Correlation of conversion of Salmonella enterica serovar enteritidis phage type 1, 4, or 6 to phage type 7 with loss of lipopolysaccharide.

ABSTRACT We have observed a high incidence of isolated nalidixic acid resistance in Salmonella enterica serovar Enteritidis isolates in Ireland, particularly isolates of phage type 1 (PT1). A group of nalidixic acid-resistant (n = 22) and nalidixic acid-susceptible (n = 28) isolates of serovar Enteritidis from multiple sites in Ireland were selected. Isolates were typed by pulsed-field gel electrophoresis (PFGE) with XbaI, and the MICs for nalidixic acid and ciprofloxacin were determined. Mutations associated with nalidixic acid resistance in clinical isolates and laboratory mutants of serovar Enteritidis and 32 nalidixic acid-resistant isolates of 15 other salmonella serovars were identified. PFGE had limited discriminatory power. A specific point mutation (G246T) associated with amino acid substitution Asp87Tyr in the quinolone resistance determining region of the gyrA gene accounted for 95% of all mutations in serovar Enteritidis and for all mutations in PT1 isolates. Greater diversity of mutations was observed among all non-Enteritidis salmonella serovars studied. Rates of nalidixic acid resistance in serovar Enteritidis may predominantly reflect clonal expansion after infrequent mutation or selection events.

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Characterization of SEN3800-associated virulence of Salmonella enterica serovar Enteritidis phage type 8

Annals of Microbiology ◽

10.1007/s13213-014-0898-8 ◽

2014 ◽

Vol 65 (2) ◽

pp. 631-637

Author(s):

Daniel C. Shippy ◽

Nicholas M. Eakley ◽

Dareen M. Mikheil ◽

Anna De La Cotera ◽

Amin A. Fadl

Keyword(s):

Salmonella Enterica ◽

Phage Type ◽

Salmonella Enterica Serovar Enteritidis

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The high-adhesive properties of the FimH adhesin of Salmonella enterica serovar Enteritidis are determined by a single F118S substitution

Microbiology ◽

10.1099/mic.0.039206-0 ◽

2010 ◽

Vol 156 (6) ◽

pp. 1738-1748 ◽

Cited By ~ 14

Author(s):

Krzysztof Grzymajło ◽

Marta Kuźmińska-Bajor ◽

Jakub Jaworski ◽

Piotr Dobryszycki ◽

Maciej Ugorski

Keyword(s):

Salmonella Enterica ◽

Site Directed Mutagenesis ◽

Chimeric Proteins ◽

Salmonella Enterica Serovar Enteritidis ◽

Adhesive Properties ◽

Type 1 Fimbriae ◽

Rnase B ◽

Donor Strand Exchange ◽

First Time

The binding properties of low- and high-adhesive forms of FimH adhesins from Salmonella enterica serovars Enteritidis and Typhimurium (S. Enteritidis and S. Typhimurium) were studied using chimeric proteins containing an additional peptide that represents an N-terminal extension of the FimF protein. This modification, by taking advantage of a donor strand exchange mechanism, closes the hydrophobic groove in the fimbrial domain of the FimH adhesin. Such self-complemented adhesins (scFimH) did not form aggregates and were more stable (resistant to proteolytic cleavage) than native FimH. High-adhesive variants of scFimH proteins, with alanine at position 61 and serine at position 118, were obtained by site-directed mutagenesis of fimH genes from low-adhesive variants of S. Enteritidis and S. Typhimurium, with glycine at position 61 and phenylalanine at position 118. Direct kinetic analysis using surface plasmon resonance (SPR) and glycoproteins carrying high-mannose carbohydrate chains (RNase B, horseradish peroxidase and mannan-BSA) revealed the existence of high- and low-adhesive allelic variants, not only in S. Typhimurium but also in S. Enteritidis. Using two additional mutants of low-adhesive FimH protein from S. Enteritidis (Gly61Ala and Phe118Ser), SPR analysis pointed to Ser118 as the major determinant of the high-adhesive phenotype of type 1 fimbriae from S. Enteritidis. These studies demonstrated for the first time that the functional differences observed with whole fimbriated bacteria could be reproduced at the level of purified adhesin. They strongly suggest that the adhesive properties of type 1 fimbriae are determined only by structural differences in the FimH proteins and are not influenced by the fimbrial shaft on which the adhesin is located.

