Publications

multidrug resistant salmonella concord is a major cause of salmonellosis in children in ethiopia.	s. concord in ethiopia. the objective of this study was to determine the aetiology of febrile and diarrhoeic illness in ethiopian children focussing on salmonella.	2011	21330737
antigen-specific iga b memory cell responses to shigella antigens elicited in volunteers immunized with live attenuated shigella flexneri 2a oral vaccine candidates.	we studied the induction of antigen-specific iga memory b cells (b(m)) in volunteers who received live attenuated shigella flexneri 2a vaccines. subjects ingested a single oral dose of 10(7), 10(8) or 10(9) cfu of s. flexneri 2a with deletions in guaba (cvd 1204) or in guaba, set and sen (cvd 1208). antigen-specific serum and stool antibody responses to lps and ipa b were measured on days 0, 7, 14, 28 and 42. iga b(m) cells specific to lps, ipa b and total iga were assessed on days 0 and 28. we ...	2011	21388888
quantification and evaluation of infectivity of shiga toxin-encoding bacteriophages in beef and salad.	stx bacteriophages in 68 samples of beef and salad were quantified by real-time quantitative pcr (qpcr). stx phages from the samples were propagated in escherichia coli c600, e. coli o157:h7, and shigella strains and further quantified. fifty percent of the samples carried infectious stx phages that were isolated from plaques generated by lysis.	2011	21441341
postinfective bile acid malabsorption: is this a long-term condition?	postinfective bile acid malabsorption comprises a group of patients with a history of an episode of acute gastroenteritis triggering chronic diarrhoea. we identified these patients retrospectively from our medical records and assessed their long-term clinical course.	2011	21389860
purification and characterization of a ca2+-dependent novel lectin from nymphaea nouchali tuber with antiproliferative activities.	a lectin (termed nntl) was purified from the extracts of nymphaea nouchali tuber followed by anion-exchange chromatography on deae-cellulose, hydrophobic chromatography on hitrap phenyl hp and by repeated anion-exchange chromatography on hitrap q ff column. the molecular mass of the purified lectin was 27.0 ± 1.0 kda, as estimated by sds/page both in the presence and in the absence of 2-mercaptoethanol. nntl was an o-nitrophenyl ß-d-galactopyranoside sugar-specific lectin that agglutinated rat, ...	2011	21291421
antibacterial activity of the enniatin b, produced by fusarium tricinctum in liquid culture, and cytotoxic effects on caco-2 cells.	the enniatins (ens) are bioactive compounds of hexadepsipeptidic structure produced by several strains of fusarium sp. the en b was purified from extracts of fusarium tricinctum growth on liquid culture of potato dextrose broth (pdb), using a semipreparative liquid chromatography (lc) followed by an analytical lc. the purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (esi-ms) stud ...	2011	21417626
synthesis, spectral analysis and in vitro microbiological evaluation of novel ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates and 4,5-dihydro-6-(napthalen-2-yl)-4-aryl-2h-indazol-3-ols.	a series of ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates 8-14 and 4,5-dihydro-6-(naphthalen-2-yl)-4-aryl-2h-indazol-3-ols 15-21 were synthesised and characterised by their spectroscopic data. in vitro microbiological evaluations were carried out for all the newly synthesised compounds 8-21 against clinically isolated bacterial and fungal strains. compounds 9, 12 and 20 against staphylococcus aureus, 10, 12, 20 against ß-haemolytic streptococcus, 11, 17 against bacillus subtil ...	2011	21299432
a comparison of disease caused by shigella and campylobacter species: 24 months community based surveillance in 4 slums of karachi, pakistan.	despite the efforts of the international community diarrheal diseases still pose a major threat to children in children less than five years of age. bacterial diarrhea has also emerged as a public health concern due to the proliferation of drug resistant species in many parts of the world. there is a paucity of population-based data about the incidence of shigellosis and campylobacter infections in pakistan. we report country specific results for shigella diarrhea that were derived from a multic ...	2011	21338955
