1
|
Blackburn JB, Schaff JA, Gutor S, Du RH, Nichols D, Sherrill T, Gutierrez AJ, Xin MK, Wickersham N, Zhang Y, Holtzman MJ, Ware LB, Banovich NE, Kropski JA, Blackwell TS, Richmond BW. Secretory Cells Are the Primary Source of pIgR in Small Airways. Am J Respir Cell Mol Biol 2022; 67:334-345. [PMID: 35687143 PMCID: PMC9447142 DOI: 10.1165/rcmb.2021-0548oc] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 06/13/2022] [Indexed: 11/24/2022] Open
Abstract
Loss of secretory IgA (SIgA) is common in chronic obstructive pulmonary disease (COPD) small airways and likely contributes to disease progression. We hypothesized that loss of SIgA results from reduced expression of pIgR (polymeric immunoglobulin receptor), a chaperone protein needed for SIgA transcytosis, in the COPD small airway epithelium. pIgR-expressing cells were defined and quantified at single-cell resolution in human airways using RNA in situ hybridization, immunostaining, and single-cell RNA sequencing. Complementary studies in mice used immunostaining, primary murine tracheal epithelial cell culture, and transgenic mice with secretory or ciliated cell-specific knockout of pIgR. SIgA degradation by human neutrophil elastase or secreted bacterial proteases from nontypeable Haemophilus influenzae was evaluated in vitro. We found that secretory cells are the predominant cell type responsible for pIgR expression in human and murine airways. Loss of SIgA in small airways was not associated with a reduction in secretory cells but rather a reduction in pIgR protein expression despite intact PIGR mRNA expression. Neutrophil elastase and nontypeable H. influenzae-secreted proteases are both capable of degrading SIgA in vitro and may also contribute to a deficient SIgA immunobarrier in COPD. Loss of the SIgA immunobarrier in small airways of patients with severe COPD is complex and likely results from both pIgR-dependent defects in IgA transcytosis and SIgA degradation.
Collapse
Affiliation(s)
- Jessica B. Blackburn
- Department of Veterans Affairs Medical Center, Nashville, Tennessee
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Jacob A. Schaff
- Department of Veterans Affairs Medical Center, Nashville, Tennessee
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Sergey Gutor
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Rui-Hong Du
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - David Nichols
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Taylor Sherrill
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | | | - Matthew K. Xin
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Nancy Wickersham
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | - Yong Zhang
- Division of Pulmonary and Critical Care Medicine, Washington University–St. Louis, St. Louis, Missouri
| | - Michael J. Holtzman
- Division of Pulmonary and Critical Care Medicine, Washington University–St. Louis, St. Louis, Missouri
| | - Lorraine B. Ware
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
| | | | - Jonathan A. Kropski
- Department of Veterans Affairs Medical Center, Nashville, Tennessee
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| | - Timothy S. Blackwell
- Department of Veterans Affairs Medical Center, Nashville, Tennessee
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| | - Bradley W. Richmond
- Department of Veterans Affairs Medical Center, Nashville, Tennessee
- Division of Allergy, Pulmonary, and Critical Care Medicine, School of Medicine, and
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| |
Collapse
|
2
|
Elsayed ZM, Eldehna WM, Abdel-Aziz MM, El Hassab MA, Elkaeed EB, Al-Warhi T, Abdel-Aziz HA, Abou-Seri SM, Mohammed ER. Development of novel isatin-nicotinohydrazide hybrids with potent activity against susceptible/resistant Mycobacterium tuberculosis and bronchitis causing-bacteria. J Enzyme Inhib Med Chem 2021; 36:384-393. [PMID: 33406941 PMCID: PMC7801109 DOI: 10.1080/14756366.2020.1868450] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 01/19/2023] Open
Abstract
Joining the global fight against Tuberculosis, the world's most deadly infectious disease, herein we present the design and synthesis of novel isatin-nicotinohydrazide hybrids (5a-m and 9a-c) as promising anti-tubercular and antibacterial agents. The anti-tubercular activity of the target hybrids was evaluated against drug-susceptible M. tuberculosis strain (ATCC 27294) where hybrids 5d, 5g and 5h were found to be as potent as INH with MIC = 0.24 µg/mL, also the activity was evaluated against Isoniazid/Streptomycin resistant M. tuberculosis (ATCC 35823) where compounds 5g and 5h showed excellent activity (MIC = 3.9 µg/mL). Moreover, the target hybrids were examined against six bronchitis causing-bacteria. Most derivatives exhibited excellent antibacterial activity. K. pneumonia emerged as the most sensitive strain with MIC range: 0.49-7.81 µg/mL. Furthermore, a molecular docking study has proposed DprE1 as a probable enzymatic target for herein reported isatin-nicotinohydrazide hybrids, and explored the binding interactions within the vicinity of DprE1 active site.
Collapse
Affiliation(s)
- Zainab M. Elsayed
- Faculty of Pharmacy, Scientific Research and Innovation Support Unit, Kafrelsheikh University, Kafrelsheikh, Egypt
| | - Wagdy M. Eldehna
- Faculty of Pharmacy, Scientific Research and Innovation Support Unit, Kafrelsheikh University, Kafrelsheikh, Egypt
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Kafrelsheikh University, Kafrelsheikh, Egypt
| | - Marwa M. Abdel-Aziz
- The Regional Center for Mycology & Biotechnology, Al-Azhar University, Cairo, Egypt
| | - Mahmoud A. El Hassab
- Department of Pharmaceutical Chemistry, School of Pharmacy, Badr University in Cairo, Badr City, Egypt
| | - Eslam B. Elkaeed
- Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Ad Diriyah, Saudi Arabia
- Faculty of Pharmacy (Boys), Department of Pharmaceutical Organic Chemistry, Al-Azhar University, Cairo, Egypt
| | - Tarfah Al-Warhi
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Hatem A. Abdel-Aziz
- Department of Applied Organic Chemistry, National Research Center, Giza, Egypt
| | - Sahar M. Abou-Seri
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Cairo University, Cairo, Egypt
| | - Eman R. Mohammed
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Cairo University, Cairo, Egypt
| |
Collapse
|
3
|
Singh RP, Saini N, Sharma G, Rahisuddin R, Patel M, Kaushik A, Kumaran S. Moonlighting Biochemistry of Cysteine Synthase: A Species-specific Global Regulator. J Mol Biol 2021; 433:167255. [PMID: 34547327 DOI: 10.1016/j.jmb.2021.167255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 11/18/2022]
Abstract
Cysteine Synthase (CS), the enzyme that synthesizes cysteine, performs non-canonical regulatory roles by binding and modulating functions of disparate proteins. Beyond its role in catalysis and regulation in the cysteine biosynthesis pathway, it exerts its moonlighting effect by binding to few other proteins which possess a C-terminal "CS-binding motif", ending with a terminal ILE. Therefore, we hypothesized that CS might regulate many other disparate proteins with the "CS-binding motif". In this study, we developed an iterative sequence matching method for mapping moonlighting biochemistry of CS and validated our prediction by analytical and structural approaches. Using a minimal protein-peptide interaction system, we show that five previously unknown CS-binder proteins that participate in diverse metabolic processes interact with CS in a species-specific manner. Furthermore, results show that signatures of protein-protein interactions, including thermodynamic, competitive-inhibition, and structural features, highly match the known CS-Binder, serine acetyltransferase (SAT). Together, the results presented in this study allow us to map the extreme multifunctional space (EMS) of CS and reveal the biochemistry of moonlighting space, a subset of EMS. We believe that the integrated computational and experimental workflow developed here could be further modified and extended to study protein-specific moonlighting properties of multifunctional proteins.
Collapse
Affiliation(s)
- Ravi Pratap Singh
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India
| | - Neha Saini
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India
| | - Gaurav Sharma
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Electronic city, Bengaluru, Karnataka 560100, India
| | - R Rahisuddin
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India. https://twitter.com/RahisuddinAlig
| | - Madhuri Patel
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India
| | - Abhishek Kaushik
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India
| | - S Kumaran
- G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh 160036, India.
| |
Collapse
|
4
|
Weidmann J, Schnölzer M, Dawson PE, Hoheisel JD. Copying Life: Synthesis of an Enzymatically Active Mirror-Image DNA-Ligase Made of D-Amino Acids. Cell Chem Biol 2019; 26:645-651.e3. [PMID: 30880154 DOI: 10.1016/j.chembiol.2019.02.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/27/2018] [Accepted: 02/07/2019] [Indexed: 11/17/2022]
Abstract
Our objective is the creation of a mirror-image synthetic biology: that is, to mimic, entirely independent of Nature, a biological system and to re-create it from artificial component parts. Utilizing enantiomeric L-nucleotides and D-amino acids rather than the natural components, we use chemical synthesis toward a basic, self-replicating mirror-image biological system. Here, we report the synthesis of a functional DNA-ligase in the D-enantiomeric conformation, which is an exact mirror-image of the natural enzyme, exhibiting DNA ligation activity on chirally inverted nucleic acids in L-conformation, but not acting on natural substrates and with natural co-factors. Starting from the known structure of the Paramecium bursaria chlorella virus 1 DNA-ligase and the homologous but shorter DNA-ligase of Haemophilus influenza, we designed and synthesized chemically peptides, which could then be assembled into a full-length molecule yielding a functional protein. The structure and the activity of the mirror-image ligase were characterized, documenting its enantiospecific functionality.
Collapse
Affiliation(s)
- Joachim Weidmann
- Functional Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany; Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Martina Schnölzer
- Functional Proteome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg, Germany
| | - Philip E Dawson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jörg D Hoheisel
- Functional Genome Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
| |
Collapse
|
5
|
Green KD, Fosso MY, Mayhoub AS, Garneau-Tsodikova S. Investigating the promiscuity of the chloramphenicol nitroreductase from Haemophilus influenzae towards the reduction of 4-nitrobenzene derivatives. Bioorg Med Chem Lett 2019; 29:1127-1132. [PMID: 30826292 DOI: 10.1016/j.bmcl.2019.02.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/13/2019] [Accepted: 02/20/2019] [Indexed: 01/28/2023]
Abstract
Chloramphenicol nitroreductase (CNR), a drug-modifying enzyme from Haemophilus influenzae, has been shown to be responsible for the conversion of the nitro group into an amine in the antibiotic chloramphenicol (CAM). Since CAM structurally bears a 4-nitrobenzene moiety, we explored the substrate promiscuity of CNR by investigating its nitroreduction of 4-nitrobenzyl derivatives. We tested twenty compounds containing a nitrobenzene core, two nitropyridines, one compound with a vinylogous nitro group, and two aliphatic nitro compounds. In addition, we also synthesized twenty-eight 4-nitrobenzyl derivatives with ether, ester, and thioether substituents and assessed the relative activity of CNR in their presence. We found several of these compounds to be modified by CNR, with the enzyme activity ranging from 1 to 150% when compared to CAM. This data provides insights into two areas: (i) chemoenzymatic reduction of select compounds to avoid harsh chemicals and heavy metals routinely used in reductions of nitro groups and (ii) functional groups that would aid CAM in overcoming the activity of this enzyme.
