[The interaction between food, nutritional status, metabolism and orally administered antimicrobial agents].
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Administration, Oral↗
Biomedical subjects
J Verhoef
Publications and source records attributed to J Verhoef.
Effect of iron on serotypes and haemagglutination patterns of Escherichia coli in bottle-fed infants.
Strains of Escherichia coli isolated from faecal specimens of ten infants receiving breast milk, six receiving a cow-milk preparation with iron supplement (5 mg/l) and six the preparation without iron supplement (less than 0.5 mg/l), were serotyped and examined for their haemagglutinating activity. The Escherichia coli flora of breast-fed and bottle-fed infants consisted of one resident strain, accompanied by one or more transient strains. Changes in the serotype of the Escherichia coli flora and in the frequency of occurrence of strains associated with urinary tract infections were more often seen in bottle-fed than in breast-fed infants. In breast-fed and bottle-fed infants without iron supplement most strains of Escherichia coli were non-haemagglutinating, while most strains in infants bottle-fed with iron supplement showed mannose-resistant haemagglutination. It is concluded that human milk favours the establishment of a stable non-pathogenic Escherichia coli flora and that a low iron content in standard cow-milk preparation favours colonization with non-adherent strains of Escherichia coli.
Animals↗
Interaction between ciprofloxacin and tobramycin or azlocillin against multiresistant strains of Acinetobacter anitratum in vitro.
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Acinetobacter↗
Effect of iron on neonatal gut flora during the first three months of life.
To study the effect of milk supplemented with iron on neonatal gut flora, faecal specimens of ten infants receiving breast milk, six receiving a cow-milk preparation supplemented with iron (5 mg/l) and seven receiving the same product without iron supplement (iron concentration less than 0.5 mg/l) were examined during the first 12 weeks of life. In breast-fed infants bifidobacteria was predominant, counts of Escherichia coli were low, and other bacteria were rarely present. Infants receiving fortified cow-milk preparation had high counts of Escherichia coli, counts and isolation frequency of bifidobacteria were low and other bacteria were frequently isolated. In those on unfortified cow-milk preparation isolation frequency of Escherichia coli, bifidobacteria and bacteroides was comparable with that in breast-fed infants; however, counts of Escherichia coli were high. It is concluded that the faecal flora of infants fed unfortified cow-milk preparation acquires characteristics of that found in breast-fed infants.
Animals↗
Effect of chlorhexidine and acetic acid on phagocytosis by polymorphonuclear leucocytes.
The effect of two disinfectants, chlorhexidine and acetic acid, on host leucocytes and bacteria was studied. At a concentration of 50 mg/l, chlorhexidine was found to be bactericidal without interfering with leucocyte function. A concentration of 500 mg/l of acetic acid was neither leucotoxic nor bactericidal. Effects equivalent to the aforementioned were achieved in serum by increasing the chlorhexidine concentration by a factor of 20 and the acetic acid concentration by a factor of 5. Acetic acid reduced leucocyte function more rapidly than it killed bacteria. On the basis of these findings, chlorhexidine is to be preferred for local application in burn wounds to prevent colonisation and infection.
Acetates↗
Effect of iron on neonatal gut flora during the first week of life.
Faecal specimens from 23 infants during the first week of life were compared. Ten infants received breast milk, six received cow-milk preparation supplemented with iron (+/- 5 mg/l) and seven unfortified cow-milk preparation (iron concentration less than 0.5 mg/l). Those on breast milk had low faecal pH, high counts of bifidobacteria and low counts of Enterobacteriaceae, bacteroides and clostridia. Infants receiving fortified cow-milk preparation had a high faecal pH and high counts of Enterobacteriaceae and putrefactive bacteria such as bacteroides and clostridia. Counts of bifidobacteria were also high. In those on unfortified cow-milk preparation a slow rise was observed in counts of Enterobacteriaceae followed by an increase in counts and isolation frequency of bifidobacteria: the latter was still rising on day 7. It is concluded that a low iron content in standard preparations of cow's milk enhances resistance of the neonatal gut to colonization.
