Eugenia uniflora: a promising natural alternative against multidrug-resistant bacteria / Eugenia uniflora: uma alternativa natural promissora contra bactérias multirresistentes

This work aimed to evaluate the chemical composition, antioxidant and antimicrobial activities from crude extract and fractions from leaves of Eugenia uniflora Linn. The crude extract was obtained by turbo extraction and their fractions by partitioning. Chromatographic analysis were performed, and the antioxidant capacity was verified by two methods (DPPH• and ABTS•+). The Minimal Inhibitory/Bactericidal Concentration were conducted against twenty-two bacteria, selecting five strains susceptible to extract/fractions and resistant to the antibiotics tested. Ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with Ethyl Acetate Fraction (EAF) against multidrug-resistant strains in modulatory and checkerboard tests. The chromatographic data showed gallic acid, ellagic acid, and myricitrin in crude extract, with enrichment in the EAF. The electron transfer activity demonstrated in the antioxidant tests is related to the presence of flavonoids. The Gram-positive strains were more susceptible to EAF, and their action spectra were improved by association, comprising Gram-negative bacilli. Synergisms were observed to ciprofloxacin and gentamicin against Pseudomonas aeruginosa colistin-resistant. The results demonstrate that the extract and enriched fraction obtained from the leaves of E. uniflora act as a promising natural alternative against multidrug-resistant bacteria.

Este trabalho teve como objetivo avaliar a composição química, as atividades antioxidantes e antimicrobianas do extrato bruto e frações de folhas de Eugenia uniflora Linn. O extrato bruto foi obtido por turbólise e suas frações por partição. Foram realizadas análises cromatográficas e a capacidade antioxidante foi verificada por dois métodos (DPPH• e ABTS•+). A Concentração Inibitória/Bactericida Mínima foi realizada contra vinte e duas bactérias, selecionando cinco cepas suscetíveis a extração/frações e resistentes aos antibióticos testados. Ampicilina, azitromicina, ciprofloxacina e gentamicina foram associados à Fração Acetato de Etila (FAE) contra cepas multirresistentes em testes modulatórios e de checkboard. Os dados cromatográficos mostraram ácido gálico, ácido elágico e miricitrina em extrato bruto, com enriquecimento na FAE. A atividade de transferência de elétrons demonstrada nos testes antioxidantes está relacionada com a presença de flavonoides. As cepas de Gram-positivas foram mais suscetíveis à FAE, e seus espectros de ação foram melhorados por associação, compreendendo bacilos Gram-negativos. Foram observados sinergismos de ciprofloxacina e gentamicina contra Pseudomonas aeruginosa resistente à colistina. Os resultados demonstram que o extrato e a fração enriquecida obtida das folhas de E. uniflora atuam como uma alternativa natural promissora contra bactérias multirresistentes.

Efficacy assessment of an intramammary formulation based on soluble polypyrrole in cows with experimentally induced mastitis / Avaliação da eficácia de uma formulação intramamária à base de polipirrol solúvel em vacas com mastite experimentalmente induzida

Considerando a necessidade de terapias alternativas para a mastite bovina, uma inflamação, normalmente de causa infecciosa, de alta prevalência e de alto impacto econômico nas fazendas leiteiras, avaliou-se a eficácia antimicrobiana, in vivo, de uma formulação intramamária à base de polipirrol (PPy) solúvel, um polímero condutor promissor para aplicações biomédicas, especialmente como potente antibacteriano. Neste ensaio, quartos mamários de vacas holandesas sadias (n = 8) foram inoculados com Staphylococcus aureus e tratados, por via intramamária, com formulação experimental à base de PPy solúvel (5%) e com formulação comercial à base de sulfato de gentamicina. O efeito desses tratamentos foi avaliado com a realização de lactoculturas, da Contagem Bacteriana Total (TBC), da Contagem de Células Somáticas (SCC) e da análise da composição do leite das amostras obtidas de quartos mamários, em sete momentos experimentais. Avaliação hematológica dos animais também foi realizada. A aplicação intramamária de três doses da formulação experimental à base de PPy solúvel resultou em maiores log/mL da TBC e da SCC quando comparadas ao grupo controle positivo e ao grupo que recebeu sulfato de gentamicina. A administração da formulação experimental não induziu alterações na composição do leite e nos parâmetros hematológicos. Alguns fatores farmacocinéticos e farmacodinâmicos do PPy solúvel podem ser atribuídos a ineficácia antimicrobiana da pomada experimental. Outras pesquisas devem ser realizados em prol do desenvolvimento de formulações que permitam a atuação antibacteriana do PPy solúvel no ambiente intramamário de vacas leiteiras.

Given the need for alternative therapies for bovine mastitis, an infectious disease of high prevalence and significant economic impact in dairy farms, this study evaluated the in vivo antimicrobial efficacy of an intramammary formulation based on soluble polypyrrole (PPy), a promising conductive polymer for biomedical applications, especially as an effective antimicrobial agent. In this assay, mammary quarters of healthy Holstein Friesian cows (n = 8) were inoculated with Staphylococcus aureus and treated, via the intramammary route, with an experimental formulation based on soluble PPy (5%) and a commercial formulation based on gentamicin sulfate. The effect of these treatments was evaluated based on milk cultures, Total Bacterial Count (TBC), Somatic Cell Count (SCC), and milk composition analysis of mammary quarter samples in seven experimental moments. In addition, hematological evaluations of the animals were also performed. The intramammary application of three levels of the experimental formulation based on soluble PPy resulted in higher log/mL of the TBC and SCC compared to a positive control group and a group that received gentamicin sulfate. The experimental formulation did not induce changes in milk composition or in hematological parameters. Certain factors related to pharmacokinetics, such as the type of carrier used in the formulation and the pharmacodynamics of soluble PPy, may have contributed to the antimicrobial ineffectiveness of the experimental formulation. The results of this study neither define nor decrease the antimicrobial potential of soluble PPy. Further research is required to develop formulations that enable the antibacterial action of soluble PPy in the intramammary environment of dairy cows.

Aeromonassp. in freshwater fish and antimicrobial resistance: emerging pathogen / Quantificação deAeromonassp. em peixes de água doce e resistência a antimicrobianos: patógeno emergente

ABSTRACT: The bacteria Aeromonassp. are naturally reported in aquatic ecosystems and possess pathogenic potential, being considered as emerging pathogens in humans and animals. They also cause considerable losses in fish farming and, through water, can contaminate numerous foods. This study quantified and analyzed the antimicrobial resistance profile of Aeromonassp. in fish. A total of 72 samples of two fish varieties (leather fish, Pseudoplatystomafasciatumx Leiariusmarmoratusand round fish, Colossomamacropomumx Piaractusmesopotamicusand Colossomamacropomumx Piaractusbrachypomus) were purchased from two types of sources (fresh and frozen) and three commercial establishments (supermarket, market, and fishmonger). The 55 isolated Aeromonascultures were evaluated for their antimicrobial resistance profile by the disc diffusion method. Upon quantification, the count of Aeromonassp. ranged from 4.22 to 6.00 Log CFU/g; ten different species, including A. eucrenophila, A. hydrophila, A. caviae, A. media, A. jandaei, A. veroniibv. sobria, A. trota, A. schubertii, A. veroniibv. veronii, and A. shigelloides, were identified. Among the 55 isolates, 64.45% showed resistance to Ampicillin-sulbactam, and 75% were sensitive to gentamicin and ciprofloxacin. It was concluded that 100% of the evaluated samples were contaminated by Aeromonassp., which may present a risk to consumer health since bacteria can be etiological agents of Foodborne Diseases. The antimicrobial resistance profile showed resistance to ampicillin and multi-resistance to different classes of antimicrobials, demonstrating problems with choosing an antimicrobial for treatment of any disease.

