[Difficulties of TB diagnosis in children: QuantiFERON TB Gold In-Tube as useful tool]. / Difficultés du diagnostic de la tuberculose chez l'enfant : intérêt du test QuantiFERON TB Gold In-Tube.

Diagnosis of childhood tuberculosis (TB), active TB or latent tuberculosis infection (LTBI), is complicated by uncommon clinical, radiological and bacteriological features. The tuberculin skin test (TST) is imperfect: difficulty of the intradermal injection for the child, lack of sensibility and specificity. The stop of the systematic inoculation by the BCG since July 2007, in France, could lead to an increase of the incidence of the childhood TB. It is urgent to find new diagnostic tools: sensitive, specific, fast, of objective reading and little expensive. Interferon-gamma assays could be useful but the data are still insufficient in paediatrics and sometimes contradictory. A prospective study which compared the usefulness of QuantiFERON TB Gold In-Tube (QFT-IT) assay with TST to detect LTBI or active disease in 51 children was realised in University Hospital of Nancy. This allowed us to confirm interest of QFT-IT; however, surprisingly, very discordant QFT-IT and TST results were obtained (only five children were QFT-IT+/TST+). A high number (14%) of indeterminate QFT-IT occurred, without explanation by pre-analytical or clinical parameters. Further studies are needed to demonstrate the usefulness of this assay in diagnosing LTBI and particularly active TB in children.

Survival of Mycobacterium avium attached to polyethylene terephtalate (PET) water bottles.

AIMS: The main objective of our study was to assess the persistence of Mycobacterium avium in an oligotrophic environment such as bottled groundwater. METHODS AND RESULTS: Filtered groundwater samples were spiked with washed Myco. avium suspension and stored in dark and under static conditions, at 20 degrees C, for 3 months in 500 ml PET bottles. The loss of Myco. avium cultivability was slow in water. On the contrary, after a 3-month storage at 20 degrees C, growth of attached cells was observed and cell adhesiveness to the PET wall increased with time. It could probably be because of the presence of an extracellular matrix. CONCLUSIONS: This study has shown the great stability of Myco. avium in bulk water as well as their adhesiveness and their growth on a PET bottle wall in an oligotrophic environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Slowly growing mycobacteria are well adapted to oligotrophic environments such as groundwater. As they stick very well to surfaces, they could be used for determining the efficiency of the cleaning of contaminated surfaces.

Efficacy of dry mist of hydrogen peroxide (DMHP) against Mycobacterium tuberculosis and use of DMHP for routine decontamination of biosafety level 3 laboratories.

Mycobacterium tuberculosis is a major cause of morbidity and mortality worldwide and is becoming a greater concern due to the development of multidrug-resistant strains. M. tuberculosis can contaminate rooms, medical equipment, and research laboratories and has the propensity to be highly resistant to decontamination. The aim of this study was to determine the efficacy of room disinfection with a dry mist of hydrogen peroxide (DMHP) in a biosafety level 3 laboratory in the event of contamination with M. tuberculosis. The biological indicators (BIs) were comprised of presterilized cotton tissues on which amounts of about 10(7) CFU/ml of M. tuberculosis H37Ra were dried. The device (Sterinis; Gloster Sante Europe) provided a DMHP of 5% hydrogen peroxide during 25 min. Three experiments were performed. The viable bacteria were reduced by values of more than 5 log(10), and no colony grew from any BI. In conclusion, DMHP shows promise as an effective and safe alternative to the currently used formaldehyde.

Respiratory infections associated with nontuberculous mycobacteria in non-HIV patients.

