Chemical composition and antibacterial activity of essential oils against pathogens often related to cattle endometritis.

INTRODUCTION: Endometritis is a condition marked by inflammation of the endometrium that affects dairy cows from 21 days after parturition, causing damage to herd fertility and economic losses on farms. The use of active compounds obtained from plant sources has gained importance as disease treatment agents in farm animals due to the high resistance rates currently observed against traditional antibiotics commonly used. The study was carried out to examine the chemical composition and to investigate the antibacterial activity of rosemary, cinnamon, cloves, eucalyptus, lemon, oregano and thyme essential oils against the reference strain of Escherichia coli (ATCC 25922), Fusobacterium necrophorum (ATCC 25286), Trueperella pyogenes (ATCC 19411) and Staphylococcus aureus (ATCC 29213), considered as typical bacteria causing endometritis. METHODOLOGY: The chemical composition of the seven essential oils were analyzed by GC-MS and their antibacterial activity was evaluated by the disc diffusion method. RESULTS: Thirty-six components were identified in total using GC-MS analyzes. The main compounds were cinnamaldehyde (86.5% for cinnamon essential oil), eugenol (85.7% for clove essential oil), 1,8-cineol (80% for eucalyptus and 47.8% rosemary essential oils), limonene (65.5% for lemon essential oil), carvacrol (72.1% for oregano essential oil) and thymol (48.8% for thyme essential oil). The disc diffusion assay revealed that cinnamon, clove, oregano, and thyme essential oils showed the best results compared to the other three essential oils, showing the largest zone of inhibition against all bacteria evaluated. CONCLUSIONS: These findings indicated that essential oils are a potential agent to be used as an alternative for bovine endometritis treatment.

Treatment considerations for potential uropathogens detected by precision microbiological testing.

PURPOSE: The clinical and microbiological data for urinary tract infections (UTIs) for 6 organisms detected by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) at community health systems were examined. SUMMARY: The use of precision microbiological diagnostic testing such as MALDI-TOF and real-time quantitative polymerase chain reaction has increased the ability to detect a wider spectrum of organisms. This has raised questions of the clinical relevance of infrequently encountered organisms, especially when cultured from urine. This article reviews clinical and microbiological data for UTIs for 6 organisms detected by MALDI-TOF at community health systems (Actinotignum schaalii, Chryseobacterium indologenes, Aerococcus urinae, Aerococcus sanguinicola, Corynebacterium riegelii, and Corynebacterium urealyticum). Since little information currently exists, most of the data associating the aforementioned organisms with UTIs were derived from case reports. Although these organisms are more readily identified using precision microbiological diagnostic testing methods, infection should not be assumed based on culture results alone since asymptomatic bacteriuria has been reported. Similar to more common urinary pathogens, clinical correlation is essential. To facilitate treatment, we provide a table of empirical options likely to achieve clinical success based on in vivo and in vitro data. If available, pathogen-specific susceptibility data should be used to direct therapy. CONCLUSION: Clinical and microbiological data and potential treatment options were presented for 6 traditionally underrecognized organisms that are increasingly being found from urinary specimens. The treatment recommendations should be interpreted cautiously as they were devised through the use of very limited data.

Are penicillin treatment failures in Arcanobacterium haemolyticum pharyngotonsillitis caused by intracellularly residing bacteria?

Arcanobacterium haemolyticum is an infrequent agent of pharyngotonsillitis in children and young adults. Despite the fact that A. haemolyticum is fully sensitive to penicillin in vitro, penicillin treatment failures are frequent. The ability of A. haemolyticum to invade HEp-2 cells and survive intracellulary was investigated. All 12 strains tested, of which 10 were isolated from patients with pharyngotonsillitis, and 2 were reference strains, were internalized by the HEp-2 cells. Four strains tested further, one of the reference strains and 3 of the clinical isolates, proved able to survive intracellularly for 4 days, thus creating intracellular reservoirs of bacteria. It was also shown that erythromycin, an antibiotic known to penetrate well intracellularly, efficiently killed these bacteria.

[Effect of the combined use of antibiotic-resistant bifidobacteria and the corresponding antibiotics on the survivability of irradiated mice]. / Vliianie sochetannogo primeneniia antibiotikoustoichivykh bifidobakterii i sootvetstvuiushchikh antibiotikov na vyzhivaemost obluchennykh myshei.

The combined administration of antibiotic-resistant bifidobacterial strains and the corresponding antibiotics (ampicillin, gentamycin or kanamycin) leads to a greater increase in the survival rate of irradiated mice than the administration of antibiotics only and is a promising method for the treatment of post-irradiation intestinal dysbacteriosis.

The effect of the herbicide atrazine on rhizosphere microflora of broad bean plants, infested with Fusarium oxysporum f. fabae and Rhizoctonia solani.

The effect of the herbicide atrazine on Fusarium oxysporum f. fabae and Rhizoctonia solani, the causative agents of wilt and rot, respectively, as well as rhizosphere microflora of broad bean plants was studied. The herbicide was applied at intervals of 30, 20, 10, and 0 days before sowing. Atrazine application reduced both densities and per cent of infection of these two pathogenic fungi, R. solani, however, was sensitive to atrazine itself, while F. oxysporum was affected by atrazine by-products. Rhizosphere flora, i.e., total microbial flora, actinomycetes, phosphate-dissolving bacteria, and fungal flora, were not affected by atrazine, but were deleteriously reduced by its by-products at early stages of plant growth. However, rhizosphere flora attained the normal levels after atrazine by-products had completely disappeared from soil (1 month after application), except for actinomycetes. Therefore, it is recommended to apply atrazine within 20 days before sowing for weed control as well as for controlling wilt and root rot infestations.