RESUMO: Aeromonas sp. são bactérias presentes naturalmente no ecossistema aquático e apresentam potencial patogênico, sendo considerados patógenos emergentes em humanos e animais. Ainda, causam perdas consideráveis em piscicultura e, através da água, podem também contaminar inúmeros alimentos. Diante disso o objetivo do trabalho foi quantificar e analisar o perfil de resistência aos antimicrobianos de bactérias do gênero Aeromonas sp. em peixes. Um total de 72 amostras foram adquiridas, sendo duas variedades de peixes (peixe de couro Pseudoplatystoma fasciatum x Leiarius marmoratus e os peixes redondos Colossoma macropomum x Piaractus mesopotamicus e Colossoma macropomum x Piaractus brachypomus), dois tipos (fresco e congelado) e de três estabelecimentos comerciais (supermercado, feira e peixaria). As 55 culturas isoladas de Aeromonas foram avaliadas quanto ao perfil de resistência aos antimicrobianos pelo método de difusão em disco. Os valores encontrados na quantificação de Aeromonas sp. variaram de 4,22 a 6,00 Log UFC/g, e foram identificadas dez espécies diferentes, sendo A. eucrenophila, A. hydrophila, A. caviae, A. media, A. jandaei, A. veronii bv. sobria, A. trota, A. schubertii, A. veronii bv. veronii e A. shigelloides. Entre os 55 isolados, 64,45% apresentaram resistência a Ampicilina-sulbactam, 75% foram sensíveis à gentamicina e ciprofloxacina. Concluiu-se que 100% das amostras avaliadas estavam contaminadas por Aeromonas sp. podendo apresentar risco à saúde do consumidor visto que estas podem ser agentes etiológicos de Doenças Transmitidas por Alimentos (DTAs). O perfil de resistência aos antimicrobianos comprovou a resistência a ampicilina e apresentou multirresistência a diferentes classes de antimicrobianos, demonstrando um problema relacionado à opção de antimicrobiano para tratamento no caso do desenvolvimento de alguma doença.

Evaluation of the antimicrobial effect of the Origanum vulgare L essential oil on strains of Klebsiella pneumoniae / Avaliação do efeito antimicrobiano do óleo essencial de Origanum vulgare L. sobre cepas de Klebsiella pneumoniae

Bacteria may be the initial cause of certain pathologies as well as a secondary agent responsible for the development of complications such as pressure ulcer infections. Pressure ulcers are a persistent health problem, especially in immunocompromised patients, and associated with infection by opportunistic microorganisms with antimicrobial resistance, such as Klebsiella pneumoniae, highlight the need for the development of new antimicrobial approaches. Thus, the aim of this study was to evaluate the antibacterial and anti-adherent activity of Origanum vulgare L. (oregano) essential oil against Klebsiella pneumoniae strains, as well as the effect of its association with synthetic antimicrobials. To this end, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analyses were performed on microdilution plates. The assay of the Minimum Inhibitory Adherence Concentration (MIAC), with test tubes. As well as, the association study through the infusion disc method containing ampicillin (AMP), gentamicin (GEN), ciprofloxacin (CIP) and ceftriaxone (CEF). Therefore, it was possible to obtain that the essential oil of oregano presents antimicrobial and bactericidal activity, with MIC ranging between 128µg/mL and 256 µg/mL and MBC between 256 µg/mL and 512 µg/mL, on the tested K. pneumoniae strains. When used in association with ampicillin and gentamicin, oregano essential oil showed synergistic effect for some strains. Therefore, it is observed that the tested essential oil can act as a promising antibacterial in the treatment of diseases caused by K. pneumoniae.

As bactérias podem ser a causa inicial de determinadas patologias como também um agente secundário responsável pelo desenvolvimento de complicações como as infecções das lesões por pressão. As lesões por pressão configuram um problema de saúde persistente, principalmente em pacientes imunocomprometidos, e associadas a infecção por microrganismos oportunistas com resistência antimicrobiana, como por exemplo a Klebisiella pneumoniae, ressaltam a necessidade do desenvolvimento de novas abordagens antimicrobianas. Assim, o objetivo deste estudo foi avaliar a atividade antibacteriana e antiaderente do óleo essencial de Origanum vulgare L. (orégano) contra cepas da Klebisiella pneumoniae, bem como o efeito da sua associação com antimicrobianos sintéticos. Para isso foram realizadas as análises da Concentração Mínima Inibitória (CIM) e Concentração Bactericida Mínima (CBM) em placas de micro diluição. O ensaio da Concentração Mínima de Aderência (CIMA), com tubos de ensaio. Como também, o estudo de associação através do método de disco de infusão contendo ampicilina, gentamicina, ciprofloxacino e ceftriaxona. Assim sendo, foi possível obter que o óleo essencial de orégano apresenta atividade antimicrobiana e bactericida, com CIM variando entre 128µg/mL e 256 µg/mL e CBM entre 256 µg/mL e 512 µg/mL, sobre as cepas de K. pneumoniae testadas. Quando utilizado em associação com a ampicilina e gentamicina, o óleo essencial de orégano demonstrou efeito sinérgico para algumas cepas. Portanto, observa-se que o óleo essencial testado pode atuar como um promissor antibacteriano no tratamento de doenças causadas por K. pneumoniae.

Detection and Antimicrobial Resistance Profile of Enteropathogenic (EPEC) and Shigatoxigenic Escherichia coli (STEC) in Conventional and Organic Broiler Chickens

Enteropatogenic Escherichia coli (EPEC) and shigatoxigenic E. coli (STEC), are generally poultry and poultry product isolate and can cause serious human infections. Many strains may become resistant to various antimicrobials, which can hinder the treatment of bacterial diseases. Organic farming seeks to avoid the selection and frequency of antimicrobial-resistant bacteria. This study aims to verify the resistance of EPEC and STEC from organic and conventional (industrial) broiler isolates to antimicrobials. All isolates were submitted to disk diffusion test with tetracycline, gentamicin, enrofloxacin, ceftriaxone and amoxicillin + clavulanate (TET, GEN, ENO, CTX, AMC) and PCR to detect specific virulence genes for EPEC and STEC. A total of 297 E. coli strains were isolated, 213 from conventional. In organic broiler, 84 strains were isolated. The strains from the conventional broiler isolates were resistant to five antimicrobials tested: TET 48.82% (104/213), ENO 28.17% (60/213), CTX 15.49% (33/213), GEN 14.55% (31/213), and AMC 7.04% (15/213), and 9.86% (21/213) were considered multidrug-resistant. Organic chicken strains were resistant to four of the antimicrobials tested: TET 35.7% (30/84), ENO 9.5% (8/84), CTX 2.4% (2/84), GEN 4.8% (4/84). Of the strains from the organic broiler chicken isolates, only 1.2% (1/84) was considered multidrug-resistant. No EPEC and STEC were found in the organic chicken samples. The multidrug resistance was characterized in 9.52% (2/21) of the EPEC and 4.76% (1/21) of the STEC. The study demonstrated the absence of EPEC and STEC strains in organic broilers and carcasses and a lower frequency of multiresistant strains compared to conventional breeding.(AU)

