Campylobacter spp. is a major cause of foodborne diseases in humans, particularly when transmitted by the handling or consumption of undercooked poultry meat. Most Campylobacter infections are self-limiting, but antimicrobial treatment ( e.g ., fluoroquinolones and macrolides) is necessary in severe or prolonged cases. The indiscriminate use of these drugs, both in clinical medicine and animal production, has a major impact on public health. The aim of the present study was to identify Campylobacter strains, isolated from turkey and broilers, using both PCR and the matrix-assisted laser desorption–ionization time-of-flight (MALDI-TOF) methods to reveal the accuracy of identification, as well to evaluate the antimicrobial and genetic resistance of the investigated strains. MALDI-TOF and PCR methods were used to show differences, if any, in the specificity of that test. In this study, MALDI-TOF mass spectrometry gave the same results as multiplex PCR, in all cases. The highest rate of resistance ( i.e ., 100% of turkey and broiler strains) was detected against ciprofloxacin, whereas 58.1% of turkey and 78.6% of broiler strains were resistant to tetracycline. Multidrug-resistant isolates were not found in the study. All ciprofloxacin-resistant strains had a mutation in the gyrA gene, at the Thr-86 position. The presence of the tetO gene was found in 71% of turkey and in 100% of broiler strains. All resistant to tetracycline strains included tetO gene. Additionally, in five turkey and three broiler strains, susceptible to tetracycline, tetO gene was present. These results indicate the high prevalence of Campylobacter strains, which are phenotypically and genetically resistant to fluoroquinolones and tetracycline.

Salmonella species are widespread in the environment, and occur in cattle, pigs, and birds, including poultry and free-living birds. In this study, we determined the occurrence of Salmonella in different wild bird species in Poland, focusing on five Salmonella serovars monitored in poultry by the European Union: Salmonella serovars Enteritidis, Typhimurium, Infantis, Virchow, and Hadar. We characterized their phenotypic and genetic variations. Isolates were classified into species and subspecies of the genus Salmonella with a polymerase chain reaction (PCR) assay. The prevalence of selected virulence genes (spvB, spiA, pagC, cdtB, msgA, invA, sipB, prgA, spaN, orgA, tolC, ironN, sitC, ipfC, sifA, sopB, and pefA) among the isolated strains was determined. We categorized all the Salmonella ser. Typhimurium strains with enterobacterial repetitive intergenic consensus (ERIC)-PCR. Sixty-four Salmonella isolates were collected from 235 cloacal swabs, 699 fecal samples, and 66 tissue samples (6.4% of 1000 samples) taken from 40 different species of wild birds in Poland between September 2011 and August 2013. The largest numbers of isolates were collected from Eurasian siskin and greenfinch: 33.3% positive samples for both. The collected strains belonged to one of three Salmonella subspecies: enterica (81.25%), salamae (17.19%), or houtenae (1.56%). Eighteen strains belonged to Salmonella ser. Typhimurium (28.13%), one to ser. Infantis (1.56%), one to ser. Virchow (1.56%), and one to ser. Hadar (1.56%). All isolates contained spiA, msgA, invA, lpfC, and sifA genes; 94.45% of isolates also contained sitC and sopB genes. None of the Salmonella ser. Typhimurium strains contained the cdtB gene. The one Salmonella ser. Hadar strain contained all the tested genes, except spvB and pefA; the one Salmonella ser. Infantis strain contained all the tested genes, except tspvB, pefA, and cdtB; and the one Salmonella ser. Virchow strain contained all the tested genes, except spvB, pefA, cdtB, and tolC. The Salmonella ser. Typhimurium strains varied across the same host species, but similarity was observed among strains isolated from the same environment (e.g., the same bird feeder or the same lake). Our results confirm that some wild avian species are reservoirs for Salmonella serotypes, especially Salmonella ser. Typhimurium.

