Campylobacter jejuni: Resistência antimicrobiana desafiada com complexo de paládio, platina, cobre e níquel

Abstract

Campylobacter spp is the zoonotic agent most commonly involved in bacterial human gastroenteritis, and the C. jejuni species is responsible for the largest number of cases and outbreaks. The ingestion of different contaminated foods is involved in campylobacteriosis, but chicken meat stands out as a source of infection, which leads to the need to implement control measures throughout the poultry production chain. Various strategies are used in an attempt to mitigate the prevalence of Campylobacter in slaughter plants, with sanitisation processes being considered critical. However, efficient sanitisation is a challenge, considering the growing resistance of Campylobacter to antibiotics and other antimicrobials, including those commonly used as sanitisers. The aim was to determine the antimicrobial activity of metallic compounds against five strains of C. jejuni resistant to ciprofloxacin and erythromycin. The strains were reactive and the Minimum Bactericidal Concentration (MBC) of the platinum, palladium, nickel and copper compounds was determined at concentrations of 100, 50, 25, 12.5, 6.25, 3.12, 1.56 and 0.78g/mL. CBM was determined by the broth microdilution test in Mueller-Hinton medium with the addition of Ca2+, Mg2+ and 5% defibrinated sheep's blood and incubation under microarophilic conditions at 37°C for 44±4 hours. After incubation, the contents of each well were sown on CCDA agar and incubated under the same conditions as before to check for the presence of colonies, with CBM determined as the lowest dilution in which no growth was observed. The results were tested for normality using the Shapiro-Wilk test and comparisons between results using the Durbin-Conover test with 95% probability using version 4.3.3 of the R programme. All the compounds exhibited bactericidal activity, but the copper and nickel compounds showed efficiency even at low concentrations (6.25 μg/mL) compared to palladium and platinum (25.00 μg/mL). It is feasible to consider these compounds as promising for the development of broad-spectrum therapeutic and/or sanitising agents, but there is a need for further studies to elucidate their effectiveness in preventing or destroying biofilms, as well as evaluating their cytotoxicity.