The role of fetal inflammatory response syndrome and fetal anemia in nonpreventable term neonatal encephalopathy.

OBJECTIVE: To evaluate asphyxial patterns in term encephalopathic newborns caused by chorioamnionitis or intrapartum blood loss that resulted in cerebral palsy and allegations of obstetrical professional liability. STUDY DESIGN: As an expert witness, JKM identified term newborns with profound neurologic impairment: 18 born in the presence of chorioamnionitis and 14 with significant anemia. RESULT: In both study groups, profound depression with low 10-min Apgars was associated with early-onset seizures (88%), multiorgan failure (94%) and a partial prolonged injury to the cortex and subcortical white matter (94%). A cord arterial pH>7.00 was noted in 68% and deep gray matter injury involving the basal ganglia and thalamus occurred in only 19% of the newborns studied. CONCLUSION: The cord arterial pH and pCO2 values, early-onset seizures and paucity of isolated deep gray matter injury support that significant injury occurred postnatally despite appropriate resuscitation. This unique pattern may refute allegations of obstetrical mismanagement in the intrapartum period.

Heat treatment enhances the antimicrobial activity of (+)-Catechin when combined with copper sulphate.

UNLABELLED: The aim of the study was to compare the antimicrobial activities of freshly made, heat-treated (HT) and 14 day stored (+)-Catechin solutions with (+)-catechin flavanol isomers in the presence of copper sulphate. (+)-Catechin activity was investigated when combined with different ratios of Cu(2+) ; 100°C heat treatment; autoclaving; and 14 day storage against Staphylococcus aureus. Cu(2+) -(+)-Catechin complexation, isomer structure-activity relationships, and H2 O2 generation were also investigated. Freshly made, HT, and 14 day stored flavanols showed no activity. While combined Cu(2+) -autoclaved (+)-Catechin and -HT(+)-Catechin activities were similar, HT(+)-Catechin was more active than either freshly made (+)-catechin (generating more H2 O2 ) or (-)-Epicatechin (though it generated less H2 O2 ) or 14 day-(+)-Catechin (which had similar activity to Cu(2+) controls-although it generated more H2 O2 ). When combined with Cu(2+) , in terms of rates of activity, HT(+)-Catechin was lower than (-)-Epigallocatechin gallate and greater than freshly made (+)-Catechin. Freshly made and HT(+)-Catechin formed acidic complexes with Cu(2+) as indicated by pH and UV-vis measurements although pH changes did not account for antimicrobial activity. Freshly made and HT(+)-Catechin both formed Cu(2+) complexes. The HT(+)-Catechin complex generated more H2 O2 which could explain its higher antimicrobial activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Natural products attract considerable attention in the search for novel antimicrobials, prebiotics and antioxidants. Enhanced biological activity of natural products has been demonstrated with chemical and heat treatment. This article extends the few publications on heat treatments of plant products and combinations with adjuncts, to raise antimicrobial activity against pathogens such as Staphylococcus aureus. We demonstrated that heat treatment could increase the activity of (+)-Catechin, a weak antimicrobial flavanol found commonly in plants in the presence of copper sulphate. Heat treatment of readily available resources merits consideration in the development of more potent substances for use in clinical settings and agriculture.

Cattle, weather and water: mapping Escherichia coli O157:H7 infections in humans in England and Scotland.

Entero-haemorrhagic Escherichia coli O157:H7 is a zoonotic pathogen, responsible for a relatively small number of food poisoning and illness outbreaks each year, when compared with other food-borne bacteria capable of causing infections in the population. Nevertheless, E. coli O157:H7 is a bacterial pathogen associated with severe human illnesses including bloody diarrhoea and haemolytic uremic syndrome occurring in both outbreak and sporadic settings. In England and Wales approximately 1% of all laboratory-confirmed cases of food poisoning are the result of E. coli O157:H7; however, in Scotland this figure increases to 3%. When the size of the population is taken into account and the rate of E. coli O157:H7 confirmed cases per 100,000 population is examined, the rate of E. coli 0157:H7 infections in Scotland is much greater than England and Wales. The routes of transmission have changed over time, with new routes of transmission such as farm visits emerging. The prevalence of E. coli O157:H7 has a seasonal dependency, with greater faecal shedding of the organism in the warmer months; this is directly mirrored in the increased reporting of E. coli O157:H7 infection among hospitalized patients. This review attempts to suggest why this phenomenon occurs, paying particular attention to weather, animal movement and private water supplies.

