Publications by authors named "Martha Inirida Guerrero"

15 Publications

  • Page 1 of 1

Leprosy in the Colombian island of Providencia

Biomedica 2020 05 1;40(Supl. 1):26-31. Epub 2020 May 1.

Oficina de Docencia e Investigación, Hospital Universitario Centro Dermatológico Federico Lleras Acosta, Bogotá, D.C., Colombia; Facultad de Medicina, Universidad de la Sabana, Chía, Colombia.

San Andrés and Providencia are Colombian islands in the Caribbean Sea. San Andrés has 68,283 inhabitants and has registered cases of leprosy in immigrants from continental Colombia. Providencia has 5,037 inhabitants and historically health programs did not have records of the disease, but in 2009 two cases of multibacillary histoid leprosy were confirmed and, subsequently, another two, which represents a prevalence of 8 cases per 10,000 inhabitants and places the island as a hyperendemic site for leprosy. Initially, a 14-year-old girl with histoid leprosy was diagnosed and, exploring this case, her father was diagnosed with the same clinical form of leprosy. Recently, a new intrafamilial patient with multibacillary leprosy and an extrafamilial case of a girl with undetermined leprosy were detected. The objective of this study was to present to the scientific community and the public health officers these clinical cases and to draw the attention of the sanitary authorities on the necessity of establishing continuous programs of leprosy epidemiological surveillance on the island using the new tools available in the Programa de Control de la Lepra (Leprosy Control Program).
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http://dx.doi.org/10.7705/biomedica.4974DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449110PMC
May 2020

Mycobacterium leprae's evolution and environmental adaptation.

Acta Trop 2019 Sep 30;197:105041. Epub 2019 May 30.

Hospital Universitario Centro Dermatológico Federico Lleras Acosta, Bogotá, Colombia. Electronic address:

Leprosy is an ancient disease caused by the acid-fast bacillus Mycobacterium leprae, also known as Hansen's bacillus. M. leprae is an obligate intracellular microorganism with a marked Schwann cell tropism and is the only human pathogen capable of invading the superficial peripheral nerves. The transmission mechanism of M. leprae is not fully understood; however, the nasal mucosa is accepted as main route of M. leprae entry to the human host. The complete sequencing and the comparative genome analysis show that M. leprae underwent a genome reductive evolution process, as result of lifestyle change and adaptation to different environments; some of lost genes are homologous to those of host cells. Thus, M. leprae reduced its genome size to 3.3 Mbp, contributing to obtain the lowest GC content (approximately 58%) among mycobacteria. The M. leprae genome contains 1614 open reading frames coding for functional proteins, and 1310 pseudogenes corresponding to 41% of the genome, approximately. Comparative analyses to different microorganisms showed that M. leprae possesses the highest content of pseudogenes among pathogenic and non-pathogenic bacteria and archaea. The pathogen adaptation into host cells, as the Schwann cells, brought about the reduction of the genome and induced multiple gene inactivation. The present review highlights the characteristics of genome's reductive evolution that M. leprae experiences in the genetic aspects compared with other pathogens. The possible mechanisms of pseudogenes formation are discussed.
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http://dx.doi.org/10.1016/j.actatropica.2019.105041DOI Listing
September 2019

A molecular platform for the diagnosis of multidrug-resistant and pre-extensively drug-resistant tuberculosis based on single nucleotide polymorphism mutations present in Colombian isolates of Mycobacterium tuberculosis.

Mem Inst Oswaldo Cruz 2016 Feb 2;111(2):93-100. Epub 2016 Feb 2.

Instituto Nacional de Salud, Bogotá, Colombia.

Developing a fast, inexpensive, and specific test that reflects the mutations present in Mycobacterium tuberculosis isolates according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant TB based on single nucleotide polymorphism (SNP) mutations present in therpoB, katG, inhA,ahpC, and gyrA genes from Colombian M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically and genotypically characterised as having susceptible or MDR M. tuberculosis. For our method, the kappa index of the sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 forrpoB, katG, inhA,ahpC, and gyrA, respectively. Sensitivity and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug resistance mutations to first and second-line drugs within a few hours.
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http://dx.doi.org/10.1590/0074-02760150306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4750448PMC
February 2016

Mycobacterium tuberculosis Genotypes Determined by Spoligotyping to Be Circulating in Colombia between 1999 and 2012 and Their Possible Associations with Transmission and Susceptibility to First-Line Drugs.

PLoS One 2015 11;10(6):e0124308. Epub 2015 Jun 11.

