Tuberculosis trends in a hot-spot region in Paris, France.

SETTING: Tuberculosis (TB) incidence is declining overall in France, but not in Paris where some areas remain relative hot spots for TB.OBJECTIVES: To obtain a better knowledge of local TB epidemiology in order to facilitate control measures.DESIGN: Analysis of demographic data of TB patients diagnosed at the Bichat-Claude Bernard Hospital from 2007 to 2016, with spoligotyping of Mycobacterium tuberculosis complex isolates.RESULTS: During the study period, 1096 TB patients were analysed. The incidence of TB diagnosis was stable, averaging 115 patients per year, predominantly males (71%), foreign-born (81%), with pulmonary TB (77%) and negative HIV serology (88%). The mean age of foreign-born TB patients decreased over the study period, most significantly in recent arrivals in France, whose average age decreased by two years (P = 0.001). The time period between arrival in France and being diagnosed with active TB decreased annually significantly by 0.75 years (P = 0.02). The proportion of L4.6.2/Cameroon and L2/Beijing sub-lineages increased annually by 0.7% (P < 0.05). Multi-drug resistant strains, representing 4% of all strains, increased annually by 0.75% (P = 0.03)CONCLUSION: The number of TB patients remained high in northern Paris and the surrounding suburbs, suggesting the need for increased control measures.

Complications following intravesical bacillus Calmette-Guerin treatment for bladder cancer: a case series of 22 patients.

BACKGROUND: Intravesical bacillus Calmette-Guerin (BCG) therapy is an effective and widely used treatment for superficial bladder carcinoma. Local complications are frequent whereas systemic complications are rare but can be serious, and their management is not well known. METHODS: We describe retrospectively the records of 22 patients treated in 3 infectious disease departments, for complications related to intravesical BCG therapy as treatment of bladder cancer. RESULTS: All the patients were male, with a median age of 68 years (range 56-88). Complications occurred after a median of 5 instillations (range 1-11) and were observed within 24 h following BCG instillation for 14 patients. Common symptoms were fever (n = 20), impaired general condition (n = 14), and shortness of breath (n = 7). Six patients had a systemic septic reaction leading to transfer into the intensive care unit for five of them. Lung infiltration was the most frequent presentation (n = 11). Mycobacterium bovis was isolated from only two patients, but histology showed the presence of a granuloma in nine patients. Antimycobacterial treatment was initialized in 17 patients; the outcome was favorable in 16 patients, with a median length of symptoms resolution of 22.5 days (range 5-425 days). Eleven patients received corticosteroids in addition to specific treatment and had a more rapid improvement. One patient died with disseminated BCGitis proved by biopsy. CONCLUSIONS: Complications following intravesical BCG therapy are rare but can be severe and fatal. Histology seems to be the method that contributes most in confirmation of the diagnosis. Antimycobacterial therapy is effective, and probably more efficient when combined with corticosteroids, but the regimen and duration of the treatment are not standardized.

Pyrazinamide resistance in Mycobacterium tuberculosis arises after rifampicin and fluoroquinolone resistance.

BACKGROUND: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (TB) constitute a major public health concern. OBJECTIVE: To determine the timing of pncA mutations that confer pyrazinamide (PZA) resistance in relation to mutations conferring resistance to isoniazid (INH) and rifampicin (RMP). DESIGN: Isolates from two major urban centres--Paris (101 strains) and Shanghai (171 strains)--were investigated for the association of pncA mutations with resistance to drugs other than PZA. RESULTS: The proportion of pncA mutations found in INH-monoresistant strains was not increased. CONCLUSION: pncA mutations associated with PZA resistance were found almost exclusively in MDR-TB strains, underlining the importance of determining PZA resistance when treating MDR- or XDR-TB.

Fluoroquinolone and pyrazinamide resistance in multidrug-resistant tuberculosis.

In a study performed in Cambodia, a higher number of tuberculosis (TB) strains with mutations in the pncA gene associated with pyrazinamide resistance (PZA-R) was found in fluoroquinolone-resistant (FQ-R) multidrug-resistant (MDR) strains (93%), compared with 47% in MDR and 3% in non-MDR strains. This emphasises the need for easy and rapid tests for identification of PZA-R for efficient treatment of MDR-TB.

Rapid identification of multidrug-resistant tuberculosis isolates in treatment failure or relapse patients in Bangui, Central African Republic.

