Salmonella spp. survival strategies within the host gastrointestinal tract

Álvarez‐Ordóñez, Avelino; Begley, Máire; Prieto, Miguel; Messens, Winy; López, Mercedes; Bernardo, Ana; Hill, Colin

doi:10.1099/mic.0.050351-0

Cited by 98 publications

(72 citation statements)

References 127 publications

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“…The ability of Salmonella to survive in bile is a longstanding observation and is utilized in selective media such as MacConkey agar, which contains bile salts, to promote the isolation of Salmonella and other Gram-negative bacteria (116,117). Salmonella serovars have several approaches for survival in the presence of bile salts, which include defense against membrane destruction and DNA damage facilitated by the detergent activity of bile compounds (3).…”

Section: Salmonella Bile Resistance Mechanismsmentioning

confidence: 99%

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

et al. 2016

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SUMMARYBacterial pathogens have coevolved with humans in order to efficiently infect, replicate within, and be transmitted to new hosts to ensure survival and a continual infection cycle. For enteric pathogens, the ability to adapt to numerous host factors under the harsh conditions of the gastrointestinal tract is critical for establishing infection. One such host factor readily encountered by enteric bacteria is bile, an innately antimicrobial detergent-like compound essential for digestion and nutrient absorption. Not only have enteric pathogens evolved to resist the bactericidal conditions of bile, but these bacteria also utilize bile as a signal to enhance virulence regulation for efficient infection. This review provides a comprehensive and up-to-date analysis of bile-related research with enteric pathogens. From common responses to the unique expression of specific virulence factors, each pathogen has overcome significant challenges to establish infection in the gastrointestinal tract. Utilization of bile as a signal to modulate virulence factor expression has led to important insights for our understanding of virulence mechanisms for many pathogens. Further research on enteric pathogens exposed to thisin vivosignal will benefit therapeutic and vaccine development and ultimately enhance our success at combating such elite pathogens.

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Section: Salmonella Bile Resistance Mechanismsmentioning

confidence: 99%

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

et al. 2016

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“…Likewise, in our study, loss of galU and therefore the complete O-antigen (26) abolished Shigella growth capability in the presence of bile salts. Analysis in Salmonella has demonstrated that both remodeling of lipid A and elongation of the O-chains of LPS are important for bile resistance (40)(41)(42). LPS length has also been demonstrated to be important for Shigella virulence.…”

Section: Figmentioning

confidence: 99%

Analysis of Shigella flexneri Resistance, Biofilm Formation, and Transcriptional Profile in Response to Bile Salts

et al. 2017

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The Shigella species cause millions of cases of watery or bloody diarrhea each year, mostly in children in developing countries. While many aspects of Shigella colonic cell invasion are known, crucial gaps in knowledge regarding how the bacteria survive, transit, and regulate gene expression prior to infection remain. In this study, we define mechanisms of resistance to bile salts and build on previous research highlighting induced virulence in Shigella flexneri strain 2457T following exposure to bile salts. Typical growth patterns were observed within the physiological range of bile salts; however, growth was inhibited at higher concentrations. Interestingly, extended periods of exposure to bile salts led to biofilm formation, a conserved phenotype that we observed among members of the Enterobacteriaceae. Characterization of S. flexneri 2457T biofilms determined that both bile salts and glucose were required for formation, dispersion was dependent upon bile salts depletion, and recovered bacteria displayed induced adherence to HT-29 cells. RNAsequencing analysis verified an important bile salt transcriptional profile in S. flexneri 2457T, including induced drug resistance and virulence gene expression. Finally, functional mutagenesis identified the importance of the AcrAB efflux pump and lipopolysaccharide O-antigen synthesis for bile salt resistance. Our data demonstrate that S. flexneri 2457T employs multiple mechanisms to survive exposure to bile salts, which may have important implications for multidrug resistance. Furthermore, our work confirms that bile salts are important physiological signals to activate S. flexneri 2457T virulence. This work provides insights into how exposure to bile likely regulates Shigella survival and virulence during host transit and subsequent colonic infection.

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“…Virülan Salmonella suşları, fagozom veya fagolizozomlardaki olumsuz koşullara karşı varlıklarını "alternatif sigma faktörü" ve "adaptif aside tolerans yanıtı" ile sürdürmektedirler. Bu nedenle bu iki özellik bakterinin önem-li virülans faktörlerindendir 6,8,18,27 .…”

Section: Vi̇rülans Genleri̇ni̇n Regülasyonuunclassified

Salmonella Pathogenicity Islands

Sırıken¹

2013

Mikrobiyol Bul

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ÖZETSalmonella türleri fakültatif hücre içi yerleşim gösteren patojen bakterilerdir. Makrofajlara, dendritik ve epitelyal hücrelere invazyon yapabilmekte ve bütün Salmonella türleri patojen olarak kabul edilmektedir. İnvazyondan, hücre içinde canlılığını sürdürebilmesinden ve ekstraintestinal yayılımdan sorumlu olan virülans faktörlerini kodlayan genler Salmonella patojenite adaları (SPA) içinde yer alır. SPA'nın horizontal gen transferi ile kazanılmış olduğu düşünülmektedir. Bazı patojenite adaları Salmonella cinsi içinde korunmuş olarak bulunurken, bazıları belirli serotipler için özgüldür. SPA'nın varlığı ve özelliklerine göre Salmonella serotipleri arasında konak hücreye adaptasyon, virülans faktörleri ve oluşturdukları enfeksiyonların şiddeti açısından farklılıklar bulunmaktadır. Salmonella virülans gen kümeleri 12 patojenite adası içinde yerleşim göstermektedir. Enfeksiyonun intestinal fazını kapsayan virülans genleri SPA-1 ve SPA-2'de yer almakta; hücre içinde sağkalım, fimbriyal ekpresyon, çoklu antibiyotik direnci, magnezyum ve demir alı-mı ve sistemik enfeksiyon oluşumu için gerekli olan virülans faktörlerini kodlayan genler diğer SPA içinde bulunmaktadır. SPA dışında, alternatif sigma faktör σ s (RpoS) regülatörü ile adaptif aside tolerans yanıtı (ATY) da Salmonella serotiplerinin diğer önemli virülans faktörleridir. Salmonella türlerinin virülan suşların-da bulunan RpoS ile ATY, enfeksiyonun intestinal fazı sırasında, mide asiditesi, safra tuzu, yetersiz oksijen, besin yetersizliği, antimikrobiyal peptidler, mukus ve doğal mikrobiyotanın varlığı gibi olumsuz çevresel koşullar altında canlılığını sürdürebilmesini ve aynı zamanda etkenin fagozom veya fagolizom gibi olumsuz koşullarda varlıklarını sürdürmesini sağlamaktadır. Bu derleme yazıda, Salmonella serotiplerinin virü-lans faktörlerini belirleyen önemli patojenite adaları ve virülans genlerinin regülasyonunda etkili bazı faktörler ile ilgili bilgiler özetlenmiştir.Anahtar sözcükler: Salmonella; patojenite adası; sigma faktörü; adaptif aside tolerans yanıtı.

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Salmonella spp. survival strategies within the host gastrointestinal tract

Cited by 98 publications

References 127 publications

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

Analysis of Shigella flexneri Resistance, Biofilm Formation, and Transcriptional Profile in Response to Bile Salts

Salmonella Pathogenicity Islands

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