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Hiller NL, Orihuela CJ. Biological puzzles solved by using Streptococcus pneumoniae: a historical review of the pneumococcal studies that have impacted medicine and shaped molecular bacteriology. J Bacteriol 2024; 206:e0005924. [PMID: 38809015 DOI: 10.1128/jb.00059-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024] Open
Abstract
The major human pathogen Streptococcus pneumoniae has been the subject of intensive clinical and basic scientific study for over 140 years. In multiple instances, these efforts have resulted in major breakthroughs in our understanding of basic biological principles as well as fundamental tenets of bacterial pathogenesis, immunology, vaccinology, and genetics. Discoveries made with S. pneumoniae have led to multiple major public health victories that have saved the lives of millions. Studies on S. pneumoniae continue today, where this bacterium is being used to dissect the impact of the host on disease processes, as a powerful cell biology model, and to better understand the consequence of human actions on commensal bacteria at the population level. Herein we review the major findings, i.e., puzzle pieces, made with S. pneumoniae and how, over the years, they have come together to shape our understanding of this bacterium's biology and the practice of medicine and modern molecular biology.
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Affiliation(s)
- N Luisa Hiller
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Carlos J Orihuela
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Li L, Ma J, Yu Z, Li M, Zhang W, Sun H. Epidemiological characteristics and antibiotic resistance mechanisms of Streptococcus pneumoniae: An updated review. Microbiol Res 2023; 266:127221. [DOI: 10.1016/j.micres.2022.127221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/13/2022] [Accepted: 10/03/2022] [Indexed: 11/27/2022]
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Geerts N, De Vooght L, Passaris I, Delputte P, Van den Bergh B, Cos P. Antibiotic Tolerance Indicative of Persistence Is Pervasive among Clinical Streptococcus pneumoniae Isolates and Shows Strong Condition Dependence. Microbiol Spectr 2022; 10:e0270122. [PMID: 36374111 PMCID: PMC9769776 DOI: 10.1128/spectrum.02701-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 10/16/2022] [Indexed: 11/16/2022] Open
Abstract
Streptococcus pneumoniae is an important human pathogen, being one of the most common causes of community-acquired pneumonia and otitis media. Antibiotic resistance in S. pneumoniae is an emerging problem, as it depletes our arsenal of effective drugs. In addition, persistence also contributes to the antibiotic crisis in many other pathogens, yet for S. pneumoniae, little is known about antibiotic-tolerant persisters and robust experimental means are lacking. Persister cells are phenotypic variants that exist as a subpopulation within a clonal culture. Being tolerant to lethal antibiotics, they underly the chronic nature of a variety of infections and even help in acquiring genetic resistance. In this study, we set out to identify and characterize persistence in S. pneumoniae. Specifically, we followed different strategies to overcome the self-limiting nature of S. pneumoniae as a confounding factor in the prolonged monitoring of antibiotic survival needed to study persistence. Under optimized conditions, we identified genuine persisters in various growth phases and for four relevant antibiotics through biphasic survival dynamics and heritability assays. Finally, we detected a high variety in antibiotic survival levels across a diverse collection of S. pneumoniae clinical isolates, which assumes that a high natural diversity in persistence is widely present in S. pneumoniae. Collectively, this proof of concept significantly progresses the understanding of the importance of antibiotic persistence in S. pneumoniae infections, which will set the stage for characterizing its relevance to clinical outcomes and advocates for increased attention to the phenotype in both fundamental and clinical research. IMPORTANCE S. pneumoniae is considered a serious threat by the Centers for Disease Control and Prevention because of rising antibiotic resistance. In addition to resistance, bacteria can also survive lethal antibiotic treatment by developing antibiotic tolerance, more specifically, antibiotic tolerance through persistence. This phenotypic variation seems omnipresent among bacterial life, is linked to therapy failure, and acts as a catalyst for resistance development. This study gives the first proof of the presence of persister cells in S. pneumoniae and shows a high variety in persistence levels among diverse strains, suggesting that persistence is a general trait in S. pneumoniae cultures. Our work advocates for higher interest for persistence in S. pneumoniae as a contributing factor for therapy failure and resistance development.
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Affiliation(s)
- Nele Geerts
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | - Linda De Vooght
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | | | - Peter Delputte
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | - Bram Van den Bergh
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
| | - Paul Cos
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
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Rapacka-Zdonczyk A, Wozniak A, Nakonieczna J, Grinholc M. Development of Antimicrobial Phototreatment Tolerance: Why the Methodology Matters. Int J Mol Sci 2021; 22:2224. [PMID: 33672375 PMCID: PMC7926562 DOI: 10.3390/ijms22042224] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/12/2022] Open
Abstract
Due to rapidly growing antimicrobial resistance, there is an urgent need to develop alternative, non-antibiotic strategies. Recently, numerous light-based approaches, demonstrating killing efficacy regardless of microbial drug resistance, have gained wide attention and are considered some of the most promising antimicrobial modalities. These light-based therapies include five treatments for which high bactericidal activity was demonstrated using numerous in vitro and in vivo studies: antimicrobial blue light (aBL), antimicrobial photodynamic inactivation (aPDI), pulsed light (PL), cold atmospheric plasma (CAP), and ultraviolet (UV) light. Based on their multitarget activity leading to deleterious effects to numerous cell structures-i.e., cell envelopes, proteins, lipids, and genetic material-light-based treatments are considered to have a low risk for the development of tolerance and/or resistance. Nevertheless, the most recent studies indicate that repetitive sublethal phototreatment may provoke tolerance development, but there is no standard methodology for the proper evaluation of this phenomenon. The statement concerning the lack of development of resistance to these modalities seem to be justified; however, the most significant motivation for this review paper was to critically discuss existing dogma concerning the lack of tolerance development, indicating that its assessment is more complex and requires better terminology and methodology.
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Affiliation(s)
- Aleksandra Rapacka-Zdonczyk
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland; (A.R.-Z.); (A.W.); (J.N.)
- Department of Pharmaceutical Microbiology, The Faculty of Pharmacy, Medical University of Gdansk, Hallera 107, 80-416 Gdansk, Poland
| | - Agata Wozniak
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland; (A.R.-Z.); (A.W.); (J.N.)
| | - Joanna Nakonieczna
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland; (A.R.-Z.); (A.W.); (J.N.)
| | - Mariusz Grinholc
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland; (A.R.-Z.); (A.W.); (J.N.)
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Suwannawong D, Seresirikachorn K, Aeumjaturapat S, Chusakul S, Kanjanaumporn J, Chitsuthipakorn W, Ruksakul W, Snidvongs K. Predicting bacteria causing acute bacterial rhinosinusitis by clinical features. Braz J Otorhinolaryngol 2019; 86:281-286. [PMID: 30685351 PMCID: PMC9422375 DOI: 10.1016/j.bjorl.2018.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/27/2018] [Accepted: 12/05/2018] [Indexed: 11/26/2022] Open
Abstract
Introduction Clinicians rely on clinical presentations to select therapeutic agents for acute bacterial rhinosinusitis. Streptococcus pneumoniae and Haemophilus influenzae are common in acute bacterial rhinosinusitis. Drug resistant Streptococcus pneumoniae and Haemophilus influenzae require different antibiotics. Objective This study aimed to evaluate the associations between clinical features of acute bacterial rhinosinusitis and pathogenic bacteria. Methods Sixty-four patients with acute bacterial rhinosinusitis were enrolled. Clinical features including nasal obstruction, discolored discharge, facial pain, smell disturbance, fever and laboratory findings of patients with acute bacterial rhinosinusitis were collected. The bacterial cultures of endoscopic middle meatal swabs were used as a reference. Results Serum C-reactive protein level elevation correlated with the bacterial species (p = 0.03), by which was increased in 80.0% of Haemophilus influenzae rhinosinusitis and 57.1% of Streptococcus pneumoniae rhinosinusitis. The elevated C-reactive protein was the significant predictor for Haemophilus influenzae rhinosinusitis with the Odds Ratio of 18.06 (95% CI 2.36–138.20). The sensitivity of serum C-reactive protein level elevation for diagnosing Haemophilus influenzae rhinosinusitis was 0.80 (95% CI 0.49–0.94). Conclusion Elevation of serum C-reactive protein level was associated with and predicted acute bacterial rhinosinusitis caused by Haemophilus influenzae.
