Phenotypic and genotypic characterizations of bacteria isolated from the respiratory microbiota of healthy turkeys with potential for probiotic composition

Desirable characteristics of Staphylococcus sp., Streptococcus sp., Bacillus sp., Klebsiella sp., Escherichia coli, and Pseudomonas pseudoalcaligenes isolated from the trachea of healthy turkeys were evaluated as probiotic candidates in the search for new alternatives to solve antimicrobial resistance issues in poultry. In current study phenotypic and genotypic capacity to produce bacteriocin-like substances, efficacy to inhibit the growth of avian pathogens, susceptibility to antimicrobials of bacteria isolated from the respiratory microbiota of healthy turkeys, and the presence of virulence-associated genes (VAGs) predictors of Avian Pathogenic Escherichia coli (APEC) were evaluated. Nine E. coli and one Klebsiella sp. strains produced bacteriocin-like substances, and all harbored the cvaA gene. Some strains also showed antagonistic activity against APEC. Multidrug-resistant profile was found in 54% of the strains. Six strains of bacteriocin-like substances producing E. coli also harbored 3-5 VAGs. The study showed that two bacterial genuses (Klebsiella sp. and E. coli) present desirable probiotic characteristics. Our results identified strains with potential for poultry's respiratory probiotic.

Kefir fermented milk as starter culture in Minas Frescal cheese production

The present work aimed to produce Minas Frescal cheese with the replacement of the commercial lactic culture by fermented kefir milk with kefir (FKM) and verify some of its physicochemical characteristics, aiming mainly at the development of a new commercial probiotic dairy product with low production cost as compared to the use of commercial probiotic cultures. Kefir grains were added to whole UHT milk and fermented at 22ºC/24 hours in an incubator, after fermentation the grains were separated and the FKM was used in the manufacture of cheeses with the addition of 1, 3 or 5% of the total volume of milk. They were analysed the concentrations of fat and protein in the milk used in cheese manufacturing; the acidity of FKM, milk, FKM-added milk, whey and cheeses; in those ones their total solids (TS), fat and fat in the total solids (FTS) and manufacturing yields were evaluated. The results obtained indicated that it was possible to produce Minas cheeses using KFM in all of the tested concentrations because the results for all treatments were close to those found in the literature with the use of commercial lactic cultures and among the treatments only the acidity had significant differences, however more studies should be carried out mainly aiming at the standardization of kefir cultures for the industrial process of manufacturing these cheeses.  

Pet dogs as reservoir of oxacillin and vancomycin-resistant Staphylococcus spp

The aim of this study was to verify the bacterial resistance profile and detect the presence of mecA gene in Staphylococcus spp. isolated from the nasal microbiota of domiciled dogs. For this purpose 100 nasal swabs from 100 domiciled dogs were collected from the central area of the city of Umuarama (PR), along with a questionnaire answered by their owners. After the isolation all Staphylococcus spp. isolates were submitted to the diffusion disc test by the Kirby-Bauer method, and only oxacillin-resistant samples were submitted to the PCR technique to search for the mecA gene and the results were then submitted to statistical analysis to verify possible risk variables. The 100 Staphylococcus spp. and coagulase negative, among which 41 isolates were resistant to oxacillin, no samples were positive for the mecA gene presence, however, 12 resistant to vancomycin were found. It can be concluded that the domiciled dogs are carriers of Staphylococcus spp. multiresistant, being these a possible source of human contamination.

Respiratory microbiota of healthy broilers can act as reservoirs for multidrug-resistant Escherichia coli

This study aimed at evaluate the presence and to study characteristics of Escherichia coli in the respiratory system microbiota of healthy broilers. Trachea, air sacs, and lungs of 20 broilers were analyzed at 21 days of age, reared in experimental conditions, without receiving antimicrobials. E. coli strains were isolated and identified using conventional bacteriology through morphological and biochemical characterization. The production of bacteriocin-like substances, the presence of virulence-associated genes (VAGs) of APEC (Avian Pathogenic Escherichia coli) predictors, and the antimicrobial susceptibility were evaluated. E. coli was found in 85 % of the animals (17/20), in the trachea, air sacs or lungs; and it was not found in 15 % of the animals (3/20). A total of 34 isolates were recovered, 13 from the air sacs, 13 from the lungs, and 8 from the trachea, which showed no production of bacteriocin-like substances nor virulence genes associated with APEC. Most isolates, 59 % (20/34), showed resistance to at least one of the tested antimicrobials, and six multiresistant strains were identified. The results demonstrated that strains of E. coli were commensal of the respiratory microbiota, and that they did not present pathogenicity to the host, since there were no clinical signs of disease, macroscopic lesions in the organs of the evaluated broilers, production of bacteriocin-like substances, nor virulence-associated genes considered as predictors of APEC in bacteria. These strains of E. coli were mostly susceptible to antimicrobials. However, the occurrence of multidrug-resistant strains suggests that these animals can act as reservoirs of resistant to antimicrobials E. coli.

