Human Gastrointestinal Diseases Research Articles

Prevalence Rate, Antibiotic Resistance and Biotyping of Thermotolerant Campylobacter Isolated from Poultry Products Vended in Wasit Markets

Campylobacter is a public cause of globally identified human gastrointestinal disease. Nonetheless, in Iraq many sides of the epidemiology of campylobacteriosis and its impact on public health remain poorly understood. Hence, this study was taken to offer reference information on the prevalence rate, sensitivity to antibiotics and biotyping of Campylobacter in poultry products sold in the Wasit markets. A total of 85 samples were collected including chicken (n = 45) and turkey (n =40) meat were surveyed for isolation and identification. Thermotolerant Campylobacter was detected in 54 samples by which Campylobacter jejuni (C. jejuni) was recognized as a main species accounting for 37(68.5%),while Campylobacter coli (C. coli) had 17 (31.5%) of the positive samples. Highest resistance was perceived to oxacillin and tetracycline as (94.4% and 85.2%), respectively. While lowest rate of resistance, 29.6% was detected against gentamicin. Campylobacter coli isolates showed higher resistance rate than C. jejuni isolates towards the selected antibiotics. In addition, multiple drug resistance (MDR) to at least three antibiotics was detected in the vast majority (90.7%) of the experienced isolates. Forty- three (79.6%) of the isolates had multiple antibiotic resistance index (MAR-index) 0.4 and above. Results of biotyping showed that biotype I was the predominant biotype in the two species as 70.2 and 76.5 proportions in C. jejuni and C. coli, respectively. Our results proposed that the presence of Campylobacter in poultry with greater resistance to erythromycin and/ or ciprofloxacin triggers the public health alarm and accentuates the education of consumers on the quality and safety of such foods.

Structure activity relationship towards design of cryptosporidium specific thymidylate synthase inhibitors

Cryptosporidiosis is a human gastrointestinal disease caused by protozoans of the genus Cryptosporidium, which can be fatal in immunocompromised individuals. The essential enzyme, thymidylate synthase (TS), is responsible for de novo synthesis of deoxythymidine monophosphate. The TS active site is relatively conserved between Cryptosporidium and human enzymes. In previous work, we identified compound 1, (2-amino-4-oxo-4,7-dihydro-pyrrolo[2,3-d]pyrimidin-methyl-phenyl-l-glutamic acid), as a promising selective Cryptosporidium hominis TS (ChTS) inhibitor. In the present study, we explore the structure-activity relationship around 1 glutamate moiety by synthesizing and biochemically evaluating the inhibitory activity of analogues against ChTS and human TS (hTS). X-Ray crystal structures were obtained for compounds bound to both ChTS and hTS. We establish the importance of the 2-phenylacetic acid moiety methylene linker in optimally positioning compounds 23, 24, and 25 within the active site. Moreover, through the comparison of structural data for 5, 14, 15, and 23 bound in both ChTS and hTS identified that active site rigidity is a driving force in determining inhibitor selectivity.

Role of hepatocyte nuclear factor 4-alpha in gastrointestinal and liver diseases.

Hepatocyte nuclear factor 4-alpha (HNF4α) is a highly conserved member of nuclear receptor superfamily of ligand-dependent transcription factors that is expressed in liver and gastrointestinal organs (pancreas, stomach, and intestine). In liver, HNF4α is best known for its role as a master regulator of liver-specific gene expression and essential for adult and fetal liver function. Dysregulation of HNF4α expression has been associated with many human diseases such as ulcerative colitis, colon cancer, maturity-onset diabetes of the young, liver cirrhosis, and hepatocellular carcinoma. However, the precise role of HNF4α in the etiology of these human pathogenesis is not well understood. Limited information is known about the role of HNF4α isoforms in liver and gastrointestinal disease progression. There is, therefore, a critical need to know how disruption of the expression of these isoforms may impact on disease progression and phenotypes. In this review, we will update our current understanding on the role of HNF4α in human liver and gastrointestinal diseases. We further provide additional information on possible use of HNF4α as a target for potential therapeutic approaches.

