Impact of a 14-year screening programme on tuberculosis transmission among the homeless in Paris.

OBJECTIVE: To evaluate the impact of an active case-finding programme on tuberculosis (TB) transmission in homeless shelters in Paris, France. DESIGN: Between 1994 and 1997, an active case-finding programme was implemented in homeless shelters using a mobile radiological screening unit, and continued from 1997 to 2007. During these periods, the strains isolated from TB cases diagnosed in the homeless were genotyped by restriction fragment length polymorphism analysis using the insertion sequence IS6110 as a probe. RESULTS: Between 1994 and 2007, 313 new TB cases were diagnosed among the homeless population: 179 through the programme among shelter users, and 134 among homeless people not using shelters. Half of the strains were clustered in 35 distinct patterns (2-48 cases/cluster). The clustering of TB cases steadily decreased in shelters during the 13 years of the survey, from 14.3 to 2.7 related cases per year (P < 0.01) and from 75% to 30% of related cases among all TB cases (P < 0.01). In contrast, there was only a slight trend towards a decrease in homeless people not using shelters. CONCLUSION: Active case finding in homeless shelters resulted in a decrease in case clustering, mainly in shelter users. Genotyping contributed to confirming the positive impact of the intervention.

[Bacteriological tests for tuberculosis]. / Les tests bactériologiques de la tuberculose maladie : standards et perspectives.

This review describes current developments for the bacteriological diagnosis of active tuberculosis. It deals mainly with molecular methods, describing their performance and how they can be integrated into more traditional diagnostic approaches. At present, microscopic examination and culture are still essential for the diagnosis of TB and to guide therapeutic decisions. Nucleic acid amplification and line probe assays speed up the identification and susceptibility testing of mycobacteria in AFB smear positive specimens or in culture. They are also efficient for comparison of M. tuberculosis strains with each other (genotyping). On the other hand, at present, molecular tests are not applicable for diagnosis in smear negative specimens and even less so for diagnosis of culture-negative tuberculosis. The use of serology for antibody/antigen detection is not useful and it is not appropriate to assays based on the release of interferon-γ release as they are currently available. Notable progress has been made but more sensitive diagnostic tests for TB are still urgently needed.

Molecular investigation of resistance to the antituberculous drug ethionamide in multidrug-resistant clinical isolates of Mycobacterium tuberculosis.

Ethionamide (ETH) needs to be activated by the mono-oxygenase EthA, which is regulated by EthR, in order to be active against Mycobacterium tuberculosis. The activated drug targets the enzyme InhA, which is involved in cell wall biosynthesis. Resistance to ETH has been reported to result from various mechanisms, including mutations altering EthA/EthR, InhA and its promoter, the NADH dehydrogenase encoded by ndh, and the MshA enzyme, involved in mycothiol biosynthesis. We searched for such mutations in 87 clinical isolates: 47 ETH-resistant (ETH(r)) isolates, 24 ETH-susceptible (ETH(s)) isolates, and 16 isolates susceptible to ETH but displaying an intermediate proportion of resistant cells (ETH(Sip); defined as ≥1% but <10% resistant cells). In 81% (38/47) of the ETH(r) isolates, we found mutations in ethA, ethR, or inhA or its promoter, which mostly corresponded to new alterations in ethA and ethR. The 9 ETH(r) isolates without a mutation in these three genes (9/47, 19%) had no mutation in ndh, and a single isolate had a mutation in mshA. Of the 16 ETH(Sip) isolates, 7 had a mutation in ethA, 8 had no detectable mutation, and 1 had a mutation in mshA. Finally, of the 24 ETH(s) isolates, 23 had no mutation in the studied genes and 1 displayed a yet unknown mutation in the inhA promoter. Globally, the mechanism of resistance to ETH remained unknown for 19% of the ETH(r) isolates, highlighting the complexity of the mechanisms of ETH resistance in M. tuberculosis.

A 10-year prospective surveillance of Mycobacterium tuberculosis drug resistance in France 1995-2004.

