RESUMO
The abrupt cessation of milking at dry-off may induce milk leakage, which may increase the risk of new intramammary infections (IMI). This study assessed the efficacy of 1 i.m. injection of 5.6 mg of cabergoline (Velactis, Ceva Santé Animale, Libourne, France) at drying-off on milk leakage after dry-off and new IMI across the dry period and postcalving compared with a placebo (negative control) and an intramammary antibiotic treatment (positive control) under field conditions. The study was a double-blind, randomized, 3-arm, multicenter, clinical trial performed under Good Clinical Practice conditions. Data from 900 dairy cows of various breeds from 63 farms in France, Germany, and Hungary were analyzed. Only quarters with no bacterial growth at drying-off and a cow somatic cell count ≤200,000 cells/mL were included. Quarters infected with major or minor pathogens or cows with high somatic cell count at time of inclusion were excluded. Cows that qualified for the study were visited 7 times in total before and after drying-off and after calving. Presence (yes/no) of milk leakage was recorded on the day after dry-off. A new infected quarter (new IMI) was defined as one with a major pathogen present in any one of the 2 postcalving samples. Two mixed logistic regression models were fitted to the data to evaluate the efficacy of cabergoline in the reduction of milk leakage and new IMI. One i.m. injection of cabergoline at drying-off significantly reduced the incidence of milk leakage the day after dry-off compared with both placebo and antibiotic treatment. Cabergoline-treated cows significantly reduced the risk of new IMI by major pathogens across the dry period and postcalving by 21% when compared with placebo cows (20.5 vs. 26.0%, respectively). However, when milk leakage was added to the model, the significance of cabergoline was reduced. We interpreted this to show that milk leakage is an intervening variable between treatment with cabergoline and lower risk of new IMI. The antibiotic treatment significantly decreased the odds of new IMI compared with both cabergoline and placebo. However, because several countries are currently disallowing the preventive use of antibiotics at dry-off in noninfected quarters, the dry-off facilitator cabergoline may therefore be of particular value to reduce the risk of new IMI across the dry period.
Assuntos
Cabergolina/farmacologia , Doenças dos Bovinos/fisiopatologia , Leite/metabolismo , Animais , Antibacterianos/farmacologia , Bovinos , Contagem de Células/veterinária , Indústria de Laticínios , Método Duplo-Cego , Feminino , França , Alemanha , Hungria , Lactação/efeitos dos fármacos , Modelos Logísticos , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/fisiopatologiaRESUMO
Different mycobacterial species are encountered in bovine medicine. The fastidiously growing mycobacteria (Mycobacterium bovis as the cause of bovine tuberculosis, and Mycobacterium avium ssp. paratuberculosis, MAP, as the cause of paratuberculosis) are well known and targeted in eradication/control or monitoring programs in different countries, whereas the rapidly growing species is only rarely identified from bovine disease. The latter have occasionally been reported as the cause of bovine clinical mastitis, but recent reports are scarce. In this study, Mycolicibacterium smegmatis (basonym Mycobacterium smegmatis) was identified as cause of granulomatous, relapsing clinical mastitis in 2 cows from one Belgian dairy herd. Milk, blood, and fecal samples were collected, as well as tissue samples after the cows were culled. Serological analysis conducted on milk and serum samples resulted in positive reactions for MAP, but negative for Mycobacterium bovis. Production of IFN-γ showed sensitization with mycobacteria or similar organisms, other than M. bovis, in one cow. Detection of MAP by bacteriological culture and IS900-based quantitative PCR on milk and feces remained negative. In conclusion, this paper describes M. smegmatis as a cause of bovine clinical mastitis in Belgium and suggests cross-reactivity of the intramammary M. smegmatis infection with routinely used serological tests for MAP.