190 Young Scholar Presentation: Early life fecal microbiome transplantation can enhance growth and performance in neonatal dairy calves

Abstract The gastrointestinal (GI) tract of a neonatal calf undergoes morphological and functional adaptations after birth. The GI tract during this period is influenced by many factors, including bioactive compounds in colostrum. Early colonization of the neonate gut microbiome can fundamentally influence the neonate predisposition to develop immune and metabolic disorders. Fecal microbiome transplantation (FMT) has demonstrated positive effects on the treatment of GI diseases in humans; therefore, we hypothesized that neonatal gut inoculation with a healthy adult gut microbiota via milk replacer can potentially improve gut development and maturation early in life. We aimed to evaluate the effects of performing an early life FMT in neonatal dairy calves using stool samples from on-farm selected adult healthy donors on growth and health performance, blood immunometabolites, and gene expression in immune cells [polymorphonuclear leukocytes cells (PMNL)]. The on-farm selection of the adult donor was based on health and production records at the Dairy Research and Training Facility (DRTF) at South Dakota State University, as well as fecal samples testing negative for Mycobacterium paratuberculosis, Salmonella, and Cryptosporidium. Sixteen healthy newborn Holstein calves (n = 8/trt) housed in individual hutches were used in a randomized complete block design from birth to 7 wk of age. Calves were fed 2.8 L/d of antibiotic-free milk replacer 2×/d during wk 1 to 5, 1×/d on wk 6, and weaned at d 42. Antibiotic-free starter pellets and water were fed ad libitum. Calves were assigned to either a baseline nutritional program (CON) or 1×/d inoculations with 25 g of fecal donor material (FMT) mixed in the milk replacer from 8 to 12 d of age. Individual intakes of milk and pellets were measured daily. Fecal and respiratory scores were recorded daily. Body weight (BW) and withers height (WH) were recorded weekly. Blood samples were collected weekly for immunometabolic profiling and PMNL isolation for gene expression analysis. Data were analyzed using the MIXED procedure of SAS. There was a trend (P = 0.09) for greater BW (50.8 vs 52.7 kg±0.7) in FMT calves. Similarly, there was a trend for greater WH (P = 0.13) in FMT (82.6 vs 83.8 kg±0.49) calves. Starter intake and fecal scores were not affected (P > 0.23) by FMT inoculation. Improvements observed in growth parameters by FMT inoculation are suggestive that neonatal dairy calves may benefit from this approach to enhance gut health and immunity, which might be further explained by blood immunometabolites and PMNL gene expression analysis.

First Case Report of Human Bacteremia With Malacobacter (Arcobacter) mytili.

Arcobacter spp. are commonly associated with shellfish and have been increasingly implicated in human gastrointestinal disease. We report the first case of human bacteremia with Malacobacter (previously Arcobacter) mytili acquired after exposure to Maryland crab. Arcobacter spp. should be considered in febrile illnesses when the history indicates exposure to seafood.

Comparative analysis reveals conservation in genome organization among intestinal Cryptosporidium species and sequence divergence in potential secreted pathogenesis determinants among major human-infecting species