Drug resistance surveillance and trend monitoring resistance rates bring some insights into tuberculosis (TB) control. The current study reports the characteristics of TB and drug resistance during a 10-yr prospective surveillance of culture-positive TB in France. Data for the current study was collected from 1995-2004 via a sentinel network of laboratories from university hospitals that complied with the international recommendations for the surveillance of drug resistance. Susceptibility test results were performed in each individual laboratory. Data on 13,283 patients were collected during the 10-yr period, 49% of whom had been born in France, 10% were HIV co-infected and 8% had previously been treated. As expected, previously treated and HIV co-infected patients were more likely to harbour resistant strains, especially rifampicin (RMP)-resistant strains. Among new patients, the mean resistance rate to at least one drug was 8.8%, and there was an upward trend in resistance to isoniazid and RMP (0.8-1%) related to the increase in the proportion of patients who had been born outside of France (38-53%). Among previously treated patients, the mean resistance rate to one drug was 20.6% and there was no significant time trend in resistance rates. The sentinel network provided valuable data on trends regarding the characteristics of tuberculosis and on drug resistance rates and reinforced the interest of analysing data by country of birth and history of treatment.

Synergistic activity of R207910 combined with pyrazinamide against murine tuberculosis.

In previous studies, the diarylquinoline R207910 (also known as TMC207) was demonstrated to have high bactericidal activity when combined with first- or second-line antituberculous drugs. Here we extend the evaluation of R207910 in the curative model of murine tuberculosis by assessing the activities of one-, two-, and three-drug combinations containing R207910 and isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), or moxifloxacin (MXF) in the setting of a high initial bacillary load (7.2 log(10) CFU). Two months of treatment with the combinations R207910-PZA, R207910-PZA-INH, R207910-PZA-RIF, or R207910-PZA-MXF resulted in culture-negative lung homogenates in 70 to 100% of the mice, while mice treated with INH-RIF-PZA (the reference regimen) or RIF-MXF-PZA remained culture positive. Combinations including R207910 but not PZA (e.g., R207910-INH-RIF and R207910-MXF-RIF) were less active than R207910-PZA-containing regimens administered either alone or with the addition of INH, RIF, or MXF. These results reveal a synergistic interaction between R207910 and PZA. Three-drug combinations containing these two drugs and INH, RIF, or MXF have the potential to significantly shorten the treatment duration in patients, provided that these results can be confirmed in long-term experiments including periods of relapse.

Efficient intermittent rifapentine-moxifloxacin-containing short-course regimen for treatment of tuberculosis in mice.

Long-half-life drugs raise the hope of once-a-week administration of antituberculous treatment. In a previous study with the murine model of tuberculosis, the most active intermittent regimen which contained rifapentine (RFP), isoniazid (INH), and moxifloxacin (MXF) given once a week during 5.5 months, preceded by 2 weeks of daily treatment with INH, rifampin (RIF), pyrazinamide (PZA), and MXF, was less active than the standard 6-month daily RIF-INH-PZA regimen. We evaluated with the same model similar regimens in which we increased the dosing of rifapentine from 10 to 15 mg/kg of body weight and of moxifloxacin from 100 to 400 mg/kg. Mice infected intravenously by 6.2 x10(6) CFU of Mycobacterium tuberculosis H37Rv were treated 2 weeks later when infection was established. After 6 months of treatment, all mice had negative lung culture. After 3 months of follow-up, no relapse occurred in the two groups that received moxifloxacin at 400 mg/kg, whatever the dosage of RFP, and in the group receiving the standard RIF-INH-PZA control regimen. In contrast, in the two groups receiving moxifloxacin at a lower dosage, the relapse rate was significantly higher (13% in mice receiving RFP at 15 mg/kg and 27% in those receiving RFP at 10 mg/kg). Finally, the fully intermittent once-a-week regimen (26 drug ingestions) of INH, RFP (15 mg/kg), and MXF (400 mg/kg) led to a relapse rate of 11%. In conclusion, when used at high dosage, rifapentine and moxifloxacin are very efficient when combined with isoniazid in a once-a-week treatment in mouse tuberculosis.

Outbreak of tuberculosis in a migrants' shelter, Paris, France, 2002.

SETTING: An overcrowded 362-bed migrants' shelter in Paris, France. OBJECTIVES: To investigate an outbreak of tuberculosis (TB), to identify a common source of contamination and to prevent further transmission. METHODS: The outbreak was identified by radiographic screening and an active search for undeclared hospital treated cases, completed by strain phenotyping and a search for contact cases. RESULTS: Between October 2001 and October 2002, 56 cases of active TB were identified, 30 by radiological screening and 20 by contacting neighbouring hospitals. All cases involved men, with a median age of 30 years. Pulmonary involvement was present in 54% of cases, and nine patients were sputum smear-positive. Thirty-four of the 37 phenotyped strains clustered together. CONCLUSION: The grouping of the cases in time and place, the large number of cases with early-stage disease and the identical RFLP banding patterns of most of the isolates indicate that this outbreak results from transmission that occurred in France. This report underlines the need for public health departments in industrialised countries to maintain effective anti-tuberculosis control programmes.

