Publications

engineering escherichia coli into a protein delivery system for mammalian cells.	many gram-negative pathogens encode type 3 secretion systems, sophisticated nanomachines that deliver proteins directly into the cytoplasm of mammalian cells. these systems present attractive opportunities for therapeutic protein delivery applications; however, their utility has been limited by their inherent pathogenicity. here, we report the reengineering of a laboratory strain of escherichia coli with a tunable type 3 secretion system that can efficiently deliver heterologous proteins into ma ...	2015	25853840
enhanced resistance to fluoroquinolones in laboratory-grown mutants & clinical isolates of shigella due to synergism between efflux pump expression & mutations in quinolone resistance determining region.	there is a worldwide emergence of fluoroquinolone resistance in shigella species. to understand the molecular mechanisms associated with fluoroquinolone resistance, naturally occurring fluoroquinolone-resistant strains and laboratory-induced spontaneous mutants of shigella spp. were used and the relative contributions of acrab-tolc efflux pumps, gyrase and topoisomerase target gene mutations towards fluoroquinolone resistance were determined.	2015	25857499
the passenger-associated transport repeat promotes virulence factor secretion efficiency and delineates a distinct autotransporter subtype.	autotransporters are a superfamily of virulence factors secreted by gram negative bacteria. they are comprised of an n-terminal passenger domain that is translocated across the outer membrane and a c-terminal domain that inserts into the outer membrane forming a β-barrel anchor. it is still poorly understood how the passenger is efficiently translocated in the absence of external energy inputs. several mechanisms have been proposed in solution of this problem, yet due to the vast diversity of si ...	2015	25869731
antimicrobial evaluation of plants used for the treatment of diarrhoea in a rural community in northern maputaland, kwazulu-natal, south africa.	zulu people living in the rural area of maputaland (kwazulu-natal, south africa) rely heavily on medicinal plants for the treatment of diarrhoea. abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against many ailments including diarrhoeal infections. with this in mind a study was designed to test the in vitro antimicrobial efficacy of 23 plant species which are used for ...	2015	25881066
clinical and microbiological profiles of shigellosis in children.	shigellosis presents with varied clinical features are dictated by the species involved, virulence factors of the strain, and the host immune status. we studied the species, virulence genes, and antibiotic susceptibility pattern of the shigella strains isolated from 33 children aged less than 12 years, with clinical features of shigellosis. identification and antibiotic sensitivity of shigella species were done using disc diffusion and e-test. multiplex pcr was done for the detection of virulenc ...	2014	25895190
the serine protease autotransporter pic modulates citrobacter rodentium pathogenesis and its innate recognition by the host.	bacterial pathogens produce a number of autotransporters that possess diverse functions. these include the family of serine protease autotransporters of enterobacteriaceae (spates) produced by enteric pathogens such as shigella flexneri and enteroaggregative escherichia coli. of these spates, one termed "protein involved in colonization," or pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown. testing a pic null (δpicc) muta ...	2015	25895966
identification and molecular characterisation of a novel mu-like bacteriophage, sfmu, of shigella flexneri.	s. flexneri is the leading cause of bacillary dysentery in the developing countries. several temperate phages originating from this host have been characterised. however, all s. flexneri phages known to date are lambdoid phages, which have the ability to confer the o-antigen modification of their host. in this study, we report the isolation and characterisation of a novel mu-like phage from a serotype 4a strain of s. flexneri. the genome of phage sfmu is composed of 37,146 bp and is predicted to ...	2015	25902138
sex, drugs and smart phone applications: findings from semistructured interviews with men who have sex with men diagnosed with shigella flexneri 3a in england and wales.	to inform control strategies undertaken as part of an outbreak of shigella flexneri 3a among men who have sex with men (msm).	2015	25921020
antibacterial activity of lactobacillus spp. isolated from the feces of healthy infants against enteropathogenic bacteria.	lactobacilli are normal microflora of the gastrointestinal (gi) tract and are a heterogeneous group of lactic acid bacteria (lab). lactobacillus strains with probiotic activity may have health benefits for human. this study investigates the probiotic potential of lactobacillus strains obtained from the feces of healthy infants and also explores antibacterial activity of lactobacillus strains with probiotic potential against enteropathogenic bacteria. fecal samples were collected from 95 healthy ...	2015	25930687
shigella flexneri serotype 3a: the rise of a superbug.		2015	25936610
intercontinental dissemination of azithromycin-resistant shigellosis through sexual transmission: a cross-sectional study.	shigellosis is an acute, severe bacterial colitis that, in high-income countries, is typically associated with travel to high-risk regions (africa, asia, and latin america). since the 1970s, shigellosis has also been reported as a sexually transmitted infection in men who have sex with men (msm), in whom transmission is an important component of shigellosis epidemiology in high-income nations. we aimed to use sophisticated subtyping and international sampling to determine factors driving shigell ...	2015	25936611
intensified shigellosis epidemic associated with sexual transmission in men who have sex with men--shigella flexneri and s. sonnei in england, 2004 to end of february 2015.	surveillance data suggest an intensification of the shigellosis epidemic associated with sexual transmissionin men who have sex with men (msm) in england with separate introductions into the population. in 2014, sexual transmission between msm might have accounted for 97%, 89%, and 43% of non-travel associated shigella flexneri 3a and s. flexneri 2a, ands. sonnei diagnoses. clinicians should sensitively ascertain sexual history for men with enteric infections to facilitate prompt diagnosis and a ...	2015	25953129
shigella flexneri: a cause of significant morbidity and associated with sexually transmitted infections in men who have sex with men.		2015	25970314
prevalence of shiga toxin-producing shigella species isolated from french travellers returning from the caribbean: an emerging pathogen with international implications.	shiga toxins (stxs) are potent cytotoxins that inhibit host cell protein synthesis, leading to cell death. classically, these toxins are associated with intestinal infections due to stx-producing escherichia coli or shigella dysenteriae serotype 1, and infections with these strains can lead to haemolytic-uraemic syndrome. over the past decade, there has been increasing recognition that stx is produced by additional shigella species. we recently reported the presence and expression of stx genes i ...	2015	25980352
