Secretome of adipose derived-mesenchymal stem cells reduces the Vibrio cholerae attachment to Caco-2 cells and subsequent inflammatory responses

Background and Objectives: Mesenchymal Stem Cells (MSCs) can repair gastrointestinal tract damage. The Secretome of MSCs has a high capacity to inhibit bacterial colonization and the subsequent inflammatory responses of Vibrio cholerae. Materials and Methods: The Caco-2 cells were treated with adipose-derived MSCs (AD-MSCs) secretome and then infected with V. cholerae. Subsequently, the bacterial attachment and invasion, cholera toxin gene expression, PGE2 and IL-6 secretion, TNF-α, IL-1β, and IL-8 expression, and apoptosis of Caco-2 cells were evaluated. Results: The secretome of AD-MSCs significantly reduced the V. cholerae attachment and internalization on Caco-2 epithelial cells (P<0.0001). The cholera toxin (Ctx-B) gene expression (FR=4.56 ± 0.66) and PGE2 production (P=0.0007) were also significantly reduced. The production of NO and TNF-α, IL-1β, and IL-8 pro-inflammatory cytokines were significantly (P<0.05) reduced in exposure to the secretome of AD-MSCs. Secretome also improved a significant 81.33% increase in IL-6 production (128.1 ± 37.6 pg/mL) and showed a 12.36% significant decrease in epithelial cell apoptosis (P< 0.0001) after exposure to V. cholerae. Conclusion: The secretome of AD-MSCs can play a critical role in inhibiting bacterial colonization, and subsequent inflammatory responses, and maintaining the integrity of the epithelial barrier. The secretome may be effective in the prevention of hypovolemic shock

International Journal of Molecular and Clinical Microbiology Hwp1 gene Expression of Candida albicans and Study its role in adherence

Candida albicans is an opportunistic fungal pathogen found as mycoflora in the human body surfaces. Sevral genes play a crucial rule in its virulence including Hwp1 (hyphal wall protein 1), BCR1 and ALS gene family. Hwp1 gene is a responsible for coding a cell surface protein, which mediates biofilm formation in candida albicans. Here we investigated the presence of the HWP1gene was characterised among Candida albicans isolates in women with recurrent vaginal canididasis and further we studies its role in cell adherence. We used 50 Candida albicans clinical isolates resistant to Fluconazole. RNA (of samples were extracted using glass bead and lysis buffer and cDNA was synthesized using reverse transcriptase enzyme. Expression of (HWP1) gene was analysed using reverse transcriptase-plolymerase chain reaction (RT-PCR). The ability of adherence of the isolates with or without the expression of HWP1 were characterized using Hela cells. Statistical analysis were performed using t-test and two-way ANOVA SPSS software. Our results showed that the HWP1 gene were present in 47 samples (94%) out of 50 isolates, 27 samples (57%) had expression of HWP1. The result of adherence assay revealed that the isolates with the expression of HWP1 gene and control isolates was statistically different (p&lt;0.05). In conclusion, the isolates with the expression of HWP1 gene has the higher ability to adhere the epithelial mucosal cell surface. Our data support a positive correlation between the expression of HWP1 gene and the ability of adherence to epithelial cells

Genomic insights into the 2016-2017 cholera epidemic in Yemen.

Yemen is currently experiencing, to our knowledge, the largest cholera epidemic in recent history. The first cases were declared in September 2016, and over 1.1 million cases and 2,300 deaths have since been reported1. Here we investigate the phylogenetic relationships, pathogenesis and determinants of antimicrobial resistance by sequencing the genomes of Vibrio cholerae isolates from the epidemic in Yemen and recent isolates from neighbouring regions. These 116 genomic sequences were placed within the phylogenetic context of a global collection of 1,087 isolates of the seventh pandemic V. cholerae serogroups O1 and O139 biotype El Tor2-4. We show that the isolates from Yemen that were collected during the two epidemiological waves of the epidemic1-the first between 28 September 2016 and 23 April 2017 (25,839 suspected cases) and the second beginning on 24 April 2017 (more than 1 million suspected cases)-are V. cholerae serotype Ogawa isolates from a single sublineage of the seventh pandemic V. cholerae O1 El Tor (7PET) lineage. Using genomic approaches, we link the epidemic in Yemen to global radiations of pandemic V. cholerae and show that this sublineage originated from South Asia and that it caused outbreaks in East Africa before appearing in Yemen. Furthermore, we show that the isolates from Yemen are susceptible to several antibiotics that are commonly used to treat cholera and to polymyxin B, resistance to which is used as a marker of the El Tor biotype

The Dual Role of Inflammatory Responses following Vibrio cholerae Infection in Cholerae pathogenesis

Cholera is an acute and dangerous intestinal diarrhea that leads to death if hypovolemic shock occures. Vibrio cholera, as a causative agent of cholera, is a noninvasive enteric gram-negative bacteria which exerts its pathological effects by producing cholerae toxin (CT). The first time, the acute inflammatory responses of Cholerae was considered when the development of laboratory techniques in the last years demonstrated that CT can induce lipid mediators synthesis like prostaglandin E2, F2 and leukotrienes and recruit neutrophils, mast cells, macrophages and other immune cells. The recruited cells respond to infection by lactoferrin and myeloperoxidase secretion in the excretory liquid and production of inflammatory cytokines like, TNF-α, IL-1 and IL-6. On the one hand, the formed inflammatory responses, stimulate innate and adaptive immune system and produce antibodies against Vibrio cholerae, but  on the other hand, it enhances the excretion of water and salts from the gastrointestinal tract epithelial cells and induces apoptosis and loss of defensive function of epithelial barrier. Although the epithelial cell shedding and excretion of infected fluids from the intestinal tract is the body’s natural defensive mechanism to remove bacteria, but in the case of the failure in bacteria reduction and lost fluid compensation by serum therapy, the disease will lead to death. Therfore the use of antibiotics and anti-inflammatory drugs will be effective besides serum therapy to reduce the number of baceria and fluid loss from the body and repair the epithelial barrier

