Gastrointestinal Tract Of Animals Research Articles

Characteristics of Microbiota in Different Segments of the Digestive Tract of Lycodon rufozonatus.

The gastrointestinal tract of animals contains microbiota, forming a complex microecosystem. Gut microbes and their metabolites can regulate the development of host innate and adaptive immune systems. Animal immune systems maintain intestinal symbiotic microbiota homeostasis. However, relatively few studies have been published on reptiles, particularly snakes, and even fewer studies on different parts of the digestive tracts of these animals. Herein, we used 16S rRNA gene sequencing to investigate the microbial community composition and adaptability in the stomach and small and large intestines of Lycodon rufozonatus. Proteobacteria, Bacteroidetes, and Firmicutes were most abundant in the stomach; Fusobacteria in the small intestine; and Proteobacteria, Bacteroidetes, Fusobacteria, and Firmicutes in the large intestine. No dominant genus could be identified in the stomach; however, dominant genera were evident in the small and large intestines. The microbial diversity index was significantly higher in the stomach than in the small and large intestines. Moreover, the influence of the microbial community structure on function was clarified through function prediction. Collectively, the gut microbes in the different segments of the digestive tract revealed the unique features of the L. rufozonatus gut microbiome. Our results provide insights into the co-evolutionary relationship between reptile gut microbiota and their hosts.

Fecal microbiota transplants modulate the gut microbiome of a two-toed sloth (Choloepus didactylus).

The microbes inhabiting an animal's gastrointestinal tracts, collectively known as the gut microbiome, are vital to animal health and wellbeing. For animals experiencing gut distress or infection, modulation of the gut microbiome, for example, via fecal microbiota transplant (FMT), provides a possible disease prevention and treatment method. The beneficial microbes present in the donor's transplanted feces can help combat pathogens, assist in digestion, and rebalance the recipient's microbiota. Investigating the efficacy of FMTs in animal health is a crucial step toward improving management strategies for species under human care. We present a case study of the use of FMTs in a two-toed sloth experiencing abnormally large, clumped, and frequent stools. We used 16 S rRNA amplicon sequencing of fecal samples to (a) compare the microbiomes of the FMT donor, a healthy, cohoused conspecific, and the FMT recipient and (b) assess the influence of multiple rounds of FMTs on the recipient's microbiome and stool consistency and frequency over time. In response to the FMTs, we found that the recipient's microbiome showed trends toward increased diversity, shifted community composition, and altered membership that more resembled the community of the donor. FMT treatment was also associated with marked, yet temporary, alleviation of the recipient's abnormal bowel movements, suggesting a broader impact on gut health. Our results provide valuable preliminary evidence that FMT treatments can augment the recipient's gut microbiome, with potential implications for animal health and management.

Fabrication of bio-engineered chitosan nanoformulations to inhibition of bacterial infection and to improve therapeutic potential of intestinal microflora, intestinal morphology, and immune response in infection induced rat model

Overdosage of antibiotics used to prevent bacterial infections in the human and animal gastrointestinal tract would result in disturbing of intestinal barrier, significant misbalancing effects of intestinal microflora and persuading bacterial resistance. The main objective of the present investigation is to design and develop novel combinations of organic curcumin (Cur) and antimicrobial peptide (Amp) loaded chitosan nanoformulations (Cur/Amp@CS NPs) to improve significant effects on antibacterial action, immune response, intestine morphology, and intentional microflora. The antibacterial efficiency of the prepared nanoformulations was evaluated using Escherichia coli (E. coli) induced bacterial infections in GUT of Rat models. Further, we studied the cytocompatibility, inflammatory responses, α-diversity, intestinal morphology, and immune responses of treated nanoformulations in rat GUT models. The results indicated that Cur/Amp@CS NPs are greatly beneficial for intestinal microflora and could be a prodigious alternative of antibiotics.