The incidence of nontuberculous mycobacteria (NTM) pulmonary diseases in HIV-negative patients was studied prospectively from January 1, 2001 to December 31, 2003 by 32 sentinel sites distributed throughout France. In total, 262 patients who yielded NTM isolates from respiratory clinical specimens, met the bacteriological, radiological and clinical criteria established by the American Thoracic Society for NTM respiratory disease. Among the 262 NTM isolates, 234 were slow-growing mycobacteria (125 Mycobacterium avium-intracellulare complex (MAC), 66 M. xenopi, 34 M. kansasii) and 28 were rapidly growing mycobacteria (25 M. abscessus complex). In the Paris area, M. xenopi was the most frequently isolated species, followed by MAC. Most patients (>50%), except those with M. kansasii, had underlying predisposing factors such as pre-existing pulmonary disease or immune deficiency. Asthenia, weight loss, chronic cough and dyspnoea were the most common clinical symptoms. The classical radiological appearance of NTM infections was indistinguishable from that observed in patients with pulmonary tuberculosis. In summary, the incidence of nontuberculous mycobacteria pulmonary infections in HIV-negative patients was estimated at 0.74, 0.73 and 0.72 cases per 100,000 inhabitants in 2001, 2002 and 2003, respectively.

Sentinel-site surveillance of Mycobacterium avium complex pulmonary disease.

The incidence of Mycobacterium avium complex (MAC) pulmonary disease in HIV-negative patients was studied prospectively from January 1, 2000 to December 31, 2002 through 32 sentinel sites distributed all over France. Among the 275 patients who yielded MAC isolates from respiratory clinical specimens, 101 (36.7%) met the bacteriological, radiographical and clinical criteria established by the American Thoracic Society for nontuberculous mycobacterial respiratory disease. Of these 101 patients, 81 had underlying lung disease, mainly previous tuberculosis, bronchectasis or chronic obstructive pulmonary disease. Among the 20 patients with no underlying lung disease, 12 had a predisposing factor such as leukaemia or immunosuppressive treatment and eight had no predisposing factor. All patients with MAC respiratory disease had clinical symptoms, commonly cough and fatigue, and 52 (51.5%) were sputum smear positive for acid-fast bacillus. The ratio of patients with Mycobacterium avium complex pulmonary disease to patients with pulmonary tuberculosis in France was estimated to be 3% and the incidence of Mycobacterium avium complex pulmonary disease in France was 0.2 per 100,000 inhabitants.

[Infection peritonitis in patients undergoing continuous ambulatory peritoneal dialysis: microbiological review during an four-year period]. / Péritonites infectieuses chez les patients traités par dialyse péritonéale: bilan microbiologique sur quatre ans.

The purpose of this study was to analyse the microbiological characteristics of infectious peritonitis in patients undergoing continuous ambulatory peritoneal dialysis. This study was conducted at the CHU Nancy from 1999 to 2002. The diagnosis of peritonitis was based on cloudy peritoneal effluent (>100 cells per mm(3)) with an elevated leukocyte count (>50%), on isolation of bacteria or fungi and on symptoms such as abdominal discomfort or pain. The majority of infections associated with continuous ambulatory peritoneal dialysis were caused by Gram-positive bacteria (68%), Gram-negative bacteria (31%), and Candida (1%). The coagulase-negative staphylococci were the most common cause of peritonitis. The antibiotic sensitivity of species corresponded to community-acquired isolation.

Mycobacterium xenopi and drinking water biofilms.

The ability of Mycobacterium xenopi to colonize an experimental drinking water distribution system (a Propella reactor) was investigated. M. xenopi was present in the biofilm within an hour following its introduction. After 9 weeks, it was always present in the outlet water (1 to 10 CFU 100 ml(-1)) and inside the biofilm (10(2) to 10(3) CFU cm(-2)). Biofilms may be considered reservoirs for the survival of M. xenopi.

In vitro sensitivity of Mycobacterium xenopi to five antibiotics.

We tested 20 strains of Mycobacterium xenopi (M. xenopi) in order to evaluate their in vitro sensitivity to amikacine, clarithromycine, ethambutol, ofloxacine and rifampicin, by establishing minimal inhibitory concentration (MIC) on agar medium. MICs of amikacine, clarithromycine and ofloxacine are low, so that these antibiotics can be used in the treatment of M. xenopi infections. MICs of ethambutol are higher than seric concentrations. Though, its therapeutic use is due to its in vivo ability to enhance penetration of other antibiotics in mycobacteria. Strain sensitivity to rifampicin seems heterogeneous but the small number of tested strains does not entitle the exclusion of rifampicin from the treatment of M. xenopi infections.

[Mycobacterium xenopi: epidemiological and bacteriological features]. / Mycobacterium xenopi: caractères épidémiologiques et bactériologiques.

