Three Salmonella enterica serovar Enteritidis bacteriophages from the Siphoviridae family are promising candidates for phage therapy

2018 ◽  
Vol 64 (11) ◽  
pp. 865-875 ◽  
Author(s):  
Yibao Chen ◽  
Erchao Sun ◽  
Jiaoyang Song ◽  
Yigang Tong ◽  
Bin Wu

Salmonella is a common and widely distributed foodborne pathogen that is frequently implicated in gastrointestinal infections. The emergence and spread of Salmonella strains resistant to multiple antibiotics poses a significant health threat, highlighting the urgent need for early and effective therapeutic strategies. We isolated a total of 32 phages from water samples and anal swabs from pigs. Of these, three phages that produced large, clear plaques were selected for further study using the following methods: electron microscopy, analysis of the life cycle parameters, genetic analysis, inhibition of bacterial growth, and activity against biofilms. The three Salmonella phages (vB_SenS_CSP01, vB_SenS_PHB06, and vB_SenS_PHB07) were assigned to the family Siphoviridae on the basis of their morphology. All showed polyvalent infectivity, and individual phages or phage cocktails could inhibit the growth of host Salmonella enterica serovar Enteritidis strains or reduce biofilm formation by Salmonella enterica serovar Typhimurium. In summary, these three phages merit further research as biocontrol agents for Salmonella infection.

2006 ◽  
Vol 69 (7) ◽  
pp. 1653-1661 ◽  
Author(s):  
H. J. KIM ◽  
S. H. PARK ◽  
T. H. LEE ◽  
B. H. NAHM ◽  
Y. H. CHUNG ◽  
...  

Salmonella enterica serovar Typhimurium is a major foodborne pathogen throughout the world. Until now, the specific target genes for the detection and identification of serovar Typhimurium have not been developed. To determine the specific probes for serovar Typhimurium, the genes of serovar Typhimurium LT2 that were expected to be unique were selected with the BLAST (Basic Local Alignment Search Tool) program within GenBank. The selected genes were compared with 11 genomic sequences of various Salmonella serovars by BLAST. Of these selected genes, 10 were expected to be specific to serovar Typhimurium and were not related to virulence factor genes of Salmonella pathogenicity island or to genes of the O and H antigens of Salmonella. Primers for the 10 selected genes were constructed, and PCRs were evaluated with various genomic DNAs of Salmonella and non-Salmonella strains for the specific identification of Salmonella serovar Typhimurium. Among all the primer sets for the 10 genes, STM4497 showed the highest degree of specificity to serovar Typhimurium. In this study, a specific primer set for Salmonella serovar Typhimurium was developed on the basis of the comparison of genomic sequences between Salmonella serovars and was validated with PCR. This method of comparative genomics to select target genes or sequences can be applied to the specific detection of microorganisms.


2004 ◽  
Vol 72 (7) ◽  
pp. 4138-4150 ◽  
Author(s):  
Bärbel Stecher ◽  
Siegfried Hapfelmeier ◽  
Catherine Müller ◽  
Marcus Kremer ◽  
Thomas Stallmach ◽  
...  

ABSTRACT Salmonella enterica subspecies 1 serovar Typhimurium is a common cause of gastrointestinal infections. The host's innate immune system and a complex set of Salmonella virulence factors are thought to contribute to enteric disease. The serovar Typhimurium virulence factors have been studied extensively by using tissue culture assays, and bovine infection models have been used to verify the role of these factors in enterocolitis. Streptomycin-pretreated mice provide an alternative animal model to study enteric salmonellosis. In this model, the Salmonella pathogenicity island 1 type III secretion system has a key virulence function. Nothing is known about the role of other virulence factors. We investigated the role of flagella in murine serovar Typhimurium colitis. A nonflagellated serovar Typhimurium mutant (fliGHI) efficiently colonized the intestine but caused little colitis during the early phase of infection (10 and 24 h postinfection). In competition assays with differentially labeled strains, the fliGHI mutant had a reduced capacity to get near the intestinal epithelium, as determined by fluorescence microscopy. A flagellated but nonchemotactic cheY mutant had the same virulence defects as the fliGHI mutant for causing colitis. In competitive infections, both mutants colonized the intestine of streptomycin-pretreated mice by day 1 postinfection but were outcompeted by the wild-type strain by day 3 postinfection. Together, these data demonstrate that flagella are required for efficient colonization and induction of colitis in streptomycin-pretreated mice. This effect is mostly attributable to chemotaxis. Recognition of flagellar subunits (i.e., flagellin) by innate immune receptors (i.e., Toll-like receptor 5) may be less important.


Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 96 ◽  
Author(s):  
Zhanna Ktsoyan ◽  
Lyudmila Budaghyan ◽  
Marina Agababova ◽  
Armine Mnatsakanyan ◽  
Karine Arakelova ◽  
...  

In this work, we investigated the potential effects of nontyphoidal Salmonella infection on autoantibody (AA) formation. The titer and profiles of autoantibodies in the sera of patients with acute salmonellosis due to Salmonella enterica serovar Typhimurium (S. Typhimurium) or Salmonella enterica serovar Enteritidis (S. Enteritidis) infection, as well as in convalescent patients, were determined with indirect immunofluorescence. A significant increase of autoantibodies in acute diseases caused by both serotypes of Salmonella and during post infection by S. Enteritidis was detected. Antibody profile analysis by multivariate statistics revealed that this increase was non-specific and was not dependent on the infectious agent or disease stage. The results obtained suggest that nontyphoidal Salmonella infection contributes to the generation of autoantibodies and may play a role in autoimmune disease.


Food Research ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 262-272
Author(s):  
H. Adnan ◽  
N. Ismail ◽  
H. Hasan ◽  
M.S. Mat-Ali

Salmonellosis infection caused by Salmonella bacteria is a public endemic problem in Malaysia with long-term morbidity and mortality effects. Thus, this study aimed to explore the antipathogenic activity of natural extracts from Mangifera odorata against two Salmonella species causing Salmonellosis. The extracts were derived from peel, flesh, and kernel seed of M. odorata. The inhibition performance of the extracts against both Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis bacteria were subsequently tested by using a bioassay-guided fractionation method. Results showed that the extracts derived from the kernel seed had the highest inhibition percentage of 83-90% against the Salmonellosis infection, followed by the peel with an inhibition of 61-67%, and lastly the flesh with an inhibition of 53-69%. The inhibition activities of hexane extracted flesh (FCH), methanol extracted peel (PCM), and methanol treated kernel seed (KTM) against S. enterica ser. Typhimurium bacteria were 59, 67 and 83%, respectively. Furthermore, the S. enterica ser. Enteritidis bacteria were found to be highly susceptible against the methanol extracted kernel seed (KCM), followed by the hexane extracted peel (PCH) and flesh (FTH) with the inhibition percentage of 90, 69 and 59%, respectively. The highly active anti-Salmonellosis performance of M. odorata extracts was attributed to its intrinsically high total phenolics content at 8-10 g GAE/g extract, high ferric reducing antioxidant power value (FRAP) at 18-22 g Fe2+/g extract and excellent scavenging activity with the inhibition performance ranges between 86% and 90%. This study revealed the antipathogenic activity of methanol extracts of M. odorata kernel seed inhibited the growth of both S. enterica ser. Typhimurium and S. enterica ser. Enteritidis bacteria. This study also discovered the prophylactic property of natural compounds in M. odorata kernel seed extracts and could be used as an anti-Salmonellosis agent. In the near future, M. odorata can be developed as an innovative functional food source for specific groups that are vulnerable to Salmonellosis


2013 ◽  
Vol 81 (12) ◽  
pp. 4453-4460 ◽  
Author(s):  
Sarah A. Zeiner ◽  
Brett E. Dwyer ◽  
Steven Clegg

ABSTRACTThe production of type 1 fimbriae inSalmonella entericaserovar Typhimurium is controlled, in part, by three proteins, FimZ, FimY, and FimW. Amino acid sequence analysis indicates that FimZ belongs to the family of bacterial response regulators of two-component systems. In these studies, we have demonstrated that introducing a mutation mimicking phosphorylation of FimZ is necessary for activation of its target gene,fimA. In addition, the interaction of FimZ with FimW, a repressor offimAexpression, occurs only when FimZ is phosphorylated. Consequently, the negative regulatory effect of FimW is most likely due to downmodulation of the active FimZ protein. FimY does not appear to function as a response regulator, and its activity can be lost by mimicking the phosphorylation of FimY. Overproduction of FimY cannot alleviate the nonfimbriate phenotype in a FimZ mutant, whereas high levels of FimZ can overcome the nonfimbriate phenotype of a FimY mutant. It appears that FimY acts upstream of FimZ to activatefimAexpression.


Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 54-61
Author(s):  
H.A. Wulan ◽  
Nurjanah S. ◽  
W.P. Rahayu

Salmonella spp. is Gram negative-pathogenic bacteria that usually found as a contaminant in chicken carcasses. This study was aimed to increase the sensitivity of PCR enrichment step and apply the enrichment-PCR combination to detect Salmonella in chicken carcasses. In this study were used Salmonella enterica serovar Hadar, Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis with the target genes were invA, STM4497, and respectively. A total of 25 g of the chicken carcasses were artificially contaminated by approximately 0.96 and 3.33 MPN/mL for each serovar separately. Samples were incubated in pre-enrichment and enrichment media for 8 hrs prior to the DNA extraction. The pre-enrichment and enrichment media was Buffered Peptone Water and Rappaport-Vassiliadis-soya. The result showed that the target genes of S. enterica ser. Hadar, S. enterica ser. Typhimurium and S. enterica ser. Enteritidis were detected in chicken carcasses, indicated by the presence of DNA band with the size was 429 bp, 311 bp and 135 bp respectively. These result in line with analysis using ISO method and BLAST-comparison analysis of DNA amplicon sequences with GenBank references. Application of this method for Salmonella detection in chicken carcasses sold in the traditional market showed a higher prevalence than the previous result without enrichment. All samples (n = 100) from unsanitary practice sellers were positively contaminated by Salmonella spp. and also high prevalence for S. enterica ser. Typhimurium and S. enterica ser. Enteritidis. It can be concluded that enrichment is an important step to increase the sensitivity detection of PCR method.


2019 ◽  
Vol 8 (43) ◽  
Author(s):  
Ketki Patil ◽  
Chi Zeng ◽  
Chandler O’Leary ◽  
Lauren Lessor ◽  
Rohit Kongari ◽  
...  

Salmonella enterica serovar Typhimurium is a foodborne pathogen that causes gastroenteritis. Due to increases in antibiotic resistance, bacteriophage therapy may be an alternative method for preventing Salmonella foodborne infections. We report here the complete genome sequence of a T5-like phage, Seabear, which was isolated against S. Typhimurium.


2021 ◽  
Vol 14 (3) ◽  
pp. 813-819
Author(s):  
Yaser H. Tarazi ◽  
Abdallah F. Al Dwekat ◽  
Zuhair Bani Ismail

Background and Aim: Salmonellosis is an important food-borne and zoonotic disease with high morbidity and mortality rates. The objectives of this study were to isolate, serotype, and genetically characterize Salmonella spp. from Zarqa river and King Talal dam waters, vegetables irrigated by such waters, and manure of poultry and livestock farms located in the Zarqa river basin in Jordan. In addition, certain virulence factors and antimicrobial resistance patterns of isolated Salmonella strains were determined. Materials and Methods: A total of 250 samples were cultured using routine microbiological methods. Suspected Salmonella spp. were identified based on colony morphology and confirmed using biochemical and molecular methods. Virulence genes including invA, stn, and pCT plasmid were detected using multiplex PCR. Phylogenetic analysis was performed using pulsed-field gel electrophoresis (PFGE). Results: In total, 32/250 (12.8%) Salmonella spp. isolates were recovered from different sources. Of these, the most common serotype was Salmonella subspecies 1 (23 isolates), followed by Salmonella enterica serovar Typhimurium (4 isolates), Salmonella enterica serovar Typhi (3 isolates), and finally Salmonella enterica serovar Enteritidis (2 isolates). The PFGE indicated that Salmonella enterica serovar Typhimurium isolated from poultry manure and from parsley were closely related (84.6%). Salmonella enterica serovar Enteritidis isolated from the dam water was closely related to Salmonella enterica serovar Enteritidis isolated from spearmint (73.8%). Salmonella enterica serovar Typhi isolated from the river and dam water were 100% related to Salmonella enterica serovar Typhi isolated from lettuce. In the antimicrobial sensitivity test, 14 out of 32 (43.8%) isolated Salmonella strains were resistant to two or more of the major antimicrobial agent groups. However, the majority of isolates were sensitive to ceftriaxone, ciprofloxacin, cefuroxime, and gentamicin (97%, 93.8%, and 87.5%, 84.4%, respectively). All isolates were resistant to erythromycin and amoxicillin. Conclusion: Results of this study indicate a serious potential threat to public health associated with consuming leafy green vegetables grown on the banks of Zarqa river and its dam because of widespread Salmonella spp. contamination. Appropriate monitoring of irrigation water must be applied to reduce the possibility of cross-contamination.


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