ABSTRACT
With most epidemiological studies focused on poultry, dogs are often overlooked as a reservoir of Campylobacter, even though these animals maintain close daily contact with humans. The present study aimed to obtain a first insight into the presence and characteristics of Campylobacter spp. in different canine populations in Portugal, and to evaluate its zoonotic potential through genomic analysis. From a total of 125 rectal swabs collected from companion (n = 71) and hunting dogs (n = 54) living in two different settings, rural (n = 75) and urban (n = 50), 32 Campylobacter spp. isolates were obtained. Four different Campylobacter species were identified by Multiplex PCR and MALDI-TOF mass spectrometry, of which Campylobacter jejuni (n = 14, 44%) was overall the most frequently found species. Relevant resistance phenotypes were detected in C. jejuni, with 93% of the isolates being resistant to ciprofloxacin, 64% to tetracycline, and 57% to ampicillin, and three isolates being multi-drug-resistant. Comparison of the phenotypic and genotypic traits with human isolates from Portuguese patients revealed great similarity between both groups. Particularly relevant, the wgMLST analysis allowed the identification of isolates from human and dogs without any apparent epidemiological relationship, sharing high genetic proximity. Notwithstanding the limited sample size, considering the high genomic diversity of C. jejuni, the genetic overlap between human and dog strains observed in this study confirmed that the occurrence of this species in dogs is of public health concern, reinforcing the call for a One Health approach.
ABSTRACT
Due to the emergence of multidrug-resistant pathogenic microorganisms, the search for new antimicrobial compounds plays an important role in current medicinal chemistry research. Inspired by lichen antimicrobial xanthones, a series of novel chlorinated xanthones was prepared using five chlorination methods (Methods Aâ»E) to obtain different patterns of substitution in the xanthone scaffold. All the synthesized compounds were evaluated for their antimicrobial activity. Among them, 3-chloro-4,6-dimethoxy-1-methyl-9H-xanthen-9-one 15 showed promising antibacterial activity against E. faecalis (ATCC 29212 and 29213) and S. aureus ATCC 29213. 2,7-Dichloro-3,4,6-trimethoxy-1-methyl-9H-xanthen-9-one 18 revealed a potent fungistatic and fungicidal activity against dermatophytes clinical strains (T. rubrum, M. canis, and E. floccosum (MIC = 4â»8 µg/mL)). Moreover, when evaluated for its synergistic effect for T. rubrum, compound 18 exhibited synergy with fluconazole (ΣFIC = 0.289). These results disclosed new hit xanthones for both antibacterial and antifungal activity.
Subject(s)
Anti-Infective Agents/chemical synthesis , Anti-Infective Agents/pharmacology , Lichens/chemistry , Xanthones/chemical synthesis , Xanthones/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/chemistry , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Enterococcus faecalis/drug effects , Epidermophyton/drug effects , Halogenation , Microbial Sensitivity Tests , Microsporum/drug effects , Molecular Structure , Plant Extracts/chemistry , Staphylococcus aureus/drug effects , Trichophyton/drug effects , Xanthones/chemistryABSTRACT
A controlled environment poultry house (1600m(2)) was divided into two separated compartments. Three hundred twenty chick containers (each containing 100 chicks) were randomly allocated to each compartment. Antimicrobial products were provided (via drinking water) to one broiler group in three different growth phases for prophylactic purposes: lincomycin associated with spectinomycin from day 1 to day 3, trimethoprim associated with sulfamethoxazole from day 19 to day 21, and tylosin from day 26 to day 28. Feed and faecal samples from both groups were obtained on days 0, 4, 9, 14, 18, 22, 25, 29 and 33. One sample of the drinking water and samples from the broiler house environment were obtained one day before bird placement. A maximum of 16 enterococci isolated from Kanamycin Aesculin Azide Agar were tested for resistance using the disk diffusion method. A high prevalence of resistance to drugs such as tetracycline, erythromycin and nitrofurantoin was detected in enterococcal isolates from medicated and unmedicated flocks. Resistance occurrence in the non-medicated group revealed a shift in resistance profiles with the gradual change of the initial strains, isolated from the day-old chicks' cloacal swabs, by others displaying a different phenotype. Resistance phenotypes obtained from faecal strains were correlated with those isolated from the farm environment and feeds.