Rapidly growing mycobacterial lung infection in association with esophageal disorders

Growing from common ground: nontuberculous mycobacteria and bronchiectasis

Bronchiectasis and nontuberculous mycobacteria (NTM) are intricately intertwined, with NTM capable of being both a cause and consequence of bronchiectatic disease. This narrative review focuses on the common ground of bronchiectasis and NTM pulmonary disease (NTM-PD) in terms of diagnostic approach, underlying risk factors and treatment strategies. NTM-PD diagnosis relies on a combination of clinical, radiological and microbiological criteria. Although their epidemiology is complicated by detection and reporting biases, the prevalence and pathogenicity of NTM species vary geographically, with Mycobacterium avium complex and Mycobacterium abscessus subspecies most frequently isolated in bronchiectasis-associated NTM-PD. Diagnosis of nodular bronchiectatic NTM-PD should prompt investigation of host factors, including disorders of mucociliary clearance, connective tissue diseases and immunodeficiencies, either genetic or acquired. Treatment of NTM-PD in bronchiectasis involves a multidisciplinary approach and considers the (sub)species involved, disease severity and comorbidities. Current guideline-based antimicrobial treatment of NTM-PD is considered long, cumbersome and unsatisfying in terms of outcomes. Novel treatment regimens and strategies are being explored, including rifampicin-free regimens and inclusion of clofazimine and inhaled antibiotics. Host-directed therapies, such as immunomodulators and cytokine-based therapies, might enhance antimycobacterial immune responses. Optimising supportive care, as well as pathogen- and host-directed strategies, is crucial, highlighting the need for personalised approaches tailored to individual patient needs. Further research is warranted to elucidate the complex interplay between host and mycobacterial factors, informing more effective management strategies.

Molecular epidemiology of nontuberculous mycobacteria isolated from tuberculosis-suspected patients

It is a growing problem around the world to deal with nontuberculous mycobacteria infection (NTM), but its clinical significance is still largely unknown. This study aims to investigate the epidemiology of NTM infections from various clinical samples and determine their clinical significance. From December 2020 to December 2021, 6125 clinical samples were collected. In addition to phenotypic detection, genotypic detection through multilocus sequence typing (hsp65, rpoB, and 16S rDNA genes) and sequencing was also conducted. Records of patients were consulted for clinical information, such as symptoms and radiological findings. Of the 6,125 patients, 351 (5.7%) were positive for acid-fast bacteria (AFB). Out of 351 AFB, 289 (82.3%) and 62 (17.7%) subjects were identified as M. tuberculosis complex (MTC) and NTM strains, respectively. Isolates of Mycobacterium simiae and M. fortuitum were the most frequent, followed by isolates of M. kansasii and M. marinum. We also isolated M. chelonae, M. canariasense, and M. jacuzzii, which are rarely reported. Symptoms (P = 0.048), radiographic findings (P = 0.013), and gender (P = 0.039) were associated with NTM isolates. M. Fortuitum, M. simiae, and M. kansasii presented with bronchiectasis, infiltration, and cavitary lesions most frequently, while cough was the most common symptom. In conclusion, Mycobacterium simiae and M. fortuitum were presented in seventeen and twelve NTM isolates from the collected samples. There is evidence that NTM infections in endemic settings may contribute to the dissemination of various diseases and the control of tuberculosis. In spite of this, further research is needed to evaluate the clinical significance of NTM isolates.

Mycobacterium infection secondary to exogenous lipoid pneumonia caused by nasal drops: a case report and literature review

BACKGROUND

Exogenous lipoid pneumonia (ELP) is a rare disease and its diagnosis is often mistaken or delayed. Secondary infection with rapidly growing non-tuberculous mycobacteria is a rare complication of lipoid pneumonia.

CASE PRESENTATION

A 38-year-old man presented with fever, cough, sputum, chest tightness, and shortness of breath. He had a 2-year history of allergic rhinitis and used liquid paraffin-containing menthol nasal drops daily. A chest CT scan showed multiple patchy ground glass opacities with blurred borders in both lungs, which were located in the inner pulmonary field and distributed along the bronchi. His ambient air PO₂ was 63 mmHg. The patient was diagnosed with ELP by CT-guided lung biopsy. The nasal drops were discontinued, and systemic glucocorticoids were administered. During treatment, the pulmonary lesions deteriorated, and bronchoalveolar lavage was performed during bronchoscopy. Additionally, Mycobacterium abscessus was detected in the lavage fluid. Upon detection of a secondary M. abscessus infection, glucocorticoids were gradually discontinued, and anti-M. abscessus treatment was implemented. The patient's symptoms rapidly ameliorated. After 11 months of anti-M. abscessus treatment, a repeat CT scan showed clear regression of the lung lesions.

CONCLUSION

Routine microbiological examination of samples, including sputum or alveolar lavage fluid, is necessary for patients with diagnosed or suspected ELP.

