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increased bile resistance in salmonella enterica mutants lacking prc periplasmic protease.prc is a periplasmic protease involved in processing of penicillin-binding protein 3 (pbp3). lack of prc suppresses bile sensitivity in dam-, wec-, phop-, damx-, and seqa- mutants of salmonella enterica, and increases bile resistance in the wild type. changes in the activity of penicillin binding proteins pbp3, pbp4, pbp5/6 and pbp7 are detected in a prc- background, suggesting that peptidoglycan remodeling might contribute to bile resistance.201324400526
muscle abscess due to salmonella enterica.non typhoidal salmonellae spp. causes clinical symptoms especially in neonates, infants, aged and immunocompromised patients. hematogenous dissemination may occur in complicated cases whereas the formation of abscess is rare. a 61-year old woman presented to our hospital with pain and a mass in her left arm, without fever and leukocytosis. she was using methotrexate, corticosteroids and quinine for rheumatoid arthritis. she had a history of cervix cancer and was given radiotherapy and chemothera ...201324396582
revised ciprofloxacin breakpoints for salmonella: is it time to write an obituary?to determine the minimum inhibitory concentration of ciprofloxacin among 50 blood stream isolates of salmonella enterica.201324392374
practical considerations of surveillance of salmonella serovars other than enteritidis and typhimurium.non-typhoid salmonella serovars other than salmonella enterica serovars s. enteritidis (se) and s.typhimurium (st) are isolated throughout the world with huge variations in prevalence. besides the more generally occurring serovars, such as s. infantis and s. hadar, there are many examples of serovars that are principally reported from the regions and are most probably associated with local reservoirs. in most countries of the world, no formal surveillance systems for human salmonellosis are in p ...201324547654
comparison of salmonella typhi and paratyphi a occurrence in a tertiary care hospital.enteric fever is an important public health problem in many underdeveloped and developing countries. in india, though salmonella enterica serotype typhi remains the predominant salmonella species causing enteric fever, isolation of salmonella enterica serotype paratyphi a is increasing. it occurs in all age groups and more common in summer season affecting mainly children.201324551623
comparative virulotyping of salmonella typhi and salmonella enteritidis.members of salmonella enterica are important foodborne pathogens of significant public health concern worldwide. this study aimed to determine a range of virulence genes among typhoidal (s. typhi) and non-typhoidal (s. enteritidis) strains isolated from different geographical regions and different years. a total of 87 s. typhi and 94 s. enteritidis strains were tested for presence of 22 virulence genes by employing multiplex pcr and the genetic relatedness of these strains was further characteri ...201324426144
interaction of phytophagous insects with salmonella enterica on plants and enhanced persistence of the pathogen with macrosteles quadrilineatus infestation or frankliniella occidentalis feeding.recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. yet, the mechanisms that allow the human pathogen salmonella enterica to contaminate and grow in plant environments remain poorly described. we examined the effect of feeding by phytophagous insects on survival of s. enterica on lettuce. larger s. enterica populations were found on leaves infested with macrosteles quadrilineatus. in contrast, pathogen populations among plant ...201324205384
analysis of triclosan-selected salmonella enterica mutants of eight serovars revealed increased aminoglycoside susceptibility and reduced growth rates.the biocide triclosan (trc) is used in a wide range of household, personal care, veterinary, industrial and medical products to control microbial growth. this extended use raises concerns about a possible association between the application of triclosan and the development of antibiotic resistance. in the present study we determined triclosan mutant prevention concentrations (mpc) for salmonella enterica isolates of eight serovars and investigated selected mutants for their mechanisms mediating ...201324205194
bioactive quinic acid derivatives from ageratina adenophora.a novel quinic acid derivative, 5-o-trans-o-coumaroylquinic acid methyl ester (1), together with three known ones, chlorogenic acid methyl ester (2), macranthoin f (3) and macranthoin g (4), were isolated from the aerial parts of the invasive plant ageratina adenophora (spreng.). the structure of new compound 1 was elucidated on the basis of extensive spectroscopic analysis, including 1d- and 2d-nmr techniques. compounds 2-4 were isolated from plant a. adenophora for the first time. all the comp ...201324241153
antimicrobial resistance among blood culture isolates of salmonella enterica in new delhi.enteric fever is a global public health problem, especially in developing countries. antimicrobial resistance is a major issue enteric fever management. this study examined current pattern of antimicrobial susceptibility among salmonella enterica isolates from enteric fever cases at a tertiary care centre in new delhi, india.201324240035
salmonella enterica serotype paratyphi a carrying ctx-m-15 type extended-spectrum beta-lactamase isolated from a japanese traveller returning from india, japan, july 2013.emerging drug resistance in salmonella typhi and s. paratyphi is a substantial public health concern. we report what appears to be the first case and isolation of multidrug resistant s. paratyphi a carrying ctxm-15-type extended-spectrum beta-lactamase from a japanese traveller returning from india.201324256887
genomic characterisation of invasive non-typhoidal salmonella enterica subspecies enterica serovar bovismorbificans isolates from malawi.invasive non-typhoidal salmonella (ints) are an important cause of bacteraemia in children and hiv-infected adults in sub-saharan africa. previous research has shown that ints strains exhibit a pattern of gene loss that resembles that of host adapted serovars such as salmonella typhi and paratyphi a. salmonella enterica serovar bovismorbificans was a common serovar in malawi between 1997 and 2004.201324244782
antimicrobial susceptibility and serovars of salmonella circulating in commercial poultry carcasses and poultry products in brazil.antimicrobial resistance was evaluated for 12,582 strains of salmonella isolated by public and private laboratories from commercial poultry carcasses and poultry products from different regions in brazil between 2007 and 2011. these isolates were submitted unsolicited to the national reference laboratory for bacterial enteroinfections, oswaldo cruz institute, oswaldo cruz foundation, rio de janeiro, brazil, for conclusive antigenic characterization. the prevalent salmonella enterica serogroups w ...201324290674
