Potential probiotic of Lactobacillus strains isolated from the intestinal tracts of pigs and feces of dogs with antibacterial activity against multidrug-resistant pathogenic bacteria

Putative Probiotic Ligilactobacillus salivarius Strains Isolated from the Intestines of Meat-Type Pigeon Squabs

This study aims to screen for potential probiotic lactic acid bacteria from the intestines of meat-type pigeon squabs. Ligilactobacillus salivarius YZU37 was identified as the best comprehensive performed strain. Being acid- and bile salt-tolerant, it displayed growth-inhibition activities against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium SL1344, exhibited sensitivity to 6 commonly used antibiotics, and endowed with good cell surface hydrophobicity, auto-aggregation property, and anti-oxidant activities. Results of in vitro experiments indicated that the bacteriostatic effects of this strain were related to the production of proteinaceous substances that depend on acidic conditions. Whole-genome sequencing of L. salivarius YZU37 was performed to elucidate the genetic basis underlying its probiotic potential. Pangenome analysis of L. salivarius YZU37 and other 212 L. salivarius strains available on NCBI database revealed a pigeon-unique gene coding choloylglycine hydrolase (CGH), which had higher enzyme-substrate binding affinity than that of the common CGH shared by L. salivarius strains of other sources. Annotation of the functional genes in the genome of L. salivarius YZU37 revealed genes involved in responses to acid, bile salt, heat, cold, heavy metal, and oxidative stresses. The whole genome analysis also revealed the absence of virulence and toxin genes and the presence of 65 genes distributed under 4 CAZymes classes, 2 CRISPR-cas regions, and 3 enterolysin A clusters which may confer the acid-dependent antimicrobial potential of L. salivarius YZU37. Altogether, our results highlighted the probiotic potential of L. salivarius YZU37. Further in vivo investigations are required to elucidate its beneficial effects on pigeons.

Isolation and Identification of Effective Probiotics on Drug-Resistant Acinetobacter baumannii Strains and Their Biofilms

Introduction

This study aimed to identify, assess, and isolate strong lactobacilli demonstrating broad antibacterial and anti-biofilm activity against drug-resistant strains of Acinetobacter baumannii. Additionally, the mechanism of inhibition of these organisms was to be determined.

Methods

Over a 6-month period (from December 2021 to June 2022), 53 clinical A. baumannii strains were collected from clinical samples. Twenty probiotic strains were isolated from local dairy products. Antibacterial activity of Lactobacillus strains' cell-free supernatant (CFS) was identified using the agar well diffusion method and the microbroth dilution test. Anti-biofilm effect was performed by the microtiter plate assay. The MTT assay was also used to look into the probiotics' cytotoxic effects on the L929 fibroblast cell line.

Results

During the 6-month period, 53 clinical A. baumannii strains were obtained and identified. Out of 20 lactobacillus strains, the CFS of a lactobacillus strain (named L9) showed an inhibitory effect against all A. baumannii strains. Using the broth microdilution method, it was shown that the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of CFS extracts of L9 strains against A. baumannii strains were both ¼ mg/mL. The result of the anti-biofilm showed that the selected probiotic could inhibit biofilm formation. The most common organic acid produced by all Lactobacillus strains, according to the HPLC method, was lactic acid, which was followed by acetic acid. The L929 fibroblast cell line was used in the cytotoxicity assay, which revealed that 100% of the cells in the L929 fibroblast cell line survived treatment with successive doses of CFSs for a full day.

Conclusion

The probiotic strain isolated from local yogurt in this study showed potential anti-biofilm and antimicrobial properties against all drug-resistant Acinetobacter isolates. Given the increasing interest in probiotic microorganisms based on their high health benefits, further studies are recommended on the mechanisms of action between probiotics and A. baumannii strains to find new solutions for biological control and treatment of these infections without the use of antibiotics.

