Virulence Factors in Staphylococcus aureus and Quality of Raw Milk from Dairy Cows in a Semiarid Region of Northeastern Brazil

Background: Milk quality is considered unsatisfactory in Brazil due to factors of a social, economic, cultural, and climatic nature. Mastitis is the main disease that affects dairy herds. Microorganisms of the genus Staphylococcus are the most frequently isolated pathogens in cases of mastitis in bovines. Staphylococcus aureus requires more attention because they have the ability to develop resistance to antimicrobials used in the treatment of mastitis. Thus, the aim of the present study was to evaluate virulence factors in isolates of S. aureus as well as analyze the hygienic-sanitary quality of raw milk produced on dairy farms in a semiarid region of northeastern Brazil.Material, Methods & Results: Samples were taken from milk containers at 44 properties. Fifty-eight isolates of Staphylococcus spp. were analyzed and genotypically identified as S. aureus. In the phenotypic characterization, 56.8% (33/58) of the isolates demonstrated moderate biofilm production. In the genotypic characterization (icaA, icaD and bap genes), icaA was the most representative among the isolates. No resistance to cephalothin or oxacillin was found, but 62% (36/58) of the isolates exhibited resistance to ampicillin, amoxicillin, and penicillin. In the genotypic evaluation in response to β-lactam antibiotics, 50% (29/58) of the isolates exhibited the blaZ gene. Total bacterial counts were determined based on the standard plate count and flow cytometry, for which a significant positive correlation was found (r = 0.61, P < 0.01). The somatic cell count was also performed using flow cytometry and demonstrated that 6.8% (3/44) of the properties had values above one million cells per mL. The analysis of Staphylococcus spp. revealed that 20% (9/44) of the properties had significant counts for the production of staphylococcal enterotoxins. Regarding total coliforms, 56.8% (25/44) of the milk analyzed had counts above 1.0 x 103 CFUs/mL. There were no cases of the isolation of Pseudomonas spp. Streptococcus spp. was isolated on 6.8% (3/44) of the properties. The results of the sequencing revealed one isolate to be Lactococcus lactis and two to be Enterococcus spp.Discussion: None of the 58 isolates of S. aureus was classified as negative in the phenotypic characterization of biofilmforming capacity, which suggests the presence of genes involved in this process. Studies have shown that the molecular techniques used to identify ica genes encoding biofilm synthesis are very important for the identification of virulent strains. The isolates demonstrated resistance to β-lactam antibiotics of the class of penicillins, which are the most widely employed antimicrobial agents for the treatment of diseases in dairy herds. The presence of the blaZ gene in 50% of the isolates is in agreement with data reported in other studies developed in northeastern Brazil. In 50% (29/58) of the isolates, the presence of the blaZ gene was not observed. Of these, (8/29) were resistant to ampicillin, amoxicillin and penicillin. This is due to the existence of other bacterial mechanisms. Research has shown that some isolates possessed three mechanisms (blaZ, mecA and msrA) of antimicrobial resistance simultaneously. The results of the quality analyses demonstrate that some properties produce milk of low quality, which underscores the need for management strategies directed at reducing the contamination of the product

COMPOSIÇÃO DO LEITE DE CABRAS SAANEN INFECTADAS EXPERIMENTALMENTE COM Staphylococcus aureus E SUBMETIDAS A DOIS PROTOCOLOS DE TRATAMENTO

Neste estudo, objetivou-se avaliar a composição química do leite após a infecção e tratamento da mastite induzida por S. Aureus. Foram utilizadas 10 fêmeas caprinas da raça Saanen. Fez-se a infecção experimental em 20 glândulas mamárias, formando-se quatro grupos experimentais, sendo cada um composto por cinco glândulas mamárias. Um grupo foi tratado com antimicrobiano comercial e outro com pomada à base de extrato natural de planta. Os demais grupos foram constituídos controles. Os valores obtidos para gordura, lactose, proteína, sólidos totais e produção leiteira foram analisados ao longo dos momentos experimentais, comparando-os entre si e entre os grupos experimentais. A mastite foi diagnosticada 24 horas pós inoculação, utilizando-se a lactocultura. Os animais não apresentaram alterações nos parâmetros clínicos avaliados. Para os percentuais de gordura, proteína e sólidos totais, observou-se uma elevação ao longo dos momentos experimentais, sem variação entre os grupos experimentais. Tendo em vista a importância da terapia antimicrobiana convencional e a crescente utilização de antimicrobianos naturais, os resultados obtidos mostram igualdade entre as duas opções terapêuticas, principalmente no aspecto de manutenção dos principais componentes do leite. Palavras-chave: cabras; composição do leite; terapia; mastite

