Maria Wesołowska

Pneumocystis jirovecii—from a commensal to pathogen: clinical and diagnostic review

Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of morbidity and mortality cases among HIV-infected patients, which later have been reduced due to the introduction of anti-retroviral therapy, as well as anti-Pneumocystis prophylaxis among these patients. Pneumocystis pneumonia, however, is still a significant cause of mortality among HIV-negative patients being under immunosuppression caused by different factors, such as transplant recipients as well as oncologically treated ones. The issue of pneumocystosis among these people is particularly emphasized in the article, since rapid onset and fast progression of severe symptoms result in high mortality rate among these patients, who thereby represent the group of highest risk of developing Pneumocystis pneumonia. In contrast, fungal invasion in immunocompetent people usually leads to asymptomatic colonization, which frequent incidence among healthy infants has even suggested the possibility of its association with sudden unexpected infant death syndrome. In the face of emerging strains with different epidemiological profiles resulting from genetic diversity, including drug-resistant genotypes, the colonization phenomenon desires particular attention, discussed in this article. We also summarize specific and sensitive methods, required for detection of Pneumocystis invasion and for distinguish colonization from the disease.

Gastroenteritis Caused by the Cryptosporidium Hedgehog Genotype in an Immunocompetent Man

ABSTRACT The Cryptosporidium hedgehog genotype, which has been reported previously in hedgehogs and horses, was identified as the cause of the diarrheal disease cryptosporidiosis in an immunocompetent man in the Czech Republic. This is the first report of human illness caused by the Cryptosporidium hedgehog genotype.

Concurrent Infection of the Urinary Tract with Encephalitozoon cuniculi and Enterocytozoon bieneusi in a Renal Transplant Recipient

ABSTRACT A urinary tract coinfection, caused by Encephalitozoon cuniculi genotype II and Enterocytozoon bieneusi genotype D, was identified in an HIV-seronegative renal transplant recipient kept under lifelong immunosuppression. To our knowledge, this is the first report describing concurrent infection with these two microsporidia species in organ transplant recipients.

Prevalence of Demodex spp. in eyelash follicles in different populations

Introduction The pathologic relevance of Demodex infestation in blepharitis is still controversial. The aim of the study was to determine the prevalence of Demodex spp. in eyelash follicles and its relationship to eye symptoms. Material and methods A total of 290 individuals were studied for the presence of Demodex folliculorum and Demodex brevis within eyelash follicles. Participants belonged to one of four groups: inpatients, drug abusers, health professionals, and medical students. Ten eyelashes were epilated from each subject, placed on microscope slides and examined for parasites. The sample was defined as positive if at least one parasite or parasites ova were present. The presence of parasites was analyzed according to age, gender, place of living, reported eye problems, and use of contact lenses or glasses. Results The prevalence of Demodex spp. infestation among all studied subjects was 41%, with the highest infestation rate among inpatients (p < 0.01) and elderly people (p < 0.001). No difference regarding the presence of Demodex was found between women and men (p = 0.76). Demodex folliculorum was about 2.4 times more frequent than D. brevis. The prevalence of Demodex spp. in subjects with and without eye complaints suggesting blepharitis was similar (41.6% vs. 40.2%, respectively, p = 0.9). On the other hand, wearing glasses was linked to Demodex infestation (48.4% vs. 32.3%, p < 0.01). Conclusions Demodex is a common saprophyte found in human eyelash follicles. Its presence might be related to some ocular discomfort; however, in the vast majority of cases the infestation seems to be asymptomatic.

Prevalence and molecular characteristics of urinary and intestinal microsporidia infections in renal transplant recipients

Transplant recipients have been identified as a new risk group for microsporidia infection. We characterize for the first time the prevalence of microsporidia in intestinal and urinary tracts of renal transplant recipients. Molecular examination of 86 patients showed that 25.5% of them were infected; 86% were confirmed to have pathogens in their urine and 45.5% in stool. Among positive patients, 32% had microsporidia confirmed in both urine and stool. Genotyping revealed Encephalitozoon cuniculi (59%) and Enterocytozoon bieneusi (23%) monoinfections as well as coinfections with both species (18%). Moreover, we found diarrhoea and fever as symptoms significantly associated with microsporidia presence. Our results indicate that microsporidial infection should be considered in the assessment of renal transplant recipients, especially in the urinary tract, even if asymptomatic. Molecular identification of microsporidia species is relevant because of their different susceptibility for treatment.

Cryptosporidium meleagridis infection: the first report in Poland of its occurrence in an HIV-positive woman

Cryptosporidium is an opportunistic protozoan parasite that can cause severe diarrhoea in immunocompromised patients. The transmission of this pathogen in humans and animals is not fully understood. C. meleagridis, originally described in birds, is the only Cryptosporidium species known to naturally infect mammalian and avian species. This study documents the first detection of C. meleagridis in an HIV-infected woman in Poland.

