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Tsvetkova N, Harizanov R, Rainova I, Ivanova A, Yancheva-Petrova N. Molecular Analysis of Dihydropteroate Synthase Gene Mutations in Pneumocystis jirovecii Isolates among Bulgarian Patients with Pneumocystis Pneumonia. Int J Mol Sci 2023; 24:16927. [PMID: 38069248 PMCID: PMC10707730 DOI: 10.3390/ijms242316927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Pneumocystis jirovecii pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the DHPS gene. This study aims to investigate the presence of DHPS gene mutations among P. jirovecii isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the P. jirovecii mitochondrial large subunit rRNA gene and further at the DHPS locus. P. jirovecii DNA was detected in 50 (15.34%) specimens. A 370 bp DHPS locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all (n = 21) P. jirovecii isolates showed DHPS genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by P. jirovecii mutants potentially resistant to sulfonamides are still rare events in Bulgaria. DHPS genotype 1 at codons 55 and 57 is the predominant P. jirovecii strain in the country.
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Affiliation(s)
- Nina Tsvetkova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Rumen Harizanov
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Iskra Rainova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Aleksandra Ivanova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Nina Yancheva-Petrova
- Department for AIDS, Specialized Hospital for Active Treatment of Infectious and Parasitic Diseases, Ivan Geshev Blvd. 17, 1431 Sofia, Bulgaria
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Zhu M, Ye N, Xu J. Clinical characteristics and prevalence of dihydropteroate synthase gene mutations in Pneumocystis jirovecii-infected AIDS patients from low endemic areas of China. PLoS One 2020; 15:e0238184. [PMID: 32911508 PMCID: PMC7482917 DOI: 10.1371/journal.pone.0238184] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 08/11/2020] [Indexed: 12/22/2022] Open
Abstract
Pneumocystis pneumonia (PCP) is an opportunistic and potentially life-threatening infection of AIDS patients caused by the fungus Pneumocystis jirovecii (P. jirovecii). Trimethoprim-sulfamethoxazole (TMP-SMX) is the most commonly used drug combination in the treatment and prophylaxis of PCP. However, with long-term use of this combination, mutations in the dihydropteroate synthase (DHPS) gene of P. jirovecii bring about the development of resistance. Data on the prevalence of P. jirovecii and its DHPS mutants in China, especially in low endemic areas, are still limited. Thus, in the present study, we measured the P. jirovecii infection rate among HIV-positive and AIDS (HIV/AIDS) patients with suspected PCP and investigated the relationship between CD4+ T cell count and PCP occurrence. As well as the polymerase chain reaction (PCR) analysis and sequencing, the restriction fragment length polymorphism (RFLP) method was used to analyze DHPS point mutation in P. jirovecii strains. P. jirovecii was detected in 40.82% of cases. The clinical symptoms and signs of PCP were not typical; with decreasing CD4+ T cell counts, PCP infection in HIV/AIDS patients increased. In only one case (1.67%), the patients' DHPS gene could not be cut by the Acc I restriction enzyme. Furthermore, mutation at codon 171 was detected in 11 cases and no mutation was found at codon 57. Patients treated with sulfamethoxazole combined with Voriconazole or Caspofungin exhibited favorable results. After treatment, the symptoms of dyspnea were alleviated, and chest computed tomography findings showed the improvement of lung shadows. These indicated that the prevalence of DHPS mutations in P. jirovecii isolates in AIDS-PCP patients in the region was low. Thus, the contribution of gene mutations to treatment failure requires further research.
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Affiliation(s)
- Mingli Zhu
- Department of Microbiology and Immunology, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Department of Clinical Laboratory, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Ning Ye
- Department of Clinical Laboratory, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
- Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, Zhejiang, China
| | - Jiru Xu
- Department of Microbiology and Immunology, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
- * E-mail:
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Singh Y, Mirdha BR, Guleria R, Kabra SK, Mohan A, Chaudhry R, Kumar L, Dwivedi SN, Agarwal SK. Novel dihydropteroate synthase gene mutation in Pneumocystis jirovecii among HIV-infected patients in India: Putative association with drug resistance and mortality. J Glob Antimicrob Resist 2019; 17:236-239. [PMID: 30658203 DOI: 10.1016/j.jgar.2019.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/14/2018] [Accepted: 01/09/2019] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES Pneumocystis pneumonia (PCP) remains a debilitating cause of death among HIV-infected patients. The combination trimethoprim/sulfamethoxazole (SXT) is the most effective anti-Pneumocystis treatment and prophylaxis. However, long-term use of this combination has raised alarms about the emergence of resistant organisms. This study was performed to investigate mutations in the dihydropteroate synthase (DHPS) gene and their clinical consequences in HIV-infected patients with PCP. METHODS A total of 76 clinically suspected cases of PCP among HIV-seropositive adult patients from March 2014 to March 2017 were included. Clinical samples (bronchoalveolar lavage fluid and sputum) were investigated for the detection of Pneumocystis jirovecii using both microscopy and nested PCR. DHPS genotyping and mutational analyses were performed and the data were correlated with clinical characteristics. RESULTS Among the 76 enrolled HIV-positive patients, only 17 (22.4%) were positive for P. jirovecii. DHPS gene sequencing showed a novel nucleotide substitution at position 288 (Val96Ile) in three patients (3/12; 25.0%). Patients infected with the mutant P. jirovecii genotype had severe episodes of PCP, did not respond to SXT and had a fatal outcome (P=0.005). All three patients had a CD4+ T-cell count <100 cells/μL, and two also had co-infections. CONCLUSION This study suggests that the emergence of a mutant P. jirovecii genotype is probably associated with drug resistance and mortality. The data also suggest that DHPS mutational analyses should be performed in HIV-seropositive patients to avoid treatment failure and death due to PCP. However, the role of underlying disease severity and co-morbidities should not be underestimated.
