Longitudinal study on the susceptibility to bacteriophages of Staphylococcus aureus strains isolated from dairy farms in Trinidad

A 6-month longitudinal study was conducted on 30 dairy cows in early lactation and their human handlers on six farms across Trinidad. Weekly samples of bulk milk, composite milk and anterior nares and hand swabs from human handlers were collected and cultured for Staphylococcus aureus on Baird-Parker agar (BPA). The susceptibility of S. aureus strains to bacteriophages and the relatedness of strains isolated over the study period were determined. Sixty-three (51.2 percent) of 123 strains of S. aureus from bulk milk were typable compared with 111 (57.3 percent) of 194 and 82 (61.7 percent) of 133 strains isolated from composite milk and human handlers, respectively. The differences were not statistically significant (P> 0.05; chi 2). Bovine phage 42D lysed 3.3 percent (4 of 123), 16.5 percent (32 of 194) and 12.0 percent (16 of 133) of S. aureus strains isolated from bulk milk, composite milk and human handlers, respectively. The differences were statistically significant (P< 0.001; chi 2). Amongst bulk milk isolates of S. aureus, 35 (31.8 percent) of 110 exhibited relatedness in 11 groups based on their phage patterns and groups. The mean maximum interval between the first and last detection of related S. aureus strains in a group was 11.5 +/- 7.3 weeks. Amongst composite milk strains of S. aureus, 23 (46.0 percent) of 50, 25 (62.5 percent) of 40 and 22 (53.7 percent) of 41 exhibited relatedness on farms IB 2, IB 27 and IC 23, respectively, but the differences were not statistically significant (P> 0.05; chi 2). On farm IB 2, five groups of related strains of S. aureus were detected with a mean maximum interval of detection of 18.2 +/- 8.5 weeks compared to farm IB 27 where five groups of related strains were also observed but with an interval of 13.8 +/- 8.2 weeks. On farm IC 23, a total of seven groups of related S. aureus strains detected with a mean interval of 8.0 +/-5.5 weeks. For human strains of S. aureus from farm IB 2, nine (56.3 percent) of 16 strains isolated from anterior nares exhibited relatedness in three groups with a mean maximum interval of 13.3 +/- 4.7 weeks compared to four (25.0 percent) of 16 hand swab isolates which exhibited relatedness in two groups with a mean maximum interval of detection of 20.5 +/- 2.1 weeks compared to hand swab isolates, with six (50.0 percent) of 12 showing relatedness in two groups and a mean interval of 10.5 +/- 2.1 weeks. (AU)

Outcome of teenage pregnancy in St. Vincent: neonatal outcome and adequacy of milk from teenage mothers

In a longitudional study, pregnancy, neonatal outcome and lactation performance of adolescent and adult primigravidae were examined and compared in 33 randomly selected women (14-25 years) in St. Vincent. The whole group of women were subdivided into three sub-groups: Group I (n=10, age 14-16 years), Group II (n=12, age 17-18 years), and Group III (n=11, age 19-25 years). Detailed data on obstetrical and neonatal (neurological) outcome were collected. After birth, information was obtained on early infant growth, maternal dietary intake and breast milk composition. Milk samples (transitional and mature milk) and maternal dietary information and neonatal anthropometric measurements were collected twice during the first month after birth through home visits. Between the 3 groups no significant differences in obstetric conditions, birthweight and early infant growth were found. The Neurological Optimality Score (NOS) was comparable for all groups, but a trend of more infants diagnosed as neurologically "suspect" infants in the younger age group shows the urgent need for more research in this field. Regarding the analysis of breastmilk samples, apart from lactose content, no major differences in the composition of macro-nutrients were found. Concerning the fatty acid composition of the milk fat, no major differences between the groups occurred, although a small number of individual fatty acids were different between the groups. Early infant growth patterns were similar in all groups. It is concluded that previously reported perinatal problems of healthy teenage primigravidae (14-16 years) were not substantiated fully in this series but neonatal outcome of infants of these mothers suggests that careful developmental follow-up of these children is indicated (AU)

Considerations for implementing an antibiotic policy in hospital practice

An antibiotic policy should aim for the safe, effective and economical use of antimicrobial drugs, and to prevent their indiscriminate use and development of resistant bacterial strains. The term 'antibiotic' is used as a general term for all antimicrobial drugs. Antibiotics prescriptions should be based on clinical evidence of bacterial infection, preferably substantiated by appropriate laboratory culture and sensitivity tests. Viral infections are not an indication for antibiotic prescriptions. Patient factors to be considered for choice and dose of an antibiotic are age, pregnancy, lactation, renal and hepatic impairment. Immunodeficient patients should receive only bactericidal drugs. Severity of infection determines the route of administration. Duration of therapy should not exceed five days, unless specifically prescribed by the physician. An antibiotic should, if started as an empirical therapy not be changed before a minimum of three days trial. Prescriptions of drugs such as aztreonam, imipenem, vancomycin, piperacillin and amphotericin are to be restricted due to cost and toxicity and should be reviewed by the microbiologist (AU)

