Non-pathogenic Microbes Research Articles

A rare occurrence of sepsis caused by Veillonella parvula in a patient with underlying choledocholithiasis

Veillonella parvula is a Gram-negative obligate anaerobe that is part of the normal anaerobic flora. The microorganism is usually regarded as colonization if isolated from the patient’s sample. Here we report a rare case of sepsis caused by V. parvula in a female patient with underlying cholelithiasis. She was successfully treated with amoxicillin-clavulanate with appropriate dosage and at the correct time of her presentation to the hospital. V. parvula should not be considered a non-pathogenic microbe in patients with a history of underlying disease such as choledocholithiasis. Keywords: Veillonella parvula, sepsis, choledocholithiasis.

DYNAMICS OF THE MICROBIOLOGICAL INDEXES AT LIME TREATMENT OF SLUDGES FROM A PURIFICATION PLANT

Microbiological indexes have been studied in dynamics at lime treatment and independent planting of lavender (Lavandula angustifolia, variety “Hemus”) and sweet basil (Ocimum basilicum, variety “Genovese”) of fresh sludges from a purification plant, with concentrations of quicklime: 10%, 20% and 30% for a 40-day period of composting. The microbiological analysis includes determining of nonpathogenic (non-spore forming bacteria, bacilli, actynomycetes, micromycetes, bacteria, which assimilate mineral nitrogen) and pathogenic (Salmonella spp., Escherichia coli and coliforms, Enterococcus, Clostridium perfringens) microflora. Out of the beneficial microflora in the sludges the quantity of the non-spore forming bacteria is the biggest, and the lowest is of the actynomycetes. A basic share in the composition of the pathogenic microflora occupies Clostridium perfringens, followed by Escherichia coli and coliforms, and Enterococcus. Absence of Salmonella spp. was established in the studied sludges. The best results for the disinfection of the sludges displays the adding of 30% quicklime (followed by the variants with 20% and 30% lime), on 5-th day of the experiment setting. The pH decrease in the period of the study leads to a repeated development of pathogenic microflora. In the meantime the creation of an alkaline medium leads to decrease in the quantity of the beneficial microorganisms. The decrease of the moisture and the drying of the sludges for the study period display a weaker effect on the dynamics of the microflora in comparison with the pH increase impact. The planting of lavender and basil independently in the sludges samples from a purification plant has a beneficial effect (a little bit better with the lavender variants) for increase of the quantity of nonpathogenic microbes and pathogens frequency of occurrence decrease. The effect is intensified by increasing the plant development period.

Deep Learning for Rapid Identification of Microbes Using Metabolomics Profiles.

Rapid detection of viable microbes remains a challenge in fields such as microbial food safety. We here present the application of deep learning algorithms to the rapid detection of pathogenic and non-pathogenic microbes using metabolomics data. Microbes were incubated for 4 h in a protein-free defined medium, followed by 1D 1H nuclear magnetic resonance (NMR) spectroscopy measurements. NMR spectra were analyzed by spectral binning in an untargeted metabolomics approach. We trained multilayer (“deep”) artificial neural networks (ANN) on the data and used the resulting models to predict spectra of unknown microbes. ANN predicted unknown microbes in this laboratory setting with an average accuracy of 99.2% when using a simple feature selection method. We also describe learning behavior of the employed ANN and the optimization strategies that worked well with these networks for our datasets. Performance was compared to other current data analysis methods, and ANN consistently scored higher than random forest models and support vector machines, highlighting the potential of deep learning in metabolomics data analysis.

Comparative hologenomics of two Ixodes scapularis tick populations in New Jersey.

Tick-borne diseases, such as those transmitted by the blacklegged tick Ixodes scapularis, are a significant and growing public health problem in the US. There is mounting evidence that co-occurring non-pathogenic microbes can also impact tick-borne disease transmission. Shotgun metagenome sequencing enables sampling of the complete tick hologenome—the collective genomes of the tick and all of the microbial species contained therein, whether pathogenic, commensal or symbiotic. This approach simultaneously uncovers taxonomic composition and allows the detection of intraspecific genetic variation, making it a useful tool to compare spatial differences across tick populations. We evaluated this approach by comparing hologenome data from two tick samples (N = 6 ticks per location) collected at a relatively fine spatial scale, approximately 23 km apart, within a single US county. Several intriguing variants in the data between the two sites were detected, including polymorphisms in both in the tick’s own mitochondrial DNA and that of a rickettsial endosymbiont. The two samples were broadly similar in terms of the microbial species present, including multiple known tick-borne pathogens (Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum), filarial nematodes, and Wolbachia and Babesia species. We assembled the complete genome of the rickettsial endosymbiont (most likely Rickettsia buchneri) from both populations. Our results provide further evidence for the use of shotgun metagenome sequencing as a tool to compare tick hologenomes and differentiate tick populations across localized spatial scales.

