1
|
Hazarika M, Wangkheimayum J, Nath K, Bhowmik D, Singha KM, Chanda DD, Bhattacharjee A. Transcriptional Response of vanB Operon in Staphylococcus aureus Against Vancomycin and Teicoplanin Stress. Curr Microbiol 2023; 80:275. [PMID: 37422582 DOI: 10.1007/s00284-023-03389-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 06/26/2023] [Indexed: 07/10/2023]
Abstract
Staphylococcus aureus is a global pathogen and is responsible for causing severe life-threatening infections. The current study was designed to investigate transcriptional expression of different core, regulatory, and accessory genes within vanB operon under differential exposure of vancomycin and teicoplanin. Four isolates selected for the study, were confirmed to harbour vanB gene in which three isolates showed MIC breakpoint above 16 µg/ml and one isolate above 8 µg/ml against vancomycin while teicoplanin showed higher MIC breakpoint as compared to vancomycin. Antibiotic susceptibility results showed that these isolates were susceptible towards imipenem and linezolid. Transcriptional expressional analysis of the core gene of vanB operon showed that expression of vanB is increased under vancomycin stress but is inversely proportional to increase in the concentration of the vancomycin while under teicoplanin stress the expression of vanB showed no significant pattern. Similar expressional pattern was found for vanH gene for both the glycopeptides. In case of vanX, expression was significantly increased at 1 µg/ml exposure of vancomycin, however, no pattern could be observed in case of teicoplanin stress. In case of regulatory gene, vanR, significant increase in expression was observed under vancomycin and teicoplanin stress of 1 µg/ml, however vanS, showed significant increase in the expression under 1 µg/ml of vancomycin. The accessory gene, vanY showed marginal increase in expression under both the antibiotic, while in case of vanW, the expressional pattern was found to be inversely proportional to the increasing antibiotic concentration.
Collapse
Affiliation(s)
- Monalisha Hazarika
- Department of Microbiology, Assam University Silchar, Cachar, 788011, Assam, India
| | | | - Kathakali Nath
- Department of Microbiology, Assam University Silchar, Cachar, 788011, Assam, India
| | - Deepshikha Bhowmik
- Department of Microbiology, Assam University Silchar, Cachar, 788011, Assam, India
| | - K Melson Singha
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, 788014, Assam, India
| | - Debadatta Dhar Chanda
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, 788014, Assam, India
| | | |
Collapse
|
2
|
BELITSKY BORISR. VanG- and D-Ala-D-Ser-dependent peptidoglycan synthesis and vancomycin resistance in Clostridioides difficile. Mol Microbiol 2022; 118:526-540. [PMID: 36065735 PMCID: PMC9671823 DOI: 10.1111/mmi.14980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022]
Abstract
A Clostridioides difficile strain deficient in the ddl gene is unable to synthesize the dipeptide D-Ala-D-Ala, an essential component of peptidoglycan and the target of vancomycin. We isolated spontaneous suppressors of a ∆ddl mutation that allowed cell growth in the absence of D-Ala-D-Ala. The mutations caused constitutive or partly constitutive expression of the vancomycin-inducible vanG operon responsible for the synthesis of D-Ala-D-Ser, which can replace D-Ala-D-Ala in peptidoglycan. The mutations mapped to the vanS or vanR genes, which regulate expression of the vanG operon. The constitutive level of vanG expression was about 10-fold above that obtained by vancomycin induction. The incorporation of D-Ala-D-Ser into peptidoglycan due to high expression of the vanG operon conferred only low-level resistance to vancomycin, but VanG was found to synthesize D-Ala-D-Ala in addition to D-Ala-D-Ser. However, the same, low resistance to vancomycin was also observed in cells completely unable to synthesize D-Ala-D-Ala and grown in the presence of D-Ala-D-Ser. D-Ala-D-Ala presence was required for efficient vancomycin induction of the vanG operon showing that vancomycin is not by itself able to activate VanS. D-Ala-D-Ser, similar to D-Ala-D-Ala, served as an anti-activator of DdlR, the positive regulator of the ddl gene, thereby coupling vanG and ddl expression.
