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D J Mevius

Publications and source records attributed to D J Mevius.

At least 19 recordsLinked to original sources
PubMed2006

Establishing the change in antibiotic resistance of Enterococcus faecium strains isolated from Dutch broilers by logistic regression and survival analysis.

In this study, we investigated the change in the resistance of Enterococcus faecium strains isolated from Dutch broilers against erythromycin and virginiamycin in 1998, 1999 and 2001 by logistic regression analysis and survival analysis. The E. faecium strains were isolated from caecal samples that had been randomly collected from six slaughterhouses. Moreover, between the sample collection in 1998 and the sample collection in 1999, virginiamycin and the macrolide antibiotics (of which erythromycin is a member) have been banned in The Netherlands from use in broiler feeds as growth promoter. In the logistic regression analysis we used the internationally accepted cut-off values to determine whether bacteria were resistant or not. In the survival analysis, inhibition of bacterial growth was the event and time to event was replaced by concentration of antibiotic to event. As a consequence, changes in the growth of bacteria can be tested over an entire range of concentrations and no cut-off value for resistance has to be determined. We performed the survival analysis by use of a Cox logistic model with an odds ratio (OR) for the increase of the odds of the basic hazard rate as outcome. Both the logistic regression and the survival analyses showed that resistance to erythromycin and virginiamycin decreased during the study period. In the logistic regression model the ORs associated with the fraction of bacteria inhibited by the antibiotics in 2001 as compared to 1998 were 3.76 (2.57-5.49) for erythromycin and 11.65 (7.68-17.66) for virginiamycin. The corresponding ORs from the survival analysis were lower; 2.88 (2.21-3.76) and 2.11 (1.80-2.49), respectively. The reason for the differences between the ORs of the survival analysis and the logistic regression analysis is probably because most changes in resistance included the cut-off value and logistic regression specifically examines those changes.

Abattoirs↗
PubMed2006

Campylobacter in primary animal production and control strategies to reduce the burden of human campylobacteriosis.

Campylobacteriosis is one of the most important bacterial food-borne illnesses in humans. One significant source of infection is the handling and consumption of poultry meat, although other sources also contribute considerably. Controlling Campylobacter in broilers reduces the human burden of illness. Broilers can easily become colonised with Campylobacter and preventive measures in primary production have a limited and unpredictable effect. Vaccination, competitive exclusion, bacteriophage therapy and the use of bacteriocins are not yet commercially available. However, measures in the slaughterhouse can reduce contamination in the final product. At present, the most promising control strategy is to keep colonised and non-colonised flocks separate during slaughter ('scheduled processing'). The virtually Campylobacter-free meat can supply the fresh poultry meat market, while the meat from infected flocks can be treated to reduce the Campylobacter concentration. Meat from infected flocks can be treated by freezing but chemical decontamination appears to be more cost effective. A variant of this scenario is to treat only highly contaminated meat. The authors conclude that, until new techniques become commercially available, scheduled processing is the most cost-effective approach. Finally, the authors describe trends in antimicrobial resistance in Campylobacter.

Animals↗
PubMed2003

Investigations of Enterococcus faecalis-induced bacteraemia in brown layer pullets through different inoculation routes in relation to the production of arthritis.

In the present aerosol experiment, assessment of the respiratory tract of 1-day-old birds as a natural route of infection for induction of Enterococcus faecalis bacteraemia and arthritis was performed. Second, the severity and type of arthritis produced through intramuscular infection in two different inoculation sites (musculus pectoralis versus musculus gastrocnemius) was studied. Third, the resulting bacteraemia was assessed qualitatively and quantitatively in relation to the occurrence of arthritis. Exposure of 1-day-old brown layer pullets to aerosolized E. faecalis with an estimated uptake of 10(4) to 10(5) colony forming units per chick resulted in bacteraemia; however, joint lesions were not induced. In contrast, 3/10 birds inoculated intratracheally with 10(8) colony forming units developed both bacteraemia and arthritis. This suggests the occurrence of a dose effect and a role for the respiratory tract as a natural infection route in young chickens. In both intramuscularly inoculated groups the incidence of arthritis was 10/10 birds and 9/10 birds, respectively. Birds inoculated in the m. pectoralis developed symmetric polyarthritis, which harmonizes with haematogenous colonization of joints. In contrast, m. gastrocnemius-inoculated chicks mostly had asymmetric (poly)arthritis of the injected leg and varus deformation of the contralateral leg, suggesting predominantly local spread. The qualitative and quantitative results of bacteriology of blood samples show that arthritis develops in those groups with the highest number of bacteraemic birds and the highest median bacterial colony forming units per millilitre of blood during the first 24 to 36 h after treatment.

Aerosols↗
PubMed2003

Explosive increase of Salmonella Java in poultry in the Netherlands: consequences for public health.

In the Netherlands Salmonella Paratyphi B variant Java increased in poultry from less than 2% of all isolates before 1996 to 60% in 2002. Despite exposure to contaminated meat is high, human patients with Java infection are rare (0.3% of all isolates). However, 50% of the human isolates showed PFGE profiles identical to the poultry clone. Resistance to flumequin in S. Java increased from 3% between 1996-2000 to 19% in 2001, and 39% in 2002, while that of other serotypes in poultry remained at about 7%. S. Java is also fast becoming less sensitive to ciprofloxacin.

Animals↗
PubMed2002

[Explosive increase in Salmonella java in poultry. Consequences for public health].

In the Netherlands S. Paratyphi B variation Java increased in poultry from less than 2% of all isolates before 1996 up to 40% in 2001. This development in poultry runs in parallel with that in Germany and appears not to occur in other European countries. A German study shows that in the late nineties it concerns isolates of only one multi-resistant clone of Java (in Holland as well) whilst isolates before the middle nineties were genetically much more heterogeneous and sensitive to antibiotics. Although the exposition of humans to contaminated poultry meat is relatively high, human patients with a Java infection are rare. Treatment of poultry flocks with quinolones was about 13% in 2000-2001. Resistance to flumequin of Java increased from 3% between 1996-1999 to 20% between 2000-2002 whilst that of other serotypes in poultry remained about 7%. Java is also fast becoming less sensitive to ciprofloxacin which is the antibiotic of first choice in serious cases of salmonellosis. The ministries of public health, agriculture and the production boards, with their research institutes, together with the poultry meat production chain integrations have recently decided to work together in order to determine the public health importance of the Java epidemic in poultry and finding measures for effective control in the poultry industry.

Animals↗
PubMed2002

Molecular epidemiology of unilateral amyloid arthropathy in broiler breeders associated with Enterococcus faecalis.

Although symmetrical polyarticular amyloidosis has been described extensively in brown layers, spontaneous unilateral amyloid arthropathy has not been described previously in chickens. Birds from nine flocks of broiler parent stock (PS) had unilateral lameness associated with severe swelling of the left hock joint and the caudal aspect of the metatarsus. Gross pathology was restricted to the left hock joint and the left digital flexor tendons in almost all cases, suggesting an association with administration of Marek's disease vaccine. Amyloid deposits were found in 83% (25/30) of affected joints by histological examination of Congo red stained sections. Systemic amyloidosis, involving mainly the liver and spleen, was found in 59% (10/17) of birds. Enterococcus faecalis was isolated from joints in 77% (23/30) of cases and Staphylococcus aureus was isolated from the joint in one case (1/30). Thirty-five E. faecalis isolates from joints, tendons and blood samples from birds in five affected PS flocks were compared using pulsed-field gel electrophoresis (PFGE) to separate genomic fragments after digestion with SmaI. All but one isolate had identical or closely related restriction endonuclease digestion (RED) patterns that were very similar to a known arthropathic and amyloidogenic E. faecalis isolate. A further 30 E. faecalis isolates from seven grandparent stock (GPS) flocks and two isolates from two unaffected PS flocks of the same genetic background were analysed by PFGE. Among these isolates, 11 originating from four GPS flocks had RED patterns identical to or closely related to the reference amyloid-inducing strain. Moreover, one E. faecalis isolate from amyloidotic joints of brown layers housed in California, USA was included in the analysis and appeared to be identical to the reference strain. This study showed that the E. faecalis isolates involved in these outbreaks of unilateral amyloid arthropathy in broiler breeders belonged to the same clone as that responsible for outbreaks in brown layers.

Amyloidosis↗
PubMed2001

Study on the vertical transmission of arthropathic and amyloidogenic Enterococcus faecalis in a flock of brown layer chickens.