Assuntos
Doenças dos Bovinos/microbiologia , Mastite Bovina/microbiologia , Mycobacterium smegmatis , Paratuberculose/diagnóstico , Animais , Bélgica , Bovinos , Doenças dos Bovinos/diagnóstico , Reações Cruzadas , Fezes/microbiologia , Feminino , Leite/microbiologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Mycobacterium bovis/imunologia , Mycobacterium smegmatis/imunologia , Paratuberculose/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Tuberculose BovinaRESUMO
Mycoplasma bovis is an important cause of pneumonia and mastitis in cattle throughout the world, often reported as emerging. In absence of an effective vaccine for M. bovis, current prevention and control strategies rely on the identification of risk factors for within- and between-herd spread. The objective of this study was to determine the prevalence of M. bovis in Belgian dairy herds and to identify risk factors associated with a positive PCR or antibody ELISA bulk tank milk (BTM) test. A cross-sectional study was performed in 2016 on 100 dairy farms, analyzing BTM using PCR and antibody ELISA. Information on herd-level risk factors focusing on biosecurity and management were collected through a questionnaire and sourced from the national herd identification system (SANITRACE, Animal Health Service Flanders). Multivariable logistic regression was used to identify herd-level risk factors for the presence of M. bovis DNA and antibodies in BTM. The apparent prevalence on BTM was 7 and 17% for PCR and antibody ELISA, respectively. The true prevalence was 7.1% [95% confidence interval (CI) = 2.1-11.5%] and 24.8% (95% CI = 16.4-33.2%). There was no overlap between ELISA- and PCR-positive farms, resulting in a combined true prevalence of 31.8% of the Belgian farms being in recent contact with M. bovis. Risk factor analysis showed that herds with a breeding bull [M. bovis-positive results for 45.5 and 13.6% of herds with and without a bull, respectively, odds ratio = 4.7 (95% CI = 1.1-19.8)] and without a calving pen [M. bovis-positive result in 52.4 and 20.6% of the herds without and with a calving pen, respectively, odds ratio = 3.7 (95% CI = 1.06-12.5)] had higher odds to harbor M. bovis antigen or antibodies in BTM. In conclusion, the present study points to a several fold increase in the prevalence of M. bovis in Belgian dairy herds. The importance of the breeding bull and calving pen in the between- and within-herd spread of M. bovis might have been underestimated in the past. Focusing on these factors might contribute to more effective control programs in the future.
Assuntos
Cruzamento , Indústria de Laticínios , Mastite Bovina/epidemiologia , Infecções por Mycoplasma/veterinária , Mycoplasma bovis/isolamento & purificação , Animais , Bélgica , Bovinos , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Masculino , Leite , Infecções por Mycoplasma/epidemiologia , Prevalência , Fatores de RiscoRESUMO
The main objectives of this study were to quantify the consumption of antimicrobials on a convenience sample of dairy herds and to determine the association between herd-level antimicrobial consumption and inhibition zone diameters (IZD) of non-aureus staphylococci and Staphylococcus aureus isolates from subclinical mastitis cases. Also, the association between the IZD of non-aureus staphylococci and Staph. aureus isolates within a herd was studied. Antimicrobial consumption data on 56 Flemish dairy farms were obtained between 2013 and 2014 by so-called garbage can audits and expressed as antimicrobial treatment incidence (ATI), with the unit of ATI being the number of defined daily doses animal (DDDA) used per 1,000 cow-days. The average total ATI in adult dairy cattle for all active substances was 18.73 DDDA per 1,000 cow-days and ranged from 6.28 to 42.13 DDDA between herds. The ATI of critically important (for human health) antimicrobials was 6.91 DDDA per 1,000 cow-days; that is, 37% of total antimicrobial consumption. The average ATI for intramammary therapy of (sub)clinical mastitis, intramammary dry-cow therapy, and systemically administered therapy was 5.20, 6.70, and 6.73 DDDA, respectively. The IZD of 239 non-aureus staphylococci and 88 Staph. aureus isolates originating from milk samples from cows with subclinical mastitis collected on selected dairy herds were determined using Kirby-Bauer disk diffusion and ranged between 6 and 42 mm. Because only a limited number of clinical breakpoints (Clinical and Laboratory Standards Institute) and epidemiological cut-off values (European Committee on Antimicrobial Susceptibility Testing) are available for mastitis-causing bacteria in bovine, IZD were used as a proxy for antimicrobial resistance. Inhibition zone diameters of non-aureus staphylococci for cefquinome, a critically important ß-lactam antibiotic, were negatively associated with the ATI of critically important ß-lactam for systemically administered therapy and positively with the ATI for intramammary therapy of (sub)clinical mastitis of critically important ß-lactam antimicrobials. Only for neomycin was a positive association between the IZD of non-aureus staphylococci and Staph. aureus isolates within the same herd observed.
