ISSN: 2008-2258

Review Article


Impact of proteomics investigations on gastric cancer treatment and diagnosis

Mohammad Rostami-Nejad, Mostafa Rezaei-Tavirani, Vahid Mansoori, Zahra Akbari, Saeed Abdi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 1-7
https://doi.org/10.22037/ghfbb.v12i0.1839

Gastric cancer is one of the epidemics diseases with a high mortality rate in different countries. It causes many health problems in the world every year. It affects the digestive tract, and in advanced cases, its treatment has many difficulties. Early detection of cancer in different parts of the gastrointestinal tract can be accompanied by inexpensive treatment. As cancer cells make different biomarkers during different stages of the disease, researchers are looking for different biomarkers for gastrointestinal cancers detection. On the other hand, with the advent of advanced techniques such as proteomics and the discovery of a large number of proteins related to gastrointestinal cancer, finding the role of these proteins is essential. Indeed, the function of large amounts of these proteins has remained unknown.

Data from databases such as genes and proteins associated with gastrointestinal cancers were collected and the proteomic data of these databases were analyzed to find a clear perspective of the impact of proteomics in gastric cancer management.

The role of heat shock proteins, metabolic proteins, membrane binding proteins, galectins, prohibitins, S100 proteins, and many different types of proteins in gastric cancer was highlighted. This article reviewed proteomic researches in cancer-related areas of the gastric cancer in order to evaluate the findings of researchers.

Keywords: Gastric cancer, Biomarker, Proteomic.

(Please cite as: Rostami-Nejad M, Rezaei-Tavirani M, Mansouri V, Akbari Z, Abdi S. Impact of proteomics investigations on gastric cancer treatment and diagnosis. Gastroenterol Hepatol Bed Bench 2019;12(Suppl. 1):S1-S7).

The association between gut microbiota, cholesterol gallstones and colorectal cancer

Sama Rezasoltani, Amir Sadeghi, Ebrahim Radinnia, Ali Naseh, Zahra Gholamrezaei, Mehdi Azizmohammad Looha, Abbas Yadegar

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 8-13
https://doi.org/10.22037/ghfbb.v12i0.1823

Gut microbiota play critical roles in maintaining the human health in several aspects. Bile acids (BAs) are endogenous cholesterol-derived molecules that can be modified by the gut microbiota and act as signaling molecules in the regulation of host metabolic and physiology processes. Gut microbiota release many enzymes that are capable to perform considerable modifications on BAs such as bile salt hydrolases (BSH), 7?-dehydroxylase (CYP7A), and hydroxysteroid dehydrogenase (HSDH). These enzymatic roles can change in the gut microbiota composition, cause alteration in BAs profile and metabolism and even gallstone formation. Patients with 15 years of asymptomatic gallstone have increased risk for colorectal cancer (CRC), which may be related to altered gut microbiota, changes in bile metabolism, as well as cellular and molecular effects in the proximal colon. In gallstone-associated CRC patients, the association between consensus molecular subtypes of CRC should be clarified to identify if specific pathways are related.

Keywords: Gut microbiota, Cholesterol gallstones, Colorectal cancer.

(Please cite as: Rezasoltani S, Sadeghi A, Radinnia E, NasehA, Gholamrezaei Z, Looha A, et al. The association between gut microbiota, cholesterol gallstones and colorectal cancer. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S8-S13).

Circulating tumor DNA applications in treatment monitoring of metastatic colorectal cancer patients

Nesa Kazemifard, Amir Sadeghi, Behnaz Varaminian, Hamid Rezvani, Ahmad Ayadi, Ramin Talaie, Arfa Moshiri

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 14-21
https://doi.org/10.22037/ghfbb.v12i0.1812

Colorectal cancer is the third most common cancer worldwide. New cancer treatment strategies such as monoclonal antibodies against growth factor and angiogenesis receptors have improved the overall survival (OS) and progression-free survival (PFS) in metastatic colorectal cancer (mCRC) patients. However, acquired resistance could happen after these therapies. Circulating tumor DNA (ctDNA) is the DNA fraction derived from tumor cells which could be applied as a non-invasive method for detecting tumor mutations before, during, and after therapies. Here, we reviewed most of the studies examining ctDNA as treatment monitoring in mCRC patients who receive different target therapies. Also, we compared ctDNA with other existing cancer-treatment monitoring methods.

Keywords:  Circulating tumor DNA, Colorectal cancer, Treatment monitoring.

(Please cite as: Kazemifard N, Sadeghi A, Varaminian B, Rezvani H, Ayadi A, Talaie R, et al. Circulating tumor DNA applications in treatment monitoring of metastatic colorectal cancer patients Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S14-S21).

Original Article


Prevalence and Prognostic Role of PIK3CA E545K Mutation in Iranian Colorectal Cancer Patients

Reza Ranjbar, Somayeh Mohammadpour, Amir Torshizi Esfahani, Sina Namazian, Mohammad Yaghob-Taleghani, Kaveh Baghaei, Seyed Abdolreza Mortazavi Tabatabaei, Leila Pasharavesh, Ehsan Nazemalhosseini Mojarad

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 22-29
https://doi.org/10.22037/ghfbb.v12i0.1829

Aim: This study aimed to evaluate the distribution of PIK3CA E545K mutation in Iranian CRC patients and explored its roles in disease prognosis.

Background: Deregulation of the phosphoinositide 3-kinase (PI3K) pathway contributes to the progression of tumors. The p110a (PIK3CA), a catalytic subunit of PIK3, is mutated in many types of cancers. Exon 9 (E545K) is the most frequently mutated hotspot in PIK3CA in colorectal cancer (CRC). However, the prognostic role of PIK3CA E545K mutation needs to be elucidated.

Methods: Tumors from 187 CRC patients were retrospectively collected from the Taleghani and Shohada Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran, between 2010 and 2017. PIK3CA E545K status was detected in Formalin-fixed paraffin-embedded (FFPE) tissues using PCR-RFLP methods, and validated by pyrosequencing. Correlations between PIK3CA E545K mutation clinicopathological features were analyzed.