effect of combination therapy between thyme oil and ciprofloxacin on ulcer-forming shigella flexneri.	shigella flexneri is a gram-negative bacteria that has the ability to invade the epithelium of the colon and cause colon ulcers.	2015	25989168
the effect of quorum sensing system for growth competitiveness on shigella flexneri.	quorum sensing (qs) regulates the onset of bacterial social responses related to cell density. comparison between the gene sequences of all components of qs system of escherichia coli and shigella strains, shows that the qs system is generally lost or mutated in shigella. since ai-2 is produced and processed by the lsr operon, we analyzed the potential function of the lsr operon. we first detected ai-2 in shigella flexneri 2a strain 301 through the reporter bacteria vibrio harveyi bb170, indicat ...	2015	25998438
prevalence and antimicrobial resistance of shigella flexneri serotype 2 variant in china.	shigella flexneri serotype 2 variant (ii:3,4,7,8) was isolated in 2008 and first reported in china in 2013. in the present study, epidemiological surveillance from 2003 to 2013 in china suggested that this serotype first appeared in guangxi in 2003; it then emerged in shanghai and xinjiang in 2004 and in henan in 2008. of the 1813 s. flexneri isolates, 58 s. flexneri serotype 2 variant strains were identified. serotype 2 variant has emerged as a prominent serotype in recent years, with 2a (32.6% ...	2015	25999941
material properties and antimicrobial activity of polyhydroxybutyrate (phb) films incorporated with vanillin.	polyhydroxybutyrate (phb) was produced by bacillus mycoides dfc 1, isolated from garden soil. antimicrobial (am) films of phb were prepared by incorporating vanillin (4-hydroxy-3-methoxybenzaldehyde) from 10 to 200 μg/g of phb. the films were assessed for antimicrobial activity against foodborne pathogens and spoilage bacteria comprising of escherichia coli, salmonella typhimurium, shigella flexneri, and staphylococcus aureus and fungi such as aspergillus flavus, aspergillus fumigatus, aspergill ...	2015	26002697
escape of actively secreting shigella flexneri from atg8/lc3-positive vacuoles formed during cell-to-cell spread is facilitated by icsb and vira.	the enteropathogenic bacterium shigella flexneri uses a type 3 secretion apparatus (t3sa) to transfer proteins dubbed translocators and effectors inside host cells, inducing bacterial uptake and subsequent lysis of the entry vacuole. once in the cytoplasm, the outer membrane protein icsa induces actin polymerization, enabling cytoplasmic movement and cell-to-cell spread of bacteria. during this infectious process, s. flexneri is targeted by atg8/lc3. the effector icsb was proposed to inhibit lc3 ...	2015	26015503
bacterial spread from cell to cell: beyond actin-based motility.	several intracellular pathogens display the ability to propagate within host tissues by displaying actin-based motility in the cytosol of infected cells. as motile bacteria reach cell-cell contacts they form plasma membrane protrusions that project into adjacent cells and resolve into vacuoles from which the pathogen escapes, thereby achieving spread from cell to cell. seminal studies have defined the bacterial and cellular factors that support actin-based motility. by contrast, the mechanisms s ...	2015	26021574
draft genome sequence of 24570, the type strain of shigella flexneri.	shigella flexneri is a diarrheal pathogen that causes a large disease burden worldwide. we sequenced the genome of the publicly available type strain (s. flexneri 2a strain 24570) of this bacterial species to increase its utility as a reference. we present genome assembly results and comparisons with other reference strains.	2015	26021915
shigella flexneri cell-to-cell spread, and growth and inflammation in mice, is limited by the outer membrane protease icsp.	the shigella flexneri autotransporter protein icsa is essential for intra- and intercellular spread, and icsa mutants are attenuated in several models. however, the pathogenic significance of the outer membrane protease icsp, which orchestrates the polar distribution of icsa on the bacterial surface, remains unclear. to further examine this point, we constructed icsp mutants in the two most commonly studied s. flexneri strains and evaluated their in vitro and in vivo performance relative to wild ...	2015	26025071
identification of a divergent o-acetyltransferase gene oac 1b from shigella flexneri serotype 1b strains.	shigella flexneri is a leading cause of bacterial dysentery in developing countries. among the 15 known serotypes, four (1b, 3a, 3b and 4b) contain a group 6 epitope due to an acetyl group connected to the o-2 position of rhamnose iii on the tetrasaccharide structure of the lipopolysaccharide. o-acetyltransferase encoded by a bacteriophage, sf6, mediates the acetylation reaction. we found that the oac gene in serotype 1b strains was very different from that in serotypes 3a, 3b and 4b strains and ...	2012	26038428
antimicrobial resistance of shigella flexneri serotype 1b isolates in china.	shigella flexneri serotype 1b is among the most prominent serotypes in developing countries, followed by serotype 2a. however, only limited data is available on the global phenotypic and genotypic characteristics of s. flexneri 1b. in the present study, 40 s. flexneri 1b isolates from different regions of china were confirmed by serotyping and biochemical characterization. antimicrobial susceptibility testing showed that 85% of these isolates were multidrug-resistant strains and antibiotic susce ...	2015	26039698
draft genomes of shigella strains used by the stopenterics consortium.	despite a significant global burden of disease, there is still no vaccine against shigellosis widely available. one aim of the european union funded stopenterics consortium is to develop vaccine candidates against shigella. given the importance of translational vaccine coverage, here we aimed to characterise the shigella strains being used by the consortium by whole genome sequencing, and report on the stability of strains cultured in different laboratories or through serial passage.	2015	26042182
antibacterial activity of ovary extract from sea urchin diadema setosum.	sea urchin gonad is considered as a highly prized delicacy in several countries. it is also rich in valuable bioactive compounds including polyunsaturated fatty acids (pufas) and β-carotene. this study was undertaken to examine the antimicrobial properties of the ovary extract from sea urchin diadema setosum against selected gram-negative and gram-positive bacteria.	2015	26044237
