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First Report of Marasmiellus palmivorus Causing Post-Emergence Damping Off on Coconut Seedlings in Malaysia

Almaliky BSA, Abidin MAZ, Kader J, Wong MY

Plant Dis, 2013 Jan;97(1):143.
PMID: 30722276 DOI: 10.1094/PDIS-07-12-0627-PDN

In April and June 2010, coconut seedlings with symptoms of very slow growth, yellowing of leaves, and general abnormal leaf growth were observed in germination beds in Teluk Intan, Perak, Malaysia. The roots were soft, rotten, and brown, extending upward and downward from these lesions. Rhizomorphs and basidiocarps were produced on coconut seeds near the germination eye and identified as Marasmiellus palmivorus according description by Turner (2). Three isolates were obtained by plating surface sterilized symptomatic roots and basidiocarp on malt extract agar (MEA) amended with 85% lactic acid (1 ml added to 11 of the medium). To confirm the identity of the fungus, genomic DNA was extracted from mycelia and basidiocarps of isolates and the large subunit (LSU) region was amplified and sequenced using LR0R/LR7 primers (3). All isolates had identical LSU sequences (GenBank Accession No. JQ654233 to JQ654235). Sequences were identical to each other and 99% similar to a M. palmivorus sequence deposited in the NCBI database (Accession No. AY639434).To confirm pathogenicity, three isolates of M. palmivorus that were obtained from symptomatic plant tissue was inoculated onto seeds of Malaysian Red Dwarf variety. Each isolate was grown in 100 ml of malt extract broth in 250 ml Erlenmeyer flasks and incubated at 27 ± 2°C for 5 days on an orbital shaker (125 rpm). The resulting culture was passed through two layers of sterile cloth. Mycelial suspension was obtained by blending mycelia in 100 ml of sterile water. Seeds were sterilized by soaking in 10% v/v sodium hypochlorite in distilled water for 3 min. The seeds were then rinsed three times over running tap water. The calyx portion of the seed was removed and five holes were made around the germination eye. The seeds were inoculated by injecting 2 ml of suspension into each hole. The control seeds were inoculated with sterile distilled water only. The seeds were transferred to 40-cm diameter plastic pots containing a mixture of sand, soil, and peat in the ratio of 3:2:1, respectively, and steam treated at 100°C for 1.5 h. Pots were placed in the glasshouse with normal exposures to day-night cycles, temperatures of 29 ± 4°C, and high relative humidity (85 to 95%) achieved by spraying water twice daily. After 2 months, 75% of the inoculated seeds failed to germinate. It was speculated that the artificial inoculum was higher than under germination bed conditions. Rhizomorphs and basidiocarps were produced on husk seeds near the germination eye. Seedlings that emerged successfully developed symptoms similar to those observed in the germination bed. No symptoms developed in the noninoculated seeds and seedlings. At 80 days post inoculation, basidiocarps were observed emerging from three diseased seedlings near the germination eye. Three reisolations were made on MEA from root lesions surface sterilized. Pathogenicity tests and LSU sequence analyses indicated that M. palmivorus is the causal agent of the symptoms observed on coconut seedlings. M. palmivorus was first recorded on coconuts and oil palm in the 1920s (1) and attacks the fruit and the petiole on oil palm (2). To our knowledge, this is the first report of M. palmivorus causing post-emergence damping off on coconut seedlings. References: (1) K. G. Singh. A check-list of host and diseases in Malaysia. Ministry of Agriculture and Fisheries, Malaysia, 1973. (2) P. D. Turner. Oil palm diseases and disorders. Oxford University Press. 1981. (3) R. Vilgalys et al. J. Bacteriol. 172:4238, 1990.
First Report of Soft Rot Disease Caused by Pectobacterium wasabiae on Sweet Potato, Tomato, and Eggplant in Malaysia