The Effect of Maternal Probiotic or Synbiotic Supplementation on Sow and Offspring Gastrointestinal Microbiota, Health, and Performance

The increasing prevalence of antimicrobial-resistant pathogens has prompted the reduction in antibiotic and antimicrobial use in commercial pig production. This has led to increased research efforts to identify alternative dietary interventions to support the health and development of the pig. The crucial role of the GIT microbiota in animal health and performance is becoming increasingly evident. Hence, promoting an improved GIT microbiota, particularly the pioneer microbiota in the young pig, is a fundamental focus. Recent research has indicated that the sow's GIT microbiota is a significant contributor to the development of the offspring's microbiota. Thus, dietary manipulation of the sow's microbiota with probiotics or synbiotics, before farrowing and during lactation, is a compelling area of exploration. This review aims to identify the potential health benefits of maternal probiotic or synbiotic supplementation to both the sow and her offspring and to explore their possible modes of action. Finally, the results of maternal sow probiotic and synbiotic supplementation studies are collated and summarized. Maternal probiotic or synbiotic supplementation offers an effective strategy to modulate the sow's microbiota and thereby enhance the formation of a health-promoting pioneer microbiota in the offspring. In addition, this strategy can potentially reduce oxidative stress and inflammation in the sow and her offspring, enhance the immune potential of the milk, the immune system development in the offspring, and the sow's feed intake during lactation. Although many studies have used probiotics in the maternal sow diet, the most effective probiotic or probiotic blends remain unclear. To this extent, further direct comparative investigations using different probiotics are warranted to advance the current understanding in this area. Moreover, the number of investigations supplementing synbiotics in the maternal sow diet is limited and is an area where further exploration is warranted.

Screening of Potential Probiotic Lactobacillaceae and Their Improvement of Type 2 Diabetes Mellitus by Promoting PI3K/AKT Signaling Pathway in db/db Mice

The study aimed to isolate Lactobacillaceae strains with in vitro hypoglycemic activity and probiotic properties and to determine their antidiabetic abilities in vivo. Lactiplantibacillus plantarum 22, L. plantarum 25, Limosilactobacillus fermentum 11, and L. fermentum 305 with high in vitro hypoglycemic activity were screened from 23 strains of Lactobacillaceae isolated from human feces and identified by 16S rDNA sequencing. The fasting blood glucose (FBG) of the mice was recorded weekly. After 12 weeks, liver, kidney, and pancreas tissues were stained with hematoxylin and eosin (H&E) to observe histomorphology; the inflammatory factors were assayed by Quantitative Real-time PCR; PI3K and AKT were measured by Western blot; the short-chain fatty acids (SCFAs) were determined by LC-MS/MS. Inhibitory activities of L. plantarum 22, L. plantarum 25, L. fermentum 11, and L. fermentum 305 against α-amylase were 62.29 ± 0.44%, 51.81 ± 3.65%, 58.40 ± 1.68%, and 57.48 ± 5.04%, respectively. Their inhibitory activities to α-glucosidase were 14.89 ± 0.38%, 15.32 ± 0.89%, 52.63 ± 3.07%, and 51.79 ± 1.13%, respectively. Their survival rate after simulated gastrointestinal test were 12.42 ± 2.84%, 9.10 ± 1.12%, 5.86 ± 0.52%, and 8.82 ± 2.50% and their adhesion rates to Caco-2 cell were 6.09 ± 0.39%, 6.37 ± 0.28%, 6.94 ± 0.27%, and 6.91 ± 0.11%, respectively. The orthogonal tests of bacterial powders of the four strains showed that the maximum inhibitory activities to α-amylase and α-glucosidase were 93.18 ± 1.19% and 75.33 ± 2.89%, respectively. The results showed that the mixture of Lactobacillaceae could lower FBG, reduce inflammation, and liver, kidney, and pancreas damage, promote PI3K/AKT signaling pathway, and increase the content of SCFAs. The combination of L. plantarum 22, L. plantarum 25, L. fermentum 11, and L. fermentum 305 can potentially improve type 2 diabetes mellitus (T2DM).