BackgroundCryptosporidiosis is a major cause of gastrointestinal diseases in humans and other vertebrates. Previous analyses of invasion-related proteins revealed that Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium ubiquitum mainly differed in copy numbers of secreted MEDLE proteins and insulinase-like proteases and sequences of mucin-type glycoproteins. Recently, Cryptosporidium chipmunk genotype I was identified as a novel zoonotic pathogen in humans. In this study, we sequenced its genome and conducted a comparative genomic analysis.ResultsThe genome of Cryptosporidium chipmunk genotype I has gene content and organization similar to C. parvum and other intestinal Cryptosporidium species sequenced to date. A total of 3783 putative protein-encoding genes were identified in the genome, 3525 of which are shared by Cryptosporidium chipmunk genotype I and three major human-pathogenic Cryptosporidium species, C. parvum, C. hominis, and Cryptosporidium meleagridis. The metabolic pathways are almost identical among these four Cryptosporidium species. Compared with C. parvum, a major reduction in gene content in Cryptosporidium chipmunk genotype I is in the number of telomeric genes encoding MEDLE proteins (two instead of six) and insulinase-like proteases (one instead of two). Highly polymorphic genes between the two species are mostly subtelomeric ones encoding secretory proteins, most of which have higher dN/dS ratios and half are members of multiple gene families. In particular, two subtelomeric ABC transporters are under strong positive selection.ConclusionsCryptosporidium chipmunk genotype I possesses genome organization, gene content, metabolic pathways and invasion-related proteins similar to the common human-pathogenic Cryptosporidium species, reaffirming its human-pathogenic nature. The loss of some subtelomeric genes encoding insulinase-like proteases and secreted MEDLE proteins and high sequence divergence in secreted pathogenesis determinants could contribute to the biological differences among human-pathogenic Cryptosporidium species.

Cellular and Mucosal Immune Responses Following Vaccination with Inactivated Mutant of Escherichia coli O157:H7

Shiga toxin-producing Escherichia coli O157:H7 (O157) can cause mild to severe gastrointestinal disease in humans. Cattle are the primary reservoir for O157, which colonizes the intestinal tract without inducing any overt clinical symptoms. Parenteral vaccination can reduce O157 shedding in cattle after challenge and limit zoonotic transmission to humans, although the impact of vaccination and vaccine formulation on cellular and mucosal immune responses are undetermined. To better characterize the cattle immune response to O157 vaccination, cattle were vaccinated with either water-in-oil-adjuvanted, formalin-inactivated hha deletion mutant of Shiga toxin 2 negative (stx2−) O157 (Adj-Vac); non-adjuvanted (NoAdj-Vac); or non-vaccinated (NoAdj-NoVac) and peripheral T cell and mucosal antibody responses assessed. Cattle in Adj-Vac group had a higher percentage of O157-specific IFNγ producing CD4+ and γδ+ T cells in recall assays compared to the NoAdj-Vac group. Furthermore, O157-specific IgA levels detected in feces of the Adj-Vac group were significantly lower in NoAdj-Vac group. Extracts prepared only from Adj-Vac group feces blocked O157 adherence to epithelial cells. Taken together, these data suggest parenteral administration of adjuvanted, inactivated whole-cell vaccines for O157 can induce O157-specific cellular and mucosal immune responses that may be an important consideration for a successful vaccination scheme.

Longitudinal assessment of microbial dysbiosis, fecal unconjugated bile acid concentrations, and disease activity in dogs with steroid-responsive chronic inflammatory enteropathy.

BackgroundMounting evidence from human studies suggests that bile acid dysmetabolism might play a role in various human chronic gastrointestinal diseases. It is unknown whether fecal bile acid dysmetabolism occurs in dogs with chronic inflammatory enteropathy (CE).ObjectiveTo assess microbial dysbiosis, fecal unconjugated bile acids (fUBA), and disease activity in dogs with steroid‐responsive CE.AnimalsTwenty‐four healthy control dogs and 23 dogs with steroid‐responsive CE.MethodsIn this retrospective study, fUBA were measured and analyzed. Fecal microbiota were assessed using a dysbiosis index. The canine inflammatory bowel disease activity index was used to evaluate remission of clinical signs. This was a multi‐institutional study where dogs with steroid‐responsive CE were evaluated over time.ResultsThe dysbiosis index was increased in dogs with CE (median, 2.5; range, −6.2 to 6.5) at baseline compared with healthy dogs (median, −4.5; range, −6.5 to −2.6; P = .002) but did not change in dogs with CE over time. Secondary fUBA were decreased in dogs with CE (median, 29%; range, 1%‐99%) compared with healthy dogs (median, 88%; 4%‐96%; P = .049). The percent of secondary fUBA in dogs with CE increased from baseline values (median, 28%; range, 1%‐99%) after 2‐3 months of treatment (median, 94%; range, 1%‐99%; P = 0.0183).Conclusions and Clinical ImportanceThese findings suggest that corticosteroids regulate fecal bile acids in dogs with CE. Additionally, resolution of clinical activity index in dogs with therapeutically managed CE and bile acid dysmetabolism are likely correlated. However, subclinical disease (i.e., microbial dysbiosis) can persist in dogs with steroid‐responsive CE.