Golkhandan E, Kamaruzaman S, Sariah M, Abidin MAZ, Nazerian E, Yassoralipour A

Plant Dis, 2013 May;97(5):685.
PMID: 30722205 DOI: 10.1094/PDIS-08-12-0759-PDN

In August 2011, sweet potato (Ipomoea batatas), tomato (Solanum lycopersicum), and eggplant (S. melongena) crops from major growing areas of the Cameron highlands and Johor state in Malaysia were affected by a soft rot disease. Disease incidence exceeded 80, 75, and 65% in severely infected fields and greenhouses of sweet potato, tomato, and eggplant, respectively. The disease was characterized by dark and small water-soaked lesions or soft rot symptoms on sweet potato tubers, tomato stems, and eggplant fruits. In addition, extensive discoloration of vascular tissues, stem hollowness, and water-soaked, soft, dark green lesions that turned brown with age were observed on the stem of tomato and eggplant. A survey was performed in these growing areas and 22 isolates of the pathogen were obtained from sweet potato (12 isolates), tomato (6 isolates), and eggplant (4 isolates) on nutrient agar (NA) and eosin methylene blue (EMB) (4). The cultures were incubated at 27°C for 2 days and colonies that were emerald green on EMB or white to gray on NA were selected for further studies. All bacterial cultures isolated from the survey exhibited pectolytic ability on potato slices. These bacterial isolates were gram negative; rod shaped; N-acetylglucosaminyl transferase, gelatin liquefaction, and OPNG positive; and were also positive for acid production from D-galactose, lactosemelibiose, raffinose, citrate, and trehalose. They were negative for indol production, phosphatase activity, reducing substances from sucrose, and negative for acid production from maltose, sorbitol, inositol, inolin, melezitose, α-mathyl-D-glocoside, and D-arabitol. The bacteria did not grow on NA at 37°C. Based on these biochemical and morphological assays, the pathogen was identified as Pectobacterium wasabiae (2). In addition, DNA was extracted and PCR assay with two primers (16SF1 and 16SR1) was performed (4). Partial sequences of 16S rRNA (GenBank Accession Nos. JQ665714, JX494234, and JX513960) of sweet potato, tomato, and eggplant, respectively, exhibited a 99% identity with P. wasabiae strain SR91 (NR_026047 and NR_026047.1). A pathogenicity assay was carried out on sweet potato tubers (cv. Oren), tomato stems (cv. 152177-A), and eggplant fruits (cv. 125066x) with 4 randomly representative isolates obtained from each crop. Sweet potato tubers, tomato stems, and eggplant fruits (4 replications) were sanitized in 70% ethyl alcohol for 30 s, washed and rinsed in sterile distilled water, and needle punctured with a bacterial suspension at a concentration of 108 CFU/ml. Inoculated tubers, stems, and fruits were incubated in a moist chamber at 90 to 100% RH for 72 h at 25°C when lesions were measured. All inoculated tubers, stems, and fruits exhibited soft rot symptoms after 72 h similar to those observed in the fields and greenhouses and the same bacteria were consistently reisolated. Symptoms were not observed on controls. The pathogenicty test was repeated with similar results. P. wasabiae have been previously reported to cause soft rot on Japanese horseradish (3), and aerial stem rot on potato in New Zealand (4), the U.S. (2), and Iran (1). To our knowledge, this is the first report of sweet potato, tomato, and eggplant soft rot caused by P. wasabiae in Malaysia. References: (1) S. Baghaee-Ravari et al. Eur. J. Plant Pathol. 129:413, 2011. (2) S. De Boer and A. Kelman. Page 56 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria, 3rd ed. N. Schaad et al., eds. APS Press, St. Paul, 2001. (3) M. Goto et al. Int. J. Syst. Bacteriol. 37:130, 1987. (4) A. R. Pitman et al. Eur. J. Plant Pathol. 126:423, 2010.
First Report of Tomato Gray Leaf Spot Disease Caused by Stemphylium solani in Malaysia

