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Abstract The development of bio-based products has increased in recent years, and species of the Bacillus genus have been widely used for product development due to their elevated production of antimicrobial molecules and resistance to extreme environmental conditions through endospore formation. In this context, the antifungal potential of Bacillus velezensis CMRP 4489 was investigated using in silico predictions of secondary metabolites in its genome and in vitro tests against the following phytopathogenic fungi: Sclerotinia sclerotiorum, Macrophomina phaseolina, and Botrytis cinerea. The in-silico predictions indicated that CMRP 4489 possesses several Biosynthetic Gene Clusters (BGCs) capable of producing molecules with antifungal properties and other non-identified BGCs. The in vitro assay results evidenced strong antifungal activity, inhibiting more than 60% of the tested fungi, and the isolate’s molecules were stable under diverse physicochemical conditions. The in vitro assay evidenced significant antifungal activity, deformation of the hyphal structure in SS, biofilm formation capacity, and swarming motility. In the colonization assay, we observed attachment, colonization, and net-shaped biofilm formation, with the strain transitioning from the seeds to nearby structures. Therefore, CMRP 4489 showed to be a potential biocontrol agent against various diseases with agronomic importance and can be used under adverse environmental conditions.

Over the last few decades, diseases have emerged as a major bottleneck in fish farming, especially with the emergence of several fish pathogens and increasing resistance to treatments [...]

Lately, bacterial drug resistance has become an important worldwide problem in one health, where bacteria have undergone mutation becoming increasingly resistant. The major problem of bacterial drug resistance is the difficulty with eliminating microorganisms from different wounds and infected patients, and the therapeutic option is most often ineffective as a result of the repeated and inappropriate use of antimicrobials. The objective of this work was to detect and identify enterobacteria, to evaluate their resistance profile and the production of extended-spectrum b-lactamases in draft horse isolates from the municipality of Umuarama, Parana, Brazil. A nasal, oral, and ear cavity swab was collected from 38 horses (used for animal traction) for isolation and bacterial identification, phenotypic antibiotic susceptibility testing, and the phenotypic test for the detection of extended-spectrum b-lactamasesproducing strains. In 12 swabs bacterial isolation was possible. Strains of Escherichia coli, Serratia rubidaea, Citrobacterdiversus, Kluyvera species, and Providenciaalcalifaciens were isolated. One hundred percent multidrug resistance was detected, and the antimicrobials that encountered the highest resistance were ertapenem (100%), cefotaxime (100%), cefoxitin (100%), ampicillin (100%), amoxicillin (100%), chloramphenicol (100%), and aztreonam (91.67%) and no extended-spectrum b-lactamases -producing strain was detected. The results of this work reveal the presence of strains of the Enterobacteriaceae family associated with high bacterial resistance in horses used for animal traction in the municipality of Umuarama, State of Parana, Brazil, and these results confirm that these horses can be considered reservoirs of multidrug-resistant microorganisms. This situation can be considered an important problem of one health.

In the present study, we evaluated the effects of administering Enterococcus faecium in food and/or water on the hematological and immunological parameters, intestinal microbiota, resistance to bacterial diseases (streptococcosis and francisellosis) and growth of Nile tilapia. Before the in vivo experiment, probiotic bacteria isolated from Nile tilapia were selected via inhibition tests. Sequencing, annotation, and assembly of the complete genome of the selected bacteria as well as other tests were performed using bioinformatics tools. Three treatments were implemented: G1 (probiotic feeding), G2 (probiotic in water), and G3 (probiotic in food and water); and a negative control (NC) was also employed. Treatment lasted 38 days, and each group consisted of fish and two repetitions. The fish were divided and infected with Streptococcus agalactiae S13 (serotype Ib) and Francisella orientalis. The G1 group had a higher average final weight gain than the G2, G3, and NC groups. Further, a significant increase in the number of thrombocytes was observed in the groups administered probiotics in the diet (G1 and G3). A statistical difference was observed in the mortality of fish infected with S. agalactiae in the NC compared to the treated groups. Cetobacterium was the 43 most abundant genus in the intestinal microbiota of all groups, including the NC group. E. faecium increased the immunity of fish administered the treatment and decreased the mortality caused by S. agalactiae. As an autochtone probiotic, E. faecium does not interfere with the local ecosystem and thus has a great probiotic potential for Nile tilapia in Brazil.

The genus Vibrio comprises an important group of ubiquitous bacteria of marine systems with a high infectious capacity for humans and fish, which can lead to death or cause economic losses in aquaculture. However, little is known about the evolutionary process that led to the adaptation and colonization of humans and also about the consequences of the uncontrollable use of antibiotics in aquaculture. Here, comparative genomics analysis and functional gene annotation showed that the species more related to humans presented a significantly higher amount of proteins associated with colonization processes, such as transcriptional factors, signal transduction mechanisms, and iron uptake. In comparison, those aquaculture-associated species possess a much higher amount of resistance-associated genes, as with those of the tetracycline class. Finally, through subtractive genomics, we propose seven new drug targets such as: UMP Kinase, required to catalyze the phosphorylation of UMP into UDP, essential for the survival of bacteria of this genus; and, new natural molecules, which have demonstrated high affinity for the active sites of these targets. These data also suggest that the species most adaptable to fish and humans have a distinct natural evolution and probably undergo changes due to anthropogenic action in aquaculture or indiscriminate/irregular use of antibiotics.

The main objective of this study was to evaluate Bacillus velezensis strain CMRP 4490 regarding its ability to inhibit soil-borne plant pathogens and to increase plant growth. The study included evaluation of in vitro antifungal control, sequencing the bacterial genome, mining genes responsible for the synthesis of secondary metabolites, root colonization ability, and greenhouse studies for the assessment of plant growth–promoting ability. The strain was obtained from soil samples in the north of Paraná in Brazil and was classified as a B. velezensis, which is considered a promising biological control agent. In vitro assay showed that B. velezensis CMRP 4490 presented antagonistic activity against Sclerotinia sclerotiorum, Macrophomina phaseolina, Botrytis cinerea, and Rhizoctonia solani with a mycelial growth inhibition of approximately 60%, without any significant difference among them. To well understand this strain and to validate its effect on growth-promoting rhizobacteria, it was decided to explore its genetic content through genome sequencing, in vitro, and greenhouse studies. The genome of CMRP 4490 was estimated at 3,996,396 bp with a GC content of 46.4% and presents 4,042 coding DNA sequences. Biosynthetic gene clusters related to the synthesis of molecules with antifungal activity were found in the genome. Genes linked to the regulation/formation of biofilms, motility, and important properties for rhizospheric colonization were also found in the genome. Application of CMRP 4490 as a coating film on soybean increased from 55.5 to 64% on germination rates when compared to the control; no differences were observed among treatments for the maize germination. The results indicated that B. velezensis CMRP 4490 could be a potential biocontrol agent with plant growth–promoting ability.