MILK COMPOSITION OF SAANEN GOATS EXPERIMENTALLY INFECTED BY Staphylococcus aureus AND SUBJECTED TO TWO TREATMENT PROTOCOLS

This study aimed to evaluate the chemical composition of milk after infection and treatment of mastitis caused by Staphylococcus aureus. Ten Saanen goats were used. Experimental infection was performed in 20 mammary glands, forming four groups, each consisting of five mammary glands. One group was treated with commercial antimicrobial and another with natural plant extract-based ointment. The other groups were constituted as control. The values obtained for fat, lactose, protein, total solids, and milk production were analyzed through the experimental moments, comparing them among each other and between experimental groups. Mastitis was diagnosed by milk microbiology after 24 hours of inoculation. The animals showed no changes in the clinical parameters evaluated. For the percentage of fat, protein, and total solids, there was an increase over the experimental moments. However, there was variation among the experimental groups. Given the importance of conventional antimicrobial therapy and the increased use of natural antimicrobials, obtained results showed equality between the two treatment options, especially regarding the maintenance of the main milk components. Keywords: goat; milk composition; therapy; mastitis

ANTI-Lentivirus, Brucella abortus AND B. ovis ANTIBODIES IN SMALL RUMINANTS RAISED IN PERNAMBUCO AND BAHIA

Goat and sheep production in the semi-arid northeast of Brazil has shown great economic potential. However, health problems can compromise the productivity of these animals. Given the scarcity of studies about the occurrence of these diseases, the aim of the present study was to analyze the serological diagnosis of anti-Brucella and anti-lentivirus antibodies among small ruminants in municipalities located in the Brazilian states of Bahia and Pernambuco. The samples were collected from local slaughterhouses and dairy farms. In total, 997 serum samples from animals in slaughterhouses and dairy herds were collected. In order to diagnose the caprine arthritis encephalitis virus (CAEV), the samples underwent agarose gel immunodiffusion (AGID) testing. The buffered acidified antigen test (goats) and agarose gel immunodiffusion test (sheep) were used to detect anti-Brucella abortus and B. ovis antibodies following the methodology recommended by the Institute of Technology of Paraná (TECPAR). With anti-CAEV antibodies, seropositivity rates of 4.1% and 2.2% were recorded for animals from the slaughterhouses and dairy farms, respectively. None of the animals (goats or sheep) were positive for anti-B. abortus antibodies. With B. ovis, a seropositivity rate of 6.5% (n = 13) was recorded among the 199 sheep serum samples. Results of the present study confirmed the presence of the CAE virus in the meat and dairy herds studied, although the prevalence was low. Natural infection by B. abortus did not occur in the goat and sheep herds assessed. Seropositivity for B. ovis was confirmed, although prevalence was low. Direct tests are required to diagnose ovine brucellosis

Indirect diagnostic tests for the detection of subclinical mastitis in dairy goats experimentally infected with Staphylococcus aureus

ABSTRACT: The aim of the present study was to assess two diagnostic techniques (California mastitis test (CMT) and the somatic cell count (SCC)) that can diagnose mastitis in dairy goats. Experimental infection was conducted using 20 mammary glands, a strain of Staphylococcus aureus, an infectious dose of 1.2x108CFU mL-1 and a volume of 1mL per mammary gland. The CMT and the SCC were used to detect subclinical mastitis. Bacterial culture (BC) was performed immediately after milk collection and was used as the gold standard. Four experimental time points were established (0, 24, 48 and 72 hours post-inoculation). Analysis of the ROC curve confirmed that the best combination of sensitivity and specificity were obtained with a cutoff point of 405.5, 6030.0 and 729.5x103 cells mL-1, respectively at M1, M2 and M3. Furthermore, considering the drop in sensitivity throughout the experimental time points, the use of serial bacterial cultures are recommended, particularly in herds with a high prevalence of S. aureus

Seminário de Dissertação (2024)

Página da disciplina de Seminário de Dissertação (MPPP, UFPE, 2022) Lista de participantes == https://docs.google.com/spreadsheets/d/1mrULe1y04yPxHUBaF50jhaM1OY8QYJ3zva4N4yvm198/edit#gid=

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora