Antibiotic sensitivity pattern of indigenous lactobacilli isolated from curd and human milk samples. - Related Documents




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605501.0000Antibiotic sensitivity pattern of indigenous lactobacilli isolated from curd and human milk samples. The gut microbiota plays a vital role in host well-being and lactic acid bacteria (LAB) have gained an overwhelming attention as health promoter. This perception has evolved from traditional dairy products to a money-spinning market of probiotics. The safety of probiotics is coupled to their intended use and LAB may act as pool of antimicrobial resistance genes that could be transferred to pathogens, either in food matrix or in gastrointestinal tract, which could be detrimental to host. This study evaluated the antibiotic susceptibility patterns of LAB isolated from curd (20) and human milk (11) samples. Antibiotic susceptibility was determined against 26 common antibiotics, following reference disc diffusion assay. A varied response in terms of susceptibility and resistance towards antibiotics was recorded. Among curd isolates, D7 (Lactobacillus plantarum) was the most resistant followed by D4, D8, D10 and D25. Among human milk isolates, HM-1 (L. casei) showed the highest resistance profile. All LAB isolates displayed high susceptibility pattern towards imipenem and meropenem. In general, high resistivity was exhibited by human milk isolates. The present study showed that antibiotic resistance is widespread among different lactobacilli, which may pose a food safety concern. Therefore, antibiotic sensitivity should be considered as a vital tool for safety assessment of probiotics.201728444600
590510.9996Characterization of Antibiotic Resistance Genes from Lactobacillus Isolated from Traditional Dairy Products. Lactobacilli are widely used as starter cultures or probiotics in yoghurt, cheese, beer, wine, pickles, preserved food, and silage. They are generally recognized as safe (GRAS). However, recent studies have shown that some lactic acid bacteria (LAB) strains carry antibiotic resistance genes and are resistant to antibiotics. Some of them may even transfer their intrinsic antibiotic resistance genes to other LAB or pathogens via horizontal gene transfer, thus threatening human health. A total of 33 Lactobacillus strains was isolated from fermented milk collected from different areas of China. We analyzed (1) their levels of antibiotic resistance using a standardized dilution method, (2) their antibiotic resistance gene profiles by polymerase chain reaction (PCR) using gene-specific primers, and (3) the transferability of some of the detected resistance markers by a filter mating assay. All Lactobacillus strains were found to be resistant to vancomycin, but susceptible to gentamicin, linezolid, neomycin, erythromycin, and clindamycin. Their susceptibilities to tetracycline, kanamycin, ciprofloxacin, streptomycin, quinupristin/dalfopristin, trimethoprim, ampicillin, rifampicin, and chloramphenicol was different. Results from our PCR analysis revealed 19 vancomycin, 10 ciprofloxacin, and 1 tetracycline-resistant bacteria that carried the van(X), van(E), gyr(A), and tet(M) genes, respectively. Finally, no transferal of the monitored antibiotic resistance genes was observed in the filter mating assay. Taken together, our study generated the antibiotic resistance profiles of some milk-originated lactobacilli isolates and preliminarily assessed their risk of transferring antibiotic gene to other bacteria. The study may provide important data concerning the safe use of LAB.201728182844
243520.9996Genotypic and Technological Characterization of Lactic Acid Bacteria and Coagulase-Negative Staphylococci Isolated from Sucuk: A Preliminary Screening of Potential Starter Cultures. This study aimed to characterize lactic acid bacteria (LAB) and coagulase-negative staphylococci (CoNS) isolated from traditionally produced sucuk for their potential use in starter culture development and food safety applications in fermented meat products. A total of 145 isolates (95 LAB and 50 CoNS) were analyzed through genetic identification, phylogenetic analysis, and assessments of technological properties. Antagonistic activity against Listeria monocytogenes and Staphylococcus aureus was also evaluated, along with antibiotic sensitivity. Among LAB, Lactiplantibacillus plantarum was the most prevalent species (60 isolates), while Staphylococcus xylosus was the predominant CoNS species (24 isolates). The isolates exhibited diverse technological properties and varying levels of antagonistic activity against the tested pathogens. Antibiotic sensitivity tests indicated that 15 selected isolates were negative for antibiotic resistance genes. Overall, this comprehensive characterization provides valuable insights for the development of starter cultures and for enhancing food safety in fermented meat products.202541154032
