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1.
Vet Clin North Am Food Anim Pract ; 37(1): 149-174, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33541696

RESUMO

Staphylococcus aureus is the most important cause of clinical mastitis in goats, and non-aureus staphylococci is the most common isolate from subclinical mastitis. Environmental streptococci are a severe problem. Somatic cell counts and California mastitis test are a screening test for mastitis and an indicator of poor udder health, but values should be interpreted differently than with dairy cattle. Somatic cell scores likely are a more useful way of viewing data. High bacterial counts in milk are common; mastitis may be involved as a cause. Proper udder preparation, milking procedure, and postmilking management are key factors in mastitis control.


Assuntos
Criação de Animais Domésticos/métodos , Indústria de Laticínios/métodos , Doenças das Cabras/prevenção & controle , Glândulas Mamárias Animais/fisiologia , Mastite/veterinária , Animais , Bovinos , Feminino , Doenças das Cabras/diagnóstico , Doenças das Cabras/microbiologia , Cabras , Glândulas Mamárias Animais/microbiologia , Mastite/diagnóstico , Mastite/microbiologia , Mastite/prevenção & controle , Leite/microbiologia , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/veterinária
2.
J Vet Sci ; 21(5): e77, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016022

RESUMO

BACKGROUND: Staphylococcus aureus is one of the main microorganisms that causes bovine mastitis, and its well-known virulence characteristics and interactions with the environment are used to aid the design of more efficient therapies. OBJECTIVES: To determine whether the virulence traits, such as antibiotic resistance and biofilm-forming and internalization abilities, of S. aureus isolated from bovine mastitis are related to dairy production system types. METHODS: The study was performed in the Mexican states of Guanajuato and Michoacan. Semi-intensive dairy farms (SIDFs) and family dairy farms (FDFs) (454 and 363 cows, respectively) were included. The 194 milk samples from mastitis affected quarters were collected and 92 strains of S. aureus were isolated and identified by biochemical and molecular tests. Antibiotic resistance, biofilm and internalization assays were performed on 30 randomly selected isolated strains to determine virulence traits, and these strains were equally allocated to the 2 dairy production systems. RESULTS: All 30 selected strains displayed a high degree of resistance (50%-91.7%) to the antibiotics tested, but no significant difference was found between SIDF and FDF isolates. S. aureus strains from SIDFs had an average biofilm forming capacity of up to 36% (18.9%-53.1%), while S. aureus strains from FDFs registered an average of up to 53% (31.5%-77.8%) (p > 0.05). Internalization assays revealed a higher frequency of internalization capacity for strains isolated from FDFs (33.3%) than for those isolated from SIDFs (6.7%) (p > 0.05). fnbpA gen was detected in 46.6% of FDF strains and 33.3% of SIDF strains, and this difference was significant (p < 0.05). CONCLUSIONS: Our findings show that the virulence traits of S. aureus isolates analyzed in this study, depend significantly on several factors, such as phenotype, genotype, and environmental conditions, which are significantly related to dairy production system type and daily management practices.


Assuntos
Biofilmes , Indústria de Laticínios/classificação , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/fisiologia , Staphylococcus aureus/patogenicidade , Animais , Biofilmes/crescimento & desenvolvimento , Bovinos , Farmacorresistência Bacteriana/genética , Fazendas , Feminino , Mastite Bovina/epidemiologia , México/epidemiologia , Prevalência , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Virulência
3.
J Vet Sci ; 21(4): e54, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32735092

RESUMO

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe infections in humans and animals worldwide. Studies elucidating the population structure, staphylococcal cassette chromosome mec types, resistance phenotypes, and virulence gene profiles of animal-associated MRSA are needed to understand spread and transmission. OBJECTIVES: The objective of this study was to determine 1) clonal complexes and spa types, 2) resistance phenotypes, and 3) virulence/resistance gene profiles of MRSA isolated from animals in Switzerland. METHODS: We analyzed 31 presumptive MRSA isolates collected from clinical infections in horses, dogs, cattle, sheep, and pigs, which had tested positive in the Staphaurex Latex Agglutination Test. The isolates were characterized by spa typing and DNA microarray profiling. In addition, we performed antimicrobial susceptibility testing using the VITEK 2 Compact system. RESULTS: Characterization of the 31 presumptive MRSA isolates revealed 3 methicillin-resistant Staphylococcus pseudintermedius isolates, which were able to grow on MRSA2 Brilliance agar. Of the 28 MRSA isolates, the majority was assigned to CC398 (86%), but CC8 (11%) and CC1 (4%) were also detected. The predominant spa type was t011 (n = 23), followed by t009 (n = 2), t034 (n = 1), t008 (n = 1), and t127 (n = 1). CONCLUSIONS: The results of this study extend the current body of knowledge on the population structure, resistance phenotypes, and virulence and resistance gene profiles of MRSA from livestock and companion animals.