The cattle are considered hosts of the Hardjo serovar, causing economic damages due to the reproductive failures like abortions and infertility. The serovar Hardjo usually remains in the reproductive tract and also in the renal tubules where it is eliminated intermittently in the urine for months. Placental remnants, the aborted fetus and contaminated urine promote the permanence of this bacterium within the herd for years. Thus, the objective of this study was to monitor for prolonged period, cows naturally infected with Leptospira ssp. through microbiological culture, serological examination and DNA detection of the pathogen in the urine. The dairy herd was composed of 50 breeding cows with a history of abortion and infertility, without leptospirosis vaccine and located in the northern region of Paraná. Blood and urine samples were collected and laboratorial diagnosis were performed five times at intervals of four months. Blood samples were collected from the all 50 animals and the serum was submitted to the microscopic agglutination test (MAT) for the detection of anti-leptospira antibodies. Of the total cows, 20 showed antibody titres ? 1: 100 in MAT and urine samples were collected from only those animals with higher titers to perform nested-PCR (n-PCR) and bacterial isolation per culture. In addition, two urine samples from five animals with antibody titers < 1: 100 were collected in MAT for n-PCR. Serovar Hardjo was considered the most frequent during the serological monitoring of the animals evaluated. The n-PCR technique was able to detect leptospiral DNA in the urine of animals with MAT ? 1: 100 antibody titers and urine from animals whose titers were < 1: 100. Sequencing of the leptospiral amplicons shared 100% nucleotide sequence identity with the Leptospira interrogans species. Positive n-PCR results from animals with titers of < 1: 100 suggest that the cut-off of MAT is could be not sufficient to detect renal carriers, so it is also important to use n-PCR as an additional diagnostic tool for identify infected animals with Hardjo serovar and whose serology was negative.

ABSTRACT: The objective of this study was to evaluate and compare the bactericidal efficacy of2% chlorhexidine surfactant solution + 70% alcohol and 2% chlorhexidine surfactant solution + 0.5% chlorhexidine-alcohol, and standardize skin antisepsis for blood collection from donor dogs. One hundred and twenty skin swabsof the jugular regions of 20 dogs were evaluated. Swabs were distributed into six treatment(T) groups according to the disinfectant used and removal or retention of local hair: T1involved neither antisepsisnorhair removal; T2comprised 2% chlorhexidine + 0.5% chlorhexidine-alcoholwithout hair removal;T3 comprised 2% chlorhexidine + 70% alcohol without hair removal; T4comprised hair removal but no antisepsis;T5comprised 2% chlorhexidine + 0.5% chlorhexidine-alcohol withhair removal; and T6comprised 2% chlorhexidine + 70% alcohol with hair removal. Antiseptic agents were continuously applied in a single direction for a total of 3 min. Use of antiseptics was effective with or without hair removal, resulting in the absence of bacterial growth. Complete efficacy of the technique used in this study may have been due to the increased antiseptic application time. In conclusion,the antisepsis protocols tested in this study can be safely used for the collection of blood from dogs; although,removal of hair prior to antisepsis is still recommended.

The Leptospira serovar Hedjo belongs to the serogroup sejroe and this serovar is the most prevalent in bovine herds worldwide. The sejroe serogroup is the most frequently detected by serology in Brazilian cattle herds suggesting that it is due serovar Hardjo. In the molecular classification, this serovar has two genotypes: Hardjobovis and Hardjoprajitno. This serovar is as considered as fastidious pathogens, and their isolation is one of the bottlenecks in leptospirosis laboratories. In addition, its molecular characterization using genomic approaches is oftentimes not simple and time-consuming. This study describes a method for isolating the two genotypes of serovar Hardjo using culture medium formulations and suggests a get-at-able molecular characterization. Ten cows naturally infected which were seropositive were selected from small dairy farms, and their urine was collected for bacterial isolation. We evaluated three modifications of liquid Leptospira medium culture supplemented with sodium pyruvate, superoxide dismutase enzyme and fetal bovine serum, and the isolates were characterized by molecular techniques. After isolation and adaptation in standard culture medium, the strains were subcultured for 1 week in the three modified culture media for morphologic evaluation using electronic microscopy. Strains were molecularly identified by multilocus variable-number tandem-repeat analysis (MLVA), partial sequencing and phylogenic analyses of gene sec Y. Combining the liquid culture medium formulations allowed growth of the Leptospira serovar Hardjo in three tubes. Two isolates were identified as genotype Hardjobovis, and the other as genotype Hardjoprajitno. Morphologically, compared with control media, cells in the medium supplemented with the superoxide dismutase enzyme were more elongated and showed many cells in division. The cells in the medium supplemented with fetal bovine serum were fewer and lost their spirochete morphology. This indicated that the additional supplementation with fetal bovine serum assisted in the initial growth and maintenance of the viable leptospires and the superoxide dismutase enzyme allowed them to adapt to the medium. These culture strategies allowed for the isolation and convenient molecular characterization of two genotypes of serovar Hardjo, creating new insight into the seroepidemiology of leptospirosis and its specific genotypes. It also provides new information for the immunoprophylaxis of bovine leptospirosis.

The increasing expansion and the rising demand for food require a greater intensification in the production of Nile tilapia (Oreochromis niloticus), and genetic improvement programs are essential to achieve this goal. In managing these programs, new genetic material is introduced after several generations of selections to reduce inbreeding and enhance genetic diversity. In this sense, analyzing the zootechnical parameters of these introductions, with an emphasis on the use of nutritional additives, is of great importance for understanding their impact on breeding programs. Thus, the aim of this study was to evaluate the zootechnical parameters and hepatosomatic index of two genetic strains of Nile tilapia from the genetic improvement program fed with β-Glucan + Mannan oligosaccharide (βG+MOS). This study utilized a 2 × 2 factorial design containing two genetic groups and two treatments with βG+MOS (Control, 0.2%). The groups were formed from the 12th generation of the Tilamax genetic improvement program (TILAMAX) and by crossing Tilamax with an introduced test strain (CBTILAMAX). In total, 96 tilapias (31.1 ± 5.73 g) were distributed into 16 aquariums, with 6 fish per aquarium, 24 per group, and four repetitions. The experimental period lasted for 41 days, and the water parameters were measured daily and maintained under ideal conditions. The condition factor and hepatosomatic index were analyzed. Final weight, total length, and standard length were measured, and other zootechnical parameters were calculated based on these data. The condition factor showed that the fish in both groups exhibited adequate health and growth during the experiment, with no differences in strain or use of additives. Similarly, the hepatosomatic index did not differ between the groups, indicating that liver size was proportional to fish body size. Similarly, no significant differences (P>0.05) were observed for the other zootechnical parameters evaluated (initial and final total and standard lengths, final weight, total weight gain, condition factor using total and standard lengths, and specific growth rate). Based on these results, it is concluded that there were no differences between TILAMAX and CBTILAMAX related to performance and health under the effect of feeding with βG+MOS. This result is positive regarding the introduction of the test strain into the Tilamax genetic improvement program and establishes a starting point for further research that may provide greater clarity on its future effects.