evaluating area-level spatial clustering of salmonella enteritidis infections and their socioeconomic determinants in the greater toronto area, ontario, canada (2007 - 2009): a retrospective population-based ecological study.there have been only a few region-level ecological studies conducted in canada investigating enteric infections in humans. our study objectives were to 1) assess the spatial clustering of salmonella enterica serotype enteritidis (s. enteritidis) human infections in the greater toronto area, and 2) identify underlying area-level associations between s. enteritidis infection rates and socioeconomic status (ses) indicators that might explain the clustering of infections.201324237666
[determination of salmonella serotypes by conventional and molecular methods].determination of salmonella enterica serotypes is crucial for epidemiological studies. salmonella serotypes are defined on the basis of somatic (o) and flagellar (h) antigens, both of which are present in the cell wall of salmonella. the aim of this study was to compare the results of molecular serotyping obtained by multiplex polymerase chain reaction (mpcr) with conventional serotyping results. conventional serotyping has been performed in ministry of health refik saydam hygiene center as part ...201324237438
complete genome sequence of salmonella enterica subsp. enterica serovar thompson strain rm6836.salmonella enterica subsp. enterica serovar thompson strain rm6836 was isolated from lettuce in 2002. we report here the complete sequence and annotation of the genome of s. thompson rm6836. this is the first reported complete genome sequence for s. thompson and it will enhance our understanding of this serovar and provide another point for comparative studies between salmonella enterica strains.201324233585
[putative temperature sensitive riboswitchers in salmonella genome].currently, a number of structurally and functionally different temperature-sensitive elements like as rna thermometers which control a variety of biological processes of bacteria, including virulence, are known. well-known rna thermometers correspond to one long step-loop structure or few hairpins which can be matched or mismatched. based on the computer and thermodynamical analysis of 25 isolates of salmonella enterica with complete genome, algorithm and the criteria of search for putative rna ...201324228493
crispr-mvlst subtyping of salmonella enterica subsp. enterica serovars typhimurium and heidelberg and application in identifying outbreak isolates.salmonella enterica subsp. enterica serovars typhimurium (s. typhimurium) and heidelberg (s. heidelberg) are major causes of foodborne salmonellosis, accounting for a fifth of all annual salmonellosis cases in the united states. rapid, efficient and accurate methods for identification are required for routine surveillance and to track specific strains during outbreaks. we used pulsed-field gel electrophoresis (pfge) and a recently developed molecular subtyping approach termed crispr-mvlst that e ...201324219629
prevalence and characterization of salmonella enterica from the feces of cattle, poultry, swine and hedgehogs in burkina faso and their comparison to human salmonella isolates.production and wild animals are major sources of human salmonellosis and animals raised for food also play an important role in transmission of antimicrobial resistant salmonella strains to humans. furthermore, in sub-saharan africa non-typhoidal salmonella serotypes are common bloodstream isolates in febrile patients. yet, little is known about the environmental reservoirs and predominant modes of transmission of these pathogens. the purpose of this study was to discover potential sources and d ...201324215206
gatifloxacin versus ofloxacin for the treatment of uncomplicated enteric fever in nepal: an open-label, randomized, controlled trial.fluoroquinolones are the most commonly used group of antimicrobials for the treatment of enteric fever, but no direct comparison between two fluoroquinolones has been performed in a large randomised trial. an open-label randomized trial was conducted to investigate whether gatifloxacin is more effective than ofloxacin in the treatment of uncomplicated enteric fever caused by nalidixic acid-resistant salmonella enterica serovars typhi and paratyphi a.201324282626
effects of water, sodium hypochlorite, peroxyacetic acid, and acidified sodium chlorite on in-shell hazelnuts inoculated with salmonella enterica serovar panama.recent foodborne disease outbreaks involving minimally processed tree nuts have generated a need for improved sanitation procedures. chemical sprays and dips have shown promise for reducing pathogens on fresh produce, but little research has been conducted for in-shell hazelnuts. this study analyzed the effectiveness of 3 chemical sanitizers for reducing salmonella on in-shell hazelnuts. treatments of water, sodium hypochlorite (naocl; 25 and 50 ppm), peroxyacetic acid (paa; 80 and 120 ppm), and ...201324279902
fever of unknown origin attributable to haematocolpos infected with salmonella enterica serotypetyphi resistant to nalidixic acid: a case report.the prevalence of nalidixic acid-resistant salmonella typhi (narst) infection is increasing worldwide. we are reporting an unusual case of infected haematocolpos presenting as urinary obstruction in a patient with fever of unknown origin (fuo). this case report highlights the importance of quinolone-resistant typhoid fever in the differential diagnosis of any acute febrile illness in countries, like india, where salmonella infection is endemic.201324288955
screening of soil actinomyectes against salmonella serovar typhi nctc 5761 and characterization of the prominent active strains.annual incidence of infection with s. typhi is estimated to be about 17 million cases worldwide. a systematic search among actinomycete isolates from soil of iran aimed at finding active actinomycetes against the causative agent of typhoid fever, salmonella typhi was carried out during this study.201325848505
plasmid-mediated quinolone resistance (pmqr) and mutations in the topoisomerase genes of salmonella enterica strains from brazil.the objective of this study was to identify mutations in the quinolone resistance determining sources regions (qrdr) of the gyra, gyrb, parc, and pare genes and to determine if any of the qnr variants or the aac(6')-ib-cr variant were present in strains of salmonella spp. isolated in brazil. a total of 126 salmonella spp. strains from epidemic (n = 114) and poultry (n = 12) origin were evaluated. one hundred and twelve strains (88.8%) were resistant to nalidixic acid (nal) and 29 (23.01%) showed ...201324294265
characterization of antibiotic resistance in salmonella enterica isolates determined from ready-to-eat (rte) salad vegetables.in the last decade, ready-to-eat (rte) salad vegetables are gaining increasing importance in human diet. however, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. during 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in ankara, and were examined for salmonella contamination. salmonella screening was performed by using ...201324294226
commercially laid eggs vs. discarded hatching eggs: contamination by salmonella spp.salmonella enterica is frequently associated with outbreaks of human salmonellosis, and products of avian origin, such as eggs and chicken meat, are the main vehicles of its transmission. the present study describes the occurrence of different serovars of salmonella enterica and phagotypes of s. enterica serovar enteritidis in eggs destined for human consumption. four thousand eggs obtained from commercial egg laying farms and one thousand discarded hatching eggs from broiler farms, which were a ...201324294223
