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1.
Yang Hong Tongrui Liu Margie D Lee Charles L Hofacre Marie Maier David G White Sherry Ayers Lihua Wang Roy Berghaus John J Maurer 《BMC microbiology》2008,8(1):178
Background
Classical Salmonella serotyping is an expensive and time consuming process that requires implementing a battery of O and H antisera to detect 2,541 different Salmonella enterica serovars. For these reasons, we developed a rapid multiplex polymerase chain reaction (PCR)-based typing scheme to screen for the prevalent S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium. 相似文献2.
Background
Salmonella enterica subspecies I includes several closely related serovars which differ in host ranges and ability to cause disease. The basis for the diversity in host range and pathogenic potential of the serovars is not well understood, and it is not known how host-restricted variants appeared and what factors were lost or acquired during adaptations to a specific environment. Differences apparent from the genomic data do not necessarily correspond to functional proteins and more importantly differential regulation of otherwise identical gene content may play a role in the diverse phenotypes of the serovars of Salmonella. 相似文献3.
Haiyan Dong Ye Hu Feng Xue Dexter Sun David M Ojcius Yafei Mao Jie Yan 《BMC microbiology》2008,8(1):223
Background
The usefulness of available vaccine and serological tests for leptospirosis is limited by the low cross-reactivity of antigens from numerous serovars of pathogenic Leptospira spp. Identification of genus-specific protein antigens (GP-Ag) of Leptospira would be important for development of universal vaccines and serodiagnostic methods. OmpL1, a transmembrane porin of pathogenic leptospires, was identified as a possible GP-Ag, but its sequence diversity and immune cross-reactivity among different serovars of pathogenic leptospires remains largely unknown. 相似文献4.
Phenotypic and genotypic profile of clinical and animal multidrug‐resistant Salmonella enterica isolates from Mexico 下载免费PDF全文
S. Aguilar‐Montes de Oca M. Talavera‐Rojas E. Soriano‐Vargas J. Barba‐León J. Vázquez‐Navarrete J. Acosta‐Dibarrat C. Salgado‐Miranda 《Journal of applied microbiology》2018,124(1):67-74
Aims
The objective of this study was to obtain a phenotypic and genotypic profile of Salmonella enterica including multidrug‐resistant (MDR) isolates from food‐producing animals and clinical isolates, as well as their genetic relatedness in two different States of Mexico (Jalisco and State of Mexico).Methods and Results
A total of 243 isolates were evaluated in terms of antimicrobial resistance (AMR) and related genes through a disk diffusion method and PCR respectively; we found 16 MDR isolates, all of them harbouring the blaCMY gene but not qnr genes, these isolates represent less than 10% of the collection. The pulsed‐field gel electrophoresis revealed a higher genotypic similitude within isolates of State of Mexico than Jalisco.Conclusions
A low percentage of Salmonella isolates were resistant to relevant antibiotics in human health, nevertheless, the AMR and involved genes were similar despite the different serovars and origin of the isolates.Significance and Impact of the Study
This investigation provided an insight of the current status of AMR of Salmonella isolates in two States of Mexico and pinpoint the genes involved in AMR and their epidemiological relationship, the information could help to determine an adequate therapy in human and veterinary medicine. 相似文献5.
Olivier Habimana Trond Møretrø Solveig Langsrud Lene K Vestby Live L Nesse Even Heir 《BMC veterinary research》2010,6(1):48
Background
The presence of Salmonella enterica serovars in feed ingredients, products and processing facilities is a well recognized problem worldwide. In Norwegian feed factories, strict control measures are implemented to avoid establishment and spreading of Salmonella throughout the processing chain. There is limited knowledge on the presence and survival of the resident microflora in feed production plants. Information on interactions between Salmonella and other bacteria in feed production plants and how they affect survival and biofilm formation of Salmonella is also limited. The aim of this study was to identify resident microbiota found in feed production environments, and to compare the survival of resident flora strains and Salmonella to stress factors typically found in feed processing environments. Moreover, the role of dominant resident flora strains in the biofilm development of Salmonella was determined. 相似文献6.
