Use of imipenem in the treatment of pulmonary nocardiosis

Nocardiosis from 1888 to 2017

The genus Nocardia is an aerobic bacterium, Gram-positive and catalase positive that is in Nocardiaceae family. This bacterium first described by Edmond Nocard in 1888 and is not in human commensal bacteria. To date, nocardiosis incidence is increasing due to increase population growth rate, increase in patients with immune disorder diseases and immunocompromised patients. We surveyed taxonomic position, isolation methods, phenotypic and molecular identification at the genus and species levels, antibiogram, treatment and epidemiology in the world from 1888 to 2017.

Clinical findings of 40 patients with nocardiosis: A retrospective analysis in a tertiary hospital

To the best of our knowledge, no Chinese case studies concerning Nocardia infection have been published to date. Therefore, the present study aimed to retrospectively evaluate the risk factors, clinical features, imaging results, laboratory abnormalities, treatments and outcomes of nocardiosis in a Chinese tertiary hospital. Data collected from patients with laboratory-confirmed nocardiosis were retrospectively analyzed. A total of 40 patients who had a positive culture of Nocardia were included. The median time between the onset of symptoms and diagnosis was 42 days. Underlying diseases were identified in 72.5% of the patients of which diabetes was the most common (32.5%). The most important risk factor was corticosteroid administration. Fever and cough were common clinical symptoms. The pleuropulmonary (85%) were the most frequently involved sites and the disseminated disease rate was 30.0%. Frequent chest computed tomography scans revealed the presence of airspace opacities, nodules and masses, in addition to cavitary lesions that were particularly common among the study group. Brain images revealed lesions associated with abscesses. The majority of the patients (71.1%) were treated with trimethoprim sulfamethoxazole alone or in combination with other drugs. The in-hospital mortality rate was 15.0%. Disseminated disease, immunocompromised patients, an older age, brain involvement and concomitant infections were associated with a poor prognosis. Nocardiosis is an uncommon but emerging disease. The present study reports the first case series on nocardiosis from China and provides important information on the clinical features and risk factors of nocardiosis. Early recognition of the disease and the initiation of appropriate treatment are essential for a good prognosis.

[Disseminated nocardiosis : Diagnostic challenge]

Nocardiosis is a rarely found bacterial infection in Europe which can particularly affect immunocompromized patients. Localized infections of the dermis and lungs, as well as disseminated infections can be observed. Suspicion of nocardiosis should be reported to the microbiological laboratory so that goal-directed molecular genetic techniques and extended cultivation can be implemented for identification of the causative agent. A multitude of antibiotics can be used for successful therapy but the duration of therapy must be extended over 6-12 months. The mortality of disseminated infections ranges between 15-85% depending on the underlying immune status of the patient. The polymorphic appearance of nocardiosis is described based on the case of an intensive care patient.

Pulmonary nocardiosis developed in a hematopoietic stem cell transplant recipient with bronchiolitis obliterans

The chronic graft-versus-host disease often requires unceasing immunosuppressive therapy (IST), which increases a risk of infectious complications in hematopoietic stem cell transplantation (HSCT) recipients. We report an adult T-cell leukemia/lymphoma case who developed pulmonary nocardiosis, a rare pulmonary complication, after allogeneic HSCT despite administration of the prophylactic trimethoprim-sulfamethoxazole (TMP/STX). The inhaled corticosteroid in addition to systemic IST had been started for bronchiolitis obliterance 4 months prior to nocardiosis development. The patient was successfully treated with an increased dose of TMP/STX combined with meropenem. Transplantation physicians should keep this rare pulmonary complication in mind during sustained IST.

Frequent exacerbation of pulmonary nocardiosis during maintenance antibiotic therapies in a hematopoietic stem cell transplant recipient

We describe a rare case of recurrent pulmonary nocardiosis (PN) in a hematopoietic stem cell transplant recipient. The patient developed Nocardia farcinica infection while receiving corticosteroid and cyclosporine for the treatment of bronchiolitis obliterans, probably due to chronic graft-versus-host disease (cGVHD). The patient responded well to the initial treatment with meropenem, but PN recurred 3 times during oral maintenance therapies using different antibiotics, which were chosen on the basis of the results of in vitro susceptibility testing against N farcinica Minocycline, amoxicillin/clavulanate, and levofloxacin were not effective as oral maintenance therapies. Frequent exacerbation of PN was considered to have resulted from the low blood concentration of these antibiotics, and decreased gastrointestinal absorption, probably due to cGVHD, might have been the underlying problem.

