Gordonia terrae: a difficult-to-diagnose emerging pathogen?
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Actinomycetales Infections↗
Biomedical subjects
P Boiron
Publications and source records attributed to P Boiron.
[Mycotic keratitis and endophthalmitis caused by unusual fungi: Lasiodiplodia theobromae].
We report a case of endophthalmitis caused by the fungus Lasiodiplodia theobromae. A 68-year-old man was referred to the hospital for right ocular pain since experiencing right ocular branch trauma 2 weeks before. The best-corrected acuity was limited to hand motion. Slit-lamp examination showed a large corneal abscess and an anterior chamber reaction. The patient underwent systemic and local antibiotic therapy, and corneal scraping for microbiological diagnosis. Sabouraud-chloramphenicol-gentamicin agar disclosed filamentous fungus, which was treated with oral itraconazole and topic amphotericin B. Molecular biology revealed Lasiodiplodia theobromae. Despite antimycotic drugs, severe panophthalmia occurred very quickly and led to evisceration. This case report describes Lasiodiplodia theobromae as the cause of keratomycosis and discusses risk factors and clinical features of fungal keratitis in order to improve prognosis by earlier treatment.
Aged↗
Nocardiosis in a teaching hospital in the Central Anatolia region of Turkey: treatment and outcome.
Predisposing factors, antimicrobial susceptibility patterns, treatment and outcome were analysed for nine consecutive patients with nocardiosis. Predisposing factors were identified in six (67%) of the nine patients. Clinical syndromes of nocardial infection were pulmonary infection (three patients), cerebral infection (five patients) and disseminated infection (one patient). The predominant (60%) species was Nocardia farcinica rather than the Nocardia asteroides complex. Treatment was started empirically, modified according to the antimicrobial susceptibility pattern, and then continued for 6-12 months. Overall mortality was 33%, with death being caused by the Nocardia infection in two cases.
Adult↗
Brain abscess caused by Nocardia cyriacigeorgica in a patient with human immunodeficiency virus infection.
Nocardia cyriacigeorgica is a recently characterized species within the genus of Nocardia. We report a brain abscess, following a primary pulmonary colonization, due to this species in a human immunodeficiency virus-infected patient. This case confirms that isolation of Nocardia in sputum is associated with a high risk of disseminated infection in immunocompromised patients.
AIDS-Related Opportunistic Infections↗
Screening of nonpolyenic antifungal metabolites produced by clinical isolates of actinomycetes.
The purpose of this work was to screen clinical isolates of actinomycetes producing nonpolyenic antifungals. This choice was made to limit the problem of rediscovery of well-known antifungal families, especially polyenic antifungals. One hundred and ten strains were tested, using two diffusion methods and two test media, against three yeast species and three filamentous fungi. Among 54 strains (49%) showing antifungal activity, five strains belonging to the genus Streptomyces were active against all test organisms and appeared promising. These results indicate that clinical and environmental isolates of actinomycetes could be an interesting source of antifungal bioactive substances. The production of nonpolyenic antifungal substances by these five active isolates was investigated using several criteria: antibacterial activity, ergosterol inhibition, and UV-visible spectra of active extracts. One active strain responded to all three selection criteria and produced potentially nonpolyenic antifungal metabolites. This strain was retained for further investigation, in particular, purification, structure elucidation, and mechanism of action of the active product.
Anti-Bacterial Agents↗
[Isolation of three species of Nocardia in a patient receiving long-term corticosteroid therapy].
INTRODUCTION: Nocardia are saprophyte bacteria of the environment responsible for systemic infections in immunodepressed patients, due essentially to long-term corticosteroids. OBSERVATION: A patient having received corticosteroids for sarcoidoses for a year was hospitalised because of disseminated granulomatosis (neurological, respiratory, abdominal and cutaneous). Culture of various bacteriological samples isolated three species of Nocardia: N. otitidiscaviarum in uretheral pus and pus from the right gland, N. nova and N. asteroides in respiratory samples (protected distal sampling and broncho-alveolar washing). COMMENTS: Other than the mixed Nocardia infections described habitually, infections with two different species of Nocardia have recently been reported. Our case report is the first to have isolated three concomitant species of Nocardia.
Adrenal Cortex Hormones↗
Case Reports. Chronic and acute Aspergillus meningitis.
Cerebral aspergillosis usually occurs in severely immunocompromized hosts, is difficult to diagnose, and has a poor prognosis. After 14 months of chronic meningitis, ventriculitis, choroid plexitis, and lumbar arachnoiditis, which was complicated by acute hydrocephalus, Aspergillus, suspected to be from the candidus group, was isolated from the cerebrospinal fluid (CSF) of a previously healthy man. Thereafter Aspergillus antigen was found in stored plasma and CSF samples. He was treated with voriconazole and itraconazole. In a haemodialysis patient affected by an acute meningococcal meningitis, following a 3-day symptom-free interval, symptoms and signs of acute meningitis had reappeared and were unresponsive to a broad antimicrobial coverage. However, they resolved within 5 days after liposomal amphotericin B treatment had been started. From his CSF Aspergillus-DNA was identified and Aspergillus fumigatus isolated by culture. These two different clinical cases show that Aspergillus-DNA and antigen detection tests represent an advance in the diagnosis and liposomal amphotericin B, voriconazole, and itraconazole are an advance in the treatment of Aspergillus meningitis.
