Pneumocystis jirovecii multilocus genotyping profiles in patients from Portugal and Spain

Abstract

Pneumonia caused by the opportunistic organism Pneumocystis jirovecii is a clinically important infection affecting AIDS and other immunocompromised patients. The present study aimed to compare and characterise the frequency pattern of DNA sequences from the P. jirovecii mitochondrial large-subunit rRNA (mtLSU rRNA) gene, the dihydropteroate synthase (DHPS) gene and the internal transcribed spacer (ITS) regions of the nuclear rRNA operon in specimens from Lisbon (Portugal) and Seville (Spain). Total DNA was extracted and used for specific molecular sequence analysis of the three loci. In both populations, mtLSU rRNA gene analysis revealed an overall prevalence of genotype 1. In the Portuguese population, genotype 2 was the second most common, followed by genotype 3. Inversely, in the Spanish population, genotype 3 was the second most common, followed by genotype 2. The DHPS wild-type sequence was the genotype observed most frequently in both populations, and the DHPS genotype frequency pattern was identical to distribution patterns revealed in other European studies. ITS types showed a significant diversity in both populations because of the high sequence variability in these genomic regions. The most prevalent ITS type in the Portuguese population was Eg, followed by Cg. In contrast to other European studies, Bi was the most common ITS type in the Spanish samples, followed by Eg. A statistically significant association between mtLSU rRNA genotype 1 and ITS type Eg was revealed.

Prevalence and Genotype Distribution of Pneumocystis jirovecii in Cuban Infants and Toddlers with Whooping Cough

“…The Cuban samples showed a high prevalence of the DHPS WT, and these data are in concordance with studies from Portugal (93%) and Spain (78%) (35) but in contrast to studies performed in the United States, where the prevalence is lower and the frequency of DHPS mutations ranges between 43% and 68% (19,(42)(43)(44)(45). These data support the hypothesis on the existence of geographical variations in the prevalence of P. jirovecii DHPS gene mutations because of intrinsic epidemiological factors in each location that influence the circulation and transmission of different genotypes and that also may reflect and contribute to the differences in the use and effects of sulfonamides for PcP prophylaxis and treatment of bacterial diseases (9,35,45,46).…”

“…These data support the hypothesis on the existence of geographical variations in the prevalence of P. jirovecii DHPS gene mutations because of intrinsic epidemiological factors in each location that influence the circulation and transmission of different genotypes and that also may reflect and contribute to the differences in the use and effects of sulfonamides for PcP prophylaxis and treatment of bacterial diseases (9,35,45,46). However, the effects of mutant strains on clinical illness and outcomes of PcP have not been clearly defined.…”

“…In contrast, a different frequency distribution was observed in Spain, with genotype 3 being the second most prevalent and genotype 2 being the third most common. Moreover, genotype 2 was absent in Australia and genotype 1 was the most frequent (29,(34)(35)(36).…”

Clinical Relevance of Multiple Single-Nucleotide Polymorphisms in Pneumocystis jirovecii Pneumonia: Development of a Multiplex PCR-Single-Base-Extension Methodology

“…The mtLSU rRNA sequencing results were similar to those reported in recent studies on Portuguese subjects (7)(8)(9). Other reports from different geographical regions (e.g., the United States and United Kingdom) (1, 26) also have revealed an mtLSU rRNA pattern identical to that of the Portuguese samples.…”

“…Other reports from different geographical regions (e.g., the United States and United Kingdom) (1, 26) also have revealed an mtLSU rRNA pattern identical to that of the Portuguese samples. A different allelic distribution pattern was detected persistently in previous studies on Spanish subjects, whereas genotypes with mt85T were the second most frequent and genotypes with mt85A were the third most common (9,28). These differences demonstrate a variation in the geographical distribution of P. jirovecii genotypes.…”