Luc Devriese

Bio: Luc Devriese is an academic researcher from Ghent University. The author has contributed to research in topics: Staphylococcus aureus & Streptococcus bovis. The author has an hindex of 58, co-authored 267 publications receiving 11699 citations. Previous affiliations of Luc Devriese include Assam Agricultural University.

Antimicrobial Growth Promoters Used in Animal Feed: Effects of Less Well Known Antibiotics on Gram-Positive Bacteria

Abstract: There are not many data available on antibiotics used solely in animals and almost exclusively for growth promotion. These products include bambermycin, avilamycin, efrotomycin, and the ionophore antibiotics (monensin, salinomycin, narasin, and lasalocid). Information is also scarce for bacitracin used only marginally in human and veterinary medicine and for streptogramin antibiotics. The mechanisms of action of and resistance mechanisms against these antibiotics are described. Special emphasis is given to the prevalence of resistance among gram-positive bacteria isolated from animals and humans. Since no susceptibility breakpoints are available for most of the antibiotics discussed, an alternative approach to the interpretation of MICs is presented. Also, some pharmacokinetic data and information on the influence of these products on the intestinal flora are presented.

Staphylococcus pseudintermedius sp. nov., a coagulase-positive species from animals.

Abstract: Four staphylococcal isolates from clinical and necropsy specimens from a cat, a dog, a horse and a parrot (Psittacus erithacus timneh) were found to constitute a distinct taxon. 16S rRNA gene sequence analysis revealed that its closest phylogenetic relatives are Staphylococcus intermedius and Staphylococcus delphini. Growth characteristics, biochemical features and DNA–DNA hybridizations demonstrated that the strains differ from these and other known species and that they represent a single, novel Staphylococcus species for which the name Staphylococcus pseudintermedius sp. nov. is proposed. The novel species is commonly confused with S. intermedius in routine diagnostic veterinary bacteriology. Although the strains described were isolated from lesions and show several characteristics typical of pathogenic staphylococci, such as coagulase, DNase and β-haemolysin production, the pathogenic significance of the novel species remains unclear. The type strain, LMG 22219T (=ON 86T=CCUG 49543T), was isolated from lung tissue of a cat.

Antimicrobial Resistance of Old and Recent Staphylococcus aureus Isolates from Poultry: First Detection of Livestock-Associated Methicillin-Resistant Strain ST398

Abstract: The susceptibilities of 12 antimicrobial agents for two collections of Staphylococcus aureus, isolated in the 1970s and in 2006 from poultry, were determined. For eight antibiotics, the percentage of resistance was significantly higher in the recent isolates. Ten recent isolates were methicillin resistant and had spa types t011 and t567, belonging to multilocus sequence type 398. This is the first report of "livestock-associated" methicillin resistant S. aureus from healthy poultry.

Methicillin (cloxacillin)-resistant Staphylococcus aureus strains isolated from bovine mastitis cases.

