Directriz para reducir el riesgo de transmisión de mycobacterium abscessus durante la práctica clínica odontológica / Guideline to reduce the risk of transmission of mycobacterium abscessusin clinical dental practice

Las medidas de bioseguridad están predestinadas a reducir el riesgo de transmisión de microorganismos a partir de fuentes de infección reconocidas o no reconocidas en clínicas dentales vinculadas con lacontaminación de los materiales, aparatos y/o instrumentos. Un microorganismo reemergente es el Mycobacterium abscessus, que es unabacteria ambiental que puede ocasionar problemas de salud muy serios, por lo que debe ser controlada y prevenida su transmisión.

Biosafety measures are designed to reduce the risk of transmission ofmicroorganisms from recognized or unrecognized sources of infectionin dental procedures associated with the contamination of materials,apparatus, and/or instruments. One reemerging microorganism isMycobacterium abscessus, which is an environmental bacterium thatcan cause serious health problems and therefore needs to be controlledand prevented.

Infections Caused by Rapidly Growing Mycobacteria spp in Children and Adolescents With Cancer.

BACKGROUND: Rapidly growing mycobacteria (RGM) infections in pediatric oncology patients have not been completely characterized. METHODS: We reviewed medical records of oncology patients at St. Jude Children's Research Hospital (St. Jude) from 1990 to 2010 with RGM infections and summarized the results of previously published cases. RESULTS: Twenty-five St. Jude patients had 27 episodes of infection. Approximately half of the cases occurred in patients with hematological malignancies and in males; infections were more common in white patients. Most patients were not neutropenic or lymphopenic. The most common causative species were Mycobacterium chelonae, Mycobacterium abscessus, and Mycobacterium fortuitum. Most isolates were susceptible to amikacin and clarithromycin; all were susceptible to at least 1 of these. Treatment regimens varied considerably, particularly with respect to the duration of antimicrobial chemotherapy. Two St. Jude patients died; both had pulmonary infections. The literature search identified an additional 58 cases of infection. Localized catheter-associated infections were more common than bloodstream infections in the current series than in previous reports, and outbreaks were not recognized. Otherwise, the demographic and clinical characteristics of patients were similar. CONCLUSIONS: Localized catheter-associated infections were most common in this largest reported single center experience reported to date. Pulmonary infection is uncommon in children but, as in adults, has a high mortality rate. Relatively short-term antimicrobial treatment and surgical debridement of infected tissue, if present, may be as effective for catheter-associated infections as prolonged antimicrobial use and may reduce adverse drug effects in these patients, who are vulnerable to drug-drug interactions and toxicity.

[Nontuberculous mycobacterial infections]. / Infections à mycobactérie non tuberculeuse.

The nontuberculous mycobacteria (NTM) denomination includes a large number of species with highly variable pathogenicity for humans. NTM infections are increasingly recognized. Several reasons explain their emergence as a human disease: increasing number of patients at risk, improved microbiological techniques, perhaps a more frequent exposure. Therefore, clinicians must know the clinical spectrum of NTM disease. This article summarizes the classification of NTM. It describes the clinical features of NTM infections and their treatment.

Current classification and status of primary immunodeficiency diseases in Taiwan.

The incidence of primary immunodeficiency diseases (PIDD) in Taiwan is estimated at 2.17 per 100,000 live births. This is much lower than in Sweden, with 8.4 per 100,000 live births. Patients with critical combined T-cell and B-cell immunodeficiency (CID) seem to be under-diagnosed because of delayed referrals to a tertiary care center which is able to organize a cooperative transplantation team encompassing, at least, a pediatric hematologist and a immunologist for severe combined immunodeficiency (SCID) classified as "pediatric emergency". Moreover, there are rare reported cases of adult-onset (over 18-years-old) common variable immunodeficiency (CVID). These cases are possibly treated as autoimmune diseases, but not PIDD. To date around the world, 206 kinds of PIDD have been found and 110 causal genetic effects were identified. Although epidemiological studies show wide geographical and racial variations in the prevalence and distribution of PIDD, we believe in Taiwan that those patients with Mendelian susceptibility to mycobacteria disease (MSMD), belonging to "congenital phagocyte defect", are often treated as isolated refractory mycobacterial infections or chronic granulomatous disease. Also, "diseases of innate immunity" and "autoimflammatory disorders" are not yet identified. To manage patients with hemophagocytic lymphohisticytosis syndromes, one of "disease of immune dysregulation, stem cell transplantation will be considered if there is poor response to chemotherapy. Patients with PIDD need better access to specialized clinical, laboratory and therapeutic resources.