Bacterial contamination of retailed syrups traded in Wukari, North East, Nigeria

There is an increasing concern that syrups may contain pathogenic or non-pathogenic microbes that can pose as public health risk to patients. This research was to investigate the bacterial contamination of retailed syrups sold in Wukari. Eighteen (18) different brands of syrups were collected from different medicine stores in Wukari, North East Nigeria. These various brands of syrups were taken to the Microbiology Laboratory, Federal University Wukari for analysis using standard bacteriological techniques. The results show that syrups samples with contaminants included the M & B paracetamol, Emzor paracetamol, M & B flagyl (Loxagyl), Emzor Chloroquin, M & B Antimalarial preparation (Artelumex), Emzor cough syrup (Emzolyn), Emzor digestion syrup (Emtrisil), Jawa digestion syrup (Jawasil), Emzor multivitamin (Emvite), Tuyil pharmacy multivitamin (Vami-vite), Emzor blood tonic, and Jawa blood tonic while those that contained no contaminants included the Emzor flagyl(Emgyl), M & B chloroquin(Vinaquin), Emzor antimalarial preparation (Lokmal), Jawa cough syrup(D-Koff), Emzor vitamin c and Tuyil pharmacy vitamin C. The researched revealed that twelve (12) of the syrups were contaminated with bacteria isolates of Bacillus spp 9 (45%), Lactobacillus spp 5 (25%), Proteus spp 2 (10%), Staphylococcus aureus 2 (10%), Pseudomonas spp 1 (5%) and Klebsiella spp 1 (5%). The presence of the isolates could possibly be as a result of the production process and improper handling and protection of the containers containing the products. It is therefore recommended that monitoring agencies should ensure that these syrups do not present health hazards to the public during production and retail of products.

Fungal Endophytes Help Grasses to Tolerate Sap-Sucking Herbivores Through a Hormone-Signaling System

Plants possess a sophisticated hormone-signaling system, which includes salicylic acid (SA) and jasmonic acid (JA), to defend themselves from herbivores. In addition, this immune system is modulated by nonpathogenic microbes that live asymptomatically within intercellular spaces of host grasses. We investigated the resistance triggered by defense hormones, and that provided by endophyte Epichloë gansuensis against aphid Rhopalosiphum padi, and how the endophyte regulates this tripartite interaction. We detected that endophyte-induced plant tolerance to the aphid feeding and exogenous SA increased plant shoot biomass, root biomass, plant length, and chlorophyll content. Endophyte colonization induces the WRKY54 factor that overrides negative effects on plant growth and possibly suppresses SA accumulation. In addition, the endophyte promotes a level of JA that is antagonistic to the SA pathway. By disabling the SA mechanism for herbivore-mediated plant growth inhibition, the endophyte induces plant tolerance to herbivory.

Antimicrobial Resistance of Escherichia coli from Broilers, Pigs, and Cattle in the Greater Kumasi Metropolis, Ghana.

Globally, resistance to antimicrobial drugs in food animals is on the rise. Escherichia coli of livestock, though commensal in nature, serves as reservoir for antimicrobial resistance genes with the potential of disseminating them. This study sought to examine the antimicrobial resistance profiles of Escherichia coli in broilers, pigs, and cattle in the Kumasi Metropolis and undertake molecular characterisation of the resistances. Faecal E. coli isolates (n = 48) were obtained from 10 broiler farms, (n = 43) from 15 pig farms, and (n = 42) from cattle from the Kumasi Abattoir using standard bacteriological techniques. The Kirby–Bauer disc diffusion method was employed in testing the sensitivities of 133 E. coli isolates to 15 antimicrobials. All 48 isolates from broilers presented no resistance to amoxicillin/clavulanic acid and ceftiofur. A 100% resistance to meropenem was observed in pig and cattle isolates. Multidrug resistance (MDR) across animal groups was 95.8% (n = 46), 95.3% (n = 41), and 64.3% (n = 27) for broilers, pigs, and cattle, respectively. Twenty-eight isolates presenting phenotypic resistance to aminopenicillins and cephalosporins were screened for the presence of extended-spectrum beta-lactamase (ESBL) genes by PCR. One isolate from poultry and another from cattle tested positive for the blaCTX-M ESBL gene. There were no positives for the blaTEM and blaSHV ESBL genes. Commensal E. coli of food animal origin represents an important reservoir of antimicrobial resistance that transfers resistance to pathogenic and nonpathogenic microbes affecting humans and animals. There is an urgent need to institute routine surveillance for the establishment of the mechanisms and molecular orientation of resistance in these organisms.

