Susceptibility Profiles of Nocardia Isolates Based on Current Taxonomy

Salais, Robert; Fisher, Mark A.; Hanson, Kent A.

doi:10.1128/aac.01531-13

Cited by 143 publications

(149 citation statements)

References 18 publications

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“…Isolates that phenotypically resemble N. asteroides are usually divided into six different drug susceptibility patterns (5). However, while correct identification to species level allows the prediction of likely antimicrobial susceptibility patterns, infrequently reported species may pose a challenge, prompting susceptibility testing of all isolates (5,11,12). Our isolate proved susceptible to the majority of antimicrobials tested for Nocardia species, with the exception of ciprofloxacin, contrasting with other reported N. thailandica isolates (7), which exhibited completely different patterns, thus suggesting important interspecies variability and/or methodological differences.…”

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confidence: 47%

Nocardia thailandica Pulmonary Nocardiosis in a Post-Solid Organ Transplant Patient

et al. 2015

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Nocardia thailandica is a rare pathogen related to Nocardia asteroides, Nocardia neocaledoniensis, and Nocardia caishijiensis that, since its original description in 2004, has only been reported to cause wound and ocular infections in humans. We report a case of pulmonary nocardiosis caused by Nocardia thailandica in a 66-year-old solid organ transplant patient from Connecticut, which was identified at the molecular taxonomic level by secA1 analysis, 16S rRNA gene sequencing, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first reported case of N. thailandica in the United States and the first report of pulmonary infection by this pathogen in the literature. CASE REPORT We report a case of pulmonary nocardiosis caused by Nocardia thailandica in a 66-year-old patient from Connecticut with a history of ischemic cardiomyopathy and heart transplant in 2013.The patient presented complaining of upper respiratory symptoms including sinus pressure, headaches, and decreased hearing in the left ear for a month prior to admission. There was no history of fevers, chills, exposure to sick contacts, or recent travel. Nine months earlier, he was admitted and underwent heart transplant surgery, for which he received and was maintained on immunosuppressive therapy with tacrolimus, mycophenolate, and prednisone, as well as prophylactic treatment with valganciclovir and trimethoprim-sulfamethoxazole (TMP-SMX). Four months after his cardiac transplant, the patient developed chronic cough. Chest X rays and computed tomography (CT) scanning performed at that time revealed bilateral patchy, ill-defined, dense nodular parenchymal opacities (Fig. 1A and B). Sputum Gram stains revealed few hyphae, and cultures performed from a bronchoalveolar lavage (BAL) fluid sample grew 1 CFU of Aspergillus fumigatus. A right upper lobe transbronchial biopsy specimen revealed mild chronic mucosal wall inflammation with no evidence of malignancy or granuloma, and the acid-fast bacillus (AFB) and Grocott-Gomori's methenamine silver (GMS) stains were negative. Routine bacterial, AFB, and mycology cultures from lavage samples were without growth, as were AFB cultures of the biopsy specimen. The patient was started on voriconazole and had subjective improvement after 2 weeks.Four months later, and while still on voriconazole, he presented with acute shortness of breath. A chest CT scan showed pulmonary embolism with a large clot burden within the right pulmonary artery and multiple areas of consolidation with cavitation, evolving from larger, denser areas of consolidation seen in the prior study ( Fig. 1C and D). In addition, a new left lower lobe consolidation was revealed. He was started on enoxaparin, and an inferior vena cava (IVC) filter was placed. A sputum Gram stain revealed Gram-negative bacilli later identified as Pseudomonas aeruginosa. Additionally, rhinovirus was detected in a BAL fluid specimen by multiplex PCR (Biofire FilmArray). A repeat right upper lobe transb...

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confidence: 47%

Nocardia thailandica Pulmonary Nocardiosis in a Post-Solid Organ Transplant Patient

et al. 2015

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“…Identification of this species in clinical settings is important as it is reported to possess some degree of resistance to cotrimoxazole and minocycline (Minero et al, 2009). Intraspecies variation in susceptibility to imipenem has also been reported in N. cyriacigeorgica (Schlaberg et al, 2014). Recently, genomic sequencing of N. cyriacigeorgica (GUH-2 strain) revealed virulence determinants such as the production of superoxide dismutase and peptide synthesis probably for siderophore/toxin production (Zoropogui et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

