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1.
Clin Microbiol Infect ; 24(12): 1305-1310, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29496597

ABSTRACT

OBJECTIVES: Antimicrobial resistance (AMR) is a priority for surveillance in bacterial infections. For leprosy, AMR has not been assessed because Mycobacterium leprae does not grow in vitro. We aim to obtain AMR data using molecular detection of resistance genes and to conduct a prospective open survey of resistance to antileprosy drugs in countries where leprosy is endemic through a WHO surveillance network. METHODS: From 2009 to 2015, multi-bacillary leprosy cases at sentinel sites of 19 countries were studied for resistance to rifampicin, dapsone and ofloxacin by PCR sequencing of the drug-resistance-determining regions of the genes rpoB, folP1 and gyrA. RESULTS: Among 1932 (1143 relapse and 789 new) cases studied, 154 (8.0%) M. leprae strains were found with mutations conferring resistance showing 182 resistance traits (74 for rifampicin, 87 for dapsone and 21 for ofloxacin). Twenty cases showed rifampicin and dapsone resistance, four showed ofloxacin and dapsone resistance, but no cases were resistant to rifampicin and ofloxacin. Rifampicin resistance was observed among relapse (58/1143, 5.1%) and new (16/789, 2.0%) cases in 12 countries. India, Brazil and Colombia reported more than five rifampicin-resistant cases. CONCLUSIONS: This is the first study reporting global data on AMR in leprosy. Rifampicin resistance emerged, stressing the need for expansion of surveillance. This is also a call for vigilance on the global use of antimicrobial agents, because ofloxacin resistance probably developed in relation to the general intake of antibiotics for other infections as it is not part of the multidrug combination used to treat leprosy.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial/genetics , Leprosy/epidemiology , Mycobacterium leprae/drug effects , Mycobacterium leprae/genetics , Anti-Bacterial Agents/adverse effects , Bacterial Proteins/genetics , Biopsy, Needle , Brazil/epidemiology , Colombia/epidemiology , DNA Gyrase/genetics , Dapsone/therapeutic use , Endemic Diseases/statistics & numerical data , Epidemiological Monitoring , Global Health , Humans , India/epidemiology , Leprosy/diagnosis , Leprosy/drug therapy , Leprosy/microbiology , Microbial Sensitivity Tests , Mutation , Ofloxacin/therapeutic use , Polymerase Chain Reaction , Prospective Studies , Recurrence , Rifampin/therapeutic use , Sentinel Surveillance , Skin/microbiology , Skin/pathology , Surveys and Questionnaires , World Health Organization
2.
Lett Appl Microbiol ; 66(4): 352-359, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29397031

ABSTRACT

Salmonella pathogenicity relies on virulence factors many of which are clustered within the Salmonella pathogenicity islands. Salmonella also harbours mobile genetic elements such as virulence plasmids, prophage-like elements and antimicrobial resistance genes which can contribute to increase its pathogenicity. Here, we have genetically characterized a selected S. Typhimurium strain (CCRJ_26) from our previous study with Multiple Drugs Resistant profile and high-frequency PFGE clonal profile which apparently persists in the pork production centre of Rio de Janeiro State, Brazil. By whole-genome sequencing, we described the strain's genome virulent content and characterized the repertoire of bacterial plasmids, antibiotic resistance genes and prophage-like elements. Here, we have shown evidence that strain CCRJ_26 genome possible represent a virulence-associated phenotype which may be potentially virulent in human infection. SIGNIFICANCE AND IMPACT OF THE STUDY: Whole-genome sequencing technologies are still costly and remain underexplored for applied microbiology in Brazil. Hence, this genomic description of S. Typhimurium strain CCRJ_26 will provide help in future molecular epidemiological studies. The analysis described here reveals a quick and useful pipeline for bacterial virulence characterization using whole-genome sequencing approach.