590730.9996Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products. Commercial starter culture bacteria are widely used in the production of dairy products and could represent a potential source for spread of genes encoding resistance to antimicrobial agents. To learn more about the antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products, a total of 189 isolates of lactic acid bacteria were examined for susceptibility to ampicillin, penicillin G, cephalothin, vancomycin, bacitracin, gentamicin, streptomycin, erythromycin, tetracycline, chloramphenicol, quinupristin/dalfopristin, ciprofloxacin, trimethoprim and sulphadiazine using Etest for MIC determination. Most of the isolates (140) originated from 39 dairy products (yoghurt, sour cream, fermented milk and cheese), while 49 were isolated directly from nine commercial cultures. The bacteria belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Streptococcus. Only one of the 189 isolates was classified as resistant to an antimicrobial agent included in the study. This isolate, a lactobacillus, was classified as high level resistant to streptomycin. The remaining isolates were not classified as resistant to the antimicrobial agents included other than to those they are known to have a natural reduced susceptibility to. Thus, starter culture bacteria in Norwegian dairy products do not seem to represent a source for spread of genes encoding resistance to antimicrobial agents.200111482563
599440.9996Characterization of Erythromycin and Tetracycline Resistance in Lactobacillus fermentum Strains. Lactobacillus fermentum colonizing gastrointestinal and urogenital tracts of humans and animals is widely used in manufacturing of fermented products and as probiotics. These bacteria may function as vehicles of antibiotic resistance genes, which can be transferred to pathogenic bacteria. Therefore, monitoring and control of transmissible antibiotic resistance determinants in these microorganisms is necessary to approve their safety status. The aim of this study was to characterize erythromycin and tetracycline resistance of L. fermentum isolates and to estimate the potential transfer of resistance genes from lactobacilli to the other Gram-positive and Gram-negative bacteria. Among six L. fermentum strains isolated from human feces and commercial dairy products, five strains demonstrated phenotypic resistance to tetracycline. PCR screening for antibiotic resistance determinants revealed plasmid-located tetracycline resistance genes tet(K) and tet(M) in all strains and erythromycin resistance genes erm(B) in the chromosome of L. fermentum 5-1 and erm(C) in the plasmid of L. fermentum 3-4. All tested lactobacilli lacked conjugative transposon Tn916 and were not able to transfer tetracycline resistance genes to Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Acinetobacter baumannii, Citrobacter freundii, and Escherichia coli by filter mating. Staphylococcus haemolyticus did not accept erythromycin resistance genes from corresponding Lactobacillus strains. Thus, in the present study, L. fermentum was not implicated in the spread of erythromycin and tetracycline resistance, but still these strains pose the threat to the environment and human health because they harbored erythromycin and tetracycline resistance genes in their plasmids and therefore should not be used in foods and probiotics.201830534155
590950.9996Antibiotic susceptibility profiles of Lactobacillus reuteri and Lactobacillus fermentum. Lactobacillus reuteri and Lactobacillus fermentum, which are commonly used as food processing aids and probiotics, can potentially act as reservoirs of antibiotic resistance genes. Acquired resistance genes may be transferred via the food chain or in the gastrointestinal tract to pathogenic bacteria. Knowledge of the distributions of antibiotic MICs for a species is needed when using a phenotypic method to assess the presence of acquired resistance genes. In the present study, 56 L. reuteri and 56 L. fermentum strains that differed by source and spatial and temporal origin were assessed for antibiotic susceptibility using an Etest kit and a broth microdilution protocol. L. fermentum strains displayed a uniform distribution of MICs for all six antibiotics tested. L. reuteri strains had a bimodal distribution of MICs or a distribution with MICs above the test range for 7 of the 14 antibiotics tested. Genetic relatedness was observed among L. reuteri strains with high MICs for both ampicillin and tetracycline and among strains with high MICs for both erythromycin and clindamycin. Results obtained with the Etest and the broth microdilution method corresponded well with each other. Thus, further research may make it possible to define microbiological breakpoints for distinguishing between strains with and without acquired resistance genes.200717340877