In Vitro Antifungal and Antibacterial Effects of Biosynthesized Zinc Oxide Nanoparticles Against Selected Pathogenic and Non-Pathogenic Strains.

We have developed a simple, robust environment-friendly and efficient method for ZnO nanoparticles biosynthesis using Dalbergia sissoo fresh leaf extract. Before using these nanoparticles for antimicrobial assay, a detailed characterization was performed using techniques like Ultraviolet/Visible (UV/Vis) spectroscopy, Particle size analysis (PSA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM),Transmission electron microscopy (TEM) etc. The average size of biosynthesized ZnO nanoparticles was around 30 nm and they were pure and crystalline by nature. The effectiveness of these biosynthesized nanoparticles were checked against both pathogenic and non-pathogenic microbes. A total of eight bacterial strains-Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsilla pneumoniae, Staphylococcus aureus, Streptococcus entericus, Bacillus cereus, Pantoea cypripedii and three fungal strains-Candida albicans, Aspergilus niger and Aspergilus flavus were studied to have a clear view of the spectrum of ZnO nanoparticles anti-microbial activity. The effectiveness of biosynthesized ZnO nanoparticles against the microbes was found to be better than the standard reference antibiotics used (streptomycin, chloramphenicol and rifampicin). The results seem to be very promising and can be used for some practical applications of ZnO nanoparticles in nearfuture.

Faecal microbiome analysis reveals Clostridiales and Bacteroidales as signature gut microbes during estrus of buffalo

The non-pathogenic intestinal microbes that conquer our intestines are not an accidental jumble of organisms, but rather a disparate community of microbes that coexist, and sustain a mutualistic and symbiotic relationship with the host. The gut microbiome has been shown to be influenced by animal physiology and vice versa. However, information is still scanty. The present study aimed to analyse the variation between faecal bacteria of three different stages (proestrus, estrus and postestrus) of the estrous cycle of Murrah buffalos. A phylogenetic study of buffalo faeces derived from three different stages of estrous cycle was conducted in order to compare the bacterial diversity among these three stages. We performed an exploratory microbiome analysis of buffalo faeces using 16S rRNA sequencing during these stages of the buffalo estrous cycle. A total of three bacterial phyla with six different bacterial orders and twenty-three different genera were identified among all the three comparative phases of the estrous cycle. Among them, the Clostridiales were found to be the most abundant, and Bacteroidales were present exclusive during the estrus phase. As faeces is a source of gut microbes and a non-invasive representative of the metabolic steroids and perceptible pheromones, the profiling of gut microbes during estrous cycle would provide clues towards the major microbes contributing to the perceptible pheromones during estrus stage. To the best of our knowledge, this is the first ever report describing the faecal bacterial diversity during estrous cycle of any ruminant species. Although future studies are required to understand the role of Clostridiales and Bacteroidales in faecal pheromone metabolism.

Evaluation of possible biological control of Fusarium concentricum sp. using plant extracts and antagonistic species of microbes in vitro

Background: Fusarium concentricum is one of the most devastating fungi responsible for fruit and vegetable crops rot worldwide. The present study was designed to find an ecofriendly control measure for pathogenic Fusarium concentricum, using suitable bioagents. Methods: Medicinal plant extracts were evaluated or their antifungal activities against Fusarium concentricum using the poisoned food and serial dilution methods. Antagonistic potency of some nonpathogenic microbes was also assessed on Fusarium concentricum using the dual culture method. Results: Highest inhibition of growth of Fusarium concentricum was observed with 68.1% (0.389 mg per 90 mm Petri plate) of mycelia on Coccinia grandis plant leaf extract, in comparison to the control grown with 100.0% (1.22 mg/dish). The tested plants extract showed MIC values rages of 80-150 µg/ml on the isolated fungus. The highest inhibition of radial growth was observed using Trichoderma viride on Fusarium concentricum (46.01% inhibition). Conclusions: The findings of present study would be benevolent for antifungal drug development to control Fusarium concentricum causing fruit and vegetable rot.