bioimage analysis of shigella infection reveals targeting of colonic crypts.	few studies within the pathogenic field have used advanced imaging and analytical tools to quantitatively measure pathogenicity in vivo. in this work, we present a novel approach for the investigation of host-pathogen processes based on medium-throughput 3d fluorescence imaging. the guinea pig model for shigella flexneri invasion of the colonic mucosa was used to monitor the infectious process over time with gfp-expressing s. flexneri. a precise quantitative imaging protocol was devised to follo ...	2015	26056271
antibacterial mode of action of the hydroethanolic extract of leonotis nepetifolia (l.) r. br. involves bacterial membrane perturbations.	leonotis nepetifolia (l) r. br., lamiaceae, a pantropical shrub, popularly known in brazil as "cordão-de-frade", "rubim", is reportedly used in brazilian ethnomedicine as well as in different countries in the treatments of ailments such as infections, inflammations, wounds, stomach disorders, among others.	2015	26102550
aerobic bacterial community of american cockroach periplaneta americana,a step toward finding suitable paratransgenesis candidates.	cockroaches mechanically spread pathogenic agents, however, little is known about their gut microbiota. identification of midgut microbial community helps targeting novel biological control strategies such as paratransgenesis. here the bacterial microbiota of periplaneta americana midgut, were identified and evaluated for finding proper paratransgenesis candidate.	2014	26114142
clonal dissemination of a single shigella sonnei strain among iranian children during fall 2012 in tehran, i.r. iran.	shigella species are a common cause of bacterial diarrhea worldwide and the disease is characterized by seasonality. shigella has been encountered by widespread resistance to commonly used antibiotics which is a serious concern. the aim of this study was to analyze the epidemiological relatedness of shigella strains isolated from children during one year period by pfge method and to investigate antimicrobial resistance determinants and cassettes among shigella species. the occurrence of shigella ...	2015	26117443
hfq regulates acid tolerance and virulence by responding to acid stress in shigella flexneri.	shigella flexneri is an important etiological agent of bacillary dysentery in developing countries. the hfq protein is thought to play a major regulatory role in various cellular processes in this organism. however, the roles of hfq in stress tolerance and virulence in s. flexneri in response to environmental stress have not been fully studied. in this study, hfq was highly expressed when s. flexneri was exposed to low ph. growth retardation was observed in the hfq deletion mutant at ph values r ...	2015	26117597
bacterial internalization, localization, and effectors shape the epithelial immune response during shigella flexneri infection.	intracellular pathogens are differentially sensed by the compartmentalized host immune system. nevertheless, gene expression studies of infected cells commonly average the immune responses, neglecting the precise pathogen localization. to overcome this limitation, we dissected the transcriptional immune response to shigella flexneri across different infection stages in bulk and single cells. this identified six distinct transcriptional profiles characterizing the dynamic, multilayered host respo ...	2015	26123804
mutations in gyra & parc genes of shigella flexneri 2a determining the fluoroquinolone resistance.		2015	26205028
species-wide whole genome sequencing reveals historical global spread and recent local persistence in shigella flexneri.	shigella flexneri is the most common cause of bacterial dysentery in low-income countries. despite this, s. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on serotyping reactions developed over half-a-century ago. here we combine whole genome sequencing with geographical and temporal data to examine the natural history of the species. our analysis subdivides s. flexneri into seven phylogenetic groups (pgs); each containing two-or-mor ...	2015	26238191
sting signaling the energic way.	the effector proteins ipaj and vira, from the bacterium shigella flexneri, block the general secretory pathway (gsp) at different stages. in this issue of cell host & microbe, dobbs et al. (2015) use these proteins as a tool to pinpoint sting trafficking and signaling to the er-golgi intermediate compartment (ergic).	2015	26269948
intracellular and membrane-damaging activities of methyl gallate isolated from terminalia chebula against multidrug-resistant shigella spp.	shigella spp. (shigella dysenteriae, shigella flexneri, shigella boydii and shigella sonnei) cause bacillary dysentery (shigellosis), which is characterized by bloody mucous diarrhoea. although a variety of antibiotics have been effective for treatment of shigellosis, options are becoming limited due to globally emerging drug resistance. in the present study, in vitro antibacterial activity of methyl gallate (mg) isolated from terminalia chebula was determined by performing mic, minimal bacteric ...	2015	26272388
quantification of cytosolic vs. vacuolar salmonella in primary macrophages by differential permeabilization.	intracellular bacterial pathogens can replicate in the cytosol or in specialized pathogen-containing vacuoles (pcvs). to reach the cytosol, bacteria like shigella flexneri and francisella novicida need to induce the rupture of the phagosome. in contrast, salmonella typhimurium replicates in a vacuolar compartment, known as salmonella-containing vacuole (scv). however certain mutants of salmonella fail to maintain scv integrity and are thus released into the cytosol. the percentage of cytosolic v ...	2015	26274778
antimicrobial activity and the presence of virulence factors and bacteriocin structural genes in enterococcus faecium cm33 isolated from ewe colostrum.	screening of lactic acid bacteria (lab) isolated from ewe colostrum led to the identification and isolation of enterococcus faecium cm33 with interesting features like high survival rates under acidic or bile salts condition, high tolerance for the simulated gastrointestinal condition, and high adhesive potential to caco-2 cells. according the inhibition of pathogen adhesion test results, this strain can reduce more than 50% adhesion capacity of escherichia coli, shigella flexneri, klebsiella pn ...	2015	26284059
detection of wzy/wzz interaction in shigella flexneri.	the o antigen (oag) component of shigella flexneri lipopolysaccharide (lps) is important for virulence and a protective antigen. it is synthesized by the wzy-dependent mechanism. s. flexneri wzy has 12 transmembrane segments and two large periplasmic loops. the modal chain length of the oag is determined by wzz. experimental evidence supports multi-protein interactions in the wzy-dependent pathway. however, evidence for direct interaction of wzy with the other proteins of the wzy-dependent pathw ...	2015	26296569
