Rhodococcus Equi Infection Research Articles

Could Serum Collectin-11, surfactant protein-A and D be suitable biomarkers for assessing pulmonary damage caused by Rhodococcus equi infection in foals on large farms?

Could Serum Collectin-11, surfactant protein-A and D be suitable biomarkers for assessing pulmonary damage caused by Rhodococcus equi infection in foals on large farms?

First description of Rhodococcus equi infection in common bottlenose dolphin (Tursiops truncatus).

Rhodococcus equi is a terrestrial bacterium and a common pathogen in foals (Equus caballus), in which causes pneumonia. This report describes for the first time the infection caused by R. equi in a common bottlenose dolphin (Tursiops truncatus) stranded in the Calabrian coast, Italy. The post mortem examination of the animal revealed lesions in lung and colon. The animal was also positive to dolphin morbillivirus. The histological study showed lesions attributable to R. equi infection, such as pyogranulomatous bacterial pneumonia and chronic granulomatous colitis. Whole genome sequencing of the isolated strain confirmed its identification as R. equi.

Antimicrobial susceptibility of Rhodococcus equi strains isolated from foals in Chile

Rhodococcus equi is responsible for foal pneumonia worldwide, with a significant economic impact on the production and breeding of horses. In Chile, the first case was reported in 2000, and since then, its incidence has been increasing. Distinctive characteristics of R. equi as an intracellular pathogen in macrophages, emergence of virulence plasmids encoding surface lipoprotein antigens, and appearance of antibiotic resistance against macrolides and rifampicin have significantly complicated the treatment of R. equi pneumonia in foals. Therefore, in vitro susceptibility studies of first-line and newer antibiotics against R. equi are the first step to establishing effective treatments and optimizing new therapeutic options. The aim of the present study is to determine the susceptibility profile of fourteen strains of R. equi isolated from foals in Chile to several antibiotics of the macrolide group including azithromycin, amikacin, tildipirosin and gamithromycin as well as others such as rifampicin, doxycycline and ceftiofur. Identification of R. equi in collected isolates from foals in Chile has been performed by CAMP test and PCR based on detecting of the gene encoding the 16 S rRNA. The presence of genes encoding virulence plasmids was also determined using PCR. Results obtained have demonstrated presence of virulent R. equi strains in Chile. In vitro susceptibility pattern to different antibiotics has shown better results for doxycycline and rifampicin similar to previous studies performed. Current macrolides have been evaluated in order to consider alternative treatment options in a context of emerging resistance to classic macrolides and rifampicin, obtaining better results with gamithromycin (MIC range of 0.125 to 128 mg/ml) than with tildipirosin (MIC range of 16 to 128 mg/ml). An adequate diagnosis of bacterial susceptibility based on antibiograms is necessary to treat the Rhodococcus equi infection in foals.

P-075 Rhodococcus equi infection in a goat: Case report

P-075 Rhodococcus equi infection in a goat: Case report

Effect of plasma transfusion on serum amyloid A concentration in healthy neonatal foals and foals with failure of transfer of passive immunity.

Anecdotal evidence suggests plasma transfusions increase serum amyloid A (SAA) concentrations in healthy neonatal foals making this marker of inflammation inappropriate for therapeutic decision making in such animals. Administration of hyperimmune fresh frozen plasma (FFP) increases SAA concentration in healthy foals and in foals with failure of transfer of passive immunity (FTPI). Eighty-six healthy foals. Prospective cohort study. Foals <24 hours of age receiving plasma transfusion for treatment of FTPI (serum immunoglobulin G [IgG] concentrations <8g/L; n=17) or as a preventative measure for Rhodococcus equi infection (IgG >8g/L; n=33) were enrolled. A healthy nontransfused group of foals (IgG >8g/L; n=21) also was included. SerumamyloidA concentration was determined before (t0h) and after (t24h) administration of FFP. Changes in blood SAA concentration were assessed using linear regression models. No statistical differences were found in SAA concentration at t0h or t24h among the 3 groups (P > .05, for all comparisons). The variation in SAA concentration before (t0h) and after (t24h) plasma transfusion showed that administration of FFP was not associated with the changes in SAA concentration (P > .05). An association between SAA concentration at t0h and at 24 hours (P < .05) was identified, where foals with higher SAA concentration at t0h also had higher SAA concentration at t24h. Administration of FFP to newborn foals was not associated with changes in SAA concentration.

Evaluation of oxidative stress in foals with Rhodococcus equi infection-induced pneumonia for the judgment of therapeutic effect.

