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Clinical Microbiology and Infection :... Mar 2019Rhodococcus equi is a recognized cause of disease in humans, especially in individuals who are immunocompromised. Because diphtheroids are regarded as part of normal... (Review)
Review
BACKGROUND
Rhodococcus equi is a recognized cause of disease in humans, especially in individuals who are immunocompromised. Because diphtheroids are regarded as part of normal respiratory flora, the importance of R. equi as a pulmonary pathogen may not be fully appreciated and its prevalence may be underestimated. Most treatment recommendations for R. equi infection were established before antiretroviral drugs became available for human immunodeficiency virus/AIDS therapy, and therapeutic strategies may need to be updated.
OBJECTIVES
To review the role of R. equi as a cause of pulmonary infection; to highlight its importance for clinicians and microbiologists; and to challenge current approaches to treatment, whether in immunodeficient or immunocompetent individuals.
SOURCES
A PubMed search using combinations of the following terms: 'Rhodococcus (automatically including Corynebacterium) equi' AND 'pneumonia' OR 'pulmonary' infection, then cross-checking references in the resulting cases, case series and reviews.
CONTENT
We provide a review that details the challenges in the diagnosis, microbiology and pathogenesis of pulmonary infection caused by R. equi and the options for treatment.
IMPLICATIONS
Ten to 14 days of treatment may be effective for pneumonia due to R. equi. Our review suggests that longer courses of therapy are needed for cavitary lesions and lung masses. However, recommendations for excessively prolonged treatment of all pulmonary infections arose during a time when many cases occurred in individuals with AIDS and before effective antiretroviral therapy was available. We suggest that the rationale for prolonged therapy with multiple antibiotics needs to be re-evaluated.
Topics: AIDS-Related Opportunistic Infections; Actinomycetales Infections; Anti-Bacterial Agents; Disease Management; Humans; Immunocompromised Host; Lung; Pneumonia, Bacterial; Rhodococcus equi
PubMed: 29777923
DOI: 10.1016/j.cmi.2018.04.033 -
Journal of Veterinary Internal Medicine 2015Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments... (Review)
Review
Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments for R. equi with limited success. With a growing focus in the medical community on understanding the genetic basis of disease susceptibility, investigators have begun to evaluate the interaction of the genetics of the foal with R. equi. This review describes past efforts to understand the genetic basis underlying R. equi susceptibility and tolerance. It also highlights the genetic technology available to study horses and describes the use of this technology in investigating R. equi. This review provides readers with a foundational understanding of candidate gene approaches, single nucleotide polymorphism-based, and copy number variant-based genome-wide association studies, and next generation sequencing (both DNA and RNA).
Topics: Actinomycetales Infections; Animals; Genetic Predisposition to Disease; Horse Diseases; Horses; Rhodococcus equi
PubMed: 26340305
DOI: 10.1111/jvim.13616 -
Revista Chilena de Infectologia :... Jun 2016
Topics: Actinomycetales; Actinomycetales Infections
PubMed: 27598282
DOI: 10.4067/S0716-10182016000300011 -
Veterinary Research 2004Rhodococcus equi is an important cause of subacute or chronic abscessating bronchopneumonia of foals up to 3-5 months of age. It shares the lipid-rich cell wall envelope... (Review)
Review
Rhodococcus equi is an important cause of subacute or chronic abscessating bronchopneumonia of foals up to 3-5 months of age. It shares the lipid-rich cell wall envelope characteristic of the mycolata, including Mycobacterium tuberculosis, as well as the ability of pathogenic members of this group to survive within macrophages. The possession of a large virulence plasmid in isolates recovered from pneumonic foals is crucial for virulence. The plasmid contains an 27 kb pathogenicity island (PI) that encodes seven related virulence-associated proteins (Vaps), including the immunodominant surface-expressed protein, VapA. Only PI genes are differentially expressed when the organism is grown in macrophages in vitro. Ten of the PI genes, including six Vap genes, have signal sequences, suggesting that they are exported from the cell to interact with the macrophage. Different PI genes are regulated by temperature, pH, iron, oxidative stress and probably also by magnesium, all environmental changes encountered after environmental R. equi are inhaled in dust and are ingested into macrophages in the lung. The basis of pathogenicity of R. equi is its ability to multiply in and eventually to destroy alveolar macrophages. Infectivity is largely or exclusively limited to cells of the monocyte-macrophage lineage. Current evidence suggests that infection of foals with virulent R. equi results in some foals in subversion of cell-mediated immunity and development of an ineffective and sometimes lethal Th2-based immune response. Significant progress has been made recently in the development of R. equi-E. coli shuttle vectors, transformation and random and site specific mutagenesis procedures, all of which will be important in molecular dissection of the mechanisms by which R. equi subverts normal macrophage killing mechanisms and cell-mediated immunity.
