STUDY ON SOME ASPECTS OF PATHOGENESIS OF RHODOCOCCUS EQUI IN MICE

In order to study some aspects of pathogenesis of Rhodococcus equi, 60 white Swiss mice were used. They were randomly divided into 2 groups. The 1s' group (40 animals) was inoculated subcutaneously with a dose of 4x10° CFU .of R.equi while the 2nd group was kept as a control. Four animals from the 1st group and 2 animals from the 2nd group were sacrified at day, 1,2,4,8,12,16,20,24,28 and 30 postinoculation (P.I) Six animals of 1stgroup were died during the first and second days P.I. Microscopical examination showed acute to subacute suppurative inflammation in the liver, lung and spleen at I to 4 days PI. While pyogranulomatous lesions and epithelioid granuloma were seen in liver, lungs and spleen at 4 to 24 days PI R.equi was isolated liver, lungs, spleen, kidney and brain in the first day PI. The bacteria persisted in the spleen from and brain up to 20th day, in the liver up to 24" day while in the lungs, and kidney bacterial isolation continuous till 28th day PI.

Rhodococcus in foal, from diagnosis to treatment: Case report

The present work reports a case of a foal affected by Rhodococcus equi, an optional intracellular gram-positive pleomorphic cocobacillus, which, when eliminated with the feces of infected animals, in the soil becomes a potential pathogen, capable of causing mainly piogranulomatous bronchopneumonia. The animal, a 23-day-old Brazilian equestrian foal, was sent to the veterinary hospital with hyperthermia, increased heart and respiratory rates, crackle in tracheal auscultation, loss of appetite and prostration. After hematological, ultrasound, radiographic examinations, and collection of tracheal lavages for culture and PCR, the definitive diagnosis of rhodococcosis was obtained, which is a bacterial disease that mainly affects foals, has a worldwide distribution and has a great economic impact on equine culture. Based on the results, treatment with azithromycin, rifampin, flunixin meglumine, sucralfate, ranitidine hydrochloride and amoxicillin with clavulanate was instituted, associated with nebulization with acetylcysteine diluted to 0.9% sodium hydrochloride solution. After a few weeks, there was no evolution in the results of the ultrasound and radiographic exams, however the hematological exams were within the reference levels, there was a significant clinical improvement, and the animal was discharged. It is noteworthy that early diagnosis was essential for the effectiveness of treatment and remission of clinical signs. Keywords: rhodococcosis; foals; rhodococcus equi.

Rhodococcus equi—Occurrence in Goats and Clinical Case Report

Background: Rhodococcus equi infection is commonly known in equine medicine to cause frequently fatal rhodococcosis. Infections in other species and people are also reported. Clinical manifestation in goats is relatively similar to horses and humans, but data regarding bacterium prevalence are scarce. Thus, the study aimed to estimate the occurrence of R. equi in goats. Methods: During post mortem examination, submandibular, mediastinal, and mesenteric lymph nodes were collected. Standard methods were used for bacteria isolation and identification. Results: A total of 134 goats were examined, and 272 lymph node samples were collected. R. equi was isolated from four animals. All four isolates carried the choE gene, and one also had traA and pVAPN plasmid genes. Conclusions: To the authors’ best knowledge, this is the first report of R. equi occurrence and genetic diversity in goats. The results may help create a model for treating rhodococcosis in other animal species and assessing the role of meat contamination as a potential source of human infection. This research should be considered a pilot study for further application of the goat as a model of R. equi infection in horses and humans.