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  1. Lo SG, Wong SF, Mak JW, Choo KK, Ng KP
    Trop Biomed, 2019 Dec 01;36(4):958-971.
    PMID: 33597466
    Cladosporium spores are ubiquitous in indoor and outdoor environment and may potentially trigger allergic responses upon inhalation. To date, there is limited investigation on the fate of Cladosporium spores after being inhaled into the respiratory tract. This study was conducted to investigate the interaction of Cladosporium sphaerospermum with Human Bronchial Epithelial Cells (BEAS-2B) and Human Pulmonary Alveolar Epithelial Cells (HPAEpiC). C. sphaerospermum conidia were harvested and co-cultured with BEAS-2B or HPAEpiC cells for 72 hours. At each time point (30 minutes, 2, 4, 24, 48 and 72 hours), adherence and invasion of the cells by C. sphaerospermum conidia (and hyphae) were investigated by immunofluorescence staining. This study demonstrated the adherence and internalization of C. sphaerospermum conidia within these epithelial cells. In addition, the conidia were able to germinate and invade the epithelial cells. The ability of the fungal conidia to adhere, internalize, germinate and invade both the bronchial and alveolar epithelial cells of the respiratory tract in vitro might contribute to the understanding of the pathogenesis of Cladosporium in respiratory infection and allergy in vivo.
    Matched MeSH terms: Epithelial Cells/microbiology*
  2. Lye HS, Khoo BY, Karim AA, Rusul G, Liong MT
    J Microbiol Biotechnol, 2012 Jul;22(7):981-9.
    PMID: 22580318
    This study aimed to evaluate the effects of electroporation on the cell growth, cholesterol removal, and adherence abilities of L. acidophilus BT 1088 and their subsequent passages. The growth of electroporated parent cells increased (P<0.05) by 4.49-21.25% compared with that of the control. This may be attributed to the alteration of cellular membrane. However, growth of first, second, and third passages of treated cells was comparable with that of the control, which may be attributed to the resealing of transient pores on the cellular membrane. Electroporation also increased (P<0.05) assimilation of cholesterol by treated parent cells (>185.40%) and first passage (>21.72%) compared with that of the control. Meanwhile, incorporation of cholesterol into the cellular membrane was also increased (P<0.05) in the treated parent cells (>108.33%) and first passage (>26.67%), accompanied by increased ratio of cholesterol:phospholipids (C:P) in these passages. Such increased ratio was also supported by increased enrichment of cholesterol in the hydrophilic heads, hydrophobic tails, and the interface regions of the membrane phospholipids of both parent and first passage cells compared with that of the control. However, such traits were not inherited by the subsequent second and third passages. Parent cells also showed decreased intestinal adherence ability (P<0.05; decreased by 1.45%) compared with that of the control, without inheritance by subsequent passages of treated cells. Our data suggest that electoporation could be a potential physical treatment to enhance the cholesterol removal ability of lactobacilli that was inherited by the first passage of treated cells without affecting their intestinal adherence ability.
    Matched MeSH terms: Epithelial Cells/microbiology
  3. Sukri A, Hanafiah A, Kosai NR, Mohamed Taher M, Mohamed Rose I
    Helicobacter, 2016 Oct;21(5):417-27.
    PMID: 26807555 DOI: 10.1111/hel.12295
    Comprehensive immunophenotyping cluster of differentiation (CD) antigens in gastric adenocarcinoma, specifically between Helicobacter pylori-infected and -uninfected gastric cancer patients by using DotScan(™) antibody microarray has not been conducted. Current immunophenotyping techniques include flow cytometry and immunohistochemistry are limited to the use of few antibodies for parallel examination. We used DotScan(™) antibody microarray consisting 144 CD antibodies to determine the distribution of CD antigens in gastric adenocarcinoma cells and to elucidate the effect of H. pylori infection toward CD antigen expression in gastric cancer.
    Matched MeSH terms: Epithelial Cells/microbiology*
  4. Jin LZ, Ho YW, Abdullah N, Ali MA, Jalaludin S
    J Appl Microbiol, 1998 Jun;84(6):1171-4.