Impact of cell-free supernatant of lactic acid bacteria on Staphylococcus aureus biofilm and its metabolites

Introduction

A safe bio-preservative agent, lactic acid bacteria (LAB) can inhibit the growth of pathogenic bacteria and spoilage organisms. Its cell-free supernatant (LAB-CFS), which is rich in bioactive compounds, is what makes LAB antibacterial work.

Methods

This study focused on the changes in biofilm activity and related metabolic pathways of S. aureus treated with lactic acid bacteria planktonic CFS (LAB-pk-CFS) and biofilm state (LAB-bf-CFS).

Results

The findings demonstrated that the LAB-CFS treatment considerably slowed Staphylococcus aureus (S. aureus) growth and prevented it from forming biofilms. Additionally, it inhibits the physiological traits of the S. aureus biofilm, including hydrophobicity, motility, eDNA, and PIA associated to the biofilm. The metabolites of S. aureus biofilm treated with LAB-CFS were greater in the LAB-bf-CFS than they were in the LAB-pk-CFS, according to metabolomics studies. Important metabolic pathways such amino acids and carbohydrates metabolism were among the most noticeably altered metabolic pathways.

Discussion

These findings show that LAB-CFS has a strong potential to combat S. aureus infections.

MRSA compendium of epidemiology, transmission, pathophysiology, treatment, and prevention within one health framework

Staphylococcus aureus is recognized as commensal as well as opportunistic pathogen of humans and animals. Methicillin resistant strain of S. aureus (MRSA) has emerged as a major pathogen in hospitals, community and veterinary settings that compromises the public health and livestock production. MRSA basically emerged from MSSA after acquiring SCCmec element through gene transfer containing mecA gene responsible for encoding PBP-2α. This protein renders the MRSA resistant to most of the β-lactam antibiotics. Due to the continuous increasing prevalence and transmission of MRSA in hospitals, community and veterinary settings posing a major threat to public health. Furthermore, high pathogenicity of MRSA due to a number of virulence factors produced by S. aureus along with antibiotic resistance help to breach the immunity of host and responsible for causing severe infections in humans and animals. The clinical manifestations of MRSA consist of skin and soft tissues infection to bacteremia, septicemia, toxic shock, and scalded skin syndrome. Moreover, due to the increasing resistance of MRSA to number of antibiotics, there is need to approach alternatives ways to overcome economic as well as human losses. This review is going to discuss various aspects of MRSA starting from emergence, transmission, epidemiology, pathophysiology, disease patterns in hosts, novel treatment, and control strategies.

Apilactobacillus kunkeei Alleviated Toxicity of Acetamiprid in Honeybee

Nowadays, colony collapse disorder extensively affects honeybees. Insecticides, including acetamiprid, are considered as critical factors. As prevalent probiotics, we speculated that supplementation with lactic acid bacteria (LAB) could alleviate acetamiprid-induced health injuries in honeybees. Apilactobacillus kunkeei was isolated from beebread; it significantly increased the survival of honeybees under acetamiprid exportation (from 84% to 92%). Based on 16S rRNA pyrosequencing, information on the intestinal bacteria of honeybees was acquired. The results showed that supplementation with A. kunkeei significantly increased survival and decreased pollen consumption by honeybees under acetamiprid exportation. Under acetamiprid exportation, some opportunistic and pathogenic bacteria invaded the intestinal regions. Subsequently, the community richness and diversity of symbiotic microbiota were decreased. The community structure of intestinal bacteria was changed and differentiated. However, with the supplementation of A. kunkeei, the community richness and community diversity of symbiotic microbiota showed an upward trend, and the community structure was stabilized. Our results showed that A. kunkeei alleviated acetamiprid-induced symbiotic microbiota dysregulation and mortality in honeybees. This demonstrates the importance of symbiotic microbiota in honeybees and supports the application of Apilactobacillus kunkeei as probiotics in beekeeping.

