scholarly journals Sensitivity of enrichment-PCR method for Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis analysis in chicken carcasses

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.

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.


2021 ◽  
Vol 41 (01) ◽  
pp. 39-44
Author(s):  
A Guerrini

Few data are available about the prevalence of Salmonella enterica serovar Enteritidis (S.E.) and Salmonella enterica serovar Typhimurium (S.T.) in ornamental poultry in Italy. The aim of this study was to investigate the seroprevalence for S.E. and S.T. using serological tests and the prevalence of Salmonella spp. in eggs by culture methods. For this purpose, 240 serum samples and 216 eggs were sampled from asymptomatic and unvaccinated ornamental hens reared in 24 farms, located in 8 different Italian regions. As screening test, a Tube Serum Agglutination test (TSA) was performed on 231 out of 240 serum samples. Four out of 24 farms (16.67%) were serologically positive for Salmonella spp. for a total of 10 samples. These positive samples were confirmed using an ELISA test and the results show that 5/231 (2.16%) and 7/231 (3.03%) serum samples were positive for S.E. and S.T. respectively, and 2/231 (0.87%) for both serotypes. Among all farms, 2/24 (8.33%) were positive for S.E. and 4/24 (16.67%) for S.T. The analysis of eggs using culture methods gave negative results for both yolk and shell pools (0/48, 0.0%). The seroconversion associated with exposure to S.E./S.T. in ornamental poultry, poses a potential public health problem. This study confirms that S.E. and S.T. are widespread in studied backyard poultry farms as asymptomatic form, and animals as potential reservoirs of Salmonella. It is necessary to inform farmers that a regular and periodic control of animals, eggs or meat, is very important to prevention of Salmonella foodborne infections and their spread.


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.


2007 ◽  
Vol 189 (23) ◽  
pp. 8447-8457 ◽  
Author(s):  
Qingfeng Wang ◽  
Yifang Zhao ◽  
Michael McClelland ◽  
Rasika M. Harshey

ABSTRACT The Rcs phosphorelay is a multicomponent signaling system that positively regulates colanic acid synthesis and negatively regulates motility and virulence. We have exploited a spontaneously isolated mutant, IgaA(T191P), that is nearly maximally activated for the Rcs system to identify a vast set of genes that respond to the stimulation, and we report new regulatory properties of this signaling system in Salmonella enterica serovar Typhimurium. Microarray data show that the Rcs system normally functions as a positive regulator of SPI-2 and other genes important for the growth of Salmonella in macrophages, although when highly activated the system completely represses the SPI-1/SPI-2 virulence, flagellar, and fimbrial biogenesis pathways. The auxiliary protein RcsA, which works with RcsB to positively regulate colanic acid and other target genes, not only stimulates but also antagonizes the positive regulation of many genes in the igaA mutant. We show that RcsB represses motility through the RcsB box in the promoter region of the master operon flhDC and that RcsA is not required for this regulation. Curiously, RcsB selectively stimulates expression of the flagellar type 3 secretion genes fliPQR; an RcsAB box located downstream of fliR influences this regulation. We show that excess colanic acid impairs swimming and inhibits swarming motility, consistent with the inverse regulation of the two pathways by the Rcs system.


1999 ◽  
Vol 55 (12) ◽  
pp. 2043-2046 ◽  
Author(s):  
Marie-France Giraud ◽  
Helen J. McMiken ◽  
Gordon A. Leonard ◽  
Paul Messner ◽  
Chris Whitfield ◽  
...  

L-Rhamnose is an essential component of the cell wall of many pathogenic bacteria. Its precursor, dTDP-L-rhamnose, is synthesized from α-D-glucose-1-phosphate and dTTP via a pathway requiring four distinct enzymes: RmlA, RmlB, RmlC and RmlD. RmlD catalyses the terminal step of this pathway by converting dTDP-6-deoxy-L-lyxo-4-hexulose to dTDP-L-rhamnose. RmlD from Salmonella enterica serovar Typhimurium has been overexpressed in Escherichia coli. The recombinant protein was purified by a two-step protocol involving anion-exchange and hydrophobic chromatography. Dynamic light-scattering experiments indicated that the recombinant protein is monodisperse. Crystals of native and selenomethionine-enriched RmlD have been obtained using the sitting-drop vapour-diffusion method with polyethylene glycol as precipitant. Diffraction data have been collected from orthorhombic crystals of both native and selenomethionyl-derivatized protein, allowing tracing of the protein structure.


2020 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. Like some other pathogenic bacteria multidrug-resistant strains of Salmonella enterica serovar Typhimurium (S. Typhimurium) are also frequently found in animals and humans which poses a major public health concern. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. Thus, this study aimed to increase the efficacy of existing antibiotics against S. Typhimurium by combining them with opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration indexes (FICI) of phenolic compound-antibiotic combinations against S. Typhimurium were determined. Based on the FICI and clinical importance, 1 combination (GA and ceftiofur) was selected for evaluating its effects on the virulence factors of this bacterium. Viability of Rattus norvegicus (IEC-6) cell in presence of this antibacterial combination was evaluated.Results: Minimum inhibitory concentrations (MICs) of GA, epigallocatechin and hamamelitannin found against different strains of S. Typhimurium were 256, (512–1024), and (512–1024) μg/mL, respectively. Synergistic antibacterial effect was obtained from the combination of erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects (FICI: 0.502–0.750) were obtained from 16 combinations against this bacterium. The time-kill assay and ultrastructural morphology showed that GA-ceftiofur combination more efficiently inhibited the growth of S. Typhimurium compared to individual antimicrobials. Biofilm viability, and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur combination were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were more significantly enhanced by GA-ceftiofur combinations than these antibacterials alone.Conclusions: This study suggests that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.


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


2001 ◽  
Vol 67 (8) ◽  
pp. 3763-3766 ◽  
Author(s):  
Steve A. Carlson ◽  
Timothy S. Frana ◽  
Ronald W. Griffith

ABSTRACT Microcin 24 is an antimicrobial peptide secreted by uropathogenicEscherichia coli. Secretion of microcin 24 provides an antibacterial defense mechanism for E. coli. In a plasmid-based system using transformed Salmonella enterica, we found that resistance to microcin 24 could be seen in concert with a multiple-antibiotic resistance phenotype. This multidrug-resistant phenotype appeared when Salmonella was exposed to an E. coli strain expressing microcin 24. Therefore, it appears that multidrug-resistant Salmonellacan arise as a result of an insult from other pathogenic bacteria.


Sign in / Sign up

Export Citation Format

Share Document