Mycoplasma isolation in milk samples from dairy herds in Chile

Mycoplasma bovine mastitis is a highly contagious disease, usually associated with clinical cases refractory to antibiotic treatment. The aim of this study was the isolation of Mycoplasma species in cattle milk samples from dairy herds in Chile. Bulk tank milk samples selected by convenience from 91 Holstein Friesian dairy herds located in Los Rios (66) and Los Lagos (25), the two most important dairy Regions in the country, were collected. Additionally, 100 individual milk samples from cows with a high incidence of clinical mastitis, refractory to antibiotic therapy, and negative bacteriological results for traditional mastitis pathogens, all from the Biobío Region and received in our diagnostic laboratory, were included. All samples were cultured for 10 days on PPLO medium. The differentiation of suspect colonies between genus Mycoplasma and Acholeplasma was performed by the digitonin test and a specific PCR. The species identification was performed by a M. bovis specific PCR and 16S rRNA sequencing. Mycoplasma was isolated from 3 (3.3%) bulk tank milk samples and 2 (2%) individual cow milk samples. All colonies were identified as Mycoplasma by the digitonin test and by a specific PCR. At species level, one strain isolated from a bulk tank milk sample was identified as M. bovis. The remaining two strains isolated from bulk tank milk samples were identified as M. bovigenitalium, while the two strains isolated from milk of individual cows were identified as M. alkalescens. These results show that not only M. bovis is present in Chilean dairy herds, but also other pathogenic species not previously described in Chile such as M. bovigenitalium and M. alkalescens, which pose a potential risk for dairy herds in southern Chile

Noninferiority study evaluating the efficacy of a teat disinfectant containing copper and zinc for prevention of naturally occurring intramammary infections in an automatic milking system

The aim of this study was to demonstrate the noninferiority of a novel teat disinfectant based on copper and zinc (ZkinCu; Copper Andino, Santiago de Chile, Chile) compared with a previously proven glycolic acid active disinfectant (OceanBlu; DeLaval, Kansas City, MO) as a positive control, with respect to the incidence of new intramammary infections under natural challenge conditions on a commercial robotic dairy farm. This study was conducted in 6 robotic pens of approximately 60 milking cows each. The pens were randomly assigned to 1 of the 2 studied disinfectants. Throughout the 8 wk study, the same pre- and post-milking teat disinfectant was used in each pen. The same milking procedures were used in each robot throughout the study. Pre-milking hygiene consisted of applying the disinfectant (OceanBlu or ZkinCu) with the robotic arm. The same product was applied on the teats after milking. At the beginning of the study, all quarters of all study cows were sampled. In successive samplings (wk 2, 4, 6, and 8), composite milk samples were collected on farm to determine SCC. Once composite SCC results were available (2 d) and based on an SCC of ≥100,000 cells/mL, quarter milk samples underwent bacteriological culture. Clinical mastitis was identified by study personnel. Intramammary infection in biweekly quarter milk samples was determined based on composite SCC levels (≥100,000 cells/mL) and the presence of bacteria. A new IMI was defined as a quarter in which the organism isolated was not present in the previous bacteriological sample, or the previous composite SCC sample was <100,000 cells/mL. Clinical mastitis samples were also considered to be new IMI. The trial was designed as a positive control field trial, in which the objective was to show noninferiority of ZkinCu versus the control (OceanBlu). The overall crude incidences of new IMI for 2 wk at risk were 4.9 and 7.3% for the ZkinCu and OceanBlu groups, respectively. The predominant organisms recovered from quarters with new IMI were Streptococcus uberis, Corynebacterium spp., and coagulase-negative staphylococci in both the ZkinCu and OceanBlu groups. The risk of infection in the OceanBlu group was higher (β = 0.644; 95% confidence interval = 0.05–1.22). The interaction of treatment by week was not significant. The new IMI rate estimates (95% confidence interval) for ZkinCu and OceanBlu were 1.7% (0.8–2.5) and 3.2% (1.7–4.7), respectively. One novel aspect of this study is that it was one of the first commercial noninferiority trials to evaluate a new pre- and post-milking teat disinfectant in a dairy herd with an automatic milking system. The experimental teat disinfectant ZkinCu, evaluated in this field trial with naturally occurring IMI, showed noninferiority relative to the positive control for the prevention of new IMI. This study was conducted in a herd with an automatic milking system, and the results are applicable to herds with similar characteristics. Additional studies are needed to ensure reproducibility under different management conditions.Fil: Vissio, Claudina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Mella, Armin. Universidad Austral de Chile; ChileFil: Amestica, Luis. R&d Copper Andino Sa; ChileFil: Pol, Martin. Lactodiagnóstico Sur SRL; Argentin