Staphylococcus aureus is the main etiological agent of bovine mastitis worldwide and knowledge about its diversity and virulence factors is vital in controlling infections caused by this pathogen. The present study aimed to perform molecular characterization of a population of S. aureus (n=153 strains isolated from 1994 to 2014 in seven Brazilian states) by pulsed-field gel electrophoresis (PFGE) and evaluate their virulence profiles via polymerase chain reaction (PCR). PFGE identified 93 pulsotypes, with the isolates organized into 26 clusters and 20 unique pulsotypes. Predominant pulsotypes were observed, with variations according to the years of isolation and geographic origin of the isolates. Based on the PCR results for the genes encoding agglutination factors (ClfA and ClfB), binding proteins (fibronectin binding protein - FnBPA, elastin binding protein - Ebps, collagen binding protein - Cna), and toxins (Hla, Hlb and Luk-ED), 40 virulence profiles were detected. The frequency of virulence genes ranged from 58 to 98% (clfA:84.3%; clfB and hlb both 81%; hla:71.2%; fnBA:82.3%; Can:94.7%; ebps:58%; and lukED:98%). The existence of prevalent genotypes in some of the Brazilian states and the time period studied suggests that these genotypes are better adapted, with favorable characteristics in host/pathogen relationships. Genes of proven importance for S. aureus pathogenesis in bovine mastitis were widely distributed in genetically divergent populations, suggesting that most of these genes may be interesting candidates in the development of vaccines to control bovine mastitis in Brazil.

The Oscar (Astronotus ocellatus) is an important Amazonian species with high production potential in fish farms and commercial value for aquarists. However, limited information on the feeding characteristics, such as the frequency of daily feeding, is available for this species in captivity. Therefore, the objective of this study was to evaluate the effects of feeding frequency on growth, hematology, blood biochemical parameters, liver histology, and intestinal microbiota parameters of juvenile Oscars. Four treatments were tested, consisting of fish fed at a feeding rate of one (T1), two (T2), three (T3), or four (T4) times daily with 1% of their biomass. There were no significant differences (p > 0.05) between treatments for growth and hematological parameters. T1 showed lower serum albumin values than T2 and T4 (p < 0.05) and higher hepatosomatic index values than T4 (p < 0.05), which was corroborated by the hepatocyte nucleus count. Intestinal microbiota analysis revealed higher taxon richness in T4 than in T1 (p < 0.05). Lower feeding frequencies (T1) positively influenced the deposition of hepatic energy reserves and decreased albumin production, possibly because of lower peptide absorption in the same treatment. Based on these results, feeding frequencies of two (T2), three (T3) and four (T4) times daily were the most suitable for juveniles of this species.

This study evaluated the effects of supplementing the diet of juvenile Nile tilapia (Oreochromis niloticus), which weighs approximately 20 g, with a blend of monoglycerides (glycerides linked to a fatty acid molecule) for 20 days during a pre-experimental challenge via the intraperitoneal route (IP). Growth performance, immunological parameters, intestinal microbiota, tissue damage, and resistance against the pathogens Streptococcus agalactiae serotypes Ib and III and Francisella orientalis were evaluated. The experimental design included a negative control (NC), a product control (NPC), a positive control for each pathogen (PC), and three groups treated with different doses (0.15, 0.25, and 0.5%). After the challenge, mortality was significantly lower in the groups treated and challenged with S. agalactiae. The treated groups showed better weight gain and food conversion rates. Innate immunity parameters showed no differences between treatments, and there was no good stimulation of diversity in the intestinal microbiota. However, in treated groups, there was a reduction in opportunistic bacteria that could cause secondary infections and increased the presence of beneficial bacteria in the intestinal tract. In this way, it is possible to validate the beneficial effects of monoglycerides as a nutritional additive for tilapia farms against streptoccocosis.

Streptococcus agalactiae is a highly invasive bacterium that causes significant economic losses in tilapia aquaculture around the world. Furthermore, it is a pathogen for mammals, including humans, emphasizing its importance in One Health. The aim of this work was to evaluate the evolution of clinical and histopathological lesions caused by acute infection with two serotypes of S. agalactiae. For this, two strains isolated from natural outbreaks in Brazilian aquaculture farms (S13, serotype Ib; S73, serotype III) were used to challenge juvenile Nile tilapia (Oreochromis niloticus) intraperitoneally. Target organ samples were collected ten times, between 1 and 96 h post-infection, for microbiological and histopathological analyses. Anorexia was the first clinical sign and the first death occurred at 24 and 30 h in the fish infected with strains S13 and S73, respectively. Serotype Ib initially caused more pronounced lesions in the nervous system; however, serotype III lesions progressed more aggressively, reaching the same severity as those of serotype Ib. This trend was repeated in the mortality curve after 32 h. These results elucidated the important stages in the pathogenesis of S. agalactiae serotypes Ib and III in tilapia and suggest “tips and tricks” to improve the positive culture rate in the clinical diagnosis of infections in some tissues.

Peacock bass (syn.: tucunaré, Cichla ocellaris) and the pearl cichlids (syn.: acará, Geophagus brasiliensis) are South American cichlids that are highly valued in both the ornamental and sport fish industries. Since 2017, a number of outbreaks of infectious spleen and kidney necrosis virus (ISKNV) have been reported on Brazilian food and ornamental fish farms. In this study, we detected ISKNV in farmed peacock bass and pearl cichlid by PCR and sequence analysis of the partial major capsid protein (MCP) gene. Moribund peacock bass (n=10) and pearl cichlids (2) from a farm experiencing elevated mortality among juveniles and adults of these species, were submitted for bacteriological and molecular diagnostics. Spleen, liver, brain, and kidney tissues were cultured on 5% sheep blood agar and cystine heart agar with 1% glucose and bovine haemoglobin. No bacteria were isolated from the 12 fish. Additionally, DNA extracts from the liver and spleen of all animals were tested for ISKNV using two conventional polymerase chain reaction (cPCR) assays and two nested PCR (nPCR) assays. ISKNV DNA was amplified in all 12 fish DNA extracts tested, in two or more of the PCR assays. Selected ISKNV amplicons were confirmed by Sanger sequencing. The nucleotide sequences derived from these animals were identical to ISKNV strains previously detected in food (e.g., tilapia and carp) and ornamental species, including strains previously detected in fish from Brazil. To the authors’ knowledge, this is the first report of ISKNV in these native Brazilian cichlids.