Antimicrobials and resistant bacteria in global fish farming and the possible risk for public health

ABSTRACT: The use of antimicrobials in fish farming is a reflection of the fast aquaculture development worldwide. The intensification of aquaculture to achieve market demands could lead to an increase in infectious diseases by pathogenic bacteria. Consequently, antimicrobials act as controls for emerging infectious diseases, but their use must follow the rules and regulations of the country where the activity is performed. Although the regulations impose limits to the use of antimicrobials in fish farming, many studies show that resistant bacteria are isolated from this system. The selection of resistant bacteria is not limited only to the use of antimicrobials, but also to co-selection of resistance genes or even with cross-resistance processes. Resistant bacteria from fish farming are a serious concern because they can be acquired by humans with handling or food chain, which may represent a public health problem. In the present review, we present an overview of antimicrobials use in aquaculture, the antimicrobial resistance and the impact of antimicrobial and bacterial resistance from a public health perspective.

Extended-spectrum β-lactamase (ESBL)-producing enterobacteria isolated from broiler breeder chickens

Devido ao uso de antibióticos para o tratamento e prevenção de infecções bacterianas durante a produção de matrizes pesadas, torna-se importante estudar o perfil de resistência e a prevalência de bactérias gram-negativas produtoras de ESBL. Dentre as várias classes de antimicrobianos disponíveis, destacam-se os agentes beta-lactâmicos, categoria antimicrobiana amplamente utilizada em clínica médica humana e veterinária. Assim, este trabalho teve como objetivo avaliar o perfil de resistência e caracterizar as cepas produtoras de beta-lactamases de espectro estendido (ESBL) isoladas de matrizes de corte por meio da coleta de 87 swabs cloacais. As bactérias Gram-negativas foram isoladas em meios seletivos, identificadas por métodos bioquímicos convencionais e MALDI-TOF® e estudadas quanto à resistência antimicrobiana, incluindo ESBL. Das 87 amostras, foram isoladas 52 bactérias gram-negativas. Houve alta resistência bacteriana às principais classes de antimicrobianos utilizados em aves: penicilinas, cefalosporinas e quinolonas. Também foi encontrado fenótipo sugestivo de produção de ESBL em 42,31% dos isolados, demonstrando resistência aos antimicrobianos beta-lactâmicos testados. Os resultados demonstram a necessidade de orientação dos profissionais que trabalham com matrizes de corte, a fim de se reduzir a presença de bactérias resistentes e produtoras de ESBL e evitar sua disseminação para o meio ambiente, ovos férteis e frangos de corte e, consequentemente, carne de frango e humanos.

AVALIAÇÃO MORFOMÉTRICA OVARIANA E RECUPERAÇÃO DE COMPLEXOS Cumulus oophorus DE CADELAS SUBMETIDAS A OVÁRIO-SALPINGO-HISTERECTOMIA EM DIFERENTES FASES DO CICLO ESTRAL

A maturação in vitro de ovócitos caninos ainda apresenta resultados insatisfatórios, devido às particularidades da fisiologia reprodutiva da cadela, incluindo as diferentes fases do ciclo estral que interferem nos resultados. Os objetivos do trabalho foram: avaliar coloração, forma, consistência, peso e dimensões do ovário de cadelas; estudar a quantidade e a qualidade dos complexos cumulus oophorus (CCOs) recuperados; mensurar a concentração plasmática de progesterona (P4) para determinar a fase do ciclo estral e correlacioná-la com os dados do experimento. Ao todo, foram avaliados os ovários de 55 cadelas submetidas à técnica de ovário-salpingo-histerectomia eletiva. Para as mensurações das dimensões e peso dos ovários foram utilizados paquímetro e balança digitais. Para a avaliação da concentração plasmática de P4 se empregou a técnica de radioimunoensaio. A recuperação dos CCOs foi realizada por fatiamento e escarificação dos ovários, enquanto que a classificação dos mesmos foi realizada por avaliação em estereomicroscópios (aumento 40x). Com relação à avaliação morfofisiométrica dos ovários, 100% apresentaram coloração rósea; 96,36% formato oval e 3,64% formato redondo; 94,55% tinham consistência fibroelástica e 5,45% consistência flácida. O peso médio dos ovários ± desvio-padrão foi de 0,58 ± 0,63 g. Já as medidas médias ± desvio-padrão de comprimento, largura e altura foram, respectivamente, de: 13,41 ± 3,72; 7,81 ± 2,33 e 6,46 ± 2,00 mm. O número médio de corpos lúteos observados foi de 3,62 ± 3,65. No total foram recuperados 1642 CCOs, cuja média e desvio-padrão foram de 29,85 ± 31,13; dentre estes 58,16% foram classificados como grau 1; 26,19% grau 2; 3,78% grau 3 e 11,88% expandido. Conclui-se que a fase do ciclo estral não influenciou no número total e na qualidade dos CCOs.