Revisiting Persistent Salmonella Infection and the Carrier State: What Do We Know?

Foster, Neil; Tang, Ying; Berchieri, Ângelo; Geng, Shizhong; Jiao, Xinan; Barrow, Paul

doi:10.3390/pathogens10101299

Cited by 38 publications

(25 citation statements)

References 187 publications

(242 reference statements)

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“…Pursuant to German federal law, antibiotic treatment of livestock is restricted and closely monitored to curb antimicrobial resistance [ 52 , 53 ]. The treatment options list a serovar-specific Salmonella vaccine for the entire cattle herd as well as the elimination of carrier animals [ 54 , 55 ]. In comparison with the situation in North America, the repeatedly published low multidrug resistance and virulence of S. Dublin in Germany evidences a lower risk and better treatment situation for human patients with S. Dublin infection.…”

Section: Discussionmentioning

confidence: 99%

Whole-Genome Investigation of Salmonella Dublin Considering Mountain Pastures as Reservoirs in Southern Bavaria, Germany

Klose¹,

Scuda²,

Ziegler³

et al. 2022

Microorganisms

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Worldwide, Salmonella Dublin (S. Dublin) is responsible for clinical disease in cattle and also in humans. In Southern Bavaria, Germany, the serovar was identified as a causative agent for 54 animal disease outbreaks in herds between 2017 and 2021. Most of these emerged from cattle herds (n = 50). Two occurred in pig farms and two in bovine herds other than cattle. Genomic analysis of 88 S. Dublin strains isolated during these animal disease outbreaks revealed 7 clusters with 3 different MLST-based sequence types and 16 subordinate cgMLST-based complex types. Antimicrobial susceptibility investigation revealed one resistant and three intermediate strains. Furthermore, only a few genes coding for bacterial virulence were found among the isolates. Genome analysis enables pathogen identification and antimicrobial susceptibility, serotyping, phylogeny, and follow-up traceback analysis. Mountain pastures turned out to be the most likely locations for transmission between cattle of different herd origins, as indicated by epidemiological data and genomic traceback analyses. In this context, S. Dublin shedding was also detected in asymptomatic herding dogs. Due to the high prevalence of S. Dublin in Upper Bavaria over the years, we suggest referring to this administrative region as “endemic”. Consequently, cattle should be screened for salmonellosis before and after mountain pasturing.

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Section: Discussionmentioning

confidence: 99%

Whole-Genome Investigation of Salmonella Dublin Considering Mountain Pastures as Reservoirs in Southern Bavaria, Germany

Klose¹,

Scuda²,

Ziegler³

et al. 2022

Microorganisms

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“…The persistent bacteria within the organs could result in increased or prolonged immune stimulation within the host (Gilbreath et al, 2012 ; Tang et al, 2018 ; Liu et al, 2020 ). Given these findings, the gene mutant strains have been considered potential live-attenuated vaccine candidates (Huang et al, 2016 ; Foster et al, 2021 ). Maintaining a delicate balance between attenuated virulence and optimal immunogenicity is a major consideration for the future development of live-attenuated vaccine strains (Gilbreath et al, 2012 ).…”

Section: Discussionmentioning

confidence: 99%

wecB Gene of Salmonella Gallinarum Plays a Critical Role in Systemic Infection of Fowl Typhoid

et al. 2022

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Salmonella enterica serovar Gallinarum (S. Gallinarum) is a host-specific pathogen causing fowl typhoid, a severe systemic infection in poultry, which leads to substantial economic losses due to high morbidity and mortality in many developing countries. However, less is known about the pathogenic characteristics and mechanism of S. Gallinarum-induced systemic infection in chickens. In this study, we deleted the S. Gallinarum UDP-N-acetylglucosamine-1-phosphate transferase gene, which contributes to the biosynthesis of enterobacterial common antigen (ECA), and studied the pathogenicity of this wecB::Cm strain in a chicken model of systemic infection. The wecB::Cm mutant strain showed comparable growth but lower resistance to bile acid and nalidixic acid than the wild-type strain in vitro. In the oral infection model of chickens, the virulence of the wecB::Cm strain was significantly attenuated in vivo. Chickens infected with wild-type strain showed typical clinical signs and pathological changes of fowl typhoid and died between 6 and 9 days post-infection, and the bacteria rapidly disseminated to systemic organs and increased in the livers and spleens. In contrast, the wecB::Cm mutant strain did not cause chicken death, there were no significant clinical changes, and the bacterial numbers in the liver and spleen of the chickens were significantly lower than those of the chickens infected with the wild-type strain. In addition, the expression of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and CXCLi1 in the livers of wecB::Cm-infected chickens was significantly lower than that of the chickens infected with the wild-type strain. Furthermore, the attenuated wecB::Cm strain could persistently colonize the liver and spleen at low levels for up to 25 days post-infection and could induce a protective immune response in the chickens. These results indicate that the wecB gene is an important virulence factor of S. Gallinarum in the chicken model of systemic infection, and the avirulent wecB::Cm mutant could possibly be used as a live-attenuated vaccine strain for controlling fowl typhoid.

