RESUMEN
BACKGROUND: Environmental contamination is a reservoir for vancomycin-resistant enterococcus (VRE) in hospitals. METHODS: Environmental sampling of surfaces was undertaken anytime before disinfection and 1 hour after disinfection utilizing a sodium dichloroisocyanurate-based, 3-staged protocol (phase 1) or benzalkonium chloride-based, single-stage clean (phase 2). VRE colonization and infection rates are presented from 2010 to 2011, and audits of cleaning completeness were also analyzed. RESULTS: Environmental samples collected before disinfection were significantly more likely to be contaminated with VRE during phase 1 than phase 2: 25.2% versus 4.6%, respectively; odds ratio (OR), 7.01 (P < .01). Environmental samples collected after disinfection were also significantly more likely to yield VRE during phase 1 compared with phase 2: 11.2% versus 1.1%, respectively; OR, 11.73 (P < .01). Rates of VRE colonization were higher during 2010 than 2011. Cleaning audits showed similar results over both time periods. CONCLUSION: During use of a chlorine-based, 3-staged protocol, significantly higher residual levels of VRE contamination were identified, compared with levels detected during use of a benzalkonium chloride-based product for disinfection. This reduction in VRE may be due to a new disinfection product, more attention to the thoroughness of cleaning, or other supplementary efforts in our institution.
Asunto(s)
Desinfectantes/farmacología , Desinfección/métodos , Enterococcus/efectos de los fármacos , Enterococcus/aislamiento & purificación , Microbiología Ambiental , Resistencia a la Vancomicina , Compuestos de Benzalconio/farmacología , Hospitales , Humanos , Triazinas/farmacologíaRESUMEN
Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world and infections with these organisms occur more frequently than do infections due to Salmonella species, Shigella species, or Escherichia coli 0157:H7. The incidence of human Campylobacter infections has increased markedly in both developed and developing countries worldwide and, more significantly, so has the rapid emergence of antibiotic-resistant Campylobacter strains, with evidence suggesting that the use of antibiotics, in particular the fluoroquinolones, as growth promoters in food animals and the veterinary industry is accelerating this trend. In this minireview, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter spp are discussed.
Asunto(s)
Antibacterianos/farmacología , Campylobacter coli/efectos de los fármacos , Campylobacter jejuni/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Farmacorresistencia Bacteriana/fisiología , Antibacterianos/metabolismo , Campylobacter coli/genética , Campylobacter jejuni/genéticaRESUMEN
DNA fragments encoding two putative zinc-dependent hydrolases, designated GLX2-1 and GLX2-2, from a clinical isolate of Campylobacter jejuni, strain 012, were cloned and sequenced. GLX2-1 was encoded by a sequence of 798 bp and GLX2-2 by a sequence of 597 bp. The amino acid sequences deduced from C. jejuni DNA showed 99% and 100% identity, respectively, to putative zinc hydrolases reported from C. jejuni ATCC strain 11168, and also shared identity (28-43%) with several hypothetical conserved proteins and known zinc-dependent hydrolases and metallo-beta-lactamase superfamily proteins. A strictly conserved motif, -H-X-H-X-D-, characteristic of the metallo-beta-lactamase superfamily of proteins, including class B metallo-beta-lactamases, was identified in both proteins. Other conserved metal-binding ligands, characteristic of the metallo-beta-lactamase superfamily of proteins, were also identified. Functional beta-lactamase could not be expressed in either Escherichia coli or Campylobacter coli transformed with C. jejuni hydrolase-containing plasmids, suggesting that they do not function as metallo-beta-lactamases, although structurally they are consistent with the zinc metallo-hydrolase family of the beta-lactamase fold.
Asunto(s)
Campylobacter jejuni/genética , Tioléster Hidrolasas/genética , Zinc/metabolismo , beta-Lactamasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Campylobacter jejuni/enzimología , Humanos , Datos de Secuencia Molecular , Tioléster Hidrolasas/metabolismo , beta-Lactamasas/metabolismoRESUMEN
A novel beta-lactamase gene, blaOXA-61, from Campylobacter jejuni GC015 was cloned and its nucleotide sequence determined. blaOXA-61 encodes a protein of 257 amino acids in which the active-site STFK tetrad and conserved class D beta-lactamase motifs YGN and KTG were identified. A conserved sequence upstream of blaOXA-61 is required for expression in Campylobacter.
Asunto(s)
Campylobacter jejuni/efectos de los fármacos , Campylobacter jejuni/enzimología , beta-Lactamasas , beta-Lactamas/farmacología , Secuencia de Aminoácidos , Antibacterianos/farmacología , Secuencia de Bases , Campylobacter jejuni/genética , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Resistencia betalactámica , beta-Lactamasas/química , beta-Lactamasas/genética , beta-Lactamasas/aislamiento & purificación , beta-Lactamasas/metabolismoRESUMEN
A small cryptic plasmid, pCJ419, was identified in a human clinical isolate of Campylobacter jejuni, cloned and sequenced. pCJ419 is a circular molecule of 4013 bp with a G+C content of 27.1%. The products of four open reading frames (ORFs) share significant sequence similarity with putative proteins from known C. jejuni and Campylobacter coli plasmids. ORF-1 encodes a putative mobilisation protein (Mob). ORF-2 and ORF-3 encode proteins that have high identity to putative RepA and RepB proteins, respectively, of known C. jejuni and C. coli plasmids. ORF-4 encodes a protein that has high identity to a hypothetical protein of unknown function, Cjp32, previously described in a pVir plasmid of C. jejuni. Tandem repeating 22-bp sequences typical of a plasmid replication origin (ori) were identified upstream of the DNA sequences encoding putative replication initiation proteins. An Escherichia coli-Campylobacter shuttle cloning vector, pGU0202, was constructed using plasmid pMW2 that harbours a Campylobacter-derived kanamycin resistance gene [aph(3')-III]. The sequences encoding pCJ419 mob, RepA and RepB proteins were inserted upstream of aph(3')-III resulting in a stable construct of 6174 bp that was used to transform both E. coli and Campylobacter.
Asunto(s)
Campylobacter jejuni/genética , Vectores Genéticos/genética , Plásmidos/genética , Secuencia de Bases , Southern Blotting , Mapeo Cromosómico , Cartilla de ADN , Escherichia coli/genética , Resistencia a la Kanamicina/genética , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Transformación BacterianaRESUMEN
We report two Australian patients with soft tissue infections due to Photorhabdus species. Recognized as important insect pathogens, Photorhabdus spp. are bioluminescent gram-negative bacilli. Bacteria belonging to the genus are emerging as a cause of both localized soft tissue and disseminated infections in humans in the United States and Australia. The source of infection in humans remains unknown.