[Differentiation of infection with Mycobacterium tuberculosis by recombinant Mycobacterium tuberculosis 11000 protein].

OBJECTIVE: To study the differentiation effect of recombinant Mycobacterium tuberculosis 11000 protein on infection of Mycobacterium tuberculosis. METHODS: Guinea pigs were immunized with different strains of mycobacterium, and then all guinea pigs were given intradermal injections with recombinant Mycobacterium tuberculosis 11000 protein and purified protein derivative of tuberculin (PPD) or purified protein derived from M. intracellulare (PPD-B). Skin reactions defined with two transverse diameters were read double-blinded after 24 and (or) 48 hours, and the means of the two transverse diameters were counted as the reaction diameters. RESULTS: All guinea pigs immunized with different strains of Mycobacteria responded to PPD or PPD-B with positive skin reactions. The recombinant Mycobacterium tuberculosis 11000 protein elicited positive skin reactions in guinea pigs infected with live Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum and Mycobacterium kansasii, and the reaction diameters were (14.7 +/- 2.0) mm, (9.3 +/- 3.8) mm, (18.7 +/- 2.4) mm and (14.8 +/- 4.2) mm, respectively. But it failed to elicit positive skin reaction in guinea pigs immunized with killed Mycobacterium tuberculosis, live BCG and other MOTT (mycobacteria other than Mycobacterium tuberculosis). CONCLUSIONS: Recombinant Mycobacterium tuberculosis 11000 protein can differentiate infection with live Mycobacterium tuberculosis from immunization with killed Mycobacterium tuberculosis, live BCG or other MOTT.

Mycobacterial infections after kidney transplant.

We looked at mycobacterial infections occurring after a kidney transplant to determine incidence, risk factors, and outcomes. Of 3921 kidney transplants performed between 1984 and 2002, 18 (0.45%) (10 men, eight women; 11 cadaveric donor, seven living donor graft) were identified as having mycobacterial infection at some time posttransplant. Mean age at transplant was 38.3 years. Racial background was: Caucasian (n = 12), African-American (n = 2), Native Indian (n = 2), Hispanic (n = 1), and Middle Eastern (n = 1). The majority had a kidney alone (n = 14). Four recipients had simultaneous transplant of a second organ: pancreas (n = 2), islets (n = 1), and liver (n = 1). None of the 18 recipients had documented mycobacterial infection pretransplant. One recipient had a positive Mantoux test at the time of transplant and then developed pulmonary tuberculosis 4 months posttransplant; the remaining 17 patients had either negative (n = 10) or unavailable (n = 7) pretransplant Mantoux results. Mean time to infection was 3.2 years (range 1 week to 12 years). The most common site of infection was respiratory (n = 8). Other sites included musculoskeletal (n = 4), skin (n = 3), gyn (n = 1), and other (n = 2). Only three of the infections were with mycobacterial tuberculi; the others were with avium (n = 5), chelonae (n = 2), or other nontuberculous mycobacteria. Risk factors included previous TB exposure, occupational exposure, or accidental soft tissue injury. Soft tissue infections often presented as chronic unhealed wounds and required extensive surgical debridements. With mean follow-up of 12.5 years since transplant and 9.2 years since infection, 13 of the recipients are alive and well; causes of death included cardiovascular (n = 3) and sepsis (n = 2).

[Pulmonary disease caused by nontuberculous mycobacteria after allogeneic hematopoietic stem cell transplantation--a case report and literature review].

OBJECTIVE: To report a case with pulmonary disease caused by nontuberculous mycobacteria (NTM) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), with a literature review. METHODS: Case report and literature review. RESULTS: A patient with acute non-lymphocytic leukemia was treated by allo-HSCT. Her NTM lung disease developed after HSCT was successfully treated with a 3 antimicrobials combination of clarithromycin, levofloxacin and capreomycin for 10 months. CONCLUSION: NTM infections are infrequent in allo-HSCT recipients and have a good clinical prognosis if correctly treated.

Liposome technology for drug delivery against mycobacterial infections.

