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Burke Ó, Zeden MS, O'Gara JP. The pathogenicity and virulence of the opportunistic pathogen Staphylococcus epidermidis. Virulence 2024; 15:2359483. [PMID: 38868991 DOI: 10.1080/21505594.2024.2359483] [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] [Received: 02/02/2024] [Accepted: 05/19/2024] [Indexed: 06/14/2024] Open
Abstract
The pervasive presence of Staphylococcus epidermidis and other coagulase-negative staphylococci on the skin and mucous membranes has long underpinned a casual disregard for the infection risk that these organisms pose to vulnerable patients in healthcare settings. Prior to the recognition of biofilm as an important virulence determinant in S. epidermidis, isolation of this microorganism in diagnostic specimens was often overlooked as clinically insignificant with potential delays in diagnosis and onset of appropriate treatment, contributing to the establishment of chronic infection and increased morbidity or mortality. While impressive progress has been made in our understanding of biofilm mechanisms in this important opportunistic pathogen, research into other virulence determinants has lagged S. aureus. In this review, the broader virulence potential of S. epidermidis including biofilm, toxins, proteases, immune evasion strategies and antibiotic resistance mechanisms is surveyed, together with current and future approaches for improved therapeutic interventions.
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Affiliation(s)
- Órla Burke
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | | | - James P O'Gara
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
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Molecular Detection and Characterization of the Staphylococcus epidermidis and Staphylococcus haemolyticus Isolated from Hospitalized Patients and Healthcare Workers in Iran. BIOMED RESEARCH INTERNATIONAL 2023; 2023:3775142. [PMID: 36644166 PMCID: PMC9839402 DOI: 10.1155/2023/3775142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/27/2022] [Accepted: 12/16/2022] [Indexed: 01/07/2023]
Abstract
Background The present study is aimed at surveying the antibiotics resistance profile, biofilm formation ability, staphylococcal cassette chromosome mec (SCCmec) types, and molecular epidemiology of Staphylococcus epidermidis and Staphylococcus haemolyticus isolated from hospitalized patients and healthcare workers in four teaching hospitals in Iran. Methods In total, 43 Staphylococcus epidermidis and 12 Staphylococcus haemolyticus were isolated from hospitalized patients, and 19 Staphylococcus epidermidis and 7 Staphylococcus haemolyticus isolated from healthcare workers were included in the present study. The antimicrobial resistance profile of isolates was determined using the disk diffusion method. Moreover, the resistance of isolates to methicillin was identified using the cefoxitin disk diffusion test. The microtiter-plate test was used for quantifying biofilm formation. Moreover, the frequency of icaA and icaD genes was determined using PCR assay. The molecular epidemiology of methicillin-resistant isolates was determined using SCCmec typing and pulsed-field gel electrophoresis methods. Results Among all coagulase-negative staphylococci isolates, the highest resistance rate (81.5%) was seen for cefoxitin and cotrimoxazole. All of the isolates were susceptible to linezolid. Out of the 66 mecA-positive isolates, the most common SCCmec type was the type I (n = 23; 34.8%) followed by type IV (n = 13; 19.7%). Using pulsed-field gel electrophoresis (PFGE) assay, 27 PFGE types including 14 common types and 13 singletons were obtained among 51 methicillin-resistant S. epidermidis (MRSE) isolates. Moreover, among 12 methicillin-resistant S. haemolyticus (MRSH) isolates, 8 PFGE types were detected, of which 5 PFGE types were singletons. Conclusion The high rate of resistance to antibiotics as well as the possibility of cross-infection shows the importance of a pattern shift in the management and controlling programs of coagulase-negative staphylococci, especially in healthcare centers. Clinical trial registration. The present study is not a clinical trial study. Thus, a registration number is not required.
