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Journal of Clinical Microbiology Jan 2018species 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... (Review)
Review
species 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 for , the type species of the genus and previously the most frequently reported nocardial taxon from human specimens. We provide background on the current taxonomy of , 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.
Topics: Algorithms; Bacteriological Techniques; Humans; Multilocus Sequence Typing; Nocardia; Nocardia Infections; Nocardia asteroides; Phylogeny; Species Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 29118169
DOI: 10.1128/JCM.01419-17 -
Clinical Microbiology Reviews Apr 2006The recent explosion of newly described species of Nocardia results from the impact in the last decade of newer molecular technology, including PCR restriction enzyme... (Review)
Review
The recent explosion of newly described species of Nocardia results from the impact in the last decade of newer molecular technology, including PCR restriction enzyme analysis and 16S rRNA sequencing. These molecular techniques have revolutionized the identification of the nocardiae by providing rapid and accurate identification of recognized nocardiae and, at the same time, revealing new species and a number of yet-to-be-described species. There are currently more than 30 species of nocardiae of human clinical significance, with the majority of isolates being N. nova complex, N. abscessus, N. transvalensis complex, N. farcinica, N. asteroides type VI (N. cyriacigeorgica), and N. brasiliensis. These species cause a wide variety of diseases and have variable drug susceptibilities. Accurate identification often requires referral to a reference laboratory with molecular capabilities, as many newer species are genetically distinct from established species yet have few or no distinguishing phenotypic characteristics. Correct identification is important in deciding the clinical relevance of a species and in the clinical management and treatment of patients with nocardial disease. This review characterizes the currently known pathogenic species of Nocardia, including clinical disease, drug susceptibility, and methods of identification.
Topics: Anti-Bacterial Agents; Bacteriological Techniques; Culture Media; DNA, Bacterial; Humans; Lung Diseases; Microbial Sensitivity Tests; Nocardia; Nocardia Infections; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Bacterial; RNA, Ribosomal, 16S; Skin Diseases; Species Specificity
PubMed: 16614249
DOI: 10.1128/CMR.19.2.259-282.2006 -
Journal of Laboratory Physicians Jan 2011Mycetoma is a chronic infection, frequently seen in tropical and sub-tropical countries and is considered as an occupational disease. Nocardia species though it can...
Mycetoma is a chronic infection, frequently seen in tropical and sub-tropical countries and is considered as an occupational disease. Nocardia species though it can infect immunocompetent individuals, it most commonly affects immunocompromised patients. A 50-year-old male, farmer presented to our hospital with serosanguineous discharging swelling over the dorsum of right foot. We have isolated Nocardia asteroides from the tissue sample. Speciation of this isolate was carried out based on phenotypic methods. Hereby we report a case of Actinomycetes Mycetoma in an immunocompetent individual.
PubMed: 21701663
DOI: 10.4103/0974-2727.78564 -
Journal of Ophthalmic Inflammation and... Dec 2020Nocardia species are an uncommon but important cause of keratitis. The purpose of this review is to discus previous published papers relation to the epidemiology,... (Review)
Review
Nocardia species are an uncommon but important cause of keratitis. The purpose of this review is to discus previous published papers relation to the epidemiology, etiology, diagnosis and management of Nocardia keratitis. Nocardia asteroides is the most frequently reported from Nocardia keratitis. Pain, photophobia, blepharospasm and lid swelling are mainly clinical manifestations. Usual risk factors for Nocardia keratitis are trauma, surgery, corticosteroids, and contact lens wear. Several antibiotics were used for treatment of Nocardia infection but according to studies, topical amikacin is the drug of choice for Nocardia keratitis. Topical steroid should not prescribe in these patients. In conclusion, although Nocardia keratitis is rare, early diagnosis and treatment are essential to prevent any scar formation and preserve a good visual acuity.
PubMed: 33263838
DOI: 10.1186/s12348-020-00228-w -
Journal of Bacteriology Apr 1967Shadowed motile elements from actinomycetes were observed with an electron microscope. Included were three strains of Actinoplanes, two of Ampullariella, two of...
Shadowed motile elements from actinomycetes were observed with an electron microscope. Included were three strains of Actinoplanes, two of Ampullariella, two of Dermatophilus, two of Spirillospora, and four of "Nocardia" turbata. In addition, three types of previously undescribed actionmycetes were represented: (i) the C(4) group (four strains) forming substrate mycelium breaking into motile rods; (ii) strain 9-41, forming Microellobosporia-like sporangia with motile spores; and (iii) strain P(2), forming aerial hyphae releasing motile cocci when put in water. All the known chemical cell wall types of actinomycetes except the Nocardia asteroides type and the Actinomyces israeli type were represented in this array of motile actinomycetes. Motile elements were, depending on the genus, cocci, rods (often curved), or pyriform. Flagella were always in tufts (or single), never peritrichous. A relationship seems to exist between the location of the tuft and the cell wall composition. The spores of one strain of Actinoplanes were herniated, thus resembling plasmoptysis forms of bacteria.
