FEMS Immunology and Medical Microbiology 26 (1999) 137^142
The e¡ect of probiotic bacteria on the adhesion of pathogens to
human intestinal mucus
Elina M. Tuomola *, Arthur C. Ouwehand, Seppo J. Salminen
Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
Received 15 April 1999; accepted 14 July 1999
Abstract
Human intestinal glycoproteins extracted from faeces were used as a model for intestinal mucus to investigate adhesion of
pathogenic Escherichia coli and Salmonella strains, and the effect of probiotics on this adhesion. S-fimbriated E. coli expressed
relatively high adhesion in the mucus model, but the other tested pathogens adhered less effectively. Probiotic strains
Lactobacillus GG and L. rhamnosus LC-705 as well as a L. rhamnosus isolated from human faeces were able to slightly reduce
S-fimbria-mediated adhesion. Adhesion of S. typhimurium was significantly inhibited by probiotic L. johnsonii LJ1 and L. casei
Shirota. Lactobacillus GG and L. rhamnosus (human isolate) increased the adhesion of S. typhimurium suggesting that the
pathogen interacts with the probiotic. ß 1999 Federation of European Microbiological Societies. Published by Elsevier
Science B.V. All rights reserved.
Keywords : Pathogen adhesion ; Probiotic adhesion; Intestinal mucus ; Adhesion inhibition
1. Introduction
Adhesion of pathogenic bacteria to mucosal surfaces is considered to be the ¢rst step of intestinal
infections [1,2]. The adhesion of pathogens is mediated by bacterial adhesins, which recognise speci¢c
mucosal receptors. Inhibition of adhesion may prevent colonisation of the intestine by the pathogen
and thereby prevent the infection. Adhesion may
be inhibited by blocking the receptor with speci¢c
adhesin analogues or by steric hindrance. Some probiotic bacteria with bene¢cial health e¡ects have
* Corresponding author. Tel: +358 (2) 3336894;
Fax: +358 (2) 3336860; E-mail: elina.tuomola@utu.¢
been found to adhere to the intestinal mucosa.
Therefore, adhesive probiotics could prevent the subsequent attachment of pathogens, referred to as competitive exclusion.
Some Lactobacillus strains, either the cells alone or
in combination with their spent culture supernatant
(SCS), have been shown to inhibit adhesion of
pathogens. For example, speci¢c Lactobacillus
strains were found to inhibit the adhesion of Escherichia coli to porcine enterocytes [3]. The SCS of
lactobacilli was reported to prevent E. coli attachment to porcine mucus [4,5]. Lactobacilli have also
been shown to inhibit the adhesion of human uropathogens to uroepithelial cells in vitro [6]. Inhibition of pathogen adhesion by probiotics has also
been reported using the Caco-2 cell line as a model
for human intestinal epithelium [7,8]. In the intestine,
0928-8244 / 99 / $20.00 ß 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
PII: S 0 9 2 8 - 8 2 4 4 ( 9 9 ) 0 0 1 3 1 - 5
FEMSIM 1116 8-10-99
138
E.M. Tuomola et al. / FEMS Immunology and Medical Microbiology 26 (1999) 137^142
epithelial cells are covered with a mucus layer protecting the epithelial cells from physical and chemical
damage as well as from pathogenic bacteria. The
mucus layer is most likely the ¢rst place of contact
between the host and the pathogen. Human intestinal glycoproteins extracted from faeces and
human ileostomy glycoproteins were recently used
as a model for intestinal mucus to investigate the
adhesion potential of probiotic bacteria [9^11]. In
this study, we investigated whether intestinal glycoproteins isolated from faeces could provide an in
vitro model for human intestinal mucus to study
adhesion of pathogenic bacteria as well as the interactions between pathogenic and probiotic bacteria.
2. Materials and methods
uct from Nestlë), L. casei Shirota (isolated from a
Yakult0 product from Yakult Ltd.), L. rhamnosus
(human isolate) and L. rhamnosus LC-705 were obtained from Dr. M. Saxelin (Valio Ltd, Finland).
Lactobacillus strains were grown in de Man, Rogosa
and Sharpe (MRS) broth at 37³C for 18^20 h. A
0.2% inoculum from stocks stored at 370³C in
40% glycerol was used. To label the bacteria, the
radiolabel was added as described above. The bacteria were harvested by centrifugation (1500Ug, 7 min)
and the pellet was washed with HH. The bacteria
were resuspended in HH. The optical density (OD)
at 600 nm of each bacterial suspension was adjusted
to 0.25 þ 0.01 give approximately 1^2U108 cfu ml31
with the exception of L. johnsonii LJ1 containing
1U107 cfu ml31 . The adhesion was tested with di¡erent dilutions of the suspension.
