Einfluss eines neuartigen Biozids auf die Prävalenz von Dermatitis digitalis bei Milchkühen

Gegenstand und Ziel: Es wurde untersucht, ob der Einsatz des Biozidprodukts T-Hexx Dragonhyde HBC (Fa. Hydromer, Branchburg, NJ, USA) die Prävalenz der Dermatitis digitalis (DD) beeinflusst. Material und Methoden: In einem Milchviehbetrieb (110 melkende Kühe) wurden 48 lahmheitsfreie Tiere randomisiert Versuchs- und Kontrollgruppe zugeteilt. Die mit 70–80% hohe Prävalenz der DD wurde 2 Monate lang vier Mal im Abstand von je 16–21 Tagen erfasst. Ein Punkteschema diente zur Dokumentation des Grades der DD-Läsionen an den Hinterklauen. Die Kühe der Versuchsgruppe wurden zweimal wöchentlich für zwei Melkzeiten nach Vorreinigung der Klauen mit Wasser durch ein Klauenbad mit T-Hexx-Dragonhyde geleitet, bei den Kontrolltieren erfolgte nur eine Klauenreinigung. Die Spritzer der Biozidlösung an Tieren und Umgebung wurden fotografisch dokumentiert und beurteilt. Wasser- und Biozidbad wurden nach Nutzung durch steigende Tierzahlen bakteriologisch untersucht. Ergebnisse: Statistisch signifikante Unterschiede der Prävalenzen der DD zwischen und innerhalb der beiden Gruppen waren nicht festzustellen. Die Punktebewertung der Läsionen differierte zwischen beiden Gruppen nicht. Im Wasserbad nahm mit steigender Zahl der Durchgänge die Zahl der koloniebildenden Einheiten (KBE) pro Milliliter sowie die der Enterobacteriaceae deutlich zu. Im T-Hexx-Dragonhyde-Bad ließen sich zu keinem Zeitpunkt KBE oder Enterobacteriaceae bestimmen. Die auffälligen Spritzer der Lösung waren bis in Höhe des Euters sichtbar. Schlussfolgerung und klinische Relevanz: Ein Einfluss des Biozidprodukts bei 4%- und 2%iger Badkonzentrationen auf die Prävalenz der DD konnte nicht nachgewiesen werden. Die hygienische Wirkung der Lösung war nicht gleichbedeutend mit einer erfolgreichen Keimreduktion an der Klaue. Eine mögliche Prävention der DD durch veterinärhygienische Maßnahmen könnte zukünftig bei geringerer Prävalenz und größerem Stichprobenumfang überprüft werden. Bei Anwendung von Klauenbädern besteht grundsätzlich die Gefahr einer Kontamination der Milch bzw. einer Mastitis durch Spritzer der Lösung.

[Influence of a new biocidal product on the prevalence of digital dermatitis in dairy cows]

OBJECTIVE

It was investigated whether usage of the biocidal product T-Hexx Dragonhyde (Hydromer, Branchburg, NJ, USA) could influence the prevalence of digital dermatitis (DD).

MATERIAL AND METHODS

On a dairy farm (110 milking cows) 48 dairy cows without lameness were selected randomly for a test group or a control (negative) group, respectively. A high prevalence of DD (70-80%) was documented over a period of 2 months, during which four examinations were made, with an interval of 16-21 days between each examination. The respective grade of the DD-lesion on the hind hoofs was documented according to a scoring scheme. After precleaning the claws with water, the test group passed through a hoof bath containing T-Hexx Dragonhyde on 2 days per week at two milking times on each day, whereas the claws of control animals were cleaned using only a water bath. Splashes contaminating the animals and the environment were documented photographically and evaluated. Bacteriological examinations of the water bath and the T-Hexx-bath were performed after increasing numbers of animals had passed through the baths.

RESULTS

Between and within groups no statistically significant differences in the prevalence of DD were found. DD-lesion scoring did not show any difference between the groups. With increasing numbers of animals having passed through the water bath, there was a significant increase in colony-forming units per millilitre and of enterobacteriaceae. In the T-Hexx Dragonhyde footbath, bacterial contamination remained below the detection limit at all times. The coloured splashes of the footbath were visible up to the level of the udder and teats.

