Mastitis is a disease of significant economical importance that affects farming and is a limiting... more Mastitis is a disease of significant economical importance that affects farming and is a limiting factor in the world agribusiness of dairy cattle. It causes a considerable economic loss in milk production as a result of mammary gland inflammation. On that matter, the infections caused by Staphylococcus aureus also present public health implications, considering that thermostable toxins produced by this bacterium may remain stable in milk. This bacterium specie stands out as the cause of the higher incidence of mastitis due to its high resistance to antibiotics as a result of the indiscriminate use of these therapeutic agents. In this context, the process of discovering new antimicrobial agents is extremely important in a stage of rapid development of bacterial resistance. Thus, medicinal plants may be explored as alternative agents for treatment of this important animal disease. This minireview intends to enlighten briefly this disease, its economical and medical features using Brazil, one of the top-ten biggest dairy producers, as an example of the mastitis economical importance to point it out as a target for further research on medicinal plants, exploring their potential as new therapeutic options for treating mastitis.
Chemical Evaluation via High-Resolution Techniques and Biopesticide Potential of Bio-Oil and Aqueous Phase from Slow Pyrolysis of Passion Fruit Seed Cake
Ecdysone modulates both ultrastructural arrangement of hindgut and attachment of Trypanosoma cruzi DM 28c to the rectum cuticle of Rhodnius prolixus fifth-instar nymph
Experimental Parasitology, 2022
Studies on the effects of azadirachtin treatment, ecdysone supplementation and ecdysone therapy o... more Studies on the effects of azadirachtin treatment, ecdysone supplementation and ecdysone therapy on both the ultrastructural organization of the rectum in 5th-instar nymph of Rhodnius prolixus and the ex vivo attachment behavior of Trypanosoma cruzi under these experimental conditions were carried out. Control insects had a typical and significant organization of the rectum cuticle consisted of four main layers (procuticle, inner epicuticle, outer epicuticle, and wax layer) during the entire period of the experiment. Both azadirachtin treatment and ecdysone supplementation avoid the development of both outer epicuticle and wax layer. Oral therapy with ecdysone partially reversed the altered organization and induce the development of the four main rectal cuticle layers. In the same way, the ex vivo attachment of T. cruzi to rectal cuticle was blocked by azadirachtin treatment but ecdysone therapy also partially recovered the parasite adhesion rates to almost those detected in control insects. These results point out that ecdysone may be a factor responsible - directly or indirectly - by the modulation of rectum ultrastructural arrangement providing a superficial wax layer to the attachment followed by metacyclogenesis of T. cruzi in the rectum of its invertebrate hosts.
Slow pyrolysis is a process for the thermochemical conversion of biomasses into bio-oils that may... more Slow pyrolysis is a process for the thermochemical conversion of biomasses into bio-oils that may contain a rich chemical composition with biotechnological potential. Bio-oil produced from crambe fruits was investigated as to their acaricidal effect. Slow pyrolysis of crambe fruits was performed in a batch reactor at 400°C and chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The bio-oil collected was used in bioassays with larvae and engorged females of the cattle tick Rhipicephalus microplus. Biological assays were performed using the larval packet test (LPT) and adult immersion test. The GC-MS of crambe fruit bio-oil revealed mainly hydrocarbons such as alkanes and alkenes, phenols, and aldehydes. The bio-oil in the LPT exhibited an LC90 of 14.4%. In addition, crambe bio-oil caused female mortality of 91.1% at a concentration of 15% and a high egg-laying inhibition. After ovary dissection of treated females, a significant reduction in gonadosomati...
This work aimed to investigate candidate biological control agents against the cattle tick Rhipic... more This work aimed to investigate candidate biological control agents against the cattle tick Rhipicephalus microplus by studying three entomopathogenic nematodes (EPN) isolates from two species, Heterorhabditis bacteriophora (isolates LPP30 and HP88) and Heterorhabditis baujardi (isolate LPP7). The study comprised the pharmacotechnical development of four test formulations, and their biological evaluation, in three stages: 1) selection of the fittest EPN isolate at 16±1 °C after 120 h of incorporation in the formulations; 2) determination of the effects of temperature and incubation time on the survival of the selected isolate in formulations; 3) evaluation of the in vitro efficacy (infectivity) of the selected EPN formulations and their components against R. microplus females after 72 h exposure. H. baujardi LPP7 presented the highest survival rates in 0.1 % carboxymethyl cellulose sodium (CMC) formulations (100 % at 25 °C, up to 10 days after incorporation). At the highest tested temperature (34.2 °C), 54 % of LPP7 survived for up to 72 h in CMC formulations. The infectivity of LPP7-containing formulation against R. microplus was 99 %, reducing oviposition, egg production index and larval hatching. Considering the pressing need for safer acaricide products, incorporation of EPNs in pharmaceutical formulations is presented as a promising approach for the biological control of cattle tick infestations, potentially reducing environmental impact and resistance development associated with chemical acaricides.
