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Cai T, Tamanini I, Odorizzi K, Gallelli L, Lanzafame M, Mazzoli S, Lanzafame P, Massidda O, Palmieri A, Wagenlehner FME, Bjerklund Johansen TE, De Nunzio C. The diagnostic yield of the Meares & Stamey test can be significantly improved by symptom-based patient selection and the experience of the test performer. Prostate Cancer Prostatic Dis 2024:10.1038/s41391-024-00824-0. [PMID: 38555411 DOI: 10.1038/s41391-024-00824-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/14/2024] [Accepted: 03/19/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Even if Meares-Stamey 4-glass (M&S) test is regarded a decisive tool for diagnosing prostatitis its use is only rarely performed in everyday clinical practice. Here, we analyze if the diagnostic yield of the M&S test could be improved by a pre-test categorization of patients due to undergo a M&S test. METHODS All clinical and microbiological data of patients who underwent M&S test in two urological centers from January 2004 to December 2021 were analyzed in this retrospective cohort study. One center has a dedicated staff member for the study of prostatitis (Cohort I), while the other center is a general urological unit (Cohort II). All patients were divided into 3 groups on the basis of the assembled data: patients with symptoms related to prostatitis only (Group I), patients with symptoms related to both prostatitis and BPH (Group II), patients with symptoms related to BPH only (Group III). The rates of positive microbiological results in each group were compared. RESULTS In the whole period, 9347 patients were analyzed and categorized as follows: Group I, 1884; Group II, 5151; Group III, 2312. Three-thousand and eight-hundred twenty-three patients showed positive culture results (40.9%). The most common isolated species was Escherichia coli (49.7%), followed by Enteroccus spp. (31.8%). The rates of positive M&S tests in the different symptom groups were: Group I, 1532 (81.4%); Group II, 1494 (29.0%); Group III, 797 (34.4%). The overall rate of positive M&S tests in each urology center showed that the center with a staff member who is dedicated to prostatitis studies (Cohort I) had a significantly higher rate of positive M&S tests than the general urological department (Cohort II) (64.3% vs 31.4%; p < 0.001). CONCLUSIONS Symptom-based patient selection and dedicated staff members will increase the diagnostic yield of the M&S test and reduce the number of unnecessary tests.
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Affiliation(s)
- Tommaso Cai
- Department of Urology, Santa Chiara Regional Hospital, Trento, Italy.
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Irene Tamanini
- Department of Urology, Santa Chiara Regional Hospital, Trento, Italy
| | - Katia Odorizzi
- Department of Urology, Santa Chiara Regional Hospital, Trento, Italy
| | - Luca Gallelli
- Department of Health Science, School of Medicine, University of Catanzaro, Catanzaro, Italy
| | | | - Sandra Mazzoli
- Microbiology Unit and STDs Centre, Santa Maria Annunziata Hospital, Firenze, Italy
| | - Paolo Lanzafame
- Department of Microbiology, Santa Chiara Regional Hospital, Trento, Italy
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
- Interdepartmental Centre of Medical Sciences (CISMed), University of Trento, Trento, Italy
| | | | - Florian M E Wagenlehner
- Clinic for Urology, Pediatric Urology and Andrology, Justus Liebig University, Giessen, Germany
| | - Truls E Bjerklund Johansen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Urology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Aarhus, Aarhus, Denmark
| | - Cosimo De Nunzio
- Department of Urology, Sant'Andrea Hospital, Sapienza University, Rome, Italy
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2
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Kurotschka PK, Borgulya G, Bucher E, Endrich I, Figueiras A, Gensichen J, Hay AD, Hapfelmeier A, Kretzschmann C, Kurzai O, Lam TT, Massidda O, Sanftenberg L, Schmiemann G, Schneider A, Simmenroth A, Stark S, Warkentin L, Ebell MH, Gàgyor I. Dipsticks and point-of-care Microscopy to reduce antibiotic use in women with an uncomplicated Urinary Tract Infection (MicUTI): protocol of a randomised controlled pilot trial in primary care. BMJ Open 2024; 14:e079345. [PMID: 38553055 PMCID: PMC10982754 DOI: 10.1136/bmjopen-2023-079345] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 03/17/2024] [Indexed: 04/02/2024] Open
Abstract
INTRODUCTION Uncomplicated urinary tract infections (uUTIs) in women are common infections encountered in primary care. Evidence suggests that rapid point-of-care tests (POCTs) to detect bacteria and erythrocytes in urine at presentation may help primary care clinicians to identify women with uUTIs in whom antibiotics can be withheld without influencing clinical outcomes. This pilot study aims to provide preliminary evidence on whether a POCT informed management of uUTI in women can safely reduce antibiotic use. METHODS AND ANALYSIS This is an open-label two-arm parallel cluster-randomised controlled pilot trial. 20 general practices affiliated with the Bavarian Practice-Based Research Network (BayFoNet) in Germany were randomly assigned to deliver patient management based on POCTs or to provide usual care. POCTs consist of phase-contrast microscopy to detect bacteria and urinary dipsticks to detect erythrocytes in urine samples. In both arms, urine samples will be obtained at presentation for POCTs (intervention arm only) and microbiological analysis. Women will be followed-up for 28 days from enrolment using self-reported symptom diaries, telephone follow-up and a review of the electronic medical record. Primary outcomes are feasibility of patient enrolment and retention rates per site, which will be summarised by means and SDs, with corresponding confidence and prediction intervals. Secondary outcomes include antibiotic use for UTI at day 28, time to symptom resolution, symptom burden, number of recurrent and upper UTIs and re-consultations and diagnostic accuracy of POCTs versus urine culture as the reference standard. These outcomes will be explored at cluster-levels and individual-levels using descriptive statistics, two-sample hypothesis tests and mixed effects models or generalised estimation equations. ETHICS AND DISSEMINATION The University of Würzburg institutional review board approved MicUTI on 16 December 2022 (protocol n. 109/22-sc). Study findings will be disseminated through peer-reviewed publications, conferences, reports addressed to clinicians and the local citizen's forums. TRIAL REGISTRATION NUMBER ClinicalTrials.gov NCT05667207.
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Affiliation(s)
- Peter K Kurotschka
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
| | - Gábor Borgulya
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
| | - Eva Bucher
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
| | - Isabell Endrich
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
| | - Adolfo Figueiras
- Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Jochen Gensichen
- Institute of General Practice and Family Medicine, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Alastair D Hay
- Centre for Academic Primary Care, Bristol Medical School: Population Health Sciences, Department of Community Based Medicine, University of Bristol, Bristol, UK
| | - Alexander Hapfelmeier
- Institute of General Practice and Health Services Research, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of AI and Informatics in Medicine, School of Medicine, Technical University of Munich School of Medicine, Munich, Germany
| | | | - Oliver Kurzai
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Thien-Tri Lam
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology, Interdepartmental Center of Medical Sciences (CISMed), University of Trento, Trento, Italy
| | - Linda Sanftenberg
- Institute of General Practice and Family Medicine, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Guido Schmiemann
- Institute of Public Health and Nursing Research (IPP), University of Bremen, Bremen, Germany
| | - Antonius Schneider
- Institute of General Practice and Health Services Research, School of Medicine, Technical University of Munich, Munich, Germany
| | - Anne Simmenroth
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
| | - Stefanie Stark
- Institute of General Practice, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Lisette Warkentin
- Institute of General Practice, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Mark H Ebell
- Department of Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, USA
| | - Ildikò Gàgyor
- Department of General Practice, University Hospital Würzburg, Würzburg, Germany
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Tsui HCT, Joseph M, Zheng JJ, Perez AJ, Manzoor I, Rued BE, Richardson JD, Branny P, Doubravová L, Massidda O, Winkler ME. Negative regulation of MurZ and MurA underlies the essentiality of GpsB- and StkP-mediated protein phosphorylation in Streptococcus pneumoniae D39. Mol Microbiol 2023; 120:351-383. [PMID: 37452010 PMCID: PMC10530524 DOI: 10.1111/mmi.15122] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [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: 03/24/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Abstract
GpsB links peptidoglycan synthases to other proteins that determine the shape of the respiratory pathogen Streptococcus pneumoniae (pneumococcus; Spn) and other low-GC Gram-positive bacteria. GpsB is also required for phosphorylation of proteins by the essential StkP(Spn) Ser/Thr protein kinase. Here we report three classes of frequently arising chromosomal duplications (≈21-176 genes) containing murZ (MurZ-family homolog of MurA) or murA that suppress ΔgpsB or ΔstkP. These duplications arose from three different repeated sequences and demonstrate the facility of pneumococcus to modulate gene dosage of numerous genes. Overproduction of MurZ or MurA alone or overproduction of MurZ caused by ΔkhpAB mutations suppressed ΔgpsB or ΔstkP phenotypes to varying extents. ΔgpsB and ΔstkP were also suppressed by MurZ amino-acid changes distant from the active site, including one in commonly studied laboratory strains, and by truncation or deletion of the homolog of IreB(ReoM). Unlike in other Gram-positive bacteria, MurZ is predominant to MurA in pneumococcal cells. However, ΔgpsB and ΔstkP were not suppressed by ΔclpCP, which did not alter MurZ or MurA amounts. These results support a model in which regulation of MurZ and MurA activity, likely by IreB(Spn), is the only essential requirement for StkP-mediated protein phosphorylation in exponentially growing D39 pneumococcal cells.