Dirección de Investigación en Salud Pública, Grupo de Micobacterias, Instituto Nacional de Salud, Bogotá, Colombia.

Introduction: Tuberculosis (TB) remains a primary public health problem worldwide. The number of multidrug-resistant tuberculosis (MDR TB) cases has increased in recent years in Colombia. Knowledge of M. tuberculosis genotypes defined by spoligotyping can help determine the circulation of genotypes that must be controlled to prevent the spread of TB.

Objective: To describe the genotypes of M. tuberculosis using spoligotyping in resistant and drug-sensitive isolates and their possible associations with susceptibility to first-line drugs.

Methods: An analytical observational study was conducted that included 741 isolates of M. tuberculosis from patients. The isolates originated from 31 departments and were obtained by systematic surveillance between 1999 and 2012.

Results: In total 61.94% of the isolates were resistant to 1 or more drugs, and 147 isolates were MDR. In total, 170 genotypes were found in the population structure of Colombian M. tuberculosis isolates. The isolates were mainly represented by four families: LAM (39.9%), Haarlem (19%), Orphan (17%) and T (9%). The SIT42 (LAM 9) was the most common genotype and contained 24.7% of the isolates, followed by the genotypes SIT62 (Haarlem1), SIT53 (T1), and SIT50 (H3). A high clustering of isolates was evident with 79.8% of the isolates classified into 32 groups. The Beijing family was associated with resistant isolates, whereas the Haarlem and T families were associated with sensitive isolates. The Haarlem family was also associated with grouped isolates (p = 0.031).

Conclusions: A high proportion (approximately 80%) of isolates was found in clusters; these clusters were not associated with resistance to first-line drugs. The Beijing family was associated with drug resistance, whereas the T and Haarlem families were associated with susceptibility in the Colombian isolates studied.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0124308PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4465906PMC
April 2016

Is drug-resistant Mycobacterium leprae a real cause for concern?: First approach to molecular monitoring of multibacillary Colombian patients with and without previous leprosy treatment.

Biomedica 2014 Apr;34 Suppl 1:137-47

Centro Dermatológico Federico Lleras Acosta, E.S.E., Bogotá, D.C, Colombia.

Introduction: There is no information in Colombia on Mycobacterium leprae primary and secondary drug resistance in regards to the WHO-multidrug therapy regime. On the other hand, public health authorities around the world have issued various recommendations, one of which prompts for the immediate organization of resistance surveillance through simple molecular methods.

Objective: To determine the prevalence of Mycobacterium leprae drug resistance to rifampicin, ofloxacin and dapsone in untreated and previously treated patients at the Centro Dermatológico Federico Lleras Acosta during the 1985-2004 period.

Materials And Methods: We conducted a retrospective study which included multibacillary patient biopsies through elective sampling: 381 of them from new patients and 560 from previously treated patients. Using a microtome, we obtained six slides from each skin biopsy preserved in paraffin, and we extracted M. leprae DNA. We amplified three molecular targets through PCR and obtained the patterns of drug resistance to dapsone, rifampicin and ofloxacin by reverse hybridization. Finally, we collected epidemiological, clinical and demographical data for analyses.

Results: From 941 samples under study, 4.14% of them were resistant to one or more drugs, and 5.77 and 3.04% had resistant genotypes in new and previously treated patients, respectively. Total resistance for each drug was 0.43% for dapsone, 3.19% for rifampicin and 1.17% for ofloxacin. We found statistically significant differences for rifampicin and for the total population when comparing the results from untreated versus previously treated patients. Two thirds of the resistant samples were resistant to rifampicin alone or combined.

Conclusions: The standard multidrug therapy schemes continue being effective for leprosy cases; however, it is necessary to guarantee adherence and regularity. Surveillance to drug resistance in new and previously treated leprosy cases should be established.
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http://dx.doi.org/10.1590/S0120-41572014000500016DOI Listing
April 2014

[Delay in leprosy diagnosis as a predictor of disability in a cohort of patients in Colombia, 2000-2010].

Rev Panam Salud Publica 2013 Feb;33(2):137-43

Instituto Nacional de Dermatología, Centro Dermatológico Federico Lleras Acosta, Bogotá, D.C., Colombia.

Objective: Evaluate predictive factors of disability at time of leprosy diagnosis in a cohort of Colombian patients, from 2000 to 2010.