Evaluation of a new vaccine against Staphylococcus aureus mastitis in dairy herds of southern Chile. I. Challenge trial

S. aureus is the most frequently isolated mastitis pathogen in southern Chile. Hygiene during milking time and DCT have not been successful to control this pathogen. Vaccination has been suggested as a useful tool to combat mastitis and several vaccines have been developed and evaluated worldwide. This study presents the results of a pilot trial to evaluate the effects of a new vaccine produced in Chile against S. aureus mastitis on udder health, humoral immune response, and milk production after an experimental intramammary challenge with a heterologous S. aureus strain. Four 2 mL doses of the vaccine were administeredintramuscularly to five pregnant heifers free of IMI infections, using another five heifers as controls. Ten days after last immunisation two mammary quarters of all heifers were challenged with a pathogenic strain of S. aureus. Heifers were monitored for clinical signs, bacterial count, SCC, differential leukocyte count in blood, S. aureus antibody, and milk yield during 14 days after challenge. No systemic effects were observed in any of the challenged heifers, and severe clinical cases were only observed in the control group. The SCCs were always higher in heifers of the control group. The challenged quarters of the control group yielded the highest counts of S. aureus, but no significant difference was observed between vaccinated and non-vaccinated groups. Serum antibody titres were twice as high in the vaccinated group compared to the control group, and average milk yield reduction was lower in the vaccinated group. In conclusion, this vaccine was able to stimulate the humoral immune response of vaccinated heifers which could have a beneficial effect against new IMI by S. aureus and help to combat this mastitis pathogen

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Bartonella spp. in households with cats : Risk factors for infection in cats and human exposure

The aim of this study was to estimate the occurrence of Bartonella spp. per household in cats and the risk factors for Bartonella spp. positivity in cats and their owners from Valdivia, Chile. A total of 464 cats (distributed within 324 households) and 326 humans (control group [n = 112] and cat owner [n = 214]) distributed in 262 households were sampled. From the cat owners (n = 214), 128 humans were in households where the cat was also sampled, totaling 84 households with dual sampling. Real-time PCR (qPCR) was used for Bartonella spp. detection in blood from cats and humans, and immunofluorescent immunoassay (IFA) anti-Bartonella henselae was performed in human serum samples. Out of the total of 324 households, 20.43% presented at least one Bartonella positive cat. From the households with dual sampling, 29.7% (25/84) presented at least one qPCR-Bartonella spp. positive cat. However, Bartonella DNA was not amplified in humans, and in 7.3% (6/82) of the households was found at least one of the cat's owners exposed to B. henselae. Cats younger than one year (Odds Ratio (OR) = 5.3), non-neutered (OR 3.46), sampled at home (OR 5.82), and with improper application of tick/flea control products (OR 3.13) showed a higher risk for Bartonella spp. presence. Humans with occupational exposure involving animal contact, were more likely to exhibit B. henselae seropositivity (OR 7.5). Bartonella spp. was present in the cats a moderate number of households, but Bartonella DNA was not detected in owners' blood, inferring that there is a low risk of recent human infection in the studied population