Unilateral Vocal Cord Paralysis as a Result of a Nocardia farcinica Laryngeal Abscess

 Nocardia farcinica is an emerging pathogen in immunocompromised hosts, accounting for 20% of Nocardia isolates in the USA and 13–44% of isolates in Europe. The case of a 72-year-old lymphoma patient with a laryngeal abscess caused by Nocardia farcinica is presented. The initial clinical manifestation was unilateral vocal cord paralysis, which improved following surgical drainage of the abscess and therapy with imipenem. The English-language literature on human Nocardia farcinica infection is reviewed.     

Review of nocardial infections in France 1987 to 1990

On the basis of the numbers ofNocardia strains referred to the National Reference Center for Mycoses and Antifungal Agents (NRC), Institut Pasteur, Paris, in the period from 1987 to 1990, it was estimated that between 150 and 250 cases of nocardiosis are diagnosed in France each year. A total of 63 clinical isolates were referred to the NRC and identified asNocardia asteroides (66.7 %),Nocardia farcinica (23.8 %),Nocardia brasiliensis (3.2 %),Nocardia otitidiscaviarum (4.8 %) andNocardia carnea (1.5 %).Nocardia asteroides accounted for 71.4 % of pulmonary infections, 80.0 % of central nervous system infections and 80.0 % of systemic infections. Patients infected withNocardia farcinica died in 57.1 % of cases, compared with 17.6 % of patients infected withNocardia asteroides. Corticosteroid therapy represented a significant factor in mortality. Isolates ofNocardia asteroides revealed variable resistance, whereas isolates ofNocardia farcinica were resistant to most antimicrobial agents. Only amoxicillin/clavulanic acid, imipenem, cefoxitin, kanamycin, amikacin, minocycline and vancomycin showed activity against both species. Nocardiosis caused byNocardia farcinica may be a growing problem because of the relatively high incidence in AIDS patients and the resistance of this species to most antimicrobial agents.     

DisseminatedNocardia farcinica infection in an AIDS patient

This report describes an AIDS patient presenting with disseminatedNocardia farcinica infection diagnosed by percutaneous kidney biopsy. The isolate was initially identified asNocardia asteroides. ThoughNocardia asteroides remains sensitive to most antimicrobial agents,Nocardia farcinica is resistant to gentamicin, tobramycin and cephalosporins and is indistinguishable fromNocardia asteroides by regular laboratory methods. In view of the rising incidence of infections withNocardia farcinica, third-generation cephalosporins should not be used in the initial management ofNocardia infections, and all isolates should be submitted for antibiotic susceptibility testing.     

Antibiotic susceptibility testing and species identification of Nocardia isolates: a retrospective analysis of data from a French expert laboratory, 2010–2015

Objectives

 Nocardia, a Gram-positive bacterium, is responsible for rare and severe infections. Accurate microbiological data are essential to guide antibiotic treatment. Our primary objective was to describe species identification and results of antimicrobial susceptibility testing (AST) for Nocardia isolates analysed over a 6-year period. Secondary objectives were to study temporal trends in species distribution and AST results.

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. Electronic Publication     

Two Cases of Nocardia bacteraemia in Solid Organ Transplant Recipients

Nocardiosis is an opportunistic infection occurring in immunosuppressed patients. While disseminated nocardiosis is common in immunosuppressed patients, Nocardia bacteraemia is rare. There are few reports of Nocardia bacteraemia following solid organ transplantation. We report two cases of Nocardia bacteraemia in solid organ transplant recipients-Nocardia cyriacigeorgica bacteraemia in liver transplant recipient and concomitant Nocardia farcinica bacteraemia and cyclosporiasis in a heart transplant recipient. Prompt recognition of early bacteraemia with initiation of antibiotic therapy may avoid the complications of disseminated disease in the solid organ transplant recipients.     

