Microaerophilic Conditions Research Articles

Genomic, probiotic, and metabolic potentials of Liquorilactobacillus nagelii AGA58, a novel bacteriocinogenic motile strain isolated from lactic acid-fermented shalgam

This study aimed to perform genomic, probiotic, and metabolic characterization of a novel Liquorilactobacillus nagelii AGA58 isolated from a lactic acid-fermented shalgam beverage to understand its metabolic potentials and probiotic features. AGA58 is gram-positive, motile, catalase-negative and appears as short rods under the light-microscope. The AGA58 chromosome comprises a single linear chromosome of 2,294,635 bp that is predicted to carry 2135 coding sequences, including 45 tRNA genes, 3 mRNA, and 3 rRNA operons. The genome has a G+C content of 36.9%, including 55 pseudogenes and a single intact prophage. AGA58 is micro-anaerobic due to achieving a shorter doubling time and faster growth rate than micro-aerophilic conditions. It carries flagellar biosynthesis protein-encoding genes predicting motile behavior, which was confirmed with the in vitro motility test. AGA58 is an obligatory homofermentative lactobacillus that can ferment hexose sugars such as galactose, glucose, fructose, sucrose, mannose, N-acetyl glucosamine, maltose, and trehalose to lactate through glycolysis. No acid production from pentoses implies that five-carbon sugars are being utilized for purine and pyrimidine synthesis. Putative pyruvate metabolism revealed formate, malate, oxaloacetate, acetate, acetaldehyde, acetoin, and lactate forms from pyruvate. AGA58 is predicted to encode the LuxS gene and biosynthesis of class IIa and Blp family class-II bacteriocins suggesting this bacterium's antimicrobial potential, linked to antagonism tests that AGA58 can inhibit Escherichia coli ATCC 43895, Salmonellaenterica serovar Typhimurium ATCC 14028, and Klebsiellapneumonia ATCC 13883. Moreover, AGA58 is tolerant to acid and bile concentrations simulating the human gastrointestinal conditions depicting the probiotic potential of the organism as the first report in literature within the same species.

Bioproduction of testosterone from phytosterol by Mycolicibacterium neoaurum strains: “one-pot”, two modes

The main male hormone, testosterone is obtained from cheap and readily available phytosterol using the strains of Mycolicibacterium neoaurum VKM Ac-1815D, or Ac-1816D. During the first “oxidative” stage, phytosterol (5–10 g/L) was aerobically converted by Ac-1815D, or Ac-1816D to form 17-ketoandrostanes: androstenedione, or androstadienedione, respectively. At the same bioreactor, the 17-ketoandrostanes were further transformed to testosterone due to the presence of 17β-hydroxysteroid dehydrogenase activity in the strains (“reductive” mode). The conditions favorable for “oxidative” and “reductive” stages have been revealed to increase the final testosterone yield. Glucose supplement and microaerophilic conditions during the “reductive” mode ensured increased testosterone production by mycolicibacteria cells. Both strains effectively produced testosterone from phytosterol, but highest ever reported testosterone yield was achieved using M. neoaurum VKM Ac-1815D: 4.59 g/l testosterone was reached from 10 g/l phytosterol thus corresponding to the molar yield of over 66%. The results contribute to the knowledge on phytosterol bioconversion by mycolicibacteria, and are of significance for one-pot testosterone bioproduction from phytosterol bypassing the intermediate isolation of the 17-ketoandrostanes.Graphical

Deep Eutectic Solvent Pretreatment of Water Hyacinth for Improved Holocellulosic Saccharification and Fermentative Co-Production of Xylitol and Lipids Using Rhodosporidium toruloides NCIM 3547