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Growth of Salmonella Enteritidis Phage Type 30 in Almond Hull and Shell Slurries and Survival in Drying Almond Hulls

Journal of Food Protection ◽

10.4315/0362-028x-69.4.712 ◽

2006 ◽

Vol 69 (4) ◽

pp. 712-718 ◽

Cited By ~ 51

Author(s):

AARON R. UESUGI ◽

LINDA J. HARRIS

Keyword(s):

Incubation Time ◽

Rapid Growth ◽

Salmonella Enterica ◽

Salmonella Enteritidis ◽

Phage Type ◽

Weather Conditions ◽

Water Sources ◽

Salmonella Enterica Serovar Enteritidis ◽

Outbreak Strain ◽

High Concentrations

Traceback investigation of a 2000 to 2001 outbreak of salmonellosis associated with consumption of raw almonds led to isolation of the outbreak strain Salmonella enterica serovar Enteritidis phage type (PT) 30 on three geographically linked almond farms. Interviews with these growers revealed that significant rain fell during the 2000 harvest when many almonds were drying on the ground. The objectives of this study were to document weather conditions during the 2000 harvest, determine the potential for growth of Salmonella Enteritidis PT 30 in hull or shell slurries, and evaluate survival of Salmonella Enteritidis PT 30 on wet almond hulls during drying. Dry almond hulls and in-shell kernels wetted for 24 h increased in weight by 250 to 300% and 100%, respectively. Both hull and shell slurries supported rapid growth of Salmonella Enteritidis PT 30 at 24°C; slurries containing hulls also supported growth at 15°C. Maximum Salmonella Enteritidis PT 30 concentrations of 6.2 and 7.8 log CFU/ml were observed at 15 and 24°C, respectively. Salmonella Enteritidis PT 30 grown in wet hulls that were incubated at 24°C survived drying at either 15 or 37°C. Reductions of 1 to 3 log CFU/g of dry hull were observed during drying; reductions generally declined as incubation time increased from 2 to 7 days. Evaluation of shipping records revealed that approximately 60% of outbreak-associated almonds had not been exposed to rain, eliminating this factor as the sole cause of the outbreak. However, the data provide evidence that wet almonds may be a greater risk for high concentrations of Salmonella, and specific guidelines should be established for harvesting and processing almonds that have been exposed to rain or other water sources.

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Effect of Rapid Product Desiccation or Hydration on Thermal Resistance of Salmonella enterica Serovar Enteritidis PT 30 in Wheat Flour

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-403 ◽

2015 ◽

Vol 78 (2) ◽

pp. 281-286 ◽

Cited By ~ 21

Author(s):

DANIELLE F. SMITH ◽

BRADLEY P. MARKS

Keyword(s):

Thermal Resistance ◽

Water Activity ◽

Wheat Flour ◽

Salmonella Enterica ◽

Phage Type ◽

Heat Treatments ◽

Salmonella Enterica Serovar Enteritidis ◽

Response Period ◽

C Value ◽

Resistance Data

Salmonella is able to survive in low-moisture environments and is known to be more heat resistant as product water activity (aw) decreases. However, it is unknown how rapidly the resistance changes if product aw is altered rapidly, as can occur in certain processes. Therefore, the objective was to determine the effect of rapid product desiccation or hydration on Salmonella thermal resistance. Two dynamic moisture treatments were compared with two static moisture treatments to determine the effect of time-at-moisture on the thermal resistance of Salmonella enterica serovar Enteritidis phage type 30 (PT 30) in wheat flour. After inoculation, two static moisture groups were equilibrated to 0.3 and 0.6 aw over 4 to 7 days, and two dynamic moisture groups then were rapidly (<4 min) desiccated from 0.6 to 0.3 aw or hydrated from 0.3 to 0.6 aw. Samples then were subjected to isothermal (80°C) heat treatments, and Salmonella thermal resistance was compared via decimal reduction times (i.e., D80°C-values). The D80°C-value in flour that was rapidly desiccated from 0.6 to 0.3 aw was statistically equivalent (P > 0.05) to the D80°C-value in flour previously equilibrated to 0.3 aw, but both were greater (P < 0.05) than the D80°C-value in flour previously equilibrated to 0.6 aw. Similarly, the D80°C-value in flour rapidly hydrated from 0.3 to 0.6 aw was statistically equivalent (P > 0.05) to the D80°C-value in flour previously equilibrated to 0.6 aw, and both were less than the D80°C-value in flour previously equilibrated to 0.3 aw. Therefore, Salmonella in the rapidly desiccated flour (0.3 aw) was as thermally resistant as that which previously had been equilibrated to 0.3 aw, and Salmonella in the rapidly hydrated flour (0.6 aw) responded similarly to that in the flour previously equilibrated to 0.6 aw. These results suggest that the response period to new aw is negligible, which is critically important in applying thermal resistance data or parameters to industrial pasteurization validations.

