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S. De Vliegher - One of the best experts on this subject based on the ideXlab platform.

  • The effect of intramammary infection in early lactation with non-aureus staphylococci in general and Staphylococcus Chromogenes specifically on quarter milk somatic cell count and quarter milk yield.
    Journal of dairy science, 2019
    Co-Authors: Dimitri Valckenier, Sofie Piepers, A. De Visscher, S. De Vliegher
    Abstract:

    ABSTRACT This longitudinal study aimed to evaluate the impact of subclinical intramammary infection (IMI) with non-aureus staphylococcal (NAS) species in the first 18 d in milk (DIM) on the quarter milk somatic cell count (qSCC) and quarter milk yield (qMY) during the first 4 mo of lactation in Holstein Friesian heifers. Quarter milk samples were collected from 82 heifers from 1 to 4 DIM until 130 DIM on a biweekly (14 d) basis for determination of the qSCC; qMY data were available through the automatic milking systems. The quarter samples collected on the first (1–4 DIM) and second (15–18 DIM) sampling days were used for bacteriological culturing to determine the IMI status. In this study, 324 quarters from 82 heifers were enrolled, of which 68 were NAS-infected at the first sampling day. Only 16 (23.5%) of these quarters were still NAS-infected at the second sampling day, demonstrating the high spontaneous cure rate of these infections shortly after calving; 9 of these 16 cases were infected with the same NAS species. Interestingly, none of the NAS-infected quarters at the first sampling day acquired a new infection with a major pathogen at the second sampling day, whereas 2.3% of the noninfected quarters did. All 102 isolates phenotypically identified as NAS were further identified to the species level. Staphylococcus Chromogenes was the most prevalent species on the first (29.4% of all NAS) and second (52.9%) sampling days. Quarters infected with Staph. Chromogenes at the first sampling day had a significantly higher qSCC in later lactation than noninfected quarters, whereas this was not true for quarters infected with all other NAS species (i.e., as a group of species). The average daily qMY in the first 4 mo of lactation did not differ between noninfected quarters and quarters infected with Staph. Chromogenes or all other NAS species at the first sampling day. Persistently NAS species-infected quarters in the first 18 DIM (i.e., infected with the same NAS species on the first and second sampling days) had the highest qSCC later in lactation, followed by quarters with a new NAS IMI (i.e., noninfected at the first sampling day and infected with NAS at the second sampling day). The qSCC from transiently NAS species-infected quarters (i.e., not infected with the same NAS species at the second sampling day) was not significantly higher in later lactation compared with that in noninfected quarters. The IMI status of quarters in the first 18 DIM, combining culture results at 1 to 4 and 15 to 18 DIM (new, persistent, and transient IMI), was not significantly associated with daily qMY in the first 4 mo after calving. In general, NAS should be considered minor pathogens with no adverse effect on daily qMY in quarters of heifers infected in the first 18 DIM and with a high spontaneous cure rate. Staphylococcus Chromogenes was the most prevalent species, causing an increase in qSCC comparable to the level of quarters infected with a major pathogen; Staph. Chromogenes caused most infections that persisted through at least the first 18 DIM.

  • Intramammary infection with coagulase-negative staphylococci at parturition: Species-specific prevalence, risk factors, and effect on udder health.
    Journal of dairy science, 2016
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections (IMI) in many countries. Despite a high prevalence of CNS IMI at parturition, species-specific risk factor studies, relying on accurate identification methods, are lacking. Therefore, this observational study aimed at determining the prevalence and distribution of different CNS species causing IMI in fresh heifers and dairy cows in Flemish dairy herds and identifying associated species- and subgroup-specific risk factors at the herd, cow, and quarter level. The effect on udder health was investigated as well. Staphylococcus Chromogenes, S. sciuri, and S. cohnii were the most frequently isolated species. The only CNS species causing IMI in fresh heifers and dairy cows in all herds was Staphylococcus Chromogenes, whereas large between-herd differences in distribution were observed for the other species. Quarters from heifers and quarters with an inverted teat end had higher odds of being infected with S. Chromogenes, S. simulans, or S. xylosus as well as with S. Chromogenes solely. Prepartum teat apex colonization with S. Chromogenes increased the likelihood of S. Chromogenes IMI in the corresponding quarters at parturition. Quarters with dirty teat apices before calving were more likely to be infected with S. cohnii, S. equorum, S. saprophyticus, or S. sciuri, supporting the environmental nature of these CNS species. Three species (S. Chromogenes, S. simulans, and S. xylosus) were associated with a higher quarter somatic cell count at parturition as compared with uninfected quarters.