Collapse
Affiliation(s)
- BORIS R. BELITSKY
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| |
Collapse
|
3
|
Anti-Quorum Sensing Activities of Gliptins against Pseudomonas aeruginosa and Staphylococcus aureus. Biomedicines 2022; 10:biomedicines10051169. [PMID: 35625906 PMCID: PMC9138634 DOI: 10.3390/biomedicines10051169] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/16/2022] [Accepted: 05/16/2022] [Indexed: 12/24/2022] Open
Abstract
The development of bacterial resistance to traditional antibiotics constitutes an emerging public health issue. Promising approaches have been innovated to conquer bacterial resistance, and targeting bacterial virulence is one of these approaches. Bacterial virulence mitigation offers several merits, as antivirulence agents do not affect the growth of bacteria and hence do not induce bacteria to develop resistance. In this direction, numerous drugs have been repurposed as antivirulence agents prior to their clinical use alone or in combination with traditional antibiotics. Quorum sensing (QS) plays a key role in controlling bacterial virulence. In the current study, dipeptidase inhibitor-4 (DPI-4) antidiabetic gliptins were screened for their antivirulence and anti-quorum sensing (anti-QS) activities against Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. Upon assessing their antibiofilm activities, the ten tested gliptins significantly diminished biofilm formation. In particular, sitagliptin exhibited the most efficient antibiofilm activity, so it was chosen as a representative of all gliptins to further investigate its antivirulence activity. Sitagliptin significantly protected mice from P. aeruginosa and S. aureus pathogenesis. Furthermore, sitagliptin downregulated QS-encoding genes in P. aeruginosa and S. aureus. To test the anti-QS activities of gliptins, a detailed molecular docking study was conducted to evaluate the gliptins’ binding affinities to P. aeruginosa and S. aureus QS receptors, which helped explain the anti-QS activities of gliptins, particularly sitagliptin and omarigliptin. In conclusion, this study evaluates the possible antivirulence and anti-QS activities of gliptins that could be promising novel candidates for the treatment of aggressive Gram-negative or -positive bacterial infections either alone or as adjuvants to other antibiotics.
Collapse
|
4
|
Khayat MT, Abbas HA, Ibrahim TS, Khayyat AN, Alharbi M, Darwish KM, Elhady SS, Khafagy ES, Safo MK, Hegazy WAH. Anti-Quorum Sensing Activities of Gliptins against Pseudomonas aeruginosa and Staphylococcus aureus. Biomedicines 2022; 10:1169. [PMID: 35625906 PMCID: PMC9138634 DOI: 10.3389/fmolb.2023.1203672activities 10.3390/biomedicines10051169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/16/2022] [Accepted: 05/16/2022] [Indexed: 07/07/2024] Open
Abstract
The development of bacterial resistance to traditional antibiotics constitutes an emerging public health issue. Promising approaches have been innovated to conquer bacterial resistance, and targeting bacterial virulence is one of these approaches. Bacterial virulence mitigation offers several merits, as antivirulence agents do not affect the growth of bacteria and hence do not induce bacteria to develop resistance. In this direction, numerous drugs have been repurposed as antivirulence agents prior to their clinical use alone or in combination with traditional antibiotics. Quorum sensing (QS) plays a key role in controlling bacterial virulence. In the current study, dipeptidase inhibitor-4 (DPI-4) antidiabetic gliptins were screened for their antivirulence and anti-quorum sensing (anti-QS) activities against Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. Upon assessing their antibiofilm activities, the ten tested gliptins significantly diminished biofilm formation. In particular, sitagliptin exhibited the most efficient antibiofilm activity, so it was chosen as a representative of all gliptins to further investigate its antivirulence activity. Sitagliptin significantly protected mice from P. aeruginosa and S. aureus pathogenesis. Furthermore, sitagliptin downregulated QS-encoding genes in P. aeruginosa and S. aureus. To test the anti-QS activities of gliptins, a detailed molecular docking study was conducted to evaluate the gliptins' binding affinities to P. aeruginosa and S. aureus QS receptors, which helped explain the anti-QS activities of gliptins, particularly sitagliptin and omarigliptin. In conclusion, this study evaluates the possible antivirulence and anti-QS activities of gliptins that could be promising novel candidates for the treatment of aggressive Gram-negative or -positive bacterial infections either alone or as adjuvants to other antibiotics.
Collapse
Affiliation(s)
- Maan T. Khayat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.S.I.); (A.N.K.); (M.A.)
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt;
| | - Tarek S. Ibrahim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.S.I.); (A.N.K.); (M.A.)
| | - Ahdab N. Khayyat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.S.I.); (A.N.K.); (M.A.)
| | - Majed Alharbi
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.S.I.); (A.N.K.); (M.A.)
| | - Khaled M. Darwish
- Department of Medicinal Chemistry, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt;
| | - Sameh S. Elhady
- Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia;
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41552, Egypt
| | - Martin K. Safo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA;
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt;
- Department of Pharmaceutical Sciences, Pharmacy Program, Oman College of Health Sciences, Muscat 113, Oman
| |
Collapse
|
5
|
Xu C, Yu M, Xie Y, Zhong J, Chen W, Lin M, Hu X, Shen Y. Screening and identification of vancomycin anti-idiotypic antibodies for against Staphylococcus aureus from a human phage display domain antibody library. Immunol Lett 2022; 246:1-9. [DOI: 10.1016/j.imlet.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 11/25/2022]
|
6
|
Lactic Acid Bacteria Antagonism of Acid-tolerant and Antibiotic-resistant Non-staphylococcal Pathogenic Species Isolated from a Fermented Cereal Beverage using Baird-Parker Agar. NUTRITION AND FOOD SCIENCES RESEARCH 2022. [DOI: 10.52547/nfsr.9.1.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
7
|
Sassine J, Pazos M, Breukink E, Vollmer W. Lytic transglycosylase MltG cleaves in nascent peptidoglycan and produces short glycan strands. Cell Surf 2021; 7:100053. [PMID: 34036206 PMCID: PMC8135044 DOI: 10.1016/j.tcsw.2021.100053] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/17/2021] [Accepted: 04/26/2021] [Indexed: 12/20/2022] Open
Abstract
Bacteria encase their cytoplasmic membrane with peptidoglycan (PG) to maintain the shape of the cell and protect it from bursting. The enlargement of the PG layer is facilitated by the coordinated activities of PG synthesising and -cleaving enzymes. In Escherichia coli, the cytoplasmic membrane-bound lytic transglycosylase MltG associates with PG synthases and was suggested to terminate the polymerisation of PG glycan strands. Using pull-down and surface plasmon resonance, we detected interactions between MltG from Bacillus subtilis and two PG synthases; the class A PBP1 and the class B PBP2B. Using in vitro PG synthesis assays with radio-labelled or fluorophore-labelled B. subtilis-type and/or E. coli-type lipid II, we showed that both, BsMltG and EcMltG, are lytic tranglycosylases and that their activity is higher during ongoing glycan strand polymerisation. MltG competed with the transpeptidase activity of class A PBPs, but had no effect on their glycosyltransferase activity, and produced glycan strands with a length of 7 disaccharide units from cleavage in the nascent strands. We hypothesize that MltG cleaves the nascent strands to produce short glycan strands that are used in the cell for a yet unknown process.