First isolation of Mycobacterium microti (Llama-type) from a dog.

We report the first isolation of Mycobacterium microti from a dog with lesions of acute peritonitis. The isolate was demonstrated to be M. microti of Llama-Type by spoligotyping. Epidemiological implications of the isolation of this possibly zoonotic agent from a dog are discussed.

Use of a high-density DNA probe array for detecting mutations involved in rifampicin resistance in Mycobacterium tuberculosis.

A Mycobacterium high-density DNA probe array designed to detect rpoB mutations conferring rifampicin resistance in Mycobacterium tuberculosis was evaluated. The rpoB hybridisation patterns produced by 41 susceptible (RifS) and 59 rifampicin-resistant (RifR) clinical isolates of M. tuberculosis were compared with the results of conventional dideoxynucleotide sequencing of the rpoB gene. For all the RifR isolates, the rpoB hybridisation patterns correlated with the rpoB sequencing results. Among the 59 isolates, 11 distinct amino-acid changes were detected by the DNA probe array. Of these, 36 (61%) corresponded to replacement of the serine residue found in position 531 (S531L in 34 isolates and S531W in two isolates), 16 (27%) affected histidine 526 (five H526D, five H526Y, four H526L, one H526N and one H526R), four (6.8%) replaced aspartate 516 with a valine, and one (1.7%) replaced glutamine 513 with a leucine. Deletion of the asparagine residue at position 519 was detected in one isolate susceptible to rifampicin, but yielding c. 0.1% resistant colonies on rifampicin-containing medium. No mutation was detected in the rpoB region from one isolate yielding c. 5% of resistant colonies on rifampicin-containing medium. Finally, a D516Y substitution was detected in association with an unexpected mutation, G523W, not tiled on the DNA probe array, but which could be detected by analysing the hybridisation pattern obtained with the wild-type probes covering codon 523. In conclusion, the Mycobacterium probe array is a promising approach to rapid detection of mutations involved in rifampicin resistance in M. tuberculosis.

[Mycobacterium fortuitum skin infection occurring after a facelift]. / Infection cutanée à Mycobacterium fortuitum après lifting.

INTRODUCTION: Mycobacterium fortuitum skin infections are rare and usually iatrogenic. We report a case with cervical involvement following a facelift. OBSERVATION: A 65 year-old woman, without past history, underwent bilateral surgical facelift, complicated by cutaneous necrosis and treated with directed healing at home. Six weeks later, an abscessed nodule appeared under the left maxillary and was drained surgically. Then other pre-auricular and left cervical inflammatory nodules appeared without adenopathy or fever. M. fortuitum was isolated in bacteriological samples. The initially probabilistic antibiotherapy with carithromycin, subsequently adapted with amikacine and cirprofloxacine and then imipeneme for a total duration of 3 months, led to the clinical cure. DISCUSSION: Mycobacterium fortuitum is a rapidly growing, ubiquitous, mycobacteria responsible for nosocomial infections in immunocompetent patients, notably following plastic surgery. Contamination occurs where there has been a rupture in the skin barrier through contact with a vector (water, surgical material, antiseptic.). Treatment, which is not codified, consists in the association of surgery and antibiotics for several months.

Multidrug-resistant tuberculosis: eight years of surveillance in France.

The aim of this study was to evaluate the annual prevalence of multidrug-resistant tuberculosis (MDRTB) and to describe the characteristics of the patients with MDRTB in France. Annual questionnaire surveys from 1992-1999 were mailed to all French microbiological laboratories performing mycobacterial cultures. A total of 264 distinct patients were reported to the National Reference Centre for Resistance of Mycobacteria to Antituberculosis Drugs during the 8-yr surveillance period resulting in a mean annual prevalence of MDRTB of 0.6%. A mean of 16% of the MDRTB patients were reported over several subsequent years. The majority of patients were male (69.7%), foreign-born (55.7%), with a previous history of treatment (65.9%), and pulmonary involvement (92.8%) with smear-positive results (59.1%). Human immunodeficiency virus (HIV) coinfection was present in 20.8% of the patients. Strains were resistant only to isoniazid and rifampin in 37.9% of the cases, and additional resistance to both streptomycin and ethambutol was present in 25.8%. HIV coinfection and female status were statistically associated with primary resistance, whereas smear-positive results were associated with secondary resistance. Foreign-birth and smear-positive results were associated with a chronic status. The prevalence of multidrug-resistant tuberculosis is low in France (<1%). However, a substantial proportion of patients remain positive for several years, suggesting nonoptimal management. Therefore, as recommended by the World Health Organization, a few reference teams, working in collaboration with national associations of physicians and microbiologists, should be established to improve the outcome of multidrug-resistant tuberculosis.

