Role of the Emp Pilus Subunits of Enterococcus faecium in Biofilm Formation, Adherence to Host Extracellular Matrix Components, and Experimental Infection

Montealegre, María Camila; Singh, Kavindra V.; Somarajan, Sudha R.; Yadav, P. S.; Chang, Chia‐Wei; Spencer, R C; Sillanpää, Jouko; Ton‐That, Hung; Murray, Barbara E.

doi:10.1128/iai.01396-15

Cited by 28 publications

(23 citation statements)

References 44 publications

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“…Literature concerning biofilm‐formation of the other pathogens only detected by sonification is scarce. These rather rare pathogens definitely need to be further investigated in regards of biofilm formation …”

Section: Discussionmentioning

confidence: 99%

Sonication culture improves microbiological diagnosis of modular megaprostheses

et al. 2016

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Modular megaprostheses are known for high infection rates followed by high rates of revisions. Microbial biofilms growing adherently on prosthetic surfaces may inhibit the detection of the pathogens causing prosthetic joint infections. We sought to answer the following questions: Does sonication culture (SC) improve the microbiological diagnosis of periprosthetic infections of megaprostheses compared to conventional tissue culture (TC)? Which pathogens were detected on the surface of megaprostheses with either SC or TC and do the findings help to identify low-grade infections? Included were 31 patients with modular megaprostheses, whose implant had been explanted due to suspected joint infection or revision surgery. SCs were performed according to the protocol by Trampuz et al. The diagnosis of infection was evaluated according to the definition of the Musculoskeletal Infection Society. The sensitivity of SC was 91.3% compared to 52.2% for TC and the specificity was 100% for SC and TC (p = 0.004). Under preoperative antibiotic therapy, the sensitivity of SC was 83.3% while the sensitivity of TC was 50%. Without preoperative antibiotic therapy the sensitivity of SC was 100% compared to 54.5% for TC. In nine cases, SCs detected microorganisms, while TC was negative. Detected bacteria were Staphylococcus epidermidis in four, Micrococcus species in one, Finegoldia magna in one, Brevibacterium casei in one, Pseudomonas fluorescens in one, and Enterococcus faecium in one. SC is a reliable method for dislodging pathogens from orthopedic implants. The SC of modular megaprostheses showed significantly higher pathogen detection than the periprosthetic TC, especially for low virulence pathogens. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1383-1387, 2017.

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Section: Discussionmentioning

confidence: 99%

Sonication culture improves microbiological diagnosis of modular megaprostheses

et al. 2016

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“…Cultures grown to an OD 600 of 1.0 Ϯ 0.1, as described above for the PBP5 Western blot assay, were used for RNA extraction, performed as previously described (30). Primers F-pbp5-218 and R-pbp5-218 (Table S2) were used for generating a pbp5 hybridization probe, which amplifies a fragment that is identical in 217 of the 218 nucleotides between pbp5-S and pbp5-R. Northern blot analyses were carried out as reported before (31,32).…”

Section: Methodsmentioning

confidence: 99%

Differential Penicillin-Binding Protein 5 (PBP5) Levels in the Enterococcus faecium Clades with Different Levels of Ampicillin Resistance

