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This multicenter study was designed to assess the accuracy and reproducibility of the Vitek MS v3.0 matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry system for identification of Mycobacterium and Nocardia species compared to DNA sequencing. A total of 963 clinical isolates representing 51 taxa were evaluated. In all, 663 isolates were correctly identified to the species level (69%), with another 231 (24%) correctly identified to the complex or group level. Fifty-five isolates (6%) could not be identified despite repeat testing. All of the tuberculous mycobacteria (45/45; 100%) and most of the nontuberculous mycobacteria (569/606; 94%) were correctly identified at least to the group or complex level. However, not all species or subspecies within the M. tuberculosis , M. abscessus , and M. avium complexes and within the M. fortuitum and M. mucogenicum groups could be differentiated. Among the 312 Nocardia isolates tested, 236 (76%) were correctly identified to the species level, with an additional 44 (14%) correctly identified to the complex level. Species within the N. nova and N. transvalensis complexes could not always be differentiated. Eleven percent of the isolates (103/963) underwent repeat testing in order to get a final result. Identification of a representative set of Mycobacterium and Nocardia species was highly reproducible, with 297 of 300 (99%) replicates correctly identified using multiple kit lots, instruments, analysts, and sites. These findings demonstrate that the system is robust and has utility for the routine identification of mycobacteria and Nocardia in clinical practice.

Summary Mass spectrometry plays a significant role in the routine identification of micro-organisms and provides the ability to incorporate newly found pathogens into the database in a cost-effective fashion. This work aims to highlight the role of mass spectrometry through improved identification of Nocardia species in a diagnostic clinical microbiology laboratory. Prior to this study we constructed a custom in-house matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) library for Nocardia isolates consisting of isolates identified to the species level. Subsequently over a period of 5 years, we isolated a further 153 Nocardia clinical isolates, of which 91.5% (140/153) were identified correctly with the custom MALDI-TOF library and 8.5% (13/153) needed further molecular sequencing for final identification. We estimate our cost savings to be approximately 9,800 AUD overall with this implementation over the study period. Continued expansion and maintenance of this custom library will eventually result in little or no 16S ribosomal DNA sequencing needed for specific identification of Nocardia isolates.

Nocardiaspecies generally grow well on culture media in contrast to limited metabolic activities. Yet there are rare studies that have examined systematically the effect of culture media on the clinical recovery of these Gram-positive branching bacilli, particularly in relation to many recently described or revisedNocardiaspecies. We analyzed 146 clinicalNocardiastrains, of 24 species, recovered at the University of Texas M. D. Anderson Cancer Center from 2002-2018 for their growth on culture media. Among media setups to culture routine bacteria, fungi, and acid-fast bacilli (AFB), the AFB media alone recovered 35 strains as did fungal media with 26 strains and routine media with 10 strains. Seventy five strains were recovered on two and three media setups. On AFB media mostNocardia novastrains (24 of 29) grew, significantly more than all other strains did. Likewise, all four strains ofNocardia mikamiiwere cultivated solely on AFB media. Fungal media yielded all six strains ofNocardia wallaceithat were resistant to tobramycin and/or amikacin; this growth could be explained by the presence of gentamycin in one fungal medium. Specimen source also affected the recovery: moreNocardiastrains grew on every media setup from normally sterile specimens than from nonsterile specimens. These results suggest that diverse culture media support the growth of manyNocardiaspecies. The better recoveries of these organisms from AFB media and fungal media are likely attributable to decontamination of specimens on AFB culture, incorporation of selective antimicrobial agents into the media, and prolonged incubation.