Antimicrobial activity against Staphylococcus aureus and genome features of Lactiplantibacillus plantarum LR-14 from Sichuan pickles

The persistence of Staphylococcus aureus within biofilm can lead to contamination of medical devices and life-threatening infections. Luckily, lactic acid bacteria (LAB) have an inhibitory effect on the growth of these bacteria. This study aims to select LAB strains from fermented vegetables, and analyze their potential inhibition activities against S. aureus. In total, 45 isolates of LAB were successfully isolated from Sichuan pickles, and the CFS of Lactiplantibacillus plantarum LR-14 exerted the strongest inhibitory effect against S. aureus. Moreover, S. aureus cells in planktonic and biofilm states both wrinkled and damaged when treated with the CFS of L. plantarum LR-14. In addition, whole genome sequencing analysis indicates that L. plantarum LR-14 contains various functional genes, including predicted extracellular polysaccharides (EPS) biosynthesis genes, and genes participating in the synthesis and metabolism of fatty acid, implying that L. plantarum LR-14 has the potential to be used as a probiotic with multiple functions.

Antidepressant Shugan Jieyu Capsule Alters Gut Microbiota and Intestinal Microbiome Function in Rats With Chronic Unpredictable Mild Stress -Induced Depression

Shugan Jieyu Capsule (SG) has been widely used in China to treat mild to moderate depression. Hypericum perforatum L. (St John’s Wort, SJW) is the main ingredient of SG and has been used as herbal medicine to treat depression in western countries. However, it is known that SJW has low bioavailability and does not easily get through the blood-brain barrier. Therefore, how SG plays an antidepressant effect in the central nervous system (CNS) remains an urgent problem to be solved. Mounting research has described the relationship between antidepressants and intestinal microbiota to illuminate antidepressive mechanisms in the CNS. We aimed to investigate the effects of therapy with SG on the function of gut microbiota and intestinal microbiota in rats with chronic unpredictable mild stress (CUMS)-induced depression. The psychophysiological state and the hypothalamic-pituitary-adrenal axis function of rats are evaluated through behavioral experiments, corticosterone levels, serotonin levels, and adrenal index measurements. 16S rDNA amplicon sequencing is used to test the changes in gut microbiota and make functional predictions of genes. With treatment of SG, the depression-like behaviors of CUMS-induced rats were reversed; the corticosterone levels and the adrenal index decreased significantly; the level of serotonin increased significantly; and the alpha and beta diversity analysis of microbiota showed an increase in the richness and uniformity of the flora were increased. SG regulated the relative abundance of Actinobacteria, Erysipelotrichaceae, Bifidobacteriaceae, Atopobiaceae, Dubosiella, and Bifidobacterium; Linear discriminant analysis effect size analysis demonstrated that Lactobacillaceae (family level), Lactobacillus (genus level), Lactobacillales (order level), Bacilli (class level), and Lactobacillus-reuteri (species level) were biomarkers in the SG group samples, and also likely to modulate metabolic pathways, such as those involved in carbohydrate metabolism, amino acid metabolism, and signal transduction. These data clearly illustrated the effect of SG on gut microbiome, thus laying the foundation for uncovering more insights on the therapeutic function of the traditional Chinese antidepressants. The potential of SG on mechanisms of antidepression to alter gut microbiota and intestinal microbiome function exposed to CUMS can be explored.