multistate outbreak of salmonella chester infections associated with frozen meals -- 18 states, 2010.on may 24, 2010, a cluster of 17 human salmonella enterica serotype chester clinical isolates with indistinguishable pulsed-field gel electrophoresis (pfge) patterns was reported to pulsenet, the national molecular subtyping network for foodborne disease surveillance. this pfge pattern had not been reported previously. subsequently, cdc conducted an investigation that identified 44 ill persons in 18 states during may 24-june 19, 2010. in a multistate case-control study, consumption of a brand a ...201324304829
biofilm formation of salmonella serotypes in simulated meat processing environments and its relationship to cell characteristics.salmonella attached to meat contact surfaces encountered in meat processing facilities may serve as a source of cross-contamination. in this study, the influence of serotypes and media on biofilm formation of salmonella was investigated in a simulated meat processing environment, and the relationships between biofilm formation and cell characteristics were also determined. all six serotypes (salmonella enterica serotype heidelberg, salmonella derby, salmonella agona, salmonella indiana, salmonel ...201324112581
evaluation of levulinic acid and sodium dodecyl sulfate as a sanitizer for use in processing georgia-grown cantaloupes.freshly harvested georgia-grown cantaloupes (cucumis melo l. var. reticulatus cv. athena and atlantis) were spot inoculated with 100 μl of a five-strain mixture of salmonella enterica serovar poona (9 log cfu/ml) at the stem scar and on the netted rind and then subjected to no treatment (control) or a 6-min treatment (tank only) in water, 120 ppm of chlorine (ph 7.0), 1% levulinic acid plus 0.1% sodium dodecyl sulfate (sds; ph 3.0), or 2% levulinic acid plus 0.2% sds (ph 3.0). the log reduction ...201324112578
campylobacter spp., yersinia enterocolitica, and salmonella enterica and their simultaneous occurrence in german fattening pig herds and their environment.campylobacter spp., salmonella enterica, and yersinia enterocolitica are common causes of foodborne infections in humans with pork as a potential source. monitoring programs at farm level are, to date, only implemented for s. enterica, while epidemiological knowledge of the other two pathogens is still lacking. this study aimed to assess the pathogen load (in the pigs' environment) in fattening pig herds, their simultaneous occurrence, and the occurrence of campylobacter spp. and y. enterocoliti ...201324112569
identification of diverse salmonella serotypes, virulotypes, and antimicrobial resistance phenotypes in waterfowl from chile.salmonella enterica is a pathogen with a wide host-range that presents great concern in developed and developing countries. to determine and characterize salmonella strains found in chile's waterfowl, we sampled 758 birds along 2000 km of the chilean coast. in this sample, 46 isolates from 10 serotypes were detected, several with multidrug resistance phenotypes and different combinations of virulence-associated genes (virulotypes). these results suggest that salmonella infection in waterfowl in ...201324107205
distribution of serotypes and genotypes of salmonella enterica species in french pig production.the population of salmonella found at various stages of pig production in france was characterised to analyse the distribution and spread of salmonella in the pig production chain. we serotyped and genotyped by pfge 174 isolates collected from breeding pigs from breeding farms, 163 collected from breeding pigs from production farms, and 325 collected from fattening pigs. forty-seven serovars and 110 genotypes were identified. the major serovars were s derby (263 isolates) and s typhimurium (162 ...201324106251
characterization of drug resistance and virulotypes of salmonella strains isolated from food and humans.the virulence of bacteria can be evaluated through both phenotypic and molecular assays. we applied these techniques to 114 strains of salmonella enterica subsp. enterica collected from july 2010 to june 2012. salmonella strains were of human origin (71/114) or isolated from food (43/114). the strain set included only the three predominant salmonella serovars isolated in italy from humans (s. enteritidis, s. typhimurium, s. 4,[5],12:i:-). these strains were screened via polymerase chain reaction ...201324102078
increase in salmonella enterica serovar paratyphi a infections in phnom penh, cambodia, january 2011 to august 2013.we report an increased number of salmonella enterica paratyphi a infections in adults in cambodia. between january 2011 and august 2013, 71 s. paratyphi a isolates were recovered from blood cultures, representing a 44-fold increase compared to july 2007 to december 2010, while monthly numbers of cultures did not change. infections with s. typhi increased two-fold in the same period. most cases came from the capital phnom penh. these findings warrant epidemiological investigation to support publi ...201324094060
draft genome sequences of two salmonella strains from the sara collection, sara64 (muenchen) and sara33 (heidelberg), provide insight into their antibiotic resistance.the salmonella enterica strains that are representatives of the s. enterica serovar typhimurium complex in reference collection a (sara) are closely related but exhibit differences in antibiotic resistance, which could have public health consequences. to better understand the mechanisms behind these resistances, we sequenced the genomes of two multidrug-resistant strains: sara64 (muenchen) and sara33 (heidelberg).201324092796
isolation of salmonella virchow from a fruit bat (pteropus giganteus).detection of zoonotic pathogens carried by bats is important both for understanding disease ecology and for developing preventive measures. pteropus fruit bats have been identified as potential carriers of salmonella enterica serotype typhi. a cross-sectional study was conducted to determine the prevalence of salmonella typhi and other salmonella serotypes in pteropus giganteus fruit bats in bangladesh. rectal swabs were collected from 302 bats and cultured for salmonella species. the bats were ...201324136382
occurrence of extended-spectrum β-lactamases among isolates of salmonella enterica subsp. enterica from food-producing animals and food products, in portugal.a total of 1120 salmonella spp. isolates, recovered from poultry, swine and food products of animal origin (bovine, swine and poultry) over the period of 2009-2011, were investigated in order to determine their serotype, susceptibility to a panel of eleven antimicrobials (a, ampicillin; ct, cefotaxime; cp, ciprofloxacin; tm, trimethoprim; su, sulfamethoxazole; c, chloramphenicol; s, streptomycin; g, gentamicin; t, tetracycline; na, nalidixic acid; fl, florfenicol), and the presence of resistance ...201324135677