Assuntos
Anti-Infecciosos/farmacologia , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação , Animais , Bovinos , Cefalosporinas/farmacologia , Feminino , Humanos , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Coagulase-negative staphylococci (CNS) have become the main pathogens causing bovine mastitis in recent years. A huge variation in species distribution among herds has been observed in several studies, emphasizing the need to identify subgroup- and species-specific herd-level factors to improve our understanding of the differences in ecological and epidemiological nature between species. The use of bulk milk samples enables the inclusion of a large(r) number of herds needed to identify herd-level risk factors and increases the likelihood of recovering enough isolates per species needed for conducting subgroup- and, eventually, species-specific analyses at the same time. This study aimed to describe the prevalence and distribution of CNS species in bulk milk samples and to identify associated subgroup- and species-specific herd-level factors. Ninety percent of all bulk milk samples yielded CNS. Staphylococcus equorum was the predominant species, followed by Staphylococcus haemolyticus and Staphylococcus epidermidis. A seasonal effect was observed for several CNS species. Bulk milk samples from herds with a loose-pack or a tiestall housing system were more likely to yield CNS species compared with herds with a freestall barn, except for S. epidermidis, Staphylococcus simulans, and Staphylococcus cohnii. In September, herds in which udders were clipped had lower odds of yielding Staphylococcus chromogenes, S. simulans, and Staphylococcus xylosus, the CNS species assumed to be most relevant for udder health, in their bulk milk than herds in which udder clipping was not practiced. Bulk milk of herds participating in a monthly veterinary udder health-monitoring program was more likely to yield these 3 CNS species. Herds always receiving their milk quality premium or predisinfecting teats before attachment of the milking cluster had lower odds of having S. equorum in their bulk milk. Herds not using a single dry cotton or paper towel for each cow during premilking udder preparation were more likely to have S. cohnii-positive bulk milk. Herds in which flushing with hot water or steam of the milking cluster after having milked a cow with a (sub)clinical mastitis was applied, were less likely to yield S. simulans, S. haemolyticus, and S. cohnii in their bulk milk. Always wearing gloves during milking decreased the odds of having Staphylococcus devriesei-positive bulk milk. Tap water from the public drinking system used as drinking water increased the odds of yielding S. simulans in the bulk milk. In conclusion, CNS are highly prevalent in bulk milk and might originate from the environment for some species (we hypothesize this is true for S. equorum or S. cohnii), or from within the udder (e.g., for S. simulans). Studies collecting bulk milk and quarter milk samples at the same time along with environmental samples are needed to determine the exact origin of the different (subgroups of) CNS species present in bulk milk using strain-typing techniques.
Assuntos
Coagulase , Leite/microbiologia , Staphylococcus/enzimologia , Animais , Bovinos , Feminino , Mastite Bovina , Leite/química , Prevalência , Fatores de Risco , Infecções Estafilocócicas/veterináriaRESUMO
The objective of this study was to assess the in vitro antimicrobial susceptibility of 73 isolates of Mycoplasma bovis isolated from milk of dairy cattle herds of Belgium, Germany, and Italy. Minimal inhibitory concentration (MIC) values were determined by the microbroth dilution method for the following antimicrobials: erythromycin, spiramycin, tilmicosin, tylosin, lincomycin, enrofloxacin, doxycycline, oxytetracycline, florfenicol, and tiamulin. Macrolides, florfenicol, oxytetracycline, and enrofloxacin, were chosen because they represent antimicrobials families commonly used in several countries for treatment of M. bovis, and their MIC values in cattle population are reported in several studies, allowing a comparison with previous data. Doxycycline and tiamulin were selected to assess the susceptibility of M. bovis to new antimicrobials, because they are not registered in the European Union for the treatment of dairy cattle. Among the agents of the different antimicrobial classes, the macrolides showed the highest concentration to inhibit 90% of isolates (MIC90), all above the highest concentration tested: >8µg/mL for erythromycin, >16µg/mL for spiramycin, and >32µg/mL for tilmicosin and tylosin. Also the MIC90 of lincomycin was above the highest concentration tested (>32µg/mL), but the distribution of the MIC values was almost perfectly bimodal: 41 isolates had a MIC ≤0.5µg/mL and 30 isolates >32µg/mL. Oxytetracycline had a 2-fold higher concentration to inhibit 50% of isolates (2 vs. 0.5µg/mL) and 1-fold higher MIC90 (4 vs. 2µg/mL) than doxycycline. Enrofloxacin and florfenicol had both a MIC90 of 2µg/mL, whereas tiamulin had a MIC90 of 0.5µg/mL. Significant differences on the MIC values were found among the 3 countries for several antimicrobials: compared with Germany, Belgium and Italy showed significantly higher MIC for lincomycin, spiramycin, and tylosin, and lower for oxytetracycline and florfenicol. The Belgian isolates showed the lowest MIC for enrofloxacin compared with Germany and Italy. The MIC results obtained in our study suggest the presence of a high level of resistance of M. bovis isolates originating from milk to macrolides in all countries involved in this study. On the contrary, a low level of resistance was found against the antimicrobials that are not used in cattle, such as tiamulin and doxycycline, highlighting a possible link between antimicrobial treatments and development of resistance in the studied M. bovis population.
