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Journal of the Medical Association of... Sep 2004Pneumocystis pneumonia is a major cause of illness and death in immunocompromised hosts. The numbers of pneumocystis pneumonia cases in Thailand have increased each year... (Review)
Review
Pneumocystis pneumonia is a major cause of illness and death in immunocompromised hosts. The numbers of pneumocystis pneumonia cases in Thailand have increased each year from 1992 to 2000 and peaked in 2000 at 6,255 cases. The microbe that causes pneumocystis pneumonia in humans is called Pneumocystis jirovecii. Pneumocystis sp. was discovered nearly a century ago, but the knowledge of Pneumocystis sp. remained poorly understood, until the molecular biology techniques help scientists verify it fungus nature. In the past, Pneumocystis sp. was misclassified as protozoan due to its morphologic features. Later, it was reclassified as fungus due to DNA analysis. Cotrimaxazole, the combination of trimethoprim-sulfamethoxazole, is the drug of choice for treatment and prophylaxis of pneumocystis pneumonia. However, increasing evidence of mutations in the enzyme dihydropteroate synthase (DHPS), the target of sulfa drugs represent emergence of sulfa resistance.
Topics: Animals; Anti-Infective Agents; Drug Resistance, Microbial; Genotype; Humans; Life Cycle Stages; Pneumocystis; Pneumocystis carinii; Pneumonia, Pneumocystis; Thailand; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 16083208
DOI: No ID Found -
Journal of Medical and Veterinary... 1996The purpose of this review is to assist mycologists in having a better understanding of Pneumocystis carinii and the disease that it causes. Now considered to be a... (Review)
Review
The purpose of this review is to assist mycologists in having a better understanding of Pneumocystis carinii and the disease that it causes. Now considered to be a fungus, P. carinii is unusual in its life cycle and relationship with the host. P. carinii pneumonia (PCP) pathogenesis, immunology and host defence mechanisms are examined, as well as epidemiological and control strategies. Most pneumocystosis pathophysiological changes result from the parasite's attachment and proliferation in the lungs, resulting in a filling of the alveoli with masses of the micro-organism. Pathological changes include an increase in alveolar capillary membrane permeability and injury to the alveolar epithelium, which may be mediated by the release of degradative enzymes from the pathogen. A host response takes place by hypertrophy, and hyperplasia involving type II epithelial alveolar cells. P carinii interacts with pulmonary surfactants by binding to the hydrophilic proteins A and D, and by modifying their phospholipid composition. Alveolar macrophages and CD4+ T cells play a key role in the host's defence against Pneumocystis. The epidemiology of PCP remains poorly understood. Airborne transmission has been established, but the actual infective form and its source remains unknown. Studies concerning P. carinii genetic diversity have shown that the parasite polymorphism is related, at least partially, to the host species. A strong host-species specificity in P. carinii has been found. From an epidemiological perspective, there appears to be no animal reservoir for the agent of human PCP. Thus, this disease should not be considered to be zoonotic. Although a significant decrease in the incidence of pneumocystosis has been obtained when employing chemoprophylaxis, anti-P. carinii drugs are not completely successful, often inducing deleterious side-effects. For these reasons, new prophylactic and therapeutic strategies need to be developed. One approach could be based on the anti-P. carinii effect of yeast killer toxins and antibiotic anti-idiotypic antibodies.
