We report a case of fatal pulmonary infection caused by Mycobacterium abscessus in a young patient with cystic fibrosis, who underwent bipulmonary transplantation after a 1-year history of severe lung disease. Fifteen days after surgery he developed septic fever with progressive deterioration in lung function. M. abscessus, initially isolated from a pleural fluid specimen, was then recovered from repeated blood samples, suggesting a disseminated nature of the mycobacterial disease. Drug susceptibility testing assay, performed on two sequential isolates of the microorganism, showed a pattern of multidrug resistance. Despite aggressive therapy with several antimycobacterial drugs, including clarithromycin, the infection persisted, and the patient died. CASE REPORTA 20-year-old man with cystic fibrosis (CF) underwent bilateral pulmonary transplantation in July of 1999. For approximately 1 year prior to admission he had been suffering from severe pulmonary disease with intermittent episodes of septic fever, and during this period he had been hospitalized several times. Sputum cultures had yielded Pseudomonas aeruginosa and Aspergillus fumigatus, whereas blood cultures (collected either via catheter and by venipuncture) were positive for Saccharomyces cerevisiae. On the basis of these microbiological findings, he had received several courses of antibiotic and antifungal therapy consisting of quinolones, third-generation cephalosporins, and amphotericin B, which had, however, produced only temporary remission of the symptoms. All cultures for mycobacteria (blood, sputum, urine, etc.) were repeatedly negative; sputum culture was contaminated by P. aeruginosa.Bilateral lung transplantation was performed on 20 July 1999. There were no intraoperative complications, and the patient was started on immunosuppressive therapy.On 5 August 1999, the patient developed a septic syndrome, and computed tomography (CT) performed on 7 August 1999 revealed a hyperdense lesion in the right paracardiac region with features of parenchymal involvement and a reactive pleural effusion. In light of the previous fungal recovery from clinical specimens, he was promptly started on intravenous amphotericin B therapy. On 6 August 1999 the pleural fluid was cultured for mycobacteria and was inoculated into Middlebrook 7H12 medium (BACTEC 12B; Becton Dickinson Diagnostic Instruments, Sparks, Md.) and Löwenstein-Jensen slant (BioMerieux, Marcy l'Etoile, France). On 8 August 1999, sputum and blood samples were also submitted for mycobacterial studies. A smear of respiratory samples showed many acid-fast bacilli.All three specimens yielded a rapidly growing mycobacterium identified as Mycobacterium chelonae and subsequently as M. abscessus, and on 20 August 1999 the patient was started on intravenous ciprofloxacin, amikacin, and clarithromycin. Sensitivity studies soon revealed, however, that the isolates were clearly resistant to all three drugs, as well as to all of the others tested (Table 1). In fact, after 1 month of antibiotic therapy the patient...

The reliability of the BACTEC MGIT 960 system, an automated version of the Mycobacteria Growth Indicator Tube (MGIT), for antimicrobial susceptibility testing of Mycobacterium tuberculosis was evaluated on 78 clinical isolates. Rifampin (RMP), isoniazid (INH), streptomycin (SM), and ethambutol (EMB) were tested at the following concentrations: 1.0 g/ml for RMP, 0.1 and 0.4 g/ml for INH, 1.0 and 4.0 g/ml for SM, and 5.0 and 7.5 g/ml for EMB. Results were compared with those obtained by the BACTEC 460 TB radiometric system. Initially the reproducibility study showed 99.5% agreement on repeat testing with all the four drugs. With susceptibility testing of clinical isolates, excellent agreement between the two systems was found for all the drugs. A total of nine major errors were observed for only three isolates, resistant according to BACTEC MGIT 960 and susceptible according to BACTEC 460 TB, to SM (4.0 g/ml), INH (0.1 g/ml), and EMB (5.0 g/ml) (one isolate) and to SM (1.0 g/ml), INH (0.4 g/ml), and EMB (5.0 g/ml) (two isolates). When these isolates were tested by using the conventional proportion method on Löwenstein-Jensen medium, agreement with BACTEC MGIT 960 was found for five results and with BACTEC 460 TB for the remainder. The time to report results was 7.9 days by MGIT 960 and 7.3 days by BACTEC 460 TB, which was not found statistically significant (P > 0.05). In conclusion, the performance of BACTEC MGIT 960 was found similar to that of BACTEC 460 TB and this new system can be considered a good alternative to the radiometric method for routine susceptibility testing of M. tuberculosis.Drug-resistant Mycobacterium tuberculosis strains represent a serious public health problem. Resistance to the four primary drugs, streptomycin (SM), isoniazid (INH), rifampin (RMP), and ethambutol (EMB) (a combination known as SIRE), makes tuberculosis difficult to treat (19). Multidrug-resistant strains have emerged within the last decade, and the rapid detection of these isolates is critical for the effective treatment of patients (28). As recommended by the National MDR TB Task Force, to combat multidrug-resistant tuberculosis (7), antimicrobial susceptibility testing (AST) must be performed on all initial and follow-up M. tuberculosis isolates from each patient. Among the methods used for drug susceptibility testing, the agar proportion method (MOP) is universally accepted as the "gold standard" (18, 33). However, it requires a long time to report (generally 21 days after the test is set up). Since 1980 the BACTEC 460 TB radiometric system (Becton Dickinson Diagnostic Instruments, Sparks, Md.), which is based on the modified version of the proportion method (26), has been introduced to perform AST. The BACTEC 460 TB method provides results within 5 to 6 days, with a significant time savings. Several studies (25) have demonstrated that AST results obtained by BACTEC 460 TB were comparable with those of MOP, thus suggesting that the former method could be adopted for routine laboratory purposes. In 1995, the Mycobacteria...

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The high percentage of biofilms in our specimens confirms the association between biofilms and CRS. Our data support the hypothesis that biofilm formation represents the latter phase of an inflammatory process that leads to complete epithelial destruction.

A total of 102 patients with recurrent upper respiratory tract infections underwent microbiological exploration with appropriate sampling and direct biopsies of the infected sites. Therapy was then started and on day 1 each patient received two intramuscular injections of thiamphenicol glycinate acetylcysteinate (TGA). From day 2 to 10 sequential therapy with the same drug was continued employing TGA administered by aerosol. All putative etiologic agents recovered were susceptible to thiamphenicol and only 24 demonstrated the ability to produce in vitro biofilms. The organisms comprised 10 Staphylococcus aureus, 6 Streptococcus pyogenes, 4 Streptococcus pneumoniae and 3 Haemophilus influenzae. Of the 24 subjects in whom biofilms were demonstrated to be present in vivo by Scanning Electron Microscopy, clinical and bacteriological cure was obtained in 21 cases (87.5%) following sequential therapy with TGA. Failures were considered to be persistent signs and symptoms at day 15 after initiation of treatment and lack of eradication of 3 S. aureus strains, despite their in vitro susceptibility to thiamphenicol. Very few adverse events attributable to TGA were reported in this cohort of patients. In no case was discontinuation of treatment deemed necessary by the attending physician.