Saintis tempatan perlu perjelas wabak coronavirus

BELUM reda isu influenza, timbul pula masalah kesihatan baharu bawaan coronavirus. Influenza ialah penyakit berpunca daripada jangkitan influenza A virus ataupun H1N1. Virus itu diklasifikasikan dalam kategori rantaian tunggal ribonuklik asid (ssRNA). Seperti influenza A virus, coronavirus (2019-nCoV) adalah sejenis virus yang terbentuk daripada satu rantaian RNA yang amat mudah termutasi. Apa yang membezakan antara kedua-dua virus itu adalah kewujudan vaksin di dalam negara di mana bagi influenza A, ia boleh diperoleh di hospital dan klinik dengan segera. Namun, tidak untuk coronavirus 2019-nCoV, di mana sehingga hari ini, masih belum ada lagi vaksin yang ditemui. Bagi menghasilkan vaksin untuk virus yang baharu ini, kajian yang segera perlu dijalankan bagi memastikan keberkesanan dan keselamatan. Bagaimanapun, antara halangan utama kepada saintis tempatan untuk turut sama menghasilkan vaksin bagi virus itu ialah kekurangan fasiliti yang mencapai piawaian Pertubuhan Kesihatan Sedunia (WHO). Di sebalik kekurangan itu, tentu timbul tanda tanya apakah peranan yang dapat dimainkan oleh saintis tanah air dalam memberikan sumbangan menghadapi wabak seperti coronavirus? Meskipun saintis kita tidak dapat terbabit secara langsung dengan penghasilan vaksin, tentu masih ada banyak peranan lain yang boleh diambil oleh saintis mikrobiologi tempatan

Polymicrobial interactions of Candida albicans and its role in oral carcinogenesis

The oral microbiome is composed of microorganisms residing in the oral cavity, which are critical components of health and disease. Disruption of the oral microbiome has been proven to influence the course of oral diseases, especially among immunocompromised patients. Oral microbiome is comprised of inter‐kingdom microorganisms, including yeasts such as Candida albicans, bacteria, archaea and viruses. These microorganisms can interact synergistically, mutualistically and antagonistically, wherein the sum of these interactions dictates the composition of the oral microbiome. For instance, polymicrobial interactions can improve the ability of C. albicans to form biofilm, which subsequently increases the colonisation of oral mucosa by the yeast. Polymicrobial interactions of C. albicans with other members of the oral microbiome have been reported to enhance the malignant phenotype of oral cancer cells, such as the attachment to extracellular matrix molecules (ECM) and epithelial mesenchymal transition (EMT). Polymicrobial interactions may also exacerbate an inflammatory response in oral epithelial cells, which may play a role in carcinogenesis. This review focuses on the role of polymicrobial interactions between C albicans and other oral microorganisms, including its role in promoting oral carcinogenesis

Oral microorganisms: how do they communicate?

Many oral diseases are related to the interaction between microorganisms in the oral cavity. These microbial interactions are necessarily associated with the development of dental plaque and can lead to oral diseases including dental caries and perhaps oral cancer. It is estimated that up to 70% of people with a healthy oral cavity possess Candida albicans in their mouth. This normally does not harm the individual, however, in the event of disease, C. albicans may cause harm especially in those with a high carbohydrate diet, tobacco smoking or drug abuse. The objective of our study was to understand the communication between the most important oral microorganisms, the yeast, C. albicans strains, and bacteria, A. naeslundii and S. mutans. o study this interaction, C. albicans that was grown as either long branching filmanets (hyphae) as well as single buddding yeast, and with A. naeslundii and S. mutans were suspended in separate sterile tubes containing buffer. The suspension was incubated for an hour at room temperature and the turbidity at 1 hour was measured using a spectrophotometer. The yeast auto-aggregated more when grown as hyphae than yeast for the majority of C. albicans strains. Further, co-aggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Finally, scanning electron microscopy images showed that A. naeslundii and S. mutans co-aggregated with C. albicans (Figure 1). We can concluded that C. albicans communicate with A. naeslundii and S. mutans and this may contribute to the development of oral diseases such as dental caries

Coaggregation of Candida albicans, Actinomyces naeslundii and Streptococcus mutans is Candida albicans strain dependent

Microbial interactions are necessarily associated with the development of polymicrobial oral bio lms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and arti cial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 106, 107 and 108 cells mL−1 respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm ( Abs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean Abs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent

The effect of Candida albicans, Actinomyces naeslundii and Streptococcus mutans biofilm effluent on the expression of interleukin-6 and interleukin-8 from normal and oral cancer cell lines