Topics: Animals; Antifungal Agents; CD4-Positive T-Lymphocytes; Disease Reservoirs; Female; Genes, Fungal; Genetic Variation; Humans; Infant, Newborn; Infectious Disease Transmission, Vertical; Macrophages, Alveolar; Pneumocystis; Pneumonia, Pneumocystis; Pregnancy; Pregnancy Complications, Infectious; Terminology as Topic
PubMed: 8873881
DOI: 10.1080/02681219680000401 -
FEMS Immunology and Medical Microbiology Sep 1998
Topics: Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 9792055
DOI: 10.1111/j.1574-695X.1998.tb01181.x -
Infection, Genetics and Evolution :... Nov 2018The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect... (Review)
Review
The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect exclusively mammals and present a strict host species specificity. These species have co-diverged with their hosts for long periods of time (> 100 MYA). Details of their biology and evolution are fragmentary mainly because of a lack of an established long-term culture system. Recent genomic advances have unlocked new areas of research and allow new hypotheses to be tested. We review here new findings of the genomic studies in relation with the evolutionary trajectory of these fungi and discuss the impact of genomic data analysis in the context of the population genetics. The combination of slow genome decay and limited expansion of specific gene families and introns reflect intimate interactions of these species with their hosts. The evolutionary adaptation of these organisms is profoundly influenced by their population structure, which in turn is determined by intrinsic features such as their self-fertilizing mating system, high host specificity, long generation times, and transmission mode. Essential key questions concerning their adaptation and speciation remain to be answered. The next cornerstone will consist in the establishment of a long-term culture system and genetic manipulation that should allow unravelling the driving forces of Pneumocystis species evolution.
Topics: Biological Evolution; Genome, Fungal; Genomics; Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 30138710
DOI: 10.1016/j.meegid.2018.08.015 -
Infection Aug 2022In the era of effective prophylaxis, the objective of this study was to describe pneumocystis pneumonia (PCP) patients' profile and evaluate the consistency of clinical...
PURPOSE
In the era of effective prophylaxis, the objective of this study was to describe pneumocystis pneumonia (PCP) patients' profile and evaluate the consistency of clinical situations encountered with the recommended indications for prophylaxis.
METHODS
This was a single-centre, retrospective study. All adults (> 18 years) with a definitive diagnosis of PCP were included. Data were collected from patients' electronic medical files.
RESULTS
The study examined the medical files of 225 patients diagnosed with PCP and treated between 1 January, 2015, and 30 June, 2020. More than 95% of the patients were not on anti-PCP prophylaxis at the time of PCP diagnosis. There were 32 (14%) deaths before the end of PCP treatment, mainly in auto-immune disease (30%) and solid tumours (38%) groups unlike the solid-organ transplants group, among whom deaths were infrequent. Indeed, 48% of our cohort (n = 107) had both corticosteroid (CS) therapy, immunosuppressive or immunomodulatory treatment, and lymphopaenia and could have been considered at high risk for PCP. Trimethoprim/sulfamethoxazole was administered as first-line PCP curative treatment in 95% of the patients. Toxicities of this drug led to treatment interruption in 25% of the patients (except death).
CONCLUSIONS
This study found a high number of PCP cases over 5 years. Unsurprisingly, most of the patients were immunosuppressed, with risk factors for PCP already described in the literature. This large number of PCP cases should be avoidable and, consequently, questions arise. Faced with these data, prophylaxis should be common sense for immunocompromised patients with risk factors, even if formalised recommendations do not exist.
Topics: Adult; Humans; Pneumocystis; Pneumocystis carinii; Pneumonia, Pneumocystis; Retrospective Studies; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 35274281
DOI: 10.1007/s15010-022-01790-2 -
Journal de Mycologie Medicale Mar 2022To provide original data on Pneumocystis primary infection in non-immunosuppressed infants from Peru.
OBJECTIVES
To provide original data on Pneumocystis primary infection in non-immunosuppressed infants from Peru.
METHODS
A cross sectional study was performed. Infants less than seven months old, without any underlying medical conditions attending the "well baby" outpatient clinic at one hospital in Lima, Peru were prospectively enrolled during a 15-month period from November 2016 to February 2018. All had a nasopharyngeal aspirate (NPA) for detection of P. jirovecii DNA using a PCR assay, regardless of respiratory symptoms. P. jirovecii DNA detection was considered to represent pulmonary colonization contemporaneous with Pneumocystis primary infection. Associations between infants' clinical and demographic characteristics and results of P. jirovecii DNA detection were analyzed.