Glucocorticoid-induced loss of beneficial gut bacterial extracellular vesicles is associated with the pathogenesis of osteonecrosis

Osteonecrosis of the femoral head (ONFH) commonly occurs after glucocorticoid (GC) therapy. The gut microbiota (GM) participates in regulating host health, and its composition can be altered by GC. Here, this study demonstrates that cohousing with healthy mice or colonization with GM from normal mice attenuates GC-induced ONFH. 16S rRNA gene sequencing shows that cohousing with healthy mice rescues the GC-induced reduction of gut Lactobacillus animalis. Oral supplementation of L. animalis mitigates GC-induced ONFH by increasing angiogenesis, augmenting osteogenesis, and reducing cell apoptosis. Extracellular vesicles from L. animalis (L. animalis-EVs) contain abundant functional proteins and can enter the femoral head to exert proangiogenic, pro-osteogenic, and antiapoptotic effects, while its abundance is reduced after exposure to GC. Our study suggests that the GM is involved in protecting the femoral head by transferring bacterial EVs, and that loss of L. animalis and its EVs is associated with the development of GC-induced ONFH.

Lactic acid bacteria and their bacteriocins: new potential weapons in the fight against methicillin-resistant Staphylococcus aureus

Alternative solutions are eminently needed to combat the escalating number of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Bacteriocins produced by lactic acid bacteria are promising candidates for next-generation antibiotics. Studies have found that these stable and nontoxic ribosomally synthesized antimicrobial peptides exhibit significant potency against other bacteria, including antibiotic-resistant strains. Here the authors review previous studies on bacteriocins that have been effectively employed to manage MRSA infections. The authors' review focuses on the beneficial traits of bacteriocins for further application as templates for the design of novel drugs. Treatments that combine bacteriocins with other antimicrobials to combat pervasive MRSA infections are also highlighted. In short, future studies should focus on the pharmacodynamics and pharmacokinetics of bacteriocins-antimicrobials to understand their interactions, as this aspect would likely determine their efficacy in MRSA inhibition.

Jia Wei Xiao Yao San ameliorates chronic stress-induced depression-like behaviors in mice by regulating the gut microbiome and brain metabolome in relation to purine metabolism

BACKGROUND

The pathogenesis of depression remains largely unknown. Accumulating evidence demonstrates the existence of a complex relationship between gut microbiome composition and brain functions. Jia Wei Xiao Yao San (JWXYS) is considered a potential antidepressant. However, the pharmacological mechanisms of JWXYS have not yet been clarified.

PURPOSE

This study aimed to explore the effects of JWXYS on chronic stress-induced depression-like behaviors in mice.

METHODS

A chronic restraint stress mouse model of depression was established. JWXYS was administered, and the responses of these mice to treatment were evaluated through several behavioral tests. The activity of astrocytes and microglia was detected by specific fluorescent labels. Inflammatory cytokines were quantified in intestinal and cerebral tissues. An integrated approach with full-length 16S rRNA sequencing and different types of untargeted metabolomics was conducted to investigate the relationship between the gut microbiome at the species level, metabolic brain functions, and JWXYS.

RESULTS

We found that behavioral symptoms were associated with the relative abundance of Lactobacillus animalis. After JWXYS treatment, the relative abundance of Ileibacterium valens with enzymes potentially involved in purine metabolism was also described. The activation of astrocytes and microglia was negatively correlated with the relative abundance of L. animalis. Combined with network pharmacological analysis, several targets predicted based on JWXYS treatment focused on purine metabolism, which was also enriched from cerebral metabolites regulated by JWXYS.

CONCLUSION

Our study suggests that L. animalis is involved in depression-like behaviors in mice. JWXYS increases the abundance of I. valens with potential enzymes in relation to cerebral purine metabolism, which is positively correlated with the activation of astrocytes in the amygdala.

In Vitro assessment of anti-Campylobacter activity of lactobacillus strains isolated from canine rectal swabs

Background

Campylobacteriosis is currently the most frequently reported zoonosis. Dogs, especially puppies or those with diarrhea, are considered a possible source of human infection. Probiotic bacteria, such as Lactobacillus species, seem to be a valuable tool in controlling of intestinal pathogenic microorganisms in dogs. The main purpose of this study was to assess the anti-Campylobacter activity and some probiotic properties, like ability to produce H₂O_2, bile salt and low pH tolerance of Lactobacillus strains isolated from gastrointestinal tract of healthy dogs.

