Antimicrobial susceptibility of Nocardia species

Nocardiosis from 1888 to 2017

The genus Nocardia is an aerobic bacterium, Gram-positive and catalase positive that is in Nocardiaceae family. This bacterium first described by Edmond Nocard in 1888 and is not in human commensal bacteria. To date, nocardiosis incidence is increasing due to increase population growth rate, increase in patients with immune disorder diseases and immunocompromised patients. We surveyed taxonomic position, isolation methods, phenotypic and molecular identification at the genus and species levels, antibiogram, treatment and epidemiology in the world from 1888 to 2017.

Pulmonary infiltrate and painful nodular leg lesions in a patient with membranous glomerulonephritis

Nocardia otitidis-cavarium is rarely isolated as an infectious pathogen in the western world. We report on a 71-year-old Caucasian man with membranous glomerulonephritis who presented with several seemingly unrelated clinical symptoms that, after laborious diagnostics, turned out to be caused by disseminated infection with N. otitidis-cavarium. This case highlights the variable clinical presentations that can occur in nocardial infections and underscores the need to search for rare pathogens in patients taking immunosuppressive medication.

A case series and focused review of nocardiosis: clinical and microbiologic aspects

Nocardia species are ubiquitous soil organisms that often infect patients with underlying immune compromise, pulmonary disease, or a history of surgery or trauma. We report 5 cases of nocardiosis representing various aspects of this "great imitator": 1) pneumonia in the setting of underlying malignancy, 2) chronic pneumonia with drug-resistant organism, 3) bacteremia and empyema with chronic hematologic malignancy, 4) primary cutaneous disease, and 5) sternal wound infection. We present a summary of the English literature from 1966 to 2003 with a focus on the teaching points of each of our 5 cases as well as the background epidemiology and microbiology of the Nocardia genus. Isolation of the organism may be achieved with routine media but longer incubation times may be necessary, delaying diagnosis and appropriate therapy. Treatment with a sulfa-containing regimen is standard of care, but resistance testing is warranted given emerging drug resistance, high rates of discontinuation due to adverse reactions, and the potential for nephrotoxicity in transplant recipients on cyclosporine.

Thoracic actinomycosis (arcanobacteriosis) or nocardiosis causing thoracic pyogranuloma formation in three dogs

OBJECTIVE

To describe three cases of canine thoracic actinomycosis (arcanobacteriosis) or nocardiosis in which the primary pathological lesion was a pyogranulomatous abscess in the mediastinum. Clinical signs, difficulties in diagnosis, treatment and prognosis are examined. Comparisons are made between human and veterinary literature to assist in formulating a rational treatment plan.

DESIGN

Retrospective clinical study.

PROCEDURE

Review of case records from 1984 to 1998.

RESULTS

Three dogs presented with large intrathoracic pyogranulomas producing variable clinical signs, not necessarily associated with the respiratory tract. Ages ranged from 2 to 5 years old. Two dogs responded to surgical opening and passive drainage of the abscess, or surgical excision of the granuloma with associated structures, and medical therapy. One dog died intra-operatively.

CONCLUSION

A combination of surgical and antimicrobial therapy may carry a fair-to-good prognosis for thoracic granuloma caused by actinomycosis (arcanobacteriosis) or nocardiosis. The extent of surgery should be based on assessment of individual cases and must include surgical biopsy for histology and culture to enable a specific diagnosis to be made. Complete surgical excision is not necessarily required. Prolonged antimicrobial therapy is indicated.

Nocardiosis. A literature review with selected case reports in two dogs

Two dogs with systemic nocardiosis are presented and the pathobiology, diagnosis, and treatment of nocardial infections are discussed. Both dogs had nonspecific respiratory signs and depression. The diagnosis was made by isolation of the organism only after surgical drainage was established and appropriate tissues were cultured. The response to surgical drainage and antimicrobial therapy was dramatic in both dogs, but one dog experienced a drug reaction to trimethoprim-potentiated sulfonamide. Although systemic nocardial infections traditionally have had a grave prognosis, through early diagnosis, surgical intervention, and the use of newer, safer and synergistically acting antimicrobials, the prognosis has improved. This article reviews current human and veterinary literature regarding the microbiology, pathogenesis, and treatment of nocardiosis and reports on the successful treatment of systemic nocardiosis in two dogs.

Inactivation of kanamycin A by phosphorylation in pathogenic Nocardia

Among the five species of pathogenic Nocardia, i.e., N. asteroides, N. brasiliensis, N. farcinica, N. nova and N. otitidiscaviarum, all strains of N. brasiliensis and N. farcinica showed resistance to an aminoglycoside antibiotic, kanamycin A, showing the MIC (minimum inhibitory concentration) values of more than 100 micrograms/ml. This species-specific difference in sensitivity was found to be explained by the production of an inactivation enzyme, aminoglycoside 3'-phosphotransferase APH(3'). Structural studies by mass and NMR spectroscopy on the inactivated substance produced by a cell-free extract of the Nocardia confirmed the conversion of kanamycin A to an inactive substance, kanamycin A 3'-phosphate. The MIC values of N. otitidiscaviarum and N. nova for kanamycin A, on the other hand, ranged from 0.78 micrograms/ml to 100 micrograms/ml, and both species were non-producers of APH(3'). Sensitivity to the antibiotic and APH(3') productivity of N. asteroides varied depending on the strain.

