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Molecular Epidemiology of Staphylococcus aureus and MRSA in Bedridden Patients and Residents of Long-Term Care Facilities. Antibiotics (Basel) 2022; 11:antibiotics11111526. [PMID: 36358181 PMCID: PMC9686811 DOI: 10.3390/antibiotics11111526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
At present, multidrug-resistant microorganisms are already responsible for community-acquired infections. Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious public health risk worldwide because of the rapid spread and diversification of pandemic clones that are characterized by increasing virulence and antimicrobial resistance. The aim of this study was to identify the prevalence and factors associated with nasal, oral and rectal carriage of S. aureus and MRSA in bedridden patients and residents of long-term care facilities for the elderly (LTCFs) in Botucatu, SP, Brazil. Nasal, oral and rectal swab isolates obtained from 226 LTCF residents or home-bedridden patients between 2017 and 2018 were submitted to susceptibility testing, detection of the mecA gene, SCCmec characterization, and molecular typing by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Logistic regression analysis was used to identify risk factors associated with the presence of S. aureus and MRSA. The prevalence of S. aureus and MRSA was 33.6% (n = 76) and 8% (n = 18), respectively. At the nine LTCFs studied, the prevalence of S. aureus ranged from 16.6% to 85.7% and that of MRSA from 13.3% to 25%. Living in an LTCF, male gender, a history of surgeries, and a high Charlson Comorbidity Index score were risk factors associated with S. aureus carriage, while MRSA carriage was positively associated with male gender. This study showed a high prevalence of S. aureus among elderly residents of small (<15 residents) and medium-sized (15−49 residents) LTCFs and a higher prevalence of MRSA in the oropharynx.
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Insights into the epidemiology of community-associated methicillin-resistant Staphylococcus aureus in special populations and at the community-healthcare interface. Braz J Infect Dis 2021; 25:101636. [PMID: 34672988 PMCID: PMC9392173 DOI: 10.1016/j.bjid.2021.101636] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
The current epidemic proportions of infections caused by Staphylococcus aureus strains and especially by methicillin-resistant S. aureus (MRSA) are one of today's many threats to global public health, particularly in underdeveloped countries where significant gaps on the subject exist. The rapid spread and diversification of pandemic clones that exhibit remarkably increasing virulence and antimicrobial resistance pose a risk to the effective prevention and treatment of a wide range of infections. Undoubtedly, the remarkable versatility involving the pathogenesis and resistance of these bacteria is perpetuated through geographic and temporal factors inherent to clonal evolution and is reflected in the dramatic epidemiological changes of MRSA which, after decades prevailing in healthcare settings, have emerged in the community. Denominated community-associated [CA]-MRSA, these strains are particularly prevalent in some population groups, facilitating the spread of successful clones that are potentially capable of triggering severe community-acquired infections. Therefore, a broad approach to local epidemiological aspects in less studied regions, but nonetheless at latent risk of endemic spread that may reach global proportions, is necessary. In Brazil, despite limited molecular epidemiology data, CA-MRSA strains predominantly characterized as SCCmec IV, often classified as CC30-ST30, CC5-ST5 and CC8-ST8, seem to be spreading across different population groups in different regions of the country. Another important fact addressed in this review is the identification of the ST398-MRSA-IV/V clone and methicillin-susceptible S. aureus (MSSA) in healthy individuals from the community. Although susceptible to methicillin, the ST398 clone is associated with severe infections in humans and animals, denominated livestock-associated MRSA. It is therefore important to encourage assertive actions by all government sectors and by society, with a reassessment of current public health measures in light of the new perspectives arising from the scientific and epidemiological data on MRSA.
