Colonization of Serratia fonticola on phylloplane of tomato and its impact on leaf cytoplasmic protein profile

Aim: The aim of the present study was to understand the impact of human enteric pathogen (Serratia fonticola) colonization on cytoplasmic protein profile of tomato leaves. Methodology: Aseptically grown plants were inoculated with S. fonticola and sampled at different interval of time. Colonization pattern was studied by leaf impression technique. Changes in cytoplasmic protein profile were studied by protein-protein crosslinking method followed by separation through SDS PAGE. Results: The colonization pattern study revealed that maximum colonies were found at 24 hr post inoculation which gradually decreased with time, showing the survival of the pathogen on phylloplane. Electrophoretic separation of cytoplasmic proteins showed crosslinking of some proteins in treated samples at 48, 72 and 96 hr post inoculation. Interpretation: This study will help in understanding the molecular changes in cytoplasmic protein profile and survival of pathogen on phylloplane, thus limiting the growth of bacteria, Serratia fonticola on phyllosphere.

Disruption of the Gut Ecosystem by Antibiotics

The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.

Shewanella algae in acute gastroenteritis.

Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. Here we report the isolation of S. algae as the sole etiological agent from a patient suffering from acute gastroenteritis with bloody diarrhoea. The bacterium was identifi ed by automated identifi cation system and 16S rRNA gene sequence analysis. Our report highlights the importance of looking for the relatively rare aetiological agents in clinical samples that does not yield common pathogens. It also underscores the usefulness of automated systems in identifi cation of rare pathogens.

Pathogenic detection of infectious diarrhea in patients in a district of Beijing from 2011 to 2013 / 中国感染控制杂志

Objective To analyze the distribution and pulsed-field gel electrophoresis (PFGE)of pathogenic bacteria causing infectious diarrhea in a district of Beijing from 2011 to 2013,and provide basis for tracing infection sources.Methods A total of 1 179 stool specimens of infectious diarrhea from patients in a diarrhea outpatient department from January 2011 to December 2013 were collected,all isolated pathogens were identified by serotyping and PFGE analysis.Results 330 enteric pathogens were isolated from 1 179 specimens,the top 4 bacteria were Shi-gella spp .(28.18%,n=93),Salmonella spp .(20.91 %,n=69),Vibrio parahaemolyticus (13.33%,n =44),and diarrheagenic Escherichia coli (3.33%,n = 11 ).18 Shigella sonnei isolates were identified as 8 PFGE patterns, clustering similarity was close to 88%;69 Salmonella spp .strains belonged to 18 serotypes and 41 PFGE patterns, Salmonella senftenberg and Salmonella enteritidis had dominant patterns;no dominant PFGE patterns were obviously identified among 23 strains ofVibrio parahaemolyticus .Conclusion The serotypes and PFGE patterns of pathogenic bacteria in infectious diarrhea in past three years showed a wide distribution characteristics,the dominant PFGE patterns of Salmonella spp .and Shigella spp .need to be paid more attention,and outbreak of infectious diarrhea caused by Salmonella spp .and Shigella spp .should be alerted.

Analysis of distribution and antimicrobial resistance of enteric pathogens in Shanxi Province / 中国基层医药

Objective To investigate the distribution and antibiotic resistance of the enteric pathogens in Shanxi province to guide the choice of antibacterials.Methods 798 cases of fecal samples from patients with diarrhea were treated in the outpatient and inpatient.The suspected pathogen was separated then PCR,biochemical test,serum agglutination tests were used for identification of suspected pathogen,and bacterial pathogens constitution and patho-genic characteristics were analyzed.Antimicrobial susceptibility testing was conducted by diskdiffusion method for the suspected pathogen with 6 antimicrobial agents.Results 81 strains isolated from 798 specimens were positive with 10.15% for pathogen detection.Diarrheagenic Escherichia coli was the first frequently pathogen,accounting for 46.91%,followed by Shigella,Salmonella and Aeromonas.Drug sensitivity monitoring showed that the most of the 81 strains had lower level of resistance to cefoitin,cefotaxime and ciorofloxacin,and higher level of resistance to tetra-cycline and nalidixic aid.Conclusion Diarrheagenic Escherichia coli,Shigella,Salmonella and Aeromonas are the major bacterial diarrheal pathogens in the hospital.Surveillance of antimicrobial resistance in these bacteria should be strengthened to provide reliable evidence for clinical anti infection treatment.

