Incremental supply of fat, lactose, or protein influences the diurnal pattern of heat production and substrate oxidation in pre-weaning calves.

Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of DE/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 week in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [Hact] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in Hact. The recovery of 13CO2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, while extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients impact metabolic processes, fat retention, and energy expenditure in young dairy calves.

Responses to incremental nutrient supply on energy and protein metabolism in pre-weaning dairy calves.

Recently reviewed development objectives and feeding practices in young dairy calves require an adaptation of nutrient recommendations set for milk replacer (MR) composition. Nutrient requirements of calves younger than 21 d of age, and those of calves fed with high levels of milk replacer are insufficiently quantified. The efficiency at which macronutrients are utilized, particularly protein, substantially diminishes with age, and there is little data for the first weeks of life. In addition, in older (pre-)ruminants, protein and energy can be simultaneously limiting for protein gain. Whether this also applies to calves in the first weeks of life is unknown. Therefore, this study aimed to quantify the responses in protein and fat gain to incremental supply of protein, fat, or lactose to MR in very young calves. Thirty-two groups of 3 mixed-sex Holstein-Frisian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments applied for 19 d: a basal MR (23.3% CP, 21.2% CF and 48.8% lactose of DM), provided at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of DE/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24) or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but did not have access to calf starter nor any other solid feed. After 2 weeks of adaptation to their respective diets, groups of calves were placed for one week in an open-circuit respiration chamber for nitrogen and energy balance measurements (5 d). The incremental nutrient efficiencies indicate what percentage of extra intake of nutrients is retained. In this study, we observed that with every 100 g increase in protein intake, 52% was converted into protein deposition, while 44% contributed to heat production. Similarly, a 100 g increase in fat intake resulted in 67% being stored as fat, 22% being released as heat, and only 5% being retained as protein. Likewise, a 100 g increment in lactose intake led to 49% being stored as fat, with 38% being released as heat. Additional protein intake was not deposited as fat, extra energy intake (fat, and additional lactose) increased post absorptive N efficiency in young calves.

Effect of postpartum collection time and colostrum quality on passive transfer of immunity, performance, and small intestinal development in preweaning calves.

This study evaluated the effects of postpartum collection time and quality of colostrum fed to calves on the failure of passive transfer, growth, and small intestine development in the first 5 wk of life. Newborn calves (Holstein-Friesian × Jersey) were identified at birth and collected either early (E; within 12 h postpartum; n = 20) or late (L; 18-24 h postpartum; n = 20) and fed either high-quality colostrum [HQC, first milking colostrum with Brix% = 23 ± standard deviation (SD) 2] or low-quality colostrum (LQC, mixed colostrum and transition milk with Brix% = 12 ± 1) to create 4 treatments: E-HQC, E-LQC, L-HQC, and L-LQC (n = 10/treatment). After collection, calves (body weight = 32.3 ± 4.6 kg/calf) were fed either HQC or LQC (7.5% of their arrival body weight per feed) for the first 3 (L calves) or 4 feedings (E calves). All calves were then managed and fed similarly using automatic feeders which recorded individual intake of milk replacer and calf starter. Blood samples were taken at d 1 (after collection from dams but before colostrum feeding), 4, 14, and 35 of age to analyze selected metabolites. All calves were killed at d 35 ± 2 of age and histomorphology of duodenum, jejunum, and ileum was evaluated. At collection, 75% of E calves and 58% of L calves had serum total protein ≤52 g/L. At d 4 of age, calves fed HQC had greater serum total protein than calves fed LQC; however, failure of passive transfer (serum total protein ≤52 g/L) incidence did not differ between HQC and LQC. Collection time did not affect the scouring duration, but the amount of electrolyte used to treat sick calves was lower in L versus E calves, whereas feeding HQC versus LQC lowered both the scouring duration and electrolyte use to treat sick calves. Calves fed HQC had a greater total surface area of the duodenum (+23%) and jejunum (+17%) compared with LQC calves. Duodenal crypts were deeper in E-LQC calves than E-HQC and L-HQC calves, whereas L-LQC calves were intermediate. Villus height to crypt depth ratio in duodenum, jejunum, and ileum was greater in HQC than LQC calves. A trend toward greater average daily gain was observed in HQC versus LQC calves (667 vs. 590 g/d) but the average daily gain was not influenced by collection time. Serum IGF-1 at d 4 was higher in HQC versus LQC calves and this might have contributed to greater average daily gain and small intestine development. Calves fed HQC had higher feed conversion ratios (FCR; total body weight gain/total dry matter intake) compared with LQC calves, and L calves had higher FCR compared with E calves. In conclusion, in comparison to feeding LQC, feeding HQC reduced the scouring duration, enhanced surface area of duodenum and jejunum, and improved FCR during the first 5 wk of calf age. Postpartum collection time of calves did not affect small intestine development, but L calves had higher FCR and required a lesser volume of electrolytes to treat scours compared with E calves during the first 35 d of life.