In this study, delignification of water hyacinth (WH) using a mild ionic liquid-like chemical deep eutectic solvent (DES) synthesized using choline chloride and urea was conducted and the process parameters were optimized by Box–Behnken design (BBD)-based response surface methodology (RSM). From the results, a delignification of 64.32 ± 4.08% (w/w) was obtained under 1:12.5 (biomass:DES ratio), 4.63 h (time) and 87 °C (temperature). Further, a dilute sulphuric acid (2%, v/v) hydrolysis was carried out to destabilize the hemicellulose that resulted in 23.7 ± 0.50 g/L of xylose. Fermentation of the obtained xylose was carried out using a red oleaginous yeast, Rhodosporidium toruloides NCIM 3547, with free and Ca2+-alginate-immobilized cells for xylitol production under microaerophilic conditions and obtained yields of 4.73 ± 0.40 g/L (168 h) and 9.18 ± 0.10 g/L (packed bed reactor with a retention time of 18 h), respectively. Further, when the same fermentation was performed under aerobic conditions about 40.93 ± 0.73% lipid accumulation was observed with free cells. For saccharification, Aspergillus-niger-derived cellulase was used and this resulted in a yield of 27.45 ± 0.04 g/L of glucose. The glucose-enriched hydrolysate was supplemented for fermentation under nitrogen starved conditions from which 46.81 ± 2.60% (w/w) lipid content was obtained.

Azospirillum baldaniorum Sp245 exploits Pseudomonas fluorescens A506 biofilm to overgrow in dual-species macrocolonies.

Biofilms are essential for plant-associated bacteria to colonize their host. In this work, we analysed the interaction of Azospirillum baldaniorum Sp245 and Pseudomonas fluorescens A506 in mixed macrocolony biofilms. We identified certain culture conditions where A. baldaniorum Sp245 exploits P. fluorescens A506 to boost its growth. Azospirillum growth increased proportionally to the initial number of pseudomonads building the biofilm, which in turn were negatively affected in their growth. Physical contact with P. fluorescens A506 was essential for A. baldaniorum Sp245 growth increase. Biofilm ultrastructure analysis revealed that Pseudomonas produces a thick structure that hosts Azospirillum cells in its interior. Additional experimentation demonstrated that Azospirillum growth boost is compromised when interacting with biofilm-deficient Pseudomonas mutants, and that a low oxygen concentration strongly induce A. baldaniorum Sp245 growth, overriding Pseudomonas stimulation. In this line, we used a microaerophilia reporter strain of A. baldaniorum Sp245 to confirm that dual-species macrocolonies contain a higher number of cells under microaerophilic conditions. Taking all the results into consideration, we propose that A. baldaniorum Sp245 can benefit from P. fluorescens A506 partnership in mixed biofilms by taking advantage of the low oxygen concentration and scaffold made up of Pseudomonas-derived matrix, to expand its growth.

Biofilm-mediated decolorization, degradation and detoxification of synthetic effluent by novel biofilm-producing bacteria isolated from textile dyeing effluent

Biofilm-mediated bioremediation of xenobiotic pollutants is an environmental friendly biological technique. In this study, 36 out of 55 bacterial isolates developed biofilms in glass test tubes containing salt-optimized broth plus 2% glycerol (SOBG). Scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and Congo red- and Calcofluor binding results showed biofilm matrices contain proteins, curli, nanocellulose-rich polysaccharides, nucleic acids, lipids, and peptidoglycans. Several functional groups including –OH, N–H, C–H, CO, COO−, –NH2, PO, C–O, and C–C were also predicted. By sequencing, ten novel biofilm-producing bacteria (BPB) were identified, including Exiguobacterium indicum ES31G, Kurthia gibsonii ES43G, Kluyvera cryocrescens ES45G, Cedecea lapagei ES48G, Enterobacter wuhouensis ES49G, Aeromonas caviae ES50G, Lysinibacillus sphaericus ES51G, Acinetobacter haemolyticus ES52G, Enterobacter soli ES53G, and Comamonas aquatica ES54G. The Direct Red (DR) 28 (a carcinogenic and mutagenic dye used in dyeing and biomedical processes) decolorization process was optimized in selected bacterial isolates. Under optimum conditions (SOBG medium, 75 mg L−1 dye, pH 7, 28 °C, microaerophilic condition and within 72 h of incubation), five of the bacteria tested could decolorize 97.8% ± 0.56–99.7% ± 0.45 of DR 28 dye. Azoreductase and laccase enzymes responsible for biodegradation were produced under the optimum condition. UV–Vis spectral analysis revealed that the azo (−NN−) bond peak at 476 nm had almost disappeared in all of the decolorized samples. FTIR data revealed that the foremost characteristic peaks had either partly or entirely vanished or were malformed or stretched. The chemical oxygen demand decreased by 83.3–91.3% in the decolorized samples, while plant probiotic bacterial growth was indistinguishable in the biodegraded metabolites and the original dye. Furthermore, seed germination (%) was higher in the biodegraded metabolites than the parent dye. Thus, examined BPB could provide potential solutions for the bioremediation of industrial dyes in wastewater.