Mycobacterium avium Complex: Addressing Gaps in Diagnosis and Management

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and an important cause of disease. The most common species causing pulmonary disease are members of Mycobacterium avium complex (MAC). MAC pulmonary disease (MAC-PD) can be chronic, debilitating, costly, and associated with a high mortality. However, MAC diagnoses are often delayed due to the nonspecific presentation of MAC-PD and radiological findings that overlap with other pulmonary diseases. Patients with risk factors and who meet the diagnostic criteria—which include clinical, radiological, and microbiologic criteria—should be considered for treatment. Diagnosis requires 2 or more positive sputum cultures or 1 bronchoscopic specimen culture. The recommendation for those who are treated is a 3-drug regimen including macrolide, rifamycin, and ethambutol that is continued for 12 months beyond sputum culture conversion to negative. MAC-PD is difficult to treat, with frequent drug-related side effects and suboptimal treatment outcomes. Refractory and recurrent disease is common, leading to lifelong follow-up of patients. There are limited treatment options for patients with macrolide-resistant or refractory disease. Amikacin liposome inhalation suspension is recommended for treatment-refractory patients whose cultures remain positive after 6 months of guideline-based therapy. Among the research priorities to improve patient outcomes and quality of life are developing new, more rapid diagnostic tests, investigating biomarkers associated with disease progression, and identifying new drugs and routes of administration as well as new, shorter, and better-tolerated regimens.

Reflux-Aspiration in Chronic Lung Disease

Microaspiration, or silent aspiration, is commonly suspected in patients with refractory respiratory symptoms, including unexplained chronic cough, asthma, chronic obstructive pulmonary disease, bronchiolitis, bronchiectasis, and idiopathic pulmonary fibrosis. This suspicion is driven by the high prevalence of gastroesophageal reflux in these otherwise disparate disorders. Frequently, patients receive aggressive treatment for gastroesophageal reflux disease as a means of treating their underlying respiratory conditions, even in the absence of overt symptoms of reflux. However, clinical trials have not demonstrated a clear impact on outcomes with this strategy, and in some instances there may be potential for harm. Mechanistic studies have increasingly used gastric biomarkers obtained directly from the airways to confirm the association between reflux and respiratory disease, but results are limited by methodologic flaws and correlation. The best evidence of aspiration directly causing respiratory disorders is the histopathologic detection of foreign bodies. For most of the other chronic respiratory disorders, microaspiration may be uncommon or a secondary aggravating factor, as in patients with acute exacerbations of chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. In some cases, microaspiration is probably not a significant factor at all, such as in unexplained chronic cough. It is important to distinguish between conditions in which aspiration is primarily or directly causal and conditions in which aspiration may be indirectly aggravating, to help identify whether interventions targeting reflux and aspiration precautions should be recommended to patients. Our clinical review examines some of the evidence supporting reflux-aspiration as a mechanism for several chronic respiratory disorders and offers some management considerations when reflux-aspiration is suspected.

Mycobacterium septicum: a 6-Year Clinical Experience from a Tertiary Hospital and Reference Laboratory

Mycobacterium septicum is a rarely identified nontuberculous mycobacterium capable of causing infections in both healthy and immunocompromised individuals. Only a few cases of M. septicum infections have been reported, which makes recognizing corresponding clinical disease more challenging for clinicians. Antimicrobial susceptibility profiles for this organism are not well described, and corresponding optimal therapeutic regimens have not been established. We report a tertiary care center's experience with M. septicum from 2014 to 2020. Twelve adult patients with positive cultures for M. septicum were identified. Most cases were identified from sputum samples of individuals with underlying lung disease. Most cases involving M. septicum isolation in culture were not felt to be clinically significant. Two cases were considered possible infections, while only one case was considered a definite infection that required antimicrobial treatment. All M. septicum isolates were susceptible in vitro to amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and trimethoprim-sulfamethoxazole. Isolates were universally resistant to clarithromycin and doxycycline. The isolation of M. septicum in culture is uncommon and requires clinical correlation to determine its clinical relevance and need for treatment. Susceptibility testing should be performed to guide therapy.

Mycobacterium avium complex infection in a patient with systemic sclerosis- associated interstitial lung disease: A case report

We describe a case of a 65-year-old male with recently diagnosed diffuse cutaneous systemic sclerosis associated with usual interstitial pneumonia and pulmonary hypertension. Patient presented to the emergency department complaining of low-grade fever, increased sputum production, progressive dyspnea and weight loss. High-resolution computed tomography scan showed multifocal bronchiectasis with multiple small nodules. Bronchoalveolar lavage culture was positive for Mycobacterium intracellulare. Antimicrobial treatment was started which improved respiratory symptoms. One month after the initiation of antibiotics, cyclophosphamide therapy was started with adequate tolerance.