Enterococcus faecalis-related amyloid arthropathy was diagnosed in a sample of birds from a flock of brown layer parent chickens aged 57 weeks. E. faecalis was isolated from amyloidotic knee joints and from blood samples from lame birds. From this flock a smaller one was kept for production purposes to study the vertical transmission of arthropathic and amyloidogenic E. faecalis. Three batches of non-soiled and thoroughly disinfected eggs, to prevent egg-shell contamination, were collected for 6 weeks and submitted for incubation every 2 weeks. No joint pathology was found in the offspring chicks (n = 458) monitored for joint disease until 16 or 21 weeks of age. Fresh and candled eggs (infertiles and dead embryos) obtained at day 18 of the incubation period had negative results at bacteriological examination of the yolk sac, except one non-hatched egg (late embryonal death in shell) from which E. faecalis was isolated. Genotyping by pulsed-field gel electrophoresis (PFGE) of all E. faecalis isolates obtained from blood and joints (except one) of the parent birds and of the non-hatched egg after Sma I digestion showed that all isolates were genetically closely related or identical to a known arthropathic and amyloidogenic E. faecalis strain. In this study, vertical transmission of E. faecalis, although it may occur on a small scale as shown by PFGE, did not seem to play a significant role. Conversely, the chronicity of the condition and the development of an immune response may have affected the efficiency of its transmission.

Amyloidosis↗
PubMed2000

[Preliminary results of antibiotic resistance monitoring in the Netherlands].

Qualitative tests are used to monitor antimicrobial resistance in bacteria of animal origin in the Netherlands. Quantitative information on trends in resistance is thus not obtained. Moreover, in general a limited panel of antibiotics is tested. The present study describes resistance in zoonotic food-borne pathogens Salmonella, Campylobacter, and Escherichia coli O157 isolated from human clinical cases and from faeces of healthy food animals in 1998 and 1999, as determined with quantitative susceptibility tests. The resistance of the indicator organisms E. coli and Enterococcus faecium isolated from faecal samples of broilers and pigs randomly sampled at slaughterhouses was also determined. For this end, faecal samples from veal calves were sampled in 1996 and 1997 at the three main Dutch veal calf slaughterhouses. In 1998 only a limited number of faecal samples of veal calves were taken at farms. For E. coli and Salmonella the following antibiotics were tested: amoxicillin, amoxicillin-clavulanic acid, piperacillin, cefotaxime, ceftazidime, imipenem, gentamicin, doxycycline, trimethoprim, trimethoprim/sulphamethoxazole, ciprofloxacin, chloramphenicol, florfenicol, carbadox, and flumequine. For E. faecium the following antibiotics were tested: amoxicillin, amoxicillin-clavulanic acid, chloramphenicol, doxycycline, erythromycin, vancomycin, teicoplanin, streptomycin ('high level' > 2000 mg/ml), gentamicin ('high level' > 500 mg/ml), ciprofloxacin, bacitracin, flavofosfolipol, salinomycin, quinupristin-dalfopristin, virginiamycin, tilmicosin, avilamycin, and everninomycin. For Campylobacter the following antibiotics were tested: erythromycin, doxycycline, gentamicin, carbadox, flavofosfolipol, ciprofloxacin, trimethoprim/sulphamethoxazole, amoxicillin, and metronidazole.

Animals↗
PubMed2000

[In vitro activity of 12 antibiotics used in veterinary medicine against Mannheimia haemolytica and Pasteurella multocida isolated from calves in the Netherlands].

Results of susceptibility tests of clinical isolates of animal pathogens are periodically summarized and reported by the Animal Health Service. However, these results are based upon qualitative test methods. In the present paper results of quantitative susceptibility tests of twelve antibacterial agents against Mannheimia haemolytica (MHA) and Pasteurella multocida (PMU) isolated from Dutch calves in 1996 and 1997 are presented. Minimum inhibitory concentrations of amoxicillin, ceftiofur, tetracycline, trimethoprim-sulphamethoxazole, tilmicosin, neomycin, gentamicin, spectinomycin, flumequine, enrofloxacin, chloramphenicol and florfenicol were determined. No resistance was detected for ceftiofur and florfenicol. Three strains had an intermediate susceptibility to tilmicosin. The resistance percentages of MHA and PMU for neomycin, gentamicin, spectinomycin, flumequine, enrofloxacin, and chloramphenicol varied from 2% to 16%. Higher resistance percentages (16%-53%) were observed for amoxicillin, tetracycline, and trimethoprim-sulphamethoxazole. The MIC breakpoints used to determine whether a strain is susceptible, intermediate, or resistant are arbitrary and discussed in this paper.

Animals↗
PubMed1999

[European strategy for control of resistance to antibiotics].

The problem of international spread of bacterial resistance requires development of a strategy at worldwide or at least at European level. Clinically relevant monitoring systems for resistance and use of antibiotics have to be implemented to support the guidelines on prescription of antibiotics. Every hospital should establish an 'antibiotics team' controlling the prescription of antimicrobials and the observance of local formulary agreements. Veterinary use of growth promoting antimicrobials related to substances used in human medicine should be terminated. Future research should be aimed at resolving the problem of resistance to antimicrobials.

