Cord formation and colony morphology for the presumptive identification of Mycobacterium tuberculosis complex

Monteiro, Paulo Henrique Tasso; Martins, Maria Conceição; Ueki, Suely Yoko Mizuka; Giampaglia, Carmen Maria Saraiva; Telles, María Alice da Silva

doi:10.1590/s1517-83822003000200016

Cited by 15 publications

(17 citation statements)

References 6 publications

(13 reference statements)

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“…Such differences seem insignificant and are lower than the approximately 10% presented by other authors. (12,17) The sensitivity of the method was greater on solid medium. We found only a 2.7% difference in sensitivity when analyzing the method using both isolation media, a quite relevant number, since most public health laboratories in Brazil use solid medium in the isolation of mycobacteria, confirming the viability of this method.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, our values are lower than the 16.9% presented by one well-known author. (12) Analyzing the performance of the method using both isolation media, only 1.5% of the strains of the M. tuberculosis complex were identified as cord factor negative, 100% of them in liquid medium. Such differences seem insignificant and are lower than the approximately 10% presented by other authors.…”

Section: Discussionmentioning

confidence: 99%

“…(11) The method has also been used as a triage in the presumptive identification of the M. tuberculosis complex, together with the evaluation of the colony morphology in solid medium, as a practical and low cost pre-test to determine whether additional identification or sensitivity tests are needed. (11,12) In view of this, and as a Regional Laboratory, we carried out this study with the objective of evaluating the presence of the cord factor as Introduction Tuberculosis (TB) is one of the most ancient diseases, with wide geographic distribution, constituting a serious public health problem worldwide and in Brazil.…”

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confidence: 99%

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Avaliação do crescimento em cordas na identificação presuntiva do complexo Mycobacterium tuberculosis

et al. 2007

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Objective: Virulent strains of the Mycobacterium tuberculosis complex, under certain appropriate conditions, grow as characteristic ropes, bundles or serpentine cords known as cord factor or growth in cords. The objective of the present study was to evaluate cord factor detection as a method of achieving presumptive identification of the M. tuberculosis complex, comparing it to conventional typing tests. Methods: A total of 743 strains were analyzed from January of 2002 to December of 2005 in the Mycobacteria Sector of the Adolfo Lutz Institute, located in the city of Santos, Brazil. Samples were obtained from clinical specimens collected from patients with respiratory symptoms treated at basic health clinics in the greater metropolitan area of Santos. Ziehl-Neelsen-stained smears were prepared, 301 (40.5%) in MB/BacT broth and 442 (59.5%) on solid media, either Lowenstein-Jensen or Ogawa-Kudoh. Results: The sensitivity, specificity, positive predictive value and negative predictive value obtained during the performance comparison of the two methods (cord factor detection and conventional typing) using both isolation media were, respectively, 98.5, 88, 97 and 93%. The method was more sensitive on solid medium (100%), and the difference in sensitivity between the two media types was only 2.7%. Conclusions: Taking into consideration the results obtained, we conclude that, in laboratories with a high incidence of M. tuberculosis complex isolation and limited economic resources, cord factor detection is a fast and valid criterion for identifying these mycobacteria using liquid or solid medium. It also enables subsequent conclusive identification tests, as well as additional sensitivity tests when necessary.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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confidence: 99%

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Avaliação do crescimento em cordas na identificação presuntiva do complexo Mycobacterium tuberculosis

et al. 2007

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“…Mycobacterium tuberculosis currently infects one-third of the world population, and cause 2.9 million deaths annually (11,24). It is reported that tuberculosis has an incidence of 8 million new cases annually in the world with >19,000 cases/year in Iran (41).…”

Section: Discussionmentioning

confidence: 99%

Characterization of Mycobacterium tuberculosis complex isolated from iranian and afghani patients by spoligotyping method

Ramazanzadeh

Farnia

Amirmozafari³

2009

Braz. J. Microbiol.

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Designing newer drugs, vaccines, and diagnostic techniques is dependent on better understanding of M. tuberculosis virulence mechanism. In this study the prevalence of pcaA gene was determined in M. tuberculosis strains typed by spoligotyping. The associated risk factors among patients with different nationalities residing in Iran were also determined. The isolated M. tuberculosis strains have been characterized by performing susceptibility tests against four first-line antituberculosis drugs and were then subjected to spoligotyping characterization. PCR was used for detection of pcaA gene and its nucleotide sequence was also determined. Spoligotyping of M. tuberculosis strains resulted in 140 different patterns. One hundred twenty two (87.1%) of these spoligotype isolates were unique and reported for the first time. The remaining18 (12.8%) spoligotype patterns were previously reported from other geographical regions of the world. Haarlem family was most prevalent than other genotype. Antibiotic resistances were higher in those isolated from the Iranian patients. The pcaA gene was detected in M. tuberculosis clinical isolates but not in saprophyte strains such as M. kansasi. The results showed that, spread of M. tuberculosis strains belonging to the Beijing family among Iranian patients has to be considered seriously. This study confirmed the widespread existence of pcaA gene in almost all the clinical isolates. It is also important to undertake studies to identify which factors are the most significant to consider in tuberculosis control program.

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“…Here we report a descriptive retrospective study of all AFB positive samples received by this laboratory in the period of tuberculosis by analysis of colony morphology (rough) and pigmentation (nonchromogen), and the presence of cord on bacilloscopy (14). Forty additional cultures did not present these characteristics at the first examination and were regarded as NTM.…”

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confidence: 99%

Identification of non-tuberculous mycobacteria from the Central Public Health Laboratory from Mato Grosso do Sul and analysis of clinical relevance

Moraes

Chimara

Telles

et al. 2008

Braz. J. Microbiol.

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Non-tuberculous mycobacteria isolated at the Central Public Health Laboratory from Mato Grosso do Sul in 2003 and 2004 were identified by conventional phenotypic methods (TI) and by PCR-Restriction Enzyme Analysis (PRA) using the hsp65 gene as target (PRA-hsp65). With 15 of the 32 analysed isolates, results of both methods were concordant, being 8 Mycobacterium avium, 3 M. fortutium, 1 M. kansasii, 1 M. flavescens, 1 M. peregrinum and 1 Nocardia brasiliensis. TI of 12 isolates was inconclusive. Novel PRA-hsp65 patterns were observed with 11 isolates. Medical data were evaluated for inference of clinical relevance of these isolates.

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Cord formation and colony morphology for the presumptive identification of Mycobacterium tuberculosis complex

Cited by 15 publications

References 6 publications

Avaliação do crescimento em cordas na identificação presuntiva do complexo Mycobacterium tuberculosis

Avaliação do crescimento em cordas na identificação presuntiva do complexo Mycobacterium tuberculosis

Characterization of Mycobacterium tuberculosis complex isolated from iranian and afghani patients by spoligotyping method

Identification of non-tuberculous mycobacteria from the Central Public Health Laboratory from Mato Grosso do Sul and analysis of clinical relevance

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