scholarly journals Salmonella enterica serovars associated with bacteremia in Canada, 2006–2019

2021 ◽  
Vol 47 (56) ◽  
pp. 259-268
Author(s):  
Sandeep Tamber ◽  
Brendan Dougherty ◽  
Kimberly Nguy
Keyword(s):  
Organ Failure ◽  
Salmonella Enterica ◽  
Surveillance Program ◽  
Bacterial Genus ◽  
Salmonella Infections ◽  
Clinical Presentations ◽  
Salmonella Serovars

Background: Members of the bacterial genus Salmonella cause salmonellosis, a disease with a spectrum of clinical presentations from a self-limiting gastroenteritis to more severe bacteremia, organ failure and sepsis. The genus consists of over 2,600 serological variants (serovars). Important differences in the pathogenesis of Salmonella serovars have been noted. Objective: The purpose of this study was to determine which Salmonella serovars were more likely to be associated with bacteremia in Canada. Methods: Information on the total number of Salmonella infections and blood isolations reported to the National Enteric Surveillance Program (NESP) from 2006 to 2019 was extracted for each serovar. The risk (proportion) and likelihood (odds) of bacteremia were calculated for all serovars. Results: Of the 96,082 Salmonella cases reported to the NESP during the 14-year study period, 4.4% (95% CI: 4.3%–4.6%) were bacteremic. Twenty nontyphoidal Salmonella (NTS) serovars were associated with lower rates of bacteremia compared to all NTS serovars, and 19 NTS serovars were identified as having higher rates. Heidelberg, Oranienburg, Schwarzengrund, Virchow, Panama and Poona among the top 25 most commonly reported serovars in Canada during the study period. Conclusion: The identification of serovars associated with Salmonella bacteremia in Canada is a first step towards understanding differences in pathogenesis and disease presentation.

scholarly journals Neonatal sepsis due to Salmonella Typhi and Paratyphi A

2009 ◽  
Vol 3 (08) ◽  
pp. 633-638 ◽  
Author(s):  
Srujana Mohanty ◽  
Rajni Gaind ◽  
Rachna Sehgal ◽  
Harish Chellani ◽  
Monorama Deb
Keyword(s):  
Differential Diagnosis ◽  
Neonatal Sepsis ◽  
Salmonella Enterica ◽  
Salmonella Typhi ◽  
Salmonella Enterica Serovar Typhi ◽  
Modes Of Transmission ◽  
Neonatal Septicaemia ◽  
Salmonella Infections ◽  
Clinical Presentations ◽  
Life Threatening

Sepsis due to Salmonella enterica serovar Typhi and Paratyphi A is rare in neonates. Though described as a mild and unrecognized illness in infants, life-threatening complications and even deaths have been reported. We present five cases of neonatal septicaemia due to S. Typhi and S. Paratyphi A. The cases were presented because of their interesting clinical presentations and possible modes of transmission. Salmonella infections should be considered in the differential diagnosis of sepsis neonatorum, especially in endemic areas.

scholarly journals Investigation of Salmonella Phage–Bacteria Infection Profiles: Network Structure Reveals a Gradient of Target-Range from Generalist to Specialist Phage Clones in Nested Subsets

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1261
Author(s):  
Khatuna Makalatia ◽  
Elene Kakabadze ◽  
Nata Bakuradze ◽  
Nino Grdzelishvili ◽  
Ben Stamp ◽  
...  
Keyword(s):  
Host Range ◽  
Salmonella Enterica ◽  
Target Range ◽  
Nested Subsets ◽  
Specific Phage ◽  
Salmonella Infections ◽  
Specialist Species ◽  
Host Infection ◽  
Salmonella Phage

Bacteriophages that lyse Salmonella enterica are potential tools to target and control Salmonella infections. Investigating the host range of Salmonella phages is a key to understand their impact on bacterial ecology, coevolution and inform their use in intervention strategies. Virus–host infection networks have been used to characterize the “predator–prey” interactions between phages and bacteria and provide insights into host range and specificity. Here, we characterize the target-range and infection profiles of 13 Salmonella phage clones against a diverse set of 141 Salmonella strains. The environmental source and taxonomy contributed to the observed infection profiles, and genetically proximal phages shared similar infection profiles. Using in vitro infection data, we analyzed the structure of the Salmonella phage–bacteria infection network. The network has a non-random nested organization and weak modularity suggesting a gradient of target-range from generalist to specialist species with nested subsets, which are also observed within and across the different phage infection profile groups. Our results have implications for our understanding of the coevolutionary mechanisms shaping the ecological interactions between Salmonella phages and their bacterial hosts and can inform strategies for targeting Salmonella enterica with specific phage preparations.