Evaluation of the antibacterial activity of trans-anethole against Enterococcus cloacae and Enterococcus faecalis strains of food origin / Avaliação da atividade antibacteriana do trans-anetol contra cepas de Enterobacter cloacae e Enterococcus faecalis de origem alimentar

The present study sought to evaluate the antibacterial activity of trans-anethole against food-borne strains of Enterobacter cloacae and Enterococcus faecalis. The study was performed using Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) methods, in addition, disc diffusion technique was used to evaluate the association of trans-anethole with synthetic antimicrobials. Minimum Inhibitory Concentration for Adherence (MICA) testing was also performed. The results revealed that trans-anethole presents no antibacterial activity at any of the concentrations used against the E. cloacae strains tested. However, trans-anethole presented antibacterial effect against five of the six E. faecalis bacterial strains tested, with MIC values ranging from 500 µg/mL to 1000 µg/mL. Further, when analyzing the MBC results against E. faecalis, it was observed that the compound presented values ranging from 500 µg/mL to 1000 µg/mL. As for the associations, it was observed that transanethole when combined with the antimicrobials ampicillin, gentamicin, ciprofloxacin, and ceftriaxone presented synergistic effect against most strains of E. faecalis. However, both trans-anethole and the control chlorhexidine (0.12%) presented no antibiofilm effects against strains of E. faecalis. In short, trans-anethole presented potential antibacterial against E. faecalis strains of food origin, and may upon further study, it may be used alone or in association with synthetic antimicrobials to combat infections caused by this bacterium.

O presente estudo procurou avaliar a atividade antibacteriana do trans-anetol contra cepas de Enterobacter cloacae e Enterococcus faecalis de origem alimentar. O estudo foi realizado utilizando métodos de Concentração Inibitória Mínima (CIM), e Concentração Bactericida Mínima (CBM), além disso, foi utilizada a técnica de difusão de disco para avaliar a associação do trans-anetol com antimicrobianos. O teste de Concentração Inibitória Mínima de Aderência (CIMA) também foi realizado. Os resultados revelaram que o trans-anetol não apresentou atividade antibacteriana em nenhuma das concentrações utilizadas contra as cepas de E. cloacae testadas. No entanto, o trans-anetol apresentou efeito antibacteriano contra cinco das seis cepas bacterianas de E. faecalis testadas, com valores de CIM variando de 500 µg/mL a 1000 µg/mL. Além disso, ao analisar os resultados da CBM contra E. faecalis, observa-se que o composto apresentou valores variando de 500 µg/mL a 1000 µg/mL. Quanto às associações, observou-se que o trans-anetol quando combinado com os antimicrobianos ampicilina, gentamicina, ciprofloxacino, e ceftriaxona apresentou efeito sinérgico contra a maioria das cepas de E. faecalis. No entanto, tanto o trans-anetol quanto o controle clorexidina (0,12%) não apresentaram efeito antibiofilme contra a cepa de E. faecalis. Em suma, o transanetol apresentou potencial antibacteriano contra cepas de E. faecalis de origem alimentar, podendo, mediante estudos mais aprofundados, ser utilizado isoladamente ou em associação com antimicrobianos sintéticos para combater infecções causadas por esta bactéria.

Laboratory changes inherent to acute kidney injury induced by aminoglycosides in wistar rats / Alterações laboratoriais inerentes à lesão renal aguda induzida por aminoglicosídeos em ratos wistar

Acute kidney injury (AKI) is defined as an increase greater than 0.3 mg/L of serum creatinine within 48 hours and is a major cause of death in patients in intensive care units. Twenty-four Wistar rats were divided into three groups: Control (0.9% saline), Genta (gentamicin 50 mg.kg-¹ BID) and Deh+Genta (gentamicin 50 mg.kg-¹ BID + water restriction) and tested in an AKI model by aminoglycoside administration and dehydration implementation. The animals in the Deh+Genta group exhibited the lowest average weight and feed intake after the fifth day of the experiment. In this same period, water consumption by the Genta group was lower than the Control group, but in the following days of the experiment, polydipsia was noted for this group. The Deh+Genta group displayed the highest mean serum urea after the fifth day. The gentamicin-treated groups exhibited higher means than the Control group for serum creatinine, which proved to be a late renal marker for AKI. Serum GGT was higher in the Deh+Genta group, whereas urinary GGT was higher in the groups that received gentamicin, characterizing enzymuria, although severe dehydration can mask the results by indicating false negative values. The urinary GGT enzyme did not act as an early AKI biomarker. Decreased glomerular filtration rates enhanced the concentration of blood components and masked urinary and tissue components.

A lesão renal aguda (LRA) é definida como um aumento superior a 0,3 mg / L da creatinina sérica em 48 horas e é a principal causa de morte em pacientes em unidades de terapia intensiva. Vinte e quatro ratos Wistar foram divididos em três grupos: Controle (solução salina 0,9%), Genta (gentamicina 50 mg.kg-¹ BID) e Deh + Genta (gentamicina 50 mg.kg-¹ BID + restrição hídrica) e testados em um Modelo AKI por administração de aminoglicosídeos e sujeição à desidratação. Os animais do grupo Deh + Genta apresentaram o menor peso médio e o menor consumo de ração após o quinto dia de experimento. Nesse mesmo período, o consumo de água do grupo Genta foi inferior ao do grupo Controle, mas nos dias posteriores do experimento, o grupo Genta apresentou polidipsia. O grupo Deh + Genta apresentou média de uréia sérica mais elevada após o quinto dia. Os grupos tratados com gentamicina apresentaram médias superiores à do grupo Controle para a creatinina sérica, que se mostrou um marcador renal tardio de IRA. O valor de GGT sérico foi maior no grupo Deh + Genta, enquanto o valor de GGT urinário foi maior nos grupos que receberam gentamicina, caracterizando enzimúria, mas a desidratação severa pode mascarar os resultados por apresentar valores falsos negativos. A enzima GGT urinária não atuou como um biomarcador precoce de IRA. A diminuição da taxa de filtração glomerular aumentou a concentração de componentes do sangue e mascarou componentes urinários e teciduais.

Topical application of gentamicin or cephalothin in the healing of surgical wounds in dogs / Aplicação tópica de gentamicina ou cefalotina na cicatrização de feridas cirúrgicas em cães

The present study aimed to evaluate the influence of local administration of gentamicin or cephalothin on the healing of surgical wounds in dogs. Thirty healthy dogs were submitted to surgical castration. They were divided into 2 groups of 15 animals. After the surgical procedure, two 0.6 cm circular cutaneous wounds were made in the abdominal region. Group 1 received 0.1 ml of 0.9% saline in one wound and 0.1 ml of gentamicin (40 mg / ml) in the other wound; and group 2 received 0.1 ml of 0.9% saline and 0.1 ml of cephalothin (200 mg / ml); respectively. All wounds were sutured and assessed macroscopically 1, 3 and 10 days after the operation. On day 10, an incisional biopsy was performed for histopathological evaluation. All analyzes of macroscopic variables did not show significant differences between groups (P <0.05). There were no significant differences between groups for microscopic evaluation of collagenization, vascularization, edema and inflammatory cells (P <0.05). Thus, the topical use of the tested antibiotics does not influence skin healing in dogs.