Use of a multicultural food frequency questionnaire with pregnant and lactating women

In a multicultural society the difficulty experienced by pregnancy care teams in asking subjects to remember what they have eaten and then adjusting the food recall for lapses in detail related to portion size, product names, food combinations, and ethnic uniqueness poses a handicap for collecting food-recall data. The purpose of this study was to design and administer a food-frequency questionnaire (FFQ) to clarify the 24 h dietary recall of pregnant and lactating women of Caribbean and African descendants. Focus groups convened in eight states around the United States determined ethnic food nomenclature, methods of preparation and cooking, types of and additions to food, and cultural differences in quantifying food servings. The FFQ assessed weekly intake patterns of six categories of foofs and described the frequency of consumption of 82 food items. Correlation analysis and paired t tests compared agreement indicators (0.80) and differences on the reporting. (AU)

Outcome of teenage pregnancy in St. Vincent: the adequacy of milk from teenage mothers in relation to neonatal growth - abstract

In a longitudinal study pregnancy, neonatal outcome and lactation performances of adolescent and adult primigravidae were examined and compared in 33 randomly selected women (14-25 years of age) in St. Vincent. The whole group of women were subdivided in three subgroups: Group I (n=10, age 14-16 years), Group II (n=12, age 17-18 years) and Group III (n=11, age 19-25 years). Detailed data on obstetrical and neonatal (neurological) outcome were collected. After birth information was obtained on early infant growth, maternal dietary intake and breast milk composition. Milk samples (transitional and mature milk) and maternal dietary information were collected twice during home visits, together with neonatal anthropometric measurements. Between the 3 groups no significant differences in obstetrical conditions, birth weight and early infant growth were found. However, in the youngest group the number of infants diagnosed as neurologically "suspect" was higher compared to the older groups. Regarding the analysis of breast milk samples, apart from lactose content, no major differences in the composition of macro-nutrients were found. Concerning the fatty acid composition of the milk fat no major differences between groups occurred, although a small number of individual fatty acids were different between the groups. It is concluded that previously reported perinatal problems of healthy teenage primigravidae (14-16 years) are not substantiated in this series (AU)

Vitamin E, lipid fractions, and fatty acid composition of colostrum, transitional milk, and mature milk: an international comparative study

Triglycerides, cholesterol, fatty acid composition, and tocopherols were determined in colustrum, transitional milk, and mature milk in St. Lucia. With progress of lactation, triglycerides and percentage medium-chain fatty acids increased whereas tocopherols, cholesterol and percentage long-chain polyunsaturated fatty acids decreased. These changes reflect augmented de novo synthesis of fatty acids (8:0, 10:0, 12:0, and 14:0) in the mammary gland and a tendency of increasing fat-globule size as milk matures. Transitional and mature milks, but particularly colustrum, contained higher concentrations of components considered to be derived from the fat-globule membrane (cholesterol, tocopherols, percentage long-chain polyunsaturated fatty acids) compared with those reported for Western countries. Percentage medium-chain fatty acids in mature milk was two to three times higher than in developed countries. Differences from data from studies in Western countries are discussed in relation to analytical methods and possible consequences for lipid digestion, lipid absorption, growth, and brain development.(AU)

Properties of the insulin receptor in the lactating rat mammary gland

This study aimed to determine binding characteristics of insulin receptors of lactating rat mammary gland acini. It was assumed that the use of monocomponent tyrosine A14 iodinated insulin would yield better data than that hitherto available. Initial studies confirmed existence of specific, high affinity, saturable insulin binding at 4 degrees C (incubated for 18h) but not at 37 degrees C due to considerable degradation of insulin. Dissociation of bound insulin from partially filled receptors (1 - 12 percent) at 4 degrees was a slow, approximately first order process (t approx. 2h) and was not significantly accelerated by the presence of unlabelled insulin. Binding data from lactating mammary gland, analysed by Scatchard and Hill plots yielded unusually complex curves not obtained for rat liver or human erythrocytes. Data from binding curve of the mid-lactating gland was interpreted as a composite of binding by 3 classes of receptor sites -- high affinity Kd(h) = 0.2nM amd number (n(h)) = 1.5 x 10(exp 9) sites/mg protein, intermediate and low affinity sites of total number (n(t)) approx. 15 x 10(exp 10) sites/mg protein. Intermediate affinity sites contributed significantly to binding in the region 0.1 - 10nM free insulin and were detectable following 2 days starvation and prolactin deprivation, at 4 days lactation but not at day 0 and after weaning. n(h) was highest (3.3 x 10(exp 9) sites/mg protein) at day 0 and n(t) highest at day 4 (19 x 10(exp 10) sites/mg protein). On weaning all parameters declined significantly, n(h) to 0.4 x 10(exp 9) sites/mg protein, n(t) to 6 x 10(exp 10) sites/mg protein. 48h starvation resulted in an increase of n(h) to 3 x 10(exp 9) sites/mg protein without a change of Kd(h) whereas 48h prolactin deprivation diminished n(h) relative to matched controls both at 4 days and mid-lactation. These effects are broadly consistent with the hypothesis that metabolic adaptation of the mammary gland during lactation is dependent on the occupancy of high affinity insulin receptors/unit tissue (with a possible contribution from receptors of intermediate affinity) involving a subtle interplay of insulin receptor number and affinity and also plasma insulin concentration. Wheat germ agglutinin (5ug/ml) did not appear to affect the general shape of the Scatchard curve, however it substantially increased both n(h) and n(t) (to 5 x 10(exp 9) and 25 x 10(exp 10) sites/mg protein respectively) as well as Kd(h) to 0.3nM. 1mM-Vanadate ion had complex effects on insulin binding depending on the nutritional state of the animal:- Acini from fed animals showed a small decline of n(h) (to 1 x 10(exp 9) sites/mg protein) without significant changes of n(t) or Kd(h); whereas acini from starved animals showed an increase of n(h) (to 11 x 10(exp 9) sites/mg protein) and Kd(h) to 0.8nM. Intermediate affinity sites were not detected in either case. Increased phosphorylation of the á-subunit of the insulin receptor may have contributed to these effects (AU)