Pig farming is an area of livestock that has been developing the most in Brazil and the world, with production increasing every year, generating jobs, and being of great importance for the Brazilian economy. In swine production, great health enables these animals to reach their highest point of development and antimicrobials are used, either prophylactically or through food, as growth promoters. Within swine culture, there is a concern regarding antibiotic-resistant bacteria; however, Staphylococcus spp. do not receive the necessary prominence in research, since the pathologies caused by them do not tend to cause great economic losses. Therefore, this review aimed to highlight the importance of bacterial resistance within breeding stock, its possible origins, the importance of Staphylococcus spp. within this topic, and its evolution in swine farming over the years. For this, studies were selected, with an emphasis on information such as country, number of samples, presence of Staphylococcus spp. resistant to methicillin, breeding phase, and phenotypic and molecular tests. In addition, publications were selected that show the importance of understanding the biological and resistance profiles of Staphylococcus spp. in swine herds in Brazil and around the world.

Goat milk presents interesting characteristics to consumers, but the production of this food faces several challenges that influence its quality. Process failures from milking to processing and commercialization can expose milk to contamination by pathogenic microorganisms, including the coagulase-positive Staphylococcus group. Although Staphylococcus aureus is the most relevant species in mastitis and food poisoning, other species in this group are also important, especially those related to food poisoning. This study aimed to identify the coagulase-positive Staphylococcus species in goat milk using biochemical tests, determine the prevalence of antimicrobial resistance using the disc diffusion test, and investigate enterotoxin-producing genes, sea, seb, sec, sed, see, seg, seh, and sei by multiplex PCR. A total of 384 coagulase-positive Staphylococcus strains obtained from raw goat milk collected from nine farms in Paraná during four seasons of the year were studied. Biochemical tests showed that 85.69% of the 384 strains were S. aureus, followed by 9.38% of S. intermedius, 4.17% of S. hyicus and 0.78% of S. delphini. For the antimicrobial resistance test, up to three strains of each species identified as coagulase-positive Staphylococci were chosen from each farm, with a total of 74 strains. Of these, 27% (20/74) showed resistance to at least one antibiotic, and among all penicillin-resistant strains, 45% (9/20) also presented resistance to tetracycline. In the search for staphylococcal enterotoxin-producing genes, 49 S. aureus strains were studied; among them, 40.81% (20/49) presented enterotoxin-producing genes. The highest prevalence was detected for the sec gene, which was present in 22.44% (11/49) of the strains, followed by the seh gene in 18.36% (9/49), and the see gene was detected in 4.08% (2/49). It was concluded that S. aureus was the predominant species in raw goat milk, with a high prevalence of penicillin- and tetracycline-resistant Staphylococci and a significant number of strains with staphylococcal enterotoxin-producing genes. The strains studied carried enterotoxin-producing genes involved in food poisoning in humans, indicating that goat milk is a possible source of contamination and, therefore, a potential danger to public health.

Research background. Despite the great properties of bacterial cellulose, its manufacture is still limited due to difficulties in large-scale production. These problems are mainly related to low production yields and high overall costs of the conventional culture media normally used. To surpass these problems, it is necessary to identify new cheap and sustainable carbon sources. Thus, this work aims to isolate and select a high cellulose-producing Komagataeibacter strain from vinegar industry, and study its potential for bacterial cellulose synthesis in an industrial soybean co-product, known as soybean molasses, used as fermentation medium. Experimental approach. One isolated strain was able to produce high amount of cellulose in the standard Hestrin-Schramm medium, so we tested its ability to produce this biopolymer in a soybean molasses medium. The characteristics and properties of the produced bacterial cellulose membranes were analyzed by thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, water-holding capacity and rehydration ratio. Genetic analysis of the selected strain served to determine its genus and species. Results and conclusions. An isolated strain that produced the highest amount of cellulose in Hestrin-Schramm medium (3.7 g/L) was genetically identified as Komagataeibacter intermedius V-05. This strain produced 10.0 g/L of cellulose in soybean molasses medium. Membranes from both substrates had similar chemical structure, crystallinity and thermal degradation. Soybean molasses proved to be a suitable alternative medium for biosynthesis of cellulose in comparison with the standard medium. In addition to providing higher production yield, the membranes showed great structural characteristics, similar to those obtained from standard medium. Novelty and scientific contribution. In this research, we have isolated and identified a Komagataeibacter strain which exhibits a high capacity for cellulose production in soybean molasses. The isolation and selection of strains with high capacity for microbial metabolite production is important for decreasing bioprocess costs. Furthermore, as there is a necessity today to find cheaper carbon sources to obtain microbial products at a lower cost, soybean molasses represents an interesting alternative medium to produce bacterial cellulose for its industrial application.

ABSTRACT The genusBryconcomprises fish species of significant socioeconomic and biological importance in Brazil. Despite that, the genetic knowledge about these species is scarce, especially regardingBrycon falcatus. Thus, the objective of this study was to evaluate the transferability of heterologous microsatellite primers inB. falcatus for the first time. Heterologous primers obtained from B. opalinus, B. hilarii, B. insignis, B. orbignyanus, B. amazonicus, Prochilodus argenteus, Prochilodus lineatus, Piaractus mesopotamicus, and Colossoma macropomum were evaluated. The primers that showed the best amplification patterns were applied to a sample of 22 individuals and the genetic parameters were calculated. Nine primers displayed satisfactory cross-amplification withB. falcatus: BoM5 (Brycon opalinus); Bh8, Bh13 and Bh16 (B. hilarii); Borg59 (B. orbignyanus); Bag22 (B. amazonicus); Par12 and Par80 (P. argenteus), and Cm1A8 (C. macropomum). The genetic parameters (number of alleles, effective alleles, allele richness, and expected and observed heterozygosity) and the polymorphic information content (PIC) confirmed the viability of these primers for population genetics analyses. Our study demonstrates the potential of transferability of microsatellite markers from related species and even different genera to B. falcatus, providing usefull tools for future population genetic studies in this species.

The reproductive efficiency of livestock is the basis for the success of livestock, dairy or beef, and having high reproductive performance depends on several factors within the production system and the presence of infectious diseases of the reproductive sphere in the herd is one of the factors that can compromise that efficiency. The aim of this study was to use molecular biology as a diagnostic tool for the detection of Leptospira spp. DNA in cows with reproductive disorders on a rural property in the municipality of Boca do Acre, Amazonas, Brazil. Vaginal mucus was collected from nine Nelore breeding cows with a history of abortion and birth of weak calves submitted to DNA extraction and nested-PCR technique for 16S gene amplification at the bacterial genus level. Of the nine samples analyzed, five (55.55%) amplified a product of 331bp. The municipality of Boca do Acre is bordered by Peru and Bolivia, and knowledge of the prevalence of the disease, serovars, and circulating Leptospira species is essential for the adoption of measures related to animal husbandry, as well as health education for ranchers and their workers to avoid a possible occupational infection since this disease is considered an important zoonosis. New molecular studies using primers that allow the identification of the Leptospira species and mainly pathogenic species should be conducted in this region in order to elucidate the possible species of this etiological agent and the possible reservoirs of the disease to begin the understanding of the epidemiology of this disease in cattle in this region of border.