A 65-Year-Old Man with Pulmonary Opacities and Worsening Cough

CASE PRESENTATION

A 65-year-old man was referred for evaluation of several years of chest congestion and cough productive of yellow sputum as well as recently noted abnormalities on chest imaging. He denied dyspnea, weight loss, fevers, chills, or hemoptysis. He had no history of systemic illness, pneumonia, other respiratory illness, gastroesophageal reflux, or sinusitis. He had a remote smoking history. He worked as a railroad conductor and had occupational exposure to asbestos, as well as to other uncharacterized dusts and fumes. The patient spent most of his life in Washington and California and regularly traveled through the California Central Valley. Other travel history included trips to Southeast Asia, Iceland, and Europe in the remote past. The patient had one dog but no exposure to other animals. His only medication was loratadine, taken daily for allergic rhinitis. He applied petroleum jelly to his nares nightly to moisturize his nasal passages.

Evaluating the clinical significance of nontuberculous mycobacteria isolated from respiratory samples in Iran: an often overlooked disease

Purpose

Nontuberculous mycobacteria (NTM) infection is an increasing problem worldwide whose clinical significance is still largely unknown. The aim of this study was to investigate the epidemiology of NTM infection from respiratory samples and to determine their clinical significance.

Patients and methods

This cross-sectional study was performed on 7,825 clinical samples from December 2015 to December 2017. Detection was conducted using phenotypic and genotypic (hsp65 PCR-RFLP, rpoB, and 16S rRNA genes sequencing) methods. All clinical information including symptoms and radiological findings was extracted from patients’ records.

Results

A total of 478 were confirmed to have respiratory samples which were culture positive for mycobacteria, with the prevalence of NTM infection obtained as 53 (11.1%). Overall, Mycobacterium (M.) fortuitum was the most frequent NTM isolate, followed by M. simiae, M. kansasii, M. gordonae, and M. conceptionense. There was a relationship between NTM isolates and gender (P=0.039), symptoms (P=0.048), and radiographic findings (P=0.013). Bronchiectasis, infiltration, and cavitary lesion were the most frequent radiological findings in M. fortuitum, M. simiae, and M. kansasii, respectively, with cough being the most frequent symptom.

Conclusion

We reported five different NTM isolates in respiratory samples with a high frequency of M. fortuitum. NTM infections may play an important role in causing pulmonary disease and in tuberculosis management in endemic settings. Nevertheless, more studies are required to further examine the clinical significance of NTM isolates.

Mycobacterium goodii pneumonia: An unusual presentation of nontuberculous mycobacterial infection requiring a novel multidisciplinary approach to management

Background

Mycobacterium goodii is a rapidly growing nontuberculous mycobacterium which has been associated with several infections including cellulitis, osteomyelitis, lymphadenitis, infected pacemakers and bursitis but it is a rare cause of respiratory infection.

Case presentation

In this case report we describe a 51-year-old woman who presented with a 6-week history of non-productive cough, pleuritic chest pain and weight loss. She had a history of gastric adenocarcinoma managed with a distal oesophagectomy and total gastrectomy and consequentially suffered severe post-operative gastric reflux. Initial cultures were negative but following a VATS lung biopsy Mycobacterium goodii was cultured and histology revealed an organising pneumonia. Treatment was with a prolonged course of steroids, amikacin and meropenem followed by oral ciprofloxacin and doxycycline. Ongoing gastric dysmotility and weight loss showed clinical improvement with a novel approach of a combination of prokinetics and somatostatin analogues controlling risk of repeat aspiration and improving symptom control.

Conclusions

This is an unusual case of organising pneumonia related to Mycobacterium goodii infection and highlights the importance of mycobacterial culture in unusual and unresolving cases of organising pneumonia. The importance of controlling symptoms related to gastric dysmotility and aspiration is also addressed.

[The Prevalence of Nontuberculous Mycobacterial Lung Disease with orwithout Reflux Esophagitis]

Background/Aims

Gastrointestinal reflux disease (GERD) is defined as 'a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications'. It is associated with various lung diseases, including bronchial asthma, chronic bronchitis, and bronchiectasis. GERD may also affect nontuberculous mycobacterial (NTM) lung disease. We presumed that the normal mucosal barrier of the bronchial epithelium is broken due to the aspiration of gastric juice and consequent chronic bronchial inflammation. This study investigated the prevalence of GERD in accordance with the presence or absence of NTM lung disease and analyzed the difference.

Methods

We screened patients with NTM lung disease in this hospital between January 2011 and December 2015. Among these patients, gastroscopic examinations as a health check-up were performed on 93 patients. We obtained the prevalence of Reflux esophagitis (RE) in patients with NTM and compared it with the prevalence of RE in the normal control subjects.

Results

Among 93 patients with NTM, patients without RE was 66.7% (62/93). RE-minimal change was diagnosed in 29.0% (27/93), and RE LA-A was diagnosed in 4.3% (4/93). Comparing the prevalence of RE minimal change, 29.0% (27/93) had NTM and 11.9% (3043/25536) did not have NTM. This was statistically significant.

Conclusions

We showed a greater prevalence of RE minimal change in patients with NTM than those without NTM with statistical significance.

High rates of Mycobacterium fortuitum isolation in respiratory samples from Iranian patients with suspected tuberculosis: is it clinically important?

PURPOSE

Although Mycobacterium fortuitum (M. fortuitum) is not an organism rarely isolated from respiratory samples, its clinical importance is still not fully understood, which therefore prompted our current study.

