Iron status evaluation as a marker of postoperative joint infection: a pilot study

We evaluated the effect of different inflammatory conditions on iron status and, as a consequence, the possible use of iron markers as indicators of infection in the diagnosis of postoperative prosthetic orthopaedic joint infections. The study population was consisted of 26 patients undergoing revision of total hip or total knee joint arthroplasty and subdivided into three groups according to the cause of prosthesis implant failure: 10 as having had previous infection (Group A), 10 patients were categorized as having infection (Group B); and the remaining 6 (Group C) as not having infection. These patients were assayed for mean corpuscular haemoglobin concentration (MCHC) and serum values of iron (Fe), ferritin (Fer), transferrin (Tf), soluble transferrin receptor (sTfR), and transferrin saturation (sat Tf). Septic patients display statistically significant lower serum iron concentration, higher sTfR and ferritin levels, lower, but not statistically significant, MCHC compared to non septic ones. Little differences were observed for Tf, sat Tf, tibc, TfR index, among the three groups of patients. Our study suggests that iron status parameters, in particular serum iron, ferritin, sTfR and TfR index, could be useful tools for the early detection and the diagnosis of orthopaedic prosthetic joint infections.

Modulation of biofilm of strains isolated from patients with chronic obstructive pulmonary disease by levofloxacin, moxifloxacin, ciprofloxacin, amoxicillin/clavulanic acid and ceftriaxone

The ability of levofloxacin, moxifloxacin, ciprofloxacin, amoxicillin/clavulanic acid and ceftriaxone to interfere on biofilm produced by Pseudomonas aeruginosa, Haemophilus influenzae and Streptococcus pneumoniae isolated from patients with chronic obstructive pulmonary disease was evaluated. The effects of antibiotics were evaluated on formation of biofilm (at 1/2, 1/4 and 1/8 X MIC) and on preformed biofilm (at epithelial lining fluid peak concentrations) by means of a spectrophotometric method. Levofloxacin was the most active compound followed by ciprofloxacin, moxifloxacin and amoxicillin/clavulanic acid and ceftriaxone. Levofloxacin may contribute to clear the reservoir of pathogens involved in chronic obstructive pulmonary disease, thus leading to decreased occurrence of acute exacerbations.

Evaluation of zebrafish Danio rerio as a model for enteric septicemia of catfish (ESC)

Zebrafish (also known as zebra danio) Danio rerio were injected intramuscularly with Edwardsiella ictaluri at doses of 6 x 10(3), 6 x 10(4), or 6 x 10(5) colony-forming units per gram (CFU/g) or sterile phosphate-buffered saline (sham) or were not injected. Mortality occurred from 2 to 5 d postinjection (dpi) at rates of 0, 76.6, and 81.3% for the low, medium, and high doses, respectively, and E. ictaluri was isolated from dead fish. Survivors were sampled at 10 dpi and E. ictaluri was not isolated. Sham-injected and noninjected controls did not suffer mortality. Histopathology trials were performed in which zebrafish were injected with 1 x 10(4) CFU/g or sham-injected and sampled at 12, 24, 48, 72, and 96 h postinjection for histological interpretation. Collectively, these zebrafish demonstrated increasing severity of splenic, hepatic, cardiac, and renal interstitial necrosis over time. To evaluate the progression of chronic infection, zebrafish were injected with 1 x 10(2) CFU/g and held for 1 month postinjection. Beginning at 12 dpi and continuing for an additional 2 weeks, zebrafish demonstrated abnormal spiraling and circling swimming behaviors. Histopathology demonstrated necrotizing encephalitis. In immersion trials, zebrafish were exposed to low, medium, and high doses (averaging 1.16 x 10(5), 1.16 x 10(6), and 1.16 x 10(7) CFU/mL of tank water) of E. ictaluri for 2 h. Mortality occurred from 5 to 9 d postexposure at rates of 0, 3.3, and 13.3% for the low, medium, and high doses, respectively; E. ictaluri was isolated from dead fish. Channel catfish Ictalurus punctatus exposed to the medium doses suffered 100% mortality, and E. ictaluri was isolated from these fish. This study demonstrates the potential use of zebrafish as a model for E. ictaluri pathogenesis.