2.1. Micro-organisms and growth conditions
2.2. Human intestinal mucus
SfaII-¢mbriated Escherichia coli HB101(pAZZ50)
[12], hereafter abbreviated as E. coli SfaII, was a gift
from Prof. J. Hacker (University of Wu«rzburg, Germany). Human and bovine enterotoxigenic E. coli
H10407 and B44, respectively, were provided by Dr
M. Saxelin (Valio Ltd, Finland). The bovine strain,
E. coli B44, was used as a non-adhering control
strain. Salmonella typhimurium (ATCC 14028) was
obtained from the American Type Culture Collection
(USA). S. enteritidis, isolated from a human patient,
was obtained from the National Public Health Institute (Turku, Finland). Pathogenic bacteria were
grown at 37³C for 18^20 h in Luria-Bertani broth
containing 5 Wl ml31 of methyl-1,2-[3 H]-thymidine
(113 Ci mmol31 ). In the case of E. coli SfaII, 50 Wg
ml31 ampicillin was added to the broth. After
growth, the radiolabelled bacteria were harvested
by centrifugation (1500Ug, 7 min), washed with
HEPES (N-2-hydroxy-ethylpiperazine-NP-2-ethanesulfonic acid)-Hanks' bu¡er (HH; 10 mmol l31
HEPES; pH 7.4) containing 0.1% (w/v) Na-azide
and resuspended in HH. The optical density of bacterial suspensions was adjusted to 0.25 þ 0.01 to give
approximately 1^2U108 colony forming units (cfu)
ml31 . Di¡erent bacterial dilutions were tested in adhesion assays.
Lactobacillus GG (L. rhamnosus GG; ATCC
53103), L. johnsonii LJ1 (isolated from a LC10 prod-
Human intestinal glycoproteins were isolated from
faeces of healthy adults (n = 10) by extraction and
dual ethanol precipitation [9,10]. Equal amounts of
lyophilised mucus from each individual were pooled
to make a stock suspension of 10 mg ml31 in HH.
Any particulate material was removed by centrifuging the suspension. The stock suspension was stored
at 320³C. For adherence assays, mucus was diluted
(0.5 mg ml31 ) in HH and 100 Wl of the suspension
was immobilised in polystyrene microtitre plate wells
(Maxisorp; Nunc, Denmark) by overnight incubation at 4³C. Excess mucus was removed by washing
twice with 250 Wl of HH.
2.3. In vitro adherence assay
Radioactively labelled bacteria (100 Wl) were
added to the wells coated with intestinal mucus
and incubated at 37³C for 1.5 h. The wells were
washed three times with 200 Wl of HH to remove
unattached bacteria. The bacteria bound to intestinal
mucus were released and lysed with 1% SDS-0.1 M
NaOH by incubation at 60³C for 1 h. The radioactivity of the lysed suspension was measured by liquid
scintillation. The adhesion ratio (%) was calculated
by comparing the radioactivity of the bacteria added
(triplicate 100-Wl samples) to the radioactivity of the
bound bacteria.
FEMSIM 1116 8-10-99
E.M. Tuomola et al. / FEMS Immunology and Medical Microbiology 26 (1999) 137^142
2.4. Competitive exclusion of S. typhimurium and
E. coli SfaII
Probiotic bacteria without radiolabel (OD
0.25 þ 0.01; 100 Wl) were added to the wells coated
with intestinal mucus and incubated at 37³C for 1 h.
To remove unbound bacteria, the wells were washed
three times with 200 Wl of HH. Radiolabelled pathogens were diluted 1:9 to avoid saturation of the substratum and 100 Wl of the suspension was added to
the wells. The wells were incubated at 37³C for 1.5 h.
The assay was performed as described above.
2.5. Coaggregation between S. typhimurium and
Lactobacillus GG
To investigate possible interaction between S. typhimurium and Lactobacillus GG, the coaggregation
ability between the two bacteria was studied according to the method of Spencer and Chesson [3] with
the exception that the test was performed in HH
since this bu¡er was also used in the adhesion assay.
The bacterial suspensions were incubated for 4 h at
37³C and the OD at 660 nm of the suspensions (both
strains alone and together) was measured. In addition, the suspension of S. typhimurium and Lactobacillus GG was Gram-stained and observed by light
microscopy.