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A severe gastroenteritis outbreak of Salmonella enterica serovar Enteritidis PT8, with PFGE profile XbaI.0024 and MLVA profile 2-9-7-3-2 following a christening reception, Greece, 2016

Epidemiology and Infection ◽

10.1017/s0950268817002667 ◽

2017 ◽

Vol 146 (1) ◽

pp. 28-36 ◽

Cited By ~ 1

Author(s):

G. MANDILARA ◽

C. M. VASSALOS ◽

A. CHRISOSTOMOU ◽

K. KARADIMAS ◽

E. MATHIOUDAKI ◽

...

Keyword(s):

Salmonella Enterica ◽

Virulent Strain ◽

Phage Type ◽

Variable Number Tandem Repeat ◽

Admission Rate ◽

Variable Number ◽

Molecular Techniques ◽

Contributing Factors ◽

Salmonella Enterica Serovar Enteritidis ◽

Hospital Admission Rate

SUMMARYIn June 2016, a Salmonella enterica serovar Enteritidis outbreak (n = 56) occurred after a christening reception in Central Greece, mainly affecting previously healthy adults; one related death caused media attention. Patients suffered from profuse diarrhoea, fever and frequent vomiting episodes requiring prolonged hospitalisation and sick leave from work, with a 54% hospital admission rate. The majority of cases experienced serious illness within <12 h of attending the party. We investigated the outbreak to identify the source(s) of infection and contributing factors to the disease severity. From the retrospective cohort study, the cheesy penne pasta was the most likely vehicle of infection (relative risk 7·8; 95% confidence interval 3·6–16·8), explaining 79% of the cases. S. enterica ser. Enteritidis isolates were typed as phage-type PT8, pulsed-field gel electrophoresis type XbaI.0024, multiple locus variable-number tandem repeat analysis-type 2-9-7-3-2. The strain did not share the single-nucleotide polymorphism address of the concurrent European S. enterica ser. Enteritidis PT8 outbreak clusters. Following five consecutive years with no documented S. enterica ser. Enteritidis outbreaks in Greece, this outbreak, likely associated with a virulent strain, prompted actions towards the enhancement of the national Salmonella molecular surveillance and control programmes including the intensification of training of food handlers for preventing similar outbreaks in the future. Advanced molecular techniques were useful in distinguishing unrelated outbreak strains.

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Differences in Gene Content between Salmonella enterica Serovar Enteritidis Isolates and Comparison to Closely Related Serovars Gallinarum and Dublin

Journal of Bacteriology ◽

10.1128/jb.187.18.6545-6555.2005 ◽

2005 ◽

Vol 187 (18) ◽

pp. 6545-6555 ◽

Cited By ~ 81

Author(s):

S. Porwollik ◽

C. A. Santiviago ◽

P. Cheng ◽

L. Florea ◽

M. McClelland

Keyword(s):

Salmonella Enterica ◽

Domestic Fowl ◽

Phage Type ◽

Gene Content ◽

Comparative Genomic ◽

Old Field ◽

Salmonella Enterica Serovar Enteritidis ◽

Cross Hybridization ◽

Reference Collection ◽

Almost All

ABSTRACT Salmonella enterica serovar Enteritidis is often transmitted into the human food supply through eggs of hens that appear healthy. This pathogen became far more prevalent in poultry following eradication of the fowl pathogen S. enterica serovar Gallinarum in the mid-20th century. To investigate whether changes in serovar Enteritidis gene content contributed to this increased prevalence, and to evaluate genetic heterogeneity within the serovar, comparative genomic hybridization was performed on eight 60-year-old and nineteen 10- to 20-year-old serovar Enteritidis strains from various hosts, using a Salmonella-specific microarray. Overall, almost all the serovar Enteritidis genomes were very similar to each other. Excluding two rare strains classified as serovar Enteritidis in the Salmonella reference collection B, only eleven regions of the serovar Enteritidis phage type 4 (PT4) chromosome (sequenced at the Sanger Center) were absent or divergent in any of the other serovar Enteritidis strains tested. The more recent isolates did not have consistent differences from 60-year-old field isolates, suggesting that no large genomic additions on a whole-gene scale were needed for serovar Enteritidis to become more prevalent in domestic fowl. Cross-hybridization of phage genes on the array with related genes in the examined genomes grouped the serovar Enteritidis isolates into two major lineages. Microarray comparisons of the sequenced serovar Enteritidis PT4 to isolates of the closely related serovars Dublin and Gallinarum (biovars Gallinarum and Pullorum) revealed several genomic areas that distinguished them from serovar Enteritidis and from each other. These differences in gene content could be useful in DNA-based typing and in understanding the different phenotypes of these related serovars.