Type I IFNs facilitate innate immune control of the opportunistic bacteria Burkholderia cenocepacia in the macrophage cytosol.

The mammalian immune system is constantly challenged by signals from both pathogenic and non-pathogenic microbes. Many of these non-pathogenic microbes have pathogenic potential if the immune system is compromised. The importance of type I interferons (IFNs) in orchestrating innate immune responses to pathogenic microbes has become clear in recent years. However, the control of opportunistic pathogens–and especially intracellular bacteria–by type I IFNs remains less appreciated. In this study, we use the opportunistic, Gram-negative bacterial pathogen Burkholderia cenocepacia (Bc) to show that type I IFNs are capable of limiting bacterial replication in macrophages, preventing illness in immunocompetent mice. Sustained type I IFN signaling through cytosolic receptors allows for increased expression of autophagy and linear ubiquitination mediators, which slows bacterial replication. Transcriptomic analyses and in vivo studies also show that LPS stimulation does not replicate the conditions of intracellular Gram-negative bacterial infection as it pertains to type I IFN stimulation or signaling. This study highlights the importance of type I IFNs in protection against opportunistic pathogens through innate immunity, without the need for damaging inflammatory responses.

Antimicrobial resistance and molecular genotyping of Escherichia coli and Staphylococcus aureus isolated from some Egyptian cheeses.

Objective:This work investigated the antimicrobial resistance (AMR) and virulence of Escherichia coli and Staphylococcus aureus in communally consumed cheeses in Egypt.Materials and Methods:This study examined 100 samples of Domiati, Tallaga, Cheddar, and Ras cheese collected from several shops and supermarkets. Samples were spread on selective media to isolate bacterial strains. Molecular characterization of bacterial isolates was carried out using polymerase chain reaction to determine Shiga toxin 1 (stx1), Shiga toxin 2 (stx2), eaeA, and nuc genes. The isolates were tested for susceptibility to 14 antibiotics by disk diffusion assay.Results:In this study, several E. coli serotypes were identified. E. coli O26:H11, O103:H2, and O111:H2 expressed stx1/2, E. coli O114:H4 expressed stx1, E. coli O17:H18, O21:H7 and O146:H21 expressed stx2, while only E. coli O26:H11 and O111:H2 expressed eaeA. The E. coli isolates were resistant to at least one antibiotic, while most isolates (82.4%) showed multidrug resistance (MDR). AMR to erythromycin was the highest (100%), followed by nalidixic acid (94.1%), cefotaxime (82.4%), vancomycin and cephalothin (64.7%), penicillin G (52.9%), sulfamethoxazole (47.1%), amikacin and kanamycin (35.3%), ampicillin (29.4%), tetracycline and ciprofloxacin (23.5%), and doxycycline (11.8%), while gentamicin showed the least resistance (5.9%). The multiple antibiotic resistance (MAR) index of the isolated E. coli ranged from 0.071 to 1 (mean = 0.478). All S. aureus isolates expressed the nuc gene and demonstrated resistance to at least one antibiotic, and 90% of isolates were MDR. AMR to kanamycin and cephalothin was the highest (100%), followed by penicillin (90%), doxycycline (70%), nalidixic acid and sulfamethoxazole (60%), erythromycin (50%), tetracycline, cefotaxime, and gentamicin (40%), ciprofloxacin and ampicillin (30%), and amikacin (20%). In comparison, vancomycin showed the least resistance (10%). MAR index of isolated S. aureus ranged from 0.143 to 1 (mean = 0.529). Conclusion:The antimicrobial-resistant E. coli and S. aureus are potential risks for public health and may have a role in disseminating AMR to other pathogenic and non-pathogenic microbes.

A comparative evaluation of probiotic formulations in prevention of dental caries: A clinical study.