Methods: Descriptive and analytical observational study of a retrospective cohort of patients admitted with a leprosy diagnosis to the Centro Dermatológico Federico Lleras Acosta in Bogotá, Colombia, from 2000 to 2010. Variables were analyzed descriptively and predictive factors for disability at diagnosis were identified through simple and multifactorial analyses (Cox proportional hazards model); hazard ratios for each factor in the model were calculated.

Results: Time between first symptoms and diagnosis in the 333 cohort patients was 2.9 years on average; 32.3% had certain degree of disability, especially for the feet. Delay in diagnosis and disability was greater in men than in women and in patients with multibacillary rather than paucibacillary leprosy. Disability was significantly associated with delays of ≥ 1 year in diagnosis, age ≥ 30 years, initial bacillary index of ≥ 2, multibacillary leprosy, and natives of the Cundinamarca or Santander departments. Protective factors were female sex, having some education, and residence in Boyacá.

Conclusions: Time between first symptoms and diagnosis is the key predictive factor of disability at time of leprosy diagnosis. Strengthening of active searching for infected people and promotion of early diagnosis are recommended.
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http://dx.doi.org/10.1590/s1020-49892013000200009DOI Listing
February 2013

[Reliability and agreement of two smear reading scales for classification and monitoring of multidrug therapy in leprosy patients].

Biomedica 2011 Jul-Sep;31(3):403-9

Centro Dermatológico Federico Lleras Acosta, E.S.E, Bogotá, D.C, Colombia.

Introduction: After the clinical diagnosis of leprosy, classification methods are necessary to define a treatment and prognosis of patients consistent with bacterial load. Bacteria are detected in skin smear, and bacterial load typically is established by the internationally used Ridley's logarithmic scale, However, in Colombia an alternative semiquantitative scale is used.

Objective: The interobserver reproducibility was established for the Ridley and Colombia scales, and the level of correlation-matching was identified between the bacillary indices obtained in order to assess the degree of interchangeability.

Materials And Methods: Standardization was attained by a reading of the smears by 2 readers with subsequent, blinded evaluation of inter-observer agreement. Each reader quantified the bacterial load of for each sample (n=325) using the Colombian and the Ridley scales. The degree of interobserver agreement was assessed with weighted kappa coefficient. The level of correlation and agreement between the measurements of the bacillary index was established with coefficient of Lin.

Results: The interobserver weighted kappa coefficient was 0.83 for the Colombia scale and 0.85 for the Ridley scale. The Lin coefficient was 0.96 for the correlation-matching of bacillary indexes.

Conclusions: Interobserver agreement obtained for both scales was excellent as the correlation-matching bacillary indices determined with both methods. With the cut-off points yielded a good level of agreement, ensuring interchangeability between the scales defining the high or low bacterial load.
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http://dx.doi.org/10.1590/S0120-41572011000300012DOI Listing
July 2013

Avian tuberculosis of zoonotic importance at a zoo on the Bogotá Andean plateau (Sabana), Colombia.

Can Vet J 2009 Aug;50(8):841-5

The LaSalle University, College of Veterinary Medicine, FMV-ULS, Bogotá DC, Colombia.

Given that exposure to captive wild animals at circuses or zoos can be a source of zoonotic infection, a case and control study was carried out with a collection of exotic fowl at a zoo in Bogotá, Colombia. The presence of Mycobacterium avium-II was directly related to the death of birds kept in the original enclosure, and of 50% of a group of sentinel birds. Failure to detect the organism in a control group of birds outside the enclosure indicated that the infection was limited to the original enclosed area. We demonstrated that M. gordonae-IV was disseminated in all organs from 1 bird with macroscopic granulomatous lesion, a finding which has not been reported previously. We emphasize the importance of establishing handling norms to reduce the risk of zoonotic transmission.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2711469PMC
August 2009

[Development of a multiantigenic serological test for tuberculosis diagnosis].

Biomedica 2005 Mar;25(1):55-64

Laboratorio de Micobacterias, Instituto Nacional de Salud, Bogotá, D.C., Colombia.

Objective: The present work evaluated a multi-antigen printing immunoassay (MAPIA) for the serological diagnosis of tuberculosis.

Materials And Methods: Sera were obtained from 66 patients with tuberculosis, verified clinically and bacteriologically and from 47 healthy individuals (control group). Sample sera were used for detection of antibodies against 3 enriched mixtures of proteins and 5 unique recombinant antigens. The antigens were presented in a solid matrix. Sensitivity, specificity and predictive values were evaluated and confirmed by a logistic regression analysis. A prevalence value was calculated and used for the selection of the best antigenic combination.