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Li J, Wang C, Shi L, Shao L, Fu P, Wang K, Xiao R, Wang S, Gu B. Rapid identification and antibiotic susceptibility test of pathogens in blood based on magnetic separation and surface-enhanced Raman scattering. Mikrochim Acta 2019; 186:475. [PMID: 31250223 DOI: 10.1007/s00604-019-3571-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/02/2019] [Indexed: 12/22/2022]
Abstract
An effective surface-enhanced Raman scattering (SERS) method is presented for the rapid identification and drug sensitivity analysis of pathogens in blood. In a first step, polyethyleneimine-modified magnetic microspheres (Fe3O4@PEI) were used to enrich bacteria from blood samples. Next, the Fe3O4@PEI@bacteria complex was cultured on both ordinary and drug-sensitive plates. Lastly, the SERS spectra of single colonies were acquired in order to identify different pathogens and their resistant strains by comparison with established standardized bacterial SERS spectras and orthogonal partial least squares discriminant analysis (OPLS-DA) method. Staphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa and their resistant strains were used to evaluate the performance of the SERS method. The results demonstrate that the method can accurately detect and identify all the tested sensitive and drug-resistant strains of bacteria, including 77 clinical blood infection samples. The method provides a way for rapid identification and susceptibility test of pathogens, and has great potential to replace currently used time-consuming methods. Graphical abstract Schematic presentation of a method for the rapid identification and drug sensitivity analysis of pathogens in blood. It is based on a combination of magnetic separation, SERS fingerprint analysis and orthogonal partial least squares discriminant analysis (OPLS-DA).
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Affiliation(s)
- Jia Li
- Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China.,Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China
| | - Chongwen Wang
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China. .,College of Life Sciences, Anhui Agricultural University, Hefei, 230036, People's Republic of China.
| | - Luoluo Shi
- Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China
| | - Liting Shao
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China
| | - Peiwen Fu
- Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China
| | - Keli Wang
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China
| | - Rui Xiao
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
| | - Shengqi Wang
- Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China. .,Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
| | - Bing Gu
- Medical Technology Institute of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China. .,Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221004, People's Republic of China.
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Veselinović AM, Toropov A, Toropova A, Stanković-Đorđević D, Veselinović JB. Design and development of novel antibiotics based on FtsZ inhibition – in silico studies. NEW J CHEM 2018. [DOI: 10.1039/c8nj01034j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
QSAR models, computer-aided drug design and the application of molecular docking were used to evaluate benzamide analogues as FtsZ inhibitors.
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Affiliation(s)
| | - Andrey Toropov
- IRCCS – Istituto di Ricerche Farmacologiche Mario Negri
- Milano
- Italy
| | - Alla Toropova
- IRCCS – Istituto di Ricerche Farmacologiche Mario Negri
- Milano
- Italy
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Moure R, Cañizares Á, Muíño M, Lobato M, Fernández A, Rodríguez M, Gude MJ, Tomás M, Bou G. Use of the cobas 4800 system for the rapid detection of toxigenic Clostridium difficile and methicillin-resistant Staphylococcus aureus. J Microbiol Methods 2016; 120:50-2. [DOI: 10.1016/j.mimet.2015.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/19/2015] [Accepted: 11/19/2015] [Indexed: 02/04/2023]
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Ahuja S, Rougé L, Swem DL, Sudhamsu J, Wu P, Russell SJ, Alexander MK, Tam C, Nishiyama M, Starovasnik MA, Koth CM. Structural analysis of bacterial ABC transporter inhibition by an antibody fragment. Structure 2015; 23:713-23. [PMID: 25752540 DOI: 10.1016/j.str.2015.01.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 12/23/2014] [Accepted: 01/26/2015] [Indexed: 12/20/2022]
Abstract
Bacterial ATP-binding cassette (ABC) importers play critical roles in nutrient acquisition and are potential antibacterial targets. However, structural bases for their inhibition are poorly defined. These pathways typically rely on substrate binding proteins (SBPs), which are essential for substrate recognition, delivery, and transporter function. We report the crystal structure of a Staphylococcus aureus SBP for Mn(II), termed MntC, in complex with FabC1, a potent antibody inhibitor of the MntABC pathway. This pathway is essential and highly expressed during S. aureus infection and facilitates the import of Mn(II), a critical cofactor for enzymes that detoxify reactive oxygen species (ROS). Structure-based functional studies indicate that FabC1 sterically blocks a structurally conserved surface of MntC, preventing its interaction with the MntB membrane importer and increasing wild-type S. aureus sensitivity to oxidative stress by more than 10-fold. The results define an SBP blocking mechanism as the basis for ABC importer inhibition by an engineered antibody fragment.