The identification of Nocardia isolates still represents a challenge for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) despite its acceptance for most bacterial and fungal isolates. In this study we evaluate the identification of Nocardia isolates using direct spotting and an updated database. Overall, 82 Nocardia isolates belonging to 13 species were identified by DNA sequence analysis of the 16S rRNA and secA1 genes. Nine of these well-characterized isolates from 6 Nocardia species were used to create an in-house library. The remaining 73 isolates were directly spotted on the target plate and on-plate protein extraction was performed. The protein spectra obtained were analyzed by MALDI-TOF MS using the BDAL database (Bruker Daltonics) updated with 6,903 MSPs or the combination of this commercial database and our in-house library. As a result, the use of the commercial database alone and in combination with the in-house library yielded 94.5% and 95.9% of correct species-level identifications, respectively, No isolate was misidentified at the genus level with either database. Besides, the use of the in-house library allowed the species-level identification of a N. otitidiscaviarum isolate that could only be identified at the genus-level with a score value1.6 using the commercial database. In conclusion, the implementation of the direct spotting method and the in-house database provided a high rate of correct species assignment of Nocardia isolates despite the low number of isolates added. Further addition of well-characterized Nocardia isolates may ensure the rapid, accurate and inexpensive identification of most isolates encountered in the routine of the microbiology laboratory.

The genus Nocardia has had a long and complex history with an equally complex taxonomy. Recent advances in molecular identification methods have vastly expanded the number of recognized Nocardia species, further complicating the taxonomy of the genus. Because of the increasing number of clinically relevant species, biochemical identification methods are no longer adequate to allow discrimination among species. Molecular methodologies, specifically gene sequencing, has now become the gold standard for nocardial identification. We present a summary of the history of the genus Nocardia and provide information on methods for the detection and identification of suspected Nocardia isolates that may be present in patient specimens.

Nocardiosis diagnosis is a major challenge. The clinical features and radiological findings are nonspecific. Traditionally, Nocardia identification is based on colonial and microscopical mor- phology and biochemical tests. However, molecular biology techniques allow a better characteri- zation of species and biotypes. PCR-RFLP of the 65-kDa heat shock protein (HSP) gene provides a rapid, sensitive, and time and labor-efficient method for this proposal. Using this technique, six of eight isolates tested were identified as Nocardia asteroides type VI. PCR-RFLP of the 65-kDa HSP gene could be very useful for determining the incidence of this pathogen in different population groups and its association with susceptibility/resistance profiles to the drugs of choice for treat- ment. This work is the first molecular detection of Nocardia species in Cuba.

We describe a case of pulmonary nocardiosis due to Nocardia asiatica in an immunocompent 64-year-old-female. Wadowsky-Yee-Okuda-α-ketoglutarate (WYOα) agar, a selective media for Legionella species, was useful for the detection based on the growth-inhibition of normal oral flora and growth-promotion of Nocardia species.

Nocardiaspecies are a complex group of organisms considered to belong to the aerobic actinomycetes. Of the validly described species, many have been implicated as the cause of serious human infections, especially in immunocompromised patients. The genus has a complicated taxonomic history; this is especially true forNocardia asteroides, the type species of the genus and previously the most frequently reported nocardial taxon from human specimens. We provide background on the current taxonomy ofNocardia, with a focus on clinically relevant species, and discuss the currently available methods used to accurately identify isolates to the species, complex, or group level.

Central venous catheter-associated bacteraemia caused by Nocardia species is very rare; the diagnosis of nocardiosis in patients with cancer is challenging because its clinical presentation is varied, sometimes mimicking metastases, and the high index of clinical suspicion is required for prompt institution of therapy. Herein, we report a case of nocardial sepsis with native aortic valve endocarditis in a patient with breast cancer in whom multidisciplinary team involvement and prompt initiation of therapy have led to successful outcome.

Nocardia species are aerobic gram-positive filamentous organisms that may cause cutaneous or pulmonary disease in humans. Primary cutaneous nocardiosis may manifest as an acute superficial pyogenic infection that can mimic more common organisms such as Staphylococcus or Streptococcus. Acute pyogenic Nocardia infection of the pediatric hand is a rare manifestation of this condition. We present a 17-month-old boy who presented with an acute abscess formation on his left fourth and fifth digits that was found to be secondary to Nocardia brasiliensis.

