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Molecular characterization of Histoplasma capsulatum isolated from an outbreak in treasure hunters Histoplasma capsulatum in treasure hunters.

Muñoz B, Martínez MA, Palma G, Ramírez A, Frías MG, Reyes MR, Taylor ML, Higuera AL, Corcho A, Manjarrez ME - BMC Infect. Dis. (2010)

Bottom Line: These were compared to eight reference strain isolates from neighboring areas.Molecular characterization of the isolates was similar in 100% with the EH-53 Hidalgo human (HG) strain (reference strain integrated into the LAm A clade described for Latin America).The severity of cases indicates that this strain is highly virulent and that it is probably prevalent in Hidalgo and Veracruz states.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratorio de Micología Médica, Depto, de Investigación en Virología, Instituto Nacional de Enfermedades Respiratorias (INER), Calzada de Tlalpan 4502, Sección XVI, Tlalpan,14080 México, DF, México.

ABSTRACT

Background: In Mexico, primary pulmonary histoplasmosis is the most relevant clinical form of the disease. The geographical distribution of specific strains of Histoplasma capsulatum circulating in Mexico has not been fully established. Outbreaks must be reported in order to have current, updated information on this disease, identifying new endemic areas, manner of exposure to the fungi, and molecular characterization of the causative agents. We report a recent outbreak of histoplasmosis in treasure hunters and the molecular characterization of two isolates obtained from these patients.

Methods: Six patients admitted to the National Institute of Respiratory Diseases (INER) in Mexico City presented severe respiratory symptoms suggestive of histoplasmosis. They acquired the infection in the Veracruz (VZ) endemic zone. Diagnosis was made by X-ray and Computed tomography (CT), liver function, immunological techniques, and culture. Identification of H. capsulatum isolates was confirmed by using Polymerase chain reaction (PCR) was conducted with a probe from the M antigen, and the isolates were characterized by means of Random amplification of polymorphic DNA (RAPD)-PCR employed the 1253 oligonucleotide and a mixture of oligonucleotides 1281 and 1283. These were compared to eight reference strain isolates from neighboring areas.

Results: X-ray and CT revealed disseminated micronodular images throughout lung parenchyma, as well as bilateral retrocaval, prevascular, subcarinal, and hilar adenopathies, hepatosplenomegaly, and altered liver function tests. Five of the six patients developed disseminated histoplasmosis. Two H. capsulatum strains were isolated. The same band profile was detected in both strains, indicating that both isolates corresponded to the sole H. capsulatum strain. Molecular characterization of the isolates was similar in 100% with the EH-53 Hidalgo human (HG) strain (reference strain integrated into the LAm A clade described for Latin America).

Conclusions: The two isolates appeared to possess the same polymorphic pattern; they are indistinguishable from each other and from EH-53. It is important to remain updated on recent outbreaks of histoplasmosis, the manner of exposure to the fungi, as well as the molecular characterization of the isolates. The severity of cases indicates that this strain is highly virulent and that it is probably prevalent in Hidalgo and Veracruz states.

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Dendrogram constructed from the molecular profiles. Genetic similarity among Histoplasma capsulatum isolates from Veracruz (VZ) with isolates from other neighboring endemic zones, in Mexico.
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Figure 3: Dendrogram constructed from the molecular profiles. Genetic similarity among Histoplasma capsulatum isolates from Veracruz (VZ) with isolates from other neighboring endemic zones, in Mexico.

Mentions: Molecular identification of the isolates was confirmed by PCR on amplifying a specific 279 base-pair (bp) band corresponding to the codifying region for the H. capsulatum-immunodominant M-antigen gene [28] (Figure 2a). Molecular characterization of the two clinical isolates of H. capsulatum from VZ was conducted oligonucleotides 1253 (figure 2b) and 1281 and 1283 (figures 2c and 2d) RAPD-PCR assays. The figure 2d shows the molecular profiles of these two isolates, compared with those of the eight H.-capsulatum reference strains. The bands obtained were located in the 800 to 200-bp range (Figure 2d). Relatedness among isolates through the polymorphic DNA patterns was analyzed by using the UPGMA program to elaborate a dendrogram (Figure 3) and three groups, according to RAPD-patterns, were identified. Group I is made up of two subgroups: subgroup 1a, which includes VZ (LFD [bronchial lavage] and EVP [sputum]) isolates, and the EH-53 (HG) reference strain, which exhibited 100% similarity, while subgroup Ib comprised bat isolates from PL. Both subgroups are related at 85% similarity. Group II comprises of EH-397 and -398 bat isolates from (OC) with 100% similarity between them. This group is related to group I with 82% similarity. Group III is made up of two subgroups: subgroup IIIa is formed by EH-317 and EH-437 bat isolates from MS, with a 100% similarity ratio, and subgroup IIIb consists of isolates from the State of Morelos (EH-449), which were 73% related to subgroup IIIa strains Finally, group III is related to the previous groups with 52% similarity.