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Affiliation(s)
- Shivani Ahuja
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Lionel Rougé
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Danielle L Swem
- Department of Infectious Diseases, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jawahar Sudhamsu
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA; Department of Biology, Gilead Sciences, 333 Lakeside Drive, Foster City, CA 94404, USA
| | - Ping Wu
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Stephen J Russell
- Analytical Operations, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Mary Kate Alexander
- Department of Infectious Diseases, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Christine Tam
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Mireille Nishiyama
- Department of Infectious Diseases, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Melissa A Starovasnik
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Christopher M Koth
- Department of Structural Biology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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Empfehlungen zur Prävention und Kontrolle von Methicillin-resistenten Staphylococcus aureus-Stämmen (MRSA) in medizinischen und pflegerischen Einrichtungen. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2014. [DOI: 10.1007/s00103-014-1980-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Panayidou S, Ioannidou E, Apidianakis Y. Human pathogenic bacteria, fungi, and viruses in Drosophila: disease modeling, lessons, and shortcomings. Virulence 2014; 5:253-69. [PMID: 24398387 DOI: 10.4161/viru.27524] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection.
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Affiliation(s)
- Stavria Panayidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
| | - Eleni Ioannidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
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Hobday RA, Dancer SJ. Roles of sunlight and natural ventilation for controlling infection: historical and current perspectives. J Hosp Infect 2013; 84:271-82. [PMID: 23790506 PMCID: PMC7132476 DOI: 10.1016/j.jhin.2013.04.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/22/2013] [Indexed: 12/24/2022]
Abstract
BACKGROUND Infections caught in buildings are a major global cause of sickness and mortality. Understanding how infections spread is pivotal to public health yet current knowledge of indoor transmission remains poor. AIM To review the roles of natural ventilation and sunlight for controlling infection within healthcare environments. METHODS Comprehensive literature search was performed, using electronic and library databases to retrieve English language papers combining infection; risk; pathogen; and mention of ventilation; fresh air; and sunlight. Foreign language articles with English translation were included, with no limit imposed on publication date. FINDINGS In the past, hospitals were designed with south-facing glazing, cross-ventilation and high ceilings because fresh air and sunlight were thought to reduce infection risk. Historical and recent studies suggest that natural ventilation offers protection from transmission of airborne pathogens. Particle size, dispersal characteristics and transmission risk require more work to justify infection control practices concerning airborne pathogens. Sunlight boosts resistance to infection, with older studies suggesting potential roles for surface decontamination. CONCLUSIONS Current knowledge of indoor transmission of pathogens is inadequate, partly due to lack of agreed definitions for particle types and mechanisms of spread. There is recent evidence to support historical data on the effects of natural ventilation but virtually none for sunlight. Modern practice of designing healthcare buildings for comfort favours pathogen persistence. As the number of effective antimicrobial agents declines, further work is required to clarify absolute risks from airborne pathogens along with any potential benefits from additional fresh air and sunlight.
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Affiliation(s)
- R A Hobday
- Department of Microbiology, Hairmyres Hospital, East Kilbride, Lanarkshire G75 8RG, UK
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Wooten DA, Winston LG. Risk factors for methicillin-resistant Staphylococcus aureus in patients with community-onset and hospital-onset pneumonia. Respir Med 2013; 107:1266-70. [PMID: 23756035 DOI: 10.1016/j.rmed.2013.05.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/07/2013] [Accepted: 05/03/2013] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia have not been fully characterized and are likely to be different depending on whether infection is acquired in the community or the hospital. METHODS We conducted a case-control study of 619 adults hospitalized between 2005 and 2010 with either MRSA or methicillin-sensitive S. aureus (MSSA) pneumonia. Patients with a respiratory culture within 48 h of hospitalization had community-onset pneumonia whereas patients with a culture collected after this time point had hospital-onset pneumonia. RESULTS Among patients with community-onset disease, the risk for MRSA was increased by tobacco use (OR 2.31, CI 1.23-4.31), chronic obstructive pulmonary disease (OR 3.76, CI 1.74-8.08), and recent antibiotic exposure (OR 4.87, CI 2.35-10.1) in multivariate analysis while patients with hospital-onset disease had an increased MRSA risk with tobacco use (OR 2.66, CI 1.38-5.14), illicit drug use (OR 3.52, CI 2.21-5.59), and recent antibiotic exposure (OR 2.04, CI 3.54-13.01). Hospitalization within the prior three months was associated with decreased risk (OR 0.64, CI 0.46-0.89) in multivariate analysis. CONCLUSIONS This study suggests there are common and distinct risk factors for MRSA pneumonia based on location of onset. The decreased risk for MRSA pneumonia associated with recent hospitalization is unexpected and warrants further investigation. SUMMARY This case-control study showed that there are common and distinct risk factors associated with MRSA pneumonia depending on whether the infection onset is in the hospital or in the community. Recent hospitalization was unexpectedly shown to be associated with decreased risk for MRSA pneumonia and warrants further investigation.
