Toddler-age children's (11 to 30 months old) play with care-giving adults and with toys and peers was observed and rated in family day-care homes. Fifty-five children, their mothers, and family daycare home providers participated in this study. The quality of the family day-care homes was assessed with the Harms and Clifford Family Day Care Rating Scale (FDCRS) and by measures of ratio and group size. Information on family stress, social support, child-rearing attitudes, and maternal role satisfaction was reported by mothers. More nurturing and supported families were associated with higher quality child care, whereas more restrictive and stressed families were associated with lower quality child care. More restrictive and stressed families were associated with more changes in childcare arrangements. Greater numbers of child-care changes also were associated with lower levels of competent play with objects and peers. When quality of care was controlled, both more nurturing and supported families and less restrictive and stressed families were associated with higher levels of competent play with adult caregivers, peers, and objects. When family characteristics were controlled, higher quality child care was associated with more competent play with adult caregivers and with peers and objects.

The oxygen tolerance and sensitivity of 57 freshly isolated anaerobic bacteria from clinical specimens was studied. All the organisms tolerated 8 h or more of exposure to oxygen in room air. Growth of the isolates in increasing oxygen concentrations demonstrated that the 57 isolates varied in oxygen sensitivity from strict to aerotolerant anaerobes. Comparison of the oxygen tolerance and sensitivity showed that the most tolerant organisms (best survival after prolonged exposure) included anaerobes capable of growth at only 0.4% or less O2 (strict) as well as those able to grow in as much as 10% O2. The least tolerant were predominately strict anaerobes. Decrease in the inoculum size from a concentration of 10(8) to 10(6) colony-forming units per ml had only a minor effect. The data indicate that the brief oxygen exposure with bench techniques in clinical laboratories would not be deleterious to the anaerobic bacteria present in clinical specimens.

The activity of the three two-drug combinations of sulfamethoxazole (SMX), trimethoprim (TMP), and polymyxin B (PB) against 52 clinical isolates of gram-negative bacilli was studied by a "checkerboard" agar dilution method. The organisms studied included strains of Enterobacter spp., Klebsiella pneumoniae, Serratia marcescens, Providence, Proteus, and Pseudomonas aeruginosa. The majority of these isolates were resistant to at least two of the three agents used in the combined studies and to the most commonly used antimicrobials.The TMP-PB combination demonstrated enhanced activity more frequently than the other two-drug combinations, showing synergism or addition in 85% of the combined studies; indifference or antagonism was also observed least frequently with TMP-PB. The great majority (83%) of Enterobacter-KlebsiellaSerratia isolates were susceptible to enhanced activity of all combinations. Proteus-Providence isolates were frequently susceptible (63%), but combined activity was indifferent or antagonistic against 60% of P. aeruginosa. Twelve isolates were selected for "killing-curve" assays in which an inoculum was incubated with SMX, TMP, and PB individually and in various two-and three-drug combinations. Surviving bacteria were counted at timed intervals over 24 h of incubation. The triple combination (SMX-TMP-PB) was synergistic against 9 of 12 isolates, whereas TMP-PB and SMX-PB showed synergism against 5 and 3 isolates, respectively. These data suggest that, although TMP-PB will often show enhanced activity against the gram-negative bacilli studied here, optimal antibacterial activity will be demonstrated when the three-drug combination is used.

Growth of Pseudomonas aeruginosa and thirty-five other species of gramnegative bacilli was observed on 0.03% cetrimide in heart infusion agar medium and Pseudosel agar (BBL). The 0.03% cetrimide agar was more selective for growth of P. aeruginosa than was Pseudosel agar; however, certain bacteria other than P. aeruginosa also grew on the former medium. Although Pseudosel agar was not a highly selective medium for P. aeruginosa, it was preferable to technicolor agar for detection of the pyocyanin and pyorubin pigments produced by P. aeruginosa.