Rhodococcus equi, primer reporte de un caso de enfermedad diseminada en el Perú / Rhodococcus equi, first case report of disseminated disease in Peru

Resumen Presentamos el caso de un paciente con infección por virus de inmunodeficiencia humana (VIH) con recuento de LTCD4+ 49 céls/mm3, que consultó por un cuadro de siete meses de baja de peso, dolor abdominal, diarrea crónica y lesiones cutáneas gomosas. El mielocultivo y hemocultivos fueron positivos para Rhodococcus equi. Además, se observaron lesiones histológicas en piel e intestino compatibles con este agente como malacoplaquia, reacción granulomatosa y cuerpos de Michaelis-Gutmann. Se descartó compromiso pulmonar mediante tomografía de tórax. Recibió terapia antibacteriana combinada con claritromicina, imipenem y vancomicina. A pesar del tratamiento, el paciente evolucionó desfavorablemente y falleció.

Abstract We present the case of a patient with human immunodeficiency virus (HIV) with a LTCD4 + 49 cells/mm3, who was admitted due to a seven-month period of weight loss, abdominal pain, chronic diarrhea and rubbery skin lesions. Myeloculture and blood cultures were positive for Rhodococcus equi. In addition, histological lesions in the skin and intestine compatible with this agent were observed, such as malacoplachy, granulomatous reaction and Michaelis-Gutmann bodies. Pulmonary involvement was ruled out by chest tomography. The patient received antibacterial therapy combined with clarithromycin, imipenem, and vancomycin. Despite the treatment, the patient evolved unfavorably and died.

Clinical and pathological findings of Rhodococcus equi infection in foals / Achados clínicos e patológicos da infecção por Rhodococcus equi em potros

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.(AU)

Infecção por Rhodococcus equi é considerado um dos maiores problemas sanitários para potros em todo o mundo. Para melhor compreender a apresentação clínica e patológica da enfermidade, foram avaliados vinte casos de infecção natural por R. equi em potros. Os casos são caracterizados de acordo com seus achados clínicos e patológicos e aspectos imuno-histoquímicos. Foram realizados exames de necropsia, histologia, bacteriologia e imuno-histoquímica para R. equi e Pneumocystis spp. Os potros tinham idade media de 60 dias e apresentaram sinais respiratórios (11/20), hipertermia (10/20), aumento de volume articular (6/20), prostração (4/20), distúrbios locomotores (3/20) e diarreia (3/20), entre outros. As lesões mais importantes eram pneumonia piogranulomatosa, vista em 19 potros, acompanhada ou não por linfadenite piogranulomatosa (10/20) e enterocolite ulcerativa (5/20). Osteomielite piogranulomatosa foi constatada em três potros, um dos quais não apresentava envolvimento pulmonar. Artrites afetando uma ou múltiplas articulações eram caracterizadas por infiltrado linfoplasmocítico (4/20), linfoplasmocítico e neutrofílico (1/20) e piogranulomatoso (1/20). A imuno-histoquímica demonstrou ser uma ferramenta valiosa na detecção de R. equi, permitindo confirmar o diagnóstico em todos os casos avaliados. Além disso, a imuno-histoquímica para Pneumocystis spp. demonstra que a coinfecção por R. equi e o agente fúngico é um evento frequente em potros, constatado em 13 casos.(AU)

Rhodococcus equi como causa de neumonía en el síndrome de inmunodeficiencia adquirida / Rhodococcus equi as a cause of pneumonia in the acquired immunodeficiency syndrome

RESUMEN Rhodococcus equi es un microorganismo emergente asociado a infecciones oportunistas en individuos inmunocomprometidos, especialmente en pacientes con infección por virus de inmunodeficiencia humana. Se desarrolló una búsqueda en la Biblioteca Virtual de Infomed, fueron revisados 215 trabajos científicos sin limitación de año y país, seleccionándose 55. El rhodococcus es un patógeno intracelular capaz de crecer y persistir dentro de los macrófagos que expresan en su superficie el receptor Mac-1 (CD11b/CC18), y posteriormente destruirlos. La manifestación clínica más frecuente es la neumonía de comienzo insidioso y en su evolución natural tiende a la cavitación. El diagnóstico se realiza mediante su identificación en cultivo de muestras de tejido afectado. Los hemocultivos son positivos en el 50% de los inmunodeprimidos En el diagnóstico radiográfico, los hallazgos más comunes referidos en la literatura científica son el compromiso lobar y la cavitación. La particular evolución que experimentan los pacientes con síndrome de inmunodeficiencia adquirida y neumonía por R. equi, obliga a implementar esquemas terapéuticos basados en antimicrobianos con actividad bactericida intracelular, administrados inicialmente por vía intravenosa y durante un tiempo prolongado e incluso la cirugía. La infección por R. equi es una complicación infrecuente en pacientes con síndrome de inmunodeficiencia adquirida, pero con una elevada tasa de letalidad, por lo que debe ser sospechado en pacientes que presenten una infección respiratoria de curso inhabitual. El diagnóstico precoz, el tratamiento antimicrobiano combinado y prolongado y el inicio de la Terapia Antiretroviral de Gran Actividad en forma temprana pueden mejorar la evolución y el pronóstico de estos pacientes.

ABSTRACT Rhodococcus equi is an emergent microorganism associated to opportunistic infections in immune-compromised individuals, especially in patients infected with the human immunodeficiency virus. A search was carried out in the Virtual Library of Infomed; 215 scientific works were reviewed without limits of publication years and countries. From them, 55 were chosen. Rhodococcus equi is an intracellular pathogen that is able to grow and live inside the macrophages expressing the Mac-1 (CD11b/CC18) receptor in the surface and destroying them later. The most common clinical manifestation is insidious beginning pneumonia, tending to cavitation in its natural evolution. The diagnosis is made through identification in culture of affected tissues samples. Blood cultures are positive in 50 % of the immune-depressed people. At the radiographic diagnosis, the most common findings referred to in the scientific literature are lobar compromise and cavitation. The particular evolution of the patients with acquired immune-deficiency syndrome and pneumonia due to Rhodococcus equi forces the implementation of therapeutic schemes based on antimicrobials with intracellular bactericide activity, administered firstly intravenously and during a long time, and even to perform the surgery. Rhodococcus equi infection is an infrequent complication in patients with acquired immunodeficiency syndrome, but having a high lethality rate, therefore it should be suspected in patients presenting a respiratory infection of unusual curse. The precocious diagnosis, combined and prolonged antimicrobial treatment and early beginning of the highly active antiretroviral therapy could improve the evolution and prognosis of these patients.

Pathologic characteristics for the Rhodococcus equi infection in foals in Jeju / 대한수의학회지

From 1996 to 2014, 14 foals from nine farms in Jeju were diagnosed with a Rhodococcus equi infection. Clinically, most foals showed characteristic respiratory signs, including hyperthermia and dyspnea. The seasonal occurrence of R. equi infection in foals was higher in summer, such as June (eight foals; 57.1%) and July (four foals; 28.6%), than in the other seasons. The major cases of R. equi infections were observed among two-month-old (eight foals; 57.1%) and three-month-old (three foals; 21.4%) foals. Histopathologically, bronchopneumonia, abscess, and granulomatous pneumonia were the most prevalent lesions in the lungs of foals. Colonic ulcers and submucosal abscesses were found in a foal. Some foals showed granulomatous lymphadenitis and abscesses in the mesenteric and other lymph nodes. According to the polymerase chain reaction using 10 tissue samples of foals and nine R. equi isolates, the vapA gene was detected in 11/11 (100%) foals. Immunohistochemical staining using the anti-VapA monoclonal antibody was applied to detect the R. equi VapA antigen in the organs of foals. R. equi VapA antigens were demonstrated in most lungs and some mesenteric and hilar lymph nodes of 13 foals. Isolated virulent R. equi VapA bacteria showed high sensitivity to gentamicin, quinolones, rifampin, and vancomycin.

Absceso glúteo por Rhodococcus Equi: presentación atípica de enfermedad emergente / Gluteus abscess due to RhodococcusEqui: atypical presentation of emerging disease

Resumen Rhodococcusequi, bacteria aislada principalmente en potros, se considera en la actualidad un patógeno zoonótico emergente en seres humanos, la mayoría inmunocomprometidos, coincidiendo con la epidemia de VIH y los avances en la medicina de trasplantes y la quimioterapia del cáncer, lo que justifica la revisión sobre su patogenia, características clínicas, diagnóstico y tratamiento. Más frecuente en hombres que en mujeres, el inicio de las infecciones es generalmente insidioso y los síntomas que presentan varían según el sitio de la infección, la enfermedad respiratoria, caracterizada por neumonía necrosante es la manifestación más común, y tiende a seguir un curso subagudo, mientras las personas inmunocompetentes son afectadas con baja frecuencia y suelen presentarse con enfermedad localizada. Las infecciones de la piel o partes blandas, incluyendo abscesos, son poco frecuentes incluso en huéspedes inmunocomprometidos y están usualmente relacionadas con contaminación ambiental. El laboratorio de microbiología juega un papel clave en la identificación del organismo, ya que este puede confundirse con flora normal de la piel. El caso que se presenta corresponde a una paciente adulta inmunocompetente, con infección de herida quirúrgica por R equiluego de una cirugía estética, requirió tratamiento antibiótico, múltiples lavados quirúrgicos y debridamientos, más drenaje de absceso, con mejoría del proceso infeccioso. Este caso sugiere la importancia clínica de la identificación precisa de patógenos inusuales, capaces de entorpecer la evolución normal de un proceso quirúrgico y de producir un alto costo de atención de salud y el alcance medidas preventivas relacionadas con la vigilancia de la salud.

Abstract Rhodococcusequi, a bacterium isolated mainly in foals, is currently considered an emerging zoonotic pathogen in humans, most of them immunocompromised, coinciding with the HIV epidemic and advances in transplant medicine and cancer chemotherapy, which justifies the review on its pathogenesis, clinical characteristics, diagnosis and treatment. More frequent in men than in women, the onset of infections is usually insidious and the symptoms they present vary according to the site of infection, the respiratory disease, characterized by necrotizing pneumonia is the most common manifestation, and tends to follow a subacute course , while immunocompetent people are affected with low frequency and usually have localized disease. Infections of the skin or soft tissues, including abscesses, are rare even in immunocompromised hosts and are usually related to environmental contamination. The microbiology laboratory plays a key role in the identification of the organism, since it can be confused with normal flora of the skin. The case presented corresponds to an adult immunocompetent patient, with surgical wound infection by R equiafter cosmetic surgery, required antibiotic treatment, multiple surgical washes and debridements, and abscess drainage, with improvement of the infectious process. This case suggests the clinical importance of the precise identification of unusual pathogens, capable of obstructing the normal evolution of a surgical process and of producing a high cost of health care and the scope of preventive measures related to health surveillance.

Biofilm formation by Rhodococcus equi and putative association with macrolide resistance / Formação de biofilme por Rhodococcus equi e possível associação com resistência a macrolídeos

Rhodococcus equi is a facultative intracellular pathogen, which cause severe pyogranulomatous pneumonia in foals and tuberculosis-like lesions in humans. Its ability to form biofilm was described in strains isolated from chronic diseases associated to treatment failures in humans. This study aimed to verify the biofilm formation by 113 R. equi isolated from equine samples (clinical and fecal) using two different methods (biofilm-culturing with and without additional glucose and epifluorescence microscopy). We also aimed to determine the efficacy of azithromycin, clarithromycin and erythromycin on R. equi in established biofilm. We found 80.5% (26/41) and 63% (58/72) biofilm-positive isolates, in fecal and clinical samples, respectively. The additional glucose increased the biofilm formation by R. equi fecal samples, but not by clinical samples. The antimicrobials tested herein were not able to eradicate R. equi in biofilm even at higher concentrations. This is the first study showing the biofilm formation by R. equi isolated from equine samples. Our findings indicate that R. equi biofilm-producers may be more resistant to the antimicrobials evaluated. Further studies are warranted to test this hypothesis...

Rhodococcus equi é um patógeno intracelular facultativo, o qual causa pneumonia piogranulosa severa em potros e lesões semelhantes à tuberculose em humanos. A sua capacidade de formar biofilme foi descrita em cepas humanas, isoladas a partir de doenças crônicas associadas a falhas de tratamento. Este estudo teve como objetivo verificar a formação de biofilme por 113 cepas de R. equi, isoladas a partir de amostras de equinos (clínicas e fecais), utilizando-se dois diferentes métodos (biofilme em cultura - com e sem adição de glicose - e microscopia de epifluorescência). Além disso, buscou-se determinar a eficácia da azitromicina, claritromicina e eritromicina sobre biofilme consolidado de R. equi. Verificou-se 80,5% (26/41) e 63% dos isolados (58/72) positivos para formação de biofilme, em amostras fecais e clínicas, respectivamente. A adição de glicose amentou a formação de biofilme em amostras fecais, mas não em amostras clínicas. Os antimicrobianos aqui testados não foram capazes de erradicar R. equi em biofilme consolidado, mesmo em concentrações elevadas. Este é o primeiro estudo a demonstrar a formação de biofilme por cepas de R. equi isoladas a partir de amostras de equinos. Os resultados indicam que os isolados de R. equi produtores de biofilme podem ser mais resistentes aos antimicrobianos avaliados. Estudos adicionais são necessários para testar essa hipótese...