Results

A total of 39 rectal swabs derived from healthy dogs and 19 from dogs with diarrhea were examined to detect Lactobacillus and Campylobacter bacteria respectively. In total, 30 strains of Lactobacillus genus and four strains of Campylobacter genus were isolated and identified. Of the 30 strains of Lactobacillus, 22 showed an inhibitory effect towards Campylobacter. Four strains with the strongest antagonism towards Campylobacter bacteria (L. salivarius 25 K/L/1, L. rhamnosus 42 K/L/2, L. sakei 50 K/L/1 and L. agilis 55 K/L/1) were selected to assess their potential probiotic traits. Three out of four analyzed strains produced extracellular H₂O_2. All displayed very good or moderate survival at pH 3.0 and 2.0 and showed high tolerance to 0.5% and 1% bile salts.

Conclusions

Among selected Lactobacillus strains, all may have a potential probiotic application in reducing Campylobacter spp. in dogs and thus prevent transmission of infection to humans, although the best candidate for probiotic seems to be L. sakei 50 K/L/1. Further in vitro and in vivo studies are needed.

A potential probiotic Leuconostoc mesenteroides TBE-8 for honey bee

An isolated bacterium TBE-8, was identified as Leuconostoc mesenteroides according to the sequences of 16S rDNA and the 16S-23S rDNA intergenic spacer region. The probiotic properties of the L. mesenteroides TBE-8 strain were characterized and revealed that TBE-8 could utilize various carbohydrates, exhibited high tolerance to sucrose's osmotic pressure and acidic conditions, and could mitigate the impact of the bee pathogen Paenibacillus larvae. In addition, we found that the TBE-8 broth increased the expression of the nutrition-related genes major royal jelly protein 1 and vitellogenin in bees by approximately 1400- and 20-fold, respectively. The expression of genes encoding two antibacterial peptides, hymenoptaecin and apidaecin, in the bee abdomen was significantly increased by 17- and 7-fold in bees fed with the TBE-8 fermented broth. Furthermore, we fed four-frame bee colonies with 50% sucrose syrup containing TBE-8 and can detect the presence of approximately 2 × 106 16S rDNA copies of TBE-8 in the guts of all bees in 24 h, and the retention of TBE-8 in the bee gut for at least 5 days. These findings indicate that the L. mesenteroides TBE-8 has high potential as a bee probiotic and could enhance the health of bee colonies.

Antimicrobial Susceptibility of Lactic Acid Bacteria Strains of Potential Use as Feed Additives - The Basic Safety and Usefulness Criterion

The spread of resistance to antibiotics is a major health concern worldwide due to the increasing rate of isolation of multidrug resistant pathogens hampering the treatment of infections. The food chain has been recognized as one of the key routes of antibiotic resistant bacteria transmission between animals and humans. Considering that lactic acid bacteria (LAB) could act as a reservoir of transferable antibiotic resistance genes, LAB strains intended to be used as feed additives should be monitored for their safety. Sixty-five LAB strains which might be potentially used as probiotic feed additives or silage inoculants, were assessed for susceptibility to eight clinically relevant antimicrobials by a minimum inhibitory concentration determination. Among antimicrobial resistant strains, a prevalence of selected genes associated with the acquired resistance was investigated. Nineteen LAB strains displayed phenotypic resistance to one antibiotic, and 15 strains were resistant to more than one of the tested antibiotics. The resistance to aminoglycosides and tetracyclines were the most prevalent and were found in 37 and 26% of the studied strains, respectively. Phenotypic resistance to other antimicrobials was found in single strains. Determinants related to resistance phenotypes were detected in 15 strains as follows, the aph(3″)-IIIa gene in 9 strains, the lnu(A) gene in three strains, the str(A)-str(B), erm(B), msr(C), and tet(M) genes in two strains and the tet(K) gene in one strain. The nucleotide sequences of the detected genes revealed homology to the sequences of the transmissible resistance genes found in lactic acid bacteria as well as pathogenic bacteria. Our study highlights that LAB may be a reservoir of antimicrobial resistance determinants, thus, the first and key step in considering the usefulness of LAB strains as feed additives should be an assessment of their antibiotic resistance. This safety criterion should always precede more complex studies, such as an assessment of adaptability of a strain or its beneficial effect on a host. These results would help in the selection of the best LAB strains for use as feed additives. Importantly, presented data can be useful for revising the current microbiological cut-off values within the genus Lactobacillus and Pediococcus.