METHODOLOGY

We evaluated respiratory samples from 6800 patients with suspected tuberculosis from May 2014 to May 2016, for the detection of M. fortuitum using phenotypic and genotyping methods.Results/Key findings. Of the 40 patients with M. fortuitum lung disease, 35 had two or more positive culture results. The mean age of these 35 patients was 50.7±18.4 years, and 20 (57.1 %) were men. Sputum (68.6 %), haemoptysis (51.4 %), cough (45.7 %) and gastroesophageal disease (22.9 %) were the major presenting symptoms. Cystic fibrosis, other bacterial lung diseases and lung cancer were the main underlying pulmonary diseases. Five patients (12.5 %) were human immunodeficiency virus (HIV) positive. The most common chest X-ray findings were reticulonodular opacities (53.3 %). Multivariate logistic regression analysis revealed that cigarette smoking history (OR 0.334, 95 % CI 0.125-0.843, P=0.048) and underlying lung disease (OR 0.393, 95 % CI 0.216-0.588, P=0.023) were significant predictors for positive M. fortuitum infection.

CONCLUSION

These results demonstrated the high frequency of M. fortuitum in respiratory samples and that this bacterium causes transient infection or colonization in patients with underlying pulmonary conditions, such as cystic fibrosis and cigarette smoking-induced. Additionally, it appears that infection with M. fortuitum is particularly common and may be important in patients with HIV.

Natural history of Mycobacterium fortuitum pulmonary infection presenting with migratory infiltrates: a case report with microbiological analysis

Background

Presence of Mycobacterium fortuitum in respiratory tracts usually indicates mere colonization or transient infection, whereas true pulmonary infection occurs in patients with gastroesophageal disease. However, little is known about the diagnostic indications for true M. fortuitum pulmonary infection and the natural history of the disease.

Case presentation

A 59-year-old man was referred to our hospital for treatment against M. fortuitum pulmonary infection. Fifteen years before the referral, he underwent total gastrectomy, after which he experienced esophageal reflux symptoms. After the referral, the patient was closely monitored without antimicrobial therapy because of mild symptoms and no pathological evidence of M. fortuitum pulmonary infection. During the observation, chest imaging showed migratory infiltrates. Two years after the referral, his lung biopsy specimen revealed foamy macrophages and multinucleated giant cells, indicating lipoid pneumonia. However, he was continually monitored without any treatment because there was no evidence of nontuberculous mycobacterial infection. Four years after the referral, he developed refractory pneumonia despite receiving adequate antibiotic therapy. After confirmation of granulomatous lesions, multiple antimicrobial therapy for M. fortuitum resulted in a remarkable improvement with no exacerbation for over 5 years. Random amplified polymorphic DNA polymerase chain reaction analysis revealed identical M. fortuitum strains in seven isolates from six sputum and one intestinal fluid specimens obtained during the course of the disease.

Conclusions

We have described a patient with M. fortuitum pulmonary infection who presented with migratory infiltrates. The pathological evidence and microbiological analysis suggested that M. fortuitum pulmonary infection was associated with lipoid pneumonia and chronic exposure to gastrointestinal fluid. Therefore, physicians should carefully monitor patients with M. fortuitum detected from lower respiratory tract specimens and consider antimicrobial therapy for M. fortuitum infection when the patient does not respond to adequate antibiotic therapy against common pneumonia pathogens.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.

Mycobacterium fortuitum empyema associated with an indwelling pleural catheter: Case report and review of the literature

Mycobacterium fortuitum is a rapidly growing mycobacterium (RGM) that is an uncommon cause of healthcare-associated infections. The most common infections caused by M. fortuitum include skin, soft tissue, and catheter-related infections. Although occasionally cultured from sputum samples, M. fortuitum is a rare cause of pulmonary disease. We report a case of M. fortuitum empyema associated with an infected pleural catheter and review M. fortuitum pulmonary infections.

Mycobacterium abscessus isolated from municipal water - a potential source of human infection

Background

Mycobacterium abscessus is a rapidly growing mycobacterium responsible for progressive pulmonary disease, soft tissue and wound infections. The incidence of disease due to M. abscessus has been increasing in Queensland. In a study of Brisbane drinking water, M. abscessus was isolated from ten different locations.

The aim of this study was to compare genotypically the M. abscessus isolates obtained from water to those obtained from human clinical specimens.

Methods

Between 2007 and 2009, eleven isolates confirmed as M. abscessus were recovered from potable water, one strain was isolated from a rainwater tank and another from a swimming pool and two from domestic taps. Seventy-four clinical isolates referred during the same time period were available for comparison using rep-PCR strain typing (Diversilab).

Results

The drinking water isolates formed two clusters with ≥97% genetic similarity (Water patterns 1 and 2). The tankwater isolate (WP4), one municipal water isolate (WP3) and the pool isolate (WP5) were distinctly different. Patient isolates formed clusters with all of the water isolates except for WP3. Further patient isolates were unrelated to the water isolates.