Pneumonia due to Rhodococcus equi in a non-Hodgkin's lymphoma patient: case report

The authors reported a lung infection by Rhodococcus equi in a 25 years-old male patient admitted to hospital with cough, dyspnea, fever, and previous diagnosis of pleural effusion. R. equi was isolated from pleural fluid and the patient acquired nosocomial infection by Acinetobacter baumannii, isolated from chest drain. The patient was treated with antibiotics. During hospitalization, he was diagnosed with non-Hodgkin lymphoma of precursor T-cell lymphoblastic lymphoma subtype in biopsy of pleura. After undergoing surgery for pulmonary decortication for drain empyema, the patient died due to septicemia(AU)

Los autores informan de una infección pulmonar por Rhodococcus equi en un paciente masculino de 25 años que fuera hospitalizado con tos seca, disnea, fiebre y diagnóstico previo de derrame pleural. R. equi se aisló del líquido pleural y el paciente adquiere una infección nosocomial con Acinetobacter baumannii aisladas de un drenaje torácico. El paciente recibió tratamiento con antibióticos y, durante la hospitalización, fue diagnosticado linfoma no Hodgkin subtipo de linfoma linfoblástico de precursoras de células T en la biopsia pleural. Después de la cirugía para decorticación pulmonar para la fuga de empiema, el paciente falleció debido a una septicemia(AU)

Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi / Melaleuca alternifolia activity in nanoformulations and terpinen-4-ol against Rhodococcus equi isolates

Rhodococcus equi é o agente etiológico da rodococose equina, importante doença respiratória de potros. Especialmente na última década, a emergência de cepas resistentes aos antimicrobianos empregados no tratamento da rodococose tem sido relatada. Nesse sentido, há a necessidade de estudos envolvendo terapias alternativas e novas tecnologias, incluindo o uso de plantas medicinais e nanotecnologia. Neste trabalho utilizou-se Melaleuca alternifolia nas seguintes formulações: óleo livre, nanocápsula, nanoemulsão e a combinação de óleo livre com nanocápsula e com nanoemulsão, além do seu composto majoritário, terpinen-4-ol, a fim de verificar a atividade antimicrobiana frente a isolados de R. equi de diferentes origens. Utilizou-se o método de microdiluição em caldo na determinação das concentrações inibitória mínima (CIM) e bactericida mínima (CBM) das diferentes formulações frente aos isolados (n=24). Verificou-se baixo potencial para atividade antibacteriana de M. alternifolia na formulação de óleo livre. Todavia, essa atividade foi potencializada quando se incorporou o óleo essencial às nanoformulações. O composto terpinen-4-ol demonstrou potencial atividade antibacteriana quando incorporado ao óleo essencial e quando utilizado isoladamente. Verificou-se que tanto M. alternifolia quanto terpinen-4-ol testados possuem atividade antimicrobiana contra isolados de R. equi, sugerindo seu emprego em estudos avaliando seu potencial para o tratamento da rodococose.

Rhodococcus equi causes rodococose in horses, characterized by bronchopneumonia in foals. Due to reports of antimicrobial resistance, it is important to develop studies involving alternative therapies and new technologies, including the use of medicinal plants and nanotechnology. In this work, the plant Melaleuca alternifolia in oil free formulations, nanocapsule, nanoemulsion and the combination of free and nanocapsule oil nanoemulsion, besides its major compound, terpinen-4-ol, were used in order to verify antimicrobial activity against isolates of R. equi. The broth microdilution method was employed to determine the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of different formulations against 24 isolates. There was low antibacterial activity of M. alternifolia in oil free formulation; however, it was observed that the activity was enhanced when incorporated as essential oil the nanoformulations. The major compound, terpinen-4-ol, showed bactericidal and bacteriostatic activity when used alone. It is suggested that M. alternifolia, in association with nanocarriers systems, as well as terpinen -4-ol, presents potential for future studies concerning the equine rodococosis therapy.

Malacoplaquia pulmonar associada à imunodeficiência por HTLV-1 e HIV / Pulmonary malakoplakia associated with immunodeficiency by HTLV-1 and HIV

Malakoplakia is a rare chronic inflammatory disease often confused with neoplasia. In this paper we report two cases of pulmonary Malakoplakia, both with typical clinical diagnosis of tuberculosis and lung cancer. A patient with human T-lymphotropic virus type I (HTLV-1) and diagnosis of adult T-cell leukemia/lymphoma, and another patient with human immunodeficiency virus (HIV), which was treated for tuberculosis, but, after pulmonary lobectomy, was evidenced Rodococosis equi, progressed to death...

Malacoplaquia é uma rara doença inflamatória crônica muitas vezes confundida com neoplasia. Neste artigo, relatam-se dois casos de malacoplaquia pulmonar, ambos com quadro clínico sugestivo de tuberculose e neoplasia pulmonar. Uma paciente com vírus T-linfotrópico humano tipo I (HTLV-1) e diagnóstico de leucemia/linfoma de células T do adulto, e um paciente com vírus da imunodeficiência humana (HIV), tratado para tuberculose, mas após lobectomia pulmonar foi evidenciado Rodococose equi, evoluindo para óbito...