Antimicrobial pomegranate rind extracts: enhancement by Cu(II) and vitamin C combinations against clinical isolates of Pseudomonas aeruginosa.

Recently, natural products have been further evaluated as sources of antimicrobial agents with efficacies against a variety of microorganisms. This study reports the antimicrobial activities of pomegranate rind extract (PRE) in combination with Fe(II) and Cu(II) salts against extended-spectrum multidrug-resistant Pseudomonas aeruginosa. Antimicrobial suspension assays were carried out using aqueous extract of pomegranate alone or in combination with metals salts against P. aeruginosa. The extract:metal salt combination was also enhanced with the addition of vitamin C. Marked activities were observed for the aqueous PRE/Cu(II) preparations, which were greatly enhanced by the addition of the reductant vitamin C. In contrast, the aqueous PRE/Fe(II) preparations were inactive, regardless of addition of vitamin C. The combination of PRE and Cu(II) salts and vitamin C showed the greatest activity against clinical isolates of P. aeruginosa. These results warrant further investigation of PRE as a potential source of new antimicrobial agents.

Predicting the thermal inactivation of bacteria in a solid matrix: simulation studies on the relative effects of microbial thermal resistance parameters and process conditions.

A combined mathematical model for predicting heat penetration and microbial inactivation in a solid body heated by conduction was tested experimentally by inoculating agar cylinders with Salmonella typhimurium or Enterococcus faecium and heating in a water bath. Regions of growth where bacteria had survived after heating were measured by image analysis and compared with model predictions. Visualisation of the regions of growth was improved by incorporating chromogenic metabolic indicators into the agar. Preliminary tests established that the model performed satisfactorily with both test organisms and with cylinders of different diameter. The model was then used in simulation studies in which the parameters D, z, inoculum size, cylinder diameter and heating temperature were systematically varied. These simulations showed that the biological variables D, z and inoculum size had a relatively small effect on the time needed to eliminate bacteria at the cylinder axis in comparison with the physical variables heating temperature and cylinder diameter, which had a much greater relative effect.

Emergence of variants with altered survival properties in stationary phase cultures of Campylobacter jejuni.

During the stationary phase of Campylobacter jejuni NCTC 11351 viable numbers fluctuate in a characteristic fashion. After reaching the maximum cell count (ca. 2 x 10(9) CFU/ml) in early stationary phase (denoted phase 1), viable numbers subsequently decrease to about 10(6) CFU/ml after 48 h and then increase again to about 10(8) CFU/ml (denoted phase 2) before decreasing once more to a value intermediate between the previous maximum and minimum values. To investigate whether the increase in viable numbers following the initial decline was due to the emergence of a new strain with a growth advantage in stationary phase analogous to the 'GASP' phenotype described in Escherichia coli [Science 259 (1993) 1757], we conducted mixed culture experiments with cells from the original culture and antibiotic-resistant marked organisms isolated from the re-growth phase. In many experiments of this type, strains isolated from phase 2 failed to out-compete the original strain and we have thus been unable to demonstrate a convincing GASP phenotype. However, strains isolated from phase 2 showed a much lower rate of viability loss in early stationary phase and a small increase in resistance to aeration, peroxide challenge and heat, indicating that the emergent strain was different from the parent. These results support the view that dynamic population changes occur during the stationary phase of C. jejuni that may play a role in the survival of this organism.

Description of a "phoenix" phenomenon in the growth of Campylobacter jejuni at temperatures close to the minimum for growth.

When Campylobacter jejuni cultures that had been grown in broth at 39 degrees C were subcultured into fresh medium at 30 degrees C, there was a transient period of growth followed by a decline in viable-cell numbers before growth resumed once more. We propose that this complex behavior is the net effect of the growth of inoculum cells followed by a loss of viability due to oxidative stress and the subsequent emergence of a spontaneously arising mutant population that takes over the culture.