autophagy in immunity and cell-autonomous defense against intracellular microbes.	autophagy was viewed until very recently primarily as a metabolic and intracellular biomass and organelle quality and quantity control pathway. it has now been recognized that autophagy represents a bona fide immunologic process with a wide array of roles in immunity. the immunologic functions of autophagy, as we understand them now, span both innate and adaptive immunity. they range from unique and sometimes highly specialized immunologic effectors and regulatory functions (referred to here as ...	2011	21349088
structural elucidation of the o-antigen of the shigella flexneri provisional serotype 88-893: structural and serological similarities with s. flexneri provisional serotype y394 (1c).	the structure of the repeating unit of the o-antigen polysaccharide from shigella flexneri provisional serotype 88-893 has been determined. (1)h and (13)c nmr spectroscopy as well as 2d nmr experiments were employed to elucidate the structure. the carbohydrate part of the hexasaccharide repeating unit is identical to the previously elucidated structure of the o-polysaccharide from s. flexneri prov. serotype y394. the o-antigen of s. flexneri prov. serotype 88-893 carries 0.7 mol o-acetyl group p ...	2011	21392735
function-specific accelerations in rates of sequence evolution suggest predictable epistatic responses to reduced effective population size.	changes in effective population size impinge on patterns of molecular evolution. notably, slightly deleterious mutations are more likely to drift to fixation in smaller populations, which should typically also lead to an overall acceleration in the rates of evolution. this prediction has been validated empirically for several endosymbiont and island taxa. here, we first show that rate accelerations are also evident in bacterial pathogens whose recent shifts in virulence make them prime candidate ...	2011	21349981
etiology of diarrhea in young children and patterns of antibiotic resistance in cambodia.	little is known about diarrhea etiology and antibiotic resistance in developing countries where diarrhea is a major public health problem.	2011	21412204
antigen-specific cd8(+) t cells fail to respond to shigella flexneri.	cd8(+) t lymphocytes often play a primary role in adaptive immunity to cytosolic microbial pathogens. surprisingly, cd8(+) t cells are not required for protective immunity to the enteric pathogen shigella flexneri, despite the ability of shigella to actively secrete proteins into the host cytoplasm, a location from which antigenic peptides are processed for presentation to cd8(+) t cells. to determine why cd8(+) t cells fail to play a role in adaptive immunity to s. flexneri, we investigated whe ...	2011	21357720
core and panmetabolism in escherichia coli.	escherichia coli exhibits a wide range of lifestyles encompassing commensalism and various pathogenic behaviors which its highly dynamic genome contributes to develop. how environmental and host factors shape the genetic structure of e. coli strains remains, however, largely unknown. following a previous study of e. coli genomic diversity, we investigated its diversity at the metabolic level by building and analyzing the genome-scale metabolic networks of 29 e. coli strains (8 commensal and 21 p ...	2011	21239590
efficient screening of a novel antimicrobial peptide from jatropha curcas by cell membrane affinity chromatography.	a novel method named cell membrane affinity chromatography was used to screen antimicrobial peptides from jatropha curcas . a cationic antimicrobial peptide (kvflglk, jcpep7) was successfully isolated and identified. antimicrobial assays indicated that jcpep7 was active against the tested microorganisms ( salmonella typhimurium atcc 50013, shigella dysenteriae atcc 51302, pseudomonas aeruginosa atcc 27553, staphylococcus aureus atcc 25923, bacillus subtilis atcc 23631, and streptococcus pneumoni ...	2011	21268582
diarrheagenic escherichia coli in acute gastroenteritis in infants in north-west italy.	enteropathogenic escherichia coli may cause diarrhoea in infancy, but it is not routinely detected and regarded as a major causative agent. the aim of the present study was to estimate the incidence of enteropathogenic e. coli infection and to investigate its epidemiology and pathogenesis from faecal specimens in infants hospitalized for acute gastroenteritis. between march 2008 and june 2009, faecal samples were collected and examined to recognize diarrhoeal aetiology, especially for e. coli, b ...	2011	21344146
