Effect of hospitalization on the antibiotic resistance of fecal Enterococcus faecalis of surgical patients over time.

The prevalence of antibiotic resistant Enterococcus faecalis was determined in fecal samples of 263 patients admitted to the surgical wards of three university-affiliated hospitals on admission, at discharge, and at 1 and 6 months after discharge. A slight increase in the prevalence of antibiotic resistance of E. faecalis was found at discharge for the antibiotics tested compared to those on admission, vancomycin excepted. At 6 months after discharge, the prevalence of resistance for amoxicillin (0%), ciprofloxacin (3%), erythromycin (47%), and oxytetracycline (60%) decreased to the level on admission (respectively 0%, 8%, 45%, and 64%). Gentamicin resistance was the same at discharge (10%) as 1 month later (12%), but decreased 6 months after discharge (8%) to the level on admission (7%). In conclusion, hospitalization resulted in the study population in a slight increase in the prevalence of resistant fecal E. faecalis isolates at discharge, which decreased again (slowly) to the level on admission 6 months after discharge. Thus, the influence of hospitalization on the prevalence of antibiotic resistance in the extramural situation disappears between 1 and 6 months after discharge in this population.

Survival of the probiotic, L. plantarum 299v and its effects on the faecal bacterial flora, with and without gastric acid inhibition.

INTRODUCTION: Probiotic bacteria have to survive passage through the gastrointestinal tract. In this placebo-controlled double-blind study, the effect of Lactobacillus plantarum 299v on the faecal flora was studied with and without gastric acid inhibition. METHODS: Thirty-two healthy volunteers were given pantoprazole (40 mg/day) or placebo for 3 weeks from week 2 until week 4. In addition, from week 3 until week 4, L. plantarum 299v in an oatmeal-fermented drink (10(9) CFU/ml) was given twice daily to both groups. From each healthy volunteer, faecal samples were collected at the end of week 1, 2, 4 and 8 (4 weeks after cessation of L. plantarum 299v and pantoprazole/placebo). Several aerobically and anaerobically growing bacteria were counted and short chain fatty acid concentrations were determined. RESULTS: In both the pantoprazole and the placebo group, median lactobacilli counts increased significantly in week 4 compared to week 1 (from log 4.5 to 8.0 CFU/g faeces in pantoprazole and from log 4.2 to 7.7 CFU/g faeces in placebo group) and decreased significantly in week 8 (to log 4.5 CFU/g faeces in pantoprazole and log 4.3 CFU/g faeces in placebo group). These lactobacilli were identified as L. plantarum 299v. No significant differences were observed in all other bacterial counts and short chain fatty acid concentrations. CONCLUSIONS: The comparable increase of faecal lactobacilli counts in both the pantoprazole and the placebo-treated group demonstrates that L. plantarum 299v survives passage through the gastrointestinal tract irrespective of gastric acidity. The increment of the intra-gastric pH in combination with L. plantarum 299v did not modulate bacterial composition and/or the production of short chain fatty acids.

Bile acids and pH values in total feces and in fecal water from habitually omnivorous and vegetarian subjects.

Twenty habitually omnivorous subjects and 19 habitually lactoovovegetarian subjects aged 59-65 y collected feces during 4 consecutive days. The concentrations of bile acids in total feces did not differ between the omnivores and vegetarians, but the bile acid concentrations in fecal water were significantly lower in the vegetarians. The concentration of the colorectal cancer-predicting bile acid deoxycholic acid in fecal water was explained by the intake of saturated fat and the daily fecal wet weight (r2 = 0.50). Fecal pH did not differ between the omnivores and vegetarians. This variable was significantly (P < 0.05) explained by the intake of calcium (r2 = 0.30); 24-h fecal wet weight and defecation frequency were significantly higher in the vegetarians. In conclusion, our vegetarian subjects had a lower concentration of deoxycholic acid in fecal water, higher fecal wet weight, and higher defecation frequency than the omnivorous subjects.

Effects of a calcium binder on the solubility of bile acids and fatty acids in the large intestine of the rat.