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Affiliation(s)
| | - Merrin Joseph
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - Jiaqi J. Zheng
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - Amilcar J. Perez
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - Irfan Manzoor
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - Britta E. Rued
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - John D. Richardson
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
| | - Pavel Branny
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Linda Doubravová
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Orietta Massidda
- Department of Cellular, Computational, and Integrative Biology, University of Trento, Italy
| | - Malcolm E. Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, USA
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Tsui HCT, Joseph M, Zheng JJ, Perez AJ, Manzoor I, Rued BE, Richardson JD, Branny P, Doubravová L, Massidda O, Winkler ME. Chromosomal Duplications of MurZ (MurA2) or MurA (MurA1), Amino Acid Substitutions in MurZ (MurA2), and Absence of KhpAB Obviate the Requirement for Protein Phosphorylation in Streptococcus pneumoniae D39. bioRxiv 2023:2023.03.26.534294. [PMID: 37034771 PMCID: PMC10081211 DOI: 10.1101/2023.03.26.534294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
GpsB links peptidoglycan synthases to other proteins that determine the shape of the respiratory pathogen Streptococcus pneumoniae (pneumococcus; Spn ) and other low-GC Gram-positive bacteria. GpsB is also required for phosphorylation of proteins by the essential StkP( Spn ) Ser/Thr protein kinase. Here we report three classes of frequently arising chromosomal duplications (≈21-176 genes) containing murZ (MurZ-family homolog of MurA) or murA that suppress Δ gpsB or Δ stkP . These duplications arose from three different repeated sequences and demonstrate the facility of pneumococcus to modulate gene dosage of numerous genes. Overproduction of MurZ or MurA alone or overexpression of MurZ caused by Δ khpAB mutations suppressed Δ gpsB or Δ stkP phenotypes to varying extents. Δ gpsB and Δ stkP were also suppressed by MurZ amino-acid changes distant from the active site, including one in commonly studied laboratory strains, and by truncation or deletion of the homolog of IreB(ReoM). Unlike in other Gram-positive bacteria, MurZ is predominant to MurA in pneumococcal cells. However, Δ gpsB and Δ stkP were not suppressed by Δ clpCP , which did not alter MurZ or MurA amounts. These results support a model in which regulation of MurZ and MurA activity, likely by IreB( Spn ), is the only essential requirement for protein phosphorylation in exponentially growing D39 pneumococcal cells.
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Lamanna MM, Manzoor I, Joseph M, Ye ZA, Benedet M, Zanardi A, Ren Z, Wang X, Massidda O, Tsui HT, Winkler ME. Roles of RodZ and class A PBP1b in the assembly and regulation of the peripheral peptidoglycan elongasome in ovoid-shaped cells of Streptococcus pneumoniae D39. Mol Microbiol 2022; 118:336-368. [PMID: 36001060 PMCID: PMC9804626 DOI: 10.1111/mmi.14969] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/30/2022] [Accepted: 08/02/2022] [Indexed: 01/17/2023]
Abstract
RodZ of rod-shaped bacteria functions to link MreB filaments to the Rod peptidoglycan (PG) synthase complex that moves circumferentially perpendicular to the long cell axis, creating hoop-like sidewall PG. Ovoid-shaped bacteria, such as Streptococcus pneumoniae (pneumococcus; Spn) that lack MreB, use a different modality for peripheral PG elongation that emanates from the midcell of dividing cells. Yet, S. pneumoniae encodes a RodZ homolog similar to RodZ in rod-shaped bacteria. We show here that the helix-turn-helix and transmembrane domains of RodZ(Spn) are essential for growth at 37°C. ΔrodZ mutations are suppressed by Δpbp1a, mpgA(Y488D), and ΔkhpA mutations that suppress ΔmreC, but not ΔcozE. Consistent with a role in PG elongation, RodZ(Spn) co-localizes with MreC and aPBP1a throughout the cell cycle and forms complexes and interacts with PG elongasome proteins and regulators. Depletion of RodZ(Spn) results in aberrantly shaped, non-growing cells and mislocalization of elongasome proteins MreC, PBP2b, and RodA. Moreover, Tn-seq reveals that RodZ(Spn), but not MreCD(Spn), displays a specific synthetic-viable genetic relationship with aPBP1b, whose function is unknown. We conclude that RodZ(Spn) acts as a scaffolding protein required for elongasome assembly and function and that aPBP1b, like aPBP1a, plays a role in elongasome regulation and possibly peripheral PG synthesis.
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Affiliation(s)
- Melissa M. Lamanna
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Irfan Manzoor
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Merrin Joseph
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Ziyun A. Ye
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Mattia Benedet
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Alessia Zanardi
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Zhongqing Ren
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Xindan Wang
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Ho‐Ching T. Tsui
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Malcolm E. Winkler
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
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Perez AJ, Villicana JB, Tsui HCT, Danforth ML, Benedet M, Massidda O, Winkler ME. FtsZ-Ring Regulation and Cell Division Are Mediated by Essential EzrA and Accessory Proteins ZapA and ZapJ in Streptococcus pneumoniae. Front Microbiol 2021; 12:780864. [PMID: 34938281 PMCID: PMC8687745 DOI: 10.3389/fmicb.2021.780864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 10/22/2021] [Indexed: 12/02/2022] Open
Abstract
The bacterial FtsZ-ring initiates division by recruiting a large repertoire of proteins (the divisome; Z-ring) needed for septation and separation of cells. Although FtsZ is essential and its role as the main orchestrator of cell division is conserved in most eubacteria, the regulators of Z-ring presence and positioning are not universal. This study characterizes factors that regulate divisome presence and placement in the ovoid-shaped pathogen, Streptococcus pneumoniae (Spn), focusing on FtsZ, EzrA, SepF, ZapA, and ZapJ, which is reported here as a partner of ZapA. Epi-fluorescence microscopy (EFm) and high-resolution microscopy experiments showed that FtsZ and EzrA co-localize during the entire Spn cell cycle, whereas ZapA and ZapJ are late-arriving divisome proteins. Depletion and conditional mutants demonstrate that EzrA is essential in Spn and required for normal cell growth, size, shape homeostasis, and chromosome segregation. Moreover, EzrA(Spn) is required for midcell placement of FtsZ-rings and PG synthesis. Notably, overexpression of EzrA leads to the appearance of extra Z-rings in Spn. Together, these observations support a role for EzrA as a positive regulator of FtsZ-ring formation in Spn. Conversely, FtsZ is required for EzrA recruitment to equatorial rings and for the organization of PG synthesis. In contrast to EzrA depletion, which causes a bacteriostatic phenotype in Spn, depletion of FtsZ results in enlarged spherical cells that are subject to LytA-dependent autolysis. Co-immunoprecipitation and bacterial two-hybrid assays show that EzrA(Spn) is in complexes with FtsZ, Z-ring regulators (FtsA, SepF, ZapA, MapZ), division proteins (FtsK, StkP), and proteins that mediate peptidoglycan synthesis (GpsB, aPBP1a), consistent with a role for EzrA at the interface of cell division and PG synthesis. In contrast to the essentiality of FtsZ and EzrA, ZapA and SepF have accessory roles in regulating pneumococcal physiology. We further show that ZapA interacts with a non-ZapB homolog, named here as ZapJ, which is conserved in Streptococcus species. The absence of the accessory proteins, ZapA, ZapJ, and SepF, exacerbates growth defects when EzrA is depleted or MapZ is deleted. Taken together, these results provide new information about the spatially and temporally distinct proteins that regulate FtsZ-ring organization and cell division in Spn.