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Westberg R, Stegger M, Söderquist B. Molecular Epidemiology of Neonatal-Associated Staphylococcus haemolyticus Reveals Endemic Outbreak. Microbiol Spectr 2022; 10:e0245222. [PMID: 36314976 PMCID: PMC9769988 DOI: 10.1128/spectrum.02452-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022] Open
Abstract
Staphylococcus haemolyticus is a major cause of late-onset sepsis in neonates, and endemic clones are often multidrug-resistant. The bacteria can also act as a genetic reservoir for more pathogenic bacteria. Molecular epidemiology is important in understanding bacterial pathogenicity and preventing infection. To describe the molecular epidemiology of S. haemolyticus isolated from neonatal blood cultures at a Swedish neonatal intensive care unit (NICU) over 4 decades, including antibiotic resistance genes (ARGs), virulence factors, and comparison to international isolates. Isolates were whole-genome sequenced, and single nucleotide polymorphisms in the core genome were used to map the relatedness. The occurrence of previously described ARGs and virulence genes were investigated. Disc diffusion and gradient tests were used to determine phenotypic resistance. The results revealed a clonal outbreak of S. haemolyticus at this NICU during the 1990s. Multidrug resistance was present in 28 (82%) of all isolates and concomitant resistance to aminoglycoside and methicillin occurred in 27 (79%). No isolates were vancomycin resistant. Genes encoding ARGs and virulence factors occurred frequently. The isolates in the outbreak were more homogenous in their genotypic and phenotypic patterns. Genotypic and phenotypic resistance combinations were consistent. Pathogenic traits previously described in S. haemolyticus occurred frequently in the present isolates, perhaps due to the hospital selection pressure resulting in epidemiological success. The clonal outbreak revealed by this study emphasizes the importance of adhering to hygiene procedures in order to prevent future endemic outbreaks. IMPORTANCE This study investigated the relatedness of Staphylococcus haemolyticus isolated from neonatal blood and revealed a clonal outbreak in the 1990s at a Swedish neonatal intensive care unit. The outbreak clone has earlier been isolated in Japan and Norway. Virulence and antibiotic resistance genes previously associated with clinical S. haemolyticus were frequently occuring in the present study as well. The majority of the isolates were multidrug-resistant. These traits should be considered important for S. haemolyticus epidemiological success and are probably caused by the hospital selection pressure. Thus, this study emphasizes the importance of restrictive antibiotic use and following the hygiene procedures, to prevent further antibiotic resistance spread and future endemic outbreaks.
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Affiliation(s)
- Ronja Westberg
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Marc Stegger
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Bo Söderquist
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
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Exploring the Biofilm Formation Capacity in S. pseudintermedius and Coagulase-Negative Staphylococci Species. Pathogens 2022; 11:pathogens11060689. [PMID: 35745543 PMCID: PMC9229561 DOI: 10.3390/pathogens11060689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 01/09/2023] Open
Abstract
The ability of biofilm formation seems to play an important role in the virulence of staphylococci. However, studies reporting biofilm formation of coagulase-negative staphylococci isolated from animals are still very scarce. Thus, we aimed to evaluate the biofilm-forming capacity of CoNS and S. pseudintermedius isolated from several animal species and to investigate the effect of conventional antimicrobials on biofilm reduction. A total of 35 S. pseudintermedius and 192 CoNS were included. Biofilm formation was accessed by the microtiter plate assay and the biofilms were stained by crystal violet. Association between biofilm formation and staphylococci species and antimicrobial resistance was also performed. Biofilm susceptibility testing was performed with tetracycline and amikacin at the minimum inhibitory concentration (MIC) and 10 × MIC. The metabolic activity of the biofilm cells after antimicrobial treatment was accessed by the XTT assay. All isolates formed biofilm, with S. urealyticus producing the most biofilm biomass and S. pseudintermedius producing the least biomass. There was a positive association between biofilm formation and multidrug resistance as well as resistance to individual antimicrobials. Neither tetracycline nor amikacin were able to eradicate the biofilm, not even at the highest concentration used. This study provides new insights into biofilm formation and the effects of antimicrobials on CoNS species.
