RESUMEN
This literature review aimed to collect investigations on the in vivo evidence for bacteria associated with fermented dairy foods to behave as probiotics with beneficial effects in the prevention and treatment of various diseases. All main bacterial groups commonly present in high numbers in fermented milks or cheeses were taken into account, namely starter lactic acid bacteria (SLAB) Lactobacillus delbrueckii subsp. bulgaricus and lactis, L. helveticus, Lactococcus lactis, Streptococcus thermophilus, non-starter LAB (NSLAB) Lacticaseibacillus spp., Lactiplantibacillus plantarum, dairy propionibacteria, and other less frequently encountered species. Only studies regarding strains of proven dairy origin were considered. Studies in animal models and clinical studies showed that dairy bacteria ameliorate symptoms of inflammatory bowel disease (IBD), mucositis, metabolic syndrome, aging and oxidative stress, cancer, bone diseases, atopic dermatitis, allergies, infections and damage caused by pollutants, mild stress, and depression. Immunomodulation and changes in the intestinal microbiota were the mechanisms most often involved in the observed effects. The results of the studies considered indicated that milk and dairy products are a rich source of beneficial bacteria that should be further exploited to the advantage of human and animal health.
RESUMEN
Traditional dry fermented meat products are obtained artisanally in many countries, where they represent a gastronomic heritage well distinguished from industrial counterparts. This food category is most often obtained from red meat, a food commodity that is under attack because of evidence of increased risk of cancer and degenerative diseases with high consumption. However, traditional fermented meat products are intended for moderate consumption and gastronomic experience, and, as such, their production must be continued, which would also help safeguard the culture and economy of the geographical areas of origin. In this review, the main risks attributed to these products are considered, and how these risks are reduced by the application of autochthonous microbial cultures is highlighted by reviewing studies reporting the effects of autochthonous lactic acid bacteria (LAB), coagulase negative staphylococci (CNS), Debaryomyces hansenii and Penicillium nalgiovense on microbiological and chemical safety and on sensory attributes. The role of dry fermented sausages as a source of microorganisms that can be beneficial to the host is also considered. From the results of the studies reviewed here it appears that the development of autochthonous cultures for these foods can ensure safety and stabilize sensory characteristics and has the capacity to be extended to a larger variety of traditional products.
RESUMEN
This study aimed to investigate the recent trends of antibiotic resistance (AR) prevalence in Staphylococcus aureus isolated from the milk of animals with clinical mastitis in areas of the Abruzzo and Molise regions in Central Italy. Fifty-four S. aureus isolates were obtained from routine testing for clinical mastitis agents carried out in the author institution in the years 2021 and 2022 and were analyzed for phenotypic resistance to eight antibiotics recommended for testing by European norms and belonging to the antibiotic classes used for mastitis treatment in milk-producing animals. Moreover, the presence of 14 transferable genetic determinants encoding resistance to the same antibiotics was analyzed using qPCR tests developed in this study. Phenotypic resistance to non-ß-lactams was infrequent, with only one 2022 isolate resistant to clindamycin. However, resistance to the ß-lactam cefoxitin at concentrations just above the threshold of 4 µg/mL was observed in 59.2% of isolates in both years, making these isolates classifiable as methicillin-resistant. The AR genotypes detected were the blaZ gene (50% of 2021 isolates and 44.4% of 2022 isolates), aphA3-blaZ- ermC/T (one 2021 isolate), aphA3-ant6-blaZ-ermC/T (one 2021 isolate), blaZ-ermB (one 2022 isolate) and mecA-mph (one 2022 isolate). An inquiry into the veterinarians who provided the samples, regarding the antimicrobials prescribed for mastitis treatment and criteria of usage, indicated a possible causal relation with the AR test results. The occurrence of AR genotypes did not increase in time, most probably reflecting how mastitis was treated and prevented in farms. However, the frequently observed cefoxitin resistance needs to be explained genotypically, further monitored and limited by modifying antibiotic usage practices. The identification of a mecA-positive isolate in 2022 suggests further investigation if this genotype is emerging locally.
RESUMEN
Despite Klebsiella pneumoniae being widely recognized as a nosocomial pathogen, there is a critical lack in defining its reservoirs and sources of infections. Most studies on risk factors have focused on multidrug-resistant (MDR) isolates and clinically-oriented questions. Over a two-year period, we sampled 131 wild animals including mammal and bird species from three regions of Central Italy. All typical colonies isolated from the analytical portions were confirmed by real-time PCR and identified by MALDI-TOF mass spectrometry (MALDI-TOF MS). All confirmed K. pneumoniae isolates were tested for antimicrobial susceptibility to 29 antimicrobials and subjected to whole genome sequencing. Typical colonies were detected in 17 samples (13%), which were identified as K. pneumoniae (n = 16) and as K. quasipneumoniae (n = 1) by MALDI-TOF MS. The antimicrobial susceptibility profile showed that all the isolates were resistant to ß-lactams (ceftobiprole, cloxacillin, cefazolin) and tetracycline; resistance to ertapenem and trimethoprim was observed and nine out of 16 K. pneumoniae isolates (56.2%) were classified as MDR. Genomic characterization allowed the detection of fluoroquinolone resistance-associated efflux pumps, fosfomycin and ß-lactamase resistance genes, and virulence genes in the overall dataset. The cluster analysis of two isolates detected from wild boar with available clinical genomes showed the closest similarity. This study highlights the link between humans, domestic animals, and wildlife, showing that the current knowledge on this ecological context is lacking and that the potential health risks are underestimated.
RESUMEN
Serratia rubidaea has emerged in recent years as an opportunistic nosocomial pathogen. Here, we present the draft genome sequence of an isolate derived from an industrial meat food product purchased in a large-scale retail store that revealed fluoroquinolone, ß-lactam, and aminoglycoside resistance genes and two different host-unspecific prophages.