O presente estudo teve como objetivo avaliar a influência da administração local de gentamicina ou cefalotina na cicatrização de feridas cirúrgicas em cães. Trinta cães saudáveis foram submetidos à cirurgia de castração. Eles foram divididos em 2 grupos de 15 animais. Após o procedimento cirúrgico, foram feitas duas feridas cutâneas circulares de 0,6 cm na região abdominal. O grupo 1 recebeu 0,1 ml de soro fisiológico 0,9% em uma ferida e 0,1 ml de gentamicina (40 mg/ml) na outra ferida; e o grupo 2 recebeu 0,1 ml de soro fisiológico 0,9% e 0,1 ml de cefalotina (200 mg/ml); respectivamente. Todas as feridas foram suturadas e avaliadas macroscopicamente 1, 3 e 10 dias após a operação. No dia 10, foi realizada biópsia incisional para avaliação histopatológica. Todas as análises das variáveis macroscópicas não mostraram diferenças significativas entre os grupos (P<0,05). Não houve diferenças significativas entre os grupos para avaliação microscópica da colagenização, vascularização, edema e células inflamatórias (P<0,05). Assim, o uso tópico dos antibióticos testados não influencia na cicatrização da pele em cães.

Canine cystitis - biofilm formation by bacterial isolates

Background: Biofilms have been reported as important virulent markers associated with drug resistance in urinary tractinfections (UTIs) in humans and dogs. However, in veterinary medicine, researches involving biofilm formation, treatments and preventions have been limited; yet, it is still possible to find few studies demonstrating biofilm-forming bacteriaassociated with different comorbidities such as otitis, wound infections, UTIs, and endometritis. These studies generallyselect dogs with chronic and recurrent infections, which could be an important factor in antibiotic resistance. We aimed toevaluate biofilms in sporadic cystitis regarding prevalence and drug resistance.Materials, Methods & Results: Urine samples were collected by cystocentesis from 36 client-owned dogs under clinicaland laboratory suspicion of non-recurrent urinary bladder infection (cystitis). Urine was aseptically plated onto bloodagar, MacConkey, and CLED, followed by incubation for 24 to 48 h. Definitive identification of a potential pathogen wasmade by subculture collected from an isolated colony to obtain a pure culture. The gram staining method and specificbiochemical tests (phenol red fermentation, lysine, phenylalanine, citrate, sulfide-indole-motility, and urease) were usedto distinguish and classify the bacteria. After identification, the bacteria were tested for antimicrobial susceptibility by astandard disk diffusion method, using the following antimicrobials: amoxicillin with clavulanic acid, ampicillin, ceftriaxone, ciprofloxacin, clindamycin, cefazolin, cephalothin, erythromycin, gentamicin, norfloxacin, and sulfamethoxazoletrimethoprim. The biofilm-forming ability was determined based on a culture...

Antimicrobial resistance profile of Staphylococcus spp. isolates in cattle herds from Western Amazon / Perfil de resistência antimicrobiana de Staphylococcus spp. isolados em rebanhos leiteiros da Amazônia Ocidental

Staphylococcus is one of the most frequent etiological agents of bovine mastitis, causing economic losses to milk farming. This study aimed to describe the milk production and management practices in 15 herds located in three microregions of the State of Rondônia and to identify the antimicrobial resistance profile of 97 isolates of the genus Staphylococcus from these herds. The isolates were subjected to antimicrobial susceptibility tests using the agar diffusion method. Twenty-nine S. aureus isolates were selected to determine their minimum inhibitory concentration (MIC). In the farms studied, the breeding system was semi-intensive, with the Girolando breed being predominant. Milking was performed predominantly using a mechanical milking system (86.7%), twice a day (66.7%), in the presence of the calf (53.8%). The average number of lactating cows in the farms was 24, with an average milk production of 204.9 L d-1 and a milk productivity of 10.2 L animal-1 d-1. The use of antimicrobials for the treatment and prevention of bovine mastitis was reported for all properties, and therapy for dry cows was adopted in 80% of the herds. The percent susceptibility to antimicrobials ranged from 85.5% to 100% for S. aureus, 22.2% to 88.9% for coagulase-positive staphylococci (CPS), and 69.2% to 100% for coagulase-negative staphylococci (CNS), with the highest resistance frequencies for penicillin, ampicillin, and tetracycline. Among the S. aureus isolates, 100% susceptibility to oxacillin, cefalexin, and gentamicin was observed, and among the CNS isolates, 100% susceptibility to gentamicin was observed. None of the antimicrobials tested showed 100% in vitro effectiveness for CPS. CPS and CNS presented lower percentages of susceptibility to penicillin, ampicillin, and tetracycline than the S. aureus isolates. Twelve resistance patterns were detected, six of which were multiresistance patterns. The most prevalent resistance patterns were penicillin and ampicillin (PEN-AMP) and penicillin, ampicillin, and tetracycline (PEN-AMP-TET). Results of the MIC assay revealed that all 29 S. aureus isolates were susceptible to cephalothin, cefoxitin, tetracycline, and erythromycin, whereas 25 (86.2%) were susceptible to penicillin.(AU)

O gênero Staphylococcus destaca-se como um dos agentes etiológicos mais frequentes da mastite bovina, causando prejuízos econômicos à pecuária de leite. Este estudo teve o objetivo de descrever a produção de leite e práticas de manejo de 15 rebanhos localizados em três microrregiões do Estado de Rondônia, e identificar o perfil de resistência aos antimicrobianos de 97 isolados do gênero Staphylococcus provenientes destes rebanhos. Os isolados foram submetidos a testes de suscetibilidade a antimicrobianos, utilizandose a técnica de difusão em ágar. Foram selecionados 29 isolados de Staphylococcus aureus (S. aureus) para determinação da concentração inibitória mínima (CIM). Nas propriedades estudadas, o sistema de criação era semi-intensivo, com predomínio da raça Girolando. A ordenha era realizada predominantemente em sistema de ordenha mecânica (86,7%), duas vezes ao dia (66,7%) e com a presença do bezerro (53,8%). A média do número de vacas em lactação das propriedades era de 24 animais, com média de produção de leite de 204,9 L d-1 e produtividade de leite de 10,2 L animal-1 d-1. O uso de antimicrobianos para o tratamento e prevenção da mastite bovina foi relatado em todas as propriedades, sendo adotada a terapia da vaca seca em 80% dos rebanhos. A percentagem de susceptibilidade aos antimicrobianos variou de 85,5 a 100% para S. aureus, 22,2 a 88,9% para Staphylococcus coagulase positivos (SCP) e 69,2 a 100% para Staphylococcus coagulase negativos (SCN), sendo as maiores frequências de resistência para penicilina, ampicilina e tetraciclina. Entre os isolados de S. aureus foi observada 100% de susceptibilidade aos antimicrobianos oxacilina, cefalexina e gentamicina, e entre os isolados de SCN, 100% de susceptibilidade à gentamicina. Nenhum dos antimicrobianos testados apresentou 100% de efetividade in vitro para SCP. SCP e SCN apresentaram menores percentagens de susceptibilidade à penicilina, ampicilina e tetraciclina do que os isolados de S. aureus. Foram observados 12 padrões de resistência, sendo seis padrões de multirresistência. Os padrões de resistência mais prevalentes foram resistência à penicilina e ampicilina (PEN-AMP) e à penicilina, ampicilina e tetraciclina (PEN-AMP-TET). A determinação da CIM dos 29 isolados de S. aureus mostraram que todos foram susceptíveis à cefalotina, cefoxitina, tetraciclina e eritromicina, e 25 (86,2%) foram susceptíveis à penicilina.(AU)