Enzymatic characterization of Nocardia spp. and related bacteria by API ZYM profile

Characterization of 62 isolates belonging to the genus Nocardia and related bacteria was obtained by using the API ZYM system. The difference in enzymatic profile should allow a relatively efficient, low-cost means to identify aerobic actinomycetes of clinical significance.

Brain abscess due to Nocardia

Cerebral Nocardiosis is a rare disease, usually occurring in immunocompromised hosts. We report here two cases of brain abscess due to Nocardia species-one due to usual N. asteroides and other by uncommon N. caviae. N. asteroides affected the brain in a post renal transplant patient, whereas N. caviae caused infection of brain in an apparently healthy individual. To the best of our knowledge, all the previous cases of brain abscess due to Nocardia caviae have been reported in compromised hosts. Agar dilution antimicrobial testing showed relatively higher resistant pattern in N. asteroides. In spite of antimicrobial therapy, both the patients succumbed, one within 4 days and other after an initial improvement for four weeks due to drainage of abscess.

Erythromycin: a microbial and clinical perspective after 30 years of clinical use (1)

Erythromycin is a macrolide that acts by inhibiting the translocation reaction during protein synthesis. Erythromycin is inactive against the Enterobacteriaceae and Pseudomonas aeruginosa except under alkaline conditions. Erythromycin is active against most gram-positive bacteria; some gram-negative bacteria, including Neisseria, Bordetella, Brucella, Campylobacter, and Legionella; and Treponema, Chlamydia, and Mycoplasma. The emergence of resistance to erythromycin is closely associated with its use and is often plasmid mediated. After its oral or parenteral administration, erythromycin diffuses readily into intracellular fluids and is actively concentrated intracellularly by polymorphonuclear leukocytes and alveolar macrophages.

Trimethoprim/sulfamethoxazole-resistant Nocardia asteroides causing multiple hepatic abscesses. Successful treatment with ampicillin, amikacin, and limited computed tomography-guided needle aspiration

Hepatic abscesses are rarely encountered in disseminated Nocardia infections. Sulfonamides alone or trimethoprim/sulfamethoxazole is often efficacious in treating infections caused by Nocardia asteroides. In vitro resistance of N. asteroides to trimethoprim/sulfamethoxazole is occasionally present. The patient described in this report had disseminated nocardiosis initially manifesting as multiple subcapsular hepatic abscesses. In vitro susceptibility studies demonstrated resistance to trimethoprim/sulfamethoxazole. Subsequent treatment with ampicillin and amikacin in conjunction with computed tomography-guided needle aspiration of several of the hepatic abscesses, surgical drainage of a right pleural empyema, and eventual discontinuation of use of corticosteroids resulted in cure of the infection.

In vitro susceptibility of Nocardia asteroides to 25 antimicrobial agents

Fifty-two clinical isolates of Nocardia asteroides were tested by agar dilution for their susceptibility to 25 antimicrobial agents. In general, susceptibility could not be predicted based on the antibiotic class tested. However, the beta-lactams, including third-generation cephalosporins, were generally ineffective (MIC for 90% of the organisms [MIC90], between 64 and greater than 256 micrograms/ml), whereas minocycline and doxycycline were generally effective (MIC90, 4 and 8 micrograms/ml, respectively). Cycloserine was not effective below 60 micrograms/ml. The MIC50 and MIC90 of sulfamethoxazole was 16 and 32 micrograms/ml, respectively, and that of trimethoprim varied widely (16 and greater than 256 micrograms/ml, respectively). Based on MIC90 data, only doxycycline, minocycline, sulfamethoxazole, and imipenem could be applied empirically.

Synergistic action of trimethoprim and sulfamethoxazole for Nocardia asteroides: efficacious therapy in five patients

Eighteen isolates of Nocardia asteroides were tested for in vitro susceptibility to trimethoprim (TMP) and sulfamethoxazole (SMZ) alone and in various combinations using disc and paper strip diffusion tests. TMP-SMZ showed synergistic action for two-thirds of teh nocardia isolates tested. Five patients with Nocardia pneumonia were treated with TMP-SMZ and all were cured. Four of the patients' isolates were tested and all showed synergistic patterns of inhibition with the spaced disc and paper strip methods. The agar diffusion disc and synergy tests of TMP-SMZ appear to correlate with clinical usefulness when the Nocardia are susceptible with large zones of inhibition around the combination TMP-SMZ disc.