Subject(s)
Genome, Bacterial/genetics , Salmonella Infections, Animal/microbiology , Salmonella typhimurium/genetics , Swine/microbiology , Animals , Anti-Bacterial Agents , Brazil , Drug Resistance, Bacterial/genetics , Genomic Islands/genetics , Humans , Microbial Sensitivity Tests , Plasmids/genetics , Prophages/genetics , Red Meat/microbiology , Salmonella typhimurium/classification , Salmonella typhimurium/isolation & purification , Virulence/genetics
4.
Arq. bras. med. vet. zootec. (Online) ; 70(6): 1699-1702, nov.-dez. 2018. ilus
Article in English | LILACS, VETINDEX | ID: biblio-969636

ABSTRACT

Canine Leproid Granuloma Syndrome (CLGS), also known as canine leprosy, is a cutaneous nodular infectious disease caused by Mycobacterium sp.. Despite being reported worldwide, it is still quite unknown and underdiagnosed. Diagnosis may be achieved by cytopathology or histopathology of skin lesions, but identification of the infectious agent is complex, since bacterial in vitro growth is not possible, relying upon molecular techniques such as PCR to confirm Mycobacterium DNA in the sample. We report a CLGS case in Niteroi, Rio de Janeiro state, Brazil, diagnosed by cytopathology and submitted to molecular identification of the agent. PCR amplification of hsp65 gene was performed and revealed 100% genetic homology to M. murphy strain. This is the first CLGS report with molecular identification in Rio de Janeiro state, and this finding should raise awareness about CLGS as a differential diagnosis among granulomatous skin diseases in this region.(AU)


A síndrome de granuloma leproide canino (SGLC), também conhecida como lepra canina, é uma doença infecciosa cutânea nodular causada por Mycobacterium sp. Apesar de ser relatada mundialmente, ainda é bastante desconhecida e subdiagnosticada. O diagnóstico pode ser conseguido por citopatologia ou histopatologia de lesões cutâneas, mas a identificação do agente infeccioso é complexa, uma vez que o crescimento in vitro bacteriano não é possível, dependendo de técnicas moleculares como a PCR para confirmar o DNA de Mycobacterium na amostra. Relatou-se um caso da SGLC em Niterói, estado do Rio de Janeiro, Brasil, diagnosticado por citopatologia e submetido à identificação molecular do agente. Foi realizada amplificação por PCR do gene hsp65, que revelou 100% de homologia genética com a cepa M. murphy. Este é o primeiro relato da SGLC com identificação molecular no estado do Rio de Janeiro, o que mostra a importância de se acrescentar a SGLC ao diagnóstico diferencial das doenças granulomatosas de pele nessa região.(AU)


Subject(s)
Animals , Dogs , Polymerase Chain Reaction/statistics & numerical data , Mycobacterium/cytology , Mycobacterium/pathogenicity , Mycobacterium Infections , Dogs
5.
s.l; s.n; 2018. 2 p.
Non-conventional in English | Sec. Est. Saúde SP, HANSEN, Hanseníase Leprosy, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1024996
7.
Res Vet Sci ; 94(1): 9-21, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22884173

ABSTRACT

Spoligotyping is the most frequently used method for genotyping isolates of Mycobacterium bovis worldwide. In the current work, we compared spoligotypes from 1684 M. bovis isolates from Argentina (816), Brazil (412), Chile (66), Mexico (274) and Venezuela (116), obtained from cattle, humans, pigs, wild boars, farmed deer, goats, buffaloes, cats, and wild animals. A total of 269 different spoligotypes were found: 142 (8.4%) isolates presented orphan spoligotypes, whereas 1542 (91.6%) formed 113 different clusters. In cattle, SB0140 was the most representative spoligotype with 355 (24.6%) isolates, followed by SB0121 with 149 (10.3%) isolates. Clustering of spoligotypes ranged from 95.2% in Argentina to 85.3% in Mexico. Orphan spoligotypes were also variable, ranging from 23.7% in Mexico to 4.1% in Brazil. A large proportion of spoligotypes were common to the neighboring countries Argentina, Brazil and Chile. In conclusion, despite the diversity of spoligotypes found in the five countries studied, there are major patterns that predominate in these neighboring countries. These clusters may reflect a long-lasting active transmission of bovine tuberculosis or common historical origins of infection.


