Cavitary pneumonia secondary to Tsukamurella in an AIDS patient. First case and a review of the literature

Uncommon finding in a pulmonary graft versus host disease: A first report of Tsukamurella pneumonia in a pulmonary graft-versus-host disease

A 64-year-old woman presented to Our Department with 2 weeks history of fever and cough. Through a series of radiological and invasive diagnostic studies we finally reach an unexpected diagnosis of Tsukamurella pneumonia; Diagnosing an ILD is a dynamic process, and that is the reason why complex cases discussed in a multidisciplinary team may need to be reconsidered in light of evolution of the disease and the results of the performed exams with a flexible approach. Tsukamurella spp. is an obligate aerobic, Gram-positive, weakly acid-fast, non-motile bacillus that belongs to the order Actinomycetales. Pneumonia caused by Tsukamurella is exceedingly rare, and only few cases are reported in the literature. Our aim is to evidence the paramount importance of Multidisciplinary team discussion in deciding the most appropriate diagnostic is of and therapeutical strategy.

Tsukamurella Bacteremia in a Surgical Patient: Case Report and Review of the Literature

Background: Tsukamurella species were first isolated in 1941. Since then, 48 cases of Tsukamurella bacteremia have been reported, a majority of which were immunosuppressed patients with central venous catheters.A case is described and previous cases of Tsukamurella bacteremia are reviewed. Patients and Methods: A 70-year-old total parenteral nutrition (TPN)-dependent female with recurrent enterocutaneous fistula (ECF), developed leukocytosis one week after a challenging ECF takedown. After starting broad-spectrum antibiotic agents, undergoing percutaneous drainage of intra-abdominal abscess, and subsequent repositioning of the drain, her leukocytosis resolved. Blood and peripherally inserted central catheter (PICC) cultures grew Tsukamurella spp. The patient was discharged to home with 14 days of daily 2 g ceftriaxone, with resolution of bacteremia. Conclusions: Tsukamurella spp. are a rare opportunistic pathogen predominantly affecting immunocompromised patients, with central venous catheters present in most cases. However, there have been few reported cases in immunocompetent individuals with predisposing conditions such as end-stage renal disease and uncontrolled diabetes mellitus.

Systematic investigation of the emerging pathogen of Tsukamurella species in a Chinese tertiary teaching hospital

Tsukamurella species have been clinically regarded as rare but emerging opportunistic pathogens causing various infections in humans. Tsukamurella pneumonia has often been misdiagnosed as pulmonary tuberculosis due to its clinical presentation resembling tuberculosis-like syndromes. Tsukamurella species have also been confused in the laboratory with other phylogenetic bacteria, such as Gordonia. This study aimed to investigate the clinical, microbiological, and molecular characteristics; species distribution; and antimicrobial susceptibility of Tsukamurella species. Immunodeficiency and chronic pulmonary disease appeared to be risk factors for Tsukamurella pneumonia, and the presence of bronchiectasis and pulmonary nodules on imaging was highly correlated with this infection. The study confirmed that groEL (heat shock protein 60) and secA (the secretion ATPase) genes are reliable for identifying Tsukamurella species. Additionally, the ssrA (stable small RNA) gene showed promise as a tool for discriminating between different Tsukamurella species with the shortest sequence length. In terms of antimicrobial susceptibility, quinolones, trimethoprim/sulfamethoxazole, amikacin, minocycline, linezolid, and tigecycline demonstrated potent in vitro activity against Tsukamurella isolates in our study. The study also proposed a resistance mechanism involving a substitution (S91R) within the quinolone-resistance-determining region of the gyrA gene, which confers resistance to levofloxacin and ciprofloxacin. Furthermore, we found that disk diffusion testing is not suitable for testing the susceptibilities of Tsukamurella isolates to ciprofloxacin, imipenem, and minocycline. In conclusion, our systematic investigation may contribute to a better understanding of this rare pathogen. Tsukamurella species are rare but emerging human pathogens that share remarkable similarities with other mycolic acid-containing genera of the order Actinomycetales, especially Mycobacterium tuberculosis. Consequently, misdiagnosis and therapeutic failures can occur in clinical settings. Despite the significance of accurate identification, antimicrobial susceptibility, and understanding the resistance mechanism of this important genus, our knowledge in these areas remains fragmentary and incomplete. In this study, we aimed to address these gaps by investigating promising identification methods, the antimicrobial susceptibility patterns, and a novel quinolone resistance mechanism in Tsukamurella species, utilizing a collection of clinical isolates. The findings of our study will contribute to improve diagnosis and successful management of infections caused by Tsukamurella species, as well as establishing well-defined performance and interpretive criteria for antimicrobial susceptibility testing.