Nocardiosis in Srinagarind Hospital, Thailand: review of 70 cases from 1996–2001

OBJECTIVE

Nocardiosis is a common opportunistic infection found in both immunocompromised and immunocompetent patients. The clinical manifestations, underlying diseases, radiologic findings, antimicrobial susceptibility and treatment of nocardial infection are presented here.

METHOD

A retrospective study at Srinagarind Hospital, Khon Kaen in Thailand was performed. Medical records from 1996-2001 were reviewed.

RESULTS

There were 81 cases of nocardiosis during the study period but data of only 70 cases were available. 80% of cases were male. The mean age was 39.7+/-14.9 years. Underlying diseases were found in 80%, of which HIV infection was the most common (34.3%). The common clinical findings were fever, cough, and cutaneous abscess. The most common clinical syndrome was pleuropulmonary infection (44.3%), followed by skin and soft tissue infection (22.8%). Multiorgan dissemination was found in 11.4% of cases. The chest X-rays were abnormal in 46 cases (65.7%); alveolar and reticulonodular infiltration was common. Only 70% had positive cultures for Nocardia spp. The resistance rate of Nocardia isolates to trimethoprim-sulfamethoxazole (TMP-SMX) was very high (57.9%) in this study. Most of the patients (85.7%) were treated with antimicrobials, of which TMP-SMX was commonly used. In-hospital mortality was 20%. Most of the cases who died had dissemination, brain abscesses or infection with TMP-SMX-resistant strains. The long-term prognosis was good, with a treatment success rate of 93.75%.

CONCLUSION

Nocardiosis is a common opportunistic infection in many immunocompromised conditions. It can present with various clinical syndromes, especially pleuropulmonary infection. Culture may not yield the organism but modified acid-fast staining is very helpful in diagnosis. Drug susceptibility testing should be performed due to increasing resistance to TMP-SMX.

Pyothorax caused by Nocardia otitidiscaviarum in a patient with rheumatoid vasculitis

We report a case of pyothorax caused by Nocardia (N.) otitidiscaviarum infection in a 69-year-old man with rheumatoid vasculitis, who was regularly treated with prednisolone in our hospital. Initially, the patient responded poorly to intravenous imipenem/cilastatin (IPM/CS), minocyclin (MINO), and oral trimethoprim-sulfamethoxazole (TMP-SMX), but later improved after treatment with levofloxacin (LVFX) and gentamicin sulfate (GM) according to in vitro susceptibility tests. To our knowledge, this is the first description of pyothorax caused by N. otitidiscaviarum infection. It is a rare disease, but recognition of the disease in immunocompromised patients and the prompt initiation of appropriate treatments based on isolation of the pathogen and susceptibility testing can lead to a successful outcome.

Pulmonary nocardiosis re-visited: experience of 35 patients at diagnosis

Pulmonary infection by Nocardia is an uncommon opportunistic infection in humans. Thirty-five patients with pulmonary nocardiosis were identified in two tertiary referral hospitals. A retrospective review of the patient characteristics, clinical and laboratory features including antimicrobial susceptibility at diagnosis was carried out. Radiological features derived from chest radiographs and CT scans were also documented. In our population, the predominant risk factors were immuno-compromised state, corticosteroid therapy, and underlying pulmonary pathology. The presenting features were similar to those previously described but disseminated infection was not common. The radiological changes were diverse and non-specific. Nocardia asteroides was the commonest species. Most Nocardia isolates were susceptible to imipenem, ceftriaxone, amikacin, and cotrimoxazole. Co-existing microbial agents are common and reflect the underlying complex disorders.

Clinical experience with linezolid for the treatment of nocardia infection

Linezolid is an oxazolidinone that has activity against most gram-positive bacteria, including in vitro activity against all Nocardia species and strains. We describe 6 clinical cases of nocardiosis that were successfully treated with linezolid. Two patients had underlying X-linked chronic granulomatous disease, and 2 patients were receiving chronic corticosteroid therapy. Four of 6 patients had disseminated disease, and 2 of these 4 patients had multiple brain abscesses. Four patients primarily received monotherapy; for the fifth patient, linezolid was added to a failing multiple-drug regimen, and, for the sixth patient, it was used as part of combination therapy. All 6 patients were successfully treated, although 1 patient had a presumed relapse of central nervous system infection after premature discontinuation of the drug. Linezolid appears to be an effective alternative for the treatment of nocardiosis.