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Comparison of methods for differentiation of Salmonella enterica serovar Enteritidis phage type 4 isolates

American Journal of Veterinary Research ◽

10.2460/ajvr.2004.65.538 ◽

2004 ◽

Vol 65 (5) ◽

pp. 538-543 ◽

Cited By ~ 3

Author(s):

Vanessa C. Lopes ◽

Binu T. Velayudhan ◽

David A. Halvorson ◽

Dale C. Lauer ◽

Richard K. Gast ◽

...

Keyword(s):

Salmonella Enterica ◽

Phage Type ◽

Comparison Of Methods ◽

Salmonella Enterica Serovar Enteritidis

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Whole-Genome Sequence of Salmonella enterica Serovar Enteritidis Phage Type 4, Isolated from a Brazilian Poultry Farm

Genome Announcements ◽

10.1128/genomea.00340-16 ◽

2016 ◽

Vol 4 (3) ◽

Cited By ~ 2

Author(s):

Guilherme Paier Milanez ◽

Leandro Costa Nascimento ◽

Adriane Holtz Tirabassi ◽

Marcelo Zuanaze ◽

Dália Prazeres Rodrigues ◽

...

Keyword(s):

Salmonella Enterica ◽

Phage Type ◽

Draft Genome ◽

Whole Genome Sequence ◽

Whole Genome ◽

Poultry Farm ◽

Salmonella Enterica Serovar Enteritidis ◽

Sequencing Platform ◽

Paulo State ◽

Illumina Sequencing Platform

The draft genome of Salmonella enterica serovar Enteritidis phage type 4 (PT4) strain IOC4647/2004, isolated from a poultry farm in São Paulo state, was obtained with high-throughput Illumina sequencing platform, generating 4,173,826 paired-end reads with 251 bp. The assembly of 4,804,382 bp in 27 scaffolds shows strong similarity to other S . Enteritidis strains.

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Phylogenetic Analysis of an Unusual Increase in Salmonella enterica serovar Paratyphi A Infection among Travelers Returning from Myanmar

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx162.156 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S65-S66

Author(s):

Takashi Matono ◽

Masatomo Morita ◽

Hidemasa Izumiya ◽

Mitsuo Kaku ◽

Makoto Ohnishi

Keyword(s):

Salmonella Enterica ◽

Enteric Fever ◽

Phage Type ◽

Health Concern ◽

Nucleotide Polymorphisms ◽

Notification Rate ◽

Single Nucleotide ◽

Epidemiological Trends ◽

Unusual Increase

Abstract Background The proportion of enteric fever cases caused by Salmonella enterica subspecies enterica serovar Paratyphi A (S. Paratyphi A) has recently been increasing in Asian counties, which is a public health concern. In 2015, an unusual increase in S. Paratyphi A infection among Japanese travelers returning from Myanmar was noted, while there is little information on this uptrend in Myanmar. Methods Isolates from travelers who returned with enteric fever from 2005 to 2015 were analyzed in order to determine country-specific notification rates (epidemiological investigation). The notification rate was defined as cases returning from each country per 100,000 Japanese travelers who visited to the country. S. Paratyphi A isolates collected from 2001 to 2015 were analyzed by whole-genome sequencing (microbiological investigation). Results Yearly notification trends indicated that enteric fever was potentially endemic to Myanmar (5–16 cases/100,000 travelers); the trends were similar to those observed in India (4–21 cases/100,000 travelers). A rapid increase in S. Paratyphi A infection occurred from 2012–2014 (2–4 cases/100,000 travelers) to 2015 (13 cases/100,000 travelers). A phylogenetic tree, constructed based on analysis of 105 S. Paratyphi A isolates (33 and 30 related to Myanmar and Cambodia, and 42 controls), revealed that most Myanmar- and Cambodia-related isolates formed clusters in the same lineage (Figure 1). Additionally, Myanmar-related isolates from 2015 harbored identical phage type 1 and were genetically closely related [each isolates had 0–10 single-nucleotide polymorphisms (SNPs), mostly within 0–7 SNPs] (Figure 2), yielding a wider SNP range than outbreak-associated isolates from Cambodia in 2013 (within a SNP distance of 0–6). Conclusion Epidemiological trends and molecular subtyping suggested a possible outbreak of S. Paratyphi A infection occurred in Myanmar in 2015. The recent uptrend of S. Paratyphi Ainfection in Myanmar is important for travelers and clinicians since infection cannot be prevented by typhoid vaccination. Figure 1. Polygenetic tree of 105 S. Paratyphi A isolates Figure 2. SNP analyses of S. Paratyphi A isolates from Myanmar in 2015 (A) and Cambodia in 2013 (B). Disclosures All authors: No reported disclosures.

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