Ivan Rychlik Daniela Karasova Alena Sebkova Jiri Volf Frantisek Sisak Hana Havlickova Vladimir Kummer Ariel Imre Annamaria Szmolka Bela Nagy 《BMC microbiology》2009,9(1):268
Background
Salmonella is a highly successful parasite of reptiles, birds and mammals. Its ability to infect and colonise such a broad range of hosts coincided with the introduction of new genetic determinants, among them 5 major pathogeniCity islands (SPI1-5), into the Salmonella genome. However, only limited information is available on how each of these pathogeniCity islands influences the ability of Salmonella to infect chickens. In this study, we therefore constructed Salmonella Enteritidis mutants with each SPI deleted separately, with single individual SPIs (i.e. with the remaining four deleted) and a mutant with all 5 SPIs deleted, and assessed their virulence in one-day-old chickens, together with the innate immune response of this host. 相似文献7.
Xiaojian Yang Jennifer Brisbin Hai Yu Qi Wang Fugui Yin Yonggang Zhang Parviz Sabour Shayan Sharif Joshua Gong 《PloS one》2014,9(4)
Background
Probiotics have been used to control Salmonella colonization/infection in chickens. Yet the mechanisms of probiotic effects are not fully understood. This study has characterized our previously-selected lactic acid-producing bacterial (LAB) isolates for controlling Salmonella infection in chickens, particularly the mechanism underlying the control.Methodology/Principal Findings
In vitro studies were conducted to characterize 14 LAB isolates for their tolerance to low pH (2.0) and high bile salt (0.3–1.5%) and susceptibility to antibiotics. Three chicken infection trials were subsequently carried out to evaluate four of the isolates for reducing the burden of Salmonella enterica serovar Typhimurium in the broiler cecum. Chicks were gavaged with LAB cultures (106–7 CFU/chick) or phosphate-buffered saline (PBS) at 1 day of age followed by Salmonella challenge (104 CFU/chick) next day. Samples of cecal digesta, spleen, and liver were examined for Salmonella counts on days 1, 3, or 4 post-challenge. Salmonella in the cecum from Trial 3 was also assessed for the expression of ten virulence genes located in its pathogenicity island-1 (SPI-1). These genes play a role in Salmonella intestinal invasion. Tested LAB isolates (individuals or mixed cultures) were unable to lower Salmonella burden in the chicken cecum, but able to attenuate Salmonella infection in the spleen and liver. The LAB treatments also reduced almost all SPI-1 virulence gene expression (9 out of 10) in the chicken cecum, particularly at the low dose. In vitro treatment with the extracellular culture fluid from a LAB culture also down-regulated most SPI-1 virulence gene expression.Conclusions/Significance
The possible correlation between attenuation of Salmonella infection in the chicken spleen and liver and reduction of Salmonella SPI-1 virulence gene expression in the chicken cecum by LAB isolates is a new observation. Suppression of Salmonella virulence gene expression in vivo can be one of the strategies for controlling Salmonella infection in chickens. 相似文献8.
Robert Klopfleisch Anja Meyer Patricia Schlieben Angelika Bondzio Chris Weise Dido Lenze Michael Hummel Ralf Einspanier Achim D Gruber 《BMC veterinary research》2012,8(1):1-11
Background
Control of currently circulating re-assorted low-pathogenicity avian influenza (LPAI) H9N2 is a major concern for both animal and human health. Thus, an improved LPAI H9N2 vaccination strategy is needed to induce complete immunity in chickens against LPAI H9N2 virus strains. Cytokines play a crucial role in mounting both the type and extent of an immune response generated following infection with a pathogen or after vaccination. To improve the efficacy of inactivated LPAI H9N2 vaccine, attenuated Salmonella enterica serovar Typhimurium was used for oral co-administration of chicken interferon-?? (chIFN-??) and chicken interleukin-18 (chIL-18) as natural immunomodulators.Results
Oral co-administration of S. enterica serovar Typhimurium expressing chIFN-?? and chIL-18, prior to vaccination with inactivated AI H9N2 vaccine, modulated the immune response of chickens against the vaccine antigen through enhanced humoral and Th1-biased cell-mediated immunity, compared to chickens that received single administration of S. enterica serovar Typhimurium expressing either chIFN-?? or chIL-18. To further test the protective efficacy of this improved vaccination regimen, immunized chickens were intra-tracheally challenged with a high dose of LPAI H9N2 virus. Combined administration of S. enterica serovar Typhimurium expressing chIFN-?? and chIL-18 showed markedly enhanced protection compared to single administration of the construct, as determined by mortality, clinical severity, and feed and water intake. This enhancement of protective immunity was further confirmed by reduced rectal shedding and replication of AIV H9N2 in different tissues of challenged chickens.Conclusions
Our results indicate the value of combined administration of chIFN-?? and chIL-18 using a Salmonella vaccine strain to generate an effective immunization strategy in chickens against LPAI H9N2. 相似文献9.