Infección por Rhodococcus equi en pacientes con SIDA: Análisis retrospectivo de 13 pacientes en Argentina / Rhodococcus equi infection in AIDS patients: Retrospective analysis of 13 patients in Argentina

Introduction: Rhodococcus equi is a gram positive coccoid rod that causes pulmonary infections in immunosuppressed patients. Methods: We retrospectively analyzed epidemiological, clinical, microbiological, radiological, and immunological features as well as the outcomes of 13 AIDS patients with R. equi infection. Results: Between January 1994 and December 2012, 13 patients attending the AIDS department of the Infectious Diseases reference hospital in Buenos Aires were diagnosed with R. equi infection. All were men, the median age was 27 years. At the time of diagnosis, the median of CD4+ T cell counts was 11 cells/μl Twelve patients presented pulmonary disease with isolation of the microorganism from sputum or bronchoalveolar lavage; in the other patient the diagnosis was postmortem with positive culture of cerebrospinal fluid. The most frequent clinical manifestations were fever, haemoptysis, and weight loss. The predominant radiological finding was lobe consolidation with cavitation. Nine patients died after a median survival of 5.5 months. In all of them, cultures persisted positive until the last admission. The other 4 patients did continue clinical follow-ups. Conclusion: The insidious course of R. equi disease and the difficulties in the isolation of the microorganism contribute to the delay in the diagnosis and to the high mortality rate of this opportunistic infection.

Introducción: Rhodococcus equi es un cocobacilo grampositivo que provoca compromiso pulmonar en pacientes inmunodeprimidos. Métodos: En el presente trabajo se analizaron de manera retrospectiva los hallazgos epidemiológicos, clínicos, microbiológicos, imagenológicos, inmunológicos y la evolución de 13 pacientes con SIDA y enfermedad por R. equi. Resultados: Entre enero de 1994 y diciembre de 2012, 13 pacientes internados en la División de VIH/SIDA del hospital de referencia para Enfermedades Infecciosas de la ciudad de Buenos Aires egresaron con diagnóstico de enfermedad por R. equi. Todos eran varones y la mediana de edad fue 27 años. La mediana de linfocitos T CD4+ fue de 11 céls/μl Doce pacientes presentaron enfermedad pulmonar con aislamiento del microorganismo del esputo o del lavado bronco-alveolar; en el restante se recibió post mortem el cultivo positivo de líquido cefalorraquídeo. Las manifestaciones clínicas más frecuentes fueron fiebre, hemoptisis y pérdida de peso. La imagen radiológica predominante fue la consolidación con cavitación. Nueve pacientes fallecieron, con una mediana de supervivencia de 5,5 meses. En todos ellos el cultivo persistió positivo hasta la última internación. Los cuatro restantes abandonaron los controles y no pudieron ser evaluados en el tiempo. Conclusión: El curso insidioso de la enfermedad por R. equi y las dificultades en la identificación del microorganismo, contribuyen al retardo en el diagnóstico y a la elevada mortalidad de esta infección oportunista en esta población de pacientes.

Genotypic and phenotypic detection of efflux pump in Rhodococcus equi

The req_39680 gene, associated to a putative efflux system, was detected in 60% (54/90) of R. equi isolates by PCR. The phenotypic expression of efflux mechanism was verified in 20% of the isolates using ethidium bromide. For the first time, the expression of efflux mechanism was demonstrated in R. equi.

Perfil de suscetibilidade antimicrobiana e presença do gene vapA em Rhodococcus equi de origem humana, ambiental e equina / Susceptibility profile of Brazilian Rhodococcus equi isolates to different antimicrobial classes and the presence of vapA gene