CONCLUSION AND CLINICAL RELEVANCE

The prevalence of DD was not influenced by the 2% or 4% concentration of the biocidal product in the footbath. Thus the microbiocidal effect of the solution did not lead to an efficient reduction in bacteria on the hoof. To demonstrate a potential preventive effect on DD, future studies would require herds with lower prevalence and a higher sample size. However, when applying footbaths there is the general risk of milk contamination or causing mastitis.

[Evaluation of a claw hygiene system concerning its cleaning effect, the cow traffic and the quality of the washing water]

OBJECTIVE

Only limited scientific information on the efficiency of claw cleaning systems for dairy cows is currently available. For this reason, this investigation aimed to test the devio AG's claw hygiene system regarding its cleaning effect as well as its impact on the cow traffic and the quality of its washing water.

MATERIAL AND METHODS

During the first of two investigative phases of this controlled study, main water was used to clean the claws, while in the second phase a biozide was additionally applied. Every 4 weeks the hind claws of approximately 55 dairy cows (German Fleckvieh breed) were evaluated and their degree of soiling classified into four categories. In addition to the system's cleaning effect, its effect on cow traffic was investigated using video recordings and the quality of the recycled washing water was tested using bacteriological sampling.

RESULTS

In the second investigation phase, claw cleanliness in the treatment group was significantly higher than in the control group. However, there was no significant difference between the two groups during the first investigation phase. The video analysis showed, that after a short period of adaptation, there was undisturbed cow traffic. Within one week of installing the claw hygiene system, the length of stay in the system increased from a mean of 23 s to 32 s and the time the cows spent waiting in front of the system was reduced from a mean of 3 min 51 s to 2 min 20 s. Water analysis revealed an increasing bacterial count from initially 1.2 × 10⁶ to 7.3 × 10⁷ CFU/ml.

CONCLUSIONS

The undisturbed cow traffic allows the easy integration of the claw cleaning system into a free-stall barn. The improvement of claw cleanliness can make a positive contribution to claw hygiene. However, the increasing bacterial contamination of the washing water gives cause for concern in terms of infections being passed between cows when using this system.

Hepatitis B-associated acute liver failure: immediate treatment with entecavir inhibits hepatitis B virus replication and potentially its sequelae

BACKGROUND

Acute hepatitis B virus (HBV) infection is followed by high viral replication rates leading to hepatocyte death and ultimately, in some cases, to acute liver failure (ALF) necessitating liver transplantation. Thus, the objective of treating HBV-induced ALF is to eliminate or significantly suppress HBV replication.

METHODS/RESULTS

This prospective study (02/2008-02/2009) included 6 patients (1 female and 5 males, median age 35.5 years). HBV DNA and hepatitis B surface antigen (HBsAg) levels were detected, and hepatocyte death was quantified in patients' sera by (a) M65 ELISA and (b) M30 ELISA. All patients received entecavir treatment at 1 mg daily within 1-18 days after admission. Upon treatment, pathologic parameters rapidly decreased and returned to normal values or trace amounts (HBV DNA) within 3 months in all of the cases. A seroconversion to anti-HBsAg was achieved in 5 out of 6 patients; one patient with late onset of treatment did not seroconvert. M65 and the difference of M65-M30 as a marker for cell necrosis dropped significantly within 1 week of treatment.

CONCLUSION

This preliminary series of 6 patients reveals that immediate treatment of HBV-induced ALF with entecavir is well tolerated and beneficially affects the course of the disease.

Outbreak of Clostridium difficile 027 infection in Vienna, Austria 2008-2009

From November 2008 to 15 April 2009, 36 isolates of CD027 identified in Austria, all originating from four hospitals in Vienna. All isolates were positive for toxin A, toxin B and the binary toxin, and showed a characteristic 18 bp deletion in the tcdC gene. Clostridium difficile is an anaerobic spore-forming bacterium. Some strains may cause diarrhoea due to formation of toxins. Symptomatic C. difficile infection (CDI) is primarily linked with hospital admission and antibiotic treatment, although antibiotic exposure is neither necessary nor sufficient for CDI [1,2]. In Belgium, for instance, one third of CDI cases reported in the hospital surveillance system are not hospital-associated [3]. Symptoms range from mild diarrhoea to serious manifestations such as pseudomembranous colitis, toxic megacolon or perforation of the colon. C. difficile challenges hygiene standards as it is forms spores. The risk of infection rises with increasing age, underlying disease and immunodeficiency [4]. In recent years, a particularly virulent strain, ribotype 027 (CD027), has emerged in a number of countries, particularly in connection with hospital outbreaks, but also in community-acquired diarrhoea cases [5]. The risk of serious disease and death associated with CD027 exceeds that of other C. difficile strains. The classical CD027 is characterised - among other things - by an increased production of toxins A and B, production of a binary toxin and resistance to newer fluoroquinolones such as moxifloxacin. The first three Austrian cases of CD027 occurred in 2006 and in March 2008 [6,7]. Since August 2006, the Austrian National Reference Centre for C. difficile has ribotyped approximately 2,700 human C. difficile isolates received from all nine Austrian provinces. In recent months, a drastic increase in CD027 cases has been noted, all originating from four hospitals in Vienna. From November 2008 to 15 April 2009, 36 isolates of CD027 were received at the National Reference Centre. The Figure summarises these C. difficile 027 cases by month of reception of the sample at the reference centre.

