The inter-talk between Mycobacterium tuberculosis and the epigenetic mechanisms

Epigenetics regulate gene function without any alteration in the DNA sequence. The epigenetics represent one of the most important regulators in different cellular processes and have initially been developed in microorganisms as a protective strategy. The evaluation of the epigenetic mechanisms is also important in achieving an efficient control strategy in tuberculosis (TB). TB is one of the most significant epidemiological concerns in human history. Despite several in vivo and in vitro studies that have evaluated different epigenetic modifications in TB, many aspects of the association between epigenetics and TB are not fully understood. The current paper is aimed at reviewing our knowledge on histone modifications and DNA methylation modifications, as well as miRNAs regulation in TB.

Immuno-proteomics analysis between OMV of vaccine and dominant wild type strains of Bordetella pertussis in Iran

Background and Objectives: Despite widespread vaccination programs against pertussis, there has been a worldwide re- surgence of the disease in recent years. We aimed to investigate protein composition of outer membrane vesicles (OMV) of Bordetella pertussis (Bp) and to evaluate the immunogenicity of OMV antigens both in the vaccine and the dominant wild type strains in Iran. Materials and Methods: The OMV were purified from both vaccine and wild type strains. The immunoreactivity of the OMVs was investigated by exposing sera taken from the patients and the vaccinated infants. The protein profiles of OMVs were compared using two-dimensional electrophoresis. The LC-MS/MS was used to analyse and identify differentially ex- pressed protein spots. Results: The two type strains showed differences in their 2D gel protein profile. Further analysis of selected proteins from the dominant Iranian strains using LC-MS/MS demonstrated that the identified proteins fell into different functional catego- ries including (i) metabolism, (ii) membrane transport and secretion system, (iii) biosynthesis and degradation, (iv) adaption, adhesion, pathogenicity, conserved hypothetical and protection responses. Moreover, a number of immunogenic proteins were identified including Bp 2434 (serine protease) and Bp 1616 (putative DNA binding protein) from the vaccine and the wild type strains, respectively which could be considered as potential antigens for an OMV vaccine. Conclusion: OMV Bp could be considered as an alternative vaccine against pertussis, containing the bacterium’s protein antigens that can confer equal efficacy compared to a whole bacterial cell vaccine with advantages such as less side effects and lower costs than acellular pertussis vaccines.

Prediction of the hidden genotype of mixed infection strains in Iranian tuberculosis patients

BACKGROUND

Patients with mixed-strain Mycobacterium tuberculosis infections may be at a high risk of poor treatment outcomes. However, the mechanisms through which mixed infections affect the clinical manifestations are not well recognized. Evidence suggests that failure to detect the pathogen diversity within the host can influence the clinical results. We aimed to investigate the effects of different genotypes in mixed infections and determine their relationship with heteroresistance in the treatment of Iranian tuberculosis patients.

METHODS

One of the genotypes was identified in the culture and another genotype pattern in the mixed infection was predicted by comparing the pattern of MIRU-VNTR between the clinical specimens and their respective cultures in each patient. For all patients, the drug susceptibility testing was carried out on three single colonies from each clinical sample. The follow-up of patients was carried out during six months of treatment.

RESULTS

Based on MIRU-VNTR profiles of clinical samples, we showed that 55.6% (25/45) of the Iranian patients included in the study had mixed infections. Patients with mixed infections had a higher rate of treatment failure, compared to others (P=0.03). By comparing clinical sample profiles to profiles obtained after culture, we were able to distinguish between major and hidden genotypes. Among hidden genotypes, Haarlem (L4.1.2) and Beijing (L2) were associated to treatment failure (6/8 patients).

CONCLUSIONS

To conclude, we propose a procedure using the MIRU-VNTR method to identify the different genotypes in mixed infections. The present findings suggest that genotypes with potentially higher pathogenicity may not be detected when performing experimental culture in patients with mixed infections.

Immuno-proteomics analysis between OMV of vaccine and dominant wild type strains of Bordetella pertussis in Iran

BACKGROUND AND OBJECTIVES

Despite widespread vaccination programs against pertussis, there has been a worldwide resurgence of the disease in recent years. We aimed to investigate protein composition of outer membrane vesicles (OMV) of Bordetella pertussis (Bp) and to evaluate the immunogenicity of OMV antigens both in the vaccine and the dominant wild type strains in Iran.