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Affiliation(s)
- Dussawan Suwannawong
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand
| | - Kachorn Seresirikachorn
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand
| | - Songklot Aeumjaturapat
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand
| | - Supinda Chusakul
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand
| | - Jesada Kanjanaumporn
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand
| | | | - Winyu Ruksakul
- Nakhon Pathom Hospital, Department of Otolaryngology, Nakhon Pathom, Thailand
| | - Kornkiat Snidvongs
- Chulalongkorn University, Faculty of Medicine, Department of Otolaryngology, Bangkok, Thailand; King Chulalongkorn Memorial Hospital, Endoscopic Nasal and Sinus Surgery Excellence Center, Bangkok, Thailand.
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Ma YH, Ye GS. Determination of multidrug resistance mechanisms in Clostridium perfringens type A isolates using RNA sequencing and 2D-electrophoresis. ACTA ACUST UNITED AC 2018; 51:e7044. [PMID: 29898034 PMCID: PMC6002133 DOI: 10.1590/1414-431x20187044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 03/16/2018] [Indexed: 11/22/2022]
Abstract
In this study, we screened differentially expressed genes in a
multidrug-resistant isolate strain of Clostridium perfringens
by RNA sequencing. We also separated and identified differentially expressed
proteins (DEPs) in the isolate strain by two-dimensional electrophoresis (2-DE)
and mass spectrometry (MS). The RNA sequencing results showed that, compared
with the control strain, 1128 genes were differentially expressed in the isolate
strain, and these included 227 up-regulated genes and 901 down-regulated genes.
Bioinformatics analysis identified the following genes and gene categories that
are potentially involved in multidrug resistance (MDR) in the isolate strain:
drug transport, drug response, hydrolase activity, transmembrane transporter,
transferase activity, amidase transmembrane transporter, efflux transmembrane
transporter, bacterial chemotaxis, ABC transporter, and others. The results of
the 2-DE showed that 70 proteins were differentially expressed in the isolate
strain, 45 of which were up-regulated and 25 down-regulated. Twenty-seven DEPs
were identified by MS and these included the following protein categories:
ribosome, antimicrobial peptide resistance, and ABC transporter, all of which
may be involved in MDR in the isolate strain of C. perfringens. The results
provide reference data for further investigations on the drug resistant
molecular mechanisms of C. perfringens.
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Affiliation(s)
- Yu-Hua Ma
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China.,College of Agriculture and Animal Husbandry, Qinghai University, Xining, China
| | - Gui-Sheng Ye
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China.,College of Agriculture and Animal Husbandry, Qinghai University, Xining, China
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Jindal HM, Ramanathan B, Le CF, Gudimella R, Razali R, Manikam R, Sekaran SD. Comparative genomic analysis of ten clinical Streptococcus pneumoniae collected from a Malaysian hospital reveal 31 new unique drug-resistant SNPs using whole genome sequencing. J Biomed Sci 2018; 25:15. [PMID: 29448938 PMCID: PMC5815235 DOI: 10.1186/s12929-018-0414-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/29/2018] [Indexed: 11/30/2022] Open
Abstract
Background Streptococcus pneumoniae or pneumococcus is a leading cause of morbidity and mortality worldwide, specifically in relation to community-acquired pneumonia. Due to the overuse of antibiotics, S. pneumoniae has developed a high degree of resistance to a wide range of antibacterial drugs. Methods In this study, whole genome sequencing (WGS) was performed for 10 clinical strains of S. pneumoniae with different levels of sensitivity to standard antibiotics. The main objective was to investigate genetic changes associated with antibiotic resistance in S. pneumoniae. Results Our results showed that resistant isolates contain a higher number of non-synonymous single nucleotide polymorphisms (SNPs) as compared to susceptible isolates. We were able to identify SNPs that alter a single amino acid in many genes involved in virulence and capsular polysaccharide synthesis. In addition, 90 SNPs were only presented in the resistant isolates, and 31 SNPs were unique and had not been previously reported, suggesting that these unique SNPs could play a key role in altering the level of resistance to different antibiotics. Conclusion Whole genome sequencing is a powerful tool for comparing the full genome of multiple isolates, especially those closely related, and for analysing the variations found within antibiotic resistance genes that lead to differences in antibiotic sensitivity. We were able to identify specific mutations within virulence genes related to resistant isolates. These findings could provide insights into understanding the role of single nucleotide mutants in conferring drug resistance. Electronic supplementary material The online version of this article (10.1186/s12929-018-0414-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hassan Mahmood Jindal
- Department of Medical Microbiology, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Babu Ramanathan
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Kuala Lumpur, Malaysia
| | - Cheng Foh Le
- School of Pharmacy, University of Nottingham Malaysia Campus, 43500, Semenyih, Selangor, Malaysia
| | | | - Rozaimi Razali
- Sengenics HIR, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Rishya Manikam
- Department of Trauma and Emergency, University Malaya Medical Centre, 50603, Kuala Lumpur, Malaysia
| | - Shamala Devi Sekaran
- Department of Microbiology, Faculty of Medicine, MAHSA University, 42610, Jenjarom, Malaysia.
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Lewis ML, Surewaard BGJ. Neutrophil evasion strategies by Streptococcus pneumoniae and Staphylococcus aureus. Cell Tissue Res 2017; 371:489-503. [PMID: 29204747 DOI: 10.1007/s00441-017-2737-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/06/2017] [Indexed: 02/05/2023]
Abstract
Humans are well equipped to defend themselves against bacteria. The innate immune system employs diverse mechanisms to recognize, control and initiate a response that can destroy millions of different microbes. Microbes that evade the sophisticated innate immune system are able to escape detection and could become pathogens. The pathogens Streptococcus pneumoniae and Staphylococcus aureus are particularly successful due to the development of a wide variety of virulence strategies for bacterial pathogenesis and they invest significant efforts towards mechanisms that allow for neutrophil evasion. Neutrophils are a primary cellular defense and can rapidly kill invading microbes, which is an indispensable function for maintaining host health. This review compares the key features of Streptococcus pneumoniae and Staphylococcus aureus in epidemiology, with a specific focus on virulence mechanisms utilized to evade neutrophils in bacterial pathogenesis. It is important to understand the complex interactions between pathogenic bacteria and neutrophils so that we can disrupt the ability of pathogens to cause disease.
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Affiliation(s)
- Megan L Lewis
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Bas G J Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Department of Medical Microbiology, University Medical Centre, Utrecht, Netherlands.
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9
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Molecular detection of genes responsible for macrolide resistance among Streptococcus pneumoniae isolated in North Lebanon. J Infect Public Health 2017; 10:745-748. [DOI: 10.1016/j.jiph.2016.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 10/10/2016] [Accepted: 11/18/2016] [Indexed: 11/23/2022] Open
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Ngo Ndjom CG, Kantor LV, Jones HP. CRH Affects the Phenotypic Expression of Sepsis-Associated Virulence Factors by Streptococcus pneumoniae Serotype 1 In vitro. Front Cell Infect Microbiol 2017; 7:263. [PMID: 28690980 PMCID: PMC5479890 DOI: 10.3389/fcimb.2017.00263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 06/02/2017] [Indexed: 12/20/2022] Open
Abstract
Sepsis is a life-threatening health condition caused by infectious pathogens of the respiratory tract, and accounts for 28–50% of annual deaths in the US alone. Current treatment regimen advocates the use of corticosteroids as adjunct treatment with antibiotics, for their broad inhibitory effect on the activity and production of pro-inflammatory mediators. However, despite their use, corticosteroids have not proven to be able to reverse the death incidence among septic patients. We have previously demonstrated the potential for neuroendocrine factors to directly influence Streptococcus pneumoniae virulence, which may in turn mediate disease outcome leading to sepsis and septic shock. The current study investigated the role of Corticotropin-releasing hormone (CRH) in mediating key markers of pneumococcal virulence as important phenotypic determinants of sepsis and septic shock risks. In vitro cultures of serotype 1 pneumococcal strain with CRH promoted growth rate, increased capsule thickness and penicillin resistance, as well as induced pneumolysin gene expression. These results thus provide significant insights of CRH–pathogen interactions useful in understanding the underlying mechanisms of neuroendocrine factor's role in the onset of community acquired pneumonias (CAP), sepsis and septic shock.