Abstract: Oral cancer is the sixth most common cancer worldwide. It is suggested that polymicrobial infection may involve in oral carcinogenesis. This study aimed to determine the effect of mono-culture and polymicrobial biofilms effluent from C. albicans, Streptococcus mutans and Actinomyces naeslundii to the expression of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) from normal and oral squamous cell carcinoma (OSCC) cell lines, with the hypothesis that biofilm effluent promote oral carcinogenesis. OKF6 cell line isolated from healthy oral cavity was grown to 80% confluent in 12-well plate and incubated with 80% (v/v) serum free medium (SFM) containing biofilm effluent from mono-culture of C. albicans (ALC3), S. mutans (SM), A. naelundii (AN) or polymicrobial (TRI) for 2 h and 24 h. Incubation of the cell line with 100% SFM (NE) was conducted to represent the negative control. To quantify the amount of IL-6 and IL-8 secreted by epithelial cells in response to biofilm effluent, the conditioned medium was collected and analysed using Bio-Plex protein array system and Bio-Rad cytokine multi-plex panel. Similar protocol was repeated with H357 cell line that was isolated from patient with OSCC. The results showed that OKF6 cell line that was incubated with ALC3 had significant decrease IL-8 expression while incubation with SM exhibited significantly increase IL-6 expression when compared to NE after 2 h incubation (P<0.05). In addition, significant increase of IL-6 and IL-8 expression were observed after 24 h incubation of OKF6 cell line with TRI effluent when compared to NE (P<0.05). The incubation of H357 with AN, SM and TRI effluent exhibited significant increase of IL-6 and IL-8 expression after 2 h incubation, whereas significant increase of the similar cytokines were observed when incubated with all effluent after 24 h in comparison to NE (P<0.05). In conclusion, biofilm effluent promotes malignant phenotype of OSCC cell line

Characterisation of osteomyelitis microbiome using specific growth media

Osteomyelitis is an inflammation of the bone caused by microbial infection. The objective of the study is to characterise the microbiome from osteomyelitis with the hypothesis that osteomyelitis is induced by polymicrobial infection. To identify the microbiome, sample was initially isolated from pin site of ortophaedic patients with osteomyelitis using sterile swab. Following that, the sample was inoculated into nutrient broth and incubated at 37° C for 24 h aerobically. Later, the sample was cultured on CHROMagar, mitis salivarius agar (MSA) and lactobacillus specific agar (LSA) for identification of Candida species, Streptococcus species and Lactobacillus species, respectively. Gram-staining was conducted to identify its phenotype under light microscope. Finally, disc diffusion test was conducted on each isolate to assess its sensitivity towards nystatin, amphotericin B, gentamicin and tetracycline. Based on the study, only Candida albicans and Streptococcus species were identified. Candida albicans and Streptococcus species were isolated from the sample with C. albicans exhibited resistance to amphotericin B, gentamicin and tetracycline while Streptococcus species were resistance to nystatin, amphotericin B and tetracyclin. In conclusion, osteomyelitis is induced by polymicrobial infection, with the microbial isolates possess various susceptibility towards common antimicrobial agents

The effect of polymicrobial interaction on the adhesion of OKF6 and H357 cell lines

Introduction: Oral cancer is classified as the sixth most common cancer in the world. It has been suggested that polymicrobial infection may have a role in oral carcinogenesis. Objective: To determine the effect of mono-culture and polymicrobial biofilms effluent from C. albicans, Streptococcus mutans and Actinomyces naeslundii to the adhesion of normal and oral cancer cell lines on extra-cellular matrix (ECM) molecules coated surfaces. Methods: Initially, OKF6 cell line isolated from healthy oral cavity was incubated in serum free medium containing effluent from mono-culture or polymicrobial biofilms of C. albicans (ALC3), S. mutans (Ingbritt), A. naelundii (NCTC 10301) for 90 minutes. Following that, the suspension was added into CytoSelect 48-well Cell Adhesion Assay ECM Array kit to determine the adhesion of the cell to fibronectin, collagen I, collagen IV, laminin and fibrinogen. Fold change of adhesion of the cells incubated in biofilm effluent in comparison to that incubated in non-effluent (NE) was enumerated. Similar protocol was repeated with H357 cell line that was isolated from patient with oral squamous cell carcinoma (OSCC). Results: The majority of OKF6 cells incubated in biofilm effluent exhibited significantly decreased adhesion to ECM molecules compared to the cells incubated in NE (P<0.05). Only when incubated with S. mutans effluent, OKF6 cells exhibited significant increase in adhesion to fibronectin (P<0.05). The incubation of H357 with C. albicans effluent exhibited significant increase of adhesion to collagen IV and laminin I when compared to NE (P < 0.05). Furthermore, the adhesion of H357 cells to laminin I were also found to increase when incubated with C. albicans (15.07-fold), S. mutans (6.54-fold), A. naeslundii (1.31-fold) and polymicrobial biofilms (10.69-fold) effluents. Conclusions: The adhesion of OKF6 and H357 to ECM are biofilm effluent-dependent and that biofilm effluent enhance the malignant phenotype of H357 when grown in medium containing biofilms effluent