The Role of Carbohydrates in Infection Strategies of Enteric Pathogens

Enteric pathogens cause considerable public health concerns worldwide including tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of the human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the function of carbohydrates in infection by <i>Salmonella enterica</i> and several bacterial species that produce a variety of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infection by these microbes; however, their usage of carbohydrates varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tract, various carbohydrate moieties are present and play a crucial role in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion process of the microbes, carbohydrates function as receptors for various microbes, but they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking the interactions with carbohydrates. In addition, similarities in mode of infection may also be utilized. Our findings will be useful in the development of new drugs for the treatment of enteric pathogens.

Metabolic Effect of FOS (Fructooligosaccharide) in Terms of Gut Incretin (GLP-1) Gut Microflora and Weight Reduction in Obese Adults.

In the recent years, obesity has increased beyond imagination. Appropriate dietary strategies which have the potential for weight loss demand patience and strong determination on part of the individual, however inclusion of functional foods like FOS that modulate gut hormones have a promising role in weight management. Methods: A randomized double-blind placebo-controlled trial was used as the study design wherein 65 obese adults were divided into experimental group (which was given 12 g of FOS) and a placebo group (which was fed with 12 g dextrose). The subjects were given the supplements daily for 12 week period. Their plasma samples were anlaysed for GLP-1 and microbial count in fecal samples were determined in terms of lactic acid bacteria, bifidobacteria and enteric pathogens. Hunger scores, dietary intake, and anthropometric parameters were assessed using standard techniques. Results: FOS supplementation resulted in improved plasma GLP-1 level by 17.0%. Significant improvement was observed in hunger score by 3.15% (p<0.05) along with reduction in dietary intake of energy (kcal) by 8%, carbohydrate (g) by 8%, protein (g) by 6% and fat (g) by 2%. Further, reductions were observed in total body weight (kg), BMI, % body fat and waist circumference (cm) levels by 4%, 1.06%, 4% and 1.66% respectively (p<0.001, p<0.001, p<0.001, p<0.05). The mean log counts of beneficial gut microbiota i.e. lactic acid bacteria and bifidobacteria increased significantly by 14 % and 10 % respectively along with 20% reduction in enteric pathogen. Conclusion: Daily intake of 12 gm FOS for 12 weeks helps in improving gut health and weight loss through increased satiety in obese individuals.

Analysis of distribution and antimicrobial resistance of enteric pathogens among children / 中国感染与化疗杂志

Objective To investigate the distribution,epidemiologic features and antibiotic resistance of the enteric pathogens i-solated from children with diarrhea.Methods Enteric pathogens were isolated from children’s stool samples.The children with diarrhea were treated in the outpatient and inpatient of Shanghai Children’s Hospital between 2008 and 2013.Antimicrobial susceptibility testing was conducted by disk diffusion method for Salmonella and Shigella with 6 antimicrobial agents.Results A total of 545 enteric pathogens were collected.Salmonella was the dominant pathogen,accounting for 67.2%,followed by Shigella (20.7%),S.aureus (4.6%),C.jejuni (3.7%),Aeromonas (2.4%),and enteropathogenic E.coli (0.9%).The main serotypes of Salmonella were S.typhimurium and S.enteritidis.Approximately 56.3% of the patients were boys.A-bout 72.7% of the patients were infants under 2 years.The prevalence of diarrhea peaked in summer and autumn (72.9%). The susceptibility of these isolates was only tested with seven antibiotics.Shigella showed higher level of resistance to ampicil-lin and trimethoprim-sulfamethoxazole than Salmonella (P<0.05).Significantly higher percentage of S.flexneri isolates were resistant to sulbactam-ampicillin,ceftriaxone,ciprofloxacin,and chloramphenicol than S.sonnei (P<0.001).Further-more,the prevalence of multidrug resistant strains in Shigella (68.3%)was much higher than that in Salmonella (44.7%,P<0.001).Conclusions A variety of diarrhea-causing enteric pathogens are isolated from the children in Shanghai Children’s Hospital.The isolates are predominantly Salmonella and Shigella species.The epidemiological features of Salmonella and Shigella species are different in terms of gender,age,season and geographical distribution.The resistance to antibiotics is a serious problem and varies with different types of pathogens. Intensive and ongoing surveillance of enteric pathogens and their changing resistant pattern is required to control diar-rhea in children.