age specific aetiological agents of diarrhoea in hospitalized children aged less than five years in dar es salaam, tanzania.	this study aimed to determine the age-specific aetiologic agents of diarrhoea in children aged less than five years. the study also assessed the efficacy of the empiric treatment of childhood diarrhoea using integrated management of childhood illness (imci) guidelines.	2011	21345186
isolation and partial characterisation of a novel lectin from aegle marmelos fruit and its effect on adherence and invasion of shigellae to ht29 cells.	lectins are a class of ubiquitous proteins/glycoproteins that are abundantly found in nature. lectins have unique carbohydrate binding property and hence have been exploited as drugs against various infectious diseases. we have isolated one such novel lectin from the fruit pulp of aegle marmelos. the isolated lectin was partially characterised and its effect against shigella dysenteriae infection was evaluated. the isolated lectin was found to be a dimeric protein with n-acetylgalactosamine, man ...	2011	21283697
seizure and altered mental status in a 12-year-old child with shigella sonnei gastroenteritis.	we report a case of shigella-associated altered mental status and seizure in a 12-year-old boy. although seizure is a known complication of shigellosis, it is quite unusual in patients older than 9 years. this case illustrates the importance of considering the diagnosis of shigellosis in any pediatric patient with altered mental status or seizure in the context of gastrointestinal symptoms such as diarrhea.	2011	21293224
structural variability of endotoxins from r-type isogenic mutants of shigella sonnei.	the structural variations in the rough-type endotoxins [lipopolysaccharides (lpss)] of shigella sonnei mutant strains (s. sonnei phase ii-4303, r41, 562h and 4350) were investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof-ms) and tandem ms. a series of s. sonnei mutants had previously been the subject of analytical studies on the biosynthesis of heptose components in the core oligosaccharide region of lpss. this study gives a complete overview o ...	2011	21184397
shigellosis outbreak linked to canteen-food consumption in a public institution: a matched case-control study.	summaryon 13 november 2009, the authorities of flemish brabant, belgium, received an alert concerning a potential outbreak of shigella sonnei at a public institution. a study was conducted to assess the extent, discover the source and to implement further measures. we performed a matched case-control study to test an association between shigellosis and canteen-food consumption. water samples and food handlers' faecal samples were tested. the reference laboratory characterized the retrospectively ...	2011	21281549
enteric glial cells: new players in mucosal defence against bacteria?		2011	21282131
analysis of shigella flexneri-mediated infections in model organism caenorhabditis elegans.	shigella flexneri is the causative agent of bacillary dysentery and generates a significant global disease burden. the aim of this study was to analyze the pathogenesis and host immune response, at both the physiological and molecular level, using the model organism caenorhabditis elegans, in response to s. flexneri. c. elegans is a nematode that responds to infection with a simple innate immune system, key aspects of which have been shown to be conserved.	2011	21254954
development of a duplex real-time pcr for differentiation between e. coli and shigella spp.	the aim of this study was to develop a real-time pcr test for differentiation between shigella spp. and e. coli, in particular enteroinvasive escherichia coli (eiec).	2011	21332893
crystal structure of the autochaperone region from the shigella flexneri autotransporter icsa.	the icsa (intracellular spread gene a) autotransporter from shigella flexneri is a key virulence factor. we identified a stable fragment comprising residues 591 to 758, which corresponds to the autochaperone region of the icsa passenger domain. we showed that thermal unfolding of the autochaperone region is reversible and determined its crystal structure at 2.0-å resolution.	2011	21335457
autophagy targeting of listeria monocytogenes and the bacterial countermeasure.	autophagy acts as an intrinsic defense system against intracellular bacterial survival. recently, multiple cellular pathways that target intracellular bacterial pathogens to autophagy have been described. these include the atg5/lc3 pathway, which targets shigella, the ubiquitin (ub)-ndp52-lc3 pathway, which targets group a streptococcus (gas) and salmonella typhimurium, the ub-p62-lc3 pathway, which targets mycobacterium tuberculosis, listeria monocytogenes and s. typhimurium, and the diacylglyc ...	2011	21193840