Background
Salmonella enterica serotype Enteritidis (SE) is considered to be one of the most potent pathogenic Salmonella serotypes causing food-borne disease in humans. Since a live bacterial vaccine based on surface display of antigens has many advantages over traditional vaccines, we have studied the surface display of the SE antigenic proteins, H:gm and SefA in Escherichia coli by the β-autotransporter system, AIDA. This procedure was compared to protein translocation in Staphylococcus carnosus, using a staphylococci hybrid vector earlier developed for surface display of other vaccine epitopes. 相似文献10.
Edel O'Regan Evonne McCabe Catherine Burgess Sheila McGuinness Thomas Barry Geraldine Duffy Paul Whyte Séamus Fanning 《BMC microbiology》2008,8(1):156
Background
A real-time multiplex PCR assay was developed for the detection of multiple Salmonella serotypes in chicken samples. Poultry-associated serotypes detected in the assay include Enteritidis, Gallinarum, Typhimurium, Kentucky and Dublin. The traditional cultural method according to EN ISO 6579:2002 for the detection of Salmonella in food was performed in parallel. The real-time PCR based method comprised a pre-enrichment step in Buffered Peptone Water (BPW) overnight, followed by a shortened selective enrichment in Rappaport Vasilliadis Soya Broth (RVS) for 6 hours and subsequent DNA extraction. 相似文献11.
Akhilesh S. Dhanani Glenn Block Ken Dewar Vincenzo Forgetta Edward Topp Robert G. Beiko Moussa S. Diarra 《PloS one》2015,10(6)
BackgroundNon-typhoidal Salmonella enterica serovars, associated with different foods including poultry products, are important causes of bacterial gastroenteritis worldwide. The colonization of the chicken gut by S. enterica could result in the contamination of the environment and food chain. The aim of this study was to compare the genomes of 25 S. enterica serovars isolated from broiler chicken farms to assess their intra- and inter-genetic variability, with a focus on virulence and antibiotic resistance characteristics.Conclusions/SignificanceThis study showed that the predominant Salmonella serovars in broiler chickens harbor genes encoding adhesins, flagellar proteins, T3SS, iron acquisition systems, and antibiotic and metal resistance genes that may explain their pathogenicity, colonization ability and persistence in chicken. The existence of mobile genetic elements indicates that isolates from a given serovar could acquire and transfer genetic material. Conserved genes in the T3SS and T4SS that we have identified are promising candidates for identification of diagnostic, antimicrobial or vaccine targets for the control of Salmonella in broiler chickens. 相似文献
12.
Background
The fliC and fljB genes in Salmonella code for the phase 1 (H1) and phase 2 (H2) flagellin respectively, the rfb cluster encodes the majority of enzymes for polysaccharide (O) antigen biosynthesis, together they determine the antigenic profile by which Salmonella are identified. Sequencing and characterisation of fliC was performed in the development of a molecular serotyping technique. 相似文献13.
Background
Salmonella spp. have been isolated from a wide range of wild animals. Opportunistic wild carnivores such as red foxes (Vulpes vulpes) and badgers (Meles meles) may act as environmental indicators or as potential sources of salmonellosis in humans. The present study characterizes Salmonella spp. isolated from the intestinal contents of hunted or dead red foxes (n?=?509) and badgers (n?=?17) in northern Italy.Findings
Thirty-one strains of Salmonella belonging to 3 Salmonella enterica subspecies were isolated. Fourteen different serovars of S. enterica subsp. enterica were identified, among which were serovars often associated with human illness.Conclusions
Wild opportunistic predators can influence the probability of infection of both domestic animals and humans through active shedding of the pathogen to the environment. The epidemiological role of wild carnivores in the spread of salmonellosis needs to be further studied.14.
15.
Background
Salmonella enterica is a facultative intracellular pathogen that replicates within a membrane-bound compartment termed Salmonella containing vacuole (SCV). The biogenesis of SCV requires Salmonella type III protein secretion/translocation system and their effector proteins which are translocated into host cells to exploit the vesicle trafficking pathways. SseF is one of these effectors required for SCV formation and Intracellular Salmonella replication through unknown mechanisms. 相似文献16.
Zhongzan Cao Zongxi Han Yuhao Shao Heyuan Geng Xiangang Kong Shengwang Liu 《Proteome science》2011,9(1):11
Background
Avian infectious bronchitis (IB) is one of the most serious diseases of economic importance in chickens; it is caused by the avian infectious coronavirus (IBV). Information remains limited about the comparative protein expression profiles of chicken embryonic tissues in response to IBV infection in ovo. In this study, we analyzed the changes of protein expression in trachea and kidney tissues from chicken embryos, following IBV infection in ovo, using two-dimensional gel electrophoresis (2-DE) coupled with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS). 相似文献17.