Impact of iron loading on the activity of isoniazid or ethambutol in the treatment of murine tuberculosis.

OBJECTIVE: To assess the impact of iron loading on the activity of isoniazid and ethambutol in the treatment of murine tuberculosis. DESIGN: Iron-loaded and iron-normal female Balb/C mice infected with 1.5 x 10(7) colony forming units of Mycobacterium tuberculosis were treated with either isoniazid or ethambutol for 28 days. RESULTS: For both treatments, the outcome was impaired by the iron loading: bactericidal activity of isoniazid was partially but significantly reduced and ethambutol bactericidal activity was totally inhibited. CONCLUSION: The treatment of tuberculosis in patients with iron loading should be longer than for normal patients or should contain an additional drug.

Multiple cerebral abscesses as a complication of Mycobacterium fortuitum infection.

Mycobacterium fortuitum is a rapidly growing, nontuberculous mycobacteria that has rarely been associated with central nervous system impairment. We describe the case of a patient who developed multiple cerebral abscesses revealing Mycobacterium fortuitum infection. Brain biopsy specimens showed suppurative, noncaseating, granulomatous inflammation consisting of epithelioid histiocytes and multinucleated giant cells. All clinical signs and CT scan cerebral lesions disappeared after institution of appropriate antimycobacterial therapy.

Effectiveness of once-weekly rifapentine and moxifloxacin regimens against Mycobacterium tuberculosis in mice.

Mice infected with 1.6 x 10(7) CFU of Mycobacterium tuberculosis were treated 14 days later for 6 months with a regimen of once-weekly 10 mg of rifapentine and 75 mg of isoniazid per kg of body weight supplemented with either 150 mg of streptomycin per kg or 100 mg of moxifloxacin per kg during either both the 2-week daily initial and once-weekly continuation phases or only in the daily 2-week initial phase. On completion of treatment, all lung cultures were negative, except for three mice, each with a single colony: two whose rifapentine-isoniazid regimen was supplemented with streptomycin during the whole course of therapy and one whose rifapentine-isoniazid regimen had no initial daily phase, but was supplemented with streptomycin and moxifloxacin during the whole course of therapy. After 3 months of follow-up, positive lung cultures were obtained from 61 and 56% of mice supplemented with streptomycin during either the full course of therapy or only the daily 2-week initial phase, respectively, and 15 and 50% of mice supplemented with moxifloxacin during either the full course of therapy or only the daily 2-week initial phase, respectively. These results suggest that moxifloxacin has sterilizing activity against M. tuberculosis.

Efficacies of clarithromycin regimens against Mycobacterium xenopi in mice.

Mice were infected intravenously with 3.5 x 10(7) CFU of Mycobacterium xenopi and treated with various clarithromycin-containing regimens or left untreated for 4 weeks. All nine of the clarithromycin-containing regimens reduced the CFU counts to the levels below the pretreatment values, indicating that these regimens had a bactericidal effect on M. xenopi in mice. The rifampin-isoniazid-ethambutol regimen was significantly less bactericidal than clarithromycin alone or clarithromycin-containing combined regimens.

Iron and Mycobacterium tuberculosis infection.

BACKGROUND: iron is known to play a role in the susceptibility to and outcome of several infections. In view of the increasing worldwide problem of tuberculosis, it may be important to ascertain whether this is also the case with this infection. OBJECTIVES: (1) to review studies conducted in vitro, in experimental animals, and in humans that provide evidence that iron status may influence the occurrence and outcome of tuberculosis. (2) To perform an in vivo study in mice, examining the effect of iron loading on experimental infection caused by a virulent strain of Mycobacterium tuberculosis. RESULTS: we studied the effect of iron loading on the growth in spleen and lungs of a virulent strain of M. tuberculosis, injected i.v. in female Balb/C mice. At sacrifice on day 42 after the experimental infection, the iron-loaded mice presented a significantly enhanced multiplication of M. tuberculosis in both the spleen and the lungs, when compared to the mice without iron loading. CONCLUSION: Most of the studies, including our experimental study in mice, tend to suggest that an excess of iron may enhance the growth of M. tuberculosis and worsen the outcome of human tuberculosis.

Antibiotic susceptibility pattern of Mycobacterium marinum.