Collapse
Affiliation(s)
- Keith D Green
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536-0596, USA
| | - Marina Y Fosso
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536-0596, USA
| | - Abdelrahman S Mayhoub
- Department of Medicinal Chemistry and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sylvie Garneau-Tsodikova
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536-0596, USA.
| |
Collapse
|
6
|
Abstract
We report the case of a 36-year-old previously healthy woman who presented with fever and headache. Blood and cerebrospinal cultures and a bacterial analysis revealed the presence of β-lactamase non-producing ampicillin-resistant Haemophilus influenzae type f (Hif) with sequence type 124. Accordingly, the patient was diagnosed with bacterial meningitis with bacteremia caused by Hif. She had normal humoral immunity, and antibiotic therapy rapidly improved her condition. Our case indicates that serotype replacement can occur in Japan and suggests that a certain sequence type causes invasive Haemophilus influenzae disease, regardless of host immunity.
Collapse
Affiliation(s)
- Shinya Sakamoto
- Department of Infectious Diseases, Tokyo Metropolitan Bokutoh General Hospital, Japan
| | - Naoya Sakamoto
- Department of Infectious Diseases, Tokyo Metropolitan Bokutoh General Hospital, Japan
| |
Collapse
|
7
|
Cho C, Chande AT, Gakhar L, Hunt J, Ketterer MR, Apicella MA. Characterization of a nontypeable Haemophilus influenzae thermonuclease. PLoS One 2018; 13:e0197010. [PMID: 29746527 PMCID: PMC5944969 DOI: 10.1371/journal.pone.0197010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/24/2018] [Indexed: 01/28/2023] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) has been shown to form biofilms, comprised of extracellular DNA (eDNA), in the middle ear and bronchus during clinical infections. Studies in our laboratory have shown that NTHi possesses a homolog of Staphylococcus aureus thermonuclease (staphylococcal thermonuclease), NTHi nuclease (NTHi Nuc, HI_1296). This enzyme had similar size, heat stability, and divalent cation requirements to those of the staphylococcal homolog as determined by light scattering and circular dichroism spectroscopy. Small angle X-ray scattering (SAXS) analysis suggested an overall shape and substrate-binding site comparable to those of staphylococcal nuclease. However, NTHi Nuc was approximately 25-fold more active in fluorescence resonance energy transfer (FRET) activity assay than staphylococcal thermonuclease. Homology modeling implicates shorter NTHi Nuc loops near the active site for this enhanced activity.
Collapse
Affiliation(s)
- Christine Cho
- Iowa Inflammation Program, The University of Iowa, Iowa City, Iowa City, IA, United States of America
- Department of Infectious Disease, University of Iowa Hospitals, Iowa City, IA, United States of America
- Physician Scientist Training Pathway, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Aroon T Chande
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- IHRC-Georgia Tech Applied Bioinformatics Laboratory, Atlanta, Georgia, United States of America
- PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Columbia
| | - Lokesh Gakhar
- Department of Biochemistry, The University of Iowa, Iowa City, IA, United States of America
- Protein Crystallography Facility, The University of Iowa, Iowa City, IA, United States of America
| | - Jason Hunt
- Institute for Environmental Studies, Western Illinois University, Macomb, IL, United States of America
| | - Margaret R Ketterer
- Department of Microbiology, The University of Iowa, Iowa City, IA, United States of America
| | - Michael A Apicella
- Department of Microbiology, The University of Iowa, Iowa City, IA, United States of America
| |
Collapse
|
8
|
Nocek B, Reidl C, Starus A, Heath T, Bienvenue D, Osipiuk J, Jedrzejczak R, Joachimiak A, Becker DP, Holz RC. Structural Evidence of a Major Conformational Change Triggered by Substrate Binding in DapE Enzymes: Impact on the Catalytic Mechanism. Biochemistry 2018; 57:574-584. [PMID: 29272107 PMCID: PMC6886521 DOI: 10.1021/acs.biochem.7b01151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The X-ray crystal structure of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase from Haemophilus influenzae (HiDapE) bound by the products of hydrolysis, succinic acid and l,l-DAP, was determined at 1.95 Å. Surprisingly, the structure bound to the products revealed that HiDapE undergoes a significant conformational change in which the catalytic domain rotates ∼50° and shifts ∼10.1 Å (as measured at the position of the Zn atoms) relative to the dimerization domain. This heretofore unobserved closed conformation revealed significant movements within the catalytic domain compared to that of wild-type HiDapE, which results in effectively closing off access to the dinuclear Zn(II) active site with the succinate carboxylate moiety bridging the dinculear Zn(II) cluster in a μ-1,3 fashion forming a bis(μ-carboxylato)dizinc(II) core with a Zn-Zn distance of 3.8 Å. Surprisingly, His194.B, which is located on the dimerization domain of the opposing chain ∼10.1 Å from the dinuclear Zn(II) active site, forms a hydrogen bond (2.9 Å) with the oxygen atom of succinic acid bound to Zn2, forming an oxyanion hole. As the closed structure forms upon substrate binding, the movement of His194.B by more than ∼10 Å is critical, based on site-directed mutagenesis data, for activation of the scissile carbonyl carbon of the substrate for nucleophilic attack by a hydroxide nucleophile. Employing the HiDapE product-bound structure as the starting point, a reverse engineering approach called product-based transition-state modeling provided structural models for each major catalytic step. These data provide insight into the catalytic reaction mechanism and also the future design of new, potent inhibitors of DapE enzymes.
Collapse
Affiliation(s)
- Boguslaw Nocek
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Cory Reidl
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 West Sheridan Road, Chicago, Illinois 60626, United States
| | - Anna Starus
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 West Sheridan Road, Chicago, Illinois 60626, United States
| | - Tahirah Heath
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 West Sheridan Road, Chicago, Illinois 60626, United States
| | - David Bienvenue
- 19010 33rd Avenue Northeast, Seattle, Washington 98155, United States
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Jerzy Osipiuk
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Robert Jedrzejczak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Daniel P. Becker
- Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 West Sheridan Road, Chicago, Illinois 60626, United States
| | - Richard C. Holz
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| |
Collapse
|
9
|
Seyama S, Wajima T, Nakaminami H, Noguchi N. Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan. Antimicrob Agents Chemother 2016; 60:3207-10. [PMID: 26953210 PMCID: PMC4862528 DOI: 10.1128/aac.00163-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/29/2016] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to clarify the clarithromycin resistance mechanisms of β-lactamase-nonproducing ampicillin-resistant Haemophilus influenzae strains. In all clarithromycin-resistant strains, the transcript level of acrB was significantly elevated, and these strains had a frameshift mutation in acrR Introduction of the acrR mutation into H. influenzae Rd generated a clarithromycin-resistant transformant with the same MIC as the donor strain. Our results indicate that the acrR mutation confers clarithromycin resistance by the increasing the transcription of acrB.
Collapse
Affiliation(s)
- Shoji Seyama
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Takeaki Wajima
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Hidemasa Nakaminami
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Norihisa Noguchi
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| |
Collapse
|
10
|
Abstract
Proper folding of deeply knotted proteins has a very low success rate even in structure-based models which favor formation of the native contacts but have no topological bias. By employing a structure-based model, we demonstrate that cotranslational folding on a model ribosome may enhance the odds to form trefoil knots for protein YibK without any need to introduce any non-native contacts. The ribosome is represented by a repulsive wall that keeps elongating the protein. On-ribosome folding proceeds through a a slipknot conformation. We elucidate the mechanics and energetics of its formation. We show that the knotting probability in on-ribosome folding is a function of temperature and that there is an optimal temperature for the process. Our model often leads to the establishment of the native contacts without formation of the knot.
Collapse
Affiliation(s)
- Mateusz Chwastyk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | | |
Collapse
|
11
|
Hergott CB, Roche AM, Naidu NA, Mesaros C, Blair IA, Weiser JN. Bacterial exploitation of phosphorylcholine mimicry suppresses inflammation to promote airway infection. J Clin Invest 2015; 125:3878-90. [PMID: 26426079 DOI: 10.1172/jci81888] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/23/2015] [Indexed: 12/22/2022] Open
Abstract
Regulation of neutrophil activity is critical for immune evasion among extracellular pathogens, yet the mechanisms by which many bacteria disrupt phagocyte function remain unclear. Here, we have shown that the respiratory pathogen Streptococcus pneumoniae disables neutrophils by exploiting molecular mimicry to degrade platelet-activating factor (PAF), a host-derived inflammatory phospholipid. Using mass spectrometry and murine upper airway infection models, we demonstrated that phosphorylcholine (ChoP) moieties that are shared by PAF and the bacterial cell wall allow S. pneumoniae to leverage a ChoP-remodeling enzyme (Pce) to remove PAF from the airway. S. pneumoniae-mediated PAF deprivation impaired viability, activation, and bactericidal capacity among responding neutrophils. In the absence of Pce, neutrophils rapidly cleared S. pneumoniae from the airway and impeded invasive disease and transmission between mice. Abrogation of PAF signaling rendered Pce dispensable for S. pneumoniae persistence, reinforcing that this enzyme deprives neutrophils of essential PAF-mediated stimulation. Accordingly, exogenous activation of neutrophils overwhelmed Pce-mediated phagocyte disruption. Haemophilus influenzae also uses an enzyme, GlpQ, to hydrolyze ChoP and subvert PAF function, suggesting that mimicry-driven immune evasion is a common paradigm among respiratory pathogens. These results identify a mechanism by which shared molecular structures enable microbial enzymes to subvert host lipid signaling, suppress inflammation, and ensure bacterial persistence at the mucosa.