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Affiliation(s)
- D A Wooten
- University of California, San Francisco, Department of Internal Medicine, USA.
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Scherer A, Vogt HR, Vilei EM, Frey J, Perreten V. Enhanced antibiotic multi-resistance in nasal and faecal bacteria after agricultural use of streptomycin. Environ Microbiol 2012; 15:297-304. [PMID: 23157680 PMCID: PMC3558797 DOI: 10.1111/1462-2920.12028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 10/05/2012] [Accepted: 10/12/2012] [Indexed: 11/30/2022]
Abstract
Streptomycin is used in arboriculture to control fire blight. Using sheep as a model, multidrug-resistant bacteria in mammals were found to be selected after the intentional release of streptomycin into the environment. Escherichia coli and Staphylococcus spp. were isolated from the faeces and nasal cavities, respectively, of sheep grazing on a field sprayed with streptomycin at concentrations used in orchards (test group) and on a field without streptomycin (control group). Before the application of streptomycin, the percentage of streptomycin-resistant E. coli isolates in faeces was 15.8% in the control group and 14.7% in the test group. After the application of streptomycin, the overall number of streptomycin-resistant E. coli isolates was significantly higher in the test group (39.9%) than in the control group (22.3%). Streptomycin-resistant Staphylococcus isolates were only detected after the application of streptomycin. Streptomycin resistance was frequently associated with resistance to sulfamethoxazole, ampicillin, tetracycline and chloramphenicol and less frequently to cefotaxime in E. coli, and to tetracycline, fusidic acid and tiamulin in Staphylococcus spp. This study shows that the application of low concentrations of streptomycin on grass, as occurs during the spraying of orchards, selects for multidrug-resistant nasal and enteric bacterial flora, including extended-spectrum beta-lactamase-producing E. coli.
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Affiliation(s)
- Alexandre Scherer
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
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Lee BY, Singh A, David MZ, Bartsch SM, Slayton RB, Huang SS, Zimmer SM, Potter MA, Macal CM, Lauderdale DS, Miller LG, Daum RS. The economic burden of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Clin Microbiol Infect 2012; 19:528-36. [PMID: 22712729 DOI: 10.1111/j.1469-0691.2012.03914.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The economic impact of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) remains unclear. We developed an economic simulation model to quantify the costs associated with CA-MRSA infection from the societal and third-party payer perspectives. A single CA-MRSA case costs third-party payers $2277-$3200 and society $7070-$20 489, depending on patient age. In the United States (US), CA-MRSA imposes an annual burden of $478 million to 2.2 billion on third-party payers and $1.4-13.8 billion on society, depending on the CA-MRSA definitions and incidences. The US jail system and Army may be experiencing annual total costs of $7-11 million ($6-10 million direct medical costs) and $15-36 million ($14-32 million direct costs), respectively. Hospitalization rates and mortality are important cost drivers. CA-MRSA confers a substantial economic burden on third-party payers and society, with CA-MRSA-attributable productivity losses being major contributors to the total societal economic burden. Although decreasing transmission and infection incidence would decrease costs, even if transmission were to continue at present levels, early identification and appropriate treatment of CA-MRSA infections before they progress could save considerable costs.