Background Nocardia species are ubiquitous in nature and mainly cause pulmonary disease in humans; however, they can also infect the central nervous system and skin. The management of cerebellar nocardiosis is troublesome and requires multiple considerations of the severity of the underlying systemic disease, difficulties in identifying the bacterium, and frequent delay in initiating adequate therapy. Case description We report a 52-year-old diabetic female patient with Nocardia paucivorans cerebellar abscesses. Brain magnetic resonance imaging (MRI) revealed innumerable small ring-enhancing lesions of posterior fossa. In this report, we present a case of primary single cerebellar abscesses due to N. paucivorans. Early diagnosis and surgical interventions were significant for the patient. The diagnosis was confirmed by DNA sequencing and the organism was susceptible to trimethoprim-sulfamethoxazole (TMP/SMX). The patient was successfully treated with drugs and surgical excision. Conclusion According to the literature, surgical excision or aspiration of cerebellar abscess seems to provide favorable outcomes. In our experience, a successful outcome was achieved with subtotal resection and prolonged adequate antibiotic therapy.

Actinomycetoma is a chronic granulomatous infection, with Nocardia species being one of the infecting pathogens. Infections caused by N. otitidiscaviarum are relatively rare compared with those caused by other Nocardia species. Conventional methods for the diagnosis of nocardiosis based on phenotypic characterization of the strains (e.g., morphology, histopathology) are relatively time consuming and nonspecific. Molecular techniques have become the better choice for prompt and accurate identification of Nocardia isolates. We report a case of actinomycetoma due to N. otitidiscaviarum characterized by 16S ribosomal RNA (16S rRNA) gene sequence analysis and the long-term follow-up.

BACKGROUND:Nocardiaspecies are rare, opportunistic organisms that cause disease in both immunocompetent and immunocompromised individuals.OBJECTIVE: To investigate the clinical presentations of variousNocardiainfections based on the 16S ribosomal RNA gene of the isolate, as well as related risk factors and susceptibility patterns to antimicrobial agentsMETHODS: Thirteen patients with a diagnosis of nocardiosis were included in the present study. SevenNocardiaspecies were identified by 16S ribosomal RNA. Susceptibility testing was performed using six antimicrobial agents.RESULTS: Five patients were immunocompromised, and eight were immunocompetent with predisposing factors including cystic fibrosis, tuberculosis and ophthalmic infections.Nocardiacaused pulmonary infections in eight patients (61.5%), invasive systemic infections in three patients (23%) and local (ophthalmic) infections in two patients (15.4%). In the patients with pulmonary disease, nocardiosis was caused by six species (Nocardia cyriacigeorgica,Nocardia otitidiscaviarum,Nocardia farcinica,Nocardia carnea,Nocardia testaceaandNocardia asiatica). The seventh species identified in the present study wasNocardia crassostreae.DISCUSSION:N crassostreaeis a multidrug-resistant organism that was reported to be an emerging human pathogen causing invasive nocardiosis in a patient with non-Hodgkin’s lymphoma.N farcinicawas isolated from blood in a patient with breast cancer. None of theNocardiaisolates were resistant to linezolid. OneN otitidiscaviarumisolate was a multidrug-resistant organism. All patients in the present study were treated with the appropriate antibiotics and their condition resolved without further sequelae.CONCLUSIONS: The present study is the first report onN crassostreaeas a human pathogen. The detection of multidrug-resistant species necessitate molecular identification and susceptibility testing, and should be performed for allNocardiainfections. Nocardiosis manifests various clinical features depending on theNocardiaspecies and underlying conditions.

Prior to protein extraction for identification by Vitek MS, mycobacterial and Nocardia samples must be inactivated for safe handling outside the biological safety cabinet ([1][1], [2][2]). Previous studies have shown bead-beating samples for 5 min in 70% ethanol (EtOH) with glass beads followed by a

Introduction: Description of Nocardia infection in lung transplantation (LTx) is limited. Case Report: This study was a retrospective case-series of LTx recipients who were infected with Nocardia species. Nocardia infection was diagnosed in 5 patients out of 87 that underwent LTx from January 2009 to September 2014 at our institution. Their histories are depicted in table 1 and figure 1. Conclusion: Although this organism is capable of producing serious and metastatic disease in this kind of host, early diagnosis and initiation of targeted treatment may allow successful outcomes.