Results: The frequency of PIK3CA E545K gene mutations in CRC patients was 10.7%. Significant correlations were observed in PIK3CA E545K mutation with tumor differentiation and TNM stage (p < 0.042 and p = 0.033, respectively). Kaplan–Meier analysis showed a worse prognosis in overall survival (OS) in patients with PIK3CA E545K mutation (p < 0.001). Multivariate analysis indicated that PIK3CA E545K mutation was a detrimental factor for OS (HR = 6.497, 95% CI: 2.859-14.768, p < 0.021).

Conclusion: A high frequency of PIK3CA E545K mutation was detected in Iranian CRC patients. The results of the present study suggested that PIK3CA E545K mutation may be associated with poor prognosis. These findings require further confirmation via prospective studies with larger samples.

Keywords: PIK3CA, Mutation, Prognosis, Colorectal cancer.

(Please cite as: Ranjbar R, Mohammadpour S, Torshizi Esfahani A, Namazian S, Yaghob-Taleghani M, Baghaei K, et al. Prevalence and prognostic role of PIK3CA E545K mutation in Iranian colorectal cancer patients. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):22-29).

High expression of Snail1 is associated with EMAST and poor prognosis in CRC patients

Somayeh Mohammadpour, Amir Torshizi Esfahani, Raana Karimpour, Farbod Bakhshian, Seyed Abdolreza Mortazavi Tabatabaei, Asma Laleh, Ehsan Nazemalhosseini Mojarad

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 30-36
https://doi.org/10.22037/ghfbb.v12i0.1828

Aim: This study aimed to determine the link between Snail1 expression and CRC patients’ survival as well as its significant association with EMAST status.

Background: Snail1 is an evolutionary preserved zinc-finger transcription protein which contributes to Epithelial-to-mesenchymal transition (EMT). EMT initiates invasion and proliferation in many tumors. Elevated microsatellite alteration at selected tetranucleotide repeats (EMAST) is a marker of poor prognosis in patients with colorectal cancer (CRC). We hypothesized that Snail1 overexpression is an important mediator of metastasis and decreased survival in CRCs that characteristically have EMAST phenotype.

Methods: Quantitative real-time polymerase chain reactions were carried out to analyze the expression levels of Snail1 in both normal and tumor specimens from a total of 122 paraffin-embedded tissues (FFPE) of CRC sample with known EMAST status. The correlation between Snail1 expression and clinicopathological characteristics, survival, and EMAST status were examined.

Results: Snail1 overexpression was detected in tumor tissues in 32% of all examined patients and its positive expression was related to metastasis (p=0.001) and EMAST+ phenotype (P=0.017). Further, positive Snail1 expression correlates with poor overall survival in CRC patients (P=0.01).

Conclusion: Our findings suggest that Snail1 overexpression is not only associated with EMAST but also with clinicopathological variables of poor prognosis. These results indicate that Snail1 expression levels may be useful for establishing novel therapeutic strategies and could help survival improvement in CRC patients.

Keywords: Snail1, Elevated microsatellite alteration at selected tetranucleotide repeats (EMAST), Survival, Colorectal cancer.

(Please cite as: Mohammadpour S, Torshizi Esfahani A, KarimpourR, BakhshianF, Mortazavi TabatabaeiSA, LalehA, et al. High expression of Snail1 is associated with EMAST and poor prognosis in CRC patients. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S30-S36).

Mixture cure model for estimating short-term and long-term colorectal cancer survival

Farzaneh Amanpour, Setareh Akbari, Mehdi Azizmohammad Looha, Mohammad Abdehagh, Mohamad Amin Pourhoseingholi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 37-43
https://doi.org/10.22037/ghfbb.v12i0.1825

Aim: We used mixture cure mode to separately investigate the risk factors for long-term and short-term survival of colorectal cancer patients.

Background: Colorectal cancer (CRC) is the second most common cancer worldwide. In cancer studies, patients’ survival is the most important indicator of patients’ status. Classical methods in analyzing the survival data usually apply Cox proportional hazard regression.

Methods: The study was performed on 1121 patients diagnosed with colorectal cancer. Mixture cure model with Weibull distribution and logit link function was fitted to data.

Results: Odds of long-term survival for rectum cancer patients were lower than for colon cancer patients (OR=0.29(0.09, 0.9)). Also, patients with the advanced stage of the disease had lower odds of long-term survival compared to early-stage patients (OR=0.24(0.06, 0.86)).

In the short-term, the hazard of death for people with normal BMI was lower than the underweight group (HR=0.4(0.21, 0.76)). The short-term hazard of death for rectum cancer was about half of the short-term hazard for colon cancer (HR=0.49(0.29, 0.81)). Further, people with moderately (HR=2.11(1.26, 3.55)) and poorly (HR=4.04(2.03, 8.03)) differentiated tumor grade had a higher short-term hazard of death compared to people with well-differentiated grade.

Conclusion: Predictive variables of colorectal cancer survival showed different effects in short- and long -terms. Site topography was a prognosis for both long-term and short-term survival; BMI and tumor grade were short-term predictors of survival while stage was a long-term predictor of survival.

Keywords: Mixture cure model, Colorectal cancer, Survival.

(Please cite as: Amanpour F, Akbari S, Azizmohammad Looha M, Abdehagh M, Pourhoseingholi MA. Mixture cure model for estimating short-term and long-term colorectal cancer survival. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S37-S43).

Predication of hub target genes of differentially expressed microRNAs contributing in Helicobacter Pylori infection in gastric non-cancerous tissue

Mohsen Norouzinia, Mona Zamanian Azodi, Diba Najafgholizadeh Seyfi, Ali Kardan, Ali Naseh, Zahra Akbari

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 44-50
https://doi.org/10.22037/ghfbb.v12i0.1840

Aim: The main goal of this investigation was to provide an overview on H.pylori effect on gastric tissue via bioinformatics analysis of microarray-identified miRNAs and its target genes.

Background: MicroRNAs which control about 30 to 60% of gene expression in human body play a critical role in different cell growth stages. Expression modification of non-coding (NC) RNAs in H.pylori infections requires further investigations to provide better understanding of their roles in the body.