Outbreak of Clostridium difficile 027 infection in Vienna, Austria 2008-2009

From November 2008 to 15 April 2009, 36 isolates of CD027 were identified in Austria, all originating from four hospitals in Vienna. All isolates were positive for toxin A, toxin B and the binary toxin, and showed a characteristic 18 bp deletion in the tcdC gene.

Fetal heart rate variability reveals differential dynamics in the intrauterine development of the sympathetic and parasympathetic branches of the autonomic nervous system

The aim of this study was to investigate the hypothesis that fetal beat-to-beat heart rate variability (fHRV) displays the different time scales of sympatho-vagal development prior to and after 32 weeks of gestation (wks GA). Ninety-two magnetocardiograms of singletons with normal courses of pregnancy between 24 + 1 and 41 + 6 wks GA were studied. Heart rate patterns were either quiet/non-accelerative (fHRP I) or active/accelerative (fHRP II) and recording quality sufficient for fHRV. The sample was divided into the GA groups <32 wks GA/>32 wks GA. Linear parameters of fHRV were calculated: mean heart rate (mHR), SDNN and RMSSD of normal-to-normal interbeat intervals, power in the low (0.04-0.15 Hz) and high frequency range (0.15-0.4 Hz) and the ratios SDNN/RMSSD and LF/HF as markers for sympatho-vagal balance. fHRP I is characterized by decreasing SDNN/RMSSD, LF/HF and mHR. The decrease is more pronounced <32 wks GA. Beyond that GA SDNN/RMSSD is predominantly determined by RMSSD during fHRP I and by SDNN during fHRP II. In contrast to fHRP I, during fHRP II, mHR is positively correlated to SDNN/RMSSD instead of SDNN >32 wks GA. LF/HF increases in fHRP II during the first half of the third trimester. Non-accelerative fHRP are indicative of parasympathetic dominance >32 wks GA. In contrast, the sympathetic accentuation during accelerative fHRP is displayed in the interrelations between mHR, SDNN and SDNN/RMSSD. Prior to 32 wks GA, fHRV reveals the increasing activity of the respective branches of the autonomic nervous system differentiating the types of fHRP.

Characterization of Clostridium difficile isolates using capillary gel electrophoresis-based PCR ribotyping

We have developed a Clostridium difficile PCR ribotyping method based on capillary gel electrophoresis and have compared it with conventional PCR ribotyping. A total of 146 C. difficile isolates were studied: five isolates were reference strains (PCR ribotypes 001, 014, 017, 027 and 053); 141 were clinical isolates comprising 39 Austrian PCR ribotypes collected in the period 2006–2007 at 25 Austrian healthcare facilities. Capillary gel electrophoresis yielded up to 11 fragments per isolate and 47 ribotype patterns. All but one of the five PCR ribotypes of reference strains were clearly reflected in the chromatograms of capillary-based typing. Capillary gel electrophoresis divided 24 isolates belonging to PCR ribotype type 014 into seven subgroups, whereas subtyping the same isolates using multiple-locus variable-number tandem-repeat analysis yielded three unrelated subgroups, without obvious correlation to sr subgroups. Using a web-based software program (http://webribo.ages.at), we were able to correctly identify these 014 isolates by simply allocating the seven subgroup patterns to one ribotype, i.e. to PCR ribotype 014. We consider capillary gel electrophoresis-based PCR ribotyping to be a way of overcoming the problems associated with inter-laboratory comparisons of typing results, while at the same time substantially diminishing the hands-on time for PCR ribotyping.