Rhodococcus equi é um micro-organismo intracelular facultativo, agente etiológico da rodococose, uma importante enfermidade que acomete principalmente potros com menos de seis meses de idade, causando a morte geralmente em decorrência de lesões pulmonares. Este agente também tem potencial zoonótico e emergiu como um patógeno oportunista no mundo, acometendo humanos imunocomprometidos, especialmente os transplantados e infectados pelo vírus da imunodeficiência humana (HIV). Entretanto, infecções por R. equi em hospedeiros hígidos tem sido relatadas, principalmente em crianças e idosos. Estudos tem mostrado um nível crescente na resistência de isolados de R. equi em relação aos antimicrobianos comumente utilizados no tratamento de animais e seres humanos infectados por este agente. A virulência deste pode estar associada a fatores como a cápsula de polissacarídeo, fosfolipase C e à enzima colesterol oxidase (fator equi). No entanto, uma proteína localizada em um plasmídeo, designada vapA, é essencial para a sobrevivência e replicação do agente em macrófagos. Com isso, os objetivos deste estudo foram avaliar o perfil de suscetibilidade de isolados de R. equi de diferentes fontes em relação aos antimicrobianos mais comumente utilizados na terapêutica animal e humana, bem como verificar a associação entre a presença do gene vapA e o índice de resistência múltipla aos antimicrobianos (IRMA). Neste estudo, 67 isolados brasileiros de R. qui de diferentes fontes foram analisados: 30 provenientes de amostras clínicas de equinos, sete de humanos e 30 ambientais (seis do solo e 24 de fezes de equinos). Para avaliar o perfil de suscetibilidade dos isolados utilizou-se o método de disco difusão, sendo testadas 16 drogas de diferentes classes de antimicrobianos. As amostras clínicas de equinos apresentaram as maiores taxas de resistência à penicilina (86,7%) e lincomicina (30%). Além disso, foram também resistentes a macrolídeos (azitromicina a 6,7%, eritromicina a 6% e ...

Rhodococcus equi is a facultative intracellular bacterium and etiological agent of rodococosis, an important disease that affects specially foals under six months old and leading the death generally due to pulmonary lesions. R. equi also has zoonotic potential, and it has emerged as an opportunistic pathogen in the world, specially infecting solid organ transplant recipients and immunocompromised human patients, mainly those infected by human immunodeficiency virus (HIV). Additionally, R. equi infections by healthy hosts have been reported principally in children and elderly individuals. Studies have shown an increasing level of resistance of isolates of R. equi against antibiotics commonly used to treat affected animals and humans. The virulence of this agent is associated with a protein located on a plasmid, designated vapA, it is essential for survival and replication of R. equi within macrophages. The present study evaluated the susceptibility profile of R.equi isolates from different sources against the antimicrobials most commonly used to treat animals and humans, as well as the occurrence and association of vapA gene and the antimicrobial multiple resistance index (AMRI). Sixty-seven Brazilian isolates of R. equi from different sources were analyzed: 30 clinical samples of horses, seven of human and 30 of environmental (six from soil and 24 from horse feces). To evaluate the susceptibility profile of R. equi isolates, the Kirby Bauer method was performed by using 16 drugs of 11 distinct antimicrobials classes. Additionally, those samples were also resistant to macrolides (azithromycin 6.7%, erythromycin 6% and clarithromycin 3.3%) as well as rifamycin (13%). All human and environmental samples were sensitive to macrolides and rifamycin. However, environmental isolates demonstrated high levels of resistance to penicillin and chloramphenicol. Similarly, human isolates had high level of resistance to ceftiofur, lincomycin and sulfazotrim. AMRI...

Identification of pathogens and virulence profile of Rhodococcus equi and Escherichia coli strains obtained from sand of parks

The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.

Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum

INTRODUCTION: Rhodococcus equi is an opportunistic pathogen, causing rhodococcosis, a condition that can be confused with tuberculosis. Often, without identifying M. tuberculosis, physicians initiate empiric treatment for tuberculosis. R. equi and M. tuberculosis have different susceptibility to drugs. Identification of R. equi is based on a variety of phenotypic, chromatographic, and genotypic characteristics. OBJECTIVE: This study aimed to characterize bacterial isolates from sputum samples suggestive of R. equi. METHODS: The phenotypic identification included biochemical assays; thin-layer chromatography (TLC) and polymerase chain reaction (PCR) were used for genotypic identification. RESULTS: Among 78 Gram-positive and partially acid-fast bacilli isolated from the sputum of tuberculosis-suspected patients, 51 were phenotypically and genotypically characterized as R. equi based on literature data. Mycolic acid analysis showed that all suspected R. equi had compounds with a retention factor (Rf) between 0.4-0.5. Genotypic characterization indicated the presence of the choE gene 959 bp fragments in 51 isolates CAMP test positive. Twenty-two CAMP test negative isolates were negative for the choE gene. Five isolates presumptively identified as R. equi, CAMP test positive, were choE gene negative, and probably belonged to other bacterial species. CONCLUSIONS: The phenotypic and molecular techniques used constitute a good methodological tool to identify R. equi.

