Antimicrobial susceptibility of Campylobacter jejuni and Campylobacter coli: comparison between Etest and a broth dilution method

Abstract Background Campylobacter is a leading cause of foodborne gasteroenteritis worldwide. Antimicrobial susceptibility testing for Campylobacter spp. is not routinely performed by most clinical laboratories. However, the emergence of resistant isolates strengthens the importance of antimicrobial susceptibility testing and the critical need for epidemiologic surveillance. The aim of this study was to compare the efficacy of Etest and Sensititre kit (a broth microdilution method) as methods for susceptibility tests and the critical need for epidemiologic surveillance. The aim of this study was to compare the efficacy of Etest and Sensititre kit (a broth microdilution method) as methods for susceptibility testing of Campylobacter spp. to tetracycline, erythromycin, and ciprofloxacin. Methods Sixty-six Campylobacter isolates were collected from feces samples and subjected to susceptibility testing by Etest and Sensititre, a broth microdilution kit for tetracycline, erythromycin, and ciprofloxacin. Minimal inhibitory concentration (MIC) results of each method were determined and compared. Results Similar MIC interpretations for tetracycline, erythromycin, and ciprofloxacin were found in 97%, 98.5%, and 100% of the isolates, respectively, indicating a good level of agreement between Etest and Sensititre (p < 0.0001); additionally, the correlation between the two methods was highly significant for the three tested antibiotics (p < 0.0001). Conclusions Both the broth microdilution and the Etest are reliable and convenient methods for testing antimicrobial susceptibility of Campylobacter spp. The Sensititre kit has the advantages of high availability and the automation

Cheap and rapid in-house method for direct identification of positive blood cultures by MALDI-TOF MS technology

Abstract Background Rapid and accurate pathogen identification in blood cultures is very important for septic patients and has major consequences on morbidity and mortality rates. In recent years, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS)-based technology has become useful for highly specific and sensitive identification of bacteria and yeasts from clinical samples including sterile body fluids. Additional in-house methods enabled direct identification from blood cultures following various preparation protocols. Methods Blood culture (5 ml) was harvested from each positive bottle following growth identification by BACTEC™ FX system and transferred into a VACUETTE® Z Serum Sep Clot Activator tube containing an inert gel, which following centrifugation separates microorganisms from the blood cells. We used MALDI-TOF MS analysis for identification of microorganisms collected from the gel surface. Results Positive blood culture bottles (186) were collected. In comparison with the routine method, 99% (184/186) and 90% (168/186) of the isolates were correctly identified by the SepsiTyper kit and the in-house method, respectively. We found high concordance (Pearson coefficient = 0.7, p <  0.0001) between our in-house method and the SepsiTyper kit. Additionally, high correlation was found in sub-groups of identified bacteria, with Pearson coefficients of 0.77 (p <  0.0001), 0.67 (p <  0.0001), and 0.73 (p <  0.007) for Gram negative, Gram positive, and anaerobic bacteria, respectively. Conclusions Our in-house method was found to be in good agreement with the SepsiTyper kit. Considering the low costs and the rapid and easy implementation of this procedure, we propose our in-house method for the direct identification of bacteria from blood cultures

Role of Single Procalcitonin Test on Admission as a Biomarker for Predicting the Severity of Clostridium difficile Infection

Objective: To evaluate whether serum Procalcitonin (PCT) at the early stage of infection can serve as a potential biomarker for determining Clostridium difficile infection (CDI) severity.Methods: Fifty-four patients diagnosed with CDI were enrolled in the study. Serum samples were obtained within a median time of 24–48 h of the lab result for presence of C. difficile. PCT levels were measured by chemiluminescence immunoassay. Demographic, clinical, and prognostic data concerning the patients were retrospectively collected from medical records. The illness severity score was determined according to “Score indices for C. difficile infection severity.”Results: We found that serum PCT levels were significantly higher in patients with moderate disease, compared to patients with mild disease (p = 0.0032). Additionally, PCT was correlated with mortality (p = 0.0002), white blood cell count (p = 0.019), and community-acquired disease (p = 0.0345).Conclusion: Early measurement of PCT may serve as a biomarker for early prediction of CDI severity, which is of great importance due to the high risk of complications and death