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Fulltext Species distribution and antifungal susceptibility patterns of Candida species: Is low susceptibility to itraconazole a trend in Malaysia?

Santhanam J, Yahaya N, Aziz MN

Med J Malaysia, 2013 Aug;68(4):343-7.
PMID: 24145264

Resistance to antifungal agents has increased in Candida spp., especially in non-albicans species. Recent findings reported a strikingly low susceptibility in Candida spp. towards itraconazole in Malaysia. In this study, a colorimetric broth dilution method was utilized to determine the susceptibility of Candida spp. isolated in Kuala Lumpur Hospital within a six month period. A total of 82 isolates from blood, peritoneal and other fluids were tested against 8 antifungal agents using the Sensititre Yeast One method. These comprised of 32 (39%) C. albicans, 17 (20.7%) C. glabrata, 15 (18.3%) C. tropicalis, 13 (15.9%) C. parapsilosis, two (2.4%) C. sake and 1 (1.2%) each of C. pelliculosa, C. rugosa and Pichia etchellsii/carsonii. Overall, susceptibility of all isolates to caspofungin was 98.8%, amphotericin B, 97.6%; 5-flucytosine, 97.6%; voriconazole, 97.6%; posaconazole, 87.8%; fluconazole, 82.9%; ketoconazole, 79.3%; and itraconazole, 56.1%. A total of 18 Candida spp. isolates (22 %) were resistant to at least one antifungal agent tested, and half of these were resistant to three or more antifungal agents. C. glabrata was the most frequently identified resistant species (10 isolates), followed by C. tropicalis (4 isolates), C. parapsilosis (3 isolates) and C. albicans (1 isolate). Resistance was highest against ketoconazole (20.9%), followed by itraconazole (13.4%). However, 30.5% of isolates were susceptible-dose dependent towards itraconazole. Long-term usage of itraconazole in Malaysia and a predominance of nonalbicans species may account for the results observed in this study. In conclusion, susceptibility to antifungal drugs is species-dependent among Candida spp.; reduced susceptibility to itraconazole is concomitant with the high number of non-albicans Candida species isolated in Malaysia.
Fulltext Polyketide and benzopyran compounds of an endophytic fungus isolated from Cinnamomum mollissimum: biological activity and structure

Santiago C, Sun L, Munro MH, Santhanam J

Asian Pac J Trop Biomed, 2014 Aug;4(8):627-32.
PMID: 25183332 DOI: 10.12980/APJTB.4.2014APJTB-2014-0030

To study bioactivity and compounds produced by an endophytic Phoma sp. fungus isolated from the medicinal plant Cinnamomum mollissimum.
Fulltext Single-tube seminested PCR assay for detecting human papillomavirus in clinical samples

Saini R, Santhanam J, Othman NH, Saini D, Tang TH

Open Microbiol J, 2009;3:106-12.
PMID: 19657463 DOI: 10.2174/1874285800903010106

There is a growing appreciation of the potential value for routine screening for the presence of HPV not only for cervical specimens but also from oral cavity. The purpose of this study was to develop and clinically evaluate a single-tube seminested PCR assay for the detection of HPV. Several parameters such as PCR primers, primer annealing temperature, the number of PCR cycles and concentration of PCR components were optimized. The assay was evaluated using HPV inserts of type 6, 11, 16, 18, 31, 33, 38 and 51. Evaluation of seminested PCR assay was performed with cervical scrapings from 30 patients and buccal swabs from 30 head and neck cancer patients and results were compared with those of two-tube nested PCR. The results were found to be comparable with a total of 60% (36/60) of samples being positive for HPV using the single-tube assay, while 62% (37/60) positivity was found with two-tube PCR assay. We succeeded in developing a single-tube seminested PCR method for HPV DNA detection which is easier than the conventional nested PCR and can be further evaluated as a potential screening tool for detecting HPV in oral and cervical regions.
Fulltext Evaluation of polymerase chain reaction (PCR) method and hybrid capture II (HCII) assay for the detection of human papillomavirus in cervical scrapings

Saini R, Shen TH, Othman NH, Santhanam J, Othman N, Tang TH

Med J Malaysia, 2007 Aug;62(3):206-9.
PMID: 18246908 MyJurnal

In order to investigate the reliability of detecting HPV DNA in cervical smears, we compared the performance of nested MY/GP PCR and FDA approved-Hybrid Capture II (HCII) using clinical cervical scrapings from 40 patients. It was found that PCR was more sensitive (81.8%) in comparison to HCII (36.4%) in detecting HPV although specificity of HCII was much higher (96.6%) than PCR (58.6%). The Negative Predictive Value (NPV) of both the techniques were quite similar but Positive Predictive Value (PPV) of HCII was much higher (80.0%) compared to PCR (42.9%). While the HCII method showed good specificity for HPV detection, its lack of sensitivity as compared to PCR may be a drawback for diagnostic use.
Determining the Pathogenic Potential of Non-sporulating Molds Isolated from Cutaneous Specimens

