Multi-drug resistant Escherichia coli in diarrhoeagenic foals: Pulsotyping, phylotyping, serotyping, antibiotic resistance and virulence profiling.

This research study focuses on the identification and characterization of multi-drug resistant strains of E. coli found in foals with diarrhoea. The investigation reveals that a significant proportion of the bacterial strains could pose potential threats to humans due to their pathogenic nature and antibiotic resistance.

Understanding the Research

• Pathogenic Escherichia coli (E. coli), specifically extraintestinal pathogenic E. coli (ExPEC), have the potential to cause serious infections outside the gut, including urinary tract infections, meningitis in newborns, and sepsis. Even though there’s significant research on pathogenic E. coli in food-producing animals, studies on the same in sports/companion animals like horses are scarce.
• This study aimed to explore the multi-drug resistance and virulence (ability to cause disease) in E. coli strains isolated from foals (baby horses) suffering from diarrhoeal disease. The study involved assessing and categorizing the bacterial strains according to their characteristics (phenotypes) and genetic makeup (genotypes).
• Several of the treatment medications used for equine infections are also commonly used in human medicine, which can potentially increase antibiotic resistance among pathogenic strains of bacteria.

Investigative Methods and Results

• E. coli strains from 83 specimens were examined. Serotyping (classifying bacteria based on their cell surface antigens) was carried out using Polymerase Chain Reaction (PCR) and sequencing, while antibiotic resistance was examined through disc diffusion (a method that determines the resistance or susceptibility of bacteria to an antibiotic).
• Genetic grouping, virulence genes, antibiotic resistance genes, and integrons (DNA elements that can capture and express genes, particularly resistance genes) were determined using PCR.
• Out of the investigated strains, 46% were identified as ExPEC and, therefore, were perceived as potentially harmful to both humans and animals. Selected serogroups (bacterial subtypes within a species) included O1, O19a, O40, O101, and O153, which have been previously reported in cases of human ExPEC infections.
• Over a quarter of the E. coli strains were grouped into the pathogenic categories B2 and D. Class 1 and 2 integrons were found in 85% of E. coli strains, indicating a high potential for multi-drug resistance transfer to other bacteria, pathogenic or otherwise.
• Around 65% of the potentially harmful strains carried one or more types of the β-lactamases (enzymes that give bacterial resistance against some antibiotics), along with a high resistance level to fluoroquinolones, a type of antibiotics.

Implications and Conclusions

• The research disclosed high levels of pathogenic and multi-drug resistant E.coli in diarrheic foals, indicating a possible threat to public health.
• These findings underscore the necessity for amplified scrutiny towards sports and companion animal reservoirs to prevent future public health issues related to antibiotic resistance.