Nocardia spp. are aerobic, Gram-positive, catalase positive, and non-motile actinomycetes. They are associated with human infections. However, some species produce important natural products, degrade toxic chemicals, and are involved in biotransformation of valuable products. The lack of robust genetic tools has hindered detailed studies and advanced research. This unit describes the major genetic engineering approaches using Nocardia sp. CS682 as a prototype. These methods will certainly help in understanding the basis of their pathogenicity as well as biosynthetic and biotransforming abilities. It can be expected that knowledge of the biochemistry behind their pathogenicity will be crucial in developing effective treatment strategies. These genetic tools can be utilized to develop rational metabolic engineering approaches for crafting host strains with higher production or biotransformation ability.

Nocardia species are difficult to identify, a consequence of the ever increasing number of species known and their homogeneous genetic characteristics. 16S rRNA analysis has been the gold standard for identifying these organisms, but proteomic techniques such as matrix-assisted laser desorption ionization-time of flight (MALDI-TOF MS) and housekeeping gene analysis, have also been explored. One hundred high (n = 25), intermediate (n = 20), and low (n = 55) prevalence (for Spain) Nocardia strains belonging to 30 species were identified via 16S rRNA and MALDI-TOF MS analysis. The manufacturer-provided database MALDI Biotyper library v4.0 (5.627 entries, Bruker Daltonik) was employed. In the high prevalence group (Nocardia farcinica, N. abscessus, N. cyriacigeorgica and N. nova), the 16S rRNA and MALDI-TOF MS methods provided the same identification for 76% of the strains examined. For the intermediate prevalence group (N. brasiliensis, N. carnea, N. otitidiscaviarum and N. transvalensis complex), this figure fell to 45%. In the low-prevalence group (22 species), these two methods were concordant only in six strains at the species level. Tetra-gene multi-locus sequencing analysis (MLSA) involving the concatemer gyrB-16S rRNA-hsp65-secA1 was used to arbitrate between discrepant identifications (n = 67). Overall, the MLSA confirmed the results provided at species level by 16S rRNA analysis in 34.3% of discrepancies, and those provided by MALDI-TOF MS in 13.4%. MALDI-TOF MS could be a strong candidate for the identification of Nocardia species, but only if its reference spectrum database improves, especially with respect to unusual, recently described species and species included in the described Nocardia complexes. This work was funded by a grant to NG from the Instituto de Salud Carlos III (MPY 1278/15). Sí

Nocardiosis is a rare disease caused by infection with Nocardia species, aerobic actinomycetes with a worldwide distribution. A rare life-threatening disseminated Nocardia brasiliensis infection is described in an elderly, immunocompromised patient. Microorganism was recovered from bronchial secretions and dermal lesions, and was identified using molecular assays. Prompt, timely diagnosis and appropriate treatment ensured a favorable outcome.

Nocardia species represent a well-recognized yet uncommon cause of opportunistic infections in humans. It most frequently presents as a pulmonary infection with or without central nervous system involvement. It is a very rare cause of spinal abscesses, with only 26 cases reported in the literature. Here we report a 49-year-old man with a history of renal transplantation who presented with low back pain and was diagnosed with epidural and paraspinal abscesses due to Nocardia cyriacigeorgica that was successfully treated with antimicrobial therapy alone. In addition to the case reported here, we also conducted a systematic review of the existing literature regarding spinal abscesses due to Nocardia species and examined the success of the various treatments utilized.

