Heifers (n = 103) ranging in age from 1d to 2 yr were sampled to determine the coagulase-negative staphylococcal flora of haircoat, nares, vagina, teat skin, and streak canal. A total of 2706 staphylococal strains were identified from 3612 bacterial isolates. Other genera or groups identified included Bacillus, Micrococcus, Corynebacterium, and coliforms. Staphylococci were identified utilizing a simplified biochemical scheme. Staphylococcus xylosus, S. chromogenes, and S. warneri were the predominant species recovered from anatomic sites and streak canal. Staphylococcal strains identified from specific body sites (expressed as percentage of heifers harboring these species) were: nares 74% S. xylosus and 48% S. warneri; haircoat, 70% S. xylosus and 57% S. chromogenes; vagina, 60% S. chromogenes and 54% S. xylosus; teat skin 62% S. chromogenes and 61% S. warneri; streak canal 53% S. chromogenes, and 43% S. warneri. The prevalent staphylococcal strains identified differed from heifers in confined housing compared with heifers on pasture. Differences observed in distribution of Staphylococcus species among body sites, particularly those between teat skin and streak canal, suggest that establishment of staphylococcal microflora depends on the ability of a species to adapt to and colonize anatomic sites as well as on environmental conditions present.

The body sites of 163 heifers, bedding and feedstuff samples, flies, and hands and nares of the research personnel were sampled in order to determine the sources of Staphylococcus aureus in a dairy herd other than the lactating mammary gland. Lesions on the udder of lactating animals and the air in the milking parlor were also sampled. Staphylococci isolated from bedding samples were identified as to species. Staphylococcus aureus was isolated from all sources examined except flies. An enrichment procedure was necessary for isolating S. aureus from two bedding samples although other Staphylococcus species were present in high numbers. The designation "environmental staphylococci" is proposed for Staphylococcus species that were apparently free-living in the environment.

Botrytis-inoculated fruit were treated with three levels of naturally occurring volatile compounds in capped bottles and rated for Botrytis development and evidence of phytotoxicity during 7 days of storage at 2 °C followed by 3−6 more days at 22 °C for strawberry and 7 days at 15 °C for blackberry and grape. Hexanal, 1-hexanol, (E)-2-hexen-1-ol, (Z)-6-nonenal, (E)-3-nonen-2-one, methyl salicylate, and methyl benzoate exhibited potential as postharvest fumigants for control of Botrytis on strawberry at the lowest level tested. Ten compounds were evaluated on blackberry and grape. None caused phytotoxic responses as with strawberry, while nearly all of the compounds inhibited Botrytis at all three test levels. Strawberry, blackberry, and grape metabolized (E)-2-hexenal with reduction of the aldehyde to an alcohol and saturation of the carbon−carbon double bond adjacent to the carbonyl, but strawberry yielded more esters as major products. Keywords: Fragaria × ananassa; Rubus; Vitis vinifera; metabolism; antifungal; (E)-2-hexenal

During a 14-mo period, 77 multiparous and 36 primiparous cows were sampled to determine the prevalence of staphylococci during the periparturient period. Distal streak canal swabs were taken at 14 d prepartum, and foremilk was sampled the first 5 consecutive wk of lactation. Staphylococcus aureus was isolated from 7.6% of quarters of primiparous cows but from only .6% of quarters of multiparous cows at parturition. Prevalence in primiparous cows declined to 3.5% by the wk-1 sampling. Quarter prevalence of coagulase-negative Staphylococcus species prepartum, at parturition, and wk 1 to 5 in primiparous cows was 38.9, 27.8, 15.3, 14.6, 13.2, 15.3, and 14.6%, respectively. In multiparous cows, prevalence at these times was 50.3, 12.3, 6.2, 8.1, 10.7, 7.1, and 8.1%. Staphylococcus chromogenes was the predominant species isolated, accounting for over 50% of the staphylococci isolated at each sampling time. Results suggest that high prevalence of staphylococci isolated prepartum is a reflection of natural skin flora and that a higher postpartum prevalence of these organisms was observed in primiparous cows than in multiparous cows. These data suggest also that the peripartum heifer could be a source of Staphylococcus aureus in the lactating herd.

The effect of feeding subtherapeutic (27.5 micrograms/g of diet for 85 d) and therapeutic (220 micrograms/g of diet for 14 d, followed by an antibiotic-free diet for 71 d) levels of chlortetracycline (CTC) on the antibiotic resistance of fecal coliforms of pigs from two herds (36 pigs/herd) with different histories of antibiotic exposure when housed in a newly constructed confinement facility was determined. The CTC-resistant coliforms were higher (65 vs 51%) for antibiotic (AB) pigs than for nonantibiotic (NAB) pigs after they had been fed an antibiotic-free diet for 21 d. Percentages of isolates resistant to ampicillin, kanamycin, neomycin and tetracycline and multiple antibiotic resistance were greater (P less than .05) in AB pigs after 21 d. Feeding subtherapeutic CTC resulted in a linear increase in CTC-resistant coliforms with time on experiment (P less than .03, NAB; P less than .06, AB). The CTC-resistant coliforms increased during the 14 d that therapeutic CTC was fed, then they decreased during the 71 d that the antibiotic-free diet was fed, resulting in a quadratic response with time (P less than .03, AB). Feeding subtherapeutic CTC resulted in a greater increase in CTC-resistant coliforms in AB (47%) than in NAB (23%) pigs. The CTC-resistant coliforms decreased after the therapeutic group had been returned to the antibiotic-free diet (P less than .05, NAB). Feeding CTC caused greater changes in the precentages of isolates from NAB pigs that were resistant to selected antibiotics and in multiple antibiotic resistance than in isolates from AB pigs.(ABSTRACT TRUNCATED AT 250 WORDS)