Leptospirosis and toxoplasmosis are diseases that may affect man and domestic and wild animals. They also have wide geographical distributions and thus cause large public health issues. The objective of the current study was to conduct leptospirosis and toxoplasmosis seroepidemiology in horses used for animal traction in small rural propertiesof the municipality of Umuarama, in northwest region of the state of Paraná, Brazil. Blood samples were collected from 312 horses from 87 small farms. Microscopic agglutination tests (MAT) and indirect immunofluorescence (IIF) analysis were performed on sera to detect leptospirosis and toxoplasmosis, respectively. These were performed in conjunction with an epidemiological questionnaire. The MAT results included 180 (57.69%) samples that were considered reactive with titers between 100 and 12800 for one or more serovars. Thirty-three (10.57%) samples subjected to IIF were considered reactive, with titers ranging between 64 and 1024. From the analyzed variables, contact with wild animals (p= 0.012) and animal exchange between properties (p = 0.004) were associated with toxoplasma infection. The study revealed that horses in the northwestern region of Paraná were exposed to Leptospira spp. and Toxoplasma gondii, with an insignificant implication of the animals’ clinical condition; however, since it is possible for animals to transmit infection to other animals as well as humans via the intermittent shedding of leptospires through urine into the environment, it may be considered a problem of one health. As for the presence of T. gondii antibodies, these horses played the role of sentinel of the infection. Environmental sanitation measures, serological studies of herds, control of rodents and felids on properties, and the dissemination of information about these diseases are relevant for disease control at the study site.

Neonatal diarrhea is the main cause of early mortality and morbidity in farm animals and the source of huge, direct and indirect, economic husbandry losses. Escherichia coli, a common harmless commensal bacterium, can turn into a main diarrheal pathogen through antibiotic resistance and the expression of genetically acquired virulence factors. In this study, fecal samples obtained from eight farms of animals with clinical signs characteristic of diarrhea were subjected to culture and bacterial isolation. Colonies suggestive of E. coli were identified through morphological and biochemical characteristics. Susceptibility tests to the main veterinary antibacterial agents were conducted using agar disk diffusion followed by phenotypical detection of extended-spectrum ?-lactamase (ESBL). A total of 301 colonies were characterized as E. coli and, out of the 192 that were tested, 134 showed resistance to three or more classes of antimicrobial drugs and were classified as multidrug resistant (MDR), and 14 were ESBL positive. Bacterial DNA was extracted for multiplex PCR (mPCR) using primers to detect ten different genes of diarrheagenic E. coli (DEC). Thirty-six bacterial strains were positive in the mPCR assay, 28 of which were classified as enterotoxigenic E. coli (ETEC) and eight as enteropathogenic E. coli (EPEC). The high prevalence of MDR strains and the detection of ESBL denote the presence of resistance genes in animal husbandry; thus, it is important to isolate and characterize those pathogens and test antimicrobial sensitivity in vitro to avoid ineffective treatments and the spread of antimicrobial resistance, which are the major concerns of Public Health and One Health.

The formation of fish breeding stocks for fish farming or conservation programs is commonly carried out from the capture of fish in natural environments. Information on the geographic and genetic origin of these stocks is important to guide actions that allow correct management in captivity and, when lost, harm production and genetic conservation. In this sense, the objective of this study was to evaluate the genetic diversity and origin of two breeding stocks of matrinxã, Brycon amazonicus (INPA, Amazonas - INPA and Nova Motum, Mato Grosso - NM). A total of 68 caudal fin samples were collected, including 33 INPA samples and 35 NM samples. Twenty pairs of microsatellite primers were tested, but only seven primers showed satisfactory amplification, amplifying 41 alleles ranging from 187-318 bp. The polymorphic information content ranged from 0.135 (Borg25) to 0.782 (Bh6). Exclusive alleles were observed for both populations (INPA: 04 and NM: 18). Allelic richness results revealed that there was increased loss of genetic variation in NM, indicating a lower evolutionary potential of this stock. The average values of the observed heterozygosity corroborated this statement; however, there were high values for INPA (0.545) and NM (0.475), signifying an adequate genetic variability. An imbalance was found in the Hardy-Weinberg equilibrium at the Borg59 locus in INPA (P < 0.05), possibly due to the effect of null alleles, but was attributed to a founder effect. For NM, an imbalance in the Hardy-Weinberg equilibrium was observed at loci BoM13 and Bh6, which together with the results of the mean inbreeding coefficient values demonstrated the presence of genetic drift. The analysis of molecular variance showed greater variation within populations than between them, and was confirmed by the genetic differentiation value (0.086 - moderate genetic differentiation) and by the distance and genetic identity values (0.273 and 0.761, respectively). Bayesian analysis designated a value of K = 2, with the presence of structuring for NM and INPA; however, with correlated allelic frequencies, confirming a common origin. This origin was corroborated by the presence of gene flow through the number of migrants (5.691). Based on these results, there was a moderate genetic variability for INPA and NM and their common origin was confirmed. Recommendations are also included to minimize the probability of inbreeding processes or genetic drift in the studied stocks.

The Amazonian fish Tambaqui (Colossoma macropomum) is the most common native species in Brazil. This species has the highest production rate in the Northern region, especially in the State of Rondônia. The genetic evaluation of Tambaqui is an extremely important to increase productivity in fish farms or improve the adaptability in restocking natural populations. The objective of this study was to evaluate the genetic diversity of three Tambaqui broodstocks in Rondônia, Brazil. Six microsatellite markers were used to analyze a total of 89 breeders collected from three fish farms located in Ji-Paraná (JP), Ouro Preto do Oeste (OP) and Presidente Médici (PM). A total of 37 alleles between 140 and 310 bp were found, including the presence of exclusive and low frequency alleles in the three broodstocks. The average values of observed heterozygosity ranged from 0.404 (PM) to 0.499 (JP). The FIS coefficient values were positive for the three broodstocks, demonstrating a deficit of heterozygotes. The Molecular Variance Analysis (AMOVA) showed greater variation within the stocks than between them. The genetic differentiation was moderate and significant between the stocks, with higher differentiation between JP x PM and lower between OP x PM. The Bayesian analysis designated an optimal value of K = 3 groupings. Although there is moderate genetic diversity between broodstocks, the high FIS indicates a possible decline of diversity in the next generations, and therefore, the incorporation of new breeders is suggested to increase the genetic diversity in the three stocks.