A Pediatric Case of Septic Pulmonary Embolism Caused by Tsukamurella paurometabola

We herein report a three-year-old boy with septic pulmonary embolism caused by Tsukamurella paurometabola bacteremia during chemotherapy for rhabdomyosarcoma. During the interval of chemotherapy, the patient was temporarily discharged with a peripherally inserted central venous catheter but was re-admitted to the hospital with a fever on the same day. A blood culture taken at the time of re-admission showed T. paurometabola. The patient had a persistent fever, and computed tomography performed on the ninth day showed septic pulmonary embolism. We stress the importance of being aware of the possibility of septic pulmonary embolism in patients with Tsukamurella bacteremia.

Chronic Pulmonary Disease Caused by Tsukamurella toyonakaense

Unidentified Mycobacterium species are sometimes detected in respiratory specimens. We identified a novel Tsukamurella species (Tsukamurella sp. TY48, RIMD 2001001, CIP 111916^T), Tsukamurella toyonakaense, from a patient given a misdiagnosis of nontuberculous mycobacterial pulmonary disease caused by unidentified mycobacteria. Genomic identification of this Tsukamurella species helped clarify its clinical characteristics and epidemiology.

Bacterial Peritonitis Caused by Tsukamurella inchonensis in a Patient Undergoing Continuous Ambulatory Peritoneal Dialysis

Background

Tsukamurella is an environmental saprophyte that potentially causes various infections in humans. It has been reported to cause rare opportunistic infections in immunocompromised patients or patients with indwelling foreign bodies.

Case Presentation

We report a case of continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis caused by Tsukamurella inchonensis (T. inchonensis). The patient was admitted to our hospital while demonstrating a cloudy peritoneal dialysate. Peritoneal fluid sample culturing yielded yellow-greyish, dry and membrane-like colonies. Gram staining showed straight, gram-positive rods. The organism was identified to be Tsukamurella species by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). It was then characterized to be homologous to T. inchonensis in the GenBank database by 16S Ribosomal RNA Sequencing. The strain was susceptible to quinolones, carbapenems and linezolid, but intermediately resistant to vancomycin in drug susceptibility testing. Eventually, the peritonitis was controlled with meropenem and the patient discharged from the hospital.

Conclusion

Here, we describe the first case of CAPD-related peritonitis caused by T. inchonensis in China. Importantly, T. inchonensis show resistance to cephalosporins and heterogeneous resistance to vancomycin, guideline-based empiric therapy occasionally fails. Further analyses of similar cases are required to understand the characteristics and formulate appropriate therapy regimen for T. inchonensis infections.

Tsukamurella pulmonis conjunctivitis in patients with an underlying nasolacrimal duct obstruction - report of two cases

Tsukamurella pulmonis (Actinobacteria), a Gram-positive, obligate aerobic and weakly or variably acid-fast bacterium, is an opportunistic pathogen. Here we report two cases of conjunctivitis caused by T. pulmonis. Both patients had a previous history of nasolacrimal duct obstruction (NLDO). Isolation of T. pulmonis was performed on chocolate, tryptic soy blood and Columbia nalidixic agars. After 24 h of incubation, odourless, white-greyish, membrane-like colonies were observed. The VITEK-2 bacterial identifier system failed to identify the species, while Vitek-MS matrix-assisted laser desorption ionization time-of-flight technology, successfully identified the isolate from case 2 but not from case 1. Final identification was verified using 16S rRNA gene sequencing. An antibiogram was performed and according to the results cefazoline in addition to vancomycin eye drops for 5 days, were suggested as a treatment in case 1. In case 2 the infection was ended without treatment. This is the first report of Tsukamurella as a pathogen that causes conjunctivitis in patients with NLDO.

