The ability of probiotic bacteria to adhere to the intestinal epithelium play an important role in colonization of the gastrointestinal tract, preventing their elimination by peristalsis and providing a competitive advantage in this ecosystem. To identify bacterial traits related to adhesion the probiotic strain L. acidophilus M92 was examined for autoaggregation ability and cell surface hydrophobicity L. acidophilus M92 exhibits a strong autoaggregation phenotype and also coaggregation with some pathogen microorganisms that may form a barrier that prevents their colonization. The examined probiotic strain manifests a good degree of hydrophobicity determined by microbial adhesion to hydrocarbons. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase, which suggests the possible role of cell surface layer (S-layer) proteins, approximated at 45 kDa, in a L. acidophilus M92. The relationship between autoaggregation and adhesion ability to intestinal tissue was investigated by observing the adhesivity of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 M LiCl reduced autaggregation and in vitro adhesion of this strain.

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

Development of reliable and eco-accommodating methods for the synthesis of nanoparticles is a vital step in the field of nanotechnology. Silver nanoparticles are important because of their exceptional chemical, physical, and biological properties, and hence applications. In the last decade, numerous efforts were made to develop green methods of synthesis to avoid the hazardous byproducts. This review describes the methods of green synthesis for Ag-NPs and their numerous applications. It also describes the comparison of efficient synthesis methods via green routes over physical and chemical methods, which provide strong evidence for the selection of suitable method for the synthesis of Ag-NPs.

A review on green synthesis of silver nanoparticles and their applications

Today, there is an ever-growing interest on natural food ingredients both by consumers and producers in the food industry. In fact, people are looking for those products in the market which are free from artificial and synthetic additives and can promote their health. These food bioactive ingredients should be formulated in such a way that protects them against harsh process and environmental conditions and safely could be delivered to the target organs and cells. Nanoencapsulation is a perfect strategy for this situation and there have been many studies in recent years for nanoencapsulation of food components and nutraceuticals by different technologies. In this review paper, our main goal is firstly to have an overview of nanoencapsulation techniques applicable to food ingredients in a systematic classification, i.e., lipid-based nanocarriers, nature-inspired nanocarriers, special-equipment-based nanocarriers, biopolymer nanocarriers, and other miscellaneous nanocarriers. Then, application of these cutting-edge nanocarriers for different nutraceuticals including phenolic compounds and antioxidants, natural food colorants, antimicrobial agents and essential oils, vitamins, minerals, flavors, fish oils and essential fatty acids will be discussed along with presenting some examples in each field.

A systematic review on nanoencapsulation of food bioactive ingredients and nutraceuticals by various nanocarriers

Recent progress of cell-penetrating peptides as new carriers for intracellular cargo delivery.

Composition and functional properties of propolis (bee glue): A review.

This study was conducted to identify and evaluate the antimicrobial activity of some Lactobacillus isolates of chicken origin. Among 90 isolates 14 Lactobacillus species were distinguished using MALDI-TOF mass spectrometry and 16S-ARDRA. The dominant species was L. salivarius (34.4%), followed by L. johnsonii (23.3%), L. crispatus (13.3%) and L. reuteri (11.1%). All lactobacilli were screened for antimicrobial activity against wild-type strains of Salmonella enterica, Escherichia coli, and Clostridium perfringens. Results from the agar slab method showed that all Lactobacillus isolates were able to produce active compounds on solid media with antagonistic properties against these pathogens. The highest sensitivity to lactobacilli was observed in C. perfringens strains, and the lowest in E. coli. Lactobacillus salivarius exhibited particularly strong antagonism towards all of the indicator bacteria. Strains of L. ingluviei and L. johnsonii and one strain of L. salivarius (10d) selectively inhibited the growth of C. perfringens. No antimicrobial activity of many Lactobacillus isolates was observed when cell-free culture supernatant was used in a well diffusion assay. All Lactobacillus isolates exhibited the ability to produce H2O2 and proved to be hydrophobic (excluding one of L. salivarius). [Int Microbiol 19(1):57-67 (2016)]Keywords: Lactobacillus spp. · avian lactobacilli · antimicrobial activity · gut health · poultry pathogens

