Shigella Flexneri 1b Research Articles

Safety and Immunogenicity of a 4-Component Generalized Modules for Membrane Antigens Shigella Vaccine in Healthy European Adults: Randomized, Phase 1/2 Study.

We report data from stage 1 of an ongoing 2-staged, phase 1/2 randomized clinical trial with a 4-component generalized modules for membrane antigens-based vaccine against Shigella sonnei and Shigella flexneri 1b, 2a, and 3a (altSonflex1-2-3; GSK). Europeans aged 18-50 years (N = 102) were randomized (2:1) to receive 2 injections of altSonflex1-2-3 or placebo at 3- or 6-month interval. Safety and immunogenicity were assessed at prespecified time points. The most common solicited administration-site event (until 7 days after each injection) and unsolicited adverse event (until 28 days after each injection) were pain (altSonflex1-2-3, 97.1%; placebo, 58.8%) and headache (32.4%; 23.5%), respectively. All serotype-specific functional IgG antibodies peaked 14-28 days after injection 1 and remained substantially higher than prevaccination at 3 or 6 months postvaccination; the second injection did not boost but restored the initial immune response. The highest seroresponse rates (≥4-fold increase in titers over baseline) were obtained against S. flexneri 2a (enzyme-linked immunosorbent assay [ELISA] after injection 1, 91.0%; after injection 2 [day 113; day 197], 100%; 97.0% and serum bactericidal activity [SBA] after injection 1, 94.4%; after injection 2, 85.7%; 88.9%) followed by S. sonnei (ELISA after injection 1, 77.6%; after injection 2, 84.6%; 78.8% and SBA after injection 1, 83.3%; after injection 2, 71.4%; 88.9%). Immune responses against S. flexneri 1b and S. flexneri 3a, as measured by both ELISA and SBA, were numerically lower compared to those against S. sonnei and S. flexneri 2a. No safety signals or concerns were identified. altSonflex1-2-3 induced functional serotype-specific immune responses, allowing further clinical development in the target population. Clinical Trials Registration . NCT05073003.

Exploring Natural Immune Responses to Shigella Exposure Using Multiplex Bead Assays on Dried Blood Spots in High-Burden Countries: Protocol From a Multisite Diarrhea Surveillance Study.

Molecular diagnostics on human fecal samples have identified a larger burden of shigellosis than previously appreciated by culture. Evidence of fold changes in immunoglobulin G (IgG) to conserved and type-specific Shigella antigens could be used to validate the molecular assignment of type-specific Shigella as the etiology of acute diarrhea and support polymerase chain reaction (PCR)-based microbiologic end points for vaccine trials. We will test dried blood spots collected at enrollment and 4 weeks later using bead-based immunoassays for IgG to invasion plasmid antigen B and type-specific lipopolysaccharide O-antigen for Shigella flexneri 1b, 2a, 3a, and 6 and Shigella sonnei in Shigella-positive cases and age-, site-, and season-matched test-negative controls from all sites in the Enterics for Global Health (EFGH) Shigella surveillance study. Fold antibody responses will be compared between culture-positive, culture-negative but PCR-attributable, and PCR-positive but not attributable cases and test-negative controls. Age- and site-specific seroprevalence distributions will be identified, and the association between baseline antibodies and Shigella attribution will be estimated. The integration of these assays into the EFGH study will help support PCR-based attribution of acute diarrhea to type-specific Shigella, describe the baseline seroprevalence of conserved and type-specific Shigella antibodies, and support correlates of protection for immunity to Shigella diarrhea. These insights can help support the development and evaluation of Shigella vaccine candidates.

Age-dependent acquisition of IgG antibodies to Shigella serotypes-a retrospective analysis of seroprevalence in Kenyan children with implications for infant vaccination.