Effect of arginine or glutamine supplementation and milk feeding allowance on small intestine development in calves.

The development of the small intestine (SI) is important for the health and growth of neonatal calves. This study evaluated the effect of arginine (Arg) and glutamine (Gln) supplementation and 2 levels of milk allowance on the histomorphological development of the SI in preweaning calves. Sixty mixed-sex Friesian × Jersey calves (3-5 d of age) were offered reconstituted whole milk (125 g/L, 26% fat, 26% protein) at either high (20% of arrival body weight/d; HM) or low (10% of arrival body weight/d; LM) milk allowance without (Ctrl) or with supplementary Arg or Gln (at 1% of milk dry matter) in a 2 × 3 factorial design (n = 10/treatment). After 35 d on the diets, all calves were slaughtered to collect tissues for examination of SI development. Calves in the HM group had higher milk intake, total weight gain, and average daily gain compared with LM calves, but no effect of AA supplementation nor an interaction between milk allowance and AA supplementation was observed. For the duodenum, we observed an AA by milk allowance interaction for villus height and width, and goblet cell number per villus (HM-Arg > HM-Gln > HM-Ctrl), and villus height to crypt depth ratio (HM-Arg > HM-Gln = HM-Ctrl), but no effect of AA supplementation in the LM group. Goblet cell numbers per 100 µm of SI were greater in Arg-supplemented calves than in unsupplemented controls, with Gln-supplemented calves intermediate to but not different from the other groups. Epithelium thickness was greater in LM than in HM calves. Villus density, crypt depth, and muscle thickness did not differ between groups. For the jejunum, there was an AA by milk allowance interaction for villus height, villus surface area, and villus height to crypt depth ratio (HM-Arg = HM-Gln > HM-Ctrl), with no effect of AA supplementation in the LM groups. Amino acid supplementation affected goblet cell number per villus (HM-Gln > HM-Ctrl calves, HM-Arg intermediate), and both LM-Arg and LM-Gln calves had greater numbers than LM-Ctrl calves. Villus width, crypt depth, and muscle thickness were greater in HM than LM calves but there was no effect of AA supplementation. Villus density, goblet cell number per 100 µm of SI, and epithelium thickness were unaffected by AA supplementation and milk allowance. Milk allowance and AA supplementation had no effect on SI morphology in the ileum. Increasing milk allowance improved villus height, width, and surface area but only in Arg- or Gln-supplemented calves, not in control calves. The observed changes in development may be important for intestinal functionality, integrity, and barrier function in preweaning calves, potentially through increased cell growth and proliferation or reduced levels of cellular atrophy.

Evidence of vitamin D synthesis in insects exposed to UVb light.

Vertebrates obtain the prohormone vitamin D primarily by endogenous cutaneous synthesis under ultraviolet b (UVb) exposure. To date, endogenous synthesis of vitamin D in insects has never been investigated. In an initial experiment, we exposed four insect species which differ in ecology and morphology (migratory locusts, house crickets, yellow mealworms and black soldier fly larvae (BSFL)) to a low irradiance UVb source. In a second experiment we exposed these species to a higher UV irradiance, and in a third we tested the effect of exposure duration on vitamin D concentrations in yellow mealworms. Low irradiance UVb tended to increase vitamin D3 levels in house crickets, vitamin D2 levels in BSFL and vitamin D2 and D3 in yellow mealworms. Higher UVb irradiance increased vitamin D3 levels in all species but BSFL. Both BSFL and migratory locusts had increased vitamin D2 levels. Longer UVb exposure of yellow mealworms increased vitamin D2 and increased vitamin D3 until a plateau was reached at 6400 IU/kg. This study shows that insects can synthesize vitamin D de novo and that the amounts depend on UVb irradiance and exposure duration.