The present research aimed to study the chemical composition and acaricidal activity of Citrus li... more The present research aimed to study the chemical composition and acaricidal activity of Citrus limonum and Piper nigrum essential oils against the cattle tick Rhipicephalus microplus. GC-MS analysis of C. limonum essential oil showed limonene (50.3%), β-pinene (14.4%), and γ-terpinene (11.7%) as the major components; P. nigrum oil was mainly composed of β-caryophyllene (26.2%), σ-ocymene (5.8%), and α-pinene (5.5%). Acaricide activity was evaluated at concentrations of 2.5, 5.0, and 10.0% (v/v) of each plant oil, as well as 1 : 1 combination of both oils (5% : 5%, 2.5% : 2.5%, and 1.25% : 1.25% each), by immersing engorged R. microplus females for one minute. The LC90 of oils from C. limonum, P. nigrum, and the combination were 4.9%, 14.8%, and 5.1%, respectively. C. limonum essential oil caused 100% mortality of engorged females at the highest concentration (10%). P. nigrum essential oil inhibited egg-laying by up to 96% in a concentration-dependent manner, suggesting it reduces ti...
Composición química y actividad acaricida de Ocotea notata (Lauraceae), una especie endémica de Brasil, contra la garrapata del ganado Rhipicephalus microplus
Latin American and Caribbean Bulletin of Medicinal and Aromatic Plants, Nov 30, 2019
Biotechnological Potential of Eugenol and Thymol Derivatives Against Staphylococcus aureus from Bovine Mastitis
Current microbiology, 2021
Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with cons... more Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with considerable economic losses. Staphylococcus aureus is the main microorganism involved in this highly contagious process, and the treatment is only using antibiotics. Currently, the search for new treatment and/or compounds is still in need due to microbial resistance. In this work, we evaluated the potential of eugenol and thymol derivatives against S. aureus strains from bovine mastitis. On that purpose, nine derivatives were synthesized from eugenol and thymol (1-9), and tested against 15 strains of S. aureus from subclinical bovine mastitis. Initially, the strains were evaluated for the biofilm production profile, and those with strong adherence were selected to the antimicrobial sensitivity determination in the Minimum Inhibitory Concentration (MIC) assays. Herein the compounds toxicity was also evaluated by in silico analysis using Osiris DataWarrior® software. The results showed that ...
A retomada da politica industrial no Brasil em 2004 colocou a biotecnologia como um setor priorit... more A retomada da politica industrial no Brasil em 2004 colocou a biotecnologia como um setor prioritario. Em funcao disso, nos ultimos anos, debates voltados para a instalacao de novas empresas do setor de biotecnologia para a saude foram promovidos em envolvendo integrantes da academia, da industria e do Governo do Estado do Rio de Janeiro. Os questionamentos sobre a disponibilidade de recursos humanos qualificados em biotecnologia para o atendimento das necessidades imediatas da bioindustria motivaram a realizacao deste trabalho. Apresentamos uma analise critica do levantamento realizado pelo GECIV-RJ com os egressos dos cursos de biotecnologia do estado do Rio de Janeiro sobre sua adequacao ao mercado de trabalho e discutimos a questao dos recursos humanos como entrave para o desenvolvimento deste setor. Percebemos que ha uma inversao da oferta de profissionais (tecnicos<graduados e pos-graduados) em relacao a aparente demanda (maior de tecnicos). Nas respostas dos egressos desse...