MATERIALS AND METHODS

The OMV were purified from both vaccine and wild type strains. The immunoreactivity of the OMVs was investigated by exposing sera taken from the patients and the vaccinated infants. The protein profiles of OMVs were compared using two-dimensional electrophoresis. The LC-MS/MS was used to analyse and identify differentially expressed protein spots.

RESULTS

The two type strains showed differences in their 2D gel protein profile. Further analysis of selected proteins from the dominant Iranian strains using LC-MS/MS demonstrated that the identified proteins fell into different functional categories including (i) metabolism, (ii) membrane transport and secretion system, (iii) biosynthesis and degradation, (iv) adaption, adhesion, pathogenicity, conserved hypothetical and protection responses. Moreover, a number of immunogenic proteins were identified including Bp 2434 (serine protease) and Bp 1616 (putative DNA binding protein) from the vaccine and the wild type strains, respectively which could be considered as potential antigens for an OMV vaccine.

CONCLUSION

OMV Bp could be considered as an alternative vaccine against pertussis, containing the bacterium's protein antigens that can confer equal efficacy compared to a whole bacterial cell vaccine with advantages such as less side effects and lower costs than acellular pertussis vaccines.

Occult hepatitis C virus infection in hemophilia patients and its correlation with interferon lambda 3 and 4 polymorphisms

Occult HCV infection (OCI) is described as the presence of HCV RNA in the liver and peripheral blood mononuclear cells (PBMCs), with no HCV RNA in the serum. Single-nucleotide polymorphisms (SNPs) near interferon lambda 3/4 (IFNL3/4) gene are associated with spontaneous clearance and treatment response in patients with hepatitis C virus (HCV) infection. In this study, we evaluated the frequency of OCI in hemophilia patients and determined the association of three IFNL3 SNPs (rs12979860, rs12980275, and rs8099917) and IFNL4 ss469415590 with OCI positivity. A total of 450 hemophilia patients with HCV negative markers were included in this study. Positive- and negative-stranded HCV-RNA was determined in peripheral blood mononuclear cells (PBMCs) samples by reverse-transcription polymerase chain reaction (RT-PCR) method. IFNL3 SNPs and IFNL4 ss469415590 were genotyped by PCR-RFLP and TaqMan® Real-Time PCR methods, respectively. The frequency of OCI was estimated at 10.2%. Among 46 OCI patients, 56.5%, 23.9%, and 19.6% were infected with HCV-1b, HCV-1a, and HCV-3a, respectively. Compared to patients without OCI, unfavorable IFNL3 rs12979860 TT, IFNL3 rs8099917 GG, IFNL3 rs12980275 GG, and IFNL4 ss469415590 ∆G/∆G genotypes were more frequently reported in OCI patients. The multivariate logistic regression analysis showed that alanine aminotransferase (ALT), cholesterol, triglyceride, IFNL3 rs12979860 (TT), IFNL3 rs8099917 (GG), IFNL3 rs12980275 (GG), and IFNL4 ss469415590 (∆G/∆G) were associated with OCI positivity. In conclusion, we studied the incidence of OCI in Iranian patients with hemophilia for the first time. Our results demonstrated that unfavorable genotypes of IFNL3 SNPs and IFNL4 ss469415590 have a strong relationship with OCI positivity. It seems that the host immune response plays a vital role in OCI positivity.

Evaluation of protective immunity responses against pneumococcal PhtD and its C-terminal in combination with outer-membrane vesicles as adjuvants

Introduction. Streptococcus pneumoniae is a significant bacterial pathogen in humans. Currently, there are two types of pneumococcal vaccines, but there are concerns regarding their application.

Aim. Since many pneumococcal proteins are serotype-independent, polyhistidine triad protein D (PhtD) has been selected as a vaccine candidate.

Methodology. We prepared recombinant PhtD and its C-terminal fragment (PhtD-C) using alum and outer-membrane vesicles (OMVs) as adjuvants. The combinations were injected intraperitoneally into mice, and then total immunoglobulin G (IgG) and specific IgG, IgG1 and IgG2a were measured. A serum bactericidal assay and opsonophagocytosis were also performed as complementary tests. Meningococcal OMVs were used as an adjuvant.