From fish excretions to high-protein dietary ingredient: Feeding intensively cultured barramundi (Lates calcarifer) a diet containing microbial biomass (biofloc) from effluent of an aquaculture system

Aquaculture is the fastest growing agricultural sector in the world, and the annual aquaculture production reached 82 million tonnes in 2018. Fish feed is the most expensive component of aquaculture. The partial replacement of commercial fish feed with biofloc was evaluated as a dietary ingredient in feed for barramundi (Lates calcarifer), a high-value carnivorous fish. Biofloc was produced from the effluent of a recirculating aquaculture system under microaerophilic conditions, as part of its water treatment process, which was based on nutrient assimilation by microbial biomass. The biofloc was harvested and used in fish feed. The experimental feed was prepared by replacing 20% (w/w) of commercial barramundi feed with dry biofloc powder. Six 100 l plastic tanks were stocked with barramundi (average weight 27 ± 0.9 g) at a density of 20 kg/m3. The fish in three tanks were fed a commercial feed and the others with the experimental diet for 8 weeks, at 2% bodyweight per day. The fish were weighed weekly. At the end of the trial, the proximate body compositions and immune functions of the fish were analyzed. Fifteen fish from each treatment were challenged with Vibrio harveyi to examine their disease resistance. Weight gain was 14% higher (p < 0.05) in the control group compared to biofloc -fed group, but fish fed biofloc showed significantly higher survival rates after bacterial challenge (89% survival) compared to control (58% survival, p = 0.01). Sera of the biofloc -fed fish had higher levels of lysozyme and myeloperoxidase activity (p < 0.001). Similarly, the expression of immune-related genes in the kidneys was significantly higher in the biofloc -fed fish than in the control (p < 0.05). These results, together with an economic evaluation, demonstrate the potential practical application of biofloc as a feed ingredient in barramundi aquaculture. Further optimization of this practice is required.

Eugenol contributes to decreased expression of rpoD and luxS genes in clinically isolated Helicobacter pylori: An in vitro study using real-time-PCR technique

Helicobacter pylori is one of the most significant human pathogens present in the gastric epithelial mucosa of >50 % of the world's population. The luxS and rpoD genes play an essential role in biofilm formation and growth of this bacterium, respectively. This study aimed at the eugenol effect on biofilm formation and the expression level of luxS and rpoD genes by H. pylori using the qRT-PCR technique.A total of the thirty-biopsy specimen were collected from the suspected patients. The samples were analyzed for the isolation of H. pylori. Out of the samples, one isolate of H. pylori was isolated based on the culture in microaerophilic conditions. The results showed that eugenol has an inhibitory effect on H. pylori growth. Semi-quantitative biofilm formation by H. pylori upon exposure to different concentrations of eugenol was evaluated, and quantitative expression of luxS and rpoD genes was investigated using qRT-PCR.Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at 6.25 and 12.5 mg/ml, respectively. Also, biofilm production was inhibited completely using eugenol at a concentration of 12.5 mg/ml. In general, a decrease of about 4 and 2-fold in the expression of luxS and rpoD genes were observed, post-exposure to eugenol at a concentration of 3.12 mg/ml, respectively. Therefore, it can be concluded that eugenol contributes to decreased expression of luxS and rpoD genes in H. pylori, which may incorporate in biofilm formation by this bacterium.

The "Infernaccio" Gorges: Microbial Diversity of Black Deposits and Isolation of Manganese-Solubilizing Bacteria.

