Ability of Chromogenic Agar, MALDI-TOF, API 20E and 20 Strep Strips, and BBL Crystal Enteric and Gram-Positive Identification Kits to Precisely Identify Common Equine Uterine Pathogens

Limitations of a chromogenic agar plate for the identifying bacteria isolated from equine endometritis samples

“…The difference in results, 96% accuracy described by Ferris et al . and 79% in our study, may be due to the different study set‐up. The most important difference between the two studies is the bacterial range included.…”

“…This percentage increases to 79% if turquoise is considered as the normal appearance of Streptococcus spp. on this agar plate, as described previously . Although, in that case, differentiation between Streptococcus spp.…”

“…Ferris et al . describes an excellent accuracy (at the species level) for identification of bacterial isolates causing endometritis in the mare using chromogenic agar plates without additional tests. The difference in results, 96% accuracy described by Ferris et al .…”

“…Regarding the wide variety of potential causative bacteria , with different optimal treatment strategies , quick and correct diagnosis of the involved pathogens is necessary. The use of chromogenic agar plates for rapid, easy and correct identification of equine endometritis‐causing bacteria has been proposed previously . These chromogenic agar plates were originally designed for the identification of bacteria causing Urinary Tract Infections (UTI) in humans .…”

“…For example, β‐glucosidase results in turquoise colouration, β‐galactosidase in a pink colouration and tryptophan deaminase (TDA) in brown colouration on this chromogenic agar plate . Recent research demonstrated that the use of custom‐made chromogenic agar plates (Spectrum‐Duo Gram Selective Culture System, VETLAB) is highly accurate (96%) for the identification of the most common endometritis‐causing bacteria in mares, namely Streptococcus equi subsp. zooepidemicus , Escherichia coli , Pseudomonas aeruginosa and Klebsiella pneumoniae .…”