590660.9995Antibiotic resistance of probiotic strains of lactic acid bacteria isolated from marketed foods and drugs. OBJECTIVE: To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probiotics. METHODS: Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR. RESULTS: Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis. CONCLUSION: Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.200920163065
590870.9995Evaluation of Tetracycline Resistance and Determination of the Tentative Microbiological Cutoff Values in Lactic Acid Bacterial Species. Lactic acid bacteria (LAB) are widely used as probiotics in the food industry owing to their beneficial effects on human health. However, numerous antibiotic resistance genes have been found in LAB strains, especially tetracycline resistance genes. Notably, the potential transferability of these genes poses safety risks. To comprehensively evaluate tetracycline resistance in LAB, we determined the tetracycline susceptibility patterns of 478 LAB strains belonging to four genera and eight species. By comparing phenotypes with genotypes based on genome-wide annotations, five tetracycline resistance genes, tet(M), tet(W/N/W), tet(L), tet(S), and tet(45), were detected in LAB. Multiple LAB strains without tetracycline resistance genes were found to be resistant to tetracycline at the currently recommended cutoff values. Thus, based on the minimum inhibitory concentrations of tetracycline for these LAB strains, the species-specific microbiological cutoff values for Lactobacillus (para)gasseri, Lactobacillus johnsonii, and Lactobacillus crispatus to tetracycline were first developed using the Turnidge, Kronvall, and eyeball methods. The cutoff values for Lactiplantibacillus plantarum were re-established and could be used to better distinguish susceptible strains from strains with acquired resistance. Finally, we verified that these five genes play a role in tetracycline resistance and found that tet(M) and tet(W/N/W) are the most widely distributed tetracycline resistance genes in LAB.202134683449
606580.9995Screening for enterocins and detection of hemolysin and vancomycin resistance in enterococci of different origins. The inhibitory activity of 122 out of 426 Enterococcus strains of geographically widespread origin and from different sources (food and feed, animal isolates, clinical and nonclinical human isolates) was tested against a wide range of indicator bacteria. Seventy-two strains, mainly belonging to the species Enterococcus faecium and Enterococcus faecalis were bacteriocinogenic. A remarkable variation of inhibitory spectra occurred among the strains tested, including inhibition of, for instance, only closely related enterococci, other lactic acid bacteria (LAB), food spoilage and pathogenic bacteria. No correlation could be found between the origin of the strains and the type of inhibitory spectrum, although a clustering of human isolates from both fecal and clinical origin was observed in the group of strains inhibiting lactic acid bacteria, Listeria, and either Staphylococcus or Clostridium. No relationship could be established between the presence of enterocin structural genes and the origin of the strain either, and hence no correlation seemed to exist between the presence of known enterocin genes and the activity spectra of these enterococci. The structural gene of enterocin A was widely distributed among E. faecium strains, whereas that of enterocin B only occurred in the presence of enterocin A. The vancomycin resistance phenotype as well as the presence of vancomycin resistance genes was also investigated. The vanA gene only occurred among E. faecium strains. The incidence of beta-hemolysis was not restricted to E. faecalis strains, but among the E. faecium strains the structural genes of cytolysin were not detected. beta-Hemolysis occurred in strains both from food and nonfood origin. It has been concluded that bacteriocin-producing E. faecium strains lacking hemolytic activity and not carrying cytolysin nor vancomycin resistance genes may be useful as starter cultures, cocultures, or probiotics.200312810293