Assuntos
Leite/microbiologia , Mycoplasma bovis , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bélgica , Bovinos , Testes de Sensibilidade Microbiana/veterinária , Leite/efeitos dos fármacos , Infecções por Mycoplasma/veterináriaRESUMO
Four studies were performed to quantify milk production, quality and consumption in the town Jimma, Ethiopia. First, 47 dairy farmers and 44 milk retailers were interviewed to gain more insights in dairy farming and marketing, and associated constraints. Second, bulk milk samples (n=188) were collected for 4 consecutive weeks to investigate milk quality [Total Bacterial Counts (TBC), Coliform Counts (CC), Somatic Cell Counts (SCC), and antimicrobial residues]. Third, (bulk) milk samples from 32 farms, 46 milk retailers and the 3 local milk collection centers were collected to determine the presence of oxacillin susceptible-and oxacillin resistant Staphylococcus aureus. Fourth, 208 adult inhabitants were interviewed to gain more insight in milk consumption and associated concerns of consumers. The average dairy farm included in the studies consisted of 5 lactating cows, produced 43 liters of milk per day and was owned by male, literate adults. Milk was sold to retailers (71% of the production) and directly to customers (25%) without any quality control, whereas 4% was self-consumed. Shortage of animal nutrition and adulteration of the milk were the main constraints for farmers and retailers, respectively. The median TBC, CC and SCC were 122,500CFU/mL, 1,005CFU/mL and 609,500cells/mL, respectively. Antimicrobial residues were detected in 20% of all samples. In general, the milk quality was considered to be poor (TBC>10,000CFU/mL, and/or CC>100CFU/mL, and/or SCC>400,000cells/mL and/or presence of antimicrobial residues) in 97% of all samples. S. aureus was isolated from 12 (38%), 13 (33%), and 2 out of 3 of the milk samples originating from the dairy farms, the milk retailers, and the milk collection centers, respectively. Seven (26%) of the isolates were resistant to oxacillin suggesting the presence of MRSA (Lee, 2003). Local milk is occasionally consumed by adults but more frequently by children. Adults mainly drink spontaneously fermented milk (57% of 105 interviewees consuming local milk) whereas most milk for children is boiled (86% of 110 households with children consuming local milk). Most consumers are concerned about adulteration and milk borne diseases but not about antimicrobial residues. Educated consumers (secondary school or higher) were more likely to boil milk for own consumption, to be concerned about antimicrobial residues in milk, to be concerned about milk borne diseases and to be willing to pay more for milk with proven good quality compared to poorly educated consumers. We conclude that milk quality incentives should be introduced in Jimma, and investments should be made in knowledge transfer, training, milk collection systems and a central milk quality lab.
Assuntos
Indústria de Laticínios/estatística & dados numéricos , Ingestão de Líquidos , Leite/metabolismo , Leite/normas , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Animais , Antibacterianos/farmacologia , Criança , Pré-Escolar , Comportamento do Consumidor , Indústria de Laticínios/economia , Farmacorresistência Bacteriana , Etiópia , Feminino , Humanos , Lactente , Recém-Nascido , Lactação , Masculino , Marketing/estatística & dados numéricos , Pessoa de Meia-Idade , Leite/microbiologia , Oxacilina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Adulto JovemRESUMO
The main objective of this study was to quantify the (compound-specific) antimicrobial consumption (AMC) in adult cattle in a convenience sample of Flemish dairy herds. Antimicrobial consumption data were obtained between 2012 and 2013 by "garbage can audits" and expressed as antimicrobial treatment incidence (ATI), with the unit of the ATI being the number of defined daily doses animal (DDDA) used per 1,000 cow-days. Herds were stratified by DDDA into low-, medium-, and high-consuming herds to study the AMC per route of administration, and associations with parameters reflecting udder health, milk quality, and production performances were examined. The average ATI in adult dairy cattle for all compounds was 20.78 DDDA (per 1,000 cow-days). Large variation existed between herds (ranging from 8.68 to 41.62 DDDA). Fourth-generation cephalosporins were used most (4.99 DDDA), followed by penicillins (3.70 DDDA) and third-generation cephalosporins (2.95 DDDA). The average ATI of the critically important antimicrobials for human health (i.e., third- and fourth-generation cephalosporins and fluoroquinolones according to the World Organisation for Animal Health classification) was somewhat lower than the average ATI of the other antimicrobials (8.59 and 12.18 DDDA, respectively). The average ATI for intramammary treatment of (sub)clinical mastitis, for dry-cow therapy, and for systemically administered antimicrobials was 6.30, 6.89, and 7.44 DDDA, respectively. In low-consuming herds, most antimicrobials were being used for dry-cow therapy, whereas in high-consuming herds, most antimicrobials were being used as injectable or intramammary mastitis therapy. The incidence rate of treated mastitis was positively associated with ATI. Herds that applied blanket dry-cow therapy tended to have a higher ATI than herds in which cows were selectively dried off with long-acting antimicrobials. The ATI decreased with an increasing prevalence of primiparous cows.