Susceptibility of Nocardia asteroides to 46 antibiotics, including 22 beta-lactams

Twelve Nocardia asteroides isolates were tested for their susceptibility to 46 antibiotics by the agar dilution method. N-Formimidoyl thienamycin was the most active of 22 beta-lactam antibiotics, inhibiting 11 of the 12 strains at 1 microgram/ml. Penicillins, including ureidopenicillins, showed poor activity. Cefotaxime, ceftriaxone, and especially cefuroxime had the best activities of the cephalosporins tested. Among the other antibiotics, amikacin and minocycline, respectively, inhibited all of the strains tested at 0.5 and 4 micrograms/ml.

Endogenous ocular nocardiosis: a clinical and experimental study

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In vitro susceptibility of Nocardia asteroides to N-formimidoyl thienamycin and several cephalosporins

The susceptibility of N. asteroides to N-formimidoyl thienamycin, cefamandole, cefoxitin, and moxalactam was determined by agar dilution. N-Formimidoyl thienamycin was the most active, inhibiting eight of nine strains at 1.56 mug/ml.

Nocardia asteroides keratitis

Nocardia asteroides has been reported as the cause of keratitis in only 7 cases and of other ocular disease in another 12 cases. We report a case of N. asteroides keratitis that presented 3 weeks after rural trauma and progressed despite trials of appropriate antibiotics. Seven weeks after the origianl injury a successful conjunctival flap was placed over the cornea. The morphology and the sensitivity testing of N. asteroides to antibiotics appears necessary before reliable information can be obtained for clinical use. Moreover, our case did not show the relatively benign course of other reported cases of nocardia keratitis.

Infections caused by Rhodochrous

Organisms conforming to "rhodochrous taxon" were isolated from three immunocompromised patients, suggesting a pathogenic role for the organisms. The organisms are partially acid-fast, gram-positive catalase positive rods which form orange or red colonies aerobically in three or four days on Sabouraud, Mueller-Hinton and Middlebrook 7H-10 agars. They are differenitated from Nocardia by morphology and ability to degrade ethylene glycol in 7H-10 media. Two of these clinical isolates and a reference strain were injected intraperitoneally into guinea pigs, half of which received methylprednisolone intramuscularly beginning three days prior to inoculation. Steroid-treated animals exhibited clinical illness, diffuse peritonitis and recovery of inoculated organisms whereas one of three nonsteroid-treated animals exhibited a localized abscess without recovery of organisms. This study suggests that rhodochrous may be pathogenic under conditions of immune compromise.

Successful treatment of Nocardia asteroides infection with minocycline in kidney transplant patients

Two cases of Noca dia asteroides infection were encountered out of 55 kidney transplant patients at Chiba University Hospital. One patient developed an extrapleural abscess and the other had a pulmonary infiltration with chest wall abscess. The patients were successfully treated by surgical drainage of the chest wall abscesses and by oral administration of minocycline. No adverse effects caused by minocycline were observed during the therapy. From 1900, when the first case of Nocardia infection was reported in Japan, there have been 60 cases reported in Japanese literature through 1973, including those we observed. This is the first report on nocardiosis in kidney transplant patients and on successful treatment of nocardiosis with minocycline in Japan.

Clinical evaluation of the addition of gentamicin to commercially prepared mycological media

A simple procedure is presented whereby an antibiotic solution can be added to prepared agar media for conversion to a selective medium to isolate fungi. Gentamicin solution was deposited onto slants of a variety of previously prepared agar media, allowed to diffuse overnight, and then the slants were inoculated with clinical specimens. Control media without gentamicin included a cycloheximide-chloramphenicol medium (CC), Sabouraud dextrose agar (SDA), and brain heart infusion agar (BHI). Of 75 specimens originating from the respiratory tract, the fungi isolated were predominantly yeast; 35, 39, and 43 were positive on CC, SDA, and SDA with gentamicin, respectively, incubated at 25 C. At 37 C, 32, 34, and 41 positive cultures were obtained with the same media, respectively. The same specimens, inoculated onto BHI with and without gentamicin, yielded 23 and 39 positive cultures, respectively. Of 90 specimens that were either urine, cutaneous, or mucocutaneous, the predominant flora again were yeasts, although on nine occasions dermatophytes were isolated. Positive cultures, 32, 34, and 41, were obtained with CC, SDA, and SDA containing gentamicin, respectively. Bacterial contamination was significantly reduced by the gentamicin, especially on BHI incubated at 37 C. None of the specimens was positive for systemically pathogenic fungi, other than species of Candida, Torulopsis, and Aspergillus. The effectiveness of varying concentrations of gentamicin was investigated by comparing growth of recently isolated bacteria. Of the bacterial isolates, 33% grew on CC, 16% grew on SDA containing gentamicin, 50 mug/ml, and 3% grew on SDA with a gentamicin concentration at 100 mug/ml. With BHI, 3% grew in the presence of 50 mug of gentamicin/ml and less than 1% grew at 100 mug of gentamicin/ml.

Treatment of a cutaneous Nocardia asteroides infection with minocycline hydrochloride

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