Molecular characterization of Histoplasma capsulatum isolated from an outbreak in treasure hunters Histoplasma capsulatum in treasure hunters.

Muñoz B, Martínez MA, Palma G, Ramírez A, Frías MG, Reyes MR, Taylor ML, Higuera AL, Corcho A, Manjarrez ME - BMC Infect. Dis. (2010)

Dendrogram constructed from the molecular profiles. Genetic similarity among Histoplasma capsulatum isolates from Veracruz (VZ) with isolates from other neighboring endemic zones, in Mexico.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2944350&req=5

Figure 3: Dendrogram constructed from the molecular profiles. Genetic similarity among Histoplasma capsulatum isolates from Veracruz (VZ) with isolates from other neighboring endemic zones, in Mexico.
Mentions: Molecular identification of the isolates was confirmed by PCR on amplifying a specific 279 base-pair (bp) band corresponding to the codifying region for the H. capsulatum-immunodominant M-antigen gene [28] (Figure 2a). Molecular characterization of the two clinical isolates of H. capsulatum from VZ was conducted oligonucleotides 1253 (figure 2b) and 1281 and 1283 (figures 2c and 2d) RAPD-PCR assays. The figure 2d shows the molecular profiles of these two isolates, compared with those of the eight H.-capsulatum reference strains. The bands obtained were located in the 800 to 200-bp range (Figure 2d). Relatedness among isolates through the polymorphic DNA patterns was analyzed by using the UPGMA program to elaborate a dendrogram (Figure 3) and three groups, according to RAPD-patterns, were identified. Group I is made up of two subgroups: subgroup 1a, which includes VZ (LFD [bronchial lavage] and EVP [sputum]) isolates, and the EH-53 (HG) reference strain, which exhibited 100% similarity, while subgroup Ib comprised bat isolates from PL. Both subgroups are related at 85% similarity. Group II comprises of EH-397 and -398 bat isolates from (OC) with 100% similarity between them. This group is related to group I with 82% similarity. Group III is made up of two subgroups: subgroup IIIa is formed by EH-317 and EH-437 bat isolates from MS, with a 100% similarity ratio, and subgroup IIIb consists of isolates from the State of Morelos (EH-449), which were 73% related to subgroup IIIa strains Finally, group III is related to the previous groups with 52% similarity.

Bottom Line: These were compared to eight reference strain isolates from neighboring areas.Molecular characterization of the isolates was similar in 100% with the EH-53 Hidalgo human (HG) strain (reference strain integrated into the LAm A clade described for Latin America).The severity of cases indicates that this strain is highly virulent and that it is probably prevalent in Hidalgo and Veracruz states.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratorio de Micología Médica, Depto, de Investigación en Virología, Instituto Nacional de Enfermedades Respiratorias (INER), Calzada de Tlalpan 4502, Sección XVI, Tlalpan,14080 México, DF, México.

ABSTRACT

Background: In Mexico, primary pulmonary histoplasmosis is the most relevant clinical form of the disease. The geographical distribution of specific strains of Histoplasma capsulatum circulating in Mexico has not been fully established. Outbreaks must be reported in order to have current, updated information on this disease, identifying new endemic areas, manner of exposure to the fungi, and molecular characterization of the causative agents. We report a recent outbreak of histoplasmosis in treasure hunters and the molecular characterization of two isolates obtained from these patients.

Methods: Six patients admitted to the National Institute of Respiratory Diseases (INER) in Mexico City presented severe respiratory symptoms suggestive of histoplasmosis. They acquired the infection in the Veracruz (VZ) endemic zone. Diagnosis was made by X-ray and Computed tomography (CT), liver function, immunological techniques, and culture. Identification of H. capsulatum isolates was confirmed by using Polymerase chain reaction (PCR) was conducted with a probe from the M antigen, and the isolates were characterized by means of Random amplification of polymorphic DNA (RAPD)-PCR employed the 1253 oligonucleotide and a mixture of oligonucleotides 1281 and 1283. These were compared to eight reference strain isolates from neighboring areas.

Results: X-ray and CT revealed disseminated micronodular images throughout lung parenchyma, as well as bilateral retrocaval, prevascular, subcarinal, and hilar adenopathies, hepatosplenomegaly, and altered liver function tests. Five of the six patients developed disseminated histoplasmosis. Two H. capsulatum strains were isolated. The same band profile was detected in both strains, indicating that both isolates corresponded to the sole H. capsulatum strain. Molecular characterization of the isolates was similar in 100% with the EH-53 Hidalgo human (HG) strain (reference strain integrated into the LAm A clade described for Latin America).

Conclusions: The two isolates appeared to possess the same polymorphic pattern; they are indistinguishable from each other and from EH-53. It is important to remain updated on recent outbreaks of histoplasmosis, the manner of exposure to the fungi, as well as the molecular characterization of the isolates. The severity of cases indicates that this strain is highly virulent and that it is probably prevalent in Hidalgo and Veracruz states.

Show MeSH
Related in: MedlinePlus