Topics: Actinomycetales Infections; Animals; Animals, Newborn; Bronchopneumonia; Horse Diseases; Horses; Rhodococcus equi
PubMed: 15236672
DOI: 10.1051/vetres:2004024 -
Frontiers in Cellular and Infection... 2018Deficiency of leptin () and/or desensitization of leptin signaling () and elevated expression of suppressor of cytokine signaling-3 (SOCS3) reported in obesity are also... (Review)
Review
Deficiency of leptin () and/or desensitization of leptin signaling () and elevated expression of suppressor of cytokine signaling-3 (SOCS3) reported in obesity are also reported in a variety of pathologies including hypertriglyceridemia, insulin resistance, and malnutrition as the risk factors in host defense system. Viral infections cause the elevated SOCS3 expression, which inhibits leptin signaling. It results in immunosuppression by T-regulatory cells (Tregs). The host immunity becomes incompetent to manage pathogens' attack and invasion, which results in the accelerated infections and diminished vaccine-specific antibody response. Leptin was successfully used as mucosal vaccine adjuvant against . Leptin induced the antibody response to vaccination in mice. An integral leptin signaling in mucosal gut epithelial cells offered resistance against and infections. We present in this review, the intervention of leptin in lethal diseases caused by microbial infections and propose the possible scope and challenges of leptin as an adjuvant tool in the development of effective vaccines.
Topics: Actinomycetales Infections; Adjuvants, Immunologic; Animals; Clostridioides difficile; Clostridium Infections; Cytokines; Epithelial Cells; Helicobacter Infections; Helicobacter pylori; Hypertriglyceridemia; Immunity; Immunity, Mucosal; Insulin Resistance; Leptin; Malnutrition; Mice; Obesity; Parasitic Diseases; Phagocytosis; Rhodococcus equi; Risk Factors; Sepsis; Signal Transduction; Suppressor of Cytokine Signaling 3 Protein; Vaccination; Vaccines; Virus Diseases
PubMed: 29868503
DOI: 10.3389/fcimb.2018.00147 -
FEMS Microbiology Reviews Sep 2009The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and... (Review)
Review
The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and multiplies in macrophages and establishes its specific niche inside the host cell. Recent research into chromosomal virulence factors and into the role of virulence plasmids in infection and host tropism has presented novel aspects of R. equi infection biology and pathogenicity. This review will focus on new findings in R. equi biology, the trafficking of R. equi-containing vacuoles inside host cells, factors involved in virulence and host resistance and on host-pathogen interaction on organismal and cellular levels.
Topics: AIDS-Related Opportunistic Infections; Actinomycetales Infections; Animals; Bacterial Proteins; Gene Expression Regulation, Bacterial; Horse Diseases; Horses; Host-Pathogen Interactions; Humans; Macrophages; Rhodococcus equi; Virulence; Virulence Factors
PubMed: 19453748
DOI: 10.1111/j.1574-6976.2009.00181.x -
Journal of Clinical Microbiology Oct 2013Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related...
Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related bacteremia in an immunocompromised patient and review four additional cases of Gordonia bacteremia seen at our institution over the past 14 years. In addition, the existing literature on Gordonia infections is reviewed.
Topics: Actinomycetales; Actinomycetales Infections; Adult; Aged; Aged, 80 and over; Bacteremia; Catheter-Related Infections; Child, Preschool; Female; Humans; Immunocompromised Host; Male; Middle Aged
PubMed: 23884999
DOI: 10.1128/JCM.01449-13 -
Emerging Infectious Diseases May 2010
Topics: Actinomycetales Infections; Humans; Terminology as Topic; Tropheryma
PubMed: 20409378
DOI: 10.3201/eid1605.e1605 -
Microbiology and Molecular Biology... May 2021The development and spread of antimicrobial resistance are major concerns for human and animal health. The effects of the overuse of antimicrobials in domestic animals... (Review)
Review
The development and spread of antimicrobial resistance are major concerns for human and animal health. The effects of the overuse of antimicrobials in domestic animals on the dissemination of resistant microbes to humans and the environment are of concern worldwide. is an ideal model to illustrate the spread of antimicrobial resistance at the animal-human-environment interface because it is a natural soil saprophyte that is an intracellular zoonotic pathogen that produces severe bronchopneumonia in many animal species and humans. Globally, is most often recognized as causing severe pneumonia in foals that results in animal suffering and increased production costs for the many horse-breeding farms where the disease occurs. Because highly effective preventive measures for are lacking, thoracic ultrasonographic screening and antimicrobial chemotherapy of subclinically affected foals have been used for controlling this disease during the last 20 years. The resultant increase in antimicrobial use attributable to this "screen-and-treat" approach at farms where the disease is endemic has likely driven the emergence of multidrug-resistant (MDR) in foals and their environment. This review summarizes the factors that contributed to the development and spread of MDR , the molecular epidemiology of the emergence of MDR , the repercussions of MDR for veterinary and human medicine, and measures that might mitigate antimicrobial resistance at horse-breeding farms, such as alternative treatments to traditional antibiotics. Knowledge of the emergence and spread of MDR is of broad importance for understanding how antimicrobial use in domestic animals can impact the health of animals, their environment, and human beings.
Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Drug Resistance, Multiple; Humans; Rhodococcus equi; Soil
PubMed: 33853933
DOI: 10.1128/MMBR.00011-21 -
Emerging Infectious Diseases Sep 2022A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s....
A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s. We report the detection of MDR-RE 2287 outside the United States. Our finding highlights the risk for MDR-RE spreading internationally with horse movements.
Topics: Actinomycetales Infections; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Horse Diseases; Horses; Humans; Macrolides; Rhodococcus equi; Rifampin; United States
PubMed: 35997496
DOI: 10.3201/eid2809.220222