Nocardia co-infection in patients with pulmonary tuberculosis

Central nervous system nocardiosis in a 54-year-old man with lateral ventricular choroid plexitis and diffused meningitis: A case report

INTRODUCTION

Nocardiosis is an unusual infection caused by aerobic gram-positive bacteria in the genus Nocardia. Infections resulting from Nocardia species are frequent in immunosuppressive patients. Weakened immune systems caused by human immunodeficiency virus infection, diabetes, cancer, and other conditions such as chronic lung disease, renal failure, etc, are the main risk factors for nocardiosis. Central nervous system (CNS) nocardiosis has been reported to represent ~2% of all and to be present in 15% to 50% of patients with systemic infection. The patient in our case had an isolated CNS nocardiosis caused by Nocardia terpenica infection, a rare reclassified Nocardia pathogen of CNS nocardiosis.

CASE

We here present a 54-year-old Chinese male with a fever and headache for 15 days who showed positive meningeal irritation signs. Magnetic resonance imaging showed the right trigone of the lateral ventricular choroid plexitis and diffused leptomeningeal meningitis involving the bilateral cerebral hemisphere, cerebellar hemisphere, and brain stem. The patient was quickly diagnosed with CNS Nocardia infection by next-generation sequencing within 48 hours after admission. Meanwhile, the diagnosis was validated by Nocardia-positive staining in cerebral spinal fluid culturing. The patient was given trimethoprim-sulfamethoxazole, and his symptoms recovered after 3 days.

CONCLUSIONS

In this case, the clinical, radiological, and microbiological findings highlight the importance of suspecting Nocardia as the potential pathogen in patients with central nervous system inflammation of doubted immune incompetence. In addition, next-generation sequencing as an effective test is also highly recommended for suspicious CNS infection patients to perform a rapid diagnosis and treatment.

Case Report: Nocardia amamiensis Infection Leading to Worsening of Chronic Obstructive Pulmonary Disease Symptoms in an Elderly Man

Nocardiosis is a rare opportunistic infection mostly affecting the lungs, brain, or skin of immunocompromised individuals. Most pulmonary nocardiosis patients present with nonspecific clinical features such as productive cough, exertional dyspnea, and fever. The disease is uncommonly suspected, especially in tuberculosis-endemic regions, and clinical diagnosis is often delayed, resulting in high mortality. Pulmonary nocardiosis in apparently immunocompetent individuals is uncommon. Here, we present the case of an elderly gentleman with a background history of poorly controlled diabetes but no history of systemic steroid use who presented with worsening symptoms of chronic obstructive pulmonary disease in the form of productive cough and dyspnea. The patient had diffuse crepitations in bilateral lung fields and an arterial oxygen saturation of 86% at admission. Sputum microscopy revealed gram-positive filamentous bacteria that could be successfully cultured and identified as Nocardia amamiensis on 16S ribosomal RNA sequencing. Contrast-enhanced computed tomography of the lungs revealed cavitary nodules and consolidation. The patient responded well to treatment with specific antibiotics based on sensitivity patterns. Because of the nonspecific clinical and radiological findings in pulmonary nocardiosis, a high index of suspicion is required, especially in tuberculosis-endemic regions.

Co-infection with Mycobacterium tuberculosis and Nocardia farcinica in a COPD patient: a case report

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by persistent airflow limitation. Infection with either Mycobacterium tuberculosis or Nocardia in COPD patients has been reported. However, co-infection with Mycobacterium tuberculosis and Nocardia is rare. Herein, we described such a patient with COPD in a primary hospital, and the diagnosis process.

CASE PRESENTATION

A 79-year-old female farmer with COPD was consecutively admitted to two hospitals with chief complaints of worsening cough, sputum and gasping since January10, 2022. Microbiological examination was not performed at the first hospital due to unknown reasons, and empirical antibiotic treatment was not effective. The patient was subsequently referred to our hospital. After screening the source of infection and the pathogen, she was diagnosed with tuberculosis. However, the patient did not benefit from antituberculosis treatment, with no remission of respiratory tract symptoms. Cerebrospinal fluid and bronchoalveolar lavage fluid specimens were subsequently sent for microbiological examination. The results indicated Mycobacterium tuberculosis and Nocardia.spp. After four days of bacterial culture, Nocardia.spp grew on medium, and Nocardia.farcinica was identified by the MALDI-TOF MS system and 16 s RNA. The patient was prescribed trimethoprim sulfamethoxazole (TMP/SMX) in combination with anti-tuberculosis drugs to treat the co-infection. She showed gradual improvement and was discharged from the hospital on February 19, 2022. However, the follow-up results were unclear.