Tick infestation in cattle reflects the main cause of economic loss to cattle producers. This is ... more Tick infestation in cattle reflects the main cause of economic loss to cattle producers. This is due to several reasons but mainly to their ability to feed on blood and generate a huge amount of eggs. Lipid transport in arthropods is achieved by highly specialized hemolymphatic lipoproteins, which resemble those described in vertebrate blood. Such lipoproteins continuously deliver lipids through the blood to growing eggs. The injection of radioactive [H] palmitic acid into tick hemocoel showed that the gut, ovary, fat body and Gene's organ were the main organs of incorporation of this labeled fatty acid. The rate of [H] palmitic acid incorporation by the organs was high up to 30 min after injection. The [H] palmitic acid incorporated by these organs was later found in phospholipids and neutral lipids. Here, we describe the purification and characterization of a key player of lipid dynamics in tick hemolymph. The Rhipicephalus microplus lipid-apolipoprotein complex (RmLCP) is a n...
To investigate the possible effects of glycoinositolphospholipid (GIPL) from Trypanosoma cruzi on... more To investigate the possible effects of glycoinositolphospholipid (GIPL) from Trypanosoma cruzi on human antigen presenting cells, we tested their effects on lipopolysaccharide (LPS)-stimulated human macrophages and dendritic cells (DC). Human macrophages or DC were incubated with GIPL (50 μg/ml) and LPS (500 pg/ml) and tumor necrosis factor alpha (TNF-α), interleukin 8 (IL-8), IL-10, and IL-12p40 levels in supernatants were analyzed by enzyme-linked immunosorbent assay. TNF-α, IL-10, and IL-12 secretion were significantly decreased by GIPL both in macrophages and DC. In contrast, GIPL did not alter IL-8 production. We also analyzed the expression of CD80, CD86, HLA-DR, CD40, and CD57 on the macrophage surface after stimulation with LPS in the presence or absence of T. cruzi GIPL. GIPL led to a down-regulation in the expression of all tested molecules. We additionally examined the influence of T. cruzi GIPL on the response of human DC to LPS. LPS-induced HLA-DR, CD83, and CD86 up-reg...
Enzymatic production ofp-nitrophenol in liver ofPiaractus mesapatamicus Holmberg, 1887 was consis... more Enzymatic production ofp-nitrophenol in liver ofPiaractus mesapatamicus Holmberg, 1887 was consistently assayed at pH 8.5 using 7.5 mM paraoxon as substrate. This pacu liver paraoxonase activity was activated by NaCI. Apparent values of KM were 2.42 x 10M in the presence of 0.5 MNaCI and 8.99 x 10Mwithout NaCI. Apparent maximum velocity values calculated in the absence and presence of 0.5 M NaCI were 1.09 x 10~moles/min/mg of proteins and 1.29 x 10~mo les/min/mg of proteins, respectively. These V max values are fifty-fold the value described for trout (Sa/ma trulta Linnaeus, 1758) liver paraoxonase. Paraoxonase activity ofpacu liver homogenates was recovered as much in cytosolic as in particulate cellular subfractions, but the particulate subfractions showed higher specific activities. The data presented here indicate that hepatic hydrolysis oforganophosphorous pesticides may not be an important detoxification process in pacu.
Fumigant activity of pyrolysis fractions derived from waste licuri's pericarp (Syagrus coronata - Arecaceae) in the control the red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
MRSA infection and colonization have been reported in both companion and food-chain animals, high... more MRSA infection and colonization have been reported in both companion and food-chain animals, highlighting MRSA as an important veterinary and zoonotic pathogen. Another mec allele, the mecC gene, also confers beta-lactam resistance in Staphylococcus aureus and shows 69% nucleotide identity to mecA. The main aim of this study was to investigate the genotypic and clonal profile of methicillin-resistant S. aureus (MRSA) from cows with mastitis in dairy herds. Thirty-five samples suggestive of bovine subclinical mastitis were evaluated, and S. aureus were detected in all of them using both phenotypic and molecular approaches. According to the multilocus sequence typing (MLST), the S. aureus isolates were assigned in five different STs, 21 (60%) showed ST 742, 6 (17%) ST97, 4 (11%) ST1, 2 (6%) ST30, and 2 (6%) ST126. The presence of mecA was not observed in any of these isolates whereas mecC was detected in nine of them (9/35; 26%). The Panton-Valentine leukocidin (PVL) genes were detected in a total of 4 isolates. Among the 35 isolates analyzed, 26 showed resistance to penicillin. Changes in the S. aureus epidemiology due to the detection of MRSA in milk samples from cows presenting with bovine subclinical mastitis may have consequences for public health in Brazil, challenging the empirical therapy and animal management, with potential medical and social outcomes. To the best of our knowledge, this is the first report describing mecC MRSA in Southeastern Brazil.