determinants of proteolysis and cell-binding for the shigella flexneri cytotoxin, siga.	shigella flexneri secretes an enterotoxic, spate family autotransporter (at), siga, which has cytopathic activity towards cultured epithelial cells. its cytopathic activity is due to its ability to degrade the cytoskeletal protein, α-fodrin. the mechanisms by which at toxins target cells and tissues differ and the details of how siga acts are not known. in the current study, the determinants of proteolysis and cell-targeting for siga were determined. we demonstrate that the siga passenger or α-d ...	2015	26297175
broad spectrum antimicrobial compounds from the bacterium exiguobacterium mexicanum mssrfs9.	clinical bacterial pathogens front a major challenge for the clinical researchers and physicians. in particular microbial pathogens like escherichia coli, shigella flexneri, klebsiella pneumonia and salmonella enterica are apparelled with systemic machineries to bring down the human immune system as well as proliferate dramatically in a short period which in turn cause a pronounced ailment to the human health. in vitro evaluation of four purified compounds isolated from rhizosphere bacterium exi ...	2015	26302848
a small conserved motif supports polarity augmentation of shigella flexneri icsa.	the rod-shaped enteric intracellular pathogen shigella flexneri and other shigella species are the causative agents of bacillary dysentery. s. flexneri are able to spread within the epithelial lining of the gut, resulting in lesion formation, cramps and bloody stools. the outer membrane protein icsa is essential for this spreading process. icsa is the initiator of an actin-based form of motility whereby it allows the formation of a filamentous actin 'tail' at the bacterial pole. importantly, ics ...	2015	26315462
investigation on the synthesis of shigella flexneri specific oligosaccharides using disaccharides as potential transglucosylase acceptor substrates.	chemo-enzymatic strategies hold great potential for the development of stereo- and regioselective syntheses of structurally defined bioactive oligosaccharides. herein, we illustrate the potential of the appropriate combination of a planned chemo-enzymatic pathway and an engineered biocatalyst for the multistep synthesis of an important decasaccharide for vaccine development. we report the stepwise investigation, which led to an efficient chemical conversion of allyl α-d-glucopyranosyl-(1→4)-α-l- ...	2015	26340432
mechanism of action and initial, in vitro sar of an inhibitor of the shigella flexneri virulence regulator virf.	shigella spp. are among the main causative agents of acute diarrheal illness and claim more than 1 million lives per year worldwide. there are multiple bacterial genes that control the pathogenesis of shigella, but the virf gene may be the most important. this gene, located on the primary pathogenicity island of shigella, encodes virf, an arac-family transcriptional activator that is responsible for initiating the pathogenesis cycle in shigella. we have previously shown that it is possible to at ...	2015	26352269
shigellosis outbreak in al batinah south governorate, oman: case-control study.	an outbreak of acute gastroenteritis due to shigella flexneri occurred in august 2012 in the catchment area of the wadi sahtan health center in rustaq, al batinah south governorate, oman. the aim of this study was to discover possible causes of this outbreak in the villages of fassa, rogh and amk and to measure the risk of exposure among cases and controls.	2015	26357558
vasodilator-stimulated phosphoprotein restricts cell-to-cell spread of shigella flexneri at the cell periphery.	shigella spp. are intracellular bacterial pathogens that cause diarrhoeal disease in humans. shigella utilize the host actin cytoskeleton to enter cells, move through the cytoplasm of cells and pass into adjacent cells. ena/vasp family proteins are highly conserved proteins that participate in actin-dependent dynamic cellular processes. we tested whether ena/vasp family members vasp (vasodilator-stimulated phosphoprotein), mena (mammalian-enabled) or evl (ena-vasp-like) contribute to shigella fl ...	2015	26358985
caspase-11 cleaves gasdermin d for non-canonical inflammasome signalling.	intracellular lipopolysaccharide from gram-negative bacteria including escherichia coli, salmonella typhimurium, shigella flexneri, and burkholderia thailandensis activates mouse caspase-11, causing pyroptotic cell death, interleukin-1β processing, and lethal septic shock. how caspase-11 executes these downstream signalling events is largely unknown. here we show that gasdermin d is essential for caspase-11-dependent pyroptosis and interleukin-1β maturation. a forward genetic screen with ethyl-n ...	2015	26375259
structural and biochemical analysis of a single amino-acid mutant of wzzbsf that alters lipopolysaccharide o-antigen chain length in shigella flexneri.	lipopolysaccharide (lps), a surface polymer of gram-negative bacteria, helps bacteria survive in different environments and acts as a virulence determinant of host infection. the o-antigen (oag) component of lps exhibits a modal chain-length distribution that is controlled by polysaccharide co-polymerases (pcps). the molecular basis of the regulation of oag chain-lengths remains unclear, despite extensive mutagenesis and structural studies of pcps from escherichia coli and shigella. here, we ide ...	2015	26378781
identification of shigella flexneri isolates carrying the shiga toxin 1-producing gene in quebec, canada, linked to travel to haiti.		2015	26401981
failure of syndrome-based diarrhea management guidelines to detect shigella infections in kenyan children.	shigella is a leading cause of childhood diarrhea mortality in sub-saharan africa. current world health organization guidelines recommend antibiotics for children in non cholera-endemic areas only in the presence of dysentery, a proxy for suspected shigella infection.	2016	26407270
report: antibacterial and antifungal activities of leaf extract of achyranthes aspera (amaranthaceae) from pakistan.	alcoholic extract and various fractions of achyranthes aspera leaves, traditionally used in pakistan for treatment of infectious diseases was screened for in vitro antibacterial and antifungal activity. the chloroform and butanol fractions were found to be the most active among the fractions, showing considerable antibacterial activity against shigella flexneri and escherichia coli. the highest activity was found in the ethylacetate fraction (17 mm zone of inhibition) against gram-negative (salm ...	2015	26408900
comparative proteomics of shigella flexneri 2a strain 301 using a rabbit ileal loop model reveals key proteins for bacterial adaptation in host niches.	many studies focusing on changes in the host following shigella spp invasion have been reported in recent years. however, the key factors required for the adaptation of these pathogens to host niches have usually been neglected.	2015	26417879
invasive shigellosis in msm.	shigella flexneri is an emerging pathogen in men who have sex with men (msm); recent outbreaks related to sexual practices have been noted in this population in the uk and other developed countries. while the majority of cases of shigellosis present with gastroenteritis, some vulnerable patients with underlying immunosuppression can develop complications like bacteraemia and may present atypically as an acute surgical emergency. this case report highlights such a case of s. flexneri bacteraemia ...	2016	26429891