Collapse
|
12
|
Mevio E, Giacobone E, Galioto P, Perano D, Bulzomi AG. Evolution of the bacterial flora in recurrent adenotonsillitis. Therapeutic implications. Adv Otorhinolaryngol 2015; 47:134-41. [PMID: 1456122 DOI: 10.1159/000421732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- E Mevio
- Department of Otorhinolaryngology, University of Pavia, IRCCS San Matteo, Italy
| | | | | | | | | |
Collapse
|
13
|
Hoffmann KM, Million-Perez HR, Merkhofer R, Nicholson H, Rowlett RS. Allosteric reversion of Haemophilus influenzae β-carbonic anhydrase via a proline shift. Biochemistry 2015; 54:598-611. [PMID: 25506786 DOI: 10.1021/bi501116e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Haemophilus influenzae β-carbonic anhydrase (HICA) has been reverse-engineered in the allosteric site region to resemble the nonallosteric Pisum sativum enzyme in order to identify critical features of allostery and intersusbunit communication. Three variants (W39V/G41A, P48S/A49P, and W39V/G41A/P48S/A49P) were identified, through a comparison with a crystal structure of nonallosteric P. sativum β-carbonic anhydrase (PSCA, PDB 1EKJ ), to potentially revert HICA to a nonallosteric enzyme. The W39V/G41A and P48S/A49P mutations decreased the apparent kcat/Km proton dependence from 4 to 2 and 1, respectively, increasing the overall maximal kcat/Km to 16 ± 2 μM(-1) s(-1) (380% of wild type) and 17 ± 3 μM(-1) s(-1) (405% of wild type). The pKa values of the metal-bound water molecule based on the pH-rate profile kinetics (8.32 ± 0.04 for W39V/G41A and 8.3 ± 0.1 for P48S/A49P) were also slightly higher than that for the wild-type enzyme (7.74 ± 0.04). The P48S/A49P variant has lost all pH-rate cooperativity. The W39V/G41A/P48S/A49P variant's kinetics were unusual and were fit with a log-linear function with a slope 0.9 ± 0.2. The crystal structure of the W39V/G41A variant revealed an active site very similar to the T-state wild-type oligomer with bicarbonate trapped in the escort site. By contrast, the X-ray crystal structure of a proline shift variant (P48S/A49P) reveals that it has adopted an active site conformation nearly identical to that of nonallosteric β-carbonic anhydrase (R-state) for one chain, including a tight association with the dimer-exchanged N-terminal helices; the second chain in the asymmetric unit is associated in a biologically relevant oligomer, but it adopts a T-state conformation that is not capped by dimer-exchanged N-terminal helices. The hybrid R/T nature of HICA P48S/A49P structurally recapitulates the interruption of pH-rate cooperativity observed for this variant. Comparison of the conformations of the R and T chains of P48S/A49P suggests a new hypothesis to explain HICA allosteric communication that is mediated by the N-terminal helices and anion binding at the dimer interface.
Collapse
Affiliation(s)
- Katherine M Hoffmann
- Department of Chemistry, Gonzaga University , 502 East Boone Avenue, Spokane, Washington 99258, United States
| | | | | | | | | |
Collapse
|
14
|
Hsieh SJM, Mallam AL, Jackson SE, Hsu STD. Backbone 1H, 13C and 15N assignments of YibK and avariant containing a unique cysteine residue at C-terminus in 8 M urea-denatured states [corrected]. Biomol NMR Assign 2014; 8:439-442. [PMID: 23853076 DOI: 10.1007/s12104-013-9510-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/29/2013] [Indexed: 06/02/2023]
Abstract
YibK is a tRNA methyltransferase from Haemophilus influenzae, which forms a stable homodimer in solution and contains a deep trefoil 31 knot encompassing the C-terminal helix that threads through a long loop. It has been a model system for investigating knotted protein folding pathways. Recent data have shown that the polypeptide chain of YibK remains loosely knotted under highly denaturing conditions. Here, we report (1)H, (13)C and (15)N chemical shift assignments for YibK and its variant in the presence of 8 M urea. This work forms the basis for further analysis using NMR techniques such as paramagnetic relaxation enhancement, residual dipolar couplings and spin-relaxation dynamics analysis.
Collapse
|
15
|
Affiliation(s)
- Jessica R. McCann
- The Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Joseph W. St. Geme
- The Department of Pediatrics, The Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
16
|
Mohd-Zain Z, Kamsani NH, Ahmad N. Molecular insights of co-trimoxazole resistance genes in Haemophilus influenzae isolated in Malaysia. Trop Biomed 2013; 30:584-590. [PMID: 24522126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the last few decades, co-trimoxazole (SXT), an antibacterial combination of trimethoprim and sulfamethoxazole, has been used for treatment of upper respiratory tract infection due to Haemophilus influenzae. The usage of this antibiotic has become less important due to emergence of SXT-resistant strains worldwide. Most reports associate SXT resistance to the presence of variants of dihydrofolate reductase (DHFR) dfrA genes which are responsible for trimethoprim resistance; while the sulfamethoxazole (SMX) resistance are due to sulfonamide (SUL) genes sul1 and sul2 and/or mutation in the chromosomal (folP) gene encoding dihydropteroate synthetase (DHPS). This study aims to detect and analyse the genes that are involved in SXT resistance in H. influenzae strains that were isolated in Malaysia. Primers targeting for variants of dfrA, fol and sul genes were used to amplify the genes in nine SXT-resistant strains. The products of amplification were sequenced and multiple alignments of the assembled sequences of the local strains were compared to the sequences of other H. influenzae strains in the Genbank. Of the five variants of the dhfA genes, dfrA1 was detected in three out of the nine strains. In contrast to intermediate strains, at least one variant of folP genes was detected in the resistant strains. Multiple nucleotide alignment of this gene revealed that strain H152 was genetically different from the others due to a 15-bp nucleotide insert in folP gene. The sequence of the insert was similar to the insert in folP of H. influenzae strain A12, a strain isolated in United Kingdom. None of the strains had sul1 gene but sul2 gene was detected in four strains. Preliminary study on the limited number of samples shows that the TMP resistance was attributed to mainly to dfrA1 and the SMX was due to folP genes. Presence of sul2 in addition to folP in seven strains apparently had increased their level of resistance. A strain that lacked sul1 or sul2 gene, its resistance to sulfonamide was attributed to a 15-bp DNA insert in the folP gene.
Collapse
Affiliation(s)
- Z Mohd-Zain
- Institute of Medical Molecular Biotechnology, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Selangor
| | - N H Kamsani
- Institute of Medical Molecular Biotechnology, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Selangor
| | - N Ahmad
- Institute for Medical Research, Jalan Pahang, Kuala Lumpur
| |
Collapse
|
17
|
Schaar V, Uddbäck I, Nordström T, Riesbeck K. Group A streptococci are protected from amoxicillin-mediated killing by vesicles containing β-lactamase derived from Haemophilus influenzae. J Antimicrob Chemother 2013; 69:117-20. [PMID: 23912886 DOI: 10.1093/jac/dkt307] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES Group A streptococci (GAS) cause, among other infections, pharyngotonsillitis in children. The species is frequently localized with the Gram-negative respiratory pathogens non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis, which both produce outer membrane vesicles (OMVs). The aim of this study was to investigate whether OMVs isolated from NTHi contain functional β-lactamase and whether the OMVs hydrolyse amoxicillin and thus protect GAS from killing by the antibiotic. METHODS The antibiotic susceptibility of isolates was determined using the Etest. The resistance genes blaTEM-1 (encoding NTHi β-lactamase), bro-1 (encoding M. catarrhalis β-lactamase) and ftsI (encoding NTHi penicillin-binding protein 3) were searched for by PCR, followed by sequencing. OMVs were isolated by ultracentrifugation and the presence of β-lactamase was detected by western blots including specific rabbit polyclonal antibodies. The chromogenic substrate nitrocefin was used to quantify and compare the β-lactamase enzyme activity in the OMVs. The hydrolysis of amoxicillin by β-lactamase was estimated by an agar diffusion method. RESULTS We showed that OMVs released from β-lactam-resistant M. catarrhalis and NTHi contain functional β-lactamase that hydrolyses amoxicillin and protects GAS from killing by amoxicillin. CONCLUSIONS This is the first report of the presence of β-lactamase in NTHi OMVs. We suggest that OMV-derived β-lactamase from coinfecting pathogens such as NTHi and M. catarrhalis may contribute to the occasional treatment failures seen in GAS tonsillitis.
Collapse
Affiliation(s)
- Viveka Schaar
- Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Malmö, Sweden
| | | | | | | |
Collapse
|
18
|
Han AR, Kim HS, Cho GY, Ki HS, Kim HY, Hwang KY. Crystallization and preliminary X-ray crystallographic analysis of the methionine sulfoxide reductase A domain of MsrAB from Haemophilus influenzae. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:557-9. [PMID: 22691787 PMCID: PMC3374512 DOI: 10.1107/s1744309112011256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Accepted: 03/14/2012] [Indexed: 11/11/2022]
Abstract
Methionine sulfoxide reductase (Msr) is a repair enzyme that reduces oxidized methionine to methionine. The Msr enzyme is divided into MsrA and MsrB, which reduce the S and R configurations of the substrate, respectively. In some pathogenic bacteria MsrA and MsrB exist in a fusion-protein form, MsrAB. In this study, the recombinant MsrA part of MsrAB from Haemophilus influenzae (HIMsrA) was overexpressed, purified and crystallized using the hanging-drop vapour-diffusion method. A diffraction data set was collected to 1.6 Å resolution. The crystal of HIMsrA was found to belong to space group P4(1)2(1)2, with unit-cell parameters a = b = 57.29, c = 186.28 Å, a calculated Matthews coefficient of 1.82 Å(3) Da(-1) and two molecules per asymmetric unit. A preliminary solution was determined by molecular replacement. Refinement of the structure is currently in progress.
Collapse
Affiliation(s)
- Ah Reum Han
- Division of Biotechnology, Korea University, Anam-dong, Seong-buk-gu, Seoul 136-713, Republic of Korea
| | - Hyun Sook Kim
- Division of Biotechnology, Korea University, Anam-dong, Seong-buk-gu, Seoul 136-713, Republic of Korea
| | - Gye Yoon Cho
- Division of Biotechnology, Korea University, Anam-dong, Seong-buk-gu, Seoul 136-713, Republic of Korea
| | - Ho Sam Ki
- Division of Biotechnology, Korea University, Anam-dong, Seong-buk-gu, Seoul 136-713, Republic of Korea
| | - Hwa-Young Kim
- Department of Biochemistry and Molecular Biology, Yeungnam University College of Medicine, Daegu 705-717, Republic of Korea
| | - Kwang Yeon Hwang
- Division of Biotechnology, Korea University, Anam-dong, Seong-buk-gu, Seoul 136-713, Republic of Korea
| |
Collapse
|
19
|
Lulitanond A, Chanawong A, Pienthaweechai K, Sribenjalux P, Tavichakorntrakool R, Wilailuckana C, Puang-Ngern P, Saetung P. Prevalence of β-lactamase-negative ampicillin-resistant haemophilus influenzae isolated from patients of a teaching hospital in Thailand. Jpn J Infect Dis 2012; 65:122-125. [PMID: 22446118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of this study was to investigate the prevalence of β-lactamase-negative ampicillin-resistant (BLNAR) Haemophilus influenzae isolated from patients of a teaching hospital in Thailand. Eighty-eight isolates of H. influenzae were collected between September 2005 and March 2008. All isolates were identified and characterized for biotypes and capsular types. The β-lactamase production of these isolates was examined, and their susceptibility to the following 12 antimicrobial agents was determined: ampicillin (AMP), amoxicillin-clavulanate (AMC), cefotaxime (CTX), cefuroxime (CXM), meropenem (MEM), clarithromycin (CLR), telithromycin (TEL), tetracycline (TET), ciprofloxacin (CIP), levofloxacin (LEV), trimethoprim-sulfamethoxazole (SXT), and chloramphenicol (CHL). Of the 88 H. influenzae isolates, 69 (78.4%), 13 (14.8%), 4 (4.5%), and 2 (2.3%) were from the respiratory tract, pus, the genital tract, and blood, respectively. Half of the isolates were biotype II (44 isolates, 50%). The other half comprised biotypes I (23 isolates, 26.1%), III (15 isolates, 17.1%), and IV (6 isolates, 6.8%). All isolates were capsular non-typeable, except for 2 isolates that were type f. Antimicrobial susceptibility showed that all isolates were susceptible to AMC, CTX, MEM, TEL, CIP, and LEV (100%), whereas 96.6%, 94.3%, 80.7%, 68.2%, 50.0%, and 44.3% were susceptible to CXM, CLR, CHL, TET, AMP, and SXT, respectively. The β-lactamase-production rate of H. influenzae isolates was 40.9%, and the prevalence of BLNAR was 18.2%.
