifty-seven samples as Escherichia coli and two samples as Klebsiella pneumoniae. Teresina and Parnaíba had the highest prevalence of animals with resistant bacteria (32.1% and 27.1%, respectively) and highest exposure risk factor (OR of 16.06 and 8.58, respectively, and p < 0.001 for all). Multidrug-resistant, ESBL-producing Enterobacterales were observed in 72.8% of the samples (43/59). For the free-living birds, the positive samples belonged to a great kiskadee (Pitangus sulphuratus) and a semipalmated sandpiper (Calidris pusilla) in migratory and resident species, respectively. For domestic animals, the swine samples showed the highest prevalence of antimicrobial resistance. The lack of access to veterinary care and information regarding antimicrobial therapy, along with the easy access to antimicrobials without medical prescription, favors the inadequate use of antimicrobials in Piauí.

Antibiotic resistant Escherichia coli from diarrheic piglets from pig farms in Thailand that harbor colistin-resistant mcr genes

Antibiotic-resistant Escherichia coli is one of the most serious problems in pig production. This study aimed to determine the antibiotic susceptibility and genotypes profiles of diarrhoeagenic E. coli that causes diarrhea in piglets. Thirty-seven pathogenic E. coli strains were used in this study. These were isolated from rectal swabs of diarrheic piglets from farms in Thailand from 2018 to 2019. Escherichia coli isolates were highly resistant to amoxicillin (100%), followed by oxytetracycline (91.9%), enrofloxacin (89.2%), trimethoprim/sulfamethoxazole (86.5%), amoxicillin: clavulanic acid (81.1%), colistin and gentamicin (75.7%), ceftriaxone and ceftiofur (64.9%), ceftazidime (35.1%) and 97.3% showed multidrug-resistance (MDR). There were 8 (21.6%) mcr-1 carriers, 10 (27.0%) mcr-3 carriers and 10 (27.0%) co-occurrent mcr-1 and mcr-3 isolates. The phenotype-genotype correlation of colistin resistance was statistically significant (performed using Cohen's kappa coefficient (κ = 0.853; p < 0.001)). In addition, PCR results determined that 28 of 37 (75.7%) isolates carried the int1 gene, and 85.7% int1-positive isolates also carried the mcr gene. Genetic profiling of E. coli isolates performed by ERIC-PCR showed diverse genetics, differentiated into thirteen groups with 65% similarity. Knowledge of the molecular origins of multidrug-resistant E. coli should be helpful for when attempting to utilize antibiotics in the pig industry. In terms of public health awareness, the possibility of transmitting antibiotic-resistant E. coli from diarrheic piglets to other bacteria in pigs and humans should be of concern.

Antimicrobial resistance in commensal Escherichia coli and Enterococcus spp. isolated from pigs subjected to different antimicrobial administration protocols

The antimicrobial resistance (AMR) in human and animal pathogens is a global concern, and antimicrobial use (AMU) is considered the most important driver for its increase. The aim of this study was to assess AMR in Escherichia coli and Enterococcus spp. in faecal samples of pigs subjected to four different AMU protocols from birth to finishing: G1, no in-feed antimicrobials; G2: a total average dose 6018 mg antimicrobials/pig; G3: a total average dose 8127 mg antimicrobials/pig; and G4: a total average dose 15,678 mg antimicrobials/pig. Faecal samples were collected at six time points and AMR was assessed in both bacteria. The microbiota composition was assessed by 16S rRNA sequencing. Minor differences on the microbiota profile was observed among groups, but a lower Firmicutes:Bacteroidetes ratio was noted in G4. Escherichia coli and Enterococcus spp. strains isolated from all groups showed a high level of multi-drug resistance (MDR). The amount of antimicrobials used was significantly positively associated with the probability of MDR in both bacteria. Approximately 43% of the variation in MIC₉₀ for colistin could be explained by AMU, and a one-day increase in administration of colistin increased MIC₉₀ by 0.05 μg mL^-1. In conclusion, the results suggest that the higher the use of antimicrobials in farms, the higher the MDR frequency and resistance to the highest priority critically important antimicrobials for humans in commensal gut bacteria of pigs.

Molecular Characterization of Multidrug-Resistant Escherichia coli Isolates from Edible Offal in Korea

HIGHLIGHTS

Edible offal is significantly contaminated by antimicrobial-resistant Escherichia coli. E. coli from edible offal is harboring various antimicrobial resistance and virulence genes. Improvements in hygienic conditions of edible offal production is required.