horizontal gene transfer of a chlamydial trna-guanine transglycosylase gene to eukaryotic microbes.	trna-guanine transglycosylases are found in all domains of life and mediate the base exchange of guanine with queuine in the anticodon loop of trnas. they can also regulate virulence in bacteria such as shigella flexneri, which has prompted the development of drugs that inhibit the function of these enzymes. here we report a group of trna-guanine transglycosylases in eukaryotic microbes (algae and protozoa) which are more similar to their bacterial counterparts than previously characterized euka ...	2016	26435002
attributes of carbapenemase encoding conjugative plasmid pndm-sal from an extensively drug-resistant salmonella enterica serovar senftenberg.	a carbapenem resistant salmonella enterica serovar senftenberg isolate bch 2406 was isolated from a diarrheal child attending an outpatient unit of b.c. roy hospital in kolkata, india. this isolate was positive for the bla ndm-1 in the pcr assay, which was confirmed by amplicon sequencing. except for tetracycline, this isolate was resistant to all the tested antimicrobials. the bla ndm-1 was found to be located on a 146.13-kb mega plasmid pndm-sal, which could be conjugally transferred into esch ...	2015	26441902
a small-scale experiment of using phage-based probiotic dietary supplement for prevention of e. coli traveler's diarrhea.	traveler's diarrhea (td) is caused by escherichia coli in 30% of cases. we have developed a phage cocktail for prophylaxis of td caused by e.coli, shigella flexneri, shigella sonnei, salmonella enterica, listeria monocytogenes or staphylococcus aureus, and investigated its effectiveness against infection caused by the non-pathogenic lac (-) strain of e.coli k12 c600 in animal and human trials. on the 6th day of both animal and human trials e. coli k12 c600 strain was detected in titer of 10(4) c ...	2017	26458758
complete sequences and characterization of two novel plasmids carrying aac(6')-ib-cr and qnrs gene in shigella flexneri.	the complete sequences of two previously reported plasmids carrying plasmid-mediated quinolone resistance genes from shigella flexneri in china have not been available. the present study using the p5-c3 assembly method revealed that (1) the plasmid psf07201 with aac(6')-ib-cr had 75,335 bp with antibiotic resistance genes ctx-m-3, tem-1, and fosa3; (2) seven fragments of psf07201 had more than 99% homology with the seven corresponding plasmids; (3) the other plasmid psf07202 with qnrs had 47,669 ...	2016	26469217
the multivalent adhesion molecule sso1327 plays a key role in shigella sonnei pathogenesis.	shigella sonnei is a bacterial pathogen and causative agent of bacillary dysentery. it deploys a type iii secretion system to inject effector proteins into host epithelial cells and macrophages, an essential step for tissue invasion and immune evasion. although the arsenal of bacterial effectors and their cellular targets have been studied extensively, little is known about the prerequisites for deployment of type iii secreted proteins during infection. here, we describe a novel s. sonnei adhesi ...	2016	26481305
kefir-isolated bacteria and yeasts inhibit shigella flexneri invasion and modulate pro-inflammatory response on intestinal epithelial cells.	the aim of this work was to evaluate the ability of a kefir-isolated microbial mixture containing three bacterial and two yeast strains (mm) to protect intestinal epithelial cells against shigella flexneri invasion, as well as to analyse the effect on pro-inflammatory response elicited by this pathogen. a significant decrease in s. flexneri strain 72 invasion was observed on both ht-29 and caco-2 cells pre-incubated with mm. pre-incubation with the individual strains saccharomyces cerevisiae cid ...	2016	26503738
effect of x-ray treatments on escherichia coli o157:h7, listeria monocytogenes, shigella flexneri, salmonella enterica and inherent microbiota on whole mangoes.	the aims of this investigation were to; (i) study the effect of x-ray treatments in reducing escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole mangoes, and (ii) study the effect of x-ray treatments on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mould counts) of whole mangoes during storage at ambient temperature (22°c) for 30 days. a mixture of three strains of each test organism was spot inoculated (100 μl; approx. ...	2016	26518738
multi-parameter flow cytometry as a process analytical technology (pat) approach for the assessment of bacterial ghost production.	flow cytometry (fcm) is a tool for the analysis of single-cell properties in a cell suspension. in this contribution, we present an improved fcm method for the assessment of e-lysis in enterobacteriaceae. the result of the e-lysis process is empty bacterial envelopes-called bacterial ghosts (bgs)-that constitute potential products in the pharmaceutical field. bgs have reduced light scattering properties when compared with intact cells. in combination with viability information obtained from stai ...	2016	26521248
microbial contamination of street vended foods from a university campus in bangladesh.	the microbiological quality of street vended food samples from dhaka, bangladesh was evaluated. the objective of the study was to identify the presence of common pathogens (escherichia coli, shigella spp, salmonella and vibrio spp) and to describe the molecular characterization of e coli, a commonly found pathogen in various street foods. fifty food samples were collected from fixed and mobile vendors from two sampling locations (mohakhali and aftabnagar) in dhaka city, bangladesh. the tested sa ...	2015	26521522
characterisation of shigella spa33 and thermotoga flim/n reveals a new model for c-ring assembly in t3ss.	flagellar type iii secretion systems (t3ss) contain an essential cytoplasmic-ring (c-ring) largely composed of two proteins flim and flin, whereas an analogous substructure for the closely related non-flagellar (nf) t3ss has not been observed in situ. we show that the spa33 gene encoding the putative nf-t3ss c-ring component in shigella flexneri is alternatively translated to produce both full-length (spa33-fl) and a short variant (spa33-c), with both required for secretion. they associate in a ...	2015	26538516
o-antigen modifications providing antigenic diversity of shigella flexneri and underlying genetic mechanisms.	o-antigens (o-specific polysaccharides) of shigella flexneri, a primary cause of shigellosis, are distinguished by a wide diversity of chemical modifications following the oligosaccharide o-unit assembly. the present review is devoted to structural, serological, and genetic aspects of these modifications, including o-acetylation and phosphorylation with phosphoethanolamine that have been identified recently. the modifications confer the host with specific immunodeterminants (o-factors or o-antig ...	2015	26542003
clinical implications of reduced susceptibility to fluoroquinolones in paediatric shigella sonnei and shigella flexneri infections.	we aimed to quantify the impact of fluoroquinolone resistance on the clinical outcome of paediatric shigellosis patients treated with fluoroquinolones in southern vietnam. such information is important to inform therapeutic management for infections caused by this increasingly drug-resistant pathogen, responsible for high morbidity and mortality in young children globally.	2016	26679253
in vitro antibacterial, antioxidant activity and total phenolic content of some essential oils.	in vitro antibacterial activity of 16 essential oils was investigated by disc diffusion method against two gram positive bacteria bacillus subtilis and staphylococcus aureus and two gram negative bacteria, shigella flexneri and escherichia coli. oils of cymbopogon citratus and ocimum basilicum showed highest antibacterial activity. gram positive bacteria were found to be more sensitive than gram negative. antioxidant activities were tested by 2,2-diphenyl-1-picrylhydrazyl (dpph) radical scavengi ...	2015	26688969
bacterial e3 ubiquitin ligase ipah4.5 of shigella flexneri targets tbk1 to dampen the host antibacterial response.	ifn regulatory factors play a pivotal role in many cellular processes, including inflammatory and immune responses. their activation is tightly regulated by tank-binding kinase 1 (tbk1). in response to microbial components, tbk1 activates ifn regulatory factor 3 (irf3) and cytokine expression. in this article, we show that tbk1 is a novel target of the ipah4.5 protein, a shigella type iii effector possessing e3 ubiquitin ligase activity. remarkably, ipah4.5 interacts with tbk1 and promotes its k ...	2016	26700764
alteration in apyrase enzyme attenuated virulence of shigella flexneri.	virulence of shigella is attributed to the genes presence in chromosome or in the megaplasmid. the apy gene which is located in the megaplasmid of shigella species encodes for apyrase enzyme, a pathogenesis-associated enzyme causing mitochondrial damage and host cell death. in this study we constructed an apy mutant of shigella flexneri by insertional activation using a kanamycin resistant gene cassette. the wild type apy gene of s. flexneri 2a was pcr amplified, cloned and mutated with insertio ...	2016	26706344
shigella infections: a two year experience in cancer patients.	to identify clinical and microbiological characteristics of shigella infections among cancer patients.	2016	26712178
prediction of intra-species protein-protein interactions in enteropathogens facilitating systems biology study.	protein-protein interactions in escherichia coli (e. coli) has been studied extensively using high throughput methods such as tandem affinity purification followed by mass spectrometry and yeast two-hybrid method. this can in turn be used to understand the mechanisms of bacterial cellular processes. however, experimental characterization of such huge amount of interactions data is not available for other important enteropathogens. here, we propose a support vector machine (svm)-based prediction ...	2015	26717407
ultrafiltration and microarray for detection of microbial source tracking marker and pathogen genes in riverine and marine systems.	pathogen identification and microbial source tracking (mst) to identify sources of fecal pollution improve evaluation of water quality. they contribute to improved assessment of human health risks and remediation of pollution sources. an mst microarray was used to simultaneously detect genes for multiple pathogens and indicators of fecal pollution in freshwater, marine water, sewage-contaminated freshwater and marine water, and treated wastewater. dead-end ultrafiltration (deuf) was used to conc ...	2016	26729716
flexibility at a glycosidic linkage revealed by molecular dynamics, stochastic modeling, and (13)c nmr spin relaxation: conformational preferences of α-l-rhap-α-(1 → 2)-α-l-rhap-ome in water and dimethyl sulfoxide solutions.	the monosaccharide l-rhamnose is common in bacterial polysaccharides and the disaccharide α-l-rhap-α-(1 → 2)-α-l-rhap-ome represents a structural model for a part of shigella flexneri o-antigen polysaccharides. utilization of [1'-(13)c]-site-specific labeling in the anomeric position at the glycosidic linkage between the two sugar residues facilitated the determination of transglycosidic nmr (3)jch and (3)jcc coupling constants. based on these spin-spin couplings the major state and the conforma ...	2016	26741055
a novel enterocin t1 with anti-pseudomonas activity produced by enterococcus faecium t1 from chinese tibet cheese.	an enterocin-producing enterococcus faecium t1 was isolated from chinese tibet cheese. the enterocin was purified by sp-sepharose and reversed phase hplc. it was identified as unique from other reported bacteriocins based on molecular weight (4629 da) and amino acid compositions; therefore it was subsequently named enterocin t1. enterocin t1 was stable at 80-100 °c and over a wide ph range, ph 3.0-10.0. protease sensitivity was observed to trypsin, pepsin, papain, proteinase k, and pronase e. im ...	2016	26745981
quantitative proteomic analysis of shigella flexneri and shigella sonnei generalized modules for membrane antigens (gmma) reveals highly pure preparations.	outer membrane blebs are naturally shed by gram-negative bacteria and are candidates of interest for vaccines development. genetic modification of bacteria to induce hyperblebbing greatly increases the yield of blebs, called generalized modules for membrane antigens (gmma). the composition of the gmma from hyperblebbing mutants of shigella flexneri 2a and shigella sonnei were quantitatively analyzed using high-sensitivity mass spectrometry with the label-free ibaq procedure and compared to the c ...	2016	26746581
[analysis of the drug resistance and the integron resistance gene cassette's characteristics of shigella flexneri].	to investigate the correlation between shigella flexneri multi-drug resistance and drug resistance gene cassette of integrons.	2015	26758113
at the crossroads: communication of bacteria-containing vacuoles with host organelles.	invasive bacterial pathogens are engulfed upon host cell entry in a vacuolar environment called the bacteria-containing vacuole (bcv). bcvs directly contact with numerous host compartments, mainly vesicles of the endocytic pathway, such as endosomes or lysosomes. in addition, they also interact with the endoplasmic reticulum and endomembranes of the secretory pathway. these connections between the pathogen and the host occur either through heterotypic membrane fusions or through membrane contact ...	2016	26762760
resin glycosides from ipomoea wolcottiana as modulators of the multidrug resistance phenotype in vitro.	recycling liquid chromatography was used for the isolation and purification of resin glycosides from the chcl3-soluble extracts prepared using flowers of ipomoea wolcottiana rose var. wolcottiana. bioassay-guided fractionation, using modulation of both antibiotic activity against multidrug-resistant strains of gram-negative bacteria and vinblastine susceptibility in breast carcinoma cells, was used to isolate the active glycolipids as modulators of the multidrug resistance phenotype. an ester-ty ...	2016	26774597
pi5p triggers icam-1 degradation in shigella infected cells, thus dampening immune cell recruitment.	shigella flexneri, the pathogen responsible for bacillary dysentery, has evolved multiple strategies to control the inflammatory response. here, we show that shigella subverts the subcellular trafficking of the intercellular adhesion molecule-1 (icam-1), a key molecule in immune cell recruitment, in a mechanism dependent on the injected bacterial enzyme ipgd and its product, the lipid mediator pi5p. overexpression of ipgd, but not a phosphatase dead mutant, induced the internalization and the de ...	2016	26776508
development of a multi-pathogen enrichment broth for simultaneous growth of five common foodborne pathogens.	the objective of the present study was to formulate a multi-pathogen enrichment broth which could support the simultaneous growth of five common foodborne pathogens (salmonella enterica, staphylococcus aureus, shigella flexneri, listeria monocytogenes and escherichia coli o157:h7). the formulated broth sssle was composed of potassium tellurite, bile salt, lithium chloride, and sodium chloride as growth-inhibitors; glucose, esculin, mannitol and sodium pyruvate as growth-promoters. compared with ...	2015	26782652
characterization of slya in shigella flexneri identifies a novel role in virulence.	the slya transcriptional regulator has important roles in the virulence and pathogenesis of several members of the enterobacteriaceae family, including salmonella enterica serovar typhimurium and escherichia coli. despite the identification of the slya gene in shigella flexneri nearly 2 decades ago, as well as the significant conservation of slya among enteric bacteria, the role of slya in shigella remains unknown. the genes regulated by slya in closely related organisms often are absent from or ...	2016	26831468
structural analysis of the active site architecture of the vapc toxin from shigella flexneri.	the vapc toxin from the shigella flexneri 2a virulence plasmid pmysh6000 belongs to the pin domain protein family, which is characterized by a conserved fold with low amino acid sequence conservation. the toxin is a bona fide mg(2+) -dependent ribonuclease and has been shown to target initiator trna(fmet) in vivo. here, we present crystal structures of active site catalytic triad mutants d7a, d7n, and d98n of the vapc toxin in absence of antitoxin. in all structures, as well as in solution, vapc ...	2016	26833558
epigenetic activation of antibacterial property of an endophytic streptomyces coelicolor strain azra 37 and identification of the induced protein using maldi tof ms/ms.	the endophytic streptomyces coelicolor strain azra 37 was isolated from the surface sterilized root of azadirachta indica a. juss., commonly known as neem plant in india. since only a few reports are available regarding epigenetic modulations of microbial entities, s. coelicolor was treated with different concentrations of 5-azacytidine for this purpose and evaluated for its antibacterial potential against five human pathogenic bacteria (aeromonas hydrophila ims/gn11, enterococcus faecalis ims/g ...	2016	26844762
microbial pathogenesis meets biomechanics.	introducing concepts from soft matter physics and mechanics has largely contributed to our understanding of a variety of biological processes. in this review, we argue that this holds true for bacterial pathogenesis. we base this argument on three examples of bacterial pathogens and their interaction with host cells during infection: (i) shigella flexneri exploits actin-dependent forces to come into close contact with epithelial cells prior to invasion of the epithelium; (ii) neisseria meningiti ...	2016	26849533
structural insights into the fluoroquinolone resistance mechanism of shigella flexneri dna gyrase and topoisomerase iv.	traveler's diarrhea (td) is an important public health concern that can result from a variety of intestinal pathogens, including bacteria, parasites, and virus. a number of antibiotics are being used to cure td, but due to widespread use of these antibiotics, the pathogens are becoming resistant to them. in this work, we performed docking studies of dna gyrasea (gyra) and topoisomerase iv (parc) of shigella flexneri and their mutants with two different fluoroquinolones, ciprofloxacin and norflox ...	2016	26859259
establishment and application of a visual dna microarray for the detection of food-borne pathogens.	the accurate detection and identification of food-borne pathogenic microorganisms is critical for food safety nowadays. in the present work, a visual dna microarray was established and applied to detect pathogens commonly found in food, including salmonella enterica, shigella flexneri, e. coli o157:h7 and listeria monocytogenes in food samples. multiplex pcr (mpcr) was employed to simultaneously amplify specific gene fragments, fimy for salmonella, ipah for shigella, iap for l. monocytogenes and ...	2016	26860568
field study on evaluation of the efficacy and usability of two disinfectants for drinking water treatment at small cattle breeders and dairy cattle farms.	the hygienic quality of drinking water for cattle originated from different sources together with the efficacy and usability of two types of disinfectants against waterborne pathogens were assessed for small cattle breeders and dairy cattle farms. a total of 120 drinking water samples were collected from water troughs representing three different water sources commonly used for cattle drinking (tap, underground and surface water; n = 65, 25, and 30, respectively). collected samples were cultured ...	2016	26861741
using tomoauto: a protocol for high-throughput automated cryo-electron tomography.	cryo-electron tomography (cryo-et) is a powerful three-dimensional (3-d) imaging technique for visualizing macromolecular complexes in their native context at a molecular level. the technique involves initially preserving the sample in its native state by rapidly freezing the specimen in vitreous ice, then collecting a series of micrographs from different angles at high magnification, and finally computationally reconstructing a 3-d density map. the frozen-hydrated specimen is extremely sensitiv ...	2016	26863591
evaluation of the safety, tolerability, and immunogenicity of an oral, inactivated whole-cell shigella flexneri 2a vaccine in healthy adult subjects.	shigella causes high morbidity and mortality worldwide, but there is no licensed vaccine for shigellosis yet. we evaluated the safety and immunogenicity of a formalin-inactivated whole-cell shigella flexneri2a vaccine, sf2awc, given orally to adult volunteers. in a double-blind, placebo-controlled trial, 82 subjects were randomized to receive three doses of vaccine in dose escalation (2.6 ± 0.8 × 10(8), × 10(9), × 10(10), and × 10(11)vaccine particles/ml). vaccine safety was actively monitored, ...	2016	26865592