scholarly journals Molecular Analyses of Salmonellaenterica Isolates from Fish Feed Factories and Fish Feed Ingredients

2003 ◽  
Vol 69 (2) ◽  
pp. 1075-1081 ◽  
Author(s):  
Live L. Nesse ◽  
Kerstin Nordby ◽  
Even Heir ◽  
Bjarne Bergsjoe ◽  
Traute Vardund ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Salmonella Enterica ◽  
Profile Analysis ◽  
Plasmid Profile ◽  
Pulsed Field Gel Electrophoresis ◽  
Fish Feed ◽  
Molecular Analyses ◽  
Feed Ingredients ◽  
Pulsed Field ◽  
Salmonella Serovars

ABSTRACT Isolates of the most commonly observed salmonella serovars in Norwegian fish feed factories from 1998 to 2000 (Salmonella enterica serovar Agona, S. enterica serovar Montevideo, S. enterica serovar Senftenberg, and S. enterica serovar Kentucky) were studied by pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis and compared to isolates of the same serovars from fish feed ingredients, humans, and other sources (a total of 112 isolates). Within each serovar, a variety of distinct PFGE types (with similarity levels less than 90%) were observed in the feed ingredients and other sources, while only two distinct types of each serovar were identified in the factories. The combined results of PFGE and plasmid analyses showed that each factory harbored only a few S. enterica clones. Some of these clones persisted for at least 3 years in the factories, indicating that there was long-lasting contamination probably due to inadequate decontamination procedures.

scholarly journals Gamma Interferon Enhances Internalization and Early Nonoxidative Killing of Salmonella enterica Serovar Typhimurium by Human Macrophages and Modifies Cytokine Responses

2005 ◽  
Vol 73 (6) ◽  
pp. 3445-3452 ◽  
Author(s):  
Melita A. Gordon ◽  
Dominic L. Jack ◽  
David H. Dockrell ◽  
Margaret E. Lee ◽  
Robert C. Read
Keyword(s):  
Oxidative Burst ◽  
Respiratory Burst ◽  
Salmonella Enterica ◽  
Gamma Interferon ◽  
Cytokine Release ◽  
Intracellular Killing ◽  
Human Macrophages ◽  
Salmonella Infections ◽  
Serovar Typhimurium ◽  
Ifn Γ

ABSTRACT Gamma interferon (IFN-γ) is a critical cytokine in host defense against salmonella infections, but its role in phagocytic killing of intracellular Salmonella spp. has been investigated mainly in animal rather than human cells. We measured the effect of recombinant IFN-γ (rIFN-γ) priming on bacterial internalization, intracellular killing, oxidative burst, and cytokine release during phagocytosis of Salmonella enterica serovar Typhimurium by human monocyte-derived macrophages (MDM). Eleven-day-old MDM, primed for 72 h with rIFN-γ (100 ng/ml) exhibited an increased proportion of cells with associated bacteria (31% versus 26%, P = 0.036) and a 67% increase in internalized bacteria per cell compared to unprimed cells (P = 0.025). Retrieval of viable bacteria following internalization was reduced 3.6-fold in 72-h primed versus unprimed MDM (interquartile range, 3.1 to 6.4) at 0.5 h due to enhanced early intracellular killing, and this difference was maintained up to 24 h. In contrast, cells primed for only 24 h exhibited no increase in early killing. MDM were competent to produce an early oxidative burst when stimulated with phorbol myristate acetate, which was fully abrogated by the respiratory burst inhibitor diphenyleneiodonium chloride (DPI), but infection of MDM with S. enterica serovar Typhimurium did not cause an increase in the early respiratory burst under unprimed or primed conditions, and DPI had no effect on the early killing of bacteria by primed or unprimed MDM. During 24 h following infection, rIFN-γ-primed MDM released more interleukin-12 (IL-12) and less IL-10 relative to unprimed cells. We conclude that 72-h priming with rIFN-γ increases the efficiency of internalization and nonoxidative early intracellular killing of S. enterica serovar Typhimurium by human macrophages and modifies subsequent cytokine release.

Identification of Salmonella enterica Serovar Typhimurium Using Specific PCR Primers Obtained by Comparative Genomics in Salmonella Serovars

2006 ◽  
Vol 69 (7) ◽  
pp. 1653-1661 ◽  
Author(s):  
H. J. KIM ◽  
S. H. PARK ◽  
T. H. LEE ◽  
B. H. NAHM ◽  
Y. H. CHUNG ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Salmonella Enterica ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Foodborne Pathogen ◽  
Pcr Primers ◽  
Genomic Sequences ◽  
Local Alignment ◽  
Serovar Typhimurium ◽  
Salmonella Serovars

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.