Nocardiosis in Quebec,Canada, 1988–2008

Nocardia is an uncommon pathogen, but immunosuppression, its main risk factor, is becoming more frequent. We aimed to evaluate changes in the annual incidence of nocardiosis and in the susceptibility profile of its aetiological agents. Demographic data were analysed for all isolates of Nocardia forwarded to the provincial public health laboratory of Quebec, Canada during the last two decades. Population incidence could be measured from 1997 onwards. Resistance patterns were analysed for those isolates selected for in vitro susceptibility testing. Throughout Quebec, 575 incident cases were identified between 1997 and 2008. The annual incidence of Nocardia infection/colonization increased from 0.33 (1997–1998) to 0.87 (2007–2008) per 100 000 inhabitants (p 0.001). In a small subset of patients for whom detailed clinical information was available, 59% of isolates corresponded to genuine infections. Nocardia farcinica predominated in specimens representing invasive infections (blood, brain, lung or pleural aspirates). Isolates were often non‐susceptible to several antimicrobials, with the exception of amikacin and linezolid. Overall, 43% of 157 isolates were non‐susceptible to trimethoprim–sulphamethoxazole. In conclusion, Nocardia infection/colonization remains rare. However, from 1997–1998, a progressive increase in incidence was noted in the province of Quebec. In regions such as ours, where a substantial proportion of invasive isolates are non‐susceptible in vitro to trimethoprim–sulphamethoxazole, the latter may no longer be the empirical treatment of choice in immunosuppressed and severely ill patients with nocardiosis.     

Speciation and susceptibility of Nocardia isolated from ocular infections

Twenty Nocardia spp. isolated from ocular infections were identified by 16S rRNA gene sequencing and susceptibility was determined using the E-test (AB Biodisk, Sweden). Species distribution among the 20 isolates was as follows: Nocardia levis (n = 7), Nocardia farcinica (n = 3), Nocardia abscessus (n = 2), Nocardia brasiliensis (n = 2), Nocardia amamiensis (n = 2), Nocardia puris (n = 1), Nocardia beijingensis (n = 1), Nocardia otitidiscaviarum (n = 1) and Nocardia thailandica (n = 1). All isolates were sensitive to amikacin. Eighteen (90%) isolates were sensitive to tobramycin, 11 (55%) to ciprofloxacin and gatifloxacin, and seven (35%) to azithromycin and clarithromycin. Molecular methods are useful for the identification and for the detection of Nocardia species that have not so far been reported in human infections.     

Two cases of multidrug-resistant Nocardia farcinica infection in immunosuppressed patients and implications for empiric therapy

Presented here are two cases of multidrug-resistant Nocardia farcinica infection that occurred in immunocompromised patients. One of the patients developed the infection despite being on trimethoprim/sulfamethoxazole prophylaxis for Pneumocystis jiroveci. These cases demonstrate the propensity of Nocardia spp. to cause disseminated disease and to develop resistance to multiple antimicrobial agents used in the initial treatment of serious Nocardia infection. These factors lead to the conclusion that empiric monotherapy with trimethoprim/sulfamethoxazole may not be sufficient. Treatment with a combination regimen of imipenem and amikacin may be a more promising initial therapy.     

Rhodococcus equi and Nocardia brasiliensis Infection of the Brain and Liver in a Patient with Acute Nonlymphoblastic Leukemia

 Resolution of neutropenia is usually followed by resolution of fever in patients with febrile neutropenia. However, in some cases fever continues even when the patient is no longer neutropenic. Described here is a case of acute myeloblastic leukemia complicated by brain abscess, pulmonary nodules, and hepatic lesions. The patient's fever had continued after the neutropenia resolved; brain and hepatic cultures grew Rhodococcus equi and Nocardia brasiliensis. Although Rhodococcus infections occur frequently in patients with HIV infection, they are uncommon in patients with acute leukemia.     