Simple Summary“Infernaccio” gorges are one of the Earth’s hidden habitats in Central Italy. Beyond the deep incisions and high slopes, these gorges are characterized by black deposits in gorge walls and covering rock surfaces. Several geological events have shaped these unique geological formations and their microbiota. This study investigated microbial contribution to black deposit formation and isolating Mn-oxide-solubilizing bacteria. Our results provided evidence of the putative role of Bacteria and Archaea in forming manganese oxide deposits. Findings also showed that these deposits are a source of valuable strains with manganese oxide bioleaching properties, essential for bioremediation and metal recovery.The present study explored the microbial diversity of black deposits found in the “Infernaccio” gorge. X-ray Powdered Diffraction (XRPD) was used to investigate the crystallinity of the samples and to identify the minerals. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDS) were used to detect the bacterial imprints, analyze microbe–mineral interactions, and highlight the chemical element distribution in the black deposits. 16S rRNA gene metabarcoding allowed the study of Archaea and Bacteria communities. Mn-oxide-solubilizing isolates were also obtained and characterized by culturable and molecular approaches. The multidisciplinary approach showed the occurrence of deposits composed of birnessite, diopside, halloysite, and leucite. Numerous bacterial imprints confirmed the role of microorganisms in forming these deposits. The Bacteria and Archaea communities associated with these deposits and runoff waters are dynamic and shaped by seasonal changes. The uncultured and unknown taxa are the most common and abundant. These amplicon sequence variants (ASVs) were mainly assigned to Proteobacteria and Bacteroidetes phyla. Six isolates showed interesting Mn solubilization abilities under microaerophilic conditions. Molecular characterization associated isolates to Brevibacterium, Bacillus, Neobacillus, and Rhodococcus genera. The findings enriched our knowledge of geomicrobiological aspects of one of the Earth’s hidden habitats. The study also unveiled the potential of this environment as an isolation source of biotechnologically relevant bacteria.

Genomic insight into iron acquisition by sulfate-reducing bacteria in microaerophilic environments.

Historically, sulfate-reducing bacteria (SRB) have been considered to be strict anaerobes, but reports in the past couple of decades indicate that SRB tolerate exposure to O2 and can even grow in aerophilic environments. With the transition from anaerobic to microaerophilic conditions, the uptake of Fe(III) from the environment by SRB would become important. In evaluating the metabolic capability for the uptake of iron, the genomes of 26 SRB, representing eight families, were examined. All SRB reviewed carry genes (feoA and feoB) for the ferrous uptake system to transport Fe(II) across the plasma membrane into the cytoplasm. In addition, all of the SRB genomes examined have putative genes for a canonical ABC transporter that may transport ferric siderophore or ferric chelated species from the environment. Gram-negative SRB have additional machinery to import ferric siderophores and ferric chelated species since they have the TonB system that can work alongside any of the outer membrane porins annotated in the genome. Included in this review is the discussion that SRB may use the putative siderophore uptake system to import metals other than iron.

Isolation and identification of Helicobacter pylori from raw chicken meat in Dhamar Governorate, Yemen.

Although Helicobacter pylori (H. pylori) is one of the most common bacterial pathogens of human, its natural reservoirs are still unclear. There is an increasing number of reports that document the occurrence of H. pylori in various foods. This study aimed at isolation of H. pylori from chicken meat sampled. Two hundred and sixty samples were collected randomly from slaughterhouses and markets in Dhamar Governorate, Yemen. Samples were enriched in Brain-Heart Infusion broth in microaerophilic conditions before inoculating the Camp-Blood agar and EYE agar plates. Results showed that 13.8% of samples were contaminated evidenced by H. pylori growth via traditional culture method on agar media. No significant differences between sample types (thighs and breast muscles) (p=0.353) or the sampling source (p=0.816) were observed. Autumn season was associated with increased occurrence of H. pylori. The source of H. pylori in food is still not identified. Proper cooking and good sanitation practices are highly recommended to avoid the infection. Further studies addressing the potential sources of H. pylori are highly suggested.

Oddziaływanie olejku cyprysowego (Cupressi aetheroleum) na bakterie mikroaerofilne

