Postnatal changes in epigenetic modifications of neutrophils of foals are associated with increased ROS function and regulation of neutrophil function.

Neonates of all species, including foals, are highly susceptible to infection, and neutrophils play a crucial role in innate immunity to infection. Evidence exists that neutrophils of neonatal foals are functionally deficient during the first weeks of life, including expression of cytokine genes such as IFNG. We hypothesized that postnatal epigenetic changes were likely to regulate the observed age-related changes in foal neutrophils.

Intramuscular administration of a synthetic CpG-oligodeoxynucleotide modulates functional responses of neutrophils of neonatal foals.

Neutrophils play an important role in protecting against infection. Foals have age-dependent deficiencies in neutrophil function that may contribute to their predisposition to infection. Thus, we investigated the ability of a CpG-ODN formulated with Emulsigen to modulate functional responses of neutrophils in neonatal foals.

Macrolide- and rifampin-resistant Rhodococcus equi on a horse breeding farm, Kentucky, USA.

Macrolide and rifampin resistance developed on a horse breeding farm after widespread use was instituted for treatment of subclinical pulmonary lesions in foals. Resistance occurred in 6 (24%) of 25 pretreatment and 8 (62%) of 13 (62%) posttreatment isolates from affected foals. Drug-resistant isolates formed 2 distinct genotypic clusters.

Association of perinatal exposure to airborne Rhodococcus equi with risk of pneumonia caused by R equi in foals.

Objective: To determine whether the concentrations of airborne virulent Rhodococcus equi in stalls housing foals during the first 2 weeks after birth are associated with subsequent development of R equi pneumonia in those foals.

Sample: Air samples collected from foaling stalls and holding pens in which foals were housed during the first 2 weeks after birth.

Procedures: At a breeding farm in Texas, air samples (500 L each) were collected (January through May 2011) from stalls and pens in which 121 foals were housed on day 1 and on days 4, 7, and 14 after birth.

Association of airborne concentration of virulent Rhodococcus equi with location (stall versus paddock) and month (January through June) on 30 horse breeding farms in central Kentucky.

Objective: To determine whether the concentration of airborne virulent Rhodococcus equi varied by location (stall vs paddock) and month on horse farms.

Sample: Air samples from stalls and paddocks used to house mares and foals on 30 horse breeding farms in central Kentucky.

Procedures: Air samples from 1 stall and 1 paddock were obtained monthly from each farm from January through June 2009.

Effects of location for collection of air samples on a farm and time of day of sample collection on airborne concentrations of virulent Rhodococcus equi at two horse breeding farms.

Objective: To determine whether airborne concentrations of virulent Rhodococcus equi at 2 horse breeding farms varied on the basis of location, time of day, and month.

Sample Population: 2 farms in central Kentucky with recurrent R equi-induced pneumonia in foals.

Procedures: From February through July 2008, air samples were collected hourly for a 24-hour period each month from stalls and paddocks used to house mares and their foals.

Antimicrobial activity of tulathromycin and 14 other antimicrobials against virulent Rhodococcus equi in vitro.

This study determined the antimicrobial activity of tulathromycin against Rhodococcus equi in vitro. Ninety-eight virulent isolates of R. equi from equine clinical cases were examined, of which 20 isolates were macrolide resistant.

Detection of strain variation in isolates of Rhodococcus equi from an affected foal using repetitive sequence-based polymerase chain reaction.

Rhodococcus equi is an important pathogen of foals aged 1-6 months. Evidence exists that foals are exposed to a wide diversity of R. equi strains in their environment.

In vitro antimicrobial activity of gallium maltolate against virulent Rhodococcus equi.

The objective of this study was to determine the in vitro antimicrobial activity of gallium maltolate (GaM) against Rhodococcus equi. A total of 98 virulent bacterial isolates from equine clinical cases were examined, of which 19 isolates were known to be resistant to macrolides and rifampin. Isolates were cultured with various concentrations of GaM and minimal inhibitory concentration (MIC) values were determined after 24 and 48 h.

Association of soil concentrations of Rhodococcus equi and incidence of pneumonia attributable to Rhodococcus equi in foals on farms in central Kentucky.

Objective: To determine whether soil concentrations of total or virulent Rhodococcus equi differed among breeding farms with and without foals with pneumonia caused by R equi.

Sample Population: 37 farms in central Kentucky. Procedures-During January, March, and July 2006, the total concentration of R equi and concentration of virulent R equi were determined by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively, in soil specimens obtained from farms.