Jeyaprakasam NK, Razak MF, Ahmad NA, Santhanam J

Mycopathologia, 2016 Jun;181(5-6):397-403.
PMID: 26847667 DOI: 10.1007/s11046-016-9984-8

Although non-sporulating molds (NSM) are frequently isolated from patients and have been recognized as agents of pulmonary disease, their clinical significance in cutaneous specimens is relatively unknown. Therefore, this study aimed to identify NSM and to determine the keratinolytic activity of isolates from cutaneous sites. NSM isolates from clinical specimens such as skin, nail, and body fluids were identified based on their ribosomal DNA sequences. Of 17 NSM isolates (7 Ascomycota, 10 Basidiomycota), eleven were identified to species level while five were identified to the genus level. These include Schizophyllum commune, a known human pathogen, Phoma multirostrata, a plant pathogen, and Perenniporia tephropora, a saprophyte. To determine fungal pathogenicity, keratinolytic activity, a major virulence factor, was evaluated ex vivo using human nail samples by measuring dye release from keratin azure, for NSM along with pathogens (Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Fusarium spp.) and nonpathogenic (endophyte) fungi for comparison. This study showed that pathogenic fungi had the highest keratinolytic activity (7.13 ± 0.552 keratinase units) while the nonpathogenic endophytes had the lowest activity (2.37 ± 0.262 keratinase units). Keratinolytic activity of two Ascomycota NSM (Guignardia mangiferae and Hypoxylon sp.) and one Basidiomycota NSM (Fomitopsis cf. meliae) was equivalent to that of pathogenic fungi, while Xylaria feejeensis showed significantly higher activity (p
Fulltext PDR Transporter ABC1 Is Involved in the Innate Azole Resistance of the Human Fungal Pathogen Fusarium keratoplasticum

James JE, Lamping E, Santhanam J, Cannon RD

Front Microbiol, 2021;12:673206.
PMID: 34149660 DOI: 10.3389/fmicb.2021.673206

Fusarium keratoplasticum is arguably the most common Fusarium solani species complex (FSSC) species associated with human infections. Invasive fusariosis is a life-threatening fungal infection that is difficult to treat with conventional azole antifungals. Azole drug resistance is often caused by the increased expression of pleiotropic drug resistance (PDR) ATP-binding cassette (ABC) transporters of the ABCG sub-family. Most investigations of Fusarium ABC transporters associated with azole antifungal drug resistance are limited to plant pathogens. Through the manual curation of the entire ABCG protein family of four FSSC species including the fully annotated genome of the plant pathogen Nectria haematococca we identified PDR transporters ABC1 and ABC2 as the efflux pump candidates most likely to be associated with the innate azole resistance phenotype of Fusarium keratoplasticum. An initial investigation of the transcriptional response of logarithmic phase F. keratoplasticum cells to 16 mg/L voriconazole confirmed strong upregulation (372-fold) of ABC1 while ABC2 mRNA levels were unaffected by voriconazole exposure over a 4 h time-period. Overexpression of F. keratoplasticum ABC1 and ABC2 in the genetically modified Saccharomyces cerevisiae host ADΔΔ caused up to ∼1,024-fold increased resistance to a number of xenobiotics, including azole antifungals. Although ABC1 and ABC2 were only moderately (20% and 10%, respectively) expressed compared to the Candida albicans multidrug efflux pump CDR1, overexpression of F. keratoplasticum ABC1 caused even higher resistance levels to certain xenobiotics (e.g., rhodamine 6G and nigericin) than CDR1. Our investigations suggest an important role for ABC1 orthologues in the innate azole resistance phenotype of FSSC species.
Fulltext Cytotoxic and Antifungal Activities of 5-Hydroxyramulosin, a Compound Produced by an Endophytic Fungus Isolated from Cinnamomum mollisimum

Santiago C, Fitchett C, Munro MH, Jalil J, Santhanam J

Evid Based Complement Alternat Med, 2012;2012:689310.
PMID: 22454674 DOI: 10.1155/2012/689310