Kidney stone patients with hypercalciuria type I are treated with an oral calcium binder. Lower intakes of calcium (Ca) in the range of 0-1500 mg/day have been associated with an increased incidence of colorectal cancer. The aim of this study is to analyze the effects of feeding ethylene diamine tetraacetic acid sodium salt (EDTA), a strong, non-absorbable binder of Ca, on the solubility of bile acids (BA) and long chain fatty acids (LCFA) in the large intestine of the rat. We have shown that the concentrations of soluble BA and LCFA in the large intestine contents remained constant while the concentration of total BA and LCFA decreased. Therefore, lowering the amount of Ca available for binding BA or LCFA is unlikely to increase the risk of colorectal cancer by that method.

Antibiotic usage in animals: impact on bacterial resistance and public health.

Antibiotic use whether for therapy or prevention of bacterial diseases, or as performance enhancers will result in antibiotic resistant micro-organisms, not only among pathogens but also among bacteria of the endogenous microflora of animals. The extent to which antibiotic use in animals will contribute to the antibiotic resistance in humans is still under much debate. In addition to the veterinary use of antibiotics, the use of these agents as antimicrobial growth promoters (AGP) greatly influences the prevalence of resistance in animal bacteria and a poses risk factor for the emergence of antibiotic resistance in human pathogens. Antibiotic resistant bacteria such as Escherichia coli, Salmonella spp., Campylobacter spp. and enterococci from animals can colonise or infect the human population via contact (occupational exposure) or via the food chain. Moreover, resistance genes can be transferred from bacteria of animals to human pathogens in the intestinal flora of humans. In humans, the control of resistance is based on hygienic measures: prevention of cross contamination and a decrease in the usage of antibiotics. In food animals housed closely together, hygienic measures, such as prevention of oral-faecal contact, are not feasible. Therefore, diminishing the need for antibiotics is the only possible way of controlling resistance in large groups of animals. This can be achieved by improvement of animal husbandry systems, feed composition and eradication of or vaccination against infectious diseases. Moreover, abolishing the use of antibiotics as feed additives for growth promotion in animals bred as a food source for humans would decrease the use of antibiotics in animals on a worldwide scale by nearly 50%. This would not only diminish the public health risk of dissemination of resistant bacteria or resistant genes from animals to humans, but would also be of major importance in maintaining the efficacy of antibiotics in veterinary medicine.

The effect of Lactobacillus plantarum 299v on the bacterial composition and metabolic activity in faeces of healthy volunteers: a placebo-controlled study on the onset and duration of effects.

AIM: To study the onset and duration of a possible effect of a fermented oatmeal drink containing Lactobacillus plantarum 299v on the composition of the faecal flora of healthy volunteers in a placebo-controlled, double-blind study. METHODS: Twenty-two participants consumed a fermented oatmeal drink with or without L. plantarum 299v for 4 weeks. Faecal samples were collected weekly: two samples before, four during and four after the consumption of the drink. Several bacterial species were counted and enzyme activities, short-chain fatty acid concentrations, endotoxin concentration and pH were determined. L. plantarum 299v was identified using randomly amplified polymorphic DNA. RESULTS: In contrast with the placebo group, median lactobacilli counts increased significantly from 4.2 (3.4-6.3) to 8.2 (7.3-8.5) log colony-forming units/gram faeces (P = 0.005) after 1 week of consumption of L. plantarum 299v, thereafter remaining stable during the treatment period. One week after cessation, a significant decrease in lactobacilli [to 4.4 (2.2-6.5) log colony-forming units/gram faeces] was observed (P = 0.003). These lactobacilli were identified as L. plantarum 299v. All other bacterial counts, enzyme activities, short-chain fatty acid concentrations, endotoxin concentration and pH remained unchanged. CONCLUSIONS: L. plantarum 299v significantly increased the number of lactobacilli in the faecal flora within 1 week, and this effect disappeared within 1 week after cessation of intake. No other changes in bacterial counts and metabolic products were observed.

Genetic characterization of glycopeptide-resistant enterococci of human and animal origin from mixed pig and poultry farms.