Shigellosis mainly affects children under 5 years of age living in low- and middle-income countries, who are the target population for vaccination. There are, however, limited data available to define the appropriate timing for vaccine administration in this age group. Information on antibody responses following natural infection, proxy for exposure, could help guide vaccination strategies. We undertook a retrospective analysis of antibodies to five of the most prevalent Shigella serotypes among children aged <5 years in Kenya. Serum samples from a cross-sectional serosurvey in three Kenyan sites (Nairobi, Siaya, and Kilifi) were analyzed by standardized ELISA to measure IgG against Shigella sonnei and Shigella flexneri 1b, 2a, 3a, and 6. We identified factors associated with seropositivity to each Shigella serotype, including seropositivity to other Shigella serotypes. A total of 474 samples, one for each participant, were analyzed: Nairobi (n = 169), Siaya (n = 185), and Kilifi (n = 120). The median age of the participants was 13.4 months (IQR 7.0-35.6), and the male:female ratio was 1:1. Geometric mean concentrations (GMCs) for each serotype increased with age, mostly in the second year of life. The overall seroprevalence of IgG antibodies increased with age except for S. flexneri 6 which was high across all age subgroups. In the second year of life, there was a statistically significant increase of antibody GMCs against all five serotypes (p = 0.01-0.0001) and a significant increase of seroprevalence for S. flexneri 2a (p = 0.006), S. flexneri 3a (p = 0.006), and S. sonnei (p = 0.05) compared with the second part of the first year of life. Among all possible pairwise comparisons of antibody seropositivity, there was a significant association between S. flexneri 1b and 2a (OR = 6.75, 95% CI 3-14, p < 0.001) and between S. flexneri 1b and 3a (OR = 23.85, 95% CI 11-54, p < 0.001). Children living in low- and middle-income settings such as Kenya are exposed to Shigella infection starting from the first year of life and acquire serotype-specific antibodies against multiple serotypes. The data from this study suggest that Shigella vaccination should be targeted to infants, ideally at 6 or at least 9 months of age, to ensure children are protected in the second year of life when exposure significantly increases.

Whole genome sequencing of increased number of azithromycin-resistant Shigella flexneri 1b isolates in Ontario

Azithromycin (AZM) resistance among Shigella is a major public health concern. Here, we investigated the epidemiology of Shigella flexneri serotype 1b recovered during 2016–2018 in Ontario, to describe the prevalence and spread of AZM resistance. We found that 72.3% (47/65) of cases were AZM–resistant (AZMR), of which 95.7% (45/47) were among males (P < 0.001). Whole-genome based phylogenetic analysis showed three major clusters, and 56.9% of isolates grouped within a single closely-related cluster (0–10 ∆SNP). A single AZMR clonal population was persistent over 3 years and involved 67.9% (36/53) of all male cases, and none reported international travel. In 2018, a different AZMR cluster appeared among adult males not reporting travel. A proportion of isolates (10.7%) with reduced susceptibility to ciprofloxacin (CIP) due to S83L mutation in gyrA were AZM susceptible, and 71.4% reported international travel. Resistance to AZM was due to the acquisition of mph gene-bearing incFII plasmids having > 95% nucleotide similarity to pKSR100. Plasmid-borne resistance limiting treatment options to AZM, ceftriaxone (CRO) and CIP was noted in a single isolate. We characterized AZMR isolates circulating locally among males and found that genomic analysis can support targeted prevention and mitigation strategies against antimicrobial-resistance.

Production of highly immunogenic and safe Triton X-100 produced bacterial ghost vaccine against Shigella flexneri 2b serotype

BackgroundBacterial ghost cells (BGCs) are cells were drained of their genetic and cytoplasmic components. This work aimed to develop vaccine candidates against the Shigella flexneri (S. flexneri) 2b serotype using the BGCs approach. For the first time, (S. flexneri) 2b serotype BGCs vaccine was prepared by incubation with Triton X-100 (TX100) for only 12 h. Its safety and immunogenicity were compared to another vaccine produced using a previously used surfactant, namely Tween 80 (TW80). Scanning electron microscopy (SEM), cellular DNA, protein contents measurements, and ghost cell re-cultivation were used to confirm the successful generation of the BGCs. Immunogenicity was assessed through mice's intraperitoneal (IP) immunization followed by infection with S. flexneri ATCC 12022. Finally, histopathological examination was carried out.ResultsViable colony forming units (CFUs) of S. flexneri were counted from stool samples as well as homogenized colon tissues of the non-immunized challenged group. Immunized mice sera showed a significant increase in serum bactericidal activity of both preparations (TX100 = 40% and TW80 = 56%) compared to the non-immunized challenged group (positive control). The IgG levels of the bacterial ghost-vaccinated groups were four and three times greater for the TX100 and TW80 ghost vaccines, respectively, compared to that of the positive control; both bacterial ghost vaccines (BGVs) were safe and effective, according to the results of the safety check tests and histopathological analysis.ConclusionsWhen comparing the BGVs prepared using TX100 and TW80 methods, the use of TX100 as a new chemical treating agent for BGC production attained robust results in terms of shorter incubation time with the targeted cells and a strong immune response against S. flexneri 2b serotype ATCC 12022 in the IP challenge test. However, a clinical study is needed to confirm the efficacy and total safety of this novel vaccine.