Pathogenicity Classification using Phylogenetic Analysis of Escherichia coli Strains

Escherichia coli (E. coli) is an adaptable gram-negative bacillus facultative an aerobic bacterium that belongs to the family of Enterobacteriaceae. It is well known to be a commensal of the human and animal gastrointestinal tract and environments unrelated to the host, such as water, soil, manure, and food. This study was focused on identifying the pathogenicity of three local isolated E. coli strains (Malaysia) compared to the other 22 completed genome strains from the available database. The local strains are INF13/18/A [1], INF32/16/A [2], and INF191/17/A [3]. which are identified as extended-spectrum beta-lactamase types. 16S rRNA was used to build a phylogenetic tree by using MUSCLE for alignment and MEGA with 1000 bootstraps to build a tree (Figure 1), and then Figtree was used for visualisation. The outlier in this phylogenetic analysis is H3RV (a mycobacterium strain).
 
 The analysis revealed that the 22 completed genome strains can be divided into two main clusters with one cluster mainly more pathogen and least pathogen. Based on previous pathogenicity studies revealed that Shiga-toxin-producing E. coli are pathogens that are ER strains that cause diarrheal disease in humans and are of a public health concern due to their ability to cause outbreaks and severe diseases such as haemorrhagic colitis or haemolytic-uremic syndrome [4].
 
 Furthermore, CVM strains also reported as pathogen (GCA_008385405.1, GCA_008386375.1, GCA_004281435.2, GCA_008385205.1, and GCA_008383145.1). Therefore, the first cluster containing all ER strains and CVM is pathogenic. The second cluster included all local strains, two of the local strains (INF13/18/A and INF191/17/A) closely with Al Ain [5] and AR-0427 (GCF_008727195.1) which both are known to be Shiga-toxin producing strains (0157). This suggested that these two local strains are true pathogens. While one of the other local strains INF32/16/A shares a recent common ancestor with a non-pathogenic laboratory strain K-12 substr. MG1655 [6], which could be probably suggested that this local strain is non-pathogenic.
 
 In addition to that the second clusters, JME strains were clustered together with ecMN1F (GCA_008824125.1). The distribution of lineage is also not related to sampling locations because the first cluster has CVM strains and ER strains from the USA and New Zealand, respectively. While the two local strains from Malaysian strains were also found close to the United States of America (K-12 substr. MG1655) [6].
 
 In conclusion, this study shows the pathogenicity group classification of E. coli strains and requires further investigation to determine the level of pathogenicity of these organisms.
 A phylogenetic of E. coli used 16S rRNA, shows dividing into two common ancestors and the outlier, the strains of the above common ancestor such as CVM and ER [7] strains are true pathogenic, while the strains of the second common ancestor are showing some pathogenic and some non-pathogenic which closely related with the local sample.

Species composition and peculiarities of the course of dog parasitoses on the territory of the city of Poltava

Dogs are parasitized by a significant number of helminth species, the largest part of which in the sexually mature stage is localized in the gastrointestinal tract of animals. These helminths cause significant damage to the health of dogs and contaminate environmental objects, contributing to the spread of infestations. The work aimed to establish the species composition of the causative agents of invasions that parasitize dogs in the city of Poltava's territory and to establish their course's peculiarities. It was found that dogs in Poltava are infected with pathogens Dipylidium caninum, Toxocara canis, Trichuris vulpis, Uncinaria stenocephala, Cystoisospora canis, and Dirofilaria sp. The average extensity of invasions by parasitoses was 28.4 %. The rates of infestation of dogs were: for trichurosis – 20.18 %, for toxocarosis – 12.84 %, for cystoisosporosis – 11.47 %, for uncinariosis – 11.01 %, for dirofilariasis – 6.42 %, for dipylidiasis – 2.29 %. It was established that parasitosis in 77.42 % of infected dogs took the form of mixinvasions, where two-component associations were registered in 41.94 % of dogs, three-component – in 22.58 %, four-component – in 12.90 %. Monoinvasions were detected in 22.58 % of infected dogs. They were represented by dirofilariasis (8.06 %), cystoisosporosis (4.83 %), toxocariasis (3.23 %), trichurosis (3.23 %) and dipylidiasis (3.23 %) infestations. A total of 14 types of mixinvasions were identified. Two-component associations are represented by seven combinations of parasites, three-component associations by four combinations, and four-component associations by three combinations. Most often, simultaneous parasitism in the body of dogs was diagnosed with trichurises and uncinaries (16.67 %), trichurises and cystoisospores (12.5 %), trichurises, uncinaries and toxocares (12.5 %), toxocares and trichurises (10.42 %), dipylidies, trichurises and dirofilaries (10.42 %), trichurises, toxocares, cystoisospores and uncinaries (10.42 %). The conducted studies allow taking into account the obtained data when diagnosing parasitosis in dogs, as well as applying effective treatment and preventive measures, taking into account the associative course of cestodoses, nematodoses and protozoans.

