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Biomedical subjects

O C Sampimon

Publications and source records attributed to O C Sampimon.

At least 19 recordsLinked to original sources
PubMed2006

[An outbreak of Klebsiella pneumoniae mastitis].

A serious outbreak of mastitis caused by Klebsiella pneumoniae is described. Shortly after drying off, three cows died of mastitis caused by Klebsiella pneumoniae and five other cows became seriously ill but survived. Sawdust contiminated with Klebsiella pneumoniae was identified as the most likely source of these infections. In addition to detection of possible sources of infection, another important aspect of eradication is the detection of quarters infected with Klebsiella pneumoniae. Rigorous application of these measures led to resolution of the outbreak within a few months.

Animals↗
PubMed2005

[Mastitis caused by Yersinia pseudotuberculosis in a cow].

Subclinical mastitis with a raised somatic cell count was diagnosed in a cow in her fifth lactation. It was caused by Yersinia pseudotuberculosis, which can also infect humans. This is the first time that Yersinia pseudotuberculosis has been isolated from a mastitis sample in The Netherlands. Despite treatment with antibiotics in the dry period, Yersinia pseudotuberculosis was still present in the same quarter in the subsequent lactation. The somatic cell count was still high and milk production was much lower than in previous lactation. The pathogen did not spread to other quarters of the same cow or to herd mates on the farm over a 1-year period.

Animals↗
PubMed2004

[Practical aspects at drying-off].

Drying off cows with antibiotics is an effective method to cure existing infections at drying off and to prevent new infections during the dry period. In the recent years, a shift has been observed from contagious to environmental pathogens. This influences the general preventive measures and the choice for the drying off treatment. Important factors influencing the efficacy of dry cow products are general hygienic measures, length of the dry period, production at drying-off, somatic cell count at drying-off and the udder pathogens circulating on the farm.

Animal Husbandry↗
PubMed2004

In vitro growth inhibition of major mastitis pathogens by Staphylococcus chromogenes originating from teat apices of dairy heifers.

Earlier field observations suggest that teat apex colonization by Staphylococcus chromogenes pre-partum in dairy heifers protects udder quarters against elevated somatic cell counts early post-partum. To explain these findings, the in vitro inhibitory capability of S. chromogenes from teat apices of heifers towards some major mastitis pathogens was tested using a modified cross-streaking method. Two out of 10 S. chromogenes isolates, both originating from two different teats from the same heifer, consistently inhibited growth of all Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis strains, but none of the Escherichia coli strains. The present study, therefore, supports the protective effect of teat apex colonization by S. chromogenes by in vitro production of inhibitory substances.

Animals↗
PubMed2003

[Drying off cows: a comparative study with two dry cow products].

From September 1998 to September 1999, at drying off 397 cows on 73 Dutch farms were treated, with two antibiotic containing dry cow products (cloxacillin; penicillin-neomycin). Farms and cows were selected on an increased bulk milk somatic cell count (BMSCC) and individual cow somatic cell count. The objective of the trial was to compare the efficacy of both products under field conditions. Both products proved to be highly effective against streptococci and penicillin sensitive staphylococci. Because of the low incidence of infections caused by Escherichia coli and penicillin resistant staphylococci no conclusions could be drawn on differences in activity for these two pathogens. No significant differences were found between the two products in cure rate of existing infections at drying off, incidence of new infections during the dry period, incidence of clinical mastitis during the dry period and the course of the individual cow cell counts during the trial.

Animals↗
PubMed2003

Clinical, epidemiological and molecular characteristics of Streptococcus uberis infections in dairy herds.

A longitudinal observational study (18 months) was carried out in two Dutch dairy herds to explore clinical, epidemiological and molecular characteristics of Streptococcus uberis mastitis. Infections (n = 84) were detected in 70 quarters of 46 cows. Bacterial isolates were characterized at strain level by random amplified polymorphic DNA (RAPD) fingerprinting. Persistent infections were usually attributable to one strain, while recurrent infections could be caused by different strains. When multiple quarters of a cow were infected, infections were mostly caused by one strain. In each herd, multiple strains were identified yet one strain predominated. The majority of all infections were subclinical, and infections attributed to predominant strains were more chronic than infections attributed to other strains. Epidemiological and molecular data suggest infection from environmental sources with a variety of S. uberis strains as well as within-cow and between-cow transmission of a limited number of S. uberis strains, with possible transfer of bacteria via the milking machine.

Animals↗
PubMed2002

Myiasis in sheep in The Netherlands.