Synthesis of bodipy-labeled bacterial polysaccharides and their interaction with human dendritic cells.

In this report, we describe the fluorescent labeling of bacterial polysaccharides (Escherichia coli O86:B7, Escherichia coli O19ab, Pseudomonas aeruginosa O10a10b, and Shigella flexneri 2b) at the "natural" amino group of their phosphoethanolamine moiety. Two protocols for labeling are compared: 1) on a scale of a few mg of the polysaccharide, with a dialysis procedure for purification from excessive reagents; and 2) on a scale of 0.1mg of the polysaccharide, with a simple precipitation procedure instead of dialysis. The microscale version is sufficient for comfortable cytofluorometric analysis. The resulting probes were found to specifically bind to human dendritic cells in a dose-dependent manner. The used limited set of polysaccharides did not allow us even to get close to understanding which dendritic cell-associated lectins and which cognate polysaccharide epitopes are involved in recognition, but the proposed microscale protocol allows to generate a library of fluorescent probes for further mapping of the polysaccharide specificity of the dendritic cells.

Functional and antigenspecific serum antibodies in mice after immunization with a candidate vaccine against Shigella flexneri 1b, 2a, 3a, 6, Y

Objective. To determine functional anti-LPS specific serum bactericidal antibody (SBA) and opsonophagocytic killing antibody (OPKA) activities in mice immunized with a pentavalent candidate vaccine against Shigella flexneri 1b, 2a, 3a, 6, Y (PF). Materials and Methods. (CBA x C57 B1/6) F1 mice were immunized with a PF. 14 days after the reimmunization, serum samples were collected and the level of specific IgG in them was determined by ELISA. The sera of mice immunized with individual modified lipopolysaccharides (mLPS), which are part of PF, were used for positive control. Serum from intact mice served as a negative control. The functional activity of serum antibodies was determined by the methods of SBA and OPKA assay. The result was evaluated by the percentage of bacteria killed. Results. In all experimental groups of mice, an increase in the titer of specific IgG is observed (p &lt; 0.05). The endpoint titer (ET) of anti-LPS S. flexneri 1b, 2a, 3a, 6, Y antibodies in the group of mice immunized with PF does not significantly differ from ET in the groups after immunizations with individual mLPS. At the same time, the indicators in the experimental groups are about 16 times higher than in the control. We determined a functional activity of S. flexneri-specific SBA and OPRA in mice immunized with PF. The rate of SBA killing was 54%, 66%, 35%, 60%, 60% for S. flexneri 1b, 2a, 3a, 6, Y serotypes, respectively. When OPKA killing in groups of immunized mice are 37%, 55%, 27%, 56%, 53% for S. flexneri 1b, 2a, 3a, 6, Y serotypes, respectively. Conclusions. PF induces the production of specific anti-LPS IgG comparable to its individual components. The sera from PF immunized mice contain functional antibodies. Serum bactericidal and opsonophagocytic assay are effective for use in a mouse model.

Public health and clinical implications of multidrug-resistant shigellosis cases in a reception centre for refugees/migrants, Greece, October-December 2019.

From October to December 2019, 18 shigellosis cases (median age: 4.3 years, range: 0-21) were identified in the Reception Center for refugees/migrants on the Greek island of Samos. Fifteen cases (83.3%) were Afghani. Median time from arrival to symptoms onset was 53 days (40-101). Isolates from 14 cases, serotyped as Shigella flexneri 1b, and from three cases, serotyped as S. sonnei phase S (I), presented a multidrug-resistant phenotype. S. flexneri 1b isolates also produced extended-spectrum β-lactamases. Shigella flexneri 2a isolate from the remaining case was resistant to sulfomethoxazole, trimethoprim and pefloxacin. Improvement of hygiene and strengthening of laboratory investigation is needed.