Introduction. The evergreen cypress (Cupressus sempervirens L.) belongs to the cypress family (Cupressaceae). It is considered a medicinal plant, and extracts from leaves, fruits and seeds are used in many ailments. The essential oil obtained from young twigs and cones of evergreen cypress contains, among others: α-pinene, δ3-carene, limonene, α-terpinene, β-myrcene, cedrol, β-pinene, δ-caryophyllene and β-caryophyllene, has antimicrobial activity and is recommended for external use. Aim. Testing the activity of cypress oil against microaerophilic bacteria occurring in the oral cavity. Material and methods. The microaerophilic bacteria for the study were isolated from the oral cavity They belonged to the species: Aggregatibacter actinomycetemcomitans, Campylobacter sputorum, Eikenella corrodens and Rothia dentocariosa. The date obtained 5 reference strains to. The susceptibility (MIC) was determined by means plate dilution technique in Brucella agar. The concentrations of cypress oil (Avicenna-oil, Wrocław) were: 5.0, 7.5, 10.0, 15.0 and 20.0 mg/ml. The inoculums containing 105 microorganisms in 1 ml were seeded with Steers replicator. Incubation performed in microaerophilic conditions in anaerobic jar with CAMPY Pak, BBL and standards strains in anaerobic atmosphere in anaerobic jars, in 37°C for 48 hours. The MIC was interpreted as the lowest concentration of cypress oil that completely inhibited the growth of tested microaerophilic bacteria. Results. The results indicated that the cypress oil was the most active in concentrations ≤ 5.0-7.5 mg/ml against 42% tested bacteria. Another concentrations in ranges 10.0-15.0 mg/ml was inhibited growth 26% strains. But 32% strains were susceptible on concentration 20.0 mg/ml and more. Tested cypress oil was the most active against strains from genus Rothia dentocariosa (MIC &lt; 5.0-7.5 mg/ml). The genus Aggregatibacter actinomycetemcomitans was the lowest sensitive. The growth of this strains was inhibited in concentrations in ranges 5.0-≥ 2.0 mg/ml. Cypress oil was the most active at concentrations &lt; 5.0-7.5 mg/ml against 47% of the assessed microaerophilic bacteria. Concentrations in the range of 10.0-15.0 mg/ml inhibited the growth of 26% of microorganisms. In contrast, 32% of the strains were sensitive to concentrations of 20.0 mg/ml and more. The tested cypress oil showed the highest activity against strains of the Rothia dentocariosa species (MIC &lt; 5.0-7.5 mg/ml). Aggregatibacter actinomycetemcomitans was characterized by the lowest sensitivity. The growth of these bacteria was inhibited by concentrations of 5.0-≥ 20.0 mg/ml. Conclusions. Cypress oil was characterized by moderate activity against the tested bacteria growing in microaerophilic conditions, and the strains of the Rothia dentocariosa species showed the highest sensitivity to this oil.

Paraburkholderia bengalensis sp. nov. isolated from roots of Oryza sativa, IR64.

Paraburkholderia bengalensis sp. nov. strain IR64_4_BI was isolated from rice roots cultivated in Madhyamgram field station of Bose Institute, West Bengal, India. IR64_4_BI is a Gram-negative, motile, nitrate-reducing, nitrogen-fixing bacterium. Whole-cell fatty acid analyses of IR64_4_BI show C16:0, summed feature 8 (comprising C18:1ω7c and/or C18:1 ω 6c) and summed feature 3(C16:1 w7c/C16:1 w6c or C16:1 ω 7c/C16:1 ω 6c) were the predominant fatty acids. 16S rRNA phylogeny showed that it was most similar to P. phymatum STM815T (98.5% identity), P. terrae KMY02T (98.44% identity) and P. hospita LMG 20598T (98.32% identity). The Average Nucleotide Identity-BLAST (ANIb) of P. bengalensis IR64_4_BI with P. hospita DSM 17164T, P. terrae DSM 17804T, P. phymatum STM815T and P. hospita LMG 20598T was 83.11, 83.52, 84.5 and 83.12% respectively. Comparison of genome sequence of IR64_4_BI with other species of Paraburkholderia using the Multi-locus species tree software show that P. bengalensis IR64_4_BI is a novel species. The ability of P. bengalensis IR64_4_BI to survive on nitrogen-free medium under microaerophilic conditions and the abundance of nitrogen metabolism-related genes makes this strain a potential candidate for developing a nitrogen-fixing system in rice. Based on genotypic, phenotypic and chemotaxonomic studies, we propose that IR64_4_BI (= MTCC 13051 = JCM 34777) is a new species of Paraburkholderia which has been assigned as Paraburkholderia bengalensis sp.nov.

