Identification and antimicrobial susceptibility of lactic acid bacteria from retail fermented foods.
One important safety criterion of using lactic acid bacteria (LAB) in food applications is to ensure that they do not carry transferable antimicrobial resistance (AR) determinants. In this study, 63 LAB belonging to six genera, Streptococcus, Lactobacillus, Lactococcus, Enterococcus, Leuconostoc, and Pediococcus, were recovered from 28 retail fermented food products in Maryland, identified to species with 16S-23S rRNA spacer PCRs, and characterized for antimicrobial susceptibility against eight antimicrobials. Besides intrinsic resistance to ciprofloxacin or vancomycin in some lactobacilli, tetracycline resistance was observed in two Streptococcus thermophilus isolates from one cheese and one sour cream sample and was associated with the presence of a nonconjugative tet(S) gene. The results indicated a low level of AR among naturally occurring and starter LAB cultures in fermented dairy and meat products in the United States; therefore, the probability for foodborne LAB to serve as reservoirs of AR is low. Further studies involving a larger sample size are needed to assess the potential risk of AR gene transfer from LAB in fermented food products.
Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA. bge@lsu.edu
Beilei
B
Ge
Ping
P
Jiang
Feifei
F
Han
Nasreen K
NK
Saleh
Nivedita
N
Dhiman
Daniel P
DP
Fedorko
Nancy A
NA
Nelson
Jianghong
J
Meng
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D015169:Colony Count, Microbial; D003227:Conjugation, Genetic; D003257:Consumer Product Safety; D004269:DNA, Bacterial / Q000032:analysis*; D021903:DNA, Ribosomal Spacer; D003611:Dairy Products / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005285:Fermentation; D005516:Food Microbiology; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects* / Q000302:isolation & purification; D017045:Lactococcus / Q000187:drug effects / Q000302:isolation & purification; D007934:Leuconostoc / Q000187:drug effects / Q000302:isolation & purification; D008461:Meat Products / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D010376:Pediococcus / Q000187:drug effects / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D012338:RNA, Ribosomal, 23S / Q000737:chemistry; D013045:Species Specificity; D013291:Streptococcus / Q000187:drug effects / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S