Effect of ginger essential oil and 6-gingerol on a multispecies biofilm of Listeria monocytogenes, Salmonella Typhimurium, and Pseudomonas aeruginosa.

The objective of this study was to evaluate the potential antimicrobial and antibiofilm effect of ginger essential oil (GEO) and 6-gingerol on a multispecies biofilm formed by Listeria monocytogenes, Salmonella Typhimurium, and Pseudomonas aeruginosa on a polypropylene surface. The minimum inhibitory concentration concentrations obtained for GEO were 100 and 50 mg/mL and for 6-gingerol 1.25 mg/mL. Sessile cell counts ranged within 5.35-7.35 log CFU/cm2 in the control biofilm, with the highest sessile growth at 72 h. GEO treatments acted on the total population regardless of concentration at 1 and 48 h. L. monocytogenes behaved similarly to the total population, showing GEO action at 1 h and keeping the same pattern at 48, 72, and 96 h. Better action on S. Typhimurium was obtained at times of 1, 72, and 96 h. P. aeruginosa showed logarithmic reduction only when treated with GEO 50 mg at 24 h. As for 6-gingerol, in general, there was no significant action (p > 0.05) on the evaluated sessile cells. GEO showed antimicrobial activity against L. monocytogenes, S. Typhimurium, and P. aeruginosa, acting as an inhibitor of biofilm formation. As for 6-gingerol, it was considered a possible antimicrobial agent but without efficacy during biofilm formation.

Occurrence and Distribution of Antibiotic-Resistant Staphylococcus aureus in a Brazilian Pork Production Chain.

ABSTRACT: Here we characterized the distribution and the antibiotic resistance of staphylococci from a Brazilian pork production chain. Samples (n = 1,114) from pig farms, pig lots, and slaughterhouses, located in two Brazilian states (Minas Gerais and Paraná), were subjected to coagulase-positive Staphylococcus enumeration. S. aureus isolates (n = 251) from this collection were further characterized for their resistance to oxacillin, cefoxitin, vancomycin, and tetracycline through phenotypic and molecular assays. Coagulase-positive Staphylococcus counts from pig farms were higher compared with other samples (P < 0.05). Other counts were relatively low but were present in all production stages. S. aureus isolates were commonly resistant to oxacillin and cefoxitin (54 of 73, 74.0%), qualifying them as methicillin-resistant S. aureus, but PCR assays indicated that few harbored the expected antimicrobial resistance genes (femB, mecA, and mecC). Lower frequencies of vancomycin and tetracycline resistance were found (6.8 to 37.0%). PCR sensitivity (34.5 to 86.7%) and specificity (26.6 to 85.0%) for detection of antibiotic resistance genes varied based on the assessed antibiotic. Antibiotic-resistant staphylococci are widely distributed in the Brazilian pork production chain, and methicillin-resistant S. aureus can become a potential health and economic impediment for the Brazilian pork industry.

Multidrug-Resistant and Extended-Spectrum ß-Lactamase-Producing Salmonella enterica Serotype Heidelberg Is Widespread in a Poultry Processing Facility in Southern Brazil.

ABSTRACT: This study was conducted to characterize the distribution of Salmonella isolates in a poultry processing facility and to identify their antibiotic resistance profiles. Salmonella enterica was detected in 146 samples (66.7%), and 125 isolates were identified as Salmonella Heidelberg (n = 123), Salmonella Abony (n = 1), and Salmonella O:4,5 (n = 1). Salmonella Heidelberg isolates were subjected to XbaI macrorestriction analysis and pulsed-field gel electrophoresis. The 66 pulsotypes obtained were grouped into four major clusters, indicating cross-contamination and persistence of this serotype in the processing facility. Selected S. enterica isolates were characterized by their antibiotic resistance, and most (n = 122, 97.6%) were multidrug resistant. Resistance to third-generation cephalosporins ceftazidime (84 isolates, 67.2%) and cefotaxime and ceftriaxone (91 isolates, 72.8%) was particularly prevalent. Production of extended-spectrum ß-lactamases (ESBL) was identified in 24 isolates (19.2%), and ESBL-producing isolates were resistant to at least eight antibiotics. This study revealed the high prevalence of Salmonella Heidelberg in the poultry chain, providing insight into the ecology of this pathogen in this facility. The high prevalence of multidrug-resistant S. enterica is a concern due to the potential consequences for public health.

Occurrence, quantification, pulse types, and antimicrobial susceptibility of Salmonella sp. isolated from chicken meat in the state of Paraná, Brazil.

