We evaluated the efficacy of disk diffusion methods for detection of low-level β-lactamase-negative ampicillin-resistant (low-BLNAR) Haemophilus influenzae. Four hundred and seventy unselected, recent clinical isolates were tested with ampicillin (10 μg), cefaclor (30 μg) and cefuroxime (30 μg) on iso-Sensitest agar enriched with nicotinamide adenine dinucleotide (NAD) and horse blood [ST agar; Swedish Reference Group for Antibiotics (SRGA) guidelines], and on chocolate agar (in-house guidelines). Selected isolates (n = 147) were subjected to partial sequencing of the ftsI gene. Forty-seven strains (10.0%) were genotypically identified as low-BLNAR, which was confirmed by determination of minimal inhibitory concentration (MIC) using microbroth dilution method: only low level resistance to ampicillin was detected [MIC ≤1 μg/mL; MIC(50) = 0.5 μg/mL, implying susceptibility by Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antibiotic Susceptibility Testing (EUCAST) interpretative criteria]. The MIC of cefuroxime varied between 1 and 4 μg/mL (MIC(50) = 2 μg/mL), indicating susceptibility to cefuroxime by CLSI but not by EUCAST guidelines. Disk diffusion methods were able to discriminate low-BLNAR H. influenzae from the wild-type population with sensitivities ranging from 87% to 98% and specificities from 96% to 99%. Cefaclor was found to be superior to cefuroxime and ampicillin. Cefaclor zone diameter breakpoints of 30/29 and 23/22 mm are suggested for ST agar and chocolate agar, respectively.
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http://dx.doi.org/10.1111/j.1600-0463.2011.02745.x | DOI Listing |
Pak J Med Sci
January 2025
Ikram Din Ujjan, PhD Department of Pathology, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan.
Objective: To determine the prevalence of antimicrobial resistance (AMR) in isolated from urine cultures of patients with uncomplicated cystitis in Pakistan. Another objective was to analyze and compare the resistance rates of to specific antibiotics, conducting a year-by-year evaluation of these rates to identify trends and changes over the past seven years.
Methods: Retrospective analysis of susceptibility data of isolated from midstream urine culture samples of patients presenting in outpatient department with uncomplicated cystitis, from January 2016 to December 2022 in the section of Microbiology, Liaquat University of Medical and Health Sciences was done.
Heliyon
January 2025
Institute of Metal Research (IMR), Chinese Academy of Science, Wenhua Road, Shenyang, China.
Recently, researchers have used silver nanoparticles (AgNPs) coupled with humic acid (HA) as antimicrobial agents. Herein, AgNPs were prepared and coupled with humic acid for their antimicrobial activities. The as-prepared AgNPs coupled with humic acid (HA) were characterized by an atomic force microscope (AFM), X-ray powder diffraction (XRD), zeta potential, zeta sizer, Fourier-transform infrared (FT-IR) spectroscopy, and UV-VIS spectrophotometer.
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January 2025
Department of Medicine, Sylhet Agricultural University, Sylhet, 3100, Bangladesh.
spp. present in the food chain have been of much interest during the last few decades due to their implication in the development of antimicrobial resistance. We determined the prevalence of spp.
View Article and Find Full Text PDFMolecules
January 2025
Hainan Key Laboratory of Storage and Processing of Fruits and Vegetables, Agricultural Products Processing Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang 524001, China.
This study aimed to determine the chemical composition of five essential oils (LEOs) using the gas chromatography-mass spectroscopy technique and to assess their antibacterial activity against four marine species, including , , , and . Sensitivity tests were performed using the disk diffusion and serial dilution methods. The results showed that all five LEOs exhibited antibacterial activity against the four tested marine species.
View Article and Find Full Text PDFMicroorganisms
January 2025
Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine of Bucharest, 050097 Bucharest, Romania.
is one of the most common pathogens in both humans and livestock. This study aimed to investigate the prevalence of isolated from raw cow milk and evaluate its antimicrobial resistance rates. A total of 1696 milk samples were collected from Romanian dairy farms from 2018 to 2022.
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