Assuntos
Antibacterianos/uso terapêutico , Lactação/efeitos dos fármacos , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Animais , Carga Bacteriana , Bélgica/epidemiologia , Bovinos , Cefalosporinas/uso terapêutico , Feminino , Fluoroquinolonas/uso terapêutico , Análise de Alimentos , Contaminação de Alimentos/análise , Incidência , Glândulas Mamárias Animais/efeitos dos fármacos , Mastite Bovina/tratamento farmacológico , Leite/química , Leite/microbiologia , Penicilinas/uso terapêuticoRESUMO
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, <60 d in milk), and with an increasing quarter milk SCC were more likely to be infected with the more relevant CNS species. Quarter milk SCC was identified as the sole statistically significant predictor for IMI with other CNS species, although the size of the effect was lower [odds ratio of 1.6 (1.4-1.9) vs. 2.1 (1.8-2.5)] than the effect for IMI with the more relevant CNS. As a strong herd effect was present, studying herd-level predictors is warranted.
Assuntos
Lactação/fisiologia , Mastite Bovina/diagnóstico , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação , Animais , Bovinos , Contagem de Células/veterinária , Feminino , Estudos Longitudinais , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Leite/química , Staphylococcus/classificaçãoRESUMO
A cross-sectional study on clinical mastitis, intramammary infection (IMI) and blind quarters was conducted on 50 smallholder dairy farms in Jimma, Ethiopia. A questionnaire was performed, and quarters of 211 cows were sampled and bacteriologically cultured. Risk factors at the herd, cow, and quarter level for clinical mastitis and (pathogen-specific) intramammary infection were studied using multilevel modeling. As well, factors associated with quarters being blind were studied. Eleven percent of the cows and 4% of the quarters had clinical mastitis whereas 85% of the cows and 51% of the quarters were infected. Eighteen percent of the cows had one or more blind quarter(s), whereas 6% of the quarters was blind. Non-aureus staphylococci were the most frequently isolated pathogens in both clinical mastitis cases and IMI. The odds of clinical mastitis was lower in herds where heifers were purchased in the last year [odds ratio (OR) with 95% confidence interval: 0.11 (0.01-0.90)], old cows (>4 years) [OR: 0.45 (0.18-1.14)], and quarters not showing teat injury [OR: 0.23 (0.07-0.77)]. The odds of IMI caused by any pathogen was higher in herds not practicing teat drying before milking (opposed to drying teats with 1 towel per cow) [OR: 1.68 (1.05-2.69)], cows in later lactation (>180 DIM opposed to ≤90 DIM) [OR: 1.81 (1.14-2.88)], cows with a high (>3) body condition score (BCS) [OR: 1.57 (1.06-2.31)], right quarters (opposed to a left quarter position) [OR: 1.47 (1.10-1.98)], and quarters showing teat injury [OR: 2.30 (0.97-5.43)]. Quarters of cows in herds practicing bucket-fed calf feeding (opposed to suckling) had higher odds of IMI caused by Staphylococcus aureus [OR: 6.05 (1.31-27.90)]. Except for BCS, IMI caused by non-aureus staphylococci was associated with the same risk factors as IMI caused by any pathogen. No access to feed and water immediately after milking [OR: 2.41 (1.26-4.60)], higher parity [OR: 3.60 (1.20-10.82)] and tick infestation [OR: 2.42 (1.02-5.71)] were risk factors for quarters being blind. In conclusion, replacement of old cows, prevention of teat injuries/lesions, drying teats with 1 towel per cow before milking, improving fertility in order to shorten the lactation period, allowing (restricted) suckling, access to feed and water immediately after milking, and improving tick control could improve udder health in Jimma.
Assuntos
Bactérias/isolamento & purificação , Mastite Bovina/epidemiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/fisiologia , Animais , Bovinos , Estudos Transversais , Etiópia/epidemiologia , Feminino , Mastite Bovina/microbiologia , Mastite Bovina/prevenção & controle , Prevalência , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/fisiologiaRESUMO
In dairy farms, antimicrobial drugs are frequently used for treatment of (sub)clinical mastitis. Determining the antimicrobial susceptibility of mastitis pathogens is needed to come to a correct use of antimicrobials. Strains of Staphylococcus aureus (n=768), Streptococcus uberis (n=939), Streptococcus dysgalactiae (n=444), Escherichia coli (n=563), and Klebsiella species (n=59) originating from routine milk samples from (sub)clinical mastitis were subjected to the disk diffusion method. Disks contained representatives of frequently used antibiotics in dairy. A limited number of clinical breakpoints were available through CLSI, and showed that susceptibility of Staph. aureus, E. coli, and Klebsiella was moderate to high. For streptococcal species however, a large variation between the tested species and the different antimicrobials was observed. In a next step, wild type populations were described based on epidemiological cut off values (EUCAST). Because of the limited number of official cut off values, the data were observed as a mastitis subpopulation and self-generated cut off values were created and a putative wild type population was suggested. The need for accurate clinical breakpoints for veterinary pathogens is high. Despite the lack of these breakpoints, however, a population study can be performed based on the distribution of inhibition zone diameters on the condition that a large number of strains is tested.
