Antimicrobial synergistic effects of apigenin, (-)-epigallocatechin-3-gallate, myricetin and luteolin in combination with some antibiotics.

INTRODUCTION AND OBJECTIVE: Antimicrobial resistance, which is considered one of the most important problems of the 21 st century, brings many problems with it, such as increasing mortality rates and treatment costs. Difficulties in the treatment of infections caused by resistant microorganisms have led to the search and need for new antimicrobials or new molecules that interact synergistically with antimicrobials. The aim of this study is to investigate whether various flavonoids have synergistic effects with some antibiotics. MATERIAL AND METHODS: During this study, standard bacterial strains Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 29213 and Staphylococcus aureus ATCC 43300 were used. Minimal inhibitory concentrations of all antibiotics and flavonoids were found by the broth microdilution method. Interactions between antibiotics and flavonoids were then determined by using the checkerboard method. Interactions between antibiotics and flavonoids were evaluated according to the FIC index (ΣFIC) results. RESULTS: According to the results of the microdilution test, the bacterial strains used in this study (except for MRSA) were generally sensitive to antibiotics. Interaction study results showed promising results regarding the synergistic interactions of antibiotics with flavonoids. Epigallocatechin gallate and luteolin especially showed synergistic interaction with antibiotics in many microorganisms. It was found that myricetin showed synergistic interaction only with levofloxacin. Likewise, it was detected that apigenin had limited synergistic interaction with antibiotics. CONCLUSIONS: The obtained results highlight that flavonoids may be a useful tool in overcoming antibiotic resistance.

Clinical and Laboratory Findings by Serum Vitamin D Levels in Children with COVID-19.

OBJECTIVE: The studies on children with COVID-19 are very limited. The aim of this study is to reveal the effect of serum 25-hydroxy vitamin D level on clinical and laboratory parameters. MATERIALS AND METHODS: The study included 74 children (35 boys and 39 girls) diagnosed with COVID-19. The retrospective data were obtained from the file records of the patients. Seventy-four patients were divided into 3 groups (group 1, deficient; group 2, insufficient; and group 3, sufficient) according to their serum 25-hydroxy vitamin D levels. RESULTS: The mean age of all patients was 113.25 ± 64.55 months. The mean leucocyte count was substantially higher in group 3 compared to groups 1 and 2 (P = .05 and P = .002, respectively). The mean lymphocyte and platelet count in group 3 was remarkably higher than both groups 1 and 2 (P = .001 and P = .002; and P = .04 and P = .01, respectively). The mean serum parathyroid hormone concentration in group 1 was markedly higher than both groups 2 and 3 (P=.003 and P = .002, respectively) while the mean serum 25-hydroxy vitamin D level in group 1 was remarkably lower than both groups 2 and 3 (P=.001 and P=.001, respectively). Serum 25-hydroxy vitamin D concentrations were positively correlated with leucocyte, lymphocyte, and platelet counts (r=0.221, P=.05; r=0.396, P=.001; and r=0.249, P=.03, respectively) while there was a negative correlation with parathyroid hormone concentrations (r=-0,436, P=.001). CONCLUSION: This study suggests that COVID-19 has a benign course in children and that serum 25-hydroxy vitamin D concentration may have a role in the lymphocyte count.

Evaluation of a New and Rapid Serologic Test for Detecting Brucellosis: Brucella Coombs Gel Test.

BACKGROUND: Many serological tests have been used for the diagnosis of human brucellosis. A new serological method is identified as Brucella Coombs gel test based on the principle of centrifugation gel system similar to the gel system used in blood group determination. In this system, if Brucella antibodies were present in the serum, antigen and antibody would remain as a pink complex on the gel. Otherwise, the pink Brucella antigens would precipitate at the bottom of the gel card system. OBJECTIVE: In this study, we aimed to compare the Brucella Coombs gel test, a new, rapid screen and titration method for detection of non-agglutinating IgG with the Brucella Coombs test. MATERIALS AND METHODS: For this study, a total of 88 serum samples were obtained from 45 healthy persons and 43 individuals who had clinical signs and symptoms of brucellosis. For each specimen, Rose Bengal test, standard agglutination test, Coombs test and Brucella Coombs gel test were carried out. RESULTS: Sensitivity and specificity of Brucella Coombs gel test were found as 100.0 and 82.2%, respectively. CONCLUSION: Brucella Coombs gel test can be used as a screening test with high sensitivity. By the help of pink Brucella antigen precipitation, the tests' evaluation is simple and objective. In addition, determination of Brucella antibody by rapid titration offers another important advantage.