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Affiliation(s)
- Amilcar J Perez
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Jesus Bazan Villicana
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Ho-Ching T Tsui
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Madeline L Danforth
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Mattia Benedet
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
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Fulgenzio C, Massari M, Traversa G, Da Cas R, Ferrante G, Aschbacher R, Moser V, Pagani E, Vestri AR, Massidda O, Kurotschka PK. Impact of Prior Antibiotic Use in Primary Care on Escherichia coli Resistance to Third Generation Cephalosporins: A Case-Control Study. Antibiotics (Basel) 2021; 10:antibiotics10040451. [PMID: 33923682 PMCID: PMC8073604 DOI: 10.3390/antibiotics10040451] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/05/2022] Open
Abstract
Research is lacking on the reversibility of antimicrobial resistance (AMR). Thus, we aimed to determine the influence of previous antibiotic use on the development and decay over time of third generation cephalosporin (3GC)-resistance of E. coli. Using the database of hospital laboratories of the Autonomous Province of Bolzano/Bozen (Italy), anonymously linked to the database of outpatient pharmaceutical prescriptions and the hospital discharge record database, this matched case-control study was conducted including as cases all those who have had a positive culture from any site for 3GC resistant E. coli (3GCREC) during a 2016 hospital stay. Data were analyzed by conditional logistic regression. 244 cases were matched to 1553 controls by the date of the first isolate. Male sex (OR 1.49, 95% CI 1.10–2.01), older age (OR 1.11, 95% CI 1.02–1.21), the number of different antibiotics taken in the previous five years (OR 1.20, 95% CI 1.08–1.33), at least one antibiotic prescription in the previous year (OR 1.92, 95% CI 1.36–2.71), and the diagnosis of diabetes (OR 1.57, 95% CI 1.08–2.30) were independent risk factors for 3GCREC colonization/infection. Patients who last received an antibiotic prescription two years or three to five years before hospitalization showed non-significant differences with controls (OR 0.97, 95% CI 0.68–1.38 and OR 0.85, 95% CI 0.59–1.24), compared to an OR of 1.92 (95% CI 1.36–2.71) in those receiving antibiotics in the year preceding hospitalization. The effect of previous antibiotic use on 3GC-resistance of E. coli is highest after greater cumulative exposure to any antibiotic as well as to 3GCs and in the first 12 months after antibiotics are taken and then decreases progressively.
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Affiliation(s)
- Chiara Fulgenzio
- Department of Public Health and Infectious Diseases, Postgraduate School of Medical Statistics and Biometry, University of Rome “La Sapienza”, 00185 Rome, Italy; (C.F.); (A.R.V.)
| | - Marco Massari
- Pharmacoepidemiology Unit, National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, 00161 Rome, Italy; (M.M.); (G.T.); (R.D.C.)
| | - Giuseppe Traversa
- Pharmacoepidemiology Unit, National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, 00161 Rome, Italy; (M.M.); (G.T.); (R.D.C.)
- Agenzia Italiana del Farmaco, 00187 Rome, Italy
| | - Roberto Da Cas
- Pharmacoepidemiology Unit, National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, 00161 Rome, Italy; (M.M.); (G.T.); (R.D.C.)
| | - Gianluigi Ferrante
- Azienda Ospedaliera, Universitaria Città della Salute e della Scienza di Torino, 10126 Turin, Italy;
| | - Richard Aschbacher
- Health Service of Bolzano/Bozen Province, 39100 Bolzano/Bozen, Italy; (R.A.); (V.M.); (E.P.)
| | - Verena Moser
- Health Service of Bolzano/Bozen Province, 39100 Bolzano/Bozen, Italy; (R.A.); (V.M.); (E.P.)
| | - Elisabetta Pagani
- Health Service of Bolzano/Bozen Province, 39100 Bolzano/Bozen, Italy; (R.A.); (V.M.); (E.P.)
| | - Anna Rita Vestri
- Department of Public Health and Infectious Diseases, Postgraduate School of Medical Statistics and Biometry, University of Rome “La Sapienza”, 00185 Rome, Italy; (C.F.); (A.R.V.)
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology, University of Trento, 38123 Povo, Italy;
| | - Peter Konstantin Kurotschka
- Department of Medical Sciences and Public Health, Faculty of Medicine and Surgery, University of Cagliari, 09124 Cagliari, Italy
- Correspondence:
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8
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Cleverley RM, Rutter ZJ, Rismondo J, Corona F, Tsui HCT, Alatawi FA, Daniel RA, Halbedel S, Massidda O, Winkler ME, Lewis RJ. The cell cycle regulator GpsB functions as cytosolic adaptor for multiple cell wall enzymes. Nat Commun 2019; 10:261. [PMID: 30651563 PMCID: PMC6335420 DOI: 10.1038/s41467-018-08056-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [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: 06/20/2018] [Accepted: 12/07/2018] [Indexed: 01/01/2023] Open
Abstract
Bacterial growth and cell division requires precise spatiotemporal regulation of the synthesis and remodelling of the peptidoglycan layer that surrounds the cytoplasmic membrane. GpsB is a cytosolic protein that affects cell wall synthesis by binding cytoplasmic mini-domains of peptidoglycan synthases to ensure their correct subcellular localisation. Here, we describe critical structural features for the interaction of GpsB with peptidoglycan synthases from three bacterial species (Bacillus subtilis, Listeria monocytogenes and Streptococcus pneumoniae) and suggest their importance for cell wall growth and viability in L. monocytogenes and S. pneumoniae. We use these structural motifs to identify novel partners of GpsB in B. subtilis and extend the members of the GpsB interactome in all three bacterial species. Our results support that GpsB functions as an adaptor protein that mediates the interaction between membrane proteins, scaffolding proteins, signalling proteins and enzymes to generate larger protein complexes at specific sites in a bacterial cell cycle-dependent manner.
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Affiliation(s)
- Robert M Cleverley
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Zoe J Rutter
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Jeanine Rismondo
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstrasse 37, 38855, Wernigerode, Germany
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2DD, UK
| | - Federico Corona
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | | | - Fuad A Alatawi
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | - Richard A Daniel
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | - Sven Halbedel
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstrasse 37, 38855, Wernigerode, Germany
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
- Department CIBIO, University of Trento, via Sommarive 9, 38123, Povo, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Richard J Lewis
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK.
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9
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Zheng JJ, Perez AJ, Tsui HCT, Massidda O, Winkler ME. Absence of the KhpA and KhpB (JAG/EloR) RNA-binding proteins suppresses the requirement for PBP2b by overproduction of FtsA in Streptococcus pneumoniae D39. Mol Microbiol 2017; 106:793-814. [PMID: 28941257 DOI: 10.1111/mmi.13847] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2017] [Indexed: 12/11/2022]
Abstract
Suppressor mutations were isolated that obviate the requirement for essential PBP2b in peripheral elongation of peptidoglycan from the midcells of dividing Streptococcus pneumoniae D39 background cells. One suppressor was in a gene encoding a single KH-domain protein (KhpA). ΔkhpA suppresses deletions in most, but not all (mltG), genes involved in peripheral PG synthesis and in the gpsB regulatory gene. ΔkhpA mutations reduce growth rate, decrease cell size, minimally affect shape and induce expression of the WalRK cell-wall stress regulon. Reciprocal co-immunoprecipitations show that KhpA forms a complex in cells with another KH-domain protein (KhpB/JAG/EloR). ΔkhpA and ΔkhpB mutants phenocopy each other exactly, consistent with a direct interaction. RNA-immunoprecipitation showed that KhpA/KhpB bind an overlapping set of RNAs in cells. Phosphorylation of KhpB reported previously does not affect KhpB function in the D39 progenitor background. A chromosome duplication implicated FtsA overproduction in Δpbp2b suppression. We show that cellular FtsA concentration is negatively regulated by KhpA/B at the post-transcriptional level and that FtsA overproduction is necessary and sufficient for suppression of Δpbp2b. However, increased FtsA only partially accounts for the phenotypes of ΔkhpA mutants. Together, these results suggest that multimeric KhpA/B may function as a pleiotropic RNA chaperone controlling pneumococcal cell division.
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Affiliation(s)
- Jiaqi J Zheng
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Amilcar J Perez
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Ho-Ching Tiffany Tsui
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, 09100 Cagliari, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
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10
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Rued BE, Zheng JJ, Mura A, Tsui HCT, Boersma MJ, Mazny JL, Corona F, Perez AJ, Fadda D, Doubravová L, Buriánková K, Branny P, Massidda O, Winkler ME. Suppression and synthetic-lethal genetic relationships of ΔgpsB mutations indicate that GpsB mediates protein phosphorylation and penicillin-binding protein interactions in Streptococcus pneumoniae D39. Mol Microbiol 2017; 103:931-957. [PMID: 28010038 DOI: 10.1111/mmi.13613] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2016] [Indexed: 01/06/2023]
Abstract
GpsB regulatory protein and StkP protein kinase have been proposed as molecular switches that balance septal and peripheral (side-wall like) peptidoglycan (PG) synthesis in Streptococcus pneumoniae (pneumococcus); yet, mechanisms of this switching remain unknown. We report that ΔdivIVA mutations are not epistatic to ΔgpsB division-protein mutations in progenitor D39 and related genetic backgrounds; nor is GpsB required for StkP localization or FDAA labeling at septal division rings. However, we confirm that reduction of GpsB amount leads to decreased protein phosphorylation by StkP and report that the essentiality of ΔgpsB mutations is suppressed by inactivation of PhpP protein phosphatase, which concomitantly restores protein phosphorylation levels. ΔgpsB mutations are also suppressed by other classes of mutations, including one that eliminates protein phosphorylation and may alter division. Moreover, ΔgpsB mutations are synthetically lethal with Δpbp1a, but not Δpbp2a or Δpbp1b mutations, suggesting GpsB activation of PBP2a activity. Consistent with this result, co-IP experiments showed that GpsB complexes with EzrA, StkP, PBP2a, PBP2b and MreC in pneumococcal cells. Furthermore, depletion of GpsB prevents PBP2x migration to septal centers. These results support a model in which GpsB negatively regulates peripheral PG synthesis by PBP2b and positively regulates septal ring closure through its interactions with StkP-PBP2x.