CONCLUSIONS

Co-infection with Nocardia and Mycobacterium tuberculosis should be considered in COPD patients. Repeated microbiological and microscopy examinations are essential in primary hospitals.

A unique case of fever with skin lesions

The incidence of Nocardiosis was c.1-2 per 100,000 population worldwide in the early 2000s. Co-infection with Nocardia and MOTT (mycobacterium other than tuberculosis) is even more uncommon and has been described only in the setting of pulmonary manifestations in an immunocompromised (HIV) patient. However, over the last two decades, the incidence of Nocardiosis has increased to about 7-8 per 100,000 population, with pulmonary manifestations being the most common. With this background, we present the case of a middle-aged immunosuppressed man (post renal transplant with rejection), who presented with fever with extensive skin lesions and features suggestive of sepsis, without pulmonary involvement.

Rapid DNA visual detection of polymicrobial bloodstream infection using filter paper

Bloodstream infection (BSI) is a major complication in patients with cancers due to therapy-induced neutropenia and underlying conditions, which increases hospitalization time and mortality rate. Targeted and timely antimicrobial management is crucial to save the patients’ lives and reduce the social and economic burdens. Blood culture is a routine clinical diagnostic method of BSI with a long turnaround time, and generally identifies monomicrobial BSI. Thus, polymicrobial BSI often goes undetected although it occurs more frequently in these patients and results in more severe outcomes compared to monomicrobial BSI. In this work, we apply glutaric anhydride, N-hydroxysuccinimide and N,N′-dicyclohexylcarbodiimide to fabricate a functional surface on cellulose filter paper. Targeting three pathogens (Escherichia coli, Saccharomyces cerevisiae, and human cytomegalovirus) commonly occurring in BSI in neutropenic patients, we demonstrate rapid and accurate triplex pathogen DNA detection using the functionalized paper. All three pathogen DNA was identified in 1–5 min with a detection limit of 0.1–0.5 ng/µL. The developed test tool has the potential to provide rapid polymicrobial BSI diagnosis in support of timely, accurate antimicrobial treatment, and could be integrated into an automatic sample-to-result portable equipment.

Clinical Characteristics and Treatment Outcome of Central Nervous System Nocardiosis: A Systematic Review of Reported Cases

BACKGROUND

The clinical spectrum of systemic nocardiosis encompasses pulmonary and disseminated disease. Central nervous system (CNS) involvement is an important feature of disseminated disease with significant mortality and high relapse rate, especially in those with suppressed cell-mediated immunity. This systematic review aimed to evaluate the epidemiology, clinical features, diagnosis, therapeutic interventions, and outcome in patients with CNS nocardiosis.

METHODS

A literature search was performed in major databases (PubMed, Google Scholar, and Scopus) by using distinct keywords: "CNS disease," "Nocardia," "meningitis," "brain abscess," "disseminated disease," and "Cotrimoxazole." We included all patients ≥18 years with CNS nocardiosis reported between January 2000 and December 2020.

RESULTS

A total of 129 papers were included in the final analysis. The mean age of patients was 55 ± 16 years, and the majority were male (70.8%). Nocardia farcinica was the commonest species (39.6%), followed by Nocardia nova (5.9%). Thirty-four percent of the patients were found to be immunocompetent. Corticosteroid use was the most common predisposing factor (55.8%). Among neuroimaging findings, brain abscess was most common (86.9%), followed by leptomeningeal enhancement (12.1%). The overall case-fatality rate in CNS disease was 22.8%. On multivariate analysis, patients who underwent surgery (OR 2.4, 95% CI 0.99-4.11, p value 0.046) had better survival than those treated with antimicrobial therapy alone. Immunodeficient state (OR 0.32, 95% CI 0.15-0.90, p value 0.019) was independently associated with poor outcome.

CONCLUSION

CNS nocardiosis carries significant mortality, especially in immunodeficient patients. We advocate the use of surgery combined with antimicrobials to improve clinical outcome.

Development of a SYBR Green Multiplex Real Time PCR for Simultaneous Detection of Mycobacterium Tuberculosis and Nocardia Asteroides in Respiratory Samples

Background

Nocardia asteroides and Mycobacterium tuberculosis are worldwide-distributed bacteria. These infectious agents can cause many infections in humans, especially in immunocompromised individuals. Pulmonary infections are more common and have similar clinical symptoms. Proper diagnosis and treatment of these patients are important for accurate treatment and could be lifesaving.

Methods

In this study, a multiplex real-time PCR assay was established for the simultaneous detection of the N. asteroides and M. tuberculosis. Both this homemade multiplex real time PCR and routine commercial tuberculosis tests were performed on 150 pulmonary specimens collected from individuals suspected to have tuberculosis.

Results

From 150 specimens, 20 samples were acid fast positive, 14 positives for M. tuberculosis by singleplex real time PCR, 10 positives for N. asteroides by singleplex real time PCR and 2 positives for M. tuberculosis and N. asteroides by multiplex real time PCR whereas 14 samples were positive for M. tuberculosis with commercial test. Differential diagnosis of pulmonary tuberculosis is useful for their proper treatment.

Conclusion

Our test had good performance for differential diagnosis of tuberculosis and nocardiosis. Therefore, it is recommended to be used to diagnose such patients.

Genotypic and phenotypic prevalence of Nocardia species in Iran: First systematic review and meta-analysis of data accumulated over years 1992-2021

Background

Nocardia species belong to the aerobic actinomycetes group of bacteria which are gram-positive and partially acid-fast Bacilli. These bacteria may sometimes be associated with nosocomial infections. Nocardia diseases are not required to be reported to public health authorities in Iran. Hence, the present study was designed to determine the prevalence of human Nocardia spp. in Iran by using a systematic review and meta-analysis according to the preferred reporting items for systematic reviews and meta-Analyses statement.

Methods

The data of the prevalence of Nocardia species were collected from databases such as Embase, PubMed/MEDLINE via Ovid, Web of Science, Scopus and Google Scholar as well as national Iranian databases, including SID, Magiran. Analyses were conducted by STATA 14.0.

Results

The meta-analyses showed that the proportion of Nocardia spp. in Iranian studies varied from 1.71(1.17, 2.24) to 0.46(0.09, 0.83). N. asteroides (21% [95% CI 1.17, 2.24]), N. cyriacigeorgica (17% [95% CI 0.99, 1.77]), N. facanica (10% [95% CI 0.75, 1.00]) were considered to be common causative agents.

Conclusions

Our study presents that despite the fact that Nocardia spp. are normally are saprophytic organisms, are currently accounts as emerging pathogens due to an increase in immunocompromised patients among Iranian populations. Considering our results, the establishment of advanced diagnostic facilities for the rapid detection of Nocardia infections are required for optimal therapeutic strategies of Nocardia spp. in Iran. Our findings could help the programmatic management of the disease within the context of Nocardia control programs.

Pulmonary Nocardiosis in Suspected Tuberculosis Patients: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

Background

nocardiosis is an opportunistic infectious disease in immunocompromised patients. The most common form of nocardiosis infection in humans is pulmonary nocrdiosis caused by inhaling Nocardia species from the environment. Thus, this study aimed to evaluate the pulmonary nocardiosis in patients with suspected tuberculosis using systematic review and meta-analysis.

Methods

We conducted a systematic search for cross-sectional studies focused on the pulmonary nocardiosis among patients with pulmonary tuberculosis based on the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) published from January 2001 to October 2019. The search was conducted in MEDLINE/PubMed, Web of Science, Scopus, Cochrane Library, Google Scholar, Science Direct databases, and Iranian databases. Medical subject headings (MeSH) and text words were searched: “pulmonary nocardiosis”, “nocardiosis”, OR “nocardial infection”, “pulmonary nocardial infections/agents”, AND “pulmonary tuberculosis”, OR “pulmonary TB”, AND “Iran”. Two of the reviewers enrolled independently articles published in English and Persian languages according to the inclusion and the exclusion criteria. Comprehensive Meta-Analysis software (Version 3.3.070) was used for meta-analysis.