The Amazonian Jundiá (Leiarius marmoratus) (Siluliformes: Pimelodidae) is a species of catfish with social and economic importance in some South American countries such as Brazil and Colombia. Genetic evaluation of this species is limited due to the lack of specific molecular markers, hindering studies on genetic diversity and structure in animals under captive conditions or in natural populations. The objective of the present study was to evaluate the transferability of heterologous microsatellite markers in Leiarius marmoratus. Thirty-two heterologous primers were tested in L. marmoratus. The primers that presented the best standards were applied to 20 specimens, and the number of alleles (Na), number of effective alleles (Ne), gene diversity per Locus (GdL) and percentage of amplification failure (Md) were calculated. Eleven primers demonstrated satisfactory transferability patterns, all from the fish of the Pimelodidae family, of which, seven were monomorphic and four polymorphic. The eleven markers presented low percentage of Md (mean was 5.9% samples per locus). Na varied from one to two alleles per locus, revealing low polymorphism in the evaluated samples. The mean Ne and GdL numbers were 1.77 and 0.32, respectively. The transferability of the heterologous microsatellite loci in L. marmoratus was shown to be possible. However, further tests are needed to apply these markers in population genetic studies.

Streptococcus agalactiae is an invasive multi-host pathogen that causes invasive diseases mainly in newborns, elderly, and individuals with underlying health complications. In fish, S. agalactiae causes streptococcosis, which is characterized by septicemia and neurological signs, and leads to great economic losses to the fish farming industry worldwide. These bacteria can be classified into different serotypes based on capsular antigens, and into different sequence types (ST) based on multilocus sequence typing (MLST). In 2015, serotype III ST283 was identified to be associated with a foodborne invasive disease in non-pregnant immunocompetent humans in Singapore, and the infection was related to raw fish consumption. In addition, a serotype III strain isolated from tilapia in Brazil has been reported to be resistant to five antibiotic classes. This specific serotype can serve as a reservoir of resistance genes and pose a serious threat to public health. Thus, new approaches for the control and treatment of S. agalactiae infections are needed. In the present study, 24 S. agalactiae serotype III complete genomes, isolated from human and fish hosts, were compared. The core genome was identified, and, using bioinformatics tools and subtractive criteria, five proteins were identified as potential drug targets. Furthermore, 5,008 drug-like natural compounds were virtually screened against the identified targets. The ligands with the best binding properties are suggested for further in vitro and in vivo analysis.

In the present study, the effects of β-glucan administration in water on growth performance and blood status (hematological indexes, immunological and biochemical parameters) were evaluated in Nile tilapia fingerlings (Oreochromis niloticus) under hypoxia-induced stress. In parallel, effect of this prebiotic (beta-glucan) was evaluated on gut microbiota diversity (16S rRNA gene) under normal oxygenation condition. Three treatments were implemented according to beta-glucan water supplementation: 0 (control), 0.1 and 0.3 mg L−1. Blood was collected before hypoxic challenge (BHC) and 9 h after hypoxic challenge (AHC). No significant differences were observed according to growh performance parameters. A significant increase in erythrocyte number and decrease in mean corpuscular volume (P

The aim of this study was to investigate the antibodies and DNA of Leptospira spp. isolated from infected cattle in a small rural dairy farm in a border region between Brazil and Paraguay. Blood and urine samples were collected from 50 Holstein cows aged between 1 and 15 years. The diagnostic tests performed were microscopic serum agglutination for antibody detection and polymerase chain reaction for Leptospira spp. detection. Out of the samples analyzed, 48% were MAT positive with titers ranging from 100 to 400, and the most prevalent antibody was to the serovar Hardjo. One serum sample was amplified to 549 bp for the sec y gene, and sequencing identified it as L. interrogans. This is the first report from northwestern Paraná (PR) State of L. interrogans identification in naturally infected milk cattle. Thus, based on these results, to enhance production efficiency, new serological and molecular studies on dairy cattle from border regions are required to characterize the epidemiology of possible genotypes and their consequences in affected herds.

The capybara (Hydrochaeris hydrochaeris L. 1766) is the largest existing rodent in the world. This animal species, being synanthropic, may serve as a transmitter of different diseases and parasitic infections in animals and humans as well. Leptospirosis is a cosmopolitan infectious disease with a high prevalence in tropical and subtropical regions that can affect humans and other domestic and wild animals. Due to the absence of regional data and the importance of this animal species in transmitting diseases to animals and humans, the aim of this study was to analyze DNA and anti-Leptospira spp. antibodies in free-living capybaras (Hydrochaeris hydrochaeris) from a university campus in the city of Araras in São Paulo, Brazil. A total of 31 capybaras (Hydrochaeris hydrochaeris) were captured for collecting their blood samples. The collected sera were analyzed using the microscopic agglutination test (MAT). For the detection of Leptospira spp. DNA, the serum samples were used to extract genomic DNA for the nested-PCR analysis. Out of the 31 serum samples, 29 (93.55%) were reactive for MAT, with titers ranging from 25 to 400. The antibody could be identified against the most probable serovar in 26 (89.65%) samples, namely: Grippotyphosa (69.23%), Autumnalis (26.92%), and Bratislava (3.85%). Presence of Leptospira via nested-PCR was found only in 3.22% of serum samples. This study revealed the presence of DNA and anti-Leptospira spp. antibodies in free-living capybara. Characterization of these animals as possible carriers and disseminators of the etiological agent in the environment is necessary for identification of infection in other animals and campus visitors.

Nutritional improvements in intensive aquaculture production systems is necessary for the reduction of stress, maximum utilization of nutritional components, and expression of the genetic potential of fish. The objective of this study was to evaluate the hemato-immunological, and histological parameters and gut microbiota of Nile tilapia fed with the microalga Schizochytrium sp. Males of Nile tilapia were distributed among eight net cages (6 m3), and fed for 105 days with two diets: control (CON), without Schizochytrium sp., and supplemented (SUP), with 1.2% Schizochytrium sp. in the diet. The final weight, mortality, hematocrit, total erythrocyte count (RBC), hemoglobin, hematimetric indices, white blood cell count (WBC), total protein, and serum lysozyme were measured. Alterations in intestinal morphology were evaluated. The gut microbiota was evaluated with next-generation sequencing. No significant differences (p>0.05) were found in the final weight and mortality between diets. Regarding the hematological parameters, a difference (p0.05) in total protein and serum lysozyme concentrations or in WBCs between diets, except for lymphocytes, which presented lower values (p0.05) in the intestinal morphology between diets. Metagenomic data indicated greater richness (represented by the Chao index) and a higher abundance of the bacterial phylum Firmicutes in the gut microbiota of the tilapia fed with the SUP diet, demonstrating that the digestion and use of the components of the microalga could influence the microbial community. The results indicated that the microalga had modulatory effects on blood cells and the intestinal microbiota, without affecting the structure and integrity of the intestinal villi.