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Affiliation(s)
- Colette G Ngo Ndjom
- Department of Molecular and Medical Genetics, University of North Texas Health Science CenterFort Worth, TX, United States
| | - Lindsay V Kantor
- Graduate School of Biomedical Sciences, University of North Texas Health Science CenterFort Worth, TX, United States
| | - Harlan P Jones
- Department of Molecular and Medical Genetics, University of North Texas Health Science CenterFort Worth, TX, United States
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Turner AG, Ong CLY, Walker MJ, Djoko KY, McEwan AG. Transition Metal Homeostasis in Streptococcus pyogenes and Streptococcus pneumoniae. Adv Microb Physiol 2017; 70:123-191. [PMID: 28528647 DOI: 10.1016/bs.ampbs.2017.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Trace metals such as Fe, Mn, Zn and Cu are essential for various biological functions including proper innate immune function. The host immune system has complicated and coordinated mechanisms in place to either starve and/or overload invading pathogens with various metals to combat the infection. Here, we discuss the roles of Fe, Mn and Zn in terms of nutritional immunity, and also the roles of Cu and Zn in metal overload in relation to the physiology and pathogenesis of two human streptococcal species, Streptococcus pneumoniae and Streptococcus pyogenes. S. pneumoniae is a major human pathogen that is carried asymptomatically in the nasopharynx by up to 70% of the population; however, transition to internal sites can cause a range of diseases such as pneumonia, otitis media, meningitis and bacteraemia. S. pyogenes is a human pathogen responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Both species have overlapping capacity with respect to metal acquisition, export and regulation and how metal homeostasis relates to their virulence and ability to invade and survive within the host. It is becoming more apparent that metals have an important role to play in the control of infection, and with further investigations, it could lead to the potential use of metals in novel antimicrobial therapies.
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Affiliation(s)
- Andrew G Turner
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Cheryl-Lynn Y Ong
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Karrera Y Djoko
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.
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Chueca B, Berdejo D, Gomes-Neto NJ, Pagán R, García-Gonzalo D. Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils. Front Microbiol 2016; 7:273. [PMID: 26973641 PMCID: PMC4777736 DOI: 10.3389/fmicb.2016.00273] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/19/2016] [Indexed: 12/04/2022] Open
Abstract
The improvement of food preservation by using essential oils (EOs) and their individual constituents (ICs) is attracting enormous interest worldwide. Until now, researchers considered that treatments with such antimicrobial compounds did not induce bacterial resistance via a phenotypic (i.e., transient) response. Nevertheless, the emergence of genotypic (i.e., stable) resistance after treatment with these compounds had not been previously tested. Our results confirm that growth of Escherichia coli MG1655 in presence of sub-inhibitory concentrations of the ICs carvacrol, citral, and (+)-limonene oxide do not increase resistance to further treatments with either the same IC (direct resistance) or with other preservation treatments (cross-resistance) such as heat or pulsed electric fields (PEF). Bacterial mutation frequency was likewise lower when those IC's were applied; however, after 10 days of re-culturing cells in presence of sub-inhibitory concentrations of the ICs, we were able to isolate several derivative strains (i.e., mutants) displaying an increased minimum inhibitory concentration to those ICs. Furthermore, when compared to the wild type (WT) strain, they also displayed direct resistance and cross-resistance. Derivative strains selected with carvacrol and citral also displayed morphological changes involving filamentation along with cell counts at late-stationary growth phase that were lower than the WT strain. In addition, co-cultures of each derivative strain with the WT strain resulted in a predominance of the original strain in absence of ICs, indicating that mutants would not out-compete WT cells under optimal growth conditions. Nevertheless, growth in the presence of ICs facilitated the selection of these resistant mutants. Thus, as a result, subsequent food preservation treatments of these bacterial cultures might be less effective than expected for WT cultures. In conclusion, this study recommends that treatment with ICs at sub-inhibitory concentrations should be generally avoided, since it could favor the emergence of hyper-resistant strains. To ascertain the true value of EOs and their ICs in the field of food preservation, further research thus needs to be conducted on the induction of increased transient and stable bacterial resistance via such antimicrobial compounds, as revealed in this study.
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Affiliation(s)
- Beatriz Chueca
- Tecnología de los Alimentos, Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Instituto Agroalimentario de Aragón, Universidad de Zaragoza-CITA Zaragoza, Spain
| | - Daniel Berdejo
- Tecnología de los Alimentos, Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Instituto Agroalimentario de Aragón, Universidad de Zaragoza-CITA Zaragoza, Spain
| | - Nelson J Gomes-Neto
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba João Pessoa, Brazil
| | - Rafael Pagán
- Tecnología de los Alimentos, Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Instituto Agroalimentario de Aragón, Universidad de Zaragoza-CITA Zaragoza, Spain
| | - Diego García-Gonzalo
- Tecnología de los Alimentos, Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Instituto Agroalimentario de Aragón, Universidad de Zaragoza-CITA Zaragoza, Spain
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Ding Y, Zhao J, He X, Li M, Guan H, Zhang Z, Li P. Antimicrobial resistance and virulence-related genes of Streptococcus obtained from dairy cows with mastitis in Inner Mongolia, China. PHARMACEUTICAL BIOLOGY 2015; 54:162-167. [PMID: 25856704 DOI: 10.3109/13880209.2015.1025290] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
CONTEXT Mastitis is the most expensive disease in the dairy cattle industry and results in decreased reproductive performance. Streptococcus, especially Streptococcus agalactiae, possesses a variety of virulence factors that contribute to pathogenicity. OBJECTIVE Streptococcus isolated from mastitis was tested to assess the prevalence of antimicrobial resistance and distribution of antibiotic resistance- and virulence-related genes. MATERIALS AND METHODS Eighty-one Streptococcus isolates were phenotypically characterized for antimicrobial resistance against 15 antibiotics by determining minimum inhibitory concentrations (MIC) using a micro-dilution method. Resistance- and virulence-related genes were detected by PCR. RESULTS High percentage of resistance to β-lactams, along with tetracycline and erythromycin, was found. Resistance to three or more of seven antimicrobial agents was observed at 88.9%, with penicillin-tetracycline-erythromycin-clindamycin as the major profile in Streptococcus isolates. Resistant genes were detected by PCR, the result showed that 86.4, 86.4, 81.5, and 38.3% of isolates were mainly carrying the pbp2b, tetL, tetM, and ermB genes, respectively. Nine virulence genes were investigated. Genes cyl, glnA, cfb, hylB, and scaA were found to be in 50% of isolates, while 3.7, 21, and 4.9% of isolates were positive for bca, lmb, and scpB, genes, respectively. None of the isolates carried the bac gene. DISCUSSION AND CONCLUSION This study suggests the need for prudent use of antimicrobial agents in veterinary clinical medicine to avoid the increase and dissemination of antimicrobial resistance arising from the use of antimicrobial drugs in animals.
