ABSTRACT
The aim of this study is to evaluate the chlorhexidine gluconate (CHG) susceptibility in both planktonic cells and biofilm of 32 Gram-negative (Gn) and 6 Gram-positive (Gp) isolates by minimal inhibitory concentration (2-256 µg/mL for Gn and 2-32 µg/mL for Gp), minimal bactericidal concentration (4-256 µg/mL for Gn and 2-32 µg/mL for Gp) in planktonic cells, and minimal biofilm elimination concentration (128 ≥ 16,384 µg/mL in Gn and 32 ≥ 16,384 µg/mL in Gp) in biofilm environment. Our study showed that Gn isolates have higher minimal concentrations than Gp and bacteria in biofilms are more tolerant than planktonic ones. No correlation between MBC or MBEC and biofilm formation was statistically confirmed. The Eagle effect, previously described for antimicrobials and antifungals, was evidenced in this work for CHG, an antiseptic. Besides that, the phenomenon was described in 23/38 isolates (60.5%), raising minimal concentration up to ≥ 16,384 µg/mL. Our study showed that clinical isolates have a high ability to form biofilm allowing them to tolerate CHG concentrations as high as the ones used in clinical practice. Therefore, attention should be given to the occurrence of this phenomenon to avoid false susceptibility results.
Subject(s)
Cross Infection , Eagles , Animals , Humans , Chlorhexidine/pharmacology , Anti-Bacterial Agents/pharmacology , Plankton , Biofilms , Microbial Sensitivity TestsABSTRACT
A novel Loop-mediated isothermal amplification (LAMP) assay, HiberGene's CD was evaluated with 82 unformed stools from patients suspected of C. difficile infection (CDI). Compared to glutamate dehydrogenase (GDH) toxins A/B test (C.diff Quik Chek®), HiberGene's LAMP showed 100% of sensitivity and 95,8% of specificity; and compared to FilmArray™ GI panel ® (BioFire), a sensitivity of 81,2% and a specificity of 100%, with 96.38% of agreement.
Subject(s)
Clostridioides difficile/genetics , Clostridium Infections/diagnosis , Clostridium Infections/microbiology , Diagnostic Tests, Routine/methods , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Adolescent , Adult , Aged , Aged, 80 and over , Bacterial Proteins/genetics , Bacterial Toxins/genetics , Child , Clostridioides difficile/isolation & purification , Feces/microbiology , Female , Glutamate Dehydrogenase/genetics , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Young AdultABSTRACT
Bordetella pertussis is the causative agent of pertussis, which mainly affects unvaccinated children, while Bordetella parapertussis causes a disease presenting clinical characteristics that are indistinguishable from whooping cough. Despite high vaccination coverage, pertussis remains a public health concern worldwide, with approximately 140000 cases reported annually. Here we determined the prevalence of B. pertussis and B. parapertussis infection among infants under one year of age by polymerase chain reaction (PCR); our aim being to identify whether the data obtained relates to the relevant sociodemographic and clinical data. The study included 86 samples of nasopharyngeal swabs from infants aged between 0-12 months, who were reported as probable cases of whooping cough by the health centers around the Ecuadorian highlands, from August 2016 to July 2017. The nasopharyngeal swabs were cultured and microbiological and molecular analyses were performed. B. pertussis was identified by PCR in 41% of the samples (30/86), more than half of which corresponded to infants aged between 0-3 months. Moreover, a statistically significant correlation (p<0.05) between the identification of bacteria in culture and the catarrhal stage of the disease was observed. The results obtained from the study highlighted the need for an active national surveillance of pertussis, in particular for laboratory testing, to provide a highly sensitive and more specific diagnosis of Bordetella infection.