Conclusion

The high degree of similarity between strains of M. abscessus from potable water and strains causing infection in humans from the same geographical area, strengthens the possibility that drinking water may be the source of infection in these patients.

Pulmonary disease caused by nontuberculous mycobacteria

The propensity of various nontuberculous mycobacteria to cause lung disease varies widely and is conditioned by host factors; infection is believed to occur from environmental sources. Nontuberculous mycobacteria pulmonary disease (PNTM) is increasing worldwide and Mycobacterium avium complex is the most common cause. PNTM usually occurs in one of three prototypical forms: hypersensitivity pneumonitis, cavitary tuberculosis-like disease or nodular bronchiectasis. PNTM has been linked in some patients to genetic variants of the cystic fibrosis transmembrane conductance regulator gene and a distinct patient phenotype. Interactions between PNTM and other comorbidities are also increasingly appreciated. Guidelines for diagnosis, emphasizing chest imaging and microbiology, have been published; speciation using molecular techniques is critical for accuracy and for treatment decisions. Clinical trials are lacking to inform treatment for many species and experience with M. avium complex and several others species serves as a guide instead. Use of multiple drugs for a period of at least 12 months following sputum conversion is the norm for most species. In vitro drug susceptibility results for many drugs may not correlate with clinical outcomes and such testing should be done on a selective basis.

Mycobacterium chelonae empyema with bronchopleural fistula in an immunocompetent patient

Mycobacterium chelonae is one of the rapidly growing mycobacteria that rarely cause lung disease. M chelonae more commonly causes skin and soft tissue infections primarily in immunosuppressed individuals. Thoracic empyema caused by rapidly growing mycobacteria and complicated with bronchopleural fistula is rarely reported, especially in immunocompetent patients. In this article we report the first immunocompetent Arabian patient presented with M chelonae-related empyema with bronchopleural fistula which mimics, clinically and radiologically, empyema caused by Mycobacterium tuberculosis.

Achalasia and mycobacterium goodii pulmonary infection

Achalasia is a common adult disorder that rarely manifests in children and infrequently can be associated with pulmonary nontuberculous mycobacteria infections. We describe here the first case of Mycobacterium goodii pulmonary infection associated with achalasia in a pediatric patient. Heller myotomy with Dor fundoplication and 12 months of treatment with ciprofloxacin and doxycycline resulted in complete clinical and radiologic improvement.

Amoebal pathogens as emerging causal agents of pneumonia

Despite using modern microbiological diagnostic approaches, the aetiological agents of pneumonia remain unidentified in about 50% of cases. Some bacteria that grow poorly or not at all in axenic media used in routine clinical bacteriology laboratory but which can develop inside amoebae may be the agents of these lower respiratory tract infections (RTIs) of unexplained aetiology. Such amoebae-resisting bacteria, which coevolved with amoebae to resist their microbicidal machinery, may have developed virulence traits that help them survive within human macrophages, i.e. the first line of innate immune defence in the lung. We review here the current evidence for the emerging pathogenic role of various amoebae-resisting microorganisms as agents of RTIs in humans. Specifically, we discuss the emerging pathogenic roles of Legionella-like amoebal pathogens, novel Chlamydiae (Parachlamydia acanthamoebae, Simkania negevensis), waterborne mycobacteria and Bradyrhizobiaceae (Bosea and Afipia spp.).

[Lung diseases and gastro-oesophageal reflux disease]

Gastro -oesophageal Reflux Disease is a consequence of pathological reflux from stomach to oesophagus. Whenever the refluxed contents extended beyond the oesophagus itself, is called Extraoesophageal Reflux Disease. The author proposes a review about pulmonary disorders and gastroesophageal reflux. Previously, it is evaluated in an abridged way, the concepts of each diseases and after that, in a systematic form, it is discussed the prevalence of gastro -oesophageal reflux in lung diseases, all the mechanisms studies and the impact of gastro -oesophageal treatment on lung disorders. The author concludes that is undeniable the link between Gastro -oesophageal reflux and lung diseases and further reaserch is mandatory in order to corroborate this association.

Bronchopulmonary actinomycosis associated with hiatal hernia

OBJECTIVES

To describe clinicoradiologic and histopathologic features of bronchopulmonary actinomycosis and to determine whether hiatal hernia (HH) is a potential predisposing factor for bronchopulmonary actinomycosis.

PATIENTS AND METHODS

We reviewed the medical charts of 10 patients who had bronchopulmonary actinomycosis between November 1, 2002, and January 31, 2008. Complete clinical data, radiologic studies (chest radiographs and computed tomographic scans), and histopathologic features were assessed to investigate clinical manifestations and predisposing factors related to bronchopulmonary actinomycosis.

