Oral and Poster Abstracts

2 Schering Plough Animal Health, R&D, Wellington, New Zealand
Streptococcus uberis is common cause of clinical and subclinical
mastitis. The objective of this study was to assess the efficacy of
vaccination of dairy cows with a whole-cell killed vaccine containing
S. uberis on the incidence and prevalence of mastitis associated with S.
uberis. Cows from 3 dairy herds were either vaccinated with a vaccine
containing S. uberis (n=695) or injected with the vaccine vehicle
(n=711 cows) on 2 occasions approximately 4 wk apart with the 2 nd
vaccination occurring on average 55 days before calving. Milk samples
were collected from all 4 glands from a randomly selected 2/3rds of the
enrolled cows between 0 and 7 days after calving, and milk samples
were collected from cows with clinical mastitis (CM) within 21 days of
calving. The prevalence of intramammary infection associated with S.
uberis and the incidence of CM associated with S. uberis were analysed
at cow and gland level using multivariable models which accounted for
the clustering of gland with cow and cow with herd and adjusted for the
effect of potential confounders such as age and breed. Vaccination
tended to reduce the prevalence of cows infected with S. uberis in any
gland within seven days of calving (0.12 (0.09-0.16) vs. 0.16 (0.13-
0.21) for vaccinated vs. control cows, respectively; p=0.057).
However, there was no difference in the prevalence of S. uberis at
gland level (0.043 (0.031-0.059) vs. 0.055 (0.042-0.072) for vaccinated
vs. control cows, respectively; p=0.18; RR=0.785 (0.548-1.124)) or in
incidence of CM associated with S. uberis between the groups at either
cow (43/670 (6.4%) vs. 44/693 (6.3%) in vaccinated vs. unvaccinated
cows, respectively; p=0.95) or gland (53/2628 (2.0%) vs. 48/2724
(1.7%) in vaccinated vs. control cows, respectively; p=0.50) level.
Vaccination reduced the number of S. uberis present in milk in glands
from which it was isolated (940 (532-1661) vs. 2476 (1200...)
geometric mean colony forming units/ml for vaccinated vs. control
cows, respectively; p=0.013). There was no difference in SCC at first
herd test between vaccinated and control cows (71 (64-78) vs. 75 (68-
83) geometric estimated marginal mean (95% CI) x 103 SCC/ml for
vaccinated and control cows, respectively; p=0.32). It was concluded
that the whole-cell killed S. uberis vaccine evaluated in this study was
not effective in reducing the prevalence and incidence of mastitis
associated with S. uberis.
84 Prototheca blaschkeae Associated with Bovine Mastitis
S. Marques 1 , E. Silva 1 , C. Kraft 2 , V. Huss 2 , G. Thompson 1
1 Universidade do Porto - ICBAS, Department of Veterinary Clinics -
Laboratory of Infectious Diseases, Vila do Conde, Portugal
2 Friedrich-Alexander - Universität Erlangen-Nürnberg, Department
für Biologie, Molekulare Pflanzenphysiologie, Erlangen, Germany
Objectives of study: Algae of the genus Prototheca and more rarely
Chlorella are the only known plants that cause infectious diseases in
humans and animals. Prototheca are ubiquitous, generally saprophytes,
and can be isolated from a great variety of environmental sources. Until
recently only two species were known to be associated with disease in
animals and humans, Prototheca zopfii and P. wickerhamii,
respectively. In 2006, a new species P. blaschkeae was described,
which has been isolated from a case of disease in men. The prevalent
form of protothecosis in animals is bovine mastitis, which generally
occurs in a chronic subclinical or a mild clinical inflammatory process
of the udder affecting cows that do not respond to routine therapy. The
objective of the present work was to characterize Prototheca spp.
isolated from bovine mastitis. We provide evidence for the first time,
that P. blaschkeae is associated with bovine mastitis.
Material and methods: Forty one Prototheca isolates obtained from
mastitic milk from dairy cows belonging to 22 different farms in the
North of Portugal were characterized by conventional microbiological
methods and by phylogenetic analysis of their 18S rDNA sequences.
The methods employed were morphological data analysis,
biochemistry profile determination by API 20C Aux and BBL Crystal
Kits (Enteric Nonfermenter and Gram positive) systems, PCR
amplification of the 18S rDNA, amplified rDNA restriction analysis
with HaeIII, and phylogenetic analysis of the 18S rDNA sequences.
Results: Macroscopical and essentially microscopical analyses
revealed two groups of algae, one that contained the majority of the
isolates and the other with only four isolates. Both groups were
confirmed by their biochemical profiles. PCR amplification of 18S
rDNA and phylogenetic analyses showed, that most of the isolates were
identified as P. zopfii var. hydrocarbonea, whereas the four isolates of
the other group were identified as P. blaschkeae.