607390.9995Molecular Assessment and Validation of the Selected Enterococcal Strains as Probiotics. Probiotics are live microorganisms which confer health benefits to the host. Lactic acid bacteria (LAB) are used as probiotics since decades. Enterococci being the member of LAB have proven probiotic strains; therefore, this study was aimed at finding out the potential probiotic candidates from the pool of locally isolated strains. For initial screening, one hundred and twenty-two strains were selected and subjected to different confirmatory and phenotypic tests to choose the best strains that have potential probiotic criteria, i.e., no potential virulence traits, antibiotic resistance, and having tolerance properties. Keeping this criterion, only eleven strains (n = 11) were selected for further assessment. All virulence traits such as production of hemolysin, gelatinase, biofilm, and DNase were performed and not found in the tested strains. The molecular assessment indicates the presence of few virulence-associated genes in Enterococcus faecalis strains with variable frequency. The phenotypic and genotypic assessments of antibiotic resistance profile indicate that the selected strain was susceptible to ten commonly used antibiotics, and there were no transferrable antibiotic resistance genes. The presence of CRISPR-Cas genes also confirmed the absence of antibiotic resistance genes. Various enterocin-producing genes like EntP, EntB, EntA, and EntQ were also identified in the selected strains which make them promising probiotic lead strains. Different tolerance assays like acid, NaCl, and gastric juice tolerance that mimic host conditions was also evaluated by providing artificial conditions. Cellular adhesion and aggregation properties like auto- and co-aggregation were also checked and their results reflect all in the favor of lead probiotic strains.202537731160
5897100.9995Characterization of microbiota in Arapaima gigas intestine and isolation of potential probiotic bacteria. AIMS: The aim of this study was to determine the intestinal microbiota of pirarucu (Arapaima gigas) in different growth stages (adult and fingerlings) and to isolate and identify potential probiotic bacteria. METHODS AND RESULTS: High-throughput sequencing analysis of the intestinal contents revealed that the majority of sequences belonged to the Proteobacteria, Fusobacteria and Firmicutes phyla. At the genus level, the greatest number of sequences belonged to Bradyrhizobium in adult fish, while Cetobacterium was the most abundant in juvenile fish. Twenty-three lactic-acid bacteria (LABs) were isolated on MRS agar from healthy juvenile fish. The isolates were tested in vitro for probiotic properties. Two isolates (identified as strains of Lactococcus lactis subsp. lactis and Enterococcus faecium) displayed antagonism against all 10 pathogens tested, were nonhaemolytic and maintained good viability for at least 3 weeks when supplemented to fish diets. The presence of a number of antibiotic resistance genes (ARGs), conferring resistance to erythromycin, tetracycline and chloramphenicol, was investigated by PCR. CONCLUSIONS: The absence of ARGs investigated the potential to antagonize pathogens, and favourable growth and survival characteristics indicate that these autochthonous isolates have the potential to be considered probiotics, which will be studied in future in vivo experiments. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has demonstrated, for the first time, the normal microbiota in the A. gigas intestine during different life stages and the presence of LAB strains. It also demonstrated LAB antibiotic resistance and antagonistic behaviour against pathogens isolated from the same fish.201728833934
5900110.9995Safety profiles of beneficial lactic acid bacteria isolated from dairy systems. This study aimed to assess the safety aspects of 15 lactic acid bacteria (LAB) strains previously isolated from a dairy environment with relation to their beneficial features. LAB strains were assessed using phenotypic methods according to their production of virulence factors at 25 °C and 37 °C, as well as by examining their potential resistance to 15 antibiotics. Polymerase chain reaction (PCR) was also used to identify the presence of 50 genes associated with virulence factors and antibiotic resistance in the strains. None of the strains presented hemolytic activity or the production of