Is There A Correlation Between Antibiotic Resistance and Decreased Susceptibility to Biocides in Different Genus of Bacterial Genera?

Abstract

Objective: Our aim was to assess a possible association between antibiotic resistance and decreased susceptibility to antiseptics or disinfectants, because published papers are contradictory. We used a great number of microorganisms from different bacterial genera and some biocides in order to conclude if there was an association between antibiotic resistances and decreased disinfectant (or antiseptic) effects. Abstract Wullt [2] and Russell [3] explain that when we talk of resistance to disinfectants, we are really talking about MIC (minimum inhibitory concentration), since resistance is actually a lack of susceptibility to a given concentration of the compound in 24 hours, whereas the quantities of disinfectant used to carry out a disinfection are large and the times short. Therefore, when we use the word “resistance” we are attempting to express a greater tolerance or a decrease in the susceptibility of a microorganism to the concentration of a disinfectant to which it is normally susceptible [3]. Keywords: Antibiotic-resistance; Bacteriostatic-effect; Correlation; ICU-bacteria Material and Methods: Serial dilutions were performed with six disinfectants and two antiseptics to study the MIC-dilution (maximal dilution of disinfectant or antiseptic that inhibits each microorganism) and that dilution was contrasted with the antibiograms of each of the 159 bacteria recently isolated from ICU patients. These antibiograms were determinated by the Kirby-Bauer method, noting only whether they were susceptible or resistant. After, univariate and multivariate analysis were run on the data. Results: With the antibiograms and MIC-dilutions for every bacteria and biocide, the bivariate analysis found that only 4.7% of the antibiotic-biocide pairs showed a significant correlation (p < 0.05%) between antibiotic resistance and decreased susceptibility to the disinfectant or antiseptic, 8.3% showed a significant inverse correlation, and the rest no correlation. Multivariate analysis of the above variables (controlling the effects of the type of microorganism and disinfectant or antiseptic used), showed that overall fit of the equation was very poor, since R2 = 0.032. Conclusion: In a large sample of different bacteria genera there was no significant correlation between antibiotic resistance and decreased susceptibility to disinfectants and antiseptics, except in 4.7% of the antibiotic-biocide pairs. List of abbreviations: OPA: Ortho-phthalaldehyde; NFGNB: Non Fermentative Gram Negative Bacteria; ROC: Receiver Operating Characteristics; COR: Correlations with p < 0.05; Cor: Correlations with p between 0.05 and 0.1; SXT: Sulfamethoxazole trimethoprim; CPH: Cephalothin; LEVO: Levofloxacin; IPM: Imipenem; TOB: Tobramycin; CAZ: Ceftazidime; GM: Gentamicin; AN: Amikacin; FO: Phosphomycin; TZP: Tazobactam; ATM: Aztreonam; TEC: Teicoplanin