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Affiliation(s)
- Britta E Rued
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Jiaqi J Zheng
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Andrea Mura
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy.,Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Ho-Ching T Tsui
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Michael J Boersma
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Jeffrey L Mazny
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Federico Corona
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Amilcar J Perez
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Daniela Fadda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Linda Doubravová
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Karolína Buriánková
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Pavel Branny
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
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11
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Whalen MB, Massidda O. Helicobacter pylori: enemy, commensal or, sometimes, friend? J Infect Dev Ctries 2015; 9:674-8. [DOI: 10.3855/jidc.7186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 05/28/2015] [Indexed: 10/31/2022] Open
Abstract
Helicobacter pylori is a Gram-negative ε-proteobacterium that colonizes about 50% of humans. Some pertinent characteristics are that it can survive the acid of the stomach, produces urease to neutralize it and is motile due to apical flagella. Not surprisingly given its wide distribution, it has long colonized mankind and its genome encodes many features that allows this. Consequently, it frequently has a persistent lifelong association with humans and, differently from most pathogens that are transmitted horizontally, it is preferentially transmitted vertically, often from mother to child. A variety of genes and polymorphisms, both in H pylori and in humans, mediate the complex host-bacterium relationship, and can also determine if and what pathologies will be triggered by the species. H. pylori is naturally transformable, very recombinogenic and has a high mutation rate. Microbiota studies of the stomach have shown it to be an important species with a potentially regulatory role for the gastric microbial community. Likewise, epidemiological work has suggested that, while it clearly increases the risk of peptic ulcers and gastric cancer in some populations, it is also associated with lower risk of esophageal cancer and several other important pathologies. More recently, antibacterial resistant strains have been isolated, posing a problem for public health officials who called for its eradication. Hence, study of H. pylori and how it interacts with us can help revealing mutualistic or pathogenic interactions and the immune response in the digestive niche.
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12
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Massidda O, Nováková L, Vollmer W. From models to pathogens: how much have we learned about Streptococcus pneumoniae cell division? Environ Microbiol 2013; 15:3133-57. [PMID: 23848140 DOI: 10.1111/1462-2920.12189] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/08/2013] [Accepted: 06/09/2013] [Indexed: 12/22/2022]
Abstract
Streptococcus pneumoniae is an oval-shaped Gram-positive coccus that lives in intimate association with its human host, both as a commensal and pathogen. The seriousness of pneumococcal infections and the spread of multi-drug resistant strains call for new lines of intervention. Bacterial cell division is an attractive target to develop antimicrobial drugs. This review discusses the recent advances in understanding S. pneumoniae growth and division, in comparison with the best studied rod-shaped models, Escherichia coli and Bacillus subtilis. To maintain their shape, these bacteria propagate by peripheral and septal peptidoglycan synthesis, involving proteins that assemble into distinct complexes called the elongasome and the divisome, respectively. Many of these proteins are conserved in S. pneumoniae, supporting the notion that the ovococcal shape is also achieved by rounds of elongation and division. Importantly, S. pneumoniae and close relatives with similar morphology differ in several aspects from the model rods. Overall, the data support a model in which a single large machinery, containing both the peripheral and septal peptidoglycan synthesis complexes, assembles at midcell and governs growth and division. The mechanisms generating the ovococcal or coccal shape in lactic-acid bacteria have likely evolved by gene reduction from a rod-shaped ancestor of the same group.
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Affiliation(s)
- Orietta Massidda
- Department of Surgical Sciences, University of Cagliari, Via Porcell, 4, 09100, Cagliari, Italy
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13
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Canullo L, Penarrocha D, Micarelli C, Massidda O, Bazzoli M. Hard tissue response to argon plasma cleaning/sterilisation of customised titanium abutments versus 5-second steam cleaning: results of a 2-year post-loading follow-up from an explanatory randomised controlled trial in periodontally healthy patients. Eur J Oral Implantol 2013; 6:251-260. [PMID: 24179979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PURPOSE The aim of this triple-blinded randomised controlled trial was to test if argon plasma cleaning/ sterilisation of customised abutments can affect peri-implant marginal bone levels when compared to 5 seconds of steam cleaning. MATERIALS AND METHODS A total of 20 consecutive periodontally healthy patients requiring single implant-supported restorations in the maxillary premolar or anterior area were selected. All patients received a single implant. At abutment connection, customised abutments were randomly allocated to control (subjected only to usually adopted steam cleaning, CG) and test groups (subjected to plasma cleaning/sterilisation, TG). Abutments were screwed in at 32 Ncm, provisional restorations adapted and periapical radiographs were taken using customised film holders. Two weeks later, definitive restorations were placed. Patients were followed-up for 2 years post-loading. Outcome measures were implant/crown success, complications, periapical marginal bone level changes on periapical standardised radiographs, and microbiological analyses of the abutments after customisation and cleaning procedures but before connection. Comparisons between groups were performed by independent sample t tests (significance threshold of P ≤ 0.05). RESULTS No patient dropped out 2 years after loading. The presence of bacterial growth (staphylococci, including Staphylococcus aureus) was observed only on the CG abutments. No implant failed and no complications occurred. After 2 years of prosthetic loading, radiographic analysis revealed a statistically significantly higher mean bone loss for the CG group (mean difference 0.4 mm; 95% CI 0.08-0.73; P = 0.018). CONCLUSIONS This study suggests that removal of contaminants from titanium abutments using plasma of argon can allow for better bone level maintenance when compared to 5-second steam cleaning of titanium abutments. It is therefore important to use cleaned and sterilised customised abutments in patients.
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14
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Keserű JS, Szabó I, Gál Z, Massidda O, Mingoia M, Kaszanyitzky É, Jánosi S, Hulvely J, Csorba A, Buzás K, Hunyadi-Gulyás É, Medzihradszky KF, Biró S. Identification of β-lactamases in human and bovine isolates of Staphylococcus aureus strains having borderline resistance to penicillinase-resistant penicillins (PRPs) with proteomic methods. Vet Microbiol 2011; 147:96-102. [DOI: 10.1016/j.vetmic.2010.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 11/15/2022]
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Maggi S, Massidda O, Luzi G, Fadda D, Paolozzi L, Ghelardini P. Division protein interaction web: identification of a phylogenetically conserved common interactome between Streptococcus pneumoniae and Escherichia coli. Microbiology (Reading) 2008; 154:3042-3052. [DOI: 10.1099/mic.0.2008/018697-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Silvia Maggi
- Dipartimento di Biologia, Università Tor Vergata, Roma, Italy
| | - Orietta Massidda
- Dipartimento di Scienze e Tecnologie Biomediche, Sez. Microbiologia Medica, Cagliari, Italy
| | - Giuseppe Luzi
- Dipartimento di Medicina Interna, Facoltà di Medicina, Università La Sapienza, Roma, Italy
| | - Daniela Fadda
- Dipartimento di Scienze e Tecnologie Biomediche, Sez. Microbiologia Medica, Cagliari, Italy
| | | | - Patrizia Ghelardini
- Istituto di Biologia e Patologia Molecolare del CNR, Roma, Italy
- Dipartimento di Biologia, Università Tor Vergata, Roma, Italy
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16
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Fadda D, Santona A, D'Ulisse V, Ghelardini P, Ennas MG, Whalen MB, Massidda O. Streptococcus pneumoniae DivIVA: localization and interactions in a MinCD-free context. J Bacteriol 2006; 189:1288-98. [PMID: 17098892 PMCID: PMC1797354 DOI: 10.1128/jb.01168-06] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [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: 11/20/2022] Open
Abstract
To clarify the function of DivIVA in Streptococcus pneumoniae, we localized this protein in exponentially growing cells by both immunofluorescence microscopy and immunoelectron microscopy and found that S. pneumoniae DivIVA (DivIVA(SPN)) had a unique localization profile: it was present simultaneously both as a ring at the division septum and as dots at the cell poles. Double-immunofluorescence analysis suggested that DivIVA is recruited to the septum at a later stage than FtsZ and is retained at the poles after cell separation. All the other cell division proteins that we tested were localized in the divIVA null mutant, although the percentage of cells having constricted Z rings was significantly reduced. In agreement with its localization profile and consistent with its coiled-coil nature, DivIVA interacted with itself and with a number of known or putative S. pneumoniae cell division proteins. Finally, a missense divIVA mutant, obtained by allelic replacement, allowed us to correlate, at the molecular level, the specific interactions and some of the facets of the divIVA mutant phenotype. Taken together, the results suggest that although the possibility of a direct role in chromosome segregation cannot be ruled out, DivIVA in S. pneumoniae seems to be primarily involved in the formation and maturation of the cell poles. The localization and the interaction properties of DivIVA(SPN) raise the intriguing possibility that a common, MinCD-independent function evolved differently in the various host backgrounds.