Selenium Nanoparticles Induce Potent Protective Immune Responses against Vibrio cholerae WC Vaccine in a Mouse Model

The aim of this study was to evaluate the efficacy of selenium nanoparticle (an immune booster) and naloxone (an opioid receptor antagonist) as a new adjuvant in increasing immune responses against killed whole-cell Vibrio cholerae in a mouse cholera model. The Se NPs were synthesized and characterized by UV-visible, DLS, and zeta potential analysis. The SEM image confirmed the uniformity of spherical morphology of nanoparticle shape with 34 nm in size. The concentration of the Se NPs was calculated as 0.654 μg/ml in the ICP method. The cytotoxic activity of Se NPs on Caco-2 cells was assessed by the MTT assay and revealed 82.05% viability of cells after 24 h exposure with 100 μg/ml of Se NPs. Female BALB/C mice were orally immunized three times on days 0, 14, and 28, and challenge experiments were performed on immunized neonates with toxigenic V. cholerae. Administration of Se NP diet led to significant increase in V. cholerae-specific IgG and IgA responses in serum and saliva and caused protective immunity and 83.3% survival in challenge experiment against 1 LD50 V. cholerae in a group receiving diet of Se NPs compared with other groups including Dukoral vaccine. The IL-4 and IL-5 were significantly increased in response to WC+daily diet of Se NPs with or without naloxone. Naloxone proved no effect on IL-4 and IL-5 increase and is proposed as null in the cytokine and antibody production process. These results reveal that daily diet of Se NPs could efficiently induce immune cell effectors in both humoral and mucosal levels

The anti-apoptotic and anti-inflammatory effect of Lactobacillus acidophilus on Shigella sonnei and Vibrio cholerae interaction with intestinal epithelial cells: A comparison between invasive and non-invasive bacteria.

The aim of this study was to compare the effect of Lactobacillus acidophilus on the attachment, invasion, and interaction of Shigella sonnei and Vibrio cholerae with Caco-2 epithelial cells. Also, the anti-apoptotic and anti-inflammatory effect of L. acidophilus was investigated on S. sonnei and V. cholerae interaction with Caco-2 cells as the representatives of invasive and non-invasive intestinal bacteria. It was found that pretreatment with L. acidophilus significantly prevented from adherence and internalization of S. sonnei/V. cholerae and reduced the expression of tumour necrosis factor-α and interleukin-8 in host cells. No significant difference was observed in inhibitory effect of Lactobacilli in V. cholerae and S. sonnei attachment, emphasizing on the role of lactobacilli as a physical barrier in inhibiting direct contact with host cell by competitive exclusion, which may affect attachment and subsequent internalization of both invasive and non-invasive pathogenic bacteria in a same scale. The evaluation of early and late apoptosis in Caco-2 cells exposed to V. cholerae/S. sonnei and pretreated by L. acidophilus indicated no remarkable difference in L. acidophilus anti-apoptotic effect on Caco-2 cells against invasive and non-invasive bacterial infection. Moreover, L. acidophilus by itself showed no apoptotic effect on Caco-2 cells. Statistical analysis revealed that L. acidophilus in S. sonnei infected cells was able to reduce pro-inflammatory immune responses (TNF-α, IL-8 and IL-1β) and NO and PGE2 secretion more strongly compared with V. cholerae infected cells. These data showed for the first time that the protective effect of Lactobacilli, as a probiotic bacterium, in interaction suppression was more in invasive bacteria including S. sonnei than in non-invasive V. cholerae

Molecular Diagnosis of Salmonella enterica and Shigella spp. in Stool Sampleof Children With Diarrhea in Tehran

Background: Diarrheal illnesses caused by Salmonella and Shigella spp remain a serious public health problem in industrializing countries, and are still an important cause of morbidity and mortality in developed as well as undeveloped countries. Rapid detection of agents that cause diarrhea may help prevent occurrence of outbreaks. Objectives: The aim of this study was to compare conventional biochemical tests, namely API 20E strip system and Polymerase Chain Reaction (PCR) for identification of Salmonella enterica and Shigella spp. isolated from stool samples of patients with diarrhea. Materials and Methods: Stool samples were collected from patients with diarrhea during a three-year period (2009-2012). Conventional biochemical tests were used for identification of Shigella spp. and Salmonella enterica isolates. API 20E strips and PCR methods with oligonucleotide primers specific for ipaH of Shigella genus and hilA of Salmonella enterica were used to confirm the identity of the isolates. Results: Of the 81 suspected S. enterica and 112 Shigella spp. identified by conventional biochemical tests, 77 and 105 were identified as S.enterica and Shigella spp. by API 20E, respectively. All of the isolates were assigned to bacterial species with 99.9% probability value. All of the 81 suspected Salmonella enterica isolates produced 784 bp amplification bands of hilA gene. Among the 112 Shigella isolates confirmed by PCR, 90 (80.35%) were positive for wbgZ and 14 (12.5%) were positive for rfc genes indicative of S. sonnei and S. flexneri , respectively. Conclusions: In conclusion, the results of this study suggest that the PCR amplification of hilA and ipaH is a promising method for identification of Salmonella enterica and Shigella spp. The outcomes of this study can help towards more accurate and easy screening oflarge population of patients with Salmonella enterica and Shigella spp infections