Comparative Analyses of the Gut Microbiota in Growing Ragdoll Cats and Felinae Cats.

Simple SummaryAccumulating studies have revealed that the gut microbiota had intimate relations with the animal gastrointestinal tract diseases. Through regulating the development of the host’s intestinal immune system, the gut microbiota could directly influence the host’s intestinal function. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were investigated and compared. Results demonstrated the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. However, the relative abundances of beneficial microbes in the Ragdoll cats were much higher than those in the Felinae cats. In all, different genetic portraits determined the different microbial communities in the feline gut. The candidate probiotics isolated in the growing cat’s gut might be applied to treat the gastrointestinal tract diseases.Today, domestic cats are important human companion animals for their appearance and favorable personalities. During the history of their domestication, the morphological and genetic portraits of domestic cats changed significantly from their wild ancestors, and the gut microbial communities of different breeds of cats also apparently differ. In the current study, the gut microbiota of Ragdoll cats and Felinae cats were analyzed and compared. Our data indicated that the diversity and richness of the gut microbiota in the Felinae cats were much higher than in the Ragdoll cats. The taxonomic analyses revealed that the most predominant phyla of the feline gut microbiota were Firmicutes, Bacteroidota, Fusobacteriota, Proteobacteria, Actinobacteriota, Campilobacterota, and others, while the most predominant genera were Anaerococcus, Fusobacterium, Bacteroides, Escherichia-Shigella, Finegoldia, Porphyromonas, Collinsella, Lactobacillus, Ruminococcus_gnavus_group, Prevotella, and others. Different microbial communities between the Ragdoll group and the Felinae group were observed, and the compared results demonstrated that the relative abundances of beneficial microbes (such as Lactobacillus, Enterococcus, Streptococcus, Blautia, Roseburia, and so on) in the Ragdoll group were much higher than in the Felinae group. The co-occurrence network revealed that the number of nodes and links in the Felinae group was significantly higher than the Ragdoll group, which meant that the network of the Felinae group was larger and more complex than that of the Ragdoll group. PICRUSt function analyses indicated that the differences in microbial genes might influence the energy metabolism and immune functions of the host. In all, our data demonstrated that the richness and diversity of beneficial microbes in the Ragdoll group were much higher than the Felinae group. Therefore, it is possible to isolate and identify more candidate probiotics in the gut microbiota of growing Ragdoll cats.

Genomic Characterization of Salmonella Typhimurium Isolated from Guinea Pigs with Salmonellosis in Lima, Peru.

Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) is one of the most important foodborne pathogens that infect humans globally. The gastrointestinal tracts of animals like pigs, poultry or cattle are the main reservoirs of Salmonella serotypes. Guinea pig meat is an important protein source for Andean countries, but this animal is commonly infected by S. Typhimurium, producing high mortality rates and generating economic losses. Despite its impact on human health, food security, and economy, there is no genomic information about the S. Typhimurium responsible for the guinea pig infections in Peru. Here, we sequence and characterize 11 S. Typhimurium genomes isolated from guinea pigs from four farms in Lima-Peru. We were able to identify two genetic clusters (HC100_9460 and HC100_9757) distinguishable at the H100 level of the Hierarchical Clustering of Core Genome Multi-Locus Sequence Typing (HierCC-cgMLST) scheme with an average of 608 SNPs of distance. All sequences belonged to sequence type 19 (ST19) and HC100_9460 isolates were typed in silico as monophasic variants (1,4,[5],12:i:-) lacking the fljA and fljB genes. Phylogenomic analysis showed that human isolates from Peru were located within the same genetic clusters as guinea pig isolates, suggesting that these lineages can infect both hosts. We identified a genetic antimicrobial resistance cassette carrying the ant(3)-Ia, dfrA15, qacE, and sul1 genes associated with transposons TnAs3 and IS21 within an IncI1 plasmid in one guinea pig isolate, while antimicrobial resistance genes (ARGs) for β-lactam (blaCTX-M-65) and colistin (mcr-1) resistance were detected in Peruvian human-derived isolates. The presence of a virulence plasmid highly similar to the pSLT plasmid (LT2 reference strain) containing the spvRABCD operon was found in all guinea pig isolates. Finally, seven phage sequences (STGP_Φ1 to STGP_Φ7) were identified in guinea pig isolates, distributed according to the genetic lineage (H50 clusters level) and forming part of the specific gene content of each cluster. This study presents, for the first time, the genomic characteristics of S. Typhimurium isolated from guinea pigs in South America, showing particular diversity and genetic elements (plasmids and prophages) that require special attention and also broader studies in different periods of time and locations to determine their impact on human health.

Transport of Pseudomonas aeruginosa in Polymer Solutions

Bacteria often live surrounded by polymer solutions, such as in animal respiratory, gastrointestinal, and reproductive tracts. In these systems, polymer solutions are often exposed to fluid flow, and their complex rheology can affect the transport of chemical compounds and microorganisms. Recent studies have focused on the effect of polymer solutions on the motility of bacteria in the absence of fluid flow. However, flow can be a game-changer on bacterial transport, as demonstrated by the depletion of motile bacteria from the low-shear regions and trapping in the high-shear regions in simple fluids, even for flows as simple as the Poiseuille one. Despite the relevance of polymer solutions in many bacterial habitats, the effect of their complex rheology on shear-induced trapping and bacterial transport in flow has remained unexplored. Using microfluidic experiments and numerical modeling, we studied how the shear rate and the rheological behavior of Newtonian and non-Newtonian polymer solutions affect the transport of motile, wild-type Pseudomonas aeruginosa in a Poiseuille flow. Our results show that, in Newtonian solutions, an increase in viscosity reduces bacterial depletion in the low-shear regions at the microchannel center, due to a reduction in the bacterial swimming velocity. Conversely, in the non-Newtonian solution, we observed a depletion comparable to the buffer case, despite its zero-shear viscosity being two orders of magnitude higher. In both cases, bacterial swimming and polymer fluid rheology control the magnitude of bacterial depletion and its shear-rate dependence. Our observations underscore the importance of the rheological behavior of the carrier fluid in controlling bacterial transport, in particular, close to surfaces giving rise to velocity gradients, with potential consequences on surface colonization and biofilm formation in many naturally relevant microbial habitats.

Descripción de un caso de sepsis abdominal por Desulfovibrio desulfuricans

Desulfovibrio spp. are strict anaerobes that are ubiquitous in nature. They can reside in the human or animal gastrointestinal tract and, as they are also environmental bacteria, may be present in soil and water. They can persist asymptomatically in the intestine or behave as opportunistic pathogens associated with primary bacteremia and intraabdominal infections. Several Desulfovibrio spp. infections may be underestimated due to their slow growth rate and because many laboratories do not routinely perform anaerobic cultures. Simple tests such as motility detection on a fresh subculture, Gram stain to confirm cell morphology, presence of H2S in SIM agar and production of a red fluorescence in alkaline pH under UV light would be indicative of Desulfovibrio spp.Here we report the case of Desulfovibrio desulfuricans bacteremia in a woman with clinical picture of abdominal sepsis due to gangrenous appendicitis with multiple organ failure.