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Affiliation(s)
- B Y Lee
- University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Current world literature. Curr Opin Otolaryngol Head Neck Surg 2012; 19:486-8. [PMID: 22555543 DOI: 10.1097/moo.0b013e32834e4a77] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Targeting RNA polymerase primary σ70 as a therapeutic strategy against methicillin-resistant Staphylococcus aureus by antisense peptide nucleic acid. PLoS One 2012; 7:e29886. [PMID: 22253815 PMCID: PMC3254626 DOI: 10.1371/journal.pone.0029886] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 12/08/2011] [Indexed: 12/03/2022] Open
Abstract
Background Methicillin-resistant Staphylococcus aureus (MRSA) causes threatening infection-related mortality worldwide. Currently, spread of multi-drug resistance (MDR) MRSA limits therapeutic options and requires new approaches to “druggable” target discovery, as well as development of novel MRSA-active antibiotics. RNA polymerase primary σ70 (encoded by gene rpoD) is a highly conserved prokaryotic factor essential for transcription initiation in exponentially growing cells of diverse S. aureus, implying potential for antisense inhibition. Methodology/Principal Findings By synthesizing a serial of cell penetrating peptide conjugated peptide nucleic acids (PPNAs) based on software predicted parameters and further design optimization, we identified a target sequence (234 to 243 nt) within rpoD mRNA conserved region 3.0 being more sensitive to antisense inhibition. A (KFF)3K peptide conjugated 10-mer complementary PNA (PPNA2332) was developed for potent micromolar-range growth inhibitory effects against four pathogenic S. aureus strains with different resistance phenotypes, including clinical vancomycin-intermediate resistance S. aureus and MDR-MRSA isolates. PPNA2332 showed bacteriocidal antisense effect at 3.2 fold of MIC value against MRSA/VISA Mu50, and its sequence specificity was demonstrated in that PPNA with scrambled PNA sequence (Scr PPNA2332) exhibited no growth inhibitory effect at higher concentrations. Also, PPNA2332 specifically interferes with rpoD mRNA, inhibiting translation of its protein product σ70 in a concentration-dependent manner. Full decay of mRNA and suppressed expression of σ70 were observed for 40 µM or 12.5 µM PPNA2332 treatment, respectively, but not for 40 µM Scr PPNA2332 treatment in pure culture of MRSA/VISA Mu50 strain. PPNA2332 (≥1 µM) essentially cleared lethal MRSA/VISA Mu50 infection in epithelial cell cultures, and eliminated viable bacterial cells in a time- and concentration- dependent manner, without showing any apparent toxicity at 10 µM. Conclusions The present result suggested that RNAP primary σ70 is a very promising candidate target for developing novel antisense antibiotic to treat severe MRSA infections.
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Abstract
Children with infectious diseases are commonly encountered in primary care settings. Identification of the subset of patients with bacterial infections is key in guiding the best possible management. Clinicians frequently care for children with infections of the upper respiratory tract, including acute otitis media, otitis externa, sinusitis, and pharyngitis. Conjunctivitis is not an uncommon reason for office visits. Bacterial pneumonia, urinary tract infections, and gastroenteritis are regularly seen. Over the last decade, a growing number of children have had infections of the skin and soft tissue, driven by the increased prevalence of infections caused by methicillin-resistant Staphylococcus aureus. The following review addresses the epidemiology and risk factors for specific infections and examines the clinical presentation and selection of appropriate diagnostic methods in such conditions. Methods to prevent these bacterial infections and recommendations for follow-up are suggested. Management of these infections requires that antimicrobial agents be used in a judicious manner in the outpatient setting. Such antibiotic therapy is recommended using both available clinical evidence and review of disease-specific treatment guidelines.