Results: The sensitivity and specificity values of individual antigens varied between 5-83% and 9-100%. The enriched mixtures values were more accurate than those obtained with the recombinant antigens. Combinations of several antigens improved the sensitivity values up to the 81% level. In most cases, specificity values of 57% or less were obtained.

Conclusions: These results suggested that the multiantigenic test can be a useful screening tool, to be used in conjunction with the more definitive diagnostic tests.
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March 2005

[Phenotypic and genotypic methods for detecting multidrug resistance in Mycobacterium tuberculosis].

Biomedica 2005 Mar;25(1):22-33

Grupo de Micobacterias, Instituto Nacional de Salud, Bogota, D.C., Colombia.

Background: Expeditious charactization of drug susceptibility in Mycobacterium tuberculosis is difficult and, calls for the design and evaluation of faster, cheaper and more effective new techniques.

Objective: The aim of the current study was to compare one genotypic and two phenotypic methods for rapid susceptibility detection of M. tuberculosis.

Material And Methods: Twenty-one M. tuberculosis strains were evaluated by phenotypic methodologies of oxidation and reduction of Alamar blue and MTT in the presence of streptomycin, isoniazid, rifampin and ethambutol. In all tests, the proportion method was applied as the comparison standard. By means of receiver operative characteristic (ROC) analysis, the performance, predictive values and threshold values for all drugs were determined. In addition, the performance of PCR and reverse line blot hybridization in establishing predictive values for sensitivity and resistance were compared in contingency tables.

Results: The susceptibility patterns established by colorimetric techniques were obtained after seven days of incubation. The performances of these tests were excellent for all drugs-the areas under curves were >0.9, 100% of sensitivity (S) and specificity (E) >80%. The genotypic method of RFLP oligotyping detected multidrug resistance with S of 100% and E of 93%. Conclusion. The results indicated that Alamar blue, MTT and RFLP methodologies are rapid and useful tools for characterizing multidrug resistance in M. tuberculosis, particularly for those patients with high risk of developing multidrug resistant tuberculosis.
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March 2005

Multicenter evaluation of mycobacteria identification by PCR restriction enzyme analysis in laboratories from Latin America and the Caribbean.

J Microbiol Methods 2005 May 25;61(2):193-9. Epub 2004 Dec 25.

Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Botucatu, 862 3 degrees andar, São Paulo 04023-062, Brazil.

The identification of mycobacterial species in clinical isolates is essential for making patient care decisions. Polymerase chain reaction (PCR) restriction enzyme analysis (PRA) is a simple and rapid identification method, based on amplification of 441 bp of the hsp65 gene and restriction with BstEII and HaeIII. As a contribution to the validation of PRA, a multicenter study was performed in eight laboratories located in Argentina, Brazil, Colombia, Chile, and Guadeloupe. Each laboratory received 18 coded isolates from the collection of the Institute of Tropical Medicine (Antwerp, Belgium), representing duplicates of nine laboratory strains: Mycobacterium terrae CIPT 140320001, Mycobacterium scrofulaceum CIPT 140220031, Mycobacterium flavescens ATCC 14474, Mycobacterium triviale ATCC 23292, Mycobacterium nonchromogenicum ATCC 19530, Mycobacterium chitae ATCC 19627, Mycobacterium abscessus ATCC 19977, Mycobacterium kansasii ATCC 12478, and Mycobacterium peregrinum ATCC 14467. A detailed protocol including amplification, enzymatic digestion, and gel preparation was provided to each laboratory. Two laboratories identified correctly all 18 (100%) isolates, one identified correctly 17 (94.5%), two identified 14 (77.7%), one identified 11 (61%), and two identified 8 (44.4%) isolates. Errors detected in laboratories with more than 77% accuracy were associated with electrophoresis running conditions and an unspecific amplicon produced by a single strain. Lower accuracy was mainly related to inappropriate use of DNA markers and insufficient training in interpretation of patterns. In conclusion, the PRA method was readily implemented in some Latin American and Caribbean laboratories of mycobacteria, but improvements in critical points, as gel running conditions and training in interpretiation of patterns, are needed in order to improve accuracy. In others, improvement in critical points is still necessary.
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http://dx.doi.org/10.1016/j.mimet.2004.11.015DOI Listing
May 2005

[Respiratory syntomatic prevalence, infection and tuberculosis disease and associated factors: population-based study].

Biomedica 2004 Jun;24 Supp 1:124-31

Subdirección de Epidemiología y LNR, Instituto Nacional de Salud, Bogotá, DC, Colombia.

