Serotypes of Rhodococcus equi isolated from horses, immunocompromised human patients and soil in Hungary.

The research investigated the different types of Rhodococcus equi bacteria found in horses, human patients with weakened immune systems, and soil in Hungary. The study found that majority of the strains belonged to serotype 1, particularly in foals and horse facilities, while serotype 2 was mostly found in human patients.

Isolation and Serotyping of Rhodococcus equi strains

In this paper, scientists examined 212 Rhodococcus equi strains acquired from a selection of sources:

• Soil samples
• Nasal and rectal swabs from horses
• Immunocompromised human patients

These strains were serotyped – a method of differentiating between species or strains of microorganisms based on their reaction to specific antibodies – using Prescott’s serotyping system.

Results of the Study

Out of 212 strains examined:

• Serotype 1 was the most prevalent with 147 strains (69.3% of the total), especially in foals and horse facilities
• Serotype 2 comprised 22 strains (10.4% of the total), and the majority of human R. equi strains belonged to this serotype
• Serotype 3 and 4 were less common with 6 (2.8%) and 1 (0.5%) strains respectively
• Serotypes 5, 6 and 7 were not present in the samples
• 36 strains (17%) could not be typed and were categorized as “untypable”

Implications of the Study

The results indicated a variation of R. equi serotype prevalence across Hungary. Furthermore, the significant prevalence of serotype 1 among horse populations and in soil around horse facilities suggests a potential biological preference or environmental influence. Similarly, the association of serotype 2 with human samples may point to host-specific factors. However, further studies would be necessary to confirm these observations and understand their implications.