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Affiliation(s)
- Yuexia Ding
- a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China
- b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China
| | - Junli Zhao
- c Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences , Hohhot , Inner Mongolia Autonomous Region , PR China , and
| | - Xiuling He
- a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China
- b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China
| | - Man Li
- a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China
- b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China
| | - Hong Guan
- a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China
- b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China
| | - Ziying Zhang
- d College of Basic, Inner Mongolia Medical University , Hohhot , Inner Mongolia Autonomous Region , PR China
| | - Peifeng Li
- a Department of Veterinary Pharmacology & Toxicology , College of Veterinary Medicine, Inner Mongolia Agricultural University , Hohhot , Inner Mongolia Autonomous Region , PR China
- b Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease , Ministry of Agriculture , Hohhot , Inner Mongolia Autonomous Region , China
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Thabit AK, Crandon JL, Nicolau DP. Antimicrobial resistance: impact on clinical and economic outcomes and the need for new antimicrobials. Expert Opin Pharmacother 2014; 16:159-77. [PMID: 25496207 DOI: 10.1517/14656566.2015.993381] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Antimicrobial resistance is a well-recognized global threat; thus, the development of strong infection control policies coupled with antimicrobial stewardship strategies and new therapies is required to reverse this process. In its 2013 report on antimicrobial resistance, the Centers for Disease Control and Prevention focused on this problem while presenting estimated annual rates of infections with antimicrobial-resistant organisms and their related mortality rates. Whereas some resistant pathogens were considered less threatening, others such as carbapenem-resistant Enterobacteriaceae were associated with higher mortality rates owing to limited treatment options. AREAS COVERED An overview of the most common antimicrobial-resistant pathogens, focusing on risk factors for acquisition, clinical and economic outcomes, as well as current treatment options. Strategies to optimize antimicrobial therapy with currently available agents, in addition to newly developed antimicrobials are also discussed. EXPERT OPINION The emergence of pathogens with a variety of resistance mechanisms has intensified the challenges associated with infection control and treatment strategies. Therefore, prudent use of currently available antimicrobial agents, as well as implementing measures to limit spread of resistance is paramount. Although several new antimicrobials have been recently approved or are in the pipeline showing promise in the battle against resistance, the appropriate use of these agents is required as the true benefits of these treatments are to be recognized in the clinical care setting.
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Affiliation(s)
- Abrar K Thabit
- Hartford Hospital, Center for Anti-infective Research and Development , 80 Seymour Street, Hartford, CT 06102 , USA +1 860 972 3941 ; +1 860 545 3992 ;
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15
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Shakrin NNSM, Masri SN, Taib NM, Nordin SA, Jamal F, Desa MNM. Genotypic characterization of Malaysian human isolates of Streptococcus pneumoniae from carriage and clinical sources. Comp Immunol Microbiol Infect Dis 2014; 37:347-54. [DOI: 10.1016/j.cimid.2014.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/08/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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16
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Molecular analysis of pbp2b in Streptococcus pneumonia isolated from clinical and normal flora samples. Curr Microbiol 2014; 70:206-11. [PMID: 25274412 DOI: 10.1007/s00284-014-0704-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Abstract
Streptococcus pneumoniae is an important bacterial pathogen responsible for respiratory infections, bacteraemia, and meningitis remains an important cause of disease and mortality in infants and younger children around the world, with penicillin being considered the drug of choice for the treatment of infections. However, penicillin-resistant S. pneumonia is now becoming endemic worldwide. In this study, a total of 80 pneumococcal isolates were collected from different clinical sources as well as normal flora. These isolates were subjected to antimicrobial susceptibility testing and MIC determination. The penicillin-binding proteins, pbp2b, were amplified by PCR, and they were sequenced. The genetic relationship of the penicillin-resistant isolates was performed by BOX PCR. Overall, 36 pneumococcal (45 %) isolates were found to be resistant to penicillin with different MICs. The majority of them (80 %) were intermediately resistant with MIC of 0.12-1 µg/ml, whereas 20 % of isolates were penicillin resistant with MICs of >2 µg/ml. The results identified seven groups which were based on the amino acid substitutions of pbp2b. Sequencing analysis revealed that the most prevalent mutation was the substitution of Adenine for Thymine at the position 445 which is next to the second PBP2b-conserved motif (SSN). This study indicates that resistance to penicillin appears to be dependent on specific mutations in pbp2b, and the substitution in S620 → T near to the third PBP2b-conserved motif appears to be important in developing highly antibiotic-resistant isolates. Moreover, there was a positive correlation between the mutations in pbp2b gene and MIC.
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17
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Targeting imperfect vaccines against drug-resistance determinants: a strategy for countering the rise of drug resistance. PLoS One 2013; 8:e68940. [PMID: 23935910 PMCID: PMC3723804 DOI: 10.1371/journal.pone.0068940] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 06/05/2013] [Indexed: 01/31/2023] Open
Abstract
The growing prevalence of antimicrobial resistance in major pathogens is outpacing discovery of new antimicrobial classes. Vaccines mitigate the effect of antimicrobial resistance by reducing the need for treatment, but vaccines for many drug-resistant pathogens remain undiscovered or have limited efficacy, in part because some vaccines selectively favor pathogen strains that escape vaccine-induced immunity. A strain with even a modest advantage in vaccinated hosts can have high fitness in a population with high vaccine coverage, which can offset a strong selection pressure such as antimicrobial use that occurs in a small fraction of hosts. We propose a strategy to target vaccines against drug-resistant pathogens, by using resistance-conferring proteins as antigens in multicomponent vaccines. Resistance determinants may be weakly immunogenic, offering only modest specific protection against resistant strains. Therefore, we assess here how varying the specific efficacy of the vaccine against resistant strains would affect the proportion of drug-resistant vs. -sensitive strains population-wide for three pathogens--Streptococcus pneumoniae, Staphylococcus aureus, and influenza virus--in which drug resistance is a problem. Notably, if such vaccines confer even slightly higher protection (additional efficacy between 1% and 8%) against resistant variants than sensitive ones, they may be an effective tool in controlling the rise of resistant strains, given current levels of use for many antimicrobial agents. We show that the population-wide impact of such vaccines depends on the additional effect on resistant strains and on the overall effect (against all strains). Resistance-conferring accessory gene products or resistant alleles of essential genes could be valuable as components of vaccines even if their specific protective effect is weak.
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Lee EK, Jun JK, Choi UY, Kwon HJ, Kim KH, Kang JH. Nasopharyngeal Carriage Rate and Serotypes of Streptococcus pneumoniae and Antimicrobial Susceptibility in Healthy Korean Children Younger than 5 Years Old: Focus on Influence of Pneumococcal Conjugate Vaccination. Infect Chemother 2013; 45:76-84. [PMID: 24265953 PMCID: PMC3780942 DOI: 10.3947/ic.2013.45.1.76] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 10/19/2012] [Accepted: 10/23/2012] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Even after pneumococcal vaccination introduction, Streptococcus pneumoniae (pneumoccocus) is still an important cause of respiratory and invasive severe infection. Pneumococcus is resided in nasal mucosa and local or systemic infection begins with the nasal mucosa damage. We studied the indirect effect of pneumococcal conjugate vaccine (PCV) on pneumococcal nasopharyngeal carriage rates, serotypes and antimicrobial susceptibility between vaccinate and non-vaccinated children. MATERIALS AND METHODS From January 2010 to October 2010, 379 healthy children under 5 years old from three university hospitals were recruited. Fully vaccinated children over 3 time doses of PCV and children with no vaccination history of PCV were enrolled, and nasopharyngeal aspirations were obtained from these children. Serotypes using multibead serotyping assay with multiplex PCR and antimicrobial susceptibility was analyzed. Antimicrobial susceptibilities were determined by the CLIS guideline. RESULTS Two hundred seventy six children were received pneumococcal vaccination while 103 were not. 137 pneumococci were isolated from nasopharyngeal aspiration specimens. Nasal carriage rate was significantly low in vaccinated group (P-value; 0.001). Nasopharyngeal carriage rate was 28.6% (79/276) in vaccinate group and 56.3% (58/103) in non-vaccinated group. Among those vaccinated group, 13.0% (36/276) of the serotypes were vaccine or vaccine related type with the most common type 19F. In contrast, 31.1% (32/103) of the serotypes in non vaccinated group were vaccine or vaccine related type with the most common type 6A. The resistant rate of penicillin was 90.5%. For antimicrobial susceptibility, amoxicillin and amoxicillin/clavulanate showed high susceptibility (73.0%), but 19F and 19A serotypes were all resistant against amoxicillin. CONCLUSIONS High nasopharyngeal carriage rate in non vaccinated group corresponded to the result of past study. However, 19F and 19A still came up as problematic serotypes with a high carriage rate and antimicrobial resistance in both vaccinated and non vaccinated groups. Also, this study showed that the resistance rate of primary oral antimicrobial agents was increased in compared to past. For solving these problems, the selective antimicrobial use with establishment of high dose amoxicillin/clavulanate regimen and active PCV immunization should be needed. Furthermore, pneumococcal carriage and serotype study concerning with antimicrobial susceptibility should be conducted in the future in 10 or 13-valent PCV received children.