Distinct accumulation of nanoplastics in human intestinal organoids

Plastic particles, especially nanoplastics, represent an emerging concern of threat to human health, oral uptake is an important pathway for the plastic particles ingestion by human. While their fate and adverse effects in animal gastrointestinal tract are increasingly investigated, knowledge about their uptake and toxicity in human intestine is still limited. Here, by exposing human intestinal organoids to polystyrene nanoplastics (PS-NPs, ~50 nm in size) with concentrations of 10 and 100 μg/mL, we present evidence of their distinct accumulation in various type cells in intestinal organoids, then causing the cell apoptosis and inflammatory response. Our results further revealed that the effective inhibition of PS-NPs accumulation in secretive cells through co-exposure to a clathrin-mediated endocytosis inhibitor (chlorpromazine), and proved the essential role of active endocytosis in the PS-NPs uptaking into enterocyte cells. Our work not only elucidated the potential uptake and toxicity of PS-NPs in human intestinal cells and the underlying mechanism, but also provide a potential therapeutic approach to relieve the toxicity of PS-NPs to human through the endocytosis inhibition.

USING ULTRAVIOLET IRRADIATION TO DISINFECTCOMPOUND FEEDS

Compound feeds are sources of not only nutrients required to maintain animals’ vital activity, but also of a complex of microorganisms inhabiting them. This complex develops in them after the heat treatment of raw materials (extrusion, conditioning, expansion, etc.), which creates non-competitive conditions for the foreign microorganisms to enter (in particular, from non-grain and animal raw materials). At the same time, the animal's gastrointestinal tract contains its own complex microbiome, which in young animals (at the time of switching to pre-starter) is not yet fully formed and not very stable. It can be disturbed by foreign microbiota, which will lead to a decrease in productivity. In addition, the foreign microbiota requires an immune response from the body, which is a very energy-consuming process. Therefore, the disinfection of compound feed for young animals at the stage of production and in finished form is reasonable and important. The most promising method of disinfection today is ultraviolet irradiation, which is widely used for disinfection of surfaces, air and water. It is cheap, easy in mounting and maintenance and effective without disrupting any properties of the product or feed. For compound feeds, it is currently used only on livestock farms, and is not used on production lines. Therefore, the task of this study was to test the effectiveness of ultraviolet irradiation of a compound feed for further implementation in manufacture. Irradiation with a bactericidal lamp of a model feed mixture (60% crushed wheat, 30% sunflower oilcake, 10% wheat bran) was conducted. The numbers of MAFAnM (mesophilic aerobic and facultatively anaerobic microorganisms) declined from 1 million to 20 thousand cells per gram after 5 hours (300 minutes) of UVC exposition (254 nm wavelength). The diagram obtained coincides well with the reference diagram for a typical bacterial strain and shows that the use of ultraviolet irradiation is quite effective even without requiring a long-time exposition. Therefore, it can be used industrially to disinfect compound feeds and their raw materials.

The new in the enteral dysbiosis correction intensified by heavy metals and mycotoxins

The study aimed to research the new treatment and pharmacorrection protocol of toxical body state intensified by heavy metals and mycotoxins in the cattle using native drugs. The studies were carried out on cows aged 3 to 4 years. 2 groups were formed (n=10 by each). The protocol of 1st group cows (n=10) was included the sorbents' complex as a supplementation to the ration (4 % per the daily rate during 14th days) and the hepatoprotective agent “Hepaton‐vet” (the compound: lac Carduus, ursodeoxycholic acid) at a dose of 100 ml per cow during 21 days. The protocol of 2 d group cows (n=10) was also included the sorbents' complex as a supplementation to the ration (4 % per the daily rate during 14th days) and the conventional fluid therapy. We were determined the sorbent net efficiency as a quantity characteristic of loading capacity. The sorption of mycotoxins was indicated by the quantity‐related method under different pH, which was affected the pH replacement of the gastrointestinal tract in animals. The heavy metals in milk and feed samples were analyzed by the periodate method and atomic adsorption spectrometry. The level of mycotoxins was tested by the Agra quant ELISA method. We were used the software program “Statistica 6” with Student's t‐test for dependent adjectives as a statistical analysis of results. The highest level of cadmium was contained in the dry forage samples (0.14±0.05 mg/kg). The difference of their between the dry forage and mixed feed with silage was 27 %. The results of the biochemical analysis were showed hypoproteinemia and hypoalbuminemia (21.23±1.12 g/l). The reason could be the dystrophic change of hepatocytes and the deranged biosynthesis of this fraction with the shift to γ‐globulins increasing. The increase of albumin level was on the 12th day of treatment (29.19±1.32 g/l). The albumin level of cows 1st group was increased by 21.2 % and 17.3 % consequently by the end of the experiment compared with the value of cows control group. Y‐globulins were decreasing by 37.3 % and 40.5 %. The atmospheric methane emissions in the 2d group were decreased by 8 % (84±3.5 mg/m3). So, we can assume that using the complex of sorbents with hepatoprotective agent “Hepaton‐vet” has a positive influence on the liver's metabolic process that has evidenced results of morpho‐biochemical analysis and clinical diagnostic of animals.