Typing of Nocardia farcinica by Pulsed-Field Gel Electrophoresis Reveals an Endemic Strain as Source of Hospital Infections

Severe postoperative wound infections caused by Nocardia farcinica were repeatedly observed in a German hospital surgical ward. A pulsed-field gel electrophoresis (PFGE) protocol was established to characterize the genetic relatedness of the bacterial isolates from these infections. All 18 isolates from postoperative infections that have occurred since 1985 belong to a common endemic genotype; organisms of this genotype were also detected in the air of two rooms of the department where these postoperative infections occurred. In contrast, two environmental isolates from another building on the same campus showed a distinct genotype. Three cases of pulmonary infections, at a department which is located in proximity to the surgical department, were also caused by the endemic type, which suggests aerogenic spread of the endemic strain to these patients. Controls consisting of epidemiologically unrelated isolates from sporadic infections in other towns belonged in each case to a different genotype. PFGE was well suited to differentiate various types of N. farcinica and revealed an endemic strain causing postoperative wound infections possibly after aerogenic transmission.     

Creation of an In-House Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Corynebacterineae Database Overcomes Difficulties in Identification of Nocardia farcinica Clinical Isolates

Nocardiosis is a rare disease that is caused by Gram-positive actinobacteria of the Nocardia genus and affects predominantly immunocompromised patients. In its disseminated form, it has a predilection for the central nervous system and is associated with high mortality rates. Therefore, prompt identification of the pathogen is critical. Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry is a relatively novel technique used for identification of microorganisms. In this work, an upgraded MALDI-TOF Biotyper database containing Corynebacterineae representatives of strains deposited in the Polish Collection of Microorganisms was created and used for identification of the strain isolated from a nocardial brain abscess, mimicking a brain tumor, in an immunocompetent patient. Testing with the API Coryne system initially incorrectly identified Rhodococcus sp., while chemotaxonomic tests, especially mycolic acid analysis, enabled correct Nocardia identification only at the genus level. Subsequent sequence analysis of 16S rRNA and secA1 genes confirmed the identification. To improve the accuracy of the results, an in-house database was constructed using optimized parameters; with the use of the database, the strain was eventually identified as Nocardia farcinica. Clinical laboratories processing various clinical strains can upgrade a commercial database to improve and to accelerate the results obtained. This is especially important in the case of Nocardia, for which valid microbial diagnosis remains challenging; reference laboratories are often required to identify and to survey these rare actinobacteria.     

DisseminatedNocardia transvalensis infection resembling pulmonary infarction in a liver transplant recipient

Infections due to Nocardia transvalensis are extremely rare: only four disseminated infections with this pathogen have been reported, three of which ended fatally. This is the first report of a liver transplant recipient with Nocardia transvalensis infection. The patient had disseminated infection with pulmonary involvement, which presented as pulmonary infarction. Despite a ten-day delay in the administration of correct therapy, he responded rapidly to trimethoprim-sulfamethoxazole. The pitfalls of differentiating nocardial infection from pulmonary thromboembolism in solid organ transplant recipients and the diagnostic considerations unique to liver transplant recipients are discussed.     

In vitro activity of fluoroquinolones against clinical isolates of Nocardia identified by partial 16S rRNA sequencing

Fluoroquinolones have several properties that make them potentially attractive candidates for the treatment of Nocardia infections, but information regarding their in vitro activity is limited. Minimum inhibitory concentrations (MIC) of five fluoroquinolones and other antimicrobials were determined by the reference broth dilution and E-test methods for 33 consecutive clinical isolates of Nocardia speciated by 16S rRNA gene sequences. The isolates included: Nocardia cyriacigeorgica (n = 6), N. nova (n = 8), N. farcinica (n = 8), N. brasiliensis (n = 3), N. asteroides (n = 4), and N. veterana (n = 4). MIC₅₀/MIC₉₀ results for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin by broth dilution were 32/32, 2/4, 1/4, 32/32, and 2/2 μg/ml, respectively. The MICs by broth dilution and E-test were within a two-fold doubling dilution for 94%, 97%, 97%, 100%, and 100% of isolates for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, respectively. For ciprofloxacin, the E-test results showed either complete categorical agreement or minor error compared to the reference broth dilution method for 97% (32/33) of the isolates. For other fluoroquinolones, using Streptococcus pneumoniae breakpoints, 94% (124/132) of MIC results by E-test showed either complete agreement or minor error compared to the reference broth dilution method. Fluoroquinolones show variable in vitro activity against clinical isolates of Nocardia spp., and MICs determined by the E-test show reasonable agreement with those determined by the reference broth dilution method.     

