Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm genes and biofilm formation in blood culture isolates from patients in a Brazilian teaching hospital

Pinheiro, Luiza; Brito, Carla Ivo; Oliveira, Alexsandra Duarte de; Pereira, Valéria Cataneli; Cunha, Maria de Lourdes Ribeiro de Souza da

doi:10.1016/j.diagmicrobio.2016.06.006

Cited by 21 publications

(16 citation statements)

References 30 publications

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“…Staphylococci were identified using the VITEK2 Microbiology automated system (VITEK®2, BioMerieux). Moreover, the identity of staphylococciwas confirmed using multiplex PCR as described previously [ 15 ]. During the study period, ten S. haemolyticus isolates were obtained from the cultures of DFUs from ten different infected patients.…”

Section: Methodsmentioning

confidence: 99%

“…Methicillin resistance was detected by initial phenotypic screening for reduced susceptibility of the isolates to cefoxitin (30 µg) and oxacillin (1 μg) disks (Mast, UK) by the disk diffusion method, according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Then, methicillin resistance was confirmed by amplification of the mecA gene by PCR assay using specific primers proposed by Pinheiro, Brito [ 15 ].…”

Section: Methodsmentioning

confidence: 99%

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Pathogenesis of Staphylococcus haemolyticus on primary human skin fibroblast cells

et al. 2020

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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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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Pathogenesis of Staphylococcus haemolyticus on primary human skin fibroblast cells

et al. 2020

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“…The expression of the icaD gene not associated with icaA was less frequent (6.5%) and two samples were non-adherent. The environmental conditions or mechanism of gene regulation may have influenced the production of the protein and studies highlight the importance of the icaA gene in the production of staphylococcal biofilm and also of other genes, such as bhp and aap, in independent PIA strains [18,19].…”

Section: Discussionmentioning

confidence: 99%

Detection of the agr System and Resistance to Antimicrobials in Biofilm-Producing S. epidermidis

et al. 2020

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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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“…According to Fey, et al, differentiating S. epidermidis as a true pathogen or contaminant in bacteremia poses a challenge especially with the formation of biofilm and increased rate of antibiotic resistance [7]. Biofilms are known to protect bacteria from the host immunity and antimicrobial agents [20].…”

Section: Discussionmentioning

confidence: 99%

“…Staphylococcus epidermidis easily accumulate multiple determinants of antibiotic resistance and its frequency of methicillin resistance reaches up to 80% globally [3]. It is associated with biofilm-mediated life-threatening infections [20,21]. Since the detection of methicillin resistance and biofilm production alone cannot be used to treat S. epidermidis bacteremia, other factors such as clinical evidence of bacteremia and the use of inflammatory markers is required.…”

Section: Discussionmentioning

confidence: 99%

Methicillin Resistance and Biofilm Formation of Staphylococcus epidermidis in Blood Culture Isolates from Children under Five: A Multicenter Study in Nigeria

Grace¹,

Olayinka²,

Onaolapo³

et al. 2018

Clin Microbiol

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The clinical impact of Staphylococcus epidermidis in bacteremia remains controversial. The aim of this study is to determine the methicillin resistance and biofilm formation of S. epidermidis isolates. A total of 102 S. epidermidis blood culture isolates from children under five attending seven selected hospitals in north-central and northwest Nigeria within 2009 to 2016 were analyzed for methicillin resistance using cefoxitin disk agar diffusion test. Phenotypic biofilm formation and molecular detection of the intercellular adhesion locus (icaA) gene was performed by the quantitative Microtitre Plate (MTP) method and conventional Polymerase Chain Reaction (PCR) respectively. Seventy-four (72.5%) Methicillin-Resistant Staphylococcus epidermidis (MRSE) was observed while biofilm formation was detected in 20 (19.6%) S. epidermidis isolates. The icaA gene positive and negative S. epidermidis were 22.5% (23/102) and 77.5% (79/102) respectively. In correlating the biofilm formation using MTP method and icaA gene detection, 19.6% were biofilm producers and icaA positive while 2.9% carried the icaA gene but did not produce biofilm on the tissue culture plate. Out of the icaA positive S. epidermidis, 91.3% were MRSE while 69.6% were MRSE among the icaA negative strains. Methicillin-Resistant Staphylococcus epidermidis is common and the majority of the biofilm-producing strains were highly resistant to methicillin. This suggests a close association between biofilm-formation in S. epidermidis with increased methicillin resistance.

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Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm genes and biofilm formation in blood culture isolates from patients in a Brazilian teaching hospital

Cited by 21 publications

References 30 publications

Pathogenesis of Staphylococcus haemolyticus on primary human skin fibroblast cells

Pathogenesis of Staphylococcus haemolyticus on primary human skin fibroblast cells

Detection of the agr System and Resistance to Antimicrobials in Biofilm-Producing S. epidermidis

Methicillin Resistance and Biofilm Formation of Staphylococcus epidermidis in Blood Culture Isolates from Children under Five: A Multicenter Study in Nigeria

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