Chromogenicity of aerobic spore-forming bacteria of the Bacillaceae family isolated from different ecological niches and physiographic zones.

To determine the distribution patterns of pigmented bacteria of the Bacilaceae family in different physiographic zones and ecological niches, we recovered 787 isolates from 185 environmental samples (including the areas with radiation pollution). Among the strains obtained, 149 pigmented representatives were detected, which synthesized intracellular and extracellular pigments of yellow, red, pink, and dark colors. In compliance with physiological, biochemical, and chemotaxonomic features, the isolates were identified as 7 species of the Bacilaceae family. We demonstrated that the ability to synthesize pigments significantly depended on the culture medium composition. According to the color of the colonies, the absorption spectra of pigment extracts, their physicochemical properties, and the implementation of several qualitative tests, the pigmented isolates were divided into ten groups. The relative number of pigmented strains in the physiographic zone was consistent with the total level of solar radiation for the year. Most pigmented members of the Bacillaceae family were recovered from deserts and semi-deserts, and fewest of them originated from mixed forests. We show that among the studied ecological niches, pigmented strains were most often isolated from the phyllosphere and aquatic environment and least often from soils. However, the isolates from soils and aquatic environments exhibited a greater diversity of pigmentation, and a lesser variety of colored strains was obtained from the phyllosphere and the gastrointestinal tract of animals. We established that the quantitative and qualitative composition of pigmented isolates from the areas with radiation contamination differed significantly from those coming from the natural radiation background.

Antimicrobial susceptibility of Citrobacter Koseri isolated on clinical samples of hospitalized patients

The genus Citrobacter includes 13 species and is often found in water, food, land and certain animals. It is part of the normal flora of a small proportion of healthy humans; however, the rates of colonization increase in patients in long-term care institutions and hospitals. Citrobacter koseri is an aerobic Gram-negative bacillus, ubiquitous in nature, opportunistic, that is frequently found in genitourinary and gastrointestinal tracts of animals and humans as a saprophyte flora. Citrobacter koseri is one of the most important pathogens, eventually causing epidemics difficult to control. Therefore, the objective of this article is to carry out a microbiological characterization of this pathogen. A transversal descriptive study was conducted in the Surgical Clinical Hospital Lucía Íñiguez Landín of Holguín, which covered the period from January to December 2019. The study universe consisted of all enterobacteriaceae isolated in clinical samples of adult patients admitted during this period and the sample was formed by 219 strains of Citrobacter koseri. Out of the total number of cases, 70 belonged to the intensive care service for a 32.0%. Out of the total number of samples, 139 were isolated in pus samples for a 63.5%. The strains were more resistant to ciprofloxacin, cefuroxime, ampicillin, aztreonam, ceftazidime and to gentamicin. Citrobacter koseri is able to develop multidrug resistance to known antibiotics, acts as opportunistic and can colonize people in community, consequently its dissemination should be controlled.