Forty-five foals with Rhodococcus equi infection and pneumonia symptoms were classified into a surviving group and a dead group. Using serum samples, the oxidative stress index (OSI) was determined at the first visit and the follow-up visit. The OSI of the surviving group was significantly lower at the follow-up than that at the first visit. No significant difference was observed between the OSI of the dead group at the first and follow-up visits. In the surviving group, treatment at the first visit mitigated inflammation and reduced OSI. However, in the dead group, poor response to the treatment provided at the first visit led to continued inflammation, and no change was observed the OSI.

Less Typical Courses of Rhodococcus equi Infections in Foals

This article aims to present several interesting and less typical courses of Rhodococcus equi infections in foals, collected during the 2019-2021 foaling seasons in some Polish studs. The study was conducted by the Division of Veterinary Epidemiology and Economics, Warsaw University of Life Sciences-SGGW, and concentrated on ultrasonographic contribution to diagnostics and treatment of the disease. Among many standard cases of rhodococcal pneumonia, some rare ones occurred. The aforementioned issues include the potential contribution of rhodococcal infection to a grave outcome in a prematurely born filly, lost as a yearling, so-called "extrapulmonary disorders" (EPD), a hypothesis of inherited immunodeficiency with grave outcome in a breeding dam line from one stud, and macrolide-induced anhidrosis. The main benefit of this report would be to supplement the general picture of clinical rhodococcosis.

Population structure and genomic footprints of selection in five major Iranian horse breeds.

The genetic structure and characteristics of Iranian native breeds are yet to be comprehensibly investigated and studied. Therefore, we employed genomic information of 364 Iranian native horses representing the Asil (n=109), Caspian (n=40), Dareshuri (n=44), Kurdish (n=95), and Turkoman (n=76) breeds to reveal the genetic structure and characteristics. For these and 19 other horse breeds, principal component analysis, Bayesian model-based, Neighbor-Net, and bootstrap-based TreeMix approaches were applied to investigate and compare their genetic structure. Additionally, three haplotype-based methods including haplotype homozygosity pooled, integrated haplotype score, and number of segregating sites by length were applied to trace genomic footprints of selection of Asil, Caspian, Dareshuri, Kurdish, and Turkoman groups. Then, the Mahalanobis distance based on the negative-log10 rank-based P-values was estimated based on the haplotype homozygosity pooled, integrated haplotype score, and number of segregating sites by length values. Asil, Caspian, Dareshuri, Kurdish, and Turkoman can be categorized into five different genetic clusters. Based on the top 1% of Mahalanobis distance based on the negative-log10 rank-based P-values of SNPs, we identified 24 SNPs formerly reported to be associated with different traits and >100 genes undergoing selection pressures in Asil, Caspian, Dareshuri, Kurdish, and Turkoman. The detected QTL undergoing selection pressures were associated with withers height, equine metabolic syndrome, overall body size, insect bite hypersensitivity, guttural pouch tympany, white markings, Rhodococcus equi infection, jumping test score, alternate gaits, and body weight traits. Our findings will aid to have a better perspective of the genetic characteristics and population structure of Asil, Caspian, Dareshuri, Kurdish, and Turkoman horses as Iranian native horse breeds.

Rhodococcus equi Infection in a Dairy Goat in Italy

Rhodococcus equi Infection in a Dairy Goat in Italy

Ion Channel and Ubiquitin Differential Expression during Erythromycin-Induced Anhidrosis in Foals.

Simple SummaryMacrolide treatment for Rhodococcus equi infections can result in severe adverse effects including hyperthermia and temporary anhidrosis. Despite these potentially lethal side effects, and a lack of understanding of the mechanisms causing them, macrolide drugs remain the recommended treatment for R. equi infections in foals. To better understand the molecular biology behind these adverse effects, we performed a differential gene expression study of skin biopsies of six healthy macrolide-treated foals experiencing anhidrosis. In total, 132 transcripts were significantly differentially expressed, and these genes belonged to functional ontologies relevant to sweat function. Genes involved in ubiquitination and ion-channel function were upregulated during the anhidrotic timepoint. These biological mechanisms play an important role in equine idiopathic anhidrosis and sweat gland function and warrant further investigation as potential targets for avoiding macrolide-induced temporary anhidrosis.Macrolide drugs are the treatment of choice for Rhodococcus equi infections, despite severe side-effects temporary anhidrosis as a. To better understand the molecular biology leading to macrolide induced anhidrosis, we performed skin biopsies and Quantitative Intradermal Terbutaline Sweat Tests (QITSTs) in six healthy pony-cross foals for three different timepoints during erythromycin administration—pre-treatment (baseline), during anhidrosis and post-recovery. RNA sequencing of biopsies followed by differential gene expression analysis compared both pre and post normal sweating timepoints to the erythromycin induced anhidrosis episode. After Bonferroni correction for multiple testing, 132 gene transcripts were significantly differentially expressed during the anhidrotic timepoint. Gene ontology analysis of the full differentially expressed gene set identified over-represented biological functions for ubiquitination and ion-channel function, both biologically relevant to sweat production. These same mechanisms were previously implicated in heritable equine idiopathic anhidrosis and sweat gland function and their involvement in macrolide-induced temporary anhidrosis warrants further investigation.