Acute Disease↗
'Nocardia asteroides' mycetoma of the foot.
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Anti-Bacterial Agents↗
Nocardia farcinica infection of a cochlear implant in an immunocompetent boy.
The first case of an infection caused by Nocardia farcinica on a cochlear implant and its progression is described. As it is difficult to diagnose Nocardia spp., the identification was confirmed by phylogenetic analysis using 16S rDNA sequencing.
Base Sequence↗
Report of human nocardiosis in Italy between 1993 and 1997.
During a 5-year period, from 1993 to 1997, nocardial infection was diagnosed in 26 patients admitted to hospitals in 11 cities in Italy. Pathogens were identified as Nocardia asteroides in 18 cases, as N. farcinica in five cases, as N. nova in two and as N. brasiliensis in one case. All cases were difficult to diagnose, as usually it happens with this disease: physicians have to be alert to suspect nocardial infection so that appropriate therapy can be early given. This is the second retrospective report on Nocardia spp. infection conducted in Italy, suggesting the utility to organise a permanent network for a national survey system for nocardiosis.
Drug Resistance, Microbial↗
Yeast identification in the clinical microbiology laboratory: phenotypical methods.
Emerging yeast pathogens are favoured by increasing numbers of immunocompromised patients and by certain current medical practices. These yeasts differ in their antifungal drug susceptibilities, and rapid species identification is imperative. A large variety of methods have been developed with the aim of facilitating rapid, accurate yeast identification. Significant recent commercial introductions have included species-specific direct enzymatic colour tests, differential chromogenic isolation plates, direct immunological tests, and enhanced manual and automated biochemical and enzymatic panels. Chromogenic isolation media demonstrate better detection rates of yeasts in mixed cultures than traditional media, and allow the direct identification of Candida albicans by means of colony colour. Comparative evaluation of rapid methods for C. albicans identification, including the germ tube test, shows that chromogenic media may be economically advantageous. Accurate tests for single species include the Bichrolatex Albicans and Krusei Color tests, both immunologically based, as well as the Remel Rapid Trehalose Assimilation Broth for C. glabrata. Among broad-spectrum tests, the RapID Yeast Plus system gives same-day identification of clinical yeasts, but performance depends on inoculum density and geographic isolate source. The API 20 C AUX system is considered a reference method, but newer systems such as Auxacolor and Fungichrom are as accurate and are more convenient. Among automated systems, the ID 32 C strip, the Vitek Yeast Biochemical Card and the Vitek 2 ID-YST system correctly identify >93% of common yeasts, but the ID-YST is the most accurate with uncommon yeasts, including C. dubliniensis. Spectroscopic methods such as Fourier transformed-infrared spectroscopy offer potential advantages for the future. Overall, the advantages of rapid yeast identification methods include relative simplicity and low cost. For all rapid methods, meticulous, standardized multicenter comparisons are needed before tests are fully accepted.
Candida↗
Molecular and biochemical analysis of AST-1, a class A beta-lactamase from Nocardia asteroides sensu stricto.
A beta-lactamase gene was cloned from a Nocardia asteroides sensu stricto clinical isolate. A recombinant plasmid, pAST-1, expressed the beta-lactamase AST-1 in Escherichia coli JM109. Its pI was 4.8, and its relative molecular mass was 31 kDa. E. coli JM109(pAST-1) was resistant to penicillins and narrow-spectrum cephalosporins. The beta-lactamase AST-1 had a restricted hydrolytic activity spectrum. Its activity was partially inhibited by clavulanic acid but not by sulbactam and tazobactam. AST-1 is an Ambler class A beta-lactamase sharing 65% amino acid identity with beta-lactamase FAR-1, the most closely related enzyme.
Adult↗
[Nocardia and human nocardiosis].
Nocardia spp. are pathogens commonly found in soil worldwide, and they cause mostly opportunistic infections in humans and animals, complicating both immunodepressive states and primary diseases. Nocardiosis is difficult to proper microbiological and clinical diagnosis because of its non-specific symptoms, which manifest as the cutaneous and sub-cutaneous infections, lung symptoms and the dissemination through the bloodstream to other organs. General characteristics of Nocardia, human nocardiosis as well as the microbiological diagnostics routine and treatment are discussed.
Aminoglycosides↗
Potential utility of random amplified polymorphic DNA (RAPD) and restriction endonuclease assay (REA) as typing systems for Madurella mycetomatis.
Two molecular methods were compared, random amplified polymorphic DNA (RAPD) and restriction endonuclease analysis (REA), in order to evaluate their ability to discriminate, and to characterize Madurella mycetomatis strains isolated from human mycetomas in different parts of the world. Both methods were able to cluster the Madurella mycetomatis isolates into the same number of distinct typing groups. However, RAPD, presenting several advantages over REA such as its rapidity, simplicity, and the accessibility for implementation in the laboratory, is a more sensitive and reproducible tool for the study of Madurella mycetomatis epidemiology than REA.