RESULTS
P. jirovecii DNA was detected in 45 of 146 infants (30.8%) and detection was not associated with concurrent respiratory symptoms in 40 of 45 infants. Infants with P. jirovecii had a lower mean age when compared to infants not colonized (p <0.05). The highest frequency of P. jirovecii was observed in 2-3-month-old infants (p < 0.01) and in the cooler winter and spring seasons (p <0.01). Multivariable analysis showed that infants living in a home with ≤ 1 bedroom were more likely to be colonized; Odds Ratio =3.03 (95%CI 1.31-7.00; p = 0.01).
CONCLUSION
Pneumocystis primary infection in this single site in Lima, Peru, was most frequently observed in 2-3-month-old infants, in winter and spring seasons, and with higher detection rates being associated with household conditions favoring close inter-individual contacts and potential transmission of P. jirovecii.
Topics: Cross-Sectional Studies; Humans; Infant; Peru; Pneumocystis; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 34598108
DOI: 10.1016/j.mycmed.2021.101202 -
FEMS Immunology and Medical Microbiology Sep 2005The detection of Pneumocystis DNA in clinical specimens by using PCR assays is leading to important advances in Pneumocystis pneumonia (PcP) clinical diagnosis, therapy... (Review)
Review
The detection of Pneumocystis DNA in clinical specimens by using PCR assays is leading to important advances in Pneumocystis pneumonia (PcP) clinical diagnosis, therapy and epidemiology. Highly sensitive and specific PCR tools improved the clinical diagnosis of PcP allowing an accurate, early diagnosis of Pneumocystis infection, which should lead to a decreased duration from onset of symptoms to treatment, a period with recognized impact on prognosis. This aspect has marked importance in HIV-negative immunocompromised patients, who develop often PcP with lower parasite rates than AIDS patients. The specific amplification of selected polymorphous sequences of Pneumocystis jirovecii genome, especially of internal transcribed spacer regions of the nuclear rRNA operon, has led to the identification of specific parasite genotypes which might be associated with PcP severity. Moreover, multi-locus genotyping revealed to be a useful tool to explore person-to-person transmission. Furthermore, PCR was recently used for detecting P. jirovecii dihydropteroate synthase gene mutations, which are apparently associated with sulfa drug resistance. PCR assays detected Pneumocystis-DNA in bronchoalveolar lavage fluid or biopsy specimens, but also in oropharyngeal washings obtained by rinsing of the mouth. This non-invasive procedure may reach 90%-sensitivity and has been used for monitoring the response to treatment in AIDS patients and for typing Pneumocystis isolates.
Topics: DNA, Fungal; DNA, Ribosomal; Dihydropteroate Synthase; Humans; Pneumocystis Infections; Pneumocystis carinii; Pneumonia, Pneumocystis; Polymerase Chain Reaction; RNA, Ribosomal
PubMed: 16061360
DOI: 10.1016/j.femsim.2005.06.006 -
Comprehensive Therapy 2002Advances in the prevention and treatment of Pneumocystis carinii pneumonia in HIV infected patients have led to a decrease in the incidence and improved outcomes.... (Review)
Review
Advances in the prevention and treatment of Pneumocystis carinii pneumonia in HIV infected patients have led to a decrease in the incidence and improved outcomes. Pneumocystis carinii pneumonia continues to be problematic in non-HIV infected immunocompromised patients.
Topics: AIDS-Related Opportunistic Infections; HIV Infections; Humans; Pneumocystis; Pneumonia, Pneumocystis; Risk Factors
PubMed: 12085467
DOI: 10.1007/s12019-002-0047-3 -
PLoS Pathogens Jan 2019
Review
Topics: Animals; Humans; Lung; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 30677096
DOI: 10.1371/journal.ppat.1007480 -
Pneumocystis pneumonia, an immunodeficiency-dependent disease (IDD): a critical historical overview.The Journal of Eukaryotic Microbiology 1999
Review
Topics: Animals; History, 20th Century; Humans; Pneumocystis; Pneumonia, Pneumocystis; Rats; Terminology as Topic
PubMed: 10519262
DOI: No ID Found