OBJECTIVE: Recently a publication of Brenner et al. introduced 11 genetically distinct species within the genus Citrobacter. These newly recognized Citrobacter species can be classified by means of their biochemical characteristics. The aim of this study was to examine the distribution and susceptibility of Citrobacter isolates in our patient population. METHODS: A total of 126 samples---containing a Citrobacter species---was collected from 116 hospitalized patients during a 6-month period. Organisms were identified according to standard procedures. Antimicrobial susceptibility testing was performed by agar dilution on Mueller-Hinton agar, and interpretation was based on NCCLS criteria. RESULTS: C. freundii was the most common organism isolated (n=59), followed by C. braakii (n=25) and C. koseri (n=23). The urinary tract and the respiratory tract were found to be the predominant sites of colonization or infection, accounting for 45% and 32% of all isolates respectively. It appeared that young children (<12 months old) and the elderly were most at risk of acquiring Citrobacter. Two-thirds of all specimens contained other organisms in addition to Citrobacter. Most Citrobacter isolates were related with a predisposing factor. Species-related differences were found in the susceptibility pattern. CONCLUSIONS: These findings suggest that citrobacteria are important opportunistic pathogens contributing to colonization or infection in our hospital population.

The performance and practicability of 2 blood glucose meters (Glucocard Memory 2 and Accutrend sensor) were evaluated. Both glucose meters produced acceptably precise results in the hyper- and normoglycaemic concentration ranges. In the hypoglycaemic concentration range, the imprecision of Accutrend sensor was much higher than recommended by the American Diabetes Association. Within-run coefficients of variation for Glucocard Memory 2 were 6.3%, 3.9% and 2.4% at glucose concentrations of 1.7 mmol/l, 5.8 mmol/l and 11.7 mmol/l, respectively: for Accutrend sensor these were 15.2%, 5.0% and 1.2% at respective concentrations of 0.9 mmol/l, 4.2 mmol/l and 19.6 mmol/l. Between-day coefficients of variation for Glucocard Memory 2 were 4.8% and 3.5% at glucose concentrations of 3.9 mmol/l and 17.2 mmol/l, respectively and for Accutrend sensor they were 3.8% and 2.9% at glucose concentrations of 3.8 mmol/l and 18.7 mmol/l, respectively. Results were linear over a range of 1.6 mmol/l -29.7 mmol/l for Glucocard Memory 2 and 1.6 mmol/l -33.3 mmol/l for Accutrend sensor. Results of both blood glucose meters correlated closely with the hexokinase/glucose-6-phosphate dehydrogenase laboratory method. Ninety-eight percent of both Glucocard Memory 2 and Accutrend sensor results were within 20% of the comparison method values. Ninety-three percent of the Glucocard Memory 2 and 96% of the Accutrend sensor results were within 15% of the comparison method results. An inverse relation between the glucose readings and haematocrit values was observed for both blood glucose meters in the hyperglycaemic range and this effect was more pronounced for Accutrend sensor. In the normo- and hypoglycaemic ranges the effect was insignificant and absent, respectively. Minimum sample volume for Glucocard Memory 2 was 3 microliters and for Accutrend sensor it was 9 microliters. Lower sample volumes gave erroneous results. Presenting more than the required volume had no effect on results.

The objective of this study was to compare 3-breed rotational crossbred calves sired by Holstein, Jersey, Montbéliarde, Normande, Viking Red, and Limousin bulls with Holstein calves fed a high milk allowance for growth, milk consumption, health scores, and profitability in an automated group feeding system. Breed groups were Holstein (n = 16), crossbreds of Montbéliarde, Viking Red and Holstein (n = 24), crossbreds of Jersey, Normande, and Viking Red (n = 6), and Limousin crossbred beef x dairy (n = 45) calves. Calves were randomly assigned within breed to one of two treatments from September 2019 to June 2020 at the University of Minnesota West Central Research and Outreach Center in Morris, MN. The 5 breed groups were balanced across the two treatment groups. Treatment groups were fed 8 L/d (8L) or ad libitum (AL) milk allowance, and calves were introduced to the automated feeder at d 5 and were weaned at 56 d. Milk feeding behaviors (drinking speeds) were collected from the automatic feeding system and analyzed by feeding and breed groups. Body weights were recorded at birth and weekly through weaning. Health scores of calves were recorded twice/wk. Variables included in the statistical model for analyses were fixed effects of birthweight, season of birth, breed group, and treatment group. Calves fed AL had a greater weaning weight (P = 0.001; 106.4 kg versus 91.4 kg) and greater (P = 0.001) average daily gain (ADG; 1.11 kg/d versus 0.87 kg/d) than calves fed 8L, respectively. The calves fed AL (1,064 ml/min) had a slower drinking speed (P = 0.01) than calves fed 8L (1,467 ml/min). Most breed groups were not different for weaning weight or ADG across the 56 d. Daily milk consumption per calf was lower (P = 0.009) for Limousin crossbred calves compared with Holstein and crossbred dairy calves. As expected, AL calves had higher (P = 0.001) milk cost ($189.52) than the 8L calves ($140.71). The average cost per kg of gain was similar for calves fed 8L ($2.89/kg) compared to AL ($3.00/kg) calves. Overall, the Limousin crossbred calves had the least milk cost ($152.75) compared with Holstein ($175.67) calves and Montbéliarde, Viking Red and Holstein crossbred calves ($177.13). The results from this study found that although feeding calves AL resulted in greater milk consumption and higher cost than 8L calves, there may be an economic advantage with costs per kg of gain to feeding calves ad libitum if increased growth rates are realized.