1
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Chen W, Xu Z, Li C, Wang C, Wang M, Liang J, Wei P. Investigation of biofilm formation and the associated genes in multidrug-resistant Salmonella pullorum in China (2018-2022). Front Vet Sci 2023; 10:1248584. [PMID: 37720478 PMCID: PMC10500350 DOI: 10.3389/fvets.2023.1248584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/10/2023] [Indexed: 09/19/2023] Open
Abstract
The study explored the biofilm (BF) formation capacity, BF-related gene profiles, and the trends in antimicrobial resistance (AMR) of Salmonella pullorum (SP) strains over several years. A total of 627 SP strains were isolated from 4,540 samples collected from chicken farms in Guangxi, China during 2018-2022. The BF-forming capacity of these isolates was assessed using crystal violet staining, and the presence of eight BF-related genes (csgA, csgB, csgD, ompR, bapA, pfs, luxS, and rpoS) in BF formation-positive strains was determined through Polymerase Chain Reaction (PCR) analysis. Antimicrobial susceptibility test was conducted to investigate the AMR of the isolates. Minimum Inhibitory Concentration (MIC) and Minimal Biofilm Eradication Concentration (MBEC) of nine SP-BF strains were determined using the broth microdilution method to assess the impact of BF formation on AMR. Additionally, the Optimal Biofilm Formation Conditions (OBFC) were investigated. The results indicated that 36.8% (231/627) of the strains exhibited a positive BF-formation capacity. Among these, 24.7% (57/231) were strong BF producers, 23.4% (54/231) were moderate BF producers, and 51.9% (120/231) were weak BF producers. Analysis of the eight BF-related genes in SP-BF strains revealed that over 90% of them were positive for all the genes. Antimicrobial susceptibility test conducted on the isolates showed that 100% (231/231) of them exhibited resistance to at least one antibiotic, with 98.3% (227/231) demonstrating multidrug resistance (MDR). Both MIC and MBEC measurements indicated varying degrees of increased AMR after BF formation of the bacteria. The optimal conditions for BF formation were observed at 37°C after 48 h of incubation, with an initial bacterial concentration of 1.2 × 106 CFU/mL. Notably, NaCl had a significant inhibitory effect on BF formation, while glucose and Trypticase Soy Broth (TSB) positively influenced BF formation. The results of the study emphasized the need for effective preventive and control strategies to address the challenges posed by the BF formation and MDR of SP in the field.
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Affiliation(s)
- Wenyan Chen
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Ziheng Xu
- School of Public Health and Management, Guangxi University of Chinese Medicine, Nanning, China
| | - Changcheng Li
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Can Wang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Min Wang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Jingzhen Liang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Ping Wei
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
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2
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Gebremichael Y, Crandall J, Mukhopadhyay R, Xu F. Salmonella Subpopulations Identified from Human Specimens Express Heterogenous Phenotypes That Are Relevant to Clinical Diagnosis. Microbiol Spectr 2023; 11:e0167922. [PMID: 36507668 PMCID: PMC9927314 DOI: 10.1128/spectrum.01679-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 11/08/2022] [Indexed: 12/15/2022] Open
Abstract
Clonal bacterial cells can give rise to functionally heterogeneous subpopulations. This diversification is considered an adaptation strategy that has been demonstrated for several bacterial species, including Salmonella enterica serovar Typhimurium. In previous studies on mouse models infected orally with pure Salmonella cultures, derived bacterial cells collected from animal tissues were found to express heterogenous phenotypes. Here, we show mixed Salmonella populations, apparently derived from the same progenitor, present in human specimens collected at a single disease time point, and in a long-term-infected patient, these Salmonella were no longer expressing surface-exposed antigen epitopes by isolates collected at earlier days of the disease. The subpopulations express different phenotypes related to cell surface antigen expression, motility, biofilm formation, biochemical metabolism, and antibiotic resistance, which can all contribute to pathogenicity. Some of the phenotypes correlate with single nucleotide polymorphisms or other sequence changes in bacterial genomes. These genetic variations can alter synthesis of cell membrane-associated molecules such as lipopolysaccharides and lipoproteins, leading to changes in bacterial surface structure and function. This study demonstrates the limitation of Salmonella diagnostic methods that are based on a single-cell population which may not represent the heterogenous bacterial community in infected humans. IMPORTANCE In animal model systems, heterogenous Salmonella phenotypes were found previously to regulate bacterial infections. We describe in this communication that different Salmonella phenotypes also exist in infected humans at a single disease time point and that their phenotypic and molecular traits are associated with different aspects of pathogenicity. Notably, variation in genes encoding antibiotic resistance and two-component systems were observed from the subpopulations of a patient suffering from persistent salmonellosis. Therefore, clinical and public health interventions of the disease that are based on diagnosis of a single-cell population may miss other subpopulations that can cause residual human infections.