Survival of Campylobacter jejuni during stationary phase: evidence for the absence of a phenotypic stationary-phase response.

When Campylobacter jejuni NCTC 11351 was grown microaerobically in rich medium at 39 degrees C, entry into stationary phase was followed by a rapid decline in viable numbers to leave a residual population of 1% of the maximum number or less. Loss of viability was preceded by sublethal injury, which was seen as a loss of the ability to grow on media containing 0.1% sodium deoxycholate or 1% sodium chloride. Resistance of cells to mild heat stress (50 degrees C) or aeration was greatest in exponential phase and declined during early stationary phase. These results show that C. jejuni does not mount the normal phenotypic stationary-phase response which results in enhanced stress resistance. This conclusion is consistent with the absence of rpoS homologues in the recently reported genome sequence of this species and their probable absence from strain NCTC 11351. During prolonged incubation of C. jejuni NCTC 11351 in stationary phase, an unusual pattern of decreasing and increasing heat resistance was observed that coincided with fluctuations in the viable count. During stationary phase of Campylobacter coli UA585, nonmotile variants and those with impaired ability to form coccoid cells were isolated at high frequency. Taken together, these observations suggest that stationary-phase cultures of campylobacters are dynamic populations and that this may be a strategy to promote survival in at least some strains. Investigation of two spontaneously arising variants (NM3 and SC4) of C. coli UA585 showed that a reduced ability to form coccoid cells did not affect survival under nongrowth conditions.

Factors associated with recurrent hospitalization in chronically ill children and adolescents.

OBJECTIVES: To determine factors associated with recurrent hospitalization in children with chronic illnesses in the Barwon Region. METHODOLOGY: Patients with four or more admissions to the Geelong Hospital children's ward over a 12-month period were identified. Their records were reviewed and the opinions of involved staff (medical, nursing, psychiatry, psychology, and social work) were sought. Multidisciplinary discussions were held to identify factors precipitating or maintaining the need for hospitalization. The numbers, illnesses and profiles of those admitted recurrently were compared with the data from the Barwon Paediatric Consultation Profile from the same period, and with those patients seen by the local counselling service for young people with chronic illnesses. RESULTS: Twenty-seven children had four or more admissions over the 12 months; these represent 0.05% of the child population regionally, or 2% of those with chronic illness. They account for 8.7% of hospital admissions and 16% of inpatient days. Two-thirds (18/27) had major psychosocial issues largely responsible for their admissions. A checklist was formulated of important medical, family, social, psychological, developmental, and institutional considerations. The most frequently identified psychosocial issues were medical dependency, psychological or medical problems affecting other family members, family and medical disparity regarding the treatment agenda, the lack of more intensive community supports, and medical controversy regarding best management. CONCLUSIONS: Ongoing medicalization and medical dependency, driven both by staff and families, can perpetuate recurrent hospitalization. Further awareness and training in these issues and development of community resources will be necessary if this process is to be changed.

Lactate and acetate production in Listeria innocua.

Listeria innocua NCTC 11289 was grown aerobically in continuous culture in defined media at 30 degrees C. Both acetate and lactate were produced, the proportion of acetate decreased with increasing dilution rate. Enzymatic analysis showed lactate dehydrogenase was activated 10-fold by fructose-1, 6-bisphosphate. The presence of phosphate acetyltransferase and acetate kinase but not pyruvate oxidase was detected, suggesting the sequential action of phosphate acetyltransferase and acetate kinase to produce acetate from acetyl CoA via acetylphosphate.

Transport of glycine-betaine by Listeria monocytogenes.

Uptake of [14C]glycine-betaine by Listeria monocytogenes was stimulated by NaCl with optimal stimulation at 0.4-0.5 M. The glycine-betaine transport system had a Km of 22 microM and a Vmax of 11.7 nmol-1 min-1 mg-1 protein when grown in the absence of NaCl. When grown in the presence of 0.8 M NaCl the Vmax increased to 27.0 nmol-1 min-1 mg-1 protein in 0.8 M NaCl. At NaCl concentrations above 0.5 M the uptake rate of glycine-betaine was reduced. Measurement of intracellular K+ concentrations and fluorescent dye quenching indicated that higher NaCl concentrations also led to a decrease in the electrochemical potential difference across the cytoplasmic membrane. Uptake of glycine was also observed, but this was not stimulated by NaCl.