Analysis of epidemiology and novel mutation of Helicobacter pylori antibiotic resistance in South Korea

BackgroundHelicobacter pylori is a Gram‐negative bacterium associated with upper gastrointestinal disease, peptic ulcer, mucosa‐associated lymphoid tissue lymphoma and eradication treatment is recommended because it is one of the causes of gastric cancer. However, resistance to some antibiotics used for treatment has developed, the eradication rate is declining worldwide. This study focused on antibiotic susceptibility test (AST) of H. pylori isolated from patient clinical specimens. The aim of this study is to identify the resistance epidemiology of H. pylori and to elucidate the resistance mechanism through gene analysis.methodsH. pylori isolated from patient clinical specimens is identified and AST for amoxicillin (AMX) and clarithromycin (CLR) are performed, and the results are analyzed through Whole Genome Sequencing (WGS) and MultiLocus Sequence Typing (MLST), respectively. The strain type of the MLST result is compared with the CLR resistance minimum inhibitory concentration (MIC) value to analyze the significant points.H. pylori is cultured on EYE Agar plate and incubated in Anaerobic Jar for 2~5 days with microaerophilic air condition (5% O2, 10% CO2, 85% N2). Cultured isolates are identified by MALDI‐TOF system and performed AST using Epsilometer test to determining MIC.Results366 H. pylori were isolated from 1952 clinical patients, and 36 AMX‐resistant H. pylori and 101 CLR‐resistant H. pylori were identified. Among the identified H. pylori, 9 AMX high MIC strains were selected and WGS was performed, and 12 CLR high MIC strains were selected and MLST was performed.As the WGS result of 9 clinical strains resistant to AMX, single nucleotide polymorphism (SNP) of the potential target gene was analyzed with reference to ATCC 26695. Six genes, Penicillin binding protein1A (PBP1), PBP2, NhaC, hofH, hofC, and hefC, were selected as potential target genes. As a result of the analysis, 8, 7, 4, 9, 16, and 2 SNPs were found, respectively, and it was specifically confirmed that there were many SNPs in the outer membrane component Gene. However, No correlation was found between AMX MIC value and target SNP.12 For the CLR resistance strain, MLST was performed using 7 housekeeping genes (atpA, efp, trpC, ppa, mutY, yphC, Ure1). In 12 strain, 10 CLR‐resistance H. pylori are not identified strain type(ST) to The National Center for Biotechnology Information(NCBI) database because they have a lots of mutation in 7 housekeeping gene. 2 CLR‐resistance H. pylori are identified the new type strains.ConclusionIn this study, we conclude that hofC, hofH related to outer membrane protein component may be associated to the AMX resistance. And additional research is continued to need about other resistance potential gene, especially hopC.

Species diversity of dominant etiologically significant bacteria circulating in industrial poultry

The problem of the spread of bacterial infections of birds associated with opportunistic microorganisms occupies a significant place in the modern infectious pathology of birds.The aim of this work is to determine the species diversity of the dominant etiologically significant bacteria circulating in industrial poultry farming. Based on the results for the period 2019 to 2020, we carried out bacteriological studies of pathological material from birds in poultry farms of various technological directions.The dominant species are Escherichia coli, which accounts for 50.7%, Enterococcus faecalis - 25.4%, and Proteus mirabilis - 8.4%. Also, thermophilic Campylobacter spp. - 4.3% were isolated from the organs, including such epidemiologically dangerous species as Campylobacter jejuni. The microorganisms were virulent and differed in their cultural and biochemical properties.Cultures such as Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis are isolated from many organs, which indicates the generalization of the infectious process, the culture of thermophilic Campylobacter spp. were isolated from the liver, which indicates the organotropy of these types of microorganisms.The species composition of the allocated microflora is determined by the epizootic situation in each individual farm, which results in a different percentage of the dominant species.Pure cultures of thermophilic campylobacter were obtained on selective Preston agar with cultivation for 7 days at a temperature of 42 ° C under microaerophilic conditions. However, culturing Campylobacter hepaticus is difficult because it is sensitive to a number of antimicrobial agents used in Campylobacter enrichment media and selective agar.The emergence of new Campylobacter species requires a revision of phenotypic identification algorithms. MALDI TOF mass spectrometry databases need to be updated and specific primers developed to identify new Campylobacter species.Significant variability of indicators of indication of one or another microflora from the liver and gallbladder indicates significant differences in the etiology of bacterial infections of birds.

Genotyping, antibiotic resistance and prevalence of Arcobacter species in milk and dairy products.