Subject(s)
Mycobacterium bovis/genetics , Tuberculosis, Bovine/microbiology , Animals , Animals, Wild/microbiology , Argentina , Brazil , Buffaloes/microbiology , Cats/microbiology , Cattle/microbiology , Humans , Mexico , Molecular Typing/veterinary , Sus scrofa/microbiology , Swine/microbiology , Tuberculosis/veterinary , Venezuela
8.
Int J Tuberc Lung Dis ; 16(10): 1377-82, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22863208

ABSTRACT

BACKGROUND: We recently described the Mycobacterium tuberculosis RD(Rio) genotype, a clonally derived sublineage within the Latin American-Mediterranean (LAM) family. Genetic diversity of M. tuberculosis likely affects the clinical aspects of tuberculosis (TB). Prospective studies that address this issue are scarce and remain controversial. OBJECTIVE: To determine the association of differential clinical features of pulmonary TB with the RD(Rio) M. tuberculosis etiology. METHODS: Culture-proven pulmonary TB patients (n = 272) were clinically evaluated, including history, physical examination, chest X-ray and anti-human immunodeficiency virus serology. Isolates were classified as RD(Rio) or non-RD(Rio) M. tuberculosis by multiplex polymerase chain reaction and further spoligotyped. Clinical and M. tuberculosis genotype data were analyzed. RESULTS: RD(Rio) M. tuberculosis caused disease in 26.5% (72/270) of all TB cases. The LAM genotype, of which RD(Rio) strains are members, was responsible for 46.0% of the TB cases. Demographic data, major signs and symptoms, radiographic presentation, microbiological features and clinical outcomes were not significantly different among patients with TB caused by RD(Rio) and non-RD(Rio) strains. CONCLUSIONS: Disease caused by M. tuberculosis RD(Rio) strains was not clinically distinctive or more severe than disease caused by non-RD(Rio) strains in this series of TB patients. Larger prospective studies specifically designed to disclose differential clinical characteristics of TB caused by specific M. tuberculosis lineages are needed.


Subject(s)
DNA, Bacterial/analysis , Mycobacterium tuberculosis/genetics , Tuberculosis, Pulmonary/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , DNA Fingerprinting , Female , Genotype , Humans , Male , Middle Aged , Mycobacterium tuberculosis/isolation & purification , Polymerase Chain Reaction , Prospective Studies , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/epidemiology , Young Adult
9.
Eur J Clin Microbiol Infect Dis ; 23(5): 408-11, 2004 May.
Article in English | MEDLINE | ID: mdl-15112073

ABSTRACT

Reported here are the cases of two HIV-positive patients with skin lesions suggestive of leprosy, based on clinical and pathological analysis, which worsened during the few weeks following initiation of highly active antiretroviral therapy. The lesions improved after a few weeks of multidrug therapy for leprosy. Mycobacterium leprae was confirmed by polymerase chain reaction analysis of blood in case 1 and of a biopsy sample in case 2. Neither Mycobacterium avium complex nucleic acid, which is usually associated with immune restoration syndrome, nor mycobacterial cutaneous manifestations were detected in either case.