Collapse
Affiliation(s)
- Jad Sassine
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Manuel Pazos
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Bijvoet Centre of Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
8
|
Guan Y, Cui Y, Qu X, Jing K. Safety and robustness aspects analysis of Lactobacillus delbrueckii ssp. bulgaricus LDB-C1 based on the genome analysis and biological tests. Arch Microbiol 2021; 203:3955-3964. [PMID: 34021387 DOI: 10.1007/s00203-021-02383-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 04/21/2021] [Accepted: 05/12/2021] [Indexed: 12/26/2022]
Abstract
Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a microaerophylic anaerobe, which is widely used in the production of yogurt, cheese, and other fermented dairy products. L. bulgaricus and its partner Streptococcus thermophilus were used as starter cultures of yogurt in the world for thousands of years. In our previous study, L. bulgaricus LDB-C1 was obtained from traditional fermented milk, and possessed some characteristics like high exopolysaccharide yield and good fermentation performance. The analysis of its CRISPR-Cas system, antibiotic resistance, virulence factors, and mobile elements, was performed to reveal the stability of the strain LDB-C1. It was found that LDB-C1 contains a plenty of spacers in the CRISPR region, indicating it might have better performance against the infection of phages and plasmids. Furthermore, the acquired or transmittable antibiotic resistance/virulence factor genes were absent in the tested L. bulgaricus strain LDB-C1.
Collapse
Affiliation(s)
- Yuxuan Guan
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China
| | - Yanhua Cui
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
| | - Xiaojun Qu
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin, 150010, People's Republic of China
| | - Kai Jing
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China
| |
Collapse
|
9
|
Cell morphology maintenance in Bacillus subtilis through balanced peptidoglycan synthesis and hydrolysis. Sci Rep 2020; 10:17910. [PMID: 33087775 PMCID: PMC7578834 DOI: 10.1038/s41598-020-74609-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/28/2020] [Indexed: 01/12/2023] Open
Abstract
The peptidoglycan layer is responsible for maintaining bacterial cell shape and permitting cell division. Cell wall growth is facilitated by peptidoglycan synthases and hydrolases and is potentially modulated by components of the central carbon metabolism. In Bacillus subtilis, UgtP synthesises the glucolipid precursor for lipoteichoic acid and has been suggested to function as a metabolic sensor governing cell size. Here we show that ugtP mutant cells have increased levels of cell wall precursors and changes in their peptidoglycan that suggest elevated DL-endopeptidase activity. The additional deletion of lytE, encoding a DL-endopeptidase important for cell elongation, in the ugtP mutant background produced cells with severe shape defects. Interestingly, the ugtP lytE mutant recovered normal rod-shape by acquiring mutations that decreased the expression of the peptidoglycan synthase PBP1. Together our results suggest that cells lacking ugtP must re-adjust the balance between peptidoglycan synthesis and hydrolysis to maintain proper cell morphology.