    PMID: 9717304
    Two Lactobacillus isolates, Lact. acidophilus I 26 and Lact. fermentum I 25, were selected, based on their poor aggregation with Escherichia coli and strong ability to adhere to ileal epithelial cells (IEC), to study in vitro interactions with E. coli O1:K1, O2:K1 and O78:K80 in an IEC radioactive-assay under the conditions of exclusion (lactobacilli and IEC, followed by the addition of E. coli), competition (lactobacilli, IEC and E. coli together) and displacement (E. coli and IEC, followed by the addition of lactobacilli). The results indicated that Lact. acidophilus I 26 and Lact. fermentum I 25 could not significantly reduce the attachment of E. coli O1:K1, O2:K1 and O78:K80 to IEC under the three conditions tested in vitro, except that the attachment of E. coli O1:K1 was slightly reduced by Lact. fermentum I 25 in the test for competition.
    Matched MeSH terms: Epithelial Cells/microbiology
  5. Vellasamy KM, Mariappan V, Shankar EM, Vadivelu J
    PLoS Negl Trop Dis, 2016 07;10(7):e0004730.
    PMID: 27367858 DOI: 10.1371/journal.pntd.0004730
    BACKGROUND: Burkholderia pseudomallei, the causative agent of melioidosis poses a serious threat to humankind. B. pseudomallei secretes numerous virulence proteins that alter host cell functions to escape from intracellular immune sensors. However, the events underlying disease pathogenesis are poorly understood.

    METHODS: We determined the ability of B. pseudomallei to invade and survive intracellularly in A549 human lung epithelial cells, and also investigated the early transcriptional responses using an Illumina HumanHT-12 v4 microarray platform, after three hours of exposure to live B. pseudomallei (BCMS) and its secreted proteins (CCMS).

    RESULTS: We found that the ability of B. pseudomallei to invade and survive intracellularly correlated with increase of multiplicity of infection and duration of contact. Activation of host carbohydrate metabolism and apoptosis as well as suppression of amino acid metabolism and innate immune responses both by live bacteria and its secreted proteins were evident. These early events might be linked to initial activation of host genes directed towards bacterial dissemination from lungs to target organs (via proposed in vivo mechanisms) or to escape potential sensing by macrophages.

    CONCLUSION: Understanding the early responses of A549 cells toward B. pseudomallei infection provide preliminary insights into the likely pathogenesis mechanisms underlying melioidosis, and could contribute to development of novel intervention strategies to combat B. pseudomallei infections.

    Matched MeSH terms: Epithelial Cells/microbiology*
  6. Mariappan V, Thimma J, Vellasamy KM, Shankar EM, Vadivelu J
    Environ Microbiol Rep, 2018 04;10(2):217-225.
    PMID: 29393577 DOI: 10.1111/1758-2229.12624
    Physiological constituents in airway surface liquids (ASL) appear to impact the adherence and invasion potentials of Burkholderia pseudomallei contributing to recrudescent melioidosis. Here, we investigated the factors present in ASL that is likely to influence bacterial adhesion and invasion leading to improved understanding of bacterial pathogenesis. Six B. pseudomallei clinical isolates from different origins were used to investigate the ability of the bacteria to adhere and invade A549 human lung epithelial cells using a system that mimics the physiological ASL with different pH, NaCl, KCl, CaCl2 and glucose concentrations. These parameters resulted in markedly differential adherence and invasion abilities of B. pseudomallei to the lung epithelial cells. The concentration of 20 mM glucose dramatically increased adherence and invasion by increasing the rate of pili formation in depiliated bacteria. Glucose significantly increased adherence and invasion of B. pseudomallei to A549 cells, and presence of NaCl, KCl and CaCl2 markedly ablated the effect despite the presence of glucose. Our data established a link between glucose, enhanced adhesion and invasion potentials of B. pseudomallei, hinting increased susceptibility of individuals with diabetes mellitus to clinical melioidosis.
    Matched MeSH terms: Epithelial Cells/microbiology
  7. Nandanwar N, Janssen T, Kühl M, Ahmed N, Ewers C, Wieler LH
    Int J Med Microbiol, 2014 Oct;304(7):835-42.
    PMID: 25037925 DOI: 10.1016/j.ijmm.2014.06.009
    Extraintestinal pathogenic Escherichia coli (ExPEC) strains of certain genetic lineages are frequently implicated in a wide range of diseases in humans and birds. ExPEC strains belonging to the phylogenetic lineage/sequence type complex 95 (STC95) are one such prominent lineage that is commonly isolated from extraintestinal infections such as systemic disease in poultry and urinary tract infections (UTIs), neonatal meningitis and sepsis in humans. Several epidemiological studies have indicated that ST95 strains obtained from such infections may share similar virulence genes and other genomic features. However, data on their ability to establish infections in vivo as deduced from the manifestation of similar virulence phenotypes remain elusive. In the present study, 116 STC95 ExPEC isolates comprising 55 human and 61 avian strains, possessing similar virulence gene patterns, were characterized in vitro using adhesion, invasion, biofilm formation and serum bactericidal assays. Overall, STC95 strains from both groups, namely human and birds, were equally capable of adhering to and invading the two mammalian kidney cell lines. Similarly, these strains were able to form strong biofilms in M63 medium. Furthermore, they were equally resistant to the bactericidal activity of human and avian serum. Our cumulative data reinforce the understanding that ST95 strains from poultry present a potential zoonotic risk and therefore need a One Health strategy for a successfull intervention.