Screening of Lactic Acid Bacteria with Inhibitory Activity against ETEC K88 as Feed Additive and the Effects on Sows and Piglets

Simple Summary

Numerous reports have suggested that lactic acid bacteria (LAB), which are important probiotics, can protect animals against pathogen-induced injury and inflammation, regulate gut microflora, enhance digestive tract function, improve animal growth performance, and decrease the incidence of diarrhea caused by enterotoxigenic (ETEC) that expresses K88. This research selected Lactobacillus (L.) reuteri P7, L. amylovorus P8, and L. johnsonii P15 with good inhibition against ETEC K88 and excellent probiotic properties screened from 295 LAB strains isolated from fecal samples from 55 healthy weaned piglets for a study on feeding of sows in late pregnancy and weaned piglets. Feed supplementation with these three strains improved reproductive performance of sows and growth performance of piglets, decreased the incidence of diarrhea in piglets, and increased the antioxidant capacity of serum in both sows and piglets. Therefore, L. reuteri P7, L. amylovorus P8, and L. johnsonii P15 might be considered as potential antibiotic alternatives for further study.

Abstract

Enterotoxigenic Escherichia coli (ETEC), which expresses K88 is the principal microorganism responsible for bacterial diarrhea in pig husbandry, and the indiscriminate use of antibiotics has caused many problems; therefore, antibiotics need to be replaced in order to prevent diarrhea caused by ETEC K88. The objective of this study was to screen excellent lactic acid bacteria (LAB) strains that inhibit ETEC K88 and explore their effects as probiotic supplementation on reproduction, growth performance, diarrheal incidence, and antioxidant capacity of serum in sows and weaned piglets. Three LAB strains, P7, P8, and P15, screened from 295 LAB strains and assigned to Lactobacillus (L.) reuteri, L. amylovorus, and L. johnsonii with high inhibitory activity against ETEC K88 were selected for a study on feeding of sows and weaned piglets. These strains were chosen for their good physiological and biochemical characteristics, excellent exopolysaccharide (EPS) production capacity, hydrophobicity, auto-aggregation ability, survival in gastrointestinal (GI) fluids, lack of hemolytic activity, and broad-spectrum activity against a wide range of microorganisms. The results indicate that LAB strains P7, P8, and P15 had significant effects on improving the reproductive performance of sows and the growth performance of weaned piglets, increasing the activity of antioxidant enzymes and immune indexes in both.

Evaluation of Probiotic Characteristics of Newly Isolated Lactic Acid Bacteria from Dry-Aged Hanwoo Beef

Dry aging is a traditional method that improves meat quality, and diverse microbial communities are changed during the process. Lactic acid bacteria (LAB) are widely present in fermented foods and has many beneficial effects, such as immune enhancement and maintenance of intestinal homeostasis. In this study, we conducted metagenomic analysis to evaluate the changes in the microbial composition of dry-aged beef. We found that lactic acid bacterial strains were abundant in dry-aged beef including Lactobacillus sakei and Enterococcus faecalis. We investigated their abilities in acid and bile tolerance, adhesion to the host, antibiotic resistance, and antimicrobial activity as potential probiotics, confirming that L. sakei and E. faecalis strains had remarkable capability as probiotics. The isolates from dry-aged beef showed at least 70% survival under acidic conditions in addition to an increase in the survival level under bile conditions. Antibiotic susceptibility and antibacterial activity assays further verified their effectiveness in inhibiting all pathogenic bacteria tested, and most of them had low resistance to antibiotics. Finally, we used the Caenorhabditis elegans model to confirm their life extension and influence on host resistance. In the model system, 12D26 and 20D48 strains had great abilities to extend the nematode lifespan and to improve host resistance, respectively. These results suggest the potential use of newly isolated LAB strains from dry-aged beef as probiotic candidates for production of fermented meat.