comparison of different preenrichment broths, egg:preenrichment broth ratios, and surface disinfection for the detection of salmonella enterica ssp. enterica serovar enteritidis in shell eggs.salmonella enterica ssp. enterica serovar enteritidis is the leading reported cause of salmonella infections. most salmonella enteritidis infections are associated with whole shell eggs and egg products. this project attempted to lay the foundation for improving the food and drug administration's current bacteriological analytical manual method for the detection of salmonella enteritidis in shell eggs. two salmonella enteritidis isolates were used for comparisons among different preenrichment an ...201324135606
mait cells detect and efficiently lyse bacterially-infected epithelial cells.mucosal associated invariant t cells (mait) are innate t lymphocytes that detect a large variety of bacteria and yeasts. this recognition depends on the detection of microbial compounds presented by the evolutionarily conserved major-histocompatibility-complex (mhc) class i molecule, mr1. here we show that mait cells display cytotoxic activity towards mr1 overexpressing non-hematopoietic cells cocultured with bacteria. the nk receptor, cd161, highly expressed by mait cells, modulated the cytokin ...201324130485
evaluation of vaccine candidate potential of deltaaroa, deltahtra and deltaaroadeltahtra mutants of salmonella enterica subspecies enterica serovar abortusequi in guinea pigs.salmonella enterica subspecies enterica serovar abortusequi (s. abortusequi), a host adapted salmonella causes abortions, still births and foal mortality in equids. though known since more than 100 years, it is still a problem in many of the developing countries including india. there is dearth of really good vaccine affording immunity lasting at least for one full gestation. in search of a potential vaccine candidate, three defined deletion mutants (deltaaroa, deltahtra and deltaaroadeltahtra) ...201324195347
salmonella enterica serotype arizonae meningitis in a neonate.typhoidal and nontyphoidal salmonella infections are common causes of gastroenteritis in the community. however, salmonella only rarely causes invasive infections like meningitis. we report a 13-day-old female neonate with signs and symptoms of meningitis whose cerebrospinal fluid (csf) culture showed salmonella enterica serotype arizonae that was sensitive to ceftriaxone. she presented with fever and failure to feed for 2 days. despite prompt treatment with ampicillin, gentamicin, and ceftriaxo ...201324187642
dynamics of spread of salmonella enterica in the systemic compartment.traditional microbiological and immunological tools, combined with modern imaging, and molecular and mathematical approaches, have revealed the dispersive nature of salmonella infections. bacterial escape from infected cells, spread in the tissues and attempts to restrain this process by the host give rise to fascinating scenarios that underpin the pathogenesis of salmonelloses.201324183878
phylogenetic diversity of the enteric pathogen salmonella enterica subsp. enterica inferred from genome-wide reference-free snp characters.the enteric pathogen salmonella enterica is one of the leading causes of foodborne illness in the world. the species is extremely diverse, containing more than 2,500 named serovars that are designated for their unique antigen characters and pathogenicity profiles-some are known to be virulent pathogens, while others are not. questions regarding the evolution of pathogenicity, significance of antigen characters, diversity of clustered regularly interspaced short palindromic repeat (crispr) loci, ...201324158624
unusual manifestation of salmonella enterica serotype enteritidis infection in a case of langerhans cell histiocytosis.nontyphoidal salmonella (nts) are established foodborne pathogens, most commonly reported in cases of gastroenteritis. these pathogens are however, increasingly being implicated in cases of bacteraemia and other extraintestinal manifestations. we report a case of a scalp abscess due to salmonella enterica serotype enteritidis, which is a serotype of nts, in a child suffering from a haematologic malignancy. the child was on steroid and anticancer chemotherapy and developed the abscess secondary t ...201324064654
study of the role of efflux pump in ciprofloxacin resistance in salmonella enterica serotype typhi.there are increasing reports on failure of clinical response to ciprofloxacin in typhoid fever despite the strain being sensitive to drug in in-vitro using standard guidelines and showing mutations in dna gyrase. but this increased mic and clinical failures with ciprofloxacin are not always co-related with mutations presently identified in gyra and parc genes. this shows that there may be other mechanisms such as an active drug efflux pump responsible as has been shown in other enterobacteriacea ...201324064645
salmonella enterica prevalence in leatherback sea turtles (dermochelys coriacea) in st. kitts, west indies.salmonella spp. are gram-negative bacteria capable of causing diseases in a wide range of aquatic and terrestrial animals, including humans. sea and terrestrial turtles have been recognized as carriers of this zoonotic pathogen. in this project, conventional and molecular diagnostic methods were combined to investigate the prevalence of salmonella enterica in leatherback sea turtles (dermochelys coriacea) that used the island of st. kitts, west indies as a nesting ground during 2011 (n = 21). is ...201324063110
increasing rates of salmonella paratyphi a and the current status of its vaccine development.enteric fever caused by salmonella enterica serovar typhi and salmonella enterica serovar paratyphi is still a major disease burden mainly in developing countries. previously, s. typhi was believed to be the major cause of enteric fever. the real situation is now becoming clear with reports emerging from many asian countries of s. paratyphi, mostly s. paratyphi a, causing a substantial number of cases of enteric fever. although there have been advances in the use of the currently available typho ...201324053396
trends in the antibiotic resistance patterns of enteric fever isolates - a three year report from a tertiary care centre.the incidence of multidrug resistant enteric fever is increasing alarmingly. this study was planned to determine the rate of isolation of salmonella spp. and to compare the isolates for their epidemiological parameters and antimicrobial susceptibility patterns at our center.201324043999
the plague of athens: an ancient act of bioterrorism?recent data implicate salmonella enterica serovar typhi as a causative pathogen of the plague of athens during the peloponnesian war (430-426 bc). according to thucydides, the sudden outbreak of the disease may link to poisoning of the water reservoirs by the spartans. the siege of a city was aimed at exhausting the supplies of a population, which often led to the outbreak and spread of epidemics. poisoning of the water reservoirs of a besieged city as an act of bioterrorism would probably short ...201324041196