development of a dna microarray for detection and identification of legionella pneumophila and ten other pathogens in drinking water.	the safety and accessibility of drinking water are major concerns throughout the world. consumption of water contaminated with infectious agents, toxic chemicals or radiological hazards represents a significant health risk and is strongly associated with mortality. therefore, we have developed an oligonucleotide-based microarray using the sequences of 16s-23s rdna internal transcribed spacer regions (its) and the gyrase subunit b gene (gyrb) found in the most prevalent and devastating waterborne ...	2011	21276629
volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of pinus densiflora and pinus thunbergii.	to investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of pinus densiflora needles (epdn) and pinus thunbergii needles (eptn), the volatile compounds of steam-distilled essential oils were analysed by gas chromatography-mass spectrometry. antibacterial activities were analysed by performing disc-agar diffusion assay and determining the minimum inhibitory concentrations (mics) of the essential oils. antioxidant activities were analysed via radica ...	2011	21213230
shiga toxin and its use in targeted cancer therapy and imaging.	shiga and the shiga-like toxins are related protein toxins produced by shigella dysenteriae and certain strains of escherichia coli. these toxins are composed of two non-covalently attached, modular parts: the a moiety (stxa) containing the enzymatically active a1 fragment, and the non-toxic, pentameric binding moiety (stxb). stx binds specifically to the glycosphingolipid globotriaosylceramide (gb3) at the surface of target cells and is then internalized by endocytosis. subsequently, in toxin-s ...	2011	21255370
immunology of gut mucosal vaccines.	understanding the mechanisms underlying the induction of immunity in the gastrointestinal mucosa following oral immunization and the cross-talk between mucosal and systemic immunity should expedite the development of vaccines to diminish the global burden caused by enteric pathogens. identifying an immunological correlate of protection in the course of field trials of efficacy, animal models (when available), or human challenge studies is also invaluable. in industrialized country populations, l ...	2011	21198669
dysbiosis of the faecal microbiota in patients with crohn's disease and their unaffected relatives.	a general dysbiosis of the intestinal microbiota has been established in patients with crohn's disease (cd), but a systematic characterisation of this dysbiosis is lacking. therefore the composition of the predominant faecal microbiota of patients with cd was studied in comparison with the predominant composition in unaffected controls. whether dysbiosis is present in relatives of patients cd was also examined.	2011	21209126
shigella enterotoxin-2 is a type iii effector that participates in shigella-induced interleukin 8 secretion by epithelial cells.	we have previously described a protein termed shigella enterotoxin 2 (shet-2), which induces rises in short-circuit current in rabbit ileum mounted in the ussing chamber. published reports have postulated that shet-2 may be secreted by the shigella type iii secretion system (t3ss). in this study, we show that shet-2 secretion into the extracellular space requires the t3ss in shigella flexneri 2a strain 2457t and a shet-2-tem fusion was translocated into epithelial cells in a t3ss-dependent manne ...	2011	21219446
genomic characterization of asymptomatic escherichia coli isolated from the neobladder.	the replacement of the bladder with a neobladder made from ileal tissue is the prescribed treatment in some cases of bladder cancer or trauma. studies have demonstrated that individuals with an ileal neobladder have recurrent colonization by escherichia coli and other species that are commonly associated with urinary tract infections; however, pyelonephritis and complicated symptomatic infections with ileal neobladders are relatively rare. this study examines the genomic content of two e. coli i ...	2011	21252277
