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PubMed2003

Interaction between probiotic lactic acid bacteria and canine enteric pathogens: a risk factor for intestinal Enterococcus faecium colonization?

Selected probiotic lactic acid bacteria (LAB) have been shown to elicit positive health effects particularly in humans. Competitive exclusion of pathogens is one of the most important beneficial health claims of probiotic bacteria. The effect of probiotic LAB on competitive exclusion of pathogens has been demonstrated in humans, chicken and pigs. In this study we evaluated the ability of certain LAB strains (Lactobacillus rhamnosus GG, Bifidobacterium lactis Bb12, Lactobacillus pentosus UK1A, L. pentosus SK2A, Enterococcus faecium M74 and E. faecium SF273) to inhibit the adhesion of selected canine and zoonotic pathogens (Staphylococcus intermedius, Salmonella Typhimurium ATCC 14028, Clostridium perfringens and Campylobacter jejuni) to immobilised mucus isolated from canine jejunal chyme in vitro. Adhesion of C. perfringens was reduced significantly by all tested LAB strains, between 53.7 and 79.1% of the control without LAB, the LAB of canine origin yielding the best reduction. The adhesion of S. Typhimurium and S. intermedius were not significantly altered by any of the LAB included in the study. Both enterococci tested significantly enhanced the adhesion of C. jejuni, to 134.6 and 205.5% of the control without LAB. E. faecium may thus favor the adhesion and colonization of C. jejuni in the dog's intestine, making it a potential carrier and possibly a source for human infection. Enhanced C. jejuni adhesion is a new potential risk factor of enterococci. Our results further emphasize the importance of safety guidelines to be established for the probiotics intended for animal use.

Animals↗

PubMed1999

An outbreak of vancomycin-dependent Enterococcus faecium in a bone marrow transplant unit.

Outbreaks of vancomycin-resistant enterococci (VRE) are well described. The presence of mutants of VRE, such as vancomycin-dependent enterococci (VDE), in individual patients has been documented, but their potential to spread nosocomially has not been known. We present the first cluster of patients who acquired VDE nosocomially. Five bone marrow transplantation patients were infected or colonized by a genotypically indistinguishable multiantibiotic-resistant strain of Enterococcus faecium. Vancomycin dependence in 3 of the 5 isolates was demonstrated. All cluster patients had received protracted prophylactic treatment with vancomycin (mean, 22.6 days), and specimens from >/=2 body sites were repeatedly culture-positive for the outbreak strain. The outbreak was controlled with aggressive infection control strategies, and prophylactic antibiotic policies were revised. Awareness of the potential for nosocomial spread of multiantibiotic-resistant VDE is vital for the care of immunocompromised patients, especially those receiving prophylactic antibiotics.

Adult↗

PubMed2001

Selection of a teicoplanin-resistant Enterococcus faecium mutant during an outbreak caused by vancomycin-resistant enterococci with the vanB phenotype.

Vancomycin-resistant enterococci (VRE) have recently become an increasing problem in hospitals in Poland, being responsible for a growing number of nosocomial outbreaks. In this work, we have analyzed the second outbreak of VRE with the VanB phenotype to be identified in the country. It was caused by clonal dissemination of a single strain of vancomycin-resistant Enterococcus faecalis (VRES) and horizontal transmission of vancomycin resistance genes among several vancomycin-resistant Enterococcus faecium (VREM) strains. Two similar restriction fragment length polymorphism types of the vanB gene cluster characterized VRES and VREM isolates, and they both contained the same vanB2 variant of the vanB gene. Two vancomycin-susceptible E. faecium (VSEM) isolates, recovered from the same wards during the outbreak, proved to be related to certain VREM isolates and could represent endemic strains that had acquired vancomycin resistance. One VSEM and four VREM isolates, all identified in the same patient, belonged to a single clone, although they revealed remarkable diversity in terms of susceptibility, PFGE patterns, plasmid content, and number of vanB gene cluster copies. Most probably they reflected the dynamic evolution of an E. faecium strain in the course of infection of a single patient. One of the VREM isolates turned out to be resistant to teicoplanin, which coincided with the use of this antibiotic in the patient's therapy. Its vanB gene variant differed by a single mutation from that found in other isolates; however, it also lacked a large part of the vanB gene cluster, including the regulatory genes vanR(B) and -S(B), and the vancomycin-inducible promoter P(YB). Expression of the resistance genes vanH(B), -B, and -X(B) was constitutive in the mutant, and this phenomenon was responsible for its unusual phenotype.