In 1999, among 164 randomly selected Dutch sheep farmers, a questionnaire was carried out to estimate the prevalence of myiasis in sheep and to investigate factors associated with the occurrence of myiasis. The total number of sheep and/or lambs on the reference date 1 August 1999 was 12,200: 5243 ewes, 225 rams, 3393 ewe- and 3339 ram lambs. On 86 (52.4%) of the farms 349 (2.9%) of all sheep and/or lambs contracted myiasis, of which two died. Myiasis was seen significantly more frequently on farms with over 25 ewes compared to smaller farms. Cases of myiasis were detected from April to September, with a peak (47.1%) in August. Occurrence of myiasis was most frequently associated with hot and humid weather and was mainly observed (69.1%) in the area around the tail.Ewes and ewe lambs had significantly more myiasis when compared with rams and ram lambs. There was no relationship with tail docking, with breed, with the time of shearing, with the kind of soil (clay, sand, etc.), with the environment (bush, trees, water, etc.), with the type of treatment (pour on, dipping, spraying), the used insecticides (synthetic pyrethroïds, diazinon, cyromazin, etc.), the number of preventive treatments, the time of treatment or the number of observations on the herd (once a day, once a week, etc.).

Animals↗
PubMed2002

Effect of preculture freezing and incubation on bacteriological isolation from subclinical mastitis samples.

In this study the sensitivity of three methods of isolation of udder pathogens from milk samples from subclinical mastitis cases was compared. For analysis 1827 quarter milk samples were selected. Milk was cultured using a standard culture technique (0.01 ml of fresh milk streaked on a sheep blood agar plate and on Edward's medium). In addition, an inoculum of 0.01 ml of the original milk sample was incubated for 24h at 37 degrees C in broth, followed by culture using the standard culture technique. In the third method, the whole milk sample was frozen for 24h, and then incubated for 24h at 37 degrees C, followed by culture using standard culture technique. The isolation percentage of Staphylococcus aureus was 4.7% for standard culture technique, 14.2% for incubation in broth, and 21.5% for the combination of freezing plus incubation. Isolation percentage of Streptococcus dysgalactiae and Streptococcus agalactiae was highest using the standard culture technique, while isolation rate of Streptococcus uberis was not different among the three methods used. With increasing somatic cell count, the likelihood of S. aureus, S. dysgalactiae and S. uberis isolation increased. Based on the relative sensitivity, defined as the isolation rate using a single technique compared to the isolation rate of the three techniques together, a combination of standard culture technique and freezing plus incubation was most attractive for achieving a high isolation rate of S. agalactiae and S. dysgalactiae. Relative sensitivity of S. uberis isolation was highest using the standard culture technique and incubation in broth, while S. aureus was most often isolated using a combination of incubation in broth and freezing plus incubation. A combination of the three methods increased the isolation rate for S. dysgalactiae, S. uberis and S. aureus. The standard culture technique, together with the combination of freezing plus incubation, can be recommended for isolating major udder pathogens. If S. aureus is the pathogen of main interest, using incubation in broth together with the combination of freezing plus incubation performed best.

Animals↗
PubMed2001

Analysis of an outbreak of Streptococcus uberis mastitis.

An outbreak of Streptococcus uberis mastitis was described to gain insight into the dynamics of Strep. uberis infections at a herd level. Data were obtained from a longitudinal observational study on a commercial Dutch dairy farm with good udder health management. Quarter milk samples for bacteriological culture were routinely collected at 3-wk intervals from all lactating animals (n = 95 +/- 5). Additional samples were collected at calving, clinical mastitis, dry-off, and culling. During the 78-wk observation period, 54 Strep. uberis infections were observed. The majority of infections occurred during a 21-wk period that constituted the disease outbreak. The incidence rate was higher in quarters that had recovered from prior Strep. uberis infection than in quarters that had not experienced Strep. uberis infection before. The incidence rate of Strep. uberis infection did not differ between quarters that were infected with other pathogens compared with quarters that were not infected with other pathogens. The expected number of new Strep. uberis infections per 3-wk interval was described by means of a Poisson logistic regression model. Significant predictor variables in the model were the number of existing Strep. uberis infections in the preceding time interval (shedders), phase of the study (early phase vs. postoutbreak phase), and prior infection status of quarters with respect to Strep. uberis, but not infection status with respect to other pathogens. Results suggest that contagious transmission may have played a role in this outbreak of Strep. uberis mastitis.

Animals↗
PubMed2001

Cow- and quarter-level risk factors for Streptococcus uberis and Staphylococcus aureus mastitis.