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Affiliation(s)
- Eu Kyoung Lee
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
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19
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Taha N, Araj GF, Wakim RH, Kanj SS, Kanafani ZA, Sabra A, Khairallah MT, Nassar FJ, Shehab M, Baroud M, Dbaibo G, Matar GM. Genotypes and serotype distribution of macrolide resistant invasive and non-invasive Streptococcus pneumoniae isolates from Lebanon. Ann Clin Microbiol Antimicrob 2012; 11:2. [PMID: 22248318 PMCID: PMC3371826 DOI: 10.1186/1476-0711-11-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 01/16/2012] [Indexed: 11/23/2022] Open
Abstract
Background This study determined macrolide resistance genotypes in clinical isolates of Streptococcus pneumoniae from multiple medical centers in Lebanon and assessed the serotype distribution in relation to these mechanism(s) of resistance and the source of isolate recovery. Methods Forty four macrolide resistant and 21 macrolide susceptible S. pneumoniae clinical isolates were tested for antimicrobial susceptibility according to CLSI guidelines (2008) and underwent molecular characterization. Serotyping of these isolates was performed by Multiplex PCR-based serotype deduction using CDC protocols. PCR amplification of macrolide resistant erm (encoding methylase) and mef (encoding macrolide efflux pump protein) genes was carried out. Results Among 44 isolates resistant to erythromycin, 35 were resistant to penicillin and 18 to ceftriaxone. Examination of 44 macrolide resistant isolates by PCR showed that 16 isolates harbored the erm(B) gene, 8 isolates harbored the mef gene, and 14 isolates harbored both the erm(B) and mef genes. There was no amplification by PCR of the erm(B) or mef genes in 6 isolates. Seven different capsular serotypes 2, 9V/9A,12F, 14,19A, 19F, and 23, were detected by multiplex PCR serotype deduction in 35 of 44 macrolide resistant isolates, with 19F being the most prevalent serotype. With the exception of serotype 2, all serotypes were invasive. Isolates belonging to the invasive serotypes 14 and 19F harbored both erm(B) and mef genes. Nine of the 44 macrolide resistant isolates were non-serotypable by our protocols. Conclusion Macrolide resistance in S. pneumoniae in Lebanon is mainly through target site modification but is also mediated through efflux pumps, with serotype 19F having dual resistance and being the most prevalent and invasive.
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Affiliation(s)
- Nedal Taha
- Department of Experimental Pathology, Immunology & Microbiology, Faculty of Medicine, American University of Beirut, Riad El-Solh, Beirut, Lebanon
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Nunes EDS, de Souza MAA, Vaz AFDM, Santana GMDS, Gomes FS, Coelho LCBB, Paiva PMG, da Silva RML, Silva-Lucca RA, Oliva MLV, Guarnieri MC, Correia MTDS. Purification of a lectin with antibacterial activity from Bothrops leucurus snake venom. Comp Biochem Physiol B Biochem Mol Biol 2011; 159:57-63. [DOI: 10.1016/j.cbpb.2011.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 02/07/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
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Pandey J, Chauhan A, Jain RK. Integrative approaches for assessing the ecological sustainability ofin situbioremediation. FEMS Microbiol Rev 2009; 33:324-75. [PMID: 19178567 DOI: 10.1111/j.1574-6976.2008.00133.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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22
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van de Sande-Bruinsma N, Grundmann H, Verloo D, Tiemersma E, Monen J, Goossens H, Ferech M. Antimicrobial drug use and resistance in Europe. Emerg Infect Dis 2009; 14:1722-30. [PMID: 18976555 PMCID: PMC2630720 DOI: 10.3201/eid1411.070467] [Citation(s) in RCA: 321] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Routine surveillance data indicate a relation between use and resistance and support interventions designed to reduce antimicrobial consumption at a national level in Europe. Our study confronts the use of antimicrobial agents in ambulatory care with the resistance trends of 2 major pathogens, Streptococcus pneumoniae and Escherichia coli, in 21 European countries in 2000–2005 and explores whether the notion that antimicrobial drug use determines resistance can be supported by surveillance data at national aggregation levels. The data obtained from the European Surveillance of Antimicrobial Consumption and the European Antimicrobial Resistance Surveillance System suggest that variation of consumption coincides with the occurrence of resistance at the country level. Linear regression analysis showed that the association between antimicrobial drug use and resistance was specific and robust for 2 of 3 compound pathogen combinations, stable over time, but not sensitive enough to explain all of the observed variations. Ecologic studies based on routine surveillance data indicate a relation between use and resistance and support interventions designed to reduce antimicrobial drug consumption at a national level in Europe.
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Häussler S, Becker T. The pseudomonas quinolone signal (PQS) balances life and death in Pseudomonas aeruginosa populations. PLoS Pathog 2008; 4:e1000166. [PMID: 18818733 PMCID: PMC2533401 DOI: 10.1371/journal.ppat.1000166] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Accepted: 08/28/2008] [Indexed: 11/18/2022] Open
Abstract
When environmental conditions deteriorate and become inhospitable, generic survival strategies for populations of bacteria may be to enter a dormant state that slows down metabolism, to develop a general tolerance to hostile parameters that characterize the habitat, and to impose a regime to eliminate damaged members. Here, we provide evidence that the pseudomonas quinolone signal (PQS) mediates induction of all of these phenotypes. For individual cells, PQS, an interbacterial signaling molecule of Pseudomonas aeruginosa, has both deleterious and beneficial activities: on the one hand, it acts as a pro-oxidant and sensitizes the bacteria towards oxidative and other stresses and, on the other, it efficiently induces a protective anti-oxidative stress response. We propose that this dual function fragments populations into less and more stress tolerant members which respond differentially to developing stresses in deteriorating habitats. This suggests that a little poison may be generically beneficial to populations, in promoting survival of the fittest, and in contributing to bacterial multi-cellular behavior. It further identifies PQS as an essential mediator of the shaping of the population structure of Pseudomonas and of its response to and survival in hostile environmental conditions.
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Affiliation(s)
- Susanne Häussler
- Department of Cell Biology, Helmholtz Center for Infection Research, Braunschweig, Germany.
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Regev-Yochay G, Trzcinski K, Thompson CM, Lipsitch M, Malley R. SpxB is a suicide gene of Streptococcus pneumoniae and confers a selective advantage in an in vivo competitive colonization model. J Bacteriol 2007; 189:6532-9. [PMID: 17631628 PMCID: PMC2045178 DOI: 10.1128/jb.00813-07] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human bacterial pathogen Streptococcus pneumoniae dies spontaneously upon reaching stationary phase. The extent of S. pneumoniae death at stationary phase is unusual in bacteria and has been conventionally attributed to autolysis by the LytA amidase. In this study, we show that spontaneous pneumococcal death is due to hydrogen peroxide (H(2)O(2)), not LytA, and that the gene responsible for H(2)O(2) production (spxB) also confers a survival advantage in colonization. Survival of S. pneumoniae in stationary phase was significantly prolonged by eliminating H(2)O(2) in any of three ways: chemically by supplementing the media with catalase, metabolically by growing the bacteria under anaerobic conditions, or genetically by constructing DeltaspxB mutants that do not produce H(2)O(2). Likewise, addition of H(2)O(2) to exponentially growing S. pneumoniae resulted in a death rate similar to that of cells in stationary phase. While DeltalytA mutants did not lyse at stationary phase, they died at a rate similar to that of the wild-type strain. Furthermore, we show that the death process induced by H(2)O(2) has features of apoptosis, as evidenced by increased annexin V staining, decreased DNA content, and appearance as assessed by transmission electron microscopy. Finally, in an in vivo rat model of competitive colonization, the presence of spxB conferred a selective advantage over the DeltaspxB mutant, suggesting an explanation for the persistence of this gene. We conclude that a suicide gene of pneumococcus is spxB, which induces an apoptosis-like death in pneumococci and confers a selective advantage in nasopharyngeal cocolonization.
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Affiliation(s)
- Gili Regev-Yochay
- Department of Epidemiology and Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115, USA.