Nasehi A, Kadir JB, Abidin MAZ, Wong MY, Mahmodi F

Plant Dis, 2012 Aug;96(8):1226.
PMID: 30727066 DOI: 10.1094/PDIS-03-12-0223-PDN

In June 2011, tomatoes (Solanum lycopersicum) in major growing areas of the Cameron Highlands and the Johor state in Malaysia were affected by a leaf spot disease. Disease incidence exceeded 80% in some severely infected regions. Symptoms on 50 observed plants initially appeared on leaves as small, brownish black specks, which later became grayish brown, angular lesions surrounded by a yellow border. As the lesions matured, the affected leaves dried up and became brittle and later developed cracks in the center of the lesions. A survey was performed in these growing areas and 27 isolates of the pathogen were isolated from the tomato leaves on potato carrot agar (PCA). The isolates were purified by the single spore technique and were transferred onto PCA and V8 agar media for conidiophore and conidia production under alternating light (8 hours per day) and darkness (16 hours per day) (4). Colonies on PCA and V8 agar exhibited grey mycelium and numerous conidia were formed at the terminal end of conidiophores. The conidiophores were up to 240 μm long. Conidia were oblong with 2 to 11 transverse and 1 to 6 longitudinal septa and were 24 to 69.6 μm long × 9.6 to 14.4 μm wide. The pathogen was identified as Stemphylium solani on the basis of morphological criteria (2). In addition, DNA was extracted and the internal transcribed spacer region (ITS) was amplified by universal primers ITS5 and ITS4 (1). The PCR product was purified by the commercial PCR purification kit and the purified PCR product sequenced. The resulting sequences were 100% identical to published S. solani sequences (GenBank Accestion Nos. AF203451 and HQ840713). The amplified ITS region was deposited with NCBI GenBank under Accession No. JQ657726. A representative isolate of the pathogen was inoculated on detached 45-day-old tomato leaves of Malaysian cultivar 152177-A for pathogenicity testing. One wounded and two nonwounded leaflets per leaf were used in this experiment. The leaves were wounded by applying pressure to leaf blades with the serrated edge of a forceps. A 20-μl drop of conidial suspension containing 105 conidia/ml was used to inoculate these leaves (3). The inoculated leaves were placed on moist filter paper in petri dishes and incubated for 48 h at 25°C. Control leaves were inoculated with sterilized distilled water. After 7 days, typical symptoms for S. solani similar to those observed in the farmers' fields developed on both wounded and nonwounded inoculated leaves, but not on noninoculated controls, and S. solani was consistently reisolated. To our knowledge, this is the first report of S. solani causing gray leaf spot of tomato in Malaysia. References: (1) M. P. S. Camara et al. Mycologia 94:660, 2002. (2) B. S. Kim et al. Plant Pathol. J. 15:348, 1999. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) E. G. Simmons. CBS Biodiversity Series 6:775, 2007.
First Report of Alternaria tenuissima Causing Leaf Spot on Eggplant in Malaysia

Nasehi A, Kadir JB, Abidin MAZ, Wong MY, Mahmodi F

Plant Dis, 2012 Aug;96(8):1226.
PMID: 30727083 DOI: 10.1094/PDIS-03-12-0237-PDN

A leaf spot on eggplant (Solanum melongena) was observed in major eggplant growing regions in Malaysia, including the Cameron Highlands and Johor State, during 2011. Disease incidence averaged approximately 30% in severely infected regions in about 150 ha of eggplant fields and greenhouses examined. Early symptoms consisted of small, circular, brown, necrotic spots uniformly distributed on leaves. The spots gradually enlarged and developed concentric rings. Eventually, the spots coalesced and caused extensive leaf senescence. A fungus was recovered consistently by plating surface-sterilized (1% NaOCl) sections of symptomatic leaf tissue onto potato dextrose agar (PDA). For conidial production, the fungus was grown on potato carrot agar (PCA) and V8 agar media under a 16-h/8-h dark/light photoperiod at 25°C (4). Fungal colonies were a dark olive color with loose, cottony mycelium. Simple conidiophores were ≤120 μm long and produced numerous conidia in long chains. Conidia averaged 20.0 × 7.5 μm and contained two to five transverse septa and the occasional longitudinal septum. Twelve isolates of the fungus were identified as Alternaria tenuissima on the basis of morphological characterization (4). Confirmation of the species identification was obtained by molecular characterization of the internal transcribed spacer (ITS) region of rDNA amplified from DNA extracted from a representative isolate using universal primers ITS4 and ITS5 (2). The 558 bp DNA band amplified was sent for direct sequencing. The sequence (GenBank Accession No. JQ736021) was subjected to BLAST analysis (1) and was 99% identical to published ITS rDNA sequences of isolates of A. tenuissima (GenBank Accession Nos. DQ323692 and AY154712). Pathogenicity tests were performed by inoculating four detached leaves from 45-day-old plants of the eggplant cv. 125066x with 20 μl drops (three drops/leaf) of a conidial suspension containing 105 conidia/ml in sterile distilled water. Four control leaves were inoculated with sterile water. Leaves inoculated with the fungus and those treated with sterile water were incubated in chambers at 25°C and 95% RH with a 12-h photoperiod/day (2). Leaf spot symptoms typical of those caused by A. tenuissima developed on leaves inoculated with the fungus 7 days after inoculation, and the fungus was consistently reisolated from these leaves. The control leaves remained asymptomatic and the pathogen was not reisolated from the leaves. The pathogenicity test was repeated with similar results. To our knowledge, this is the first report of A. tenuissima causing a leaf spot on eggplant in Malaysia. A. tenuissima has been reported to cause leaf spot and fruit rot on eggplant in India (3). References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (3) P. Raja et al. New Disease Rep. 12:31, 2005. (4) E. G. Simmons. Page 1 in: Alternaria Biology, Plant Diseases and Metabolites. J. Chelchowski and A. Visconti, eds. Elsevier, Amsterdam, 1992.
First Report of Gray Leaf Spot on Pepper Caused by Stemphylium solani in Malaysia

