Genotypes and Phenotypes of Enterococci Isolated From Broiler Chickens

The objective of this study was to investigate the distribution and persistence of antimicrobial resistance genotypes of enterococci from broilers fed bambermycin (BAM), penicillin (PEN), salinomycin (SAL), bacitracin (BAC), or a salinomycin/bacitracin combination (SALBAC) for 35 days. A total of 95 enterococci from cloacal (n = 40), cecal (n = 38), and litter samples collected on day 36 (n = 17) were isolated weekly from day 7 to 36. All isolates were identified by API-20 Strep and their antimicrobial susceptibilities were evaluated using the Sensititre system with the plates for Gram positive bacteria. Whole genome sequencing (WGS) was used to assess their intra- and inter-genetic variability, with a focus on virulence and antibiotic resistance characteristics. All isolates were further characterized for hemolysin production (HEM), bile salt hydrolysis (BSH), and gelatinase (GEL) activities. Of the 95 isolates, Enterococcus faecium (n = 58) and Enterococcus faecalis (n = 24) were the most common Enterococcus species identified. Significant differences in the level of resistance for the E. faecium isolates to ciprofloxacin, macrolide, penicillin and tetracycline were observed among treatments. The bcrR, mefA, and aac(6) genes were higher in BAM treatment than the other groups whereas bcrR, ermA, ermB, aphA(3), and tetL were more prevalent in PEN and BAC treatments. Overall, E. faecium isolates showed a higher prevalence of antimicrobial resistance, but E. faecalis from litter also exhibited a significant level of resistance. A range of 4–15 different virulence genes was detected in E. faecalis. All isolates from litter but one (94.1%) showed BSH activities while 52.9% of them produced GEL. HEM activity was observed only in isolates collected on Day 7 (n = 9) and Day 14 (n = 1). This study confirmed that genetically diverse AMR enterococci harboring virulence factors can be promoted by the use of certain antimicrobials in feed. Such enterococci could persist in broiler chickens and their litter, which can potentially contaminate the soil upon land application

Three Novel Mutations in the PHEX Gene in Chinese Subjects with Hypophosphatemic Rickets Extends Genotypic Variability

Mutations in the phosphate-regulating endopeptidase homolog, X-linked, gene (PHEX), which encodes a zinc-dependent endopeptidase that is involved in bone mineralization and renal phosphate reabsorption, cause the most common form of hypophosphatemic rickets, X-linked hypophosphatemic rickets (XLH). The distribution of PHEX mutations is extensive, but few mutations have been identified in Chinese with XLH. We extracted genomic DNA and total RNA from leukocytes obtained from nine unrelated Chinese subjects (three males and six females, age range 11–36 years) who were living in Taiwan. The PHEX gene was amplified from DNA by PCR, and the amplicons were directly sequenced. Expression studies were performed by reverse-transcription PCR of leukocyte RNA. Serum levels of FGF23 were significantly greater in the patients than in normal subjects (mean 69.4 ± 18.8 vs. 27.2 ± 8.4 pg/mL, P < 0.005), and eight of the nine patients had elevated levels of FGF23. Germline mutations in the PHEX gene were identified in five of 9 patients, including novel c.1843 delA, donor splice site mutations c.663+2delT and c.1899+2T>A, and two previously reported missense mutations, p.C733Y and p.G579R. These data extend the spectrum of mutations in the PHEX gene in Han Chinese and confirm variability for XLH in Taiwan

Screening of the Antimicrobial Activities of Some Plants Used Traditionally in Ethiopia for the Treatment of Skin Disorders

The antimicrobial activities of the extracts of the leaves of Jasminum abyssinicum (Oleaceae), and Solanecio gigas (Asteraceae); the leaves, seeds and fruit-flesh of Lagenaria siceraria (Cucurbitaceae), plants widely used in Ethiopian traditional medicine for the treatment of skin disorders, have been assessed in vitro on selected species of bacteria and fungi. The total extract was prepared by maceration with 80% methanol and agar-well diffusion method was used for antimicrobial activity tests. The results of this study revealed that all the extracts have activity against Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pyogenes with the exception of the fruit-flesh of L. siceraria which showed no activity against clinical isolate S. aureus. The fractions of J. abyssinicum demonstrate less activity as compared to its crude whole extract. All the extracts failed to show any activity against Escherchia coli. Similarly following the method used in this study, the extracts were shown to be devoid of activity against Aspergillus flavus, A. niger, Trichophyton mentagrophyte and the clinical isolate of Candida albicans. Keywords: antibacterial activity, antifungal activity, Jasminum abyssinicum, Lagenaria siceraria, Solanecio gigas Ethiopian Pharmaceutical Journal Vol. 24 (2) 2006: pp. 130-13

Immunomagnetic capture of Bacillus anthracis spores from food

Food is a vulnerable target for potential bioterrorist attacks; therefore, a critical mitigation strategy is needed for the rapid concentration and detection of biothreat agents from food matrices. Magnetic beads offer a unique advantage in that they have a large surface area for efficient capture of bacteria. We have demonstrated the efficient capture and concentration of Bacillus anthracis (Sterne) spores using immunomagnetic beads for a potential food application. Magnetic beads from three different sources, with varying sizes and surface chemistries, were functionalized with monoclonal antibodies and polyclonal antibodies from commercial sources and used to capture and concentrate anthrax spores from spiked food matrices, including milk, apple juice, bagged salad, processed meat, and bottled water. The results indicated that the Pathatrix beads were more effective in the binding and capture of anthrax spores than the other two bead types investigated. Furthermore, it was observed that the use of polyclonal antibodies resulted in a more efficient recovery of anthrax spores than the use of monoclonal antibodies. Three different magnetic capture methods, inversion, the Pathatrix Auto system, and the new i CropTheBug system, were investigated. The i CropTheBug system yielded a much higher recovery of spores than the Pathatrix Auto system. Spore recoveries ranged from 80 to 100% for the i CropTheBug system when using pure spore preparations, whereas the Pathatrix Auto system had recoveries from 20 to 30%. Spore capture from food samples inoculated at a level of 1 CFU/ml resulted in 80 to 100% capture for milk, bottled water, and juice samples and 60 to 80% for processed meat and bagged salad when using the i CropTheBug system. This efficient capture of anthrax spores at very low concentrations without enrichment has the potential to enhance the sensitivity of downstream detection technologies and will be a useful method in a foodborne bioterrorism response.Peer reviewed: YesNRC publication: Ye