Assuntos
Resistência Microbiana a Medicamentos/genética , Staphylococcus aureus Resistente à Meticilina/genética , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Infecções Estafilocócicas/veterinária , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças do Cão/microbiologia , Cães , Doenças dos Cavalos/microbiologia , Cavalos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Fenótipo , Ovinos , Doenças dos Ovinos/microbiologia , Infecções Estafilocócicas/microbiologia , Suínos , Doenças dos Suínos/microbiologia
4.
BMC Infect Dis ; 20(1): 602, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32799799

RESUMO

BACKGROUND: The objectives of this study were to determine for the first time, in Morocco, the nasal carriage rate, antimicrobial susceptibility profiles and virulence genes of Staphylococcus. aureus isolated from animals and breeders in close contact. METHODS: From 2015 to 2016, 421 nasal swab samples were collected from 26 different livestock areas in Tangier. Antimicrobial susceptibility phenotypes were determined by disk diffusion according to EUCAST 2015. The presence of nuc, mecA, mecC, lukS/F-PV, and tst genes were determined by Polymerase Chain Reaction (PCR) for all isolates. RESULTS: The overall S. aureus nasal carriage rate was low in animals (9.97%) and high in breeders (60%) with a statistically significant difference, (OR = 13.536; 95% CI = 7.070-25.912; p < 0.001). In general, S. aureus strains were susceptible to the majority of antibiotics and the highest resistance rates were found against tetracycline (16.7% in animals and 10% in breeders). No Methicillin-Resistant S. aureus (MRSA) was detected in animals and breeders. A high rate of tst and lukS/F-PV genes has been recovered only from animals (11.9 and 16.7%, respectively). CONCLUSION: Despite the lower rate of nasal carriage of S. aureus and the absence of MRSA strains in our study, S. aureus strains harbored a higher frequency of tst and lukS/F-PV virulence genes, which is associated to an increased risk of infection dissemination in humans. This highlights the need for further larger and multi-center studies to better define the transmission of the pathogenic S. aureus between livestock, environment, and humans.


Assuntos
Nariz/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Animais Domésticos/microbiologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Portador Sadio , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Nuclease do Micrococo/genética , Marrocos/epidemiologia , Proteínas de Ligação às Penicilinas/genética , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Tetraciclina/farmacologia , Virulência/genética
5.
Vet J ; 262: 105473, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32792091

RESUMO

This study aimed to evaluate the effects of chronic subclinical mastitis (CSM) on milk production and component yields in dairy cows. A total of six herds located in the Midwest area of São Paulo State, Brazil were selected. Herds were visited once every 2 weeks to measure milk yield and to collect milk samples from lactating Holstein cows. Milk samples were collected at two stages (1 and 2), and each stage comprised three milk samplings. In stage 1, a total of 117 of 647 cows were diagnosed with CSM based on at least two of three repeated somatic cell counts (SCC) > 2000,000 cells/mL and positive bacterial milk culture results (BC). Cows with CSM were selected for the second stage. In stage 2, selected cows had quarter sampling aseptically collected for BC analyses prior to milking, and quarter milk yield was measured. Milk components (total protein, fat, lactose, and total solids) were measured using mid-infrared spectroscopy. Mammary quarters were considered healthy if all three repeated SCC results were ≤ 200,000 cells/mL and no bacterial growth was detected on BC. All quarters with positive bacterial growth were classified as having (non-chronic) subclinical mastitis when only one of three SCC results were > 200,000 cells/mL, and CSM when at least two of three SCC results were > 200,000 cells/mL. The effects of CSM by type of pathogen on milk and components yield were assessed using a linear mixed model. Mammary quarters with CSM caused by major pathogens had milk loss of 1.1 kg/quarter milking in comparison to healthy quarters. Milk losses were 0.8 and 1.3 kg/quarter milking when CSM was caused by Staphylococcus aureus or environmental streptococci, respectively. In addition, healthy quarters produced more milk components than quarters with CSM caused by major pathogens. Minor pathogens causing CSM (non-aureus staphylococci and Corynebacterium spp.) had no effect on milk yield. Quarters with CSM had lower milk and component yields when compared with healthy quarters. Milk losses varied according to the type of pathogen and were higher when associated with major pathogens such as S. aureus and environmental streptococci compared with healthy quarters.


