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Fulltext Epidemiology of fungal infections at an infectious disease reference centre in Malaysia

Tzar, M.N., Suhaila, B., Shamsul, A.S., Azizah, M.

International Medical Journal Malaysia, 2013;12(1):39-42.
MyJurnal

Introduction: Epidemiology of fungal infections in an infectious disease reference centre is different from other institutions. This study aimed to look at the scenario of fungal infections at an infectious disease reference centre in Malaysia. Methods: All positive fungal cultures from an infectious disease reference centre were identified by routine mycology laboratory methods. Patient demographic, laboratory and clinical data were collected and analyzed. Duplicate data were excluded. Results: Middle-aged Malay males were the most common group. However, increased proportions of Chinese, Myanmar and Indonesians reduced the Malay predominance in HIV-positive group. In all patients, Candida species represented 64.1% isolates, followed by Cryptococcus neoformans (14.7%) and Penicillium marneffei (14.7%). Among HIVpositive individuals, C. neoformans (37.9%) was the most common species, followed by P. marneffei (35.6%) and all Candida species (17.2%). In contrast to other non-infectious disease reference centres, common causes of fungaemia included P. marneffei (43.5%), Candida species (25.8%), C. neoformans (24.2%) and H. capsulatum (6.5%). Conclusion: The prevalence of fungal infection at an infectious disease reference centre is different from other non-infectious disease reference centres. This may have an impact on current antifungal practice especially empiric antifungal therapy, patient morbidity and mortality.

Matched MeSH terms: Cryptococcus neoformans
Fulltext Cell surface proteins of cryptococcus neoformans mediate adherence and internalisation into mammalian cells

Choo, K.K., Chin, V.K., Chong, P.P., Ho, S.H., Yong, V.C.

JUMMEC, 2019;22(2):24-30.
MyJurnal

Cryptococcus neoformans is an encapsulated fungal pathogen that causes severe disease primarily in
immunocompromised patients. Adherence and internalisation of microbial pathogens into host cells often
begin with engagement of microbes to the surface receptors of host. However, the mechanisms involved
remain poorly understood. In this study, we investigated the association of cell surface determinants of C.
neoformans with mammalian cells. Our results showed that treatment with trypsin, but not paraformaldehyde
or heat killing, could reduce host-cryptococci interaction, suggesting the involvement of cell surface proteins
(CSPs) of C. neoformans in the interaction. We extended our investigations to determine the roles of CSPs
during cryptococci-host cells interaction by extracting and conjugating CSPs of C. neoformans to latex beads.
Conjugation of CSPs with both encapsulated and acapsular C. neoformans increased the association of latex
beads with mammalian alveolar epithelial cells, alveolar macrophages and monocyte-derived macrophages.
Further examination on the actin organisation of the host cells implied the involvement of actin-dependent
phagocytosis in the internalisation of C. neoformans in CSP-conjugated latex beads. We hypothesised that
CSPs present on the cell wall of C. neoformans mediate the adherence and actin-dependent phagocytosis
of cryptococci by mammalian cells. Our results warrant further studies on the exact role of CSPs in the
pathogenesis of cryptococcosis.

Matched MeSH terms: Cryptococcus neoformans
Detection of IgM and IgG antibodies to Cryptococcus neoformans proteins in blood donors and HIV patients with active cryptococcosis

Chai HC, Tay ST

Mycoses, 2009 Mar;52(2):166-70.
PMID: 18643920 DOI: 10.1111/j.1439-0507.2008.01549.x

The serological responses to Cryptococcus neoformans proteins of blood donors and HIV patients with active cryptococcosis from a tropical region were investigated in this study. Exposure to C. neoformans, an organism ubiquitous in the environment, contributes to the antibody responses observed in the blood donors. IgG responses to cryptococcal proteins were stronger than IgM responses in most sera tested in this study. A 53-kDa cryptococcal protein fragment was identified as the most immunoreactive protein on the IgM immunoblots of both blood donors and patients. Overall, there was no obvious difference in IgG responses of patients when compared with blood donors. Some immunogenic protein fragments (27.5, 76, 78 and 91.5 kDa) were detected at least two times more frequently on IgM immunoblots of patients compared with those of blood donors. It is yet to be investigated whether the proteins identified in this study may have any potential to be used as biomarker for cryptococcosis.

Matched MeSH terms: Cryptococcus neoformans/immunology*
Fulltext Tuberculous meningitis is a major cause of mortality and morbidity in adults with central nervous system infections in Kota Kinabalu, Sabah, Malaysia: an observational study

Lee HG, William T, Menon J, Ralph AP, Ooi EE, Hou Y, et al.