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Affiliation(s)
- Daniela Fadda
- Dipartimento di Scienze e Tecnologie Biomediche, Sez. Microbiologia Medica, Via Porcell, 4, 09100 Cagliari, Italy
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17
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Vicente M, Hodgson J, Massidda O, Tonjum T, Henriques-Normark B, Ron EZ. The fallacies of hope: will we discover new antibiotics to combat pathogenic bacteria in time? FEMS Microbiol Rev 2006; 30:841-52. [PMID: 17064283 DOI: 10.1111/j.1574-6976.2006.00038.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [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: 11/29/2022] Open
Abstract
While newly developed technologies have revolutionized the classical approaches to combating infectious diseases, the difficulties associated with developing novel antimicrobials mean that these technologies have not yet been used to introduce new compounds into the market. The new technologies, including genomics and structural biology, open up exciting possibilities for the discovery of antibiotics. However, a substantial effort to pursue research, and moreover to incorporate the results into the production chain, is required in order to bring new antimicrobials to the final user. In the current scenario of emerging diseases and the rapid spread of antibiotic resistance, an active policy to support these requirements is vital. Otherwise, many valuable programmes may never be fully developed for lack of "interest" and funds (private and public). Will we react in time to avoid potential disaster?
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Affiliation(s)
- Miguel Vicente
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, Madrid, Spain.
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18
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Massidda O, Mingoia M, Fadda D, Whalen MB, Montanari MP, Varaldo PE. Analysis of the beta-lactamase plasmid of borderline methicillin-susceptible Staphylococcus aureus: focus on bla complex genes and cadmium resistance determinants cadD and cadX. Plasmid 2005; 55:114-27. [PMID: 16229889 DOI: 10.1016/j.plasmid.2005.08.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [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: 06/01/2005] [Revised: 07/27/2005] [Accepted: 08/08/2005] [Indexed: 11/16/2022]
Abstract
Borderline methicillin-susceptible Staphylococcus aureus strains are a rather homogeneous group, characterized by MICs of penicillinase-resistant penicillins (PRPs) at or just below the susceptibility breakpoint. Other features unique to this group include the presence of a pBW15-like beta-lactamase plasmid, the association with phage complex 94/96, and the production of a PRP-hydrolyzing beta-lactamase activity in addition to the classical penicillinase activity. The four HindIII fragments of pBORa53, a pBW15-like plasmid from the well-studied borderline S. aureus strain a53, were cloned in Escherichia coli, sequenced and analyzed. The plasmid (17,334 bp in size) contains 14 open reading frames (ORFs) and a complete copy of transposon Tn552, which harbors the three genes of the bla complex (blaZ, blaR1, and blaI) necessary for penicillinase production. Among the other 11 ORFs identified, two were homologous to cadmium resistance determinants of Staphylococcus lugdunensis and to the cadD and cadX genes recently detected in S. aureus. Consistent with this, strain a53 was found to be cadmium resistant. From a collection of 30 S. aureus isolates with borderline PRP MIC levels, 27 matched strain a53 in the positive amplification reactions with all of the four primer pairs targeting the cadD-cadX region, the presence of the 17.3-kb plasmid, and the level of cadmium resistance. The well-established S. aureus laboratory strain ATCC 29213 was also found to express cadD-cadX-mediated cadmium resistance. pBORa53 could be re-isolated from transformants obtained by transferring it into a PRP-susceptible recipient. However, while the transformants demonstrated levels of cadmium and penicillin resistance similar to those of strain a53, they remained fully susceptible to PRPs.
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Affiliation(s)
- Orietta Massidda
- Department of Biomedical Sciences and Technologies, Section of Medical Microbiology, University of Cagliari Medical School, Via Porcell 4, 09100 Cagliari, Italy.
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Smith AM, Feldman C, Massidda O, McCarthy K, Ndiweni D, Klugman KP. Altered PBP 2A and its role in the development of penicillin, cefotaxime, and ceftriaxone resistance in a clinical isolate of Streptococcus pneumoniae. Antimicrob Agents Chemother 2005; 49:2002-7. [PMID: 15855525 PMCID: PMC1087663 DOI: 10.1128/aac.49.5.2002-2007.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [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
We report the unusual involvement of altered PBP 2A in the development of beta-lactam resistance in Streptococcus pneumoniae. This was investigated amid three identical serotype 14 isolates (designated isolates 1, 2, and 3, respectively) of pneumococci cultured successfully from the blood of a human immunodeficiency virus-seropositive child with recurrent pneumonia. The passage of this strain through its human host induced several changes in the bacterium, which is typical of the adaptive and evolving nature of the pneumococcus. An efflux resistance mechanism, which conferred increased ciprofloxacin resistance, was induced in isolates 2 and 3. In addition, faster growth rates and larger capsules were also observed for these isolates, with respect to isolate 1. Notably, compared to isolates 1 and 2, isolate 3 showed a decrease in penicillin, cefotaxime, and ceftriaxone resistance. This change was associated with the replacement of an altered PBP 2A for an unaltered PBP 2A. In all likelihood, these events produced a strain which evolved into a fitter and more virulent type, isolate 3, that resulted in an aggravated pneumococcal infection and ultimately in the patient's death.
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Affiliation(s)
- Anthony M Smith
- MRC/NICD/WITS Respiratory and Meningeal Pathogens Research Unit, National Institute for Communicable Diseases, P.O. Box 1038, Johannesburg 2000, South Africa.
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20
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Lara B, Rico AI, Petruzzelli S, Santona A, Dumas J, Biton J, Vicente M, Mingorance J, Massidda O. Cell division in cocci: localization and properties of the Streptococcus pneumoniae FtsA protein. Mol Microbiol 2005; 55:699-711. [PMID: 15660997 DOI: 10.1111/j.1365-2958.2004.04432.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [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: 11/29/2022]
Abstract
We studied the cytological and biochemical properties of the FtsA protein of Streptococcus pneumoniae. FtsA is a widespread bacterial cell division protein that belongs to the actin superfamily. In Escherichia coli and Bacillus subtilis, FtsA localizes to the septal ring after FtsZ, but its exact role in septation is not known. In S. pneumoniae, we found that, during exponential growth, the protein localizes to the nascent septa, at the equatorial zones of the dividing cells, where an average of 2200 FtsA molecules per cell are present. Likewise, FtsZ was found to localize with the same pattern and to be present at an average of 3000 molecules per cell. Consistent with the colocalization, FtsA was found to interact with FtsZ and with itself. Purified FtsA is able to bind several nucleotides, the affinity being highest for adenosine triphosphate (ATP), and lower for other triphosphates and diphosphates. The protein polymerizes in vitro, in a nucleotide-dependent manner, forming long corkscrew-like helixes, composed of 2 + 2 paired protofilaments. No nucleotide hydrolytic activity was detected. Consistent with the absence of an ATPase activity, the polymers are highly stable and not dynamic. These results suggest that the FtsA protein could also polymerize in vivo and the polymers participate in septation.
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Affiliation(s)
- Beatriz Lara
- Aventis Pharma, 102 Route de Noisy, F-93235 Romainville cedex, France
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21
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Fadda D, Pischedda C, Caldara F, Whalen MB, Anderluzzi D, Domenici E, Massidda O. Characterization of divIVA and other genes located in the chromosomal region downstream of the dcw cluster in Streptococcus pneumoniae. J Bacteriol 2003; 185:6209-14. [PMID: 14526035 PMCID: PMC225046 DOI: 10.1128/jb.185.20.6209-6214.2003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [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: 11/20/2022] Open
Abstract
We analyzed the chromosome region of Streptococcus pneumoniae located downstream of the division and cell wall (dcw) cluster that contains the homolog of the Bacillus subtilis cell division gene divIVA and some genes of unknown function. Inactivation of divIVA in S. pneumoniae resulted in severe growth inhibition and defects in cell shape, nucleoid segregation, and cell division. Inactivation of the ylm genes resulted in some morphological and/or division abnormalities, depending on the inactivated gene. Transcriptional analysis revealed a relationship between these genes and the ftsA and ftsZ cell division genes, also indicating that the connection between the dcw cluster and the divIVA region is more extensive than just chromosomal position and gene organization.
