Cargando…

Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis

PURPOSE: To study the susceptibilities of Aspergillus species against amphotericin B in infectious keratitis and to find out if drug resistance had any association with the molecular characteristics of the fungi. MATERIALS AND METHODS: One hundred and sixty Aspergillus isolates from the corneal scra...

Descripción completa

Detalles Bibliográficos
Autores principales: Nayak, Niranjan, Satpathy, Gita, Prasad, Sujata, Titiyal, Jeewan S, Pandey, R M, Vajpayee, Rasik B
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Medknow Publications 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3159319/
https://www.ncbi.nlm.nih.gov/pubmed/21836343
http://dx.doi.org/10.4103/0301-4738.83614
_version_ 1782210450069389312
author Nayak, Niranjan
Satpathy, Gita
Prasad, Sujata
Titiyal, Jeewan S
Pandey, R M
Vajpayee, Rasik B
author_facet Nayak, Niranjan
Satpathy, Gita
Prasad, Sujata
Titiyal, Jeewan S
Pandey, R M
Vajpayee, Rasik B
author_sort Nayak, Niranjan
collection PubMed
description PURPOSE: To study the susceptibilities of Aspergillus species against amphotericin B in infectious keratitis and to find out if drug resistance had any association with the molecular characteristics of the fungi. MATERIALS AND METHODS: One hundred and sixty Aspergillus isolates from the corneal scrapings of patients with keratitis were tested for susceptibilities to amphotericin B by broth microdilution method. These included Aspergillus flavus (64 isolates), A. fumigatus (43) and A. niger (53). Fungal DNA was extracted by glass bead vertexing technique. Polymerase chain reaction (PCR) assay was standardized and used to amplify the 28S rRNA gene. Single-stranded conformational polymorphism (SSCP) of the PCR product was performed by the standard protocol. RESULTS: Of the 160 isolates, 84 (52.5%) showed low minimum inhibitory concentration (MIC) values (≤ 1.56 μg/ml) and were designated as amphotercin B-sensitive. Similarly, 76 (47.5%) had high MICs (≥ 3.12 μg/ml) and were categorized as amphotericin B-resistant. MIC(50) and MIC(90) values ranged between 3.12-6.25 μg/ml and 3.12-12.5 μg/ml respectively. A. flavus and A. niger showed higher MIC(50) and MIC(90) values than A. fumigatus. The SSCP pattern exhibited three extra bands (150 bp, 200 bp and 250 bp each) in addition to the 260 bp amplicon. Strains (lanes 1 and 7) lacking the 150 bp band showed low MIC values (≤ 1.56 μg/ml). CONCLUSION: A. niger and A. flavus isolates had higher MICs compared to A. fumigatus, suggesting a high index of suspicion for amphotericin B resistance. PCR-SSCP was a good molecular tool to characterize Aspergillus phenotypes in fungal keratitis.
format Online
Article
Text
id pubmed-3159319
institution National Center for Biotechnology Information
language English
publishDate 2011
publisher Medknow Publications
record_format MEDLINE/PubMed
spelling pubmed-31593192011-09-07 Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis Nayak, Niranjan Satpathy, Gita Prasad, Sujata Titiyal, Jeewan S Pandey, R M Vajpayee, Rasik B Indian J Ophthalmol Original Article PURPOSE: To study the susceptibilities of Aspergillus species against amphotericin B in infectious keratitis and to find out if drug resistance had any association with the molecular characteristics of the fungi. MATERIALS AND METHODS: One hundred and sixty Aspergillus isolates from the corneal scrapings of patients with keratitis were tested for susceptibilities to amphotericin B by broth microdilution method. These included Aspergillus flavus (64 isolates), A. fumigatus (43) and A. niger (53). Fungal DNA was extracted by glass bead vertexing technique. Polymerase chain reaction (PCR) assay was standardized and used to amplify the 28S rRNA gene. Single-stranded conformational polymorphism (SSCP) of the PCR product was performed by the standard protocol. RESULTS: Of the 160 isolates, 84 (52.5%) showed low minimum inhibitory concentration (MIC) values (≤ 1.56 μg/ml) and were designated as amphotercin B-sensitive. Similarly, 76 (47.5%) had high MICs (≥ 3.12 μg/ml) and were categorized as amphotericin B-resistant. MIC(50) and MIC(90) values ranged between 3.12-6.25 μg/ml and 3.12-12.5 μg/ml respectively. A. flavus and A. niger showed higher MIC(50) and MIC(90) values than A. fumigatus. The SSCP pattern exhibited three extra bands (150 bp, 200 bp and 250 bp each) in addition to the 260 bp amplicon. Strains (lanes 1 and 7) lacking the 150 bp band showed low MIC values (≤ 1.56 μg/ml). CONCLUSION: A. niger and A. flavus isolates had higher MICs compared to A. fumigatus, suggesting a high index of suspicion for amphotericin B resistance. PCR-SSCP was a good molecular tool to characterize Aspergillus phenotypes in fungal keratitis. Medknow Publications 2011 /pmc/articles/PMC3159319/ /pubmed/21836343 http://dx.doi.org/10.4103/0301-4738.83614 Text en Copyright: © Indian Journal of Ophthalmology http://creativecommons.org/licenses/by-nc-sa/3.0 This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Article
Nayak, Niranjan
Satpathy, Gita
Prasad, Sujata
Titiyal, Jeewan S
Pandey, R M
Vajpayee, Rasik B
Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title_full Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title_fullStr Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title_full_unstemmed Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title_short Molecular characterization of drug-resistant and drug-sensitive Aspergillus isolates causing infectious keratitis
title_sort molecular characterization of drug-resistant and drug-sensitive aspergillus isolates causing infectious keratitis
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3159319/
https://www.ncbi.nlm.nih.gov/pubmed/21836343
http://dx.doi.org/10.4103/0301-4738.83614
work_keys_str_mv AT nayakniranjan molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis
AT satpathygita molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis
AT prasadsujata molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis
AT titiyaljeewans molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis
AT pandeyrm molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis
AT vajpayeerasikb molecularcharacterizationofdrugresistantanddrugsensitiveaspergillusisolatescausinginfectiouskeratitis