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Affiliation(s)
- Yismashoa Gebremichael
- Microbial Diseases Laboratory, California Department of Public Health, Richmond, California, USA
| | - John Crandall
- Microbial Diseases Laboratory, California Department of Public Health, Richmond, California, USA
| | - Rituparna Mukhopadhyay
- Microbial Diseases Laboratory, California Department of Public Health, Richmond, California, USA
| | - Fengfeng Xu
- Microbial Diseases Laboratory, California Department of Public Health, Richmond, California, USA
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3
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Deblais L, Ranjit S, Vrisman C, Antony L, Scaria J, Miller SA, Rajashekara G. Role of Stress-Induced Proteins RpoS and YicC in the Persistence of Salmonella enterica subsp. enterica Serotype Typhimurium in Tomato Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:109-118. [PMID: 36394339 DOI: 10.1094/mpmi-07-22-0152-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Understanding the functional role of bacterial genes in the persistence of Salmonella in plant organs can facilitate the development of agricultural practices to mitigate food safety risks associated with the consumption of fresh produce contaminated with Salmonella spp. Our study showed that Salmonella enterica subsp. enterica serotype Typhimurium (strain MDD14) persisted less in inoculated tomato plants than other Salmonella Typhimurium strains tested (JSG210, JSG626, JSG634, JSG637, JSG3444, and EV030415; P < 0.01). In-vitro assays performed in limited-nutrient conditions (growth rate, biofilm production, and motility) were inconclusive in explaining the in-planta phenotype observed with MDD14. Whole-genome sequencing combined with non-synonymous single nucleotide variations analysis was performed to identify genomic differences between MDD14 and the other Salmonella Typhimurium strains. The genome of MDD14 contained a truncated version (123 bp N-terminal) of yicC and a mutated version of rpoS (two non-synonymous substitutions, i.e., G66E and R82C), which are two stress-induced proteins involved in iron acquisition, environmental sensing, and cell envelope integrity. The rpoS and yicC genes were deleted in Salmonella Typhimurium JSG210 with the Lambda Red recombining system. Both mutants had limited persistence in tomato plant organs, similar to that of MDD14. In conclusion, we demonstrated that YicC and RpoS are involved in the persistence of Salmonella in tomato plants in greenhouse conditions and, thus, could represent potential targets to mitigate persistence of Salmonella spp. in planta. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Loïc Deblais
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
| | - Sochina Ranjit
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
| | - Claudio Vrisman
- Department of Plant Pathology, The Ohio State University, Wooster, OH, U.S.A
| | - Linto Antony
- Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD, U.S.A
| | - Joy Scaria
- Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD, U.S.A
| | - Sally A Miller
- Department of Plant Pathology, The Ohio State University, Wooster, OH, U.S.A
| | - Gireesh Rajashekara
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
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4
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Transcriptome sequencing reveals the difference in the expression of biofilm and planktonic cells between two strains of Salmonella Typhimurium. Biofilm 2022; 4:100086. [PMID: 36254114 PMCID: PMC9568869 DOI: 10.1016/j.bioflm.2022.100086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 11/22/2022] Open
Abstract
Salmonela enterica serovar Typhimurium (S. Typhimurium) is a food-borne pathogen that can form biofilms to increase its resistance to the external environment. Through the detection of biofilm of several S. Typhimurium strains in this study, strain CDC3 with strong biofilm forming capacity and strain CVCC3384 with weak biofilm forming capacity were identified. The genes expressed in planktonic and biofilm cells of two S. Typhimurium strains were analysed by transcriptome sequencing. Results showed that the genes related to the signal transduction pathway were upregulated and genes related to motility were downregulated in strain CDC3. By comparing biofilms and planktonic cells of the two strains, we found that CDC3 regulates biofilm formation mainly through the two-component system kdpABC, while strain CVCC3384 does so mainly through motility and quorum sensing. This study revealed regulation mechanism of biofilms formation between different biofilm forming capacity strains, and provided a theoretical basis for subsequent research.