Collapse
|
10
|
Salgueiro V, Manageiro V, Bandarra NM, Reis L, Ferreira E, Caniça M. Bacterial Diversity and Antibiotic Susceptibility of Sparus aurata from Aquaculture. Microorganisms 2020; 8:E1343. [PMID: 32887439 PMCID: PMC7564983 DOI: 10.3390/microorganisms8091343] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 02/02/2023] Open
Abstract
In a world where the population continues to increase and the volume of fishing catches stagnates or even falls, the aquaculture sector has great growth potential. This study aimed to contribute to the depth of knowledge of the diversity of bacterial species found in Sparus aurata collected from a fish farm and to understand which profiles of diminished susceptibility to antibiotics would be found in these bacteria that might be disseminated in the environment. One hundred thirty-six bacterial strains were recovered from the S. aurata samples. These strains belonged to Bacillaceae, Bacillales Family XII. Incertae Sedis, Comamonadaceae, Enterobacteriaceae, Enterococcaceae, Erwiniaceae, Micrococcaceae, Pseudomonadaceae and Staphylococcaceae families. Enterobacter sp. was more frequently found in gills, intestine and skin groups than in muscle groups (p ≤ 0.01). Antibiotic susceptibility tests found that non-susceptibility to phenicols was significantly higher in gills, intestine and skin samples (45%) than in muscle samples (24%) (p ≤ 0.01) and was the most frequently found non-susceptibility in both groups of samples. The group of Enterobacteriaceae from muscles presented less decreased susceptibility to florfenicol (44%) than in the group of gills, intestine and skin samples (76%). We found decreased susceptibilities to β-lactams and glycopeptides in the Bacillaceae family, to quinolones and mupirocin in the Staphylococcaceae family, and mostly to β-lactams, phenicols and quinolones in the Enterobacteriaceae and Pseudomonadaceae families. Seven Enterobacter spp. and five Pseudomonas spp. strains showed non-susceptibility to ertapenem and meropenem, respectively, which is of concern because they are antibiotics used as a last resort in serious clinical infections. To our knowledge, this is the first description of species Exiguobacterium acetylicum, Klebsiella michiganensis, Lelliottia sp. and Pantoea vagans associated with S. aurata (excluding cases where these bacteria are used as probiotics) and of plasmid-mediated quinolone resistance qnrB19-producing Leclercia adecarboxylata strain. The non-synonymous G385T and C402A mutations at parC gene (within quinolone resistance-determining regions) were also identified in a Klebsiella pneumoniae, revealing decreased susceptibility to ciprofloxacin. In this study, we found not only bacteria from the natural microbiota of fish but also pathogenic bacteria associated with fish and humans. Several antibiotics for which decreased susceptibility was found here are integrated into the World Health Organization list of "critically important antimicrobials" and "highly important antimicrobials" for human medicine.
Collapse
Affiliation(s)
- Vanessa Salgueiro
- National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (V.S.); (V.M.); (L.R.); (E.F.)
- Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal
| | - Vera Manageiro
- National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (V.S.); (V.M.); (L.R.); (E.F.)
- Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal
| | - Narcisa M. Bandarra
- Department of Sea and Marine Resources, Portuguese Institute for the Sea and Atmosphere (IPMA, IP), 1749-077 Lisbon, Portugal;
| | - Lígia Reis
- National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (V.S.); (V.M.); (L.R.); (E.F.)
| | - Eugénia Ferreira
- National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (V.S.); (V.M.); (L.R.); (E.F.)
- Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal
| | - Manuela Caniça
- National Reference Laboratory of Antibiotic Resistances and Healthcare Associated Infections (NRL-AMR-HAI), Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (V.S.); (V.M.); (L.R.); (E.F.)
- Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4051-401 Oporto, Portugal
| |
Collapse
|
11
|
Wu X, Zhou H, Li L, Wang E, Zhou X, Gu Y, Wu X, Shen L, Zeng W. Whole Genome Sequencing and Comparative Genomic Analyses of Lysinibacillus pakistanensis LZH-9, a Halotolerant Strain with Excellent COD Removal Capability. Microorganisms 2020; 8:microorganisms8050716. [PMID: 32408484 PMCID: PMC7284689 DOI: 10.3390/microorganisms8050716] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 11/26/2022] Open
Abstract
Halotolerant microorganisms are promising in bio-treatment of hypersaline industrial wastewater. Four halotolerant bacteria strains were isolated from wastewater treatment plant, of which a strain LZH-9 could grow in the presence of up to 14% (w/v) NaCl, and it removed 81.9% chemical oxygen demand (COD) at 96 h after optimization. Whole genome sequencing of Lysinibacillus pakistanensis LZH-9 and comparative genomic analysis revealed metabolic versatility of different species of Lysinibacillus, and abundant genes involved in xenobiotics biodegradation, resistance to toxic compound, and salinity were found in all tested species of Lysinibacillus, in which Horizontal Gene Transfer (HGT) contributed to the acquisition of many important properties of Lysinibacillus spp. such as toxic compound resistance and osmotic stress resistance as revealed by phylogenetic analyses. Besides, genome wide positive selection analyses revealed seven genes that contained adaptive mutations in Lysinibacillus spp., most of which were multifunctional. Further expression assessment with Codon Adaption Index (CAI) also reflected the high metabolic rate of L. pakistanensis to digest potential carbon or nitrogen sources in organic contaminants, which was closely linked with efficient COD removal ability of strain LZH-9. The high COD removal efficiency and halotolerance as well as genomic evidences suggested that L. pakistanensis LZH-9 was promising in treating hypersaline industrial wastewater.
Collapse
Affiliation(s)
- Xueling Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Han Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Liangzhi Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Enhui Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Xiangyu Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Yichao Gu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Xiaoyan Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (X.W.); (H.Z.); (L.L.); (E.W.); (X.Z.); (Y.G.); (X.W.); (L.S.)