Results. The levels of specific IgG and IgG1 against combinations of PhtD and its C-terminal with OMVs and alum as adjuvants increased at the time of the third mouse immunization on day 35. Forty per cent and 60% of S. pneumoniae ATCC 6303 (serotype 3) as a virulent pneumococcal strain, respectively, were killed in the opsonophagocytosis test and these results could also be observed in the serum bactericidal assay. Mice mmunized iwith PhtD and its C-terminal with OMVs and alum as adjuvants survived after 10 days of pneumococcal challenge.

Conclusion. The combination of PhtD and PhtD-C with alum produced optimal results, but the combination of PhtD and PhtD-C with OMVs produced minimal results by comparison. The survival rates were also measured, and these corresponded with the results of the immunological assessments. Our findings showed that mice receiving PhtD and PhtD-C plus OMV and alum had higher survival rates than the mice in the other groups.

A randomized controlled trial investigating the effect of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols on the intestinal microbiome and inflammation in patients with ulcerative colitis: study protocol for a randomized controlled trial

Background

No conclusive treatment is available for irritable bowel disease (IBD). Adherence to a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) might alleviate clinical symptoms of IBD. However, no study has investigated the effect of low FODMAPs diet on the intestinal microbiota and inflammatory biomarkers in patients with IBD. The aim of current study is to examine the effect a low FODMAP diet on IBD symptoms, inflammation, and the intestinal microbiota in patients with ulcerative colitis.

Methods and analysis

This study is a randomized clinical trial. Thirty patients with mild to moderate ulcerative colitis will be randomly allocated to receive a low FODMAP diet (n = 15) or to continue their usual diet as control (n = 15), for 4 weeks. The quantity of intestinal microbiota including Clostridium cluster IV, Faecalibacterium prausnitzii, Rosburia spp., Lactobacillus spp., Bifidobacteria spp., Akkermansia muciniphila, Bacteroides fragilis, and Ruminococcus spp., and the Firmicutes to Bacteroidetes ratio and calprotectin and lactoferrin levels will be explored in fecal samples from patients. In addition, anthropometric measures and biochemical assessments including serum concentrations of highly sensitive-C reactive protein (hs-CRP), tumour necrosis factor-α (TNF-α) and IL-1β will be taken from patients at baseline and end of the study. The study has been registered in IRCT (IRCT20181126041763N1; registration date: 2019-01-18).

Discussion

Consumption of a low-FODMAP diet might decrease systemic and intestinal inflammation, change the bacterial population in the gut, and modulate clinical symptoms in patients with ulcerative colitis. Further studies investigating the effect of such a diet on other variables, including other bacterial species and inflammatory cytokines, are required to confirm future findings of this trial.

Main gut bacterial composition differs between patients with type 1 and type 2 diabetes and non-diabetic adults

Background

Regarding the role of gut microbial dysbiosis in hyperglycemia, we aimed to compare the main gut bacterial composition among type 1 and type 2 diabetic patients and healthy non-diabetic adults.

Methods

A total of 110 adult subjects (49 patients diagnosed with type 2 diabetes, 21 patients diagnosed with type 1 diabetes and 40 healthy persons) were included in this case-control study. The intestinal microbiota composition was investigated by quantitative real-time polymerase chain reaction (qPCR) method targeting bacterial 16S rRNA gene. Comparison between three groups was done using one-way analysis of variance.

Results

The participants' mean age in the type 1 diabetes, type 2 diabetes and control groups was 35.4, 57.2 and 38.0 years, respectively. Higher level of Escherichia, Prevotella and Lactobacillus was observed in both type 1 and type 2 diabetic patients compared with the healthy group (P ˂0.001). In contrast, bacterial load of Bifidobacterium, Roseburia and Bacteroides was higher in healthy control group (P < 0.05). Faecalibacterium was significantly lower in type 1 diabetic patients compared with the other two groups (P ˂0.001). No significant difference was found in Akkermansia level among three groups.

Conclusions

Gut microbial alterations have been observed among patients suffering from type 1 and type 2 diabetes mellitus and healthy control adults. Butyrate producing genera including Roseburia and Faecalibacterium decreased while Escherichia, Prevotella and Lactobacillus increased in diabetic patients compared to healthy subjects. Modulating approaches of gut microbiota composition could be helpful in diabetes management.