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Low Concentration of the Neutrophil Proteases Cathepsin G, Cathepsin B, Proteinase-3 and Metalloproteinase-9 Induce Biofilm Formation in Non-Biofilm-Forming Staphylococcus epidermidis Isolates. Int J Mol Sci 2022; 23:ijms23094992. [PMID: 35563384 PMCID: PMC9102557 DOI: 10.3390/ijms23094992] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 12/04/2022] Open
Abstract
Neutrophils play a crucial role in eliminating bacteria that invade the human body; however, cathepsin G can induce biofilm formation in a non-biofilm-forming Staphylococcus epidermidis 1457 strain, suggesting that neutrophil proteases may be involved in biofilm formation. Cathepsin G, cathepsin B, proteinase-3, and metalloproteinase-9 (MMP-9) from neutrophils were tested on the biofilm induction in commensal (skin isolated) and clinical non-biofilm-forming S. epidermidis isolates. From 81 isolates, 53 (74%) were aap+, icaA−, icaD− genotype, and without the capacity of biofilm formation under conditions of 1% glucose, 4% ethanol or 4% NaCl, but these 53 non-biofilm-forming isolates induced biofilm by the use of different neutrophil proteases. Of these, 62.3% induced biofilm with proteinase-3, 15% with cathepsin G, 10% with cathepsin B and 5% with MMP -9, where most of the protease-induced biofilm isolates were commensal strains (skin). In the biofilm formation kinetics analysis, the addition of phenylmethylsulfonyl fluoride (PMSF; a proteinase-3 inhibitor) showed that proteinase-3 participates in the cell aggregation stage of biofilm formation. A biofilm induced with proteinase-3 and DNAse-treated significantly reduced biofilm formation at an early time (initial adhesion stage of biofilm formation) compared to untreated proteinase-3-induced biofilm (p < 0.05). A catheter inoculated with a commensal (skin) non-biofilm-forming S. epidermidis isolate treated with proteinase-3 and another one without the enzyme were inserted into the back of a mouse. After 7 days of incubation period, the catheters were recovered and the number of grown bacteria was quantified, finding a higher amount of adhered proteinase-3-treated bacteria in the catheter than non-proteinase-3-treated bacteria (p < 0.05). Commensal non-biofilm-forming S. epidermidis in the presence of neutrophil cells significantly induced the biofilm formation when multiplicity of infection (MOI) 1:0.01 (neutrophil:bacteria) was used, but the addition of a cocktail of protease inhibitors impeded biofilm formation. A neutrophil:bacteria assay did not induce neutrophil extracellular traps (NETs). Our results suggest that neutrophils, in the presence of commensal non-biofilm-forming S. epidermidis, do not generate NETs formation. The effect of neutrophils is the production of proteases, and proteinase-3 releases bacterial DNA at the initial adhesion, favoring cell aggregation and subsequently leading to biofilm formation.
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Eltwisy HO, Abdel-Fattah M, Elsisi AM, Omar MM, Abdelmoteleb AA, El-Mokhtar MA. Pathogenesis of Staphylococcus haemolyticus on primary human skin fibroblast cells. Virulence 2021; 11:1142-1157. [PMID: 32799619 PMCID: PMC7549902 DOI: 10.1080/21505594.2020.1809962] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
STAPHYLOCOCCUS HAEMOLYTICUS (S. haemolyticus) is one of the Coagulase-negative staphylococci (CoNS) that inhabits the skin as a commensal. It is increasingly implicated in opportunistic infections, including diabetic foot ulcer (DFU) infections. In contrast to the abundance of information available for S. aureus and S. epidermidis, little is known about the pathogenicity of S. haemolyticus, despite the increased prevalence of this pathogen in hospitalized patients. We described, for the first time, the pathogenesis of different clinical isolates of S. haemolyticus isolated from DFU on primary human skin fibroblast (PHSF) cells. Virulence-related genes were investigated, adhesion and invasion assays were carried out using Giemsa stain, transmission electron microscopy (TEM), MTT and flowcytometry assays. Our results showed that most S. haemolyticus carried different sets of virulence-related genes. S. haemolyticus adhered to the PHSF cells to variable degrees. TEM showed that the bacteria were engulfed in a zipper-like mechanism into a vacuole inside the cell. Bacterial internalization was confirmed using flowcytometry and achieved high intracellular levels. PHSF cells infected with S.haemolyticus suffered from amarked decrease in viability and increased apoptosis when treated with whole bacterial suspensions or cell-free supernatants but not with heat-treated cells. After co-culture with PBMCs, S. haemolyticus induced high levels of pro-inflammatory cytokines. This study highlights the significant development of S. haemolyticus, which was previously considered a contaminant when detected in cultures of clinical samples. Their high ability to adhere, invade and kill the PHSF cells illustrate the severe damage associated with DFU infections. ABBREVIATIONS CoNS, coagulase-negative staphylococci; DFU, diabetic foot ulcer; DM, diabetes mellitus; DMEM, Dulbecco's Modified Eagle Medium; MTT, 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide; PBMCs,peripheral blood mononuclear cells; PHSF, primary human skin fibroblast; CFU, colony-forming unit.