Shigellosis Outbreak Associated with Contaminated Well Water in a Rural Elementary School: Sichuan Province, China, June 7–16, 2009

ObjectivesWe investigated a shigellosis outbreak in an elementary school to identify the source of infection, mode of transmission and risk factors for illness.MethodsIn a case-control investigation, we compared the source of drinking water, consumption of untreated well water and suspected food items, and hygienic habits between case-students and randomly selected asymptomatic control-students, frequency-matched by class on a 1∶1 ratio.Results18% of the 533 students and no teachers developed Shigella. 52%(44/85) of case-students and 17% (12/71) of control-students drank untreated well water (OR = 2.3, 95% CI = 1.1–5.8); 47% (n = 40/85) of case-students and 14% (10/71) of control-students drank untreated water from Well A (OR = 3.7, 95% CI = 1.3–11). The odds ratio increased with the amount of untreated Well A water consumed (p = 0.035, χ2 test for trend). Rectal swabs from 5 of 6 case-students and water from Well A yielded Shigella flexneri 2b.ConclusionsThis shigellosis outbreak was caused by drinking untreated water from a well polluted by Shigella flexneri 2b.

Recovery and Characterization of Environmental Variants of Shigella flexneri from Surface Water in Bangladesh

Little is known about the distribution, survival, and transmission of Shigella in environmental surface waters. To gain more insight into the environmental biology of Shigella we isolated five bacterial strains serotyped as Shigella flexneri 2b from a freshwater lake in Bangladesh using a modified nutrient broth supplemented with nucleic acid bases. The biochemical properties of the isolates, including inability to ferment lactose and a negative lysine decarboxylase test, indicated common physiological characteristics with Shigella, but differed significantly from that of standard clinical strains. The isolates possessed the ipaH virulence gene and a megaplasmid, but lacked other Shigella-related virulence marker genes. Genetic fingerprinting and sequence analysis of housekeeping genes confirmed the strains as S. flexneri isolates. An apparent clonal origin of strains recovered with a one-year interval indicates a strong environmental selection pressure on Shigella for persistence in the freshwater environment. The lack of a complete set of virulence genes as well as uncommon biochemical properties suggest that these strains might represent a group of non-invasive and atypical environmental Shigella variants, with the potential for further elucidation of the survival mechanism, diversity, and emergence of virulent Shigella in tropical freshwater environments.

A pH‐Based High‐Throughput Screening of Sucrose‐Utilizing Transglucosidases for the Development of Enzymatic Glucosylation Tools

AbstractSucrose‐utilizing transglucosidases are valuable enzymatic tools for the diversification of carbohydrate‐based molecules. Among them, recombinant amylosucrase from Neisseria polysaccharea is a glucansucrase that naturally catalyzes the synthesis of an amylose‐like polymer as well as the transglucosylation of exogenous hydroxylated acceptors. A semirational engineering approach was recently undertaken to redesign the enzyme active site and adapt it to the glucosylation of a nonnatural acceptor, allyl 2‐N‐acetyl‐2‐deoxy‐α‐D‐glucopyranoside (α‐D‐GlcpNAcOAll), to produce a key building block in the chemoenzymatic synthesis of Shigella flexneri 1b serotype O‐antigen repeating unit. This prior work shows the beneficial effect of single amino acid mutations at two positions (228 and 290) on the recognition of the acceptor by amylosucrase. On the basis of these first results, a library of about 8000 amylosucrase variants combining mutations at these two positions is constructed by saturation mutagenesis. The library is prescreened using a novel pH‐sensitive colorimetric screening method for the detection of sucrose‐utilizing amylosucrase variants, thereby reducing by about 95 % the size of the library to be subsequently screened for acceptor glucosylation. Active clones (5 % of the initial library) are then screened for acceptor recognition, leading to the isolation of 20 variants of potential interest for the production of the target disaccharide α‐D‐Glcp‐(1→4)‐α‐D‐GlcpNAc.

Study on the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains

To study the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains. A series of primers were designed based on potential integration site of SfII and SfX prophages in Shigella flexneri serotype 2b strains, and PCR were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. PCR products were sequenced to identify integration sites and arrangement of SfII and SfX. In all the serotype 2b strains, prophage SfII and SfX were adjacent to each other, and integrated into the thrW tRNA gene of the host, which were located between genes proA and yaiC of host. Prophage SfX was located immediately upstream of prophage SfII in all the detected 50 serotype 2b strains exception for strain 51251. This was the first report on the integration site and arrangement of serotype-converting prophages SfII and SfX in Shigella flexneri 2b strains.