Zoonotic microsporidia in dogs and cats in Poland

This study investigated the prevalence, genetic diversity, and zoonotic concerns of microsporidia in household dogs and cats in Poland. A total of 126 (82 dogs and 44 cats) fecal specimens were analyzed for the presence of specific DNA of Enterocytozoon bieneusi and Encephalitozoon spp. using a nested PCR protocol amplifying the internal transcribed spacer region of the rRNA gene. Microsporidia were found in 10 (7.9%) out of the 126 examined stool samples. Of the 82 dogs, 4 (4.9%) and 2 (2.4%) were positive for E. bieneusi (genotypes D and PtEbIX) and Encephalitozoon cuniculi genotype II, respectively. Of the 44 cats, 4 (9.1%) were positive for E. bieneusi (genotypes PtEbIX and eb52). Additionally, one cat (2.3%) was concurrently infected with E. bieneusi (PtEbIX) and E. cuniculi (genotype II). Considering that all detected microsporidia in dogs and cats have been previously associated with human microsporidiosis, companion animals may be a potential source of microsporidia infections in humans.

Genotyping of Pneumocystis jirovecii in colonized patients with various pulmonary diseases

Pneumocystis jirovecii is an opportunistic fungus causing Pneumocystis pneumonia primarily in immunosuppressed patients. However, immunocompetent individuals may become colonized and, as asymptomatic carriers, serve as reservoirs of the pathogen. Moreover, these asymptomatic carriers are at higher risk of developing pneumonia if favorable conditions occur. This study aimed to determine the prevalence of P. jirovecii in patients with various pulmonary diseases and to characterize the genetic diversity of organisms circulating in the studied population. Bronchial washing specimens from 105 patients were tested for presence of P. jirovecii using nested polymerase chain reaction (PCR) targeting the mtLSU rRNA gene, as well as immunofluorescence microscopy. Multilocus sequence typing involving analysis of three loci-mtLSU rRNA, CYB, and SOD-was used for genotyping analysis. P. jirovecii DNA was detected in 17 (16.2%) patients. Amplification of the SOD locus was successful only in five cases (29.4% of the positive patients), while mtLSU rRNA and CYB were genotyped in all positive samples. Therefore, combined genotypes were identified based only on mtLSU rRNA and CYB loci. Eight different genotypes were identified, with Pj 1 and Pj 2 being the most prevalent (29.4% of patients each). There was no statistical correlation between these genotypes and demographic or clinical data; however, we found that infection with mutant CYB strains occurred only in patients diagnosed with lung cancer. Of the potential predictors examined, only immunosuppressive treatment was significantly associated with colonization. In conclusion, patients with various respiratory diseases, especially when immunosuppressed, are at risk of Pneumocystis colonization.

Respiratory microsporidiosis caused by Enterocytozoon bieneusi in an HIV-negative hematopoietic stem cell transplant recipient

A 23-year-old, HIV-negative woman who had undergone a hematopoietic stem cell transplantation was admitted to the hospital with respiratory failure and symptoms of bronchiolitis obliterans. A chest computed tomography scan revealed diffuse ground-glass opacification and fibrous plugs. Due to worsening respiratory failure despite treatment, ventilation was provided through a tracheostomy tube. Molecular examination of bronchoalveolar lavage and urine revealed Enterocytozoon bieneusi infection. After treatment with albendazole the patient gradually improved, but the pathogen was not eradicated and reappeared on follow-up examination. E. bieneusi belongs to the most clinically important microsporidial species infecting humans, mostly those who are immunocompromised. This fungus tends to infect enterocytes of the intestine, and there are limited studies concerning its extraintestinal location. This is the first report of a case of disseminated respiratory and urinary E. bieneusi infection in a transplant recipient.

Disseminated Infection of Encephalitozoon cuniculi Associated With Osteolysis of Hip Periprosthetic Tissue

Background Among patients with hip joint endoprosthesis, periprosthetic osteolysis is the most common complication following primary arthroplasty, and subsequent implant loosening is the leading cause of arthroplasty revision. Causes of stability loss, though not always evident, can be mechanical, allergic, or infectious (bacterial and fungal agents) in nature. Microsporidia, widespread opportunistic fungal pathogens that infect most human tissues, are a potential infectious cause of stability loss. Infections caused by Encephalitozoon species-one of the most common microsporidial pathogens in humans-primarily localize to intestinal and respiratory tracts, but can disseminate to tissues throughout the body. Methods We examined 53 immunocompetent patients, 23 after revision and 30 after primary hip arthroplasty, for infection by Encephalitozoon species. Periprosthetic tissue, urine sediments, and stool samples were tested by microscopic examination and genus-specific nested polymerase chain reaction followed by genotyping. Results Ten patients had Encephalitozoon-positive periprosthetic tissues, 9 (39%) after revision and 1 (3.3%) after primary hip arthroplasty. Among the tissue-positive postrevision patients, 7 had a positive urine sample and 1 had a positive stool sample. Encephalitozoon cuniculi genotype II was identified in 88.8% (16/18) of samples. Two urine samples were positive for a novel Encephalitozoon species. Conclusions Encephalitozoon cuniculi should be considered as a cause of osteolysis in hip periprosthetic tissue, leading to a loss of implant stability.