  • Teat apex colonization with coagulase-negative Staphylococcus species before parturition: Distribution and species-specific risk factors
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections and are also abundantly present in extramammary habitats such as teat apices. Teat apex colonization (TAC) with CNS has already been explored in lactating dairy cows at the species level, whereas this is not true for dry cows and end-term heifers. Therefore, the aim of this observational study was to describe CNS TAC in nonlactating dairy cows and end-term heifers in Flemish dairy herds and to identify associated risk factors at the herd, cow, and quarter level. All CNS were molecularly identified to the species level using transfer RNA intergenic spacer PCR (tDNA-PCR) and sequencing of the 16S rRNA gene, allowing for species-specific statistical analyses using multivariable, multilevel logistic regression. Staphylococcus devriesei, Staphylococcus Chromogenes, Staphylococcus haemolyticus, and Staphylococcus equorum were the most frequently isolated species. Staphylococcus Chromogenes was the sole species colonizing teat apices of cows and heifers in all herds, whereas large between-herd differences were observed for the other species. Teat apices of red and white Holstein Friesians, of quarters dried off without an internal teat sealer, and swabbed in months with lower precipitation and higher ambient temperature were significantly more likely to be colonized by S. devriesei. Slightly dirty teat apices and teat apices swabbed in months with lower precipitation had higher odds of being colonized by S. Chromogenes, whereas teat apices sampled in months with lower precipitation and higher ambient temperature were more likely to be colonized by S. haemolyticus. Dirty teat apices and teat apices swabbed in months with lower ambient temperature in combination with low precipitation had higher odds of being colonized by S. equorum. Diverse factors explaining CNS TAC, yet mostly related to humidity, ambient temperature, and hygiene, substantiate differences in epidemiological behavior and ecology between species.

  • Short communication: Species group-specific predictors at the cow and quarter level for intramammary infection with coagulase-negative staphylococci in dairy cattle throughout lactation.
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, K. Supré, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are frequently isolated from quarters with subclinical mastitis, teat apices, and the cows' environment. Virulence, ecology, epidemiological behavior, and effect on udder health vary between different CNS species. Staphylococcus Chromogenes, Staph. simulans, and Staph. xylosus are frequently present in milk and have a more substantial effect on quarter milk somatic cell count than other species. Therefore, these species are considered the "more relevant" CNS. As species-specific factors associated with CNS intramammary infection (IMI) have not yet been identified and susceptibility for IMI differs between cows and quarters, this study aimed to identify predictors for CNS IMI at the cow and quarter level (some of them changing over time) with a specific focus on the aforementioned more relevant CNS. Precise data were available from a longitudinal study (3,052 observations from 344 quarters from 86 dairy cows belonging to 3 commercial dairy herds). All CNS were molecularly identified to the species level, and multivariable, multilevel logistic regression models taking into account the longitudinal nature of the data, were fit to study the likelihood of infection. Staphylococcus Chromogenes, Staph. xylosus, and Staph. cohnii were the most frequently isolated species from CNS IMI in older cows, whereas Staph. Chromogenes, Staph. xylosus, and Staph. simulans were the main species found in IMI in heifers. Quarters from heifers (as opposed to multiparous cows), from heifers and multiparous cows in third or fourth month in lactation (as opposed to early lactation,

  • distribution of coagulase negative Staphylococcus species from milk and environment of dairy cows differs between herds
    Journal of Dairy Science, 2011
    Co-Authors: Veerle Piessens, K. Supré, E Van Coillie, Bert Verbist, G Braem, A Van Nuffel, L De Vuyst, Marc Heyndrickx, S. De Vliegher
    Abstract:

    Abstract In many parts of the world, coagulase-negative staphylococci (CNS) are the predominant pathogens causing intramammary infections (IMI) in dairy cows. The cows' environment is thought to be a possible source for CNS mastitis and this was investigated in the present paper. A longitudinal field study was carried out in 6 well-managed dairy herds to determine the distribution and epidemiology of various CNS species isolated from milk, causing IMI and living freely in the cows' environment, respectively. In each herd, quarter milk samples from a cohort of 10 lactating cows and environmental samples from stall air, slatted floor, sawdust from cubicles, and sawdust stock were collected monthly (n=13). Isolates from quarter milk samples (n=134) and the environment (n=637) were identified to species level using amplified fragment length polymorphism (AFLP) genotyping. Staphylococcus Chromogenes , S. haemolyticus , S. epidermidis , and S. simulans accounted for 81.3% of all CNS milk isolates. Quarters were considered infected with CNS (positive IMI status) only when 2 out of 3 consecutive milk samples yielded the same CNS AFLP type. The species causing IMI were S. Chromogenes (n=35 samples with positive IMI status), S. haemolyticus (n=29), S. simulans (n=14), and S. epidermidis (n=6). The observed persistent IMI cases (n=17) had a mean duration of 149.4 d (range 63.0 to 329.8 d). The CNS species predominating in the environment were S. equorum , S. sciuri , S. haemolyticus , and S. fleurettii . Herd-to-herd differences in distribution of CNS species were observed in both milk and the environment, suggesting that herd-level factors are involved in the establishment of particular species in a dairy herd. Primary reservoirs of the species causing IMI varied. Staphylococcus Chromogenes and S. epidermidis were rarely found in the environment, indicating that other reservoirs were more important in their epidemiology. For S. haemolyticus and S. simulans , the environment was found as a reservoir, suggesting that IMI with these species were possibly environmental in origin.