RESULTS

The series consisted of 6 men and 4 women, with a mean age of 63.5 years; 8 of the patients were smokers. Cough and fever were the most common symptoms. Chest imaging showed mass-like consolidation in 4 patients, bronchial thickening or lung atelectasis with pleural thickening in 2 patients each, and perihilar irregular mass or multiple bilateral nodules in 1 patient each. Primary or metastatic lung cancer was suspected clinically in 8 of the 10 patients. Foreign body-related endobronchial actinomycosis was diagnosed in 6 patients, 5 of whom had HH; only 1 had gastroesophageal reflux-related symptoms. Because of bronchial obstruction, rigid bronchoscopy was performed in 3 patients, lobectomy in 2, and atypical resection in 1. Antibiotic therapy with amoxicillin was given to all patients, with resolution of actinomycosis.

CONCLUSION

Bronchopulmonary actinomycosis is a rare condition that mimics pulmonary malignancy on clinical and radiologic grounds. Diagnosis relies on an accurate patient history and histopathologic examination. Although further confirmation is required, esophageal HH appears to be a potential predisposing factor.

Bronchopulmonary actinomycosis associated with hiatal hernia

OBJECTIVES

To describe clinicoradiologic and histopathologic features of bronchopulmonary actinomycosis and to determine whether hiatal hernia (HH) is a potential predisposing factor for bronchopulmonary actinomycosis.

PATIENTS AND METHODS

We reviewed the medical charts of 10 patients who had bronchopulmonary actinomycosis between November 1, 2002, and January 31, 2008. Complete clinical data, radiologic studies (chest radiographs and computed tomographic scans), and histopathologic features were assessed to investigate clinical manifestations and predisposing factors related to bronchopulmonary actinomycosis.

RESULTS

The series consisted of 6 men and 4 women, with a mean age of 63.5 years; 8 of the patients were smokers. Cough and fever were the most common symptoms. Chest imaging showed mass-like consolidation in 4 patients, bronchial thickening or lung atelectasis with pleural thickening in 2 patients each, and perihilar irregular mass or multiple bilateral nodules in 1 patient each. Primary or metastatic lung cancer was suspected clinically in 8 of the 10 patients. Foreign body-related endobronchial actinomycosis was diagnosed in 6 patients, 5 of whom had HH; only 1 had gastroesophageal reflux-related symptoms. Because of bronchial obstruction, rigid bronchoscopy was performed in 3 patients, lobectomy in 2, and atypical resection in 1. Antibiotic therapy with amoxicillin was given to all patients, with resolution of actinomycosis.

CONCLUSION

Bronchopulmonary actinomycosis is a rare condition that mimics pulmonary malignancy on clinical and radiologic grounds. Diagnosis relies on an accurate patient history and histopathologic examination. Although further confirmation is required, esophageal HH appears to be a potential predisposing factor.

Nontuberculous mycobacterial pulmonary infections in Non-HIV patients

Nontuberculous mycobacteria (NTM) are ubiquitous organisms with nearly 100 different species found in soil and water. The fatty-acid and wax-rich impermeable cell wall of the mycobacteria allow for adherence to solid substrates such as pipes and leaves, allowing the organism to persist despite treatment with common disinfectants. Mycobacteria can cause infection in both humans and animals. It is difficult to assess the incidence or prevalence of NTM disease due to multiple factors. Nontuberculous mycobacteria infection may be difficult to differentiate from colonization, and when NTM infection is diagnosed, it is not a reportable disease. Furthermore, some species such as Mycobacterium gordonae may be a contaminant. Nontuberculous mycobacteria infection is not a communicable disease, although health care-associated outbreaks have been reported, associated with a single facility or procedure. While the nontuberculous infection may affect other organs, the most common site is the lung, and the most common species is Mycobacterium avium complex, commonly referred to as MAC infection. An increasing occurrence of MAC has been reported, especially in certain populations such as middle-aged or elderly thin women, patients with chronic lung disease, human immunodeficiency virus infection, and cystic fibrosis. An association of NTM infection with gastroesophageal reflux disease has also been noted. The clinical presentation often includes chronic productive cough. Other less common symptoms include dyspnea and hemoptysis. With increased use of computed tomography and high-resolution computed tomography, patterns of MAC pulmonary infection have been described. Recently, the American Thoracic Society has outlined guidelines for the diagnosis and management of NTM infection. Treatment of NTM infection requires at least 3 effective drugs for a minimum of 12 months after sputum conversion to negative cultures. Surgical therapy may be considered for localized disease which has failed medical management. In this article, the clinical presentation, radiographic features, diagnostic evaluation, and management are discussed.

Guidelines on the diagnosis and treatment of pulmonary non-tuberculous mycobacteria infection

While the prevalence of Mycobacterium tuberculosis continues to decline in the developed world, the same cannot be said for non-tuberculous mycobacteria (NTM). These organisms are increasing in incidence and prevalence throughout the world. This is probably because of a combination of increased exposure, improved diagnostic methods and an increase in the prevalence of risk factors that predispose individuals to infection. Considerable confusion can arise in determining in the wide range of species whether an isolated NTM is in fact a contaminant or a pathogenic organism when isolated in sputum or bronchoalveolar lavage. This confusion combined with increasing requests for advice on the treatment of disease has led to the development of guidelines to assist the clinician in diagnosing and treating infection accurately.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

Clinical significance of Mycobacterium fortuitum isolated from respiratory specimens

BACKGROUND

Although Mycobacterium fortuitum is not an uncommon organism among the non-tuberculous mycobacteria isolated from respiratory specimens, its clinical significance had not been well studied.