Collapse
Affiliation(s)
- Aroonlug Lulitanond
- Centre for Research and Development of Medical Diagnostic Laboratories, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand. arolul@kku.ac.th
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Witherden EA, Kunde D, Tristram SG. An evaluation of SNP-based PCR methods for the detection of β-lactamase-negative ampicillin-resistant Haemophilus influenzae. J Infect Chemother 2011; 18:451-5. [PMID: 22203122 DOI: 10.1007/s10156-011-0356-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 11/29/2011] [Indexed: 11/27/2022]
Abstract
Forty-four previously characterized strains of Haemophilus influenzae were used to evaluate the specificity of previously published SNP PCR primers for the detection of the N526K substitution in PBP3 of BLNAR isolates using real-time PCR. Hasegawa et al. primers that amplify strains without a substitution at 526 and fail to amplify strains with N526K were 100% sensitive and specific for detecting N526K. However, primer sets of Hasegawa et al. and Nakamura et al. designed to amplify strains with N526K, but not strains without a substitution, were unable to do this reliably because the primers were specific for N526K encoded by AAG and failed to amplify strains with N526K encoded by AAA. A review of N526K strains deposited on GenBank revealed an even distribution of AAG and AAA codons for N526K in European and Australian BLNAR strains, whereas only the AAG codon was seen in Japanese strains. The exclusive presence of the AAG codon in Japanese strains appears to be independent of the use of the SNP PCR primers evaluated here and remains unexplained.
Collapse
Affiliation(s)
- Elizabeth A Witherden
- School of Human Life Sciences, University of Tasmania, Launceston, TAS, 7250, Australia.
| | | | | |
Collapse
|
21
|
Gedi V, Moon JY, Lim WM, Lee MY, Lee SC, Koo BS, Govindwar S, Yoon MY. Identification and characterization of inhibitors of Haemophilus influenzae acetohydroxyacid synthase. Enzyme Microb Technol 2011; 49:1-5. [PMID: 22112263 DOI: 10.1016/j.enzmictec.2011.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 03/24/2011] [Accepted: 04/02/2011] [Indexed: 11/18/2022]
Abstract
Acetohydroxyacid synthase (AHAS), a potential target for antimicrobial agents, catalyzes the first common step in the biosynthesis of branched-chain amino acids. The gene coding for the AHAS catalytic subunit from Haemophilus influenzae (Hi) was cloned, overexpressed in Escherichia coli, and purified. To identify new inhibitory scaffolds, we used a high-throughput screen to test 221 small diverse chemical compounds against Hi-AHAS. Compounds were selected for their ability to inhibit AHAS in vitro. The screen identified 3 compounds, each representing a structural class, as Hi-AHAS inhibitors with an IC(50) in the low micromolar range (4.4-14.6 μM). The chemical scaffolds of the three compounds were oxa-1-thia-4-aza-cyclopenta[b]naphthalene (KHG25229), phenyl-2,3-dihydro-isothiazole (KHG25386), and phenyl-pyrrolidine-3-carboxylic acid phenylamide (KHG25056). Further, molecular docking of the two most potent chemicals, KHG25229 and KHG25386, in Hi-AHAS yielded binding energies of -10.41 and -9.21 kcal/mol, respectively. The binding modes were consistent with inhibition mechanisms, as both chemicals oriented outside the active site. As the need for novel antibiotic classes to combat drug resistant bacteria increases, screening compounds that act against Hi-AHAS may assist in the identification of potential new anti-Hi drugs.
Collapse
Affiliation(s)
- Vinayakumar Gedi
- Department of Chemistry and Research institute of Natural sciences, Hanyang University, Seoul 133-791, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Singh H, Schuermann JP, Reilly TJ, Calcutt MJ, Tanner JJ. Recognition of nucleoside monophosphate substrates by Haemophilus influenzae class C acid phosphatase. J Mol Biol 2010; 404:639-49. [PMID: 20934434 DOI: 10.1016/j.jmb.2010.09.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 09/27/2010] [Accepted: 09/30/2010] [Indexed: 11/17/2022]
Abstract
The e (P4) phosphatase from Haemophilus influenzae functions in a vestigial NAD(+) utilization pathway by dephosphorylating nicotinamide mononucleotide to nicotinamide riboside. P4 is also the prototype of class C acid phosphatases (CCAPs), which are nonspecific 5',3'-nucleotidases localized to the bacterial outer membrane. To understand substrate recognition by P4 and other class C phosphatases, we have determined the crystal structures of a substrate-trapping mutant P4 enzyme complexed with nicotinamide mononucleotide, 5'-AMP, 3'-AMP, and 2'-AMP. The structures reveal an anchor-shaped substrate-binding cavity comprising a conserved hydrophobic box that clamps the nucleotide base, a buried phosphoryl binding site, and three solvent-filled pockets that contact the ribose and the hydrogen-bonding edge of the base. The span between the hydrophobic box and the phosphoryl site is optimal for recognizing nucleoside monophosphates, explaining the general preference for this class of substrate. The base makes no hydrogen bonds with the enzyme, consistent with an observed lack of base specificity. Two solvent-filled pockets flanking the ribose are key to the dual recognition of 5'-nucleotides and 3'-nucleotides. These pockets minimize the enzyme's direct interactions with the ribose and provide sufficient space to accommodate 5' substrates in an anti conformation and 3' substrates in a syn conformation. Finally, the structures suggest that class B acid phosphatases and CCAPs share a common strategy for nucleotide recognition.
Collapse
Affiliation(s)
- Harkewal Singh
- Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA
| | | | | | | | | |
Collapse
|
23
|
Ilki A, Sağiroğlu P, Elgörmüş N, Söyletir G. [Trends in antibiotic susceptibility patterns of Streptococcus pneumoniae and Haemophilus influenzae isolates: four years follow up]. MIKROBIYOL BUL 2010; 44:169-175. [PMID: 20549950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This study was aimed to follow up the antibiotic resistance trends in Streptococcus pneumoniae and Haemophilus influenzae isolated from clinical specimens between 2003-2006 at Marmara University Hospital, Istanbul, Turkey. Antibiotic susceptibilities were performed by disk diffusion method, and penicillin susceptibility was determined by E-test (AB Biodisk, Sweden). Results were evaluated by CLSI standards. During this period a total of 258 S. pneumoniae and 548 H. influenzae were isolated in our laboratory. According to the 2006 CLSI penicillin breakpoints, overall resistance of S. pneumoniae isolates to penicillin was 39.9% and intermediate and high level penicillin resistance rates were 30.2% and 9.7%, respectively. The rates of high level penicillin resistant pneumococci by years were 11.1% in 2003; 10.9% in 2004; 6% in 2005, 12.1% in 2006 and except for 2005 no significant change in resistance rates was detected. However, according to the 2008 CLSI penicillin breakpoints, resistance was found to be 3.5%, intermediate and high level penicillin resistance being 3.1% and 0.4%, respectively. While penicillin resistance rates by years were as 4.4% in 2003, 5.5% in 2004, 0% in 2005 and 4.4% in 2006, high level penicillin resistance was detected only in 2003 as 2.2%. Resistance rates of chloramphenicol, erythromycin, tetracyline and trimethoprim-sulphametoxazole (TMP-SMX) were detected as 10.1%, 19%, 26.8% and 49.2%, respectively while erythromycin, tetracycline and TMP-SMX multi-drug resistance was detected in 12.4% of the isolates. No resistance was detected to vancomycin. Beta-lactamase production rate in H. influenzae isolates was 3.3%, being 1.6% in 2003 with a raise up to 4% in 2006. No beta-lactamase negative ampicillin-resistant isolate was detected. Although chloramphenicol and cefaclor resistance were in low levels (2.2% and 0.7%, respectively), TMP-SMX resistance was detected as 25.5%. TMP-SMX resistance was two fold more in beta-lactamase producers compared with the non-producers, whereas chloramphenicol resistance revealed a significant increase in beta-lactamase producers (1% versus 44.5%). In conclusion, doubling of beta-lactamase production rate in H. influenzae within years indicates the importance of continuous follow-up of antibiotic resistance in specific pathogens. The evaluation of penicillin results obtained for pneumococci according to modified 2008 CLSI criteria revealed that penicillin can still be used effectively in the treatment of pneumococcal respiratory tract infections. Continuous active surveillance of resistance rates provides important data for the determination of the empirical therapy protocols for S. pneumoniae and H. influenzae infections.
Collapse
Affiliation(s)
- Arzu Ilki
- Marmara Universitesi Tip Fakültesi, Mikrobiyoloji Anabilim Dali, Istanbul.
| | | | | | | |
Collapse
|
24
|
Kresge N, Simoni RD, Hill RL. The characterization of restriction endonucleases: the work of Hamilton Smith. J Biol Chem 2010; 285:e2-e3. [PMID: 21491685 PMCID: PMC2804378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
Purification of the HhaII Restriction Endonuclease from an Overproducer Escherichia coli Clone (Kelly, S., Kaddurah-Daouk, R., and Smith, H. O. (1985) J. Biol. Chem. 260, 15339–15344) Catalytic Properties of the HhaII Restriction Endonuclease (Kaddurah-Daouk, R., Cho, P., and Smith, H. O. (1985) J. Biol. Chem. 260, 15345–15351)
Collapse
|
25
|
Jin BS, Han SG, Lee WK, Ryoo SW, Lee SJ, Suh SW, Yu YG. Inhibitory mechanism of novel inhibitors of UDP-N-acetylglucosamine enolpyruvyl transferase from Haemophilus influenzae. J Microbiol Biotechnol 2009; 19:1582-1589. [PMID: 20075623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bacterial UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) catalyzes the transfer of enolpyruvate from phosphoenolphyruvate (PEP) to uridine diphospho-N-acetylglucosamine (UNAG), which is the first step of bacterial cell wall synthesis. We identified thimerosal, thiram, and ebselen as effective inhibitors of Heamophilus influenzae MurA by screening a chemical library that consisted of a wide range of bioactive compounds. When MurA was preincubated with these inhibitors, their 50% inhibitory concentrations (IC50s) were found to range from 0.1 to 0.7 microM. In particular, thimerosal suppressed the growth of several different Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium at a concentration range of 1-2 microg/ml. These inhibitors covalently modified the cysteine residue near the active site of MurA. This modification changed the open conformation of MurA to a more closed configuration, which may have prevented the necessary conformational change from occurring during the enzyme reaction.