Campylobacter jejuni/coli infections are the leading cause of bacterial diarrheal illnesses in humans. Many epidemiological studies indicate that improperly prepared meat from chickens that carry a high load of Campylobacter in their intestinal tracts is the key source of human infections. LAB, mainly members of the Lactococcus and Lactobacillus genera, increasingly have been tested as vehicles for the delivery of heterologous bacterial or viral antigens to animal mucosal immune systems. Thus, the objective of this study was to isolate, identify, and characterize Lactobacillus spp. strains isolated from chickens bred in Poland. Their ability to decrease the level of bird gut colonization by C. jejuni strain was also analyzed. First, the influence of the different chicken rearing systems was evaluated, especially the effect of diets on the Lactobacillus species that colonize the gut of chickens. Next, selected strains were analyzed in terms of their anti‐Campylobacter activity in vitro; potential probiotic traits such as adhesion properties, bile and low pH tolerance; and their ability to grow on a defined carbon source. Given that improperly prepared chicken meat is the main source of human infection by Campylobacter, the selected strains were also assessed for their ability to inhibit Campylobacter colonization in the bird's intestine. These experiments revealed enormous physiological diversity among the Lactobacillus genus strains. Altogether, our results showed that L. plantarum strains isolated from the digestive tracts of chickens bred in Poland displayed some probiotic attributes in vitro and were able to decrease the level of bird gut colonization by C. jejuni strain. This suggests that they can be employed as vectors to deliver Campylobacter immunodominant proteins to the bird's immune system to strengthen the efficacy of in ovo vaccination.

Salmonella entericaserovar Enteritidis has emerged during the last 20 years as the major causative agent of food-borne gastroenteritis in humans and as the major infectious agent on poultry farms, replacingSalmonella entericaserovar Typhimurium as the dominant pathogenic serovar. Because adhesion to gut tissues and colonization of the alimentary tract, mediated in large part by the FimH adhesins located on type 1 fimbriae, is an important stage in the pathogenesis of both serovars, the binding properties of the FimH adhesins from these two enteropathogens were compared.SalmonellaEnteritidis FimH protein and theSalmonellaTyphimurium low-adhesive variant of this adhesin were expressed inEscherichia coliand the recombinant proteins were analysed for their ability to bind glycoproteins carrying different oligomannosidic structures and different types of eukaryotic cells. In static binding assays (ELISA and Western blotting) both FimH proteins bound equally well to all three tested glycoproteins (RNase B, horseradish peroxidase and mannan-BSA). In addition, no differences were found in the binding specificity of the FimH proteins and intact cells ofSalmonellaEnteritidis andSalmonellaTyphimurium to human colon carcinoma or bladder cancer cells. The presence of the same amino acid residues at positions 61 (glycine) and 118 (phenylalanine) and the similar binding properties of these two adhesins suggest that the newly described FimH protein ofSalmonellaEnteritidis represents the low-adhesive variant found inSalmonellaTyphimurium. To study the binding specificity ofSalmonellaEnteritidis FimH protein further, direct kinetic analysis using surface plasmon resonance was performed. With this method it was found thatSalmonellaEnteritidis FimH adhesin bound with the highestK_dvalue to high-mannose typeN-glycans carried by RNase B; about 100 times lowerK_dvalues were obtained in the interactions with mannan-BSA and horseradish peroxidase.

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

Salmonella enterica ser. Enteritidis (S. enterica ser. Enteritidis) is the most frequently detected serovar in human salmonellosis, and its ability to produce a biofilm and the risk of transmission from animals and food of animal origin to humans are significant. The main aim of the present work was to compare S. enterica ser. Enteritidis strains isolated from poultry and human feces in terms of resistance profiles, prevalence of selected resistance genes, and their potential for biofilm formation, by assessing their biofilm growth intensity, the prevalence and expression of selected genes associated with this phenomenon, and the correlation between increased antimicrobial resistance and biofilm formation ability of the two tested groups of S. enterica ser. Enteritidis. This study showed a difference in antimicrobial resistance (minimal inhibitory concentration value) between S. enterica ser. Enteritidis groups; however, the majority of multidrug-resistant (MDR) strains were isolated from poultry (environmental samples from chicken broilers, turkey broilers, and laying hens). Differences in the prevalence of resistance genes were observed; the most common gene among poultry strains was floR, and that among strains from humans was blaTEM. S. enterica ser. Enteritidis strains isolated from poultry under the tested incubation conditions exhibited better biofilm growth than strains isolated from humans. A higher level of gene expression associated with the production of cellulose was only detected in the S48 strain isolated from poultry. On the other hand, increased expression of genes associated with quorum sensing was observed in two strains isolated from poultry farms and one strain isolated from human feces.