Assuntos
Mastite Bovina/fisiopatologia , Leite/química , Leite/metabolismo , Infecções Estafilocócicas/veterinária , Infecções Estreptocócicas/veterinária , Animais , Infecções Assintomáticas , Brasil , Bovinos , Doença Crônica/veterinária , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/fisiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/fisiopatologia , Streptococcus/fisiologia
6.
Anim Sci J ; 91(1): e13406, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578314

RESUMO

The present study assessed the effects of intramammary infusion of Bifidobacterium breve (B. breve) on mastitis-causing pathogens and on the somatic cell counts (SCC) in lactating cows with chronic subclinical mastitis. The bacteriological cure rates of 42 quarters from 42 cows infected with Staphylococcus aureus, Corynebacterium bovis, coagulase-negative staphylococci, and environmental streptococci were 18.2% (2/11), 14.3% (1/7), 58.8% (10/17), and 28.6% (2/7), respectively, on day 14 after B. breve infusion. In a second trial, B. breve was infused into 18 quarters from 18 cows with chronic subclinical mastitis from which pathogens had not been isolated; the rates of quarters showing SCC > 50 × 104 cells/ml prior to B. breve infusion that decreased to < 30 × 104 cells/ml after infusion were significantly (p < .01) increased to 61.1% (11/18) on day 14 compared to that prior to infusion (0/18). The intramammary infusion of B. breve appears to be a non-antibiotic approach for elimination of minor pathogens and decreasing SCC in quarters with chronic subclinical mastitis in dairy cows.


Assuntos
Bifidobacterium breve , Infecções por Corynebacterium , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Mastite Bovina/terapia , Infecções Estafilocócicas , Animais , Bovinos , Corynebacterium , Infecções por Corynebacterium/veterinária , Feminino , Infusões Intralesionais , Infecções Estafilocócicas/veterinária , Staphylococcus aureus , Resultado do Tratamento
7.
Lett Appl Microbiol ; 71(4): 394-399, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32557652

RESUMO

The aims of the present study were to examine the occurrence of Staphylococcus spp. in the tonsils of slaughtered pigs in a regional slaughterhouse in Greece, the antibiotic resistance of the Staphylococcus spp. isolates, and the enteroxigenicity of the S. aureus isolates. Staphylococcus spp. were isolated in 70 (48·61%) out of the total 144 tonsil samples. The predominant species was S. aureus in coagulase-positive staphylococci (CoPS), while the predominant species were Staphylococcus epidermidis and Staphylococcus saprophyticus in the coagulase-negative staphylococci (CoNS). Staphylococcus spp. isolates presented high antibiotic resistance frequencies to tetracycline (97·1%) or clindamycin (80·0%) and low antibiotic resistance frequencies to fusidic acid (14·3%). No methicillin-resistant S. aureus (MRSA) strains were identified, and all Staphylococcus spp. isolates were susceptible to vancomycin. Among the 26 S. aureus isolates, 21 (80·76%) possessed staphylococcal enterotoxin genes with seven different enterotoxin gene profiles. The predominant enterotoxin profile was seg, sei and sej with seven S. aureus isolates. The occurrence of multidrug resistant Staphylococcus spp. in pig tonsils indicate public health risk to pork consumers and handlers in developing antimicrobial resistance.


Assuntos
Farmacorresistência Bacteriana , Enterotoxinas/metabolismo , Tonsila Palatina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação , Doenças dos Suínos/microbiologia , Matadouros/estatística & dados numéricos , Animais , Antibacterianos/farmacologia , Clindamicina/farmacologia , Grécia/epidemiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Suínos , Doenças dos Suínos/epidemiologia
8.
PLoS One ; 15(6): e0235006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559258

RESUMO

Distal limb wounds are common injuries sustained by horses and their healing is fraught with complications due to equine anatomy, prevalence of infection, and challenges associated with wound management. Gallium is a semi-metallic element that has been shown to possess antimicrobial properties and aid in wound healing in various preclinical models. The effects of Gallium have not been studied in equine wound healing. Therefore, the objective of this study was to compare healing rates between gallium-treated and untreated wounds of equine distal limbs and to demonstrate the antimicrobial effects of gallium on wounds inoculated with S. aureus. Using an established model of equine wound healing we demonstrated beneficial effects of 0.5% topical gallium maltolate on equine wound healing. Specifically we documented reduced healing times, reduced bioburden, and reduced formation of exuberant granulation tissue in wounds treated with gallium maltolate as compared with untreated wounds. Gallium appeared to exert its beneficial effects via its well-described antimicrobial actions as well as by altering the expression of specific genes known to be involved in wound healing of horses and other animals. Specifically, gallium maltolate appeared to increase expression of transforming growth factor-ß in both infected and un-infected wounds. Further work is needed to document the effects of gallium on naturally occurring equine wounds and to compare the effects of gallium with other wound treatment options. These data, however, suggest that gallium may be an attractive and novel means of improving equine distal limb wound healing.