Background Nocardia spp. are ubiquitous Gram-positive weakly acid-fast environmental microorganisms. Although considered an opportunistic infection, approximately 1/3 of the reported infections are in immunocompetent patients. Treatment is usually challenging, prolonged and involves multiple agents depending on the site of infection, clinical syndrome and the immune status of the patient. Methods We conducted a retrospective review of clinical samples with positive cultures for Nocardia spp. from 2011 to 2017. Specimens were cultured in MGIT broth or on Middlebrook agar biplates and isolated colony growth was then identified using MALDI-TOF MS or 16S rDNA gene sequencing. Antimicrobial susceptibility testing was performed using the TREK Sensititre Rapid Growing Mycobacteria Plate. Results We reviewed total of 1,840 samples positive for Nocardia spp. Most commonly isolated species included N. cyriacigeorgica (16.9%), N. nova complex (15.7%), N. farcinica complex (14.8%), N. brasiliensis (11.5%) and N. abscessus complex (8.2%). Susceptibilities of the more common Nocardia species are shown in the graph. Source of the positive cultures was variable with majority (>60%) from pulmonary source (sputum, BAL and lung tissue), blood in 5.7% and brain in 3.6%. Most common Nocardia species isolated from brain specimens were N. farcinica complex (24/59) followed by N. abscessus complex (17/59). Most common Nocardia species isolated from blood were N. farcinica complex (38/99) followed by N. nova complex (22/99) and N. cyriacigeorgica (15/99). Conclusion The antimicrobials that continue to show high activity against most Nocardia species (>95%) are: amikacin, linezolid and TMP/SMX. N. pseudobrasiliensis was noted to have high rates of resistance to TMP/SMX (87%). N. farcinia, N. brasiliensis and N. transvalensis/wallacei complex were >90% susceptible to amoxicillin/clavulanate. Clarithromycin had >99% activity against N. nova complex while both ceftriaxone and doxycycline had> 90% activity against N. abscessus complex. It is crucial to identify Nocardia species and obtain susceptibilities to help better choose the regimen with the best clinical outcome. Disclosures All authors: No reported disclosures.

Rationale:Nocardia species is known as conditional pathogenic bacteria. Among Nocardia species, pulmonary infection caused by Nocardia cyriacigeorgica associated with Aspergillus fumigatus complex lung disease is rarely reported.Patient concerns:A 55-year-old female with a history of product

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.

Resume Introduction Nocardia species est une bacterie aerobie tellurique, a l’origine d’infections opportunistes, principalement pulmonaires chez l’homme. Elle rend compte de 1 a 2 % des abces cerebraux. L’abces cerebral a Nocardia se distingue par son mauvais pronostic. Objectif Nous en rapportons cinq observations cliniques et, a la lumiere des donnees de la litterature, cherchons a etablir les eventuelles caracteristiques radiocliniques des abces cerebraux a Nocardia et en determiner la prise en charge optimale. Resultats Le mode de revelation clinique est souvent insidieux, sur un terrain d’immunodepression sous-jacent patente ou latente, l’hyperthermie n’est pas systematique. L’aspect radiologique est celui d’une lesion a centre necrotique, en cocarde, a coque epaisse polylobee, unique ou multiple. La realisation premiere de prelevements par biopsie ou enucleation chirurgicale, puis l’instauration d’une antibiotherapie adaptee parenterale conditionnent le pronostic.

Summary A review of all cases of nocardiosis in a large hospital in South Florida over the last 6years was conducted. There were 25 cases of nocardiosis and 76% of them were also infected with HIV. Of the HIV infected patients, all of them had CD4 counts less than 100cells/mm 3 and most cases were localized in the lungs.

Nocardia spp. are aerobic, Gram-positive, catalase-positive, non-motile actinomycetes. Various species of the genus Nocardia have attracted attention due to their detrimental effects on human health. Recent discoveries, however, have exposed their importance as producers of bioactive compounds and degraders of complex organic compounds, as well as their involvement in biotransformation into valuable products. This unit includes general protocols for the laboratory maintenance of Nocardia spp., including growth in liquid medium, growth on solid agar, and long-term storage. Nocardia sp. CS682 (KCTC11297BP), isolated from soil collected in Jeonnam, Korea, is used as a prototype for explaining the considerations for efficient laboratory maintenance of Nocardia spp.

Matrix-assisted laser desorption ionization–time of flight mass spectrometry for identification of Nocardia species remains challenging. By identifying 83.1% (64 of 77) and 80% (8 of 10) to the species and complex levels, respectively, and 94.3% (82 of 87) to the genus level, we show that an approach using routine sample preparation, an up-to-date commercial database minimally augmented with custom spectra, and testing at an early stage of growth is promising.

