Barbro Carlsson

Intestinal colonization with enterobacteriaceae in Pakistani and Swedish hospital-delivered infants.

ABSTRACT. Rectal cultures from Swedish and Pakistani hospital‐delivered newborn infants were analysed regarding the early aquisition of enterobacteria. Swedish infants were delivered vaginally, Pakistani infants were delivered either vaginally or by caesarean section. The Swedish infants were all breast‐fed, whereas breastfeeding was incomplete and often started late among the Pakistani infants. Both groups of Pakistani infants were more rapidly colonized with enterobacteria than were the Swedish infants. Cultures from Swedish infants seldom yielded more than one kind of enterobacteria; E. coli and Klebsiefla were most frequently isolated. E. coli dominated in both Pakistani groups, but especially caesarean section delivered infants were in addition often colonized with Proteus, Klebsiella, Enterobacter or Citrobacterspecies. Breastfeeding from the first day of life reduced colonization with Klebsiella/Enterobacter/Citrobucter.The results suggest that environmental exposure, delivery mode and early feeding habits all influence the early intestinal colonization with enterobacteria.

Appearance of secretory IgM and IgA antibodies to Escherichia coli in saliva during early infancy and childhood

Unstimulated whole saliva was collected from 203 uninfected individuals at various ages from birth until adulthood. Levels of specific antibodies against Escherichia coli O antigens of secretory IgA, secretory IgM and IgG, as well as total amounts of SIgA, were determined using ELISA. Levels of SIgA antibodies found in adults were approached by the age of 12 months, but high levels could be attained earlier, presumably in response to antigenic exposure at the mucosal level. During the first few months of life, secretory IgM antibodies appeared in the saliva, possibly compensating for the relative lack of IgA.

NEW KNOWLEDGE IN HUMAN MILK IMMUNOGLOBULIN

ABSTRACT. One of the anti‐infection principles of maternal milk is the predominant milk immunoglobulin, secretory IgA. This immunoglobulin contains antibodies against many pathogens and potential pathogens, viruses as well as bacteria, including several members of Enterobacteriacae, The antigenic stimuli for these milk antibodies seem to take place in the Peyers patches of the intestine. Lymphoid cells leaving the patches after antigenic exposure seem to home to the mammary glands via the lymph and blood circulation. As a result, the milk contains secretory IgA antibodies against, among other things, the intestinal bacteria of the mother. These milk antibodies might reflect the spectrum of bacteria and viruses in the community and may be important for the protection of the breast‐fed baby. Via the same homing mechanism the maternal milk obtains antibodies against dietary antigens, including cows milk proteins. Studies of infants on mixed feeding suggest that the secretory IgA antibodies against the bovine proteins diminish the antigenic exposure, indicating the possibility of an anti‐allergic mechanism.

Anti-idiotypic Antibodies to Poliovirus Antibodies in Commercial Immunoglobulin Preparations, Human Serum, and Milk

ABSTRACT: Our previous studies have suggested that fetal antibody production can be induced by maternal antiidiotypic antibodies transferred to the fetus via the placenta. We tested commercial Ig, sera, and milk for the presence of anti-idiotypic antibodies to polio virus type 1, using affinity chromatography combined with ELISA systems and virus neutralization techniques. Our results indicate that commercial Ig, serum, and milk samples contain antibodies recognizing idiotypic determinants on antibodies to poliovirus. Several lines of evidence support this conclusion. Thus, in an ELISA with poliovirus as a solid phase, binding of specific antibodies could be inhibited by addition of an eluate from the Ig preparation containing anti-idiotypic antibodies against poliovirus type 1. Also, antiidiotypic antibodies from pooled human Ig, serum, and colostrum samples against poliovirus bound directly to solid-phase-attached MAb against poliovirus type 1. In addition, in a competitive inhibition ELISA, where antiidiotypic antibodies isolated from the Ig preparation competed with the poliovirus antigen for binding to monoclonal or polyclonal idiotypic antibodies on the solid phase, inhibition of antigen binding was seen at low antigen concentrations. When single-donor serum or milk was used, this inhibition was even more pronounced and could be demonstrated at almost all antigen concentrations. The finding that anti-idiotypes are present in maternal serum and milk imply, in agreement with our previous studies, that antiidiotypes may actively induce a specific immune response in the fetus without previous exposure to the antigen by being transferred across the placenta or by being passively transferred to the newborn via mothers milk.