    Matched MeSH terms: Epithelial Cells/microbiology
  8. Al-Maleki AR, Mariappan V, Vellasamy KM, Shankar EM, Tay ST, Vadivelu J
    J Proteomics, 2014 Jun 25;106:205-20.
    PMID: 24742602 DOI: 10.1016/j.jprot.2014.04.005
    Colony morphology variation is a characteristic of Burkholderia pseudomallei primary clinical isolates, associated with variations in expression of virulence factors. Here, we performed comparative investigations on adhesion, invasion, plaque-forming abilities and protein profiles of B. pseudomallei wild-type (WT) and a small colony variant (SCV). The percentage of SCV adherence to A549 cells was significantly higher (2.73%) than WT (1.91%). In contrast, WT was significantly more efficient (0.63%) than SCV (0.31%) in invasiveness and in inducing cellular damage. Using 2-DE and MALDI TOF/TOF, 263 and 258 protein spots were detected in WT and SCV, respectively. Comparatively, 49 proteins were differentially expressed in SCV when compared with WT. Of these, 31 proteins were up-regulated, namely, nucleoside diphosphate kinase (Ndk), phosphoglycerate kinase (Pgk), thioredoxin (TrxA), putative ferritin DPS-family DNA-binding protein (DPS) and oxidoreductase (AhpC) that are known to be involved in adhesion, intracellular survival and persistence. However, among the 18 down-regulated proteins, enolase (Eno), elongation factor (EF-Tu) and universal stress-related proteins were associated with invasion and virulence. Differences observed in these protein profiles provide ample clues to their association with the morphotypic and phenotypic characteristics of colony variants, providing additional insights into the potential association of B. pseudomallei colony morphotypes with disease pathogenesis.
    Matched MeSH terms: Epithelial Cells/microbiology*
  9. Mariappan V, Vellasamy KM, Thimma J, Hashim OH, Vadivelu J
    PLoS One, 2013;8(10):e77418.
    PMID: 24116227 DOI: 10.1371/journal.pone.0077418
    Burkholderia cepacia is an opportunistic human pathogen associated with life-threatening pulmonary infections in immunocompromised individuals. Pathogenesis of B. cepacia infection involves adherence, colonisation, invasion, survival and persistence in the host. In addition, B. cepacia are also known to secrete factors, which are associated with virulence in the pathogenesis of the infection. In this study, the host factor that may be the cause of the infection was elucidated in human epithelial cell line, A549, that was exposed to live B. cepacia (mid-log phase) and its secretory proteins (mid-log and early-stationary phases) using the Illumina Human Ref-8 microarray platform. The non-infection A549 cells were used as a control. Expression of the host genes that are related to apoptosis, inflammation and cell cycle as well as metabolic pathways were differentially regulated during the infection. Apoptosis of the host cells and secretion of pro-inflammatory cytokines were found to be inhibited by both live B. cepacia and its secretory proteins. In contrast, the host cell cycle and metabolic processes, particularly glycolysis/glycogenesis and fatty acid metabolism were transcriptionally up-regulated during the infection. Our microarray analysis provided preliminary insights into mechanisms of B. cepacia pathogenesis. The understanding of host response to an infection would provide novel therapeutic targets both for enhancing the host's defences and repressing detrimental responses induced by the invading pathogen.
    Matched MeSH terms: Epithelial Cells/microbiology
  10. Mariappan V, Vellasamy KM, Hashim OH, Vadivelu J
    PLoS One, 2011;6(10):e26518.
    PMID: 22046299 DOI: 10.1371/journal.pone.0026518
    Burkholderia cepacia is a Gram-negative pathogen that causes serious respiratory infections in immunocompromised patients and individuals with cystic fibrosis. This bacterium is known to release extracellular proteins that may be involved in virulence.
    Matched MeSH terms: Epithelial Cells/microbiology
  11. Castaño-Rodríguez N, Kaakoush NO, Goh KL, Fock KM, Mitchell HM
    Helicobacter, 2015 Oct;20(5):353-69.