Multidrug-resistant (MDR) strains were identified in 40% of 54 strains from patients presenting with tuberculosis (TB) treatment failure or relapse in Bangui, Central African Republic. Results obtained with the MTBDRplus line-probe assay or rpoB sequencing were 86% concordant with rifampicin (RMP) resistant phenotypes, while the amplification refractory mutation system test was 71% concordant. No mutation was found in RMP-susceptible strains. MTBDRplus and sequencing were concordant with the detection of the S315T mutation in katG in 95% of MDR strains. Sequencing of pncA suggested pyrazinamide resistance in 50% of MDR strains. Knowledge of these resistances should help to implement treatment in low-income countries.

hsp65 sequencing for identification of rapidly growing mycobacteria.

Partial sequencing of the hsp65 gene was used for the identification of rapidly growing mycobacteria (RGM). A 441-bp fragment (A. Telenti, F. Marchesi, M. Balz, F. Bally, E. Böttger, and T. Bodmer, J. Clin. Microbiol. 31:175-178, 1993) was amplified and sequenced by an automated fluorescence-based method involving capillary electrophoresis. Type strains of 10 RGM species were first studied. Each species had a unique nucleotide sequence, distinguishing it clearly from the other species. A panel of strains from the four main RGM species responsible for human infections, Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium fortuitum, and Mycobacterium peregrinum, was also studied. There were few sequence differences within each of these species (<2% of bases were different from the type strain sequence), and they had no effect on species assignment. hsp65 sequencing unambiguously differentiated M. chelonae and M. abscessus, two species difficult to identify by classical methods and 16S rRNA gene sequencing. The devised procedure is a rapid and reliable tool for the identification of RGM species.

Molecular fingerprinting of Mycobacterium tuberculosis and risk factors for tuberculosis transmission in Paris, France, and surrounding area.

Forty-three percent of the tuberculosis cases reported in France are from the Ile de France region. The incidence of tuberculosis in this region is 33 cases per 100,000 inhabitants, twice the national average. A restriction fragment length polymorphism (RFLP) analysis was performed with clinical isolates of Mycobacterium tuberculosis isolated during 1995 in 10 hospitals in Paris and surrounding areas to detect tuberculosis transmission and define the factors associated with clustering in this population. The molecular markers used were the insertion sequence IS6110 and the direct repeat (DR) sequence. Social, demographic, and clinical data were collected from the patients' medical files. Ten patients with isolates with a single copy of IS6110 were excluded from further analysis. Twenty-four patients with false-positive cultures due to laboratory contamination (based on RFLP analysis with IS6110 and examination of patient data) were also excluded. The study was then conducted with 272 strains isolated from 272 patients. Further fingerprinting was performed by using the DR element with strains with patterns by RFLP analysis with IS6110 that differed by one band only and strains with identical patterns by RFLP analysis with IS6110 and with low numbers of copies of IS6110. The combined use of both markers identified unique patterns for 177 strains and clustered 95 (35.7%) strains in 26 groups, each containing isolates from 2 to 12 patients. The clustering was strongly associated with homelessness and the male sex. It was not associated with age, birth in a foreign country, human immunodeficiency virus positivity, or residence in hostels or prison. Isolates from homeless people were often included in large clusters, and homeless people could be the source of tuberculosis transmission for more than 50% of the clustered patients. These results suggest that homeless people play a key role in the spread of M. tuberculosis in the community and that poor socioeconomic conditions are the main risk factors associated with active tuberculosis transmission.

Fatal disseminated Mycobacterium smegmatis infection in a child with inherited interferon gamma receptor deficiency.

Mycobacterium smegmatis is a common environmental mycobacterium that was first identified in 1884, yet is a rare pathogen in humans. The few M. smegmatis infections reported to date have been localized and have occurred in association with a primary lesion in otherwise immunocompetent individuals. To our knowledge, no case of disseminated M. smegmatis infection has ever been reported, even in patients with severe immune deficiencies. We report a case of disseminated mycobacterial infection that was diagnosed in a 3-year-old girl. The pathogen was not identified as M. smegmatis until the patient was 6 years old. Her condition gradually worsened, and she died when she was 8 years old despite appropriate antimycobacterial therapy. No other opportunistic infections were documented. Immunological investigations revealed an inherited interferon gamma receptor 1 deficiency. This report identifies M. smegmatis as a new opportunistic agent that may be responsible for disseminated disease in immunocompromised individuals.