Collapse
Affiliation(s)
- Bong-Suk Jin
- Department of Chemistry, Kookmin University, 861-1 Jeongneung, Seongbuk, Seoul, 136-702, Korea
| | | | | | | | | | | | | |
Collapse
|
26
|
Qiu YH, Zhang Y, Hua CZ, Zhang ZX, Li JP. [Serotypes and ampicillin resistance of Haemophilus influenzae isolates from children with respiratory infection in Hangzhou]. Zhongguo Dang Dai Er Ke Za Zhi 2009; 11:217-220. [PMID: 19292964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To investigate the serotypes distribution and ampicillin resistance of Haemophilus influenzae isolates from children with respiratory infection in Hangzhou. METHODS Haemophilus influenzae strains were identified with V factor and X factor tests. Serotypes were determined with the slide agglutination method. Nitrocefin test was used to detect beta-lactamase. The sensitivities of ampicillin to Haemophilus influenzae were determined with the Kirby-Bauer diffusion method and the E-test method. RESULTS One hundred and fifty-two Haemophilus influenzae isolates, 108 from boys and 44 from girls, were identified between December 2006 and July 2007. Of the 152 isolates, 148 (97.4%) were untypable, only 4 (2.6%) were typable, including type a, type d, type e and type f (n=1 each type). Haemophilus influenzae type b and c strain was not found. Thirty-four isolates (22.4%) were beta-lactamase-positive. One hundred and thirteen isolates (74.3%) were susceptible to ampicillin, while 34 isolates (22.4%) were resistant to ampicillin. CONCLUSIONS Untypable strains were the most common in Haemophilus influenzae isolates from children with respiratory infection in Hangzhou. The isolates of Haemophilus influenzae kept susceptibity to ampicillin to a certain extent.
Collapse
Affiliation(s)
- Yi-Hui Qiu
- Clinical Medical School of Hangzhou Normal University, Hangzhou 310018, China
| | | | | | | | | |
Collapse
|
27
|
Little EJ, Babic AC, Horton NC. Early interrogation and recognition of DNA sequence by indirect readout. Structure 2008; 16:1828-37. [PMID: 19081059 PMCID: PMC2637360 DOI: 10.1016/j.str.2008.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 08/28/2008] [Accepted: 09/21/2008] [Indexed: 01/07/2023]
Abstract
Control of replication, transcription, recombination and repair requires proteins capable of finding particular DNA sequences in a background of a large excess of nonspecific sequences. Such recognition can involve direct readout, with direct contacts to the bases of DNA, or in some cases through the less well-characterized indirect readout mechanisms. In order to measure the relative contributions of direct and indirect readout by a sequence specific endonuclease, HincII, a mutant enzyme deficient in a direct contact, was characterized, and surprisingly showed no loss of sequence specificity. The three dimensional crystal structure shows the loss of most of the direct readout contacts to the DNA, possibly capturing an early stage in target site recognition using predominately indirect readout to prescreen sites before full sequence interrogation.
Collapse
Affiliation(s)
- Elizabeth J Little
- Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA
| | | | | |
Collapse
|
28
|
Yano R, Takayanagi N, Kagiyama N, Harasawa K, Matusita F, Yoneda K, Miyahara Y, Yamaguchi S, Tokunaga D, Saito H, Kurashima K, Ubukata M, Yanagisawa T, Sugita Y. [Case of pneumonia caused by beta-lactamase-producing and amoxicillin/clavulanate resistant strains of H. influenzae]. Nihon Kokyuki Gakkai Zasshi 2008; 46:753-758. [PMID: 18939421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
An 80-year-old woman presenting with fever and cough was given a diagnosis of community-acquired pneumonia. She was hospitalized and treated with ampicillin/sulbactam (ABPC/SBT) and clarithromycin (CAM). Gram stain images and sputum culture results led us to believe that the causative agent was Haemophilus influenzae. Drug sensitivity testing indicated that the H. influenzae was a beta-lactamase-positive, ABPC-resistant (BLPAR) strain. Treatment with ABPC/SBT was not clinically effective. We considered the possibility of beta-lactamase-positive amoxicillin/clavulanate-resistant (BLPACR) strains. Further testing revealed that the MIC of ABPC was 128 microg/ml, that of SBT/ABPC was 8 microg/ml, and that of AMPC/CVA was 4 microg/ml. Furthermore, genetic analysis indicated the H. influenzae to be a BLPACR-I strain. The poor clinical course eventually led to a diagnosis of BLPACR. When beta-lactamase-producing H. influenzae is cultured, the possibility of a BLPACR strain resistant to ABPC/SBT and AMPC/CVA must be considered.
Collapse
Affiliation(s)
- Ryozo Yano
- Department of Respiratory Medicine, Saitama Cardiovascular and Respiratory Center
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Wang CC, Kuo HY, Chiang DH, Tsai CC, Lin ML, Chan YJ, Yang SP, Liu CY. Invasive Haemophilus influenzae disease in adults in Taiwan. J Microbiol Immunol Infect 2008; 41:209-214. [PMID: 18629415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND PURPOSE Haemophilus influenzae is an important cause of invasive infection in infants and children, but it has been considered an uncommon cause of invasive disease in adults. We conducted a retrospective survey of invasive H. influenzae disease in adults in order to better understand the characteristics of clinical presentation and microbiology. METHODS Patients older than 18 years with H. influenzae isolated from normally sterile sites, between July 1999 and June 2002 in a teaching hospital for adult patients were retrospectively analyzed. Data on demographics, clinical presentation, serotype, antibiotic susceptibility, and beta-lactamase production of H. influenzae isolates were analyzed. RESULTS Fifteen patients were enrolled. The infectious diagnosis of invasive diseases comprised: pneumonia (5 patients), empyema (2), pelvic inflammatory disease (2), peritonitis (2), periorbital cellulitis with abscess formation (2), endophthalmitis (1) and primary bacteremia (1). Most patients were elderly with underlying illness. Of ten H. influenzae isolates available for analysis, two were serotype b and eight were nontypeable. Beta-lactamase production and ampicillin resistance were found in 6 H. influenzae isolates (5 nontypeable, and 1 type b). CONCLUSION These data show H. influenzae disease in adults to be rare in Taiwan. Our limited number of cases suggest that nontypeable strains predominate in patients with invasive infection due to H. influenzae. Most patients had respiratory tract infections. Ampicillin resistance was found in more than one-half of H. influenzae isolates, and should be taken into consideration when antibiotics are prescribed on an empirical basis.
Collapse
Affiliation(s)
- Chien-Chun Wang
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, and National Yang-Ming University, Taipei, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
30
|
De Vecchi E, Nicola L, Larosa M, Drago L. In vitro activity of telithromycin against Haemophilus influenzae at epithelial lining fluid concentrations. BMC Microbiol 2008; 8:23. [PMID: 18230154 PMCID: PMC2270277 DOI: 10.1186/1471-2180-8-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Accepted: 01/29/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Haemophilus influenzae is one of the main aetiological agents of community-acquired respiratory tract infections. The primary aim of this study was to evaluate the antibacterial activity of telithromycin against H. influenzae clinical isolates showing different pattern of resistance in comparison with azithromycin and clarithromycin at 1/4 x, 1/2 x, 1 x, 2 x, 4 x minimum inhibitory concentration (MIC) and to peak concentrations in epithelial lining fluid (ELF). The secondary aim was to determine the influence of CO2 enriched atmosphere on bacterial susceptibility. RESULTS Telithromycin showed high activity against H. influenzae, including strains susceptible to beta-lactams (n = 200), beta-lactamase producer (n = 50) and beta-lactamase negative ampicillin resistant (BLNAR) (n = 10), with MIC from < or =0.03 to 4 mg/L, and MIC50/MIC90 of 1/2 mg/L with susceptibility rate of 100%, and minimum bactericidal concentrations (MBC) from 2 to 4-fold higher than the MIC. Azithromycin was the most active tested macrolide (range: 0.25 - 4 mg/L; MIC50/MIC90: 1/2 mg/L), comparable to telithromycin, while clarithromycin showed the highest MICs and MBCs (range: 0.25 - 8 mg/L; MIC50/MIC90: 2/8 mg/L). In time-kill studies, telithromycin showed a bactericidal activity at the higher concentrations (4 - 2 x MIC and ELF) against all the strains, being complete after 12 - 24 hours from drug exposition. At MIC concentrations, at ambient air, bactericidal activity of telithromycin and azithromycin was quite similar at 12 hours, and better than that of clarithromycin. Besides, telithromycin and clarithromycin at ELF concentrations were bactericidal after 12 hours of incubation for most strains, while 24 hours were needed to azithromycin to be bactericidal. Incubation in CO2 significantly influenced the MICs and MBCs, and only slightly the in vitro killing curves. CONCLUSION Telithromycin showed an in-vitro potency against H. influenzae comparable to azithromycin, with an in-vitro killing rate more rapid and superior to clarithromycin at 2X-MIC against beta-lactamase producers and BLNAR strains, and to azithromycin at ELF concentrations against beta-lactamase negative strains. Against all strains, MICs and MBCs were lower in the absence of CO2 for the tested antibiotics, showing an adverse effect of incubation in a CO2 environment. The in-vitro potency together with the tissue concentrations of the antimicrobial, should be considered in predicting efficacy.