Mastitis is a disease of significant economical importance that affects farming and is a limiting... more Mastitis is a disease of significant economical importance that affects farming and is a limiting factor in the world agribusiness of dairy cattle. It causes a considerable economic loss in milk production as a result of mammary gland inflammation. On that matter, the infections caused by Staphylococcus aureus also present public health implications, considering that thermostable toxins produced by this bacterium may remain stable in milk. This bacterium specie stands out as the cause of the higher incidence of mastitis due to its high resistance to antibiotics as a result of the indiscriminate use of these therapeutic agents. In this context, the process of discovering new antimicrobial agents is extremely important in a stage of rapid development of bacterial resistance. Thus, medicinal plants may be explored as alternative agents for treatment of this important animal disease. This minireview intends to enlighten briefly this disease, its economical and medical features using Brazil, one of the top-ten biggest dairy producers, as an example of the mastitis economical importance to point it out as a target for further research on medicinal plants, exploring their potential as new therapeutic options for treating mastitis.
Chemical Evaluation via High-Resolution Techniques and Biopesticide Potential of Bio-Oil and Aqueous Phase from Slow Pyrolysis of Passion Fruit Seed Cake
Ecdysone modulates both ultrastructural arrangement of hindgut and attachment of Trypanosoma cruzi DM 28c to the rectum cuticle of Rhodnius prolixus fifth-instar nymph
Experimental Parasitology, 2022
Studies on the effects of azadirachtin treatment, ecdysone supplementation and ecdysone therapy o... more Studies on the effects of azadirachtin treatment, ecdysone supplementation and ecdysone therapy on both the ultrastructural organization of the rectum in 5th-instar nymph of Rhodnius prolixus and the ex vivo attachment behavior of Trypanosoma cruzi under these experimental conditions were carried out. Control insects had a typical and significant organization of the rectum cuticle consisted of four main layers (procuticle, inner epicuticle, outer epicuticle, and wax layer) during the entire period of the experiment. Both azadirachtin treatment and ecdysone supplementation avoid the development of both outer epicuticle and wax layer. Oral therapy with ecdysone partially reversed the altered organization and induce the development of the four main rectal cuticle layers. In the same way, the ex vivo attachment of T. cruzi to rectal cuticle was blocked by azadirachtin treatment but ecdysone therapy also partially recovered the parasite adhesion rates to almost those detected in control insects. These results point out that ecdysone may be a factor responsible - directly or indirectly - by the modulation of rectum ultrastructural arrangement providing a superficial wax layer to the attachment followed by metacyclogenesis of T. cruzi in the rectum of its invertebrate hosts.
Slow pyrolysis is a process for the thermochemical conversion of biomasses into bio-oils that may... more Slow pyrolysis is a process for the thermochemical conversion of biomasses into bio-oils that may contain a rich chemical composition with biotechnological potential. Bio-oil produced from crambe fruits was investigated as to their acaricidal effect. Slow pyrolysis of crambe fruits was performed in a batch reactor at 400°C and chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The bio-oil collected was used in bioassays with larvae and engorged females of the cattle tick Rhipicephalus microplus. Biological assays were performed using the larval packet test (LPT) and adult immersion test. The GC-MS of crambe fruit bio-oil revealed mainly hydrocarbons such as alkanes and alkenes, phenols, and aldehydes. The bio-oil in the LPT exhibited an LC90 of 14.4%. In addition, crambe bio-oil caused female mortality of 91.1% at a concentration of 15% and a high egg-laying inhibition. After ovary dissection of treated females, a significant reduction in gonadosomati...
This work aimed to investigate candidate biological control agents against the cattle tick Rhipic... more This work aimed to investigate candidate biological control agents against the cattle tick Rhipicephalus microplus by studying three entomopathogenic nematodes (EPN) isolates from two species, Heterorhabditis bacteriophora (isolates LPP30 and HP88) and Heterorhabditis baujardi (isolate LPP7). The study comprised the pharmacotechnical development of four test formulations, and their biological evaluation, in three stages: 1) selection of the fittest EPN isolate at 16±1 °C after 120 h of incorporation in the formulations; 2) determination of the effects of temperature and incubation time on the survival of the selected isolate in formulations; 3) evaluation of the in vitro efficacy (infectivity) of the selected EPN formulations and their components against R. microplus females after 72 h exposure. H. baujardi LPP7 presented the highest survival rates in 0.1 % carboxymethyl cellulose sodium (CMC) formulations (100 % at 25 °C, up to 10 days after incorporation). At the highest tested temperature (34.2 °C), 54 % of LPP7 survived for up to 72 h in CMC formulations. The infectivity of LPP7-containing formulation against R. microplus was 99 %, reducing oviposition, egg production index and larval hatching. Considering the pressing need for safer acaricide products, incorporation of EPNs in pharmaceutical formulations is presented as a promising approach for the biological control of cattle tick infestations, potentially reducing environmental impact and resistance development associated with chemical acaricides.
