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1.
Background
The swine-adapted serovar Choleraesuis of Salmonella enterica subspecies enterica is found rarely in domestic pigs in Germany. However, a considerable and increasing number of S. Choleraesuis organisms have been isolated from wild boars in Germany in recent years. To investigate a possible epidemiological context, S. Choleraesuis strains from a regional German wild boar population and other hosts were characterised by genotyping methods.Results
Macrorestriction analysis, biochemical differentiation and antimicrobial susceptibility typing enabled the identification of several clusters of S. Choleraesuis. Some clusters occurred almost permanently in a certain district, whereas other groups circulated among different wild boar herds in larger regions. Non-porcine hosts were infected with the same cluster as the wild boars.Conclusions
The emergence of S. Choleraesuis in wild boars might be caused by a higher prevalence in the wild boar population, but also the higher awareness to infections with African swine fever may have resulted in a higher number of examined animals. Separation of wild boar populations and, as a result, also the diverse S. Choleraesuis organisms might be due to natural barriers and artificial barriers like arterial roads. The findings of S. Choleraesuis in domestic pigs emphasize the importance of strict biosecurity measures to prevent transmission from wild boars of this but also other pathogens. To avoid risks for humans by zoonotic pathogens regular inspections of meat from wildlife need to be conducted.2.
Chai-Hoon Khoo Yoke-Kqueen Cheah Learn-Han Lee Jiun-Horng Sim Noorzaleha Awang Salleh Shiran Mohd Sidik Son Radu Sabrina Sukardi 《Antonie van Leeuwenhoek》2009,96(4):441-457
The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect
the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex
PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella
enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70%
of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay
was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration
of DNA 0.8 pg μl−1. This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast
and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies. 相似文献
3.
Gerald Reiner Christina Fresen Sebastian Bronnert Ingo Haack Hermann Willems 《European Journal of Wildlife Research》2010,56(5):815-818
Haemophilus parasuis is the etiological agent of Glässer’s disease, often involved in pneumonia, and also an early colonizer of the upper respiratory tract of healthy domestic pigs. Little information is available on H. parasuis in wild boars. The aim of the present study was to evaluate H. parasuis infection in wild boars in Germany. Tissue samples from the lungs and tonsils of 531 wild boars from 52 hunts during the hunting seasons 2004/2005 to 2006/2007 were examined independently for H. parasuis by PCR because H. parasuis is a fastidious organism, which hampers its isolation from clinical samples. The overall prevalence of H. parasuis in wild boars in Germany was 74.2%. H. parasuis was detected in 69.1% of tonsils and 40.4% of lungs. In conclusion, the present study demonstrates a wide distribution of H. parasuis in German wild boar populations and further research is required to understand the virulence of H. parasuis strains in wild boars, as well as the distribution and potential exchange of different strains between wild boars and domestic pigs. 相似文献
4.
Huang LJ Cui J Piao HH Hong Y Choy HE Ryu PY 《Journal of microbiology (Seoul, Korea)》2010,48(5):663-667
Cytolysin A (ClyA) is a pore-forming hemolytic protein encoded by the clyA gene. It has been identified in Salmonella enterica serovars Typhi and Paratyphi A. To identify and characterize the clyA genes in various Salmonella enterica strains, 21 different serotypes of strains isolated from clinical specimens were presently examined. Full-length clyA genes were found in S. enterica serovar Brandenburg, Indiana, Panama, and Schwarzengrund strains by polymerase chain reaction amplification. The ClyA proteins
from these four strains showed >97% amino acid identity to that of S. enterica serovar Typhi. Although all four serovars expressed detectable levels of ClyA as determined by Western blot analysis, they
did not show a strong hemolytic effect on blood agar, indicating that ClyA may not be efficiently expressed or secreted. Escherichia coli transformed with clyA genes from the four serovars enhanced production of ClyA proteins and hemolytic activities to a level similar to S. enterica serovar Typhi ClyA. The present results suggest that ClyA may play a role in the pathogenesis of S. enterica serovar Brandenburg, Indiana, Panama and Schwarzengrund. 相似文献
5.
Alicia Alonso-Hernando Rosa Capita Miguel Prieto Carlos Alonso-Calleja 《Journal of microbiology (Seoul, Korea)》2009,47(2):142-146
Information on the potential for acquired reduced susceptibility of bacteria to poultry decontaminants occurring is lacking.
Minimal Inhibitory Concentrations (MICs) were established for assessing the initial susceptibility and the adaptative and
cross-adaptative responses of four bacterial strains (Listeria monocytogenes serovar l/2a, L. monocytogenes serovar 4b, Salmonella enterica serotype Typhimurium, and S. enterica serotype Enteritidis) to four poultry decontaminants (trisodium phosphate, acidified sodium chlorite -ASC-, citric acid,
and peroxyacetic acid). The initial susceptibility was observed to differ among species (all decontaminants) and between Salmonella strains (ASC). These inter- and intra-specific variations highlight (1) the need for strict monitoring of decontaminant concentrations
to inactivate all target pathogens of concern, and (2) the importance of selecting adequate test strains in decontamination
studies. MICs of ASC (0.17±0.02 to 0.21±0.02 mg/ml) were higher than the U.S. authorized concentration when applied as a pre-chiller
or chiller solution (0.05 to 0.15 mg/ml). Progressively increasing decontaminant concentrations resulted in reduced susceptibility
of strains. The highest increase in MIC was 1.88 to 2.71-fold (ASC). All decontaminants were shown to cause cross-adaptation
of strains between both related and unrelated compounds, the highest increase in MIC being 1.82-fold (ASC). Our results suggest
that the in-use concentrations of ASC could, in certain conditions, be ineffective against Listeria and Salmonella strains. The adaptative and cross-adaptative responses of strains tested to poultry decontaminants are of minor concern.
However, the observations being presented here are based on in vitro studies, and further research into practical applications are needed in order to confirm these findings. 相似文献
6.
Systemic administration of Salmonella to tumor-bearing mice leads to preferential accumulation within tumor sites and retardation of tumor growth. However, the
detailed mechanism of Salmonella-induced antitumor immune response via host T cell remains uncertain. Herein, we used wild-type, CD4+ T-cell-deficient, and CD8+ T-cell-deficient mice to study the role of T cell in the antitumor immune responses induced by Salmonella enterica serovar Choleraesuis (Salmonella Choleraesuis). When systemically administered into mice bearing tumors, Salmonella Choleraesuis significantly inhibited tumor growth by 50%. In contrast, in T-cell-deficient mice, there was only 34–42% inhibition
of tumor growth. We found that treatment with Salmonella Choleraesuis significantly upregulates interferon-γ in wild-type and CD8+ T-cell-deficient mice, but not in CD4+ T-cell-deficient mice. Furthermore, immunohistochemical staining of the tumors revealed more infiltration of macrophages
and neutrophils in wild-type mice after Salmonella Choleraesuis treatment compared with those in T-cell-deficient mice. The antitumor therapeutic effect mediated by Salmonella Choleraesuis is associated with an inflammatory immune response at the tumor site and a tumor T helper 1-type immune response.
In conclusion, these results suggest that tumor-targeted therapy using Salmonella Choleraesuis, which exerts tumoricidal effects and stimulates T cell activities, represents a potential strategy for the
treatment of tumor. 相似文献
7.
G. Vengust R. Lindtner-Knific D. Zele A. Bidovec 《European Journal of Wildlife Research》2008,54(4):749-752
Serum samples collected from 437 shot wild boars (Sus scrofa) were tested for the presence of antibodies against Leptospira interrogans sensu lato in wild boar in Slovenia. Assessment of leptospira-specific antibodies was performed by microscopic agglutination
test. Antibodies against at least one of the pathogenic serovars were detected in 200 (45.8%) sera. From 200 positive samples,
100 samples (50%) had positive titre against a single serovar, while 100 (50%) samples had positive titres against two or
more serovars. The most frequently detected antibodies were those against serovar Tarassovi. This investigation confirmed
the presence of different pathogenic serovars in wild boar across Slovenia. It can be concluded that wild boars are natural
reservoirs of at least some of the leptospiral serovars that represent a potential source of leptospirosis for other wild
and domestic animals, as well as for humans. 相似文献
8.
Natural variation in the presence or the absence of STM0517-0529 genes allowing allantoin utilisation has been described in
field isolates of the multidrug resistant Salmonella enterica serovar Typhimurium belonging to the phage type DT104. Interestingly, S. enterica subspecies enterica serovar Typhimurium DT104 is quite frequent in pigs and cattle, but rarely present in egg-laying hens. Taking into account
the different mode of allantoin metabolism in birds and mammals, we were interested in whether the absence of STM0517-0529
genes may disable this clone in poultry colonisation. We have therefore constructed the allB (also designated as STM0523) mutants in S. enterica subspecies enterica serovar Typhimurium and S. enterica subspecies enterica serovar Enteritidis, and with these, we infected mice, newly hatched chickens and adult egg-laying hens to show that the
defect in allantoin utilisation does not influence S. enterica virulence for mice or adult hens, but slightly decreases virulence of S. enterica for chickens. The decrease in virulence of the allB mutant was relatively minor as it could be observed only after a mixed infection model, consistent with a lower prevalence,
but not a total absence of such clones in poultry flocks. 相似文献
9.
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.10.
In-Cheol Cho Sang-Hyun Han Meiying Fang Sung-Soo Lee Moon-Suck Ko Hang Lee Hyun-Tae Lim Chae-Kyoung Yoo Jun-Heon Lee Jin-Tae Jeon 《Molecules and cells》2009,28(5):423-430
In order to elucidate the precise phylogenetic relationships of Korean wild boar (Sus scrofa coreanus), a partial mtDNA D-loop region (1,274 bp, NC_000845 nucleotide positions 16576-1236) was sequenced among 56 Korean wild
boars. In total, 25 haplotypes were identified and classified into four distinct subgroups (K1 to K4) based on Bayesian phylogenetic
analysis using Markov chain Monte Carlo methods. An extended analysis, adding 139 wild boars sampled worldwide, confirmed
that Korean wild boars clearly belong to the Asian wild boar cluster. Unexpectedly, the Myanmarese/Thai wild boar population
was detected on the same branch as Korean wild boar subgroups K3 and K4. A parsimonious median-joining network analysis including
all Asian wild boar haplotypes again revealed four maternal lineages of Korean wild boars, which corresponded to the four
Korean wild boar subgroups identified previously. In an additional analysis, we supplemented the Asian wild boar network with
34 Korean and Chinese domestic pig haplotypes. We found only one haplotype, C31, that was shared by Chinese wild, Chinese
domestic and Korean domestic pigs. In contrast to our expectation that Korean wild boars contributed to the gene pool of Korean
native pigs, these data clearly suggest that Korean native pigs would be introduced from China after domestication from Chinese
wild boars. 相似文献
11.
Salmonella enterica is divided into four subspecies containing a large number of different serovars, several of which are important zoonotic
pathogens and some show a high degree of host specificity or host preference. We compare 45 sequenced S. enterica genomes that are publicly available (22 complete and 23 draft genome sequences). Of these, 35 were found to be of sufficiently
good quality to allow a detailed analysis, along with two Escherichia coli strains (K-12 substr. DH10B and the avian pathogenic E. coli (APEC O1) strain). All genomes were subjected to standardized gene finding, and the core and pan-genome of Salmonella were estimated to be around 2,800 and 10,000 gene families, respectively. The constructed pan-genomic dendrograms suggest
that gene content is often, but not uniformly correlated to serotype. Any given Salmonella strain has a large stable core, whilst there is an abundance of accessory genes, including the Salmonella pathogenicity islands (SPIs), transposable elements, phages, and plasmid DNA. We visualize conservation in the genomes in
relation to chromosomal location and DNA structural features and find that variation in gene content is localized in a selection
of variable genomic regions or islands. These include the SPIs but also encompass phage insertion sites and transposable elements.
The islands were typically well conserved in several, but not all, isolates—a difference which may have implications in, e.g.,
host specificity. 相似文献
12.
In seawater, enteric bacteria evolve toward a stressed state that is difficult to identify because of major alterations of
their phenotype. In this study, we incubated four reference strains of S. enterica serovar Typhimurium in seawater microcosms for 10 months and studied the modifications of their main phenotypic characters.
All of the strains lost some key characters used for traditional identification of the Salmonella genus. They became able to produce acetoin, and tryptophane deaminase activity became positive, but they lost the capacity
to use rhamnose. We were able to show some modifications of the level of enzymatic profile as well as in their antibiotic
susceptibility. The atypical cells of S. enterica serovar Typhimurium were identified by polymerase chain reaction (PCR) methods using the internal transcribed spacer region,
and they were confirmed by multiplex PCR after the simultaneous amplification of the phoP, Hin, and H-li genes. 相似文献
13.