METHODS

We identified all patients whose respiratory specimens were positive for M. fortuitum between January 2003 and December 2005. Among 182 patients whose specimens were positive for M. fortuitum, 26 were positive at least twice. We retrospectively reviewed their characteristics, and clinical courses.

RESULTS

Of the 26 patients, 15 had two positive culture results for M. fortuitum; the other 11 had three or more. Sixteen patients were male and the median age was 61.5 years. Major presenting symptoms were cough (65%) and sputum (58%). Most patients had known underlying lung diseases, including prior tuberculosis (54%), lung cancer (15%), idiopathic pulmonary fibrosis (15%), and other mycobacterial lung disease (15%). The most common CT findings were bronchiectasis (80%). Only one patient received specific prolonged antibiotic therapy against M. fortuitum infection; the other 25 did not. No patients showed clinical aggravation during the follow-up period, although in five patients their underlying lung diseases continued to progress. The median follow-up duration was 12.5 months and none of the patients whose sputum specimens were available had persistent positive cultures for M. fortuitum.

CONCLUSION

M. fortuitum usually causes colonization or transient infection in patients with underlying lung disease, such as prior tuberculosis or bronchiectasis. The majority of patients may not need to receive prolonged antibiotic therapy for M. fortuitum isolates.

The Many Faces of Pulmonary Nontuberculous Mycobacterial Infection

OBJECTIVE

The purpose of this article is to review clinical and radiologic manifestations of pulmonary nontuberculous mycobacterial infection.

CONCLUSION

Common and well-recognized patterns of infection include cavitary and bronchiectatic disease and infection in AIDS patients. Less common or well-recognized manifestations include nodules or masses mimicking malignancy, hypersensitivity pneumonitis, and others. Definitive diagnosis can be difficult and patterns may overlap. Timely diagnosis requires a high index of suspicion and knowledge of the spectrum of clinical and radiologic features.

Prevalence of Gastroesophageal Reflux Disease in Patients With Nontuberculous Mycobacterial Lung Disease

BACKGROUND

Knowledge of the relationship between respiratory disorders and gastroesophageal reflux disease (GERD) is increasing. However, the association between GERD and pulmonary disease caused by nontuberculous mycobacteria (NTM) has not been studied in detail. We investigated the prevalence of GERD in patients with the nodular bronchiectatic form of NTM lung disease.

METHODS

Fifty-eight patients with the nodular bronchiectatic form of NTM lung disease underwent ambulatory 24-h esophageal pH monitoring. Of the 58 patients, 27 patients were identified as having Mycobacterium avium complex infection (15 with Mycobacterium intracellulare and 12 with M avium), and 31 patients had Mycobacterium abscessus pulmonary infection.

RESULTS

The prevalence of GERD in patients with the nodular bronchiectatic form of NTM lung disease was 26% (15 of 58 patients). Only 27% (4 of 15 patients) had typical GERD symptoms. No statistically significant differences were found between patients with GERD and those without GERD with regard to age, sex, body mass index, or pulmonary function test results. However, patients with GERD were more likely to have a sputum smear that was positive for acid-fast bacilli (12 of 15 patients, 80%), compared with patients without GERD (19 of 43 patients, 44%) [p = 0.033]. In addition, bronchiectasis and bronchiolitis were observed in more lobes in patients with GERD than in patients without GERD (p = 0.008 and p = 0.005, respectively).

CONCLUSIONS

Patients with the nodular bronchiectatic form of NTM lung disease have a high prevalence of increased esophageal acid exposure, usually without typical GERD symptoms.

Gastroesophageal Reflux Disease, Acid Suppression, and Mycobacterium avium Complex Pulmonary Disease

BACKGROUND

Weekly symptoms of gastroesophageal reflux disease (GERD) occur in 20% of the population, and GERD has been implicated in the pathophysiology of many respiratory diseases. Microaspiration of contaminated water is a potential portal of entry for Mycobacterium avium complex (MAC) organisms into the respiratory tract, and acid-suppression therapy may enhance the survival of mycobacteria in the stomach. This study aimed to assess the prevalence of GERD, swallowing disorders, reflux symptoms, and acid-suppression therapy in patients with MAC lung disease (MAC positive [MAC+]), and to compare these patients to control subjects without MAC lung disease (MAC negative [MAC-]).

METHODS

Clinical information was collected on 58 MAC+ patients and 58 age- and sex-matched MAC- patients who were asked to complete a DeMeester questionnaire of reflux symptoms and to identify any acid-suppressive medication consumed.