Methods: GSE54397, the microRNA microarray dataset, was analyzed by GEO2R, the online GEO database for detection of differentially expressed microRNAs and lastly the potential target genes as well as their associated pathways.

Results: A total of 244 miRNAs were detected as differentially expressed (p<0.05 and FC>2) in non-cancerous tissue of gastric with H.pylori infection in comparison with tissues without H.pylori infection. The findings indicated that hub microRNAs and target genes of up-regulated network are KIF9, DCTN3, and CA5BP1 along with hsa-miR-519d, hsa-miR-573, hsa-miR-646, hsa-miR-92a-1, hsa-miR-186, and hsa-miR-892a, respectively. For the down-regulated network, genes of RABGAP1, HSPB11 and microRNAs of hsa-miR-620, hsa-miR-19b-2, hsa-miR-555, and hsa-let-7f-2 were hubs. Most of the up-regulated microRNAs are involved in gastric cancer development while there is no evidence for the down-regulated ones. Yet, all of the hub down-regulated miRNAs are reported to have associations with different kinds of cancer.

Conclusion: The introduced hub miRNAs and genes may serve as feasible markers in the mechanisms of H.pylori infection for different kinds of gastric diseases, in particular gastric cancer. However, their role requires further investigations.

Keywords: MicroRNA, Helicobacter pylori, Regulatory network, Target genes, Hubs, Functional analysis.

(Please cite as: Norouzinia M, Zamanian Azodi M, Najafgholizadeh Seyfi D, Kardan A, Naseh A, Akbari Z. Comparison of Predication of hub target genes of differentially expressed microRNAs contributing in Helicobacter pylori infection in gastric non-cancerous tissue. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S44-S50).

Paracrine signals of mesenchymal stem cells induce epithelial to mesenchymal transition in gastric cancer cells

Parisa Azizi, Sogol Mazhari, Samaneh Tokhanbigli, Fatemeh Naderi Noukabadi, Elahe Daskar Abkenar, Esmaeil Shamsafzali, Kaveh Baghaei

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 51-57
https://doi.org/10.22037/ghfbb.v12i0.1836

Aim: Given the high similarity of phenotypical and secretory properties of mesenchymal stem cells and fibroblasts, this study investigated the possibility of inducing EMT process by mesenchymal stem cells.

Background: Annually, more than 13% of deaths worldwide occur due to cancer. One of the main reasons for the high mortality rate is due to the metastasis of cancer stem cells. Induction of metastasis occurs during the EMT process, which can also be stimulated by fibroblast cells.

Methods: Mesenchymal stem cells (MSCs) were isolated and sub-cultured until passage 3 or 4. AGS cells were co-cultured with MSCs for 4 days. As the positive control group, AGS cells were treated with TGF-? (10ng/ml) for 48h. Finally, the mRNA expression level of Vimentin, ?-catenin, Snail, and E-cadherin as the EMT pattern, were evaluated by RT-PCR technique.

Results: Our findings indicated that AGS cells’ crosstalk with MSCs significantly upregulated fibroblast markers including Vimentin and Snail expression. However, no significant changes were identified for ?-catenin gene expression. Additionally, AGS treatment with MSCs resulted in diminished E-cadherin in the targeted cells.

Conclusion: Based on the results, the AGS cells crosstalk with MSCs activates induction of epithelial mesenchymal transition, which is confirmed through the elevation of Vimentin and Snail expression and reduction of E-cadherin expression as a specific epithelial marker. However, it seems that MSc was not effective on Wnt/ ?-catenin signal gastric cancer cell line.

Keywords: Gastric Cancer, Epithelial mesenchymal transition, Mesenchymal stem cells.

(Please cite as: Azizi P, Mazhari S, Tokhanbigli S, Naderi NoukabadiF, Daskar AbkenarE, Shamsafzali E, et al. Paracrine signals of mesenchymal stem cells induce epithelial to mesenchymal transition in gastric cancer cells. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S51-S57).

Evaluation of MALAT1 promoter DNA methylation patterns in early colorectal lesions and tumors

Vahid Chaleshi, Shiva Irani, Masoud Alebouyeh, Reza Mirfakhraie, Hamid Asadzadeh Aghdaei

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 58-65
https://doi.org/10.22037/ghfbb.v12i0.1820

Background

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is one of the long non-coding RNAs that plays an important role in invasion, cell proliferation and metastasis of various cancers. However, insufficient information on the association of MALAT1 with the methylation process and its role in the development of colorectal cancer is not yet fully available. This study set out to determine the effect of methylation on MALAT1 gene in primary colorectal lesions and tumors to gain further knowledge about the diagnostic and prognostic value of MALAT1.

Materials and methods

Methylation Pattern of MALAT1 promoter determined by Methylation-Specific Polymerase Chain Reaction (MSP) in 86 colorectal primary lesions, tumors and normal specimens. MALAT1 methylation pattern was compared in tumor and polyp tissue. In order to obtain more accurate results, we investigated the association of MALAT1 promoter methylation pattern with clinicopathologic factors in patients.

Results

The results indicated that the MALAT1 promoter methylation pattern in tumor tissue, primary lesions tissue and normal was not significant difference (p=0.430). Moreover, compared, the MALAT1 promoter methylation pattern between polyp types and tumor tissue groups was not significant (p=0.437). Surprisingly, the methylation frequency of MALAT1 methylation was significantly higher in colon lesions in comparison with their rectum lesion, p = 0.035. In addition, significant hypermethylation of MALAT1 was not observed between the other patients’ clinicopathological data at both polyps 46/66 and tumor tissue 20/66.

Conclusion

This study suggests that the MALAT1 promoter methylation pattern in patients with colorectal primary lesions and tumors compared with normal tissue as not a significant risk factor for colorectal cancer. Moreover, clearance the significantly higher methylation frequency in colon lesions in comparison with their rectum lesion need to be further explored.