Susceptibilidade a antimicrobianos de bactérias isoladas de leite caprino em Sergipe - Brasil / Antimicrobial susceptibility of bacteria isolated from goat milk in Sergipe - Brazil

Background: Bacterial resistance is a fundamental aspect of One Health, which is defined as the inseparable unity of animal, human, and environmental health. Epidemiological surveillance on the spread of bacterial resistance in animals and their derived products is essential given that meat, milk, and dairy products can carry resistant microorganisms that may reach humans through the food chain either by direct consumption or by handling the product. To eliminate the scarcity of information, it is necessary to characterize the epidemiological situation in terms of bacterial resistance in dairy production in northeastern Brazil. Thus, the objective of this study was to determine the frequency and antimicrobial susceptibility profile of bacteria isolated from goat milk samples from some municipalities in the Brazilian state of Sergipe. Materials, Methods & Results: The study included 28 goat farms in 4 municipalities of the Semiarid region of the State of Sergipe in Northeastern Brazil, namely Canindé de São Francisco (n = 11), Nossa Senhora da Glória (n = 6), Poço Verde (n = 6), and Porto da Folha (n = 5). All lactating does of each herd (n = 263) aged >1 year were, sampled randomly by non-probabilistic convenience sampling. Milk samples were collected from both teats, resulting in 526 samples in total. Bacterial culturing and isolation were performed, followed by antimicrobial susceptibility profile analysis to the following active principles: amoxicillin with and without clavulanic acid, amikacin, ampicillin with sulbactam, ciprofloxacin, cefalexin, cefalotin, ceftriaxone, chloramphenicol, doxycycline, enrofloxacin, gentamicin, levofloxacin, ofloxacin, penicillin G, and tetracycline. A survey form was used to obtain zootechnical information for each farm. Data are described as absolute and relative frequencies. The significance assessment of the differences between herd characteristics and bacterial isolation was performed using Pearson's chi-squared test. Bacterial isolation occurred in 15.4% (81/526) of the samples from 23.2% (61/263) of the goats. Escherichia coli (45.9% = 28/61), Staphylococcus caprae (16.4% = 10/61) and Enterococcus faecalis (11.5% = 7/61), were the most frequently isolated species. Bacterial isolations were predominant in dairy herds with up to 50 animals, production of 20 to 50 L/day and in the municipality of Porto da Folha. In terms of antimicrobial susceptibility, most isolates demonstrated resistance to penicillin and amoxicillin (88.5%), followed by ceftriaxone (23%), ofloxacin (23%), tetracycline (23%), doxycycline (19.7%), chloramphenicol (11.5%), levofloxacin (11.5%), ampicillin/ sulbactam (8.2%), amikacin (6.6%), cephalothin (4.9%), cephalexin (3.3%) and gentamicin (3.3%). Approximately 20% of the isolates were multidrug resistant, especially E. coli (50%) and S. aureus (16.7%). Discussion: E. coli was the most frequently isolated species from the samples. It is considered an environmental pathogen, and its high frequency in different herds indicates poor milking hygiene. E. coli also stood out as the species presenting the most multidrug-resistant (MDR) isolates (50%), with strains resistant to beta-lactams, aminoglycosides, quinolones, tetracycline, and chloramphenicol. Coagulase-negative staphylococci are recognized as a public health problem as they are etiological agents of various diseases and can easily acquire antimicrobial resistance genes. Although it was not the most frequently isolated species, S. aureus was the species with the second-highest frequency of MDR strains. The presence of MDR species is relevant and indicates the need for urgent action to reduce the dissemination of antimicrobial resistance. Relevant steps must be taken jointly by professionals involved in human, animal, and environmental health.

Isolation and antimicrobial resistance of coagulase-negative staphylococci recovered from healthy tortoises in Minas Gerais, Brazil / Isolamento e resistência aos antimicrobianos de estafilococos coagulase negativos recuperados de jabutis saudáveis em Minas Gerais, Brasil

In the last few decades, there has been a global increase in the adoption of reptiles as companion animals, mainly turtles and tortoises. Considering the popularity of reptiles as pets in Brazil, and a notable lack of data about potentially pathogenic staphylococci in these animals, this study isolated and evaluate the antimicrobial susceptibility of staphylococcal species from healthy tortoises (Chelonoidis carbonaria) in Brazil. During a 12-month period (February 2019 to February 2020), cloacal swabs from 66 healthy tortoises were collected at the Wild Animals Screening Center in Belo Horizonte, Minas Gerais, Brazil. The swabs were plated onto mannitol salt agar for staphylococci isolation, and species identification was performed using MALDI-TOF MS. Antimicrobial susceptibility was investigated using the disk diffusion method, and the presence of the mecA gene was investigated by PCR to detect methicillin resistance. Of the tested animals, 72.7% were positive for staphylococcal isolation. All isolates were coagulase-negative staphylococci (CoNS), and Staphylococcus sciuri (81.3%), and S. xylosus (12.5%) were the most frequently isolated species. The majority of the isolates (56%) were resistant to at least one antimicrobial agent. A high frequency of resistance was observed for penicillin (35.5%) and tetracycline (29.1 %). All strains were susceptible to cefoxitin, chloramphenicol, ciprofloxacin, erythromycin, and gentamicin. All isolates were negative for the mecA gene. The present work suggests that healthy tortoises are mainly colonized by CoNS, especially S. sciuri. Half of the isolates were resistant to at least one antimicrobial, raising questions regarding the possible role of these animals as reservoirs of antimicrobial resistance genes.