DNA Restriction Enzymes↗
Infection caused by Nocardia farcinica: case report and review.
Nocardia farcinica is a rare Nocardia species causing localised and disseminated infections. A case of Nocardia farcinica infection is presented, and 52 cases previously reported in the literature are reviewed. The hosts usually had predisposing conditions (85%), and acquired the infection through the respiratory tract or skin; the infection then often spread to the brain, kidney, joints, bones and eyes. Pulmonary or pleural infections (43%), brain abscesses (30%) and wound infections (15%) which failed to respond to conventional antimicrobial therapy were the more frequent forms of infection. Nocardia farcinica was frequently isolated from pus (100% of samples), bronchial secretions (41%) and biopsy specimens (63%), but isolation from blood and urine, as in the case presented here, is rare. Antibiotic therapy was adequate in 61% of the patients in whom it was specified, the agents most frequently given being trimethoprim-sulfamethoxazole (54%), amikacin combined with imipenem (7%) and amoxicillin-clavulanate (7%). The high mortality (31%) can be attributed to the severe underlying diseases present, difficulties encountered in identifying the pathogen, inappropriate therapy and late initiation of therapy. Although an infrequent pathogen, Nocardia farcinica should be kept in mind as a cause of infection especially in immunosuppressed patients with indolent infections not responding to third-generation cephalosporins.
Aged↗
Genetic relatedness analysis of nocardia strains by random amplification polymorphic Dna: validation and applications.
Until now, no simple and rapid technique existed for epidemiological study of strains belonging to the Nocardia genus. The application of the arbitrarily primed PCR procedure to generate randomly amplified polymorphic DNA (RAPD) fingerprints for such analysis of Nocardia isolates was investigated. Fifty-one unrelated clinical isolates of N. asteroides were tested. Two conditions of RAPD using two different primers generated RAPD fingerprints that allowed the differentiation of all strains. The patterns were reproducible and discriminating. The results highlight the diversity of N. asteroides species and confirm that RAPD analysis is a highly valuable tool for studying the epidemiology of the Nocardia genus. Several examples describe the advantage of RAPD analysis for establishing the relationship between isolates from a given patient (long-term infections, coinfections) and from different patients (i.e. during an outbreak). In the future, this technique will help us to investigate the source of infection in cases of nosocomial transmission, to understand the outcome of nocardiosis, and to follow the evolution and acquisition of resistance to Nocardia strains.
Bacterial Typing Techniques↗
Antimicrobial susceptibility profile of soil isolates of Nocardia asteroides from Kuwait.
OBJECTIVES: To find the antimicrobial susceptibility profile of 42 soil isolates of Nocardia asteroides against 14 antimicrobial agents representing beta-lactams, aminoglycosides, ciprofloxacin, minocycline, erythromycin and third generation cephalosporins. METHODS: The antimicrobial susceptibility was determined by the disk diffusion method using Mueller-Hinton agar medium. A homogeneous suspension giving an inoculum of 106-108 CFU/mL was used to streak the plates. The zone of inhibition was read after 36-48 h of incubation at 37 degrees C. RESULTS: All the soil isolates of N. asteroides were susceptible to amikacin, imipenem and tobramycin. Susceptibility to cephalosporins was quite variable; 86% of the isolates were susceptible to cefotaxime, 57% to ceftriaxone and 40% to cefamandole. Fifty-seven per cent of the isolates showed intermediate susceptibility to cefamandole, 33% to ceftriaxone and 5% to cefotaxime. Ninety-three per cent of the isolates were resistant to sulfamethoxazole alone or in combination with trimethoprim. CONCLUSIONS: The study reports a wide variation in the antimicrobial susceptibility profile of soil isolates of N. asteroides originating from a single geographical area. Of interest is the finding that over 90% of N. asteroides isolates were resistant to sulfamethoxazole without any previous exposure to this drug. This may have serious therapeutic implications as sulphonamides or the combination of trimethoprim-sulfamethoxazole is the therapy of choice for nocardiosis. Demonstration of resistance to beta-lactam antibiotics may be attributed to the presence of beta-lactamases which was detectable in > 90% of the soil strains of N. asteroides. The study underscores the importance of antimicrobial susceptibility testing for clinical isolates of Nocardia since individual strains show considerable differences in their susceptibility patterns necessitating therapeutic adjustments.
Anti-Bacterial Agents↗
News & notes: diversity of superoxide-dismutases among clinical and soil isolates of Streptomyces species.
Comparison of the nature, activity, and cellular localization of superoxide-dismutases (SOD) from soil and clinical isolates of Streptomyces species was investigated to identify possible factors that could account for the pathological role of the strains isolated from human lesions. Results showed that all of the studied strains possessed a cytoplasmic Ni-SOD. This particular SOD, found in isolates from patients, could be a new taxonomic criterion to identify Streptomyces species with greater precision. A second minor SOD, assimilated to an Fe/Zn-SOD, was detected in some strains, but no relationship was established between the presence of this enzyme and the clinical origin of the strains.
Electrophoresis, Polyacrylamide Gel↗