The Public Health Burden of Virulent Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Strains Isolated from Diseased Horses.

The research article investigates the public health implications of a certain type of bacteria strain known as “Virulent Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae” isolated from sick horses. This bacteria strain can resist multiple drug treatments and has been associated with both hospital-acquired and general population infections, worldwide.

Methodology and Findings

• The study involved the collection of nasal and rectal swabs from 100 horses afflicted with diseases – 50 suffering from diarrhea, and another 50 experiencing respiratory illnesses.
• These collected samples were then scrutinized for the presence of the specially named Klebsiella pneumoniae strains, using a selective isolation medium, later followed by an identification process involving both phenotypic and molecular methods.
• In this analysis, 13 percent of the horses were found with these bacteria strains. The rate of isolation varied depending on the illness type, with a higher rate (20 percent) seen in horses with diarrhea compared to those with respiratory illnesses (6 percent).

Isolate Resistance and Virulence Genes

• Throughout these isolates, certain resistance genes named TEM and SHV were detected in all of them, followed by another gene, CTX-M, in about 92.3 percent of the strains. However, none of them had the OXA gene. All of these isolates exhibited Multidrug Resistance (MDR) behavior.
• The virulence genes distribution showed that type 3 fimbrial adhesin (MrkD) and enterobactin (EntB) dominated in all observed strains. Meanwhile, regulator of mucoid phenotype A (RmpA) was found in about 77 percent of them, and Klebsiella ferric iron uptake (Kfu) in around 46 percent.
• Two other genes, mucoviscosity-associated gene A (MagA), and type 2 capsular polysaccharide (K2), were absent in all studied bacterial strains.

Implication of Findings

• This study also delivered four partial sequences of the MrkD gene that demonstrated a high genetic correlation with sequences isolated from human hosts. This evidence suggests a potential contamination pathway and highlights the public health threat posed by this particular bacteria type.
• Overall, the study emphasizes the alarming role of horses in transmitting these robust, multi-resistant, and highly virulent bacterial strains, posing a significant public health hazard.