Gallbladder cancer integrated bioinformatics analysis of protein profile data

Mohammad Reza Zali, Mona Zamanian Azodi, Zahra Razzaghi, Mohammad Hossain Heydari

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 66-73
https://doi.org/10.22037/ghfbb.v12i0.1811

Aim: Identifying the critical genes that differentiate gall bladder cancer from a normal gall bladder and the related biological terms was the aim of this study.

Background: The molecular mechanism underlying gall bladder cancer (GBC) trigger and development still requires investigations. Potential therapeutic biomarkers can be identified through protein-protein interaction network prediction of proteome as a complementary study.

Methods: Here, a literature review of proteomics studies of gall bladder cancer from 2010 to 2019 was undertaken to screen differentially expressed proteins in this cancer. A network of 27 differentially expressed proteins (DEPs) via Cytoscape 3.7.1 and its plug-ins was constructed and analyzed.

Results: Ten proteins were introduced as hub-bottlenecks among which four were from DEPs. The gene ontology analysis also indicated that positive regulation of multi-organism process and regulation of response to biotic stimulus are the most disrupted biological processes of GBC considering their relationships with the DEPs.

Conclusion: ACTG, ALB, GGH, and DYNC1H1, and relative biological terms were introduced as drug targets and possible diagnostic biomarkers.

Keywords: Gallbladder cancer, Protein-protein interaction network analysis, Hub-bottleneck proteins, Biological process.

(Please cite as: Zali MR, Zamanian Azodi M, Razaghi Z, Heydari MH. Gallbladder cancer integrated bioinformatics analysis of protein profile data. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S66-S73).

The effect of intestinal microbiota metabolites on HT29 cell line using MTT method in patients with colorectal cancer

Somayeh Jahani-Sherafat, Masoumeh Azimirad, Hajieh Ghasemian-Safaei, Hadi Ahmadi Amoli, Sharareh Moghim, Ghazal Sherkat, Esmaeil Shamsafzali, Mohammad Reza Zali

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 74-79
https://doi.org/10.22037/ghfbb.v12i0.1815

Aim: The aim of this study was to evaluate the effect of intestinal microbiota metabolites in colorectal cancer patients on HT29 cell line using MTT assay.

Background: Colorectal cancer is one of the most common malignant tumors. Human guts harbor abundant microbes that adjust many aspects of the host physiology. Increasing studies suggest that gut microbiota play a significant role in the incidence and expansion of CRC, as a result of virulence factors, bacterial metabolites, or inflammatory pathways.

Methods: In this cross-sectional study, 60 biopsy samples including 30 cancerous and 30 adjacent healthy tissues were collected from patients with CRC during 2017. Biopsy samples were first cultured on Thioglycollate broth medium for 24hr after which the microbiota metabolites were filtered and stored at -20 C° for further evaluation. HT29 cells were treated by microbiota metabolites at different times (3, 6, 12, 18h) and its viability was assessed by MTT assay.

Results: The cells treated with microbiota metabolites showed increased viability and proliferation in time-dependent analysis by MTT assay, but there was not significant differences between the two groups.

Conclusion: It seems that microbial metabolites are able to induce proliferation and increase cell viability and thus induce colorectal cancer.

Keywords: Metabolites, Cell line, MTT, Colorectal cancer.

(Please cite as: Jahani-Sherafat S, Azimirad M, Ghasemian-Safaei H, Ahmadi Amoli H, Moghim SH, Sherkat Gh, et al. The effect of intestinal microbiota metabolites on HT29 cell line using MTT method in patients with colorectal cancer. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S74-S79).

Contribution of NOTCH signaling pathway along with TNF-? in the intestinal inflammation of ulcerative colitis

Mahsa Ghorbaninejad, Raheleh Heydari, Parvaneh Mohammadi, Shabnam Shahrokh, Mehrdad Haghazali, Binazir Khanabadi, Anna Meyfour

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 80-86
https://doi.org/10.22037/ghfbb.v12i0.1821

Aim: The aim of this study was to determine gene expression levels of TNF-?, NOTCH1, and HES1 in patients with UC.

Background: Intestinal inflammation and epithelial injury are the leading actors of inflammatory bowel disease (IBD), causing an excessive expression of pro-inflammatory cytokines such as TNF-?. Also, target genes of NOTCH signaling are involved in the regulation of intestinal homeostasis. Previous studies have demonstrated that TNF-? increases in ulcerative colitis (UC) patients, but the relationship between TNF-? and NOTCH signaling pathway in UC etiopathology needs further study.

Methods: Twelve active UC patients and twelve healthy controls were enrolled in this study. RNA was extracted and the mRNA expression levels of TNF-?, NOTCH1, and HES1 were examined using real-time PCR analyses. Further, transcriptome data deposited in Gene Expression Omnibus (GEO) database were analyzed to detect the differential expression of TNF superfamily and NOTCH1 gene in IBD patients. Finally, the interaction of TNF-? and NOTCH signaling was obtained from The SIGnaling Network Open Resource 2.0 (SIGNOR 2.0) database.

Results: The transcription levels of TNF-?, NOTCH1, and HES1 genes were significantly elevated in UC patients compared with control (p < 0.05). In addition, GEO results confirmed our expression results. SIGNOR analysis showed that TNF-? interacts with NOTCH signaling components.

Conclusion: Based on our data, we observed that NOTCH1 and HES1 in co-operation of TNF-?, may play an important role in pathogenesis of UC. The members of NOTCH signaling pathway can be ideal candidates to target the therapy of IBD.

Keywords: Ulcerative colitis, TNF-?, NOTCH signaling, HES1.

(Please cite as: Ghorbaninejad M, Heydari R, Mohammadi P, Shahrokh SH, Haghazali M, Khanabadi B, et al. Contribution of NOTCH signaling pathway along with TNF-? in intestinal inflammation of ulcerative colitis. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S80-S86).

Estimation the direct cost of inflammatory bowel disease in Iranian patients: the one-year follow-up

Hedieh Balaii, Meysam Olfatifar, Sepideh Olianasab Narab, Asghar Arab Hosseini, Ali Seyed Salehi, Shabnam Shahrokh

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 87-93
https://doi.org/10.22037/ghfbb.v12i0.1824

Aim: We conducted this study to estimate the direct medical cost of Iranian IBD patients.