Mycobacterium xenopi is a scotochromogenic slow-growing atypical mycobacteria, with a thermostable catalase, no production of niacin and whose cell wall contains types I and VI long-chain fatty acids. Cosmopolitan, it is mainly recovered in tap-warm water. The contamination occurs through aerosol inhalation, water ingestion or use of contaminated medical or surgical equipment. M. xenopi is an opportunistic pathogen; the infection is facilitated by the incidental introduction of the bacteria in the body, pre-existing pulmonary lesions and an immunodepression. M. xenopi is mainly involved in infections of lungs, bones and joints. The treatment consists in the combination of three or four antibiotics, among rifampicin, rifabutin, ethambutol, macrolides, amikacin and fluoroquinolones.

Evaluation of the bactericidal efficiency of a 2% alkaline glutaraldehyde solution on Mycobacterium xenopi.

Mycobacterium xenopi (M. xenopi) has been implicated in hospital-acquired infections associated with colonization of hospital water systems. M. xenopi is considered to be as resistant as other atypical mycobacteria, which are known to be resistant to many disinfecting treatments. However, the efficacy of disinfectants on this organism has not yet been studied. Therefore we decided to evaluate its susceptibility to 2% alkaline glutaraldehyde solution, which is commonly used in hospitals. Tests were conducted using five strains of M. xenopi: three isolated from human samples, an environmental strain and a collection strain. We used a membrane filtration assay and counted surviving bacteria before and after several exposure times (5, 15, 30 and 60 min) with the disinfecting solution. The log10 reduction factor of organisms achieved within 60 min contact ranged from 2.5 to 7.5. This showed M. xenopi to be more resistant to disinfectants than M. tuberculosis or M. smegmatis and suggested that environmental strains may be more resistant to alkaline glutaraldehyde than those isolated from human samples.

Effect of methodology on the tuberculocidal activity of a glutaraldehyde-based disinfectant.

Although official guidelines recommend a plate counting method for testing the susceptibility of mycobacteria to disinfectants, manufacturers usually prefer to employ the BACTEC procedure. Data showing that the BACTEC method overestimates the activity of a glutaraldehyde-based disinfectant against Mycobacterium tuberculosis in comparison with a conventional plate counting procedure are presented.

Tuberculosis in Lorraine, France: study of prognostic factors.

AIM: To identify factors predicting short-term mortality in patients with tuberculosis in the Lorraine region of France. METHOD: Retrospective survey in nine voluntarily participating hospitals between January 1990 and December 1994. RESULTS: In total 351 files were analyzed. The average age of patients was 49 +/- 19 years; 77% were of French origin, 60% were male; 35% were in paid employment at the time of the diagnosis, 42% were unemployed and 23% were retired. Twenty-three patients were infected by the human immunodeficiency virus (HIV), and 34 patients had a prior history of tuberculosis; 79% of all cases were exclusively pulmonary, 14% were exclusively extra-pulmonary (more frequent in women) and 7% were mixed. Extra-pulmonary sites of involvement were more frequent in HIV-infected patients. Chest X-ray was suggestive of tuberculosis in 158 patients with pulmonary involvement, and non-suggestive in 145 (more frequently in HIV-infected patients). In univariate analysis, HIV co-infection, increasing age and unemployment were linked to death during treatment. In multivariate analysis (logistic regression), HIV co-infection, old age, unemployment, pulmonary involvement and French origin were significantly linked to the risk of death during treatment.

A blind study of the polymerase chain reaction for the detection of Mycobacterium tuberculosis DNA. Azay Mycobacteria Study Group.

SETTING: Nine French laboratories routinely involved in mycobacterial work. OBJECTIVE: To assess the detection of Mycobacterium tuberculosis in experimental samples by polymerase chain reaction (PCR) using the insertion sequence IS6110 as a target for deoxyribonucleic acid (DNA) amplification. DESIGN: Nine laboratories participated in a blind study of the detection of M. tuberculosis by PCR in 20 coded samples containing either a definite number of M. tuberculosis complex (positive samples) or environmental mycobacteria (four samples) or no mycobacteria (five samples). RESULTS: Five laboratories reported false-positive PCR results, with an average rate of 7%. All laboratories except one reported positive PCR results for samples containing 10(5) cfu/ml or more. M. tuberculosis DNA was detected in two thirds of samples containing 10(4) and 10(3) cfu/ml, and in one third of the samples containing 10(2) cfu/ml. CONCLUSION: The results of the study suggest that PCR using IS6110 as a target for DNA amplication is neither very sensitive nor really specific for the detection of M. tuberculosis.