decreased susceptibility to ciprofloxacin among shigella isolates in the united states, 2006 to 2009.	we characterized 20 shigella isolates with decreased susceptibility to fluoroquinolones. most patients (80%) from whom a travel history was obtained reported travel to south or southeast asia. mutations within the quinolone resistance determining regions of gyra and parc and plasmid-mediated resistance determinants (qnrb, qnrs, and aac(6')-ib-cr) were identified. the rise in antimicrobial resistance among shigella isolates may necessitate the increased use of extended-spectrum cephalosporins or ...	2011	21220535
structural and functional studies indicate that the epec effector, espg, directly binds p21-activated kinase.	bacterial pathogens secrete effectors into their hosts that subvert host defenses and redirect host processes. espg is a type three secretion effector with a disputed function that is found in enteropathogenic escherichia coli. here we show that espg is structurally similar to vira, a shigella virulence factor; espg has a large, conserved pocket on its surface; espg binds directly to the amino-terminal inhibitory domain of human p21-activated kinase (pak); and mutations to conserved residues in ...	2011	21235237
extended spectrum beta-lactamase production in shigella isolates - a matter of concern.		2011	21304205
molecular characterization of extended-spectrum β-lactamase-producing shigella isolates from humans in south africa, 2003-2009.		2012	21903820
Rotavirus in adults requiring hospitalization.	To determine the prevalence and epidemiological characteristics of rotavirus among adults admitted to the hospital with diarrhea that have bacterial stool cultures sent.	2012	21939687
Simultaneous Detection of Six Diarrhea-Causing Bacterial Pathogens with an In-House PCR-Luminex Assay.	Diarrhea can be caused by a range of pathogens, including several bacteria. Conventional diagnostic methods, such as culture, biochemical tests, and enzyme-linked immunosorbent assay (ELISA), are laborious. We developed a 7-plex PCR-Luminex assay to simultaneously screen for several of the major diarrhea-causing bacteria directly in fecal specimens, including pathogenic Aeromonas, Campylobacter jejuni, Campylobacter coli, Salmonella, Shigella, enteroinvasive Escherichia coli (EIEC), Vibrio, and ...	2012	22075596
How We Didn't Clean Up Until We Washed Our Hands: Shigellosis in an Elementary and Middle School in North Texas.	Shigella outbreaks often continue for months and are linked frequently to poor hygiene and hand washing. Such outbreaks are found often in day care facilities, but rarely are reported in schools. We present the investigation of an outbreak in autumn 2007 at a building that housed an elementary school and a middle school in separate wings in a small Texas city north of Dallas-Fort Worth.	2012	22189658
approach to the patient with infectious colitis.	to provide current recommendations for evaluation and treatment of patients with infectious colitis. infectious colitis is diagnosed in someone with diarrhea and one or more of the following: fever and/or dysentery, stools containing inflammatory markers such as leukocytes, lactoferrin, or calprotectin, or positive stool culture for an invasive or inflammatory bacterial enteropathogen including shigella, salmonella, campylobacter, shiga toxin-producing escherichia coli (stec) or clostridium diff ...	2012	22080825
evaluation of a quantitative h(2)s mpn test for fecal microbes analysis of water using biochemical and molecular identification.	the sensitivity and specificity of the h(2)s test to detect fecal bacteria in water has been variable and uncertain in previous studies, partly due to its presence-absence results. furthermore, in groundwater samples false-positive results have been reported, with h(2)s-positive samples containing no fecal coliforms or escherichia coli. false-negative results also have been reported in other studies, with h(2)s-negative samples found to contain e. coli. using biochemical and molecular methods an ...	2012	22244995
characterization and comparative genomic analysis of a novel bacteriophage, sfp10, simultaneously inhibiting both salmonella enterica and escherichia coli o157:h7.	salmonella enterica and escherichia coli o157:h7 are major food-borne pathogens causing serious illness. phage sfp10, which revealed effective infection of both s. enterica and e. coli o157:h7, was isolated and characterized. sfp10 contains a 158-kb double-stranded dna genome belonging to the vi01 phage-like family myoviridae. in vitro adsorption assays showed that the adsorption constant rates to both salmonella enterica serovar typhimurium and e. coli o157:h7 were 2.50 × 10(-8) ml/min and 1.91 ...	2012	22020516