Assuntos
Antibacterianos/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/veterinária , Farmacorresistência Bacteriana/genética , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Leite/microbiologia , Animais , Bélgica/epidemiologia , Bovinos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Feminino , Especificidade da Espécie , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Streptococcus/efeitos dos fármacos , Streptococcus/genéticaRESUMO
The prevalence of subclinical mastitis and associated risk factors at the herd, cow and quarter level were studied using multilevel modelling in smallholder dairy farms in Jimma, Ethiopia. Forty-two herds, out of the 55 dairy farms located in Jimma (76%), were visited, a questionnaire was performed, and 635 quarters belonging to 176 lactating cows were screened to detect the presence of subclinical mastitis using the California Mastitis Test (CMT). Sixty-two percent of the cows and 51% of the quarters were subclinically infected. Quarters from cows in later stage of lactation (>180 DIM) [opposed to early lactation (<90 DIM)] were more likely to be subclinically infected (OR=2.40, 95% CI=1.44-3.99). Overall, quarters from cows milked by squeezing (as opposed to stripping) were less likely to be subclinically infected (OR=0.45, 95% CI=0.29-0.71), although quarters from cows with tick-infested udders were more likely to be subclinically infected when milked by squeezing (as opposed to stripping). The milking technique did not influence the likelihood of infection in cows without ticks on the udder. This study stresses the high prevalence of subclinical mastitis in smallholder dairy farms in Jimma and a lack of awareness of the existence of the disease among dairy farmers. Implementation of a mastitis prevention program adapted to the local needs, including a focus on milking technique, application of appropriate tick control measurements as well as fertility management, allowing cows to be dried-off at a more appropriate moment, are needed. To conclude, milking by squeezing instead of stripping, but not of cows with tick-infested udders, as well as fertility management could reduce the subclinical mastitis prevalence (and incidence) on the short term.
Assuntos
Infecções Assintomáticas/epidemiologia , Indústria de Laticínios , Lactação , Mastite Bovina/epidemiologia , Animais , Bovinos , Etiópia/epidemiologia , Feminino , Mastite Bovina/microbiologia , Mastite Bovina/prevenção & controle , Prevalência , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
This study aimed at testing the applicability of mannitol salt agar (MSA), a medium generally used in human medicine for differentiating Staphylococcus aureus from coagulase-negative staphylococci (CNS), for culturing bovine-associated CNS species. All test isolates from a comprehensive collection of well-identified CNS species, including both reference strains and field isolates, were able to grow. Subsequently, bulk milk samples and teat apex swabs were used to examine the capability of MSA for yielding CNS under field conditions. Sixty-nine and 47 phenotypically different colonies were retrieved from bulk milk and teat apices, respectively. The majority of isolates from teat apices were staphylococci, whereas in bulk milk, staphylococci formed a minority. After 24h of growth, recovery of separate colonies of CNS was much more convenient on MSA compared to a non-selective blood agar. The results of this study indicate that MSA is a suitable medium for both growth and recovery of bovine-associated CNS.
Assuntos
Ágar/química , Coagulase/metabolismo , Manitol/química , Staphylococcus/enzimologia , Staphylococcus/fisiologia , Animais , Técnicas Bacteriológicas , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/microbiologia , Indústria de Laticínios , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Leite/microbiologia , Especificidade da Espécie , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterináriaRESUMO
In many parts of the world, coagulase-negative staphylococci (CNS) are the predominant cause of intramammary infections (IMI) in dairy cows and in water buffaloes, as well. A longitudinal field study was carried out on one well-managed dairy water buffalo herd to determine the prevalence and distribution of CNS and a recently described CNS-species, Staphylococcus rostri, in milk samples to explore its relevance for buffaloes' udder health throughout lactation, and to gain insight into the susceptibility of the latter species toward commonly used antimicrobials. Twice weekly quarter milk samples from a cohort of 11 lactating water buffaloes were collected over an 8-mo period. The CNS (n=109; 76.2% of all culture-positive samples) were the predominant pathogens causing IMI, followed by Corynebacterium bovis (n=11; 7.6%) and Streptococcus spp. (n=9; 6.2%) other than Stretococcus uberis (n=2; 1.4%). Thirty-seven hemolytic staphylococci suspected to be Staphylococcus aureus were further differentiated using transfer DNA-intergenic spacer-PCR and rpoB-gene sequencing because they were coagulase-negative. Thirty-three of those isolates were identified as Staph. rostri, whereas 2 others were identified as Staphylococcus epidermidis. None of the Staph. rostri isolates displayed resistance to the antimicrobial agents tested. Mean quarter milk somatic cell count (qSCC) of all samples collected throughout lactation was 20,970 cells/mL. The qSCC at sampling of quarters infected with Staph. rostri (34,466 cells/mL) and CNS other than Staph. rostri (34,813 cells/mL) were significantly higher than the qSCC of noninfected quarters (20,287 cells/mL), yet not significantly different from each other. These findings provide novel insight into the prevalence and distribution, antimicrobial susceptibility, and relevance of Staph. rostri compared with other CNS species causing IMI in water buffaloes. Further studies are needed to pinpoint the relevance, niches, and transmission routes of Staph. rostri, as well as other CNS in water buffaloes.