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Affiliation(s)
- Daniela Fadda
- Dipartimento di Scienze Chirurgiche Sez. Microbiologia, Università di Cagliari, 09100 Cagliari, Italy
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22
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Carettoni D, Gómez-Puertas P, Yim L, Mingorance J, Massidda O, Vicente M, Valencia A, Domenici E, Anderluzzi D. Phage-display and correlated mutations identify an essential region of subdomain 1C involved in homodimerization of Escherichia coli FtsA. Proteins 2003; 50:192-206. [PMID: 12486713 DOI: 10.1002/prot.10244] [Citation(s) in RCA: 34] [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: 11/10/2022]
Abstract
FtsA plays an essential role in Escherichia coli cell division and is nearly ubiquitous in eubacteria. Several evidences postulated the ability of FtsA to interact with other septation proteins and with itself. To investigate these binding properties, we screened a phage-display library with FtsA. The isolated peptides defined a degenerate consensus sequence, which in turn displayed a striking similarity with residues 126-133 of FtsA itself. This result suggested that residues 126-133 were involved in homodimerization of FtsA. The hypothesis was supported by the analysis of correlated mutations, which identified a mutual relationship between a group of amino acids encompassing the ATP-binding site and a set of residues immediately downstream to amino acids 126-133. This information was used to assemble a model of a FtsA homodimer, whose accuracy was confirmed by probing multiple alternative docking solutions. Moreover, a prediction of residues responsible for protein-protein interaction validated the proposed model and confirmed once more the importance of residues 126-133 for homodimerization. To functionally characterize this region, we introduced a deletion in ftsA, where residues 126-133 were skipped. This mutant failed to complement conditional lethal alleles of ftsA, demonstrating that amino acids 126-133 play an essential role in E. coli.
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Affiliation(s)
- Daniele Carettoni
- GlaxoSmithKline Medicines Research Center, Via Fleming 4, 37135 Verona, Italy.
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Abstract
Knowledge of the chemistry, ultrastructure, biosynthesis, assembly, and function of bacterial cell walls has expanded enormously since the opening of this field of research approximately 40 years ago, primarily by the early work of Milton Salton. It has become abundantly clear that, in most environments, walls are essential to the survival and growth of bacteria and in many ways are structurally and functionally unique. A common but not universal feature of bacterial walls is the presence of peptidoglycan (PG; murein, or in the case of certain Archae the analogous structure-pseudomurein). PGs are considered to be primarily responsible for the protective and shape-maintaining properties of walls. They are a biologically unique class of macro-molecules in that they are not linear or even branched macromolecules. Instead they are two- or three-dimensional net like polymers that are linked together by three different chemical bonds (glycosidic, amide, and peptide). In addition, they contain the D-isomers of some amino acids and therefore may possess DL, LD, and DD linkages. Furthermore, the exact chemical structure of a PG may vary depending on environmental factors, however, retaining the essential protective and shape maintaining properties of the wall. Thus, the overall architectural plan of the wall may be more important than the exact shape of the bricks used for the construct. Another somewhat unique feature of PGs (and walls) is their final assembly in situ on the outside of the cellular permeability barrier. A broad variety of bacteria have been shown to possess enzymes that can hydrolyze bonds in the wall PG. Hydrolysis of a sufficient number of bonds can result in the weakening of, or serious damage to, the protective properties of the PG. Frequently, a bacterial strain may possess more than one PG hydrolase activity. A commonly believed, but as yet unproven, hypothesis is that PG hydrolases play one or more roles in PG assembly and/or surface growth and cell division. At a minimum, such potentially suicidal activities must be exquisitely well regulated. Currently we know little concerning the regulation of these activities, or how they communicate with, and integrate with, chromosome replication, synthesis of cytoplasmic macromolecules, cell growth, and division, although such, probably two-way, communications must occur in growing and dividing cells. Recent data indicate that the psr element in Enterococcus hirae described by Fontana and collaborators as a genetic element that is involved in the regulation of the synthesis of PBP 5, also is involved in the regulation of several other surface properties. These properties include (1) autolysis rates of exponential phase. cells, (2) the retention of this property after cells enter the stationary phase, (3) lysozyme sensitivity, and (4) the ratio of rhamnose-containing wall polysaccharide to PG in the walls. Thus the psr element may be a part of a "global" regulation and communication system in E. hirae.
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Affiliation(s)
- G D Shockman
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Montanari MP, Massidda O, Mingoia M, Varaldo PE. Borderline susceptibility to methicillin in Staphylococcus aureus: a new mechanism of resistance? Microb Drug Resist 2000; 2:257-60. [PMID: 9158769 DOI: 10.1089/mdr.1996.2.257] [Citation(s) in RCA: 22] [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] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus strains with borderline levels of susceptibility or resistance to antistaphylococcal penicillinase-resistant penicillins (PRPs) were initially reported as neither heteroresistant nor multiply resistant organisms, producing large amounts of beta-lactamase, and becoming fully susceptible to PRPs in the presence of beta-lactamase inhibitors. This borderline susceptibility or low-level resistance was suggested to be due to beta-lactamase hyperproduction: according to this hypothesis, the staphylococcal beta-lactamase, when hyperproduced, would succeed in partially hydrolyzing methicillin and related PRPs. However, later studies demonstrated that borderline PRP susceptibility cannot be explained soley on this basis, beta-lactamase hyperproduction being neither sufficient nor necessary to determine the borderline phenotype. Intrinsic mechanisms have also been reported to be associated with some borderline PRP susceptible S. aureus strains. The more recent discovery of a PRP-hydrolyzing beta-lactamase (methicillinase) produced, in addition to the conventional penicillinase, by borderline S. aureus strains suggests that this second, more specific beta-lactamase is more likely to be responsible for the borderline phenotype than an increased amount of the penicillinase. The slow kinetics of PRP hydrolysis by methicillinase is consistent with its association with reduced susceptibility rather than true resistance to PRPs. The combined effect of methicillinase plus penicillinase on some common substrates might explain the increased beta-lactamase activity often observed in borderline S. aureus strains.
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Affiliation(s)
- M P Montanari
- Institute of Microbiology, University of Ancona Medical School, Italy
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25
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Abstract
Comparison of several cell wall-related properties of the ATCC 9790 strain and the R40 strain, a penicillin-resistant, PBP5 overproducing strain, and Rev14, a penicillin-hypersensitive, PBP5-deficient strain, is consistent with a role of the genetic element, psr, in the global regulation of lysozyme sensitivity, autolytic capacity, and wall-rhamnose-containing polysaccharide content. These parameters appear to be independently regulated by a system that involves psr in a currently unknown manner.
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Affiliation(s)
- L Daneo-Moore
- Department of Microbiology and Immunology, Temple University, School of Medicine, Philadelphia, Pennsylvania 19140, USA
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26
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Massidda O, Anderluzzi D, Friedli L, Feger G. Unconventional organization of the division and cell wall gene cluster of Streptococcus pneumoniae. Microbiology (Reading) 1998; 144 ( Pt 11):3069-3078. [PMID: 9846742 DOI: 10.1099/00221287-144-11-3069] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The genes responsible for cell wall biosynthesis and cell division (dcw genes) were identified and sequenced in Streptococcus pneumoniae. The genetic organization of the dcw cluster in Streptococcus pneumoniae differed significantly from the clusters of other bacteria reported to date. In particular, the genes corresponding to the 2 min region of the Escherichia coli chromosome were found distributed in three genetically separate regions of the Streptococcus pneumoniae chromosome. The first region contained the expected ftsA and ftsZ cell division genes at one end and pbp2b, ddl and murF at the other end. The murD, murG and divIB genes, always found located upstream of ftsA, were found in a second region separated from the first. A third region contained the yllC, yllD, pbp2x and mraY genes. The chromosomal region downstream of ftsZ was also sequenced and characterized. In Streptococcus pneumoniae this region contains four ORFs, all of unknown function, and an ORF encoding the Bacillus subtilis DivIVA homologue. The gene order and the organization of this region was found to be conserved in Staphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis, raising the possibility that previously unidentified loci may also be involved in division.