2.6. Statistical analysis
Student's t-test was used to determine the signi¢cant di¡erence (P 6 0.05) between the control and
the test strain. The results shown are the average
of at least three independent experiments performed
in triplicate.
3. Results
3.1. Adherence of strains to human intestinal mucus
E. coli SfaII expressed relatively high adhesion to
mucus glycoproteins with approximately 13% of the
applied bacteria adhering (Table 1). The adhesion of
the other tested pathogens was not signi¢cantly different from the adhesion of the non-adhesive control
strain (adhesion; 0.94%). SfaII-¢mbriated E. coli and
139
type 1 ¢mbriated S. typhimurium were chosen for the
competitive exclusion studies.
Among the probiotic strains, Lactobacillus GG,
L. johnsonii LJ1 and L. rhamnosus (human isolate)
expressed high adhesion, but L. rhamnosus LC-705
and L. casei Shirota adhered poorly.
3.2. Competitive exclusion of S. typhimurium and
E. coli SfaII by probiotic strains
The adhesion of S. typhimurium and E. coli SfaII
to intestinal mucus was assigned to 100% and adhesion to intestinal mucus that was incubated with a
probiotic strain prior to pathogen adhesion was
compared to this control (Table 2). Lactobacillus
GG, L. rhamnosus LC-705 and L. rhamnosus (human
isolate) reduced the adhesion of E. coli SfaII to
90^91%, but only the reduction by Lactobacillus
GG and L. rhamnosus (human isolate) was signi¢cant (P 6 0.05).
The adherence of S. typhimurium was reduced to
77% by L. johnsonii LJ1 and to 83% by L. casei
Shirota (P 6 0.05). Lactobacillus GG and L. rhamnosus (human isolate) were found to signi¢cantly increase the adhesion of S. typhimurium to 190% and
332%, respectively. When Lactobacillus GG was further diluted (1 to 100) for the pre-treatment, the
adhesion was not increased compared to the control
(data not shown).
Table 1
Adherence of bacterial strains to human intestinal mucus glycoproteins
Bacterial strain
Adhesion (%)a
(mean þ S.D.)
E. coli SfaII
E. coli H10407
S. enteritidis
S. typhimurium (ATCC 14028)
E. coli B44 (non-adhesive control)
L. casei Shirota
L. johnsonii LJ1
Lactobacillus GG
L. rhamnosus LC-705
L. rhamnosus (human isolate)
13 þ 2.2b
0.54 þ 0.31
0.47 þ 0.01c
1.4 þ 1.0
0.94 þ 0.17
0.25 þ 0.02c
25 þ 5.9b
39 þ 2.6b
0.43 þ 0.21c
24 þ 2.2b
a
Mean þ S.D. of individual experiments (n = 2 for S. enteritidis
and E. coli H 10407, n = 6 for the rest of the strains).
b
Signi¢cantly higher than the non-adhesive control (P 6 0.05).
c
Signi¢cantly lower than the non-adhesive control (P 6 0.05).
FEMSIM 1116 8-10-99
140
E.M. Tuomola et al. / FEMS Immunology and Medical Microbiology 26 (1999) 137^142
Table 2
Adherence of E. coli SfaII and S. typhimurium (ATCC 14028) to human intestinal mucus glycoproteins pre-treated with probiotic strain
Adhesion (%)a (mean þ S.D.)
Probiotic strain
Control (bu¡er only)
L. casei Shirota
L. johnsonii LJ1
L. rhamnosus LC-705
Lactobacillus GG
L. rhamnosus (human isolate)
E. coli SfaII
S. typhimurium
100
97 þ 24
96 þ 16
90 þ 15
90 þ 7.6b
91 þ 7.1b
100
83 þ 18b
77 þ 13b
96 þ 31
190 þ 45c
332 þ 116c
a
Mean þ S.D. of individual experiments (n = 6).
Signi¢cantly lower than the control (P 6 0.05).
c
Signi¢cantly higher than the control (P 6 0.001).
b
3.3. Coaggregation between S. typhimurium and
Lactobacillus GG
No coaggregation between S. typhimurium and
Lactobacillus GG was measured after the incubation.
Coaggregation was neither observed after Gram
staining, although a number of S. typhimurium cells
seemed to be attached to Lactobacillus GG cells.