Mycobacteria are intracellular pathogens that invade and reside inside macrophages. There has been a rapid resurgence in infections caused by the genus mycobacteria. Chemotherapy of mycobacterial infections is prolonged, hepatotoxic and very often inadequate in achieving optimal drug concentrations inside the cells. Recent advances in controlled delivery systems for drugs such as liposomes have sparked a renewed interest in their potential application for the treatment of mycobacterial infections. The versatility of liposomes in incorporation of hydrophilic/hydrophobic components, non-toxic nature, biodegradability, biocompatibility and property of sustained release makes them attractive candidates for the delivery of antitubercular drugs. Liposome research in the area of mycobacterial diseases has evolved and matured through several phases; from the laboratory to the clinics. This review, thus focuses on the use of liposomes for the treatment of various types of mycobacterial diseases.

Mycobacterial infection after renal transplantation in a Western population.

Mycobacterial infection is a serious opportunistic infection in renal transplant recipients. The incidence is higher in developing than in developed Western countries. This study is a single-centre retrospective review of the records of 2502 renal transplant recipients in Belgium. Fourteen cases of mycobacterial infection (9 Mycobacterium tuberculosis and 5 atypical mycobacterial infection) were diagnosed. The time interval between transplantation and diagnosis was 64 +/- 80 months (mean +/- SD, range 5-188) for M. tuberculosis and 92 +/- 75 months (range 14-209) for atypical mycobacterial infection. The localisation of M. tuberculosis was pulmonary/pleural in 67% and extrapulmonary in 33%. The atypical mycobacterial infections were located in skin, tendons, and joints. Eight patients received IV prednisolone pulse therapy for acute rejection long before the time of mycobacterial infection. The initial antimycobacterial therapy consisted of a combination of isoniazid, rifampicin, and ethambutol in all patients. In patients with M. tuberculosis infection, a good response to antimycobacterial therapy was obtained. In patients with atypical mycobacterial infection, initial treatment was successful in 3 out of 5 patients, in 1 patient recurrence was diagnosed and in another patient, who is still under treatment at present, the initial treatment was adjusted after identification of the atypical mycobacterium and its antibiogram. The incidence of mycobacterial infection after renal transplantation did not increase with newer immunosuppressive therapy. The major risk factor is the total dose of corticosteroids. All patients responded well without major reductions in immunosuppressive therapy. Chemoprophylaxis for high-risk patients still is recommended.

[Histopathological findings of Buruli ulcer: cases from Benin in west Africa].

"AFIP classification" by light microscopy was of help to analyze the skin lesions of Buruli ulcer, in which the histopathology were classified into 6 stages i.e. active, healing, active but healing, consistent with active and chronic stages. In this paper, skin lesions biopsied from 41 cases of Buruli ulcer were observed by light microscopy. Those were sent from Benin in west Africa at 1997, and under the control of Armed Forces Institute of Pathology(AFIP) in Washington DC, USA. Each age, sex, biopsy lesions and histopathological stage and corresponding characteristic histopathological findings of 41 cases except that of chronic stage were analyzed and herewith reported by this paper.

Detection of a new Mycobacterium species in wild striped bass in the Chesapeake Bay.

Investigation into recent declines in striped bass health in the Chesapeake Bay in Maryland resulted in the isolation of a putative new species of Mycobacterium. This isolate was obtained from fish showing skin ulcers and internal granulomas in various organs. The isolate was slow growing at 28 degrees C; was nonchromogenic; showed no activities of nitrate reduction, catalase activity, Tween 80 hydrolysis, tellurite reduction, or arylsulfatase reduction; grew best at low salt concentrations; and was urease and pyrazinamidase positive. By PCR a unique insertional sequence was identified which matched nothing in any database. Analysis of the nearly complete 16S rRNA gene sequence also indicated a unique sequence which had 87.7% sequence homology to Mycobacterium ulcerans, 87.6% homology to Mycobacterium tuberculosis, and 85.9% homology to Mycobacterium marinum. Phylogenetic analysis placed the organism close to the tuberculosis complex. These data support the conclusion that the isolate probably represents a new mycobacterial species.

Does size matter? Utility of size of tuberculin reactions for the diagnosis of mycobacterial disease.