commensal akkermansia muciniphila exacerbates gut inflammation in salmonella typhimurium-infected gnotobiotic mice.excessive mucin degradation by intestinal bacteria may contribute to inflammatory bowel diseases because access of luminal antigens to the intestinal immune system is facilitated. this study investigated how the presence of a mucin degrading commensal bacterium affects the severity of an intestinal salmonella enterica typhimurium-induced gut inflammation. using a gnotobiotic c3h mouse model with a background microbiota of eight bacterial species (sihumi) the impact of the mucin-degrading commens ...201324040367
stochastic simulation of endemic salmonella enterica serovar typhi: the importance of long lasting immunity and the carrier state.typhoid fever caused by salmonella enterica serovar typhi (s. typhi) remains a serious burden of disease, especially in developing countries of asia and africa. it is estimated that it causes 200,000 deaths per year, mainly in children. s. typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. newer control methods ...201324040177
the genomic blueprint of salmonella enterica subspecies enterica serovar typhi p-stx-12.salmonella enterica subspecies enterica serovar typhi is a rod-shaped, gram-negative, facultatively anaerobic bacterium. it belongs to the family enterobacteriaceae in the class gammaproteobacteria, and has the capability of residing in the human gallbladder by forming a biofilm and hence causing the person to become a typhoid carrier. here we present the complete genome of salmonella enterica subspecies enterica serotype typhi strain p-stx-12, which was isolated from a chronic carrier in varana ...201324019994
the wbak acetyltransferase of salmonella enterica group e gives insights into o antigen evolution.o antigens are polysaccharides consisting of repeat units of three to eight sugars, generally assembled by genes in a discrete o antigen gene cluster. salmonella enterica produces 46 forms of o antigen, and most of the variation is determined by genes in the gene cluster. however in some cases the structures are modified by enzymes encoded outside of the gene cluster, and several such modifications have been reported for salmonella enterica group e, some with the genes on bacteriophages and one ...201324014662
foodborne illness outbreaks from microbial contaminants in spices, 1973-2010.this review identified fourteen reported illness outbreaks attributed to consumption of pathogen-contaminated spice during the period 1973-2010. countries reporting outbreaks included canada, denmark, england and wales, france, germany, new zealand, norway, serbia, and the united states. together, these outbreaks resulted in 1946 reported human illnesses, 128 hospitalizations and two deaths. infants/children were the primary population segments impacted by 36% (5/14) of spice-attributed outbreak ...201324010629
atlas salmonella detection method using transcription mediated amplification (tma) to detect salmonella enterica in a variety of foods and select surfaces.the atlas salmonella detection assay was compared to the reference culture methods for 12 foods and three surfaces. comparison of the atlas method to the u.s. food and drug administration bacteriological analytical manual (fda/bam) and u.s. department of agriculture-food safety and inspection service/microbiology laboratory guidebook (usda-fsis/mlg) reference methods required an unpaired approach. each method had a total of 320 samples inoculated with an s. enterica strain. each food and surface ...201324000758
identification of virulence properties in salmonella typhimurium dt104 using caenorhabditis elegans.salmonella enterica serover typhimurium definitive phage type dt104, resistant to multiple antibiotics, is one of the most widespread salmonella species in human infection worldwide. although several cohort studies indicate that dt104 carrying the multidrug resistance (mdr) locus on salmonella genomic island 1 is a possible hyper-virulent strain compared to dt104 strains without mdr, or other salmonella enterica serotypes, existing experimental evidence regarding virulence properties associated ...201324124587
role of salmonella enterica exposure in chilean crohn's disease patients.to study the association between exposure to salmonella enterica (se) and crohn's disease (cd) and its clinical implications in chilean patients.201324124330
salmonella gallinarum field isolates from laying hens are related to the vaccine strain sg9r.salmonella enterica subspecies enterica serotype gallinarum can cause severe systemic disease in chickens and a live salmonella gallinarum 9r vaccine (sg9r) has been used widely to control disease. using whole-genome sequencing we found point mutations in the pyruvate dehydrogenase (acee) and/or lipopolysaccharide 1,2-glucosyltransferase (rfaj) genes that likely explain the attenuation of the sg9r vaccine strain. molecular typing using pulsed field gel electrophoresis and multiple-locus variable ...201323994381
a novel method for purification of vi capsular polysaccharide produced by salmonella enterica subspecies enterica serovar typhi.vi capsular polysaccharide is the major component of vi polysaccharide typhoid vaccines. vi is synthesized during growth of salmonella enterica subspecies enterica serovar typhi and is released into the fermentation broth in large quantities. along with the vi considerable amounts of impurities consisting of bacterial protein, nucleic acid and lipopolysaccharide (lps) as well as media components contaminate the fermentation broth. a purification method based on selective precipitation of vi usin ...201323994374
gene expression analysis of salmonella enterica spi in macrophages indicates differences between serovars that induce systemic disease from those normally causing enteritis.global gene expression of the invasive salmonella serovars s. enteritidis and s. typhimurium, and the less-invasive s. infantis and s. hadar was studied during infection of a chicken macrophage cell line. major functional gene groups responsible for intracellular physiological changes were regulated similarly in all four serovars. however, spi1 and spi4 genes of s. enteritidis and s. typhimurium were strongly repressed in the macrophages whereas s. infantis, s. hadar and other similar serovars m ...201324080352
lymph node colonization dynamics after oral salmonella typhimurium infection in mice.an understanding of how pathogens colonize their hosts is crucial for the rational design of vaccines or therapy. while the molecular factors facilitating the invasion and systemic infection by pathogens are a central focus of research in microbiology, the population biological aspects of colonization are still poorly understood. here, we investigated the early colonization dynamics of salmonella enterica subspecies 1 serovar typhimurium (s. tm) in the streptomycin mouse model for diarrhea. we f ...201324068916
highly drug-resistant salmonella enterica serotype kentucky st198-x1: a microbiological study.salmonella enterica is a major global food-borne pathogen, causing life-threatening infections. ciprofloxacin and extended-spectrum cephalosporins (escs) are the drugs of choice for severe infections. we previously reported a ciprofloxacin-resistant s. enterica serotype kentucky (s kentucky) st198-x1 strain that emerged in egypt and spread throughout africa and the middle east from 2002 to 2008. we aimed to monitor recent trends in the location of transmission and antimicrobial resistance of thi ...201323721756
