Phenotypic, genetic and symbiotic characterization of Erythrina velutina rhizobia from Caatinga dry forest

Abstract Erythrina velutina ("mulungu") is a legume tree from Caatinga that associates with rhizobia but the diversity and symbiotic ability of "mulungu" rhizobia are poorly understood. The aim of this study was to characterize "mulungu" rhizobia from Caatinga. Bacteria were obteined from Serra Talhada and Caruaru in Caatinga under natural regeneration. The bacteria were evaluated to the amplification of nifH and nodC and to metabolic characteristics. Ten selected bacteria identified by 16S rRNA sequences. They were tested in vitro to NaCl and temperature tolerance, auxin production and calcium phosphate solubilization. The symbiotic ability were assessed in an greenhouse experiment. A total of 32 bacteria were obtained and 17 amplified both symbiotic genes. The bacteria showed a high variable metabolic profile. Bradyrhizobium (6), Rhizobium (3) and Paraburkholderia (1) were identified, differing from their geographic origin. The isolates grew up to 45 °C to 0.51 mol L-1 of NaCl. Bacteria which produced more auxin in the medium with l-tryptophan and two Rhizobium and one Bradyrhizobium were phosphate solubilizers. All bacteria nodulated and ESA 90 (Rhizobium sp.) plus ESA 96 (Paraburkholderia sp.) were more efficient symbiotically. Diverse and efficient rhizobia inhabit the soils of Caatinga dry forests, with the bacterial differentiation by the sampling sites.

Extended-spectrum beta-lactamase-positive Escherichia coli causing complicated upper urinary tract infection: urologist should act in time

Recently, many articles reported increased incidence of urinary tract infection [UTI] due to Extended-Spectrum Beta-Lactamase [ESBL]-producing E. coli. No data are available to date regarding patients presenting with complicated upper ESBL-positive E. coli UTI and sepsis. We report the clinical presentation, management, and outcomes in seven cases. This prospective study was carried out between January 2008 and September 2011. Follow-ups varied in patients according to their disease presentation and clinical outcomes. All strains were cultured and identified by the Clinical Microbiology Laboratory and were recovered from blood and urine cultures. In-vitro presence of ESBL was confirmed with Clinical and Laboratory Standard Institute double disc method. In the study period, 49 patients needed hospitalization for upper UTI. Overall, in 25 patients [51%], cultures were negative. In the remaining, seven patients [14.3%] presented positive blood and urine-culture for ESBL + E. coli. Of these, four were female and three were male. Their median age was 73 years [range 66-84]. The median hospital stay of these patients was 23 days [range 13 to 45 days]. The current situation of multiple bacterial antibiotic resistance has become a worrisome issue in UTI. Multi-drug-resistant E. coli can be readily encountered in hospital settings during daily clinical practice, and urologist should act timely. The management of such infections is extremely important for the future, with particular reference to prevention of new antibiotic resistance patterns

Do we really know the prevalence of multi-drug resistant Escherichia coli in the territorial and nosocomial population?

The purpose of this work was to evaluate the prevalence of the Quinolones resistant Escherichia coli and/or ESBL producers in the population of our catchment area and hospital component, from january 2008 to December 2010, all data concerning urine cultures in patients with suspected urinary tract infection and/or asymptomatic bacteriuria referring at our center located in the south of Milan were prospectively evaluated. In 2008, 2136 outpatient and 1232 hospital urine cultures were analyzed. The presence of quinolone-resistant strains was 21% at a local level and 53% in hospital. ESBL-producing strains were isolated in 3.5% of cases at a local level and 20.5% in hospital. In 2009, 2396 outpatient and 1320 hospital urine cultures were analyzed. The presence of quinolone-resistant strains was 21% at a local level and 46% in hospitals. ESBL-producing strains were isolated in 5.4% of cases at a local level and 20% in hospitals. In 2010, 2601 outpatient and 1717 hospital urine cultures were analyzed. The presence of quinolone-resistant strains was 34% at a local level and 26% in hospitals. ESBL- producing strains were isolated in 6.7% of cases at a local level and 20.6% in hospitals. The multidrug resistance was significantly [P < 0.01] higher in ESBL-positive strains. Due to rising antibiotic resistance among uropathogens, it is important to have knowledge of the organisms causing urinary tract infections and their antibiotic sensitivity patterns. In areas with high prevalence of E. Coli resistance, performing urine culture before every surgical procedure became mandatory, in order to prevent fatal sepsis