The functionality of nutraceutical foods is attributed to their bioactive compounds. These compounds are widely produced by plants, such as phenolic compounds, which have antioxidant activity and/or antimicrobial activity, acting against damage to macromolecules such as lipids, proteins, and nucleic acids. Secondary plant metabolites, including classes such as phenolic compounds, alkaloids, and terpenoids, have a wide variety of biological activities with medicinal potential. These secondary metabolites are considered bioactive compounds. The Zingiberaceae family received special attention for their large bioactive compound production. Such compounds are useful in foods as herbs, spices, flavorings, and seasonings and in the pharmaceutical and cosmetic industries as antioxidants and antimicrobials. Gingers are recognized as safe by the American Food and Drug Administration (FDA), resulting in no side effects when consumed in moderate amounts. Recent studies show that, in addition to rhizomes, the leaves and flowers of some ginger species have antioxidant activity and consequent medicinal potential. Studies have demonstrated that in vitro and in vivo research is needed to evaluate the efficacy of ginger extracts and understand their role in the modulation of biological and molecular pathways, thus enabling the development of new therapeutic strategies. Thereby, the present work aims to provide a bibliographic review on the antimicrobial activity of Zingiber officinale Roscoe and Alpinia purpurata (Vieill.) K. Schum. (Zingiberaceae), popularly known as ginger and red ginger respectively, and their potential use in the One Health initiative.

Populations of nonhuman primates are often considered to be a link in the chain of emerging infectious diseases, as they are reservoirs for different zoonotic pathogens. The objective of this study was to identify the presence of bacteria from the family Enterobacteriaceae in free-living nonhuman primates. The research was carried out in an urban park located in a city in the northern region of the State of Paraná, Brazil. The animals were captured in Tomahawk-type traps and chemically restrained, being oral and rectal samples collected with sterile swabs. For bacterial isolation, the samples were seeded on MacConkey agar plates and grown under anaerobic conditions. The subsequent identification was conducted using a commercial biochemical kit. Sixteen primates identified as black-capuchin-monkeys (Sapajus nigritus) were captured. Seven different enterobacterial species were identified from the oral cavity swabs: six Escherichia coli (42.9%), three Kluyvera species (21.40%), one Serratia rubidaea (7.14%), one Enterobacter aerogenes (7.14%), one Enterobacter cloacae (7.14%), one Hafnia alvei (7.14%), and one Erwinia herbicola (7.14%). Seven different species were identified from the rectal swabs: six Escherichia coli (40%), three Kluyvera species (20%), two Enterobacter aerogenes (13.32%), one Erwinia herbicola (6.67%), one Serratia rubidaea (6.67%), one Pragia fontium (6.67%), and one Edwardsiella tarda (6.67%). The results indicate that the isolated bacteria belong mainly to the human microbiota and had crossed the interspecific barrier, contaminating the nonhuman primates.

Leptospirosis is an important socioeconomic disease in humans, as well as in domestic and wild animals, being caused by Leptospira spp. Bovine animals are considered reservoirs of this disease, because they intermittently disseminate the bacteria into the environment through their urine. In this way, the cattle an important source of Leptospira infection. The objective of this study was to detect Leptospira spp. antibodies and DNA in bovine females from two refrigerated slaughterhouses in the microregion of Umuarama, Paraná, Brazil. In particular, blood and urine samples from 52 crossbred bovine females older than 36 months from the two slaughterhouses were used. The microscopic agglutination test (MAT) was used to detect leptospiral antibodies, and the polymerase chain reaction (PCR) and subsequent sequencing were used to detect Leptospira DNA. The MAT yielded 22 (42.3%) serum samples considered reagent, while the nested PCR test resulted in one amplified sample (1.9%) of 289 bp. This single sample was then amplified again using primers for the SecY gene (549 bp). Sequencing of this gene characterized the bacteria as L. borgpetersenii that were similar to the serovar Hardjo of the genotype Hardjobovis. This is the first molecular confirmation of Hardjobovis-like L. borgpetersenii in the urine of crossbred bovine females older than 36 months from slaughterhouses in the microregion of Umuarama. This study’s results show that it is important to combine serological and molecular diagnosis in the detection of Leptospira spp. Therefore, both methods were used to improve our understanding of the epidemiology of this disease in bovine animals from the microregion of Umuarama. In addition, the analysis informed the subsequent adoption of preventive measures and educational One Health actions to prevent economic losses related to the herd, as well as social losses related to workers and the environment.

Mastitis is one of the most common and costly infectious diseases in dairy cattle worldwide. This is a multifactorial illness caused by different microorganisms, including virus, yeasts, algae, parasites, and several species of bacteria. Among these bacteria, Streptococcus uberis is an important environmental pathogen that is responsible for a large range of clinical and subclinical mammary infections, especially in intensively managed herds. Despite the increasing importance of this pathogen in the etiology of bovine mastitis, data on its virulence and diversity in Brazilian dairy herds are scarce. The aims of the present study were to investigate the virulence characteristics of S. uberis isolated from bovine mastitis and to assess the molecular epidemiology of the Brazilian isolates using pulsed-field gel electrophoresis (PFGE). In this work, 46 strains of S. uberis isolated from bovine mastitis from 26 Brazilian dairy herds were evaluated regarding their genetic diversity by PFGE using with the SmaI enzyme. Additionally, the presence of the virulence genes skc and pauA, which encode plasminogen activators, and the gene sua, which encodes an adhesion molecule in mammary epithelial cells, were assessed by PCR. Our results showed a high genetic diversity in the population, displaying many different patterns in the PFGE analysis. A high proportion of strains was positive for virulence genes in the sampled population (sua [100%], pauA [91%], and skc [91%]). The high frequency of skc, pauA, and sua genes among the studied strains suggests the importance of these virulence factors, possibly helping S. uberis in the colonization of the bovine mammary gland. Surveys of the genetic and molecular characteristics of this pathogen can improve our knowledge of bacterial activity and identify molecules that have roles in the establishment of the infection. This might help in the development of more effective measures to control and prevent bovine mastitis.

The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified 12 upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and we suggesting that may involve in the biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