Bacteria↗
Testing phagocytic cell function.
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Blood Bactericidal Activity↗
Cardiopulmonary bypass and host defense functions in human beings: I. Serum levels and role of immunoglobulins and complement in phagocytosis.
In patients undergoing open-heart surgical procedures, the serum levels of immunoglobulins and complement were determined as well as the functional capacity of these defense proteins as opsonins to facilitate phagocytosis by polymorphonuclear leukocytes. A considerable decrease in serum levels of the proteins studied was found after cardiopulmonary bypass (CPB). As a result, the opsonic capacity of post-CPB plasma was diminished. After correction for hemodilution, however, no difference between pre- and post-CPB plasma, as measured by the activity of thermolabile (e.g., complement C3) and thermostabile (e.g., immunoglobulin IgG) opsonins, could be demonstrated. It is concluded that CPB causes a quantitative but no functional decrease in levels of IgG and C3.
Adult↗
Activation and inhibition of Hageman factor-dependent pathways and the complement system in uncomplicated bacteremia or bacterial shock.
Levels of components of the contact activation, coagulation, and complement systems and their main inhibitors were measured in 45 critically ill patients during 61 episodes of uncomplicated bacteremia or bacterial shock. Levels of Hageman factor (factor XII), prekallikrein, high-molecular-weight kininogen, factor XI, factor VII, total hemolytic complement, alternative pathway activity, and C3 were within the normal range during uncomplicated bacteremia (n = 29), but during fatal bacterial shock (n = 13) a significant decrease by 40%-50% was observed in all measurements. During nonfatal bacterial shock (n = 19) a moderate decrease was observed in most of these measurements. The capacity of plasma to inactivate kallikrein was significantly higher during bacteremia than during bacterial shock because of a significant increase in the level of C1 esterase inhibitor. Levels of antithrombin III and alpha 2-macroglobulin were below normal in all groups. Thus increased inhibition of the contact activation and complement systems is beneficial during bacteremia.
Angiotensin III↗
Ciprofloxacin for selective decontamination of the alimentary tract in patients with acute leukemia during remission induction treatment: the effect on fecal flora.
Ciprofloxacin, a new quinolone derivative, was given prophylactically (500 mg twice a day) to 15 patients with acute leukemia during remission induction treatment for a mean duration of 42 days. The effect on the microbial flora of the alimentary tract was evaluated. A rapid elimination of Enterobacteriaceae within three to five days was observed. Bacteroides and Clostridium species were not affected, but the number of anerobic nonsporeforming gram-positive bacilli and anaerobic cocci was decreased. Nine ciprofloxacin-resistant gram-negative rods (Pseudomonas and Acinetobacter species) were isolated but without colonization or subsequent infection. Four of the five bacteriologically documented infections in these patients were caused by gram-positive cocci. Ciprofloxacin was well tolerated, and no side effects were noticed.
Acinetobacter↗
Induction of the early hypotensive phase by Escherichia coli: role of bacterial surface structures and inflammatory mediators.
An early hypotensive phase was induced in rats by different strains of Escherichia coli and cell wall fractions to study the role of the bacterial surface structure, the complement system, histamine, and serotonin in induction of hypotension. E. coli strains with only core glycolipid (E. coli strain J5) or with intact lipopolysaccharide O antigens on their surface induced hypotension and thrombopenia within 5 min after intravenous administration. This response was reduced by prior decomplementation of the rats and by methysergide, a serotonin antagonist. Two K antigen-positive strains induced no hypotension except after removal of K antigen. The isolated lipopolysaccharide fractions and the lipid A subfractions, but not the polysaccharide subfractions, were also able to induce hypotension. Thus the core glycolipid structure, by interactions that involve platelets and the complement system, is mainly responsible for induction of an early hypotensive phase in rats, and K antigens interfere with this response.