Symbiotic microbes and potential pathogens in the intestine of dead southern right whale (Eubalaena australis) calves

Between 2003 and 2017, at least 706 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground in Argentina. Pathogenic microbes are often suggested to be the cause of stranding events in cetaceans; however, to date there is no evidence supporting bacterial infections as a leading cause of right whale calf deaths in Argentina. We used high-throughput sequencing and culture methods to characterize the bacterial communities and to detect potential pathogens from the intestine of stranded calves. We analyzed small and large intestinal contents from 44 dead calves that stranded at Península Valdés from 2005 to 2010 and found 108 bacterial genera, most identified as Firmicutes or Bacteroidetes, and 9 genera that have been previously implicated in diseases of marine mammals. Only one operational taxonomic unit was present in all samples and identified as Clostridium perfringens type A. PCR results showed that all C. perfringens isolates (n = 38) were positive for alpha, 50% for beta 2 (n = 19) and 47% for enterotoxin (CPE) genes (n = 18). The latter is associated with food-poisoning and gastrointestinal diseases in humans and possibly other animals. The prevalence of the cpe gene found in the Valdés’ calves is unusually high compared with other mammals. However, insufficient histologic evidence of gastrointestinal inflammation or necrosis (the latter possibly masked by autolysis) in the gut of stranded calves, and absence of enterotoxin detection precludes conclusions about the role of C. perfringens in calf deaths. Further work is required to determine whether C. perfringens or other pathogens detected in this study are causative agents of calf deaths at Península Valdés.

Potential Therapeutic Effects of Mepacrine against Clostridium perfringens Enterotoxin in a Mouse Model of Enterotoxemia.

Clostridium perfringens enterotoxin (CPE) is a pore-forming toxin that causes the symptoms of common bacterial food poisoning and several non-foodborne human gastrointestinal diseases, including antibiotic-associated diarrhea and sporadic diarrhea. In some cases, CPE-mediated disease can be very severe or fatal due to the involvement of enterotoxemia. Therefore, the development of potential therapeutics against CPE action during enterotoxemia is warranted. Mepacrine, an acridine derivative drug with broad-spectrum effects on pores and channels in mammalian membranes, has been used to treat protozoal intestinal infections in human patients. A previous study showed that the presence of mepacrine inhibits CPE-induced pore formation and activity in enterocyte-like Caco-2 cells, reducing the cytotoxicity caused by this toxin in vitro Whether mepacrine is similarly protective against CPE action in vivo has not been tested. When the current study evaluated whether mepacrine protects against CPE-induced death and intestinal damage using a murine ligated intestinal loop model, mepacrine protected mice from the enterotoxemic lethality caused by CPE. This protection was accompanied by a reduction in the severity of intestinal lesions induced by the toxin. Mepacrine did not reduce CPE pore formation in the intestine but inhibited absorption of the toxin into the blood of some mice. Protection from enterotoxemic death correlated with the ability of this drug to reduce CPE-induced hyperpotassemia. These in vivo findings, coupled with previous in vitro studies, support mepacrine as a potential therapeutic against CPE-mediated enterotoxemic disease.