This study was designed to identify risk factors for intramammary infections with Streptococcus uberis and Staphylococcus aureus under field conditions. An 18-mo survey with sampling of all quarters of all lactating cows at 3-wk intervals was carried out in three Dutch dairy herds with medium bulk milk somatic cell count (200,000 to 300,000 cells/ml). Quarter milk samples were used for bacteriology and somatic cell counting. Data on parity, lactation stage, and bovine herpesvirus 4-serology were recorded for each animal. During the last year of the study, body condition score, and teat-end callosity scores were recorded at 3-wk intervals. A total of 93 new infections with Strep. uberis were detected in 22,665 observations on quarters at risk for Strep. uberis infection, and 100 new infections with Staph. aureus were detected in 22,593 observations on quarters at risk for Staph. aureus infection. Multivariable Poisson regression analysis with clustering at herd and cow level was used to identify risk factors for infection. Rate of infection with Strep. uberis was lower in first- and second-parity cows than in older cows, and depended on stage of lactation in one herd. Quarters that were infected with Arcanobacterium pyogenes or enterococci, quarters that had recovered from Strep. uberis- or Staph. aureus-infection in the past, and quarters that were exposed to another Strep. uberis infected quarter in the same cow had a higher rate of Strep. uberis infection. Teat-end callosity and infection with coagulase-negative staphylococci or corynebacteria were not significant as risk factors. Rate of Staph. aureus infection was higher in bovine herpesvirus 4-seropositive cows, in right quarters, in quarters that had recovered from Staph. aureus or Strep. uberis infection, in quarters exposed to other Staph. aureus infected quarters in the same cow, and in quarters with extremely callused teat ends. Infection with coagulase-negative staphylococci was not significant as a risk factor. The effect of infection with corynebacteria on rate of infection with Staph. aureus depended on herd, stage of lactation, and teat-end roughness. Herd level prevalence of Strep. uberis or Staph. aureus, and low quarter milk somatic cell count were not associated with an increased rate of infection for Strep. uberis or Staph. aureus.

Animals↗
PubMed2000

Factors associated with cure after therapy of clinical mastitis caused by Staphylococcus aureus.

One hundred and fifty-nine cases of clinical Staphylococcus aureus mastitis were analyzed to detect factors associated with bacteriological cure after therapy. On 100 Dutch dairy farms, data were collected from four clinical trials with five intramammary treatment regimes designed to treat beta-lactamase-positive pathogens. Infected quarters were treated three times, with a 12-h interval between treatments. Treatment was extended for 2 d if results of the trial treatment were, according to the owner, not satisfactory. The overall bacteriological cure rate was 52%. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was significantly higher than that of clinical beta-lactamase-positive S. aureus mastitis. Bacteriological cure was also significantly higher if somatic cell count of the cow was low at the milk recording prior to the onset of the clinical mastitis. The bacteriological cure rate of clinical beta-lactamase-negative S. aureus mastitis was also significantly higher after an extended treatment compared with no extended treatment. The seriousness of the various clinical symptoms and the bacteriological cure rate of clinical S. aureus mastitis were not associated.

Ampicillin↗
PubMed1997

[Warble fly: an update].

The cycle of the warble fly, the possibilities for detection and treatment and the prevalence in Europe are described. In the Netherlands in 1953 a warble fly law was enacted. The eradication of warble fly in the Netherlands was completed in the early eighties. Therefore prevention of a reinfestation is necessary by control of imported cattle and of farms along the border with Belgium and Germany.

Animals↗
PubMed1997

[Factors affecting the cure rate of Staphylococcus aureus in the drying out of cows using antibiotics: a literature review].

The choice of dry cow antibiotics should be based on clinical efficacy studies. The choice also depends on the sensitivity pattern of S. aureus, and the expected length of the dry period. There are many quarter, cow and herd factors that influence efficacy of dry cow therapy. These factors include somatic cell count, front-versus-hind quarter, age, and the number of infected quarters in a cow. Nutrition of cows at the end of the lactation and hygienic conditions on the farm and off are also important. The effect of extra treatments at dry off are questionable.

Animals↗
PubMed1997

Factors associated with bacteriological cure during lactation after therapy for subclinical mastitis caused by Staphylococcus aureus.

The objective of this study was to determine the factors that were associated with the cure of subclinical mastitis caused by Staphylococcus aureus treated during lactation. One hundred forty-three quarters that were infected with S. aureus were available from a number of treatment trials. Analysis of these data showed that the most important factors associated with cure were age of the cow, somatic cell count at the time of treatment, presence of the infection in the front quarters, and stage of lactation. Other factors, such as number of infected quarters per cow and sensitivity or resistance of the strain to penicillin, were not significant. Because of the relatively low probability of cure, it is important to know risk factors for cure and, hence, to choose cows for treatment with great care. Using these data, a prediction equation was developed to determine the cure rate of subclinical mastitis caused by S. aureus when treated during lactation.

Animals↗
PubMed1994

Factors associated with bacteriological cure after dry cow treatment of subclinical staphylococcal mastitis with antibiotics.

Data from five dry cow antibiotic therapy trials were analyzed. Records were only included for cows with > or = 1 culture-positive quarters that were subclinically infected with Staphylococcus aureus. Data for 406 quarters affected with S. aureus from 283 cows on 73 farms were analyzed for quarters, cows, and herds. The probability of cure of an infected quarter decreased when SCC increased, when another quarter was infected in the same cow, when the infection was in a hind quarter, and when the percentage of samples that were positive for S. aureus was higher before drying off. Variables predicting complete bacteriological cure of a cow were log SCC, age of the cow, and the number of infected quarters. The probability of a cure decreased as SCC increased. The probability of cure decreased as age increased, and cows with more than one quarter infected were .57 times less likely to be cured than cows with 1 infected quarter.

Aging↗