Chronic Cavitary Infections Other than Tuberculosis: Clinical Aspects

Lung cavitation may be due to infectious or noninfectious pathologic processes. The latter category includes nonmalignant conditions, such as granulomatosis with polyangiitis, and malignant conditions, such as squamous cell carcinoma of the lung. Infectious etiologies that produce lung cavitation usually cause chronic illness, although some, particularly pyogenic bacteria, may produce acute cavitary disease. Tuberculosis is the most common cause of chronic pulmonary infection with cavitation. The goal of this review was to highlight a selection of the better-known infectious agents, other than tuberculosis, that can cause chronic lung disease with cavitation. Emphasis is placed on the following organisms: nontuberculous mycobacteria, Histoplasma, Blastomyces, Coccidioides, Paracoccidioides, Aspergillus, Burkholderia pseudomallei, Paragonimus westermani, and Rhodococcus equi. These organisms generally produce clinical features and radiologic findings that overlap or mimic those of tuberculosis. In a companion article, we have further emphasized aspects of the same conditions that are more pertinent to radiologists.

Structural elucidation of Tsukamurella pulmonis neutral polysaccharide and its visualization in infected mouse tissues by specific monoclonal antibodies

Tsukamurella pulmonis is an opportunistic actinomycetal pathogen associated with a variety of rarely diagnosed human infections. In clinical cases of infection, T. pulmonis usually accompanies other bacterial pathogens. Because of these mixed infections, a robust diagnostic assay is important. The bacteria cell surface polysaccharides are considered not only useful targets for diagnostics but also intriguing subjects for analysis of the interactions that regulate the host response in general. Here, the structure of the polysaccharide component of the T. pulmonis cell wall was established. Sugar and methylation analysis and 2D-NMR techniques revealed that its polysaccharide belongs to the class of arabinomannan composed of branched tetrasaccharide repeating units, with addition of linear →6)-α-D-Manp-(1→ mannan. Rabbit polyclonal sera against T. pulmonis and T. paurometabola bacterial cells revealed cross reactivity between their antigens. Tissue samples from mice infected with T. pulmonis revealed liver abscesses and pathologic granules located intracellularly when immunohistochemically stained with monoclonal antibodies raised against T. pulmonis polysaccharide. Ultrastructural studies revealed that these granules contain T. pulmonis cells. These observations indicate that T. pulmonis is a pathogenic species capable of spreading within the organism, presumably through the blood.

MALDI-TOF MS for identification of Tsukamurella species: Tsukamurella tyrosinosolvens as the predominant species associated with ocular infections

Although Tsukamurella infections have been increasingly reported in Europe, Asia, America, and Africa, indicating that diseases caused by this group of bacteria are emerging in a global scale, species identification within this genus is difficult in most clinical microbiology laboratories. Recently, we showed that groEL gene sequencing is useful for identification of all existing Tsukamurella species. Nevertheless, PCR sequencing is still considered expensive, time-consuming, and technically demanding, and therefore is yet to be incorporated as a routine identification method in clinical laboratories. Using groEL gene sequencing as the reference method, 60 Tsukamurella isolates were identified as five different Tsukamurella species [T. tyrosinosolvens (n = 31), T. pulmonis (n = 25), T. hongkongensis (n = 2), T. strandjordii (n = 1), and T. sinensis (n = 1)]. The most common source of the patient isolates were the eye (n = 18), sputum (n = 6), and blood (n = 6). None of the 60 isolates were identified correctly to species level by MALDI-TOF MS with the original Bruker database V.6.0.0.0. Using the Bruker database extended with 15 type and reference strains which covered all the currently recognized 11 Tsukamurella species, 59 of the 60 isolates were correctly identified to the species level with score ≥2.0. MALDI-TOF MS should be useful for routine species identification of Tsukamurella in clinical microbiology laboratories after optimization of the database. T. tyrosinosolvens was the most common species observed in patients with Tsukamurella infections and the predominant species associated with ocular infections.