Results

Only 4 studies met the eligibility criteria. The pulmonary nocardiosis prevalence varied from 1.7% to 6.7%. The combined prevalence of nocardiosis among patients with suspected pulmonary tuberculosis in Iran was 4.8% (95% CI: 3–7.3, Q=5.8, Z=12.7). No heterogeneity was observed between studies because I² was 48.3. N. cyriacigeorgica and N. asteroides were reported as the prevalent isolates, respectively.

Conclusions

This review showed in patients suspected TB when they were negative in all diagnosis laboratory tests, nocardiosis cases which be considered.

Disseminated Nocardia beijingensis Masquerading as Pulmonary Tuberculosis in a Patient With Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome

Case of disseminated Nocardia beijingensis, initially diagnosed and treated by health department as tuberculosis, presented with worsening symptoms and new lesions. Adjustment to antinocardial treatment resulted in significant clinical and radiographic improvement. Maintain a high index of suspicion for Nocardia in patients diagnosed with tuberculosis with worsening lesions despite therapy.

Nocardiosis: A Neglected Disease

Nocardiosis is a neglected tropical disease. It has varied geographical presence and a spectrum of clinical presentations. This review aims to focus on the epidemiology of nocardial infections with a systematic approach to their diagnosis and treatment. Nocardiacauses chronic infections and ailments, and may remain cryptic but progressive in its course. Unless suspected, diagnosis can be easily missed resulting in increased morbidity and mortality. Thorough knowledge of local epidemiology, demography, clinical course and presentation, diagnostic modalities, and antibiotic susceptibility patterns of the prevalent Nocardia species is essential to curb spread of this infection. This is a systematic review in which internet search has been done for citation indices (Embase, PubMed, Ovid, and other individual journals) till March 2020 utilizing the following key words "Nocardia," "taxonomy," "prevalence," "clinical features," "diagnosis," "treatment," and "susceptibility." We selected a total of 87 review articles, case series, and case reports all in English language.

Nocardia polymerase chain reaction (PCR)-based assay performed on bronchoalveolar lavage fluid after lung transplantation: A prospective pilot study

BACKGROUND

Transplant recipients are at risk of pulmonary nocardiosis, a life-threatening opportunistic infection caused by Nocardia species. Given the limitations of conventional diagnostic techniques (i.e., microscopy and culture), a polymerase chain reaction (PCR)-based assay was developed to detect Nocardia spp. on clinical samples. While this test is increasingly being used by transplant physicians, its performance characteristics are not well documented. We evaluated the performance characteristics of this test on bronchoalveolar lavage (BAL) fluid samples from lung transplant recipients (LTRs).

METHODS

We prospectively included all BAL samples from LTRs undergoing bronchoscopy at our institution between December 2016 and June 2017 (either surveillance or clinically-indicated bronchoscopies). Presence of microbial pathogens was assessed using techniques available locally (including microscopy and 10-day culture for Nocardia). BAL samples were also sent to the French Nocardiosis Observatory (Lyon, France) for the Nocardia PCR-based assay. Transplant physicians and patients were blinded to the Nocardia PCR results.

RESULTS

We included 29 BAL samples from 21 patients (18 surveillance and 11 clinically-indicated bronchoscopies). Nocardiosis was not diagnosed in any of these patients by conventional techniques. However, Nocardia PCR was positive in five BAL samples from five of the patients (24%, 95% confidence interval: 11-45%); four were asymptomatic and undergoing surveillance bronchoscopy, and one was symptomatic and was later diagnosed with influenza virus infection. None of the five PCR-positive patients died or were diagnosed with nocardiosis during the median follow-up of 21 months after the index bronchoscopy (range: 20-23 months).

CONCLUSIONS

In this prospective study, Nocardia PCR was positive on BAL fluid from one fourth of the LTRs. Nocardia PCR-based assays should be used with caution on respiratory samples from LTRs because of the possible detection of airway colonization using this technique. Larger studies are required to determine the usefulness of the Nocardia PCR-based assay in transplant recipients.