    PMID: 25664588 DOI: 10.1111/hel.12211
    Autophagy, a degradation pathway in which cytoplasmic content is engulfed and degraded by lysosomal hydrolases, plays a pivotal role in infection and inflammation. Given that defects in autophagy lead to increased susceptibility to infection, we investigated the role of autophagy in Helicobacter pylori-related gastric cancer (GC).
    Matched MeSH terms: Epithelial Cells/microbiology
  12. Schmidt HM, Andres S, Nilsson C, Kovach Z, Kaakoush NO, Engstrand L, et al.
    Eur J Clin Microbiol Infect Dis, 2010 Apr;29(4):439-51.
    PMID: 20157752 DOI: 10.1007/s10096-010-0881-7
    Helicobacter pylori-related disease is at least partially attributable to the genotype of the infecting strain, particularly the presence of specific virulence factors. We investigated the prevalence of a novel combination of H. pylori virulence factors, including the cag pathogenicity island (PAI), and their association with severe disease in isolates from the three major ethnicities in Malaysia and Singapore, and evaluated whether the cag PAI was intact and functional in vitro. Polymerase chain reaction (PCR) was used to detect dupA, cagA, cagE, cagT, cagL and babA, and to type vacA, the EPIYA motifs, HP0521 alleles and oipA ON status in 159 H. pylori clinical isolates. Twenty-two strains were investigated for IL-8 induction and CagA translocation in vitro. The prevalence of cagA, cagE, cagL, cagT, babA, oipA ON and vacA s1 and i1 was >85%, irrespective of the disease state or ethnicity. The prevalence of dupA and the predominant HP0521 allele and EPIYA motif varied significantly with ethnicity (p < 0.05). A high prevalence of an intact cag PAI was found in all ethnic groups; however, no association was observed between any virulence factor and disease state. The novel association between the HP0521 alleles, EPIYA motifs and host ethnicity indicates that further studies to determine the function of this gene are important.
    Matched MeSH terms: Epithelial Cells/microbiology
  13. Khan S, Zakariah M, Palaniappan S
    Tumour Biol., 2016 Aug;37(8):10805-13.
    PMID: 26874727 DOI: 10.1007/s13277-016-4970-9
    Cancer has long been assumed to be a genetic disease. However, recent evidence supports the enigmatic connection of bacterial infection with the growth and development of various types of cancers. The cause and mechanism of the growth and development of prostate cancer due to Mycoplasma hominis remain unclear. Prostate cancer cells are infected and colonized by enteroinvasive M. hominis, which controls several factors that can affect prostate cancer growth in susceptible persons. We investigated M. hominis proteins targeting the nucleus of host cells and their implications in prostate cancer etiology. Many vital processes are controlled in the nucleus, where the proteins targeting M. hominis may have various potential implications. A total of 29/563 M. hominis proteins were predicted to target the nucleus of host cells. These include numerous proteins with the capability to alter normal growth activities. In conclusion, our results emphasize that various proteins of M. hominis targeted the nucleus of host cells and were involved in prostate cancer etiology through different mechanisms and strategies.
    Matched MeSH terms: Epithelial Cells/microbiology
  14. Abbasiliasi S, Tan JS, Bashokouh F, Ibrahim TAT, Mustafa S, Vakhshiteh F, et al.
    BMC Microbiol, 2017 May 23;17(1):121.
    PMID: 28535747 DOI: 10.1186/s12866-017-1000-z
    BACKGROUND: Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro.

    RESULTS: P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities.

    CONCLUSION: The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

    Matched MeSH terms: Epithelial Cells/microbiology
  15. Beatson SA, Ben Zakour NL, Totsika M, Forde BM, Watts RE, Mabbett AN, et al.
    Infect Immun, 2015 May;83(5):1749-64.