Animals↗
PubMed1999

EU conference 'The Microbial Threat'.

A global or European strategy should be developed to deal with increasing antimicrobial resistance. This strategy includes surveillance of antimicrobial resistance and monitoring of the use of antimicrobial agents in animals and humans. In animals, surveillance should be focussed on potential transfer of resistant, zoonotic, food-born pathogens and resistance genes to humans. In humans the surveillance should be clinically relevant. Guidelines for rational therapy should be implemented and 'antibiotic teams' should be installed in each hospital to evaluate the prescription of antibiotics and its compliance with guidelines. Keeping animals for food production involves the responsibility for their well being. This includes treatment of infections. However, the use of feed additive, growth-promoting antimicrobials related to therapeutics in human medicine, should be banned immediately. Research aimed at intervention strategies for antimicrobial resistance should be given a high priority with adequate financing both nationally and in Europe. Well co-ordinated European research programmes should have priority; this includes the need to install a European multidisciplinary scientific advisory group.

Animals↗
PubMed1999

Sensitivity testing of veterinary pathogens with a semi-automatic image analysis system compared with tablet diffusion and agar dilution tests.

Recently a commercial computer-controlled image analysis system (IAS) was introduced to measure automatically the diameters of inhibition zones in the agar diffusion test. However, there is little information on the precision of this method. In the present study clinical isolates of Salmonella spp. (N = 104), Escherichia coli (N = 100), Pasteurella spp. (N = 99), Actinobacillus pleuropneumoniae (N = 85), porcine streptococci (N = 100), and Staphylococcus aureus (N = 95) were tested in the agar diffusion test, using nineteen different antibiotics in tablets. All inhibition zone diameters were first measured by a laboratory technician and then by the IAS. Although the zone diameters of all bacteria-antibiotic combinations measured by the IAS and those measured by the laboratory technician showed a significant positive correlation, the size of the inhibition zone diameters measured by the technician and the IAS differed significantly in 59% of the combinations. However, these differences were very small and may have no clinical relevance. The IAS was also used to calculate minimum inhibitory concentrations (MIC values) from the zone diameters. In 82% of the bacteria-antibiotic combinations MIC values calculated by the IAS showed a significant positive correlation with MIC values obtained with the reference agar dilution test. However, in 92% of the bacteria-antibiotic combinations, the calculated MIC values differed significantly from the reference values. In some cases these differences were so large that they could be of clinical relevance. The IAS was unable to measure the diameter of inhibition zones of porcine streptococci properly, due to poor contrast. We concluded that when tablets are used as antibiotic carriers the IAS accurately measures the diameter of inhibition zones for bacteria species that give good contrast between the agar and bacterial growth. MIC values determined with the IAS were only indicative of those determined with the reference agar dilution test.

Agar↗
PubMed1999

Molecular diversity and evolutionary relationships of Tn1546-like elements in enterococci from humans and animals.

We report on a detailed study on the molecular diversity and evolutionary relationships of Tn1546-like elements in vancomycin-resistant enterococci (VRE) from humans and animals. Restriction fragment length polymorphism (RFLP) analysis of the VanA transposon of 97 VRE revealed seven different Tn1546 types. Subsequent sequencing of the complete VanA transposons of 13 VRE isolates representing the seven RFLP types followed by sequencing of the identified polymorphic regions in 84 other VanA transposons resulted in the identification of 22 different Tn1546 derivatives. Differences between the Tn1546 types included point mutations in orf1, vanS, vanA, vanX, and vanY. Moreover, insertions of an IS1216V-IS3-like element in orf1, of IS1251 in the vanS-vanH intergenic region, and of IS1216V in the vanX-vanY intergenic region were found. The presence of insertion sequence elements was often associated with deletions in Tn1546. Identical Tn1546 types were found among isolates from humans and farm animals in The Netherlands, suggesting the sharing of a common vancomycin resistance gene pool. Application of the genetic analysis of Tn1546 to VRE isolates causing infections in Hospitals in Oxford, United Kingdom, and Chicago, Ill., suggested the possibility of the horizontal transmission of the vancomycin resistance transposon. The genetic diversity in Tn1546 combined with epidemiological data suggest that the DNA polymorphism among Tn1546 variants can successfully be exploited for the tracing of the routes of transmission of vancomycin resistance genes.

Animals↗
PubMed1996

Bioequivalence study in calves of three commercial penicillin/dihydrostreptomycin fixed combination products for intramuscular injection.