Subject(s)
Antiretroviral Therapy, Highly Active , HIV Infections/complications , HIV Infections/drug therapy , Inflammation/etiology , Leprosy/complications , AIDS-Related Opportunistic Infections/drug therapy , AIDS-Related Opportunistic Infections/microbiology , Adult , Female , Humans , Hypersensitivity, Delayed/etiology , Male , Middle Aged , Mycobacterium leprae
10.
s.l; s.n; 2004. 4 p.
Non-conventional in English | Sec. Est. Saúde SP, HANSEN, Hanseníase Leprosy, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1241636

ABSTRACT

Reported here are the cases of two HIV-positive patients with skin lesions suggestive of leprosy, based on clinical and pathological analysis, which worsened during the few weeks following initiation of highly active antiretroviral therapy. The lesions improved after a few weeks of multidrug therapy for leprosy. Mycobacterium leprae was confirmed by polymerase chain reaction analysis of blood in case 1 and of a biopsy sample in case 2. Neither Mycobacterium avium complex nucleic acid, which is usually associated with immune restoration syndrome, nor mycobacterial cutaneous manifestations were detected in either case


Subject(s)
Leprosy , Hypersensitivity, Delayed , AIDS-Related Opportunistic Infections , HIV Infections , Inflammation , Mycobacterium leprae , Antiretroviral Therapy, Highly Active
11.
J Clin Microbiol ; 40(11): 4191-6, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12409396

ABSTRACT

Human isolates of Mycobacterium collected in 16 different states of Brazil were submitted to PCR-restriction analysis (PRA) of a 439-bp fragment of the hsp65 gene with HaeIII and BstEII. Fourteen allelic variants not described in clinical isolates so far were observed among 36 (10%) of 356 Brazilian strains, including a new pattern for Mycobacterium scrofulaceum, M. intracellulare, and M. flavescens, two new patterns for M. fortuitum, three new patterns each for M. gordonae and M. terrae, and one new pattern for M. avium complex-like strains. Two unidentified strains each also presented a new pattern, strongly suggesting that Mycobacterium genotypes are distributed biogeographically. The PRA procedure was also performed with 43 reference isolates belonging to 34 species, adding a further six new patterns to the identification algorithm. A database containing the normalized restriction patterns of both enzymes was constructed. Patterns available on the Internet can be introduced into this database, which will make possible the comparison of genotypes from isolates from different parts of the world.


Subject(s)
Alleles , Bacterial Proteins , Chaperonins/genetics , Genetic Variation , Mycobacterium Infections/microbiology , Mycobacterium/classification , Polymerase Chain Reaction/methods , Brazil , Chaperonin 60 , Databases, Genetic , Deoxyribonucleases, Type II Site-Specific , Humans , Image Processing, Computer-Assisted , Molecular Sequence Data , Mycobacterium/genetics , Mycobacterium/isolation & purification
12.
J Clin Microbiol ; 39(12): 4477-82, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11724865

ABSTRACT

INNO-LiPA Mycobacteria (LiPA; Innogenetics, Zwijnaarde, Belgium) is a kit for the simultaneous detection and identification of Mycobacterium species in culture and identifies the Mycobacterium tuberculosis complex, the M. avium complex (MAC), and the following Mycobacterium species: M. kansasii, M. avium, M. intracellulare, M. scrofulaceum, M. gordonae, M. xenopi, and the M. chelonae-M. abscessus complex. The assay, which targets the 16S-23S rRNA spacer region, was evaluated on 157 mycobacterial strains that had been identified by conventional techniques and PCR-restriction enzyme analysis of the hsp65 gene (PRA). Forty-seven reference strains consisting of 37 different species and 110 human clinical isolates were submitted to the test, and all were hybridized with the Mycobacterium genus probe (MYC) on the LiPA strip (100% sensitivity). Ninety-four isolates hybridized to their corresponding species- or complex-specific probes; only one isolate phenotypically identified as M. gordonae did not react with its specific probe (99.4% accuracy). Thirty-seven MAC strains were phenotypically identified to the complex level and to the species level by LiPA as M. avium (n = 18) or M. intracellulare (n = 7) or as belonging to the M. avium-M. intracellulare-M. scrofulaceum complex (n = 12). Of the last 12 strains, 10 had M. avium PRA patterns and 2 had M. intracellulare PRA patterns. Three isolates that had been identified as a single species by conventional identification were proven to be mixed cultures by the LiPA assay. The whole procedure can be performed in 1 working day, starting with the supernatant of a small amount of bacterial mass that had been treated by freezing and then boiling.