Candidate genes associated with the heritable humoral response to Mycobacterium avium ssp. paratuberculosis in dairy cows have factors in common with gastrointestinal diseases in humans

Infection of cattle with bovine paratuberculosis (i.e., Johne's disease) is caused by Mycobacterium avium ssp. paratuberculosis (MAP) and results in a chronic incurable gastroenteritis. This disease, which has economic ramifications for the cattle industry, is increasing in detected prevalence globally; subclinically infected animals can silently shed the bacterium into the environment for years, exposing contemporaries and hampering disease-control programs. The objective of the present study was to first quantify the genetic parameters for humoral response to MAP in dairy cattle. This was followed by a genome-based association analysis and subsequent downstream bioinformatic analyses from imputed whole genome sequence SNP data. After edits, ELISA test records were available on 136,767 cows; analyses were also undertaken on a subset of 33,818 of these animals from herds with at least 5 MAP ELISA-positive cows, with at least 1 of those positive cows being homebred. Variance components were estimated using univariate animal and sire linear mixed models. The heritability calculated from the animal model for humoral response to MAP using alternative phenotype definitions varied from 0.02 (standard error = 0.003) to 0.05 (standard error = 0.008). The genome-based associations were undertaken within a mixed model framework using weighted deregressed estimated breeding values as a dependent variable on 1,883 phenotyped animals that were ≥87.5% Holstein-Friesian. Putative susceptibility quantitative trait loci (QTL) were identified on Bos taurus autosome 1, 3, 5, 6, 8, 9, 10, 11, 13, 14, 18, 21, 23, 25, 26, 27, and 29; mapping the most significant SNP to genes within and overlapping these QTL revealed that the most significant associations were with the 10 functional candidate genes KALRN, ZBTB20, LPP, SLA2, FI3A1, LRCH3, DNAJC6, ZDHHC14, SNX1, and HAS2. Pathway analysis failed to reveal significantly enriched biological pathways, when both bovine-specific pathway data and human ortholog data were taken into account. The existence of genetic variation for MAP susceptibility in a large data set of dairy cows signifies the potential of breeding programs for reducing MAP susceptibility. Furthermore, the identification of susceptible QTL facilitates greater biological understanding of bovine paratuberculosis and potential therapeutic targets for future investigation. The novel molecular similarities identified between bovine paratuberculosis and human inflammatory bowel disease suggest potential for human therapeutic interventions to be translated to veterinary medicine and vice versa.

Antimicrobial resistance in non-O157 Shiga-toxin producing Escherichia coli

Objectives Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens that cause severe gastrointestinal disease in humans. Monitoring antimicrobial resistance (AMR) in STEC from symptomatic human cases may provide evidence for the extent of transmission of resistant strains and resistance genes from ruminants to humans. The aim of this study was to assess AMR in non-O157 STEC in England and Wales between 2014 and 2016, and to compare phenotypic and Whole Genome Sequencing (WGS) derived AMR profiles. Methods Six hundred and fifty-three non-O157 STEC isolates were analysed. WGS and bioinformatic analysis were performed on 457 isolates in the top 10 Clonal Complexes (CC) (193 were excluded on the basis of CC) and phenotypic susceptibility typing via breakpoint and minimum inhibitory concentration testing was undertaken on 100 isolates exhibiting resistance to at least one antimicrobial. Results Of 457 isolates, 332 lacked identifiable resistance genes and were predicted to be fully susceptible to 11 diverse classes of antimicrobials, 125 were found to carry one or more resistance genes and 83 were multi-drug resistant. Four isolates were identified as extended-spectrum b-lactamase-producers. In total, 46 different genes were detected – which conferred resistance to 8 different antibiotic classes. An overall concordance of 97.5 % was demonstrated between the two methods. Conclusions Phenotypic and genome-derived AMR comparisons showed good correlation for non-O157 STEC. This has added to the evidence base to support the use of genotypic approaches for antimicrobial susceptibility typing, to replace phenotypic typing for surveillance purposes, and guide clinical decision making in the more distant future.