Assuntos
Búfalos , Farmacorresistência Bacteriana , Mastite/veterinária , Leite/citologia , Leite/microbiologia , Staphylococcus/efeitos dos fármacos , Animais , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Feminino , Lactação , Estudos Longitudinais , Glândulas Mamárias Animais/patologia , Mastite/microbiologia , Mastite/patologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/patologia , Staphylococcus/isolamento & purificaçãoRESUMO
Coagulase-negative staphylococci (CNS) are the most commonly isolated bacteria from goat milk, but they have often been identified with phenotypic methods, which may have resulted in misclassification. The aims of this paper were to assess the amount of misclassification of a phenotypic test for identifying CNS species from goat milk compared with transfer RNA intergenic spacer PCR (tDNA-PCR) followed by capillary electrophoresis, and to apply the tDNA-PCR technique on different capillary electrophoresis equipment. Milk samples were collected from 416 does in 5 Californian dairy goat herds on 3 occasions during lactation. In total, 219 CNS isolates were identified at the species level with tDNA-PCR and subjected to the API 20 Staph identification test kit (API Staph; bioMérieux, Durham, NC). If the same species was isolated multiple times from the same udder gland, only the first isolate was used for further analyses, resulting in 115 unique CNS isolates. According to the tDNA-PCR test, the most prevalent CNS species were Staphylococcus epidermidis, Staphylococcus caprae, and Staphylococcus simulans. Typeability with API staph was low (72%). Although the API Staph test was capable of identifying the majority of Staph. epidermidis and Staph. caprae isolates, sensitivity for identification of Staph. simulans was low. The true positive fraction was high for the 3 most prevalent species. It was concluded that the overall performance of API Staph in differentiating CNS species from goat milk was moderate to low, mainly because of the low typeability, and that genotypic methods such as tDNA-PCR are preferred.
Assuntos
Leite/microbiologia , Staphylococcus/genética , Animais , Eletroforese Capilar/métodos , Eletroforese Capilar/veterinária , Feminino , Cabras/microbiologia , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , RNA Bacteriano/genética , RNA de Transferência/genética , Staphylococcus/classificação , Staphylococcus epidermidis/genéticaRESUMO
Coagulase-negative staphylococci (CNS) are the most commonly isolated bacteria from goat milk. The goal of this study was to explore and describe differences between CNS species in persistence of intramammary infection (IMI) and in effect on somatic cell count (SCC) and milk yield (MY). Milk samples were collected from 530 does from 5 Dutch dairy goat herds on 3 occasions during 1 lactation. Coagulase-negative staphylococci species were identified at the species level by transfer RNA-intergenic spacer PCR (tDNA-PCR) followed by capillary electrophoresis. The most prevalent CNS species were Staphylococcus caprae, Staphylococcus epidermidis, Staphylococcus simulans, and Staphylococcus xylosus, but large differences were seen in species distribution between herds. Staphylococcus caprae and Staph. xylosus appeared to be more persistent than other species, but confidence intervals were overlapping. The effect of IMI caused by the 4 most prevalent CNS species on SCC and on MY was determined with linear regression models, and Staph. aureus and Corynebacterium bovis were included in the analyses as reference organisms. Most species were associated with a significantly higher SCC than noninfected udder halves, but the effect of CNS species on SCC was much smaller than the effect of Staph. aureus on SCC. We found a significant positive association between infection with Staph. caprae and MY. Intramammary infection caused by Staph. xylosus, on the other hand, had a negative association with milk yield, comparable to the effect of Staph. aureus, but these effects were not significantly different from zero. Intramammary infections with CNS species have a high prevalence in goats and are persistent, but have a limited effect on SCC compared with IMI with Staph. aureus. The effect of CNS species on MY differed between species, but differences were nonsignificant because limited numbers per species were available for analysis. Therefore, CNS species appear to behave as minor pathogens in goats, but larger studies are needed to give better estimates for the effect on MY.