Assuntos
Antibacterianos/uso terapêutico , Doenças dos Cavalos/tratamento farmacológico , Traumatismos da Perna/tratamento farmacológico , Compostos Organometálicos/uso terapêutico , Pironas/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Administração Tópica , Animais , Antibacterianos/administração & dosagem , Carga Bacteriana , Citocinas/genética , Citocinas/metabolismo , Doenças dos Cavalos/metabolismo , Cavalos , Traumatismos da Perna/metabolismo , Traumatismos da Perna/veterinária , Compostos Organometálicos/administração & dosagem , Pironas/administração & dosagem , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/veterinária , Cicatrização
9.
J Appl Microbiol ; 129(5): 1102-1119, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32416020

RESUMO

Staphylococcus aureus is an important agent of contagious bovine intramammary infections in dairy cattle. Its ability to persist inside the udder is based on the presence of important mechanisms such as its ability to form biofilms, polysaccharide capsules small colony variants, and their ability to invade professional and nonprofessional cells, which will protect S. aureus from the innate and adaptive immune response of the cow, and from antibiotics that are no longer considered to be sufficient against S. aureus bovine mastitis. In this review, we present the recent research outlining S. aureus persistence properties inside the mammary gland, including its regulation mechanisms, and we highlight alternative therapeutic strategies that were tested against S. aureus isolated from bovine mastitis such as the use of probiotic bacteria, bacteriocins and bacteriophages. Overall, the persistence of S. aureus inside the mammary gland remains a pressing veterinary problem. A thorough understanding of staphylococcal persistence mechanisms will elucidate novel ways that can help in the identification of novel treatments.


Assuntos
Mastite Bovina/microbiologia , Mastite Bovina/terapia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/fisiologia , Animais , Bacteriocinas/uso terapêutico , Bovinos , Feminino , Glândulas Mamárias Animais/microbiologia , Terapia por Fagos/veterinária , Probióticos/uso terapêutico , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/terapia , Staphylococcus aureus/isolamento & purificação
10.
Appl Environ Microbiol ; 86(13)2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32358001

RESUMO

Livestock-associated methicillin-resistant Staphylococcus aureus sequence type (ST) 398 (LA-MRSA ST398) is a genetic lineage for which pigs are regarded as the main reservoir. An increasing prevalence of LA-MRSA ST398 has been reported in areas with high livestock density throughout Europe. In this study, we investigated the drivers contributing to the introduction and spread of LA-MRSA ST398 through the pig farming system in southern Italy. Whole-genome sequencing (WGS) of LA-MRSA ST398 isolates collected in 2018 from pigs (n = 53) and employees (n = 14) from 10 farms in the Calabria region of Italy were comparatively analyzed with previously published WGS data from Italian ST398 isolates (n = 45), an international ST398 reference collection (n = 89), and isolates from Danish pig farms (n = 283), which are the main suppliers of pigs imported to Italy. Single-nucleotide polymorphisms (SNP) were used to infer isolate relatedness, and these data were used together with data from animal trading to identify factors contributing to LA-MRSA ST398 dissemination. The analyses support the existence of two concurrent pathways for the spread of LA-MRSA ST398 in southern Italy: (i) multiple introductions of LA-MRSA ST398 through the import of colonized pigs from other European countries, including Denmark and France, and (ii) the spread of distinct clones dependent on local trading of pigs between farms. Phylogenetically related Italian and Danish LA-MRSA ST398 isolates shared extensive similarities, including carriage of antimicrobial resistance genes. Our findings highlight the potential risk of transboundary transmission of antimicrobial-resistant bacterial clones with a high zoonotic potential during import of pigs from countries with high LA-MRSA prevalence.IMPORTANCE Over the past decade, livestock-associated methicillin-resistant Staphylococcus aureus sequence type 398 (LA-MRSA ST398) has spread among pig holdings throughout Europe, in parallel with the increased incidence of infections among humans, especially in intensive pig farming regions. Despite the growing prevalence of LA-MRSA ST398 in Italian pig farms, the transmission dynamics of this clone in Italy remains unclear. This work provides genome-based evidence to suggest transboundary LA-MRSA ST398 transmission through trading of colonized pigs between European countries and Italy, as well as between farms in the same Italian region. Our findings show that both international trading and local trading of colonized pigs are important factors contributing to the global spread of LA-MRSA ST398 and underscore the need for control measures on and off the farm to reduce the dissemination of this zoonotic pathogen.