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Affiliation(s)
- Hala O Eltwisy
- Department of Microbiology, Faculty of Science, Beni-Suef University , Beni-Suef, Egypt
| | - Medhat Abdel-Fattah
- Department of Microbiology and Botany, Faculty of Science, Beni-Suef University , Beni-Suef, Egypt
| | - Amani M Elsisi
- Department of Pharmaceutics and Industrial Pharmacy, Beni-Suef University , Beni-Suef, Egypt
| | - Mahmoud M Omar
- Department of Pharmaceutics and Industrial Pharmacy, Deraya University , El-Minia, Egypt
| | | | - Mohamed A El-Mokhtar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University , Assiut, Egypt
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Oliveira MTD, Cunha LMS, Cruz FC, Batista NKR, Gil EDS, Alves VF, Bara MTF, Torres IMS. Potentially pathogenic bacteria isolated from neglected air and surfaces in hospitals. BRAZ J PHARM SCI 2021. [DOI: 10.1590/s2175-97902020000418989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Cataneli Pereira V, Pinheiro-Hubinger L, de Oliveira A, Moraes Riboli DF, Benini Martins K, Calixto Romero L, Ribeiro de Souza da Cunha MDL. Detection of the agr System and Resistance to Antimicrobials in Biofilm-Producing S. epidermidis. Molecules 2020; 25:molecules25235715. [PMID: 33287389 PMCID: PMC7729762 DOI: 10.3390/molecules25235715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 11/19/2022] Open
Abstract
The ability of Staphylococcus epidermidis to produce virulence factors, such as biofilm, added to its increased resistance to antimicrobials can cause infections that are difficult to treat. Many staphylococcal virulence factors are under the control of the accessory gene regulator (agr). The objective of this study was to establish the agr locus and susceptibility of biofilm-producing S. epidermidis specimens to antimicrobial agents, through PCR reactions, reverse transcription polymerase chain reaction (RT-PCR), and the determination of minimum inhibitory concentration (MIC), and to analyze the clonal profile of 300 strains isolated from blood culture specimens from inpatients at a University Hospital in Brazil, over a 20-year period by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) techniques. The ica operon expression was shown in 83.6% strains, bhp gene in 11.5%, and aap gene in 32.8%. Oxacillin resistance was detected in 90.1%, while 4.9% showed tigecycline resistance, and intermediate resistance to quinupristin/dalfopristin was identified in 0.4%. Clonal profile determination showed 11 clusters, with the ST2 type determined as the major cluster. The S. epidermidis biofilm producer demonstrated a predominance of agr I locus, oxacillin resistance, and SCCmec III as well as the potential dissemination of pathogenic clones in hospital settings over long periods.
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Affiliation(s)
- Valéria Cataneli Pereira
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
- Sector of Microbiology and Immunology, UNOESTE—University of West Paulista, Presidente Prudente CEP 19050-920, São Paulo, Brazil
| | - Luiza Pinheiro-Hubinger
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
| | - Adilson de Oliveira
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
| | - Danilo Flávio Moraes Riboli
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
| | - Katheryne Benini Martins
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
| | - Letícia Calixto Romero
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
| | - Maria de Lourdes Ribeiro de Souza da Cunha
- Sector of Microbiology and Immunology, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP—University Estadual Paulista, Botucatu CEP 18618-689, São Paulo, Brazil; (V.C.P.); (L.P.-H.); (A.d.O.); (D.F.M.R.); (K.B.M.); (L.C.R.)
- Correspondence: ; Tel.: +55-14-3880-0428
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Yong YY, Dykes GA, Choo WS. Biofilm formation by staphylococci in health-related environments and recent reports on their control using natural compounds. Crit Rev Microbiol 2019; 45:201-222. [PMID: 30786799 DOI: 10.1080/1040841x.2019.1573802] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Staphylococci are Gram-positive bacteria that are ubiquitous in the environment and able to form biofilms on a range of surfaces. They have been associated with a range of human health issues such as medical device-related infection, localized skin infection, or direct infection caused by toxin production. The extracellular material produced by these bacteria resists antibiotics and host defence mechanism which complicates the treatment process. The commonly reported Staphylococcus species are Staphylococcus aureus and S. epidermidis as they inhabit human bodies. However, the emergence of other staphylococci, such as S. haemolyticus, S. lugdunensis, S. saprophyticus, S. capitis, S. saccharolyticus, S. warneri, S. cohnii, and S. hominis, is also of concern and they have been associated with biofilm formation. This review critically assesses recent cases on the biofilm formation by S. aureus, S. epidermidis, and other staphylococci reported in health-related environments. The control of biofilm formation by staphylococci using natural compounds is specifically discussed as they represent potential anti-biofilm agents which may reduce the burden of antibiotic resistance.