Roles of carbohydrates in the infection strategies of enteric pathogens

Enteric pathogens cause considerable public health concerns worldwideincluding the tropical regions. Here, we review the roles of carbohydrates inthe infection strategies of various enteric pathogens including viruses,bacteria and protozoa, which infect the epithelial lining of human and animalintestine. At host cell entry, enteric viruses, including norovirus, recognize mainlyhisto-blood group antigens. At the initial step of bacterial infections,carbohydrates also function as receptors for attachment. Here, we describe the functionsof carbohydrates in infection by <i>Salmonellaenterica</i> and several bacterial species that produce varieties of fimbrialadhesions. During invasion by enteropathogenic protozoa, apicomplexan parasitesutilize sialic acids or sulfated glycans. Carbohydrates serve as receptors forinfections by these microbes; however, the usage of carbohydrates by themvaries depending on the microbe. On the surface of the mucosal tissues of thegastrointestinal tracts, various carbohydrate moieties are present and playcrucial roles in infection, representing the site of infection or route ofaccess for most microbes. During the infectionand/or invasion processes of the microbes, carbohydrates function as receptorsfor various microbes, while they can also function as abarrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobialagents is to modify the drug structure. Another approach is to modify the modeof inhibition of infection depending on the individual pathogen by using andmimicking these interactions with carbohydrate. In addition, similarities inmode of infection may also be utilized. Thesefindings we described are useful in development of the new drugs for treatmentsof enteric pathogens.

Fructooligosaccharide (FOS) Supplementation in Type 2 Diabetic Adults Improves Systolic Blood Pressure, Serum Lipid, and Gut Microbiota.

Fructooligosaccharide (FOS) is a prebiotic, becoming apparent for its therapeutic role for diseased conditions like CHD, hypertension, diabetes and obesity. CHD and hypertension are one of the most prevalent NCD’s encountered in diabetic adults. Present study aims to assess the effect of FOS supplementation in type 2 diabetic adults on their lipemic, biophysical parameters and gut microflora parameters. A cross-sectional study was designed with 65 adult type 2 diabetics enrolled from Health clinic of The M.S. University of Baroda, Gujarat. All the subjects were randomly divided into two groups control and experimental. The experimental group was given 10 g of fructooligosaccharide and compared with the controls for lipemic parameters, hypertension and fecal counts in terms of lactic acid bacteria, bifidobacteria and enteric pathogen. Eight week supplementation of FOS resulted in an appreciable reduction in serum TC, TG and LDL levels by 10%, 4.9% and 7.8% respectively. A significant reduction (p<0.05) in systolic blood pressure was also observed as a result of FOS supplementation in the experimental group. A decline was seen in TC/HDL, LDL/HDL and non-HDL by 10.4%, 7.6% and 6.6% respectively (p<0.05, p<0.001). Gut microbiota values exhibited a significant increment in fecal log10 counts of Lactic acid bacteria and bifidobacteria by 9.3% and 10.9% respectively (p<0.001) while a significant reduction by 4.8% (p<0.001) was observed for Enteric pathogen. These outcomes revealed an efficacy of FOS in reducing serum lipid parameters, systolic BP and improving the gut microbiota in type 2 diabetic adults.

The molecular regulating mechanisms of intestinal epithelial tight junctions response to pathogenic bacteria / 肠外与肠内营养

Tight junctions(TJ) are the basic structure of intestinal barrier,which serve as the rate-limitting barrier to passive movement across intestinal epithelial cell and the maintenance of epithelial cell polarity.Recently some progress has been achieved in the structure of TJ proteins.This review is about the regulating mechanisms of TJs response to common enteric pathogens and other factors.