[Value of nucleic acid amplification methods Amplicor (Roche) and Amplified MTD (Gen-Probe) for the rapid diagnosis of tuberculosis]. / Intérêt des méthodes d'amplification d'acides nucléiques Amplicor (Roche) et Amplified MTD (Gen-Probe) pour le diagnostic rapide de la tuberculose.

The nucleic acid amplification methods: Amplicor (Roche diagnostic) and AMTD Amplified Mycobacterium tuberculosis Test Direct-(Gen-Probe) were tested in 278 specimens from 231 patients suspect to be affected by mycobacterial infection. When results of both methods: Amplicor and AMTD were compared with culture results (specimens grow M tuberculosis) and clinical characteristics, the sensitivity and specificity were 91.4% and 97.9% respectively for pulmonary specimens and 61.1% and 98.6% respectively for extrapulmonary specimens. Detection of amplification inhibitors reduce false-negative reactions and control of specimen with microscopic negative and amplification positive, reduce the false-positive reactions. Amplicor and AMTD kits can be used in clinical laboratories. Both assays have the potential to reduce the time of tuberculosis diagnosis to one day.

Diagnosis of tuberculosis by Amplicor Mycobacterium tuberculosis test: a multicenter study.

The Amplicor Mycobacterium tuberculosis test is a new PCR assay for the direct detection of Mycobacterium tuberculosis from clinical samples. A multicenter study that included six laboratories was done to evaluate the Amplicor test in comparison with direct microscopy and culture (solid or radiometric media), and the culture method was used as the "gold standard." A total of 2,073 specimens, i.e., 1,749 respiratory specimens and 324 other specimens, were tested. A total of 184 cultures yielded M. tuberculosis. Of these 184 cultures, 77 (42%) were smear negative and 23 (12.5%) concerned extrapulmonary specimens. The sensitivity of the Amplicor test for all of the specimens and for extrapulmonary, smear-positive, and smear-negative specimens was 86, 83, 94.5, and 74%, respectively. The sensitivity of direct microscopy in comparison with that of culture was 58%. A total of 95% of patients with culture-proven tuberculosis were diagnosed by the Amplicor test, whereas direct microscopy detected mycobacteria in only 72% of these patients. The Amplicor test exhibited a high degree of specificity (98%). The assay was very rapid and easy to perform.

[Isolation of an acid-alcohol resistant bacillus (BAAR) in the febrile HIV infected patients: Mycobacterium tuberculosis (MT) or Mycobacterium avium complex (MAC)?]. / Isolement d'un bacille acido-alcoolorésistant (BAAR) chez le patient VIH+ fébrile: bacille de Koch (BK) ou Mycobacterium avium complex (MAC)?

The detection of BAAR in HIV infected patients with CD4 < 100/mm3 and with an infectious syndrome urge on beginning an effective treatment against Mycobacterium tuberculosis and/or Mycobacterium avium Complex, before the results of the culture are known. Our purpose was to search clinical and biological features to angle directly the diagnosis towards a tuberculosis or not, and to start the most suitable treatment. This retrospective study, from 1986 to 1993, stated on 54 patients who had at least one sample with positive BAAR (blood, marrow, stools, sputum or urine cultures). From these cultures, MAC was isolated on 37 patients and BK on 17. The both groups were similar for age, sex, risk factor, number of opportunistic infections, delay between the date of AIDS and the discovery of a positive BAAR, and Ag p24. However, a significant difference in favor of a MAC disease exists regarding about: disseminated infections (92% vs 53%), digestive troubles (57% vs 23.5%), anterior or concomitant CMV infection (49% vs 9%), isolation of BAAR in blood culture (54% vs 20%) or in stools culture (76% vs 33%), leucopenia (2850/mm3 +/- 1520 vs 4124/mm3 +/- 2232), anémia (Hb 9.1 g/dl +/- 1.5 vs 10.1 g/dl +/- 1.6). The univariated analysis of results allowed us to conclude that the presence of one among those parameters must induce the prescription of a suitable treatment against MAC.