Antimicrobial activity of

Infections in poultry are an economic and health problem in Europe and worldwide. The most common infections are associated with salmonellosis, colibacillosis, campylobacteriosis, and others. The prevalence of Campylobacter-positive poultry flocks in European countries varies from 18% to 90%. In the United States, the prevalence of infected flocks is nearly 90%. A similar percentage of infection has been noted for salmonellosis (about 75–90%) and E. coli (90–95%). The occurence of Clostridium perfringens is a major problem for the poultry industry, with some estimates suggesting colonization of as many as 95% of chickens, resulting in clinical or subclinical infections. In the US, annual economic losses due to Salmonella infections run from $1.188 billion to over $11.588 billion, based on an estimated 1.92 million cases. Similar costs are observed in the case of other types of infections. In 2005 economic losses in the the poultry industry due to mortalities reached 1,000,000 USD. Infections caused by these pathogens, often through poultry products, are also a serious public health issue. The progressive increase in the number of multi-drug resistant bacteria and the complete ban on the use of antibiotics in livestock feed in the EU, as well as the partial ban in the US, have led to the growth of research on the use of bacteriophages to combat bacterial infections in humans and animals. The high success rate and safety of phage therapy in comparison with antibiotics are partly due to their specificity for selected bacteria and the ability to infect only one species, serotype or strain. This mechanism does not cause the destruction of commensal bacterial flora. Phages are currently being used with success in humans and animals in targeted therapies for slow-healing infections. They have also found application in the US in eliminating pathogens from the surface of foods of animal and plant origin. At a time of growing antibiotic resistance in bacteria and the resulting restrictions on the use of antibiotics, bacteriophages can provide an alternative means of eliminating pathogens.

Bacteriophage therapy to combat bacterial infections in poultry.

Background: A global problem of multi-drug resistance (MDR) among bacteria is the cause of hundreds of thousands of deaths every year. In response to the significant increase of MDR bacteria, legislative measures have widely been taken to limit or eliminate the use of antibiotics, including in the form of feed additives for livestock, but also in metaphylaxis and its treatment, which was the subject of EU Regulation in 2019/6. Numerous studies have documented that bacteria use both phenotypis and gentic strategies enabling a natural defence against antibiotics and the induction of mechanisms in increasing resistance to the used antibacterial chemicals. The mechanisms presented in this review developed by the bacteria have a significant impact on reducing the ability to combat bacterial infections in humans and animals. Moreover, the high prevalence of multi-resistant strains in the environment and the ease of transmission of drug-resistance genes between the different bacterial species including commensal flora and pathogenic like foodborne pathogens (E. coli, Campylobacter spp., Enterococcus spp., Salmonella spp., Listeria spp., Staphylococcus spp.) favor the rapid spread of multi-resistance among bacteria in humans and animals. Given the global threat posed by the widespread phenomenon of multi-drug resistance among bacteria which are dangerous for humans and animals, the subject of this study is the presentation of the mechanisms of resistance in most frequent bacteria called as “foodborne pathoges” isolated from human and animals. In order to present the significance of the global problem related to multi-drug resistance among selected pathogens, especially those danger to humans, the publication also presents statistical data on the percentage range of occurrence of drug resistance among selected bacteria in various regions of the world. In addition to the phenotypic characteristics of pathogen resistance, this review also presents detailed information on the detection of drug resistance genes for specific groups of antibiotics. It should be emphasized that the manuscript also presents the results of own research i.e., Campylobacter spp., E. coli or Enetrococcus spp. This subject and the presentation of data on the risks of drug resistance among bacteria will contribute to initiating research in implementing the prevention of drug resistance and the development of alternatives for antimicrobials methods of controlling bacteria.

