Whole-genome sequencing analysis of Vancomycin-resistant Enterococcus faecium isolates from the Frankfurt metropolitan region revealed that 78/94 isolates were MLST type ST117, cgMLST complex type CT71 with a common vanB chromosomal insertion site. This indicates circulation of a single VRE clone in a catchment area of 5,000-km2 with 3 million inhabitants.
21 September 2016 in Expert Review of Anti-infective Therapy
Introduction: Urinary tract infections (UTIs) are among the most common bacterial infections and constitute for a considerable number of all antibiotic prescriptions. The surge of multi-resistant bacteria has significantly complicated empirical treatment leading to wide use of broad-spectrum antibiotics, further driving resistance development. New ways to detect and quantify host and bacterial molecules in urine promise opportunities to improve diagnostics of UTIs, which can translate to new approaches in treatment regimens. Areas covered: Limitations of traditional techniques like urine dipsticks and microscopy, biomarkers as potential aid in differentiating the different types of bacteriuria, limitations of traditional and alternative urine culture are discussed. Additionally, the strengths and limitations of modern bacterial detection and identification methods such as flow cytometry, mass spectrometry, near-infrared spectroscopy, nucleic acid based technologies, isothermal microcalorimetry, biosensors and modern test strips in the scope of UTIs are covered. Literature search was performed using Pubmed, focusing on recent publications about diagnostics and ABS/AMS in urinary tract infections. Expert commentary: We comment on the potential impact of new technologies with a focus on antibiotic stewardship and speculate how the abundance of technological methods may change the way UTIs are perceived and diagnosed in the future.
Multi-drug resistant Klebsiella pneumoniae strains are a common cause of health care associated infections worldwide. Clonal spread of Klebsiella pneumoniae isolates carrying plasmid mediated CTX-M-15 have been commonly reported. Limited data is available regarding dissemination of chromosomally encoded CTX-M-15 in Klebsiella pneumoniae worldwide. We examined 23 non-repetitive ESBL-producing Klebsiella pneumoniae strains isolated from clinical specimens over a period of 4 months in a German University Hospital. All isolates were characterized to determine their genetic relatedness using Pulsed-Field Gel Electrophoresis (PFGE) and Multi Locus Sequence Typing (MLST). PFGE revealed three clusters (B1, B2, and B3) with a sub-cluster (A3) comprising of 10 isolates with an identical PFGE pattern. All strains of the cluster B3 with similar PFGE patterns were typed as ST101, indicating an outbreak situation. The ESBL allele bla CTX-M-15 was identified in 16 (69.6 %) of all isolates, including all of the outbreak strains. Within the A3 sub-cluster, the CTX-M-15 allele could not be transferred by conjugation. DNA hybridization studies suggested a chromosomal location of bla CTX-M-15. Whole genome sequencing located CTX-M-15 within a complete ISEcp-1 transposition unit inserted into an ORF encoding for a putative membrane protein. PCR-based analysis of the flanking regions demonstrated that insertion into this region is unique and present in all outbreak isolates. This is the first characterization of a chromosomal insertion of bla CTX-M-15 in Klebsiella pneumonia ST101, a finding suggesting that in Enterobacteriaceae, chromosomal locations may also act as reservoirs for the spread of bla CTX-M-15 encoding transposition units.
Diffuse unilateral subacute neuroretinitis is an ocular infectious disease caused by several distinct nematodes. Definite identification of the involved nematodes is rarely achieved. We report on the molecular-based genetic identification of an Ancylostoma ceylanicum hookworm implicated in a case of diffuse unilateral subacute neuroretinitis in a child.
The reassessment of known but neglected natural compounds is a vital strategy for providing novel lead structures urgently needed to overcome antimicrobial resistance. Scaffolds with resistance-breaking properties represent the most promising candidates for a successful translation into future therapeutics. Our study focuses on chelocardin, a member of the atypical tetracyclines, and its bioengineered derivative amidochelocardin, both showing broad-spectrum antibacterial activity within the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) panel. Further lead development of chelocardins requires extensive biological and chemical profiling to achieve favorable pharmaceutical properties and efficacy. This study shows that both molecules possess resistance-breaking properties enabling the escape from most common tetracycline resistance mechanisms. Further, we show that these compounds are potent candidates for treatment of urinary tract infections due to their in vitro activity against a large panel of multidrug-resistant uropathogenic clinical isolates. In addition, the mechanism of resistance to natural chelocardin was identified as relying on efflux processes, both in the chelocardin producer Amycolatopsis sulphurea and in the pathogen Klebsiella pneumoniae. Resistance development in Klebsiella led primarily to mutations in ramR, causing increased expression of the acrAB-tolC efflux pump. Most importantly, amidochelocardin overcomes this resistance mechanism, revealing not only the improved activity profile but also superior resistance-breaking properties of this novel antibacterial compound.
1 November 2016 in Clinical Microbiology and Infection