Background Arcobacter spp. has been considered an emerging foodborne pathogen and a hazard to human health. The dairy chain has been isolated from different sources; nevertheless, data on Arcobacter occurrence in raw milk and dairy products in Iran are still scant.ObjectiveThe present study investigates the prevalence, antimicrobial susceptibility and the presence of virulence genes of Arcobacters species isolated from milk and dairy products.MethodsThen, a total of 350 raw milk samples and 400 dairy product samples were collected from dairy supply centers in Isfahan, Iran. Presumptive Arcobacter strains were obtained by enriching samples in Oxoid Arcobacter enrichment broth (AEB) followed by the filtration of enrichment product through 0.45‐μm pore size membrane filters laid onto non‐selective blood at 30°C under microaerophilic conditions. Molecular identification of Arcobacter cryaerophilus and A. butzleri was performed by Polymerase chain reaction (PCR) amplification of the 16S rRNA gene, followed by sequencing. The disc diffusion method was used to determine the antimicrobial susceptibility of isolates. Targeted resistance and virulence genes were detected using multiplex PCR.ResultsThe results show a low recovery rate of Arcobacter spp. in milk. Arcobacters were found in all types of milk, except raw camel milk, but were absent from all dairy products. Arcobacter butzleri was the predominant species in raw milk. Detection of virulence genes shows that all virulence genes targeted were found among A. butzleri, and six (cadF, cj1349, irgA, mviN, pldA, tlyA) were found among A. cryaerophilus. All A. butzleri strains and some A. cryaerophilus strains isolated from milk were resistant to amoxicillin‐clavulanic acid and tetracycline. All A. cryaerophilus isolates from milk were susceptible to gentamycin, streptomycin, erythromycin and ciprofloxacin. The distribution of resistance genes in Arcobacter strains in milk shows that all isolates carried tet(O) and blaOXA‐61 genes.ConclusionsIn conclusion, the results indicate a low recovery rate of Arcobacter spp. in milk and milk products. However, a significant number of Arcobacter strains with putative virulence genes may be potential pathogens for humans and an overall increase in Arcobacter resistance to first‐line antibiotics. These results highlight the need for regular surveillance of Arcobacter strains in milk and milk products in Iran.

Stone Mineral Salt Solution As A Potential Nutrient For Biosurfactant And Biosolvent Production On Meor Application

Bioproduct from microbial enzymatic activities such as biosurfactant, bioacid, biosolvent, and biopolimer is a useful product in improving oil recovery. The nutrient factors such as the difference and variation of the nutrient, influence microbial growth and enzymatic activities. The objective of this study is to examine the feasibility of Stone Medium Salt Solution (SMSS) as a potential nutrient for biosurfactant and biosolvent production on MEOR application. In the tube test, microbial mixed culture and 3 asphaltic crude oils, tested as C1, C2, and C3, were examined in 0%, 25%, 75%, and 100% SMSS concentrations. The microbial activities were determined by pH, viscosity, and interfacial tension measurements under microaerophilic and aerophilic conditions at 0-day and 7-day incubations. The Microbial Core Flooding (MCF) experiment was measured to observe in field application. The microbial consortia in all crudes had good growth using 100 % SMSS medium. After 7 days, the population increased in both microaerophilic and aerophilic conditions. The interfacial tension and viscosity of all crudes decreased except the viscosity of C1 in microaerophilic condition. The highest decrease occurred in C2 crude, which reduced 51% of interfacial tension and 58.73% of viscosity. Although the result of MCF experiment showed insignificant recovery (only 1.63% from Original Oil in Place), this study proves that SMSS nutrient can be applied in MEOR research by ex situ biosurfactant and biosolvent production for enhancing oil recovery.