It is a common belief that larger tuberculin reactions are more serious, and more likely to indicate patients with active tuberculosis (TB) or at high risk of disease in the future. Among 182 close contacts, and 502 patients suspected of possible active TB, 529 underwent tuberculin skin testing (TST) and 605 had a chest radiograph. Final diagnoses, based on all available clinical, microbiological, histological, and radiographic information, were active TB, 68; inactive TB, 274; nontuberculous mycobacterial disease, 14; conditions associated with anergy, 36; no detectable abnormality (except a positive TST) or condition unrelated to TB, 213; and negative TST, no further evaluation, 79. Among these patients, TST of 5 mm or larger was significantly more likely to indicate active or inactive TB (p < 0.001). However, among patients with TST of 5 mm or greater, the size and frequency distribution of tuberculin reactions were not different between subjects with different diagnoses, nor between subjects with different types or extent of radiographic findings. As well, TST reactions were no different in 121 subjects with or 176 subjects without a history of BCG vaccination. In close contacts or patients suspected of active TB, reactions less than 5 mm indicated lower likelihood of active or inactive disease, but above that threshold, size of tuberculin reaction did not matter.

Nontuberculous mycobacterial infections in hematopoietic stem cell transplant recipients: characteristics of respiratory and catheter-related infections.

Over a 20-year period, 40 nontuberculous mycobacteria (NTM) were isolated from 6259 hematopoietic stem cell transplant (HSCT) recipients (0.64%), of which 28 were considered to have probable or definite infection (0.44%). Only 3 of 15 lower respiratory isolates obtained by bronchoalveolar lavage (BAL) and/or biopsy; (Mycobacterium avium complex [n = 2] and M. gordonae [n = 1]) caused definite or probable lower respiratory tract disease, whereas 12 of 15 were considered to cause possible lower respiratory tract disease according to Centers for Disease Control and Prevention definitions. The median time to diagnosis was 251 days following HSCT. All 3 patients with definite NTM disease were successfully treated with 3 antimicrobials for several months. Twenty-three patients had catheter-related infections, including exit site infection (n = 5), tunnel infection (n = 7), and catheter-related bacteremia (n = 11). All were caused by rapidly growing mycobacteria. The median time to diagnosis was 61 days following HSCT. All patients with catheter-related infections were successfully treated with an average of 2 antibiotics for a median of 3 weeks for exit site infection and 6 weeks for tunnel infection and catheter-related bacteremia. Soft tissue debridement was performed in all cases with tunnel infection. The catheter was removed in 21 of 23 patients with catheter-related infections. Two additional patients were diagnosed, one with lymphadenitis and one with skin lesion, due to NTM. In conclusion, NTM infections are infrequent in HSCT recipients and carry a good clinical prognosis. In the majority of lower NTM respiratory isolates obtained by BAL, a pathogenic role could not be established. However, lower respiratory tract disease can occur late after HSCT and should be considered if patients fail to respond to the treatment of concomitant infections or if evidence of tissue infection or concomitant bacteremia is present. Therapy should be performed with 2 to 3 antimicrobials, guided by antimicrobial susceptibilities, with additional surgical debridement in patients with tunnel infection.

Evaluation of the LiPA MYCOBACTERIA assay for identification of mycobacterial species from BACTEC 12B bottles.

The LiPA MYCOBACTERIA (Innogenetics NV, Ghent, Belgium) assay was used to identify mycobacterial isolates using culture fluid from positive BACTEC 12B bottles. The LiPA method involves reverse hybridization of a biotinylated mycobacterial PCR fragment, a 16 to 23S rRNA spacer region, to oligonucleotide probes arranged in lines on a membrane strip, with detection via biotin-streptavidin coupling by a colorimetric system. This system identifies Mycobacterium species and differentiates M. tuberculosis complex, M. avium-M. intracellulare complex, and the following mycobacterial species: M. avium, M. intracellulare, M. kansasii, M. chelonae group, M. gordonae, M. xenopi, and M. scrofulaceum. The mycobacteria were identified in the laboratory by a series of tests, including the Roche AMPLICOR Mycobacterium tuberculosis (MTB) test, the Gen-Probe ACCUPROBE, and a PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 65-kDa heat shock protein gene. The LiPA MYCOBACTERIA assay detected 60 mycobacterium isolates from 59 patients. There was complete agreement between LiPA and the laboratory identification tests for 26 M. tuberculosis complex, 9 M. avium, 3 M. intracellulare complex, 3 M. kansasii, 4 M. gordonae, and 5 M. chelonae group (all were M. abscessus) isolates. Three patient samples were LiPA positive for M. avium-M. intracellulare complex, and all were identified as M. intracellulare by the PCR-RFLP analysis. Seven additional mycobacterial species were LiPA positive for Mycobacterium spp. (six were M. fortuitum, and one was M. szulgai). The LiPA MYCOBACTERIA assay was easy to perform, and the interpretation of the positive bands was clear-cut. Following PCR amplification and gel electrophoresis, the LiPA assay was completed within 3 h.