4. Discussion
In this study the potential of some probiotic
strains to adhere and to a¡ect the adhesion of pathogens to human intestinal glycoproteins was investigated. Lactobacillus GG, L. johnsonii LJ1 and L.
casei Shirota have documented probiotic e¡ects on
human health [13]. Lactobacillus GG and L. johnsonii LJ1 have been previously reported to adhere
to Caco-2 intestinal tissue culture cells [8,14,15], to
intestinal mucus extracted from faeces [9] and to human ileostomy glycoproteins [11]. The strains expressed high adhesion also in the present study, as
did L. rhamnosus (human isolate) which was previously shown to adhere both to Caco-2 cells [15] and
to ileostomy glycoproteins [11]. Strain LC-705 was
known to adhere to Caco-2 cells [15], but it adhered
poorly to human ileostomy glycoproteins [11] as well
as to intestinal mucus used in the current study. L.
casei Shirota adhered poorly, previously it was also
shown to adhere poorly both to Caco-2 cells [15] and
to ileostomy glycoproteins [11].
E. coli B44 has been used as a non-adhering control strain in studies with human intestinal cells from
ileostomy lavage [16], with the Caco-2 cell line
[14,15] and with ileostomy glycoproteins [11]. The
strain adhered poorly also in the present study. Surprisingly, S. typhimurium expressing mannose-sensitive type 1 ¢mbriae [17] did not adhere signi¢cantly
better than the non-adhesive control strain suggesting that the mannose-containing receptors are not
present or not available in great numbers in the current mucus model. In our previous study [18], the
same Salmonella strain adhered to Caco-2 cells (approximately 7% of the applied bacteria adhered).
The adhesion to Caco-2 cells was partly inhibited
by pre-treating the bacteria with mannose [18] indicating that the type 1 ¢mbriae were expressed in
Luria-Bertani broth used also in the present study.
Craven and Williams [19] reported the adhesion of S.
typhimurium to chicken caecal mucus, but the level
of adhesion was not shown making the comparison
of the adhesion ability of Salmonella between the
studies impossible. Also E. coli H10407 (CFA/I ¢mbriae) and S. enteritidis adhered poorly, although E.
coli H10407 has been shown to adhere to human
intestinal cells [16] and to the Caco-2 cell line
[14,15]. Ouwehand and Conway [5] reported that
E. coli expressing CFA/I, II or IV also adhered
poorly to human ileostomy glycoproteins. Therefore,
it may be possible that the type 1 ¢mbriae and CFA/
I ¢mbriae, known to mediate adhesion to epithelial
cells, do not mediate the adhesion to human mucus.
In contrast to Salmonella and other E. coli strains,
the S-¢mbriated E. coli strain adhered signi¢cantly
better to intestinal mucus than the non-adhesive control strain. S-¢mbriated E. coli is associated with
newborn meningitis [20], but the gastrointestinal
FEMSIM 1116 8-10-99
E.M. Tuomola et al. / FEMS Immunology and Medical Microbiology 26 (1999) 137^142
tract and the oropharynx seem to be the reservoir for
E. coli with the translocation ability [21]. Therefore,
the inhibition of adhesion in the intestine could prevent the translocation and subsequently the infection. Ouwehand et al. [22] used the same E. coli SfaII
strain, and showed that the strain was able to produce the SfaII ¢mbriae recognising sialyl galactosides
[23] under similar culture conditions as used in the
present study. The level of adhesion of the S-¢mbriated E. coli reported here was similar to the adherence to human ileostomy glycoproteins reported in
previous studies [11,22]. However, the same number
of bacteria used with ileostomy glycoproteins saturated the substratum in the present study suggesting
that fewer receptors were available. Therefore, it is
important to optimise the number of bacteria used in
in vitro studies.
Strongly adhesive Lactobacillus GG and L. rhamnosus (human isolate) and low-adhering L. rhamnosus LC-705 were able to slightly reduce the S-¢mbriated E. coli adhesion. Similarly, the adhesion of S.
typhimurium was partially inhibited by the adhesive
L. johnsonii LJ1 and low-adhering L. casei Shirota.
The results indicate that the inhibition was not related to the adhesion potential of the Lactobacillus
strain. Craven and Williams [19] reported that the
pre-treatment of immobilised chicken caecal mucus
with Lactobacillus cells or with the SCSs inhibited
the binding of S. typhimurium. The adhesion of S.
typhimurium was reduced to 60% by one L. salivarius
and one L. delbrueckii ssp. delbrueckii strain. Similar
to the present study, not all tested isolates inhibited
the Salmonella adhesion. In the present study SCS
and inhibitory components excreted by the bacteria
were not involved in the inhibition. Therefore, the
detected inhibition is due to the adhesion of whole
probiotic bacterial cells or products released during
the incubation. The adhesion of the pathogens was
inhibited by 10^23% and it is di¤cult to estimate the
biological signi¢cance of the inhibition. However,
the infective doses of pathogens in general are relatively low and therefore even partial inhibition may
be important in preventing infection.
S. typhimurium adhesion was signi¢cantly
(P 6 0.001) increased by Lactobacillus GG and L.
rhamnosus (human isolate). Interestingly, only the
two strongly adhesive L. rhamnosus strains (Lactobacillus GG and L. rhamnosus (human isolate)) in-
141
creased the adhesion although all three L. rhamnosus
strains (including the poorly adhering L. rhamnosus
LC-705) were able to reduce E. coli SfaII adhesion.
Reid et al. [24] observed that type 1 ¢mbriated E.
coli coaggregated with L. casei spp. rhamnosus GR-1
and suggested the potential of lactobacilli to prevent
pathogenic adhesion in the urinary tract by coaggregation. Also intestinal lactobacilli have been shown
to coaggregate with pathogens, for example lactobacilli of porcine origin coaggregated with a porcine
pathogen (E. coli K88) [3], indicating that similar
prevention could be obtained in the intestine. Coaggregation was not observed between S. typhimurium
and Lactobacillus GG in the present study. However,
microscopic observations demonstrated that some of
the S. typhimurium and Lactobacillus GG cells were
attached to each other although the binding was not
strong enough to aggregate the bacteria. Further
studies are needed to clarify the mechanisms of the
interactions between S. typhimurium and adhering
probiotics, and the biological importance of the observed increase in adhesion needs to be investigated.
In conclusion, the tested bacteria showed a straindependent adhesion to intestinal glycoproteins. The
probiotics had di¡erent e¡ects on the subsequent
adhesion of S-¢mbriated E. coli and type 1 ¢mbriae
expressing S. typhimurium. This may imply that the
mechanisms for probiotic action depend on the probiotic and the pathogenic strain. In addition, intestinal glycoproteins were shown to provide a new model of human origin to investigate the interactions
between pathogens and probiotics at mucosal surfaces.
Acknowledgements
Mrs. Satu To«lkko« is thanked for skilful technical
assistance. This work was supported by the Academy
of Finland.
References
[1] Beachey, E.H. (1981) Bacterial adherence: adhesin-receptor
interactions mediating the attachment of bacteria to mucosal
surfaces. J. Infect. Dis. 143, 325^345.
[2] Finlay, B.B. and Falkow, S. (1997) Common themes in micro-
FEMSIM 1116 8-10-99
142
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
E.M. Tuomola et al. / FEMS Immunology and Medical Microbiology 26 (1999) 137^142
bial pathogenicity revisited. Microbiol. Mol. Biol. Rev. 61,
136^169.
Spencer, R.J. and Chesson, A. (1994) The e¡ect of Lactobacillus spp. on the attachment of enterotoxigenic Escherichia
coli to isolated porcine enterocytes. J. Appl. Bacteriol. 77,
215^220.
Blomberg, L., Henriksson, A. and Conway, P.L. (1993) Inhibition of adhesion of Escherichia coli K88 to piglet ileal mucus
by Lactobacillus spp. Appl. Environ. Microbiol. 59, 34^39.
Ouwehand, A.C. and Conway, P.L. (1996) Speci¢city of spent
culture £uids of Lactobacillus spp. to inhibit adhesion of enteropathogenic ¢mbriated Escherichia coli cells. Microb. Ecol.
Health Dis. 9, 239^246.
Chan, R.C.Y., Reid, G., Irvin, R.T., Bruce, A.W. and Costerton, J.W. (1985) Competitive exclusion of uropathogens from
human uroepithelial cells by Lactobacillus whole cells and cell
wall fragments. Infect. Immun. 47, 84^89.
Chauvie©re, G., Coconnier, M.-H., Kernëis, S., Darfeuille-Michaud, A., Joly, B. and Servin, A.L. (1992) Competitive exclusion of diarrheagenic Escherichia coli (ETEC) from human
enterocyte-like Caco-2 cells by heat-killed Lactobacillus.
FEMS Microbiol. Lett. 91, 213^218.
Bernet, M.-F., Brassart, D., Neeser, J.R. and Servin, A.L.
(1994) Lactobacillus acidophilus LA1 binds to cultured human
intestinal cell lines and inhibits cell attachment and cell invasion by enterovirulent bacteria. Gut 35, 483^489.
Kirjavainen, P.V., Ouwehand, A.C., Isolauri, E. and Salminen, S. (1998) The ability of probiotic bacteria to bind to
human intestinal mucus. FEMS Microbiol. Lett. 167, 185^
189.
Ouwehand, A.C., Isolauri, E., Kirjavainen, P.V. and Salminen, S.J. (1999) Adhesion of four Bi¢dobacterium strains to
human intestinal mucus from subjects in di¡erent age groups.
FEMS Microbiol. Lett., 172, 61^64.
Tuomola, E.M., Ouwehand, A.C. and Salminen, S.J. (1999)
Human ileostomy glycoproteins as a model for small intestinal
mucus to investigate adhesion of probiotics. Lett. Appl. Microbiol. 28, 159^163.
Hacker, J., Kestler, H., Hoschu«tzky, H., Jann, K., Lottspeich,
F. and Korhonen, T.K. (1993) Cloning and characterization
of the S ¢mbrial adhesin II complex of an Escherichia coli
O18:K1 meningitis isolate. Infect. Immun. 61, 544^550.
Salminen, S., Isolauri, E. and Salminen, E. (1996) Clinical
uses of probiotics for stabilising the gut mucosal barrier: successful strains and future challenges. Antonie van Leeuwenhoek 70, 347^358.
[14] Elo, S., Saxelin, M. and Salminen, S. (1991) Attachment of
Lactobacillus casei strain GG to human colon carcinoma cell
line Caco-2: comparison with other dairy strains. Lett. Appl.
Microbiol. 13, 154^156.
[15] Tuomola (nëe Lehto), E.M. and Salminen, S.J. (1998) Adhesion of some probiotic and dairy Lactobacillus strains to
Caco-2 cell cultures. Int. J. Food Microbiol. 41, 45^51.
[16] Deneke, C.F., McGowan, K., Larson, A.D. and Gorbach,
S.L. (1984) Attachment of human and pig (K88) enterotoxigenic Escherichia coli strains to either human or porcine small
intestinal cells. Infect. Immun. 45, 522^524.
[17] Glegg, S. and Swenson, D.L. (1994) Salmonella Fimbriae. In:
Fimbriae : Adhesion, Genetics, Biogenesis and Vaccines
(Klemm, P., Ed.), pp. 105^112. CRC Press, Boca Raton, FL.
[18] Lehto, E.M. and Salminen, S.J. (1997) Inhibition of Salmonella typhimurium adhesion to Caco-2 cell cultures by Lactobacillus strain GG spent culture supernate: only a pH e¡ect?
FEMS Immunol. Med. Microbiol. 18, 125^132.
[19] Craven, S.E. and Williams, D.D. (1998) In vitro attachment of
Salmonella typhimurium to chicken cecal mucus: e¡ect of cations and pretreatment with Lactobacillus spp. isolated from
the intestinal tracts of chickens. J. Food Protect. 61, 265^271.
[20] Korhonen, T.K., Valtonen, M.V., Parkkinen, J., Va«isa«nenRhen, V., Finne, J., Òrskov, F., Òrskov, I., Svenson, S.B.
and Ma«kela«, P.H. (1985) Serotypes, hemolysin production
and receptor recognition of Escherichia coli strains associated
with neonatal sepsis and meningitis. Infect. Immun. 48, 486^
491.
[21] Guerina, N.G., Kessler, T.W., Guerina, V.J., Neutra, M.R.,
Clegg, H.W., Langermann, S., Scannapieco, F.A. and Goldmann, D.A. (1983) The role of pili and capsule in the pathogenesis of neonatal infection with Escherichia coli K1. J. Infect. Dis. 148, 395^405.
[22] Ouwehand, A.C., Conway, P.L. and Salminen, S.J. (1995)
Inhibition of S-¢mbria-mediated adhesion to human ileostomy glycoproteins by a protein isolated from bovine colostrum. Infect. Immun. 63, 4917^4920.
[23] Korhonen, T.K., Ra«isa«nen-Rhen, V., Rhen, M., Pere, A.,
Parkkinen, J. and Finne, J. (1984) Escherichia coli ¢mbriae
recognising sialyl galactosides. J. Bacteriol. 159, 762^766.
[24] Reid, G., McGroarty, J.A., Angotti, R. and Cook, R.L.
(1988) Lactobacillus inhibitor production against Escherichia
coli and coaggregation ability with uropathogens. Can. J. Microbiol. 34, 344^351.
FEMSIM 1116 8-10-99