Identification of an Important Orphan Histidine Kinase for the Initiation of Sporulation and Enterotoxin Production by Clostridium perfringens Type F Strain SM101.

Clostridium perfringens type F strains cause a common human foodborne illness and many cases of nonfoodborne human gastrointestinal diseases. Sporulation plays two critical roles during type F enteric disease. First, it produces broadly resistant spores that facilitate type F strain survival in the food and nosocomial environments. Second, production of C. perfringens enterotoxin (CPE), the toxin responsible for causing the enteric symptoms of type F diseases, is restricted to cells in the process of sporulation. While later steps in the regulation of C. perfringens sporulation have been discerned, the process leading to phosphorylation of Spo0A, the master early regulator of sporulation and consequent CPE production, has remained unknown. Using an insertional mutagenesis approach, the current study identified the orphan histidine kinase CPR0195 as an important factor regulating C. perfringens sporulation and CPE production. Specifically, a CPR0195 null mutant of type F strain SM101 made 103-fold fewer spores than its wild-type parent and produced no detectable CPE. In contrast, a null mutant of another putative C. perfringens orphan histidine kinase (CPR1055) did not significantly affect sporulation or CPE production. Studies using a spoIIA operon promoter-driven reporter plasmid indicated that CPR0195 functions early during sporulation, i.e., prior to production of sporulation-associated sigma factors. Furthermore, in vitro studies showed that the CPR0195 kinase domain can autophosphorylate and phosphorylate Spo0A. These results support the idea of CPR0195 as an important kinase that initiates C. perfringens sporulation by directly phosphorylating Spo0A. This kinase could represent a novel therapeutic target to block C. perfringens sporulation and CPE production during type F disease.IMPORTANCEClostridium perfringens type F enteric diseases, which include a very common form of food poisoning and many cases of antibiotic-associated diarrhea, develop when type F strains sporulate and produce C. perfringens enterotoxin (CPE) in the intestines. Spores are also important for transmission of type F disease. Despite the importance of sporulation for type F disease and the evidence that C. perfringens sporulation begins with phosphorylation of the Spo0A transcriptional regulator, the kinase phosphorylating Spo0A to initiate sporulation and CPE production had not been ascertained. In response, the current report now provides identification of an orphan histidine kinase named CPR0195 that can directly phosphorylate Spo0A. Results using a CPR0195 null mutant indicate that this kinase is very important for initiating C. perfringens sporulation and CPE production. Therefore, the CPR0195 kinase represents a potential target to block type F disease by interfering with intestinal C. perfringens sporulation and CPE production.

CRISPR analysis suggests that small circular single-stranded DNA smacoviruses infect Archaea instead of humans

Smacoviridae is a family of small (~2.5 Kb) CRESS-DNA (Circular Rep Encoding Single-Stranded (ss) DNA) viruses. These viruses have been found in faeces, were thought to infect eukaryotes and are suspected to cause gastrointestinal disease in humans. CRISPR-Cas systems are adaptive immune systems in prokaryotes, wherein snippets of genomes from invaders are stored as spacers that are interspersed between a repeated CRISPR sequence. Here we report several spacer sequences in the faecal archaeon Candidatus Methanomassiliicoccus intestinalis matching smacoviruses, implicating the archaeon as a firm candidate for a host. This finding may be relevant to understanding the potential origin of smacovirus-associated human diseases. Our results support that CRESS-DNA viruses can infect non-eukaryotes, which would mean that smacoviruses are the viruses with the smallest genomes to infect prokaryotes known to date. A probable target strand bias suggests that, in addition to double-stranded DNA, the CRISPR-Cas system can target ssDNA.