Freddy Haesebrouck - One of the best experts on this subject based on the ideXlab platform.

  • Intramammary infection with coagulase-negative staphylococci at parturition: Species-specific prevalence, risk factors, and effect on udder health.
    Journal of dairy science, 2016
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections (IMI) in many countries. Despite a high prevalence of CNS IMI at parturition, species-specific risk factor studies, relying on accurate identification methods, are lacking. Therefore, this observational study aimed at determining the prevalence and distribution of different CNS species causing IMI in fresh heifers and dairy cows in Flemish dairy herds and identifying associated species- and subgroup-specific risk factors at the herd, cow, and quarter level. The effect on udder health was investigated as well. Staphylococcus Chromogenes, S. sciuri, and S. cohnii were the most frequently isolated species. The only CNS species causing IMI in fresh heifers and dairy cows in all herds was Staphylococcus Chromogenes, whereas large between-herd differences in distribution were observed for the other species. Quarters from heifers and quarters with an inverted teat end had higher odds of being infected with S. Chromogenes, S. simulans, or S. xylosus as well as with S. Chromogenes solely. Prepartum teat apex colonization with S. Chromogenes increased the likelihood of S. Chromogenes IMI in the corresponding quarters at parturition. Quarters with dirty teat apices before calving were more likely to be infected with S. cohnii, S. equorum, S. saprophyticus, or S. sciuri, supporting the environmental nature of these CNS species. Three species (S. Chromogenes, S. simulans, and S. xylosus) were associated with a higher quarter somatic cell count at parturition as compared with uninfected quarters.

  • Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus Chromogenes in dairy heifers
    Veterinary Research, 2016
    Co-Authors: Kristine Piccart, Freddy Haesebrouck, Joren Verbeke, Anneleen De Visscher, Sofie Piepers, Sarne De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus Chromogenes strain originating from a persistent intramammary infection ( S. Chromogenes IM) and a S. Chromogenes strain isolated from a heifer’s teat apex ( S. Chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 × 10^6 colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii -inoculated quarters, although the strain was eliminated within 12 h. The two S. Chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. Chromogenes IM than with S. Chromogenes TA. In conclusion, these results suggest that S. Chromogenes might be better adapted to the mammary gland than S. fleurettii . Furthermore, not all S. Chromogenes strains induce the same local host response.

  • Teat apex colonization with coagulase-negative Staphylococcus species before parturition: Distribution and species-specific risk factors
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections and are also abundantly present in extramammary habitats such as teat apices. Teat apex colonization (TAC) with CNS has already been explored in lactating dairy cows at the species level, whereas this is not true for dry cows and end-term heifers. Therefore, the aim of this observational study was to describe CNS TAC in nonlactating dairy cows and end-term heifers in Flemish dairy herds and to identify associated risk factors at the herd, cow, and quarter level. All CNS were molecularly identified to the species level using transfer RNA intergenic spacer PCR (tDNA-PCR) and sequencing of the 16S rRNA gene, allowing for species-specific statistical analyses using multivariable, multilevel logistic regression. Staphylococcus devriesei, Staphylococcus Chromogenes, Staphylococcus haemolyticus, and Staphylococcus equorum were the most frequently isolated species. Staphylococcus Chromogenes was the sole species colonizing teat apices of cows and heifers in all herds, whereas large between-herd differences were observed for the other species. Teat apices of red and white Holstein Friesians, of quarters dried off without an internal teat sealer, and swabbed in months with lower precipitation and higher ambient temperature were significantly more likely to be colonized by S. devriesei. Slightly dirty teat apices and teat apices swabbed in months with lower precipitation had higher odds of being colonized by S. Chromogenes, whereas teat apices sampled in months with lower precipitation and higher ambient temperature were more likely to be colonized by S. haemolyticus. Dirty teat apices and teat apices swabbed in months with lower ambient temperature in combination with low precipitation had higher odds of being colonized by S. equorum. Diverse factors explaining CNS TAC, yet mostly related to humidity, ambient temperature, and hygiene, substantiate differences in epidemiological behavior and ecology between species.