    PMID: 25667270 DOI: 10.1128/IAI.02810-14
    Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli responsible for >80% of all cases. One extreme of UTI is asymptomatic bacteriuria (ABU), which occurs as an asymptomatic carrier state that resembles commensalism. To understand the evolution and molecular mechanisms that underpin ABU, the genome of the ABU E. coli strain VR50 was sequenced. Analysis of the complete genome indicated that it most resembles E. coli K-12, with the addition of a 94-kb genomic island (GI-VR50-pheV), eight prophages, and multiple plasmids. GI-VR50-pheV has a mosaic structure and contains genes encoding a number of UTI-associated virulence factors, namely, Afa (afimbrial adhesin), two autotransporter proteins (Ag43 and Sat), and aerobactin. We demonstrated that the presence of this island in VR50 confers its ability to colonize the murine bladder, as a VR50 mutant with GI-VR50-pheV deleted was attenuated in a mouse model of UTI in vivo. We established that Afa is the island-encoded factor responsible for this phenotype using two independent deletion (Afa operon and AfaE adhesin) mutants. E. coli VR50afa and VR50afaE displayed significantly decreased ability to adhere to human bladder epithelial cells. In the mouse model of UTI, VR50afa and VR50afaE displayed reduced bladder colonization compared to wild-type VR50, similar to the colonization level of the GI-VR50-pheV mutant. Our study suggests that E. coli VR50 is a commensal-like strain that has acquired fitness factors that facilitate colonization of the human bladder.
    Matched MeSH terms: Epithelial Cells/microbiology
  16. Al-Maleki AR, Loke MF, Lui SY, Ramli NSK, Khosravi Y, Ng CG, et al.
    Cell. Microbiol., 2017 12;19(12).
    PMID: 28776327 DOI: 10.1111/cmi.12771
    Outer inflammatory protein A (OipA) is an important virulence factor associated with gastric cancer and ulcer development; however, the results have not been well established and turned out to be controversial. This study aims to elucidate the role of OipA in Helicobacter pylori infection using clinical strains harbouring oipA "on" and "off" motifs. Proteomics analysis was performed on AGS cell pre-infection and postinfection with H. pylori oipA "on" and "off" strains, using liquid chromatography/mass spectrometry. AGS apoptosis and cell cycle assays were performed. Moreover, expression of vacuolating cytotoxin A (VacA) was screened using Western blotting. AGS proteins that have been suggested previously to play a role or associated with gastric disease were down-regulated postinfection with oipA "off" strains comparing to oipA "on" strains. Furthermore, oipA "off" and ΔoipA cause higher level of AGS cells apoptosis and G0/G1 cell-cycle arrest than oipA "on" strains. Interestingly, deletion of oipA increased bacterial VacA production. The capability of H. pylori to induce apoptosis and suppress expression of proteins having roles in human disease in the absence of oipA suggests that strains not expressing OipA may be less virulent or may even be protective against carcinogenesis compared those expressing OipA. This potentially explains the higher incidence of gastric cancer in East Asia where oipA "on" strains predominates.
    Matched MeSH terms: Epithelial Cells/microbiology*
  17. Fitzgerald SF, Beckett AE, Palarea-Albaladejo J, McAteer S, Shaaban S, Morgan J, et al.
    PLoS Pathog, 2019 10;15(10):e1008003.
    PMID: 31581229 DOI: 10.1371/journal.ppat.1008003
    Specific Escherichia coli isolates lysogenised with prophages that express Shiga toxin (Stx) can be a threat to human health, with cattle being an important natural reservoir. In many countries the most severe pathology is associated with enterohaemorrhagic E. coli (EHEC) serogroups that express Stx subtype 2a. In the United Kingdom, phage type (PT) 21/28 O157 strains have emerged as the predominant cause of life-threatening EHEC infections and this phage type commonly encodes both Stx2a and Stx2c toxin types. PT21/28 is also epidemiologically linked to super-shedding (>103 cfu/g of faeces) which is significant for inter-animal transmission and human infection as demonstrated using modelling studies. We demonstrate that Stx2a is the main toxin produced by stx2a+/stx2c+ PT21/28 strains induced with mitomycin C and this is associated with more rapid induction of gene expression from the Stx2a-encoding prophage compared to that from the Stx2c-encoding prophage. Bacterial supernatants containing either Stx2a and/or Stx2c were demonstrated to restrict growth of bovine gastrointestinal organoids with no restriction when toxin production was not induced or prevented by mutation. Isogenic strains that differed in their capacity to produce Stx2a were selected for experimental oral colonisation of calves to assess the significance of Stx2a for both super-shedding and transmission between animals. Restoration of Stx2a expression in a PT21/28 background significantly increased animal-to-animal transmission and the number of sentinel animals that became super-shedders. We propose that while both Stx2a and Stx2c can restrict regeneration of the epithelium, it is the relatively rapid and higher levels of Stx2a induction, compared to Stx2c, that have contributed to the successful emergence of Stx2a+ E. coli isolates in cattle in the last 40 years. We propose a model in which Stx2a enhances E. coli O157 colonisation of in-contact animals by restricting regeneration and turnover of the colonised gastrointestinal epithelium.
    Matched MeSH terms: Epithelial Cells/microbiology*
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