Using a set of synthetic oligonucleotides homologous to broadly conserved sequences in-vitro amplification via the polymerase chain reaction followed by direct sequencing results in almost complete nucleotide determination of a gene coding for 16S ribosomal RNA. As a model system the nucleotide sequence of the 16S rRNA gene of M.kansasii was determined and found to be 98.7% homologous to that of M.bovis BCG. This is the first report on a contiguous sequence information of an entire amplified gene spanning 1.5 kb without any subcloning procedures.

Abstract Nontuberculous mycobacteria (NTM) represent over 190 species and subspecies, some of which can produce disease in humans of all ages and can affect both pulmonary and extrapulmonary sites. This guideline focuses on pulmonary disease in adults (without cystic fibrosis or human immunodeficiency virus infection) caused by the most common NTM pathogens such as Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi among the slowly growing NTM and Mycobacterium abscessus among the rapidly growing NTM. A panel of experts was carefully selected by leading international respiratory medicine and infectious diseases societies (ATS, ERS, ESCMID, IDSA) and included specialists in pulmonary medicine, infectious diseases and clinical microbiology, laboratory medicine, and patient advocacy. Systematic reviews were conducted around each of 22 PICO (Population, Intervention, Comparator, Outcome) questions and the recommendations were formulated, written, and graded using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Thirty-one evidence-based recommendations about treatment of NTM pulmonary disease are provided. This guideline is intended for use by healthcare professionals who care for patients with NTM pulmonary disease, including specialists in infectious diseases and pulmonary diseases.

A method for the rapid identification of mycobacteria to the species level was developed on the basis of evaluation by the polymerase chain reaction (PCR) of the gene encoding for the 65-kDa protein. The method involves restriction enzyme analysis of PCR products obtained with primers common to all mycobacteria. Using two restriction enzymes, BstEII and HaeIll, medically relevant and other frequent laboratory isolates were differentiated to the species or subspecies level by PCR-restriction enzyme pattern analysis. PCRrestriction enzyme pattern analysis was performed on isolates (n = 330) from solid and fluid culture media, including BACTEC, or from frozen and lyophilized stocks. The procedure does not involve hybridization steps or the use of radioactivity and can be completed within 1 working day.

Nontuberculous mycobacteria (NTM) represent over 190 species and subspecies, some of which can produce disease in humans of all ages and can affect both pulmonary and extrapulmonary sites. This guideline focuses on pulmonary disease in adults (without cystic fibrosis or human immunodeficiency virus infection) caused by the most common NTM pathogens such as Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi among the slowly growing NTM and Mycobacterium abscessus among the rapidly growing NTM. A panel of experts was carefully selected by leading international respiratory medicine and infectious diseases societies (ATS, ERS, ESCMID, IDSA) and included specialists in pulmonary medicine, infectious diseases and clinical microbiology, laboratory medicine, and patient advocacy. Systematic reviews were conducted around each of 22 PICO (Population, Intervention, Comparator, Outcome) questions and the recommendations were formulated, written, and graded using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Thirty-one evidence-based recommendations about treatment of NTM pulmonary disease are provided. This guideline is intended for use by healthcare professionals who care for patients with NTM pulmonary disease, including specialists in infectious diseases and pulmonary diseases.

were determined and compared. The sequence data were used to infer a phylogenetic tree, which provided the basis for a systematic phylogenetic analysis of the genus Mycobacterium. The groups of slow-and fast-growing mycobacteria could be differentiated as distinct entities. We found that M. simiae occupies phylogenetically an intermediate position between these two groups. The phylogenetic relatedness within the slow-growing species did not reflect the Runyon classification of photochromogenic, scotochromogenic, and nonchromogenic mycobacteria. In general, the phylogenetic units identified by using rRNA sequences confirmed the validity of phenotypically defined species; an exception was M. gastri, which was indistinguishable from M. kunsasii when this kind of analysis was used.Mycobacteria are aerobic, nonmobile bacteria that are characteristically acid fast. The property of acid fastness, which is due to waxy materials in cell walls, is particularly important for recognizing mycobacteria. Members of the genus Mycobacterium are widespread in nature and range from soil-dwelling saprophytes to pathogens of humans and animals (22, 34). A major descriptive division of mycobacteria is related to growth rate and pigmentation. On the basis of these criteria, the genus Mycobacterium has been divided into four groups. Group I consists of the photochromogenic (pigmented) species of slow growers; members of group I1 are scotochromogenic slow growers; group I11 contains the nonchromogenic slow growers; and group IV consists of rapid growers (defined as maturing in less than 1 week) (22,34).Taxonomic analysis of the genus Mycobacterium is complicated by the fact that a variety of specialized and complex tests must be used. Numerical taxonomic analysis, which requires that some dozens of characters be tested (e.g., enzymatic activity, growth, morphology, and drug susceptibility), is now being applied to circumscription of clusters and description of strains. Early on, the problems and difficulties of traditional taxonomy with respect to mycobacteria were recognized, prompting a number of investigators in the field to organize themselves into the International Working Group on Mycobacterial Taxonomy and to undertake a number of cooperative taxonomic studies (18, 29, Attempts to subdivide mycobacterial species by using immunological approaches, DNA composition, and similar characteristics (1-3,9,10) proved to be taxonomically useful but gave little phylogenetic information. The use of macromolecular comparisons to infer phylogenetic relationships is generally accepted and well established. Of the macromolecules used for phylogenetic analysis, the rRNAs, in particular 16s rRNA, have proven to be the most useful for establishing phylogenetic relationships because of their high information content, conservative nature, and universal dis-31-33).* Corresponding author. tribution (7,35). We recently developed a general procedure for the isolation and direct complete nucleotide determination of entire genes coding for 16s rRNA in w...

Nontuberculous mycobacteria (NTM) represent over 190 species and subspecies, some of which can produce disease in humans of all ages and can affect both pulmonary and extrapulmonary sites. This guideline focuses on pulmonary disease in adults (without cystic fibrosis or human immunodeficiency virus infection) caused by the most common NTM pathogens such as Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi among the slowly growing NTM and Mycobacterium abscessus among the rapidly growing NTM. A panel of experts was carefully selected by leading international respiratory medicine and infectious diseases societies (ATS, ERS, ESCMID, IDSA) and included specialists in pulmonary medicine, infectious diseases and clinical microbiology, laboratory medicine, and patient advocacy. Systematic reviews were conducted around each of 22 PICO (Population, Intervention, Comparator, Outcome) questions and the recommendations were formulated, written, and graded using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Thirty-one evidence-based recommendations about treatment of NTM pulmonary disease are provided. This guideline is intended for use by healthcare professionals who care for patients with NTM pulmonary disease, including specialists in infectious diseases and pulmonary diseases.

The epidemiological and microbiological features of this prolonged outbreak provided evidence for the airborne transmission of M. chimaera from contaminated heater-cooler unit water tanks to patients during open-heart surgery.

Healthcare-associated infections due to M. chimaera occurred in patients subsequent to cardiac surgery with extracorporeal circulation and implantation of prosthetic material. Infections became clinically apparent after a time lag of months to years. Mycobacterium chimaera infections are easily missed by routine bacterial diagnostics and outcome is poor despite long-term antimycobacterial therapy, probably because biofilm formation hinders eradication of pathogens.