Glycopeptide resistant enterococci (GRE) isolated from animals and humans were characterised using both AFPL typing and genetic characterisation of the glycopeptide resistance transposon Tn1546. All isolates were collected in 1997 when the glycopeptide avoparcin was still being used as growth promoter. All investigated animal isolates were from mixed pig and poultry farms in the Netherlands and the human isolated from the farmers of these farms. A total of 24 isolates were investigated. AFLP and Tn1546 typing revealed that both pig and poultry related enterococcal and vanA transposon genotypes were found among the human isolates indicating spread of glycopeptide resistance from both pig and poultry to the farmers. These findings contradict previous finding that showed that GRE recovered from the general population were genotypically undistinguishable from GRE isolated from pigs but are in line with other studies that demonstrated spread of GRE from poultry to farmers in poultry farms.

Antibiotic usage and resistance in different regions of the Dutch community.

Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different regions: 11.19, 10.84, and 7.16 DDD (defined daily dosage) per 1,000 inhabitants per day, respectively. No significant regional differences were found in the prevalence of antibiotic resistance for both E. coli and enterococci. However, the differences in antibiotic consumption observed might lead to changes in antibiotic resistance in the near future. Surveillance of antibiotic use and antibiotic resistance is strongly recommended to control the development of antibiotic resistance because it provides epidemiological data to set up and control antibiotic guidelines.

Epidemiology of resistance to antibiotics. Links between animals and humans.

An inevitable side effect of the use of antibiotics is the emergence and dissemination of resistant bacteria. Most retrospective and prospective studies show that after the introduction of an antibiotic not only the level of resistance of pathogenic bacteria, but also of commensal bacteria increases. Commensal bacteria constitute a reservior of resistance genes for (potentially) pathogenic bacteria. Their level of resistance is considered to be a good indicator for selection pressure by antibiotic use and for resistance problems to be expected in pathogens. Resistant commensal bacteria of food animals might contaminate, like zoonotic bacteria, meat (products) and so reach the intestinal tract of humans. Monitoring the prevalence of resistance in indicator bacteria such as faecal Escherichia coli and enterococci in different populations, animals, patients and healthy humans, makes it feasible to compare the prevalence of resistance and to detect transfer of resistant bacteria or resistance genes from animals to humans and vice versa. Only in countries that use or used avoparcin (a glycopeptide antibiotic, like vancomycin) as antimicrobial growth promoter (AMGP), is vancomycin resistance common in intestinal enterococci, not only in exposed animals, but also in the human population outside hospitals. Resistance genes against antibiotics, that are or have only been used in animals, i.e. nourseothricin, apramycin etc. were found soon after their introduction, not only in animal bacteria but also in the commensal flora of humans, in zoonotic pathogens like salmonellae, but also in strictly human pathogens, like shigellae. This makes it clear that not only clonal spread of resistant strains occurs, but also transfer of resistance genes between human and animal bacteria. Moreover, since the EU ban of avoparcin, a significant decrease has been observed in several European countries in the prevalence of vancomycin resistant enterococci in meat (products), in faecal samples of food animals and healthy humans, which underlines the role of antimicrobial usage in food animals in the selection of bacterial resistance and the transport of these resistances via the food chain to humans. To safeguard public health, the selection and dissemination of resistant bacteria from animals should be controlled. This can only be achieved by reducing the amounts of antibiotics used in animals. Discontinuing the practice of routinely adding AMGP to animal feeds would reduce the amounts of antibiotics used for animals in the EU by a minimum of 30% and in some member states even by 50%.

A veterinary antibiotic policy: a personal view on the perspectives in The Netherlands.