Assuntos
Comércio , Infecções Estafilocócicas/veterinária , Doenças dos Suínos/transmissão , Criação de Animais Domésticos/economia , Animais , Itália , Staphylococcus aureus Resistente à Meticilina/fisiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Sus scrofa , Suínos , Doenças dos Suínos/microbiologia
11.
APMIS ; 128(6): 451-462, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32358920

RESUMO

Bacteria and viruses were analysed in the upper respiratory tract of symptomatic pig farmers and their domestic pigs. Eighty six human nasal and 495 (50 pools) porcine snout swabs were collected in Schleswig-Holstein, Germany. Staphylococcus (S.) aureus (62.8%, 54/86), human rhino- and coronaviruses (HRV, 29.1%, 25/86; HCoV, 16.3%, 14/86) were frequently detected in humans, while Haemophilus parasuis (90.0%, 45/50), Mycoplasma hyorhinis (78.6%, 11/14), Enterovirus G (EV-G, 56.0%, 28/50) and S. aureus (36.0%, 18/50), respectively, were highly prevalent in pigs. The detection of S. aureus in human follow-up samples indicates a carrier status. The methicillin-resistant phenotype (MRSA) was identified in 33.3% (18/54) of nasal swabs and in one of 18 (5.6%) pooled snout swabs that were tested positive for S. aureus. Strains were indicative of the livestock-associated clonal complex CC398, with t011 being the most common staphylococcal protein A type. Enterobacterales and non-fermenters were frequently isolated from swabs. Their detection in follow-up samples suggests a carrier status. All were classified as being non-multiresistant. There was no example for cross-species transmission of viruses. In contrast, transmission of S. aureus through occupational contact to pigs seems possible. The study contributes to the 'One Health' approach.


Assuntos
Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Infecções Estafilocócicas/veterinária , Sus scrofa/microbiologia , Sus scrofa/virologia , Doenças dos Suínos/epidemiologia , Animais , Portador Sadio , Humanos , Gado , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Mucosa Nasal/microbiologia , Mucosa Nasal/virologia , Doenças Profissionais/microbiologia , Prevalência , Infecções Respiratórias/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/transmissão , Suínos , Doenças dos Suínos/microbiologia , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia , Viroses/epidemiologia , Viroses/transmissão , Viroses/veterinária
12.
J Dairy Sci ; 103(7): 6364-6373, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32307160

RESUMO

Infection and inflammation of the mammary gland, and especially prevention of mastitis, are still major challenges for the dairy industry. Different approaches have been tried to reduce the incidence of mastitis. Genetic selection of cows with lower susceptibility to mastitis promises sustainable success in this regard. Bos taurus autosome (BTA) 18, particularly the region between 43 and 59 Mb, harbors quantitative trait loci (QTL) for somatic cell score, a surrogate trait for mastitis susceptibility. Scrutinizing the molecular bases hereof, we challenged udders from half-sib heifers having inherited either favorable paternal haplotypes for somatic cell score (Q) or unfavorable haplotypes (q) with the Staphylococcus aureus pathogen. RNA sequencing was used for an in-depth analysis of challenge-related alterations in the hepatic transcriptome. Liver exerts highly relevant immune functions aside from being the key metabolic organ. Hence, a holistic approach focusing on the liver enabled us to identify challenge-related and genotype-dependent differentially expressed genes and underlying regulatory networks. In response to the S. aureus challenge, we found that heifers with Q haplotypes displayed more activated immune genes and pathways after S. aureus challenge compared with their q half-sibs. Furthermore, we found a significant enrichment of differentially expressed loci in the genomic target region on BTA18, suggesting the existence of a regionally acting regulatory element with effects on a variety of genes in this region.


Assuntos
Predisposição Genética para Doença , Fígado/metabolismo , Mastite Bovina/imunologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus , Transcriptoma , Animais , Bovinos , Indústria de Laticínios , Suscetibilidade a Doenças/veterinária , Feminino , Haplótipos , Glândulas Mamárias Animais/metabolismo , Mastite Bovina/genética , Fenótipo , Locos de Características Quantitativas , Seleção Genética , Análise de Sequência de RNA , Infecções Estafilocócicas/genética , Staphylococcus aureus/genética , Vacinação/veterinária
13.
Vet Microbiol ; 243: 108631, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32273010