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Affiliation(s)
- Yogita Singh
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi 110029, India
| | - Bijay Ranjan Mirdha
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi 110029, India.
| | - Randeep Guleria
- All India Institute of Medical Sciences, Department of Pulmonary Medicine and Sleep Disorders, New Delhi 110029, India
| | - Sushil K Kabra
- All India Institute of Medical Sciences, Department of Pediatrics, New Delhi 110029, India
| | - Anant Mohan
- All India Institute of Medical Sciences, Department of Pulmonary Medicine and Sleep Disorders, New Delhi 110029, India
| | - Rama Chaudhry
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi 110029, India
| | - Lalit Kumar
- All India Institute of Medical Sciences, Department of Medical Oncology, New Delhi 110029, India
| | - Sada Nand Dwivedi
- All India Institute of Medical Sciences, Department of Biostatistics, New Delhi 110029, India
| | - Sanjay K Agarwal
- All India Institute of Medical Sciences, Department of Nephrology, New Delhi 110029, India
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Low prevalence of DHFR and DHPS mutations in Pneumocystis jirovecii strains obtained from a German cohort. Infection 2017; 45:341-347. [PMID: 28303545 DOI: 10.1007/s15010-017-1005-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/07/2017] [Indexed: 12/30/2022]
Abstract
BACKGROUND Pneumocystis pneumonia (PCP) is an opportunistic and potentially life-threatening infection of immunocompromised individuals. A combination of trimethoprim-sulfamethoxazole is widely used for prophylaxis and treatment of PCP. Polymorphisms in the drug targets, the dihydropteroate synthase (DHPS) or the dihydrofolate reductase (DHFR) are presumably a reason for treatment failure. METHODS We retrospectively examined the prevalence of DHPS and DHFR mutations in Pneumocystis jirovecii isolates obtained from HIV-infected and non-HIV-infected PCP patients. DHFR and DHPS genes were amplified using semi-nested PCR followed by sequencing. Obtained data were correlated with clinical findings. RESULTS Sequencing of the DHPS gene was achieved in 81 out of 128 isolates (63%), the DHFR-gene was successfully sequenced in 96 isolates (75%). The vast majority of DHFR and DHPS sequences were either wild-type or showed synonymous single nucleotide polymorphisms. Only one sample contained a double mutation at DHPS codon 55 and codon 57 which was associated with treatment failure in some studies. No linkage of treatment failure to a DHFR or DHPS genotype was observed. In our cohort, 35 of 95 Patients (37%) were HIV-positive and 60 (63%) were HIV-negative. The overall mortality rate was 24% with a much higher rate among non-HIV patients. CONCLUSION DHPS and DHFR mutations exist but are infrequent in our cohort. The contribution of gene polymorphisms to treatment failure needs further research. In immunocompromised HIV-negative patients PCP is associated with high mortality rates. Prophylactic treatment is warranted in this patient subset.
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Long Y, Zhang C, Su L, Que C. Pneumocystis jirovecii dihydropteroate synthase gene mutations in a group of HIV-negative immunocompromised patients with Pneumocystis pneumonia. Exp Ther Med 2014; 8:1825-1830. [PMID: 25371739 PMCID: PMC4218695 DOI: 10.3892/etm.2014.2002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 09/04/2014] [Indexed: 12/28/2022] Open
Abstract
The purpose of this study was to investigate dihydropteroate synthase (DHPS) mutations and their clinical context in non-HIV-infected patients with Pneumocystis pneumonia (PCP). DHPS genes in respiratory samples collected from HIV-negative patients with PCP presented between January 2008 and April 2011 were amplified by polymerase chain reaction (PCR) and sequenced. Basic clinical data from the medical records of the patients were also reviewed. The most common point mutations, which result in Thr55Ala and Pro57Ser amino acid substitutions, were not detected in the Pneumocystis jirovecii sampled from the HIV-negative patients. Two other point mutations, which result in nonsynonymous mutation, Asp90Asn and Glu98Lys, were identified in P. jirovecii from two patients. Among the patients, the levels of lactate dehydrogenase (LDH), C-reactive protein (CRP) and plasma (1-3) β-D-glucan were elevated in 75, 92.31 and 42.86% of patients, respectively. The percentage of circulating lymphocytes was significantly lower in non-survivors than in survivors [4.2%, interquartile range (IQR) 2.4-5.85 versus 10.1%, IQR 5.65-23.4; P=0.019]. The neutrophil proportion in bronchoalveolar lavage fluid (BALF) was significantly higher in non-survivors than in survivors (49.78±27.67 versus 21.33±15.03%; P=0.047). Thirteen patients had received adjunctive corticosteroids (1 mg/kg/day prednisone equivalent) and nine (69.23%) of them eventually experienced treatment failure. No common DHPS gene mutations of P. jirovecii were detected in the HIV-negative PCP patients. However, other mutations did exist, the significance of which remains to be further identified. The elevation of neutrophil counts in BALF and reduction of the number of lymphocytes in peripheral blood may be associated with poor outcome. The efficacy of adjunctive steroid therapy in HIV-negative patients with P. jirovecii infection requires further investigation.