Subject(s)
Bacterial Proteins , DNA, Ribosomal Spacer/genetics , Mycobacterium Infections/microbiology , Mycobacterium/classification , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Reagent Kits, Diagnostic , Chaperonin 60 , Chaperonins/genetics , DNA Probes , Humans , Mycobacterium/genetics , Nucleic Acid Hybridization/methods , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , Species Specificity , Time Factors
14.
Mem Inst Oswaldo Cruz ; 96(8): 1129-33, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11784934

ABSTRACT

Thirty eight patients with indeterminate leprosy (HI), at least 4 to 6 years after discharge from multibacillary (MB) or paucibacillary (PB) schemes of anti leprosy multidrug therapy (MDT), were submitted to traditional diagnostic procedures for leprosy and to polymerase chain reaction (PCR) analysis of different clinical samples for detection of Mycobacterium leprae DNA. No significant difference was observed for any of the parameters analyzed between PB or MB schemes of treatment and no indications were found for more efficient outcome of HI using the MB scheme. Remarkably, 18 (54.5%) of the individuals were PCR positive in at least one of the samples: positivity of PCR was highest in blood samples and four individuals were PCR positive in blood and some other sample. Upon comparison of PCR results with clinical and histopathological parameters, no correlation was found between PCR-positivity and eventual relapse. This is the first report on detection of M. leprae DNA in PB patients, more than half a decade after completion of MDT, suggesting that live bacilli are present and circulating much longer than expected, although reinfection of the individuals can not be excluded. Overall, we feel that because of the high sensitivity of the assay, extreme care should be taken about association of PCR results, efficacy of treatment and disease status.


Subject(s)
DNA, Bacterial/blood , Leprostatic Agents/administration & dosage , Leprosy/drug therapy , Mycobacterium leprae/isolation & purification , Drug Administration Schedule , Humans , Lepromin/analysis , Leprosy/blood , Mycobacterium leprae/drug effects , Mycobacterium leprae/genetics , Polymerase Chain Reaction , Retrospective Studies
15.
Mem Inst Oswaldo Cruz ; 96(8): 1137-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11784936

ABSTRACT

With the objective to evaluate PCR-mediated detection of Mycobacterium tuberculosis DNA as a diagnostic procedure for diagnosis of tuberculosis in individuals attending ambulatory services in Primary Health Units of the City Tuberculosis Program in Rio de Janeiro, Brazil, their sputum samples were collected and treated with a DNA extraction procedure using silica-guanidiniumthiocyanate. This procedure has been described to be highly efficient for extraction of different kind of nucleic acids from bacteria and clinical samples. Upon comparing PCR results with the number of acid-fast bacilli, no direct relation was observed between the number of bacilli present in the sample and PCR positivity. Part of the processed samples was therefore spiked with pure DNA of M. tuberculosis and inhibition of the PCR reaction was verified in 22 out of 36 (61%) of the samples, demonstrating that the extraction procedure as originally described should not be used for PCR analysis of sputum samples.


Subject(s)
DNA, Bacterial/isolation & purification , Mycobacterium tuberculosis/isolation & purification , Polymerase Chain Reaction/methods , Sputum/microbiology , Tuberculosis, Pulmonary/diagnosis , Disinfectants , Guanidines , Humans , Mycobacterium tuberculosis/genetics , Sensitivity and Specificity , Thiocyanates
16.
Mem. Inst. Oswaldo Cruz ; 95(6): 777-82, Nov.-Dec. 2000. ilus
Article in English | LILACS | ID: lil-273430