  • Short communication: Species group-specific predictors at the cow and quarter level for intramammary infection with coagulase-negative staphylococci in dairy cattle throughout lactation.
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, K. Supré, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are frequently isolated from quarters with subclinical mastitis, teat apices, and the cows' environment. Virulence, ecology, epidemiological behavior, and effect on udder health vary between different CNS species. Staphylococcus Chromogenes, Staph. simulans, and Staph. xylosus are frequently present in milk and have a more substantial effect on quarter milk somatic cell count than other species. Therefore, these species are considered the "more relevant" CNS. As species-specific factors associated with CNS intramammary infection (IMI) have not yet been identified and susceptibility for IMI differs between cows and quarters, this study aimed to identify predictors for CNS IMI at the cow and quarter level (some of them changing over time) with a specific focus on the aforementioned more relevant CNS. Precise data were available from a longitudinal study (3,052 observations from 344 quarters from 86 dairy cows belonging to 3 commercial dairy herds). All CNS were molecularly identified to the species level, and multivariable, multilevel logistic regression models taking into account the longitudinal nature of the data, were fit to study the likelihood of infection. Staphylococcus Chromogenes, Staph. xylosus, and Staph. cohnii were the most frequently isolated species from CNS IMI in older cows, whereas Staph. Chromogenes, Staph. xylosus, and Staph. simulans were the main species found in IMI in heifers. Quarters from heifers (as opposed to multiparous cows), from heifers and multiparous cows in third or fourth month in lactation (as opposed to early lactation,

  • some coagulase negative Staphylococcus species affect udder health more than others
    Journal of Dairy Science, 2011
    Co-Authors: K. Supré, Freddy Haesebrouck, Mario Vaneechoutte, Sofie Piepers, Ruth N. Zadoks, S. De Vliegher
    Abstract:

    A longitudinal study in 3 dairy herds was conducted to profile the distribution of coagulase-negative Staphylococcus (CNS) species causing bovine intramammary infection (IMI) using molecular identification and to gain more insight in the pathogenic potential of CNS as a group and of the most prevalent species causing IMI. Monthly milk samples from 25 cows in each herd as well as samples from clinical mastitis were collected over a 13-mo period. Coagulase-negative staphylococci were identified to the species level using transfer-RNA intergenic spacer PCR. The distribution of CNS causing IMI was highly herd-dependent, but overall, Staphylococcus Chromogenes, Staphylococcus xylosus, Staphylococcus cohnii, and Staphylococcus simulans were the most prevalent. No CNS species were found to cause clinical mastitis. The effect of the most prevalent species on the quarter milk somatic cell count (SCC) was analyzed using a linear mixed model, showing that Staph. Chromogenes, Staph. simulans, and Staph. xylosus induced an increase in the SCC that is comparable with that of Staphylococcus aureus. Almost all CNS species were able to cause persistent IMI, with Staph. Chromogenes causing the most persistent infections. In conclusion, accurate species identification cannot be ignored when studying the effect of CNS on udder health, as the effect on SCC differs between species and species distribution is herd-specific. Staphylococcus Chromogenes, Staph. simulans, and Staph. xylosus seem to be the more important species and deserve special attention in further studies. Reasons for herd dependency and possible cow- and quarter-level risk factors should be examined in detail for the different species, eventually leading to cost-benefit analyses for management changes and, if needed, treatment recommendations.

Sofie Piepers - One of the best experts on this subject based on the ideXlab platform.

  • The effect of intramammary infection in early lactation with non-aureus staphylococci in general and Staphylococcus Chromogenes specifically on quarter milk somatic cell count and quarter milk yield.
    Journal of dairy science, 2019
    Co-Authors: Dimitri Valckenier, Sofie Piepers, A. De Visscher, S. De Vliegher
    Abstract:

    ABSTRACT This longitudinal study aimed to evaluate the impact of subclinical intramammary infection (IMI) with non-aureus staphylococcal (NAS) species in the first 18 d in milk (DIM) on the quarter milk somatic cell count (qSCC) and quarter milk yield (qMY) during the first 4 mo of lactation in Holstein Friesian heifers. Quarter milk samples were collected from 82 heifers from 1 to 4 DIM until 130 DIM on a biweekly (14 d) basis for determination of the qSCC; qMY data were available through the automatic milking systems. The quarter samples collected on the first (1–4 DIM) and second (15–18 DIM) sampling days were used for bacteriological culturing to determine the IMI status. In this study, 324 quarters from 82 heifers were enrolled, of which 68 were NAS-infected at the first sampling day. Only 16 (23.5%) of these quarters were still NAS-infected at the second sampling day, demonstrating the high spontaneous cure rate of these infections shortly after calving; 9 of these 16 cases were infected with the same NAS species. Interestingly, none of the NAS-infected quarters at the first sampling day acquired a new infection with a major pathogen at the second sampling day, whereas 2.3% of the noninfected quarters did. All 102 isolates phenotypically identified as NAS were further identified to the species level. Staphylococcus Chromogenes was the most prevalent species on the first (29.4% of all NAS) and second (52.9%) sampling days. Quarters infected with Staph. Chromogenes at the first sampling day had a significantly higher qSCC in later lactation than noninfected quarters, whereas this was not true for quarters infected with all other NAS species (i.e., as a group of species). The average daily qMY in the first 4 mo of lactation did not differ between noninfected quarters and quarters infected with Staph. Chromogenes or all other NAS species at the first sampling day. Persistently NAS species-infected quarters in the first 18 DIM (i.e., infected with the same NAS species on the first and second sampling days) had the highest qSCC later in lactation, followed by quarters with a new NAS IMI (i.e., noninfected at the first sampling day and infected with NAS at the second sampling day). The qSCC from transiently NAS species-infected quarters (i.e., not infected with the same NAS species at the second sampling day) was not significantly higher in later lactation compared with that in noninfected quarters. The IMI status of quarters in the first 18 DIM, combining culture results at 1 to 4 and 15 to 18 DIM (new, persistent, and transient IMI), was not significantly associated with daily qMY in the first 4 mo after calving. In general, NAS should be considered minor pathogens with no adverse effect on daily qMY in quarters of heifers infected in the first 18 DIM and with a high spontaneous cure rate. Staphylococcus Chromogenes was the most prevalent species, causing an increase in qSCC comparable to the level of quarters infected with a major pathogen; Staph. Chromogenes caused most infections that persisted through at least the first 18 DIM.

  • Intramammary infection with coagulase-negative staphylococci at parturition: Species-specific prevalence, risk factors, and effect on udder health.
    Journal of dairy science, 2016
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections (IMI) in many countries. Despite a high prevalence of CNS IMI at parturition, species-specific risk factor studies, relying on accurate identification methods, are lacking. Therefore, this observational study aimed at determining the prevalence and distribution of different CNS species causing IMI in fresh heifers and dairy cows in Flemish dairy herds and identifying associated species- and subgroup-specific risk factors at the herd, cow, and quarter level. The effect on udder health was investigated as well. Staphylococcus Chromogenes, S. sciuri, and S. cohnii were the most frequently isolated species. The only CNS species causing IMI in fresh heifers and dairy cows in all herds was Staphylococcus Chromogenes, whereas large between-herd differences in distribution were observed for the other species. Quarters from heifers and quarters with an inverted teat end had higher odds of being infected with S. Chromogenes, S. simulans, or S. xylosus as well as with S. Chromogenes solely. Prepartum teat apex colonization with S. Chromogenes increased the likelihood of S. Chromogenes IMI in the corresponding quarters at parturition. Quarters with dirty teat apices before calving were more likely to be infected with S. cohnii, S. equorum, S. saprophyticus, or S. sciuri, supporting the environmental nature of these CNS species. Three species (S. Chromogenes, S. simulans, and S. xylosus) were associated with a higher quarter somatic cell count at parturition as compared with uninfected quarters.

  • Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus Chromogenes in dairy heifers
    Veterinary Research, 2016
    Co-Authors: Kristine Piccart, Freddy Haesebrouck, Joren Verbeke, Anneleen De Visscher, Sofie Piepers, Sarne De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus Chromogenes strain originating from a persistent intramammary infection ( S. Chromogenes IM) and a S. Chromogenes strain isolated from a heifer’s teat apex ( S. Chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 × 10^6 colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii -inoculated quarters, although the strain was eliminated within 12 h. The two S. Chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. Chromogenes IM than with S. Chromogenes TA. In conclusion, these results suggest that S. Chromogenes might be better adapted to the mammary gland than S. fleurettii . Furthermore, not all S. Chromogenes strains induce the same local host response.

