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Lund, Bodil
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Lund, B., Billström, H. & Edlund, C. (2006). Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene esp. Clinical Microbiology and Infection, 12(6), 588-591
Öppna denna publikation i ny flik eller fönster >>Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene esp
2006 (Engelska)Ingår i: Clinical Microbiology and Infection, ISSN 1198-743X, E-ISSN 1469-0691, Vol. 12, nr 6, s. 588-591Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp-) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp- isolates (p < 0.001), with a median value of 6.4 x 10(-6) transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-14298 (URN)10.1111/j.1469-0691.2006.01436.x (DOI)000237515600017 ()16700712 (PubMedID)2-s2.0-33646702110 (Scopus ID)
Anmärkning

Som manuskript i avhandling. As manuscript in dissertation.

Tillgänglig från: 2011-12-20 Skapad: 2011-12-20 Senast uppdaterad: 2017-12-08Bibliografiskt granskad
Lund, B. & Edlund, C. (2003). Bloodstream isolates of Enterococcus faecium enriched with the enterococcal surface protein gene, esp, show increased adhesion to eukaryotic cells. Journal of Clinical Microbiology, 41(11), 5183-5185
Öppna denna publikation i ny flik eller fönster >>Bloodstream isolates of Enterococcus faecium enriched with the enterococcal surface protein gene, esp, show increased adhesion to eukaryotic cells
2003 (Engelska)Ingår i: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 41, nr 11, s. 5183-5185Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Infection-derived Enterococcus faecium strains enriched with esp had increased ability to adhere to Caco-2 cells (P < 0.05) and were less genetically diverse than esp-negative isolates. esp-negative E. faecium fecal isolates from healthy individuals adhered significantly better than esp-negative infection isolates (P < 0.05), indicating additional factors of importance to adhesion.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-15524 (URN)10.1128/JCM.41.11.5183-5185.2003 (DOI)000186665500040 ()14605157 (PubMedID)2-s2.0-0242593799 (Scopus ID)
Anmärkning

Som manuskript i avhandling. As manuscript in dissertation, with title:

Increased adhesion to eukaryotic cells in Enterococcus faecium bloodstream isolates enriched with enterococcal surface protein gene, esp

Tillgänglig från: 2012-02-21 Skapad: 2012-02-21 Senast uppdaterad: 2017-07-19Bibliografiskt granskad
Lund, B. (2003). Different roles of enterococcus faecium from a human perspective. (Doctoral dissertation). Stockholm: Karolinska Instiutet
Öppna denna publikation i ny flik eller fönster >>Different roles of enterococcus faecium from a human perspective
2003 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Food supplements containing viable bacteria, so called probiotics, have been suggested to have beneficial health effects due to their influence on the normal microflora. However, there has been safety concern regarding probiotics containing Enterococcus faecium. Although part of the normal intestinal microflora in humans, enterococci can cause infections such as urinary tract infections, septicaemia, and endocarditis. Enterococci are also inclined to develop antibiotic resistance and their hardy nature promotes survival and dissemination in the hospital setting. Although the importance of E.faecium as a bloodstream isolate is increasing, little regarding its virulence is known. One virulence trait attributed to E. faecium is the enterococcal surface protein, Esp, encoded by the esp gene. Since enterococci have different roles from the human perspective, such as occurrence in food, as probiotic strains, members of the normal intestinal microflora, and as the cause of nosocomial infections, it is important to study differences and similarities between strains of different origin. The aims of the present investigation were to study some safety aspects of a probiotic product containing Efaecium, the colonization and transmission of enterococci from a nosocomial perspective, and differences between E.faecium isolates of different origin in some characteristics of probable importance for virulence. Faecal samples were collected from healthy volunteers administered an E. faecium probiotic. Half of the volunteers received simultaneous peroral vancomycin. The E. faecium isolates were subtyped and an in vitro conjugation assay was performed. The investigated strain could survive gastrointestinal transit in humans, and intake temporarily increased the number of enterococci in the faecal microflora. The vancomycin administration prevented detection of the probiotic strain. The probiotic strain could gain the vanA gene cluster under in vitro conditions. Samples from the respiratory tract and stomach were collected from 20 consecutive patients undergoing mechanical ventilation. The enterococci isolated were subsequently subtyped. Seventeen of the 20 subjects were colonized with enterococci in the respiratory tract. Genotype analyses suggested that 13 patients were involved in a transmission event, including all patients intubated more than 12 days. The E. faecium isolates were more resistant to antimicrobial agents compared to E. faecalis. The E. faecium isolates from different origins, i.e., infections, faeces, and probiotic products, were investigated for the presence of esp, their ability to conjugate, and adhere to epithelial cells in vitro. The esp gene was significantly more common among blood isolates. E. faecium strains enriched with esp adhered significantly better, were less genetically diverse, and had a higher conjugation frequency compared to esp-negative blood isolates. Antibiotic resistance was only detected among the infection-derived isolates. The adhesion among esp-negative isolates from the normal microflora was higher compared to the esp-negative bacteraemia isolates. In conclusion, the investigated probiotic E. faecium strain can survive gastrointestinal transit in humans, and intake may transiently increase the number of enterococci in the faecal microflora. The same strain can gain the vanA operon. Enterococci are frequently disseminated between mechanically ventilated patients, and isolates from different subpopulations seem to have different characteristics in terms of occurrence of esp, adhesion properties, antibiotic resistance, and conjugation frequencies.