first report of salmonella enterica serovar infantis in common swifts (apus apus).forty common swifts (apus apus), synanthropic birds living in an urban environment closely with humans and other animals, were hospitalized in the public veterinary hospital of the regional reference center of urban veterinary hygiene located in naples, campania region, italy. each bird was sampled for bacteriological analyses. out of 40 common swifts examined, eight were found positive for salmonella enterica serovar infantis although no sign of salmonellosis (e.g. diarrhoea) was shown. this is ...201323721074
[search for new potential rna thermometers in the salmonella enterica genome]. 201323718050
emergence of multidrug-resistant salmonella enterica serotype 4,[5],12:i:- involving human cases in canada: results from the canadian integrated program on antimicrobial resistance surveillance (cipars), 2003-10.over the last decade, a marked increase in salmonella enterica serotype 4,[5],12:i:- with a core resistance to ampicillin, streptomycin, sulphonamides and tetracycline (assut) has been observed in europe. this study describes the emergence and characterization of isolates of multidrug-resistant salmonella 4,[5],12:i:- in canada.201323710071
characterisation of plasmids implicated in the mobilisation of extended-spectrum and ampc β-lactamase genes in clinical salmonella enterica isolates and temporal stability of the resistance genotype.plasmids implicated in the mobilisation of β-lactamase genes in extended-spectrum β-lactamase (esbl)- and ampc-producing salmonella enterica isolates recovered from three spanish hospitals were characterised. the temporal stability of these plasmids and of the resistance phenotype without antimicrobial pressure was also assessed in the laboratory setting. the resistance determinants and their genetic environments were characterised by pcr sequencing, and their genomic location was analysed by s1 ...201323706977
genome sequence of salmonella enterica serotype tennessee strain cdc07-0191, implicated in the 2006-2007 multistate food-borne outbreak linked to peanut butter in the united states.salmonella enterica serotype tennessee strain cdc07-0191 was isolated from the 2006-2007 multistate food-borne outbreak linked to peanut butter in the united states. here we report a high-quality draft assembly of the genome sequence of this strain, derived from a patient. this is the first reported high-quality draft genome sequence for s. enterica serotype tennessee, which will enable in-depth studies of its transmission and virulence.201323704182
antimicrobial susceptibility of salmonella enterica serovars in a tertiary care hospital in southern india.salmonella enterica serovars typhi and paratyphi are predominantly known to cause enteric fever. multidrug resistance in s. tphi and s. paratyphi has emerged as a cause of concern. this study was done to evaluate status in antimicrobial susceptibility patterns of salmonella enterica serovar typhi (s. typhi) and s. paratyphi obtained from blood culture in a tertiary care hospital in south india.201323703350
ß-lactamases in salmonella enterica isolated in australia.understanding the antibiotic susceptibility of salmonella enterica is important both from a clinical treatment and a public health perspective. the emergence of extended spectrum ß-lactamases (esßls) and ampc ß-lactamases in s. enterica is important, as this will limit treatment options and could provide a strain with a significant selective advantage. the aim of the study was to screen isolates of s. enterica, including isolates that had previously shown antibiotic resistance, to gauge the exte ...201323692158
salmonella enterica mtan at 1.36 å resolution: a structure-based design of tailored transition state analogs.accumulation of 5'-methylthioadenosine (mta) and s-adenosylhomocysteine (sah) in bacteria disrupts the s-adenosylmethionine pool to alter biological methylations, synthesis of polyamines, and production of quorum-sensing molecules. bacterial metabolism of mta and sah depends on mta/sah nucleosidase (mtan), an enzyme not present in humans and a target for quorum sensing because mtan activity is essential for synthesis of autoinducer-2 molecules. crystals of salmonella enterica mtan with product a ...201323685211
spi1 defective mutants of salmonella enterica induce cross-protective immunity in chickens against challenge with serovars typhimurium and enteritidis.in this study we were interested in the serovar cross-protection potential of salmonella pathogenicity island 1 (spi1) attenuated vaccine strains of salmonella enterica serovars enteritidis and typhimurium and immune response of vaccinated and naive chickens to salmonella infection. the immune response was characterized by real time pcr quantifying transcripts of interleukins il1β, il17, il22, interferon gamma (ifnγ), inducible no synthase (inos), immunoglobulins igm, iga, igy and ig light chain ...201323684831
survey of enterobacteriaceae contamination of table eggs collected from layer flocks in australia.in the present study, eggs from commercial caged layer flocks at different stages of lay in australia were collected. enterobacteriaceae populations from eggshell surface and eggshell pore were enumerated and these populations characterized using api® rapid 20e strips. the eggshell surface, eggshell pore and egg internal content samples were also processed for the isolation of salmonella and these isolates were tested for the presence or absence of several virulence genes (prgh, sopb, spic, orfl ...201323680799
safety and efficacy of a metabolic drift live attenuated salmonella gallinarum vaccine against fowl typhoid.fowl typhoid (ft), a systemic disease that results in septicemia in poultry, is caused by salmonella enterica serovar gallinarum biovar gallinarum (sg). mortality and morbidity rates from ft can reach up to 80%. attenuated live salmonella vaccine candidates have received considerable attention because they confer solid immunity, and they can produce systemic and mucosal immunity in the gut when administered orally. in the present study, five metabolic drift (md) mutants with a single-(designated ...201323678726
subtyping of salmonella enterica serovar newport outbreak isolates by crispr-mvlst and determination of the relationship between crispr-mvlst and pfge results.salmonella enterica subsp. enterica serovar newport (s. newport) is the third most prevalent cause of food-borne salmonellosis. rapid, efficient, and accurate methods for identification are required to track specific strains of s. newport during outbreaks. by exploiting the hypervariable nature of virulence genes and clustered regularly interspaced short palindromic repeats (crisprs), we previously developed a sequence-based subtyping approach, designated crispr-multi-virulence-locus sequence ty ...201323678062
presence of β-lactamases in extended-spectrum-cephalosporin-resistant salmonella enterica of 30 different serovars in germany 2005-11.between 20 000 and 35 000 cases of salmonellosis are detected annually in germany, but only a few salmonella are resistant to third-generation cephalosporins. the german national reference centre for salmonella and other enterics obtained 150 salmonella enterica isolates from human infections between 2005 and 2011. in the present study we identified the β-lactamase genes causing resistance to third-generation cephalosporins in these isolates.201323674765