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Affiliation(s)
- Orietta Massidda
- Department of Microbiology, Medicine Research Center,GlaxoWellcome,37100 Verona,Italy
| | - Daniela Anderluzzi
- Department of Microbiology, Medicine Research Center,GlaxoWellcome,37100 Verona,Italy
| | - Laurence Friedli
- Geneva Biomedical Research InstitUte,GlaxoWellcome, 14 Chemin des Aulx, CH-1228 Plans-les-Ouates, Geneva,Switzerland
| | - Georg Feger
- Geneva Biomedical Research InstitUte,GlaxoWellcome, 14 Chemin des Aulx, CH-1228 Plans-les-Ouates, Geneva,Switzerland
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Massidda O, Dardenne O, Whalen MB, Zorzi W, Coyette J, Shockman GD, Daneo-Moore L. The PBP 5 synthesis repressor (psr) gene of Enterococcus hirae ATCC 9790 is substantially longer than previously reported. FEMS Microbiol Lett 1998; 166:355-60. [PMID: 9770293 DOI: 10.1111/j.1574-6968.1998.tb13912.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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] [Indexed: 12/01/2022] Open
Abstract
A reexamination of the nucleotide sequence of the psr gene of Enterococcus hirae revealed the presence of two additional nucleotides at residues 1190 and 1191. As a result, instead of a stop codon after 148 aa, the psr gene product would contain 293 aa residues. The revised size of the gene product was confirmed by subsequently cloning and expressing the psr gene in Escherichia coli. The derived amino acid sequence of the revised psr gene product was found to be similar to several other proteins in the combined GenBank/EMBL database. The protein products of some of these genes are thought to play regulatory role(s) in exo or capsular polysaccharide synthesis and/or in cell wall metabolism. All the putative homologs of the revised Psr appear to have a putative membrane-anchoring domain at their N-termini. Amino acid blocks with high degrees of similarity have been identified in the aligned sequences, and it is suggested that these common motifs could be of structural or functional importance.
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Affiliation(s)
- O Massidda
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
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28
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Massidda O, Montanari MP, Mingoia M, Varaldo PE. Borderline methicillin-susceptible Staphylococcus aureus strains have more in common than reduced susceptibility to penicillinase-resistant penicillins. Antimicrob Agents Chemother 1996; 40:2769-74. [PMID: 9124838 PMCID: PMC163619 DOI: 10.1128/aac.40.12.2769] [Citation(s) in RCA: 18] [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] [Indexed: 02/04/2023] Open
Abstract
Ten epidemiologically unrelated Staphylococcus aureus isolates with borderline levels of susceptibility to antistaphylococcal penicillinase-resistant penicillins (PRPs) were investigated together with appropriate S. aureus control strains. By a nitrocefin microplate assay, all borderline PRP-susceptible test strains were found to produce comparable amounts of beta-lactamase. Hydrolytic activity against another chromogenic substrate (PADAC) and against the PRPs was also demonstrated in membrane preparations from induced cells of 9 of the 10 borderline test strains. When bacterial membranes were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two methicillin-inducible bands of about 32 and 31 kDa were detected, after Coomassie blue staining, in the membrane protein patterns of the same nine borderline test strains. By gel renaturation and zymographic detection of beta-lactamase activity, both methicillin-inducible membrane proteins were detected with nitrocefin as a substrate, whereas only one band (presumably the smaller protein) was detected with PADAC. With the remaining borderline test strain (a40), only the larger band was detected in the renatured gels with nitrocefin as a substrate. Plasmid DNA analysis revealed that the borderline susceptible test strains, again with the exception of a40, shared a 17.2-kb plasmid yielding four HindIII fragments of 7.0, 5.3, 3.5, and 1.4 kb. In Western blot (immunoblot) experiments using rabbit antiserum to penicillin-binding protein (PBP) 2a, test strain a40, which did not share a number of features characteristically associated with the other borderline test strains, was eventually shown to produce PBP 2a. Five other S. aureus strains, belonging to phage group 94/96, were found to display the borderline phenotype, including such distinguishing features as the membrane-associated PRP- and PADAC-hydrolyzing activity, the two methicillin-inducible membrane proteins, and the 17.2-kb plasmid. These results suggest that borderline susceptible S. aureus strains share more common features than reduced susceptibility to PRPs.
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Affiliation(s)
- O Massidda
- Institute of Microbiology, University of Ancona Medical School, Italy
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Massidda O, Kariyama R, Daneo-Moore L, Shockman GD. Evidence that the PBP 5 synthesis repressor (psr) of Enterococcus hirae is also involved in the regulation of cell wall composition and other cell wall-related properties. J Bacteriol 1996; 178:5272-8. [PMID: 8752348 PMCID: PMC178327 DOI: 10.1128/jb.178.17.5272-5278.1996] [Citation(s) in RCA: 24] [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] [Indexed: 02/02/2023] Open
Abstract
psr has been reported by M. Ligozzi, F. Pittaluga, and R. Fontana, (J. Bacteriol. 175:2046-2051, 1993) to be a genetic element located just upstream of the structural gene for the low-affinity penicillin-binding protein 5 (PBP 5) in the chromosome of Enterococcus hirae ATCC 9790 and to be involved in the repression of PBP 5 synthesis. By comparing properties of strains of E. hirae that contain a full-length, functional psr with those of strains that possess a truncated form of the gene, we have obtained data that indicate that psr is involved in the regulation of several additional surface-related properties. We observed that cells of strains that possessed a truncated psr were more sensitive to lysozyme-catalyzed protoplast formation, autolyzed more rapidly in 10 mM sodium phosphate (pH 6.8), and, in contrast to strains that possess a functional psr, retained these characteristics after the cultures entered the stationary growth phase. Cellular lytic properties did not correlate with differences in the cellular contents of muramidase-1 or muramidase-2, with the levels of PBP 5 produced, or with the penicillin susceptibilities of the strains. However, a strong correlation was observed with the amounts of rhamnose present in the cell walls of the various strains. All of the strains examined that possessed a truncated form of psr also possessed approximately one-half of the rhamnose content present in the walls of strains that possessed a functional psr. These data suggest that psr is also involved in the regulation of the synthesis of, or covalent linkage to the cell wall peptidoglycan of, a rhamnose-rich polysaccharide. These differences in cell wall composition could be responsible for the observed phenotypic differences. However, the multiple effects of psr suggest that it is part of a global regulatory system that, perhaps independently, affects several cell surface-related properties.
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Affiliation(s)
- O Massidda
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Marzocchi B, Magi B, Bini L, Cellesi C, Rossolini A, Massidda O, Pallini V. Two-dimensional gel electrophoresis and immunoblotting of human serum albumin modified by reaction with penicillins. Electrophoresis 1995; 16:851-3. [PMID: 7588574 DOI: 10.1002/elps.11501601140] [Citation(s) in RCA: 5] [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: 01/26/2023]
Abstract
A two-dimensional gel electrophoresis and immunoblotting procedure has been developed to assess the level of modification by penicillins in human serum albumin. The procedure can be used in in vitro experiments and in clinical studies with sera from patients treated with penicillins.
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Affiliation(s)
- B Marzocchi
- Dipartimento di Biologia Molecolare, Università di Siena, Italia
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Massidda O, Montanari MP, Mingoia M, Varaldo PE. Cloning and expression of the penicillinase from a borderline methicillin-susceptible Staphylococcus aureus strain in Escherichia coli. FEMS Microbiol Lett 1994; 119:263-9. [PMID: 8050709 DOI: 10.1111/j.1574-6968.1994.tb06899.x] [Citation(s) in RCA: 11] [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: 01/28/2023] Open
Abstract
The blaZ gene contained in a single 17.2-kb beta-lactamase plasmid from a borderline methicillin-susceptible Staphylococcus aureus strain (a53) has been cloned in Escherichia coli. A Bluescript II derivative in which the ampicillin resistance gene has been replaced with the chloramphenicol resistance gene was used as a multi-copy vector. One ampicillin-resistant colony was detected among 31 chloramphenicol-resistant transformants selected. This E. coli clone harbored a recombinant plasmid (pAH12) containing two different staphylococcal HindIII inserts (7.0 and 5.3 kb), of which only the former hybridized with a blaZ probe. The clone showed an ampicillin MIC of > 1024 micrograms ml-1, independently of the inoculum size used, and produced large amounts of beta-lactamase, which hydrolyzed nitrocefin and penicillin G but not methicillin of the beta-lactamase substrate, padac. In contrast, S. aureus a53 hydrolyzed all four substrates. The fact that high levels of staphylococcal penicillinase are unable to cause methicillin hydrolysis confirms that penicillinase hyperproduction is unlikely to be the true mechanism responsible for the borderline phenotype. These results also suggest that the two different beta-lactamases (penicillinase and methicillinase) associated with borderline S. aureus strains have a different genetic origin.
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Affiliation(s)
- O Massidda
- Istituto di Microbiologia, Università degli Studi di Ancona, Italy
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Abstract
In-vitro antimicrobial activity of cefpodoxime was evaluated against several microbial species by both conventional tests and additional parameters which take into consideration some of the conditions likely to be encountered in infected tissues. MICs for 414 recent clinical isolates, including staphylococci, streptococci, Haemophilus influenzae, Moraxella catarrhalis, several Enterobacteriaceae, Aeromonas hydrophila and Campylobacter jejuni were determined. MIC values overall were similar to those observed for strains from other geographical areas. Inhibition of growth by cefpodoxime was virtually unaffected by the inoculum size, even using bacterial populations as large as 10(9) cfu of Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, H. influenzae, beta-lactamase-negative M. catarrhalis, Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. Growth in the presence of human serum as the only source of nutrients did not significantly affect the inhibition exerted by cefpodoxime, even against large bacterial populations of S. aureus, S. pneumoniae, E. coli, and K. pneumoniae. For K. pneumoniae, E. coli, P. mirabilis and beta-lactamase-negative M. catarrhalis it was also found that sub-MIC concentrations of cefpodoxime were still able to inhibit the majority of cells in microbial populations as large as 10(9) cfu. Evaluation of bactericidal activity demonstrated that cefpodoxime concentrations comparable to those achievable in plasma or in the respiratory tract were able to kill rapidly large bacterial populations of S. pneumoniae and S. pyogenes. The bactericidal activity was apparently lower against M. catarrhalis, H. influenzae, S. aureus, E. coli, and K. pneumoniae.