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Pottumarthy S, Sader HS, Jones RN. Bactericidal activity of cefepime and ceftriaxone tested against Streptococcus pneumoniae. Diagn Microbiol Infect Dis 2007; 57:345-9. [PMID: 17141459 DOI: 10.1016/j.diagmicrobio.2006.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 08/18/2006] [Indexed: 11/21/2022]
Abstract
The bactericidal activities of cefepime and ceftriaxone were assessed by testing a contemporary collection of 50 Streptococcus pneumoniae strains. Minimum inhibitory and bactericidal concentrations (MIC and MBC, respectively) of cefepime and ceftriaxone were determined, and time-kill studies were performed on 14 selected strains (10 penicillin-resistant, 2-intermediate, and 2-susceptible). Cefepime and ceftriaxone showed essentially identical potency (MIC50, 1 microg/mL and MIC90, 2 microg/mL, for both compounds) and MBC values (MBC50, 1 microg/mL for both). MBC/MIC ratios were < or = 4 for cefepime and < or = 8 for ceftriaxone on 48 (96.0%) strains, and 2 strains (4.0%) displayed MBC/MIC ratios > or = 32 (tolerance) to the 2 cephalosporins. Time-kill curves corroborated the MBC/MIC studies. Cefepime and ceftriaxone bactericidal activity (> or = 3 log10 CFU/mL reduction in inoculum) was demonstrable after 24 h of exposure to 8x MIC for 13 (92.9%) of 14 strains, whereas 1 strain showed approximately 2 log10 CFU/mL reduction. In conclusion, our results indicate that cefepime and ceftriaxone exhibit comparable potency and bactericidal activities when tested against contemporary pneumococcal strains with varying penicillin susceptibility patterns. Both parenteral cephems offer alternative therapeutic choices for the treatment of invasive pneumococcal infections.
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Affiliation(s)
- Sudha Pottumarthy
- Houston Department of Health and Human Services, Houston, TX 77054, USA
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26
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Bourgeois I, Pestel-Caron M, Lemeland JF, Pons JL, Caron F. Tolerance to the glycopeptides vancomycin and teicoplanin in coagulase-negative staphylococci. Antimicrob Agents Chemother 2006; 51:740-3. [PMID: 17116684 PMCID: PMC1797755 DOI: 10.1128/aac.00719-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tolerance to vancomycin and teicoplanin in 90 clinical isolates of coagulase-negative staphylococci (CoNS) was investigated by time-kill curve methodology. Only six strains, belonging to the Staphylococcus lugdunensis species, exhibited tolerance. The seven other S. lugdunensis strains tested displayed weak susceptibility to the bactericidal activity of glycopeptides compared to the other CoNS. These phenomena are of concern, since S. lugdunensis is recognized as one of the most pathogenic CoNS.
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Affiliation(s)
- Ingrid Bourgeois
- Groupe de Recherce sur les Antimicrobiens et les Microorganismes, U.P.R.E.S. EA 2656, I.F.R. 23, Université de Rouen, and Centre Hospitalier Universitaire, Rouen, France
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Biçmen M, Gülay Z, Ramaswamy SV, Musher DM, Gür D. Analysis of mutations in the pbp genes of penicillin-non-susceptible pneumococci from Turkey. Clin Microbiol Infect 2006; 12:150-5. [PMID: 16441453 DOI: 10.1111/j.1469-0691.2005.01334.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sequence analysis of the pbp genes from 20 Streptococcus pneumoniae isolates from Turkey (eight with high-level penicillin-resistance, nine with low-level penicillin-resistance, and three that were penicillin-susceptible) was performed and phylogenetic trees were constructed. Most isolates clustered together within a single branch that was distinct from sequences deposited previously in GenBank, which suggests that these isolates have probably evolved following new recombination events. The most prominent active-site mutations, which have also been associated previously with resistance, were T371A in PBP1a, E481G followed by T451A in PBP2b, and T338A in PBP2x. All isolates also possessed a (570)SVES/TK(574) block in the PBP2b sequence, instead of the QLQPT sequence of R6, which is fairly uncommon in GenBank sequences. This is the first study to analyse alterations in the pbp sequences of pneumococci isolated in Turkey.
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Affiliation(s)
- M Biçmen
- Department of Microbiology and Clinical Microbiology, Dokuz Eylul University, School of Medicine, Inciralti, Izmir, Turkey
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28
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Muñoz-Elías EJ, McKinney JD. Mycobacterium tuberculosis isocitrate lyases 1 and 2 are jointly required for in vivo growth and virulence. Nat Med 2005; 11:638-44. [PMID: 15895072 PMCID: PMC1464426 DOI: 10.1038/nm1252] [Citation(s) in RCA: 557] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Accepted: 04/29/2005] [Indexed: 01/01/2023]
Abstract
Genes involved in fatty acid catabolism have undergone extensive duplication in the genus Mycobacterium, which includes the etiologic agents of leprosy and tuberculosis. Here, we show that prokaryotic- and eukaryotic-like isoforms of the glyoxylate cycle enzyme isocitrate lyase (ICL) are jointly required for fatty acid catabolism and virulence in Mycobacterium tuberculosis. Although deletion of icl1 or icl2, the genes that encode ICL1 and ICL2, respectively, had little effect on bacterial growth in macrophages and mice, deletion of both genes resulted in complete impairment of intracellular replication and rapid elimination from the lungs. The feasibility of targeting ICL1 and ICL2 for chemical inhibition was shown using a dual-specific ICL inhibitor, which blocked growth of M. tuberculosis on fatty acids and in macrophages. The absence of ICL orthologs in mammals should facilitate the development of glyoxylate cycle inhibitors as new drugs for the treatment of tuberculosis.
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Affiliation(s)
| | - John D. McKinney
- Laboratory of Infection Biology, The Rockefeller University, New York, NY 10021 USA
- *Corresponding author: John D. McKinney, Ph.D. Laboratory of Infection Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021 USA. Tel: (+1) 212-327-7081. Fax: (+1) 212-327-7083. E-mail:
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Fisher JF, Meroueh SO, Mobashery S. Bacterial resistance to beta-lactam antibiotics: compelling opportunism, compelling opportunity. Chem Rev 2005; 105:395-424. [PMID: 15700950 DOI: 10.1021/cr030102i] [Citation(s) in RCA: 684] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Reed SM, Bayly WM, Sellon DC. Mechanisms of Infectious Disease. EQUINE INTERNAL MEDICINE 2004. [PMCID: PMC7278211 DOI: 10.1016/b0-72-169777-1/50004-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Virulence factors, antibiotic resistance mechanisms and the prevalence of resistance worldwide in Streptococcus pneumoniae. ACTA ACUST UNITED AC 2004. [DOI: 10.1097/01.revmedmi.0000131429.20976.8f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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García-Rey C, Aguilar L, Rubio-Calvo MC, Nogueira JM, García-Riestra C. Differences in co-resistance to ciprofloxacin and penicillin depending upon the phenotype of erythromycin resistance in Streptococcus pneumoniae. J Chemother 2003; 15:512-4. [PMID: 14598946 DOI: 10.1179/joc.2003.15.5.512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Abstract
Through billions of years of evolution, microbes have developed myriad defense mechanisms designed to ensure their survival. This protection is readily transferred to their fellow life forms via transposable elements. Despite very early warnings, humans have chosen to abuse the gift of antibiotics and have created a situation where all microorganisms are resistant to some antibiotics and some microorganisms are resistant to all antibiotics. When antibiotics are used, six events may occur with only one being beneficial: when the antibiotic aids the host defenses to gain control and eliminate the infection. Alternatively, the antibiotic may cause toxicity or allergy, initiate a superinfection with resistant bacteria, promote microbial chromosomal mutations to resistance, encourage resistance gene transfer to susceptible species, or promote the expression of dormant resistance genes.
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Affiliation(s)
- Thomas J Pallasch
- School of Dentistry, University of Southern California, Los Angeles, CA, USA.