A novel method for the extraction of outer membrane vesicles (OMVs) from Bordetella pertussis Tohama strain

BACKGROUND AND OBJECTIVES

There are many pertussis outbreaks which is mainly due to the reduction in the immunity of acellular pertussis (aP) vaccines. Therefore, there is a crucial necessity to develop a new generation of pertussis vaccine. Preceding researches have shown that Bordetella pertussis outer membrane vesicles (OMVs) have appropriate specifications, making them a suitable vaccine candidate against pertussis.

MATERIALS AND METHODS

The OMVs were separated by a new serial ultra centrifugation technique. Transmission electron microscopy (TEM) examination, SDS-PAGE, Western blotting and ELISA assay were used to characterize the OMVs.

RESULTS

TEM studies showed the size of the extracted OMVs at 40-200 nm. The presence of pertussis toxin, filamentous hemagglutinin, and pertactin was verified using Western blot and ELISA assay.

CONCLUSION

The presented technique is a simple and effective way to obtain OMVs from Bordetella pertussis. So it can be utilized as an appropriate procedure in the development of an OMV-based vaccine against pertussis.

Socio-demographic Characteristics, Biochemical and Cytokine Levels in Bulimia Nervosa Candidates for Sleeve Gastrectomy

BACKGROUND

Eating disorders (EDs) are widely known by abnormal eating behaviors associated with significant medical complications. Bulimia nervosa (BN) is an eating disorder characterized by uncontrolled episodes of overeating typically followed by some form of compensatory behaviors. We aimed to determine the relationships between socio-demographic characteristics, biochemical markers, and cytokine levels in BN candidates for laparoscopic sleeve gastrectomy (LSG).

METHODS

A case-control study was designed among 76 BN participants of Iranian descent who were candidates for LSG based on defined criteria for Bulimia by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The healthy control subjects (n = 42) were selected at random from academic staff in the college. Moreover, levels of biochemical parameters and serum cytokines were measured in serum samples.

RESULTS

Routine consumption of caffeine (odds ratio [OR] = 3.1, 95% CI: 1.23-6.41, P = 0.013), tobacco (OR = 1.8, 95% CI: 0.67-3.57, P = 0.03), and alcohol (OR = 3.6, 95% CI: 0.84-7.18, P = 0.048), and depression history (OR = 2.8, 95% CI: 0.76- 5.79, P = 0.037) were substantially more common among patients with bulimia. Also, the serum levels of fasting blood sugar (P < 0.001), HbA1c (P = 0.04), cholesterol (P = 0.03), triglycerides (P = 0.01), blood urea nitrogen (P = 0.03), and pro-inflammatory cytokines including IL-1β, IL-6, and TNF-α were significantly higher in BN candidates for LSG (P ≤ 0.001).

CONCLUSION

Our findings reveal that lifestyle-related risk factors and a depression history were both related with a significantly increased risk of BN among the candidates for LSG. Furthermore, there is a relationship between clinical characteristics as well as levels of various biochemical and cytokines parameters in serum of BN patients.

Positional Vertigo and Unilateral Gradual Hearing Loss Following Sleeve Gastrectomy: A Case Report

Laparoscopic sleeve gastrectomy (LSG) is an effective treatment option in patients with morbid obesity, with rare long-term sideeffects. In this report, we present a 42-year-old woman who reported positional vertigo and unilateral gradual hearing loss plus continuous tinnitus after LSG. The patient had no signs or symptoms of mental health disorders and the results of the haematological and serum biochemical tests were normal. However, audiometric test revealed mild sensorineural hearing loss with magnitude in high-frequency tones. Also, acoustic reflex threshold showed neural pathway damage, particularly at high frequencies, with no reflex. Pure tone audiometry showed signs of nerve damage in the inner ear. One possible justification for these complications might be eustachian tube dysfunction due to muscle relaxation. Muscle relaxation itself may occur as a result of adipose tissue loss around the ear muscles. Further evidence, however, would be required to better determine whether these complications are attributable to LSG, and to illuminate exact underlying reasons for such complications.

