Mycobacterium conspicuum sp. nov., a new species isolated from patients with disseminated infections.

A new type of slowly growing, nonphotochromogenic mycobacterium was recovered from two patients with disseminated disease. The growth characteristics, acid fastness, acids were consistent with those for Mycobacterium species. The results of biochemical investigations, lipid analyses, and comparative 16S rRNA sequencing showed that these isolates represent a new slowly growing Mycobacterium species which is named Mycobacterium conspicuum.     

Report of two fatal cases of Mycobacterium mucogenicum central nervous system infection in immunocompetent patients

Neurological infections due to rapidly growing mycobacteria (RGM) have rarely been reported. We recently investigated two unrelated immunocompetent patients, one with community-acquired lymphocytic meningitis and the other with cerebral thrombophlebitis. Mycobacterium mucogenicum was isolated in pure culture and detected by PCR sequencing of cerebrospinal fluid samples. Both patients eventually died. The two isolates exhibited an overlapping antimicrobial susceptibility pattern. They were susceptible in vitro to tetracyclines, macrolides, quinolones, amikacin, imipenem, cefoxitin, and trimethoprim-sulfamethoxazole and resistant to ceftriaxone. They shared 100% 16S rRNA gene sequence similarity with M. mucogenicum ATCC 49650^T over 1,482 bp. Their partial rpoB sequences shared 97.8% and 98.1% similarity with M. mucogenicum ATCC 49650^T, suggesting that the two isolates were representative of two sequevars of M. mucogenicum species. This case report should make clinicians aware that M. mucogenicum, an RGM frequently isolated from tap water or from respiratory specimens and mostly without clinical significance, can even be encountered in the central nervous system of immunocompetent patients.     

Simultaneous infection with two drug-susceptible Mycobacterium tuberculosis strains in an immunocompetent host

An important assumption for DNA fingerprinting of Mycobacterium tuberculosis is that patients are infected with only one strain at a time. Nonetheless, we demonstrate a case of simultaneous infection with two drug-susceptible strains of M. tuberculosis in an immunocompetent patient by IS6110 restriction fragment length polymorphism and spoligotyping. Epidemiological data prove the patient's involvement in two independent clusters. Thus, double infections should be suspected with fingerprints showing divergent band intensities.     

Mycobacterium simiae complex infection in an immunocompetent child

Nontuberculous mycobacteria are ubiquitous in the environment but rarely infect immunocompetent patients. We describe a pediatric case of Mycobacterium simiae complex lymphadenitis in an immunocompetent child and review the natural history, clinical manifestations, diagnosis, and current management of the disease.     

Mycobacterium flavescens vertebral osteomyelitis in an immunocompetent host

The aim of this paper is to describe a rare case of vertebral osteomyelitis caused by Mycobacterium flavescens in an immunocompetent patient. Mycobacterium flavescens is a rapidly growing, pigmented, non-tuberculous mycobacterium, usually described as non-pathogenic for humans but occasionally reported as the cause of serious infectious complications recognized in clinical practice. This study stressed the importance of recent reports that describe the occurrence of vertebral osteomyelitis due to non-tuberculous mycobacteria that have also been recognized with an increasing incidence among immunocompetent hosts. A brief review of the current literature on human disease caused by Mycobacterium flavescens is also reported.     

Isolation of a fastidious Mycobacterium species from two AIDS patients.

Two strains of fastidious mycobacteria were isolated from two patients with AIDS and clinical disease suggestive of Mycobacterium avium complex infection. Acid-fast bacilli were isolated from blood and bone marrow of both patients in BACTEC 12B and/or 13A media. The acid-fast bacilli failed to grow on subculture to routine L?wenstein-Jensen medium containing pyruvate and egg yolk agar. After several attempts, the strain from one patient was finally cultured on Middlebrook 7H9 medium with agar, charcoal, and yeast extract 13 months after the initial specimens were received in the laboratory. The second patient's strain was cultured on the same medium 6 weeks postinoculation with fresh BACTEC fluid and 5 months after specimen collection. Routine biochemical and growth tests were performed on these isolates but failed to give definitive identifications. 16S rRNA gene sequencing suggested that the organisms share at least 98.9% homology with M. simiae. Even greater homology (99.86%) was found with the recently described species "M. genavense." Recognition of the fastidious nature of some mycobacteria that infect AIDS patients is important in the treatment of infections in these patients and in understanding the epidemiology of atypical mycobacterial infections. It is suggested that a liquid culture medium such as BACTEC be employed for primary isolation of mycobacteria from AIDS patients and that subculture to the charcoal medium described here be carried out for those organisms that fail to grow on subculture to routine media.     