Backyard Farms Represent a Source of Wide Host Range Salmonella Phages That Lysed the Most Common Salmonella Serovars

2018 ◽  
Vol 81 (2) ◽  
pp. 272-278 ◽  
Author(s):  
DÁCIL RIVERA ◽  
VIVIANA TOLEDO ◽  
FRANCISCA DI PILLO ◽  
FERNANDO DUEÑAS ◽  
RODOLFO TARDONE ◽  
...  
Keyword(s):  
Host Range ◽  
Salmonella Enteritidis ◽  
Genetic Relatedness ◽  
Production Systems ◽  
Lytic Cycle ◽  
Salmonella Infections ◽  
Wide Host Range ◽  
Wide Range ◽  
Salmonella Serovars ◽  
Phage Isolation

ABSTRACT The genus Salmonella has more than 2,600 serovars, and this trait is important when considering interventions for Salmonella control. Bacteriophages that are used for biocontrol must have an exclusively lytic cycle and the ability to lyse several Salmonella serovars under a wide range of environmental conditions. Salmonella phages were isolated and characterized from 34 backyard production systems (BPSs) with a history of Salmonella infections. BPSs were visited once, and cloacal or fecal samples were processed for phage isolation. Four hosts, Salmonella serovars Enteritidis, Heidelberg, Infantis, and Typhimurium, were used for phage isolation. The host range of the phages was later characterized with a panel of 23 Salmonella serovars (serovar diversity set) and 31 isolates obtained from the same farms (native set). Genetic relatedness for 10 phages with a wide host range was characterized by restriction fragment length polymorphism, and phages clustered based on the host range. We purified 63 phages, and 36 phage isolates were obtained on Salmonella Enteritidis, 16 on Salmonella Heidelberg, and 11 on Salmonella Infantis. Phages were classified in three clusters: (i) phages with a wide host range (cluster I), (ii) phages that lysed the most susceptible Salmonella serovars (serogroup D) and other isolates (cluster II), and (iii) phages that lysed only isolates of serogroup D (cluster III). The most susceptible Salmonella serovars were Enteritidis, Javiana, and Dublin. Seven of 34 farms yielded phages with a wide host range, and these phages had low levels of genetic relatedness. Our study showed an adaptation of the phages in the sampled BPSs to serogroup D Salmonella isolates and indicated that isolation of Salmonella phages with wide host range differs by farm. A better understanding of the factors driving the Salmonella phage host range could be useful when designing risk-based sampling strategies to obtain phages with a wide lytic host range for biocontrol purposes.

scholarly journals Salmonella Serovars in the Herpetofauna of Indiana County, Pennsylvania

2006 ◽  
Vol 72 (5) ◽  
pp. 3771-3773 ◽  
Author(s):  
David L. Chambers ◽  
Arthur C. Hulse
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Serovars ◽  
Indiana County

ABSTRACT Herpetofaunal Salmonella enterica serovars have not been fully examined in any U.S. region. Thirty-three Salmonella serovars were isolated from 156 samples from 34 species, all within Indiana County, Pennsylvania. Results suggest that herpetofaunas could potentially pose a threat to humans. Further understanding of Salmonella in herpetofaunas may prevent future human cases.

Salmonella Sofia Differs from Other Poultry-Associated Salmonella Serovars with Respect to Cell Surface Hydrophobicity

2008 ◽  
Vol 71 (12) ◽  
pp. 2421-2428 ◽  
Author(s):  
T. W. R. CHIA ◽  
N. FEGAN ◽  
T. A. McMEEKIN ◽  
G. A. DYKES
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Physicochemical Properties ◽  
Surface Charge ◽  
Hydrophobic Interaction ◽  
Salmonella Enterica ◽  
Food System ◽  
Cell Surface Hydrophobicity ◽  
Bacterial Attachment ◽  
Salmonella Serovars

Salmonella enterica is one of the most important foodborne pathogens. Salmonella enterica subsp. II 4,12:b:– (Salmonella Sofia) is commonly found in Australian poultry. It has been suggested that physicochemical properties such as surface charge and hydrophobicity may affect bacterial attachment to surfaces and their ability to persist in food systems. A possible link between hydrophobicity cell surface charge and persistence of Salmonella from the poultry system was examined. Hydrophobicity of Salmonella Sofia (n = 14), Salmonella Typhimurium (n = 6), Salmonella Infantis (n = 3), and Salmonella Virchow (n = 2) was assayed using hydrophobic interaction chromatography, bacterial adherence to hydrocarbons (BATH), using xylene or hexadecane, and the contact angle method (CAM). Cellular surface charge (CSC) of the isolates was determined using zeta potential measurements. The majority (12 of 14) of Salmonella Sofia isolates were found to be hydrophobic when assayed using BATH with xylene, except isolates S1635 and S1636, and the other serovars were found to be hydrophilic. Salmonella Sofia isolates were not significantly different (P > 0.05) from isolates of other serovars as measured by hydrophobic interaction, BATH with hexadecane, or the CAM. No significant differences (P > 0.05) in zeta potential measurements were observed between isolates. Principal component analysis using results from all four measures of hydrophobicity allowed clear differentiation between isolates of the serovar Salmonella Sofia (except S1635 and S1636) and those of other Salmonella serovars. Differences in physicochemical properties may be a contributing factor to the Salmonella Sofia serovar's ability to attach to surfaces and persist in a food system.