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
- Correspondence: ; Tel.: +86-0731-88877472
| |
Collapse
|
12
|
d-Methionine and d-Phenylalanine Improve Lactococcus lactis F44 Acid Resistance and Nisin Yield by Governing Cell Wall Remodeling. Appl Environ Microbiol 2020; 86:AEM.02981-19. [PMID: 32111594 DOI: 10.1128/aem.02981-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 02/22/2020] [Indexed: 12/30/2022] Open
Abstract
Lactococcus lactis encounters various environmental challenges, especially acid stress, during its growth. The cell wall can maintain the integrity and shape of the cell under environmental stress, and d-amino acids play an important role in cell wall synthesis. Here, by analyzing the effects of 19 different d-amino acids on the physiology of L. lactis F44, we found that exogenously supplied d-methionine and d-phenylalanine increased the nisin yield by 93.22% and 101.29%, respectively, as well as significantly increasing the acid resistance of L. lactis F44. The composition of the cell wall in L. lactis F44 with exogenously supplied d-Met or d-Phe was further investigated via a vancomycin fluorescence experiment and a liquid chromatography-mass spectrometry assay, which demonstrated that d-Met could be incorporated into the fifth position of peptidoglycan (PG) muropeptides and d-Phe could be added to the fourth and fifth positions. Moreover, overexpression of the PG synthesis gene murF further enhanced the levels of d-Met and d-Phe involved in PG and increased the survival rate under acid stress and the nisin yield of the strain. This study reveals that the exogenous supply of d-Met or d-Phe can change the composition of the cell wall and influence acid tolerance as well as nisin yield in L. lactis IMPORTANCE As d-amino acids play an important role in cell wall synthesis, we analyzed the effects of 19 different d-amino acids on L. lactis F44, demonstrating that d-Met and d-Phe can participate in peptidoglycan (PG) synthesis and improve the acid resistance and nisin yield of this strain. murF overexpression further increased the levels of d-Met and d-Phe incorporated into PG and contributed to the acid resistance of the strain. These findings suggest that d-Met and d-Phe can be incorporated into PG to improve the acid resistance and nisin yield of L. lactis, and this study provides new ideas for the enhancement of nisin production.
Collapse
|
13
|
Wilke KE, Fihn CA, Carlson EE. Screening serine/threonine and tyrosine kinase inhibitors for histidine kinase inhibition. Bioorg Med Chem 2018; 26:5322-5326. [PMID: 29706527 DOI: 10.1016/j.bmc.2018.04.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 10/17/2022]
Abstract
Histidine kinases of bacterial two-component systems are promising antibacterial targets. Despite their varied, numerous roles, enzymes in the histidine kinase superfamily share a catalytic core that may be exploited to inhibit multiple histidine kinases simultaneously. Characterized by the Bergerat fold, the features of the histidine kinase ATP-binding domain are not found in serine/threonine and tyrosine kinases. However, because each kinase family binds the same ATP substrate, we sought to determine if published serine/threonine and tyrosine kinase inhibitors contained scaffolds that would also inhibit histidine kinases. Using select assays, 222 inhibitors from the Roche Published Kinase Set were screened for binding, deactivation, and aggregation of histidine kinases. Not only do the results of our screen support the distinctions between ATP-binding domains of different kinase families, but the lead molecule identified also presents inspiration for further histidine kinase inhibitor development.
Collapse
Affiliation(s)
- Kaelyn E Wilke
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, United States
| | - Conrad A Fihn
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street SE, Minneapolis, MN 55455, United States
| | - Erin E Carlson
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, United States; Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street SE, Minneapolis, MN 55455, United States; Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55454, United States; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church Street SE, Minneapolis, MN 55455, United States; Department of Molecular and Cellular Biochemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, IN 47405, United States.
| |
Collapse
|
14
|
Screening of Heterologous Signal Peptides for Optimization of the LIKE-Expression System. BIONANOSCIENCE 2016. [DOI: 10.1007/s12668-016-0357-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
15
|
Bem AE, Velikova N, Pellicer MT, Baarlen PV, Marina A, Wells JM. Bacterial histidine kinases as novel antibacterial drug targets. ACS Chem Biol 2015; 10:213-24. [PMID: 25436989 DOI: 10.1021/cb5007135] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bacterial histidine kinases (HKs) are promising targets for novel antibacterials. Bacterial HKs are part of bacterial two-component systems (TCSs), the main signal transduction pathways in bacteria, regulating various processes including virulence, secretion systems and antibiotic resistance. In this review, we discuss the biological importance of TCSs and bacterial HKs for the discovery of novel antibacterials, as well as published TCS and HK inhibitors that can be used as a starting point for structure-based approaches to develop novel antibacterials.