First report of a brain abscess caused by Nocardia veterana

Among Nocardia species causing infections, Nocardia veterana is rarely isolated and is mostly described as causing pulmonary infections. This is the first presentation of a case of brain abscess attributable to an N. veterana infection in a patient with type 2 diabetes. Prolonged antibiotic therapy with trimethoprim-sulfamethoxazole led to successful clinical recovery.     

Colonization and infection withMoraxella catarrhalis in childhood

In a prospective clinical study, rates of isolation ofMoraxella catarrhalis in nasopharyngeal aspirates from 122 children with respiratory tract infection and 72 healthy controls were compared. In the patient group,Moraxella catarrhalis andStreptococcus pneumoniae were the most frequently isolated pathogens (38% and 42%, respectively). Monocultures of each pathogen were equally distributed in patients and controls (41% vs. 42%), whereas mixed infections were found more frequently in the patient group (42% vs. 14%; normal flora, 17% vs. 44%).Moraxella catarrhalis appears to be a relevant respiratory pathogen. The isolation of two or more pathogens in nasopharyngeal aspirates seems to be as indicative of relevant infection as is monoculture.     

Clinical and microbiological characteristics of Nocardiosis including those caused by emerging Nocardia species in Taiwan, 1998–2008

The genus of Nocardia is rapidly expanding and the species distribution varies with different geographical locations. We retrospectively reviewed the laboratory records of the bacteriology laboratory at National Taiwan University Hospital from January 1998 to June 2008 to identify patients with nocardiosis. During the study period, 164 isolates of Nocardia spp. were identified from 134 patients but only 113 patients had Nocardia infection. Nocardia brasiliensis (n = 54) was the most common pathogen, followed by N. asteroides (n = 36), N. farcinica (n = 7), N. flavorosea (n = 4), N. otitidiscaviarum (n = 3), N. nova (n = 3), N. beijingensis (n = 2) and one each of N. puris, N. jinanensis and N. takedensis. The major types of infection were cutaneous infection (56.6%), pulmonary infection (33.6%) and disseminated infection (7.1%). Eighty-eight patients received sulfonamide-containing antibiotic and eight of 100 patients with available data on outcomes died during the episode of nocardiosis. In conclusion, the clinical and microbiological manifestations of Nocardiosis vary with the different Nocardia species. Accurate identification of the species is crucial to make the diagnosis.     

Use of Voriconazole to Successfully Treat Disseminated <Emphasis Type="Italic">Trichosporon asahii</Emphasis> Infection in a Patient with Acute Myeloid Leukaemia

Trichosporon spp. is an emerging fungal pathogen in immunocompromised hosts, and disseminated infection is often fatal in neutropenic patients. Reported here is a case of disseminated infection in a neutropenic patient with acute leukaemia. After failure of amphotericin B and fluconazole therapy, the course of infection dramatically improved with voriconazole treatment. A literature search revealed 69 additional cases of disseminated Trichosporon spp. infections in neutropenic patients, and these are also reviewed. Clinical symptoms that suggest infection include fever, disseminated papulopustular cutaneous lesions and pulmonary involvement. Despite treatment with antifungal agents (amphotericin B, fluconazole), 78% of patients died. Voriconazole may represent a promising therapy for this life-threatening infection. Electronic Publication     

Breakthrough infection of Trichosporon asahii during posaconazole treatment in a patient with acute myeloid leukaemia

A neutropenic patient with acute myeloid leukaemia experienced a breakthrough infection of Trichosporon asahii during posaconazole treatment. After treatment was changed to a combination therapy with voriconazole and liposomal amphotericin B, the infection resolved. Posaconazole works effectively as an antifungal prophylaxis and salvage therapy in rare invasive fungal infections. This case however illustrates that breakthrough infections with T. asahii may occur during posaconazole treatment.