Anti-Bacterial Agents↗

PubMed1999

Determination of the nucleotide sequence of the 23S ribosomal RNA and flanking spacers of an Enterococcus faecium strain, reveals insertion-deletion events in the ribosomal spacer 1 of enterococci.

The usefulness of 16S-23S (ITS1) and 23S-5S (ITS2) ribosomal spacer nucleotide sequence determination, as a complementary approach to the biochemical tests traditionally used for enterococcal species identification, is shown by its application to the identification of a strain, E27, isolated from a natural bacteria mixture used for cheese production. Using combined approaches we showed, unambiguously, that strain E27 belongs to the Enterococcus faecium species. However, its ITS1 region has an interesting peculiarity. In our previous study of ITS1s from various enterococcal species (NAIMI et al., 1997, Microbiology 143, 823-834), the ITS1s of the two E. faecium strains studied, were found to contain an additional 115-nt long stem-loop structure as compared to the ITS1s of other enterococci, only one out of the 3 ITS1s of E. hirae ATCC 9790, was found to contain a similar 107-nt long stem-loop structure. The ITS1 of strain E27 is 100% identical to that of E. faecium ATCC 19434T, except that the 115-nt additional fragment is absent. This strongly suggests the existence of lateral DNA transfer or DNA recombination events at a hot spot position of the ITS1s from E. faecium and E. hirae. Small and large ITS1 nucleotide sequence determination for strain E27 generalized the notion of two kinds of ITSs in enterococci: one with a tRNA(Ala) gene, one without tRNA gene. To complete strain E27 characterization, its 23S rRNA sequence was established. This is the first complete 23S rRNA nucleotide sequence determined for an enterococcal species.

Base Sequence↗

PubMed2006

Persistence of vanA-type Enterococcus faecium in Korean livestock after ban on avoparcin.

Prevalence of vancomycin-resistant enterococci (VRE) was investigated in Korean livestock 4 years after the ban of avoparcin in feed additives. VRE were isolated from approximately 16.7% of the chicken samples (57 strains from 342 meat samples) and 1.9% of the pig samples (4 from 214 fecal samples). No VRE, however, was isolated from 110 bovine fecal samples. All the 61 VRE isolates were vanA-type Enterococcus faecium expressing a high-level resistance to vancomycin, and showed resistance to teicoplanin as well except two poultry isolates. In addition, the VRE isolates had heterogeneous pulsed-field gel electrophoresis (PFGE) patterns of SmaI-digested DNA, although identical or closely related profiles were observed among strains isolated from the same farm. Although the chicken isolates were all poultry type with G at position 8,234 of the vanX gene, the pig isolates were all swine type with T at position 8,234 of the vanX gene.

Animal Feed↗

PubMed2005

Effects of a probiotic strain of Enterococcus faecium on the rate of natural chlamydia infection in swine.

Chlamydiae are obligately intracellular pathogens which cause infections associated with a broad range of diseases in both livestock and humans. In addition, a large proportion of animals may become persistently infected asymptomatic carriers and serve as reservoirs for other animals which also shed these potential zoonotic pathogens. Reducing the chlamydial load of animals is therefore of major importance, and since large-scale antibiotic treatment is neither desired nor feasible, alternative means of prevention are needed. Here we performed a study comparing the efficacy of a probiotic strain of Enterococcus faecium on the reduction of both the rate of natural infection and the shedding of chlamydiae in swine. The presence of Chlamydiaceae was detected by species-specific PCR of fecal samples of sows taken at three times prior to the birth of piglets. Piglets delivered from chlamydia-positive sows in either the control or the probiotic group were also examined for the frequency of chlamydiae at various ages. Eighty-five percent of the piglets from the control group were found to be chlamydia positive, whereas chlamydiae were found in only 60% of piglets from the probiotic group, results confirmed by fluorescence in situ hybridization and immunohistology, which showed higher rates of infection in the control group. In addition to the reduced frequency of chlamydia-positive piglets in the probiotic group, the time of appearance of positive samples was delayed. To our knowledge, these data show for the first time that a probiotic strain of E. faecium can reduce the rate of carryover infections of piglets by obligate intracellular pathogens.

Animals↗

PubMed1994

[Enterococcus faecium obtained from surveillance cultures of the stool of the patients with hematological malignancies].