Evaluation of brilliance MRSA 2 agar for detection of methicillin-resistant Staphylococcus aureus in clinical samples.

We compared 2 chromogenic media (Oxoid Brilliance MRSA 2 agar [Thermo Fisher Scientific] and MRSA-ID [bioMérieux]) for the detection of methicillin-resistant Staphylococcus aureus (MRSA) in 1,368 hospital samples. For both media, broth enrichment was essential to obtain satisfactory diagnostic performance. Although with direct cultures only, the diagnostic performance (particularly sensitivity) of Brilliance MRSA 2 agar appears better than that of MRSA-ID, no difference in sensitivity or specificity between the media was detected after inclusion of an enrichment step.

Secular trends in nosocomial bloodstream infections: antibiotic-resistant bacteria increase the total burden of infection.

BACKGROUND: It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. METHODS: We investigated temporal trends in annual incidence densities (events per 100 000 patient-days) of nosocomial BSIs caused by methicillin-resistant Staphylococcus aureus (MRSA), ARB other than MRSA, and ASB in 7 ARB-endemic and 7 ARB-nonendemic hospitals between 1998 and 2007. RESULTS: 33 130 nosocomial BSIs (14% caused by ARB) yielded 36 679 microorganisms. From 1998 to 2007, the MRSA incidence density increased from 0.2 to 0.7 (annual increase, 22%) in ARB-nonendemic hospitals, and from 3.1 to 11.7 (annual increase, 10%) in ARB-endemic hospitals (P = .2), increasing the incidence density difference between ARB-endemic and ARB-nonendemic hospitals from 2.9 to 11.0. The non-MRSA ARB incidence density increased from 2.8 to 4.1 (annual increase, 5%) in ARB-nonendemic hospitals, and from 1.5 to 17.4 (annual increase, 22%) in ARB-endemic hospitals (P < .001), changing the incidence density difference from -1.3 to 13.3. Trends in ASB incidence densities were similar in both groups (P = .7). With annual increases of 3.8% and 5.4% of all nosocomial BSIs in ARB-nonendemic and ARB-endemic hospitals, respectively (P < .001), the overall incidence density difference of 3.8 increased to 24.4. CONCLUSIONS: Increased nosocomial BSI rates due to ARB occur in addition to infections caused by ASB, increasing the total burden of disease. Hospitals with high ARB infection rates in 2005 had an excess burden of BSI of 20.6 per 100 000 patient-days in a 10-year period, mainly caused by infections with ARB.

Effect of manganese in test media on in vitro susceptibility of Enterobacteriaceae and Acinetobacter baumannii to tigecycline.

We assessed the effect of increasing manganese concentrations in test media (0.001 to 1,024 mg/liter) on MICs of tigecycline. For both broth microdilution (BMD) and Etests, this effect was negligible for physiological concentrations, but MICs increased when concentrations exceeded 8 mg/liter. Susceptibility testing should be performed on media with standardized low manganese content.

Evaluation of S. aureus ID, a chromogenic agar medium for the detection of Staphylococcus aureus.

BACKGROUND: Screening for staphylococci among various patient populations has become important for appropriate therapeutic management and for control of nosocomial infections. The purpose of this study is to evaluate the in vitro sensitivity and specificity of a chromogenic agar medium, S. aureus ID (bioMérieux, France), for the identification of Staphylococcus aureus. MATERIALS AND METHODS: A well-defined collection of S. aureus and coagulase-negative staphylococci (CNS) was used. The methicillin-resistant S. aureus (MRSA) isolates were collected in The Netherlands and all had a unique typing pattern. The methicillin-susceptible S. aureus (MSSA) and CNS were isolated from cultures of blood. The isolates were inoculated on Columbia agar plates with 5% sheep blood and incubated for 24 h at 35 degrees C. From the resulting cultures, a suspension of 0.5 McFarland was made and subsequently 10 mul was streaked on a S. aureus ID plate using a sterile loop. The results were read after 24 h and 48 h of incubation at 35 degrees C. Growth of colonies showing green coloration was considered to be positive (indicating S. aureus). RESULTS: A total of 519 S. aureus strains were tested (249 MSSA, 270 MRSA). The sensitivity to detect S. aureus was 96.5% (501/519) after 24 h and 97.5% (506/519) after 48 h. A total of 478 CNS were tested. The specificity was 98.5% (471/478) after 24 h and 98.3% (470/478) after 48 h. The differences between 24 h and 48 h incubation were not statistically significant. CONCLUSION: S. aureus ID is highly sensitive and specific to differentiate between S. aureus and CNS in vitro. Since the performance does not significantly differ between 24 h or 48 h of incubation, samples need only 1 day of incubation before optimal results can be obtained.