Nas últimas décadas, houve um aumento global na adoção de répteis como animais de companhia, principalmente tartarugas e jabutis. Considerando a popularidade dos répteis como animais de estimação no Brasil e a notável falta de dados sobre estafilococos potencialmente patogênicos nesses animais, o objetivo deste estudo foi isolar e avaliar a susceptibilidade antimicrobiana de espécies estafilocócicas de jabutis (Chelonoidis carbonaria) saudáveis no Brasil. Durante um período de 12 meses (fevereiro de 2019 a fevereiro de 2020), suabes cloacais de 66 jabutis saudáveis foram coletados no Centro de Triagem de Animais Silvestres em Belo Horizonte, Minas Gerais, Brasil. Os suabes foram plaqueados em ágar manitol salgado para isolamento de estafilococos e a identificação das espécies foi realizada usando MALDI-TOF MS. A susceptibilidade aos antimicrobianos foi investigada pelo método de difusão em disco, e a presença do gene mecA foi investigada por PCR para detectar resistência à meticilina. Dos animais testados, 72,7% foram positivos para o isolamento estafilocócico. Todos os isolados eram estafilococos coagulase-negativos (CoNS), sendo Staphylococcus sciuri (81,3%) e S. xylosus (12,5%) as espécies mais frequentemente isoladas. A maioria dos isolados (56%) foi resistente a pelo menos um antimicrobiano. Alta frequência de resistência foi observada para penicilina (35,5%) e tetraciclina (29,1%). Todas as estirpes foram sensíveis à cefoxitina, cloranfenicol, ciprofloxacina, eritromicina e gentamicina. Todos os isolados foram negativos para o gene mecA. O presente trabalho sugere que jabutis saudáveis são colonizados principalmente por CoNS, especialmente S. sciuri. Metade dos isolados foram resistentes a pelo menos um antimicrobiano, levantando questões sobre o possível papel desses animais como reservatórios de genes de resistência aos antimicrobianos.

Streptococcus spp. in equines - infection and antimicrobial susceptibility profiles

Background: Empirical antimicrobial prescribing is commonly used in equine veterinary. Therefore, professionals can obtain information about antimicrobial susceptibility profile of the bacterial strains based on veterinary literature. Considering equine infections, Streptococcus spp. are important pathogens that can cause serious damage in horses. Therefore, the aim of this study was to describe the antimicrobial susceptibility testing (AST) and infection profiles of Streptococcus spp. strains isolated from equines with infectious diseases subjected to microbiological analysis. Materials, Methods & Results: Veterinarians sent 13 samples and culture in Blood and MacConkey Agar were performed. After the incubation period, suspected colonies, which showed significative growth, were analyzed by Gram-staining, biochemical tests, and subjected to confirmatory identification in Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. In vitro AST analysis were performed by disc diffusion method, in accordance with the veterinarians' request. The antimicrobials tested in this study were: ceftiofur, gentamicin, ampicillin, enrofloxacin, amikacin, penicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, doxycycline, vancomycin and metronidazole. The samples included uterine exudate, hock fistula, osteosynthesis exudate, exudate from the guttural pouch, and were originated from animals located in different and distant geographical regions in the cities of Porto Alegre, Pelotas, and Bagé, Rio Grande do Sul, Brazil. Streptococcus dysgalactiae, Streptococcus equi and Streptococcus thoraltensis were the Streptococcus species identified in the samples. S. dysgalactiae was the mainly species found in the uterus samples, while S. thoraltensis, an unusual Streptococcus species, was identified as etiological agent of endometritis in 2 of the analyzed animals. On the other hand, S. equi was found in both the guttural pouch, representing the etiological agent of the strangle case, and in the osteosynthesis exudate, as infectious agent of post-osteosynthesis surgery. The majority of streptococci strains were susceptible to ceftiofur drug. Amikacin and ciprofloxacin, however, were the drugs for which the strains were mainly resistant according to the results. Discussion: The present study provided the AST and infection profile of Streptococcus species related to equine infectious diseases. S. dysgalactiae is considered an unusual bacterium isolated from horses that can be related to endometritis, S. equi is the causative agent of strangles, and S. thoraltensis is unusual in equines. Generally, the observed susceptibility to ceftiofur of the strains analyzed was in agreement with previous results reported in the literature. However, ceftiofur is a third-generation cephalosporin and is considered a critically important antibiotic for human health and its use in veterinary medicine should be cautious. Considering the resistance profile found, Streptococcus spp. can be intrinsically resistant to low drug concentrations of aminoglycosides. Moreover, the emergence and spread of fluoroquinolones resistance may also be due to the acquisition of resistance via horizontal gene transfer. Therefore, the present study described both infection and antimicrobial susceptibility patterns of Streptococcus strains related to equine infectious diseases. Considering the findings, the results found in this study might contribute to the decision-making by veterinarians to further equine treatments.

Antimicrobial resistance profile of bacteria isolated from canine and feline samples at the Preventive Veterinary Laboratory of the Federal University of Rio Grande do Sul (UFRGS) - Brazil

Background: Antimicrobial resistance (AMR) is a major global health threat. In small animals such as dogs and cats, antimicrobials are most commonly prescribed for skin and genitourinary diseases; therefore, the AMR of bacteria involved in these infections should be monitored. In addition, the results of antimicrobial susceptibility testing (AST) may be interpreted as a local epidemiological history of AMR. The Preventive Veterinary Medicine Laboratory (PVML) received clinical samples from dogs and cats for bacterial isolation and AST. Thus, this study aimed to assess the AMR of bacteria isolated from the samples of dogs and cats received at the Preventive Veterinary Medicine Laboratory (PVML). Materials, Methods & Results: Data from bacteriological examinations performed at the PVML of the Universidade Federal do Rio Grande do Sul (UFRGS) during 5 years were analyzed. Skin and ear canal samples were inoculated in 5% sheep blood agar, and urine samples were streaked on CHROMagar™ orientation. After incubation at 36±1°C for up to 72 h, identification and AST were performed according to routine protocols. Of 1,534 samples submitted to the PVML, 1,086 (70.8%) were collected from dogs and 29.2% from feline patients. Otological swabs (n = 533, 49.1%) were the most frequent samples from dogs, while cat urine samples (n = 384, 84.8%) predominated by far. Considering the canine samples, no bacterial growth (NBG) was observed in 443 (40.8%) samples, while only one colony type was noted in 516 (47.5%) samples. Gram-positive bacteria (n = 298) were more frequent than gram-negative bacteria (n = 77) in the skin. In urine samples, gram-negative bacteria (n = 94) were isolated more frequently than gram-positive bacteria (n = 47). In feline samples, a high number of NBG (n = 308, 68%) was observed. Gram-positive (n = 22) was predominant in comparison to gram-negative bacteria (n = 9) in cultures from the ear and skin swabs. Enterococcus spp. and Escherichia coli were the most frequently identified bacteria in urine samples. Among the Staphylococcus sp. strains of any origin, AMR frequency varied from 4.22% (amikacin) to 50.70% (sulfa/trimethoprim). Enterococcus spp. showed AMR frequencies from 12.5% (amoxicillin/clavulanic acid) to 62.06% (enrofloxacin). Among the gram-negative genera, E. coli presented AMR frequencies from 10.20% (gentamicin) to 60.0% (neomycin). The frequency of AMR was stable over time, and a profile of much higher resistance to fluoroquinolones in comparison to beta-lactams was observed. Discussion: The recurrence of skin and urinary infections implies the need for frequent treatment with antibiotics, which exerts selection pressure for resistance and multidrug resistance. In this study, the frequency of multidrug resistance was low, and the resistance to the tested antimicrobials showed high variation. However, a trend of high resistance to the fluoroquinolone group was observed in contrast to the low resistance to beta-lactams. This trend was consistent among the isolated bacteria, regardless of the type of sample or origin. The overprescription of fluoroquinolones in small animal practices has been widely documented in several countries. However, this class of antimicrobials, is highly prioritized for the treatment of infections in humans. Therefore, the selection of resistant strains has gained special emphasis, especially when considering the possibility of the transmission of resistant bacteria between pets and humans. In summary, the results of bacteriological tests conducted at the PVML-Universidade Federal do Rio Grande do Sul confirmed that ubiquitous bacteria predominate in clinical samples of dogs and cats. The high frequency of resistance to the fluoroquinolone group, while a predominance of susceptible strains in the first-choice drugs such as amoxicillin/clavulanic acid, may indicate excessive and empirical use of the second-choice drugs in clinical practice.