Plasmid-mediated quinolone resistance conferred by qnrS1 in Salmonella enterica serovar Virchow isolated from Turkish food of avian origin

To study the molecular characteristics of the quinolone and associated ampicillin resistance mechanisms present in Salmonella enterica serovar Virchow isolated from Turkish foods. Nine epidemiologically unrelated Salmonella Virchow strains isolated from foods (chicken and minced meat) sold in different markets in Ankara were analysed for their susceptibility to 17 antimicrobials. The strains were typed by PFGE and plasmid profiling and investigated by molecular methods (PCR/sequencing) for the presence of several resistance genes, class 1 integrons and mutations in the quinolone resistance-determining regions. Plasmids conferring quinolone resistance were analysed by restriction fragment length polymorphism (RFLP) analysis, DNA hybridization, sequencing, replicon-typing PCR and mating experiments. All strains showed nalidixic acid resistance (MIC >or= 128 mg/L) together with a decreased susceptibility to ciprofloxacin (three strains with an MIC of 1 mg/L and six with an MIC of 0.25 mg/L), associated with mutations within the gyrA gene (Asp-87 --> Tyr-87). In three strains, qnrS1 genes were detected. Ampicillin resistance encoded by a bla(CTX-M3) gene and/or bla(TEM-1-like) gene was found in four strains. Three of these strains carried an approximately 45 kb conjugative plasmid, designated pRQ2006, harbouring qnrS1 and a Tn3-like transposon. Partial sequencing and RFLP of pRQ2006 indicated its similarity to the qnrS1 plasmid pAH03786 found in a Japanese Shigella flexneri 2b isolate. This is the first study describing the presence of qnrS1 genes in bacterial isolates from Turkey. The pRQ2006 plasmid seems to be more related to the S. flexneri 2b qnrS1 plasmid pAH0376 than to the Salmonella qnrS1-carrying plasmids pINF5 and TPqnrS-2.

A Molecular Fingerprint Analysis of Shigella flexneri 1b in Bacillary Dysentery Outbreaks in a Nursing Home in Lungchi Township, Tainan County

A Molecular Fingerprint Analysis of Shigella flexneri 1b in Bacillary Dysentery Outbreaks in a Nursing Home in Lungchi Township, Tainan County

Population-based study of the incidence of Shigella diarrhea and causative serotypes in Santiago, Chile.

Shigella is an important cause of diarrheal disease in children in developing countries. The increasing prevalence of antibiotic-resistant strains has stimulated interest in the use of multivalent Shigella vaccines. Because Shigella vaccines under development are based on eliciting immunity to O antigens, monitoring the distribution of serotypes in defined target populations is critical. We initiated health center-based surveillance in a poor semirural community in Colina, Santiago (7489 children <60 months of age) to determine the age-specific incidence of Shigella disease and the responsible serotypes. Surveillance was maintained at the 2 health centers during warm seasons (November 1 through April 30) for 4 successive years (1994 to 1998). Shigella was recovered from 54 of 243 cases of dysentery (22%) and from 215 of 3966 cases of nondysenteric diarrhea (5.4%) (P < 0.001). The peak mean annual incidence of shigellosis occurred among children 12 to 47 months of age (9.0 to 12.6 cases/10(3) children), although the incidence in infants (5.2/10(3)) and children 48 to 59 months of age (6.2/10(3)) was also substantial. During the 1995 through 1996 season, an age-matched healthy control was cultured for every child <60 months of age with diarrhea. Shigella isolation from cases (34 of 576, 5.9%) was >8-fold higher than controls (4 of 576, 0.7%) (P < 0.01). Four serotypes, Shigella sonnei (45%), Shigella flexneri 2b (19%), S. flexneri 2a (14%) and S. flexneri 6 (11%), accounted for 89% of all cases. Shigella remains an important pediatric pathogen in Santiago. The serotype distribution from Colina, which closely resembles data from a population-based surveillance study in Santiago in the mid-1980s, demonstrates a remarkable degree of serotype stability in Santiago during a 15-year period.

Immune response against lipopolysaccharide and invasion plasmid-coded antigens of shigellae in Vietnamese and Swedish dysenteric patients

The peripheral immune responses of adult Vietnamese patients infected with Shigella dysenteriae 1 and Shigella flexneri 1b and 2a and those of S. flexneri-infected Swedish patients were studied against various lipopolysaccharide and invasion plasmid-coded antigens (Ipa-s) and compared with the titers for the corresponding local healthy populations. Both Vietnamese and Swedish patients reacted with significant (P, < 0.05) titer increases in the immunoglobulin A and G classes against the homologous lipopolysaccharide antigen. However, significant titer responses against the Ipa-s were seen among only the Swedish patients. We surmise that the weak-to-moderate responses against the Ipa-s in Vietnamese patients are due to the fact that the high level of titers induced by previous infections in the local population could not be considerably increased further by a recent infection.