RESULTS

A clinical diagnosis of GERD was documented in 23 of 52 MAC+ patients (44.2%), compared to 16 MAC- patients (27.6%) [p = 0.019]. MAC+ patients consumed significantly more histamine type 2 receptor antagonists and prokinetic agents, and MAC- patients consumed more antacids. The mean DeMeester questionnaire score (+/- SD) for MAC+ patients was 1.39 +/- 1.8, and for MAC- patients was 0.88 +/- 1.4. (p = 0.098). Aspiration was suspected in nine MAC+ patients (15.5%), compared to three MAC- patients (5.2%) [p = 0.032]. There was no association between GERD and radiologic presentation of MAC disease. Consolidation and nodules > 5 mm were more common in those receiving acid suppression than those who were not.

CONCLUSIONS

GERD, acid suppression, and clinically suspected aspiration are more common in patients with MAC lung disease than in similar patients without MAC disease.

Pulmonary infection with rapidly growing mycobacteria in a singer with achalasia: a case report

We report the case of a 37-year-old male patient with prolonged pneumonia and achalasia. Culture and molecular genetic typing identified Mycobacterium abscessus as causative agent. Treatment with clarithromycin and minocycline over 8 months gradually resolved the infection. Rapidly growing, non-obligate pathogenic mycobacteria are widespread in the environment. Several cases of pulmonary infections with these mycobacteria in patients with achalasia have been reported, suggesting a causative association. This is the first report of a case with isolation of M. abscessus in this context.

Pulmonary infection with Mycobacterium neoaurum identified by 16S ribosomal DNA sequence

Mycobacterium neoaurum infection has rarely been found in humans, and only a limited number of cases have been reported. We describe the first case of pulmonary infection with M. neoaurum. We speculate that unrecognized aspiration and long-term corticosteroid therapy predisposed our patient to this rare mycobacterial infection.

Non-tuberculous mycobacteria masquerading as aspiration pneumonia in patients with gastrointestinal problems

The association between non-tuberculous mycobacterial pulmonary disease and achalasia, although previously documented in the respiratory literature, is not well recognised generally. We present a case of a female who presents with weight loss, cough and radiological findings of aspiration pneumonia and achalasia. A discussion of mechanisms for this association are presented.

Lung Disease Due to the More Common Nontuberculous Mycobacteria

As the prevalence of tuberculosis (TB) declines in the developed world, the proportion of mycobacterial lung disease due to nontuberculous mycobacteria (NTM) is increasing. It is not clear whether there is a real increase in prevalence or whether NTM disease is being recognized more often because of the introduction of more sensitive laboratory techniques, and that more specimens are being submitted for mycobacterial staining and culture as the result of a greater understanding of the role of NTM in conditions such as cystic fibrosis, posttransplantation and other forms of iatrogenic immunosuppression, immune reconstitution inflammatory syndrome, fibronodular bronchiectasis, and hypersensitivity pneumonitis. The introduction of BACTEC liquid culture systems (BD; Franklin Lakes, NJ) and the development of nucleic acid amplification and DNA probes allow more rapid diagnosis of mycobacterial disease and the quicker differentiation of NTM from TB isolates. High-performance liquid chromatography, polymerase chain reaction, and restriction fragment length polymorphism analysis have helped to identify new NTM species. Although treatment regimens that include the newer macrolides are more effective than the earlier regimens, failure rates are still too high and relapse may occur after apparently successful therapy. Moreover, treatment regimens are difficult to adhere to because of their long duration, adverse effects, and interactions with the other medications that these patients require. The purpose of this article is to review the common presentations of NTM lung disease, the conditions associated with NTM lung disease, and the clinical features and treatment of the NTM that most commonly cause lung disease.

Exogenous lipoid pneumonia superinfected with acid-fast bacilli in infants: a report of nine cases

Super-infection of an exogenous lipoid pneumonia by nontuberculous mycobacteria has been described in the literature. It produces a distinctive histologic picture with suppurative, noncaseating granulomas surrounding lipid vacuoles containing acid-fast bacilli. Mainly isolated cases have been found, but seldom in children. We describe a series of 9 children with similar histological findings. All our patients were under 1 year of age, malnourished, and with chronic respiratory symptoms. The diagnosis, based on the characteristic histology with acid-fast rods, was established at autopsy in 4 cases, on lobectomy specimens in 4 and by open lung biopsy in 1. Mycobacterium fortuitum-chelonei was cultured in 1 case. Gastro-esophageal reflux was documented in all 4 cases in which it was explored. Aspiration of lipid gastric contents or of oil given as medication can result in exogenous lipoid pneumonia, which in turn becomes super-infected with mycobacteria. Recognition of the distinctive histology permits the diagnosis of this complication.

Pneumonia due to Mycobacterium abscessus in two domestic ferrets (Mustelo putorius furo)

Two ferrets were diagnosed with pneumonia due to Mycobacterium abscessus. Both cases were treated successfully using clarithromycin after positive cultures were obtained via unguided bronchoalveolar lavage. This is the first time M abscessus has been isolated in our laboratory and the first report of this organism causing disease in companion animals in Australia. Underlying respiratory tract disease was thought to be an important factor in the development of the infections. Thorough investigation of chronic lower respiratory tract disease in ferrets is recommended as this species appears predisposed to atypical infections.