gelatinase, lipase, deoxyribonuclease, or the tested biogenic amines. Based on the disk diffusion assay, all strains were resistant to oxacillin and sulfa/trimethoprim. Further, some were resistant to gentamicin (14), clindamycin (11), vancomycin (9), rifampicin (8), erythromycin (5), tetracycline (4), ampicillin (2), and chloramphenicol (1); no strain was resistant to imipenem. Regarding virulence- and antibiotic-resistance-related genes, 19 out of 50 tested genes were present in some strains; there was a variable association of expression. Based on the obtained data, the isolates presented relatively safe characteristics and behavior, findings that should lead to further studies to assess their potential usage as beneficial cultures in the food industry.202031970700
3663120.9995Microbiological Quality and Antimicrobial Resistance of Commercial Probiotic Products for Food-Producing Animals. Probiotics have been popularly used in livestock production as an alternative to antibiotics. This study aimed to investigate the microbiological quality and phenotypic and genotypic antimicrobial resistance of bacteria in probiotic products sold for food animals. A total of 45 probiotic products were examined for the number of viable cells, species, and antimicrobial susceptibility; the contamination of Escherichia coli and Salmonella; and the presence of 112 genes encoding resistance to clinically important antimicrobials and transferability of AMR determinants. The results showed that 29 of 45 products (64.4%) were incorrectly labeled in either number of viable cells or bacterial species. None of the tested products were contaminated with E. coli and Salmonella. A total of 33 out of 64 bacterial isolates (51.6%) exhibited resistance to at least one antimicrobial agent. Of the 45 products tested, 16 (35.5%) carried AMR genes. Almost all AMR genes detected in probiotic products were not correlated to the AMR phenotype of probiotic strains formulated in the products. Three streptomycin-resistant Lactobacillus isolates could horizontally transfer their AMR determinants. The findings demonstrated that the probiotic products could serve as reservoirs for the spread of AMR genes and may not yield benefits to animals as claimed. The need for the adequate quality control of probiotic products is highlighted.202438391534
6051130.9995Antibiotic susceptibility of different lactic acid bacteria strains. Five lactic acid bacteria (LAB) strains belonging to species Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis and Streptococcus thermophilus were tested for their susceptibility to 27 antibiotics. The minimum inhibitory concentrations of each antimicrobial were determined using a microdilution test. Among the strains a high susceptibility was detected for most of the cell-wall synthesis inhibitors (penicillins, cefoxitin and vancomycin) and resistance toward inhibitors of DNA synthesis (trimethoprim/sulfonamides and fluoroquinolones). Generally, the Lactobacillus strains were inhibited by antibiotics such as chloramphenicol, erythromycin and tetracycline at breakpoint levels lower or equal to the levels defined by the European Food Safety Authority. Despite the very similar profile of S. thermophilus LC201 to lactobacilli, the detection of resistance toward erythromycin necessitates the performance of additional tests in order to prove the absence of transferable resistance genes.201122146692
6063140.9995A potentially probiotic strain of Enterococcus faecalis from human milk that is avirulent, antibiotic sensitive, and nonbreaching of the gut barrier. Human milk is a key source of promising probiotic lactic acid bacteria. The Enterococcus species, because of their dual commensal and pathogenic nature, demand critical safety analysis to establish them as probiotic candidates. In this study, eighteen E. faecalis strains from human milk of mothers living in Pakistan were typed at the strain level by riboprinting. The typed strains were then evaluated in vitro for physiological safety and the presence of transmissible antibiotic resistance genes, adhesion genes, biogenic amines, and virulence factors. Selected strains were then checked for tolerance to gastrointestinal acid and bile as criteria for probiotic efficacy. Molecular typing revealed that the strains fell into five distinct clusters or ribotypes. Testing revealed that they were non-hemolytic; however, all strains had gelatinase activity except NPL-493. The isolates were susceptible to most clinically important antibiotics except streptomycin. Molecular screening for antibiotic resistance