First ovulation in lactating mothers: a study conducted at the University Hospital of the West Indies

Sixty-seven endometrial biopsies were obtained from randomly selected lactating mothers at six weeks post-partum and examined histologically. There was evidence of ovulation (secretory activity) in 3 cases (4.5 percent) and endometritis in 9 (13.4 percent). Breastfeeding more than 5 times per day did not prevent ovulation in 5.4 percent of cases. However, a history of recent vaginal bleeding was correlated with an increased risk on both ovulation and endometritis. We do not recommend the use of additional contraceptives in women without a history of vaginal bleeding as the risk of ovulation is only 2 percent. However, we have discussed the guidelines for the use of additional contraceptives in women with a history of vaginal bleeding as the risk increases to 11.8 (AU)

Estimating genetic values for milk production in the tropics

Variance components and predicted sire values were estimated using 305-d projected and unprojected milk records of varying lenghts. Original data consisted of 15,512 lactation records of daughters of 138 Jamaica Hope sires that calved between 1969 and 1981 in 38 commercial dairy herds in Jamaica. Classification of records had little effect on components of variance. Herd-year-season variance decreased from 36 percent using all lactations to 28 percent with first lactations only. Sire variance was consistently about 10 percent. Cow component of variance accounted for 17 percent of the total variation using all lactations and 36 percent using all lactations of cows with recorded first lactations. Heritabilities for milk by Henderson's method 1 were five to six times larger than estimated from method 3 due to sire by herd confounding. Predicted sire values were between +400 kg and -400 kg. Ranking of sires with at least 5 progeny were considerably infleunced by record classification, especially for sires with highest predicted values. There was less infleunce on rankings when at least 10 progeny per sire were used while the range in predicted sire values was larger using first lactation records only (AU)

Nutritional status in pregnancy and lactation: a report of two case studies

In these 2 case studies information was sought on maternal nutritional status and its relationship to outcome of pregnancy and growth of the infants in the first 10 to 12 weeks of life. Information was also obtained on the macronutrient content of the mothers' milk and hence the nutrient intake of the infants. The Calorie intakes of the mothers were 2063 +/- 41 (SEM) and 1946 +/- 41 (SEM) Calories during pregnancy. Protein intakes were 68 +/- 3 (SEM) and 74 +/- 3 g/day during pregnancy. Dietary iron intakes were 15 +/- 1 (SEM) and 13 +/- 0.2 (SEM) g/day during pregnancy. Both mothers achieved weight gain of 7.8 Kg (PB) between weeks 28 to 41 and 2.8 kg (CA) between weeks 28 to 42. Both mothers gave birth to healthy full term infants with birth weights of 3.25 kg and 3.26 kg. The infants' calculated nutrient intakes 76 to 135 Cals/day (SB) and 86 - 129 Cals/day (FA) of protein, were lower than the recommended dietary allowances, yet both gained weight satisfactorily. By 10 weeks FA gained 1.71 kg, and at 12 weeks SB gained 2.88 kg. Mean energy intakes of PB during lactation was 1968 +/- 170 (SEM) Calories/day and 2106 +/- 95 (SEM) Calories/day for CA. Mean protein intakes were 50 +/-2 (SEM) g/day and 84 +/- 8 (SEM) g/day, and mean iron intakes were 11 +/- 1 (SEM) and 15 +/- 2 (SEM) mg/day. Body weights of the 2 mothers remained relatively constant. Fluctuations in body weight were of the order of 1 - 2 percent after the fifth week post partum. This suggest that the mothers' dietary intakes were adequate for maintenance, activity and adequate lactation. (AU)