An endophytic fungus isolated from the plant Cinnamomum mollissimum was investigated for the bioactivity of its metabolites. The fungus, similar to a Phoma sp., was cultured in potato dextrose broth for two weeks, followed by extraction with ethyl acetate. The crude extract obtained was fractionated by high-performance liquid chromatography. Both crude extract and fractions were assayed for cytotoxicity against P388 murine leukemic cells and inhibition of bacterial and fungal pathogens. The bioactive extract fraction was purified further and characterized by nuclear magnetic resonance, mass spectral and X-ray crystallography analysis. A polyketide compound, 5-hydroxyramulosin, was identified as the constituent of the bioactive fungal extract fraction. This compound inhibited the fungal pathogen Aspergillus niger (IC(50) 1.56 μg/mL) and was cytotoxic against murine leukemia cells (IC(50) 2.10 μg/mL). 5-Hydroxyramulosin was the major compound produced by the endophytic fungus. This research suggests that fungal endophytes are a good source of bioactive metabolites which have potential applications in medicine.
Association of human papillomavirus with denture wearing

Saini R, Osman NB, Ismail M, Sobri FM, Tang TH, Santhanam J

J Investig Clin Dent, 2011 Nov;2(4):241-7.
PMID: 25426895 DOI: 10.1111/j.2041-1626.2011.00068.x

To determine the prevalence of human papillomavirus in the oral cavity of denture wearers.
Fulltext Comparison of DR. HPV Chip Kit with hybrid capture II assay for the detection of human papillomavirus in clinical samples: a preliminary study

Rajan S, Shen TH, Santhanam J, Othman NH, Othman N, Hock TT

Trop Biomed, 2007 Jun;24(1):17-22.
PMID: 17568373

Human papillomavirus (HPV) is well known as an etiological factor for the development of anogenital carcinomas. The aim of our study was to compare the performance of USFDA approved Hybrid II (HCII) Assay and recently introduced DR. HPV Chip Kit for the detection of HPV DNA in clinical cervical scrapings from 40 patients. HPV DNA testing was performed using the automated HCII Assay system and DR. HPV Chip Kit. Taking cytological results as gold standard, it was found that HCII was more sensitive (36.4%) than DR. HPV Chip Kit (18.2%) although specificity was 100% with the latter method. In addition, both these molecular methods had comparable negative and positive predictive values. It was concluded that both HCII and DR. HPV Chip Kit have comparable specificity. However, sensitivity for detection of HPV in clinical samples with HCII is almost double as compared to DR. HPV Chip Kit.
Fulltext A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

James JE, Lamping E, Santhanam J, Milne TJ, Abd Razak MF, Zakaria L, et al.

Front Microbiol, 2020;11:272.
PMID: 32296397 DOI: 10.3389/fmicb.2020.00272

In the fungal pathogen Aspergillus fumigatus, resistance to azole antifungals is often linked to mutations in CYP51A, a gene that encodes the azole antifungal drug target lanosterol 14α-demethylase. The aim of this study was to investigate whether similar changes could be associated with azole resistance in a Malaysian Fusarium solani species complex (FSSC) isolate collection. Most (11 of 15) clinical FSSC isolates were Neocosmospora keratoplastica and the majority (6 of 10) of environmental isolates were Neocosmospora suttoniana strains. All 25 FSSC isolates had high minimum inhibitory concentrations (MICs) for itraconazole and posaconazole, low MICs for amphotericin B, and various (1 to >32 mg/l) voriconazole susceptibilities. There was a tight association between a 23 bp CYP51A promoter deletion and high (>32 mg/l) voriconazole MICs; of 19 FSSC strains sequenced, nine isolates had voriconazole MICs > 32 mg/l, and they all contained the 23 bp CYP51A promoter deletion, although it was absent in the ten remaining isolates with low (≤12 mg/l) voriconazole MICs. Surprisingly, this association between voriconazole resistance and the 23 bp CYP51A promoter deletion held true across species boundaries. It was randomly distributed within and across species boundaries and both types of FSSC isolates were found among environmental and clinical isolates. Three randomly selected N. keratoplastica isolates with low (≤8 mg/l) voriconazole MICs had significantly lower (1.3-7.5 times) CYP51A mRNA expression levels than three randomly selected N. keratoplastica isolates with high (>32 mg/l) voriconazole MICs. CYP51A expression levels, however, were equally strongly induced (~6,500-fold) by voriconazole in two representative strains reaching levels, after 80 min of induction, that were comparable to those of CYP51B. Our results suggest that FSSC isolates with high voriconazole MICs have a 23 bp CYP51A promoter deletion that provides a potentially useful marker for voriconazole resistance in FSSC isolates. Early detection of possible voriconazole resistance is critical for choosing the correct treatment option for patients with invasive fusariosis.
In Vitro Antifungal Susceptibility of Neoscytalidium dimidiatum Clinical Isolates from Malaysia

James JE, Santhanam J, Lee MC, Wong CX, Sabaratnam P, Yusoff H, et al.

