Antimicrobial activity and safety features assessment of Weissella spp. from environmental sources

Abstract

Weissella strains have been reported to be useful in biotechnological and probiotic determinations, and some of them are considered opportunistic pathogens. Given the widespread interest about antimicrobial susceptibilities, transmission of resistances, and virulence factors, there is little research available on such topics for Weissella. The aim of this study was to assess the safety aspects and antimicrobial potential of 54 Weissella spp. strains from different environmental sources. Antibiotic susceptibility, hemolytic activity, horizontal transfer, and antibacterial activity were studied, as well as the detection of biogenic amine BA production on decarboxylase medium and PCR was performed. All the strains were nonhemolytic and sensitive to chloramphenicol and ampicillin. Several strains were classified as resistant to fusidic acid, and very low resistance rates were detected to ciprofloxacin, tetracycline, streptomycin, lincomycin, erythromycin, and rifampicin, although all strains had intrinsic resistance to vancomycin, nalidixic acid, kanamycin, and teicoplanin. Two BA‐producing strains (W. halotolerans FAS30 and FAS29) exhibited tyrosine decarboxylase activity, and just one W. confusa FS077 produced both tyramine and histamine, and their genetic determinants were identified. Ornithine decarboxylase/odc gene was found in 16 of the Weissella strains, although 3 of them synthesize putrescine. Interestingly, eight strains with good properties displayed antibacterial activity. Conjugation frequencies of erythromycin from Bacillus to Weissella spp. varied in the average of 3 × 10−9 transconjugants/recipient. However, no tetracycline‐resistant transconjugant was obtained with Enterococcus faecalis JH2‐2 as recipient. The obtained results support the safe status of Weissella strains, derived from environmental sources, when used as probiotics in animal feed.

Probiotic Potential and Safety Assessment of Type Strains of Weissella and Periweissella Species

“…With the exception of P. beninensis LMG 25373 T and W. diestrammenae DSM 27940 T , all the analyzed type strains were classified as resistant to chloramphenicol. Similar to our findings, high MIC values for chloramphenicol (even 16 and 32 mg/L) were also reported for some Weissella confusa strains in previous studies ( 63 , 65 ). Considering this, the presence of specific chloramphenicol resistance genes was suggested in Weissella spp.…”

“…( 65 ). Nonetheless, the presence of the cat gene coding for a chloramphenicol acetyltransferase, which is the most common chloramphenicol resistance gene in LAB ( 64 ), was not detected in chloramphenicol-resistant Weissella strains ( 63 ), in line with our results. In light of this, and as proposed for the related genus Leuconostoc ( 64 ), the possibility of an intrinsic resistance to chloramphenicol in Weissella spp.…”

“…This antibiotic interferes with precursors of peptidoglycan synthesis, binding to d -Ala/ d -Ala dipeptide and inhibiting polymerization ( 15 ), thus inhibiting cell wall biosynthesis. Resistance to vancomycin was noticed within the Weissella genus, as reported by Fhoula et al ( 63 ) and Abriouel et al ( 11 ), and, due to this resistance (besides their unusual Gram stain morphology), Weissella spp. have been often confused with Lactobacillus spp.…”

“…In light of this, and as proposed for the related genus Leuconostoc ( 64 ), the possibility of an intrinsic resistance to chloramphenicol in Weissella spp. has been postulated ( 63 ), indicating that horizontal gene transfer of such resistance to other bacteria would not occur. Resistance to aminoglycosides was shown by W. diestrammenae DSM 27940 T (resistant to gentamicin, kanamycin, and streptomycin) and P. fabaria LMG 24289 T (resistant to gentamicin and kanamycin).…”

Comparative genomics of 40 Weissella paramesenteroides strains

“…Although Weissella are intrinsically resistant to vancomycin (Ahmed et al, 2022), the resistance is most likely not easily transferred to pathogenic microbes. A very recent study by Fhoula et al (2022) showed that although W. paramesenteroides strain could receive antibiotic resistance genes from Bacillus strains at very low frequency of 10 −9 transconjugant per recipient, Weissella strains were not able to transfer their antibiotic resistance genes to Enterococcus strains. Biogenic amines accumulated by the microorganisms in fermented foods can cause adverse effects to human (Alvarez and Moreno-Arribas, 2014).…”