Caries is a multifactorial disease, microbes being an important etiological factor. "Probiotics" are nonpathogenic microbes which can stimulate health-promoting flora and suppress pathogens. It's the era of prevention, clinical approach toward prevention by altering bacterial ecology is the need of the hour. The aim of the study was to evaluate anticariogenic effect of probiotic curd (Amul's Probiotic Dahi) containing Lactobacillus acidophilus (La5) and Bifidobacterium lactis (Bb12) in 6-12 years of age group. This was a prospective, randomized, nonblinded study conducted on school children aged between 6 and 12 years having Decayed, Missing, and Filled Teeth and/or deft ≥2. Selected subjects were divided into two groups of 31 each, study group received probiotic curd ("Amul's Probiotic Dahi") two times a day in a quantity of 100 g, respectively, for 21 days and control group did not receive any intervention. Salivary Streptococcus mutans count and salivary pH estimation were done at the baseline, after 7 days and at the end after 24 days, for comparison. No statistical difference was seen in salivary S. mutans count between both groups, after intervention of 7 days. However, there was significant difference in salivary S. mutans count at the end of 24 days. There was no statistical difference in salivary pH between both groups. The present study concludes that probiotics substitute decreases salivary S. mutans count after continuous consumption for 3 weeks and there is no short-term effect on salivary pH.

Evaluation of possible biological control of Fusarium sp. using plant extracts and antagonistic species of microbes in vitro

Background: Fusarium species is one of the most devastating fungi responsible for fruit and vegetable crops rot worldwide. The present study was designed to find an ecofriendly control measure for pathogenic Fusarium species, using suitable bioagents. Methods: Medicinal plant extracts were evaluated or their antifungal activities against Fusarium species using the poisoned food method. Antagonistic potency of some nonpathogenic microbes was also assessed on Fusarium species using the dual culture method. Results: Highest inhibitionofgrowth of Fusariumsp. wasobservedwith 68.1% (0.389 mg per 90 mm Petri plate) of mycelia on Coccinia grandis plant leaf extract, in comparison to the control grown with 100.0% (1.22 mg/dish). The highest inhibition of radial growth was observed using Trichoderma viride on Fusarium sp. (46.01% inhibition). Conclusions: The findings of present study would be benevolent for antifungal drug development to control Fusarium sp. causing fruit and vegetable rot.

Shaping the leaf microbiota: plant-microbe-microbe interactions.

The aerial portion of a plant, namely the leaf, is inhabited by pathogenic and non-pathogenic microbes. The leaf’s physical and chemical properties, combined with fluctuating and often challenging environmental factors, create surfaces that require a high degree of adaptation for microbial colonization. As a consequence, specific interactive processes have evolved to establish a plant leaf niche. Little is known about the impact of the host immune system on phyllosphere colonization by non-pathogenic microbes. These organisms can trigger plant basal defenses and benefit the host by priming for enhanced resistance to pathogens. In most disease resistance responses, microbial signals are recognized by extra- or intracellular receptors. The interactions tend to be species specific and it is unclear how they shape leaf microbial communities. In natural habitats, microbe–microbe interactions are also important for shaping leaf communities. To protect resources, plant colonizers have developed direct antagonistic or host manipulation strategies to fight competitors. Phyllosphere-colonizing microbes respond to abiotic and biotic fluctuations and are therefore an important resource for adaptive and protective traits. Understanding the complex regulatory host–microbe–microbe networks is needed to transfer current knowledge to biotechnological applications such as plant-protective probiotics.

Microbial Mind Control

Every animal is in constant communication with populations of microbes. In a recent study, O'Donnell and colleagues (2020) uncover an inter-domain conversation, defining a relationship in which a non-pathogenic microbe directly synthesizes a signal that alters host behavior for a mutually beneficial outcome.

Transdermal entry of yeast components elicits transient B cell-associated responses in skin-draining lymph nodes

Immune responses to non-pathogenic yeasts induced within the draining lymph node remain to be understood. In this study, we have investigated the changes in lymphocytes and their activity in skin-draining lymph nodes in response to transdermally injected zymosan (component of the yeast cell wall). Zymosan elicited the transient increase of B cell number and activation status without affecting the capacity for proliferation. The increased B cell content in the regional lymph nodes was likely due to the reduction of B cell egress from the tissue and in part the increase of homing from the circulation. Zymosan also upregulated the inflammatory cytokines, such as IL-1β, IL-6, IL-12, and IFNγ, regulatory cytokines IL-10 and TGFβ, and lymphoid chemokine CXCL13. Among these, the expression of IL-12 and IL-10 was markedly high in B cells. Altogether, these findings demonstrate a unique B cell-associated response to non-pathogenic yeast component in the draining lymph nodes. This will provide insights into the clinical and healthcare applications of non-pathogenic beneficial microbes.

