Dairy goats helminthosis and its potential predictors in Greece: Findings from an extensive countrywide study.

The objectives of the present study were: (a) to describe the prevalence of helminth infections from pooled faecal samples from goat herds across Greece, (b) to evaluate herd-related factors potentially associated with the presence of these infections in the herds and (c) to compare the findings to those of a previous relevant study performed in sheep flocks. A cross-sectional study was carried out in 119 goat herds around Greece. Helminths were recovered from samples from 93.3% of herds: Dicrocoelium dendriticum (from 15.1% of herds), Paramphistomum cervi (from 0.8% of herds), Moniezia spp. (from 25.2% of herds), Trichostrongylidae (from 89.1% of herds), Nematodirus spp. (from 16.8% of herds), Strongyloides papillosus (from 5.0% of herds), Trichuris spp. (from 18.5% of herds) and lungworms (from 23.5% of herds). Mean epg counts in all herds in the study were 219 epg. In multivariable analyses, for 'high (> 300) epg counts in faecal samples' the age of kid removal from their dams (p = 0.045) was found to be a significant factor, for 'high proportion (> 64%) of Teladorsagia spp. in faecal samples' the month of the start of the kidding season (p = 0.045) was a significant factor, for 'high proportion (> 27%) of Haemonchus contortus in faecal samples' nutritional modifications during gestation (p = 0.002) and application of reproductive control practices in the farm (p = 0.013) were the significant factors and for 'presence of D. dendriticum in faecal samples' the number of veterinary visits to the farm annually (p = 0.040) was found to be significant.

Experimental study for evaluation of the efficacy of a biofilm-embedded bacteria-based vaccine against Staphylococcus chromogenes-associated mastitis in sheep.

Although coagulase-negative staphylococci are the primary aetiological agents of subclinical mastitis in ewes, there is little information regarding vaccination against that infection. The objective of this study was to evaluate the efficacy of a vaccine against staphylococcal mastitis in ewes under experimental conditions. The antigen in the vaccine is based on a bacterin of Staphylococcus aureus strain, expressing the exopolysaccharide poly-N-acetylglucosamine (PNAG), which is involved in biofilm formation by these bacteria. Ewes in groups A (n = 17) or B (n = 6) were given an initial vaccination 5 weeks before expected lambing, followed by a repeat administration 21 days later. Ewes in groups C (n = 8) or D (n = 6) were unvaccinated controls. Ewes in group A (n = 17) or C (n = 8) were challenged with a biofilm-forming S. chromogenes; animals in subgroups A1 or C1 were challenged on the 10th and those in A2 or C2 on the 50th day after lambing. Ewes in groups B or D were uninoculated controls. Clinical examinations of ewes, ultrasonographic examinations of udder, milk yield measurements, blood sampling for detection of anti-PNAG specific antibodies and milk sample collection for bacteriological and cytological examinations were performed up to 52nd day post-challenge. Finally, biopsies were performed for mammary tissue collection for histopathological examination. Among group A ewes, 29% developed systemic signs and 59% signs in the inoculated gland; the respective figures for group C were 50% and 100% (P =  0.040 for mammary signs). The median total clinical score was 2.0 for A and 5.5 for C ewes (P =  0.025). For A, but not for C, clinical scores decreased progressively during the study (P =  0.018 and P =  0.47, respectively). The duration of mastitis was shorter in A (4 days) than in C (17.5 days) ewes (P =  0.022). Bacterial counts were lower in milk samples from A than from C ewes, for samples collected from the inoculated and the uninoculated (P <  0.01) mammary glands of these ewes. Somatic cell counts in samples from inoculated and uninoculated mammary glands of A ewes were higher than in samples of C ewes (P <  0.02). There were differences for gray-scale evaluations during ultrasonographic examination and for milk yield measurements between groups (P <  0.01). Median bacterial counts in tissue samples from A ewes (0 cfu g-1) were lower than in ones from C (6.5 cfu g-1) ewes (P =  0.041). The median score for histopathological findings in tissue samples from inoculated glands of A was lower than that for C ewes: 1 versus 2 (P =  0.014). It is concluded that mastitis was less severe in vaccinated animals, as indicated by a wide array of measures.

