Multilocus Genotyping of Pneumocystis jirovecii from Deceased Cuban AIDS Patients Using Formalin-Fixed and
Vicente Friaza1,2, Yaxsier de Armas3,4, Virginia Capó4
1Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain.
Insights
A 14-year study of AIDS patients in Cuba found that a specific genotype of Pneumocystis jirovecii (85T/248C//160A/196T) was predominant. This genotype showed no signs of sulfonamide resistance, indicating limited pathogen diversity.
Area of Science:
- Medical Mycology
- Molecular Epidemiology
- Infectious Diseases
Background:
- Pneumocystis jirovecii pneumonia (PCP) is a significant opportunistic infection in individuals with acquired immunodeficiency syndrome (AIDS).
- Understanding the genetic diversity and characteristics of P. jirovecii strains is crucial for managing PCP outbreaks and treatment resistance.
Purpose of the Study:
- To genotypically characterize Pneumocystis jirovecii in lung tissue samples from Cuban AIDS patients who died of pneumocystosis.
- To investigate the predominant genotypes and assess potential sulfonamide resistance in circulating P. jirovecii strains over a 14-year period.
Main Methods:
- Analysis of lung tissue samples from 41 Cuban AIDS patients (1995-2008).
- Histological examination of formalin-fixed, paraffin-embedded tissue sections.
- Polymerase chain reaction (PCR) amplification and nucleotide sequencing of two mitochondrial genes (large and small) of P. jirovecii.
Main Results:
- A predominant genotype, 85T/248C (large mitochondrial gene) and 160A/196T (small mitochondrial gene), was identified in 81.3% of cases.
- Multilocus analysis revealed limited circulation of P. jirovecii genotypes in Cuba, suggesting a clonal structure.
- No mutations associated with sulfonamide resistance were detected in the circulating strains.
Conclusions:
- The 85T/248C//160A/196T genotype of P. jirovecii is the most frequent among AIDS patients in Cuba.
- The study highlights a limited diversity and potential clonal nature of P. jirovecii strains in the region.
- Formalin-fixed, paraffin-embedded samples are effective for molecular epidemiological studies of P. jirovecii.
Abstract:
The results of the genotypic characterization of Pneumocystis jirovecii are described in lung tissue samples from 41 Cubans who died of AIDS with pneumocystosis between 1995 and 2008. Histological sections of the lung preserved as formalin-fixed and paraffin-embedded tissue were examined. PCR amplification and nucleotide sequencing of the two mitochondrial genes (large and small) of the pathogen allowed verification of a predominance of genotype 3 (85T/248C) of the large mitochondrial gene and genotype 3 (160A/196T) of the small mitochondrial gene over a period of 14 years (1995-2008). These results suggest that the 85T/248C//160A/196T genotype circulates with the highest frequency (81.3%) among AIDS patients in Cuba. Multilocus analysis indicates a limited circulation of pathogen genotypes on the island with the existence of a clonal genotype with an epidemic structure. Furthermore, it appears that circulating strains of P. jirovecii have not developed mutations related to sulfonamide resistance. Taken together, the data in this study revealed important elements about pneumocystosis in Cuban patients dying of AIDS and the usefulness of formalin-fixed and paraffin-embedded samples to carry out molecular epidemiology studies of P. jirovecii.
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