Evaluating the Contribution of Nocardia spp. and Mycobacterium tuberculosis to Pulmonary Infections among HIV and Non-HIV Patients at the Komfo Anokye Teaching Hospital, Ghana

Tuberculosis (TB) is a major cause of human mortality particularly in association with the human immunodeficiency virus (HIV). Nocardia spp. has emerged as an opportunistic infection especially in HIV patients. The high prevalence of TB and HIV coupled with the lack of a definitive laboratory diagnosis for Nocardia spp. could lead to misdiagnosed pulmonary TB. This study determined the prevalence of pulmonary infections due to Nocardia spp. and Mycobacterium tuberculosis in sputum of HIV and non-HIV patients with suspected pulmonary tuberculosis at KATH. A total of sixty sputum samples were obtained from HIV and non-HIV patients with suspected pulmonary tuberculosis. Samples were examined by fluorescence based Ziehl–Neelsen staining, culture, and PCR methods. The prevalence of Nocardia spp. and Mycobacterium tuberculosis was 18.3% and 20%, respectively, with the latter having the highest rate among patients aged 21–40 years (P=0.075). The prevalence of Nocardia spp. among HIV patients was 90.9% whilst 16.7% of the patients had HIV/Nocardia spp. coinfection. Detection of Mycobacterium tuberculosis by fluorescence-based Ziehl–Neelsen staining, culture, and PCR yielded 9 (15%), 11 (18.3%), and 12 (20%), respectively. There is a high prevalence of nocardiosis especially in HIV patients. PCR is a better diagnostic method that detects both Nocardia spp. and Mycobacterium tuberculosis and should be incorporated into routine diagnosis for pulmonary infections.

Nocardia infections in solid organ and hematopoietic stem cell transplant recipients

PURPOSE OF REVIEW

Nocardia spp. is a gram-positive bacteria that may cause infections in humans. Nocardiosis has been described since the early years of transplantation. This review aims to provide an overview of present knowledge regarding posttransplant nocardiosis, with a focus on recent findings.

RECENT FINDINGS

Nocardiosis is not rare among transplant recipients, especially after thoracic transplantation and/or in case of intense immunosuppressive regimen or use of tacrolimus. Low-dose cotrimoxazole is not effective to prevent nocardiosis. Although lung is the most common site of infection, more than 40% of organ transplant patients have a disseminated infection. As central nervous system involvement is frequent (about 1/3 of the patients) and possibly asymptomatic, brain imaging is mandatory. Diagnosis relies on direct examination and culture; molecular species identification is useful to guide treatment. Although cotrimoxazole is the drug for which we have the strongest clinical experience, other antibiotics such as linezolid, parenteral cephalosporins, carbapenems, and amikacin can be used to treat nocardiosis. Although treatment duration has historically been set to at least 6 months, shorter durations (<120 days) seem associated with a good outcome in selected patients.

SUMMARY

Physicians in charge of transplant patients should be aware of nocardiosis. Diagnosis and management of transplant recipients with nocardiosis require a multidisciplinary approach.

Pulmonary Nocardiosis and Scrub Typhus in an Immunocompromised Host

Pulmonary infections are not uncommon in patients with an underlying immunocompromised condition. Unusual combination of microorganisms causing concomitant infections among these patients has also been reported. However, certain rare dual occurrences are usually unanticipated as in the case we present here. This case highlights the importance of being aware of the possible coexistence of infections in immunocompromised patients. To the best of our knowledge, this is the first report of coinfection with Nocardia otitidiscaviarum and Orientia tsutsugamushi in a critically ill immunocompromised patient from South India.

Nocardia beijingensis pericarditis presenting with cardiac tamponade: A case report

We report the first case of Nocardia beijingensis pericarditis in a 32-year-old HIV-infected patient. He presented with cardiac tamponade after failing to respond to treatment for smear-negative pulmonary and pericardial tuberculosis (TB). The pericardial fluid was examined several times before it eventually revealed filamentous branching organisms in Gram and modified acid-fast bacilli stain. The culture grew Nocardia spp. and was identified by 16s rRNA sequencing as N. beijingensis. Eight previously reported cases of Nocardia pericarditis in HIV-infected patients were caused by Nocardia asteroides. All patients had low CD4 cell count (range: 17-239 cells/mm³) and 50% of patients were treated for tuberculous pericarditis prior to making the correct diagnosis of Nocardia pericarditis. This report revisits the issue of nocardiosis as a great TB mimicker. It should always be considered in the differential diagnosis among HIV-infected patients suspected of having pericardial TB that is failing treatment.