Topics: Actinomycetales; Amino Acids; Carbohydrates; Cell Wall; Flagella; Microscopy, Electron; Nocardia; Pimelic Acids
PubMed: 6032515
DOI: 10.1128/jb.93.4.1446-1451.1967 -
Revista Chilena de Infectologia :... Dec 2006
Topics: Anti-Infective Agents; Bacterial Typing Techniques; Humans; Nocardia Infections; Nocardia asteroides; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 17186085
DOI: 10.4067/s0716-10182006000400011 -
Clinical Microbiology Reviews Apr 1994The nocardiae are bacteria belonging to the aerobic actinomycetes. They are an important part of the normal soil microflora worldwide. The type species, Nocardia... (Review)
Review
The nocardiae are bacteria belonging to the aerobic actinomycetes. They are an important part of the normal soil microflora worldwide. The type species, Nocardia asteroides, and N. brasiliensis, N. farcinica, N. otitidiscaviarum, N. nova, and N. transvalensis cause a variety of diseases in both normal and immunocompromised humans and animals. The mechanisms of pathogenesis are complex, not fully understood, and include the capacity to evade or neutralize the myriad microbicidal activities of the host. The relative virulence of N. asteroides correlates with the ability to inhibit phagosome-lysosome fusion in phagocytes; to neutralize phagosomal acidification; to detoxify the microbicidal products of oxidative metabolism; to modify phagocyte function; to grow within phagocytic cells; and to attach to, penetrate, and grow within host cells. Both activated macrophages and immunologically specific T lymphocytes constitute the major mechanisms for host resistance to nocardial infection, whereas B lymphocytes and humoral immunity do not appear to be as important in protecting the host. Thus, the nocardiae are facultative intracellular pathogens that can persist within the host, probably in a cryptic form (L-form), for life. Silent invasion of brain cells by some Nocardia strains can induce neurodegeneration in experimental animals; however, the role of nocardiae in neurodegenerative diseases in humans needs to be investigated.
Topics: AIDS-Related Opportunistic Infections; Animals; Brain Diseases; Humans; Nocardia; Nocardia Infections; Phagocytosis
PubMed: 8055469
DOI: 10.1128/CMR.7.2.213 -
Microbiology Resource Announcements Aug 2019We report four draft genome sequences of spp. The strains are the DSM 44484 pathogenic type strain; two environmental isolates, EML446 and EML1456; and the ATCC...
We report four draft genome sequences of spp. The strains are the DSM 44484 pathogenic type strain; two environmental isolates, EML446 and EML1456; and the ATCC 19247 nonpathogenic type strain, with estimated genome sizes of 6.3 to 6.8 Mb. The study of these isolates will provide insight into physiology, evolution, and pathogenicity of spp.
PubMed: 31416867
DOI: 10.1128/MRA.00600-19 -
Postgraduate Medical Journal Jul 1986Nocardia asteroides osteomyelitis has previously been described only in acutely ill patients. It may occur as an isolated event or part of the disease spectrum of...
Nocardia asteroides osteomyelitis has previously been described only in acutely ill patients. It may occur as an isolated event or part of the disease spectrum of disseminated nocardiosis. An 84 year old immune competent man with N. asteroides right tibial osteomyelitis had an unusual presentation, presumed mechanism of disease and outcome. His course affords an opportunity to review the literature on N. asteroides osteomyelitis and to discuss the unique features of his case.
Topics: Aged; Humans; Male; Nocardia Infections; Nocardia asteroides; Osteomyelitis
PubMed: 3529069
DOI: 10.1136/pgmj.62.729.673 -
Brazilian Journal of Microbiology :... Jun 2023Nocardia are ubiquitous, saprophytic and opportunistic bacteria. They cause a set of pyogenic clinical infections in animals and humans, particularly immunocompromised...
Nocardia are ubiquitous, saprophytic and opportunistic bacteria. They cause a set of pyogenic clinical infections in animals and humans, particularly immunocompromised patients, mostly affecting the skin and respiratory tract, with refractoriness to conventional therapy. The most descriptions of nocardial infections in companion animals involve case reports, and there are scarce case series studies focused on canine and feline nocardiosis in which diagnosis has been based on molecular techniques. We investigated epidemiological aspects, clinical findings, in vitro susceptibility profile, and molecular identification of Nocardia using PCR-based method targeted 16S rRNA gene in twelve dogs and two cats. Among dogs were observed cutaneous lesions (8/12 = 67%), pneumonia (3/12 = 25%), and encephalitis (2/12 = 17%), whereas cats developed cutaneous lesions and osteomyelitis. Nocardia and canine morbillivirus coinfection was described in six dogs (6/12 = 50%). A high mortality rate (6/8 = 75%) was seen among dogs. Three dogs (3/4 = 75%) and one cat (1/2 = 50%) with systemic signs (pneumonia, encephalitis, osteomyelitis), and 83% (5/6) of dogs with a history of concomitant morbillivirus infection died. N. nova (5/12 = 42%), N. cyriacigeorgica (3/12 = 25%), N. farcinica (2/12 = 17%), N. veterana (1/12 = 8%), and N. asteroides (1/12 = 8%) species were identified in dogs, whereas N. africana and N. veterana in cats. Among the isolates from dogs, cefuroxime (12/12 = 100%), amikacin (10/12 = 83%), gentamycin (10/12 = 83%), and imipenem (10/12 = 83%) were the most effective antimicrobials, whereas cefuroxime, cephalexin, amoxicillin/clavulanic acid, imipenem, and gentamycin were efficient against isolates from cats. Multidrug resistance was observed in 36% (5/14) of isolates. We describe a variety of Nocardia species infecting dogs and cats, multidrug-resistant ones, and a high mortality rate, highlighting a poor prognosis of nocardiosis in companion animals, particularly among animals systemically compromised or coinfected by canine morbillivirus. Our study contributes to species identification, in vitro antimicrobial susceptibility profile, clinical-epidemiological aspects, and outcome of natural Nocardia-acquired infections in dogs and cats.
Topics: Cats; Animals; Dogs; Humans; Nocardia; Anti-Bacterial Agents; Cat Diseases; Cefuroxime; RNA, Ribosomal, 16S; Drug Resistance, Bacterial; Dog Diseases; Nocardia Infections; Anti-Infective Agents; Osteomyelitis; Imipenem; Gentamicins; Microbial Sensitivity Tests
PubMed: 37079272
DOI: 10.1007/s42770-023-00968-6