Strangles, the most frequently diagnosed infectious disease of horses worldwide, is caused by Streptococcus equi. Despite its prevalence, the global diversity and mechanisms underlying the evolution of S. equi as a host-restricted pathogen remain poorly understood. Here, we define the global population structure of this important pathogen and reveal a population replacement in the late 19th or ...

Susceptibility of foals to Rhodococcus equi pneumonia is exclusive to the first few months of life. The objective of this study was to investigate the immediate immunologic response of foal and adult horse antigen-presenting cells (APCs) upon infection with R. equi. We measured the activation of the antigen-presenting major histocompatibility complex (MHC) class II molecule, costimulatory molec...

The host-restricted bacterium Streptococcus equi is the causative agent of equine strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation of the lymph nodes of the head and neck, leading to significant welfare and economic cost. S. equi is believed to have evolved from an ancestral strain of Streptococcus zooepidemicus, an op...

Equine piroplasmosis is a tick-transmitted protozoan disease caused by Theileria equi and/or Babesia caballi. In the present study, we expressed a 53kDa protein from the truncated EMA-2 gene of T. equi (Indian strain) and developed EMA-2ELISA using this expressed protein. This ELISA is able to detect T. equi-specific antibodies in experimentally infected animals as early as 9 days post-infectio...

To isolate Babesia equi genes encoding immunodominant proteins, a cDNA expression library prepared from B. equi mRNA was immunoscreened with B. equi-infected horse serum. Eighteen positive cDNA clones were obtained, and the clone that showed the strongest immunoreactivity, designated Be82, was further characterized. The Be82 gene consisted of 1,953 bp and contained a partial open reading frame ...

We previously showed that the facultative intracellular pathogen Rhodococcus equi produces a nondiffusible and catecholate-containing siderophore (rhequibactin) involved in iron acquisition during saprophytic growth. Here, we provide evidence that the rhbABCDE cluster directs the biosynthesis of a hydroxamate siderophore, rhequichelin, that plays a key role in virulence. The rhbC gene encodes a...

The gene encoding the putative reductase component (KshB) of 3-ketosteroid 9α-hydroxylase was cloned from Rhodococcus equi USA-18, a cholesterol oxidase-producing strain formerly named Arthrobacter simplex USA-18, by PCR according to consensus amino acid motifs of several bacterial KshB subunits. Deletion of the gene in R. equi USA-18 by a PCR-targeted gene disruption method resulted in a mutan...

We describe a case of pulmonary malacoplakia and Rhodococcus equi cavitary pneumonia in a patient with AIDS. The relationship between Rhodococcus equi, a rare bacterial human pathogen, and malacoplakia, an unusual type of chronic granulomatous inflammation, is discussed.

Two-dimensional ridge structures are induced by equi-biaxial compression with large equi-biaxial pre-stretch in a thin film by using a micro-fluidics technique. Whereas wrinkles tend to be uniformly distributed, ridges are localized. The wrinkle-to-ridge transition is unstable (subcritical), resulting in large amplitude changes. The nature and morphology of the ridges is studied and quantified ...

Theileria equi merozoite surface antigens have been an important candidate for development of diagnostics. We developed ELISA based on EMA-1 recombinant antigen, so as to widen our diagnostic confidence in detection of antibodies against T. equi in sero-surveillance studies. The 547 bp EMA-1 gene fragment encoding high hydrophilic antigenic region was expressed with glutathione-S-transferase ta...