Peripherally inserted central catheter-related bloodstream infection due to Tsukamurella pulmonis: a case report and literature review

BACKGROUND

Tsukamurella pulmonis is an aerobic gram-positive and rod-shaped organism that causes central catheter-related bloodstream infections in immunocompromised hosts. However, peripherally inserted central catheter (PICC)-related bloodstream infections due to this organism have not been reported.

CASE PRESENTATION

We describe a case of a 48-year-old man with acquired immunodeficiency syndrome and diffuse large B cell lymphoma who received five courses of chemotherapy including rituximab , cyclophosphamide , doxorubicin hydrochloride , vincristine , and prednisone via a PICC. Five days after the last chemotherapy course, he presented with a high fever and shaking chills. His absolute neutrophil count was 4200/μL. Cultures obtained from blood and PICC culture revealed T. pulmonis. The colony count of T. pulmonis grown from PICC culture was 103 colony-forming units. Therefore, he was diagnosed with T. pulmonis bacteremia resulting from PICC-related bloodstream infection. The patient's condition improved and he became afebrile within 48 h after intravenous administration of cefozopran hydrochloride, which is a fourth generation cephalosporin.

CONCLUSIONS

PICCs can be associated with T. pulmonis bacteremia, and fourth generation cephalosporins may be effective treatment.

Role of Tsukamurella species in human infections: first literature review

Tsukamurella is an aerobic, Gram-positive and nonmotile bacterium. It was first isolated in 1941 from the mycetoma and ovaries of the bedbug. The primary strains were named Corynebacterium paurometabolum and Gordona aurantiaca and are different from the Collins et al., 1988 classification of the new Tsukamurella genus. Human infections with Tsukamurella species are rare because the species is a kind of saprophyte bacterium; however, most information regarding this species comes from case reports. Molecular markers for the identification Tsukamurella include sequencing of 16S rRNA, groEL, rpoB, secA1 and ssrA genes. Given the lack of information on the treatment of Tsukamurella infections, a combination of various antibiotic agents is recommended.

Aerobic Actinomycetes of Clinical Significance

The group of Gram-positive bacillary organisms broadly known as "aerobic actinomycetes" consists of heterogeneous and taxonomically divergent genera. They are found in a wide variety of natural and man-made environments but are rarely considered a part of the normal human flora, with infections normally originating from exogenous sources. An extensive number of genera have been described, but only a minority of these has been associated with human or veterinary health. The association with human disease is usually of an opportunistic nature, either through accidental means of inoculation or through involvement with immunocompromising conditions in the host. They cause a wide spectrum of diseases in humans, which may differ greatly between the genera and even between species, but which also may have a great amount of overlap. The occurrence of such infections is probably greater than appreciated, since many may go unrecognized. Etiologic prevalence of specific genera and species varies geographically within the United States and worldwide. Traditional phenotypic identification methods for separation of the many genera and species of aerobic actinomycetes have found great difficulties. Recent use of chemotaxonomic analyses and emerging technologies such as molecular analysis of nucleic acids, and more recently proteomics for identification to the genus/species level, has provided a far more robust technique to understand the organisms' relatedness, distribution, epidemiology, and pathogenicity in humans.

Community-acquired Tsukamurella pneumonia in a young immunocompetent adult: a case misdiagnosed as pulmonary tuberculosis and literature review

This report describes a case of Tsukamurella pneumonia in a 24-year-old immunocompetent woman. The patient was diagnosed as having pulmonary tuberculosis and was treated for nearly 9 months. The correct diagnosis was suspected only when the results of mycobacteria nucleic acid amplification tests on cultural colonies were negative. Tsukamurella was identified from the patient's sputum and bronchoalveolar lavage fluid by using 16S rRNA sequence analysis. Here, the clinical presentation, diagnosis, and treatment strategies of Tsukamurella pneumonia are discussed, along with a literature review. Tsukamurella pneumonia may be highly underdiagnosed owing to its similarity with pulmonary tuberculosis and the habitual thinking of doctors in countries with a high tuberculosis burden. Tsukamurella should be carefully considered in the etiology of tuberculosis-like lung diseases.

