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Microsatellite typing and susceptibilities of serial Cryptococcus neoformans isolates from Cuban patients with recurrent cryptococcal meningitis.

Illnait-Zaragozí MT, Martínez-Machín GF, Fernández-Andreu CM, Hagen F, Boekhout T, Klaassen CH, Meis JF - BMC Infect. Dis. (2010)

Bottom Line: The average number of isolates/patient was 2.71.All strains were identified as C. neoformans var. grubii (serotype Aα).The four other patients had relapse isolates which were genotypically different from the initial infecting strain.

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Affiliation: Department of Bacteriology and Mycology, Instituto Pedro Kourí, Havana, Cuba.

ABSTRACT

Background: Cryptococcus neoformans is commonly associated with meningoencephalitis in immunocompromised patients and occasionally in apparently healthy individuals. Recurrence of infection after initial treatment is not uncommon. We studied C. neoformans isolates from 7 Cuban patients with recurrent cryptococcal meningitis. Antifungal susceptibility and genotyping with microsatellite molecular typing were carried out.

Methods: Isolates (n = 19) were recovered from cerebrospinal fluid, blood, urine and semen. Antifungal susceptibilities for amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, posaconazole and isavuconazole were tested by CLSI M27A3 broth microdilution method. Genotyping was done using a panel of 9 microsatellite (STR) markers: (CT)n, (TG)n, (TA)n, (CTA)n, (TCT)n, (CCA)n, (TTAT)n, (ATCC)n and (TATT)n.

Results: The average number of isolates/patient was 2.71. The mean time interval between the collection of any two isolates was 52.5 days. All strains were identified as C. neoformans var. grubii (serotype Aα). Although none of the strains were resistant to the studied drugs, in serial isolates from two patients, MICs values of triazoles increased 4-5 log2 dilutions over time. STR patterns showed 14 distinctive profiles. In three patients the recurrent infection was associated with genotypically identical isolates. The four other patients had relapse isolates which were genotypically different from the initial infecting strain.

Conclusion: Recurrences of cryptococcal meningitis in our series of patients was not associated with development of drug resistance of the original strain but by an initial infection with different strains or a reinfection with a new strain.

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Details of the 19 C. neoformans isolates from 7 patients and relationship between the obtained genotypes. The numbers below the genotype correspond to the number of repetitions observed in markers CNA2a, CNA2b, CNA2c, CNA3a, CNA3b, CNA3c, CNA4a, CNA4b and CNA4c, respectively. A hyphen indicates that no result was obtained. The dendrogram is based on a categorical analysis using UPGMA clustering. The scale bar indicates the percentage similarity.
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Figure 1: Details of the 19 C. neoformans isolates from 7 patients and relationship between the obtained genotypes. The numbers below the genotype correspond to the number of repetitions observed in markers CNA2a, CNA2b, CNA2c, CNA3a, CNA3b, CNA3c, CNA4a, CNA4b and CNA4c, respectively. A hyphen indicates that no result was obtained. The dendrogram is based on a categorical analysis using UPGMA clustering. The scale bar indicates the percentage similarity.

Mentions: STR patterns of the 19 isolates showed 14 distinct profiles. Three patients (patients 2, 3 and 6) had genotypically identical isolates over the course of time. The serial isolates from patient 6 were genotypically identical but also showed the largest difference in MIC for the triazoles including drugs which have not been used (itraconazole, voriconazole, isavuconazole). The other four patients were probably infected by more than one genotype (Figure 1) although this might be biased because from each positive CSF culture only one colony was archived for future study.


Microsatellite typing and susceptibilities of serial Cryptococcus neoformans isolates from Cuban patients with recurrent cryptococcal meningitis.

Illnait-Zaragozí MT, Martínez-Machín GF, Fernández-Andreu CM, Hagen F, Boekhout T, Klaassen CH, Meis JF - BMC Infect. Dis. (2010)

Details of the 19 C. neoformans isolates from 7 patients and relationship between the obtained genotypes. The numbers below the genotype correspond to the number of repetitions observed in markers CNA2a, CNA2b, CNA2c, CNA3a, CNA3b, CNA3c, CNA4a, CNA4b and CNA4c, respectively. A hyphen indicates that no result was obtained. The dendrogram is based on a categorical analysis using UPGMA clustering. The scale bar indicates the percentage similarity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2959061&req=5

Figure 1: Details of the 19 C. neoformans isolates from 7 patients and relationship between the obtained genotypes. The numbers below the genotype correspond to the number of repetitions observed in markers CNA2a, CNA2b, CNA2c, CNA3a, CNA3b, CNA3c, CNA4a, CNA4b and CNA4c, respectively. A hyphen indicates that no result was obtained. The dendrogram is based on a categorical analysis using UPGMA clustering. The scale bar indicates the percentage similarity.
Mentions: STR patterns of the 19 isolates showed 14 distinct profiles. Three patients (patients 2, 3 and 6) had genotypically identical isolates over the course of time. The serial isolates from patient 6 were genotypically identical but also showed the largest difference in MIC for the triazoles including drugs which have not been used (itraconazole, voriconazole, isavuconazole). The other four patients were probably infected by more than one genotype (Figure 1) although this might be biased because from each positive CSF culture only one colony was archived for future study.

Bottom Line: The average number of isolates/patient was 2.71.All strains were identified as C. neoformans var. grubii (serotype Aα).The four other patients had relapse isolates which were genotypically different from the initial infecting strain.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Bacteriology and Mycology, Instituto Pedro Kourí, Havana, Cuba.

ABSTRACT

Background: Cryptococcus neoformans is commonly associated with meningoencephalitis in immunocompromised patients and occasionally in apparently healthy individuals. Recurrence of infection after initial treatment is not uncommon. We studied C. neoformans isolates from 7 Cuban patients with recurrent cryptococcal meningitis. Antifungal susceptibility and genotyping with microsatellite molecular typing were carried out.

Methods: Isolates (n = 19) were recovered from cerebrospinal fluid, blood, urine and semen. Antifungal susceptibilities for amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, posaconazole and isavuconazole were tested by CLSI M27A3 broth microdilution method. Genotyping was done using a panel of 9 microsatellite (STR) markers: (CT)n, (TG)n, (TA)n, (CTA)n, (TCT)n, (CCA)n, (TTAT)n, (ATCC)n and (TATT)n.

Results: The average number of isolates/patient was 2.71. The mean time interval between the collection of any two isolates was 52.5 days. All strains were identified as C. neoformans var. grubii (serotype Aα). Although none of the strains were resistant to the studied drugs, in serial isolates from two patients, MICs values of triazoles increased 4-5 log2 dilutions over time. STR patterns showed 14 distinctive profiles. In three patients the recurrent infection was associated with genotypically identical isolates. The four other patients had relapse isolates which were genotypically different from the initial infecting strain.

Conclusion: Recurrences of cryptococcal meningitis in our series of patients was not associated with development of drug resistance of the original strain but by an initial infection with different strains or a reinfection with a new strain.

Show MeSH
Related in: MedlinePlus