RESUMO

This work aimed at characterizing four Staphylococcus aureus and 68 coagulase-negative staphylococci (CoNS), recovered from the air and liquid manure tank of two swine farms with intensive- and semi-extensive-production types, for their antimicrobial resistance pheno-/genotypes and their virulence gene content. Molecular typing was performed by spa typing, MLST, agr typing, and SCCmec typing, where applicable. Conjugation experiments were performed to assess the transferability of the linezolid resistance gene cfr, and its genetic environment was determined by Whole-Genome-Sequencing. The four S. aureus (intensive-production farm, IP-farm) were typed as t011-agrI-CC398-ST398, were scn-negative and two of them were methicillin-resistant (MRSA) with the mecA gene (SCCmec-V). Multidrug resistance was seen in 87 % of the CoNS. Statistically significant differences among the antimicrobial resistance rates of CoNS from the two farms were observed for cefoxitin, aminoglycosides, tetracycline, ciprofloxacin and trimethoprim-sulfamethoxazole. Eight methicillin-resistant CoNS, which were recovered from the IP-farm, carried the mecA gene. One S. simulans isolate was PVL-positive and three S. cohnii eta-positive. One S. equorum and one S. arlettae showed linezolid resistance and carried the cfr gene (IP-farm), which was non-transferable by conjugation into S. aureus. The cfr genetic context in both isolates was identical, with the lsa(B) gene located upstream of cfr. The environment of swine farms might contribute to the dissemination of CoNS that show multidrug resistance and harbor important virulence factors.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Exotoxinas/genética , Leucocidinas/genética , Infecções Estafilocócicas/veterinária , Staphylococcus/genética , Microbiologia do Ar , Animais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Coagulase , Farmacorresistência Bacteriana Múltipla/genética , Fazendas , Genes Bacterianos , Esterco/microbiologia , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Staphylococcus/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Suínos , Fatores de Virulência/genética
14.
J Dairy Sci ; 103(5): 4732-4737, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32113752

RESUMO

Staphylococcus aureus is an important intramammary pathogen for dairy cows that also is remarkably important for public health. Multiple virulence factors can be involved simultaneously during the pathogenesis of a staphylococcal disease, including adhesion proteins, extracellular enzymes, and toxins. The main objective of this study was to assess virulence factors that are associated with cow intramammary infection (IMI) and of human health concern among Staph. aureus isolates obtained from bulk tank milk (BTM) and adherences on milking equipment surfaces. A total of 166 Staph. aureus isolates from 23 dairy farms were characterized according to their virulence profiles. For virulence factors of importance in IMI, the presence of the virulence markers thermonuclease (nuc) and coagulase (coa) and virulence genes such as fibronectin (fnbA) and intercellular adhesion (icaA, icaD) were assessed. For virulence factors of public health concern, presence of antimicrobial resistance (mecA and mecC) and enterotoxin (sea and seb) genes were analyzed. Among all Staph. aureus isolates, 5 virulence profiles were found; the profile nuc(+)coa(+)fnbA(+)icaA(+)icaD(+)mecA(-)mecC(-)sea(-)seb(-) was the most frequently observed (21 out of 23 dairy farms). No differences were found between the virulence profile frequencies of Staph. aureus from BTM and adherences on milking equipment surfaces. The virulence profiles most frequently observed included genes involved in the adherence and biofilm-forming ability of Staph. aureus, which could represent a potential advantage for the bacterium during the early stages of IMI colonization and for persistence on surfaces. Our results indicate a greater frequency of virulence factors of importance for IMI pathogenesis than virulence factors of public health concern, consistent with the dairy origin of isolates. The mecA, mecC, and seb genes were not observed among Staph. aureus isolates analyzed in this study. However, the sea gene was detected in 3 Staph. aureus isolated from BTM, thus posing a potential public health threat. Our results emphasize the importance of understanding the epidemiology and dynamics of Staph. aureus on dairy farms as a tool for the improvement of udder health and milk safety.


Assuntos
Biofilmes/crescimento & desenvolvimento , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/patogenicidade , Fatores de Virulência/genética , Animais , Bovinos , Chile , Coagulase/genética , Indústria de Laticínios/instrumentação , Enterotoxinas/genética , Fazendas , Feminino , Glândulas Mamárias Animais/microbiologia , Nuclease do Micrococo/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Virulência
15.
J Dairy Sci ; 103(5): 4588-4605, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32113759

RESUMO

Staphylococcus aureus is one of the pathogens most frequently isolated from cases of mastitis worldwide. To decrease the effect of S. aureus mastitis in dairy farming, alternative strategies for controlling mastitis are needed that depend on a better knowledge of cow-to-cow variations in S. aureus antibody production. The present study sought to explore the diversity of S. aureus antibodies produced by dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine. We obtained protein extracts from S. aureus isolates derived from persistent subclinical mastitis. Proteins were fractionated using 2-dimensional gel electrophoresis and Western blotting. Then, Western blotting membranes were exposed to sera from 24 dairy cows that had been divided into the following groups: vaccinated dairy cows that were infected with S. aureus, further subdivided according to whether they (a) remained infected by S. aureus or (b) recovered from the intramammary infection; unvaccinated dairy cows infected with S. aureus; and vaccinated healthy dairy cows with no history of S. aureus mastitis. Proteins found to be reactive by Western blot were identified by mass spectrometry (MALDI/TOF-TOF). Our most important finding was that F0F1 ATP synthase subunit α, succinyl-diaminopimelate desuccinylase, and cysteinyl-tRNA synthetase were potential candidate proteins for the prevention of S. aureus mastitis. This study strengthens the notion that variations among animals should not be ignored and shows that the heterogeneity of antibody production against anti-staphylococcal antigens in animals may enable the identification of new immunotherapy targets.