Abstract: ummary Eighteen methicillin (cloxacillin)-resistant Staphylococcus aureus isolates were obtained from 17 cows (2.2%) out of 776 which yielded S. aureus positive milk samples. Resistant strains were found on 12 (5.2%) of 232 farms. The physiological characteristics (production of haemolysins and fibrinolysin) of 17 of these isolates were similar to those of the common bovine strains. Their antibiotic resistance characteristics were similar to those of the methicillin-resistant strains which have been described from human sources. The epidemiology of methicillin-resistant S. aureus strains and the methods which can be used in their routine detection are briefly discussed. Resume Souches de staphylocoques dores resistantes a la methicilline (cloxacilline) isolees chez les bovins Au cours de l'examen de 776 echantillons de lait contenant des staphylocoques dores, on a trouve 18 souches resistantes a la methicilline (cloxacilline) chez 17 bovins (2,2%). Les souches resistantes provenaient de 12 fermes (sur les 232 examinees au total) (soit 5,2%). Les proprietes physiologiques de ces souches sont les memes que celles des souches trouvees habituellement chez les bovins. Le developpement de la resistance aux antibiotiques ne differe pas de celui des souches resistantes a la methicilline isolees chez l'homme. On discute brievement l'epidemiologie des souches de S. aureus resistantes a la methicilline, ainsi que les methodes pour leur mise en evidence de routine. Resumen Cepas de Staphylococcus aureus resistentes a la meticilina (cloxacilina) isoladas en casos de mastitis bovina Al analizar 776 muestras de leche, positivas de Staphylococcus aureus, se hallaron 18 estirpes resistentes a la meticilina (cloxacilina) en 17 vacas (2,3%). Las estirpes resistentes procedian de 12 (5,2%) explotaciones entre un total de 232 examinadas. Las propiedades fisiologicas de estas cepas eran las mismas que las normales ubicadas en vacas. La conformacion de su resistencia frente a los antibioticos no se diferencio de las estirpes resistentes a la meticilina aisladas en personas. Se discuten de forma sucinta la epidemiologia de las estirpes S. aureus resistentes a la meticilina y las tecnicas para su hallada rutinaria. Zusammenfassung Bei der Untersuchung von 776 Staphylococcus aureus-positiven Milchproben wurden 18 Methicillin (cloxacillin)-resistente Stamme bei 17 Rindern (2,2%) gefunden. Die resistenten Stamme stammten aus 12 (5,2%) von insgesamt 232 untersuchten Farmen. Die physiologischen Eigenschaften dieser Stamme waren die gleichen wie die normaler, beim Rind vorkommender Stamme. Die Ausbildung ihrer Anti-biotikaresistenz unterschied sich nicht von der beim Menschen isolierter Methicillin-resistenter Stamme. Die Epidemiologie von Methicillin-resistenten S. aureus-Stammen sowie Methoden zu ihrer routinemafiigen Auffindung werden kurz diskutiert.

Acinetobacter baumannii: Emergence of a Successful Pathogen

Abstract: Acinetobacter baumannii has emerged as a highly troublesome pathogen for many institutions globally. As a consequence of its immense ability to acquire or upregulate antibiotic drug resistance determinants, it has justifiably been propelled to the forefront of scientific attention. Apart from its predilection for the seriously ill within intensive care units, A. baumannii has more recently caused a range of infectious syndromes in military personnel injured in the Iraq and Afghanistan conflicts. This review details the significant advances that have been made in our understanding of this remarkable organism over the last 10 years, including current taxonomy and species identification, issues with susceptibility testing, mechanisms of antibiotic resistance, global epidemiology, clinical impact of infection, host-pathogen interactions, and infection control and therapeutic considerations.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic.

Abstract: Summary: Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.

Proposed minimal standards for describing new taxa of the family Flavobacteriaceae and emended description of the family.

Abstract: In this paper minimal standards for the description of new genera and cultivable species in the family Flavobacteriaceae are proposed in accordance with Recommendation 30b of the Bacteriological Code (1990 Revision). In addition to specified phenotypic characteristics, the description of new species should be based on DNA-DNA hybridization data, and the placement of new taxa should be consistent with phylogenetic data derived from 16S rRNA sequencing. An emended description of the family is also proposed as several new taxa have been described since 1996. These proposals have been endorsed by the members of the Subcommittee on the taxonomy of Flavobacterium and Cytophaga-like bacteria of the International Committee on Systematics of Prokaryotes.

Food Animals and Antimicrobials: Impacts on Human Health

Abstract: Antimicrobials are valuable therapeutics whose efficacy is seriously compromised by the emergence and spread of antimicrobial resistance. The provision of antibiotics to food animals encompasses a wide variety of nontherapeutic purposes that include growth promotion. The concern over resistance emergence and spread to people by nontherapeutic use of antimicrobials has led to conflicted practices and opinions. Considerable evidence supported the removal of nontherapeutic antimicrobials (NTAs) in Europe, based on the "precautionary principle." Still, concrete scientific evidence of the favorable versus unfavorable consequences of NTAs is not clear to all stakeholders. Substantial data show elevated antibiotic resistance in bacteria associated with animals fed NTAs and their food products. This resistance spreads to other animals and humans-directly by contact and indirectly via the food chain, water, air, and manured and sludge-fertilized soils. Modern genetic techniques are making advances in deciphering the ecological impact of NTAs, but modeling efforts are thwarted by deficits in key knowledge of microbial and antibiotic loads at each stage of the transmission chain. Still, the substantial and expanding volume of evidence reporting animal-to-human spread of resistant bacteria, including that arising from use of NTAs, supports eliminating NTA use in order to reduce the growing environmental load of resistance genes.