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Affiliation(s)
- S Valentini
- Dipartimento di Biologia Molecolare, Università di Siena, Italy
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Segatore B, Massidda O, Satta G, Setacci D, Amicosante G. High specificity of cphA-encoded metallo-beta-lactamase from Aeromonas hydrophila AE036 for carbapenems and its contribution to beta-lactam resistance. Antimicrob Agents Chemother 1993; 37:1324-8. [PMID: 8328781 PMCID: PMC187960 DOI: 10.1128/aac.37.6.1324] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [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: 01/29/2023] Open
Abstract
The Aeromonas hydrophila AE036 chromosome contains a cphA gene encoding a metallo-beta-lactamase highly active against carbapenem antibiotics. This enzyme was induced in strain AE036 to the same extent by both benzylpenicillin and imipenem. When the cphA gene was inserted into plasmid pACYC184, used to transform Escherichia coli DH5 alpha, the MICs of imipenem, meropenem, and penem HRE664 for recombinant clone DH5 alpha(pAA20R), expressing the Aeromonas metallo-beta-lactamase, were significantly increased, but those of penicillins and cephalosporins were not. When the metallo-beta-lactamase purified from E. coli DH5 alpha(pAA20R) was assayed with several beta-lactam substrates, it hydrolyzed carbapenems but not penicillins or cephalosporins efficiently. These results demonstrate that this metallo-beta-lactamase possesses an unusual spectrum of activity compared with all the other class B enzymes identified so far, being active on penems and carbapenems only. This enzyme may thus contribute to the development of resistance to penems and carbapenems but not other beta-lactams.
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Affiliation(s)
- B Segatore
- Department of Biomedical Sciences and Technologies and of Biometrics, Faculty of Medicine, University of L'Aquila, Italy
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Massidda O, Montanari MP, Varaldo PE. Evidence for a methicillin-hydrolysing beta-lactamase in Staphylococcus aureus strains with borderline susceptibility to this drug. FEMS Microbiol Lett 1992; 71:223-7. [PMID: 1624119 DOI: 10.1016/0378-1097(92)90713-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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: 12/27/2022] Open
Abstract
A new beta-lactamase that hydrolyses methicillin was found in the membrane fraction of two clinical isolates of Staphylococcus aureus with borderline susceptibility to this drug. 'Methicillinase' activity was detected in renatured sodium dodecyl sulfate polyacrylamide gel electrophoretograms of staphylococcal membrane proteins. The enzyme activity appeared to be inducible and was more easily detected using penicillin G (or methicillin) rather than nitrocefin as substrate. Similar activity was not detected in the membrane fraction of a methicillin-susceptible strain. These results suggest that, in the two borderline susceptible strains, rather than a hyperproduction of the penicillinase a specific methicillin-hydrolysing activity is responsible for the borderline susceptible phenotype.
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Affiliation(s)
- O Massidda
- Dipartimento di Biologia Molecolare, Sezione Microbiologia, Università degli Studi di Siena, Italy
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35
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Massidda O, Montanari MP, Varaldo PE. Evidence for a methicillin-hydrolysing β-lactamase in Staphylococcus aureusstrains with borderline susceptibility to this drug. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05265.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
An Aeromonas hydrophila gene, named cphA, coding for a carbapenem-hydrolyzing metallo-beta-lactamase, was cloned in Escherichia coli by screening an Aeromonas genomic library for clones able to grow on imipenem-containing medium. From sequencing data, the cloned cphA gene appeared able to code for a polypeptide of 254 amino acids whose sequence includes a potential N-terminal leader sequence for targeting the protein to the periplasmic space. These data were in agreement with the molecular mass of the original Aeromonas enzyme and of the recombinant enzyme produced in E. coli, evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude beta-lactamase preparations followed by renaturation treatment for proteins separated in the gel and localization of protein bands showing carbapenem-hydrolyzing beta-lactamase activity by a modified iodometric technique. The deduced amino acid sequence of the CphA enzyme showed regions of partial homology with both the beta-lactamase II of Bacillus cereus and the CfiA beta-lactamase of Bacteroides fragilis. Sequence homologies were more pronounced in the regions encompassing the amino acid residues known in the enzyme of B. cereus to function as ligand-binding residues for the metal cofactor. The CphA enzyme, however, appeared to share a lower degree of similarity with the two other enzymes, which, in turn, seemed more closely related to each other. These results, therefore, suggest the existence of at least two molecular subclasses within molecular class B metallo-beta-lactamases.
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Affiliation(s)
- O Massidda
- Dipartimento di Biologia Molecolare, Sezione Microbiologia, Universitá degli Studi di Siena, Italy
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37
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Satta G, Massidda O, D'Andrea L. The mechanism of staphylococci resistance to methicillin: a critical analysis of dominant opinions. J Chemother 1991; 3 Suppl 1:144-8. [PMID: 12041750] [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: 02/25/2023]
Abstract
Resistance to methicillin has been reported to be constantly associated with production of a novel penicillin-binding protein (PBP), indicated as PBP2a. This PBP is always present in strains that are homogeneously resistant to the drug, but is also constantly present in the strains heterogeneously resistant, where by far the vast majority of the cells are indeed sensitive to the antibiotic. This apparent lack of correlation between the presence of PBP2a and methicillin resistance has led to the idea, shared by most scientists, that the presence of PBP2a alone cannot explain resistance of staphylococci to methicillin. This confusion has implications also for clinical microbiology. In fact in in-vitro assays, not rarely, strains that are resistant to methicillin appear sensitive to other beta-lactams. However, clinical experience has demonstrated that when infections caused by methicillin-resistant staphylococci, which, in in vitro assays, become sensitive to other beta-lactams, are treated with the latter antibiotics, the incidence of failures is higher than that observed when the same antibiotics are used to treat infections caused by staphylococci sensitive to methicillin. Also in consideration of the fact that the mechanism of resistance to methicillin is not yet understood, many authors recommend to consider methicillin-resistant staphylococci as being in-vivo resistant also to the beta-lactams to which they may become sensitive in in-vitro assays. In the opinion of the authors, the mechanism of staphylococcal resistance to methicillin is reasonably explainable at least in its fundamental aspects. The present dominant opinions concerning methicillin-resistant staphylococci will be critically analyzed on the basis both of data presented in the literature and of data obtained in the authors' laboratory.
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Affiliation(s)
- G Satta
- Institute of Microbiology of the University of Siena, Italy
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Kariyama R, Massidda O, Daneo-Moore L, Shockman GD. Properties of cell wall-associated DD-carboxypeptidase of Enterococcus hirae (Streptococcus faecium) ATCC 9790 extracted with alkali. J Bacteriol 1990; 172:3718-24. [PMID: 2361945 PMCID: PMC213349 DOI: 10.1128/jb.172.7.3718-3724.1990] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [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] [Indexed: 12/31/2022] Open
Abstract
DD-Carboxypeptidase (DD-CPase) activity of Enterococcus hirae (Streptococcus faecium) ATCC 9790 was extracted from intact bacteria and from the insoluble residue (crude cell wall fraction) of mechanically disrupted bacteria by a brief treatment at pH 10.0 (10 mM glycine-NaOH) at 0 degrees C or by extraction with any of several detergents. Extractions with high salt concentrations failed to remove DD-CPase activity from the crude wall fraction. In contrast to N-acetylmuramoylhydrolase (both muramidase 2 and muramidase 1) activities, DD-CPase activity failed to bind to insoluble cell walls or peptidoglycan matrices. Thus, whereas muramidase 1 and muramidase 2 activities can be considered to be cell wall proteins, the bulk of the data are consistent with the interpretation that the DD-CPase of this species is a membrane protein that is sometimes found in the cell wall fraction, presumably because of hydrophobic interactions with other proteins and cell wall polymers. The binding of [14C]penicillin to penicillin-binding protein 6 (43 kilodaltons) was proportional to DD-CPase activity. Kinetic parameters were also consistent with the presence of only one DD-CPase (penicillin-binding protein 6) in E. hirae.
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Affiliation(s)
- R Kariyama
- Department of Microbiology and Immunology, School of Medicine, Temple University, Philadelphia, Pennsylvania 19140
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