Cloning, Expression and Purification of Espc, Espb and Espc/Espb Proteins of Mycobacterium tuberculosis ESX-1 Secretion System

BACKGROUND

It is estimated that one third of the world's population is infected with Mycobacterium tuberculosis (Mtb), the causative agent of Tuberculosis (TB). The BCG vaccine is widely used to fight against TB; however, many question its ability to provide complete protection from Mtb. Recently, the "Region of Difference 1" (RD1) set of genes were shown to be involved in the pathogenesis of Mtb. Downstream of RD1 transcription region, two proteins are encoded, known as EspB and EspC, which were found to contribute to Mtb virulence.In this study these two proteins are targeted as potential vaccine candidates against TB.

METHODS

The EspB and EspC Mtb genes were codon-optimized for expression and synthesis in Escherichia coli (E. coli). The amplicons were cloned into a pET21a expression vector and transformed into E. coli BL21(DE3). The expression and purity of the expressed proteins (i.e. rEspC, rEspB and rEspC/EspB) were confirmed by SDS-PAGE and Western blotting. Moreover, BALB/c mice were immunized against Mtb using the recombinant proteins. Finally, the mice sera were analyzed via Western blotting.

RESULTS

EspC, EspB, and EspC/EspB fusion genes were cloned and expressed in E. coli. Both SDS-PAGE and Western blots confirmed the presence and successful purification of the desired proteins. Moreover, antisera produced against the purified recombinant proteins reacted with Mtb proteins.

CONCLUSION

rEspC, rEspB, and rEspC/EspB could be expressed and purified using an E. coli expression system. The recombinant proteins induced the production of antibodies in BALB/c mice that reacted with Mtb proteins.

Coronavirus disease 2019 (COVID-19) and pediatric gastroenterology

The coronavirus disease 2019 (COVID-19) is responsible for the new pandemic, which remains an important health and economic challenge worldwide. The causative agent is a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is similar to SARS-CoV-1 and Middle East respiratory syndrome coronavirus (MERS-CoV). Adult infection with respiratory symptoms was considered in the beginning of the pandemic. Now, it has been reported that SARS-CoV-2 infects children and other organs such as the gastrointestinal tract. SARS-CoV-2 enters the host cells through angiotensin converting enzyme-2 (ACE2) receptors as the main receptor expressed in various organs such as the lungs and gastrointestinal tract. Studies on children and the clinical manifestations of COVID-19 do not completely explain the natural course of infection in children, and precisely how the GI tract is involved is not understood. The present article highlights the gastrointestinal manifestations and pathological findings in children with COVID-19. According to the evidence, SARS-CoV-2 infection is milder in children and may present different clinical symptoms from adults. Common clinical manifestations of pediatric COVID-19 include cough, fever, sore throat, malaise, fatigue, and GI symptoms such as diarrhea, abdominal pain, nausea, and vomiting. Furthermore, liver and pancreatic enzymes may be elevated during the pediatric COVID-19 course. Asymptomatic children carriers are potential sources of infection for adults, especially elderly ones. Diagnosis, treatment, and isolation of children are the most effective ways to control the expansion of the COVID-19 pandemic.

Extraction and Evaluation of Outer Membrane Vesicles from Two Important Gut Microbiota Members, Bacteroides fragilis and Bacteroides thetaiotaomicron

Objective

The gastrointestinal tract (GI) is colonized by a complex microbial community of gut microbiota. Bacteroides spp. have significant roles in gut microbiota and they host interactions by various mechanisms, including outer membrane vesicle (OMVs) production. In the present study, we extracted and assessed Bacteroides fragilis (B. fragilis) and Bacteroides thetaiotaomicron (B. thetaiotaomicron) OMVs in order to evaluate their possible utility for in vivo studies.

Materials and Methods

In this experimental study, OMVs extraction was performed using multiple centrifugations and tris-ethylenediaminetetraacetic acid (EDTA)-sodium deoxycholate buffers. Morphology, diameter, protein content, profile, and lipopolysaccharide (LPS) concentrations of the OMVs were assessed by scanning electron microscopy (SEM), nanodrop, Bradford assay, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and the Limulus Amoebocyte Lysate (LAL) test, respectively. Zeta potential (ζ-P) was also assessed. The viability effect of OMVs was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay in Caco-2 cells.

