Detection by multiplex PCR of Mycoplasma species associated with dairy cattle in Argentina.

There is scarce information about the frequency and epidemiological and clinical features associated with the presence of Mycoplasma spp. in Argentine dairy herds. The objectives of this study were to develop a multiplex PCR for identifying M.

Efficacy of extract combined with cephalexin as a dry cow therapy.

Our objective was to evaluate the efficacy of intramammary administration, at drying-off, of a Panax ginseng extract (PGe) combined with cephalexin (Ceph) on the post-calving bacteriological cure rate of pre-existing intramammary infections (IMI) and on the occurrence of new IMI during the dry period. In addition, milk yield and somatic cell count (SCC) in the post-treatment lactation were evaluated. One hundred and eight late-lactation cows were randomly divided into two experimental groups and were treated at drying-off with Ceph alone or PGe combined with Ceph.

Risk factors of intramammary infection in pre partum dairy heifers under grazing conditions and molecular characterization of isolates from heifers and cows.

The aims of the research reported here were to identify potential risk factors associated with the presence of Staphylococcus aureus intramammary infection (IMI) in pre partum dairy heifers on 17 dairy farms from three provinces of Argentina and to characterize, at molecular level, isolates from those heifers and lactating cows from two selected herds. A total of 1474 heifers and 4878 lactating cows were studied. The prevalence of Staphylococcus aureus IMI in the heifers, heifers at quarter level and lactating cow mammary quarters was 14.

First report of Mycoplasma leachii isolation associated with disease in dairy calves in Argentina.

There are few reports about the isolation of Mycoplasma species associated with cattle disease in Argentina. In this work we describe the detection of Mycoplasma leachii associated with disease in dairy calves in Santa Fe Province, Argentina. Samples obtained from a 4 day-old dairy calf suffering from polyarthritis and from two other calves, one with arthritis and the other one with a mandibular abscess, were subjected to microbiological culture.

Comparison of phenotypic tests for detecting penicillin G resistance with presence of blaZ gene in Staphylococcus aureus isolated from bovine intramammary infections.

Few studies have described the relationship between genotypic and phenotypic methods for detecting penicillin resistance in Staphylococcus aureus isolated from bovine intramammary infection (IMI). Six phenotypic methods for penicillinase detection were compared with a genotypic method testing the presence of the β-lactamase gene blaZ in Staph. aureus (n = 150) isolated from bovine IMI.

Association between milking practices and psychrotrophic bacterial counts in bulk tank milk.

The objective of this work was to determine on-farm risk factors for psychrotrophic bacterial counts in bulk tank milk from dairy farms in Argentina. Raw milk samples from bulk tanks of 27 dairy farms were examined for total psychrotrophic counts (TPC), proteolytic psychrotrophic counts (PPC) and lipolytic psychrotrophic counts (LPC) (dependent or outcome variables). A survey recording infrastructure conditions, milking equipment and milking management (independent variables) was performed.

Presence of enterotoxigenic Staphylococcus aureus in bulk tank milk from Argentine dairy farms.

Staphylococcus aureus is the most prevalent bovine mastitis pathogen in Argentina. The ability of this organism to produce enterotoxins is linked to staphylococcal food poisoning. Staphylococcal enterotoxins are low molecular weight proteins, highly resistant to heat and proteolytic enzyme activity.