Mannheimia varigena as the etiologic agent of lameness and coronary band lesion in cattle / Mannheimia varigena como agente etiológico de claudicação e lesão na banda coronária em bovinos

Mannheimia varigena was identified as the etiologic agent of lameness and coronary band lesion in 30% of cattle in a farm located in Rio Grande do Sul, Brazil. Swab samples from the lesions were cultured in McConkey Agar and Blood Agar for microbiological identification. Culture growth was submitted to Gram staining and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) identification. Antimicrobial susceptibility test based on disc diffusion was performed for three antibiotics: ceftiofur, gentamicin and florfenicol. Furthermore, molecular characterization of 16S rDNA gene sequencing was performed and the data was used in a phylogenetic analysis. For that purpose, total DNA was extracted by thermo extraction directly from the bacterial colonies and the polymerase chain reaction (PCR) was performed. Gram-negative Mannheimia varigena strain LBV010/22 was identified as the causative of the lesions. The strain was susceptible to all antibiotics tested. The phylogenetic analysis demonstrated that the analyzed strain is closely related to M. varigena strains from pyelonephritis and respiratory tract. Overall, this is the first report of M. varigena as the causative agent of coronary band injury in bovine. Therefore, our findings show the importance of an accurate microbiological identification of infectious agent in lameness cases in order to prevent the occurrence and perform an appropriate treatment in the future.

Mannheimia varigena foi identificada como agente etiológico de claudicação e lesão de banda coronária em 30% dos bovinos de uma fazenda localizada no Rio Grande do Sul, Brasil. Amostras de swab das lesões foram cultivadas em Ágar McConkey e Ágar Sangue para identificação microbiológica. O crescimento da cultura foi submetido à coloração de Gram e identificação por Espectrometria de Massa de Ionização por Dessorção a Laser Assistida por Matriz (MALDI-TOF MS). O teste de suscetibilidade antimicrobiana baseado na difusão em disco foi realizado para três antibióticos: ceftiofur, gentamicina e florfenicol. Além disso, foi realizada a caracterização molecular do sequenciamento do gene 16S rDNA e o resultado utilizado para análise filogenética. Para tanto, o DNA total foi extraído por termoextração diretamente das colônias bacterianas e uma reação em cadeia da polimerase (PCR) foi realizada. Foi identificada como causadora das lesões a cepa gram-negativa de Mannheimia varigenaLBV010/22. Ela foi suscetível a todos os antibióticos testados. A análise filogenética demonstrou que a cepa analisada está intimamente relacionada às M. varigena presentes em pielonefrite e no trato respiratório. No geral, este é o primeiro relato de M. varigenacomo agente causador de lesão de banda coronária em bovinos. Portanto, nossos achados mostram a importância de uma identificação microbiológica precisa do agente infeccioso nos casos de claudicação, a fim de prevenir a ocorrência e realizar um tratamento adequado no futuro.

Ceftiofur efficacy in the intramammary extended treatment of staphylococcal subclinical mastitis in primiparous cows / Eficácia do ceftiofur no tratamento estendido intramamário da mastite subclínica por estafilococos em vacas primíparas

Extended therapy is an alternative approach to treat nonresponsive staphylococcal mastitis, although it has been used mainly in adult cows. This study investigated the efficacy of intramammary ceftiofur in the treatment of staphylococcal subclinical mastitis in primiparous cows. Sixty primiparous cows Holstein were divided into four groups (G1 = Group negative to staphylococci infection, G2 = Group positive to staphylococci infection untreated with intramammary ceftiofur, Group, G3 = Group treated with intramammary ceftiofur early lactation, G4 = Group treated with intramammary ceftiofur late lactation group) with milk samples collected at five moments (M0 = diagnosis of subclinical mastitis, M1 = 7 days after diagnosis of subclinical mastitis and early extended therapy, M2 = 14 after the diagnosis of subclinical mastitis, M3 = 21 days after diagnosis of mastitis) and M4 = 28 days after diagnosis of mastitis). In groups G3 and G4, which were treated with intramammary ceftiofur, the microbiological cure was evidenced by a reduction in SCC of 73.3% and 46.7%, respectively. Thus, in the treated groups (G3 + G4) and untreated (G2), cure rates were 60% and 26.7%, respectively (P <0.05). Forty-five strains of staphylococci were Motta, R. G. et al.1958Semina: Ciênc. Agrár. Londrina, v. 43, n. 5, p. 1957-1974, set./out. 2022isolated, with a predominance of S. aureus (51,1%) and S. intermedius (48,8%). The in vitro antimicrobial susceptibility pattern showed higher sensitivity indices of isolates for oxacillin (80%), ceftiofur (77.8%), cephalexin (77.8%), ciprofloxacin (66.7%), and gentamicin (60%). In contrast, cloxacillin (24.4%), penicillin (35.6%), and tetracycline (44.5%) were ineffective antimicrobials for staphylococci isolates. Among the milk samples taken when M0 and M1 (7 days after isolation), 13.3% were positive for the detection of the inhibiting substances (antimicrobials) in Delvotest™ and all negative in the Snap test™, whereas in the M2 (14 days after isolation), 55% were positive in Delvotest™ and 46.7% in the Snap test™. Twenty-one days after diagnosis (M3), 16.7% revealed positive results in Delvotest™ and 11.7% in the Snap test™. For M4 (28 days after isolation), 11.7% showed positive results in Delvotest™, and 8.3% revealed positive results in the Snap test™. There was a reduction in SCC among all cured animals. Significant results were identified for milk production in the M0, so G1 produced more milk than the other three groups, G2, G3, and G4. A statistical association was observed between the reduction in the volume of daily milk and production in animals with subclinical mastitis, denoting losses in milk production in primiparous bovines infected during lactation by staphylococci. Extended intramammary therapy with ceftiofur in bovine primiparous cows subclinically affected by staphylococcal mastitis is effective mainly in cases treated at the beginning of lactation, showing microbiological cure and reduction in SCC.(AU)