unique class 1 integron and multiple resistance genes co-located on inchi2 plasmid is associated with the emerging multidrug resistance of salmonella indiana isolated from chicken in china.the objective of this study was to clarify the molecular antimicrobial resistance mechanisms of salmonella enterica serovar indiana isolated from chickens in china. a total of 327 chicken intestinal content and feces were collected in shandong, china in 2009. isolates were serotyped and antimicrobial susceptibility testing was performed. thirty-five (10.7%) salmonella isolates were recovered, and 16 (45.7%) were salmonella enterica serovar indiana, which were resistant to at least 14 of 15 antim ...201323672474
desirability for a typhoid fever vaccine among rural residents, pemba island, tanzania.surveillance data indicate that salmonella enterica serotype typhi (s. typhi) is a significant cause of morbidity and mortality in africa. with limited anticipated short-term improvements in sanitation and water infrastructure, targeted vaccination campaigns may be an important prevention tool for typhoid fever.201323664993
a flagellated motile salmonella gallinarum mutant (sg fla+) elicits a pro-inflammatory response from avian epithelial cells and macrophages and is less virulent to chickens.salmonella enterica subspecies enterica serovar gallinarum biovar gallinarum (sg) is a non-flagellated bacterium which causes fowl typhoid, a systemic disease associated with high mortality in birds. it has been suggested that the absence of flagella in sg is advantageous in the early stages of systemic infection through absence of tlr-5 activation. in order to investigate this hypothesis in more detail a flagellated and motile sg mutant (sg fla(+)) was constructed. the presence of flagella incr ...201323664623
morbidity among child travellers with sickle-cell disease visiting tropical areas: an observational study in a french tertiary care centre.to examine morbidity among children with sickle-cell disease (scd) during and after travel to a tropical area.201323661574
whole-genome sequences of four salmonella enterica serotype newport strains from humans.salmonellosis contributes significantly to the public health burden globally. salmonella enterica serotype newport is among salmonella serotypes most associated with food-borne illness in the united states and china. it was thought to be polyphyletic and to contain different lineages. we report draft genomes of four s. newport strains isolated from humans in china.201323661485
living with stress: a lesson from the enteric pathogen salmonella enterica.the ability to sense and respond to the environment is essential for the survival of all living organisms. bacterial pathogens such as salmonella enterica are of particular interest due to their ability to sense and adapt to the diverse range of conditions they encounter, both in vivo and in environmental reservoirs. during this cycling from host to non-host environments, salmonella encounter a variety of environmental insults ranging from temperature fluctuations, nutrient availability and chan ...201323651595
resistance to essential oils affects survival of salmonella enterica serovars in growing and harvested basil.the number of outbreaks of food-borne illness associated with consumption of fresh products has increased. a recent and noteworthy outbreak occurred in 2007. basil contaminated with salmonella enterica serovar senftenberg was the source of this outbreak. since basil produces high levels of antibacterial compounds the aim of this study was to investigate if the emerging outbreak reflects ecological changes that occurred as a result of development of resistance to ingredients of the basil oil. we ...201323648052
isolation and characterization of a rare waterborne lytic phage of salmonella enterica serovar paratyphi b.a lytic phage of salmonella serovar paratyphi b, named φspb, was isolated from surface waters of the pavana river in india. phage φspb is a member of the podoviridae family and is morphologically similar to the 7-11 phages of the c3 morphotype of tailed phages, characterized by a very long, cigar-shaped head. the head measured approximately 153 × 57 nm, and the tail size was 12 × 7 nm. the phage was stable over a wide range of ph (4-9) and temperature (4-40 °c). the adsorption rate constant was ...201323647344
low-ph rescue of acid-sensitive salmonella enterica serovar typhi strains by a rhamnose-regulated arginine decarboxylase system.for salmonella, transient exposure to gastric ph prepares invading bacteria for the stresses of host-cell interactions. to resist the effects of low ph, wild-type salmonella enterica uses the acid tolerance response and the arginine decarboxylase acid resistance system. however, arginine decarboxylase is typically repressed under routine culture conditions, and for many live attenuated salmonella vaccine strains, the acid tolerance response is unable to provide the necessary protection. the obje ...201323645603
development of antimicrobial coatings for improving the microbiological safety and quality of shell eggs.this study was conducted to develop antimicrobial coatings to decontaminate and prevent cross-contamination of shell eggs. egg shells were inoculated with nalidixic acid-resistant salmonella enterica enteritidis strains ob030832, ob040159, and c405 and treated with antimicrobial coatings. polylactic acid served as a nonedible polymer, and chitosan served as an edible polymer carrier of natural antimicrobials, including nisin, allyl isothiocyanate (ait), lauric arginate ester (lae), and organic a ...201323643119
fluorescence in situ hybridization (fish) for rapid identification of salmonella spp. from agar and blood culture broth--an option for the tropics?salmonella enterica is an important cause of diarrhea with the potential to cause systemic infection including sepsis, particularly in the tropics. sepsis in particular requires quick and reliable identification to allow a rapid optimization of antibiotic therapy. we describe the establishment and evaluation of fluorescence in situ hybridization (fish) as a rapid and easy-to-perform molecular identification procedure from agar and blood culture broths.201323642903
identification and characterization of a cis-encoded antisense rna associated with the replication process of salmonella enterica serovar typhi.antisense rnas that originate from the complementary strand of protein coding genes are involved in the regulation of gene expression in all domains of life. in bacteria, some of these antisense rnas are transcriptional noise while others play a vital role to adapt the cell to changing environmental conditions. by deep sequencing analysis of transcriptome of salmonella enterica serovar typhi, a partial rna sequence encoded in-cis to the dnaa gene was revealed. northern blot and race analysis con ...201323637809