Pulmonary nocardiosis in a patient treated with corticosteroid therapy

We report a case of pulmonary nocardiosis in a 69-year-old man with rheumatoid arthritis who was receiving corticosteroid treatment. The patient received prednisolone for rheumatoid arthritis and antibiotics for his fever and pneumonia in another hospital, but the response to the therapy was poor. After admission to our hospital, he improved following treatment with imipenem/cilastatin for Nocardia asteroides. Pulmonary nocardiosis is difficult to diagnose and should be considered in the differential diagnosis, especially in an immunocompromised host.

Carbapenems and monobactams: imipenem, meropenem, and aztreonam

Imipenem and meropenem, members of the carbapenem class of beta-lactam antibiotics, are among the most broadly active antibiotics available for systemic use in humans. They are active against streptococci, methicillin-sensitive staphylococci, Neisseria, Haemophilus, anaerobes, and the common aerobic gram-negative nosocomial pathogens including Pseudomonas. Resistance to imipenem and meropenem may emerge during treatment of P. aeruginosa infections, as has occurred with other beta-lactam agents; Stenotrophomonas maltophilia is typically resistant to both imipenem and meropenem. Like the penicillins, the carbapenems have inhibitory activity against enterococci. In general, the in vitro activity of imipenem against aerobic gram-positive cocci is somewhat greater than that of meropenem, whereas the in vitro activity of meropenem against aerobic gram-negative bacilli is somewhat greater than that of imipenem. Daily dosages may range from 0.5 to 1 g every 6 to 8 hours in patients with normal renal function; the daily dose of meropenem, however, can be safely increased to 6 g. Infusion-related nausea and vomiting, as well as seizures, which have been the main toxic effects of imipenem, occur no more frequently during treatment with meropenem than during treatment with other beta-lactam antibiotics. The carbapenems should be considered for treatment of mixed bacterial infections and aerobic gram-negative bacteria that are not susceptible to other beta-lactam agents. Indiscriminate use of these drugs will promote resistance to them. Aztreonam, the first marketed monobactam, has activity against most aerobic gram-negative bacilli including P. aeruginosa. The drug is not nephrotoxic, is weakly immunogenic, and has not been associated with disorders of coagulation. Aztreonam may be administered intramuscularly or intravenously; the primary route of elimination is urinary excretion. In patients with normal renal function, the recommended dosing interval is every 8 hours. Patients with renal impairment require dosage adjustment. Aztreonam is used primarily as an alternative to aminoglycosides and for the treatment of aerobic gram-negative infections. It is often used in combination therapy for mixed aerobic and anaerobic infections. Approved indications for its use include infections of the urinary tract or lower respiratory tract, intra-abdominal and gynecologic infections, septicemia, and cutaneous infections caused by susceptible organisms. Concurrent initial therapy with other antimicrobial agents is recommended before the causative organism has been determined in patients who are seriously ill or at risk for gram-positive or anaerobic infection.

Cryptococcal meningitis and intracranial tuberculoma in a patient with Waldenstrom's macroglobulinemia treated with fludarabine

We report a patient with Waldenstrom's Macroglobulinemia who presented with cryptococcal meningitis followed by an intracranial tuberculoma during the 18 months period after termination of cytotoxic therapy with Fludarabine. Opportunistic infections due to intracellular organisms are extremely rare in the course of this malignancy and we review the predisposing factors of these infectious entities.

Nocardiosis in systemic lupus erythematosus

OBJECTIVES

This study was performed to study the clinical presentations, treatment, and outcome of six cases of nocardial infection in the systemic lupus erythematosus (SLE) population living in Hong Kong and compare these cases with those reported in the English literature.

METHODS

Records of 215 SLE patients who attended our lupus and rheumatology clinics were reviewed, and cases of nocardial infection were retrieved and studied in detail. A Medline search from 1966 to 1995 was performed to identify other reported cases. The microbiology, diagnosis, and treatment strategies of nocardiosis were assessed.

RESULTS

Six cases of nocardiosis were found in our lupus series, giving a prevalence of 2.8%. Another 26 cases of nocardial infection in SLE were reported in the literature. All except one were caused by Nocardia asteroides. The lung was the commonest site of involvement (81%), followed by the central nervous system (CNS) (13%). The mortality was high (35%), especially when the CNS was involved (75%). Sulphonamides were the mainstay of treatment, and adjunctive surgical procedures may be needed for suppurative complications.

CONCLUSIONS

Nocardiosis has been increasingly recognized in SLE. Although still uncommon, it is an important opportunistic infection because it is curable and mortality is usually caused by delay in diagnosis and treatment. A high index of suspicion, an aggressive approach to diagnosis, and early empirical therapy are essential principles of management.