  • Teat apex colonization with coagulase-negative Staphylococcus species before parturition: Distribution and species-specific risk factors
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections and are also abundantly present in extramammary habitats such as teat apices. Teat apex colonization (TAC) with CNS has already been explored in lactating dairy cows at the species level, whereas this is not true for dry cows and end-term heifers. Therefore, the aim of this observational study was to describe CNS TAC in nonlactating dairy cows and end-term heifers in Flemish dairy herds and to identify associated risk factors at the herd, cow, and quarter level. All CNS were molecularly identified to the species level using transfer RNA intergenic spacer PCR (tDNA-PCR) and sequencing of the 16S rRNA gene, allowing for species-specific statistical analyses using multivariable, multilevel logistic regression. Staphylococcus devriesei, Staphylococcus Chromogenes, Staphylococcus haemolyticus, and Staphylococcus equorum were the most frequently isolated species. Staphylococcus Chromogenes was the sole species colonizing teat apices of cows and heifers in all herds, whereas large between-herd differences were observed for the other species. Teat apices of red and white Holstein Friesians, of quarters dried off without an internal teat sealer, and swabbed in months with lower precipitation and higher ambient temperature were significantly more likely to be colonized by S. devriesei. Slightly dirty teat apices and teat apices swabbed in months with lower precipitation had higher odds of being colonized by S. Chromogenes, whereas teat apices sampled in months with lower precipitation and higher ambient temperature were more likely to be colonized by S. haemolyticus. Dirty teat apices and teat apices swabbed in months with lower ambient temperature in combination with low precipitation had higher odds of being colonized by S. equorum. Diverse factors explaining CNS TAC, yet mostly related to humidity, ambient temperature, and hygiene, substantiate differences in epidemiological behavior and ecology between species.

  • Short communication: Species group-specific predictors at the cow and quarter level for intramammary infection with coagulase-negative staphylococci in dairy cattle throughout lactation.
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, K. Supré, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are frequently isolated from quarters with subclinical mastitis, teat apices, and the cows' environment. Virulence, ecology, epidemiological behavior, and effect on udder health vary between different CNS species. Staphylococcus Chromogenes, Staph. simulans, and Staph. xylosus are frequently present in milk and have a more substantial effect on quarter milk somatic cell count than other species. Therefore, these species are considered the "more relevant" CNS. As species-specific factors associated with CNS intramammary infection (IMI) have not yet been identified and susceptibility for IMI differs between cows and quarters, this study aimed to identify predictors for CNS IMI at the cow and quarter level (some of them changing over time) with a specific focus on the aforementioned more relevant CNS. Precise data were available from a longitudinal study (3,052 observations from 344 quarters from 86 dairy cows belonging to 3 commercial dairy herds). All CNS were molecularly identified to the species level, and multivariable, multilevel logistic regression models taking into account the longitudinal nature of the data, were fit to study the likelihood of infection. Staphylococcus Chromogenes, Staph. xylosus, and Staph. cohnii were the most frequently isolated species from CNS IMI in older cows, whereas Staph. Chromogenes, Staph. xylosus, and Staph. simulans were the main species found in IMI in heifers. Quarters from heifers (as opposed to multiparous cows), from heifers and multiparous cows in third or fourth month in lactation (as opposed to early lactation,

A. De Kruif - One of the best experts on this subject based on the ideXlab platform.

  • In vitro growth inhibition of major mastitis pathogens by Staphylococcus Chromogenes originating from teat apices of dairy heifers.
    Veterinary microbiology, 2004
    Co-Authors: S. De Vliegher, Luc Devriese, Geert Opsomer, A Vanrolleghem, O.c. Sampimon, J. Sol, Herman W. Barkema, Freddy Haesebrouck, A. De Kruif
    Abstract:

    Earlier field observations suggest that teat apex colonization by Staphylococcus Chromogenes pre-partum in dairy heifers protects udder quarters against elevated somatic cell counts early post-partum. To explain these findings, the in vitro inhibitory capability of S. Chromogenes from teat apices of heifers towards some major mastitis pathogens was tested using a modified cross-streaking method. Two out of 10 S. Chromogenes isolates, both originating from two different teats from the same heifer, consistently inhibited growth of all Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis strains, but none of the Escherichia coli strains. The present study, therefore, supports the protective effect of teat apex colonization by S. Chromogenes by in vitro production of inhibitory substances.