Conclusion: Although the type of mastitis induced by all Prototheca
isolates had similar clinical manifestations, we show for the first time, that
besides P. zopfii also P. blaschkeae may be involved in bovine mastitis.
Key words: bovine mastitis, Prototheca, genotyping
127 Controlling Highly Prevalent Staphylococcus aureus Mastitis
from the Dairy Farm
H. Nagahata 1 , H. Maruta 1 , S. Matsuki 1 , H. Higuchi 1 , K. Kawai 2 ,
A. Anri 3
1
Rakuno Gakuen University, Department of Animal Health, Ebetsu,
Japan
2
Tokachi NOSAI, Seibu veterinary clinical center, Obihiro, Hokkaido,
Japan
3
Hokkaido NOSAI, Unit of Animal Health Management, Ebetsu,
Japan
Objective: Staphylococcus aureus, a contagious pathogen that spreads
easily from cow to cow, usually manifests as subclinical mastitis. A
dairy farm with increasingly elevated somatic cell counts (SCC) in the
bulk milk and a high rate of S. aureus-mastitis was referred. Our study
monitored the herd for 3.5 years after we instituted a mastitis control
program. In addition, to evaluate whether a high prevalence of S.
aureus infection in lactating cows affects the occurrence of S. aureus
infection in heifers in the herd, bacteriological findings in mammary
secretions from heifers were examined.
Methods: Dairy farm had 57 lactating Holstein cows were housed in freestall
barns. A total of 15 heifers, 23-26months old, were also used for the
survey of microbiological findings in mammary secretions. Quarter milk
samples from lactating cows were cultured, and pathogens were identified.
Mastitis control program: To determine the contributory causes of S.
aureus infection, we checked the milking procedures and implemented the
following mastitis control measures: (a) maintenance of the correct
milking order, (b) recommended milking procedures, (c) post-milking teat
dipping with approved disinfectants, and (d) culling of cows infected with
S. aureus in 2 or more quarters or cows having chronic S. aureus infection.
Results: S. aureus was detected in 24 (41.2%) of the 54 lactating cows
and in 29 (12.8%) of 227 quarters of the 57 milking cows in the herd. The
S. aureus infection rate decreased steadily from 42.1% at the time of our
first visit to 10.5% seven months after start of the control program, then
decreased to 4% at 14 months, and no isolate of S. aureus was found in
milk samples at 18 months. In the course of the 3.5-year monitoring
period, 24 lactating cows infected with S. aureus were culled. The average
SCC in the bulk tank milk decreased gradually from 52.3 x 10 4 cells/ml
(21 to 94 x 10 4 cells/ml ) to 14.5 x 10 4 cells/ml (4 to 21 x 10 4 cells/ml), as
observed 18 months after start of the control program. No S. aureus isolate
was detected in 58 mammary secretions from 15 heifers at 4-5 weeks
before parturition.
Conclusion: The program implemented is effective in controlling S.
aureus mastitis on the dairy herd. A high S. aureus prevalence in the herd
may not necessarily be a decisive factor for S. aureus infection in heifers.
Key words: long-term monitoring, mastitis control program, S. aureus
128 The Recoveries from Acute Mastitis and Fertility Indices of
Cows Treated with Antibiotics and Additional Medicine
E. Malinowski, S. Smulski, H. Markiewicz
National Veterinary Research Institute, Department of
Pathophysiology of Reproduction and Mammary Gland, Bydgoszcz,
Poland
The aim of studies was to establish the effect of antioxidants,
immunomodulator or NSAID single injection on results of mastitis
therapy and fertility indices of mastitic cows treated intramammarily with
antibiotics. Examinations were performed in 4 farms on 240 dairy cows
that showed acute form of mastitis as only clinical disease between 10 th
and 100 th day after parturition and on 60 healthy cows calved at the same
time. Mastitic cows were treated with approved intramammary products
in doses recommended by manufacturers. Animals included to I group
received only intramammary therapy (IMT). Cows from group II, III and
IV, apart from IMT, were once injected with antioxidants (vit. C, vit. E, bcarotene,
Se), lysozyme dimer) or flunixin meglumine, respectively.
Healthy cows from group V consisted the control for fertility indicators of
mastitic animals. In average, 55.6% of cows recovered as an effect of the
first course of the intramammary treatment. A single injection of
antioxidants or lysozyme dimer increased recovery rates. Fertility indices:
calving to the first service, conception rate, insemination index and
Mastitis / Udder Health and Milk Quality 49