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Affiliation(s)
- Yi Yi Yong
- a School of Science , Monash University Malaysia , Selangor , Malaysia
| | - Gary A Dykes
- b School of Public Health , Curtin University , Bentley , Australia
| | - Wee Sim Choo
- a School of Science , Monash University Malaysia , Selangor , Malaysia
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Rampelotto RF, Lorenzoni VV, Silva DDC, Coelho SS, Wust V, Garzon LR, Nunes MS, Meneghetti B, Brites PC, Hörner M, Hörner R. Assessment of different methods for the detection of biofilm production in coagulase-negative staphylococci isolated from blood cultures of newborns. Rev Soc Bras Med Trop 2018; 51:761-767. [DOI: 10.1590/0037-8682-0171-2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/31/2018] [Indexed: 11/21/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Melise Silveira Nunes
- Universidade Federal de Santa Maria, Brazil; Hospital Universitário de Santa Maria, Brasil
| | - Bettina Meneghetti
- Universidade Federal de Santa Maria, Brazil; Hospital Universitário de Santa Maria, Brasil
| | | | | | - Rosmari Hörner
- Universidade Federal de Santa Maria, Brazil; Universidade Federal de Santa Maria, Brazil
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Clinical features, outcomes, and molecular characteristics of an outbreak of Staphylococcus haemolyticus infection, among a mass-burn casualty patient group, in a tertiary center in northern Taiwan. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2018; 51:847-855. [PMID: 30166249 DOI: 10.1016/j.jmii.2018.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND/PURPOSE We reported an outbreak of Staphylococcus haemolyticus (SH) infection in a group of young patients (mean age 21.6) simultaneously hospitalized due to a mass-burn incident. This study analyzed the clinical features of these patients and the microbiological characteristics of the outbreak. METHODS All 50 patients hospitalized for burns were enrolled, and their clinical differences were analyzed based on culture results. A drug sensitivity test and pulsed-field gel electrophoresis (PFGE) were conducted to analyze the microbiological difference between SH isolates from the mass-burn casualty patients (the study group) and SH isolates from other patients hospitalized during the same period (the control group) with the intention of identifying the strain of SH outbreak. RESULTS Patients with isolated SH (N = 36) had a significantly higher disease severity (higher revised Baux score, APACHE II score, and concurrent bacteremia rate), and a significantly poorer clinical outcome (longer ICU and hospital stay, and longer MV usage). Significant differences in the phenotype (antibiotics drug sensitivity test) and genotype (PFGE typing) were observed between the study and control groups. The dominant PFGE type C identified among the study group was related to poorer outcomes in a subgroup analysis. CONCLUSION A dominant PFGE type of SH infection was found in these mass-burn casualty patients. Pathogenesis or virulence factors may have contributed to our results. Further study of isolated SH should be conducted.
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Freitas AI, Lopes N, Oliveira F, Brás S, França Â, Vasconcelos C, Vilanova M, Cerca N. Comparative analysis between biofilm formation and gene expression in Staphylococcus epidermidis isolates. Future Microbiol 2018; 13:415-427. [PMID: 29469610 DOI: 10.2217/fmb-2017-0140] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To understand the relationship between ica, aap and bhp gene expression and the implications in biofilm formation in selected clinical and commensal Staphylococcus epidermidis isolates. MATERIAL & METHODS Isolates were analyzed regarding their biofilm-forming capacity, biochemical matrix composition, biofilm spatial organization and expression of biofilm-related genes. RESULTS On polysaccharide intercellular adhesin-dependent biofilms, aap and bhp contributions for the biofilm growth were negligible, despite very high levels of expression. In contrast, smaller increases in icaA expression contributed significantly to biofilm growth. Interestingly, no biological differences were observed between clinical and commensal strains. CONCLUSION These results reinforce the concept that S. epidermidis is an 'accidental pathogen,' and that the ica operon is the main mechanism of biofilm formation in clinical and commensal isolates.
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Affiliation(s)
- Ana I Freitas
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal
| | - Nathalie Lopes
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Fernando Oliveira
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Susana Brás
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Ângela França
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Carlos Vasconcelos
- Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal.,Hospital Santo António, Centro Hospitalar do Porto, Porto, 4099-001, Portugal
| | - Manuel Vilanova
- Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde & Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Nuno Cerca
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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