Evaluation of tuberculosis transmission in a community by 1 year of systematic typing of Mycobacterium tuberculosis clinical isolates.

Interhuman transmission of Mycobacterium tuberculosis was investigated by using molecular typing, including restriction fragment length polymorphism with probes IS6110, DR (direct repeat) and PGRS (polymorphic GC-rich sequence) and a PCR method using the inverted repeat sequences of IS6110 as primers. From 105 patients hospitalized for tuberculosis during a 1-year survey in three hospitals in Paris, France, 111 isolates were collected and analyzed. Eighty-eight patients were infected with genetically different isolates, demonstrating the clonal heterogeneity of M. tuberculosis in these patients originating from various geographical areas. Fourteen patients were infected by strains clustered with identical fingerprints. An epidemiological relatedness was demonstrated for isolates from only seven of these patients. Thus, the typing of isolates from all tuberculous patients in hospitals during 1 year allows the detection of transmission in the general community. This would improve the case findings, thereby further improving the detection of outbreaks.

[Recent biological techniques for the diagnosis of mycobacterial infections]. / Techniques biologiques récentes pour le diagnostic des infections à mycobactéries.

More rapid and more sensitive techniques have replaced traditional methods of direct examination and culturing for diagnosing mycobacterial infections. Among the most recent methods are Isolator blood culture, radiometric detection, hybridization and amplification, each with its advantages and disadvantages. The Isolator blood culture system improves the sensitivity of mycobacteria detection, especially for Mycobacterium avium-intracellulare. In terms of cost and culture time, this system is similar to traditional methods, although it is limited to blood cultures. Radiometric detection, associated with culture in a liquid medium, greatly improves diagnostic power. The main advantage lies in the reduced delay before detection, 13.4 days compared with 21.7 days on solid media (for M. tuberculosis) and 5.1 days instead of 18.6 days for other mycobacteria. A culture is considered to be negative after 6 weeks without growth compared with 12 weeks for the Löwenstein-Jensen medium. The disadvantages of this system include the cost of equipment, personnel and radio-active products. In addition, as for all culture methods, a sufficient bacterial population is required in the sample. Hybridization techniques rely on DNA or RNA probes which recognize mycobacterial sequences. The Gen-Probe recognizes M. tuberculosis, M. avium, M. intracellulare and M. gordonae ribosomal RNA. Syngene probes recognize M. tuberculosis and M. avium-intracellulare DNA sequences. Rapid identification in less than 2 hours is a major advantage. At the present time 50 pg of DNA are required, a quantity which is not usually present in clinical samples. Combining this technique with primary culture in liquid medium or amplification techniques improves sensitivity. Polymerase chain reaction amplifies a specific sequence of double strand DNA. This method provides a means of identifying mycobacterial DNA in a clinical sample within 24-48 hours, a major improvement over traditional culture. Cost however may be a barrier although the cost/benefit ration remains to be determined.

T cell receptor repertoire of T lymphocytes recovered from the lung and blood of patients with sarcoidosis.

We evaluated the repertoire of V beta segments used in forming the T-cell receptor of lavage and blood T lymphocytes from 11 sarcoid patients and 10 normal subjects using procedures based on quantitative polymerase chain reaction, permitting analysis of both the abundance of transcripts using each of 20 different V beta families and the diversity of the VDJC beta rearrangements within each V beta family. Blood and lung T cells from sarcoid patients had a very diverse V beta repertoire. For all V beta families but one, the abundance of the V beta transcripts fell within the mean +/- 2 SD of that observed for normal blood lymphocytes; no difference in the overall abundance was observed comparing lavage and blood T cells, and the length of VDJC beta rearrangements for a given V beta family in samples from sarcoid patients was usually quite heterogeneous. Despite the overall polyclonality, evidence for selective expansion of T cells was found, in that an increased abundance of V beta 19 transcripts was observed for sarcoid blood and/or lung T cells in eight out of 11 patients studied, and rearrangements of a single predominant length using certain (e.g., V beta 19, V beta 14), but not all, V beta families were present. Sequencing confirmed the presence of a single predominant VDJC beta rearrangement in these cases. These findings suggest that the alveolitis in sarcoidosis results from two distinct processes, a local clonal expansion of T cells associated with an apparently nonspecific accumulation of T cells with an extremely diverse V beta repertoire.