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Affiliation(s)
- Yingjiao Long
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Cheng Zhang
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Li Su
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Chengli Que
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
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Pneumocystis jirovecii infection and the associated dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) mutations in HIV-positive individuals from Pune, India. Mycopathologia 2014; 179:141-5. [PMID: 25266324 DOI: 10.1007/s11046-014-9818-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 09/23/2014] [Indexed: 10/24/2022]
Abstract
The present study was undertaken to detect Pneumocystis jirovecii infection among HIV-positive patients presenting with symptoms of lower respiratory tract infection and analyze the associated dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) mutations. P. jirovecii infection was detected in 12.6% cases. We did not find DHPS gene mutations at the commonest positions of codon 55 and 57; however, mutation at codon 171 was detected in two cases. No mutations in DHFR gene were detected. The results indicate low prevalence of DHPS and DHFR mutations in Indian P. jirovecii isolates, suggesting that the selective pressure of sulfa drugs on the local strains has probably not reached the levels found in developed nations.
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Riebold D, Enoh DO, Kinge TN, Akam W, Bumah MK, Russow K, Klammt S, Loebermann M, Fritzsche C, Eyong JE, Eppel G, Kundt G, Hemmer CJ, Reisinger EC. Pneumocystis jirovecii colonisation in HIV-positive and HIV-negative subjects in Cameroon. Trop Med Int Health 2014; 19:643-655. [PMID: 24645978 DOI: 10.1111/tmi.12299] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the prevalence of Pneumocystis pneumonia (PCP), a major opportunistic infection in AIDS patients in Europe and the USA, in Cameroon. MATERIALS AND METHODS Induced sputum samples from 237 patients without pulmonary symptoms (126 HIV-positive and 111 HIV-negative outpatients) treated at a regional hospital in Cameroon were examined for the prevalence of Pneumocystis jirovecii by specific nested polymerase chain reaction (nPCR) and staining methods. CD4 counts and the history of antiretroviral therapy of the subjects were obtained through the ESOPE database system. RESULTS AND CONCLUSION Seventy-five of 237 study participants (31.6%) were colonised with Pneumocystis, but none showed active PCP. The Pneumocystis colonisation rate in HIV-positive subjects was more than double that of HIV-negative subjects (42.9% vs. 18.9%, P < 0.001). In the HIV-positive group, the colonisation rate corresponds to the reduction in the CD4 lymphocyte counts. Subjects with CD4 counts >500 cells/μl were colonised at a rate of 20.0%, subjects with CD4 counts between 200 and 500 cells/μl of 42.5%, and subjects with CD4 counts <200 cells/μl of 57.1%. Colonisation with Pneumocystis in Cameroon seems to be comparable to rates found in Western Europe. Prophylactic and therapeutic measures against Pneumocystis should be taken into account in HIV care in western Africa.
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Affiliation(s)
- D Riebold
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - D O Enoh
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany.,Regional Hospital Limbe, Limbe, Cameroon
| | - T N Kinge
- Regional Hospital Limbe, Limbe, Cameroon
| | - W Akam
- Regional Hospital Limbe, Limbe, Cameroon
| | - M K Bumah
- Regional Hospital Limbe, Limbe, Cameroon
| | - K Russow
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - S Klammt
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - M Loebermann
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - C Fritzsche
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - J E Eyong
- Ministry of Health, Yaoundé, Cameroon
| | - G Eppel
- Gesellschaft für Internationale Zusammenarbeit, Yaoundé, Cameroon
| | - G Kundt
- Institute of Biostatistics and Informatics in Medicine and Ageing Research, University of Rostock Medical School, Rostock, Germany
| | - C J Hemmer
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
| | - E C Reisinger
- Division of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany
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Dimonte S, Berrilli F, D’Orazi C, D’Alfonso R, Placco F, Bordi E, Perno C, Di Cave D. Molecular analysis based on mtLSU-rRNA and DHPS sequences of Pneumocystis jirovecii from immunocompromised and immunocompetent patients in Italy. INFECTION GENETICS AND EVOLUTION 2013. [DOI: 10.1016/j.meegid.2012.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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