Assuntos
Doenças das Cabras/microbiologia , Lactação/fisiologia , Mastite/veterinária , Leite/citologia , Infecções Estafilocócicas/veterinária , Staphylococcus , Animais , Contagem de Células/veterinária , Feminino , Doenças das Cabras/fisiopatologia , Cabras/microbiologia , Cabras/fisiologia , Mastite/microbiologia , Mastite/fisiopatologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus/fisiologia , Staphylococcus epidermidis/fisiologiaRESUMO
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.
Assuntos
Coagulase/análise , Microbiologia Ambiental , Leite/microbiologia , Staphylococcus/enzimologia , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Indústria de Laticínios/métodos , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/veterinária , Feminino , Mastite Bovina/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Infecções Estafilocócicas/veterinária , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Staphylococcus/patogenicidadeRESUMO
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.
Assuntos
Coagulase/análise , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/enzimologia , Animais , Bovinos , Feminino , Estudos Longitudinais , Leite/citologia , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Especificidade da Espécie , Infecções Estafilocócicas/microbiologia , Staphylococcus/classificação , Staphylococcus/isolamento & purificaçãoRESUMO
Due to significant financial losses in the dairy cattle farming industry caused by mastitis and the possible influence of coagulase-negative staphylococci (CNS) in the development of this disease, accurate identification methods are needed that untangle the different species of the diverse CNS group. In this study, 39 Staphylococcus type strains and 253 field isolates were subjected to (GTG)(5)-PCR fingerprinting to construct a reference framework for the classification and identification of different CNS from (sub)clinical milk samples and teat apices swabs. Validation of the reference framework was performed by dividing the field isolates in two separate groups and testing whether one group of field isolates, in combination with type strains, could be used for a correct classification and identification of a second group of field isolates. (GTG)(5)-PCR fingerprinting achieved a typeability of 94.7% and an accuracy of 94.3% compared to identifications based on gene sequencing. The study shows the usefulness of the method to determine the identity of bovine Staphylococcus species, provided an identification framework updated with field isolates is available.
Assuntos
Impressões Digitais de DNA/veterinária , Indústria de Laticínios/métodos , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/classificação , Staphylococcus/genética , Animais , Bovinos , Análise por Conglomerados , Coagulase/metabolismo , Feminino , Reação em Cadeia da Polimerase/veterinária , Padrões de Referência , Reprodutibilidade dos Testes , Especificidade da Espécie , Infecções Estafilocócicas/microbiologia , Staphylococcus/enzimologiaRESUMO
The objectives of the study were to define the sensitivity and specificity of the California Mastitis Test (CMT) in determining the presence of intramammary infection in postpartum dairy goats and to determine whether antibiotic therapy increased bacteriological cure rate and lowered somatic cell count (SCC) compared with untreated controls. A CMT was performed and milk samples were collected for bacteriology from 211 glands of 106 does between 0 and 10 d after kidding. From a population of 3,239 glands from goats in 4 commercial herds, goats with one or both glands with a CMT score of >1 and from which bacteria were isolated were either assigned to be treated with 3 intramammary infusions at 12-h intervals of 75 mg of sodium ampicillin and 250 mg of sodium cloxacillin (n=57 glands) or left as untreated controls (n=49 glands). Milk samples were collected again 14 ± 3 and 21 ± 3 d later for bacteriology and SCC determination. Composite milk yield, goat SCC, length of lactation, and survival data were collected. A partial budget was constructed to assess the cost effectiveness of treatment. At a cut point of greater than trace, the sensitivity, specificity, and positive and negative predictive values of the CMT were 0.74, 0.74, 0.42, and 0.92, respectively. Treatment increased the bacteriological cure rate compared with no treatment [30/57 (53%) vs. 6/49 (12%)], but there was a pathogen by treatment interaction whereby treatment increased cure proportion in glands infected with minor, but not major, pathogens. Treatment reduced the foremilk gland-level SCC [1,595 (95% CI=1,106-2,300) vs. 3,028 (95% CI=2,091-4,385) geometric mean (× 1,000) cells/mL] but not the SCC at goat level [1,596 (95% CI=1,219-2,090) vs. 1,488 (95% CI=1,132-1,955) geometric mean (× 1,000) cells/mL] compared with no treatment. Milk yield, risk of removal from the herd, and length of lactation were not altered by treatment. Treatment resulted in a loss of NZ$20.39/doe. It was concluded that use of the CMT as a screening test resulted in a higher likelihood of finding a gland that would be infected than selecting a gland at random. Treatment increased bacteriological cure rate and reduced SCC at gland level compared with no treatment. However, at goat level, milk yield, SCC, and survival were not altered, resulting in no economic benefit of treatment.