To reach a more adequate and responsible use of antibiotics in veterinary medicine a broad approach is required. The growing interest in the optimum use of antibiotics in veterinary medicine is stimulated by awareness of the necessity to prevent the emergence of resistance and the spread of resistant bacteria. This is a matter of primary importance to safeguard the efficacy of antibiotic therapy in animals now and in the future, but will also minimise possible public health risks. As resistance develops in rough relation to antibiotic use, the best way to minimise emergence of resistance, without interfering with optimal veterinary care, is to rationalize the use of antibiotics by, or under responsibility of, a veterinary surgeon. A second further improvement can be reached by developing a veterinary antibiotic policy to prevent emergence and spread of resistance as much as possible. Measures that must be taken in combination are: 1. Establishing a policy for the use of antibiotics jointly by veterinary practitioners and experts resulting in a formulary. 2. Systemic registration and analysis of patterns of bacterial resistance (not only of pathogens but of faecal flora as well) and the use (qualitative and quantitative) of antibiotics in veterinary medicine. 3. Regular feedback of these data to the veterinary practitioners and consultation about the efficacy of the formulary guidelines in daily practise. 4. Systemic monitoring and evaluation the impact of the antibiotic policy and, if indicated, updating of the formulary. 5. Continuous education of veterinary surgeons about infectious diseases and antimicrobial therapy and development of a veterinary audit system. The first step to rationalize the veterinary use of antibiotics was taken by publishing a veterinary antibiotic formulary in 1987, compiled by a group of experts. Despite the fact that this was a pure top down approach and bottom up input from veterinary practitioners was lacking, this first formulary was very well received. However the impact of this formulary on the veterinary use of antibiotics and prevalence of resistance has not been evaluated at this moment. Until now regular and nationwide systemic monitoring of resistance and registration of veterinary use of antibiotics is not practically feasible in the Netherlands. A new formulary, based on a veterinary antibiotic will be published by the end of 1992. However, to be able to evaluate the impact of this policy on the prevalence of resistance and, if necessary, to adapt the policy the development of facilities for resistance epidemiology is urgently needed.

The detection of obligate anaerobic bacteria in swine abscesses. A comparison between gas-liquid chromatography and bacteriological culturing methods.

From the 62 swine abscesses examined, 56 yielded positive cultures, of which 38 cases were mixtures of facultative aerobes and obligate anaerobic bacteria (OAB). Only 6 species appeared to be sterile. In all specimens, which yielded OAB, VFA (C4-C6) could be detected by gas-liquid chromatography (GLC). False negatives were not recorded, and only one false positive was found, which might have been due to faulty culture technique, or to the fact that the metabolic markers may persist longer than the OAB themselves. Because current methods to isolate non-sporulating OAB are laborious and not available in most veterinary clinical situations and because there is a need to evaluate the importance of non-sporulating OAB in veterinary medicine, GLC seems to be a useful alternative to culture techniques for detecting the presence of OAB in infectious processes in animals.

The detection of obligate anaerobic bacteria in udder secretions of dry cattle with mastitis during summer: a comparison between gas-liquid chromatography and bacteriological culturing methods.

Udder secretions sampled during the summer in 1984 and 1985 from mastitic quarters of 51 non-lactating cattle, mainly heifers less than 2 years of age, were examined bacteriologically for the presence of (facultative) aerobic and obligate anaerobic bacteria (OAB) and by gas-liquid chromatography (GLC) in order to detect volatile fatty acids (VFA), metabolic end-products of OAB. Forty-nine samples yielded positive cultures and in 20 cases these were mixtures of (facultative) aerobes and OAB. Only two specimens appeared to be sterile and from one specimen only were OAB cultured. Corynebacterium pyogenes was isolated from 35% of the cases and Peptococcus indolicus and Fusobacterium necrophorum from 31 and 22%, respectively. In most specimens (19/21) which yielded OAB after culturing, VFA (C3-C6) could be detected by GLC. Detection of VFA in summer mastitis secretions appeared to be a useful technique to evaluate the importance and association of OAB with summer mastitis. Because samples can be easily collected and stored at -20 degrees C, this is especially advantageous in situations where adequate facilities for the isolation of OAB are not readily available.

Removal of attached nymphs and adults of Ixodes ricinus (Acari: Ixodidae).

Chemical and mechanical methods of removing Ixodes ricinus (L.) attached to the skin of pigs and sheep were tested experimentally. Three frequently advocated chemical treatments (gasoline, fingernail polish, and methylated spirit) failed to induce self-detachment of the ticks within 30 min. Also, the success of the subsequent mechanical removal was not influenced by chemical treatment. Two methods of mechanical removal of the ticks also were compared: (1) pulling straight out with a blunt forceps and (2) rotation of the tick around its body axis, using a "Tick Solution" forceps (Instruments of Sweden, Stamford, CT). Pulling frequently resulted in the complete removal of the tick, but fragments of the mouthparts that remained in the skin were often quite large. In contrast, if the tick was removed by rotation without pulling, the tip of the hypostome usually broke off and remained in the skin, but this portion was generally quite small.