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“…The positive control exhibited increased IL-6, IL-10, and IL-4 (Table 2) because S.P. caused in ammation, and the immune system tried to modulate the in ammation caused by S.P., similar to what occurs in the newborn animal [41,42]. None of the strains studied increased IL-6, strain A increased IL-10, and the IL-4 level was similar to that in P.C.…”

Section: Discussionmentioning

confidence: 90%

Selection of Bacillus subtilis for animal and chicken embryo supplementation

Reis

Hoepers

Carvalho

et al. 2022

Preprint

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Bacillus subtilis (B.S.) has been used as an excellent probiotic; however, some B.S. strains seem to be opportunist pathogens or do not present inhibitory effects in the pathogenic bacterium, so the characterization of B.S. strains for use in animals is mandatory. This study aimed to select nonpathogenic strains of B.S., which have beneficial effects on birds and can inhibit Salmonella spp., avian pathogenic Escherichia coli coli (APEC) and Campylobacter jejuni (C.J.). We tested nine (9) strains of B.S. isolated from several sources (named A to I) in in vitro by tests of mucin degradation activity, haemolytic activity, apoptosis, and necrosis in fibroblasts from chickens. After the in vitro test, we tested the remaining seven (7) strains (strains A to G) in a chicken embryo (C.E.) as an in vivo model and target animal. We inoculated 3 log CFU/CE of each strain via allantoic fluid at the 10th day postincubation (DPI). Each treatment group consisted of eight C.Es. At the 17th DPI. We checked C.E. mortality, gross lesions, C.E. weight, and whether B.S. strains were still viable. To perform the cytokine, total protein, albumin, and reactive C protein analysis, we collected the C.E. blood from the allantoic vessel and intestine fragments in the duodenum portion for histomorphometric analysis. After the results in C.Es., we tested the inhibition capacity of the selected B.S. strains for diverse strains of Salmonella Heidelberg (S.H.), S. Typhimurium (S.T.), S. Enteritidis (S.E.), S. Minnesota (S.M.), S. Infantis (S.I.), Salmonella var. monophasic (S.V.M) and C. jejuni. After the in vitro trial (mucin degradation activity, haemolytic activity, apoptosis, and necrosis), we removed two (2) strains (H and I) that showed β-haemolysis, mucin degradation, and/or high apoptosis and necrosis effects. Although all strains of B.S. were viable in C.Es. at the 17th DPI, we removed four (4) strains (A, B, D, F) once they led to the highest mortality in C.Es. or a high albumin/protein ratio. C. jejuni inoculated with strain G had greater weight than the commercial strain, which could be further used for egg inoculation with benefits to the C.E. Moreover, the cytokine analysis indicated that strains E and G have immunomodulatory effects on C.Es. From the tests in C.Es., we selected the strains C, E, and G for their ability to inhibit pathogenic strains of relevant foodborne pathogens. We found that the inhibition effect was strain dependent. In general, strains E and/or G presented better or similar results than commercial control strains in the inhibition of S.H., S.T., S.I., APEC and two (2) strains of C.J. In this study, we selected B.S. strains C, E and G due to their in vitro and in vivo safety and beneficial effects. In addition, we emphasize the value of C.E. as an in vivo experimental model for assessing B.S.'s safety and possible benefits for poultry and other animals.

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Revisiting Persistent Salmonella Infection and the Carrier State: What Do We Know?

Cited by 38 publications

References 187 publications

Whole-Genome Investigation of Salmonella Dublin Considering Mountain Pastures as Reservoirs in Southern Bavaria, Germany

Whole-Genome Investigation of Salmonella Dublin Considering Mountain Pastures as Reservoirs in Southern Bavaria, Germany

wecB Gene of Salmonella Gallinarum Plays a Critical Role in Systemic Infection of Fowl Typhoid

Selection of Bacillus subtilis for animal and chicken embryo supplementation

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