The antibody response in breast-fed and non-breast-fed infants after artificial colonization of the intestine with Escherichia coli O83

ABSTRACT: The local and systemic antibody response after oral administration of a nonenteropathogenic type 1 fimbriated Escherichia coli O83 strain was followed in nine breast-fed and eight formula-fed infants during their first 15 wk of life. Five breast-fed and six formula-fed infants were followed as controls. E. coli O83 was detected in the stools of colonized infants from d 2 after colonization and persisted in the intestine for up to 26 wk. The percentage of children successfully colonized with E. coli O83 was higher among breast-fed than among formula-fed colonized infants. Also, the O83 bacteria isolated from the breastfed children had a higher capacity to attach to colonic epithelial cells of the HT-29 cell line than those isolated from bottle-fed infants. E. coli O83 IgA and IgM antibodies estimated by ELISA were significantly elevated in the saliva of colonized as compared with control infants 2–7 wk after colonization. IgA antibodies against O83 were also higher in the stool of colonized formula-fed infants than in formula-fed controls. The results suggest that the mucosal immune system of the newborn infant can be triggered early to produce specific antibodies against bacteria colonizing the intestine.

Studies on Human Milk III. Secretory IgA Quantity and Antibody Levels against Escherichia coli in Colostrum and Milk from Underprivileged and Privileged Mothers

Summary: We studied the milk content of secretory IgA (SIgA) and of specific IgA antibodies to E. coli in relation to volume, in 24 h samples from mothers belonging to different socio-economic groups and living under different ecologic conditions in Ethiopia, Guatemala and Sweden. There were no statistically significant differences in the daily output of milk SIgA among the population groups investigated at different times after onset of lactation. There was, however, a certain trend towards lower SIgA levels among the Guatemalan poor women, compared to the corresponding privileged ones (Tables 2 and 3). Three days after delivery the underprivileged Ethiopian mothers showed significantly lower antibody levels than the privileged Ethiopian. These differences were no longer seen when the values were corrected for differences in volume (Table 5).One month after delivery, the levels of SIgA antibodies in milk from Swedish women and Guatemalan privileged women against a pool of eight E. coli somatic antigens were comparable; these two groups of mothers had significantly higher antibody levels than the Guatemalan rural and urban ones (Table 4). The same pattern was observed after correction for differences in 24 h volumes (Table 5).At 3 months after delivery, the Guatemalan urban privileged women, again showed higher levels and daily output of antibodies against the E. coli antigens than the urban poor and rural mothers (Tables 4 and 5). The milk samples taken from a population where malnutrition is evident, i.e., mothers from Santa María Cauqué, did not show any changes in the levels of SIgA and the anti-E. coli antibodies 3, 6 and 9 months after initiation of lactation. The data presented here provide evidence that chronically malnourished mothers are able to produce SIgA and transfer it to their offspring via breast milk. Furthermore, they do so in quantities that are comparable to those observed in well-nourished populations. There was a wide range of concentrations and daily output of SIgA and of specific antibodies in all groups, suggesting that some of the infants get less than others. The observed differences in levels of antibodies against E. coli may be explained by differences in exposure to E. coli strains of the eight serogroups studied here. The possibility of a deficiency in the SIgA antibody response in the undernourished mothers still remains unanswered.Speculation: After antigenic exposure in the Peyers patches, committed lymphocytes come from the intestine to the mammary gland, where they produce IgA antibodies. A certain transfer of IgA dimers via the circulation from the intestine to the mammary gland, is also possible. These antibodies are secreted in breast milk and reflect the intestinal exposure of the host to microorganisms and microbial products. It may be feasible to increase the protective potential of breast milk by local intestinal vaccination of pregnant and lactating women, or by parentera] booster following intestinal priming.

Presence of non-maternal antibodies in newborns of mothers with antibody deficiencies.