Collapse
Affiliation(s)
- Elena De Vecchi
- Laboratory of Clinical Microbiology, Department of Preclinical Sciences LITA Vialba, University of Milan, Via GB Grassi 74, 20159 Milan, Italy
| | - Lucia Nicola
- Laboratory of Clinical Microbiology, Department of Preclinical Sciences LITA Vialba, University of Milan, Via GB Grassi 74, 20159 Milan, Italy
| | - Monica Larosa
- Medical Affairs & Scientific Relations, sanofi-aventis, v.le L. Bodio 37/b – Milano Milan, Italy
| | - Lorenzo Drago
- Laboratory of Clinical Microbiology, Department of Preclinical Sciences LITA Vialba, University of Milan, Via GB Grassi 74, 20159 Milan, Italy
| |
Collapse
|
31
|
Mochalkin I, Lightle S, Zhu Y, Ohren JF, Spessard C, Chirgadze NY, Banotai C, Melnick M, McDowell L. Characterization of substrate binding and catalysis in the potential antibacterial target N-acetylglucosamine-1-phosphate uridyltransferase (GlmU). Protein Sci 2007; 16:2657-66. [PMID: 18029420 PMCID: PMC2222810 DOI: 10.1110/ps.073135107] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 09/17/2007] [Accepted: 09/18/2007] [Indexed: 10/22/2022]
Abstract
N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) catalyzes the first step in peptidoglycan biosynthesis in both Gram-positive and Gram-negative bacteria. The products of the GlmU reaction are essential for bacterial survival, making this enzyme an attractive target for antibiotic drug discovery. A series of Haemophilus influenzae GlmU (hiGlmU) structures were determined by X-ray crystallography in order to provide structural and functional insights into GlmU activity and inhibition. The information derived from these structures was combined with biochemical characterization of the K25A, Q76A, D105A, Y103A, V223A, and E224A hiGlmU mutants in order to map these active-site residues to catalytic activity of the enzyme and refine the mechanistic model of the GlmU uridyltransferase reaction. These studies suggest that GlmU activity follows a sequential substrate-binding order that begins with UTP binding noncovalently to the GlmU enzyme. The uridyltransferase active site then remains in an open apo-like conformation until N-acetylglucosamine-1-phosphate (GlcNAc-1-P) binds and induces a conformational change at the GlcNAc-binding subsite. Following the binding of GlcNAc-1-P to the UTP-charged uridyltransferase active site, the non-esterified oxygen of GlcNAc-1-P performs a nucleophilic attack on the alpha-phosphate group of UTP. The new data strongly suggest that the mechanism of phosphotransfer in the uridyltransferase reaction in GlmU is primarily through an associative mechanism with a pentavalent phosphate intermediate and an inversion of stereochemistry. Finally, the structural and biochemical characterization of the uridyltransferase active site and catalytic mechanism described herein provides a basis for the structure-guided design of novel antibacterial agents targeting GlmU activity.
Collapse
Affiliation(s)
- Igor Mochalkin
- Pfizer Global Research and Development, Michigan Laboratories, Ann Arbor, Michigan 48105, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Ohno A, Ishii Y, Kobayashi I, Yamaguchi K. Antibacterial activity and PK/PD of ceftriaxone against penicillin-resistant Streptococcus pneumoniae and beta-lactamase-negative ampicillin-resistant Haemophilus influenzae isolates from patients with community-acquired pneumonia. J Infect Chemother 2007; 13:296-301. [PMID: 17982717 DOI: 10.1007/s10156-007-0539-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 05/22/2007] [Indexed: 11/26/2022]
Abstract
The suitability of ceftriaxone for penicillin-resistant Streptococcus pneumoniae (PRSP) and ampicillin-resistant Haemophilus influenzae (especially beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae) and the relationship between in vitro antimicrobial activities and pharmacokinetic parameters were evaluated. The values for percentage of time above the MIC (%T>MIC) for ceftriaxone, cefotiam, flomoxef, sulbactam/cefoperazone, sulbactam/ampicillin, and meropenem, using 400 S. pneumoniae isolates and 430 H. influenzae isolates from patients with community-acquired pneumonia (CAP) from more than 100 geographically diverse medical centers during January to July of 2005, were calculated by measuring the MIC for each isolate and by using patameters of pharmacokinetics. A broth microdilution method was used to determine the MIC, using the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Meropenem showed the lowest MIC against penicillin-susceptible S. pneumoniae, followed by sulbactam/cefoperazone and ceftriaxone. Ceftriaxone had the best activity against penicillin-resistant S. pneumoniae and beta-lactamase-negative and beta-lactamase-producing ampicillin-resistant H. influenzae. Ceftriaxone was unique, showing a long elimination half-life and low MIC values where its serum level duration time was above the MIC for longer than other cephalosporins. Accordingly, the %T>MIC of ceftriaxone for a once-daily administration greatly exceeded the efficacy levels of those for the other antibacterial agents tested. Ceftriaxone has an excellent balance between in vitro antimicrobial activities and pharmacokinetic profiles; and therefore remains effective as a therapeutic agent against PRSP and BLNAR H. influenzae in CAP.
Collapse
Affiliation(s)
- Akira Ohno
- Departments of Microbiology and Infectious Disease, Faculty of Medicine, Toho University, 5-21-16 Omorinishi, Ota-ku, Tokyo 143-8540, Japan.
| | | | | | | |
Collapse
|
33
|
Nakamura S, Yanagihara K, Seki M, Izumikawa K, Higashiyama Y, Miyazaki Y, Hirakata Y, Mizuta Y, Kohno S. Clinical characteristics of pneumonia caused by beta-lactamase negative ampicillin resistant Haemophilus influenzae (BLNAR). ACTA ACUST UNITED AC 2007; 39:521-4. [PMID: 17577813 DOI: 10.1080/00365540701199816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We wished to assess the clinical differences between beta-lactamase-negative, ampicillin-sensitive and beta-lactamase-negative, ampicillin-resistant Haemophilus influenzae pneumonia. The medical records of 118 patients with H. influenzae pneumonia admitted between March 1998 and March 2003 to Nagasaki University Hospital and affiliated institutions were reviewed. In line with CLSI (Clinical and Laboratory Standards Institute) criteria, we classified H. influenzae according to sensitivity to ampicillin as follows: S (sensitive), minimum inhibitory concentration (MIC) =1; I (intermediate sensitivity), MIC =2; R (resistant), MIC =4. We defined the R strains as the BLNAR group and the S and I strains as the non-BLNAR group. We measured the patient's background, Pneumonia Severity Index (PSI), drug sensitivity of H. influenzae, and evaluation of antibiotic choices. There were no significant clinical differences between the beta-lactamase-negative, ampicillin-susceptible and the beta-lactamase-negative, ampicillin-resistant groups. However, BLNAR pneumonia was more prominent in the younger than the older patients. This study should provide useful information for understanding the clinical characteristics of BLNAR pneumonia.
Collapse
Affiliation(s)
- Shigeki Nakamura
- Second Department of Internal Medicine, Nagasaki University Graduate School of Pharmaceutical Sciences, Nagasaki, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Choi KJ, Noh KM, Kim DE, Ha BH, Kim EE, Yoon MY. Identification of the catalytic subunit of acetohydroxyacid synthase in Haemophilus influenzae and its potent inhibitors. Arch Biochem Biophys 2007; 466:24-30. [PMID: 17718999 DOI: 10.1016/j.abb.2007.07.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 07/07/2007] [Accepted: 07/11/2007] [Indexed: 11/22/2022]
Abstract
Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is a thiamin diphosphate- (ThDP)- and FAD-dependent enzyme that catalyzes the first common step in the biosynthetic pathway of the branched-amino acids (BCAAs) leucine, isoleucine, and valine. The gene from Haemophilus influenzae that encodes the AHAS catalytic subunit was cloned, overexpressed in Escherichia coli BL21(DE3), and purified to homogeneity. The purified H. influenzae AHAS catalytic subunit (Hin-AHAS) appeared as a single band on SDS-PAGE gel, with a molecular mass of approximately 63 kDa. The enzyme catalyzes the condensation of two molecules of pyruvate to form acetolactate, with a K(m) of 9.2mM and the specific activity of 1.5 micromol/min/mg. The cofactor activation constant (K(c)=13.5 microM) and the dissociation constant (K(d)=3.3 microM) of ThDP were also determined by enzymatic assay and tryptophan fluorescence quenching studies, respectively. We screened a chemical library to discover new inhibitors of the Hin AHAS catalytic subunit. Through which, AVS-2087 (IC(50)=0.53 microM), KSW30191 (IC(50)=1.42 microM), and KHG20612 (IC(50)=4.91 microM) displayed potent inhibition as compare to sulfometuron methyl (IC(50)=276.31 microM).
Collapse
Affiliation(s)
- Kyoung-Jae Choi
- Department of Chemistry, Hanyang University, 17 Haedang-dong, Sungdong-gu, Seoul 133-791, Republic of Korea
| | | | | | | | | | | |
Collapse
|
35
|
Pillai B, Cherney M, Diaper CM, Sutherland A, Blanchard JS, Vederas JC, James MNG. Dynamics of catalysis revealed from the crystal structures of mutants of diaminopimelate epimerase. Biochem Biophys Res Commun 2007; 363:547-53. [PMID: 17889830 DOI: 10.1016/j.bbrc.2007.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Accepted: 09/04/2007] [Indexed: 10/22/2022]
Abstract
Diaminopimelate (DAP) epimerase catalyzes the stereoinversion of ll-DAP to meso-DAP, a precursor of l-lysine and an essential component of the bacterial peptidoglycan. This function is vital to bacteria and the enzyme therefore represents an attractive target for the design of novel anti-bacterials. DAP epimerase belongs to the group of PLP-independent amino acid racemases that function through a rather unusual mechanism involving two cysteines acting in concert as a base (thiolate) and an acid (thiol). We have solved the crystal structures of the apo-forms of DAP epimerase mutants (C73S and C217S) from Haemophilus influenzae at 2.3A and 2.2A resolution, respectively. These structures provide a snapshot of the enzyme in the first step of the catalytic cycle. Comparisons with the structures of the inhibitor-bound form reveal that the enzyme adopts an 'open conformation' in the absence of substrates or inhibitors with the two active site cysteines existing as a thiol-thiolate pair. Substrate binding to the C-terminal domain triggers the closure of the N-terminal domain coupled with tight encapsulation of the ligand, stabilization of the conformation of an active site loop containing Cys73 and expulsion of water molecules with concomitant desolvation of the thiolate base. This structural rearrangement is critical for catalysis.