Objective: Acid fast bacilli (AFB) for sputum smear microscopy is the affordable method used for prompt diagnosis of tuberculosis in Nigeria despite its lack of specificity and limited sensitivity. The study aims to identify Mycobacterium tuberculosis and other acid fast organisms isolated from sputum of of HIV positive adult patients with pulmonary disease in Jos, Nigeria. Methods: Acid fast organisms isolated from 80 AFB positive sputa of HIV positive adult patients suspected for tuberculosis in Jos, Nigeria were identified for members of M. tuberculosis Complex (M tuberculosis, M bovis, M africanum, M canetti M. microti and M. caprae) by use of spoligootyping, Multiplex Gen Probe, Hain genotype assay and gene sequencing for spoligotype negative isolates. Results: Seven different spoligotypes of M. tuberculosis complex were identified from 70/80 (87.5%) total number of isolates. M. kansasii (1), M. dulvalii (1) Nocardia species (1) and Tsukamurella species (2) were detected from 5/10 spoligotype negative isolates. Conclusion and Recommendation: Although M. tuberculosis is the dominant AFB associated with chronic pulmonary disease in Jos, Nigeria, other clinically relevant mycobacteria were observed in the study. This suggests that other AFB positive microorganisms associated withtuberculosis -like symptoms could be misdiagnosed and incorrectly treated as M. tuberculosis. It is therefore necessary for laboratories in TB high burden countries to step up diagnostic procedures beyond routine smear microscopy.

The soil-borne pathogen Nocardia sp. causes severe cutaneous, pulmonary, and central nervous system infections. Against them, co-trimoxazole (SXT) constitutes the mainstay of antimicrobial therapy. However, some Nocardia strains show resistance to SXT, but the underlying genetic basis is unknown. We investigated the presence of genetic resistance determinants and class 1-3 integrons in 76 SXT-resistant Nocardia strains by PCR and sequencing. By E test, these clinical strains showed SXT minimum inhibitory concentrations of ≥32:608 mg/L (ratio of 1:19 for trimethoprim: sulfamethoxazole). They belonged to 12 species, being the main representatives Nocardia farcinica (32%), followed by N. flavorosea (6.5%), N. nova (11.8%), N. carnea (10.5%), N. transvalensis (10.5%), and Nocardia sp. (6.5%). The prevalence of resistance genes in the SXT-resistant strains was as follows: sul1 and sul2 93.4 and 78.9%, respectively, dfrA(S1) 14.7%, blaTEM-1 and blaZ 2.6 and 2.6%, respectively, VIM-2 1.3%, aph(3')-IIIa 40.8%, ermA, ermB, mefA, and msrD 2.6, 77.6, 14.4, and 5.2%, respectively, and tet(O), tet(M), and tet(L) 48.6, 25.0, and 3.9%, respectively. Detected amino acid changes in GyrA were not related to fluoroquinolone resistance, but probably linked to species polymorphism. Class 1 and 3 integrons were found in 93.42 and 56.57% strains, respectively. Class 2 integrons and sul3 genes were not detected. Other mechanisms, different than dfrA(S1), dfrD, dfrF, dfrG, and dfrK, could explain the strong trimethoprim resistance shown by the other 64 strains. For first time, resistance determinants commonly found in clinically important bacteria were detected in Nocardia sp. sul1, sul2, erm(B), and tet(O) were the most prevalent in the SXT-resistant strains. The similarity in their resistome could be due to a common genetic platform, in which these determinants are co-transferred. This study was presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy, ICAAC2014, Washington, DC, USA. We thank Adrian Burton for editing and language assistance (http://physicalevidence.es/english/welcome). We are very grateful to all persons who took part in this study, and to the sample providers. Sí

Nocardia infection following anterior cruciate ligament (ACL) allograft reconstruction is a rare occurrence. We report a case of Nocardia infection of an allograft ACL reconstruction and septic arthritis of the knee joint due to an organism most similar to the novel Nocardia species Nocardia aobensis .