Molecular identification of clinical Nocardia isolates from India

Rudramurthy

Honnavar

Kaur

et al. 2015

Journal of Medical Microbiology

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The epidemiology of nocardiosis is evolving with increasing number of Nocardia spp. causing human infection. In recent years, molecular techniques have been used to identify Nocardia spp. There are limited data available on the spectrum of Nocardia spp. isolated from clinical samples in India. Here, a molecular study was carried on 30 clinical isolates maintained in our National Culture Collection to evaluate the techniques used for identifying the agents. The isolates were identified by sequencing two promising genes: the 16S rRNA gene and hsp65. Both hsp65 and the 16S rRNA gene could reliably identify 90 % of Nocardia isolates, i.e. N. farcinica, N. cyriacigeorgica, N. brasiliensis, N. otitidiscaviarum, N. amamiensis and N. pneumoniae. The mean percentage dissimilarity of sequence identification was higher using the hsp65 gene (4 %, range 0-7.9 %) compared with the 16S rRNA gene (2.3 %, range 0-8.9 %). Two isolates that showed ambiguous results in both the short segment of the 16S rRNA gene and hsp65 sequences could be resolved by sequencing a larger fragment (,1000 bp) of the 16S rRNA gene. Both of these isolates were identified as N. beijingensis with similarities of 99.8 and 100 % compared with the standard strain. Genotyping of N. cyriacigeorgica strains was performed using hsp65 gene sequences and compared with previously described genotypes. Our N. cyriacigeorgica isolates belonged to genotype 1 (n54) and genotype 2 (n52). The present study highlights a wide spectrum of Nocardia spp. in India and emphasizes the need for molecular techniques for identification to the species level.

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“…Nocardia species exhibit a species-predictable antimicrobial susceptibility pattern, and early species identification may be a crucial step to start an adapted antibiotherapy (11). When bacterial cultures were positive, the isolates were correctly identified by MALDI-TOF at the genus level, and the lack of accurate identification at the species level is easily explained because N. cerradoensis was not included in the database.…”

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confidence: 98%

“…In our case, we decided to initiate treatment with wide-spectrum antibiotics that also cross the blood-brain barrier. Actually, Nocardia shows a lower percentage of resistance to linezolid, SXT, and amikacin (11,15). Carbapenem usually displays a low MIC, and meropenem exhibits the best cerebral diffusion among this class.…”

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First Case of Disseminated Infection with Nocardia cerradoensis in a Human

et al. 2015

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iHere we report in a human, a renal transplant patient, the first disseminated infection with Nocardia cerradoensis, isolated after a brain biopsy. Species identification was based on 16S rRNA, gyrB, and hsp65 gene analyses. Antibiotic treatment was successful by combining carbapenems and aminoglycosides and then switching to oral trimethoprim-sulfamethoxazole. CASE REPORTA 59-year-old woman with a history of end-stage renal disease, secondary to autosomal-dominant polycystic kidney disease, received a renal transplant in 2010. Her immunosupressive regimen included tacrolimus at 12 mg/day and prednisolone at 7.5 mg/day. Prophylaxis with trimethoprim-sulfamethoxazole (SXT) was given for 6 months after the transplantation and then stopped due to intolerance symptoms. The patient had no history of recent travel. Two weeks before admission, she had had a mild headache with fever and chills and she was empirically treated with amoxicillin and prednisone for 7 days. After a brief improvement, she developed a nonproductive cough with dyspnea. Based on the hypothesis of pneumonia, antibiotic treatment was switched to ceftriaxone combined with aerosol bronchodilators. The patient's pulmonary symptoms rapidly worsened, and in September 2013, she was admitted to the hospital for further investigation.On examination, the patient was awake and complained of inspiratory dyspnea. Diarrhea was noted a few days after the initiation of antibiotic treatment and resolved spontaneously. The patient's temperature was measured at 37.8°C, blood pressure was 150/90 mm Hg, pulse was 97 beats/min, respiratory rate was 36/ min, and oxygen saturation was 97% while she was breathing ambient air. The auscultation evidenced bilateral basal crepitus and no other abnormal sounds. Heart sounds were normal, abdomen was soft, without tenderness, distention, or organomegaly, and neurologic examination was normal. No peripheral lymph nodes were detected. Subcutaneous nodules of the lower extremities appeared a few days after the patient was admitted (Fig. 1A). The white cell count was 18.6 ϫ 10 9 /liter, with 95% neutrophils, and the blood level of C-reactive protein was 159 mg/liter. A chest X-ray and a computed tomography (CT) scan showed wall thickening of the right main bronchus, moderate ground-glass opacities of the right upper lobe, a right hilar lymph node, a small right parenchymal nodule (Ͻ10 mm), and moderate homolateral pleural effusion (Fig. 1B). An abdominal CT scan revealed diffuse peritoneal and right retroperitoneal nodules (Fig. 1C) and a thickening of the cecal wall. Bronchoalveolar lavage (BAL) fluid, bronchial, and subcutaneous biopsy specimens were collected, and examination of stained smears (using Gram, Ziehl-Neelsen, May-Grünwald-Giemsa, Papanicolaou, Perls, and hematoxylin-safranin stains) showed no bacteria or abnormal cells. Cultures for bacteria, fungi, and mycobacteria were all negative. Histological examination of the subcutaneous nodule identified an erythema nodosum. Amplification of bacterial 16S rRNA gene from the c...

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Susceptibility Profiles of Nocardia Isolates Based on Current Taxonomy

Cited by 143 publications

References 18 publications

Nocardia thailandica Pulmonary Nocardiosis in a Post-Solid Organ Transplant Patient

Nocardia thailandica Pulmonary Nocardiosis in a Post-Solid Organ Transplant Patient

Molecular identification of clinical Nocardia isolates from India

First Case of Disseminated Infection with Nocardia cerradoensis in a Human

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