Background: In the economic evaluation setting, descriptive epidemiological studies can provide substantial information for health system policymakers in taking accountable decisions for diseases such as Inflammatory Bowel Disease (IBD).

Methods: To do so, we used a self-designed checklist to collect demographic and medical cost information for IBD patients. We also tried to have a national estimation of IBD costs.

Results: The mean annual medical cost of IBD was 18354.52 PPP$. Crohn's disease (CD) vs. ulcerative colitis (UC) and UC township patients vs. Tehran resident patients had higher medical costs (31160.79 PPP$; P<0.001) and (20840.23 PPP$, P<0.025). The largest medical cost spent in both IBD subtypes (CD/UC) was attributed to biological agents, especially in UC patients. We estimated that the mean annual cost of IBD in Iran for 2017 was 746315864 (95% CI: 602964172, 964685749) PPP$ (constant incidence) and 862776811 (95% CI: 697055402, 1115222835) PPP$ (increment incidence) respectively.

Conclusion: Our results suggest that for management of IBD patients, policymakers should address shifting the medical costs to biological agents, the higher cost of CD, and the impact of underlying factors on the distribution of these medical costs.

Keywords: Inflammatory bowel disease; Medical cost; Crohn's disease; Ulcerative colitis.

(Please cite as: Balaii H, Olfatifar M, Olianasab Narab S, Arab Hosseini A, Seyed Salehi A, Shahrokh SH. Estimation the direct cost of inflammatory bowel disease in Iranian patients; the one- year follow-up. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S87-S93).

Association between variants of the autophagy related gene ATG16L1 in inflammatory bowel diseases and clinical statues

Shaghayegh Baradaran Ghavami, Fateme Kabiri, Mahyar Nourian, Hedieh Balaii, Shabnam Shahrokh, Vahid Chaleshi, Ghazal Sherkat, Farzaneh Shalileh, Hamid Asadzadeh Aghdaei

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 94-100
https://doi.org/10.22037/ghfbb.v12i0.1838

Aim: In the present study, two main variants of ATG16L1 gene, rs2241880 T300A and rs2241879 C/T, were evaluated in IBD patients as well as in remission and flareup phase across an Iranian population for the first time.

Background: Inflammatory bowel disease (IBD) has found increasing global incidence and prevalence in recent years especially among pediatrics. ATG16L1 is the major gene that regulates autophagy pathway. The autophagy pathway also affects dysbiosis.

Methods: Genomic DNA was isolated from peripheral blood samples following salting out extraction method. The genotypes of ATG16L1 polymorphisms rs2241880 T300A and rs2241879 C/T were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results: In this case control study, a total of 101 IBD patients (75 ulcerative colitis (UC) and 26 Crohn’s disease (CD)) and 99 healthy controls were evaluated. In the present study, a significant association was found between rs2241879 single nucleotide polymorphism on ATG16L1 gene and increased risk of IBD among an Iranian population (P=0.01). There was no statistically significant relationship between rs2241880 and IBD risk (P= 0.42). The effect on these two variants was investigated in relapse and flareup phase which was not significant either, but in CD, rs2241879 and rs2241880 were difference in the relapse phase.

Conclusion: The results showed that ATG16L1 gene rs2241879 has a significant relationship with increased risk of IBD among an Iranian population. Individuals with C allele showed a significant relationship with 1.68-fold increased risk of IBD (P=0.01; adjusted OR=1.68; 95% CI=1.13-2.50).

Keywords: Autophagy, ATG16L1, Inflammatory bowel disease, Diseases status.

(Please cite as: Baradaran Ghavami SH, Kabiri F, Nourian M, Balaii H, Shahrokh SH, Chaleshi V, et al. Association between variants of the autophagy related gene ATG16L1 in inflammatory bowel diseases and clinical statues. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S94-S100).

The effect of working in auto factory on functional constipation and bowel habit

Hadis Najafimehr, Hosein Yadegari, Hamed Taherinejad, Khosrow Manhoie, Seyed Ramin Rasooli, Abbas Moradi, Mohamad Javad Akbariju, Hosein Mohseni, Sabah Ghadimi, Hamid Mohaghegh Shalmani

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 101-107
https://doi.org/10.22037/ghfbb.v12i0.1681

Aim: The aim of the present study was to evaluate the factors associated with functional constipation (FC) and to determine a normal range of bowel movement (BM) in an Iranian Auto factory’s workers.

Background: The digestive system may be affected by workplace conditions. Some occupational conditions can affect the bowel habit and FC.

Methods: In this cross-sectional study, 3590 workers who worked in Tehran suburb in 2017 were evaluated. The workers worked in morning or rotatory shifts and in the official and non-official sections. In addition to demographic and stool frequency questions, workers were asked to complete the Rome IV Questionnaire.

Results: The normal range of BM frequency was determined between one and three per day. The BM frequency had a significant association with age (P=0.002), marital status (P=0.024), education (P=0.011), exposure to chemical materials (P<0.001), and work section (P<0.001). The total prevalence of FC was 9.7% which was greater among rotatory shift working than among only morning shift workers (10% vs 6%; P=0.02). Independent factors associated with FC were found as age (for 30- 40 years old: OR=1.88; 95% CI (1.20, 3.03) and for ?41 years old: OR=1.91; 95% CI (1.12,3.17)), smoking (OR=1.52; 95% CI (1.20,1.93)) and work section (for Paint section: OR=0.33; 95% CI (0.12,0.87), for montage section: OR=0.44; 95% CI (0.18,1.10), for press & platform section: OR=0.12; 95% CI (0.05,0.37)).

Conclusion: Occupational condition may make a difference in bowel habit. Rotatory shift, official working, and smoking may increase the risk of constipation.

Keywords: Bowel movement, Constipation, Work shift, Auto factory.

(Please cite as: Najafimehr H, Yadegari H, Taherinejad H, ManhoieK, RasooliSR, Moradi A, et al. The effect of working in auto factory on functional constipation and bowel habit. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S101-S107).