Collapse
Affiliation(s)
- Bindu Pillai
- Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton, Alta, Canada T6G 2H7
| | | | | | | | | | | | | |
Collapse
|
36
|
Tristram SG, Burdach JG. Effect of cloned inhibitor-resistant TEM -lactamases on the susceptibility of Haemophilus influenzae to amoxicillin/clavulanate. J Antimicrob Chemother 2007; 60:1151-4. [PMID: 17827143 DOI: 10.1093/jac/dkm311] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To determine the effect of cloned inhibitor-resistant TEM beta-lactamases (IRTs) on the susceptibility of Haemophilus influenzae to amoxicillin/clavulanate. METHODS IRT-2, -4 and -5 genes with various promoters were cloned into control strains of H. influenzae and the amoxicillin/clavulanate MICs were measured using Etests. RESULTS IRT enzymes were able to raise the amoxicillin/clavulanate MICs to between 0.38/0.19 and 4.0/2.0 mg/L depending on the IRT and promoter genotype, compared with MICs of 0.19/0.09 to 0.5/0.25 mg/L for the corresponding strains with TEM-1. Strains with an IRT and altered penicillin-binding proteins had amoxicillin/clavulanate MICs as high as 8.0/4.0 mg/L. CONCLUSIONS Cloned IRT enzymes in H. influenzae raise the amoxicillin/clavulanate MICs to an extent comparable to naturally occurring strains with decreased amoxicillin/clavulanate susceptibility.
Collapse
Affiliation(s)
- Stephen G Tristram
- School of Human Life Sciences, University of Tasmania, Launceston, Tasmania 7250, Australia.
| | | |
Collapse
|
37
|
Liu H, Pattabiraman VR, Vederas JC. Stereoselective syntheses of 4-oxa diaminopimelic acid and its protected derivatives via aziridine ring opening. Org Lett 2007; 9:4211-4. [PMID: 17850092 DOI: 10.1021/ol701742x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Regio- and stereoselective aziridine ring opening with oxygen nucleophiles derived from serine and threonine provides a route to stereochemically pure 4-oxa-2,6-diaminopimelic acid (oxa-DAP) and its methyl-substituted derivatives. Oxa-DAP is a substrate of DAP epimerase, a key enzyme for biosynthesis of l-lysine and formation of peptidoglycan precursors. Orthogonally protected analogues of lanthionine and beta-methyllanthionine wherein oxygen replaces sulfur were prepared that could be used for solid-supported peptide synthesis to make oxa derivatives of lantibiotics.
Collapse
Affiliation(s)
- Hongqiang Liu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | | | | |
Collapse
|
38
|
Felts RL, Ou Z, Reilly TJ, Tanner JJ. Structure of recombinant Haemophilus influenzae e (P4) acid phosphatase reveals a new member of the haloacid dehalogenase superfamily. Biochemistry 2007; 46:11110-9. [PMID: 17824671 DOI: 10.1021/bi701016m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipoprotein e (P4) from Haemophilus influenzae belongs to the "DDDD" superfamily of phosphohydrolases and is the prototype of class C nonspecific acid phosphatases. P4 is also a component of a H. influenzae vaccine. We report the crystal structures of recombinant P4 in the ligand-free and tungstate-inhibited forms, which are the first structures of a class C phosphatase. P4 has a two-domain architecture consisting of a core alpha/beta domain and a smaller alpha domain. The core domain features a five-stranded beta-sheet flanked by helices on both sides that is reminiscent of the haloacid dehalogenase superfamily. The alpha domain appears to be unique and plays roles in substrate binding and dimerization. The active site is solvent accessible and located in a cleft between the two domains. The structure shows that P4 is a metalloenzyme and that magnesium is the most likely metal ion in the crystalline recombinant enzyme. The ligands of the metal ion are the carboxyl groups of the first and third Asp residues of the DDDD motif, the backbone carbonyl of the second Asp of the DDDD motif, and two water molecules. The structure of the tungstate-bound enzyme suggests that Asp64 is the nucleophile that attacks the substrate P atom. Dimerization appears to be important for catalysis because intersubunit contacts stabilize the active site. Analysis of the structural context of mutations engineered for vaccine studies shows that the most promising mutations are located in the dimer interface. This observation suggests a structure-based vaccine design strategy in which the dimer interface is disrupted in order to expose epitopes that are buried in dimeric P4.
Collapse
Affiliation(s)
- Richard L Felts
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | | | | | | |
Collapse
|
39
|
Shen XZ, Lu Q, Deng L, Yu S, Zhang H, Deng Q, Jiang M, Hu Y, Yao KH, Yang YH. Resistance of Haemophilus influenzae isolates in children under 5 years old with acute respiratory infections in China between 2000 and 2002. J Int Med Res 2007; 35:554-63. [PMID: 17697534 DOI: 10.1177/147323000703500416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This prospective, three-centre study tested for antimicrobial susceptibility in 898 isolates of Haemophilus influenzae between 2000 and 2002 in Chinese children aged under 5 years with acute upper respiratory tract infection. The average incidence of beta-lactamase production was 12.0%. Overall, 88.0% of isolates were susceptible to ampicillin, 100.0% were susceptible to amoxicillin/clavulanic acid, ceftriaxone, cefuroxime and azithromycin, and 99.0% were susceptible to ciprofloxacin. Isolates from Beijing and Shanghai had a lower susceptibility to tetracycline (57.0% and 61.0%, respectively) compared with those from Guangzhou (81.0%), while trimethoprim/sulfamethoxazole susceptibilities in Shanghai (47.0%) and Guangzhou (54.0%) were significantly higher than in Beijing (35.0%). A total of 34.5% of all the isolates were susceptible to all eight of these antimicrobial agents and 12.8% were multi-drug resistant. Ampicillin resistance increased over the duration of the study. These findings show that beta-lactamase production and ampicillin resistance among isolates from Chinese children with upper respiratory tract infection are increasing, and highlight the strong correlation between ampicillin resistance and resistance to cefaclor, chloramphenicol and tetracycline in H. influenzae isolates.
Collapse
Affiliation(s)
- X Z Shen
- Beijing Children's Hospital Affiliated to Capital Medical University, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Fox KL, Dowideit SJ, Erwin AL, Srikhanta YN, Smith AL, Jennings MP. Haemophilus influenzae phasevarions have evolved from type III DNA restriction systems into epigenetic regulators of gene expression. Nucleic Acids Res 2007; 35:5242-52. [PMID: 17675301 PMCID: PMC1976455 DOI: 10.1093/nar/gkm571] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Phase variably expressed (randomly switching) methyltransferases associated with type III restriction-modification (R-M) systems have been identified in a variety of pathogenic bacteria. We have previously shown that a phase variable methyltransferase (Mod) associated with a type III R-M system in Haemophilus influenzae strain Rd coordinates the random switching of expression of multiple genes, and constitutes a phase variable regulon—‘phasevarion’. We have now identified the recognition site for the Mod methyltransferase in H. influenzae strain Rd as 5′-CGAAT-3′. This is the same recognition site as the previously described HinfIII system. A survey of 59 H. influenzae strains indicated significant sequence heterogeneity in the central, variable region of the mod gene associated with target site recognition. Intra- and inter-strain transformation experiments using Mod methylated or non-methylated plasmids, and a methylation site assay demonstrated that the sequence heterogeneity seen in the region encoding target site specificity does correlate to distinct target sites. Mutations were identified within the res gene in several strains surveyed indicating that Res is not functional. These data suggest that evolution of this type III R-M system into an epigenetic mechanism for controlling gene expression has, in some strains, resulted in loss of the DNA restriction function.
Collapse
Affiliation(s)
- Kate L. Fox
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Stefanie J. Dowideit
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Alice L. Erwin
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Yogitha N. Srikhanta
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Arnold L. Smith
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Michael P. Jennings
- School of Molecular and Microbial Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia, Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109 and Department of Pathobiology, School of Public Health, University of Washington, Seattle, WA 98195, USA
- *To whom correspondence should be addressed.+61 733654639+61 733654620
| |
Collapse
|
41
|
Ferreira JAS, Castro ACD, Rocha MP, Riboldi G, d'Azevedo PA. beta-lactamase production Haemophilus spp. and resistance to ampicillin in a general hospital in Porto Alegre city, RS, Brazil (2001-2005). Braz J Infect Dis 2007; 11:50-2. [PMID: 17625727 DOI: 10.1590/s1413-86702007000100013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Indexed: 11/22/2022] Open
Abstract
In a four-year period (July/2001-June/2005), 410 Haemophilus spp. isolates were studied. Those were isolated from sputum at Hospital Nossa Senhora da Conceição (NSC) in Porto Alegre city (RS). beta-lactamase enzyme was detected in 113 (27.6%) of isolates through chromogenic cephalosporin method. Fifty-eight (51.3%) of them showed sensibility to ampicillin through disc-diffusion method using Haemophilus Test Medium (HTM) by NCCLS criteria. In 297 (72.4%) isolates beta-lactamase was not detected by chromogenic cephalosporin method. Five (1.7%) of them were resistant and 1 (0.3%) intermediate to ampicillin using disc-diffusion method. The authors emphasized the importance of Haemophilus spp. resistance to ampicillin research in clinical laboratories routine and the use of more than one method for this analysis was proposed, due to different resistance mechanisms in Haemophilus spp.
Collapse
Affiliation(s)
- Jorge A S Ferreira
- Department of Microbiology, Hospital Nossa Senhora da Conceição, Porto Alegre - RS - Brazil
| | | | | | | | | |
Collapse
|
42
|
Oguzkaya-Artan M, Baykan Z, Artan C. Carriage rate of Haemophilus influenzae among preschool children in Turkey. Jpn J Infect Dis 2007; 60:179-82. [PMID: 17642526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This study was designed to determine the prevalence of healthy Haemophilus influenzae carriers in a random sample of the preschool population in Kayseri, Turkey. The lack of H. influenzae type b (Hib) disease surveillance and epidemiological data on the throat carriage of Turkish children has caused a delay in the introduction of conjugated Hib vaccination into proposed national vaccination programs. Oropharyngeal cultures were collected and cultured on chocolate agar supplemented with 260 microg/ml bacitracin from 683 children between May and June, 2006. One hundred seven (15,6%) of the 683 children studied were found to be as H. influenzae carriers, and 29 (4,2%) isolates were serotype b. Beta-lactamase production was detected in four isolates (3.7%). According to multivariate analysis, the sex of the child and the number of people sharing the same room with the child significantly influenced the odds of carrying H. influenzae. Age, having older siblings, passive smoking, respiratory infection during the last 30 days, number of people in the household, attending kindergarten or a day-care center, and household income were not significant variables. Our results suggest that there is a strong relationship between exposure to large numbers of children and H. influenzae carriage.