Detection of multi-antibiotic resistant Campylobacter coli and Campylobacter jejuni in beef, mutton, chicken and water buffalo meat in Ahvaz, Iran.

Campylobacter jejuni and C. coli are the main causes of gastrointestinal diseases in humans even in industrialized countries affecting public health. The aim of the current study was to evaluate the occurrence and antibiotic resistance of C. jejuni and C. coli in chicken meat, beef, mutton and water buffalo meat slaughtered in Ahvaz city, Iran. A total of 380 samples including chicken meat from industrial abattoirs (n = 150), chicken meat from traditional abattoirs (n = 50), fresh packed chicken meat from local markets (n = 30) and beef, mutton and water buffalo meat from industrial abattoirs (50 samples for each meat) in Ahvaz,were collected and tested for the presence of Campylobacter spp. The procedure was one-step enrichment in Preston enrichment broth followed by plating on supplemented blood agar for 24 hr under microaerophilic conditions at 42 ˚C. Suspected colonies were tested by polymerase chain reaction assay and susceptibility of the confirmed isolates to various antibiotics was investigated by the Kirby-Bauer disk diffusion method. Overall, 32 samples (8.40%) were contaminated with Campylobacter spp. Mutton was the most contaminated meat (24%), while fresh packed chicken meat were not contaminated. Among the 32 isolates, 40.60%, 34.40%, 21.90%, and 15.60% were resistant to tetracycline, ciprofloxacin, ampicillin, and streptomycin, respectively. Moreover, a high number of multi-antibiotic resistant Campylobacter spp. was determined. Since foods of animal origin are the most sources of Campylobacter infection, the presence of resistant strains to antibiotics is a potential risk to public health.

Substrate specificities in Salmonella typhi outer membrane protease (PgtE) from omptin family – An in silico proteomic approach

Salmonella typhi is a Gram-negative pathogen that causes severe systemic infections like typhoid fever and gastrointestinal disease in humans. PgtE belongs to the Omptin family, and plays a central role at the host-pathogen interface. In the present study, the S. typhi PgtE sequence was retrieved and the cleavage sites were predicted. Owing to the non-existence of a crystalline structure of S. typhi PgtE, theoretical 3D modeled structures were predicted using the I-TASSER server, which helps to understand the protease inhibitory mechanism. Molecular interaction studies with known protease inhibitors revealed that aspartic protease inhibitor Indinavir has the best interaction with S. typhi PgtE. From the metal ion docking studies, Mg2+ has better interaction compared to the Zn2+ and Cu2+ ions. The multiple pathogen sequence alignment of the Omptin proteases family shows that interacting residues were conserved among the Omptins. These results will provide new knowledge for the development of novel therapeutic strategies against S. typhi PgtE and Omptin family proteases.

An Unwanted Guest in the Biliary Tract: A Case Report

Ascariasis is a frequent human gastrointestinal tract helminthic disease caused by Ascaris lumbricoide. It usually stays in the intestinal lumen and occasionally migrates into the biliary tract through ampulla of Vater .Biliary ascariasis is a critical complication of intestinal ascariasis with life-threatening manifestations .We report a case of a-38 year-old lady who presented with colicky type epigastric pain radiating to back with diffuse tenderness over abdomen on examination. Ultrasonography abdomen showed linear echogenic structure in common bile duct .Biliary ascariasis was noted on Endoscopic Retrograde CholangioPancreaticography following which extraction was done .Our report highlights the varied clinical features of biliary ascariasis. Keywords: ascariasis; ascaris lumbricoides; cholangiopancreatography endoscopic retrograde; common bile duct.

Intestinal renewal across the animal kingdom: comparing stem cell activity in mouse and Drosophila.