In vitro activities of 17 antibiotics against 53 clinical strains of Mycobacterium marinum, an atypical mycobacterium responsible for cutaneous infections, were determined using the reference agar dilution method. Rifampin and rifabutin were the most active drugs (MICs at which 90% of the isolates tested were inhibited [MIC(90)s], 0.5 and 0.6 microgram/ml, respectively). MICs of minocycline (MIC(90), 4 microgram/ml), doxycycline (MIC(90), 16 microgram/ml), clarithromycin (MIC(90), 4 microgram/ml), sparfloxacin (MIC(90), 2 microgram/ml), moxifloxacin (MIC(90), 1 microgram/ml), imipenem (MIC(90), 8 microgram/ml), sulfamethoxazole (MIC(90), 8 microgram/ml) and amikacin (MIC(90), 4 microgram/ml) were close to the susceptibility breakpoints. MICs of isoniazid, ethambutol, trimethoprim, azithromycin, ciprofloxacin, ofloxacin, and levofloxacin were above the concentrations usually obtained in vivo. For each drug, the MIC(50), geometric mean MIC, and modal MIC were very close, showing that all the strains had a similar susceptibility pattern. Percent agreement (within +/-1 log(2) dilution) between MICs yielded by the Etest method and by the agar dilution method used as reference were 83, 59, 43, and 24% for minocycline, rifampin, clarithromycin, and sparfloxacin, respectively. Reproducibility with the Etest was low, in contrast to that with the agar dilution method. In conclusion, M. marinum is a naturally multidrug-resistant species for which the agar dilution method is more accurate than the Etest for antibiotic susceptibility testing.

Surveillance of Mycobacterium tuberculosis drug resistance in France, 1995-1997. AZAY Mycobacteria Study Group.

OBJECTIVE: To measure the rate of primary and secondary drug resistance of Mycobacterium tuberculosis on an ongoing basis. DESIGN: Data on all culture-positive tuberculosis were collected prospectively from 1995 through 1997 from a microbiological laboratory network of 19 university hospitals throughout France, and submitted quarterly to the National Reference Centre for Surveillance of Mycobacterial Diseases. RESULTS: A total of 2998 patients were included in the study. Among the 2333 (78%) previously untreated patients, 8.6% had isolates resistant to any drug, 4.8% to streptomycin (SM) alone, 1.2% to isoniazid (INH) alone, 1.8% to SM + INH, and 0.3% to INH + rifampicin (RMP) or multidrug resistance (MDR). Foreign birth was independently associated with a higher risk of primary resistance to any drug (odds ratio [OR] 1.5). Among the 268 (9%) previously treated patients, 20.9% had isolates resistant to any drug, 6.3% to SM alone, 3.4% to INH alone, 4.1% to SM + INH, and 3.7% to INH + RMP. Foreign birth (OR = 2.3), and human immunodeficiency virus positive status (OR = 4.4) were independently associated with a higher risk of secondary resistance to any drug. CONCLUSION: During the last 30 years there has been no increase in resistance to any drug among previously untreated patients. As expected, secondary resistance was highly associated with foreign birth. MDR-TB remains a rare event in France.

Twenty-five years of tuberculosis in a French university hospital: a laboratory perspective.

OBJECTIVE: To determine the impact of recent changes in the epidemiology of tuberculosis in France and other industrialised countries on the primary trends of tuberculosis case rates in a French university hospital. DESIGN: Descriptive study of all 4549 culture-positive tuberculosis cases hospitalised at Pitié-Salpêtrière Hospital between 1972 and 1996. RESULTS: From 1972, there was a decline of 5% per year in the tuberculosis case rate, which levelled off in 1983. The proportion of tuberculosis patients who were human immunodeficiency virus (HIV) positive increased from 2% in 1983 to 28% in 1990, and thereafter remained stable. The proportion of foreign-born tuberculosis patients also increased, from 40% in 1972 to 55% in 1985. These two changes affected drug resistance patterns. Drug resistance was more common among foreign-born than among French-born patients, whether previously treated or not. Resistance to rifampicin and multidrug resistance among previously untreated patients was highly related to HIV co-infection. Extrapulmonary sites of tuberculosis were more often smear-positive in HIV-positive than in non-HIV-positive patients (22.8% vs 12.6%), and bacteraemia was diagnosed almost exclusively in HIV-positive patients. CONCLUSION: The changes in clinical and bacteriological tuberculosis patterns at the hospital level over the last 25 years have paralleled those observed at national and international level in industrialised countries, including a slowing in the decrease in the case rate, due in part to the HIV epidemic, a higher proportion of foreign-born patients and an increase in drug resistance.