BMC Infect Dis, 2016 06 16;16:296.
PMID: 27306100 DOI: 10.1186/s12879-016-1640-x

BACKGROUND: Central nervous system (CNS) infections are a significant contributor to morbidity and mortality globally. However, most published studies have been conducted in developed countries where the epidemiology and aetiology differ significantly from less developed areas. Additionally, there may be regional differences due to variation in the socio-economic levels, public health services and vaccination policies. Currently, no prospective studies have been conducted in Sabah, East Malaysia to define the epidemiology and aetiology of CNS infections. A better understanding of these is essential for the development of local guidelines for diagnosis and management.
METHODS: We conducted a prospective observational cohort study in patients aged 12 years and older with suspected central nervous system infections at Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia between February 2012 and March 2013. Cerebrospinal fluid was sent for microscopy, biochemistry, bacterial and mycobacterial cultures, Mycobacterium tuberculosis polymerase chain reaction (PCR), and multiplex and MassCode PCR for various viral and bacterial pathogens.
RESULTS: A total of 84 patients with clinically suspected meningitis and encephalitis were enrolled. An aetiological agent was confirmed in 37/84 (44 %) of the patients. The most common diagnoses were tuberculous meningitis (TBM) (41/84, 48.8 %) and cryptococcal meningoencephalitis (14/84, 16.6 %). Mycobacterium tuberculosis was confirmed in 13/41 (31.7 %) clinically diagnosed TBM patients by cerebrospinal fluid PCR or culture. The acute case fatality rate during hospital admission was 16/84 (19 %) in all patients, 4/43 (9 %) in non-TBM, and 12/41 (29 %) in TBM patients respectively (p = 0.02).
CONCLUSION: TBM is the most common cause of CNS infection in patients aged 12 years or older in Kota Kinabalu, Sabah, Malaysia and is associated with high mortality and morbidity. Further studies are required to improve the management and outcome of TBM.

Matched MeSH terms: Cryptococcus neoformans/genetics; Cryptococcus neoformans/isolation & purification
Fulltext Cryptococcal Meningitis in an immunocompetent Swiftlet Rancher – first reported case

Tan, Sin Nee, Lim, Thiam Seong Christopher

Malaysian Journal of Medicine and Health Sciences, 2019;15(1):82-84.
MyJurnal

Cryptococcal meningitis is a central nervous system infection cause by Cryptococcus neoformans. Although Cryptococcus is found in bird droppings, it has never been reported for those ranchers involved in the niche swiftlet ranching industry despite having close proximity with the bird droppings. We present here a case of a 41-year-old healthy swiftlet rancher who presents with a history of prolonged fever, headache and altered behaviour of a month duration. Cerebral spinal fluid analysis revealed the presence of Cryptococcus. He was treated with intravenous amphotericin B and flucytosine and discharged well with fluconazole consolidation therapy for 8 weeks, followed by maintenance therapy for 1 year. We believe this is the first reported case of Cryptococcal meningitis (CM) occurring in an immunocompetent swiftlet rancher. This case should highlight the needs to wear a proper personal protective equipment inside a swiftlet ranch due to the constant exposure to the potential cryptococcal-rich environment. A high index of suspicion, careful history taking and physical examination focusing on neurologic assessment is key to early diagnosis and timely management of CM.

Matched MeSH terms: Cryptococcus neoformans
Fulltext Lung-infiltrating T helper 17 cells as the major source of interleukin-17A production during pulmonary Cryptococcus neoformans infection

Movahed E, Cheok YY, Tan GMY, Lee CYQ, Cheong HC, Velayuthan RD, et al.