Matiasovicova J Adams P Barrow PA Hradecka H Malcova M Karpiskova R Budinska E Pilousova L Rychlik I 《Archives of microbiology》2007,187(5):415-424
The origin of multidrug-resistant Salmonella enterica serovar typhimurium (S. typhimurium) harboring the Salmonella Genomic Island 1 (SGI1), which was detected for the first time in the mid-1980s is unknown. In this study, we performed microarray
genomotyping of four multidrug-resistant SGI1 positive strains and found that unlike the S. typhimurium LT2 strain, the multidrug-resistant strains lacked genes STM0517-0529 allowing the utilization of allantoin as a sole nitrogen
source. We extended this observation by PCR screening of additional 120 S. typhimurium field strains and found that this locus was absent in all SGI1 positive and also in 24% of SGI1 negative strains, which were
proposed to be the original recipients of SGI1. To prove this hypothesis, we compared the STM0517-0529 negative strains (with
or without the SGI1) by PFGE and PCR prophage typing and found that 8 out of 11 of the SGI1 negative strains and 17 out of
22 SGI1 positive strains were of identical PFGE pattern and PCR prophage pattern, while this specific pattern was never observed
among STM0517-0529 positive strains. We therefore propose that a lineage of the S. typhimurium DT104 sensitive strain first lost the ability to metabolize allantoin and then acquired SGI1. 相似文献
14.
Porteen Kannan Mahesh Dharne Allen Smith Jeffrey Karns Arvind A. Bhagwat 《Current microbiology》2009,59(6):641-645
15.
Ammini Parvathi Jasna Vijayan Greeshma Murali Preethi Chandran 《Current microbiology》2011,62(1):21-26
Salmonella
enterica serotype Newport is an important cause of non-typhoidal salmonellosis, a clinically less severe infection than typhoid fever
caused by S. enterica serotype Typhi. In this investigation, the virulence genotypes of S. enterica Newport isolated from a backwater environment were compared with Salmonella Typhi from clinical cases in the same region where salmonellosis is endemic. Genotyping was done by PCR screening for virulence
markers associated with Salmonella pathogenicity islands (SPIs) and plasmids. The virulence genes associated with SPIs I–VI were detected in 95–100% of all
the isolates, while the viaB locus representing SPI-7 was detectable in 66 and 73% of the environmental and clinical isolates, respectively. A significant
number of Salmonella Newport lacked virulence genes shdA and sopE compared to S. Typhi. All S. Typhi and S. Newport isolates lacked large plasmid-borne virulence genes spvR and pefA. Further investigations into the antimicrobial resistance of S. Newport revealed multiple drug resistance to ampicillin, amoxicillin/clavulanic acid, trimethorprim-sulfamethoxazole, chloramphenicol,
tetracycline, cephalothin, and cephalexin. In comparison, S. Typhi were susceptible to all clinically relevant antimicrobials. The results of this study will help in understanding the
spread of virulence genotypes and antibiotic resistance in S. Newport in the region of study. 相似文献
16.
Yoke-Kqueen Cheah Noorzaleha Awang Salleh Learn-Han Lee Son Radu Sabrina Sukardi Jiun-Horng Sim 《World journal of microbiology & biotechnology》2008,24(3):327-335
Salmonella enterica subsp. enterica (S.) serovar Weltevreden has emerged as a public health problem in many countries. Genomic DNA of S. Weltevreden from indigenous vegetables namely ‘selom’ (Oenanthe stolonifera), ‘pegaga’ (Centella asiatica), ‘kesum’ (Polygonum minus) and ‘kangkong’ (Ipomoea aquatica) were characterized by duplex-polymerase chain reaction (duplex-PCR), multiplex-polymerase chain reaction (multiplex-PCR),
random amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)
and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results demonstrated that a total of
four clusters and three single isolates were generated from ERIC-PCR with primers ERIC-1 and ERIC-2 whereas RAPD with arbitrary
primers OPAR2, OPAR17 and OPAR19 discriminated the S. Weltevreden into nine clusters and eight single isolates at a common 65% similarity level with discriminatory index (D) of 0.7443 and 0.9394 respectively. Composite analysis of banding profiles generated from RAPD-PCR and ERIC-PCR showed eight
clusters and six single isolates at 65% similarity level with the highest D value that is 0.9508. On the other hand, PCR-RFLP and duplex PCR data exhibited a consistent profile for S. Weltevreden. Multiplex-PCR targeting three different antibiotic resistance genes and a common Salmonella specific gene segment produced two distinguishing profiles among the S. Weltevreden examined. These results demonstrated that the combined analysis of RAPD-PCR and ERIC-PCR is a better tool for
characterizing S. Weltevreden than individual methods. 相似文献
17.