scholarly journals An Attenuated Salmonella enterica Serovar Typhimurium Strain and Galacto-Oligosaccharides Accelerate Clearance of Salmonella Infections in Poultry through Modifications to the Gut Microbiome

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
M. Andrea Azcarate-Peril ◽  
Natasha Butz ◽  
Maria Belen Cadenas ◽  
Matthew Koci ◽  
Anne Ballou ◽  
...  
Keyword(s):  
United States ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Salmonella Enterica ◽  
The United States ◽  
Wild Type ◽  
Content Type ◽  
Salmonella Infections ◽  
Serovar Typhimurium ◽  
The Impact

ABSTRACT Salmonella is estimated to cause one million foodborne illnesses in the United States every year. Salmonella -contaminated poultry products are one of the major sources of salmonellosis. Given the critical role of the gut microbiota in Salmonella transmission, a manipulation of the chicken intestinal microenvironment could prevent animal colonization by the pathogen. In Salmonella , the global regulator gene fnr ( f umarate n itrate r eduction) regulates anaerobic metabolism and is essential for adapting to the gut environment. This study tested the hypothesis that an attenuated Fnr mutant of Salmonella enterica serovar Typhimurium (attST) or prebiotic galacto-oligosaccharides (GOS) could improve resistance to wild-type Salmonella via modifications to the structure of the chicken gut microbiome. Intestinal samples from a total of 273 animals were collected weekly for 9 weeks to evaluate the impact of attST or prebiotic supplementation on microbial species of the cecum, duodenum, jejunum, and ileum. We next analyzed changes to the gut microbiome induced by challenging the animals with a wild-type Salmonella serovar 4,[5],12:r:− (Nal r ) strain and determined the clearance rate of the virulent strain in the treated and control groups. Both GOS and the attenuated Salmonella strain modified the gut microbiome but elicited alterations of different taxonomic groups. The attST produced significant increases of Alistipes and undefined Lactobacillus , while GOS increased Christensenellaceae and Lactobacillus reuteri . The microbiome structural changes induced by both treatments resulted in a faster clearance after a Salmonella challenge. IMPORTANCE With an average annual incidence of 13.1 cases/100,000 individuals, salmonellosis has been deemed a nationally notifiable condition in the United States by the Centers for Disease Control and Prevention (CDC). Earlier studies demonstrated that Salmonella is transmitted by a subset of animals (supershedders). The supershedder phenotype can be induced by antibiotics, ascertaining an essential role for the gut microbiota in Salmonella transmission. Consequently, modulation of the gut microbiota and modification of the intestinal microenvironment could assist in preventing animal colonization by the pathogen. Our study demonstrated that a manipulation of the chicken gut microbiota by the administration of an attenuated Salmonella strain or prebiotic galacto-oligosaccharides (GOS) can promote resistance to Salmonella colonization via increases of beneficial microorganisms that translate into a less hospitable gut microenvironment.

scholarly journals Prevalence and Antimicrobial Resistance of Campylobacter spp. and Salmonella Serovars in Organic Chickens from Maryland Retail Stores

2005 ◽  
Vol 71 (7) ◽  
pp. 4108-4111 ◽  
Author(s):  
Shenghui Cui ◽  
Beilei Ge ◽  
Jie Zheng ◽  
Jianghong Meng
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Retail Stores ◽  
Serovar Typhimurium ◽  
Salmonella Serovars ◽  
Campylobacter Spp

ABSTRACT Retail organic (n = 198) and conventional (n = 61) chickens were analyzed. Most organic (76%) and conventional (74%) chickens were contaminated with campylobacters. Salmonellae were recovered from 61% of organic and 44% of conventional chickens. All Salmonella enterica serovar Typhimurium isolates from conventional chickens were resistant to five or more antimicrobials, whereas most S. enterica serovar Typhimurium isolates (79%) from organic chickens were susceptible to 17 antimicrobials tested.

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