Animals↗
Opsonic defense to Staphylococcus epidermidis in the premature neonate.
The determinants of opsonic defense to Staphylococcus epidermidis were studied in 47 premature newborns. Opsonic activity for S. epidermidis in serum from premature newborns proved to be proportional to gestational age (r = .664, P less than .001). The level of IgG antibodies to staphylococcal peptidoglycan in neonatal sera was similarly proportional to gestational age (r = .604, P less than .001). However, all opsonic activity of premature neonatal serum proved to be heat labile, i.e., dependent on activation of complement. Thus, no heat-stable, IgG-dependent opsonic activity to S. epidermidis was detected in any of the preterm sera, despite the presence of IgG antibodies to peptidoglycan. Further studies with purified IgG isolated from paired sera from term neonates and their mothers revealed that at similar concentrations the opsonic activity to S. epidermidis of neonatal, transplacentally derived IgG was only 26% of the activity of maternal IgG, a finding that may explain the absence of heat-stable opsonic activity in preterm newborns.
Antibodies, Bacterial↗
Microbiologic risk of invasive hemodynamic monitoring in patients undergoing open-heart operations.
The microbiologic risk of invasive hemodynamic monitoring was studied prospectively in 574 patients undergoing open-heart surgery under cover of cephalothin prophylaxis. Of a total of 2277 catheters inserted in these patients, 1.5% yielded positive cultures. The rate of positive cultures was not significantly different between percutaneous and surgically placed catheters (1.7% vs. 0.8%, respectively). Specifically, the incidence of positive catheter tips for intravenous, central venous, arterial, and pulmonary artery catheters was 1.1%, 3.9%, 1.5%, and 2.1%, respectively; while the corresponding rates for surgically inserted right atrial and left atrial catheters were 0.8% and 0, respectively. Pulmonary artery catheters had a significantly (p less than .01) higher incidence of positive catheter tips after 72 h in situ. However, there was no relationship between the in situ time and the incidence of positive tips for arterial and intravenous catheters. Although the rate of positive catheter tip cultures was low, it affected 4.9% of the patients. Nevertheless, no patient developed catheter-related septicemia or endocarditis, and the data generally supported the microbiologic safety of invasive hemodynamic monitoring in patients undergoing open-heart surgery.
Bacterial Infections↗
Damage to chromosomal and plasmid DNA by toxic oxygen species.
Bacterial DNA was incubated with xanthine plus xanthine oxidase plus excess iron as an oxygen-species-generating system, and DNA injury was measured by agarose gel electrophoresis and by the ability of the DNA to transform competent bacteria. After 5 to 10 min incubation, the covalently closed circular form of plasmid DNA was converted into the open circular form, and after 30 min, to some extent into the linear form. Biological activity, measured as the number of transformed bacteria, decreased rapidly after 10 min incubation. Incubation of chromosomal DNA with the enzymic oxygen-species-generating system resulted in the degradation of DNA to small fragments within about 1 h. Excess iron was essential for the damaging effect of xanthine plus xanthine oxidase. Damage to DNA could be prevented by oxygen scavengers such as superoxide dismutase, catalase, mannitol and thiourea. Our results suggest that hydroxyl radical is the injurious oxidant for bacterial DNA, and that it can mediate physicochemical as well as biological alterations in DNA.
Chromosomes, Bacterial↗
Interactions between human polymorphonuclear leukocytes and influenza virus.