Serodiagnosis of Lyme borreliosis using detection of different immunoglobulin (sub)classes by enzyme-linked immunosorbent assay and Western blotting.

To improve the performance of enzyme-linked immunosorbent assays for the serodiagnosis of Lyme borreliosis, the prevalence of several immunoglobulin classes and subclasses against various antigens of Borrelia burgdorferi was investigated by Western blotting. The sera of 40 early Lyme borreliosis patients (ELB), 27 late Lyme borreliosis patients (LLB), 62 healthy controls and 140 non-Lyme borreliosis patients were used. Detection of IgG1 versus total IgG was found to be more sensitive in detecting Borrelia burgdorferi antigens, especially flagellin (41 kD) protein, but did not improve the performance of Western blotting. The use of IgG1 detection showed an increase in sensitivity and specificity for the early Lyme borreliosis patient group compared to the standard IgG and IgM detection method by enzyme immunoassays using purified Borrelia burgdorferi flagellum. However, in an enzyme immunoassay using a total sonicate, sensitivity in detecting early Lyme borreliosis and late Lyme borreliosis with IgG1 remained lower compared to the detection of early Lyme borreliosis by IgM antibodies and late Lyme borreliosis by total IgG antibodies.

Percutaneous dilatational versus conventional open tracheotomy in a growing animal: a study in goats.

Percutaneous dilatational tracheotomy (PDT) is a new technique for the introduction of a tracheal cannula. It has been performed successfully in adults; however, in children, the open conventional technique is preferred because of the technical limitations of PDT, with fear of tracheal stenosis and adverse effects on tracheal growth. The authors studied the applicability of PDT in a growing animal. Two groups of goat kids (aged 10 days) underwent PDT or conventional open tracheotomy. They were cannulated for 7 days. Three months after decannulation, the tracheas were analyzed macroscopically and microscopically. The coronal (lateral) diameter and the cross-sectional area at the level of the stoma were 4.7 mm (SEM, 0.23 mm) and 41 mm2 (SEM, 3.0 mm2) after open tracheotomy, versus 8.1 mm (SEM, 0.13 mm) and 58 mm2 (SEM, 4.6 mm2) after PDT (P < .001 and P = .023, respectively). The quotient of the stomal cross-sectional area and the normal cross-sectional area was significantly smaller after open tracheotomy than after PDT (P < .001), with a cross-sectional area reduction of 24% to 40% in the open group. The authors conclude that PDT can be performed in growing animals without an increased risk of tracheal stenosis and adverse effects on tracheal growth. They recommended that PDT be investigated in children in a clinical setting.

Bacterial contamination of fetal fluids at the time of cesarean section in the cow.

Complications after cesarean section delivery in cattle are mainly the result of infections. The bacteria responsible for this infection can be of exogenous or endogenous origin. In this investigation endogenous contamination was studied. Fetal fluid samples of 23 cows were collected from the uterine cavity during cesarean section just after the removal of the calf, by means of a sterile disposable plastic syringe. The uterine flora was cultured, quantitated and presumptively identified by using selective and elective agarplates. Nineteen samples were positive after culture. Eleven samples contained obligate anaerobic bacteria. When the amniotic sac was broken before the obstetrical examination, the total number of bacteria was significantly higher. Vaginal exploration by the farmer had no significant influence on the number of bacteria encountered. Cesarean section is considered a clean contaminated procedure. One must always take into account that the fetal fluids are contaminated with the endogenous vaginal flora. This leads inevitably to contamination of the wound and the peritoneal cavity. Properly antimicrobial prophylaxis is certainly indicated.

Rapid presumptive diagnosis of anaerobic infections in animals by gas-liquid chromatography.

The detection of volatile fatty acids (VFA) by gas chromatography of 85 purulent specimens from abscesses or pyogenic infections in cats, dogs, rodents, and ruminants was compared with the results of bacteriologic culturing, and proved to be a rapid means of presumptively diagnosing anaerobic infections. Of 83 bacteriologically positive specimens, 52 (61%) yielded obligate anaerobes and in 50 specimens, 1 or more VFA (butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, or isocaproic acid) was detected. Forty-six specimens were positive for culturing of anaerobes and for detection of 1 or more of these VFA. By contrast, pus from infections caused by (facultative) aerobic microorganisms contained no VFA or only acetic and/or propionic acid.