Rhodococcus equi en paciente VIH/sida: primera detección molecular en Cuba / First molecular detection of Rhodococcus equi in a HIV/aids patient in Cuba

Introducción: Rhodococcus equi es reconocido como un patógeno emergente que causa importante morbilidad y mortalidad entre los pacientes inmunocomprometidos. Objetivo: confirmar la presencia de R. equi en líquido pleural mediante la técnica del polimorfismo en la longitud de los fragmentos de restricción. Métodos: se empleó muestra de líquido pleural de un paciente sida con síntomas respiratorios. Se realizaron cultivos microbiológicos, pruebas de tinción, fenotípicas, bioquímicas y la técnica del polimorfismo en la longitud de los fragmentos de restricción para el diagnóstico del microorganismo. Resultados: las técnicas de tinción, fenotípicas y bioquímicas brindaron un diagnóstico sugestivo de infección por R. equi, el cual fue confirmado por las técnicas moleculares utilizadas. Conclusiones: este trabajo reporta la detección molecular, por primera vez en Cuba, de R. equi en paciente VIH/sida. Los resultados obtenidos permiten sugerir que técnicas de biología molecular pueden ser aplicadas en el diagnóstico y la identificación de R. equi.

Introduction: Rhodococcus equi is recognized as an emerging pathogen that causes important morbidity and mortality among immunocompromised patients. Objective: to confirm the presence of R. equi in pleural fluid through the restriction fragment length polymorphism technique. Methods: the pleural fluid sample from one AIDS patient with respiratory symptoms was used. Microbiologic culture, staining tests, phenotypic and biochemical tests and restriction fragment length polymorphism technique for the diagnosis of microorganism were performed. Results: the staining technique along with the phenotypic and biochemical tests provided the presumptive diagnosis of R. equi infection, which was further confirmed by the molecular techniques. Conclusions: this paper reported the molecular detection of R. equi from one HIV/aids patient for the first time in Cuba. The results suggested that the molecular biology techniques could be used in the diagnosis and identification of R. equi.

Rhodococcus equi infection after reduction mammaplasty in an immunocompetent patient / Infección por Rhodococcus equi luego de cirugía de reducción mamaria en huésped inmunocompetente

The majority of infections caused by R. equi occur in hosts with some degree of cell-mediated immunodeficiency. Immunocompetent individuals are infrequently affected and usually present with localized disease. Infections of the skin or related structures are uncommon and are usually related to environmental contamination. The microbiology laboratory plays a key role in the identification of the organism since it may be mistaken for common skin flora. We describe a 31 year-old woman without medical problems who presented nine weeks after breast reduction with right breast cellulitis and purulent drainage from the surgical wound. She underwent incision and drainage, and cultures of the wound yielded Rhodococcus equi. The patient completed six weeks of antimicrobial therapy with moxifloxacin and rifampin with complete resolution.

La mayoría de las infecciones causadas por Rhodococcus equi ocurren en huéspedes con algún grado de inmunodeficiencia celular. Los individuos inmunocompetentes son afectados con baja frecuencia y suelen presentarse con enfermedad localizada. Las infecciones de la piel o partes blandas son poco frecuentes y están usualmente relacionadas con contaminación ambiental. El laboratorio de microbiología juega un papel clave en la identificación del organismo, ya que este puede confundirse con flora normal de la piel. Se describe una mujer de 31 años sin problemas médicos que consultó nueve semanas después de haber sido sometida a cirugía de reducción mamaria, con celulitis del seno derecho y drenaje purulento de la herida quirúrgica. Se practicó incisión y drenaje quirúrgico y los cultivos de la herida demostraron R. equi. La paciente recibió seis semanas de tratamiento antimicrobiano con moxifloxacina y rifampicina demostrando resolución completa.

Bacteremia due to Rhodococcus equi in an immunocompetent infant.

Rhodococcus equi , previously known as Corynebacterium equi, is one of the most important causes of zoonotic infection in grazing animals. Increased cases of human infection with R. equi have been reported especially in immunocompromised patients. Infection in immunocompetent patients is extremely rare. We report a case of R. equi bacteremia in a 26-day-old immunocompetent infant with recurrent swellings on different parts of the body. To the best of our knowledge, this is the first ever report of R. equi bacteremia from an immunocompetent patient from Northern India.