Results

Spherical OMVs with diameters of 30-110 nm were produced. The OMVs had different protein profiles. The LPS concentrations of the B. fragilis and B. thetaiotaomicron OMVs were 1.80 and 1.68 EU/mL, respectively. ζ-P of the B. fragilis OMVs was -34.2 mV and, for B. thetaiotaomicron. it was -44.7 mV. The viability of Caco-2 cells treated with OMVs was more than 95%.

Conclusion

The endotoxin concentrations of the spherical OMVs from B. fragilis and B. thetaiotaomicron were within the safe limits. Both OMVs had suitable stability in sucrose solution and did not have any cytotoxic effects on human intestinal cells. Based on our results and previous studies, further molecular evaluations can be undertaken to design OMVs as possible agents that promote health properties.

Enhancing the differentiation of specific genotypes in Mycobacterium tuberculosis population

Today, significant attention is directed towards the global lineages and sublineages of Mycobacterium tuberculosis (Mtb). NEW-1 (SIT 127) and CAS1-Delhi (SIT 26) strains are recognized as growing and circulating Mtb genotypes, especially in Asian countries. It is crucial to develop or enhance Mtb genotyping methods for a more accurate and simple differentiation of these families. We used 24-loci mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing for genotyping 217 Mtb isolates. To select the optimal MIRU-VNTR loci, we calculated the Hunter-Gaston discriminatory index (HGDI), allelic diversity, and accumulation of percentage differences (APDs) between the strains among different groups of genotypes (NEW-1 and non-NEW-1; CAS1-Delhi and non-CAS). Finally, the minimum spanning tree was constructed for clustering analysis. In the NEW-1 population, loci with APD > 60% were found to have a high discriminatory power. VNTR loci with APD > 50% showed high discrimination power for the CAS population. Our findings suggest that APDs, which are valuable for the selection of VNTR loci sets, may improve the discriminatory power of MIRU-VNTR typing for identification of Mtb genotypes in specific regions.

Gut Bacteria and their Metabolites: Which One Is the Defendant for Colorectal Cancer?

Colorectal cancer (CRC) is a worldwide health concern which requires efficient therapeutic strategies. The mechanisms underlying CRC remain an essential subject of investigations in the cancer biology field. The evaluation of human microbiota can be critical in this regard, since the disruption of the normal community of gut bacteria is an important issue in the development of CRC. However, several studies have already evaluated the different aspects of the association between microbiota and CRC. The current study aimed at reviewing and summarizing most of the studies on the modifications of gut bacteria detected in stool and tissue samples of CRC cases. In addition, the importance of metabolites derived from gut bacteria, their relationship with the microbiota, and epigenetic modifications have been evaluated.

Gentamicin-Loaded Chitosan Nanoparticles Improve Its Therapeutic Effects on Brucella-Infected J774A.1 Murine Cells

BACKGROUND

Final elimination of some intracellular bacterial agents, such as Brucella, is often a complex issue and impossible to achieve, primarily due to the presence and survival of the bacteria within phagocytic cells. By penetrating into the cell membrane, drug delivery nanosystems can reduce the number of intracellular bacteria. The aim of this study was to assess the efficacy of chitosan nanoparticles on the delivery of gentamicin into Brucella infected J774A.1 murine cells in vitro.

MATERIALS AND METHODS

Chitosan nanoparticles (NPs) were synthesized using ionic gelation technique. The shape, size and charge of NPs, loading rate and release of the drug were investigated. Finally, the effects of gentamicin-loaded chitosan NPs (Gen-Cs) and free gentamicin on J774A.1 murine cells infected with these bacteria were examined.

RESULTS

The mean size and charge of NPs were computed as 100 nm and +28mV, respectively. The loading capacity of NPs was 22%. About 70% of the drug was released from NPs during the first 8 hours. Antimicrobial activity of the two formulations showed that MIC (minimum inhibitory concentration) of the Gen-Cs and free drug was 3.1 and 6.25 µg, respectively. The minimum bactericidal concentration of the NPs-loaded drug and free drug was 6.25 and 12.5 µg, respectively. Cell culture analysis revealed that there was a significant reduction in the load of the intercellular bacteria in J774A.1 murine cells in both formulations.

CONCLUSION

Our results showed the Gen-Cs have a proper potential for optimal treatment of intracellular bacterial agents.