Meningococcal pericarditis and tamponade.

We report the case of a 37-year-old female with a complex manifestation of serogroup C meningococcal disease. The patient presented with symptoms and signs of pneumonia, sepsis and diffuse intravascular coagulation. Moreover, she suffered from a culture-proven pyogenic pericarditis that deteriorated into cardiac tamponade. Immediate pericardiocentesis was successful and eventually the patient recovered.

Low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) at hospital admission in the Netherlands: the value of search and destroy and restrictive antibiotic use.

In the Netherlands, less than 1% of clinical isolates of Staphylococcus aureus are methicillin-resistant (MRSA). A national search and destroy policy prevents MRSA from becoming endemic. Some MRSA outbreaks cannot be related to patients at risk for MRSA carriage. This study was designed to measure the prevalence of MRSA among patients without risk factors for MRSA carriage at the time of admission to the hospital. In four Dutch hospitals, patients admitted to non-surgical departments in the period 1999-2000 were screened for MRSA nasal carriage. Nasal swabs were streaked on 5% sheep blood agar (BA), submerged in a selective broth, and incubated for two to three days at 35 degrees C. Colonies suspected of being S. aureus were identified with an agglutination test. Susceptibility testing was performed by an automated system and additional oxacillin disk diffusion. Methicillin resistance was confirmed by a DNA hybridization test and mecA PCR. MRSA strains were genotyped by pulsed-field gel electrophoresis (PFGE). Twenty-four percent (2332/9859) of the patients were S. aureus nasal carriers. Only three (0.03%) patients were MRSA carriers. These patients were not repatriated, nor known to be MRSA carriers before screening. Genotyping revealed that the strains were not clonally related and were not related to MRSA outbreaks in the hospital where the patients were admitted. We conclude that at routine admission to a Dutch hospital (excluding high-risk foreign admissions) the MRSA prevalence is low (0.03%), due to the Dutch search and destroy policy and restrictive antibiotic prescribing.

Nosocomial influenza infection among post-influenza-vaccinated patients with severe pulmonary diseases.

OBJECTIVES: To report an outbreak of nosocomial influenza in thirteen out of twenty-two admitted patients suffering from severe lung emphysema. METHODS: Acute-phase and convalescent serum samples of nine patients were collected. An antihaemagglutinin assay was performed to detect a rise in antibodies against influenza A virus. Further information about vaccination history of the patients and healthcare workers was included. RESULTS: The majority of these twenty-two patients was vaccinated with a trivalent vaccine six months earlier. The immunological response showed that the influenza A (H3N2) strain which caused these infections is similar to the vaccine strain A/Sydney/5/97. CONCLUSIONS: The staff of our institute which was not systematically vaccinated may have been the source of infection. The time elapsed between the vaccination and the infection is the probable explanation of this event.

Outbreak of meningococcal disease caused by PorA-deficient meningococci.

An outbreak of 7 cases of group C meningococcal disease occurred during the last week of July and the first week of August 2001 in the southwestern part of The Netherlands. Characterization of the 7 patients' isolates by various typing methods showed that the isolates were identical, except for the expression of PorA. Isolates from 5 patients were PorA deficient. These results show that transmission of PorA-deficient meningococci occurs and that PorA-deficient meningococci can cause invasive disease. PorA-based meningococcal vaccines may provide limited protection.

[Melioidosis]. / Melioidosis.