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.

Equine antimicrobial therapy: Current and past issues facing practitioners.

Equine antimicrobial therapy has advanced over time with the availability of increasing pharmacokinetic and pharmacodynamic studies in horses, allowing for greater evidence-based clinical decision-making. However, many challenges to optimal antimicrobial therapy remain and further research is needed to address these areas. There are a limited number of approved antimicrobials for use in horses, which creates a need for compounded preparations for clinicians. Extra-label drug use is commonplace in equine practice, which warrants continual education of veterinarians about policies and updates. Performance and competitive horses have their own unique concerns when it comes to antimicrobial use and drug testing. In keeping with the use of a broader range of antimicrobials over time, antimicrobial resistance is emerging as an important issue facing veterinary medicine, including equine practice. Another challenge is that of drug interactions and adverse drug events for which there are little scientific data available for horses, especially for critically important diseases such as Rhodococcus equi infection. Finally, much progress has been made in the availability of equine-specific antimicrobial susceptibility break points. These aid clinicians in interpreting culture and susceptibility results and antimicrobial selection. Even with these advances, continuing education and further research are needed in this area.

Plasma lipidome of healthy and Rhodococcus equi-infected foals over time.

Many foals that develop thoracic ultrasonographic lesions as a result of Rhodococcus equi infection heal on their own. However, most of these foals receive antimicrobials because foals at risk of developing clinical pneumonia cannot be identified. Untargeted lipidomics is useful to identify candidate biomarkers. (a) To describe the changes that occur in foal lipidomics as a result of ageing (birth to 8weeks) and (b) To compare these results with those observed in foals after experimental infection with R. equi. Experimental study. Healthy newborn foals (n=9) were challenged with R. equi intratracheally the first week of life. Foals were treated with antimicrobials if they developed clinical pneumonia (n=4, "clinical group") or were closely monitored if they showed no signs of disease (n=5 "subclinical group"). An unchallenged group (n=4) was also included. All foals were free of disease (transtracheal wash fluid evaluation and culture as well as thoracic ultrasonography) by 8weeks of life. Plasma lipidomics was determined by LC-MS weekly for the study duration (8weeks). Both ageing and experimental infection altered the foal's plasma lipidome as demonstrated by multivariate statistical analysis. The intensities of 31 lipids were altered by ageing and 12 by infection (P<.05). Furthermore, nine lipids changed by more than twofold between clinical and subclinical groups. The number of foals is limited. Foals were experimentally challenged with R. equi. Ageing and R. equi infection induced changes in the plasma lipidome of foals. These experimental results provide the background for future work in the discovery of earlier biomarkers of R. equi pneumonia. Early identification of foals at risk of developing clinical pneumonia is key in order to decrease antimicrobial use and development of antimicrobial resistance.

Rhodococcus equi infection in Marwari male foal: A case report

A 2-months-old Marwari male foal was anorectic, febrile, and showed difficulty in breathing. Haematology revealed anemia and severe neutrophilic leukocytosis with left shift. Symptomatic treatment was given, however the animal died within 48 hours. On necropsy, multifocal, raised, well-demarcated, off-white to grey, firm, abscesses of 10 to 15 cm diameter effaced the normal lung parenchyma. Colon wall showed multifocal to coalescing, raised, well-demarcated, off-white to grey, firm, transmural, variable-sized abscesses. On histopathological examination, the lung showed pyogranulomatous bronchopneumonia. Frequently cytoplasm of macrophages was filled with numerous fine basophilic bacteria. Colon showed necro-pyogranulomatous inflammation with intracytoplasmic bacilli. On Taylor’s Gram staining of tissue, the cytoplasm of macrophages was filled with numerous blue Gram-positive bacilli. Sample collected at the time of necropsy were subjected to microbiological and molecular investigation. Based on colony morphology, bacterial morphology, gram reactivity, and biochemical tests, the isolates were presumptively diagnosed as Rhodococcus equi (R.equi). Further, the isolates were confirmed as R. equi by species-specific primers. Moreover, all the isolates were also found positive for the presence of virulence-associated antigens (VapA), indicative of the pathogenic nature of the isolates. This case report described R. equi induced bronchopneumonia, and colitis in foal

Rhodococcus infection in HIV infected patients: Clinical presentation and diagnoses