The present research aimed to study the chemical composition and acaricidal activity of Citrus li... more The present research aimed to study the chemical composition and acaricidal activity of Citrus limonum and Piper nigrum essential oils against the cattle tick Rhipicephalus microplus. GC-MS analysis of C. limonum essential oil showed limonene (50.3%), β-pinene (14.4%), and γ-terpinene (11.7%) as the major components; P. nigrum oil was mainly composed of β-caryophyllene (26.2%), σ-ocymene (5.8%), and α-pinene (5.5%). Acaricide activity was evaluated at concentrations of 2.5, 5.0, and 10.0% (v/v) of each plant oil, as well as 1 : 1 combination of both oils (5% : 5%, 2.5% : 2.5%, and 1.25% : 1.25% each), by immersing engorged R. microplus females for one minute. The LC90 of oils from C. limonum, P. nigrum, and the combination were 4.9%, 14.8%, and 5.1%, respectively. C. limonum essential oil caused 100% mortality of engorged females at the highest concentration (10%). P. nigrum essential oil inhibited egg-laying by up to 96% in a concentration-dependent manner, suggesting it reduces ti...
Composición química y actividad acaricida de Ocotea notata (Lauraceae), una especie endémica de Brasil, contra la garrapata del ganado Rhipicephalus microplus
Latin American and Caribbean Bulletin of Medicinal and Aromatic Plants, Nov 30, 2019
Biotechnological Potential of Eugenol and Thymol Derivatives Against Staphylococcus aureus from Bovine Mastitis
Current microbiology, 2021
Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with cons... more Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with considerable economic losses. Staphylococcus aureus is the main microorganism involved in this highly contagious process, and the treatment is only using antibiotics. Currently, the search for new treatment and/or compounds is still in need due to microbial resistance. In this work, we evaluated the potential of eugenol and thymol derivatives against S. aureus strains from bovine mastitis. On that purpose, nine derivatives were synthesized from eugenol and thymol (1-9), and tested against 15 strains of S. aureus from subclinical bovine mastitis. Initially, the strains were evaluated for the biofilm production profile, and those with strong adherence were selected to the antimicrobial sensitivity determination in the Minimum Inhibitory Concentration (MIC) assays. Herein the compounds toxicity was also evaluated by in silico analysis using Osiris DataWarrior® software. The results showed that ...
A retomada da politica industrial no Brasil em 2004 colocou a biotecnologia como um setor priorit... more A retomada da politica industrial no Brasil em 2004 colocou a biotecnologia como um setor prioritario. Em funcao disso, nos ultimos anos, debates voltados para a instalacao de novas empresas do setor de biotecnologia para a saude foram promovidos em envolvendo integrantes da academia, da industria e do Governo do Estado do Rio de Janeiro. Os questionamentos sobre a disponibilidade de recursos humanos qualificados em biotecnologia para o atendimento das necessidades imediatas da bioindustria motivaram a realizacao deste trabalho. Apresentamos uma analise critica do levantamento realizado pelo GECIV-RJ com os egressos dos cursos de biotecnologia do estado do Rio de Janeiro sobre sua adequacao ao mercado de trabalho e discutimos a questao dos recursos humanos como entrave para o desenvolvimento deste setor. Percebemos que ha uma inversao da oferta de profissionais (tecnicos<graduados e pos-graduados) em relacao a aparente demanda (maior de tecnicos). Nas respostas dos egressos desse...