Assuntos
Anticorpos Antibacterianos/sangue , Mastite Bovina/imunologia , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/administração & dosagem , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Bovinos , Feminino , Humanos , Mastite Bovina/microbiologia , Mastite Bovina/prevenção & controle , Leite , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Vacinas Antiestafilocócicas/imunologia
16.
Sci Total Environ ; 722: 137845, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32199375

RESUMO

A methicillin-resistant Staphylococcus aureus CC398 was recovered from a wild female boar (Sus scrofa) in the north of Portugal, in 2013 (Sousa et al. 2017). Whole genome sequencing (WGS) revealed this strain carries a new variant of a mecA-containing staphylococcal chromosomal gene cassette (SCCmec) type IV with an uncommon J3 region. WGS studies can facilitate surveillance and provide more detailed characterization of bacterial clones circulating in the wild, reinforcing the need for a one health perspective to better understand and control antimicrobial resistance.


Assuntos
Infecções Estafilocócicas , Animais , Antibacterianos , Proteínas de Bactérias , Feminino , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Portugal , Infecções Estafilocócicas/veterinária , Sus scrofa , Suínos
17.
J Dairy Sci ; 103(5): 4717-4731, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32171518

RESUMO

Mastitis is an important constraint to milk production in pastoralist camel (Camelus dromedarius) herds in Kenya. The objective of this study was to investigate the prevalence, risk factors, and bacterial panorama of subclinical mastitis (SCM) in pastoralist camel herds in Isiolo County, Kenya. Furthermore, antimicrobial susceptibility in udder pathogens was studied. A cross-sectional sample of 206 camels from 20 milking herds was screened using the California Mastitis Test (CMT), and quarter milk was subjected to bacterial culturing. Isolates were confirmed using MALDI-TOF mass spectrometry analysis, and antimicrobial susceptibility was determined using the broth microdilution method. Interviews focusing on herd management were conducted with camel owners. Subclinical mastitis, defined as a CMT score ≥ 3 (scale 1 to 5) and absence of clinical symptoms in the udder, were present in all visited herds. On the individual level, 46% of the camels had at least 1 quarter affected with SCM, and on the quarter level the prevalence was 26%. Intramammary infections (IMI) were common; out of 798 quarter milk samples, 33% yielded conclusive bacterial growth. The sensitivity and specificity of CMT for correctly identifying quarters with IMI were 82% and 92%, respectively. The most prevalent pathogen was Streptococcus agalactiae (72% of IMI-positive quarters), followed by non-aureus staphylococci (19%) and Staphylococcus aureus (13%). Antimicrobial susceptibility testing revealed that only a low proportion (4.9%) of Strep. agalactiae isolates was sensitive to tetracycline. For Staph. aureus, 59.1% of isolates exhibited sensitivity to penicillin. Skin lesions on the teats or udder were a risk factor for SCM. Increased age, parity, and stage of lactation were associated with increased risk of both SCM and IMI. Older camels with a blind teat or a previous history of mastitis were more likely to be infected with Strep. agalactiae. Hygiene routines for milking were largely absent in the observed herds, and knowledge of adequate milk handling was limited. The poor udder health is likely to depend on multiple factors, most prominently the within-herd maintenance of contagious udder pathogens, in combination with difficult sanitary conditions and lack of awareness among camel keepers. This study showed that in pastoralist camel herds around Isiolo town, SCM and IMI specifically caused by Strep. agalactiae are common udder health problems and are associated with increasing age, parity, and stage of lactation, and skin lesions on the teats and udder. Resistance to tetracycline in Strep. agalactiae was common. Control strategies specifically targeting SCM and adapted to pastorally managed camel herds need to be developed to reduce disease, combat antimicrobial resistance, and improve the livelihoods of pastoralists.


Assuntos
Antibacterianos/farmacologia , Camelus/microbiologia , Farmacorresistência Bacteriana , Mastite/veterinária , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Streptococcus/classificação , Animais , Estudos Transversais , Feminino , Geografia , Higiene , Quênia/epidemiologia , Lactação , Glândulas Mamárias Animais/microbiologia , Mastite/epidemiologia , Mastite/microbiologia , Leite/metabolismo , Prevalência , Fatores de Risco , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Streptococcus agalactiae/classificação , Tetraciclina/farmacologia
18.
Vet Res ; 51(1): 32, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32122405