Collapse
Affiliation(s)
- Agnieszka E. Bem
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
| | - Nadya Velikova
- Instituto
de Biomedicina
de Valencia-Consejo Superior de Investigaciones Cientificas (IBV-CSIC), Jaume Roig 11, 46010-Valencia, Spain
| | - M. Teresa Pellicer
- R&D Department Interquim, Ferrer HealthTech, Joan Buscalla 10, 08137-Sant Cugat del Valles Barcelona, Spain
| | - Peter van Baarlen
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
| | - Alberto Marina
- Instituto
de Biomedicina
de Valencia-Consejo Superior de Investigaciones Cientificas (IBV-CSIC), Jaume Roig 11, 46010-Valencia, Spain
- Centro de Investigacion
Biomedica en Red de Enfermedades Raras (CIBER-ISCIII), Jaume Roig 11, 46010-Valencia, Spain
| | - Jerry M. Wells
- Host−Microbe
Interactomics, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands
| |
Collapse
|
16
|
Santos-Beneit F, Fernández-Martínez LT, Rodríguez-García A, Martín-Martín S, Ordóñez-Robles M, Yagüe P, Manteca A, Martín JF. Transcriptional response to vancomycin in a highly vancomycin-resistant Streptomyces coelicolor mutant. Future Microbiol 2014; 9:603-22. [DOI: 10.2217/fmb.14.21] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT: Aim: The main objective of this study is to understand the mechanism of vancomycin resistance in a Streptomyces coelicolor disrupted mutant highly resistant to vancomycin. Materials & methods: Different techniques have been performed in the study including gene disruption, primer extension, antibiotic susceptibility tests, electron microscopy, confocal microscopy, cell wall analysis and microarrays. Results: During the phenotypical characterization of mutant strains affected in phosphate-regulated genes of unknown function, we found that the S. coelicolor SCO2594 disrupted mutant was highly resistant to vancomycin and had other phenotypic alterations such as antibiotic overproduction, impaired growth and reduction of phosphate cell wall content. Transcriptomic studies with this mutant indicated a relationship between vancomycin resistance and cell wall stress. Conclusion: We identified a S. coelicolor mutant highly resistant to vancomycin in both high and low phosphate media. In addition to Van proteins, others such as WhiB or SigE appear to be involved in this regulatory mechanism.
Collapse
Affiliation(s)
- Fernando Santos-Beneit
- Instituto de Biotecnología de León (INBIOTEC), Avda. Real 1, 24006 León, Spain
- Departamento de Biología Molecular & IBBTEC, Facultad de Medicina, Universidad de Cantabria, 39011 Santander, Spain
| | - Lorena T Fernández-Martínez
- Instituto de Biotecnología de León (INBIOTEC), Avda. Real 1, 24006 León, Spain
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Antonio Rodríguez-García
- Instituto de Biotecnología de León (INBIOTEC), Avda. Real 1, 24006 León, Spain
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | | | - María Ordóñez-Robles
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Paula Yagüe
- Área de Microbiología, Departamento de Biología Funcional & IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Angel Manteca
- Área de Microbiología, Departamento de Biología Funcional & IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Juan F Martín
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| |
Collapse
|
17
|
Fang C, Stiegeler E, Cook GM, Mascher T, Gebhard S. Bacillus subtilis as a platform for molecular characterisation of regulatory mechanisms of Enterococcus faecalis resistance against cell wall antibiotics. PLoS One 2014; 9:e93169. [PMID: 24676422 PMCID: PMC3968067 DOI: 10.1371/journal.pone.0093169] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 02/28/2014] [Indexed: 11/19/2022] Open
Abstract
To combat antibiotic resistance of Enterococcus faecalis, a better understanding of the molecular mechanisms, particularly of antibiotic detection, signal transduction and gene regulation is needed. Because molecular studies in this bacterium can be challenging, we aimed at exploiting the genetically highly tractable Gram-positive model organism Bacillus subtilis as a heterologous host. Two fundamentally different regulators of E. faecalis resistance against cell wall antibiotics, the bacitracin sensor BcrR and the vancomycin-sensing two-component system VanSB-VanRB, were produced in B. subtilis and their functions were monitored using target promoters fused to reporter genes (lacZ and luxABCDE). The bacitracin resistance system BcrR-BcrAB of E. faecalis was fully functional in B. subtilis, both regarding regulation of bcrAB expression and resistance mediated by the transporter BcrAB. Removal of intrinsic bacitracin resistance of B. subtilis increased the sensitivity of the system. The lacZ and luxABCDE reporters were found to both offer sensitive detection of promoter induction on solid media, which is useful for screening of large mutant libraries. The VanSB-VanRB system displayed a gradual dose-response behaviour to vancomycin, but only when produced at low levels in the cell. Taken together, our data show that B. subtilis is a well-suited host for the molecular characterization of regulatory systems controlling resistance against cell wall active compounds in E. faecalis. Importantly, B. subtilis facilitates the careful adjustment of expression levels and genetic background required for full functionality of the introduced regulators.