neutral genomic microevolution of a recently emerged pathogen, salmonella enterica serovar agona.salmonella enterica serovar agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. we analyzed the genomes of 73 isolates from global sources, comparing five distinct outbreaks with sporadic infections as well as food contamination and the environment. agona consists of three lineages with minimal mutational diversity: only 846 single nucleotide polymorphisms (snps) have accumulated in the non-repetitive, core genome since agona evolved in 1932 and ...201323637636
comprehensive assignment of roles for salmonella typhimurium genes in intestinal colonization of food-producing animals.chickens, pigs, and cattle are key reservoirs of salmonella enterica, a foodborne pathogen of worldwide importance. though a decade has elapsed since publication of the first salmonella genome, thousands of genes remain of hypothetical or unknown function, and the basis of colonization of reservoir hosts is ill-defined. moreover, previous surveys of the role of salmonella genes in vivo have focused on systemic virulence in murine typhoid models, and the genetic basis of intestinal persistence an ...201323637626
emergence of extended-spectrum-β-lactamase ctx-m-2-producing salmonella enterica serovars schwarzengrund and agona in poultry farms. 201323629722
isolation and molecular characterization of salmonella enterica serovar javiana from food, environmental and clinical samples.a total of 50 salmonella enterica serovar javiana isolates, isolated from food, environmental and clinical samples, were analyzed for antibiotic resistance, presence of virulence genes, plasmids and plasmid replicon types. to assess the genetic diversity, pulsed-field gel electrophoresis (pfge) fingerprinting and plasmid profiles were performed. all of the isolates were sensitive to chloramphenicol, nalidixic acid, and sulfisoxazole, and four isolates showed intermediate resistance to gentamicin ...201323628778
inhibition of polymerase chain reaction for the detection of escherichia coli o157:h7 and salmonella enterica on walnut kernels.the aim of this study was to determine whether escherichia coli o157:h7 can be reliably detected and isolated from walnut kernels using standard methods of analysis. the limit of detection approached 1 cell per analytical unit (25 g) for e. coli o157:h7 on walnut kernels enriched in modified tryptic soy broth with 20 μg/ml novobiocin and plating onto selective agar media. the presence of pcr inhibitors in walnut kernels was indicated by the failure to detect e. coli o157:h7 from culture positive ...201323628609
salmonella type iii effector sopb modulates host cell exocytosis.salmonella enterica pathogenesis is dependent on its ability to enter and replicate inside host cells. replication occurs inside the salmonella-containing vacuole (scv), a vacuolar compartment that is modified by bacterial effectors secreted through the two type iii secretion systems (t3ss-1 and t3ss-2). type iii effectors interact with the host cell endocytic pathway to aid replication. we investigated whether salmonella effector proteins may also interact with the host's exocytic pathway. a se ...201326038467
salmonella enterica diversity in central californian coastal waterways.salmonella enterica is one of the most important bacterial enteric pathogens worldwide. however, little is known about its distribution and diversity in the environment. the present study explored the diversity of 104 strains of salmonella enterica isolated over 2 years from 12 coastal waterways in central california. pulsed-field gel electrophoresis (pfge) and multilocus sequence typing were used to probe species diversity. seventy-four pfge patterns and 38 sequence types (sts) were found, incl ...201323624479
loop region-specific oligonucleotide probes for loop-mediated isothermal amplification-enzyme-linked immunosorbent assay truly minimize the instrument needed for detection process.enteric fever represents a significant public health burden in less-developed countries. therefore, there is a great need for developing an improved diagnostic tool adapted to the demands of poor-resource clinical laboratories in those countries. the current study has developed a reliable loop-mediated isothermal amplification (lamp)-enzyme-linked immunosorbent assay (elisa) for diagnosis of enteric fever with a minimal equipment dependency. the lamp-elisa assay involves direct incorporation of ...201323624347
antimicrobial resistance and virulence-associated genes of salmonella enterica subsp. enterica serotypes muenster, florian, omuna, and noya strains isolated from clinically diarrheic humans in egypt.four serotypes recovered from clinically diarrheic human faecal samples (salmonella muenster, salmonella florian, salmonella omuna and salmonella noya) were investigated for the presence of 11 virulence genes (inva, avra, ssaq, mgtc, siid, sopb, gipa, sodc1, sope1, spvc, and bcfc) and their association with antibiotic resistance. the 4 salmonella serotypes lacked virulence genes gipa and spvc. resistance to 7 of the 14 antimicrobials was detected. the frequency of resistance, to lincomycin and s ...201323621859
prevalence and antimicrobial susceptibility of salmonella isolates in pekin ducks from south korea.an investigation was carried out to determine the prevalence and antibiotic resistance of salmonella serotypes at south korean duck farms. a total of 7119 samples collected from 72 duck farms in five provinces were examined from 2011 to 2012. the overall prevalence of salmonella serotypes was 43.4% (69/159) in duck flocks from 65.2% (47/72) of the duck farms. eighty-five strains were isolated from 69 duck flocks. three serotypes of salmonella enterica were identified such as s. typhimurium (39/8 ...201323618792
rapid, sensitive recovery of recombinant attenuated salmonella enterica serovar typhi vaccine strains from human blood.prior to initiating a phase 1 dose escalation trial of the safety and immunogenicity of live, oral, recombinant, attenuated salmonella enterica serovar typhi vaccine strains in human subjects, the suitability of conventional blood culture procedures to rapidly and reliably detect the organisms in human blood was investigated. blood culture specimens, with and without added growth supplements, were inoculated with study organism concentrations ranging from approximately 300 to as few as 1 to 2 cf ...201323885029
prevalence of salmonella in wild snakes in japan.a total of 87 wild snakes of 6 species in 2 families collected in japan were examined for the presence of salmonella. the prevalence of salmonella was 58.6%, and that of salmonella enterica subspecies i, which includes most human pathogenic serotypes, accounted for 12.6%. s. enterica subspecies i was isolated from japanese grass snakes and japanese four-striped snakes, and the isolates belonged to 6 serotypes: s. enterica subspecies enterica serotypes eastbourne, mikawashima, narashino, newport, ...201323883839
outbreak-associated salmonella enterica serotypes and food commodities, united states, 1998-2008.salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. to clarify links between salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998-2008. more than 80% of outbreaks caused by serotypes enteritidis, heidelberg, and hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes javiana, l ...201323876503
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