Tick infestation in cattle reflects the main cause of economic loss to cattle producers. This is ... more Tick infestation in cattle reflects the main cause of economic loss to cattle producers. This is due to several reasons but mainly to their ability to feed on blood and generate a huge amount of eggs. Lipid transport in arthropods is achieved by highly specialized hemolymphatic lipoproteins, which resemble those described in vertebrate blood. Such lipoproteins continuously deliver lipids through the blood to growing eggs. The injection of radioactive [H] palmitic acid into tick hemocoel showed that the gut, ovary, fat body and Gene's organ were the main organs of incorporation of this labeled fatty acid. The rate of [H] palmitic acid incorporation by the organs was high up to 30 min after injection. The [H] palmitic acid incorporated by these organs was later found in phospholipids and neutral lipids. Here, we describe the purification and characterization of a key player of lipid dynamics in tick hemolymph. The Rhipicephalus microplus lipid-apolipoprotein complex (RmLCP) is a n...
To investigate the possible effects of glycoinositolphospholipid (GIPL) from Trypanosoma cruzi on... more To investigate the possible effects of glycoinositolphospholipid (GIPL) from Trypanosoma cruzi on human antigen presenting cells, we tested their effects on lipopolysaccharide (LPS)-stimulated human macrophages and dendritic cells (DC). Human macrophages or DC were incubated with GIPL (50 μg/ml) and LPS (500 pg/ml) and tumor necrosis factor alpha (TNF-α), interleukin 8 (IL-8), IL-10, and IL-12p40 levels in supernatants were analyzed by enzyme-linked immunosorbent assay. TNF-α, IL-10, and IL-12 secretion were significantly decreased by GIPL both in macrophages and DC. In contrast, GIPL did not alter IL-8 production. We also analyzed the expression of CD80, CD86, HLA-DR, CD40, and CD57 on the macrophage surface after stimulation with LPS in the presence or absence of T. cruzi GIPL. GIPL led to a down-regulation in the expression of all tested molecules. We additionally examined the influence of T. cruzi GIPL on the response of human DC to LPS. LPS-induced HLA-DR, CD83, and CD86 up-reg...
Enzymatic production ofp-nitrophenol in liver ofPiaractus mesapatamicus Holmberg, 1887 was consis... more Enzymatic production ofp-nitrophenol in liver ofPiaractus mesapatamicus Holmberg, 1887 was consistently assayed at pH 8.5 using 7.5 mM paraoxon as substrate. This pacu liver paraoxonase activity was activated by NaCI. Apparent values of KM were 2.42 x 10M in the presence of 0.5 MNaCI and 8.99 x 10Mwithout NaCI. Apparent maximum velocity values calculated in the absence and presence of 0.5 M NaCI were 1.09 x 10~moles/min/mg of proteins and 1.29 x 10~mo les/min/mg of proteins, respectively. These V max values are fifty-fold the value described for trout (Sa/ma trulta Linnaeus, 1758) liver paraoxonase. Paraoxonase activity ofpacu liver homogenates was recovered as much in cytosolic as in particulate cellular subfractions, but the particulate subfractions showed higher specific activities. The data presented here indicate that hepatic hydrolysis oforganophosphorous pesticides may not be an important detoxification process in pacu.
Fumigant activity of pyrolysis fractions derived from waste licuri's pericarp (Syagrus coronata - Arecaceae) in the control the red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
MRSA infection and colonization have been reported in both companion and food-chain animals, high... more MRSA infection and colonization have been reported in both companion and food-chain animals, highlighting MRSA as an important veterinary and zoonotic pathogen. Another mec allele, the mecC gene, also confers beta-lactam resistance in Staphylococcus aureus and shows 69% nucleotide identity to mecA. The main aim of this study was to investigate the genotypic and clonal profile of methicillin-resistant S. aureus (MRSA) from cows with mastitis in dairy herds. Thirty-five samples suggestive of bovine subclinical mastitis were evaluated, and S. aureus were detected in all of them using both phenotypic and molecular approaches. According to the multilocus sequence typing (MLST), the S. aureus isolates were assigned in five different STs, 21 (60%) showed ST 742, 6 (17%) ST97, 4 (11%) ST1, 2 (6%) ST30, and 2 (6%) ST126. The presence of mecA was not observed in any of these isolates whereas mecC was detected in nine of them (9/35; 26%). The Panton-Valentine leukocidin (PVL) genes were detected in a total of 4 isolates. Among the 35 isolates analyzed, 26 showed resistance to penicillin. Changes in the S. aureus epidemiology due to the detection of MRSA in milk samples from cows presenting with bovine subclinical mastitis may have consequences for public health in Brazil, challenging the empirical therapy and animal management, with potential medical and social outcomes. To the best of our knowledge, this is the first report describing mecC MRSA in Southeastern Brazil.
Uploads
Papers by Evelize Folly