ABSTRACT

Methicillin resistant Staphylococcus aureus (MRSA) is an organism that is frequently transmitted in hospitals and perinatal units. The MRSA is considered a public health problem in neonatology because of its strong potential for dissemination in the wards associated with high rates of morbidity and mortality. In this study we describe the bacteriological, epidemiological and molecular characteristics of MRSA isolated from anterior nares and blood cultures of newborns hospitalized in a public maternity hospital in the city of Rio de Janeiro, Brazil. The frequency of MRSA isolated from nasal swabs of newborns was 47.8 percent (43/90). The genetic analysis of MRSA strains from anterior nares, showed 8 different pulsed field gel electrophoresis patterns (PFGE). Upon analysis of PFGE patterns of the 12 MRSA strains isolated from blood cultures, 8 different patterns were observed, 9 (75 percent) strains were genetic related to nasal secretion isolates patterns. In conclusion, our data demonstrate the importance of screening of newborns for the presence of MRSA in Brazilian hospitals and the usefulness of genetic typing of these pathogen during epidemiologic studies. This should lead to a better knowledge on the significancy and spreading of MRSA in the hospitals


Subject(s)
Humans , Infant, Newborn , Methicillin Resistance/genetics , Staphylococcal Infections/epidemiology , Staphylococcus aureus/genetics , Brazil/epidemiology , Electrophoresis, Agar Gel/methods , Prospective Studies , Staphylococcus aureus/drug effects
17.
Mem Inst Oswaldo Cruz ; 95(6): 777-82, 2000.
Article in English | MEDLINE | ID: mdl-11080760

ABSTRACT

Methicillin resistant Staphylococcus aureus (MRSA) is an organism that is frequently transmitted in hospitals and perinatal units. The MRSA is considered a public health problem in neonatology because of its strong potential for dissemination in the wards associated with high rates of morbidity and mortality. In this study we describe the bacteriological, epidemiological and molecular characteristics of MRSA isolated from anterior nares and blood cultures of newborns hospitalized in a public maternity hospital in the city of Rio de Janeiro, Brazil. The frequency of MRSA isolated from nasal swabs of newborns was 47.8% (43/90). The genetic analysis of MRSA strains from anterior nares, showed 8 different pulsed field gel electrophoresis patterns (PFGE). Upon analysis of PFGE patterns of the 12 MRSA strains isolated from blood cultures, 8 different patterns were observed, 9 (75%) strains were genetic related to nasal secretion isolates patterns. In conclusion, our data demonstrate the importance of screening of newborns for the presence of MRSA in Brazilian hospitals and the usefulness of genetic typing of these pathogen during epidemiologic studies. This should lead to a better knowledge on the significancy and spreading of MRSA in the hospitals.


Subject(s)
Cross Infection/microbiology , Methicillin Resistance/genetics , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Brazil/epidemiology , Cross Infection/epidemiology , Electrophoresis, Agar Gel/methods , Humans , Infant, Newborn , Prospective Studies , Staphylococcal Infections/epidemiology , Staphylococcus aureus/drug effects
18.
Res Microbiol ; 151(5): 343-51, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10919514

ABSTRACT

Strains of Mycobacterium tuberculosis isolated from 219 different tuberculosis patients, 115 from patients residing in Rio de Janeiro, 79 from Rio Grande do Sul and the remaining from other regions of the country, were analyzed by IS6110-restriction fragment length polymorphism fingerprinting. The IS6110-DNA patterns from these strains were highly polymorphic: 174 different patterns were observed and 25 patterns were shared by 70 isolates (32%). Most strains (93.4%) had multicopy patterns and only 17% of clustered strains had less than six IS6110 copies. Strain clustering was significantly higher for isolates from Rio Grande do Sul (36.7%) in comparison with strains from Rio de Janeiro (22.6%), but only when using high stringency during cluster analysis. Upon screening of an international database containing 3,970 fingerprints of M. tuberculosis strains, 15% of the patterns of Brazilian strains (21% of the strains) were identical to a fingerprint of an isolate from another country and one particular eight-band pattern forming the largest Brazilian cluster was detected in seven additional countries, suggesting that international transmission of tuberculosis from and to Brazil could be occurring frequently. Alternatively,preferential use of certain IS6110 integration sites could also be important in high-copy number strains, having important consequences for the use of databases for epidemiological studies on a large scale.