Surveillance cultures of the stool were obtained from 55 patients with hematological malignancies, who have been receiving norfloxacin or tosufloxacin during their neutropenic periods, from May, 1991 to September, 1992. Cultures were performed using 5% blood agar with piperacillin 300 micrograms/ml and amikacin 20 micrograms/ml and bacteria resistant to these antibiotics were analyzed further. Thirty-four over 55 patients were positive for enterococci and 22 strains of 23 examined were Enterococcus faecium. They are resistant to quinolones, aminoglycosides, cephalosporins and penicillins but not to vancomycin. Eighteen of them were also resistant to high-dose gentamicin. Appropriate measures should be used to prevent intrahospital spread of these resistant isolates.

4-Quinolones↗

PubMed2001

Outbreak of vancomycin-resistant Enterococcus faecium of the phenotype VanB in a hospital in Warsaw, Poland: probable transmission of the resistance determinants into an endemic vancomycin-susceptible strain.

The first outbreak caused by vancomycin-resistant enterococci of the VanB phenotype in Poland was analyzed. It occurred in a single ward of a Warsaw hospital which is a specialized center for the treatment of hematological disorders. Between July 1999 and February 2000, 11 patients in the ward were found to be infected and/or colonized by Enterococcus faecium that was resistant in vitro to vancomycin and susceptible to teicoplanin. PCR analysis confirmed that the vancomycin-resistant E. faecium (VREM) isolates carried the vanB gene, which is responsible for the VanB phenotype. Pulsed-field gel electrophoresis (PFGE) typing revealed that the isolates belonged to four distinct PFGE types and that one of these was clearly predominant, including isolates collected from seven different patients. The isolates contained one or more copies of the vanB gene cluster of the identical, unique DraI/PagI (BspHI) restriction fragment length polymorphism type, which resided in either the same or different plasmid molecules or chromosomal regions. All this data suggested that the outbreak was due to both clonal spread of a single strain and horizontal transfer of resistance genes among nonrelated strains, which could be mediated by plasmids and/or by vanB gene cluster-containing transposons. The comparative analysis of vancomycin-susceptible E. faecium (VSEM) isolates collected from infections in the same ward at the time of the VREM outbreak has led to identification of a widespread VSEM strain that was possibly related to the major VREM clone. It is very likely that this endemic VSEM strain has acquired vancomycin-resistance determinants and that the acquisition occurred more than once during the outbreak.

Anti-Bacterial Agents↗

PubMed2005

Potential use of a host associated molecular marker in Enterococcus faecium as an index of human fecal pollution.

Several genotypic and phenotypic microbial source tracking (MST) methods have been proposed and utilized to differentiate groups of microorganisms, usually indicator organisms, for the purpose of tracking sources of fecal pollution. Targeting of host-specific microorganisms is one of the approaches currently being tested. These methods are useful as they circumvent the need to isolate individual microorganisms and do not require the establishment of reference databases. Several studies have demonstrated that the presence and distribution of Enterococcus spp. in feces seems to be influenced by the host species. Here, we present a method for detection of genetic sequences in culturable enterococci capable of identifying human sources of fecal pollution in the environment. The human fecal pollution marker designed in this study targets a putative virulence factor, the enterococcal surface protein (esp), in Enterococcus faecium. This gene was detected in 97% of sewage and septic samples but was not detected in any livestock waste lagoons or in bird or animal fecal samples. Epidemiological studies in recreational and groundwaters have shown enterococci to be useful indicators of public health risk for gastroenteritis. By identifying the presence of human fecal pollution, and therefore the possible presence of human enteric pathogens, this marker allows for further resolution of the source of this risk.

DNA, Bacterial↗

PubMed2004

Increasing prevalence of vancomycin-resistant Enterococcus faecium, expanded-spectrum cephalosporin-resistant Klebsiella pneumoniae, and imipenem-resistant Pseudomonas aeruginosa in Korea: KONSAR study in 2001.

