Peritonitis bacteriana espontánea y bacteriemia por Aeromonas hydrophila

La peritonitis bacteriana es una complicación frecuente en los pacientes cirróticos. De los gérmenes etiológicos, Aeromonas es muy poco frecuente. Presentamos un caso clínico de un paciente cirrótico con peritonitis y bacteriemia por Aeromonas hydrophila. Este microorganismo es un bacilo gramnegativo de la familia Vibrionaceae. En el ser humano produce gastroenteritis con mucha frecuencia. De forma excepcional puede dar origen a infecciones extraintestinales, sobre todo en pacientes inmunodeprimidos. La peritonitis por Aeromonas se ha descrito en asociación a peritonitis bacteriana espontánea en pacientes cirróticos, en pacientes en diálisis peritoneal y en casos de peritonitis secundaria a perforación intestinal

B:2a:P1.5 Meningococcal Strains Likely Arisen from Capsular Switching Event Still Spreading in Spain▿

Eighteen clustered cases of meningococcal disease associated with B:2a:P1.5 strains doubled the annual incidence up to 4.3 × 105 in Navarra, Spain, in 2007. Eleven percent of cases were fatalities, and 74% of cases were individuals 10 to 24 years old. This is the third cluster associated with this strain in northern Spain since 2001

Quorum sensing network in clinical strains of A. baumannii : AidA is a new quorum quenching enzyme

Acinetobacter baumannii is an important pathogen that causes nosocomial infections generally associated with high mortality and morbidity in Intensive Care Units (ICUs). Currently, little is known about the Quorum Sensing (QS)/Quorum Quenching (QQ) systems of this pathogen. We analyzed these mechanisms in seven clinical isolates of A. baumannii. Microarray analysis of one of these clinical isolates, Ab1 (A. baumannii ST-2-clon-2010), previously cultured in the presence of 3-oxo-C12-HSL (a QS signalling molecule) revealed a putative QQ enzyme (α/β hydrolase gene, AidA). This QQ enzyme was present in all nonmotile clinical isolates (67% of which were isolated from the respiratory tract) cultured in nutrient depleted LB medium. Interestingly, this gene was not located in the genome of the only motile clinical strain growing in this medium (A. baumannii strain Ab421-GEIH-2010 [Ab7], isolated from a blood sample). The AidA protein expressed in E. coli showed QQ activity. Finally, we observed downregulation of the AidA protein (QQ system attenuation) in the presence of HO (ROS stress). In conclusion, most of the A. baumannii clinical strains were not surface motile (84%) and were of respiratory origin (67%). Only the pilT gene was involved in surface motility and related to the QS system. Finally, a new QQ enzyme (α/β hydrolase gene, AidA protein) was detected in these strains