Tsukamurella tyrosinosolvens bacteremia with coinfection of Mycobacterium bovis pneumonia: case report and literature review

Introduction

We describe an immunocompromised patient with Tsukamurella tyrosinosolvens bacteremia and coinfection of Mycobacterium bovis pneumonia.

Case Description

A 75-year-old male was admitted to our hospital complaining of persistent fever with general malaise. His medical history showed that he had diabetes mellitus (HbA1C 9.2%). A chest computed tomography (CT) showed left upper lung consolidation . Two sets of blood culture at admission finally showed Tsukamurella tyrosinosolvens. Moreover, three transbronchoscopy washing specimen cultures revealed Mycobacterium bovis.

Discussion and Evaluation

The organism Tsukamurella tyrosinosolvens was identified using conventional biochemical identification methods, PCR-restriction DNA fragment analysis, and 16S rRNA gene sequencing. The clinical mycobacterial isolates were identified to the species level by combining Polymerase Chain Reaction (PCR) with an oligonucleotide microarray to detect the M. bovis amplicons.

Conclusion

According to our literature review, our patient’s case was the first of a coinfection with Tsukamurella tyrosinosolvens and Mycobacterium bovis. Prolonged antibiotic treatment and underlying disease control are necessary for this type of patient.

Tsukamurella hongkongensis sp. nov. and Tsukamurella sinensis sp. nov., isolated from patients with keratitis, catheter-related bacteraemia and conjunctivitis

Three bacterial strains, HKU51T, HKU52T and HKU53, were isolated from a conjunctival swab, corneal scraping and blood culture of three patients in Hong Kong with conjunctivitis, keratitis and catheter-related bacteraemia, respectively. Cells were Gram-stain-positive, aerobic, catalase-positive, non-sporulating and non-motile bacilli. The three strains had unique biochemical profiles that were distinguishable from those of closely related species of the genus Tsukamurella. Fatty acids, mycolic acids, cell-wall sugars and peptidoglycan analyses showed that they were typical of members of Tsukamurella. 16S rRNA gene sequence analysis revealed 100 % sequence identity between HKU52T and HKU53, and the two strains shared 99.5 % sequence identity with Tsukamurella sunchonensis JCM 15929T and Tsukamurella pseudospumae JCM 13375T; HKU51T shared 99.6 % sequence identity with Tsukamurella pulmonis CCUG 35732T. The DNA G+C contents of strains HKU51T, HKU52T and HKU53 were 70.9 ± 2.2, 71.3 ± 2.1 and 71.2 ± 2.3 mol% (mean ± sd; n = 3), respectively. DNA-DNA hybridization confirmed that the novel strains were distinct from other known species of the genus Tsukamurella ( ≤ 50.1 ± 3.7 % DNA-DNA relatedness); two of the isolates, HKU52T and HKU53, represented the same species ( ≥ 94.6 ± 5.6 % DNA-DNA relatedness), while the third isolate, HKU51T, represented another species. The novel species Tsukamurella hongkongensis sp. nov. is proposed to accommodate strains HKU52T and HKU53, with HKU52T ( = JCM 30715T = DSM 100208T) as the type strain; whilst another novel species, Tsukamurella sinensis sp. nov., is proposed to accommodate the third isolate, HKU51T ( = JCM 30714T = DSM 100207T), which is designated the type strain.

Tsukamurella infection: a rare cause of community-acquired pneumonia

A 79-year-old Asian man was admitted with community-acquired pneumonia. Antimycobacterial therapy was initiated when sputum smears revealed acid fast bacilli. The patient was, however, diagnosed to have pneumonia secondary to Tsukamurella spp. This is an exceedingly rare cause of pneumonia, especially in immunocompetent individuals. Clinical presentation, diagnosis and treatment strategies of Tsukamurella pneumonia are discussed with a literature review.

Nocardia cyriacigeorgica: a case of endocarditis with disseminated soft-tissue infection

Nocardia cyriacigeorgica is a common environmental organism. It has been isolated from clinical samples in Europe, Asia and North America, predominantly from respiratory samples but also from samples from several other sites. We present a case report of an 85-year-old female patient in the UK who was found to have a multi-focal soft-tissue infection from which N. cyriacigeorgica was isolated. She had a background history of chronic obstructive pulmonary disease and corticosteroid use for polymyalgia rheumatica. During the course of her treatment echocardiography showed the presence of a mobile heart mass attached to a valve leaflet, a major Dukes criterion for endocarditis. We suggest that in cases of disseminated Nocardia infection, endocarditis should be tested for, particularly in cases failing to respond to treatment. We also review previous reports of both N. cyriacigeorgica infection, and of endocarditis due to Nocardia species and related genera.