Cloning, Expression, Invasion, and Immunological Reactivity of a Mammalian Cell Entry Protein Encoded by the mce1 Operon of Nocardia farcinica

Bacterial mammalian cell entry (Mce) proteins have been implicated in pathogen invasion of mammalian host cells. The aim of this study was to examine the invasion-conferring ability of mce1E operon-encoded proteins, in vivo expression of Mce1E in cells from infected mice and rabbits, and Mce1E immunogenicity. Nocardia farcinica mce1E was cloned into pet30a(+) vectors, expressed in Escherichia coli, and purified. Invasion assays, transmission electron microscopy (TEM), immunoblots, and enzyme-linked immunosorbent assay (ELISA) detection of cytokines were conducted. TEM confirmed the invasion of HeLa cells by Mce1E-coated beads. The antigenicity of E. coli-expressed recombinant Mce1E was confirmed in immunoblots with sera from N. farcinica-infected mouse and rabbit sera. Co-incubation of Mce1E with splenocytes of N. farcinica-infected mice demonstrated upregulation of interferon (IFN-γ), but not interleukin (IL)-4 or IL-10, in the cultural supernatant. These findings demonstrate that Mce1E may facilitate N. farcinica interactions with and invasion of mammalian cells. Notably, Mce1E are expressed and elicited antibody responses in mice and rabbits during infection. Besides, it may play a role in cell-mediated immune reactions and cause host inflammation responses to N. farcinica infection.

Disseminated Nocardiosis in renal transplant recipient under therapy for pulmonary tuberculosis: a case report

Background

Nocardiosis is an opportunistic infection in a patient with underlying immune suppression and organ transplant. Clinical syndromes are varied and ranges from pulmonary, disseminated, cutaneous along with central nervous system involvement.

Case presentation

Herein, we report a rare case of disseminated pulmonary nocardiosis with cerebral manifestation in a 66 year-old-Nepali farmer; with a history of renal transplantation and undergoing therapy for pulmonary tuberculosis. Radiographic imaging revealed multiple opacities of varying sizes in bilateral lung field mediastinal, retroperitoneal lymphadenopathy, and ill-defined lesion with surrounding edema seen in left occipitoparietal region of brain. Bacteriological assessments of bronchoalveolar lavage and purulent fluid extracted intra-operatively from the lesion confirmed the case as Nocardiosis.

Conclusion

Disseminated Pulmonary nocardiosis with central nervous system involvement carries a poor prognosis. However, early diagnosis of the case, the administration of appropriate antibiotic, stereotactic aspiration alone or craniotomy has a successful outcomes even in a post renal transplant patient treated with anti tuberculosis treatment.

Pulmonary nocardiosis in Chronic Obstructive Pulmonary Disease: A new clinical challenge

Pulmonary nocardiosis (PN) is a rare but severe disease caused by Nocardia spp. Despite the traditional description as opportunistic infection, case reports and case series of pulmonary nocardiosis have recently been reported in immunocompetent patients too, in particular among people with chronic pulmonary diseases such as advanced Chronic Obstructive Pulmonary Disease (COPD). PN is characterized by non-specific symptoms and radiological findings; bacteriological culture can be difficult. For the reasons above, diagnosis of PN is challenging, sometimes resulting in a misdiagnosis of tuberculosis. We report an interesting case of PN in a 75-year-old male with COPD. He complained a 3-months history of fatigue, evening rise in body temperature, night sweats, unexplained weight loss of 5 kg, worsening dyspnea, cough and mucopurulent sputum. The chest X-ray showed multiple nodules with cavitations bilaterally in the apical and subclavian regions. Nocardia cyriacigeorgica with 100% identity was identified in three sputum samples. Since the patient has never undergone a systemic and/or inhaled steroid therapy, and has no respiratory failure and comorbidities entailing immunodepression, it is conceivable that, in this immunocompetent patient, the COPD could represent an isolated risk factor for PN. Risk factors, clinical presentations, radiographic findings, differential diagnosis and review of the literature of PN cases in COPD, pointing out the similarities and differences, are also described.