A cross sectional survey on TB epidemiological characteristics was carried out in Mitú (Vaupes, Colombia) with the aim of measuring the prevalence of TB cases, the prevalence of TB suspected cases, the coverage with BCG vaccine and the prevalence of infection with Mycobacterium tuberculosis. One hundred and sixty five (165) households were included in the survey using a randomized cluster sampling design (n=20 clusters) which yielded a sample size of 972 subjects. The prevalence of TB suspect cases was 3.6% (C.I.95% 2.6-4.9%); coverage with BCG vaccine was 94%. Vaccinated people had a lower chance of being a TB suspected case (OR=0.37 C.I.95% 0.15-0.95). TB prevalence was 1.4%. People vaccinated with BCG had a lower chance of having been a TB case (OR=3.3 C.I.95% 1.0-14). These data recommend that 10% of people with respiratory symptoms be screened for in the National Control Program,and that the results be reviewed with surveys based at health centers. The data also reinforce the need for better vaccination coverages with BCG in high endemic areas.
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June 2004

[Situation of tuberculosis in Colombia, 2002].

Biomedica 2004 Jun;24 Supp 1:102-14

Departamento Administrativo Nacional de Estadśtica, Dirección de Censos y Demografía, Estadísticas Vitales, Bogotá, DC, Colombia.

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June 2004

IS6110 fingerprinting of sensitive and resistant strains (1991-1992) of Mycobacterium tuberculosis in Colombia.

Mem Inst Oswaldo Cruz 2002 Oct;97(7):1005-8

Centro de Investigaciones Biomedicas, Facultad de Medicina, Universidad del Quindio, Colombia.

The standardized method to study the polymorphism of IS 6110 was used to characterize 53 isolates of Mycobacterium tuberculosis obtained during 1991-1992 from 14 regions in Colombia. In Valle region cluster rate was 25% (4/16). The mean number of IS6110 band was 10 +/- 3. Similarity between strains was of 60% in 81% of strains and this tended to be correlated with geographic origin. For the first time M. tuberculosis without IS6110 bands in restriction fragment length polymorphism analysis was found in Colombia. Additional studies are necessaries in order to best characterize the situation in relation to human immunodeficiency virus epidemic and recent changes in tuberculosis control program.
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http://dx.doi.org/10.1590/s0074-02762002000700013DOI Listing
October 2002

[Developing and using a PCR test to detect subclinical Mycobacterium leprae infection].

Rev Panam Salud Publica 2002 Apr;11(4):228-34

Laboratorio de Micobacterias, Subdirección de Investigación y Desarrollo, Instituto Nacional de Salud, Bogotá, Colombia.

Objective: While the prevalence of leprosy has declined around the world, there has not been a corresponding decrease in its incidence, thus indicating that it has not been possible to prevent transmission of the disease. Despite the small number of patients with lepromatous leprosy, the majority of the inhabitants of endemic areas show signs of exposure to Mycobacterium leprae, which could be explained by the presence of subclinical bacilliferous infections in the community. The objective of this study was to investigate the use of a polymerase chain reaction (PCR) test to detect M. leprae in samples of nasal mucus from asymptomatic household contacts of patients with leprosy.

Methods: We standardized and optimized a PCR technique to amplify a 321 base pair DNA fragment, using a pair of primers complementary to a segment of an LSR/A15 gene that codes for the 15 kDa M. leprae antigen. We investigated the optimal concentrations of all the test components. We used dimethyl sulfoxide (DMSO) to achieve a more specific amplification. We applied the PCR test to 70 healthy household contacts of leprosy patients from eight municipalities in Colombia where there was a high prevalence of the disease.

Results: The test's detection limit was 100 fg of DNA. With the optimized technique, bacillus was detected in the nasal mucus samples of 9 (12.8%) of the 70 household contacts. The 3 PCR-positive household contacts of paucibacillary cases were from municipalities with very high prevalence levels. In comparison to contacts who were PCR-negative, the contacts who were PCR-positive had spent significantly less time, as a proportion of their age, living with a patient (P = 0.028). This finding demonstrates the test's capacity for early detection.

Conclusions: The PCR test that we developed is useful as a tool for detection and early follow-up of possible leprosy cases. It can be used to monitor high-risk populations and also to maintain the achievements of leprosy elimination programs in countries where the disease's prevalence has been significantly reduced.
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http://dx.doi.org/10.1590/s1020-49892002000400004DOI Listing
April 2002
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