Pneumocystis jirovecii multilocus genotyping profiles in Northern Ireland

Abstract

Pneumocystis jirovecii causes pneumonia, a severe opportunistic infection in immunosuppressed patients that has both person-to-person airborne transmission and environmental transmission as important routes of infection. An increasing incidence of P. jirovecii in Northern Ireland prompted a detailed epidemiological and molecular review that included enhanced surveillance on all lower respiratory specimens. Genotyping of these P. jirovecii positive specimens was undertaken using multiple locus sequence typing (MLST) targeting known variable regions of the P. jirovecii genome. Multiple circulating types were found among all patient risk categories. However, a predominance of one MLST type was found in a P. jirovecii outbreak amongst the renal transplant population. Our results demonstrate the diversity of P. jirovecii strains amongst the local immunosuppressed cohort and highlight the importance of genotyping in the investigation of common sources of P. jirovecii amongst immunosuppressed patients.

Genetic diversity of Pneumocystis jirovecii from a cluster of cases of pneumonia in renal transplant patients: Cross‐sectional study

“…Since Pneumocystis cannot be cultured, molecular typing methods have been developed, and have primarily included single nucleotide polymorphisms, multilocus sequence typing (MSLT), restriction fragment length polymorphism (RFLP), and analysis of tandem repeats. Multiple studies using such typing methods have shown that outbreaks of PCP are often caused by one or a limited number of strains of Pneumocystis …”

“…Multiple studies using such typing methods have shown that outbreaks of PCP are often caused by one or a limited number of strains of Pneumocystis. [3][4][5]9,10,[13][14][15][16][17] Few Pneumocystis typing studies have been carried out using samples derived from FFPE tissues, 18 in part because it is difficult to obtain good-quality DNA from such tissues due to potential crosslinking of DNA, the presence of inhibitors, and other factors. 19 This study reports on the molecular epidemiology of a cluster of PCP cases in renal transplant patients that occurred in a single medical centre in the city of São Paulo, Brazil; most cases developed more than 6 months after transplantation, the period traditionally considered highest risk for development of PCP.…”

Pneumocystis jirovecii Rtt109, a Novel Drug Target for Pneumocystis Pneumonia in Immunosuppressed Humans

“…The moderate divergence between these two closely related species is not unexpected, as several features in the mitochondrial DNA of P. murina and P. carinii diverge from those of P. jirovecii (56), and this pattern of sequence similarity has also been observed between P. carinii and P. jirovecii dihydrofolate reductases (47,57). In addition, there appears to be significant genetic diversity at several regions among P. jirovecii isolates, based on genetic analyses (58)(59)(60)(61). The putative PjRtt109 sequence showed several conserved regions in comparison with other previously characterized fungal Rtt109 proteins, such as those of Saccharomyces cerevisiae (GenBank accession number Q07794), Schizosaccharomyces pombe (GenBank accession number Q9Y7Y5), and Candida albicans (GenBank accession number Q5AAJ8) (Fig.…”

Investigation of outbreaks of Pneumocystis jirovecii pneumonia in two Scottish renal units

“…11 Data from Northern Ireland found a diverse population with 15 different strain types circulating from samples from eight hospitals. 8 Environmental sources are also a possibility, but air sampling has proved inconclusive in previous outbreak reports. 10 This study identified two different PCP genotypes in the outbreaks belonging to alleles A3 and B. Outbreaks with multiple genotypes have been reported.…”

“…7 However, based on previous outbreak investigations in both Belfast and Liverpool, the WoSSVC chose to sequence the ITS and the mt26sRNA regions alone as these regions were most sensitive and discriminatory. 8,9 The ITS and mt26sRNA regions were amplified by nested PCR using Roche Expand High Fidelity Roche Master Mix (Roche-Basel, Switzerland) using the reaction and cycling conditions and primer concentrations as described in the protocol. Following electrophoresis on a 1.2% gel, the relevant-sized DNA amplicons (ITS1 204 bp, mt26S 347 bp) were purified using QIAquick Gel Extraction Kit (Qiagen-Hilden, Germany) and eluted in 50 mL of AE buffer (Qiagen-Hilden, Germany).…”