Aberrant methylation of host macrophages induced by tuberculosis infection

DNA methylation has been introduced as a promising biomarker for different diseases. Alterations in macrophage DNA methylation status have been documented during Mycobacterium tuberculosis (Mtb) infection. We conducted this study using a human methylation PCR array kit, which comprised a panel of 22 genes in TLR2 signaling pathway, in order to gain insights into epigenetic interactions between drug-susceptible and -resistant Mtb strains and THP-1-derived macrophages (one of the main host immunity cells during TB infection). We also evaluated the expression of Rv1988 gene in the studied isolates. It was found that the methylation level of all of the studied inflammatory genes, except Irak-2 and Tbk-1, increased in THP-1 macrophages, which were infected by extensively drug-resistant (XDR) Mtb strains, compared with the mock cells (P < 0.05). In susceptible strains, we only found hypomethylation in Irak-2 gene, in addition to a slight increase in the methylation levels of Ubev, Ube2n, and Traf6 genes. The present findings provide new insights into the potential role of resistant and susceptible Mtb strains in promoting aberrant epigenetic modifications in macrophages. Further investigations on the host epigenomes, infected with different Mtb isolates, are needed to elucidate their functions in immunological responses and to introduce new effective tools against Mtb infection.

Akkermansia muciniphila-Derived Extracellular Vesicles as a Mucosal Delivery Vector for Amelioration of Obesity in Mice

Recent evidence suggests that probiotics can restore the mucosal barrier integrity, ameliorate inflammation, and promote homeostasis required for metabolism in obesity by affecting the gut microbiota composition. In this study, we investigated the effect of Akkermansia muciniphila and its extracellular vesicles (EVs) on obesity-related genes in microarray datasets and evaluated the cell line and C57BL/6 mice by conducting RT-PCR and ELISA assays. A. muciniphila-derived EVs caused a more significant loss in body and fat weight of high-fat diet (HFD)-fed mice, compared with the bacterium itself. Moreover, treatment with A. muciniphila and EVs had significant effects on lipid metabolism and expression of inflammatory markers in adipose tissues. Both treatments improved the intestinal barrier integrity, inflammation, energy balance, and blood parameters (i.e., lipid profile and glucose level). Our findings showed that A. muciniphila-derived EVs contain various biomolecules, which can have a positive impact on obesity by affecting the involved genes. Also, our results showed that A. muciniphila and its EVs had a significant relationship with intestinal homeostasis, which highlights their positive role in obesity treatment. In conclusion, A. muciniphila-derived EVs can be used as new therapeutic strategies to ameliorate HFD-induced obesity by affecting various mechanisms.

Single-Chain Variable Fragment-Based Bispecific Antibodies: Hitting Two Targets with One Sophisticated Arrow

Despite the success of monoclonal antibodies (mAbs) to treat some disorders, the monospecific molecular entity of mAbs as well as the presence of multiple factors and pathways involved in the pathogenesis of disorders, such as various malignancies, infectious diseases, and autoimmune disorders, and resistance to therapy have restricted the therapeutic efficacy of mAbs in clinical use. Bispecific antibodies (bsAbs), by concurrently recognizing two targets, can partly circumvent these problems. Serial killing of tumor cells by bsAb-redirected T cells, simultaneous blocking of two antigens involved in the HIV-1 infection, and concurrent targeting of the activating and inhibitory receptors on B cells to modulate autoimmunity are part of the capabilities of bsAbs. After designing and developing a large number of bsAbs for years, catumaxomab, a full-length bsAb targeting EpCAM and CD3, was approved in 2009 to treat EpCAM-positive carcinomas besides blinatumomab, a bispecific T cell engager antibody targeting CD19 and CD3, which was approved in 2014 to treat relapsed or refractory acute lymphoblastic leukemia. Furthermore, approximately 60 bsAbs are under investigation in clinical trials. The current review aims at portraying different formats of the single-chain variable fragment (scFv)-based bsAbs and shedding light on the scFv-based bsAbs in preclinical development, different phases of clinical trials, and the market.

Pulmonary Infection Associated with Mycobacterium canariasense in Suspected Tuberculosis Patient, Iran

Mycobacterium canariasense had only been isolated in humans from blood and contaminated catheters. We report a case of pulmonary disease associated with M. canariasense infection that was identified by multilocus sequence analysis; the illness was initially ascribed to M. tuberculosis. M. canariasense should be considered a cause of respiratory infection.