Background: Rhodococcus Equi is a gram positive coryneform bacterium that causes zoonotic infections in the animal kingdom and ias been reported in immunocompromised humans as emerging opportunistic pathogens. Methods & Materials: Retrospective review of patients electronic records from y 2006 to 2011, that were microbiologically confirmed rhodococcus equi infection. Results: A total of 26 patients were HIV positive with a median CD4 ount of 14 cells/ul.Mode of hiv transmission were 40.7% injecting drug use (11 patients), 51.7% sexual contact and 7.6% were unknown. None of the patients had a known history of contact with any animal sources for rhodococcus. 70.4%(19) patients were antiretroviral naïve at the time of presentation, 48%(13) patients had other concurrent AIDS defining illnesses. Pulmonary involvement with confirmed bacteraemia was seen in 77.8% (21) cases.18.5% (5) had primary bacteraemia with no other source of infection. One patient had isolated right suppurative lymphadenitis. Cavitatory pneumonia were seen in majority of the cases. In comparison to the available literature data, we saw a similar sensitivity pattern for most of our isolates with a resistance towards penicillin and ampicillin. Most patients were treated with a combination of antibiotics Conclusion: Increase awareness of rhodococcus infection as an opportunistic pathoegn,prompt microbiological diagnosis and combined antimicrobial treatment seem to be the cornerstone pf effective treatment. Early initiation of antiretroviral treatment and adherence seem to be necessary to improve outcome.

Rhodococcus equi infection as inaugural manifestation of idiopathic CD4+ lymphopenia: A rare entity and a therapeutic challenge

We report a case of disseminated infection by Rhodococcus equi as the inaugural manifestation of idiopathic T-CD4+ lymphopenia. We aim to demonstrate our diagnostic and therapeutic approach and focus on the major dilemmas arising from the lack of scientific evidence regarding best clinical practice of this infection in humans.

Indications for the use of highest priority critically important antimicrobials in the veterinary sector.

Among the measures taken to preserve the clinical efficacy of highest priority critically important antimicrobials (HP-CIAs), the WHO has recommended avoiding their use in food-producing animals. Little is known regarding the indications for which different antimicrobial classes are used in animals, even in countries where data on antimicrobial use are available. To outline, in a narrative review, the diseases for which HP-CIAs are used in veterinary medicine, highlighting incongruences with international guidelines and disease conditions where effective alternatives to HP-CIAs are missing. Scientific literature, national reports and expert opinion were used to describe the indications for the use of HP-CIAs in the main food-producing (pigs, cattle and poultry) and companion (horses, dogs and cats) animal species. The most common indications for use of HP-CIAs are enteric and respiratory infections in pigs, cattle and poultry, urogenital infections in dogs and cats and respiratory infections in horses. In some instances, no valid and convenient alternatives to colistin and macrolides are available against certain porcine enteric and bovine respiratory pathogens. Effective, legal and convenient alternatives to HP-CIAs are also lacking for managing common infections in cats, for which oral administration is difficult, Rhodococcus equi infections in horses, some enteric and respiratory infections in poultry and MDR infections in all companion animal species. Future research and stewardship programmes should focus on the disease conditions identified by this review to reduce the use of HP-CIAs in the veterinary sector.

269 Rare Case of Pulmonary Necrotic Rhodococcus Equi Infection in a Kidney Pancreas Transplant Recipient.

269 Rare Case of Pulmonary Necrotic Rhodococcus Equi Infection in a Kidney Pancreas Transplant Recipient.

Clinical and pathological findings of Rhodococcus equi infection in foals

ABSTRACT: Infection by Rhodococcus equi is considered one of the major health concerns for foals worldwide. In order to better understand the disease’s clinical and pathological features, we studied twenty cases of natural infection by R. equi in foals. These cases are characterized according to their clinical and pathological findings and immunohistochemical aspects. Necropsy, histologic examination, bacterial culture, R. equi and Pneumocystis spp. immunohistochemistry were performed. The foals had a mean age of 60 days and presented respiratory signs (11/20), hyperthermia (10/20), articular swelling (6/20), prostration (4/20), locomotor impairment (3/20) and diarrhea (3/20), among others. The main lesions were of pyogranulomatous pneumonia, seen in 19 foals, accompanied or not by pyogranulomatous lymphadenitis (10/20) and pyogranulomatous and ulcerative enterocolitis (5/20). Pyogranulomatous osteomyelitis was seen in 3 foals, one of which did not have pulmonary involvement. There was lymphoplasmacytic (4/20), lymphoplasmacytic and neutrophilic (1/20) or pyogranulomatous arthritis (1/20), affecting multiple or singular joints. Immunohistochemistry revealed to be a valuable tool for the detection of R. equi, confirming the diagnosis in all cases. Furthermore, pulmonary immunostaining for Pneumocystis spp. demonstrates that a coinfection with R. equi and this fungal agent is a common event in foals, seen in 13 cases.

Pathologic characteristics for the Rhodococcus equi infection in foals in Jeju

Pathologic characteristics for the Rhodococcus equi infection in foals in Jeju