Imaging and pathological findings of AIDS complicated by pulmonary Rhodococcus equi infection / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Rhodococcus equi (R. equi) infection commonly occurs in grazing areas, especially in patients with AIDS or with T-lymphocyte immuno-deficiencies. Literature reviews revealed that cases radiologically and pathologically diagnosed of AIDS complicated by R. equi infection are rare. This study aimed to investigate the imaging features and pathological basis of AIDS complicated by pulmonary R. equi infection.</p><p><b>METHODS</b>A total of 13 cases of AIDS complicated by pulmonary R. equi infection were retrospectively analyzed based on their imaging, bacterial culture and pathological data, including 10 cases by chest CT scanning and X-ray radiology and 3 cases by only X-ray radiology. All 13 cases were definitely diagnosed by bacterial culture, including one by CT-guided pulmonary puncture with following H&E staining and periodic acid-Schiff (PAS) staining for diagnostic biopsy and another one by bronchial biopsy with following H&E staining and PAS staining for pathological diagnosis. The imaging findings and the pathological findings of AIDS complicated by pulmonary R. equi infection were compared and evaluated.</p><p><b>RESULTS</b>Totally 9 subjects (70%) had radiological demonstrations of central ball liked high density shadows in unilateral pulmonary hilus areas; 10 (77%), cavities and liquefied levels; 3 (23%), pleural effussion. The foci were found in pulmonary inner zone in 10 subjects (77%) and in pulmonary outer zone in one subject (7%). The pathological findings included intra-alveolar hemorrhage, lymphocyte infiltration and granulation tissue proliferation, which were in line with the pathological process of necrotic pneumonia. After 8-month follow-up of anti-R. equi therapy of these 13 cases, 9 cases had obviously decreased or shrunk pulmonary cavities, one died, one missed follow-up, one completely absorbed foci and one did not receive reexaminations.</p><p><b>CONCLUSIONS</b>The radiological demonstrations of AIDS complicated by pulmonary R. equi infection are central ball liked high density areas in unilateral pulmonary hilus area, parenchymal changes, secondary cavities, ground glass liked changes in the lung fields, nodules and treeinbuds sign, which are characteristic rather than specific.</p>

Neumonía por Rhodococcus equi: hallazgos clínico-radiológicos en ocho pacientes con sida / Pneumonia caused by Rhodococcus equi: clinical and radiological findings in 8 AIDS patients

INTRODUCIÓN: el Rhodococcus equi, es una bacteria que pertenece al orden de los Actinomicetales. Su presentación en el hombre es poco frecuente. Es con la epidemia del VIH/sida que se han ido incrementando los casos. En los humanos el órgano principal de esta infección es el pulmón, provoca una neumonía que se caracteriza por una evolución clínica y radiológica lenta. OBJETIVO: describir las alteraciones radiográficas iniciales causadas por la infección por R. equi en 8 pacientes con sida, su evolución radiológica y la presentación clínica e inmunológica. MÉTODOS: se realizó un estudio retrospectivo descriptivo de las imágenes radiológicas pulmonares observadas en el período entre agosto de 1994 y enero de 2008 en pacientes con síndrome de inmunodeficiencia humana adquirida (sida) e infección respiratoria causada por Rhodococcus equi. RESULTADOS: el cuadro clínico se caracterizó por la fiebre elevada hasta 39 °C, tos con expectoración y disnea. La presentación radiológica más frecuente fue la opacidad homogénea en 62,5 por ciento de los casos, predominó la afectación pulmonar en los lóbulos inferiores. La evolución radiológica se caracterizó por la opacidad con cavitación en su interior en 4 casos, fibrosis en 4 casos y 1 tuvo resolución total de las lesiones. El conteo de linfocitos T CD4 + estuvo disminuido en los 8 pacientes. La evolución de los pacientes osciló entre los 2 y 33 meses. CONCLUSIONES: el diagnóstico de neumonía por R. equi debe ser considerado, en aquellos pacientes portadores de VIH/sida con estado inmunológico comprometido y proceso respiratorio con manifestación radiológica de consolidación pulmonar con evolución hacia la cavitación, con evolución clínica y radiológica tórpida y prolongada.

INTRODUCTION: the Rhodococcus equi is one bacterium of the order Actinomycetales. It rarely appears in humans, but the HIV/AIDS epidemic has increased the number of cases and the main affected organ is the lung. It causes pneumonia characterized by a slow clinical and radiological progression. OBJECTIVE: to describe the initial radiological alterations from R. equi infection in 8 AIDS patients, the radiological evolution and the clinical and immunological presentation. METHODS: a retrospective descriptive study of radiological pulmonary images from AIDS patients with respiratory infection due to Rhodococcus equi was conducted. RESULTS: these patients presented with high fever (39ºC), cough with expectoration and shortness of breath. Homogeneous opacity was the most frequent radiological presentation (62,5 percent of cases), located predominantly in the lower lobules. The radiological evolution was characterized by opacity with inner cavitation in 4 cases, fibrosis in 4 cases, and one case showed total recovery of lesions. The CD4+ T-cell count was low in all the patients. The evolution ranged from 2 to 33 months. CONCLUSIONS: the R equi pneumonia diagnosis should be borne in mind when dealing with HIV/AIDS patients with compromised immunological condition and breathing process with radiological manifestation of pulmonary consolidation evolving into cavitation, and torpid and prolonged clinical and radiological evolution.