BMC Immunol, 2018 Nov 08;19(1):32.
PMID: 30409128 DOI: 10.1186/s12865-018-0269-5

BACKGROUND: IL-17A has emerged as a key player in the pathologies of inflammation, autoimmune disease, and immunity to microbes since its discovery two decades ago. In this study, we aim to elucidate the activity of IL-17A in the protection against Cryptococcus neoformans, an opportunistic fungus that causes fatal meningoencephalitis among AIDS patients. For this purpose, we examined if C. neoformans infection triggers IL-17A secretion in vivo using wildtype C57BL/6 mice. In addition, an enhanced green fluorescence protein (EGFP) reporter and a knockout (KO) mouse models were used to track the source of IL-17A secretion and explore the protective function of IL-17A, respectively.
RESULTS: Our findings showed that in vivo model of C. neoformans infection demonstrated induction of abundant IL-17A secretion. By examining the lung bronchoalveolar lavage fluid (BALF), mediastinal lymph node (mLN) and spleen of the IL-17A-EGFP reporter mice, we showed that intranasal inoculation with C. neoformans promoted leukocytes lung infiltration. A large proportion (~ 50%) of the infiltrated CD4+ helper T cell population secreted EGFP, indicating vigorous TH17 activity in the C. neoformans-infected lung. The infection study in IL-17A-KO mice, on the other hand, revealed that absence of IL-17A marginally boosted fungal burden in the lung and accelerated the mouse death.
CONCLUSION: Therefore, our data suggest that IL-17A is released predominantly from TH17 cells in vivo, which plays a supporting role in the protective immunity against C. neoformans infection.

Matched MeSH terms: Cryptococcus neoformans
Fulltext Saprophytic yeasts: effective biocontrol agents against Aspergillus flavus

Afsah-Hejri, L.

International Food Research Journal, 2013;20(6):3403-3409.
MyJurnal

Aflatoxins are carcinogenic, mutagenic and teratogenic fungal toxins predominantly produced by Aspergillus flavus (A. flavus) and Aspergillus parasiticus (A. parasiticus). Members of the Aspergillus family are wound-invading pathogens that can infect pistachio trees and nuts. The pistachio nut is a favorite tree nut worldwide, and more than half of the world’s pistachio production is from Iran. Pistachio nuts can easily be infected with Aspergillus spp. due to early splitting or due to animal, insect or physical damage. Any established infection of Aspergillus under high relative humidity and temperature results in the production and rapid accumulation of aflatoxins in pistachio nuts. It is impractical to remove aflatoxins from pistachio nuts after they are produced. Some microorganisms (such as saprophytic yeasts) have been reported to have an antagonistic effect against Aspergillus spp. This study aimed to isolate saprophytic yeasts from pistachio fruits and leaves and investigate their biocontrol activities against a toxigenic strain of Aspergillus flavus (A. flavus). Saprophytic yeasts were identified based on their morphological properties and biochemical tests. In total, 24 yeast isolates were obtained from pistachio fruits and leaves, and their antagonistic effect on A. flavus (PTCC 5006) was investigated. Five saprophytic yeast isolates, displaying the highest biocontrol activities against A. flavus (PTCC 5006), were identified as Pseudozyma fusiformata, Cryptococcus albidus, Rhodotorula fragaria, Cryptococcus hungaricus and Rhodotorula hinula. The biocontrol activities of these yeast isolates were evaluated by their inhibitory effects on sporulation, colony expansion, biomass production and prevention of aflatoxin B1 (AFB1) production. Pseudozyma fusiformata was the most effective yeast isolate in terms of spore reduction (84.6%) and inhibition of AFB1 production (89.1%). Cryptococcus albidus produced the maximum reduction in fungal dry weight (77.9%). Based on these results, isolated saprophytic yeasts from pistachio fruits and leaves can be used as effective biocontrol agents against the growth of Aspergillus and aflatoxin production.

Matched MeSH terms: Cryptococcus
Exploring the potential of halotolerant bacteria for biodegradation of polycyclic aromatic hydrocarbon

Al Farraj DA, Hadibarata T, Yuniarto A, Alkufeidy RM, Alshammari MK, Syafiuddin A

Bioprocess Biosyst Eng, 2020 Dec;43(12):2305-2314.
PMID: 32812060 DOI: 10.1007/s00449-020-02415-4

The present study aimed to determine the degradation and transformation of three-ring PAHs phenanthrene and anthracene by Cryptococcus sp. MR22 and Halomonas sp. BR04 under halophilic conditions. The growth progress of Cryptococcus sp. MR22 and Halomonas sp. BR04 on anthracene and phenanthrene was monitored by colony-forming unit (CFU) technique. The growth of the bacteria was maintained at a maximum concentration of 200 mg/L of all tested hydrocarbon, indicating that Cryptococcus sp. MR22 and Halomonas sp. BR04 significantly perform in the removal of the PAH-contaminated medium at low concentrations. The fit model to represent the biodegradation kinetics of both PAHs was first-order rate equation The extract prepared from cells supplemented with three different substrates exhibited some enzymes such as hydroxylase, dioxygenase, laccase and peroxidase. The results suggest that both strains had an impressive ability in the degradation of aromatic and aliphatic hydrocarbon but also could tolerate in the extreme salinity condition.

Matched MeSH terms: Cryptococcus