Effect of sodium chloride on the intracellular solute pools of Listeria monocytogenes.

The concentrations of intracellular solutes in Listeria monocytogenes were examined in cells grown at various concentrations of NaCl. At 5% NaCl, cells contained elevated concentrations of potassium and glycine betaine compared with concentrations in cells grown without NaCl. At 7.5% NaCl, cells contained increased concentrations of K+, glycine betaine, glycine, alanine, and proline. Only glycine betaine, choline, or glycine promoted growth on a solidified defined medium containing 4% NaCl; there was no growth at higher concentrations of NaCl in the defined medium.

The adsorption of bacteria to immobilized lectins.

The agglutination of a selection of bacteria by some lectins was examined. The lectin from Codium fragile agglutinated seven strains of Salmonella typhimurium. The lectin from Helix pomatia agglutinated eight of 12 strains of Listeria monocytogenes and a further two strains gave a weak agglutination reaction. Helix pomatia lectin conjugated to magnetic microspheres enabled the adsorption of L. monocytogenes from suspension with subsequent elution by the competing ligand N-acetyl galactosamine. Affinity chromatography of a suspension of L. monocytogenes through a column of H. pomatia lectin immobilized on agarose, also adsorbed cells and enabled subsequent elution with N-acetyl galactosamine. The column technique enabled the more rapid adsorption of bacteria perhaps because of improved interactions between bacteria and immobilized lectin.

Respiratory activity in Listeria monocytogenes.

Listeria monocytogenes possessed glucose oxidase and NADH oxidase activities in whole cells and lysed protoplasts respectively. The NADH oxidase activity sedimented with the membrane fraction and was inhibited by the respiratory inhibitors rotenone, 2-heptyl-4-hydroxy-quinoline-N-oxide and cyanide, suggesting the presence of a membrane associated respiratory chain.

Investigation of a simple amperometric electrode system to rapidly quantify and detect bacteria in foods.

A two electrode system mounted as a single probe was developed to measure electrochemically the rate of reduction of a redox mediator (thionine) by bacteria. The system gave a rapid (2 min) bacterial-dependent current above 2.5 x 10(5) cfu/ml with pure cultures of bacteria, but when applied to the measurement of the bacterial contamination in samples of meat and milk it was unable to detect or quantify the contamination reliably. Incubation of samples for a few hours before examination enabled the system to detect bacteria in excess of 10(6) cfu/ml.

Use of the direct epifluorescent filter technique for the enumeration of bacterial spores.

Heat treatment at 80 degrees C for 10 min effectively destroyed all vegetative cells (except for Gram-positive cocci) and made easier the counting of bacterial spores, which stained orange, green or rarely transparent/black with a dull green halo, in the direct epifluorescent filter technique. The numbers of both orange- or green-staining spores were lower than the plate count. A variety of physiological conditions were used to investigate the relationship of the different staining patterns with germination status. It was concluded that orange-staining spores had germinated and their number agreed with the plate count after incubation in yeast glucose broth at 30 degrees C for 4 h. This observation was unreliable, however, but it was found that a total spore count in the DEFT gave a good agreement with the plate count.

Auditory event-related potentials in schizophrenia and depression.

Event-related potentials in two auditory target detection paradigms and two auditory paradigms without overt tasks were studied in 22 schizophrenic, 21 depressed, and 28 matched control subjects meeting Research Diagnostic Criteria. In the target detection paradigms, schizophrenics showed a pattern of reduced N120 amplitude and shorter P200 latency to frequently occurring tones, and reduced P300 and Slow Wave amplitude to infrequent target and nontarget tones. This pattern is consistent with impaired selective attention for stimuli. For depressed patients these variables were generally intermediate between those of schizophrenics and controls. In the other paradigms N120 latency was greater for schizophrenics, and P200 amplitude was less for depressed patients.