The 5th year KONSAR surveillance in 2001 was based on routine test data at 30 participating hospitals. It was of particular interest to find a trend in the resistances of enterococci to vancomycin, of Enterobacteriaceae to the 3rd generation cephalosporin and fluoroquinolone, and of Pseudomonas aeruginosa and acinetobacters to carbapenem. Resistance rates of Gram-positive cocci were: 70% of Staphylococcus aureus to oxacillin; 88% and 16% of Enterococcus faecium to ampicillin and vancomycin, respectively. Seventy-two percent of pneumococci were nonsusceptible to penicillin. The resistance rates of Enterobacteriaceae were: Escherichia coli, 28% to fluoroquinolone; Klebsiella pneumoniae, 27% to ceftazidime, and 20% to cefoxitin; and Enterobacter cloacae, > or =40% to cefotaxime and ceftazidime. The resistance rates of P. aeruginosa were 21% to ceftazidime, 17% to imipenem, and those of the acinetobacters were > or =61% to ceftazidime, aminoglycosides, fluoroquinolone and cotrimoxazole. Thirty-five percent of non-typhoidal salmonellae were ampicillin resistant, and 66% of Haemophilus influenzae were beta-lactamase producers. Notable changes over the 1997-2001 period were: increases in vancomycin-resistant E. faecium, and amikacin- and fluoroquinolone-resistant acinetobacters. With the increasing prevalence of resistant bacteria, nationwide surveillance has become more important for optimal patient management, for the control of nosocomial infection, and for the conservation of the newer antimicrobial agents.

Anti-Bacterial Agents↗

PubMed2005

[Factors of virulence and mechanisms of resistance to aminoglycosides in clinical isolates of Enterococcus faecalis and Enterococcus faecium with high-level gentamicin resistance].

Enterococcus faecalis and E. faecium are grampositive commensal bacteria that may become pathogenic under the selection pressure. In view of natural resistance and effective mechanisms of genetic transfer, the treatment of enterococcal diseases is rather complicated. Aminoglycosides are clinically relevant antimicrobials that are frequently prescribed in practice since having good pharmacokinetics and showing synergism with beta-lactam and glycopeptides. One of the major mechanisms involved in aminoglycoside resistance is inactivation of the antibiotic agent by aminoglycoside-modifying enzymes (AGMEs) differing in the capacity for inactivation of specific types of aminoglycosides. The factors of virulence are also involved in enterococcal pathogenicity but their role in the pathogenesis of infectious diseases remains unclear. Production of beta-hemolysin (Hly), gelatinase (Gel), and aggregation substance (AS), and synthesis of enterococcal surface protein (Esp) are among the most frequently studied potential virulence factors.

Drug Resistance, Bacterial↗

PubMed2026

Development of linezolid and daptomycin resistance in vancomycin resistant Enterococcus faecium during antibiotic treatment.

The increasing incidence of vancomycin-resistant enterococci (VRE) over the past decade has reduced treatment options largely to linezolid and daptomycin. However, the emergence of resistance to both agents further complicates the management of VRE infections. While the mechanisms of linezolid resistance are relatively well understood, those underlying daptomycin resistance remain less clearly defined. In this study, we analyzed genomic changes associated with the development of linezolid and daptomycin resistance in initially susceptible isolates following treatment at a Danish university hospital. Phenotypic susceptibility testing and whole-genome sequencing were performed on eight isolates obtained from the same patient. We identified two distinct Enterococcus faecium clones with different mechanisms of linezolid resistance. Linezolid resistance was associated with a G2576T mutation in the 23S rRNA gene (ST80 clone) and the presence of the poxtA gene (ST3082 clone). The ST80 clone also developed daptomycin resistance during therapy. We found that daptomycin resistance might result from either a G173R substitution in a gene annotated as an "ABC transporter ATP-binding protein (LolD)" or a nonsense mutation (Q58*) in phosphoketolase, with both alterations potentially acting synergistically, but further studies are warranted to confirm if these mutations can confer resistance. Together with these findings, the study demonstrates that a single patient may harbor multiple E. faecium clones simultaneously, highlighting the risk of treatment failure if all clones are not accurately identified.

Daptomycin↗

PubMed2000

Vancomycin-resistant Enterococcus faecium infection in three children given allogeneic hematopoietic stem cell transplantation: clinical and microbiologic features.