  • Prepartum teat apex colonization with Staphylococcus Chromogenes in dairy heifers is associated with low somatic cell count in early lactation.
    Veterinary microbiology, 2003
    Co-Authors: S. De Vliegher, Luc Devriese, Geert Opsomer, Herman W. Barkema, Hans Laevens, J.l.m.r. Leroy, A. De Kruif
    Abstract:

    Abstract A high number of dairy heifers freshen with udder health problems. The prevalence of teat apex colonization (TAC) with Staphylococcus Chromogenes , one of the most widespread coagulase-negative staphylococci (CNS) in milk samples from freshly calved dairy heifers, was measured cross-sectionally in non-lactating heifers on eight commercial dairy farms in Belgium. The influence of age on this prevalence, and the association between teat apex colonization with S. Chromogenes prepartum and quarter milk somatic cell count (SCC) in early lactation were studied. In total, 492 teat apices were sampled from 123 heifers. The age of the heifers varied from 8 to 34 months. Overall, 20% of the heifers had at least one teat apex colonized with S. Chromogenes . Of all teats sampled, 10% were colonized with S. Chromogenes . The chance of having at least one teat apex colonized with S. Chromogenes increased with age of the heifer. The presence of prepartum teat apex colonization with S. Chromogenes was not associated with intramammary infection (IMI) early postpartum with the same bacterium. On the contrary, teat apex colonization with S. Chromogenes prepartum appeared to protect quarters in the first few days of lactation from having somatic cell count ≥200,000 cells/ml milk, commonly accepted as the threshold for intramammary infection.

A. De Visscher - One of the best experts on this subject based on the ideXlab platform.

  • The effect of intramammary infection in early lactation with non-aureus staphylococci in general and Staphylococcus Chromogenes specifically on quarter milk somatic cell count and quarter milk yield.
    Journal of dairy science, 2019
    Co-Authors: Dimitri Valckenier, Sofie Piepers, A. De Visscher, S. De Vliegher
    Abstract:

    ABSTRACT This longitudinal study aimed to evaluate the impact of subclinical intramammary infection (IMI) with non-aureus staphylococcal (NAS) species in the first 18 d in milk (DIM) on the quarter milk somatic cell count (qSCC) and quarter milk yield (qMY) during the first 4 mo of lactation in Holstein Friesian heifers. Quarter milk samples were collected from 82 heifers from 1 to 4 DIM until 130 DIM on a biweekly (14 d) basis for determination of the qSCC; qMY data were available through the automatic milking systems. The quarter samples collected on the first (1–4 DIM) and second (15–18 DIM) sampling days were used for bacteriological culturing to determine the IMI status. In this study, 324 quarters from 82 heifers were enrolled, of which 68 were NAS-infected at the first sampling day. Only 16 (23.5%) of these quarters were still NAS-infected at the second sampling day, demonstrating the high spontaneous cure rate of these infections shortly after calving; 9 of these 16 cases were infected with the same NAS species. Interestingly, none of the NAS-infected quarters at the first sampling day acquired a new infection with a major pathogen at the second sampling day, whereas 2.3% of the noninfected quarters did. All 102 isolates phenotypically identified as NAS were further identified to the species level. Staphylococcus Chromogenes was the most prevalent species on the first (29.4% of all NAS) and second (52.9%) sampling days. Quarters infected with Staph. Chromogenes at the first sampling day had a significantly higher qSCC in later lactation than noninfected quarters, whereas this was not true for quarters infected with all other NAS species (i.e., as a group of species). The average daily qMY in the first 4 mo of lactation did not differ between noninfected quarters and quarters infected with Staph. Chromogenes or all other NAS species at the first sampling day. Persistently NAS species-infected quarters in the first 18 DIM (i.e., infected with the same NAS species on the first and second sampling days) had the highest qSCC later in lactation, followed by quarters with a new NAS IMI (i.e., noninfected at the first sampling day and infected with NAS at the second sampling day). The qSCC from transiently NAS species-infected quarters (i.e., not infected with the same NAS species at the second sampling day) was not significantly higher in later lactation compared with that in noninfected quarters. The IMI status of quarters in the first 18 DIM, combining culture results at 1 to 4 and 15 to 18 DIM (new, persistent, and transient IMI), was not significantly associated with daily qMY in the first 4 mo after calving. In general, NAS should be considered minor pathogens with no adverse effect on daily qMY in quarters of heifers infected in the first 18 DIM and with a high spontaneous cure rate. Staphylococcus Chromogenes was the most prevalent species, causing an increase in qSCC comparable to the level of quarters infected with a major pathogen; Staph. Chromogenes caused most infections that persisted through at least the first 18 DIM.