The aim of this work was to verify the occurrence, quantification, pulse types, and antimicrobial susceptibility profiles of Salmonella sp. isolated from chicken meat produced and marketed in the state of Paraná, considered to be the state with the highest production of poultry meat in Brazil. Ninety-five of 300 (31.5%) frozen cuts of chicken were found to contain Salmonella sp., and 98 different isolates of Salmonella sp. were cultured from the positive samples. Quantification showed low Salmonella sp. loading, ranging from 0.12 to 6.4 MPN/g. The antimicrobial resistance test was performed against 16 agents from 6 different classes. All isolates were sensitive to meropenem, imipenem, chloramphenicol, and amikacin. The highest resistance rates were observed for nalidixic acid (95%), tetracycline (94%), doxycycline (94%), ampicillin (87%), amoxicillin with clavulanic acid (84%), ceftriaxone (79%), and ciprofloxacin (76%). A total of 84 (85.7%) of the isolates were identified with a multidrug resistant profile, 13 of which were found to have encoding genes extended-spectrum beta-lactamase (ESBL), especially blaCTX-M-2 e blaTEM-1. The major serovars identified were S. Typhimurium (43%) and S. Heidelberg (39%). The third most isolated serovar was S. Ndolo (6%), without previous reports of its presence in poultry meat in Brazil. Molecular characterization of S. Typhimurium and S. Heidelberg isolates by pulsed field gel electrophoresis (PFGE) showed a clonal relationship between all isolates of the same serovar (genetic similarity greater than 80%). Isolates of S. Typhimurium and S. Heidelberg with 100% similarity were found in up to five different geographic regions of the state, showing the potential for the spread of this pathogen in the Paraná poultry chain. Epidemiological surveys like this are important to understand the dynamics of dissemination and to monitor the prevalence of pathogens in the final products of poultry chains. In addition, to know the resistance profile of strains of Salmonella sp. present in food that contributes to the adoption of faster and more effective therapeutic measures, when necessary.

Prevalence, Antimicrobial Resistance, and Diversity of Salmonella along the Pig Production Chain in Southern Brazil.

Control of Salmonella spp. in food production chains is very important to ensure safe foods and minimize the risks of foodborne disease occurrence. This study aimed to identify the prevalence and main contamination sources of Salmonella spp. in a pig production chain in southern Brazil. Six lots of piglets produced at different farms were tracked until their slaughter, and samples were subjected to Salmonella spp. detection. The obtained isolates were serotyped, subjected to antimicrobial resistance testing, and pulsed field gel electrophoresis (PFGE). Salmonella spp. was detected in 160 (10.2%) samples, and not detected in pig carcasses after final washing or chilling. Among the 210 Salmonella spp. isolates, S. Typhimurium was the most prevalent (n = 101) and resistant to at least one antimicrobial. High resistance rates were detected against tetracycline (83.8%), chloramphenicol (54.3%), and trimethoprim-sulfamethoxazole (33.3%). The isolates that were non-susceptible to three or more classes of antimicrobials (n = 60) were considered multidrug-resistant (MDR), and isolates resistant to up to six of the tested antimicrobials were found. PFGE allowed the identification of genetic diversity and demonstrated that farm environment and feed supply may be sources for the dissemination of Salmonella spp. along the production chain. The results revealed the sources of Salmonella contamination in the pig production chain and highlighted the risks of antimicrobial resistance spread.

Distribution, diversity, virulence genotypes and antibiotic resistance for Salmonella isolated from a Brazilian pork production chain.

Pigs infected with Salmonella are an important source of contamination at slaughterhouses. We characterized the distribution, virulence genotypes and antimicrobial-resistance phenotypes for Salmonella isolates that were collected from different stages of a pork production chain. Each of ten pig lots were sampled for feed (n = 10), water (n = 10), barn floor (n = 10), lairage floor (n = 10), mesenteric lymph nodes (n = 100), tonsils (n = 100), processing environment (n = 120), pork cuts (n = 40) and carcasses after bleeding (n = 100), after singeing (n = 100), after evisceration (n = 100), and after final rinsing (n = 100). Salmonella was isolated according to ISO 6579, and after confirmation the isolates were subjected to serogrouping, macro-restriction digests and pulsed-field gel electrophoresis (PFGE), detection of virulence-related genes and antimicrobial-resistance phenotyping. Salmonella was recovered from barn floors from 3 pig farms (3/10), lairage floors (7/10), carcasses after bleeding (2/100) and final washing (1/100), palatine tonsils (45/100), mesenteric lymph nodes (43/100), utensils (3/120) and cuts (4/40). The most prevalent serogroup was O: 4 (82%) followed by O:3 (7.7%); O:9 (5.1%); O:8 (2.6%) and O:7 (2.6%). Recovered strains (n = 109) were classified into 24 different pulsotypes (XbaI restriction digest), which were arranged into five different clusters. Fourteen different virulence genotypes were observed based on 15 loci, and all isolates were positive for invA, sitC, pagC and tolC. There was a high prevalence of antimicrobial resistance against streptomycin (90.5%), tetracycline (88.1%), ampicillin (81.0%), chloramphenicol (71.4%), and ciprofloxacin (50.0%). No strain was resistant to ertapenem, meropenem or kanamycin. A majority (80.9%) of isolates were considered multidrug resistant (resistant to ≥3 antibiotic classes). This study provides valuable insight about the epidemiology of Salmonella in swine production, and despite the low presence of this pathogen in carcasses and meat cuts, the majority of isolates was multidrug resistant.