Exploring Coagulase-Negative Staphylococci Diversity from Artisanal Llama Sausages: Assessment of Technological and Safety Traits

Abstract

Llama sausage is still produced following artisanal procedures, with the autochthonous microbiota being mainly responsible for the fermentation process. In this work, the taxonomical identification and technological-safety criteria of coagulase-negative staphylococci (CNS) isolated from two different productions of llama sausages (P: pilot and A: artisanal) were investigated. Staphylococcus (S) equorum and S. saprophyticus were the species most frequently found in P production, followed by S. succinis and S. warneri; a wider species variability was observed in A factory being S. equorum, S. capitis, S. xylosus, S. pasteuri, S. epidermidis and S. saprophyticus as the main identified species. The technological characterization of 28 CNS strains showed their ability to hydrolyze gelatin and tributyrin together with a relevant nitrate reductase activity. Phenotypic and genotypic approaches were conducted to investigate the main safety traits. Llama’s CNS strains exhibited weak decarboxylase and hemolytic activity and low biofilm production; additionally, no enterotoxin genes were detected. Correlation analysis between phenotypic and genotypic data showed low values for the biofilm parameters, while high correlation was observed for oxacillin, ampicillin, tetracycline and aminoglycosides resistance and their genetic determinants. Data obtained may contribute to broaden knowledge about the autochthonous strains of this poorly studied fermented product, thus helping to select an appropriate combination of potential starter cultures to improve llama sausage safety and quality.

Incidence of Tetracycline and Erythromycin Resistance in Meat-Associated Bacteria: Impact of Different Livestock Management Strategies

“…Among lactobacilli, more discrepancies were observed regarding to tetracycline phenotype/genotype, while a high number of ERY-R CNS resulted as genetically susceptible. This discordance between the phenotype and genotype was already reported by other authors [ 18 , 31 , 36 ] and may be explained by the presence of additional genes conferring resistance different than those investigated herein [ 20 , 34 , 37 ]. For example, many genes conferring tetracycline resistance were described, and among these, tet O, tet Q, tet 36, tet Z, tet O/W/32/O/W/O, tet W/O genes were also identified among lactobacilli [ 38 ].…”

“…Resistance to relevant antibiotics has been already demonstrated for the bacterial strains under investigation as previously reported [ 11 , 12 , 18 , 22 ]. In this study, the same reference methods were used to assess the susceptibility to tetracycline and erythromycin of all L. sakei and L. plantarum and CNS isolates, in order to ensure a uniform approach and allow data comparison.…”

“…A total of 121 LAB and 84 CNS strains included in this study were previously isolated from Italian Piacentino Salami DOP [ 11 , 22 ] and from fermented pork and llama meat produced in Argentina [ 12 , 18 , 23 ].…”

“…However, the authors found a strong reduction in AR strains in the final product, suggesting that the manufacturing process may contribute to the reduction in AR bacteria. Very recently, the phenotypic and genotypic AR profiles of CNS from Argentinean artisanal llama sausages were investigated [ 18 ]; as a result, a high incidence of resistance to oxacillin, ampicillin and erythromycin followed by tetracycline, kanamycin and gentamicin was shown. BlaZ and tetK were found in all the ampicillin-resistant and tetracycline-resistant strains, respectively, while the mec A gene was only detected in half of oxacillin-resistant CNS.…”

Quality of traditionally produced Istrian sausage and identification of autochthonous lactic acid bacteria strains as potential functional starter cultures

“…Our results recorded at the end of ripening were by 1 log CFU/g higher relative to comparison results, thus being inconsistent to the studies that found low coagulase-negative cocci counts in the final ripening stage [24]. According to some authors, the coagulase-negative cocci count varies depending on the sausage kind, ranging from 2 to 9 log CFU/g [30,35]. In our study, a total of 50 isolates of coagulase-negative cocci were isolated from sausages during ripening.…”