  • Intramammary infection with coagulase-negative staphylococci at parturition: Species-specific prevalence, risk factors, and effect on udder health.
    Journal of dairy science, 2016
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections (IMI) in many countries. Despite a high prevalence of CNS IMI at parturition, species-specific risk factor studies, relying on accurate identification methods, are lacking. Therefore, this observational study aimed at determining the prevalence and distribution of different CNS species causing IMI in fresh heifers and dairy cows in Flemish dairy herds and identifying associated species- and subgroup-specific risk factors at the herd, cow, and quarter level. The effect on udder health was investigated as well. Staphylococcus Chromogenes, S. sciuri, and S. cohnii were the most frequently isolated species. The only CNS species causing IMI in fresh heifers and dairy cows in all herds was Staphylococcus Chromogenes, whereas large between-herd differences in distribution were observed for the other species. Quarters from heifers and quarters with an inverted teat end had higher odds of being infected with S. Chromogenes, S. simulans, or S. xylosus as well as with S. Chromogenes solely. Prepartum teat apex colonization with S. Chromogenes increased the likelihood of S. Chromogenes IMI in the corresponding quarters at parturition. Quarters with dirty teat apices before calving were more likely to be infected with S. cohnii, S. equorum, S. saprophyticus, or S. sciuri, supporting the environmental nature of these CNS species. Three species (S. Chromogenes, S. simulans, and S. xylosus) were associated with a higher quarter somatic cell count at parturition as compared with uninfected quarters.

  • Teat apex colonization with coagulase-negative Staphylococcus species before parturition: Distribution and species-specific risk factors
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections and are also abundantly present in extramammary habitats such as teat apices. Teat apex colonization (TAC) with CNS has already been explored in lactating dairy cows at the species level, whereas this is not true for dry cows and end-term heifers. Therefore, the aim of this observational study was to describe CNS TAC in nonlactating dairy cows and end-term heifers in Flemish dairy herds and to identify associated risk factors at the herd, cow, and quarter level. All CNS were molecularly identified to the species level using transfer RNA intergenic spacer PCR (tDNA-PCR) and sequencing of the 16S rRNA gene, allowing for species-specific statistical analyses using multivariable, multilevel logistic regression. Staphylococcus devriesei, Staphylococcus Chromogenes, Staphylococcus haemolyticus, and Staphylococcus equorum were the most frequently isolated species. Staphylococcus Chromogenes was the sole species colonizing teat apices of cows and heifers in all herds, whereas large between-herd differences were observed for the other species. Teat apices of red and white Holstein Friesians, of quarters dried off without an internal teat sealer, and swabbed in months with lower precipitation and higher ambient temperature were significantly more likely to be colonized by S. devriesei. Slightly dirty teat apices and teat apices swabbed in months with lower precipitation had higher odds of being colonized by S. Chromogenes, whereas teat apices sampled in months with lower precipitation and higher ambient temperature were more likely to be colonized by S. haemolyticus. Dirty teat apices and teat apices swabbed in months with lower ambient temperature in combination with low precipitation had higher odds of being colonized by S. equorum. Diverse factors explaining CNS TAC, yet mostly related to humidity, ambient temperature, and hygiene, substantiate differences in epidemiological behavior and ecology between species.

  • Short communication: Species group-specific predictors at the cow and quarter level for intramammary infection with coagulase-negative staphylococci in dairy cattle throughout lactation.
    Journal of dairy science, 2015
    Co-Authors: A. De Visscher, Sofie Piepers, Freddy Haesebrouck, K. Supré, S. De Vliegher
    Abstract:

    Coagulase-negative staphylococci (CNS) are frequently isolated from quarters with subclinical mastitis, teat apices, and the cows' environment. Virulence, ecology, epidemiological behavior, and effect on udder health vary between different CNS species. Staphylococcus Chromogenes, Staph. simulans, and Staph. xylosus are frequently present in milk and have a more substantial effect on quarter milk somatic cell count than other species. Therefore, these species are considered the "more relevant" CNS. As species-specific factors associated with CNS intramammary infection (IMI) have not yet been identified and susceptibility for IMI differs between cows and quarters, this study aimed to identify predictors for CNS IMI at the cow and quarter level (some of them changing over time) with a specific focus on the aforementioned more relevant CNS. Precise data were available from a longitudinal study (3,052 observations from 344 quarters from 86 dairy cows belonging to 3 commercial dairy herds). All CNS were molecularly identified to the species level, and multivariable, multilevel logistic regression models taking into account the longitudinal nature of the data, were fit to study the likelihood of infection. Staphylococcus Chromogenes, Staph. xylosus, and Staph. cohnii were the most frequently isolated species from CNS IMI in older cows, whereas Staph. Chromogenes, Staph. xylosus, and Staph. simulans were the main species found in IMI in heifers. Quarters from heifers (as opposed to multiparous cows), from heifers and multiparous cows in third or fourth month in lactation (as opposed to early lactation,