[Comparative study of ofloxacin+amoxicillin-clavulanic acid versus doxycycline+amoxicillin-clavulanic acid combination in the treatment of pelvic Chlamydia trachomatis infections]. / Etude comparative des associations ofloxacine+amoxicilline-acide clavulanique versus doxycycline+amoxicilline-acide clavulanique dans le traitement des infections génitales hautes à Chlamydia trachomatis.

OBJECTIVE: To evaluate the efficacy and safety of ofloxacin+coamoxiclav versus doxycycline-coamoxiclav in the treatment of chlamydial pelvic infections. DESIGN: An open, comparative, randomised, monocentric study. SUBJECTS: A hundred and eighteen patients (85 endometritis and 33 salpingitis) were included. Clinical, laparoscopic and bacteriological assessments were performed before treatment. 30.4% of salpingitis were considered as severe (COGIT score > 6). 25.4% of acute pelvic infections were only caused by Chlamydia trachomatis. TREATMENT: A hundred and eighteen patients were treated orally with 3 week combination ofloxacin (200 mg b.i.d.) + coamoxiclav (1 g b.i.d.) (n = 60) or with a 6 week coamoxiclav (1 g b.i.d.) + doxycycline (100 mg b.i.d.) (n = 58). RESULTS: Oral combination ofloxacin-coamoxiclav is as effective as oral combination doxycycline+coamoxyclav with respectively 96.7% versus 96.6% and 100% versus 98.4% satisfactory clinical et bacteriological results.

[Value of the stool bacteriological test in Mycobacterium avium complex infections in AIDS]. / Intérêt de l'examen bactériologique des selles dans les infections à Mycobacterium complex avium au cours du SIDA.

Incidence of Mycobacterium avium complex (MAC) infection has increased in HIV infected patients. We report a retrospective study of 25 cases of MAC infection occurring in HIV patients. Stools examination was performed in 5 (31%) of the patients without digestive symptoms and in the 9 (100%) patients presenting with diarrhoea. The stools culture are positive in 79% of cases (11/14). In all the patients with diarrhoea, direct examination of the stools gave the diagnosis of MAC infection. All the patients had profound immunodepression with CD4+ cell count < 5/mm3. The mean survival time from mycobacteriosis diagnosis was 122 +/- 90 days despite antimycobacteriosis therapy.

[Electron microscopic studies of the action of erythromycin, doxycycline and ofloxacin on the growth cycle of Chlamydia trachomatis]. / Observations en microscopie électronique de l'action de l'érythromycine, doxycycline et ofloxacine sur le cycle de multiplication de Chlamydia trachomatis.

The aim of this work is to realise an ultra structural study of the action of antibiotics (doxycycline, erythromycin and ofloxacin) on the intracellular growth cycle of chlamydia. All assays were done on McCoy cells. Antibiotics were added to the culture medium two hours after inoculation with C. trachomatis. 24 and 48 hours, cells were removed and treated by standard procedure for transmission electron microscopy. No difference between control-cells and cells treated with doxycycline, erythromycin (0.015 mg/l) and ofloxacin (0.15 mg/l), was observed in the inclusions (number and size). However 48 hours, the quantity of elementary bodies (E.B.) was lower in treated culture. The organisms were not morphologically different from those seen in untreated culture. At higher concentrations of doxycycline and erythromycin (0.03 mg/l - 0.06 mg/l), the inclusions were smaller. Reticulate bodies (RB) were each in separate inclusion indicating that no fission has taken place. At 48 hours, no infectious forms (EB) were observed. Small or large RBs appeared with an apparent normal cytoplasmic membrane within an inflated cell wall. With ofloxacin (0.3 - 0.6 mg/l), inclusions contained enlarged and sometimes empty bacterial cells. Doxycycline and erythromycin (0.03 mg/l) inhibit the division of RBs and there maturation to EBs Ofloxacin (0.3 mg/l) induces the production of large abnormal forms which may not be able to revert towards viable bacteria.