antimicrobial activity of ulopterol isolated from toddalia asiatica (l.) lam.: a traditional medicinal plant.	aim of the study: the leaves of toddalia asiatica (l.) lam. (rutaceae) are widely used in folk medicine in india to treat various ailments. in our earlier communication we have reported the antimicrobial study on the various extracts of the leaves and the isolation and identification of flindersine, a quinolone alkaloid as the major active principle. in the present study, we report the antibacterial and antifungal activities of ulopterol, a coumarin isolated as another major active antimicrobial ...	2012	22265751
epidemiological, clinical features and susceptibility pattern of shigellosis in the buea health district, cameroon.	abstract: background: shigellosis is an acute invasive enteric infection caused by bacteria belonging to the genus shigella; it is clinically manifested by bloody diarrhoea. shigellosis is endemic in many developing countries including cameroon and also occurs in epidemics causing considerable morbidity and mortality. this study evaluated the epidemiological and clinical features of shigella and the resistance pattern of isolates to commonly used antibiotics in the buea health district in camer ...	2012	22264300
[characterisation of a ctx-m-15-producing shigella sonnei in a spanish patient who had not travelled abroad.]	one hundred and seven shigella spp. strains were isolated in our laboratory during the years 2000 to 2010. one shigella sonnei harboured the genes that coded the β-lactamases tem-1 and ctx-m-15, identifying the structure, isecp1+bla(ctx-m-15)+orf477, in their genetic environment. the strain also carried a class 2 integron with the gene cassettes dfra1+sat+aada1. a plasmid group inci1 st31 (cc-31) was detected and its mobilization by conjugation was demonstrated. we describe for the first time a ...	2012	22244530
the patient presenting with acute dysentery - a systematic review.	objectives: the etiologies, clinical presentations and diagnosis of acute pathogen-specific dysentery in children and adults in industrialized and developing regions is described to help develop recommendations for therapy. methods: we conducted a systematic review of literature published between january 2000 and june 2011 to determine the frequency of occurrence of pathogen-specific dysentery. results: shigella, salmonella, and campylobacter remain the most frequent bacterial causes of dysenter ...	2012	22266388
analysis of the global transcriptional profiles of enterotoxigenic escherichia coli (etec) isolate e24377a.	enterotoxigenic escherichia coli (etec) is an important pathogenic variant (pathovar) of e. coli in developing countries from a human health perspective, causing significant morbidity and mortality. previous studies have examined specific regulatory networks in etec, although little is known about the global effects of inter- and intra-kingdom signaling on the expression of virulence and colonization factors in etec. in this study, an e.coli/shigella pan-genome microarray, combined with quantita ...	2012	22215741
the evolution of the escherichia coli phylogeny.	escherichia coli are familiar to biologists as a classical model system, ubiquitous in molecular biology laboratories around the world. outside of the laboratory, e. coli strains exist as an almost universal component of the lower-gut flora of humans and animals. although usually a commensal, e. coli has an alter ego as a pathogen, and is associated with diarrhoeal disease and extra-intestinal infections. the study of e. coli diversity predates the availability of molecular data, with strains in ...	2012	22266241
galectin 8 targets damaged vesicles for autophagy to defend cells against bacterial invasion.	autophagy defends the mammalian cytosol against bacterial infection. efficient pathogen engulfment is mediated by cargo-selecting autophagy adaptors that rely on unidentified pattern-recognition or danger receptors to label invading pathogens as autophagy cargo, typically by polyubiquitin coating. here we show in human cells that galectin 8 (also known as lgals8), a cytosolic lectin, is a danger receptor that restricts salmonella proliferation. galectin 8 monitors endosomal and lysosomal integri ...	2012	22246324