genes, adhesion genes, biogenic amines, and virulence factors indicated that none of the strains possessed resistance genes for aminoglycosides, vancomycin, bacitracin, tetracycline, or clindamycin. Most virulence factors were absent except for the genes gelE and efaAs associated with gut adhesion and translocation, which were present in all except NPL-493. Strain NPL-493 was the most promising probiotic candidate demonstrating significant tolerance to the acid, bile, and digestive enzymes in the human GIT and antibacterial activity against multiple pathogens. The study concluded that E. faecalis NPL-493 from human milk was safe among all the strains and could be considered a potential probiotic.202235107663
6059150.9995Identification and functional traits of lactic acid bacteria isolated from Ciauscolo salami produced in Central Italy. Lactic acid bacteria (LAB) from Ciauscolo salami produced in Marche Region of Central Italy, and LAB strains belonging to our laboratory collection were examined for their capability to survive at low pH and bile, to adhere to Caco-2 cells, and for antibiotic resistance. LAB from Ciauscolo were identified by ARDRA and RAPD-PCR. Our study showed that all LAB strains had good adaptation to gastric juice and moderate tolerance to bile. The adhesiveness was variable among strains but significantly lower in LAB from food. Antibiotic resistance was broadly spread among food strains, with level of resistance exceeding 15% for all the antibiotics tested. The resistance determinants erm(B) and tet(M) were found in nine strains of food origin (21.4%) while tet(L) in one strain of our collection (5%). Our work suggests that fermented foods are valuable sources of bacterial strains with functional traits of intestinal lactobacilli. These bacteria may be further studied for their use in probiotic applications.201425089780
2822160.9995Antimicrobial resistance of bacterial flora associated with bovine products in South Africa. The administration of subtherapeutic doses of antibiotics to livestock introduces selective pressures that may lead to the emergence and dissemination of resistant bacteria. This study determined the antibiotic-resistance spectra of the microbial flora found on freshly slaughtered and retail beef and in unpasteurized and pasteurized packaged milk. Staphylococci, Enterobacteriaeae, and isolates from total aerobic plate counts were tested for resistance to vancomycin, streptomycin, methicillin, tetracycline, and gentamicin using the disc diffusion susceptibility test and resistance to penicillin was determined by using oxacillin. A larger proportion of resistance to most antibiotics, except for vancomycin, was displayed by isolates from abattoir samples. The incidence of multiple antibiotic resistance (MAR) pathogenic bacteria is also higher in the abattoir. Resistance genes lost because of lack of selective pressure or resistant flora being replaced by more sensitive flora during processing is the reason for the lower incidence of MAR pathogenic bacteria among retail samples. These resistant bacteria can be transferred to humans through the consumption of rare or raw beef and unpasteurized milk, thus rendering the resultant food-related infections difficult to treat. The present findings clearly demonstrate that antibiotic-resistant bacteria in beef and milk pose a serious problem in South Africa.199910382649
3643170.9995Antimicrobial Resistance of Lactic Acid Bacteria from Nono, a Naturally Fermented Milk Product. BACKGROUND: Antimicrobial resistance (AMR) is one of the biggest threats to public health. The food chain has been recognised as a vehicle for transmitting AMR bacteria. However, information about resistant strains isolated from African traditional fermented foods remains limited. Nono is a traditional, naturally fermented milk product consumed by many pastoral communities across West Africa. The main aim of this study was to investigate and determine the AMR patterns of lactic acid bacteria (LAB) involved in the traditional fermentation of milk for Nono production, and the presence of transferable AMR determinants. METHODS: One hundred (100) LAB isolates from Nono identified in a previous study as Limosilactobacillus fermentum, Lactobacillus delbrueckii, Streptococcus thermophilus, Streptococcus infantarius, Lentilactobacillus senioris, Leuconostoc pseudomesenteriodes, and Enterococcus thailandicus were investigated. The minimum inhibitory concentration (MIC) was determined for 18 antimicrobials using the micro-broth dilution method. In addition, LAB isolates were screened