Persistent Rhodococcus equi infection in a renal transplant patient: case report and review of the literature

Pleural empyema with endobronchial mass due to Rhodococcus equi infection after renal transplantation: A case report and review of literature

BACKGROUND

Kidney transplantation is the best option for patients with end-stage renal disease. However, the need for lifelong immunosuppression results in renal transplant recipients being susceptible to various infections. Rhodococcus equi (R. equi) is a rare opportunistic pathogen in humans, and there are limited reports of infection with R. equi in post-renal transplant recipients and no uniform standard of treatment. This article reports on the diagnosis and treatment of a renal transplant recipient infected with R. equi 21 mo postoperatively and summarizes the characteristics of infection with R. equi after renal transplantation, along with a detailed review of the literature.

CASE SUMMARY

Here, we present the case of a 25-year-old man who was infected with R. equi 21 mo after renal transplantation. Although the clinical features at the time of presentation were not specific, chest computed tomography (CT) showed a large volume of pus in the right thoracic cavity and right middle lung atelectasis, and fiberoptic bronchoscopy showed an endobronchial mass in the right middle and lower lobe orifices. Bacterial culture and metagenomic next-generation sequencing sequencing of the pus were suggestive of R. equi infection. The immunosuppressive drugs were immediately suspended and intravenous vancomycin and azithromycin were administered, along with adequate drainage of the abscess. The endobronchial mass was then resected. After the patient's clinical symptoms and chest CT presentation resolved, he was switched to intravenous ciprofloxacin and azithromycin, followed by oral ciprofloxacin and azithromycin. The patient was re-hospitalized 2 wk after discharge for recurrence of R. equi infection. He recovered after another round of adequate abscess drainage and intravenous ciprofloxacin and azithromycin.

CONCLUSION

Infection with R. equi in renal transplant recipients is rare and complex, and the clinical presentation lacks specificity. Elaborate antibiotic therapy is required, and adequate abscess drainage and surgical excision are necessary. Given the recurrent nature of R. equi, patients need to be followed-up closely.

Rhodococcus equi Pneumonia in Kidney Transplant Recipient Affected by Acute Intermittent Porphyria: A Case Report

Rhodococcus equi is a gram-positive coccobacillus responsible for severe infections in patients with weakened immune systems. R equi generally causes pnumonia that may evolve into fatal systemic infection if left untreated. Here, we present a case of a 67-year-old woman affected by acute intermittent porphyria (AIP) who developed R equi pneumonia 7 months after kidney transplantation. Although clinical features at presentation were nonspecific, lung computed tomography showed right perihilar consolidation with a mass-like appearance causing bronchial obstruction. Appropriate antibiotic including intravenous meropenem and oral azithromycin that was then switched to oral levofloxacin and oral azithromycin along with reduction of immunosuppressive therapy resolved pneumonia without provoking an acute attack of porphyria. AIP limited the choice of antibiotics for the treatment of R equi infection because some potentially porphyrinogenic antibacterial agents were avoided. Based on this experience, azithromycin and meropenem can be safely administered for the treatment of R Equi infection in patients with AIP.

Bacterial pneumonia in kidney transplant recipients

Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections. The most commonly encountered pathogens during this period are gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa …), but gram-positive coccus such as Staphylococcus aureus or Streptococcus pneumoniae and anaerobic bacteria can also be found. Empirical antibiotic therapy should be guided by previous colonisation of the recipient and bacterial resistance pattern in the hospital. Six months after transplantation, pneumonias are mostly due to community-acquired bacteria (S. pneumonia, H. influenza, Mycoplasma, Chlamydia and others). Opportunistic pathogens take advantage of the state of immunosuppression which is usually highest from one to six months after transplantation. During this period, but also occurring many years later in the setting of a chronically depressed immune system, bacterial pathogens with low intrinsic virulence can cause pneumonia. The diagnosis of pneumonia caused by opportunistic pathogens can be challenging. The delay in diagnosis preventing the early instauration of adequate treatment in kidney transplant recipients with a depressed immune system, frequently coupled with co-morbid conditions and a state of frailty, will affect prognosis and outcome, increasing morbidity and mortality. This review will focus on the most common opportunistic bacterial pathogens causing pneumonia in kidney transplant recipients: Legionella, Nocardia, Mycobacterium tuberculosis/nontuberculous, and Rhodococcus. Recognition of their specificities in the setting of immunosuppression will allow early diagnosis, crucial for initiation of effective therapy and successful outcome. Interactions with immunosuppressive therapy should be considered as well as reducing immunosuppression if necessary.