Jun Sik Lee In Duk Jung Chang-Min Lee Jin Wook Park Sung Hak Chun Soo Kyung Jeong Tae kwun Ha Yong Kyoo Shin Dae Jin Kim Yeong-Min Park 《BMC microbiology》2010,10(1):263
Background
Typhoid, which is caused by Salmonella enterica serovar Typhimurium, remains a major health concern worldwide. Multidrug-resistant strains of Salmonella have emerged which exhibit increased survivability and virulence, thus leading to increased morbidity. However, little is known about the protective immune response against this microorganism. The outer membrane protein (Omp)A of bacteria plays an important role in pathogenesis. 相似文献18.
Forty-three epidemiologically unrelated emerging Salmonella enterica subsp. enterica serovar 4,[5],12:i:- strains isolated during the period 2009–2010 in Slovakia were characterized by phenotypic and genotypic
methods. Thirty-one isolates (72.1%) expressed resistance to ampicillin, streptomycin, sulfizoxazole, and tetracycline [R-type
ASSuT]. The majority of the strains belonged to both definitive phage types DT193 (30.2%) and U311 (27.9%). Other phage types
identified were U302 (6.9%), DT18 (4.7%), and DT194 (2.3%). Twelve strains (27.9%) were not typeable. Pulsed-field gel electrophoresis
analysis identified three closely related major banding profiles (X1, X1a, and X2), suggesting the similarity and close epidemiological
relationship between S. enterica serovar 4,[5],12:i:- strains. In two isolates with R-type ASSuT, phage type NT and in one isolate with R-type ACROSSuSxTTTMPNA,
phage type DT193 class 1 integrons were found encoding blaPSE-1 and dfrA, aadA1, respectively. 相似文献
19.
Hong Hua Piao Vo Thi Minh Tam Hee Sam Na Hyun Ju Kim Phil Youl Ryu Soo Young Kim Joon Haeng Rhee Hyon E. Choy Suhng Wook Kim Yeongjin Hong 《Journal of microbiology (Seoul, Korea)》2010,48(4):486-495
Attenuated bacteria have long been developed as vaccine candidates but can have some disadvantages, such as the potential
for damage to immune organs due to insufficient clearance. To minimize these disadvantages, we generated Salmonella enterica serovar Typhimurium mutants SHJ2104 (asd::cm) and HTSaYA (wzy::km, asd::cm). The wzy gene codes for the O-antigen polymerase, which is involved in lipopolysaccharide (LPS) biosynthesis, and asd codes for aspartate β-semialdehyde dehydrogenase, which participates in cell wall formation. The strains synthesized LPS
with a short-chain length, and showed lower cytotoxicity and reduced intracellular proliferation in animal cells compared
to wild-type bacteria. After oral infection, the mutants were cleared in immune tissues, including the Peyer’s patch, mesenteric
lymph node, and spleen, within 5 days. The LD50 of the mutants in Balb/c mice was estimated to be 106 higher than wild-type bacteria when administered either via an oral or i.p. route, indicating that the two strains are highly attenuated. To compare the immune response to and protective effects of
the mutants against wild-type bacterial infection, we inoculated the mutants into mice via an oral (1×1010CFU) or i.p. (1×107 CFU) route once or twice at a two week interval. All immune responses, such as serum IgG and secretory IgA levels, cytokine
production, and delayed hypersensitivity, were highly induced by two rounds of immunization. HTSaYA and SHJ2104 induced similar
immune responses, and mice immunized with HTSaYA or SHJ2104 via an i.p. route were protected against wild-type Salmonella infection even at 100-fold of the LD50 (5×106 CFU). Taken together, these data indicate that HTSaYA and SHJ2104 could be developed as live attenuated Salmonella vaccine candidates. 相似文献
20.