Collapse
Affiliation(s)
- Muge Oguzkaya-Artan
- Halil Bayraktar Health Services Vocational College, Erciyes University, Kayseri, Turkey.
| | | | | |
Collapse
|
43
|
Kidd SP, Jiang D, Jennings MP, McEwan AG. Glutathione-dependent alcohol dehydrogenase AdhC is required for defense against nitrosative stress in Haemophilus influenzae. Infect Immun 2007; 75:4506-13. [PMID: 17591795 PMCID: PMC1951181 DOI: 10.1128/iai.00487-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In Haemophilus influenzae Rd KW20, we identified a gene, adhC, which encodes a class III alcohol dehydrogenase (AdhC) and has S-nitrosoglutathione reductase activity. adhC exists on an operon with estD, which encodes an esterase. Divergent to the adhC-estD operon is the Haemophilus influenzae nmlR gene (nmlR(HI)), which encodes a MerR family regulator that is homologous to the Neisseria MerR-like regulator (NmlR). Analysis of an nmlR(HI) mutant indicated that expression of the adhC-estD operon is regulated by NmlR(HI) in strain Rd KW20. Chromosomal inactivation of either adhC or nmlR(HI) resulted in sensitivity to S-nitrosoglutathione and decreased S-nitrosoglutathione reductase activity. Examination of the NmlR(HI)-AdhC system in the genome sequences of nontypeable H. influenzae strains R2846, R2866, and 86-028NP identified significant variations. The adhC gene of 86-028NP was predicted to be nonfunctional due to a premature stop codon. Polymorphisms in the operator/promoter region of R2866 resulted in reduced enzyme activity. This correlated with an increased sensitivity to S-nitrosoglutathione. The adhC-nmlR(HI) system was examined in thirty-three clinical isolates (both capsular and nontypeable strains). Nucleic acid sequence data showed that only strain 86-028NP contained a premature stop codon. There were some variations in the DNA sequence of the operator/promoter region which altered the nmlR(HI) promoter. However, the clinical isolates still possessed S-nitrosoglutathione reductase activity and showed at least the equivalent ability to grow in the presence of S-nitrosoglutathione as Rd KW20. These data suggest that the nmlR(HI)-adhC system has a role in the defense against nitrosative stress in Haemophilus influenzae.
Collapse
Affiliation(s)
- Stephen P Kidd
- Australian Bacterial Pathogenesis Program and Centre for Metals in Biology, School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | | | | | | |
Collapse
|
44
|
Zubieta C, Krishna SS, McMullan D, Miller MD, Abdubek P, Agarwalla S, Ambing E, Astakhova T, Axelrod HL, Carlton D, Chiu HJ, Clayton T, Deller M, DiDonato M, Duan L, Elsliger MA, Grzechnik SK, Hale J, Hampton E, Han GW, Haugen J, Jaroszewski L, Jin KK, Klock HE, Knuth MW, Koesema E, Kumar A, Marciano D, Morse AT, Nigoghossian E, Oommachen S, Reyes R, Rife CL, van den Bedem H, Weekes D, White A, Xu Q, Hodgson KO, Wooley J, Deacon AM, Godzik A, Lesley SA, Wilson IA. Crystal structure of homoserine O-succinyltransferase from Bacillus cereus at 2.4 Å resolution. Proteins 2007; 68:999-1005. [PMID: 17546672 DOI: 10.1002/prot.21208] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Chloe Zubieta
- Joint Center for Structural Genomics, Stanford University, Menlo Park, California, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Smith AL, Erwin AL, Kline T, Unrath WCT, Nelson K, Weber A, Howald WN. Chloramphenicol is a substrate for a novel nitroreductase pathway in Haemophilus influenzae. Antimicrob Agents Chemother 2007; 51:2820-9. [PMID: 17526758 PMCID: PMC1932534 DOI: 10.1128/aac.00087-07] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The p-nitroaromatic antibiotic chloramphenicol has been used extensively to treat life-threatening infections due to Haemophilus influenzae and Neisseria meningitidis; its mechanism of action is the inhibition of protein synthesis. We found that during incubation with H. influenzae cells and lysates, chloramphenicol is converted to a 4-aminophenyl allylic alcohol that lacks antibacterial activity. The allylic alcohol moiety undergoes facile re-addition of water to restore the 1,3-diol, as well as further dehydration driven by the aromatic amine to form the iminoquinone. Several Neisseria species and most chloramphenicol-susceptible Haemophilus species, but not Escherichia coli or other gram-negative or gram-positive bacteria we examined, were also found to metabolize chloramphenicol. The products of chloramphenicol metabolism by species other than H. influenzae have not yet been characterized. The strains reducing the antibiotic were chloramphenicol susceptible, indicating that the pathway does not appear to mediate chloramphenicol resistance. The role of this novel nitroreductase pathway in the physiology of H. influenzae and Neisseria species is unknown. Further understanding of the H. influenzae chloramphenicol reduction pathway will contribute to our knowledge of the diversity of prokaryotic nitroreductase mechanisms.
Collapse
Affiliation(s)
- Arnold L Smith
- Microbial Pathogens Program, Seattle Biomedical Research Institute, Seattle, WA 98109-5219, USA.
| | | | | | | | | | | | | |
Collapse
|
46
|
Randriantsoa M, Drouillard S, Breton C, Samain E. Synthesis of globopentaose using a novel β1,3-galactosyltransferase activity of theHaemophilus influenzaeβ1,3-N-acetylgalactosaminyltransferase LgtD. FEBS Lett 2007; 581:2652-6. [PMID: 17517393 DOI: 10.1016/j.febslet.2007.05.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 04/26/2007] [Accepted: 05/02/2007] [Indexed: 11/30/2022]
Abstract
We have previously described a bacterial system for the conversion of globotriaose (Gb3) into globotetraose (Gb4) by a metabolically engineered Escherichia coli strain expressing the Haemophilus influenzae lgtD gene encoding beta1,3-N-acetylgalactosaminyltransferase [Antoine, T., Bosso, C., Heyraud, A. Samain, E. (2005) Large scale in vivo synthesis of globotriose and globotetraose by high cell density culture of metabolically engineered Escherichia coli. Biochimie 87, 197-203]. Here, we found that LgtD has an additional beta1,3-galactosyltransferase activity which allows our bacterial system to be extended to the synthesis of the carbohydrate portion of globopentaosylceramide (Galbeta-3GalNAcbeta-3Galalpha-4Galbeta-4Glc) which reacts with the monoclonal antibody defining the stage-specific embryonic antigen-3. In vitro assays confirmed that LgtD had both beta1,3-GalT and beta1,3-GalNAcT activities and showed that differences in the affinity for Gb3 and Gb4 explain the specific and exclusive formation of globopentaose.
Collapse
Affiliation(s)
- Mialy Randriantsoa
- Centre de Recherches sur les Macromolécules Végétales, BP 53, 38041 Grenoble Cedex 9, France
| | | | | | | |
Collapse
|
47
|
García-Cobos S, Campos J, Lázaro E, Román F, Cercenado E, García-Rey C, Pérez-Vázquez M, Oteo J, de Abajo F. Ampicillin-resistant non-beta-lactamase-producing Haemophilus influenzae in Spain: recent emergence of clonal isolates with increased resistance to cefotaxime and cefixime. Antimicrob Agents Chemother 2007; 51:2564-73. [PMID: 17470649 PMCID: PMC1913223 DOI: 10.1128/aac.00354-07] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The sequence of the ftsI gene encoding the transpeptidase domain of penicillin-binding protein 3 (PBP 3) was determined for 354 nonconsecutive Haemophilus influenzae isolates from Spain; 17.8% of them were ampicillin susceptible, 56% were beta-lactamase nonproducing ampicillin resistant (BLNAR), 15.8% were beta-lactamase producers and ampicillin resistant, and 10.4% displayed both resistance mechanisms. The ftsI gene sequences had 28 different mutation patterns and amino acid substitutions at 23 positions. Some 93.2% of the BLNAR strains had amino acid substitutions at the Lys-Thr-Gly (KTG) motif, the two most common being Asn526 to Lys (83.9%) and Arg517 to His (9.3%). Amino acid substitutions at positions 377, 385, and 389, which conferred cefotaxime and cefixime MICs 10 to 60 times higher than those of susceptible strains, were found for the first time in Europe. In 72 isolates for which the repressor acrR gene of the AcrAB efflux pump was sequenced, numerous amino acid substitutions were found. Eight isolates with ampicillin MICs of 0.25 to 2 microg/ml showed changes that predicted the early termination of the acrR reading frame. Pulsed-field gel electrophoresis analysis demonstrated that most BLNAR strains were genetically diverse, although clonal dissemination was detected in a group of isolates presenting with increased resistance to cefotaxime and cefixime. Background antibiotic use at the community level revealed a marked trend toward increased amoxicillin-clavulanic acid consumption. BLNAR H. influenzae strains have arisen by vertical and horizontal spread and have evolved to adapt rapidly to the increased selective pressures posed by the use of oral penicillins and cephalosporins.
Collapse
Affiliation(s)
- Silvia García-Cobos
- Antibiotic Laboratory, Bacteriology Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
García-de-Lomas J, Lerma M, Cebrián L, Juan-Bañón JL, Coronel P, Giménez MJ, Aguilar L. Influence of Haemophilus influenzae beta-lactamase production and/or ftsI gene mutations on in vitro activity of and susceptibility rates to aminopenicillins and second- and third-generation cephalosporins. Int J Antimicrob Agents 2007; 30:190-2. [PMID: 17459665 DOI: 10.1016/j.ijantimicag.2007.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 02/20/2007] [Accepted: 02/21/2007] [Indexed: 11/16/2022]
|
49
|
Sreenivas K, Amarnath PVS, Mallik A, Sarnaik H, Kumar NS, Takhi M, Trehan S, Kumar MS, Iqbal J, Rajagopalan R, Chakrabarti R. In vitro and in vivo antibacterial evaluation of DRF 8417, a new oxazolidinone. J Antimicrob Chemother 2007; 60:159-61. [PMID: 17449889 DOI: 10.1093/jac/dkm116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES AND METHODS DRF 8417, a novel oxazolidinone, has been evaluated against Gram-positive and fastidious Gram-negative bacteria. In vitro activity of DRF 8417 was determined by broth microdilution method and in vivo efficacy studies were carried out in different murine systemic infection models. RESULTS DRF 8417 exhibited potent activity against Gram-positive pathogens with MIC(50) and MIC(90) values ranging from 0.06 to 1 mg/L. MICs against Haemophilus influenzae and Moraxella catarrhalis were one to two dilutions lower than those of linezolid. The in vivo efficacy, by oral route, in different susceptible and resistant Gram-positive systemic bacterial infection models ranged from 2.0 to 2.9 mg/kg. CONCLUSIONS These studies displayed the excellent in vitro and in vivo activity of DRF 8417 against Gram-positive pathogens and lower MICs when compared with linezolid against H. influenzae and M. catarrhalis.
Collapse
Affiliation(s)
- K Sreenivas
- Anti-infective Group, Discovery Research, Dr Reddy's Laboratories Ltd, Miyapur, Hyderabad 500 049, India.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
The recent determination of protein structures with knots in their backbone topology has defied previous conventional wisdom. How proteins can fold with a knot is an intriguing question that has been explored for YibK from Haemophilus influenzae in this issue of Structure.
Collapse
Affiliation(s)
- Lisa M Gloss
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
| |
Collapse
|