Mycobacterium malmoense bacteremia in two AIDS patients.

We report two cases of Mycobacterium malmoense bacteremia in two patients with AIDS. These are the first reported cases of disseminated M. malmoense in human immunodeficiency virus patients occurring in the United States. This slow-growing organism can cause invasive disease mimicking Mycobacterium avium complex infection; recognition and identification of this organism by mycobacteriology laboratories are essential for appropriate diagnosis and therapy of disseminated disease.     

First isolation of Mycobacterium kyorinense from clinical specimens in Brazil

In this article, the first isolation of Mycobacterium kyorinense specimens in Brazil is described. M. kyorinense is a recently identified species, with a few strains reported only in Japan. The Brazilian isolates were initially identified as Mycobacterium celatum by PCR restriction enzyme pattern analysis (PRA) with hsp65. However, biochemical tests indicated the same profile of M. kyorinense and distinguished them from M. celatum and Mycobacterium branderi. The sequencing of the hsp65, rpoB, and 16S rRNA genes allowed the accurate identification of isolates as M. kyorinense.     

Disseminated penicilliosis marneffei in immunocompetent patients: A report of two cases

Disseminated penicilliosis marneffei is rarely seen in immunocompetent persons. We report here two cases of disseminated penicilliosis marneffei in immunocompetent hosts. Penicillium marneffei disseminated to the brain in one patient and to the bone marrow in the other patient. Both patients received amphotericin B liposome. The cases illustrate the importance of considering penicilliosis marneffei as causes of systemic infections in immunocompetent patients.     

Cryptosporidiosis in immunocompetent patients

The intestinal protozoan cryptosporidium is known to cause diarrhea in immunocompromised patients, but few cases have been reported in detail in immunocompetent persons. During a 12-month period, we identified cryptosporidium in the stools of 43 immunocompetent patients. The numbers of cases were increased in those under 4 years old and in those from 30 to 39 years old. Of 30 index cases, 23 (77 per cent) were diagnosed in the late summer or the fall. Fifteen of the 43 patients (35 per cent) had other gastrointestinal pathogens, of which only Giardia lamblia was statistically associated with cryptosporidium. In the 28 patients in whom other gastrointestinal pathogens were not identified, the clinical manifestations were predominantly watery, nonbloody diarrhea and, less commonly, abdominal discomfort, anorexia, fever, nausea, and weight loss. The infection was self-limited in all 43 patients. Clustering of cases occurred in a day-care center and in two families. These clinical observations confirm worldwide findings and suggest that cryptosporidium is a relatively common nonviral cause of self-limited diarrhea in immunocompetent persons in the northeastern United States.     

<Emphasis Type="Italic">Mycobacterium malmoense</Emphasis> lymphadenitis in Spain: first two cases in immunocompetent patients

Reported here are two cases of Mycobacterium malmoense lymphadenitis that occurred in two immunocompetent children in Spain. To the best of our knowledge, these are the first documented cases of extrapulmonary infection by M. malmoense in Spain. This report serves to draw attention to this emerging nontuberculous mycobacterium that is gaining increasing recognition as a pulmonary and extrapulmonary pathogen in different countries.     

Comparison of two 2,3-diacyl trehalose antigens from Mycobacterium tuberculosis and Mycobacterium fortuitum for serology in tuberculosis patients.

Immunoglobulin G antibodies against two 2,3-diacyl trehalose (DAT) antigens from Mycobacterium tuberculosis (DATT) and Mycobacterium fortuitum (DATF) were studied by enzyme-linked immunosorbent assay of 356 serum samples. The sera were obtained from non-tuberculosis-infected individuals (282 serum samples) and tuberculosis patients (74 serum samples). Non-tuberculosis-infected individuals were healthy people (120 serum samples; positive purified-protein-derivative skin test, 60 patients; negative purified-protein-derivative skin test, 60 patients) patients with nontuberculosis lung disease (59 serum samples), contacts of sputum-smear-positive tuberculosis patients (57 serum samples), and human immunodeficiency virus-infected patients with nontuberculosis lung disease (46 serum samples). Of the 74 patients with tuberculosis, 14 were human immunodeficiency virus infected. The sensitivity of the method using DATT was 44.5%, and that with DATF was 48.6%. The specificities with both antigens were 99.1%. There were no significant differences between the mean values for both antigens (P = 0.2815). We therefore concluded that both antigens were interchangeable. As M. fortuitum, a fast-growing mycobacterium, could be a good source of antigen DAT, these results deserve consideration in the serology of tuberculosis.     