Comparison of cytokine and gene activities in tissue and blood samples of patients with celiac disease

Ensieh Khalkhal, Zahra Razaghi, Hakimeh Zali, Ayad Bahadorimonfared, Majid Iranshahi, Mohammad Rostami-Nejad

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 108-116
https://doi.org/10.22037/ghfbb.v12i0.1813

Aim: The aim of this study is to explore the expression of genes associated to celiac disease (CD) in the target tissue and peripheral blood monocytes (PBMC) or serum to introduce possible potential biomarkers.

Background: Celiac disease (CD) is an autoimmune disease induced by gluten ingestion in genetically predisposed individuals. Despite technological progress, small intestine biopsy is still the gold standard for diagnosis of CD.

Methods: CD data were collected from public databases (proteomics and microarray-based techniques documents). Differentially expressed genes (DEGs) in PBMC or serum as well as small intestinal biopsies from celiac patients compared to normal were collected and analyzed to introduce common individuals. Gene ontology was done to identify the involved biological terms.

Results: Among 598 CD genes in biopsies and 260 genes in PBMC or serum, 32 common genes with a similar expression pattern in both sources were identified. A total of 48 biological terms were introduced which were involved in the CD via the determined DEGs. “Cytokine activity” was the most expanded one of the biological terms.

Conclusion: In this analysis, it was concluded that 32 potential biomarkers of CD can be assessed by complementary research to introduce effective and available biomarkers in biopsy and blood.

Keywords: Celiac disease, PBMs, Gene expression, Intestine biopsy.

(Please cite as: KhalKhal E, Razaghi Z, Zali H, Bahadorimonfared A, Iranshahi M, Rostami-Nejad M. Comparison of cytokine and gene activities in tissue and blood samples of patients with celiac disease. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S108-S116).

The effects of IL-8, IL- 6 and IL-1 on the risk of celiac disease: a bayesian regression analysis

Maryam Naserinejad, Sadjad Shojaee, Mehdi Ghobakhlou, Elena Lak, Pegah Eslami, Mohamad Amin Pourhoseingholi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 117-122
https://doi.org/10.22037/ghfbb.v12i0.1826

Aim: The present study aimed to evaluate the association between serum levels of interleukin IL-1, IL-6, IL-8 genes as well as interferon (IFN)-? and the risk of celiac disease (CD).

Background: The role of serum cytokine levels in the pathophysiology of CD is still an open field to be explored.

Methods: This case-control study was performed on 110 patients with CD and 46 healthy controls referring to Taleghani Hospital, Tehran, Iran. Expression levels of IL-1, IL-6, IL-8, and IFN-? were assessed by enzyme-linked immunosorbent assay (ELISA) kits.

Results: The Bayesian intervention odds ratio (OR) and Highest Posterior Density (HPD) interval were 1.133 (95% credible interval 1.018- 1.269), 0.947 (95% credible interval 0.898 - 0.996) and 1.004 (95% credible interval 1.001- 1.009) for IL-1, IL-6, and IL-8 respectively.

Conclusion: The serum level of IFN-? has no effect on the risk of CD, but given the OR and the HPD interval obtained for serum levels of IL-1, IL-6 and IL-8, with one unit increase in IL-1 serum, the risk of CD grows by 1.13 times while one unit increase in IL-6 serum reduces the risk of CD by 15%. Finally, regarding IL-8, the risk of CD increases by 0.004 times with a unit increase in IL-8 serum.

Keywords: Celiac disease, Cytokines, Bayesian logistic regression model.

(Please cite as: Nasserinejad M, Shojaee S, Ghobakhlou M, Lak E, Eslami P, Pourhoseingholi MA. The effects of IL-8, IL- 6 and IL-1 on the risk of celiac disease: a Bayesian regression analysis Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S117-S122).

Introducing tumor necrosis factor as a prominent player in celiac disease and type 1 diabetes mellitus

Sina Rezaei-Tavirani, Mohammad Rostami-Nejad, Reza Vafaee, Enseih Khalkhal, Aliasghar Keramatinia, Mohammad Javad Ehsani Ardakani, Mohammadreza Razzaghi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 123-129
https://doi.org/10.22037/ghfbb.v12i0.1833

Aim: This study aimed to screen the common genes between celiac disease (CD) and type 1 diabetes mellitus to find critical ones.

Background: Celiac disease is a chronic autoimmune disorder which is correlated to type 1 diabetes mellitus (T1DM) in several molecular pathways. Understanding the clear common molecular mechanism of both diseases is of interest to scientists.

Methods: The related genes to the CD and T1DM were obtained from disease query of STRING and included in two separated PPI networks by Cytoscape software version 3.7.1. The networks were analyzed by network analyzer and the hub nodes were determined. The common hubs between the two networks were selected for further analysis and enriched via gene ontology using ClueGO plugin of Cytoscape software. Also, an action map was provided by Cluepedia application of Cytoscape software.

Results: Two separated networks of 2000 and 430 genes were constructed related to T1DM and CD, respectively. A total of 84 and 28 hubs were determined for T1DM and CD, respectively. There were 11 common hubs between the two networks. The first top hubs of Type 1 Diabetes Mellitus and CD networks were insulin (INS) and tumor necrosis factor (TNF), respectively.  Also, 77 biological terms and pathways (in five clusters) were related to the common hubs. Action map revealed a close relationship between hubs.

Conclusion: The result of this study indicated that TNF is key mediator of immune reactions in celiac disease and type 1 diabetes mellitus.

Keywords: Celiac disease, Type 1 diabetes mellitus, TNF, Insulin.

(Please cite as: Rezaei-Tavirani S, Rostami-Nejad M, Vafaee R, Khalkhal E, Keramatinia AA, Ehsani-Ardakani MJ, et al. Introducing tumor necrosis factor as a prominent player in celiac disease and type 1 diabetes mellitus. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S123-S129).