Eighty-six Nocardia strains isolated from clinical samples in Belgium were identified by 16S rRNA gene sequencing. Eighty-three (96%) strains belonged to only six Nocardia species: N. farcinica (38 [44%]), N. nova (19 [22%]), N. cyriacigeorgica (13 [15%]), N. brasiliensis (6 [6.9%]), N. abscessus (5 [5.8%]), and N. paucivorans (2 [2.3%]). A gallery of nine conventional and enzymatic tests was developed for the rapid identification of the most common species isolated during this survey. Pyrrolidonyl aminopeptidase, γ-glutamyl aminopeptidase, α-mannosidase, and α-glucosidase were found to be highly discriminating and could be used to develop an identification scheme.

The phytoestrogen daidzein was metabolized by Nocardia species NRRL 5646 to give two metabolites obtained by hydroxylation and methylation. These metabolites were spectrally characterized as 7-methoxy-4'-hydroxyisoflavone (isoformononetin) and 7,8-dimethoxy-4'-hydroxyisoflavone. Mortierella isabellina ATCC 38063 was able to metabolize daidzein to the unusual metabolite daidzein-4'-rhamnopyranoside.

We report a unique case of ascending cutaneous lymphangitis in a 72-year-old immunocompromised man from which a newly described Nocardia species was isolated by 16S ribosomal gene sequencing. Treatment with trimethoprim-sulfamethoxazole resulted in successful resolution of symptoms. To the best of our knowledge, this is the first case report of N. veterana implicated in causing ascending cutaneous lymphangitis.

Because the number of recognized Nocardia species is continuing to increase, members of the genus Nocardia are becoming increasingly difficult to identify using phenotypic criteria. Molecular techniques, such as restriction endonuclease analysis and 16S rRNA gene sequencing, have become increasingly useful methodologies for the definitive identification of clinical isolates in this genus. While molecular methods have been useful for rapid and accurate identification, their use has complicated nocardial taxonomy by revealing new, clinically relevant species that are genetically distinct from known species but which may have few distinguishing phenotypic characteristics. We present here an overview of some taxonomic issues concerning Nocardia species and describe molecular techniques that are useful in the identification of the majority of clinically relevant species.

Nocardia species are aerobic, Gram-positive bacteria with branched filaments reported as opportunistic microorganisms associated with infectious diseases of the skin. We report the isolation of N. wallacei in Mexico from a 43-year-old man, an HIV-positive construction worker who sought care for difficulty breathing and abundant sputum.

Background: Nocardiosis is a localized or disseminated infection caused by an aerobic actinomycete that usually affects immunocompromised patients. Nocardiosis has been described in patients receiving immunosuppressive therapy, organ transplant recipients, subjects with chronic pulmonary diseases, and patients infected with the human immunodeficiency virus (HIV).Data review: Nocardial infection shows a broad and variable geographic distribution. The clinical forms include pulmonary involvement, skin or soft tissue infection, and disseminated forms with brain and pulmonary lesions. Primary nocardial infection includes pulmonary or cutaneous and/or subcutaneous lesions. Disseminated disease is defined by the identification of nocardial infection in two or more organs. The lung is the most commonly involved organ, followed by the skin and the brain. HIV-related nocardiosis usually appears in patients with advanced immunodepression and CD4 counts less than 50 cells/mL. Sulfonamides are the standard therapy for nocardiosis and are effective in the majority of cases. Several other drugs, such as imipenem, amikacin, minocycline, amoxicillin clavulanic acid and third-generation cephalosporins, have also been used in these patients. Surgery is usually reserved for the drainage of abscesses.Conclusions: Nocardiosis is an important cause of opportunistic infection in immunosuppressed patients. Early recognition and prompt treatment usually results in complete cure, except for patients with nocardial brain abscesses, in whom the mortality remains at approximately 50%.

The in vitro activities of TP-271, a novel fluorocycline antimicrobial, against 22 isolates of Mycobacterium abscessus , 22 isolates of Mycobacterium fortuitum , and 19 isolates of Nocardia spp. were studied by a microtiter broth dilution method. The MIC 90 s for M. abscessus , M. fortuitum , and Nocardia spp. were 0.5 μg/ml, 0.03 μg/ml, and 8 μg/ml, respectively. TP-271 was significantly more active than the respective control drug in virtually all tests.