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Tan TQ. Antibiotic resistant infections due to Streptococcus pneumoniae: impact on therapeutic options and clinical outcome. Curr Opin Infect Dis 2003; 16:271-7. [PMID: 12821820 DOI: 10.1097/00001432-200306000-00015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW Streptococcus pneumoniae is a major cause of morbidity and mortality in the pediatric population. The development of increasing resistance to multiple classes of antibiotics is making treatment of infections due to this organism much more difficult. The ultimate impact of high-level antibiotic resistance on therapeutic options and clinical outcomes of various pneumococcal infections is unclear and remains to be determined. Use of the conjugate pneumococcal vaccine has markedly decreased invasive pneumococcal disease in children under 5 years of age; however, its impact on decreasing antibiotic resistance is currently unknown. RECENT FINDINGS Studies suggest that response to therapy and clinical outcome of infections due to pneumococcal isolates with intermediate resistance to the beta-lactam antibiotics is no different from that of infections due to susceptible isolates. However, evidence is accumulating that infections caused by highly resistant pneumococcal isolates are associated with higher rates of treatment failure and mortality than infections due to susceptible strains. SUMMARY Use of a conjugate pneumococcal vaccine in conjunction with educational intervention programs that promote appropriate and judicious antibiotic use is a safe and effective means of decreasing the prevalence of pneumococcal disease in the pediatric population, decreasing the use of broad-spectrum antibiotic agents and potentially decreasing the amount of antibiotic resistance currently being seen.
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Affiliation(s)
- Tina Q Tan
- Division of Infectious Diseases, Children's Memorial Hospital, Chicago, Illinois 60614, USA.
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35
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Zwijnenburg PJG, van der Poll T, Florquin S, Akira S, Takeda K, Roord JJ, van Furth AM. Interleukin-18 gene-deficient mice show enhanced defense and reduced inflammation during pneumococcal meningitis. J Neuroimmunol 2003; 138:31-7. [PMID: 12742650 DOI: 10.1016/s0165-5728(03)00088-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
To determine the role of endogenous interleukin-18 (IL-18) in pneumococcal meningitis, meningitis was induced in IL-18 gene-deficient (IL-18(-/-)) and wild-type (WT) mice by intranasal inoculation of Streptococcus pneumoniae with hyaluronidase. Induction of meningitis resulted in an upregulation of both pro- and mature IL-18 in brain tissue in WT mice. IL-18(-/-) and WT mice were equally susceptible to develop meningitis after intranasal infection, yet IL-18(-/-) mice showed a prolonged survival and a suppressed inflammatory response, as reflected by a less profound inflammatory infiltrate around the meninges and lower concentrations of cytokines and chemokines in brain tissue. These findings suggest that endogenous IL-18 contributes to a detrimental inflammatory response during pneumococcal meningitis and that elimination of IL-18 may improve the outcome of this disease.
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MESH Headings
- Adjuvants, Immunologic/biosynthesis
- Adjuvants, Immunologic/deficiency
- Adjuvants, Immunologic/genetics
- Adjuvants, Immunologic/physiology
- Animals
- Brain/pathology
- Cell Movement/genetics
- Cell Movement/immunology
- Cerebrospinal Fluid/cytology
- Chemokines/metabolism
- Colony Count, Microbial
- Cytokines/metabolism
- Down-Regulation/genetics
- Down-Regulation/immunology
- Immunity, Innate/genetics
- Interleukin-18/biosynthesis
- Interleukin-18/deficiency
- Interleukin-18/genetics
- Interleukin-18/physiology
- Leukocytes/pathology
- Meningitis, Pneumococcal/genetics
- Meningitis, Pneumococcal/immunology
- Meningitis, Pneumococcal/microbiology
- Meningitis, Pneumococcal/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Streptococcus pneumoniae/growth & development
- Streptococcus pneumoniae/immunology
- Survival Rate
- Up-Regulation/genetics
- Up-Regulation/immunology
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Affiliation(s)
- Petra J G Zwijnenburg
- Department of Pediatrics, Vrije Universiteit Medical Center, de Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
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36
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Hava DL, Hemsley CJ, Camilli A. Transcriptional regulation in the Streptococcus pneumoniae rlrA pathogenicity islet by RlrA. J Bacteriol 2003; 185:413-21. [PMID: 12511486 PMCID: PMC145342 DOI: 10.1128/jb.185.2.413-421.2003] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The proper temporal expression of virulence genes during infection is crucial to the infectious life cycle of microbial pathogens, particularly in pathogens that encounter a multitude of environments in eukaryotic hosts. Streptococcus pneumoniae normally colonizes the nasopharynges of healthy adults but can cause a range of diseases at a variety of host sites. Transcriptional regulators that are essential for full virulence of S. pneumoniae in different animal models have been identified. One such regulator, rlrA, is required for colonization of the nasopharynx and lung infection but is dispensable for systemic infection. Previous work has shown that rlrA lies in a 12-kb pathogenicity islet, divergently opposed to three putative sortase-anchored surface proteins and three sortase enzymes. In addition to rlrA, one of the putative surface proteins and one of the sortases have also been shown to be essential for lung infection. In this work, we demonstrate that RlrA is a positive regulator of all seven genes in the rlrA pathogenicity islet, with transcriptional activation occurring at four different promoters in the islet with AT-rich sequences. These promoters direct the expression of rlrA itself, the three sortases, rrgA, and rrgBC. These data are consistent with the model whereby the rlrA pathogenicity islet acts in an autonomous manner to alter the bacterial surface components that interact with the pulmonary and nasopharyngeal environments.
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Affiliation(s)
- David L Hava
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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37
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Koedel U, Scheld WM, Pfister HW. Pathogenesis and pathophysiology of pneumococcal meningitis. THE LANCET. INFECTIOUS DISEASES 2002; 2:721-36. [PMID: 12467688 DOI: 10.1016/s1473-3099(02)00450-4] [Citation(s) in RCA: 267] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Until the introduction of antibiotics in the 1930s and 1940s, acute bacterial meningitis was fatal in most cases. Since then it has become curable with a variable mortality and morbidity rate for individual pathogens and patients. Neuropathological and clinical studies have shown that a fatal outcome of the disease is often due to central nervous system (CNS) complications including cerebrovascular involvement, brain oedema formation, and hydrocephalus resulting in increased intracranial pressure and seizure activity. During recent years, experimental studies with animal models have substantially increased our knowledge of the interactions of bacterial pathogens with mammalian cells and their entry into the CNS, and the complex pathophysiological mechanisms of brain dysfunction during acute bacterial meningitis. There is now a substantial body of evidence that cytokines, chemokines, proteolytic enzymes, and oxidants are involved in the inflammatory cascade that leads to tissue destruction in bacterial meningitis. Genetic targeting and/or pharmacological blockade of these pathways was beneficial in experimental bacterial meningitis. Apart from dexamethasone, these treatment strategies hold major promise for the adjunctive therapy of acute bacterial meningitis in clinical practice.
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Affiliation(s)
- Uwe Koedel
- UK and H-WP are at the Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University, Munich, Germany
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38
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Scheld WM, Koedel U, Nathan B, Pfister HW. Pathophysiology of bacterial meningitis: mechanism(s) of neuronal injury. J Infect Dis 2002; 186 Suppl 2:S225-33. [PMID: 12424702 DOI: 10.1086/344939] [Citation(s) in RCA: 221] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
No bacterial disease has undergone a more dramatic change in epidemiology during the past decade than acute bacterial meningitis. This review describes the changing epidemiology and considers some important recent observations that contribute to our understanding of the pathogenesis and pathophysiology of meningitis. The major focus is on the mechanisms of neuronal injury and the pathophysiologic concepts responsible for death and neurologic sequelae. In recent years, experimental studies have amplified our understanding of the substantial body of evidence that now implicates cytokines and chemokines, proteolytic enzymes, and oxidants in the inflammatory cascade leading to tissue destruction in bacterial meningitis. The molecular mechanisms responsible for oxidant-induced neuronal injury in meningitis are explored in some depth. Genetic targeting and/or pharmacologic blockade of the implicated pathways may be a future strategy for therapeutic adjunctive measures to improve outcome and may hold substantial promise, in concert with antimicrobial agents, in humans with acute bacterial meningitis.
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Affiliation(s)
- W Michael Scheld
- Division of Infectious Diseases, Department of Internal Medicine, University of Virginia School of Medicine, PO Box 801342, Charlottesville, VA 22908, USA.