Subject(s)
DNA Fingerprinting , DNA Transposable Elements , Databases, Factual , Mycobacterium tuberculosis/classification , Polymorphism, Restriction Fragment Length , Tuberculosis, Pulmonary/microbiology , Bacterial Typing Techniques , Brazil , Humans , International Cooperation , Mycobacterium tuberculosis/genetics , Tuberculosis, Pulmonary/transmission
19.
Int J Tuberc Lung Dis ; 4(2): 179-83, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10694098

ABSTRACT

The development of nucleic acid-based technologies has improved the sensitivity, specificity and speed of detection of Mycobacterium tuberculosis in clinical samples. Both commercially available and 'in-house' polymerase chain reaction (PCR) systems are in use, and a significant number of reports compare such systems with more traditional diagnostic tools for tuberculosis. Few studies, however, have focused on the reproducibility of the results when submitting a sample batch to PCR in different laboratories, especially in developing countries. Consequently, PCR results obtained from six laboratories in six different Latin American countries for samples reconstituted with defined amounts of M. tuberculosis cells were evaluated. Each laboratory used specific conditions of sample processing, nucleic acid amplification and amplicon detection. Analysis of results allowed large differences in sensitivity and specificity to be observed. We conclude that in its present setting, in-house PCR cannot be used as a single diagnostic tool for tuberculosis, and that special care needs to be taken upon interpretation of results by inclusion of a proper number of positive and negative controls.


Subject(s)
Mycobacterium tuberculosis/isolation & purification , Polymerase Chain Reaction , Evaluation Studies as Topic , Humans , Sensitivity and Specificity , Sputum/microbiology , Tuberculosis, Pulmonary/diagnosis
20.
Lepr Rev ; 71 Suppl: S154-8; discussion S158-60, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11201873

ABSTRACT

Studies carried out over the last decade have strongly suggested that TNF alpha both overtly participates in the cell-mediated immune response against Mycobacterium leprae, and is overproduced during reaction. In addition, reactions are intimately related to the onset of nerve damage. Finally, TNF alpha has been implicated in the pathogenesis of many human and experimental autoimmune peripheral neuropathies that, as in leprosy, result in demyelination and axonal lesions. Because of recent findings associating human TNF alpha mutant alleles at the -308 position with increased production of TNF alpha in many immunological and infectious diseases, an investigation of the role of TNF2 in predisposing leprosy patients to reaction has been undertaken. Analysis of 300 patients with leprosy--210 multibacillary and 90 paucibacillary--has shown that the percentage of reactional patients was similar among both carriers and non-carriers of the TNF2 allele. However, a separate analysis of 57 carriers of TNF2 found that reactions occurred much more frequently among heterozygous than among homozygous patients. Moreover, the frequency of neuritis was somewhat greater among the heterozygous patients than among the non-carriers. Enhanced serum levels of TNF alpha have been noted in both TNF-1 and TNF-2 mutant patients in the course of leprosy reaction. Our observations to date suggest that other factors not related to the presence of the mutant gene may lead to the TNF alpha hyper-responsiveness observed during reaction.


Subject(s)
Genetic Predisposition to Disease , Leprosy/genetics , Peripheral Nervous System Diseases/genetics , Polymorphism, Genetic , Tumor Necrosis Factor-alpha/genetics , Alleles , Enzyme-Linked Immunosorbent Assay , Female , Genetic Testing , Humans , Male , Population Surveillance , Sensitivity and Specificity , Tumor Necrosis Factor-alpha/analysis
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