Effects of high fat medium condition on cellular gene expression profile: a network analysis approach

Hamid Asadzadeh-Aghdaei, Mohammad-Mehdi Zadeh-Esmaeel, Somayeh Esmaeili, Mostafa Rezaei –Tavirani, Sina Rezaei –Tavirani, Vahid Mansouri, Fatemeh Montazer

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 130-135
https://doi.org/10.22037/ghfbb.v12i0.1738

Aim: This study aimed to evaluate high fat medium (HFM) effect on the gene expression profile of human Sk-hep1 cells and to determine critical differential proteins.

Background: There is a correlation between high fat diet (HFD), obesity, and non-alcoholic fatty liver disease. Despite wide range of investigations, understanding molecular mechanism of HFD effect on onset and progression of NAFLD warrants further examination. In this study, network analysis is applied to obtain a clear perspective about HFD effects and NAFLD.

Methods: Gene expression profiles of human Sk-hep1 cells treated with HFM versus controls were extracted from GEO. Data were analyzed by GEO2R where the significant and characterized DEGs were included in the PPI network. The top 10 nodes of query DEGs based on four centrality parameters were selected to determine central nodes. The common hub nodes with at least other one central group were identified as central nodes. Action map was provided for the introduced central nodes.

Results: Heterogeneous nuclear ribonucleoprotein family including A1, A2/B1, D, R, and D-like, and five proteins (PRPF40A, SRSF1, PCF11, LSM8, and HSP90AA1) were introduced as differential proteins.

Conclusion: mRNA processing and several biological terms including hypoxia and oxidative stress, apoptosis, regulation of cell morphology and cytoskeletal organization, and differentiation of micro tubes were introduced as dysregulated terms under HFM condition.

Keywords: HFM, Gene expression, PPI network.

(Please cite as: Asadzadeh-Aghdaei H, Zadeh-Esmaeel MM, Esmaeili S, Rezaei Tavirani M, Rezaei Tavirani S, Mansouri V, et al. Effects of high fat medium condition on cellular gene expression profile: a network analysis approach. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S130-S135).

How much does vaccination reduce the rate of HBV infection in Iranian population? a Bayesian adjustment analysis

Sajad Shojaee, Farid Zayeri, Maryam Nasserinejad, Ali Ghasemzadeh, Saeedeh Sadat Beheshti Shirazi, Mahsa Khodadoostan

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 136-144
https://doi.org/10.22037/ghfbb.v12i0.1822

Aim:

The aim of this research was to estimate the changing rate of odds ratio (OR) by varying degrees of hepatitis B virus (HBV) underreporting.

Background:

Data registering is usually associated with much errors such as misclassification, under-reporting, missing data due to lack of co-operation, error prone factor, and also in medical studies due to inadequate diagnosis of physician or low accuracy of laboratory tests. In the present study, which discuss about the actual impact of vaccination on HBV prevention, exposure and response were prone to various errors. Furthermore, some people in the community possibly infected to virus while were not reported in the count of patients with HBV infected.

Methods:

This was a Case control study. Cases include patients with HBV who were referred to the gastroenterology and liver disease research center. Control group include patients without HBV who were performed a fatty liver test at Taleghani hospital laboratory. Bayesian approach and Gibbs sampling algorithm were used to estimate OR.

Results:

According to results, misclassification rate was mild in raw data but with an increase in degree of underreporting for 50 and 500 of unreported cases, OR increased about half and more than double, respectively, while sensitivity decreased strikingly.

Conclusion:

Our analysis asserted that knowing the degree of underreporting is essential to accurately calculate OR and sensitivity. In addition, despite varying OR in the different samples, overall results were similar according to the pattern of exposure and response association.

Key Words: Vaccination, Hepatitis B virus, Misclassification, Underreporting, Bayesian adjustment

Comparative study on guidelines in determining HBV phases in Iranian patients

Sara Ashtari, Afsaneh Sharifian, Behzad Hatami, Seyed Reza Mohebbi, GholamReza Nouri, Monireh Bazdar, Nosratollah Naderi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 145-148
https://doi.org/10.22037/ghfbb.v12i0.1832

Aim: The aim of this study was to compare the different phases of chronic Hepatitis B virus (HBV) infection with different values for normal ALT.

Background: For many years, the upper limit of 40 IU was considered normal for ALT for both sexes, but in recent years this value is challenged and some guidelines have lowered their limit.

Methods: In this cross-sectional study, 2000 HBsAg positive patients who were referred to Taleghani Hospital, Tehran, Iran, from 2011 through 2018 were classified in four groups according to American Association of the study of the liver disease (AASLD), European Association of the study of the liver (EASL) /Asian-Pacific Association of the study of the liver (APASL) and American Collage of Gastroenterology (ACG) guidelines. The frequency of each group based on 3 different guidelines was compared.

Results: In HBeAg positive patients (n=100), the percentage of immune tolerance phase was 43% according to AASLD cutoff for normal ALT (35 IU for men, 25 IU for women), while it was 68% and 28% with regard to EASL/APASL and ACG (30 IU for men, 19 IU for women) cutoffs respectively. In HBeAg negative patients (n=1900), 66.68% were inactive carriers according to AASLD, but the percentage changed to 82.89% and 52.42% considering EASL/APASL and ACG values, respectively.

Conclusion: Using ACG and to a lesser extent AASLD cutoff for ALT, many patients shift from immune tolerance and inactive carrier state into the immune active phase. Thus, more patients are candidates for treatment or intensive workup to determine the extent of liver damage.

Keywords: Chronic hepatitis B, ALT level, CHB phases, Iran.

(Please cite as: Ashtari S, Sharifian A, Hatami B, Mohebbi SR, Nouri G, Bazdar M, et al. Comparative study on guidelines in determining HBV phases in Iranian patients. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S145-S148).

Risk factors of transmission and natural history of chronic hepatitis B infection in Iranian patients

Afsaneh Sharifian, Sara Ashtari, Behzad Hatami, Seyed Reza Mohebbi, Nosratollah Naderi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 149-155
https://doi.org/10.22037/ghfbb.v12i0.1841

Aim: To investigate routes of transmission, demographic characteristics, and frequency of different phases of chronic hepatitis B (CHB) in 2000 Iranian patients.

Background: Knowledge about the most frequent risk factors of CHB and its different phases is very important for optimal prevention and management policy making.