Selected Topics in Aerobic Bacteriology

Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.

Unusual Extrapulmonary Rhodococcus Equi Infection in a Kidney Transplant Patient

Rhodococcus equi is a well-recognized pathogen in veterinary medicine that can also affect immuno-compromised human subjects. The most common clinical features in humans include necrotizing pneumonia with subacute pulmonary disease, progressive cough, chest pain and fever. We report a case of a 49-year-old kidney transplant patient who developed a Rhodococcus equi infection characterized by multiple abscesses of the soft tissues and muscles without any respiratory manifestation. Combining specific antibiotic therapy and surgical management of the abscesses without immunosuppression discontinuation led to a complete recovery of both patient and graft.

Rhodococcus equi Sepsis in a Renal Transplant Recipient: A Case Study

Rhodococcus equi is an unusual cause of infection in humans, but has emerged as an opportunistic pathogen among immunocompromised patients. Primary pulmonary involvement is the most common clinical presentation, although the spectrum of disease is broad. Diagnosing R. equi infections remains challenging, both from clinical and microbiological view, and no standard treatment has been established. In this report, we present a detailed case of a 57-year-old male renal transplant recipient who developed R. equi bacteremia with a concomitant Pneumocystis jirovecii pneumonia. We describe the clinical features of R. equi infections, highlight the importance of an early diagnosis, and briefly review treatment options for this rare infection.

Antibiotic failure in a renal transplant patient with Rhodococcus equi infection: an indication for surgical lobectomy

Rhodococcus equi is an animal pathogen that causes infrequent but challenging infections in immunocompromised individuals, few of which have been described in solid organ transplant recipients. Common clinical presentations include indolent cough, fever, and dyspnea, with necrotizing pneumonia and cavitation. We report a case of a dense right upper lung pneumonia with resultant R. equi bacteremia in a renal transplant recipient. Our patient initially responded to antibiotic treatment with resolution of bacteremia and clinical recovery, followed by interval progression in her right upper lobe consolidation on follow-up computed tomography scans. She underwent lobectomy for definitive therapy with resolution of symptoms. Lobectomy can be utilized in isolated infection after antibiotic failure with excellent clinical outcomes.

Clinical features, outcomes and treatment-related pneumonitis in elderly patients with esophageal carcinoma

AIM: To investigate the clinical features and prognoses of elderly patients with esophageal carcinoma and to compare the effects of radiotherapy and rates of treatment-related pneumonitis (TRP) between elderly and non-elderly patients.

METHODS: A total of 236 patients with esophageal carcinoma who received radiotherapy between 2002 and 2012 were enrolled. The patients were divided into two groups: an elderly group (age ≥ 65 years) and a non-elderly group (age < 65 years). The tumor position and stage, lymph node and distant metastases, and incidence and severity of TRP were compared. Multivariate analysis was applied to identify independent prognostic factors.

RESULTS: The median overall survival times after radiotherapy in the elderly and non-elderly groups were 18.5 and 20.5 mo, respectively. Cox regression analysis showed that TRP grade and tumor-node-metastasis (TNM) stage were independent prognostic factors in the elderly group. High-dose radiotherapy (> 60 Gy) was associated with a high incidence of TRP. Tumor TNM staging was significantly different between the two groups in which TRP occurred. Multivariate analysis showed that TNM stage was an independent prognostic factor. Esophageal carcinoma in elderly patients was relatively less malignant compared with that in non-elderly patients.

CONCLUSION: An appropriate dose should be used to decrease the incidence of TRP in radiotherapy, and intensity modulated radiation therapy should be selected if possible.