Montealegre

Roh

Rae

et al. 2017

Antimicrob Agents Chemother

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Ampicillin resistance in Enterococcus faecium is a serious concern worldwide, complicating the treatment of E. faecium infections. Penicillin-binding protein 5 (PBP5) is considered the main ampicillin resistance determinant in E. faecium. The three known E. faecium clades showed sequence variations in the pbp5 gene that are associated with their ampicillin resistance phenotype; however, these changes alone do not explain the array of resistance levels observed among E. faecium clinical strains. We aimed to determine if the levels of PBP5 are differentially regulated between the E. faecium clades, with the hypothesis that variations in PBP5 levels could help account for the spectrum of ampicillin MICs seen in E. faecium. We studied pbp5 mRNA levels and PBP5 protein levels as well as the genetic environment upstream of pbp5 in 16 E. faecium strains that belong to the different E. faecium clades and for which the ampicillin MICs covered a wide range. Our results found that pbp5 and PBP5 levels are increased in subclade A1 and A2 ampicillin-resistant strains compared to those in clade B and subclade A2 ampicillin-susceptible strains. Furthermore, we found evidence of major clade-associated rearrangements in the region upstream of pbp5, including large DNA fragment insertions, deletions, and single nucleotide polymorphisms, that may be associated with the differential regulation of PBP5 levels between the E. faecium clades. Overall, these findings highlight the contribution of the clade background to the regulation of PBP5 abundance and point to differences in the region upstream of pbp5 as likely contributors to the differential expression of ampicillin resistance.KEYWORDS ampicillin, Enterococcus faecium, penicillin-binding protein 5, protein levels, resistance A mpicillin-resistant Enterococcus faecium has emerged to be one of the leading pathogens in the hospital setting (1, 2). In the United States, the incidence of infections caused by ampicillin-resistant E. faecium strains has increased since the 1980s, and this has been accompanied by a progressive increase in the MICs over time (3, 4); currently, the majority of E. faecium isolates recovered in hospitals around the United States are resistant to this ␤-lactam antibiotic (1, 2). The decreased susceptibility of E. faecium to ampicillin and other ␤-lactams has been mainly attributed to the high-molecular-weight penicillin-binding protein 5 (PBP5) (3-5). The proposed mechanism of PBP5-mediated action is a low affinity for ␤-lactam antibiotics, allowing peptidoglycan synthesis (transpeptidation) and bacterial growth when the other PBPs are inhibited by the drug (6, 7).

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“…In lactobacilli, many of the characterized attachment factors are surface moonlighting proteins, that recognize a spectrum of host receptors, among the most common being extracellular matrix components (ECM) . Being ubiquitously and profusely distributed, the ECM proteins are also attractive targets for adhesion and invasion by various human pathogen microorganisms . It has been reported that many of them use moonlighting proteins as adhesin .…”

Section: Introductionmentioning

confidence: 99%

Pyruvate dehydrogenase subunit β of Lactobacillus plantarum is a collagen adhesin involved in biofilm formation

Salzillo¹,

Vastano²,

Capri³

et al. 2016

J Basic Microbiol

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Multi-functional surface proteins have been observed in a variety of pathogenic bacteria, where they mediate host cell adhesion and invasion, as well as in commensal bacterial species, were they mediate positive interaction with the host. Among these proteins, some glycolytic enzymes, expressed on the bacterial cell surface, can bind human extracellular matrix components (ECM). A major target for them is collagen, an abundant glycoprotein of connective tissues. We have previously shown that the enolase EnoA1 of Lactobacillus plantarum, one of the most predominant species in the gut microbiota of healthy individuals, is involved in binding with collagen type I (CnI). In this study, we found that PDHB, a component of the pyruvate dehydrogenase complex, contributes to the L. plantarum LM3 adhesion to CnI. By a cellular adhesion assay to immobilized CnI, we show that LM3-B1 cells, carrying a null mutation in the pdhB gene, bind to CnI - coated surfaces less efficiently than wild-type cells. Moreover, we show that the PDHB-CnI interaction requires a native state for PDHB. We also analyzed the ability to develop biofilm in wild-type and mutant strains and we found that the lack of the PDHB on cell surface generates cells partially impaired in biofilm development.

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Role of the Emp Pilus Subunits of Enterococcus faecium in Biofilm Formation, Adherence to Host Extracellular Matrix Components, and Experimental Infection

Cited by 28 publications

References 44 publications

Sonication culture improves microbiological diagnosis of modular megaprostheses

Sonication culture improves microbiological diagnosis of modular megaprostheses

Differential Penicillin-Binding Protein 5 (PBP5) Levels in the Enterococcus faecium Clades with Different Levels of Ampicillin Resistance

Pyruvate dehydrogenase subunit β of Lactobacillus plantarum is a collagen adhesin involved in biofilm formation

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