Antibiotic Resistance Crisis: An Update on Antagonistic Interactions between Probiotics and Methicillin-Resistant Staphylococcus aureus (MRSA)

Antimicrobial resistance (AMR) havoc is a global multifaceted crisis endowing a significant challenge for the successful eradication of devastating pathogens. Methicillin-Resistant Staphylococcus aureus (MRSA) is an enduring superbug involved in causing devastating infections. Although MRSA is a frequent colonizer of human skin, wound, and anterior nares, the intestinal colonization of MRSA has greatly increased the risk of inducing MRSA-associated colitis besides creating a conducive environment for horizontal transfer of resistant genes to commensal microbes. On the other hand, staphylococcal resistance to last-resort antibiotics has urged the development of novel antimicrobial agents for the effective decolonization of MRSA. In response, probiotics and their metabolites (postbiotics) have been proposed as the adjunct therapeutic avenues. Probiotics exhibit a multitude of anti-MRSA actions (anti-bacterial, anti-biofilm, anti-virulence, anti-drug resistance, co-aggregation, and anti-quorum sensing) through the production of numerous antagonistic compounds such as organic acids, hydrogen peroxide, low molecular weight compounds, biosurfactants, bacteriocins, and bacteriocins like inhibitory substances. Besides, probiotics stabilize the epithelial barrier function and positively modulate the host immune system via regulating various signal transduction mechanisms. Preclinical and human intervention studies have suggested that probiotics outcompete with MRSA by exhibiting anti-colonization mechanisms via protective, competitive, and displacement mode. In this review, we aim to highlight the dynamics of MRSA associated virulence and drug resistance properties, and how probiotics antagonize MRSA through various mechanism of action.

State-of-the-Art of the Nutritional Alternatives to the Use of Antibiotics in Humans and Monogastric Animals

Simple Summary

Antibiotic resistance represents a worldwide recognized issue affecting both human and veterinary medicine, with a particular focus being directed towards monogastric animals destined for human consumption. This scenario is the result of frequent utilization of the antibiotics either for therapeutic purposes (humans and animals) or as growth promoters (farmed animals). Therefore, the search for nutritional alternatives has progressively been the object of significant efforts by the scientific community. So far, probiotics, prebiotics and postbiotics are considered the most promising products, as they are capable of preventing or treating gastrointestinal diseases as well as restoring a eubiosis condition after antibiotic-induced dysbiosis development. This review provides an updated state-of-the-art of these nutritional alternatives in both humans and monogastric animals.

Abstract

In recent years, the indiscriminate use of antibiotics has been perpetrated across human medicine, animals destined for zootechnical productions and companion animals. Apart from increasing the resistance rate of numerous microorganisms and generating multi-drug resistance (MDR), the nonrational administration of antibiotics causes sudden changes in the structure of the intestinal microbiota such as dysbiotic phenomena that can have a great clinical significance for both humans and animals. The aim of this review is to describe the state-of-the-art of alternative therapies to the use of antibiotics and their effectiveness in humans and monogastric animals (poultry, pigs, fish, rabbits, dogs and cats). In particular, those molecules (probiotics, prebiotics and postbiotics) which have a direct function on the gastrointestinal health are herein critically analysed in the prevention or treatment of gastrointestinal diseases or dysbiosis induced by the consumption of antibiotics.