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Antibiotic Resistance in Bacteria—A Review

The aim of this study was to identify Lactobacillus isolates derived from turkeys from six Polish farms and to characterize their phenotypic and genotypic antibiotic resistance profiles. Among 62 isolates identified by MALDI-TOF mass spectrometry and restriction analysis of 16S rDNA, the dominant species was L. salivarius (35%), followed by L. crispatus (21%), L. ingluviei (14.5%) and L. johnsonii (10%). A high prevalence of resistance to tetracycline (68% resistant isolates), lincomycin (64.5%) and enrofloxacin (60%) among the lactobacilli tested was observed. Fewer than 50% isolates were resistant to ampicillin (47%), erythromycin (45%), streptomycin (31%), chloramphenicol (29%) and gentamicin (10%). As many as 64,5% of the isolates showed multidrug resistance. High MIC values for ampicillin (≥64 μg/ml) were usually accompanied by elevated MICs for cephalosporins (≥16 μg/ml) and high MICs for tiamulin, i.e. ≥32 μg/ml, were noted in most of the turkey lactobacilli (61%). The occurrence of resistance genes was associated with phenotypic resistance, with the exception of five phenotypically susceptible isolates that contained the tetM, tetL, ermC, ermB or cat genes. The most frequently identified were ermB (45% isolates), tetL (40%), tetW (37%) and tetM (29%), and the occurrence of lnuA (18%), cat (10%), ermC (6%), ant(6)-Ia (5%) and aadE (5%) was less frequent. The mechanism of ampicillin resistance has not been elucidated, but the results of nitrocefin test confirmed that it is not involved in the production of beta-lactamases. The high rate of antibiotic resistance observed in this study indicates the need to implement the principles of rational use of antibiotics in poultry. The presence of transmissible resistant genes in lactobacilli may contribute to the development of antibiotic resistant pathogenic strains that pose a threat to both poultry and consumers. The results of these studies may be useful for committees providing guidance on antibiotic susceptibility of microorganisms in order to revise and supplement current microbiological cut-offs values within the genus Lactobacillus.

/pdf/identification-and-antibiotic-susceptibility-of-lactobacilli-2z27dfzt3e.pdf

Identification and antibiotic susceptibility of lactobacilli isolated from turkeys.

We assessed the antibiotic resistance and genetic diversity of 27 Enterococcus faecalis isolates from 25 wild bird species in Poland. Resistance to lincomycin (100%) was most common followed by tetracycline (48%), erythromycin (44%), and ciprofloxacin (22%). High-level resistance to streptomycin and kanamycin was observed in 19% and 15% of isolates, respectively. One isolate (4%) exhibited low-level resistance to penicillin and vancomycin, and all isolates were susceptible to gentamicin and chloramphenicol. Antibiotic resistance was linked to the tet(M), tet(L), erm(A), erm(B), msr(A/B), ant(6)-Ia, and aph(3′)-IIIa genes. None of the tested van (vanA, vanB, vanC1, vanC2/C3, vanD, vanE, vanG) genes were found in the vancomycin-resistant isolate. Based on pulsed-field gel electrophoresis and multilocus sequence typing analysis, the E. faecalis population from wild birds revealed high genetic diversity. All isolates were divided into 22 pulsotypes and 18 sequence types (STs), among which seven STs...

https://bioone.org/journals/Journal-of-Wildlife-Diseases/volume-54/issue-2/2017-05-118/WILD-BIRDS-AS-A-POTENTIAL-SOURCE-OF-KNOWN-AND-NOVEL/10.7589/2017-05-118.pdf

Anna Nowaczek

Papers

Antimicrobial activity of

Bacteriophage therapy to combat bacterial infections in poultry.

Antibiotic Resistance in Bacteria—A Review

Identification and antibiotic susceptibility of lactobacilli isolated from turkeys.

Wild birds as a potential source of known and novel multilocus sequence types of antibiotic-resistant enterococcus faecalis