Nasehi A, Kadir JB, Abidin MAZ, Wong MY, Ashtiani FA

Plant Dis, 2012 Aug;96(8):1227.
PMID: 30727084 DOI: 10.1094/PDIS-03-12-0262-PDN

Symptoms of gray leaf spot were first observed in June 2011 on pepper (Capsicum annuum) plants cultivated in the Cameron Highlands and Johor State, the two main regions of pepper production in Malaysia (about 1,000 ha). Disease incidence exceeded 70% in severely infected fields and greenhouses. Symptoms initially appeared as tiny (average 1.3 mm in diameter), round, orange-brown spots on the leaves, with the center of each spot turning gray to white as the disease developed, and the margin of each spot remaining dark brown. A fungus was isolated consistently from the lesions using sections of symptomatic leaf tissue surface-sterilized in 1% NaOCl for 2 min, rinsed in sterile water, dried, and plated onto PDA and V8 agar media (3). After 7 days, the fungal colonies were gray, dematiaceous conidia had formed at the end of long conidiophores (19.2 to 33.6 × 12.0 to 21.6 μm), and the conidia typically had two to six transverse and one to four longitudinal septa. Fifteen isolates were identified as Stemphylium solani on the basis of morphological criteria described by Kim et al. (3). The universal primers ITS5 and ITS4 were used to amplify the internal transcribed spacer region (ITS1, 5.8, and ITS2) of ribosomal DNA (rDNA) of a representative isolate (2). A 570 bp fragment was amplified, purified, sequenced, and identified as S. solani using a BLAST search with 100% identity to the published ITS sequence of an S. solani isolate in GenBank (1). The sequence was deposited in GenBank (Accession No. JQ736024). Pathogenicity of the fungal isolate was tested by inoculating healthy pepper leaves of cv. 152177-A. A 20-μl drop of conidial suspension (105 spores/ml) was used to inoculate each of four detached, 45-day-old pepper leaves placed on moist filter papers in petri dishes (4). Four control leaves were inoculated similarly with sterilized, distilled water. The leaves were incubated at 25°C at 95% relative humidity for 7 days. Gray leaf spot symptoms similar to those observed on the original pepper plants began to develop on leaves inoculated with the fungus after 3 days, and S. solani was consistently reisolated from the leaves. Control leaves did not develop symptoms and the fungus was not reisolated from these leaves. Pathogenicity testing was repeated with the same results. To our knowledge, this is the first report of S. solani causing gray leaf spot on pepper in Malaysia. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) M. P. S. Camara et al. Mycologia 94:660, 2002. (3) B. S. Kim et al. Plant Pathol. J. 15:348, 1999. (4) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002.
Fulltext Glycemic Patterns and Factors Associated with Post-Hemodialysis Hyperglycemia among End-Stage Renal Disease Patients undergoing Maintenance Hemodialysis

Khan AHKY, Zakaria NF, Abidin MAZ, Lim CTS, Kamaruddin NA

J ASEAN Fed Endocr Soc, 2020;35(1):68-76.
PMID: 33442172 DOI: 10.15605/jafes.035.01.12

Introduction: Chronic and post-prandial hyperglycemia are independent risk factors for diabetic complications. Glycemic patterns among hemodialysis end-stage-renal-disease (ESRD) differ as glucose metabolism changes with declining kidney function with more pronounced glycemic fluctuations. The objectives of this study are to determine glycemic patterns on hemodialysis days, the magnitude of post-hemodialysis rebound hyperglycemia (PHH) and their associated factors.
Methodology: 148 patients on hemodialysis were analysed, 91 patients had end-stage-diabetic-renal disease (DM-ESRD), and 57 patients had end-stage-non-diabetic renal disease (NDM-ESRD). Glycemic patterns and PHH data were obtained from 11-point and 7-point self-monitoring blood glucose (SMBG) profiles on hemodialysis and non-hemodialysis days. PHH and its associated factors were analysed with logistic regression.
Results: Mean blood glucose on hemodialysis days was 9.33 [SD 2.7] mmol/L in DM-ESRD patients compared to 6.07 [SD 0.85] mmol/L in those with NDM-ESRD (p<0.001). PHH occurred in 70% of patients and was more pronounced in DM-ESRD compared to NDM-ESRD patients (72.5% vs 27.5%; OR 4.5). Asymptomatic hypoglycemia was observed in 18% of patients. DM-ESRD, older age, previous IHD, obesity, high HbA1c, elevated highly-sensitive CRP and low albumin were associated with PHH.
Conclusion: DM-ESRD patients experienced significant PHH in our cohort. Other associated factors include older age, previous IHD, obesity, high HbA1c, elevated hs-CRP and low albumin.
Cross-reactivity analysis of milk proteins from different goat breeds with cow's milk allergens using a proteomic approach