Palaeomicrobiology: Application of Ancient DNA Sequencing to Better Understand Bacterial Genome Evolution and Adaptation

Next Generation Sequencing (NGS) has unlocked access to the wide range of non-cultivable microorganisms, including those present in the ancient past. The study of microorganisms from ancient sources (palaeomicrobiology) using DNA sequencing now provides a unique opportunity to examine ancient microbial genomic content, explore pathogenicity, and understand microbial evolution in greater detail than ever before. As a result, current studies have focused on reconstructing the evolutionary history of a number of human pathogens involved in ancient and historic pandemic events. These studies have opened the door for a variety of future palaeomicrobiology studies, which can focus on commensal microorganisms, species from non-human hosts, information from host-genomics, and the use of bacteria as proxies for additional information about past human health, behavior, migration, and culture. Here, we describe the origin and the historical and recent advances in the field of palaeomicrobiology, review some of the most notable ancient pathogenic microorganism studies, and provide perspectives on how NGS and whole genome information from ancient microorganisms contribute to our understanding of bacterial evolution on a broader scale. We conclude by exploring the application of newly developed tools in palaeomicrobiology and discussing how future studies can improve our current understanding of the co-evolution relationships between humans and non-pathogenic microbes.

Resistance of Tick Gut Microbiome to Anti-Tick Vaccines, Pathogen Infection and Antimicrobial Peptides.

Ixodes scapularis ticks harbor microbial communities including pathogenic and non-pathogenic microbes. Pathogen infection increases the expression of several tick gut proteins, which disturb the tick gut microbiota and impact bacterial biofilm formation. Anaplasma phagocytophilum induces ticks to express I. scapularis antifreeze glycoprotein (IAFGP), a protein with antimicrobial activity, while Borrelia burgdorferi induces the expression of PIXR. Here, we tested the resistance of I. scapularis microbiome to A. phagocytophilum infection, antimicrobial peptide IAFGP, and anti-tick immunity specific to PIXR. We demonstrate that A. phagocytophilum infection and IAFGP affect the taxonomic composition and taxa co-occurrence networks, but had limited impact on the functional traits of tick microbiome. In contrast, anti-tick immunity disturbed the taxonomic composition and the functional profile of tick microbiome, by increasing both the taxonomic and pathways diversity. Mechanistically, we show that anti-tick immunity increases the representation and importance of the polysaccharide biosynthesis pathways involved in biofilm formation, while these pathways are under-represented in the microbiome of ticks infected by A. phagocytophilum or exposed to IAFGP. These analyses revealed that tick microbiota is highly sensitive to anti-tick immunity, while it is less sensitive to pathogen infection and antimicrobial peptides. Results suggest that biofilm formation may be a defensive response of tick microbiome to anti-tick immunity.

Identification, tissue characterization, and innate immune role of Angiogenin-4 expression in young broiler chickens

Intestinal epithelial cells are major producers of antimicrobial proteins, which play an important role in innate immunity. In addition to defensins, the Ribonuclease A superfamily includes important antimicrobial proteins involved in host-defense mechanisms in vertebrates. Angiogenin-4 (Ang4), a member of this RNase superfamily, has been demonstrated to be secreted by Paneth cells in mice. We have successfully cloned and characterized a new chicken gene (chAng4), found for the first time in a nonmammalian species, from intestinal epithelial and lymphoid cells. Characterization of chAng4 revealed 99% nucleotide and 97% amino acid sequence homology to mouse Ang4. Similar functional regions were identified, suggesting a role in innate immunity and regulation of gut microbiota. Furthermore, the mRNA expression pattern of chAng4 was studied in broilers in the presence or absence of beneficial bacteria (probiotics) and organic acids. The results showed that one-day-old chickens expressed low levels of Ang4 in almost all the evaluated tissues (crop, proventriculus, duodenum, jejunum, ileum, and cecal tonsils), except in the bursa of Fabricius that presented the highest expression level. The addition of probiotics and organic acids for either 7 or 14 consecutive days demonstrated a direct effect of probiotics and organic acids on chAng4 expression; moreover, broilers receiving probiotics and organic acids for only 7 D showed higher levels of chAng4 expression compared with those treated for 14 D. Broilers without treatment had a constant high level of expression in cecal tonsils and bursa. In conclusion, we were able to identify and characterize a new antimicrobial gene in chickens (chAng4) throughout the gastrointestinal tract. chAng4 mRNA gene expression was associated with the presence of naturally occurring and supplemented (probiotic) bacteria. The encoded protein might have a potential bactericidal effect against intestinal nonpathogenic and pathogenic microbes, modulating the intestinal microbiota and the innate immunity, and thereby may help minimize the use of antibiotics in poultry feed.