An Ribonuclease T2 Family Protein Modulates Acinetobacter baumannii Abiotic Surface Colonization

Acinetobacter baumannii is an emerging bacterial pathogen of considerable medical concern. The organism's transmission and ability to cause disease has been associated with its propensity to colonize and form biofilms on abiotic surfaces in health care settings. To better understand the genetic determinants that affect biomaterial attachment, we performed a transposon mutagenesis analysis of abiotic surface-colonization using A. baumannii strain 98-37-09. Disruption of an RNase T2 family gene was found to limit the organism's ability to colonize polystyrene, polypropylene, glass, and stainless steel surfaces. DNA microarray analyses revealed that in comparison to wild type and complemented cells, the RNase T2 family mutant exhibited reduced expression of 29 genes, 15 of which are predicted to be associated with bacterial attachment and surface-associated motility. Motility assays confirmed that RNase T2 mutant displays a severe motility defect. Taken together, our results indicate that the RNase T2 family protein identified in this study is a positive regulator of A. baumannii's ability to colonize inanimate surfaces and motility. Moreover, the enzyme may be an effective target for the intervention of biomaterial colonization, and consequently limit the organism's transmission within the hospital setting

Profilaxia antimicrobiana em cirurgia vascular periférica: cefalosporina ainda é o padrão-ouro? Antimicrobial prophylaxis in peripheral vascular surgery: is cephalosporin still the gold standard?

Nas cirurgias vasculares periféricas, as cefalosporinas têm seu uso consagrado como agente antimicrobiano profilático de escolha. Recentemente, observamos uma mudança nos padrões de colonização, prevalência de patógenos e suscetibilidade geral aos antimicrobianos. Os patógenos multirresistentes vêm se tornando cada vez mais freqüentes nas infecções de ferida cirúrgica vascular, demonstrando variações regionais e locais quanto à suscetibilidade aos antimicrobianos profiláticos utilizados na rotina cirúrgica. Os dados e a literatura disponível até o momento demonstram que não existe evidência suficiente para uma mudança na rotina profilática perioperatória. Entretanto, devemos levar em consideração os padrões regionais e institucionais de prevalência de patógenos resistentes e padrões de suscetibilidade aos antimicrobianos para estabelecer guias e orientações específicas para a utilização de antimicrobianos profiláticos alternativos.<br>In peripheral vascular surgery, cephalosporins are nowadays regarded as the first choice for operative antibiotic prophylaxis. We have recently observed changes in colonizing patterns, pathogen prevalence and antibiotic susceptibility to antimicrobials. Multiresistant pathogens are becoming more frequent in vascular surgical wound infections, showing regional and local variations as to prophylactic antibiotic susceptibility. Data from the available literature so far have shown no strong evidence for a change in routine surgical antibiotic prophylaxis. We must consider regional and institutional prevalence of pathogen resistance and patterns of antibiotic susceptibility to establish specific guidelines for the use of alternative antibiotics