Background
Salmonella enterica serovar Typhimurium (Typhimurium) is an important pathogen that infects a broad range of hosts. In humans, Typhimurium causes a gastroenteritis characterized by vomiting, diarrhea, and abdominal pains. Typhimurium infection occurs mainly through the ingestion of contaminated food including poultry, pork, eggs, and milk. Chickens that are asymptomatic carriers of Typhimurium constitute a potential reservoir for infection. The type three secretion systems encoded by Salmonella pathogeniCity islands (SPI) 1 and 2 are major virulence factors of Salmonella. However, only a few studies have investigated their role during the infection of chickens. 相似文献18.
N. Salmon P. M. Hocking P. M. van Diemen M. P. Stevens P. Kaiser 《Animal genetics》2011,42(2):134-140
Salmonella‐infected poultry products are a major source of human Salmonella infection. The prophylactic use of antimicrobials in poultry production was recently banned in the EU, increasing the need for alternative methods to control Salmonella infections in poultry flocks. Genetic selection of chickens more resistant to Salmonella colonization provides an attractive means of sustainably controlling the pathogen in commercial poultry flocks and its subsequent entry into the food chain. Analysis of different inbred chickens has shown that individual lines are consistently either susceptible or resistant to the many serovars of Salmonella that have been tested. In this study, two inbred chicken lines with differential susceptibility to Salmonella colonization (61(R) and N(S)) were used in a backcross experimental design. Unlike previous studies that used a candidate gene approach or low‐density genome‐wide screens, we have exploited a high‐density marker set of 1255 SNPs covering the whole genome to identify quantitative trait loci (QTL). Analysis of log‐transformed caecal bacterial levels between the parental lines revealed a significant difference at 1, 2, 3 and 4 days post‐infection (P < 0.05). Analysis of the genotypes of the backcross (F1 × N) population (n = 288) revealed four QTL on chromosomes 2, 3, 12 and 25 for the two traits examined in this study: log‐transformed bacterial counts in the caeca and presence of a hardened caseous caecal core. These included one genome‐wide significant QTL on chromosome 2 at 20 Mb and three additional QTL, on chromosomes 3, 12 and 25 at 96, 15 and 1 Mb, respectively, which were significant at the chromosome‐wide level (P < 0.05). The results generated in this study will inform future breeding strategies to control these pathogens in commercial poultry flocks. 相似文献
19.
Karolina Varmuzova Marta Elsheimer Matulova Alena Sebkova Zuzana Sekelova Hana Havlickova Frantisek Sisak Vladimir Babak Ivan Rychlik 《PloS one》2014,9(4)
Salmonella vaccines used in poultry in the EU are based on attenuated strains of either Salmonella serovar Enteritidis or Typhimurium which results in a decrease in S. Enteritidis and S. Typhimurium but may allow other Salmonella serovars to fill an empty ecological niche. In this study we were therefore interested in the early interactions of chicken immune system with S. Infantis compared to S. Enteritidis and S. Typhimurium, and a role of O-antigen in these interactions. To reach this aim, we orally infected newly hatched chickens with 7 wild type strains of Salmonella serovars Enteritidis, Typhimurium and Infantis as well as with their rfaL mutants and characterized the early Salmonella-chicken interactions. Inflammation was characterized in the cecum 4 days post-infection by measuring expression of 43 different genes. All wild type strains stimulated a greater inflammatory response than any of the rfaL mutants. However, there were large differences in chicken responses to different wild type strains not reflecting their serovar classification. The initial interaction between newly-hatched chickens and Salmonella was found to be dependent on the presence of O-antigen but not on its structure, i.e. not on serovar classification. In addition, we observed that the expression of calbindin or aquaporin 8 in the cecum did not change if inflammatory gene expression remained within a 10 fold fluctuation, indicating the buffering capacity of the cecum, preserving normal gut functions even in the presence of minor inflammatory stimuli. 相似文献
20.
Sharon M. Tennant Souleymane Diallo Haim Levy Sofie Livio Samba O. Sow Milagritos Tapia Patricia I. Fields Matthew Mikoleit Boubou Tamboura Karen L. Kotloff James P. Nataro James E. Galen Myron M. Levine 《PLoS neglected tropical diseases》2010,4(3)