Clinical trials of new culture media for staphylococcus isolation

Polosenko, O.V.; Шепелин, А П; Azhermacheva, N I; Abaev, Igor

doi:10.51620/0869-2084-2021-66-2-115-121

Cited by 1 publication

(2 citation statements)

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“…The morphological, cultural, and chemical properties of microorganisms have been studied by generally accepted methods using differential diagnostic media and test systems [29,30]. Bacterial phenotypes of the strains used in the experiment corresponded to Bergey's classification from 1984 to 1989 [31].…”

Section: Phenotypic Characterization Of Bacteriamentioning

confidence: 99%

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Anatomical, pathological, and histological features of experimental respiratory infection of birds by biofilm-forming bacteria Staphylococcus aureus

Lenchenko,

Sachivkina,

Petrukhina

et al. 2024

Vet World

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Background and Aim: The pathogenesis of staphylococcal infections is mediated by virulence factors, such as enzymes, toxins, and biofilms, which increase the resistance of microorganisms to host immune system evasion. Testing and searching for standardized multi-level algorithms for the indication and differentiation of biofilms at the early stages of diagnosis will contribute to the development of preventive measures to control the critical points of technology and manage dangerous risk factors for the spread of infectious diseases. This research aimed to study the main stages of Staphylococcus aureus biofilm formation in in vitro experiments and to analyze the dynamics of respiratory syndrome development in chickens infected with these bacteria. Materials and Methods: Experimental reproduction of the infectious process was performed using laboratory models: 10-day-old White Leghorn chickens (n = 20). Before the experiments, the birds were divided into two groups according to the principle of analogs: Group I (control, n = 10): the birds were intranasally inoculated with 0.5 cm3 of 0.9% NaCl solution; Group II (experiment, n = 10): the birds were intranasally inoculated with a suspension of S. aureus bacteria, 0.5 cm3, concentration 1 billion/cm3. Results: Colonization of individual areas of the substrate under study in vitro occurred gradually from the sedimentation and adhesion of single motile planktonic cells to the attachment stage of microcolony development. Staining preparations with gentian violet due to the â€œmetachromosiaâ€ property of this dye are a quick and fairly simple way to differentiate cells and the intercellular matrix of biofilms. Fixation with vapors of glutaraldehyde and osmium tetroxide preserves the natural architecture of biofilms under optical and scanning electron microscopy. Pure cultures of S. aureus microorganisms were isolated from the blood, lungs, small intestine, liver, kidneys, and spleen after 5â€“10 days during experimental infection of chickens. Clinical signs of respiratory syndrome developed within 5â€“6 days after infection. Acute and subacute serousfibrinous airsacculitis, characterized by edema and thickening of the membranes of the air sacs and the presence of turbid, watery, foamy contents in the cavity, was the most characteristic pathomorphological sign. The signs of acute congestive hyperemia and one-sided serous-fibrinous pneumonia developed with significant thickening of fibrinous deposits. In Garderâ€™s gland, there was an increase in the number of secretory sections, indicating hypersecretion of the glands. In the lymphoid follicles of Meckelâ€™s diverticulum, leukocytes, usually lymphocytes, and pseudoeosinophils were detected. Conclusion: Hydration and heteromorphism of the internal environment of biofilms determine the localization of differentiated cells in a three-dimensional matrix for protection against adverse factors. The most characteristic pathomorphological sign was the development of acute and subacute serous-fibrinous airsacculitis when reproducing the infectious process in susceptible models. There was a significant thickening of fibrinous deposits and signs of acute congestive hyperemia and one or two serous-fibrinous pneumonia developed. Keywords: airsacculitis, avian, biofilm, pathogenesis, respiratory syndrome pneumonia, Staphylococcus aureus.

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Section: Phenotypic Characterization Of Bacteriamentioning

confidence: 99%

“…A sterile spatula was used to evenly distribute the cut surface to the surface of the nutrient medium in the center of the Petri dish. The morphological, cultural, and biochemical properties of microbial strains isolated from avian pathological material were studied using differential media and API test systems [29,30].…”

Section: Experimental Designmentioning

confidence: 99%