BACKGROUND AND OBJECTIVES: The emergence of vancomycin-resistant enterococci (VRE) as nosocomial pathogens is a major problem in the US; in Europe, VRE nosocomial infections are uncommon and only rarely have been reported in Pediatric or Neonatal Units. The aim of this study is to report on the clinical and microbiological features of VRE infections in 3 children given hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: Five episodes of vancomycin-resistant Enterococcus faecium (VREF) infection were diagnosed in 3 children given an allogeneic HSCT. Molecular methods, such as random amplification of polymorphic DNA (RAPD) fingerprinting and automated ribotyping, were used in order to define the circulation of strains. RESULTS: All the isolates were resistant to all commercially available agents and showed the VanA genotypic profile. All children were successfully treated with the combination of quinupristin/dalfopristin (QD) plus teicoplanin (TEC), although treatment was not sufficient to eradicate the micro-organism promptly from the gastrointestinal tract. All our children are still alive. After the first isolation of VRE, a surveillance protocol was started and we documented that the rate of colonization in children and their mothers was less than 1.5%. The RAPD method demonstrated the possible nosocomial transmission of one strain. INTERPRETATION AND CONCLUSIONS: Our experience demonstrates that VRE infection is a life-threatening complication in children given HSCT. Prompt diagnosis of this infection and its treatment with the combination of QD and TEC can successfully manage this severe infection in profoundly immunocompromised patients.

Anti-Bacterial Agents↗

PubMed2003

Prevalence of resistance to ampicillin, gentamicin and vancomycin in Enterococcus faecalis and Enterococcus faecium isolates from clinical specimens and use of antimicrobials in five Nordic hospitals.

We determined the species distribution and prevalence of ampicillin resistance, high-level gentamicin resistance (HLGR) and vancomycin resistance among clinical enterococcal isolates from five Nordic laboratories (Bergen, Tromsø, Uppsala, Aarhus and Reykjavik). Isolates represented three different groups: (i) all blood culture isolates from 1999; (ii) consecutive in-patient isolates (maximum 40); and (iii) consecutive outpatient isolates (maximum 40) collected during March to May 2000. Antimicrobial use data were collected at the national and hospital level. A high proportion (31.4%) of Enterococcus faecium was detected among blood culture isolates, in contrast to only 4.2% among isolates from outpatients. Ampicillin resistance was not found in Enterococcus faecalis, in contrast to 48.8% in E. faecium isolates. HLGR rates varied considerably between laboratories (1.1-27.6%). Acquired vancomycin resistance was not detected. There were no significant differences in the prevalences of HLGR between in-patient and outpatient isolates at individual hospitals. A cluster of clonally related ampicillin-resistant and HLGR E. faecium isolates was demonstrated in one of the hospitals. The lowest level of hospital antimicrobial use, the lowest proportion of E. faecium and the lowest prevalence of resistance were observed in Reykjavik. The study showed a relatively low level of resistance in enterococci, as compared with most European countries and the USA. However, there were large differences between hospitals with regard to the relative proportion of E. faecium isolates, their susceptibility to ampicillin and gentamicin, as well as the prevalence of HLGR in E. faecalis isolates. This indicates a potential for further improvement of antibiotic policies, and possibly hospital infection control, to maintain the low resistance levels observed in these countries.

Ampicillin Resistance↗

PubMedDate not supplied

[Detection of vancomycin-resistant Enterococcus faecium: 2 years' experience in a high complexity hospital ].

The presence of vancomycin-resistant enterococci (VRE) in our hospital prompted us to apply an appropriate method for assessing its rectal carriage. A screening method with bile-esculin azide agar plus different concentrations of vancomycin was used. The antimicrobial susceptibility study of enterococci isolated from clinical samples was also emphasized. The present study includes the surveillance and detection of VRE in our hospital during two years. A total of 260 samples corresponding to 138 patients were studied, 158 of them resulting positive. All EVR were Van A Enterococcus faecium, with MICs of vancomycin > or = 256 micrograms/ml. The analysis of susceptibility patterns shows variations with chloramphenicol, tetracycline and high level gentamicin concentrations. This method was easily applied because materials could be available in any clinical microbiology laboratory, and in our hands it has demonstrated to be useful for epidemiological surveillance for EVR.

Argentina↗

PubMed1998

Pharmacodynamic analysis of the activity of quinupristin-dalfopristin against vancomycin-resistant Enterococcus faecium with differing MBCs via time-kill-curve and postantibiotic effect methods.