RESUMO

The presence of non-aureus staphylococci (NAS) in bovine rectal feces has recently been described. Similar to other mastitis causing pathogens, shedding of NAS in the environment could result in intramammary infection. The objective of this study was to investigate whether NAS strains present in feces can cause intramammary infection, likely via teat apex colonization. During a cross-sectional study in 5 dairy herds, samples were collected from the habitats quarter milk, teat apices, and rectal feces from 25%, 10%, and 25% of the lactating cows, respectively, with a cow serving as the source of one type of sample only. Samples from clinical mastitis cases were continuously collected during the 1-year study period as well. The 6 most prevalent NAS species, Staphylococcus (S.) chromogenes, S. cohnii, S. devriesei, S. equorum, S. haemolyticus, and S. hominis, were further subtyped by random amplification of polymorphic deoxyribonucleic acid polymerase chain reaction (RAPD-PCR), when the same NAS species was present in the same herd in the three habitats. For S. chromogenes, S. cohnii, S. devriesei, and S. haemolyticus, the same RAPD type was found in rectal feces, teat apices, and quarter milk, indicating that fecal NAS can infect the mammary gland. For S. hominis and S. equorum, we were unable to confirm the presence of the same RAPD types in the three habitats.


Assuntos
Doenças Mamárias/veterinária , Doenças dos Bovinos/microbiologia , Glândulas Mamárias Animais/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação , Animais , Bélgica , Doenças Mamárias/microbiologia , Bovinos , Estudos Transversais , Fezes/microbiologia , Feminino , Infecções Estafilocócicas/microbiologia , Staphylococcus/classificação
19.
Vet Microbiol ; 242: 108594, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122598

RESUMO

Non-S. aureus staphylococci (NAS) are the most frequently isolated pathogens from bovine milk and can cause intramammary infections (IMI). They can also be found in teat canals, on bovine skin and in cows' environment, which may lead to unnoticed contamination of milk samples. The aim of this study was to investigate the role of NAS species as mastitis-causing pathogens or contaminants, and to identify possible differences between NAS species. A longitudinal study was conducted with consecutive milk sampling in five German dairy herds. Species identification was performed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Infections were distinguished from contaminations using two different definitions based on the repeated detection of an NAS species. Of 15 NAS species found, eight and ten, respectively, were associated with an IMI. Staphylococcus simulans and S. chromogenes were associated with IMI in more than 90 % of the findings. S. warneri, S. xylosus, S. microti, S. haemolyticus, and S. succinus seem to be frequent causes of IMI as well as contaminants. If a species-differentiation is available after cultivating NAS, the findings should be interpreted in consideration of the observations made in this study, whether it is more likely a question of a contaminant or a cause of intramammary infection. The bacteria shedding intensity of the NAS species with a more substantially adverse effect on udder health seems to be higher than that of the less important NAS pathogens.


Assuntos
Contaminação de Alimentos/análise , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação , Animais , Derrame de Bactérias , Bovinos , Contagem de Colônia Microbiana , Indústria de Laticínios , Feminino , Alemanha , Inflamação , Estudos Longitudinais , Mastite Bovina/diagnóstico , Infecções Estafilocócicas/diagnóstico , Staphylococcus/classificação , Staphylococcus aureus
20.
Vet Microbiol ; 242: 108600, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122605

RESUMO

Based on antimicrobial susceptibility testing (AST), correct classifications as susceptible, intermediate or resistant are challenging for some antimicrobial agent-bacterial species combinations. In this study, we investigated 19 equine Staphylococcus aureus isolates for their susceptibility to the combination sulfamethoxazole/trimethoprim (SXT) by using broth microdilution (BMD), agar disk diffusion (DD) and automated test systems. To elucidate the presence of the corresponding genetic resistance properties among the isolates, whole genome sequence analysis was performed and the genomes were screened for trimethoprim (TMP) resistance genes and mutations in the deduced FolP amino acid (aa) sequences, known to confer sulfonamide resistance. To check for hetero-resistance, zone diameters in DD were screened after 18 and 42 h of incubation. All 19 isolates harboured one of the TMP resistance genes dfrG or dfrS1. Three isolates had an aa exchange in their FolP aa sequence (F17L), which has previously been described to result in sulfonamide resistance. These isolates were classified as SXT-resistant by all methods. The remaining 16 isolates were classified as SXT-susceptible or -intermediate (BMD and/or DD) or SXT-resistant (mainly automated test systems). None of the isolates had relevant aa variations in their FolP aa sequences. All 19 isolates showed slight growth within their SXT inhibition zone by DD, pointing towards hetero-resistance. Overall, automated test systems classified isolates lacking genetic resistance determinants more frequently as SXT-resistant than DD and BMD. Therefore, further studies are needed to define a reliable method for SXT susceptibility testing.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Animais , Proteínas de Bactérias/genética , Cavalos/microbiologia , Testes de Sensibilidade Microbiana , Mutação , Infecções Estafilocócicas/microbiologia , Sequenciamento Completo do Genoma
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