Collapse
Affiliation(s)
- Chong Fang
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Emanuel Stiegeler
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Gregory M. Cook
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Thorsten Mascher
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Susanne Gebhard
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
- * E-mail:
| |
Collapse
|
18
|
Cava F, de Pedro MA. Peptidoglycan plasticity in bacteria: emerging variability of the murein sacculus and their associated biological functions. Curr Opin Microbiol 2014; 18:46-53. [PMID: 24607990 DOI: 10.1016/j.mib.2014.01.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/13/2014] [Accepted: 01/20/2014] [Indexed: 12/26/2022]
Abstract
The peptidoglycan (PG) sacculus once thought to be just a reinforcing, static and uniform structure, is fast becoming recognized as a dynamic cell constituent involved in every aspect of bacterial physiology. Recent advances showed that in addition to 'classical' tasks-as an essential element to define bacterial shape, size, division and resistance to osmotic stress-the sacculus plays very important roles in many other fields. The very few chemical and structural changes that were once considered as bizarre, or maybe exotic exceptions, are now universally accepted as fundamental pieces in bacterial cell wall adaptation to different kinds of environmental stresses; immune response; intra-specific and inter-specific signalling and antibiotics, just to mention a few. Most, if not all, of these implications are a consequence of the enormous adaptability of PG metabolism to cope with changing conditions, a characteristic for which the term plasticity is proposed. Here we overview and comment on a number of recent contributions on the cell wall adaptive responses to environmental challenges that has greatly impacted the already high complexity of the PG biology field. These new evidences have revived the interest in PG plasticity as an exciting and trendy topic in current microbiology which considers this variability as the trustworthy picture of bacterial PG in nature.
Collapse
Affiliation(s)
- Felipe Cava
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå 90187, Sweden.
| | - Miguel A de Pedro
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain
| |
Collapse
|
19
|
Moreno Switt AI, Andrus AD, Ranieri ML, Orsi RH, Ivy R, den Bakker HC, Martin NH, Wiedmann M, Boor KJ. Genomic comparison of sporeforming bacilli isolated from milk. BMC Genomics 2014; 15:26. [PMID: 24422886 PMCID: PMC3902026 DOI: 10.1186/1471-2164-15-26] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 01/08/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Sporeformers in the order Bacillales are important contributors to spoilage of pasteurized milk. While only a few Bacillus and Viridibacillus strains can grow in milk at 6°C, the majority of Paenibacillus isolated from pasteurized fluid milk can grow under these conditions. To gain a better understanding of genomic features of these important spoilage organisms and to identify candidate genomic features that may facilitate cold growth in milk, we performed a comparative genomic analysis of selected dairy associated sporeformers representing isolates that can and cannot grow in milk at 6°C. RESULTS The genomes for seven Paenibacillus spp., two Bacillus spp., and one Viridibacillus sp. isolates were sequenced. Across the genomes sequenced, we identified numerous genes encoding antimicrobial resistance mechanisms, bacteriocins, and pathways for synthesis of non-ribosomal peptide antibiotics. Phylogenetic analysis placed genomes representing Bacillus, Paenibacillus and Viridibacillus into three distinct well supported clades and further classified the Paenibacillus strains characterized here into three distinct clades, including (i) clade I, which contains one strain able to grow at 6°C in skim milk broth and one strain not able to grow under these conditions, (ii) clade II, which contains three strains able to grow at 6°C in skim milk broth, and (iii) clade III, which contains two strains unable to grow under these conditions. While all Paenibacillus genomes were found to include multiple copies of genes encoding β-galactosidases, clade II strains showed significantly higher numbers of genes encoding these enzymes as compared to clade III strains. Genome comparison of strains able to grow at 6°C and strains unable to grow at this temperature identified numerous genes encoding features that might facilitate the growth of Paenibacillus in milk at 6°C, including peptidases with cold-adapted features (flexibility and disorder regions in the protein structure) and cold-adaptation related proteins (DEAD-box helicases, chaperone DnaJ). CONCLUSIONS Through a comparative genomics approach we identified a number of genomic features that may relate to the ability of selected Paenibacillus strains to cause spoilage of refrigerated fluid milk. With additional experimental evidence, these data will facilitate identification of targets to detect and control Gram positive spore formers in fluid milk.
Collapse
Affiliation(s)
- Andrea I Moreno Switt
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Alexis D Andrus
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Matthew L Ranieri
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Renato H Orsi
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Reid Ivy
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Henk C den Bakker
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Nicole H Martin
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Martin Wiedmann
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Kathryn J Boor
- 345 Stocking Hall, Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
20
|
Ammam F, Meziane-Cherif D, Mengin-Lecreulx D, Blanot D, Patin D, Boneca IG, Courvalin P, Lambert T, Candela T. The functional vanGCd cluster of Clostridium difficile does not confer vancomycin resistance. Mol Microbiol 2013; 89:612-25. [PMID: 23782343 DOI: 10.1111/mmi.12299] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2013] [Indexed: 12/19/2022]
Abstract
vanGCd, a cryptic gene cluster highly homologous to the vanG gene cluster of Enterococcus faecalis is largely spread in Clostridium difficile. Since emergence of vancomycin resistance would have dramatic clinical consequences, we have evaluated the capacity of the vanGCd cluster to confer resistance. We showed that expression of vanGCd is inducible by vancomycin and that VanGCd , VanXYCd and VanTCd are functional, exhibiting D-Ala : D-Ser ligase, D,D-dipeptidase and D-Ser racemase activities respectively. In other bacteria, these enzymes are sufficient to promote vancomycin resistance. Trans-complementation of C. difficile with the vanC resistance operon of Enterococcus gallinarum faintly impacted the MIC of vancomycin, but did not promote vancomycin resistance in C. difficile. Sublethal concentration of vancomycin led to production of UDP-MurNAc-pentapeptide[D-Ser], suggesting that the vanGCd gene cluster is able to modify the peptidoglycan precursors. Our results indicated amidation of UDP-MurNAc-tetrapeptide, UDP-MurNAc-pentapeptide[D-Ala] and UDP-MurNAc-pentapeptide[D-Ser]. This modification is passed on the mature peptidoglycan where a muropeptide Tetra-Tetra is amidated on the meso-diaminopimelic acid. Taken together, our results suggest that the vanGCd gene cluster is functional and is prevented from promoting vancomycin resistance in C. difficile.