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5
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Genome-wide analysis of fitness factors in uropathogenic Escherichia coli in a pig urinary tract infection model. Microbiol Res 2022; 265:127202. [PMID: 36167007 DOI: 10.1016/j.micres.2022.127202] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/24/2022] [Accepted: 09/13/2022] [Indexed: 11/20/2022]
Abstract
Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infections (UTIs) in animals and humans. We applied Transposon-Directed Insertion Site sequencing (TraDIS) to determine the fitness genes in two well-characterized UPEC strains, UTI89 and CFT073, in order to identify fitness factors during UTI in a pig model. This novel animal model better reflects the course of UTI in humans than the commonly used mouse model, and facilitates the differentiation between sessile and planktonic UPEC populations. A total of 854 and 483 genes in UTI89 and CFT073, respectively, were predicted to contribute to growth in pig urine, and 1257 and 764, were scored as required for colonization of the bladder. The combined list of fitness genes for growth in urine and cystitis contained 741 (UTI89) and 439 (CFT073) genes. The essential genes for growth on LB agar media supplemented with kanamycin and the fitness factors during growth in human urine were also analyzed in CFT073. A total of 457 essential genes were identified and the pool of fitness genes for growth in human urine included 215 genes. The gene rfaG, which is involved in lipopolysaccharide biosynthesis, was included in all the fitness-gene-lists and was further confirmed to be relevant for all the conditions tested regardless of the host and the strain. Thus, this gene may represent a promising target for the development of new therapeutic strategies against UTI UPEC-associated. Besides this important observation, the study revealed strain-specific differences in gene-essentiality as well as in the fitness-gene-repertoire for growth in human urine and UTI of the pig model, and it identified novel factors required for UPEC-induced UTIs.
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6
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Medina-Aparicio L, Rodriguez-Gutierrez S, Rebollar-Flores JE, Martínez-Batallar ÁG, Mendoza-Mejía BD, Aguirre-Partida ED, Vázquez A, Encarnación S, Calva E, Hernández-Lucas I. The CRISPR-Cas System Is Involved in OmpR Genetic Regulation for Outer Membrane Protein Synthesis in Salmonella Typhi. Front Microbiol 2021; 12:657404. [PMID: 33854491 PMCID: PMC8039139 DOI: 10.3389/fmicb.2021.657404] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
The CRISPR-Cas cluster is found in many prokaryotic genomes including those of the Enterobacteriaceae family. Salmonella enterica serovar Typhi (S. Typhi) harbors a Type I-E CRISPR-Cas locus composed of cas3, cse1, cse2, cas7, cas5, cas6e, cas1, cas2, and a CRISPR1 array. In this work, it was determined that, in the absence of cas5 or cas2, the amount of the OmpC porin decreased substantially, whereas in individual cse2, cas6e, cas1, or cas3 null mutants, the OmpF porin was not observed in an electrophoretic profile of outer membrane proteins. Furthermore, the LysR-type transcriptional regulator LeuO was unable to positively regulate the expression of the quiescent OmpS2 porin, in individual S. Typhi cse2, cas5, cas6e, cas1, cas2, and cas3 mutants. Remarkably, the expression of the master porin regulator OmpR was dependent on the Cse2, Cas5, Cas6e, Cas1, Cas2, and Cas3 proteins. Therefore, the data suggest that the CRISPR-Cas system acts hierarchically on OmpR to control the synthesis of outer membrane proteins in S. Typhi.