Tsukamurella tyrosinosolvens--an unusual case report of bacteremic pneumonia after lung transplantation

BACKGROUND

Lung transplant recipients have an increased risk for actinomycetales infection secondary to immunosuppressive regimen.

CASE PRESENTATION

A case of pulmonary infection with bacteremia due to Tsukamurella tyrosinosolvens in a 54-year old man who underwent a double lung transplantation four years previously is presented.

CONCLUSION

The identification by conventional biochemical assays was unsuccessful and hsp gene sequencing was used to identify Tsukamurella tyrosinosolvens.

Brain abscess caused by Tsukamurella tyrosinosolvens in an immunocompetent patient

We describe a previously healthy patient with chronic otitis media complicated with cerebellar abscess caused by Tsukamurella tyrosinosolvens. The organism was identified based on conventional biochemical identification methods, PCR-restriction fragment length polymorphism analysis of the hsp65 gene, and 16S rRNA gene sequencing. The patient was treated successfully with debridements and prolonged antibiotic therapy.

Coexistence of primary adenocarcinoma of the lung and Tsukamurella infection: a case report and review of the literature

Introduction

A major diagnostic challenge in the evaluation of a cavitary lung lesion is to distinguish between infectious and malignant etiologies.

Case presentation

We present the case of an elderly man presenting with fever, hemoptysis and a left upper lobe cavitary lesion. Serial sputum cultures grew Tsukamurella pulmonis, a rare pathogen associated with cavitary pneumonia in immunocompromised patients. However, despite clinical improvement with antibiotic therapy targeted to the organism, concomitant discovery of a papillary thyroid carcinoma led to a needle biopsy of the cavitary lesion, which showed evidence of primary lung adenocarcinoma.

Conclusion

This is the first description of Tsukamurella infection in the setting of primary lung carcinoma. The report also illustrates the potential complex nature of cavitary lesions and emphasizes the need to consider the coexistence of malignant and infectious processes in all patients, especially those with risk factors for malignancy that fail to improve on antibiotic therapy.

Pneumonia associated with HIV infection

PURPOSE OF REVIEW

Pneumonia occurs commonly in HIV-infected patients and this review highlights some of the recent findings in the epidemiology, pathogenesis, clinical features, treatment and prevention of this condition.

RECENT FINDINGS

Pneumonia remains an important cause of morbidity and mortality in HIV-infected patients. A number of factors have been identified that increase the risk of pneumonia. Cigarette smoking increases the risk of lung colonization, as well acute pneumonia due to Pneumocystis jiroveci, and has been documented to produce significant depression of the phagocytic function of alveolar macrophages in HIV-infected patients, which may underlie this risk. Legionella pneumophila infections appear to be uncommon in HIV-infected patients, while pneumonia with Streptococcus pneumoniae continues to occur with regularity, including infections with antibiotic-resistant isolates. Pneumocystis pneumonia occurs with a low incidence in patients receiving HAART, once the CD4 count increases to over 200 microl. Studies of invasive pneumococcal infections (predominantly pneumonia) indicate that in critically ill cases, including HIV-seropositive patients, combination antibiotic therapy is associated with a lower mortality than monotherapy. The 23-polyvalent pneumococcal vaccine has been shown to reduce the risk of pneumococcal infection in HIV-infected adults receiving HAART, and a 9-valent conjugate pneumococcal vaccine has been shown to reduce the incidence of radiologically confirmed pneumonia in HIV-seropositive and HIV-seronegative children.

SUMMARY

Pneumonia remains an important condition in HIV-infected patients, but recent studies demonstrate that antibiotic prophylaxis, the introduction of HAART, recognition of specific risk factors, new antibiotic treatment strategies and effective vaccines should serve to decrease its impact.