Ort, förlag, år, upplaga, sidor
Stockholm: Karolinska Instiutet, 2003. s. 79
Nationell ämneskategori
Biologiska vetenskaper
Identifikatorer
urn:nbn:se:sh:diva-32071 (URN)91-7349-607-3 (ISBN)
Disputation
2003-10-15, Birkeaulan 2, F-huset, plan 5, Huddinge Universitetssjukhus, Huddinge, 10:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2017-02-15 Skapad: 2017-02-15 Senast uppdaterad: 2017-02-15Bibliografiskt granskad
Lund, B., Agvald-Öhman, C., Hultberg, A. & Edlund, C. (2002). Frequent transmission of enterococcal strains between mechanically ventilated patients treated at an intensive care unit. Journal of Clinical Microbiology, 40(6), 2084-2088
Öppna denna publikation i ny flik eller fönster >>Frequent transmission of enterococcal strains between mechanically ventilated patients treated at an intensive care unit
2002 (Engelska)Ingår i: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 40, nr 6, s. 2084-2088Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The objectives of this investigation were to study the respiratory tract colonization and transmission of enterococci between 20 patients treated with mechanical ventilation at an intensive care unit (ICU), to compare genotyping with phenotyping, and to determine the antibiotic susceptibilities of the isolated enterococci. Samples were collected from the oropharynx, stomach, subglottic space, and trachea within 24 It of intubation, every third day until day 18, and thereafter every fifth day until day 33. Enterococcal isolates (n = 170) were analyzed by pulsed-field gel electrophoresis and with the PhenePlate (PhP) system. The antimicrobial susceptibilities to five agents were determined. Seventeen of the 20 subjects were colonized with enterococci in the respiratory tract; 12 were colonized in the lower respiratory tract. Genotype analyses suggested that 13 patients were involved in a transmission event, including all patients intubated more than 12 days. In conclusion, colonization of resistant enterococci in the respiratory tract of intubated patients treated at an ICU was common. Transmission of enterococci between patients occurred frequently. Prolonged intubation period seems to be a risk factor for enterococcal cross-transmission.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-15803 (URN)10.1128/JCM.40.6.2084-2088.2002 (DOI)000176159200031 ()12037069 (PubMedID)2-s2.0-0036263059 (Scopus ID)
Tillgänglig från: 2012-03-08 Skapad: 2012-03-07 Senast uppdaterad: 2017-07-20Bibliografiskt granskad
Lund, B., Adamsson, I. & Edlund, C. (2002). Gastrointestinal transit survival of an Enterococcus faecium probiotic strain administered with or without vancomycin. International Journal of Food Microbiology, 77(1-2), 109-115
Öppna denna publikation i ny flik eller fönster >>Gastrointestinal transit survival of an Enterococcus faecium probiotic strain administered with or without vancomycin
2002 (Engelska)Ingår i: International Journal of Food Microbiology, ISSN 0168-1605, E-ISSN 1879-3460, Vol. 77, nr 1-2, s. 109-115Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The primary aim of this study was to evaluate if an ingested probiotic, containing viable Enterococcus faecium could survive gastrointestinal transit and if so, correlate the amount of the recovered probiotic strain with the host's own enterococci. The second aim was to investigate if simultaneous vancomycin intake influenced the survival and persistence of the probiotic strain and the stability of endogenous enterococci strains. Twenty healthy volunteers were given the probiotic product once daily for 10 days. Half of the subjects were simultaneously given vancomycin. Isolates of E. faecium strains were genotypically or phenotypically analysed with pulsed-field gel electrophoresis (PFGE) and the PhenePlate(TM) system, respectively. In eight of the ten volunteers given only the probiotic, the ingested E. faecium could be detected on day 10, while in none on day 31. From subjects given both probiotic and vancomycin no ingested E. faecium could be detected on day 10 or day 31. The estimated amount of ingested E. faecium recovered from faeces on day 10 ranged from 1.2 x 10(3) to 4.2 x 10(6) colony forming units per gram faeces, which in several cases were a substantial part of the total amount of E. faecium. The E. faecium isolated before probiotic plus vancomycin administration showed no close relationship to the ones isolated 3 weeks after ceased intake in any subjects. In conclusion, the ingested E. faecium strain can survive gastrointestinal transit. After intake, the E. faecium probiotic strain might become a large part of the total E, faecium population. The occurrence of the probiotic strain in the human gut seems to be transient after intake stop. Re-colonization of E. faecium after simultaneous probiotic plus vancomycin intake occurs mainly with strains without close genetic relationship to the strains harboured before treatment or to the ingested E. faecium strain.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-15792 (URN)10.1016/S0168-1605(02)00047-8 (DOI)000176056800012 ()12076027 (PubMedID)2-s2.0-0037173481 (Scopus ID)
Tillgänglig från: 2012-03-08 Skapad: 2012-03-07 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
Lund, B., Edlund, C., Rynnel-Dagoo, B., Lundgren, Y., Sterner, J. & Nord, C. E. (2001). Ecological effects on the oro- and nasopharyngeal microflora in children after treatment of acute otitis media with cefuroxime axetil or amoxycillin-clavulanate as suspensions. Clinical Microbiology and Infection, 7(5), 230-237
Öppna denna publikation i ny flik eller fönster >>Ecological effects on the oro- and nasopharyngeal microflora in children after treatment of acute otitis media with cefuroxime axetil or amoxycillin-clavulanate as suspensions
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2001 (Engelska)Ingår i: Clinical Microbiology and Infection, ISSN 1198-743X, E-ISSN 1469-0691, Vol. 7, nr 5, s. 230-237Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Objective To evaluate if the extent of normal microflora disturbances differed between treatment with amoxycillin-clavulanate administered in an active form and cefuroxime axetil administered as an inactive prodrug. Methods Twenty-eight children, 0.5-5 years old, diagnosed with acute otitis media (AOM), were treated with either amoxycillin-clavulanate (13.3 mg/kg 3 times daily) or cefuroxime axetil (15 mg/kg twice daily) for 7 days. Saliva samples and nasopharyngeal swabs were collected before, directly after and 2 weeks after treatment. The saliva samples were quantitatively and qualitatively analyzed and the nasopharyngeal swabs were qualitatively analyzed. All isolated strains were tested for beta -lactamase production. Results Both treatment regimens gave rise to similar alterations of the normal oropharyngeal microflora. In both groups, the amount of Streptococcus salivarius was significantly reduced (P < 0.05). The most common causative pathogens of acute otitis were S. pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. On the day of enrollment, approximately half of the patients, in both groups, were infected with more than one pathogen. The rate of infection or colonization with more than one potential pathogen was low on day 7 but recurred 2 weeks after treatment to similar levels as on day 0. The total number of patients with reinfection, recolonization or recurrence of pathogens on day 21 was 11/12 in the amoxycillin-clavulanate group and 4/7 in the cefuroxime axetil group. The most common <beta>-lactamase producer was M. catarrhalis. Conclusion The local high concentration of antibiotics in the oropharynx immediately after intake of antibiotic suspensions seem to have little or no impact on the extent of disturbance of the microflora in this region. Children of this age group seem prone to either reinfection, recolonization or persistence of pathogens within 2 weeks after treatment. Furthermore, co-infection with more than one pathogen seems common in children with AOM and infection with beta -lactamase producing microorganisms occurs frequently.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-17664 (URN)10.1046/j.1469-0691.2001.00242.x (DOI)000169614800002 ()11422249 (PubMedID)2-s2.0-0035352189 (Scopus ID)
Tillgänglig från: 2012-12-14 Skapad: 2012-12-14 Senast uppdaterad: 2017-12-06Bibliografiskt granskad
Lund, B. & Edlund, C. (2001). Probiotic Enterococcus faecium strain is a possible recipient of the vanA gene cluster. Clinical Infectious Diseases, 32(9), 1384-1385
Öppna denna publikation i ny flik eller fönster >>Probiotic Enterococcus faecium strain is a possible recipient of the vanA gene cluster
2001 (Engelska)Ingår i: Clinical Infectious Diseases, ISSN 1058-4838, E-ISSN 1537-6591, Vol. 32, nr 9, s. 1384-1385Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The characteristics of Enterococcus faecium have led to concern regarding the safety of probiotics that contain this bacterium. The results of an in vitro filter mating assay indicate that a probiotic E. faecium strain might be a potential recipient of vancomycin resistance genes.

Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:sh:diva-15857 (URN)10.1086/319994 (DOI)000168517900018 ()11303279 (PubMedID)2-s2.0-0035341415 (Scopus ID)
Tillgänglig från: 2012-03-12 Skapad: 2012-03-09 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
Lund, B., Edlund, C., Barkholt, L., Nord, C. E., Tvede, M. & Poulsen, R. L. (2000). Impact on human intestinal microflora of an Enterococcus faecium probiotic and vancomycin. Scandinavian Journal of Infectious Diseases, 32(6), 627-632
Öppna denna publikation i ny flik eller fönster >>Impact on human intestinal microflora of an Enterococcus faecium probiotic and vancomycin
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2000 (Engelska)Ingår i: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 32, nr 6, s. 627-632Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The aims of this study were to evaluate the impact of a fermented milk product containing viable Enterococcus faecium on human intestinal microflora and to evaluate any risk of development of vancomycin-resistant enterococci (VRE). Twenty Danish and 20 Swedish healthy volunteers were given 150 mi of the fermented mill;. product once daily, equivalent to a daily dose of 4.5 x 10(9) to 7.5 x 10(9) CFU E. faecium, for 10 d. Half of the volunteers also received 125 mg vancomycin orally q.i.d. for 10 d. Faecal samples were collected on day 0 before intake, on day 10 directly after end of intake and on day 31, 3 weeks after the end of the experiment. There,Fas a significant increase in the total number of enterococci on day 10 (p < 0.01) in the group receiving only the E. faecium supplement, but 3 weeks later the level was as before intake. In the vancomycin group, the total number of enterococci was reduced on day 10 (p < 0.01) but had increased on day 31 (p < 0.01) in relation to day 0. In none of the Swedish and 4 of the Danish volunteers, VRE were sporadically detected, but without relation to intake of the probiotic or vancomycin. In healthy young Danish individuals the VRE carrier rate tended to be higher than previously found.

Nationell ämneskategori
Biologiska vetenskaper
Identifikatorer
urn:nbn:se:sh:diva-32072 (URN)10.1080/003655400459531 (DOI)000166340400007 ()11200372 (PubMedID)2-s2.0-0034525626 (Scopus ID)
Tillgänglig från: 2017-02-15 Skapad: 2017-02-15 Senast uppdaterad: 2017-11-29Bibliografiskt granskad
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