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Affiliation(s)
- Liliana Medina-Aparicio
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Sarahí Rodriguez-Gutierrez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Javier E Rebollar-Flores
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | - Blanca D Mendoza-Mejía
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Eira D Aguirre-Partida
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alejandra Vázquez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Sergio Encarnación
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Edmundo Calva
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Ismael Hernández-Lucas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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7
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Feng Z, El Hag M, Qin T, Du Y, Chen S, Peng D. Residue L193P Mutant of RpoS Affects Its Activity During Biofilm Formation in Salmonella Pullorum. Front Vet Sci 2020; 7:571361. [PMID: 33251260 PMCID: PMC7674402 DOI: 10.3389/fvets.2020.571361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/16/2020] [Indexed: 11/21/2022] Open
Abstract
The role of alternative sigma factor RpoS in regulating biofilm formation may differ in various Salmonella Pullorum strains. In this study, the biofilm-forming ability of two Salmonella Pullorum strains S6702 and S11923-3 were compared. The biofilm forming ability of S11923-3 was much stronger than that of S6702. After knocking out the rpoS gene, S11923-3ΔrpoS had significantly reduced biofilm while S6702ΔrpoS demonstrated similar biofilm compared with each parent strain. The analysis of RpoS sequences indicated two amino acid substitutions (L193P and R293C) between S6702 and S11923-3 RpoS. A complementation study confirmed that the expression of S11923-3 RpoS rather than S6702 RpoS could restore the biofilm-forming ability of ΔrpoS strains and the L193P mutation contributed to the restoration of the biofilm-forming ability. Further study indicated that RpoS with the L193P mutant had significantly improved expression level and binding activity to RNAP and csgD gene promoter, which increased the efficacy of the csgD gene promoter and biofilm-forming ability. Therefore, the L193P mutation of RpoS is critical for stronger biofilm formation of Salmonella Pullorum.
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Affiliation(s)
- Zheng Feng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
| | - Muhanad El Hag
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
| | - Tao Qin
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
| | - Yinping Du
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
| | - Sujuan Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
| | - Daxin Peng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China.,Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China
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8
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Kotian A, Aditya V, Jazeela K, Karunasagar I, Karunasagar I, Deekshit VK. Effect of bile on growth and biofilm formation of non-typhoidal salmonella serovars isolated from seafood and poultry. Res Microbiol 2020; 171:165-173. [PMID: 32569709 DOI: 10.1016/j.resmic.2020.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/06/2020] [Accepted: 06/08/2020] [Indexed: 11/16/2022]
Abstract
Bacterial cells adopt various strategies to adapt themselves in diverse environmental conditions. Salmonella is one such bacteria with diverse mechanisms to survive, replicate and infect in wide host range. This study aims at investigating the biofilm-forming ability of multidrug-resistant and sensitive Salmonella serovars on exposure to bile. Antibiogram of all the isolates was determined by disk diffusion method and their biofilm-forming ability in the presence or absence of bile was assessed by microtiter plate assay. Biofilm results were validated by calcofluor, Congo red plate and test tube method. Few isolates were selected for further study of their expression of biofilm related genes on exposure to bile using real time PCR. Among the 59 isolates of Salmonella isolated from seafood and poultry, 30 isolates were multi-drug resistant (MDR). Under control conditions, 57% (n = 25) of the serovars were able to form biofilm. While, 86% (n = 51) of the serovars produced biofilm in the presence of bile. The relative gene expression study of the selected serovars for 8 different genes showed a striking difference in the expression levels, supporting the hypothesis that the presence of bile triggers biofilm formation in food associated strains of non-typhoidal Salmonella by upregulation of genes involved in biofilm production.
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Affiliation(s)
- Akshatha Kotian
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
| | - Vankadari Aditya
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
| | - Kadeeja Jazeela
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
| | - Iddya Karunasagar
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
| | - Indrani Karunasagar
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
| | - Vijaya Kumar Deekshit
- Nitte University Center for Science Education and Research, Division of Infectious Diseases, Nitte (Deemed to Be University), Deralakatte, Mangaluru 575018, Karnataka, India.
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9
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El Hag M, Feng Z, Su Y, Wang X, Yassin A, Chen S, Peng D, Liu X. Contribution of the csgA and bcsA genes to Salmonella enterica serovar Pullorum biofilm formation and virulence. Avian Pathol 2017; 46:541-547. [PMID: 28470089 DOI: 10.1080/03079457.2017.1324198] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Salmonella biofilm formation is important to environmental stress resistance and virulence. However, the roles of the csgA and bcsA genes, which affect curli protein and cellulose production, respectively, in Salmonella enterica serovar Pullorum, are unknown. Here we constructed deletions in the csgA and bcsA genes in S. enterica serovar Pullorum strain S6702 and evaluated several aspects of biofilm formation and virulence. ΔcsgA showed decreased production of curli fimbriae, while ΔbcsA had reduced cellulose production. Both mutants had a reduced ability to form biofilms. ΔcsgA was reduced in adhesion and invasion to HeLa cells and exhibited decreased intracellular proliferation in HD11 macrophages. ΔbcsA exhibited increased proliferation in HD11 cells and replicated better in chicken spleens, as compared to the wild-type strain. ΔcsgA virulence was attenuated in assays involving oral challenge of one-day-old chickens.