Methods: In this cross-sectional study, 2000 HBsAg positive patients who were referred to Taleghani Hospital from 2011 through 2018 were enrolled. ELISA method was employed to detect serological markers of CHB. Taking into account the HBV DNA and ALT levels and HBeAg status, the patients were classified in four groups, according to AASLD 2017 guideline.

Results: Male and female patients had nearly equal frequencies in our study and 82.5 % of them aged more than 20 years. A great number of our patients (95%) were HBeAg negative and the most frequent risk factors of HBV infection were positive periodontal and family history (40.3% and 24.9%, respectively). The majority of our patients were inactive carriers (63.35%), while s mall number of them were in the immune tolerant group (2.15 %).

Conclusion: Immune tolerance phase group had the minimum number of members in our study and most of them were above 20 years old. This can be due to the mass vaccination of neonates since 1993. Most of CHB patients were in inactive carrier group. Although it is recommended not to treat these patients, performing periodic liver function tests and disease severity assessment is warranted, especially in patients above 40 years old.

Keywords: Chronic hepatitis B, Risk factors, Natural history, Iran.

(Please cite as: Sharifian A, Ashtari S, Hatami B, Mohebbi SR, Naderi N. Risk factors of transmission and natural history of chronic hepatitis B infection in Iranian patients. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S149-S155).

Association of IL28B (IFNL3) rs12979860 mRNA levels, viral load and liver function among HCV genotype 1a infection patients: a cross-sectional study in iranian patients

Seyed Dawood Mousavi Nasab, Abbas Ahmadi Vasmehjani, Homan Kaghazian, Rajab Mardani, Fatemeh Zali, Nayeb Ali Ahmadi, Mohsen Norouzinia, Mohammadreza Razzaghi

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 156-162
https://doi.org/10.22037/ghfbb.v12i0.1834

Aim: The present study was designed to evaluate the correlation of interleukin 28B (IL28B, IFNL3) rs12979860 mRNA levels, viral load, and liver function among hepatitis C virus (HCV) patients genotype 1a.

Background: HCV is considered essentially hepatotropic and is a major health problem around the world.

Methods: This study included 100 HCV-infected patients with HCV genotype1a (G1a) and rs12979860 CC genotype. These patients were divided into two groups according to HCV treatment. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and HCV Load were measured and recorded for each patient. IL28B mRNA levels were determined using real-time polymerase chain reaction assay, and their correlation with clinical data were analyzed. STRING was applied to construct a network and identify interactions between IL28B (IFNL3) and its significant neighbor proteins.

Results: The results revealed a significant relationship between the ALT as well as ALP levels with IL28B rs12979860 mRNA expression level in men, and also with age >50 years. In the treated group, AST level and HCV load had a significant relationship with IL28B mRNA expression level. The results showed that the level of ALP and AST decreased significantly with increased IL28B mRNA expression level in the treated and untreated group, respectively. STRING database showed that IL28B (IFNL3) interacted with ten important neighbor proteins with some of these proteins being involved in signal transduction pathway activating antiviral response.

Conclusion: This study indicated that rs12979860CC genotype could predict IL28B mRNA expression level in HCV-infected patients with G1a. Furthermore, IL28B mRNA expression level may serve as a useful marker for the development of G1a HCV-associated outcomes.

Keywords: HCV patients, Interleukin 28B, IFNL3, mRNA levels, Liver enzyme.

(Please cite as: Mousavi Nasab SD, Ahmadi Vasmehjani A, Kaghazian H, Mardani R, Zali F, Ahmadi NA, et al. Association of IL28B (IFNL3) rs12979860 mRNA levels, viral load and liver function among HCV genotype 1a patients. Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S156-S162).

Effect of sub-MIC values of metronidazole, ciprofloxacin, and imipenem on growth and toxin production in Clostridioides difficile

Farahnaz Sadat Shayegan Mehr, Masoumeh Azimirad, Seyedeh Nazanin Mansouri Gilani, Ayub Ghafurian, Abbas Yadegar

Gastroenterology and Hepatology from Bed to Bench, , 7 December 2019 , Page 163
https://doi.org/10.22037/ghfbb.v12i0.1831

Aim: This study intends to investigate the effect of sub-minimum inhibitory concentration (sub-MIC) of metronidazole, ciprofloxacin, and imipenem on the growth and toxin production in Clostridioides difficile.

Background: C. difficile is the most common causative agent of hospital-acquired diarrhea. Toxin production in C. difficile appears to be a critical process for induction of the disease. Several factors such as antibiotics can facilitate growth and toxin production in C. difficile.

Methods: Five C. difficile strains were grown with and without sub-MIC concentrations of metronidazole, ciprofloxacin, and imipenem (0.5x MIC). The bacterial growth was measured by density at OD620 nm in 0, 4, 8, 12 and 24 h post inoculation. Toxin production was detected using ELISA in culture supernatants as well as in cell pellet.

Results: The five strains showed minor growth variations in the presence and absence of antibiotic sub-MIC values, except for metronidazole, in which the sub-MIC concentration reduced the growth rate of the resistant isolate in comparison with the control without antibiotic. There were no significant variations in the levels of toxin production with the sub-MIC values of antibiotics examined in comparison with antibiotic-free controls. However, the amount of toxin production in the culture supernatant was greater than in the cell pellet.

Conclusion: The findings of this study suggested that sub-MIC concentrations of antibiotics may have minor effects on bacterial growth and toxin production of C. difficile. Taken together, these findings suggest that presence of antimicrobial agents increased expression levels of certain genes, particularly virulence genes, which may help C. difficile to survive.

Keywords: Clostridioides difficile, Toxin production, Bacterial growth, Antibiotics, sub-MIC.

(Please cite as: Shayegan Mehr FS, Azimirad M, Mansouri Gilani SN, Ghafurian A, Yadegar A. Effect of sub-MIC values of metronidazole, ciprofloxacin, and imipenem on growth and toxin production in Clostridioides difficile Gastroenterol Hepatol Bed Bench 2019;12(Suppl.1):S163-S168).