Minimum inhibitory concentration values and problematic disk break points of tigecycline against vancomycin and/or high-level aminoglycoside-resistant enterococci

Antibacterial Activity of Gallic Acid from the Leaves of Altingia excelsa Noronha to Enterococcus faecalis

AIM : The aim of this study was to determine the antibacterial compound of Altingia excelsa leaves to inhibit the growth of Entrococcus faecalis. METHODS : The study was true experimental laboratory design. Separating the ethyl acetate extract via their compounds using various chromatographic techniques. Four extracts from A. excelsa leaves was obtained by the maceration method. The highest inhibitory effect was then continued to be isolated until one compound was obtained. Therefore, additional assay to determine chemical structure of compounds was done using UV spectra, infrared (IR), core magnetic resonance (NMR), and comparison with spectra data from the literature. The data were analyzed by ANACOVA assay. RESULTS : The highest inhibitory effect was the ethyl acetate extract. The chemical structure of compound 1 was identified as an acidic compound 3,4,5 -trihydroxy benzoate, namely as the gallic acid which had inhibitory effect against Enterococcus faecalis. Antibacterial test against Enterococcus faecalis was done to determine inhibitory effect by its compound and MIC values showed of 12.25 µg/mL. CONCLUSION : Gallic acid as the compound of Altingia excelsa leaves had a strong inhibitory effect to Enterococcus faecalis.

Frequency and co-colonization of vancomycin-resistant Enterococci and Candida in ICU-hospitalized children

In the time span between January 2018 and September 2020, 205 patients were enrolled in a prospective cohort study at Mofid Children's Hospital. Demographic information and clinical data on all the participating children were collected and rectal swabs were performed for the sampling method. All samples were analysed so as to identify the presence of Enterococcus and Candida colonization by the use of conventional biochemical tests. Resistance to vancomycin in Enterococcus isolates was phenotypically identified using an E-test kit and MIC value, interpreted according to the CLSI criteria. The presence of vanA and vanB genes, which encode the resistance to vancomycin, was screened by PCR assay. Candida species were detected in 21.5% of rectal swab samples. Candida glabrata (56.8%) and Candida albicans (43.2%) were the only Candida species detected. Enterococcus species were detected in 29.3% of rectal swab samples. Out of 60 Enterococcus isolates, 33 (55%) were resistant to vancomycin. Moreover, vanA was detected in 84.8% and vanB was detected in 3% of the 33 vancomycin-resistant Enterococcus isolates. Enterococcus and Candida species were frequently detected in the <1 year and 1–3 years age groups, respectively. Central venous access catheter and brain tumour were the main reasons for hospital admissions, 32.2% and 20.1% of total admissions, respectively. Furthermore, it must be noted that the most frequent underlying medical conditions in participating patients were esophageal atresia and hydrocephalus. The results of the present study demonstrated the necessity of determining the susceptibility of Enterococcus isolates to vancomycin before prescribing antibiotics.

Detection of antibiotic resistance profiles and aminoglycoside-modifying enzyme (AME) genes in high-level aminoglycoside-resistant (HLAR) enterococci isolated from raw milk and traditional cheeses in Turkey

The aim of this study was isolation and identification of the high-level aminoglycoside-resistant (HLAR) enterococci in raw milk and dairy products and to analyze their antibiotic resistance and the presence of aminoglycoside-modifying enzyme (AME) genes. A total of 59 HLAR enterococci were isolated from raw milk and traditional cheese samples. Thirty-nine of the 59 HLAR enterococci were isolated on streptomycin-containing agar medium, while the other 20 HLAR strains were isolated on gentamicin containing agar medium. The 59 HLAR enterococci were identified as 26 E. faecalis (44.07%), 18 E. faecium (30.51%), 13 E. durans (22.03%), and two E. gallinarum (3.39%) by species-specific PCR. Disk diffusion tests showed that teicoplanin were the most effective antibiotics used in this study, while 89.83% of isolates were found to be resistant to tetracycline. High rates of multiple antibiotic resistance were detected in HLAR isolates. Minimum inhibitory concentration (MIC) values of HLAR enterococci against streptomycin and gentamicin were found in the range of 64 to > 4096 µg/mL. Forty-seven (79.66%) of the 59 HLAR enterococci were found to be both high-level streptomycin-resistant (HLSR) and high-level gentamicin-resistant (HLGR) by MIC tests. However, no correlation was found between the results of the disk diffusion and MIC tests for gentamicin and streptomycin in some HLAR strains. The aph(3')-IIIa (94.92%) was found to be most prevalent AME gene followed by ant(4')-Ia (45.76%), ant(6')-Ia (20.34%) and aph(2'')-Ic (10.17%). None of the isolates contained the aac(6')-Ie-aph(2'')-Ia, aph(2'')-Ib or aph(2'')-Id genes. None of the AME-encoding genes were identified in E. durans RG20.1, E. faecalis RG22.4, or RG26.1. In conclusion, HLAR enterococci strains isolated in this study may act as reservoirs in the dissemination of antibiotic resistance genes.