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Affiliation(s)
- Muhanad El Hag
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China.,d Faculty of Public and Environmental Health , University of Khartoum , Khartoum , Sudan
| | - Zheng Feng
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
| | - Yangyang Su
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
| | - Xiao Wang
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
| | - Afrah Yassin
- b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,d Faculty of Public and Environmental Health , University of Khartoum , Khartoum , Sudan
| | - Sujuan Chen
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
| | - Daxin Peng
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
| | - Xiufan Liu
- a College of Veterinary Medicine , Yangzhou University , Yangzhou , People's Republic of China.,b Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses , Yangzhou , People' Republic of China.,c Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease , Yangzhou , People' Republic of China
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10
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Arrebola E, Carrión VJ, Gutiérrez-Barranquero JA, Pérez-García A, Rodríguez-Palenzuela P, Cazorla FM, de Vicente A. Cellulose production inPseudomonas syringaepv.syringae: a compromise between epiphytic and pathogenic lifestyles. FEMS Microbiol Ecol 2015; 91:fiv071. [DOI: 10.1093/femsec/fiv071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2015] [Indexed: 01/11/2023] Open
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11
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Yap KP, Gan HM, Teh CSJ, Chai LC, Thong KL. Comparative genomics of closely related Salmonella enterica serovar Typhi strains reveals genome dynamics and the acquisition of novel pathogenic elements. BMC Genomics 2014; 15:1007. [PMID: 25412680 PMCID: PMC4289253 DOI: 10.1186/1471-2164-15-1007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/06/2014] [Indexed: 12/31/2022] Open
Abstract
Background Typhoid fever is an infectious disease of global importance that is caused by Salmonella enterica subsp. enterica serovar Typhi (S. Typhi). This disease causes an estimated 200,000 deaths per year and remains a serious global health threat. S. Typhi is strictly a human pathogen, and some recovered individuals become long-term carriers who continue to shed the bacteria in their faeces, thus becoming main reservoirs of infection. Results A comparative genomics analysis combined with a phylogenomic analysis revealed that the strains from the outbreak and carrier were closely related with microvariations and possibly derived from a common ancestor. Additionally, the comparative genomics analysis with all of the other completely sequenced S. Typhi genomes revealed that strains BL196 and CR0044 exhibit unusual genomic variations despite S. Typhi being generally regarded as highly clonal. The two genomes shared distinct chromosomal architectures and uncommon genome features; notably, the presence of a ~10 kb novel genomic island containing uncharacterised virulence-related genes, and zot in particular. Variations were also detected in the T6SS system and genes that were related to SPI-10, insertion sequences, CRISPRs and nsSNPs among the studied genomes. Interestingly, the carrier strain CR0044 harboured far more genetic polymorphisms (83% mutant nsSNPs) compared with the closely related BL196 outbreak strain. Notably, the two highly related virulence-determinant genes, rpoS and tviE, were mutated in strains BL196 and CR0044, respectively, which revealed that the mutation in rpoS is stabilising, while that in tviE is destabilising. These microvariations provide novel insight into the optimisation of genes by the pathogens. However, the sporadic strain was found to be far more conserved compared with the others. Conclusions The uncommon genomic variations in the two closely related BL196 and CR0044 strains suggests that S. Typhi is more diverse than previously thought. Our study has demonstrated that the pathogen is continually acquiring new genes through horizontal gene transfer in the process of host adaptation, providing novel insight into its unusual genomic dynamics. The understanding of these strains and virulence factors, and particularly the strain that is associated with the large outbreak and the less studied asymptomatic Typhi carrier in the population, will have important impact on disease control. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1007) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | - Kwai Lin Thong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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