Improved technique for isolation of Mycobacterium kansasii from water.

A new concentration procedure, together with a new isolation medium, resulted in a 10- to 100-fold increase in the possibility of identifying Mycobacterium kansasii from water samples in comparison to a previously used procedure. In a survey which included both potable and natural water samples from many sites within the state of Texas, nine isolations of high-catalase strains of M. kansasii were obtained from 232 water samples tested. Acid-fast smear results were compared with mycobacterial isolations. An isolate from a river in central Texas is the first high-catalase strain of M. kansasii encountered in a natural water supply. Surveys of water samples from two Texas towns indicate that chlorine levels may influence the number of recoverable mycobacteria in water supplies.     

First report of isolation of Mycobacterium novocastrense from water supplies

We herein present the first documented report associated with the isolation of Mycobacterium novocastrense from environment. The identification and characterization of four unrelated isolates, one from the surface water and the other three from hospital water, were achieved by various conventional and molecular tests including a genus‐specific PCR for Mycobacterium based on 65‐kDa heat shock protein (hsp) gene and 16S rDNA sequencing. Our findings might shed further light on the natural habitat of this rare Mycobacterium.     

Cryptococcal meningitis in immunocompetent patients

Five cases of cryptococcal meningitis (CM) in immunocompetent patients who were initially diagnosed as either tuberculous meningitis or partially treated pyogenic meningitis are presented. There were 3 male and 2 female patients in the age range of 21 to 42 years. These patients presented as subacute meningitis. Additional features were visual impairment (4 cases), papilloedema (3 cases), sixth cranial nerve palsy (3 cases) and ataxic hemiparesis (one case). There was a mediastinal mass of fungal aetiology in one patient. While routine analysis of CSF showed a variable picture, it is the India ink preparation, test for cryptococcal antigen and culture for fungus which gave the diagnosis. These patients were treated with standard antifungal therapy. While one patient died and one patient recovered completely, three other patients were left with permanent visual impairment. It is concluded that CM is uncommon but an important cause of non-acute meningitis and should be included in the list of causes of preventable blindness.     

Unusual clinical presentation of Mycobacterium fortuitum infection in an immunocompetent woman

The Mycobacterium fortuitum group of rapidly growing nontuberculous mycobacteria is an uncommon cause of renal infection, particularly in otherwise healthy hosts. We describe a case of nephritis due to M. fortuitum in an immunocompetent woman with a clinical and radiological diagnosis of renal tuberculosis.     

Effect of carnosine on immunocompetent cells from alcoholic patients

We studied the effect of natural dipeptide carnosine on phagocytosis, respiratory burst in neutrophils, and subpopulation composition of lymphocytes from healthy donors and alcoholic patients. Carnosine in vitro produced different effects on immunocompetent cells from healthy donors and patients with alcoholism. In patients with alcoholism phagocytic activity of leukocytes and generation of reaction oxygen species increased under the influence of carnosine in a concentration of 0.01 mM, but decreased after treatment with this compound in a concentration of 1 mM. Carnosine in both concentrations stimulated the respiratory burst, but had no effect on the count of phagocytic cells in healthy donors. Carnosine in a concentration of 0.01 mM increased the number of lymphocytes carrying apoptosis markers (CD95{su+}) in patients with alcoholism not receiving therapy. Our results indicate that carnosine holds much promise for the therapy of alcoholism.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 9, pp. 289–292, September, 2004     

Effect of carnosine on immunocompetent cells from alcoholic patients

We studied the effect of natural dipeptide carnosine on phagocytosis, respiratory burst in neutrophils, and subpopulation composition of lymphocytes from healthy donors and alcoholic patients. Carnosinein vitro produced different effects on immunocompetent cells from healthy donors and patients with alcoholism. In patients with alcoholism phagocytic activity of leukocytes and generation of reaction oxygen species increased under the influence of carnosine in a concentration of 0.01 mM, but decreased after treatment with this compound in a concentration of 1 mM. Carnosine in both concentrations stimulated the respiratory burst, but had no effect on the count of phagocytic cells in healthy donors. Carnosine in a concentration of 0.01 mM increased the number of lymphocytes carrying apoptosis markers (CD95⁺) in patients with alcoholism not receiving therapy. Our results indicate that carnosine holds much promise for the therapy of alcoholism. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 289–292, September, 2004