Mycopathologia, 2017 Apr;182(3-4):305-313.
PMID: 27815659 DOI: 10.1007/s11046-016-0085-5

Neoscytalidium dimidiatum is an opportunistic fungus causing cutaneous infections mostly, which are difficult to treat due to antifungal resistance. In Malaysia, N. dimidiatum is associated with skin and nail infections, especially in the elderly. These infections may be mistaken for dermatophyte infections due to similar clinical appearance. In this study, Neoscytalidium isolates from cutaneous specimens, identified using morphological and molecular methods (28 Neoscytalidium dimidiatum and 1 Neoscytalidium sp.), were evaluated for susceptibility towards antifungal agents using the CLSI broth microdilution (M38-A2) and Etest methods. Amphotericin B, voriconazole, miconazole and clotrimazole showed high in vitro activity against all isolates with MIC ranging from 0.0313 to 1 µg/mL. Susceptibility towards fluconazole and itraconazole was noted in up to 10% of isolates, while ketoconazole was inactive against all isolates. Clinical breakpoints for antifungal drugs are not yet available for most filamentous fungi, including Neoscytalidium species. However, the results indicate that clinical isolates of N. dimidiatum in Malaysia were sensitive towards miconazole, clotrimazole, voriconazole and amphotericin B, in vitro.
Molecular epidemiology of Sporothrix schenkii isolates in Malaysia

Kamal Azam NK, Selvarajah GT, Santhanam J, Abdul Razak MF, Ginsapu SJ, James JE, et al.

Med Mycol, 2020 Jul 01;58(5):617-625.
PMID: 31642485 DOI: 10.1093/mmy/myz106

Sporothrix schenkii is a dimorphic fungus that causes infections in both humans and animals. We report on 25 S. schenkii isolates collected in 2017 from humans and cats clinically diagnosed with sporotrichosis, in Malaysia. These isolates were phenotypically identified as S. schenkii sensu lato and further defined as S. schenckii sensu stricto based on partial calmodulin gene sequence. Isolates from both humans and cats were genotypically identical but displayed phenotypic variation. Phylogenetic analyses based on partial calmodulin sequence showed that the Malaysian isolates clustered with global S. schenkii sensu stricto strains, in particular, of the AFLP type E. This analysis also revealed that partial calmodulin sequence alone was sufficient for classifying global S. schenckii sensu stricto strains into their respective AFLP types, from A to E. The genetically conserved S. schenkii sensu stricto species isolated from humans and cats is suggestive of a clonal strain present in Malaysia. To the best of our knowledge, this is the first report on molecular identification of Sporothrix schenkii strains from human infections in Malaysia. Further studies are required in order to elucidate the clonal nature of Malaysian S. schenkii isolates. Our findings indicate the presence of a predominant S. schenkii genotype in the environment, causing infections in both cats and humans in Malaysia.
Fulltext In Vitro Antifungal Activities against Moulds Isolated from Dermatological Specimens

Mohd Nizam T, Binting RA, Mohd Saari S, Kumar TV, Muhammad M, Satim H, et al.

Malays J Med Sci, 2016 May;23(3):32-9.
PMID: 27418867 MyJurnal

This study aimed to determine the minimum inhibitory concentrations (MICs) of various antifungal agents against moulds isolated from dermatological specimens.
Significant association of high-risk human papillomavirus (HPV) but not of p53 polymorphisms with oral squamous cell carcinomas in Malaysia

Saini R, Tang TH, Zain RB, Cheong SC, Musa KI, Saini D, et al.

J Cancer Res Clin Oncol, 2011 Feb;137(2):311-20.
PMID: 20419384 DOI: 10.1007/s00432-010-0886-8

PURPOSE: The purpose of this study was to evaluate the role of HPV and p53 polymorphisms in oral squamous cell carcinomas (OSCC) affecting Malaysian population.
METHODS: We analysed frozen samples from 105 OSCC as well as 105 oral specimens derived from healthy individuals. PCR assays targeting two regions of the virus were used. PCR amplification for the analysis of p53 codon 72 arginine/proline alleles was carried out in a separate reaction.
RESULTS: HPV DNA was detected in 51.4% OSCC samples, while 24.8% controls were found to be HPV positive. HPV was found to be significantly associated with OSCC (P

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