A bioequivalence study with three penicillin/dihydrostreptomycin fixed combination products for intramuscular administration was performed in dairy calves. In addition to plasma concentrations of penicillin and dihydrostreptomycin, creatine phosphokinase concentrations were determined during a period of 72 h after administration of the drug products. Considerable differences were observed in the pharmacokinetics of penicillin from the three products. Although the extent of absorption was similar for all products, one product showed a significantly slower release from the site of injection. Except for the AUC, the 90% confidence intervals for these parameters exceeded the acceptable range of 0.80-1.20. Therefore, these products are not bioequivalent with respect to the rate of absorption of penicillin. Concerning the pharmacokinetics of dihydrostreptomycin in calves, it could not be concluded that the products were bioequivalent, since the 90% confidence intervals of the ratios for Cmax, tmax and MRT exceeded the range of 0.80-1.20. From this study in calves, it was also found that the product with the slowest release of penicillin from the injection site caused the most severe tissue damage, based on plasma creatine phosphokinase concentrations. Comparing the results from this study in calves with those from a previous study in rabbits, it can be concluded that the rabbit is a good animal model that could substitute for large animals, at least calves, in bioequivalence studies for penicillin/dihydrostreptomycin fixed combination products.

Analysis of Variance↗
PubMed1994

A comparative study of the pharmacokinetics of intravenous and oral trimethoprim/sulfadiazine formulations in the horse.

The biopharmaceutical properties of four fixed trimethoprim/sulfonamide combinations were investigated in the horse. Eight fasted horses were dosed at 1 week intervals in a sequentially designed study with one intravenous (i.v.) and three oral trimethoprim/sulfadiazine (TMP/SDZ) formulations (1, 2 and 3) administered at a dose of 5 mg/kg trimethoprim (TMP) and 25 mg/kg sulfadiazine (SDZ). Plasma concentrations of each compound were monitored for 48 h. Pharmacokinetic parameters (volume of distribution, bioavailability and total body clearance) for TMP and SDZ were calculated and compared. After oral administration plasma concentrations of TMP and SDZ increased rapidly. With all three paste formulations, TMP peak plasma concentrations were attained within 2 h. SDZ mean peak plasma concentrations were reached at 2.59 +/- 0.48 h for a commercial paste (1), and at 1.84 +/- 0.66 h and 1.95 +/- 0.61 h for the two self-made formulations (2 and 3). Mean peak plasma TMP concentrations (+/- SD) were 1.72 +/- 0.36 micrograms/ml, 1.42 +/- 0.37 micrograms/ml and 1.31 +/- 0.36 micrograms/ml, and mean peak plasma SDZ concentrations 12.11 +/- 4.55 micrograms/ml, 12.72 +/- 3.47 micrograms/ml and 15.45 +/- 4.74 micrograms/ml for preparations 1, 2 and 3. The bioavailability of TMP was 67.0 +/- 20.3%, 57.7 +/- 21.6% and 60.9 +/- 18.9% and of SDZ 57.6 +/- 14.8%, 59.3 +/- 19.5% and 65.9 +/- 5.8% for SDZ for 1, 2 and 3, respectively. Following i.v. administration TMP/SDZ plasma concentration ratios approached the optimal 1:20 ratio (+/- 10%) for about 5 h, but following the oral administrations this ratio was only achieved for a very short time-span.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Effects of different iron contents in the milk replacer on the development of iron deficiency anaemia in veal calves.

The effect of different iron concentrations in the milk replacer on the development of iron deficiency anaemia during a fattening period of 28 weeks was studied in three groups of 14 calves. The iron contents in the milk replacer differed during the first seven weeks: 60, 100 and 150 mg Fe/kg in groups A, B and C, respectively. In all three groups blood haemoglobin, mean corpuscular volume, plasma iron concentration and saturation decreased during the fattening period, whereas the total iron-binding capacity increased. At week 7, liver iron concentrations were high with a large individual variation [A: 201 (61-706), B: 99 (47-129), C: 296 (77-1572) micrograms/g dry matter]. During the fattening period, liver iron concentrations decreased, with the lowest values at week 25 [A: 54 (34-82), B: 55 (44-83), C: 57 (42-79) micrograms/g dry matter]. Muscle iron concentrations decreased between week 7 and 19. Except plasma iron and saturation in group C, no differences in haematological and tissue iron variables were found throughout the fattening period in spite of different iron contents in the milk replacer during the first seven weeks.

Anemia, Hypochromic↗