Evaluation of a simplified key for the identification of coagulase-positive Staphylococcus isolated from bovine mastitis. Three hundred fourty four strains of coagulasepositive Staphylococcus (CPS), isolated from mastitis cases, underwent phenotypic and genotypictests to evaluate the efficiency of a simplified key, based on phenotypic tests for the discrimination of these microorganisms. The tests consisted of amplification of the femA gene and hemolysis in blood agar, production of acetoin and fermentation of maltose, mannitol and trehalose. Strains that showed negative results in the amplification test of the femA gene or that were not identified as Staphylococcus aureus (S. aureus) by phenotypic tests were tested with the APISTAPH kit (Biomériux-France), for precise identification of species. Phenotypic tests revealed 338 strains (98.25%) as S. aureus, three strains (0.86%) as Staphylococcus hyicus, and threemicroorganisms (0.86%) as Staphylococcus intermedius. PCR demonstrated that 338 (98.25%) strains belonged to the S. aureus species, confirming the results for 336 strains from 338 identified, through a simplified phenotypic key. A high rate of correlation (98.83%) was verifeid between the results of genotypic and phenotypic tests for the identification of S. aureus, demonstrating the applicability of the proposed key, for the discrimination of this microorganism in CPS isolated from bovine mastitis.Visando testar a eficiência de uma chave simplificada baseada em testes fenotípicos para a discriminação de Staphylocococcus coagulasepositivos (SCP) isolados de infecções intramamárias de bovinos, 344 amostras destes microrganismos foram submetidas a testes fenotípicos e genotípicos. Estes consistiram na amplificação do gene femA, na observação de hemólise em ágar sangue, produção de acetoína efermentação de maltose, manitol e trealose. Amostras que apresentaram resultado negativo na amplificação do gene femA ou que foram identificadas com não Staphylococcus aureus (S. aureus) por meio dos testes fenotípicos foram submetidas ao kit APISTAPH (Biomériux-França) para identificação mais precisa. Os testes fenotípicos utilizados na chave simplificada permitiram identificar 338 amostras (98,25%) como S. aureus, três amostras (0,86%) como Staphylococcus hyicus e três (0,86%) como Staphylococcus intermedius. Por meio da reação em cadeia da polimerase (PCR) 338 (98,25%) amostras foram identificadas como S. aureus, ratificando os resultados para 336 das338 amostras identificadas por meio da chave fenotípica simplificada. Observou-se elevada concordância (98,83%) entre os resultados dos testes genotípicos e fenotípicos para a identificação de S. aureus, demonstrando a aplicabilidade da chave de identificação proposta para a discriminação deste microrganismo entre SCP isolados de casos de mastite bovina.

O objetivo deste trabalho foi estudar a freqüência de infecções intramamárias ocasionadas por leveduras a partir de amostras de leite (n=1710) coletadas em 40 rebanhos leiteiros do Estado de Minas Gerais. Cinqüenta e seis estirpes de leveduras do gênero Candida e uma linhagem de Trichosporon loubieri foram isoladas. Candida albicans foi a espécie dominante (28,1% das cepas), seguida por Candida parapsilosis (19,3%), Candida catenulata (14,0%), Candida glabrata (14,0%) e Candida tropicalis (8,8%). Infecções mistas foram detectadas em 29,8% das vacas levedura-positivas. Amostras positivas para leveduras foram predominantemente obtidas (84%) de vacas com mastite subclínica. A baixa taxa de isolamento de leveduras sugere que estes microrganismos não são relevantes para mastite bovina na região estudada.The objective of this study was to report the frequency of intramammary infections by yeasts, in Minas Gerais State, from milk samples (n = 1710) collected in 40 dairy herds. Fifty six yeast strains of the genus Candida and one strain of Trichosporon loubieri were isolated. Candida albicans was the dominant species (28.1% of the strains), followed by Candida parapsilosis (19.3%), Candida catenulata (14.0%), Candida glabrata (14.0%), Candida tropicalis (8.8%). Mixed infections were detected in 29.8% of yeast-positive cows. The yeast infection was more frequent (84%) in cows with subclinical mastitis. The low rate of isolation of yeasts suggests that these microorganisms are not relevant to bovine mastitis in the studied region.

O objetivo deste estudo foi descrever um surto de mastite bovina causada por leveduras em um rebanho leiteiro localizado no Estado de Minas Gerais, Brasil. Análises microbiológicas de amostras de leite (106) dos quartos mamários infectados de vacas em lactação demonstraram que Corynebacterium bovis (43,48%) e leveduras do gênero Candida (29,35%) foram os principais agentes isolados no rebanho. C. albicans (33,34%), C. catenulata (22,23%) e C. glabrata (18,52%) foram as espécies mais comumente isoladas. A elevada prevalência da mastite por leveduras foi associada à falta de treinamento dos ordenhadores, ao tratamento intramamário repetitivo e a falhas na higienização de tetas antes da infusão intramamária. Medidas adequadas de manejo, tratamento específico com drogas antifúngicas e descarte de animais cronicamente infectados foram eficazes para o controle do surto.

Evaluation of a simplified key for the identification of coagulase-positive Staphylococcus isolated from bovine mastitis. Three hundred fourty four strains of coagulase-positive Staphylococcus (CPS), isolated from mastitis cases, underwent phenotypic and genotypic tests to evaluate the efficiency of a simplified key, based on phenotypic tests for the discrimination of these microorganisms. The tests consisted of amplification of the femA gene and hemolysis in blood agar, production of acetoin and fermentation of maltose, mannitol and trehalose. Strains that showed negative results in the amplification test of the femA gene or that were not identified as Staphylococcus aureus (S. aureus) by phenotypic tests were tested with the APISTAPH kit (Biomériux-France), for precise identification of species. Phenotypic tests revealed 338 strains (98.25%) as S. aureus, three strains (0.86%) as Staphylococcus hyicus, and three microorganisms (0.86%) as Staphylococcus intermedius. PCR demonstrated that 338 (98.25%) strains belonged to the S. aureus species, confirming the results for 336 strains from 338 identified, through a simplified phenotypic key. A high rate of correlation (98.83%) was verifeid between the results of genotypic and phenotypic tests for the identification of S. aureus, demonstrating the applicability of the proposed key, for the discrimination of this microorganism in CPS isolated from bovine mastitis.

Staphylococcus aureus (S. aureus) destaca-se como um dos agentes etiológicos mais frequentes da mastite bovina, que causa os maiores prejuízos econômicos à pecuária leiteira brasileira. Visando avaliar o perfil de sensibilidade deste agente aos antimicrobianos, 352 isolados provenientes de 35 rebanhos leiteiros localizados em Minas Gerais foram submetidos a testes de antibiograma, utilizando-se a técnica de difusão em disco. Nitrofurantoína, bem como as associações de neomicina, bacitracina e tetraciclina (NBT) e penicilina, nafcilina e dihidroestreptomicina (PND), apresentaram 100% de eficiência in vitro. Foram verificados baixos índices de resistência no grupo das cefalosporinas, com valores de 0, 0,28 e 0,40% para cefquimona, cefalotina e ceftiofur, respectivamente. Entre os aminoglicosídeos, observou-se 1,69% de resistência para gentamicina e 3,35% para a neomicina. O maior índice de resistência foi observado para polimixina B (82%), seguido pelos betalactâmicos, ampicilina e penicilina, com índices de resistência de 80,92 e 80,45%, respectivamente. Níveis intermediários de resistência foram observados para tetraciclina, lincomicina, cefoperazona e sulfazotrim. Entre os isolados testados, 65 (18,15%), oriundos de 24 dentre os 35 rebanhos estudados, apresentaram multirresistência (índice MAR ≥ 0,2). Os resultados apontaram grande variação nos perfis de resistência aos antimicrobianos, assim como a ocorrência de múltipla resistência entre algumas cepas estudadas, salientando a necessidade de testes de antibiograma para a escolha dos antimicrobianos mais adequados para o tratamento ou prevenção de mastite causada por S. aureus.