The effects of influenza virus A (H3N2) on several functions of human polymorphonuclear leukocytes (PMN) were examined. Incubation of PMN with virus induced chemiluminescence, aggregation, and degranulation of the leukocytes. The amount of chemiluminescence generated increased from 1 X 10(6) to 6 X 10(6) cpm when 2.5 X 10(6) to 2 X 10(7) virus particles were added to 2.5 X 10(6) PMN. Maximal aggregation occurred within 2 min and the response depended on the amount of virus added to the PMN. Release of acid phosphatase by virus-treated PMN was 62 +/- 12% within 1 h compared with 7 +/- 7% by control PMN (P less than 0.005). Incubation of PMN with influenza virus resulted in a diminished phagocytic activity of the phagocytes. PMN from a patient with chronic granulomatous disease were similarly affected. It was thus concluded that the observed defect in phagocytic activity was not due to the reactive oxygen species generated by the PMN during incubation with virus.
Cell Aggregation↗
Phagocytosis of staphylococci by human polymorphonuclear leukocytes is enhanced in the presence of endothelial cells.
The role of various surfaces in the phagocytosis of Staphylococcus aureus by human polymorphonuclear leukocytes (PMN) was studied. Uptake of both opsonized and unopsonized staphylococci on the surface of a monolayer of human venous endothelial cells was compared with uptake on an inert plastic surface, with an assay that uses radiolabeled bacteria. Uptake of unopsonized S. aureus was threefold higher on the endothelial cell surface than on the plastic surface and was followed by efficient killing of the phagocytosed staphylococci. Uptake of unopsonized S. aureus on endothelial cells was not inhibited by treatment of the PMN with pronase or 2-deoxy-D-glucose and was only partially inhibited by cytochalasin B treatment of the PMN. The supporting effect of endothelial cells on the phagocytosis of unopsonized S. aureus was not due to opsonization of the bacteria by immunoglobulin or complement from the endothelial cell surface, nor to coating with fibronectin.
Adhesiveness↗
Detection of antibodies against lipopolysaccharides of Escherichia coli and Salmonella R and S strains by immunoblotting.
Antisera raised against several smooth and rough strains of Escherichia coli and Salmonella typhimurium were tested against lipopolysaccharides (LPS) of homologous and heterologous strains. The LPS were separated by sodium dodecyl sulfate-gel electrophoresis, transferred to nitrocellulose paper, and overlaid with antisera. The results showed that antisera raised against smooth strains reacted with high- as well as low-molecular-weight bands of their corresponding LPS and showed very few cross-reactions. Anti-E. coli J5 antiserum cross-reacted with few strains in the core region. But, anti-S. typhimurium Ra antiserum cross-reacted with many more strains. When these sera were absorbed with either the homologous- or a heterologous-positive strain, reactions were abolished. It appears that reactions of anti-E. coli J5 antiserum and anti-S. typhimurium Ra antiserum with homologous and heterologous strains were not due to the same antibody. This immunoblotting technique proved to be a useful method to distinguish different antibodies in antiserum raised against LPS of gram-negative bacteria.
Animals↗
Electron microscopic study of phagocytosis of Escherichia coli by human polymorphonuclear leukocytes.
The fate of Escherichia coli strains within the polymorphonuclear leukocytes was studied by determining the killing of bacteria, measuring the release of degradation products, and examining the phagocytic bacteria by electron microscopy. When sufficiently opsonized, both unencapsulated and encapsulated E. coli strains were rapidly phagocytized by polymorphonuclear leukocytes. Once phagocytized, the two unencapsulated E. coli strains (K-12 and O111) were rapidly killed (99% of the bacteria were killed during the first 5 min of phagocytosis) and extensively degraded (about 40% of the radiolabeled material was released from bacteria after 15 min of phagocytosis). Electron micrographs taken after 15 min of phagocytosis revealed extensive structural changes in most of the internalized bacteria. In contrast to the rapid killing and extensive breakdown of these strains, encapsulated E. coli O78:K80 was more resistant to killing and withstood degradation by polymorphonuclear leukocytes (only 5% of the radioactivity was released from the radiolabeled bacteria after 1 h of phagocytosis). Electron micrographs of thin sections taken after 1 h of phagocytosis revealed virtually no structural changes. Most of the internalized bacteria were still surrounded by thick capsular material.
Antigens, Bacterial↗