Warfarin pharmacokinetics in the horse.

The pharmacokinetics of racemic warfarin were studied in 6 adult horses. After IV administration, the plasma concentration of warfarin showed a biphasic decline in time. Analysis of the data, according to 2-compartment kinetics, revealed the following constants: biological half-life was 13.3 hours, apparent volume of distribution was 0.46 L X kg-1, body clearance was 25.3 ml X hour-1 X kg-1. Warfarin was bound (91.5%) to plasma proteins. Unchanged warfarin was not detected in the urine. Absorption from the gastrointestinal tract was almost complete. Concentrations of warfarin in tissue were examined in 4 foals that were given 1 g of warfarin orally 14 hours before they were euthanatized. The concentrations in the kidney were higher than those in plasma (about 2 fold). The hypothrombogenic effect of the acute IV and oral administration of warfarin (0.75 mg/kg of body weight) was noticeable only after 60 hours and lasted for about 30 hours. The effect was weak; the maximum effect was a prolongation of 2.3 s (from 11.5 s to 13.8 s) in thromboplastin time.

Simultaneous measurement of metabolic flux in portally-drained viscera, liver, spleen, kidney and hindquarter in the conscious pig.

A method was developed to measure metabolic fluxes simultaneously across the portally-drained viscera (PDV), liver, spleen, kidney and hindquarter (HQ) in the conscious pig (20-25 kg). For this purpose, sampling catheters were implanted in the abdominal artery, portal vein, hepatic vein, splenic vein, renal vein and caval vein. Further, two extra infusion catheters were implanted in the splenic vein and abdominal artery. These allow continuous infusion of para-aminohippuric acid (PAH), providing a method for estimating the plasma flow of the liver, PDV, spleen, kidney and HQ. To minimize the postoperative recovery period of the pigs, great attention was paid to the housing conditions. After a recovery period of seven days, pigs were used for experiments twice a week. During the three weeks experimental period, food intake, body temperature, weight gain, blood gas data and plasma flow were monitored. Mean plasma flow was: liver 52 +/- 6, PDV 40 +/- 5, HQ 20 +/- 2, spleen 4 +/- 1 and kidneys 15 +/- 2 ml/kg body weight/min. These data were characteristic for a pig in a conscious normal resting and unstressed state. The long-term patency rate of the sampling catheters was very high (ranging from 75% to 100%). This was probably due to the prevention of catheter-related infections using a gentamicin (20 mg/ ml), alpha-chymotrypsin (225 U/ml) solution as catheter filling. We conclude that this model enables simultaneously liver, PDV, intestine, spleen, liver, kidney and HQ flux measurement of many metabolic substances in the conscious pig.

Antibiotic resistance of Enterobacteriaceae isolated from the faecal flora of fattening pigs.

From June 1991 to April 1992 407 faecal samples were collected from three groups of pigs (I n = 248, II n = 87, III n = 72) at a pig fattening farm to determine the prevalence and the degree of antibiotic resistance of Enterobacteriaceae as well as the antibiotic susceptibility of the strains isolated. Despite the absence of mass medication during the observation period, the prevalence of resistance to the most commonly used antimicrobial agents in veterinary medicine was high (range amoxicillin 70%-97%, oxytetracycline 89%-100%, sulfamethoxazole 88%-100%, trimethoprim 78%-100%). The high degree of resistance to oxytetracycline and sulfamethoxazole ranged from 8%-67% and 4%-46%, respectively. The percentage of the isolated Escherichia coli strains resistant to oxytetracycline, streptomycin and sulfamethoxazole ranged from 49% to 68%; the other agents tested showed lower percentages (0-13%). Resistance to three or more antibiotics was observed in 43% of the isolates. Of the 52 resistance patterns that could be distinguished, 51% was accounted by only four patterns: oxytetracycline+streptomycin+sulfamethoxazole 20%, sulfamethoxazole 12%, streptomycin+sulfamethoxazole 11% and streptomycin+oxytetracycline 8%.