Collapse
Affiliation(s)
- Fariza Ammam
- EA4043, Faculté de Pharmacie, Université Paris Sud, Châtenay-Malabry, France
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Khera M, Pathengay A, Jindal A, Jalali S, Mathai A, Pappuru RR, Relhan N, Das T, Sharma S, Flynn HW. Vancomycin-resistant Gram-positive bacterial endophthalmitis: epidemiology, treatment options, and outcomes. J Ophthalmic Inflamm Infect 2013; 3:46. [PMID: 23607574 PMCID: PMC3637534 DOI: 10.1186/1869-5760-3-46] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 04/12/2013] [Indexed: 11/16/2022] Open
Abstract
Background The purpose of this study is to evaluate the microbiological profile and treatment outcomes of vancomycin-resistant Gram-positive bacterial endophthalmitis. Medical records of all patients with Gram-positive bacterial endophthalmitis resistant to vancomycin presenting between 1 January 2005 and 31 December 2010 were reviewed in this noncomparative, consecutive, retrospective case series. Favorable outcome was defined as a best-corrected visual acuity of ≥20/200. Results Out of 682 culture-positive endophthalmitis isolates, 448/682 (65.6%) were associated with Gram-positive bacteria. In vitro resistance to vancomycin was noted in 7/448 (1.56%). Three cases were posttraumatic, three were postoperative, and one was endogenous in origin. Four Bacillus isolates, two Staphylococcus isolates, and an Enterococcus isolate were resistant. Isolates resistant to vancomycin were sensitive in vitro to ciprofloxacin in 6/7 (86%) patients. Presenting visual acuity was light perception in all seven cases. Favorable outcome was achieved in only 1/7 (14.3%) cases. Conclusions Vancomycin-resistant endophthalmitis is uncommon and usually associated with poor visual outcome. Bacillus sp. is the most frequent Gram-positive bacteria resistant to vancomycin. Fluoroquinolones like ciprofloxacin may be considered as a useful alternative in vancomycin-resistant endophthalmitis.
Collapse
Affiliation(s)
- Manav Khera
- LV Prasad Eye Institute, GMR Varalakshmi Campus, Visakhapatnam 530040, India.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Chancey ST, Zähner D, Stephens DS. Acquired inducible antimicrobial resistance in Gram-positive bacteria. Future Microbiol 2013; 7:959-78. [PMID: 22913355 DOI: 10.2217/fmb.12.63] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A major contributor to the emergence of antibiotic resistance in Gram-positive bacterial pathogens is the expansion of acquired, inducible genetic elements. Although acquired, inducible antibiotic resistance is not new, the interest in its molecular basis has been accelerated by the widening distribution and often 'silent' spread of the elements responsible, the diagnostic challenges of such resistance and the mounting limitations of available agents to treat Gram-positive infections. Acquired, inducible antibiotic resistance elements belong to the accessory genome of a species and are horizontally acquired by transformation/recombination or through the transfer of mobile DNA elements. The two key, but mechanistically very different, induction mechanisms are: ribosome-sensed induction, characteristic of the macrolide-lincosamide-streptogramin B antibiotics and tetracycline resistance, leading to ribosomal modifications or efflux pump activation; and resistance by cell surface-associated sensing of β-lactams (e.g., oxacillin), glycopeptides (e.g., vancomycin) and the polypeptide bacitracin, leading to drug inactivation or resistance due to cell wall alterations.
Collapse
Affiliation(s)
- Scott T Chancey
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | |
Collapse
|
23
|
Boudreau MA, Fisher JF, Mobashery S. Messenger functions of the bacterial cell wall-derived muropeptides. Biochemistry 2012; 51:2974-90. [PMID: 22409164 DOI: 10.1021/bi300174x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bacterial muropeptides are soluble peptidoglycan structures central to recycling of the bacterial cell wall and messengers in diverse cell signaling events. Bacteria sense muropeptides as signals that antibiotics targeting cell-wall biosynthesis are present, and eukaryotes detect muropeptides during the innate immune response to bacterial infection. This review summarizes the roles of bacterial muropeptides as messengers, with a special emphasis on bacterial muropeptide structures and the relationship of structure to the biochemical events that the muropeptides elicit. Muropeptide sensing and recycling in both Gram-positive and Gram-negative bacteria are discussed, followed by muropeptide sensing by eukaryotes as a crucial event in the innate immune response of insects (via peptidoglycan-recognition proteins) and mammals (through Nod-like receptors) to bacterial invasion.
Collapse
Affiliation(s)
- Marc A Boudreau
- Department of Chemistry and Biochemistry, Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | | | | |
Collapse
|