for 28 antimicrobial resistance genes using PCR. The ability of LAB isolates to transfer tetracycline and streptomycin resistance genes to Enterococcus faecalis was also investigated. RESULTS: The experiments revealed variable antimicrobial susceptibility according to the LAB isolate and the antimicrobial tested. The tetracycline resistance genes tet(S) and tet(M) were detected in isolates Ent. thailandicus 52 and S. infantarius 10. Additionally, aad(E) encoding resistance to streptomycin was detected in Ent. thailandicus 52. The conjugation experiments suggested that the tet(S) and aad(E) genes were transferable in vitro from isolate Ent. thailandicus 52 to Ent. faecalis JH2-2. SIGNIFICANCE AND IMPACT: Traditional fermented foods play a significant role in the diet of millions of people in Africa, yet their contribution to the burden of AMR is largely unknown. This study highlights that LAB involved in traditionally fermented foods could be potential reservoirs of AMR. It also underscores the relevant safety issues of Ent. thailandicus 52 and S. infantarius 10 for use as starter cultures as they carry transferable AMR genes. Starter cultures are an essential aspect of improving the safety and quality attributes of African fermented foods. However, AMR monitoring is an important safety aspect in the selection of starter cultures for improving traditional fermentation technologies.202337237746
5598180.9995Antibiotic Resistance in Lactic Acid Bacteria from Dairy Products in Northern Italy. Background: The spread of antibiotic resistance genes (ARGs) from the food chain is a significant public health concern. Dairy products from raw milk containing lactic acid bacteria (LAB) resistant to antimicrobials may serve as vectors for the transfer of resistance to commensal or potentially pathogenic bacteria in the human gut. Detecting ARGs in dairy products and milk is, therefore, crucial and could aid in the development of strategies to mitigate resistance dissemination through the food chain. Objectives: This study aimed to determine the presence of ARGs and assess the antibiotic susceptibility of LAB strains isolated from dairy products made from raw milk. Methods: Fifty-four LAB strains were isolated from 41 dairy samples and were tested for antimicrobial susceptibility using broth microdilution to determine Minimal Inhibitory Concentration (MIC). Moreover, the presence of resistance genes related to tetracyclines, beta-lactams, quinolones, and erythromycin was examined using six multiplex PCR assays. Results: Lactobacillus spp. and Leuconostoc spp. strains exhibited a high level of resistance to vancomycin (93-100%). Low-level resistance (4.2-20%) was observed in Lactococcus spp. and Lactobacillus spp. strains against tetracycline. Additionally, Lactococcus spp. strains showed resistance to trimethoprim/sulfamethoxazole, erythromycin, and clindamycin. Twenty-two out of 54 LAB strains (40.7%) carried at least one antibiotic resistance gene, and five of these were multidrug-resistant. Genes associated with acquired resistance to tetracycline were commonly detected, with tetK being the most frequent determinant. Conclusions: This study demonstrated that LABs in dairy products can act as reservoirs for ARGs, potentially contributing to the horizontal transfer of resistance within microbial communities in food and consumers. These findings highlight the need for the ongoing surveillance of antibiotic resistance in LAB and the implementation of control measures to minimize the dissemination of resistance through dairy products.202540298519
3660190.9995Graduate Student Literature Review: Enterotoxigenic potential and antimicrobial resistance of staphylococci from Brazilian artisanal raw milk cheeses. More than 30 types of artisanal cheeses are known in Brazil; however, microorganisms, such as Staphylococcus spp., can contaminate raw milk cheeses through different sources, from milking to processing. Staphylococcal food poisoning results from the consumption of food in which coagulase-positive staphylococci, mostly Staphylococcus aureus, have developed and produced enterotoxins. In addition, an emerging public health concern is the increasing antimicrobial resistance of some Staphylococcus strains. Furthermore, the ability of Staphylococcus spp. in sharing antibiotic resistance-related genes with other bacteria increases this problem. In light of these observations, this review aims to discuss the presence of, enterotoxins of, and antibiotic-resistant of Staphylococcus spp. in Brazilian artisanal cheese produced with raw milk.202235636996