ABSTRACT: To explain the mechanism for induction and production of specific antibodies found in the newborn already at birth, without previous known exposure to the antigen, we chose a model that presumably excluded the possibility of specific antibodies being transferred from the mother to the fetus. Specific IgG, IgA, and IgM antibodies against Escherichia coli and poliovirus antigens were determined with ELISA in serum, saliva, and amniotic fluid from hypogammaglobulinemic and IgA-deficient mothers as well as in cord serum, saliva, and meconium from their offspring. All the mothers lacked IgA and some also lacked IgM antibodies, which were found in their healthy newborns. The amniotic fluid from a hypogammaglobulinemic mother lacking IgA contained small amounts of IgA antibodies, which were also found in the neonate, suggesting a fetal origin. There was evidence for the presence of antiidiotypic antibodies to poliovirus in the cord sera. We propose that idiotypic and/or antiidiotypic IgG antibodies transferred via the placenta from the mother to the fetus can initiate specific immune responses seen in the newborn. Thus, it may be that transplacental IgG not only passively protects the newborn, but also actively primes the fetus during fetal life via its content of idiotypic and/or antiidiotypic antibodies.

Multiresistant CTX-M-15 ESBL-producing Escherichia coli in southern Sweden: Description of an outbreak

An outbreak caused by a multiresistant Escherichia coli producing CTX-M-15 ESBL occurred during autumn 2005 and spring 2006 in Kristianstad, a town in southern Sweden. The outbreak comprised 27 cases and was related to an infectious diseases ward and a neighbouring long-term care facility. Our primary objective was to investigate the epidemiology in order to control the outbreak. In addition, we studied the time of carriage of multiresistant ESBL-producing Escherichia coli by follow-up samples and measured the frequency of carriage of ESBL-producing bacteria in the patient population admitted to the infectious diseases ward during autumn 2006. The outbreak described is one of the first caused by ESBL-producing Escherichia coli in Sweden. The source of the outbreak was not found. Infection control measures were reinforced in the outbreak situation, and epidemiological and microbiological methods, including PFGE typing, were used for analysis. The carriage time of multiresistant Escherichia coli was longer in several of the affected patients than has previously been reported. The longest carriage time to date is 33 months. This demonstrates the risk for new outbreaks unless strict infection control measures are implemented. Among the patients admitted to the ward during autumn 2006, 2.5% carried ESBL-producing enterobacteria.

Studies of human milk. II. Concentration of antibodies against Salmonella and Shigella in milk of women from different populations and the daily intake by their breast-fed infants.

ABSTRACT. The concentration in human milk of IgA antibodies against six Salmonella and two Shigella groups was determined in specimens obtained from Swedish and Guatemalan nursing mothers of three different socioeconomic levels. The daily intakes of milk antibodies by their children were also estimated. The results show that the concentrations of specific IgA antibodies in milk vary among the different population groups. There is, however, no difference in daily intake of specific IgA by the children.

Food antibodies in milk from Guatemalan women

This study investigates the presence of antibodies against food products in milk samples from 30 Guatemalan women of 3 different socioeconomic status: 10 rural poor, 10 urban poor, and 10 urban privileged. The 3 groups had varied dietary habits. Both the rural and urban poor mothers do not consume cows milk. Black beans are consumed more often by the urban groups while soy bean products are consumed by both rural and urban poor regularly. Milk samples were collected from the mothers. The volume of milk produced in a 24-hour period was estimated by weighing the children before and after every meal. The enzyme-linked immunosorbent assay (ELISA) described by Sohe-Akerlund et.al. was used in quantitating milk secretory immunoglobulin A (SIgA). A modification of the ELISA method was used to determine levels of specific IgA antibodies directed against cows milk, black beans and soybeans. The Wilcoxon rank sum test was used in statistical analysis. Comparable amounts of SIgA were produced by the 3 groups of mothers in a 24-hour period (p0.1). The urban privileged mothers exhibited significantly higher antibody levels against cows milk (p0.01) and black beans (p0.05) compared to the other 2 groups. There were no differences in the level of anti-soybean antibodies among the 3 groups. The notion that antibodies found in the breast milk reflect the mothers intestinal antigenic experience is supported by this study. It has been suggested that anti-food protein antibodies contribute in the prevention of allergies. If so, cows milk fed among the rural and urban poor children may be expected to produce negative reactions. This negative reaction can be prevented by feeding the mother, before delivery, cows milk products to induce them to produce milk antibodies against cows milk.