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39
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Abstract
When bacteria such as Staphylococcus aureus and Streptococcus pneumoniae are exposed to lytic antibiotics such as penicillin and vancomycin, a self-induced killing process is initiated in the organism. This killing occurs via both non-lytic and lytic processes. Recent data suggest that the non-lytic killing system, which might affect the cytoplasmic membrane, secondarily activates murein hydrolases that eventually lyse the cell. Disturbances in this suicide pathway can lead to antibiotic tolerance, a process whereby the antibiotic still exerts its bacteriostatic effects but the self-induced killing system is impaired. In mutants obtained in vitro, signaling pathways have been affected that show either increased or decreased antibiotic-induced killing. Among clinical isolates of S. pneumoniae that are tolerant to penicillin and/or vancomycin, we do not yet know whether these signaling pathways are affected. We could, however, demonstrate that the activity of murein hydrolases is negatively controlled by the production of capsular polysaccharides in one vancomycin-tolerant isolate. Hence, type and level of capsular expression might constitute one factor that determines the degree of lysis, once the killing signal has been elicited by the antibiotic.
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Affiliation(s)
- Benriques Henriques Normark
- Swedish Institute for Infectious Disease Control and Microbiology and Tumorbiology Center, Karolinska Institutet, Stockholm Sweden.
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40
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Migliani R, Clouzeau J, Decousser JW, Ravelomanana N, Rasamoelisoa J, Rabijaona H, Dromigny JA, Pfister P, Roux JF. [Non-tubercular bacterial meningitis in children in Antananarivo, Madagascar]. Arch Pediatr 2002; 9:892-7. [PMID: 12387168 DOI: 10.1016/s0929-693x(02)00018-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine the bacterial causal agents of meningitis and their pattern of resistance, in children more than one month to 14 years of age. METHODS A 2 years, prospective study (June 1998 to June 2000) on bacterial meningitis in children was carried out in the main hospitals in Antananarivo. The enrollment criteria upon admission were fever with symptoms of meningitis and/or convulsions and/or coma. A lumbar puncture was systematically performed in each child. The aspect of the cerebrospinal fluid was described, the level of protein and glucose estimated, soluble antigens measured. Following the examination of a Gram straining, an aliquot of the fluid was cultured on specific medium. Antimicrobial sensitivity testing of isolated pathogens was performed. RESULTS Bacterial meningitis was confirmed in 119 children: 95 (80%) and 111 (93%) were less than 12 and 24 months of age, respectively. The sex distribution was 1:1. Three predominant microorganisms were identified: Streptococcus pneumoniae (45%), Haemophilus influenzae b (43%) and Neisseria meningitidis (10%) of which ten of 12 cases were belonging to serogroup B. The other microorganisms isolated were E. coli (2%). S. pneumoniae were found to be sensitive to penicillin G and H. influenzae were found to be sensitive to the third generation cephalosporins. Seven percent of the S. pneumoniae strains were mildly resistant (R + I) to chloramphenicol and between 29 and 50% to aminoglucosides. A moderate resistance against gentamicin and amoxicillin was found in 22-29% of the H. influenzae strains. The mortality rate was high (31%) and among the surviving children 30% presented with neurosensitive disorders. CONCLUSION According to these data we may recommend the inclusion of vaccination against H. influenzae in the children immunization program in Madagascar. The early diagnosis and treatment with appropriate antibiotics, such as third generation of cephalosporins, are other critical measures to be taken in order to reduce the risk of developing severe complications associated to bacterial meningitis.
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MESH Headings
- Adolescent
- Age Distribution
- Anti-Bacterial Agents/therapeutic use
- Cerebrospinal Fluid/microbiology
- Child
- Child, Preschool
- Drug Resistance, Microbial
- Female
- Haemophilus influenzae
- Hospitalization/statistics & numerical data
- Humans
- Infant
- Madagascar/epidemiology
- Male
- Meningitis, Bacterial/diagnosis
- Meningitis, Bacterial/epidemiology
- Meningitis, Bacterial/microbiology
- Meningitis, Bacterial/prevention & control
- Meningitis, Haemophilus/epidemiology
- Meningitis, Haemophilus/microbiology
- Meningitis, Meningococcal/epidemiology
- Meningitis, Meningococcal/microbiology
- Meningitis, Pneumococcal/epidemiology
- Meningitis, Pneumococcal/microbiology
- Microbial Sensitivity Tests
- Population Surveillance
- Prospective Studies
- Urban Population/statistics & numerical data
- Vaccination
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Affiliation(s)
- R Migliani
- Institut Pasteur, BP 1274, Antananarivo, Madagascar.
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41
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Abstract
Antibiotic resistance is a clinical and socioeconomical problem that is here to stay. Resistance can be natural or acquired. Some bacterial species, such as Pseudomonas aeruginosa, show a high intrinsic resistance to a number of antibiotics whereas others are normally highly antibiotic susceptible such as group A streptococci. Acquired resistance evolve via genetic alterations in the microbes own genome or by horizontal transfer of resistance genes located on various types of mobile DNA elements. Mutation frequencies to resistance can vary dramatically depending on the mechanism of resistance and whether or not the organism exhibits a mutator phenotype. Resistance usually has a biological cost for the microorganism, but compensatory mutations accumulate rapidly that abolish this fitness cost, explaining why many types of resistances may never disappear in a bacterial population. Resistance frequently occurs stepwise making it important to identify organisms with low level resistance that otherwise may constitute the genetic platform for development of higher resistance levels. Self-replicating plasmids, prophages, transposons, integrons and resistance islands all represent DNA elements that frequently carry resistance genes into sensitive organisms. These elements add DNA to the microbe and utilize site-specific recombinases/integrases for their integration into the genome. However, resistance may also be created by homologous recombination events creating mosaic genes where each piece of the gene may come from a different microbe. The selection with antibiotics have informed us much about the various genetic mechanisms that are responsible for microbial evolution.
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Affiliation(s)
- B Henriques Normark
- Swedish Institute of Infectious Disease Control and the Microbiology and Tumor Biology Center, Karolinska Institutet, Stockholm, Sweden
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van Selm S, Kolkman MAB, van der Zeijst BAM, Zwaagstra KA, Gaastra W, van Putten JPM. Organization and characterization of the capsule biosynthesis locus of Streptococcus pneumoniae serotype 9V. MICROBIOLOGY (READING, ENGLAND) 2002; 148:1747-1755. [PMID: 12055294 DOI: 10.1099/00221287-148-6-1747] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The capsular polysaccharide (CPS) synthesis locus of Streptococcus pneumoniae serotype 9V was amplified by long-range PCR and sequenced. The locus was 17368 bp in size and contained 15 ORFs. The genetic organization of the cluster shared many features with other S. pneumoniae capsule loci, including the presence of four putative regulatory genes at the 5' end. Comparative sequence analyses allowed putative functions to be assigned to each of the gene products. The ORFs appeared to encode, besides the four regulatory genes, five glycosyltransferases, two O-acetyltransferases, an N-acetylglucosamine 2-epimerase, a glucose 6-dehydrogenase, an oligosaccharide transporter protein and a polysaccharide repeating unit polymerase. These functions covered the steps proposed in the CPS biosynthesis of serotype 9V. TLC of carbohydrate intermediates formed after incubation of bacterial membrane preparations with 14C-labelled precursors demonstrated that the fifth ORF (cps9vE) encoded a UDP-glucosyl-1-phosphate transferase. This function was confirmed with the help of a cps9vE mutant that carried a deletion of a guanine residue located adjacent to a stretch of adenines. The identification and characterization of the serotype 9V locus is a major step in unravelling the 9V capsule biosynthesis pathway and broadens the insight into the genetic diversity of the S. pneumoniae capsule loci.
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Affiliation(s)
- Saskia van Selm
- Bacteriology Division, Department of Infectious Diseases and Immunology, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands1
| | | | | | - Kornelisje A Zwaagstra
- Bacteriology Division, Department of Infectious Diseases and Immunology, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands1
| | - Wim Gaastra
- Bacteriology Division, Department of Infectious Diseases and Immunology, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands1
| | - Jos P M van Putten
- Bacteriology Division, Department of Infectious Diseases and Immunology, Utrecht University, PO Box 80.165, 3508 TD Utrecht, The Netherlands1
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