O estudo presente investigou a eficácia do ceftiofur intramamário no tratamento da mastite subclínica por estafilococos em primíparas bovinas. Foram utilizados 60 animais da raça holandesa, divididos em quadro grupos (G1 = Grupo negativo, G2 = Grupo positivo não tratado com ceftiofur intramamário, G3 = Grupo tratado com ceftiofur intramamário no início da lactação, G4 = Grupo tratado com ceftiofur intramamário no final da lactação), com amostras de leite coletadas em cinco momentos (M0 = diagnóstico da mastite subclínica, M1 = 7 dias após diagnóstico e início da terapia estendida, M2 = dia 14 após o diagnóstico da mastite subclínica, M3 = dia 21 após o diagnóstico da mastite, M4 = dia 28 após o diagnóstico da mastite). Nos grupos tratados com ceftiofur intramamário, foi evidenciada a cura microbiológica com redução na CCS em 73,3% no G3 e 46,7% no G4. Nos grupos tratados (G3+G4) e não tratado (G2), as taxas de cura foram, respectivamente, 60% e 26,7% (p<0,05). Foram isoladas 45 linhagens de estafilococos, com predomínio de S. aureus (51,1%) e S. intermedius (48,8%). O perfil de sensibilidade microbiana "in vitro" dos isolados apresentou maiores índices de sensibilidade para oxacilina (80%), ceftiofur (77,8%) e cefalexina (77,8%), ciprofloxacino (66,7%) e gentamicina (60%). Em contraste, cloxacilina (24,4%), penicilina (35,6%) e tetraciclina (44,5%) foram os antimicrobianos menos efetivos diante dos estafilococos isolados. Nas amostras de leite colhidas nos momentos M0 e M1, 13,3% foram positivas para o teste de detecção de substâncias inibidoras na prova de Delvotest™ e todas negativas no Snap test™. Já, no M2, 55% foram positivas no Delvotest™ e 46,7% no Snap test™. No M3, 16,7% positivas no Delvotest™ e no 11,7% no Snap test™. No M4, 11,7% positivas no Delvotest™ e 8,3% no Snaptest™, dois dias após o término do tratamento (M2). Foram identificados nos grupos G3 e G4 a presença de animais positivos em 96,7% para o Delvotest™ e 90% para o Snap test™. Ocorreu redução na CCS em todos os animais curados. Foram identificados resultados significativos para a produção de leite no MO, posto que o G1 produziu mais leite se comparado aos outros três grupos G2, G3 e G4. Foi observada associação estatística entre a redução no volume de leite diário e a produção nos animais com mastite subclínica, denotando prejuízos na produção de leite em primíparas bovinas infectadas na lactação por estafilococos. A terapia intramamária estendida com ceftiofur em primíparas com mastite estafilocócica é eficaz principalmente nos casos tratados no início da lactação, mostrando cura microbiológica e redução da CCS, indicando que esta abordagem terapêutica alternativa pode ser utilizada para o tratamento de novilhas.(AU)

Influence of antibiotics on bacterial load and sperm parameters during short-term preservation of collared peccary semen

Abstract Studies on semen and sperm cells are critical to develop assisted reproductive technologies for the conservation of the collared peccary. The objective of the study was to compare the effect of different antibiotics on the bacterial load and sperm quality during short-term storage of peccary semen. Fresh semen samples from 10 males were extended in Tris-egg yolk or Tris-Aloe vera supplemented with streptomycin-penicillin (SP; 1 mg/mL - 1000 IU/mL or 2 mg/mL - 2000 IU/mL) or gentamicin (30 µg/mL or 70 µg/mL) before storage at 5°C. Bacterial load and sperm motility, membrane integrity and function, mitochondrial activity, and morphology, were evaluated at different time points for 36 h. The SP and gentamicin treatments concentration inhibited (p < 0.05) bacterial growth for 36 h regardless of the extender. Compared to the other treatments, Tris-egg yolk plus 70 µg/mL gentamicin maintained the sperm parameters for longer, including total motility (41.9 ± 6.1%) at 24 h, and membrane integrity (58.3 ± 2.1%) at 36 h. In contrast, the highest SP concentration in both extenders impaired sperm membrane integrity at 36 h (p < 0.05). For the liquid storage of collared peccary semen, it therefore is recommended to use Tris extender supplemented with egg yolk and gentamicin (70 µg/mL).

Influence of antibiotics on bacterial load and sperm parameters during short-term preservation of collared peccary semen

Studies on semen and sperm cells are critical to develop assisted reproductive technologies for the conservation of the collared peccary. The objective of the study was to compare the effect of different antibiotics on the bacterial load and sperm quality during short-term storage of peccary semen. Fresh semen samples from 10 males were extended in Tris-egg yolk or Tris-Aloe vera supplemented with streptomycin-penicillin (SP; 1 mg/mL - 1000 IU/mL or 2 mg/mL - 2000 IU/mL) or gentamicin (30 µg/mL or 70 µg/mL) before storage at 5°C. Bacterial load and sperm motility, membrane integrity and function, mitochondrial activity, and morphology, were evaluated at different time points for 36 h. The SP and gentamicin treatments concentration inhibited (p < 0.05) bacterial growth for 36 h regardless of the extender. Compared to the other treatments, Tris-egg yolk plus 70 µg/mL gentamicin maintained the sperm parameters for longer, including total motility (41.9 ± 6.1%) at 24 h, and membrane integrity (58.3 ± 2.1%) at 36 h. In contrast, the highest SP concentration in both extenders impaired sperm membrane integrity at 36 h (p < 0.05). For the liquid storage of collared peccary semen, it therefore is recommended to use Tris extender supplemented with egg yolk and gentamicin (70 µg/mL).(AU)

Parâmetros morfofuncionais dos espermatozoides de catetos criopreservados com diferentes antimicrobianos / Morphofunctional parameters of collared peccary sperm frozen with different antimicrobials

The aim was to evaluate the effects of the addition of antimicrobials to the diluent for the cryopreservation of the semen of collectors, especially on the morphofunctional parameters. Ten ejaculates from adult males were obtained by electroejaculation. The samples were evaluated for volume, concentration, motility, morphology, membrane functionality, sperm viability, mitochondrial activity and binding capacity. Subsequently, they were cryopreserved in Tris with egg yolk (20%) and glycerol (3%) added or not (control) with gentamicin (70µg/mL), or with the penicillin (1000 IU/mL) + streptomycin (1mgE/mL). After one week, the samples were thawed and evaluated according to the fresh semen. As for the results, no significant differences were observed between the control treatment and those added with antimicrobials, emphasizing that these do not damage the sperm morphofunctional parameters during cryopreservation. In this sense, it is suggested that both gentamicin and the penicillin/streptomycin combination could be added to the extender for the cryopreservation of the collared peccary semen.

Impacto de antimicrobianos nos parâmetros cinéticos de espermatozoides criopreservados de catetos / Impact of antimicrobials on the kinetic parameters of collared peccary frozen sperm

The objective was to verify the impact of the addition of antimicrobials on the kinetic parameters of sperm in the cryopreserved semen of collared peccaries. Ejaculates from 10 adult male, obtained by electroejaculation, were used. The samples had their kinetic parameters evaluated by computer analysis (CASA). Subsequently, they were cryopreserved in Tris plus egg yolk (20%) and glycerol (3%), whether or not (control) added gentamicin (70µg/mL) or the combination penicillin (1000 IU/mL) and streptomycin (1mgE/mL) (P+E). After one week, the samples were thawed and evaluated similarly to fresh semen. In fresh semen, total motility of 95.3±0.8% and 72.1±3.5% progressive motility were observed. After thawing, there were no differences between treatments, except for the cross-beat frequency (BCF) parameter, which was negatively influenced by P+E, in relation to fresh semen (p <0.05). In conclusion, it is suggested the use of gentamicin as an antimicrobial for the cryopreservation of semen from peccaries.