Monoclonal antibodies against Salmonella porins: Generation and characterization

Monoclonal antibodies (mAbs) were generated against porins, one of the major outer membrane proteins of Salmonella typhi. Six clones, designated MP1, MP2, MP3 (IgG2ak), MPN4, MPN6 (IgG1k) and MPN5 (IgG2bk) were characterized by enzyme immunoassay (ELISA) for their reactivity to porins from S. typhi, Salmonella paratyphi A, S. paratyphi B, S. paratyphi C, Salmonella choleraesuis, Salmonella enteritidis, Salmonella krefeld, Salmonella panama, Salmonella typhimurium, Escherichia coli B, Shigella flexneri 1b and Pseudomonas aeruginosa. All the clones positive for S. typhi porins showed varying reactivity towards several Salmonella species. However, none of them was positive for porins from other Gram-negative bacteria or for lipopolysaccharide (LPS). The affinity constant of these mAbs, except MPN4, was found to be in the higher range. Dot ELISA revealed that the mAbs recognized porins only in their native form. The results of inhibition ELISA using horseradish peroxidase (HRP)-conjugated MP1 suggest that the clones MP1, MP2, MP3, MPN5 and MPN6 secreted antibodies to identical epitope(s) of a 36-kDa peptide and MPN4 to a different epitope of a 35-kDa peptide. The possible applications of these mAbs were discussed.

Monoclonal antibodies against the surface antigens of Shigella flexneri serotype 1b and Shigella dysenteriae serotype 1.

Monoclonal antibodies against the surface antigens of Shigella flexneri 1b and S. dysenteriae 1 were prepared. The specificities of the antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA), and quantitative agglutination using microtiter plate. Monoclonal antibodies against S. flexneri 1b, designated Sf2B2 and Sf2G4, belonged to IgG2a and IgG1 subclass, respectively. The former was specific for S. flexneri 1b, whereas the latter was reactive not only to S. flexneri 1b, but also weakly to 3a and 4b. Monoclonal antibody against S. dysenteriae 1, Sd5E1 (IgM), reacted with S. dysenteriae 1, 3, 6, 7, and S. boydii 2.

Effect of guinea pig or monkey colonic mucus on Shigella aggregation and invasion of HeLa cells by Shigella flexneri 1b and 2a.

The effects of guinea pig and rhesus monkey colonic mucus preparations on Shigella aggregation and invasion of HeLa cell monolayers by Shigella flexneri serotype 1b, 2a, and 5 strains were investigated. Guinea pig mucus caused agglutination of S. flexneri serotype 1b but not of S. flexneri serotype 2a or 5. Guinea pig mucus also inhibited HeLa cell invasion by S. flexneri serotypes 1b and 2a. Monkey mucus neither agglutinated any Shigella strain nor inhibited HeLa cell invasion.

Oligosaccharide structural specificity of the soluble agglutinin released from guinea pig colonic epithelial cells

Guinea pig colonic epithelial cells release a soluble lectin capable of agglutinating numerous strains of Shigella and Escherichia coli as well as other bacteria. Using pure oligosaccharides and glycopeptides with well-defined structures to inhibit the agglutination of Shigella flexneri 1b by the soluble intestinal lectin, we have been able to demonstrate that the latter recognises different structural types. Inhibition by human milk glucoprotein glycopeptides with biantennary glycans of the N-acetyllactosamine type was dependent on the simultaneous presence of unsubstituted terminal non-reducing galactose residues and of a fucose residue α-1,6-linked to the asparagine-conjugated N-acetylglucosamine residue. Unsubstituted terminal non-reducing galactose was also determinant for inhibition by human milk oligosaccharides. Finally oligosaccharides possessing the Man (α1–2) Man structure inhibited more effectively than those with a Man(α1–3)Man sequence. The fact that these different structural motifs were all inhibitory raises the problem of the possible existence of a multispecific lectin or of several different lectins in the guinea pig colonic mucosa mediating bacterial adherence.