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Background: Burden of aspergillosis is reported to be significant from developing countries including those in South Asia. The estimated burden in Pakistan is also high on the background of tuberculosis and chronic lung diseases. There is concern for management of aspergillosis with the emergence of azole resistant Aspergillus species in neighbouring countries in Central and South Asia. Hence the aim of this study was to screen significant Aspergillus species isolates at the Microbiology Section of Aga Khan Clinical Laboratories, Pakistan, for triazole resistance.
Methods: A descriptive cross-sectional study, conducted at the Aga Khan University Laboratories, Karachi, from September 2016-May 2019. One hundred and fourteen, clinically significant Aspergillus isolates [A. fumigatus (38; 33.3%), A. flavus (64; 56.1%), A. niger (9; 7.9%) A. terreus (3; 2.6%)] were included. The clinical spectrum ranged from invasive aspergillosis (IA) (n=25; 21.9%), chronic pulmonary aspergillosis (CPA) (n=58; 50.9%), allergic bronchopulmonary aspergillosis (ABPA) (n=4; 3.5%), severe asthma with fungal sensitization (SAFS) (n=4; 3.5%), saprophytic tracheobronchial aspergillosis (n=23; 20.2%). Screening for triazole resistance was performed by antifungal agar screening method. The minimum inhibitory concentration (MIC) of 41 representative isolates were tested and interpreted according to the Clinical and Laboratory Standards Institute broth microdilution method.
Results: All the isolates were triazole-susceptible on agar screening. MICs of three azole antifungals for 41 tested isolates were found to be ≤1 ml/L; all isolates tested were categorized as triazole-susceptible, including 4 isolates from patients previously on triazole therapy for more than two weeks. The minimum inhibitory concentration required to inhibit the growth of 90% organisms (MIC90) of itraconazole, voriconazole and posaconazole of the representative Aspergillus isolates was 1 mg/L, 1 mg/L and 0.5 mg/L, respectively.
Conclusion: Triazole resistance could not be detected amongst clinical Aspergillus isolates from the South of Pakistan. However, environmental strains remain to be tested for a holistic assessment of the situation. This study will set precedence for future periodic antifungal resistance surveillance in our region on Aspergillus isolates. Keywords: Aspergillosis, Aspergullus flavus, Aspergullus fumigatus, Aspergullus niger, Aspergullus terreus, itraconazole, voriconazole and posaconazole.
Keywords
Aspergillosis, Aspergullus flavus, Aspergullus fumigatus, Aspergullus niger, Aspergullus terreus, itraconazole, voriconazole and posaconazole
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View the published article at Antimicrobial Resistance & Infection Control.
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Editorial decision: Accept
On 04 May, 2020
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On 30 Mar, 2020
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On 29 Mar, 2020
Editor invited
On 29 Mar, 2020
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Posted 26 Nov, 2019
No comments provided
Editorial decision: Minor revision
On 02 Mar, 2020
Review #2 received
Received 26 Feb, 2020
Reviewer #2 agreed
On 11 Feb, 2020
Review #1 received
Received 30 Dec, 2019
Reviewer #1 agreed
On 15 Dec, 2019
Reviewers invited
Invitations sent on 11 Dec, 2019
Editor assigned
On 26 Nov, 2019
Editor invited
On 25 Nov, 2019
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On 22 Nov, 2019
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On 21 Nov, 2019
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This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
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This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
View the published article at Antimicrobial Resistance & Infection Control.
No community comments so far
Editorial decision: Accept
On 04 May, 2020
Editor assigned
On 30 Mar, 2020
Submission checks complete
On 29 Mar, 2020
Editor invited
On 29 Mar, 2020
Version 1
Posted 26 Nov, 2019
No comments provided
Editorial decision: Minor revision
On 02 Mar, 2020
Review #2 received
Received 26 Feb, 2020
Reviewer #2 agreed
On 11 Feb, 2020
Review #1 received
Received 30 Dec, 2019
Reviewer #1 agreed
On 15 Dec, 2019
Reviewers invited
Invitations sent on 11 Dec, 2019
Editor assigned
On 26 Nov, 2019
Editor invited
On 25 Nov, 2019
Submission checks complete
On 22 Nov, 2019
First submitted
On 21 Nov, 2019
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
General Microbiology
License:
This work is licensed under a CC BY 4.0 License. Read Full License
View the published article at Antimicrobial Resistance & Infection Control.
Background: Burden of aspergillosis is reported to be significant from developing countries including those in South Asia. The estimated burden in Pakistan is also high on the background of tuberculosis and chronic lung diseases. There is concern for management of aspergillosis with the emergence of azole resistant Aspergillus species in neighbouring countries in Central and South Asia. Hence the aim of this study was to screen significant Aspergillus species isolates at the Microbiology Section of Aga Khan Clinical Laboratories, Pakistan, for triazole resistance.
Methods: A descriptive cross-sectional study, conducted at the Aga Khan University Laboratories, Karachi, from September 2016-May 2019. One hundred and fourteen, clinically significant Aspergillus isolates [A. fumigatus (38; 33.3%), A. flavus (64; 56.1%), A. niger (9; 7.9%) A. terreus (3; 2.6%)] were included. The clinical spectrum ranged from invasive aspergillosis (IA) (n=25; 21.9%), chronic pulmonary aspergillosis (CPA) (n=58; 50.9%), allergic bronchopulmonary aspergillosis (ABPA) (n=4; 3.5%), severe asthma with fungal sensitization (SAFS) (n=4; 3.5%), saprophytic tracheobronchial aspergillosis (n=23; 20.2%). Screening for triazole resistance was performed by antifungal agar screening method. The minimum inhibitory concentration (MIC) of 41 representative isolates were tested and interpreted according to the Clinical and Laboratory Standards Institute broth microdilution method.
Results: All the isolates were triazole-susceptible on agar screening. MICs of three azole antifungals for 41 tested isolates were found to be ≤1 ml/L; all isolates tested were categorized as triazole-susceptible, including 4 isolates from patients previously on triazole therapy for more than two weeks. The minimum inhibitory concentration required to inhibit the growth of 90% organisms (MIC90) of itraconazole, voriconazole and posaconazole of the representative Aspergillus isolates was 1 mg/L, 1 mg/L and 0.5 mg/L, respectively.
Conclusion: Triazole resistance could not be detected amongst clinical Aspergillus isolates from the South of Pakistan. However, environmental strains remain to be tested for a holistic assessment of the situation. This study will set precedence for future periodic antifungal resistance surveillance in our region on Aspergillus isolates. Keywords: Aspergillosis, Aspergullus flavus, Aspergullus fumigatus, Aspergullus niger, Aspergullus terreus, itraconazole, voriconazole and posaconazole.
Figure 1
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