A 34-year-old woman presented two weeks after a visit to Burma with fever peaking up to 39 degrees C, chills, non-productive cough, headache, muscle pain, shortness of breath and a painful swelling on the left lower leg. She was treated immediately with intravenous amoxycillin-clavulanic acid. The Gram negative causative agent of melioidosis, Burkholderia (previously Pseudomonas) pseudomallei, was cultured from samples taken beforehand. The patient then received ceftazidime. She recovered. In view of the risk of relapse she was treated with amoxycillin-clavulanic acid for a further six months. Melioidosis is endemic in Southeast Asia and Northern Australia. It is rarely seen outside these areas. The clinical spectrum of the disease is wide and varies from fulminating sepsis to a subclinical disease and may affect any organ system, usually the lungs. The mortality of the septicaemic form after adequate treatment is 40%. Surviving patients have a high relapse rate (4-20%). Melioidosis can become chronic with formation of abscesses or can remain subclinical for many years, probably because the microorganism can survive within phagocytic cells with a risk of reactivation at moments of immunosuppression. The optimal treatment consists of ceftazidime intravenously for at least two weeks followed by an eradication phase consisting of oral antibiotics for at least 3 months.

[Tick-encephalitis after a vacation in Southern Germany]. / Teken-encefalitis na een vakantie in Zuid-Duitsland.

A 38-year-old man was admitted with signs of meningoencephalitis. Tick-borne encephalitis was considered because the patient reported a tick bite during a vacation in South Germany and because of the biphasic course of the symptoms. Serology for tick-borne encephalitis was positive: this constituted the first reported positive serology outcome in the National Institute for Public Health and Environment in the Netherlands. Tick-borne encephalitis is an infection with a flavivirus transmitted by an infected tick, which is endemic in parts of Central and Eastern Europe. The neurological symptoms are meningitis, meningoencephalitis or meningoradiculomyelitis. In a small percentage of patients neurological symptoms persist. A reliable vaccine is available, but is not routinely recommended for tourists.

Multicenter evaluation of a modified protocol for the RAPIDEC staph system for direct identification of Staphylococcus aureus in blood cultures.

A modified protocol for the RAPIDEC Staph system (bioMérieux, Marcy-l'Etoile, France) for direct identification of Staphylococcus aureus in blood cultures was evaluated in a multicenter study. A total of 129 blood cultures (BACTEC 9000 Blood Culture System; Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) containing gram-positive cocci in clusters were analyzed by conventional methods and by RAPIDEC Staph in accordance with the manufacturer's protocol and in accordance with a modified protocol. The sensitivity, specificity, and positive and negative predictive values obtained with the manufacturer's protocol were 90.5, 97.7, 95. 0, and 95.5%, respectively, and those obtained with the modified protocol were 100, 96.6, 93.3, and 100%, respectively. The modified protocol for the RAPIDEC Staph is easier to perform than the manufacturer's protocol and is very reliable.

[Extra-intestinal infections caused by Vibrio spp. in The Netherlands]. / Extra-intestinale infecties door Vibrio spp. in Nederland.

Six patients with serious cellulitis or ear infection due to Vibrio vulnificus, V. parahaemolyticus or V. alginolyticus are described. Four patients were infected during the summer in the Netherlands and two outside the Netherlands. Contact with seawater was the most probable source in four patients. In two patients the infection, caused by V. vulnificus, was transmitted by eel. This is a new way of transmission.

The effect of respiration on diastolic blood flow velocities in the human heart.

This study was performed to evaluate the effects of respiration on diastolic blood flow velocity and its relevance for the determination of pulsed Doppler reference values from diastolic blood flow. Doppler signals were recorded from both the atrial and ventricular sides of the mitral valve and the tricuspid valve in 215 healthy volunteers (120 males and 95 females, with ages ranging from 1-65 years). Respiratory signals were recorded simultaneously by a mercury strain gauge around the thorax. From the medians of Doppler spectra the maximum velocity during early diastole (VmaxE), during atrial contraction (VmaxA) and the ratio between VmaxE and VmaxA (EA ratio) were obtained. On the atrial side of the tricuspid valve, VmaxE and VmaxA were significantly higher during inspiration than during expiration. On the ventricular side of the tricuspid valve, this was only found for VmaxE. On the atrial side of the mitral valve, VmaxE and VmaxA were significantly lower during inspiration than during expiration. At the ventricular side of the mitral valve, this was found only for VmaxE. No significant effect of respiration was found on the EA ratio. We conclude that there is a respiration-related effect on VmaxE and VmaxA. However, no significant effect is found on the EA ratio. Thus, for the determination of the EA ratio in intersubject studies, information about the respiratory cycle is not relevant.