The gastrointestinal (GI) tract renews frequently to sustain nutrient digestion and absorption in the face of consistent tissue stress. In many species, proliferative intestinal stem cells (ISCs) are responsible for the repair of the damage arising from chemical and mechanical aspects of food breakdown and exposure to pathogens. As the cellular source of all mature cell types of the intestinal epithelium throughout adulthood, ISCs hold tremendous therapeutic potential for understanding and treating GI disease in humans. This review focuses on recent advances in our understanding of ISC identity, behavior, and regulation during homeostasis and injury-induced repair, as revealed by two major animal models used to study regeneration of the small intestine: Drosophila melanogaster and Mus musculus. We emphasize recent findings from Drosophila that are likely to translate to the mammalian GI system, as well as challenging topics in mouse ISC biology that may be ideally suited for investigation in flies. For context, we begin by reviewing major physiological similarities and distinctions between the Drosophila midgut and mouse small intestine.

NanI Sialidase Is an Important Contributor to Clostridium perfringens Type F Strain F4969 Intestinal Colonization in Mice.

Clostridium perfringens type F (formerly enterotoxigenic C. perfringens type A) strains produce an enterotoxin (CPE) to cause acute cases of food poisoning and chronic nonfoodborne human gastrointestinal diseases (NFD), e.g., antibiotic-associated diarrhea (AAD). NFD strains also produce NanI sialidase, an extracellular enzyme that releases sialic acids from sialyated host macromolecules. Recent in vitro studies suggested that NanI may contribute to NFD strain intestinal colonization by enhancing the adherence of such strains to intestinal cells and promoting their bacterial growth using generated sialic acid as an energy source. The current study tested this hypothesis by developing a mouse intestinal colonization model involving clindamycin pretreatment to produce conditions mimicking those during AAD. In this model, the type F NFD strain F4969 persisted for at least 4 days in the small intestine, cecum, and colon. When clindamycin-pretreated mice were challenged by oral gavage with equivalent numbers of F4969 bacteria or its isogenic nanI null mutant, significantly lower numbers of the nanI mutant were recovered from all intestinal segments, and it was completely cleared from the small intestine by day 4. Complementation of the mutant to restore NanI production also promoted colonization. When the same nanI null mutant strain was coinoculated into the mouse model together with a nanI-producing strain, the numbers of this mutant were restored to wild-type F4969 levels in all intestinal segments. This result suggests that sialidases produced by other bacteria might also provide some support for C. perfringens intestinal colonization. Collectively, these in vivo findings identify NanI to be the first known significant contributor to chronic intestinal colonization by NFD strains.

Ethnobotanical Survey of Dracaena cinnabari and Investigation of the Pharmacognostical Properties, Antifungal and Antioxidant Activity of Its Resin.

Dracaena cinnabari Balf. f. (Dracaenaceae) is an important plant endemic to Soqotra Island, Yemen. Dragon’s blood (Dam Alakhwin) is the resin that exudes from the plant stem. The ethnobotanical survey was carried out by semi-structured questionnaires and open interviews to document the ethnobotanical data of the plant. According to the collected ethnobotanical data, the resin of D. cinnabari is widely used in the traditional folk medicine in Soqotra for treatment of dermal, dental, eye and gastrointestinal diseases in humans. The resin samples found on the local Yemeni markets were partly or totally substituted by different adulterants. Organoleptic properties, solubility and extractive value were demonstrated as preliminary methods to identify the authentic pure Soqotri resin as well as the adulterants. In addition, the resin extracts and its solution in methanol were investigated for their in vitro antifungal activities against six human pathogenic fungal strains by the agar diffusion method, for antioxidant activities using the DPPH assay and for cytotoxic activity using the neutral red uptake assay. The crude authentic resin dissolves completely in methanol. In comparison with different resin extracts, the methanolic solution of the whole resin showed the strongest biological activities. It showed strong antifungal activity, especially against Microsporum gypseum and Trichophyton mentagrophytes besides antioxidant activities and toxicity against FL-cells. These findings confirm and explain the traditional uses of the resin for the treatment of skin diseases and mouth fungal infections.