Mansor M, Al-Obaidi JR, Ismail IH, Abidin MAZ, Zakaria AF, Lau BYC, et al.

Mol Immunol, 2023 Mar;155:44-57.
PMID: 36696839 DOI: 10.1016/j.molimm.2022.12.016

INTRODUCTION: Goat's milk thought to be a good substitute for cow's milk protein allergic (CMPA) individuals. However, there is growing evidence that their proteins have cross-reactivities with cow's milk allergens. This study aimed to profile and compare milk proteins from different goat breeds that have cross-reactivity to cow's milk allergens.
METHODOLOGY: Proteomics was used to compare protein extracts of skim milk from Saanen, Jamnapari, and Toggenburg. Cow's milk was used as a control. IgE-immunoblotting and mass spectrometry were used to compare and identify proteins that cross-reacted with serum IgE from CMPA patients (n = 10).
RESULTS: The analysis of IgE-reactive proteins revealed that the protein spots identified with high confidence were proteins homologous to common cow's milk allergens such as α-S1-casein (αS1-CN), β-casein (β-CN), κ-casein (κ-CN), and beta-lactoglobulin (β-LG). Jamnapari's milk proteins were found to cross-react with four major milk allergens: α-S1-CN, β-CN, κ-CN, and β-LG. Saanen goat's milk proteins, on the other hand, cross-reacted with two major milk allergens, α-S1-CN and β-LG, whereas Toggenburg goat's milk proteins only react with one of the major milk allergens, κ-CN.
CONCLUSION: These findings may help in the development of hypoallergenic goat milk through cross-breeding strategies of goat breeds with lower allergenic milk protein contents.
Fulltext Clinical and demographic pattern of chronic granulomatous disease (CGD) from a multicenter perspective: Malaysia's experience over 26 years

Noh LM, Latiff AHA, Ismail IH, Noah RM, Wahab AA, Hamid IJA, et al.

Allergy Asthma Clin Immunol, 2021 May 17;17(1):50.
PMID: 34001231 DOI: 10.1186/s13223-021-00551-4

BACKGROUND: A retrospective review of clinical manifestations and demographic pattern of patients diagnosed as chronic granulomatous disease (CGD) from 7 hospitals in Malaysia. An analysis of the available database would establish clinical characteristics, diagnoses and outcome including microbiologic pattern. Studying the demography allows us to document the occurrence of CGD amongst multiethnic groups and its geographical distribution for Malaysia.
METHODS: Data from the Malaysia Primary Immunodeficiency Network (MyPIN) with cases of CGD diagnosed from 1991 until 2016 were collated and analysed.
RESULTS: Twenty patients were diagnosed as CGD. Males (N = 13, 65%) outnumber females (N = 7, 35%). CGD is commonest amongst the Malays (65%) followed by the Chinese (15.0%), Indians (10.0%) and natives of Borneo (10.0%), reflecting the ethnic composition of the country. The mean age of diagnosis was 3.7 years. There was a positive family history in 40% of the cases. Abscess was the main presenting feature in 16 patients (80%) with one involving the brain. Pneumonia occurred in 10 (50%) and one with complicated bronchiectasis. Catalase-positive bacteria were the most commonly isolated pathogen with Chromobacterium violaceum predominating (N = 5, 25%) with consequent high mortality (N = 4, 80%). All CGD patients with C. violaceum infection displayed CD4 + (T helper cells) lymphopenia.
CONCLUSION: This study has shown CGD occurs in the major ethnic groups of Malaysia. To the best of our knowledge, this is the first and the largest series of chronic granulomatous disease in South East Asia which may be reflective of similar clinical pattern in the region. C. violaceum infection is associated with a higher mortality in CGD patients in Malaysia. All the CGD patients with C. violaceum infection in this patient series displayed CD4 + (T helper) lymphopenia. We recorded rare clinical manifestation of CGD viz. brain abscess and bronchiectasis.