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Rarey KA, Shanks RMQ, Romanowski EG, Mah FS, Kowalski RP. Staphylococcus aureus isolated from endophthalmitis are hospital-acquired based on Panton-Valentine leukocidin and antibiotic susceptibility testing. J Ocul Pharmacol Ther 2011; 28:12-6. [PMID: 22014156 DOI: 10.1089/jop.2011.0107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Staphylococcus aureus (SA) endophthalmitis is generally a postsurgical infection with an undefined source of entry. Hospital-acquired (HA) SA infections are associated with multi-antibiotic resistance and absence of the Panton-Valentine Leukocidin (PVL) toxin. Community-acquired (CA) SA infections are not associated with multi-antibiotic resistance and possess the PVL toxin. We hypothesize that CA infection is more common than HA for SA endophthalmitis. METHODS Twenty de-identified SA isolates, collected from the vitreous and/or aqueous of clinical endophthalmitis, were tested for the presence of PVL toxin and antibiotic susceptibility. PVL testing was performed using a kit to detect the Staphylococcal toxin by reversed passive latex agglutination (PVL-RPLA "Seiken," Denka Seiken Co., LTD). SA isolates were tested for antibiotic susceptibility using disk diffusion at the time of isolation. Multi-antibiotic resistance was defined as resistance to at least 3 classes of antibiotics. RESULTS Of the 20 isolates, 15 were multi-antibiotic resistant and PVL-negative consistent with HA, and 1 was not multi-antibiotic resistant and PVL-positive, consistent with CA. Two isolates tested positive for PVL with one demonstrating both methicillin and fluoroquinolone (FQ) resistance. Of the 18 PVL-negative SA isolates, 15 (83%) were multi-antibiotic resistant (12 methicillin-resistant SA, 14 FQ resistant). CONCLUSIONS Our results reject the hypothesis that SA isolated from endophthalmitis is consistent with CA sources due to the lack of the PVL toxin and multiple resistant patterns of the SA. PVL does not appear to be a key virulence factor for the development of SA endophthalmitis.
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Affiliation(s)
- Kristin A Rarey
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
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Shittu AO, Okon K, Adesida S, Oyedara O, Witte W, Strommenger B, Layer F, Nübel U. Antibiotic resistance and molecular epidemiology of Staphylococcus aureus in Nigeria. BMC Microbiol 2011; 11:92. [PMID: 21545717 PMCID: PMC3112067 DOI: 10.1186/1471-2180-11-92] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 05/05/2011] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Staphylococcus aureus is an important pathogen causing a wide range of infections in the hospital and community setting. In order to have adequate information for treatment of S. aureus infections, it is crucial to understand the trends in the antibiotic-resistance patterns. In addition, the occurrence and changes in types of S. aureus, clonal identities, and their geographic spread is essential for the establishment of adequate infection control programmes. In this study, 68 S. aureus isolates obtained from clinical and non-clinical sources in Nigeria between January and April 2009 were characterized using phenotypic and molecular methods. RESULTS All the S. aureus isolates were susceptible to teicoplanin, vancomycin, phosphomycin, fusidic acid, rifampicin, daptomycin, mupirocin, linezolid and tigecycline. Sixteen percent of the isolates were resistant to oxacillin, while 55% and 72% of isolates were resistant to tetracycline and trimethoprim/sulphamethoxazole (cotrimoxazole), respectively (Table 1). There was excellent correlation between the broth microdilution assay and detection of antibiotic resistance genes by the multiplex PCR, in the determination of S. aureus resistance to erythromycin, gentamicin, methicillin and tetracycline. A total of 28 spa types were identified in the study, and the predominant spa type among the methicillin-susceptible S. aureus (MSSA) isolates was t084 (13 isolates). The t037-ST241-SCCmecIII type was the only clone identified in Maiduguri (North-East Nigeria) while in South-West Nigeria, diversity among the MRSA isolates (t451-ST8-SCCmecV; t008-ST94-SCCmecIV; t002-ST5-SCCmecV; t064-ST8-SCCmecV) was observed. The toxin genes seh and etd were detected in isolates affiliated with clonal complexes CC1, CC80 and sequence type ST25, respectively. The proportion of PVL-positive isolates among MSSA was high (40%). Most of the PVL-positive MSSA isolates were obtained from wound infections and associated with clonal complexes CC1, CC30, CC121 and with sequence type ST152. CONCLUSIONS The use of phenotypic and molecular methods provided useful information on antibiotic resistance and molecular diversity of S. aureus in Nigeria. The high proportion of PVL-positive MSSA isolates affiliated to various clonal complexes and detected in all the health institutions is a major concern, both as a source of severe infections and as a potential reservoir that could lead to the emergence of PVL-positive MRSA. This study presents the first baseline information on the nature of the antibiotic resistance genes from S. aureus isolates in Nigeria. There is the need to curtail the spread and establishment of MRSA and PVL-positive MSSA clones in Nigerian health care institutions.
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Affiliation(s)
- Adebayo O Shittu
- Department of Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria.
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