Clinically Relevant Enterococcus Species and PCR Screening of Antibiotic Resistance and Virulence Factor Coding Genes

Enterococci are Gram positive cocci which are common residence of gastro intestinal tracts of humans and animals. But they are capable of causing severe infections, most often in hospitalised patients. Enterococci are important nosocomial pathogens and their intrinsic property of antibiotic resistance makes treatment difficult. Against this clinical significance, a study was conducted on the prevalence of vancomycin resistant enterococcal infections and their antibiotic sensitivity patterns at Sunrise Institute of Medical Sciences, a tertiary care hospital in Kochi, Kerala state. Various clinical specimens like blood, urine, abscess, vaginal swab etc. were microbiologically screened for the presence of antibiotic resistant Enterococci. The common phenotyping methods and genotyping protocols were used to identify the species for the study. The vancomycin resistant strains were typed genotypically by using 16S rDNA sequencing and the isolates were speciated to be E. faecium. A molecular screening of the isolates was also done for the presence of various virulence factor coding genes and for the genes which confer antibiotic resistance. The findings of the study revealed that 89.1 % isolated strains were multidrug resistant and a total of 4 antibiotic resistance genes were detected. Among the isolates the vancomycin resistance genes vanA, vanB; tetracycline resistance genes tetA and macrolide resistance gene ermA were screened. The presence of genes coding for various virulence factors were also detected among the isolates. However, we present an overview of antibiotic resistance pattern and virulence factors present in enterococci and we strongly believe that these results will surely help to design a new disinfection regime and antibiotic stewardship to control the incidence of infection.

Microbiome-host-phylogeny relationships in animal gastrointestinal tract microbiomes.

Among the factors influencing the animal gastrointestinal tract microbiome (AGM) diversity, diet and phylogeny have been extensively studied. However, what made the studies particularly challenging is that diet characteristics per se are product of evolution, and hence totally disentangling both effects is unrealistic, likely explaining the lack of consensus in existing literatures. To further explore microbial diversity and host-phylogeny-diet relationships, we performed a big-data meta-analysis with 4903 16S rRNA AGM samples from 318 animal species covering all six vertebrate and four major invertebrate classes. We discovered that the relationship between AGM-diversity and phylogenetic timeline (PT) follows a power-law or log-linear model, including diet specific power-law relationships. The log-linear nature predicts a generally rising trend of AGM diversity along the evolutionary tree starting from the root, which explains the observation why Mammalia exhibited the highest AGM-diversity. The power-law property suggests that a handful of taxa carry disproportionally large weights to the evolution of diversity patterns than the majority of taxa, which explains why the species richness of Insecta was significant different than those from the other nine classes. Finally, we hypothesize that the diversity-PT power-law relationship explains why species-abundance distributions generally follow highly skewed probability distributions.

Presence of Helicobacter Species in Gastric Mucosa of Human Patients and Outcome of Helicobacter Eradication Treatment.

The genus Helicobacter is composed of bacteria that colonize both the human and animal gastrointestinal tract. Helicobacter pylori infects half of the world’s population, causing various disorders, such as gastritis, duodenitis and gastric cancer. Additionally, non-Helicobacter pylori Helicobacter species (NHPH) are commonly found in the stomach of pigs, dogs and cats. Most of these species have zoonotic potential and prevalence rates of 0.2–6.0%, and have been described in human patients suffering from gastric disorders undergoing a gastric biopsy. The aim of this study was to determine the occurrence of Helicobacter spp. in the stomach of patients with gastric cancer (n = 17) and obese (n = 63) patients. Furthermore, the outcome of the Helicobacter eradication treatment and the current infection status was evaluated. Overall, based on the genus-specific PCR followed by sequencing, DNA from Helicobacter spp. was detected in 46.3% of the patients, including single infections with H. pylori in 43.8% of the patients and mixed infections with H. pylori and canine- or feline-associated H. felis in 2.5%. About 32.5% of the patients had been subjected to previous Helicobacter eradication therapy and the triple standard therapy was the most frequent scheme (42.3%). In 48.0% of the patients who received eradication treatment, bacteria were still detected, including one mixed infection. In 23.1% of the patients who reported that a subsequent test had been performed to confirm the elimination of the bacteria, Helicobacter were still detected. In conclusion, although in a smaller percentage, NHPH may also be present in the human stomach. Thus, specific NHPH screening should be included in the diagnostic routine. The continued presence of H. pylori in the stomach of patients recently subjected to eradication schemes raises questions about the efficacy of the current Helicobacter treatments.

