Bacteraemia in neonatal foals: clinicopathological differences between Gram‐positive and Gram‐negative infections, and single organism and mixed infections

Abstract

Recognising particular patterns of clinical and clinicopathological findings associated with infection with specific groups of bacteria may, in the future, aid antimicrobial selection and influence prognosis in bacteraemic foals.

Bacterial isolates, antimicrobial susceptibility patterns, and factors associated with infection and outcome in foals with septic arthritis: 83 cases (1998–2013)

“…Staphylococcus spp are the bacteria most frequently isolated from the joints of children with septic arthritis 22,23 and adult horses with septic arthritis secondary to intra-articular injections, penetrating wounds, idiopathic infections, and surgical procedures. 21,24 Given that the joints of foals are generally infected by the hematogenous route, it is not surprising that E coli was the most common gramnegative bacteria isolated from the septic joints of the foals in the present study as well as other studies. In the present study, age was not significantly associated with the isolation of either gram-negative or gram-positive organisms from the infected joint; however, results of another study 20 indicate that gram-negative bacteremia and sepsis were more prevalent in younger foals than in older foals.…”

The molecular basis for recognition of bacterial ligands at equine TLR2, TLR1 and TLR6

“…TLR2 recognition of Gram positive bacteria is, therefore, fundamental to successfully controlling infections with these organisms. Gram positive bacterial infections in young horses are common, and involved in a range of syndromes from reduced performance in young racing thoroughbreds to life-threatening sepsis in neonates [8,9]. Equine peripheral blood mononuclear cells (PBMC) stimulated with the TLR2/1 ligand Pam3CSK4 produce tumour necrosis factor-α (TNF-α), and LTA and PepG also stimulate release of TNF-α in equine whole blood assays [10,11].…”

Prognostic factors in the sick neonatal foal

“…However the studies on the role of blood culture and of multiple foci of infection provided conflicting results (Stewart et al 2002;Sanchez 2005;Peek et al 2006). Other factors significantly related to survival, are: WBC and N count, serum albumin concentration, serum glucose concentration, blood pH, base excess and plasma administration on admission (Gayle et al 1998), standing on admission (Rohrbach et al 2006;Corley et al 2007). In a final multivariate model the foollowing variables have been included: standing, duration of clinical signs prior to admission, respiratory rate, N count and age (Gayle et al 1998).…”

“…A sepsis score >23 has reported to have 100% diagnostic accuracy and has been associated with mortality (White et al 2001). Other factors associated to failure to survive are: pneumonia and severe depression at presentation, neutropenia persisting for 24 hours, degenerative left shift, low N:L ratio (Raisis et al 1996), ACTH/cortisol ratio and vasopressin levels (Gold et al 2006a), overzealous IL-6 response (Gold et al 2006b), positive blood culture with a Gram-negative bacterium isolated, especially Actinobacillus spp (Stewart et al 2002;Corley et al 2007). However the studies on the role of blood culture and of multiple foci of infection provided conflicting results (Stewart et al 2002;Sanchez 2005;Peek et al 2006).…”