Evaluation of efficacy of a biofilm-embedded bacteria-based vaccine against staphylococcal mastitis in sheep-A randomized, placebo-controlled field study.

Our objective was to evaluate the efficacy of a vaccine against staphylococcal mastitis in 5 dairy sheep farms, with 316 ewes in the vaccinated (V) group and 307 in the control (C) group studied throughout a lactation period. Two administrations of the vaccine were performed during the last stage of gestation of ewes. Starting 15 d after lambing and at monthly intervals thereafter, up to 9 milk samplings were performed for bacteriological and cytological examinations. Staphylococcal isolates recovered were examined for biofilm formation. Blood samples were collected for measurement of IgG poly-N-acetylglucosamine-specific antibodies. The most frequently isolated bacteria were staphylococci: 56.4 and 76.1%, respectively, of total isolates recovered from ewes of group V and C, respectively; staphylococci as causal agents of mastitis were isolated less frequently from V (5.3%) than in ewes in C (10.3%). Among mastitis-associated staphylococcal isolates recovered from V ewes, a smaller proportion was biofilm-forming than among ones from C: 53.2% versus 74.9% of isolates; biofilm-forming staphylococci as causal agents of mastitis were isolated less frequently from ewes in group V (2.3%) than in ewes in group C (6.0%). Anti-poly-N-acetylglucosamine-specific antibody values increased in V ewes and were higher than in C; a greater proportion of ewes with low antibody titers developed staphylococcal mastitis (41.4%) than of V ewes with high antibody titers (17.0%). Incidence risk of mastitis, staphylococcal mastitis, and biofilm-associated staphylococcal mastitis was smaller in V than in C: 36.7, 17.1, and 8.0% versus 44.3, 30.9, and 18.9%, respectively. The first case of staphylococcal mastitis occurred later in V than in C: third versus second sampling point. Overall, efficacy of the vaccine was 44.6% for staphylococcal mastitis, 57.7% for biofilm-associated staphylococcal mastitis, 33.1% for staphylococcal intramammary infection, and 51.5% for biofilm-associated staphylococcal intramammary infection. Nevertheless, vaccination should not be the only means for controlling mastitis; other udder health management measures should be included therein to improve control of the infection.

Field evidence for association between increased gastrointestinal nematode burden and subclinical mastitis in dairy sheep.

The objective of the present study was to study, under field conditions, potential associations between gastrointestinal nematode parasitism and subclinical mastitis in ewes during the lactation period. Faecal and milk samples were collected from 240 ewes in 16 farms, for parasitological and bacteriological plus cytological examination, respectively. In the population sampled, prevalence of gastrointestinal nematode infection was 63.0%; mean faecal count was 357.7 ± 32.4 eggs per gram (epg); Teladorsagia spp. larvae were identified more frequently in coprocultures (median proportion among farms: 53.0%). The prevalence of subclinical mastitis was 22.6%; coagulase-negative Staphylococcus spp. were identified more frequently as causal agents (64.7% of isolates recovered from cases of the disease). There was clear evidence that the prevalence of subclinical mastitis was higher among ewes with gastrointestinal nematode infection than among ewes without: 26.4% and 16.1% (P = 0.047), respectively. Further, the prevalence of subclinical mastitis was higher in ewes with high faecal epg: 31.1% versus 18.6% in ewes with low faecal epg (P = 0.027). Mean epg counts in ewes with mastitis were significantly higher: 500 ± 84 (mean ± standard error of the mean), than epg counts in healthy ewes: 316 ± 36 (P = 0.024). The findings further underline the importance of concurrent parasitic and bacterial infections. Moreover, results also suggest further factors that can play a role in development of mastitis in ewes.