Analysis of Clostridium botulinum toxigenic types A, B, and E for fatty and carbohydrate content.
Lyophilized, 48-hr log-phase vegetative cells were extracted with chloroform-methanol (2:1, v/v) and ethanol-ether (3:1, v/v) and then saponified with methanolic KOH. Gas-liquid chromatography of the methyl esters of extractable fatty acids revealed distinctive "pattern profiles" of Clostridium botulinum toxigenic types "A," "B," and "E." C. perfringens type "A" and Escherichia coli strain "B" were also studied in a similar manner and were found to give pattern profiles which were distinct even from those obtained for the C. botulinum microorganisms. Amino sugar content of the five microorganisms was determined by using a Beckman amino acid analyzer. The molar ratio of glucosamine to that of galactosamine was found to be of further assistance in distinguishing the individual microorganisms.
Cellular monosaccharide patterns of Neisseriaceae.
Sixty-four strains of Neisseria, Moraxella, and Acinetobacter were screened for cellular monosaccharides by gas-liquid chromatography and other chromatographic techniques. The four sugars ribose, glucose, glucosamine, and 2-keto-3-deoxyoctonate (KDO) were detected in all strains. Heptose was detected only in "true neisseriae" (Neisseria gonorrhoeae, N. meningitidis, N. sicca, N. cinerea, N. flavescens, and N. elongata) and in the tentaively named species Moraxella urethralis. Some marked interspecies dissimilarities within groups were revealed. Thus, N. ovis and M. atlantae were characterized by the presence of mannose. Intraspecies differences were also encountered. N. meningitidis strains of serogroups B and C were distinguished from strains of serogroup A by their sialic acid content. This sugar was also detected in two out of three examined strains of M. nonliquefaciens. In Acinetobacter, heterogeneity of monosaccharide patterns was rather pronounced. The results show the applicability of gas chromatographic "monosaccharide" profiles fo whole cells or extracted carbohydrate in bacterial classification and identification, including differentiation at the subspecies level. In addition, such profiles may be useful for monitoring during purification of cellular polysaccharides.
Stroking different body regions of dairy cows: effects on avoidance and approach behavior toward humans.
Understanding perception of dairy cows to common human contact such as stroking is important for improving the human-animal relationship, animal welfare, and production. We hypothesized that repeated stroking of body regions licked most during social grooming, especially the ventral neck, would reduce cows' avoidance of and increase their approach to humans. Sixty tethered dairy cows were randomly allocated to 4 treatment groups that received 5 min of daily human contact 5 d/wk during 3 consecutive weeks: 3 groups were stroked on different body regions. The first group was stroked on the ventral part of the neck (neck); the second group on the withers (both licked often in social grooming); the third group on the lateral side of the chest (chest, licked rarely); and the last group (control) was exposed to simple human presence. The reactions to the person who had provided the treatment were measured using 2 tests in the home tie-stall assessing avoidance from an approaching person who tried to touch the head (approaching person test) and avoidance/approach reactions to a stationary person (stationary person test). Approach behavior was recorded in a novel environment using a standard arena test. In the home tie-stall, cows stroked on the neck showed less avoidance (median avoidance score: 3.33) in the approaching person test compared with cows stroked on the chest and the controls (both: 4.00). That is, at least 75% of the animals stroked on the neck tolerated the touching of their heads (75th percentile <or= 3.75), whereas at least 50% of the cows in the other treatment groups did not accept it. The stationary person test did not reveal any differences between the treatment groups. In the arena test, the 3 stroked groups showed more approach behavior (median latencies to contact: from 145 to 240 s) compared with simple human presence (300 s), but stroking treatments did not differ from each other. Stroking, particularly the neck, reduced avoidance of and increased approach reactions to humans in both the home tie-stall and the arena. Increasing acceptance of being touched after being stroked on the neck suggests that this procedure should be adopted to improve routine handling of dairy cattle.