purification and characteristics of a novel bacteriocin produced by enterococcus faecalis l11 isolated from chinese traditional fermented cucumber.	to purify and characterize a novel bacteriocin with broad inhibitory spectrum produced by an isolate of enterococcus faecalis from chinese fermented cucumber.	2016	26875092
prevalence and virulence genes of shigella spp. isolated from patients with diarrhea in rosario, argentina.	the aim of this study was to determine the prevalence and virulence factors of shigella species isolated from patients with diarrhea. shigella species were isolated from 1,022 stool samples collected from different hospitals in rosario, argentina. the isolates were characterized using phenotypic tests, serotyping, and detection of virulence genes by pcr. one hundred strains (9.8% of samples collected) of shigella were isolated. shigella flexneri was the most frequently identified species (74%), ...	2016	26902216
interactions between shigella flexneri and the autophagy machinery.	autophagy, an intracellular degradation process, is increasingly recognized as having important roles in host defense. interactions between shigella flexneri and the autophagy machinery were first discovered in 2005. since then, work has shown that multiple autophagy pathways are triggered by s. flexneri, and autophagic responses can have different roles during shigella infection. here, we review the interactions between s. flexneri and the autophagy machinery, highlighting that studies using sh ...	2016	26904515
a synthetic carbohydrate conjugate vaccine candidate against shigellosis: improved bioconjugation and impact of alum on immunogenicity.	conjugation chemistry is among the most important parameters governing the efficacy of glycoconjugate vaccines. high robustness is required to ensure high yields and batch to batch reproducibility. herein, we have established a robust bioconjugation protocol based on the thiol-maleimide addition. major variables were determined and acceptable margins were investigated for a synthetic pentadecasaccharide-tetanus toxoid conjugate, which is a promising vaccine candidate against shigella flexneri se ...	2016	26918643
visualizing the translocation and localization of bacterial type iii effector proteins by using a genetically encoded reporter system.	bacterial type iii secretion system (t3ss) effector proteins are critical determinants of infection for many animal and plant pathogens. however, monitoring of the translocation and delivery of these important virulence determinants has proved to be technically challenging. here, we used a genetically engineered lov (light-oxygen-voltage) sensing domain derivative to monitor the expression, translocation, and localization of bacterial t3ss effectors. we found the escherichia coli o157:h7 bacteri ...	2016	26921426
rainbow vectors for broad-range bacterial fluorescence labeling.	since their discovery, fluorescent proteins have been widely used to study protein function, localization or interaction, promoter activity and regulation, drug discovery or for non-invasive imaging. they have been extensively modified to improve brightness, stability, and oligomerization state. however, only a few studies have focused on understanding the dynamics of fluorescent proteins expression in bacteria. in this work, we developed a set plasmids encoding 12 fluorescent proteins for bacte ...	2016	26937640
gallesia integrifolia (spreng.) harms: in vitro and in vivo antibacterial activities and mode of action.	gallesia integrifolia (phytolaccaceae) is commonly known as "pau-d'alho" in brazil or "garlic plant" due to the strong scent of garlic peculiar to all parts of the plant. the bark decoction is used for the treatment of microbial infections among other diseases by different ethnic groups in brazil, peruvian amazonians, bolivia and mosetene indians. this study aimed to advance in the antibacterial activity and characterize the mode of action of the hydroethanolic extract of the inner stem bark of ...	2016	26945980
spa47 is an oligomerization-activated type three secretion system (t3ss) atpase from shigella flexneri.	gram-negative pathogens often use conserved type three secretion systems (t3ss) for virulence. the shigella type three secretion apparatus (t3sa) penetrates the host cell membrane and provides a unidirectional conduit for injection of effectors into host cells. the protein spa47 localizes to the base of the apparatus and is speculated to be an atpase that provides the energy for t3sa formation and secretion. here, we developed an expression and purification protocol, producing active spa47 and p ...	2016	26947936
the serine protease pic as a virulence factor of atypical enteropathogenic escherichia coli.	autotransporter proteins (at) are associated with bacterial virulence attributes. originally identified in enteroaggregative escherichia coli (eaec), shigella flexneri 2a and uropathogenic e. coli, the serine protease pic is one of these at. we have previously detected one atypical enteropathogenic e. coli strain (ba589) carrying the pic gene. in the present study, we characterized the biological activities of pic produced by ba589 both in vitro and in vivo. contrarily to other pic-producers bac ...	2016	26963626
evaluation of molecular methods for serotyping shigella flexneri.	shigella flexneri can be phenotypically serotyped using antisera raised to type-specific somatic antigens and group factor antigens and genotypically serotyped using pcr targeting o-antigen synthesis or modification genes. the aim of this study was to evaluate a real-time pcr for serotyping s. flexneri and to use whole-genome sequencing (wgs) to investigate the phenotypic and genotypic serotype identifications. of the 244 cultures tested retrospectively, 226 (92.6%) had concordant results betwee ...	2016	26984974
multidrug resistant shigella flexneri infection simulating intestinal intussusception.	shigella enteritis remains an important cause of mortality and morbidity in all age groups, in developing as well as developed countries. owing to the emerging resistance to multiple antibiotics among shigella spp., it has been recognized as a major global public health concern and warrants constant monitoring of its resistance pattern. we report a case of segmental ileitis caused by non.-esbl producing multidrug resistant shigella flexneri in an infant clinically mimicking intussusception, whic ...	2016	27013815
a novel small rna regulates tolerance and virulence in shigella flexneri by responding to acidic environmental changes.	shigella flexneri is an important cause of bacillary dysentery in developing countries. small regulatory rnas (srnas) play essential roles in diverse cellular processes. we found a novel srna ssr1 based on rt-pcr, northern blot, and 5'race in s. flexneri. ssr1 responds to acidic environmental changes, as shown by a strong linear correlation between the ph value and ssr1 expression (r = 0.785, p < 0.05) using the qrt-pcr method. deletion of ssr1 results in growth retardation at ph values ranging ...	2016	27014636