Quinupristin-dalfopristin (Q-D) is a new water-soluble, semisynthetic antibiotic that is derived from natural streptogramins and that is combined in a 30:70 ratio. A number of studies have described the pharmacodynamic properties of this drug, but most have investigated only staphylococci or streptococci. We evaluated the relationship between Q-D, quinupristin (Q), and/or dalfopristin (D) susceptibility parameters and antibacterial activities against 22 clinical isolates of vancomycin-resistant Enterococcus faecium (VREF) by using the concentration-time-kill-curve method and by measuring postantibiotic effects. Q-D, Q, and D MICs and minimum bactericidal concentrations (MBCs) ranged from 0.125 to 1 and 0.25 to 64, 8 to 512 and >512, and 2 to 8 and 8 to 512 microgram/ml, respectively. There were no significant relationships between susceptibilities to the individual components and the susceptibilities to the Q-D combination product. In the time-kill-curves studies, Q-D at a concentration of 6 microgram/ml was at least bacteriostatic against all VREF tested. There was increased activity against more susceptible isolates when the isolates were grouped either by Q-D MBCs or by Q MICs. By multivariate regression analyses, the percent change in the inoculum from that at the baseline was significantly correlated with the Q MIC (R = 0.74; P = 0.008) and the Q-D concentration-to-MBC ratio (R = 0.58; P = 0.02) and was inversely correlated with the Q-D MBC-to-MIC ratio (R = 0.68; P = 0.003). A strong correlation existed between the killing rate and the Q-D concentration-to-MBC ratio (R = 0.99; P < 0.0001). Time to 99.9% killing was best correlated with the Q-D MBC (R = 0.96; P < 0.0001). The postantibiotic effect ranged from 0.2 to 3.2 h and was highly correlated with the Q-D concentration-to-MBC ratio (R = 0.96; P < 0.0001) and was less highly correlated with the Q MIC (R = 0.42; P = 0.04). Further study of these relationships with in vitro or in vivo infection models that simulate Q-D pharmacokinetics should further define the utility of these pharmacodynamic parameters in the prediction of Q-D activity for the treatment of VREF infections in humans.

Drug Resistance, Microbial↗

PubMed2003

Susceptibility of Escherichia coli and Enterococcus faecium isolated from pigs and broiler chickens to tetracycline degradation products and distribution of tetracycline resistance determinants in E. coli from food animals.

One hundred Escherichia coli isolates from diseased and healthy pigs, cattle and broiler chickens were screened for the presence of tetracycline resistance genes tet(A), (B), (C), (D) or (E). The tet(A) gene was the most abundant (71% of the 100 isolates) followed by tet(B) (25%). The predominance of tet(A) and tet(B) applied to all three animal species, and there was no difference between the distribution of tet(A) and tet(B) genes among non-pathogenic and pathogenic E. coli in any of the animal species. The susceptibility of 20 of these isolates together with 10 tetracycline sensitive E. coli and 18 tetracycline resistant and 10 sensitive Enterococcus faecium to tetracyclines and tetracycline degradation products was determined. The resistant isolates showed reduced resistance to anhydrotetracycline, 4-epi-anhydrotetracycline, anhydrochlortetracycline and 4-epi-anhydrochlortetracycline. In general both the tetracycline resistant and susceptible E. faecium were more susceptible to the compounds tested than E. coli.

Animals↗

PubMed2005

Cloning, production and functional expression of enterocin P, a sec-dependent bacteriocin produced by Enterococcus faecium P13, in Escherichia coli.

The cloning and expression of enterocin P (EntP), a sec-dependent bacteriocin produced by Enterococcus faecium P13, was studied in Escherichia coli. PCR-amplified products of the preenterocin P gene (entP) or entP plus the putative EntP immunity gene (entiP), were cloned in plasmid pETBlue-1 under the control of the inducible T7lac promoter. Although target genes in derivative plasmids pJG01 (entP) and pJG02 (entP plus entiP) did not generate products with antimicrobial activity after an in vitro combined transcription/translation reaction, they were expressed as biologically active products following transformation and induction in the E. coli Tuner(DE3)pLacI host. The use of specific antibodies and an ELISA permitted the detection and quantification of EntP in the supernatant (SN), cellular soluble protein fraction (CSF), and inclusion bodies (IB) of E. coli Tuner(DE3)pLacI cells transformed with either pJG01 or pJG02. Functional EntP from the supernatants of E. coli Tuner(DE3)pLacI (pJG01) cultures grown in a complex medium was recovered, at a high efficiency, by immunoaffinity chromatography in a single step. A purification method based on hydrophobic adsorption and reverse-phase chromatographies also permitted the recovery of active EntP from the supernatants of the same cultures grown in a minimally defined medium. The E. coli Tuner(DE3)pLacI (pJG01) cells would merit consideration as an alternative experimental model for the heterologous production and functional expression of EntP, as well as for the fast and efficient recovery of this bacteriocin from the supernatant of this recombinant producer.

Bacteriocins↗