Efflux-Mediated bile Resistance in Gram-Positive Pathogens

Gram-positive pathogens are causing many serious infections that affect humans and result in mild to severe diseases worldwide. In order to survive and initiate infection, enteric pathogens must resist the physiochemical defence factors in the human intestinal tract. One of these defence factors is bile, a potent antibacterial like compound in the intestine. Efflux pumps are the important mechanism by which bacteria resist antibacterial agents such as bile. Efflux of antimicrobial substances outside the bacterial cell is considered as a key factor for intestinal colonization and virulence of enteric pathogens. This paper will review the research conducted on efflux–mediated bile resistance in Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis and Clostridium perfringens. These bacteria colonize in the human & animal gastrointestinal tract and they have a multiple mechanism to resist the innate defences in the gut and antibacterial activity of bile. However, bile resistance in these bacteria is not fully understood. The evidence from this review suggests that Gram-positive pathogens have the ability to active transport of bile. Further research is needed to know how these pathogens sense bile and how bile regulates its virulence factor. In general, therefore, it seems that understanding the specific mechanism of bile resistance in enteric bacteria including gram-positive pathogens may involve in the development of novel strategies to control and treatment of gastrointestinal infections.

APTC-EC-2A: A Lytic Phage Targeting Multidrug Resistant E. coli Planktonic Cells and Biofilms.

Escherichia coli (E. coli) are common bacteria that colonize the human and animal gastrointestinal tract, where they help maintain a balanced microbiome. However, some E. coli strains are pathogenic and can cause serious infectious diseases and life-threatening complications. Due to the overuse of antibiotics and limited development of novel antibiotics, the emergence of antibiotic-resistant strains has threatened modern medicine, whereby common infections can become lethal. Phage therapy has once again attracted interest in recent years as an alternative treatment option to antibiotics for severe infections with antibiotic-resistant strains. The aim of this study was to isolate and characterize phage against multi-drug resistant E. coli isolated from clinical samples and hospital wastewater. For phage isolation, wastewater samples were collected from The Queen Elizabeth Hospital (Adelaide, SA, Australia) followed by phage enrichment as required. Microbiological assays, electron microscopy and genomic sequencing were carried out to characterize the phage. From the 10 isolated E. coli phages, E. coli phage APTC-EC-2A was the most promising and could lyse 6/7 E. coli clinical isolates. APTC-EC-2A was stable at a broad pH range (3–11) and could lyse the host E. coli at temperatures ranging between 30–50 °C. Furthermore, APTC-EC-2A could kill E. coli in planktonic and biofilm form. Electron microscopy and genomic sequencing indicated the phage to be from the Myoviridae family and of lytic nature. In conclusion, the newly isolated phage APTC-EC-2A has the desired properties that support its potential for development as a therapeutic agent against therapy refractory E. coli infections.

Effects of probiotics on digestive enzymes of fish (finfish and shellfish); status and prospects: a mini review.

Digestive enzymes are found in the digestive tract of animals which assist in the breakdown of larger food molecules into more easily absorbed particles that can then be used by the body. The ability of fish to break down a diet is highly dependent on the availability of suitable digestive enzymes which mediate specific degradation pathways and on both the physical and chemical nature of food. Probiotics are known to produce helpful enzymes that aid in digestion and protect the gastrointestinal tract (GIT) of animals. When applied appropriately, probiotics improve intestinal microbial balance which also improves digestive enzyme activities, food absorption, and decrease pathogenic issues in the GIT. They work hand-in-hand with the digestive enzymes in the GIT of animals as supplements thereby improvings nutrition. This in turn leads to higher feed efficiency and growth as well as the prevention of antinutritional factors present in the ingredients, intestinal disorders, and pre-digestion. This review seeks to present summaries of the results of research findings on the application of probiotics on the activities of digestive enzymes including amylase, lipase, and protease. Further, this review points out gaps in available literature and suggests ideas that could be explored in further investigations to better understand and enhance the activities of these digestive enzymes to increase feed and nutrient utilization and the production of aquaculture species.