Aerossacolitis and Pneumonia in an Indian Peafowl Caused by Lactobacillus agilis

Background: The peafowl is an ornamental bird that has the habit of eating directly from the earthy soil, which makes this bird more susceptible to endoparasites. One important endoparasite is Eucoleus contortus, which leads to inflammatory processes that alter the local microbiota, potentializing disease. By the other way, a member of the bird’s microbiota there is the genus Lactobacillus, but when occurs some imbalance, these bacteria can overgrowth and even cause some infection. This report describes the pathological and microbiological findings of chronic necrotizing pneumonia and aerossacolitis caused by Lactobacillus agilis in a peafowl, associated with parasitism by E. contortus. Case: A peafowl (Pavo cristatus), adult, male, who lived on a farm with contact with other species of animal, was submitted to post-mortem examination due to sudden death. This animal lived in an extensive system on the property and was the only one of its species. During the gross evaluation, the air sacs were filled with solid yellowish crumbly material. The same material was observed forming well-defined nodules that occupied &gt; 50% of the lung parenchyma. Histological analysis showed multiple parabronchi dilated and filled with caseous necrosis, characterized by abundant cellular debris and fibrin deposition. These areas were surrounded by the proliferation of fibrous connective tissue and inflammatory infiltrate of macrophages, giant cells, lymphocytes, and plasma cells. The air sacs parenchyma showed fibrin deposition and mixed inflammatory infiltrate. Multiple gram-positive bacilli were observed within the caseous foci in Gram-stained slides. In the crop and esophageal mucosa, cross-sections of filiform nematodes morphologically compatible with E. contortus were associated with chronic inflammatory infiltrate and epidermal hyperkeratosis. A lung section was submitted to Gram-Brown-Hopps and Ziehl-Neelsen (ZN) stains for bacterial investigation, and Grocott's methenamine silver (GMS) stain for fungal investigation. Short gram-positive bacilli bacteria are observed within the caseous foci in Gram-stained slides. By the other way, no agents were identified on the ZN and GMS stains. Following the analysis, lung fragments were cultivated at aerobic and microaerophilic conditions on sheep blood agar and McConkey agar. All the microbial cultures were incubated at 37°C to 48 h. Pure culture, in microaerophilic condition, of Gram-positive bacilli, was observed. The isolated bacterium was identified by MALDI-TOF MS as L. agilis.Discussion: Although uncommon, L. agilis was the single bacterium identified and therefore, associated as a primary cause of necrotic pneumonia and aerossacolitis in the studied peafowl. The presence of E. contortus could induce the aspiration of regurgitated of little amount of material from the gastrointestinal tract with sufficient bacterial load to initiate an infection, but not enough to smother the animal. The gradual aspiration can induce a chronic inflammatory condition. Infections by bacteria from the host microbiota have been observed in animals and humans with immunodeficiency. In summary, both the parasitosis and the inflammation could be resulted by the parasite and the aspiration of gastric product, which probably interfered in the immune response and allowed the overgrowth of L. agilis. In the current case report, based on macroscopic, microscopic and bacteriological results, we have provided insights to understand how the parasitosis made possible a pneumonia from a bacterium from the host's microbiota. Finally, to the best of our knowledge, this is the first report of L. agilis as causal agent of fatal necrotic pneumonia and aerossacolitis in peafowl.Keywords: respiratory infection, ornamental birds, secondary infection, parasitosis.

Using biobeds for the treatment of fungicide-contaminated effluents from various agro-food processing industries: Microbiome responses and mobile genetic element dynamics

Agro-food processing industries generate large amounts of pesticide-contaminated effluents that pose a significant environmental threat if managed improperly. Biopurification systems like biobeds could be utilized for the depuration of these effluents although direct evidence for their efficiency are still lacking. We employed a column leaching experiment with pilot biobeds to (i) assess the depuration potential of biobeds against fungicide-contaminated effluents from seed-producing (carboxin, metalaxyl-M, fluxapyroxad), bulb-handling (thiabendazole, fludioxonil and chlorothalonil) and fruit-packaging (fludioxonil, imazalil) industries, (ii) to monitor microbial succession via amplicon sequencing and (iii) to determine the presence and dynamics of mobile genetic elements like intl1, IS1071, IncP-1 and IncP-1ε often associated with the transposition of pesticide-degrading genes. Biobeds could effectively retain (adsorbed but extractable with organic solvents) and dissipate (degraded and/or not extractable with organic solvents) the fungicides that were contained in the agro-industrial effluents with 93.1–99.98% removal efficiency in all cases. Lipophilic substances like fluxapyroxad were mostly retained in the biobed while more polar substances like metalaxyl-M and carboxin were mostly dissipated or showed higher leaching potential like metalaxyl-M. Biobeds supported a bacterial and fungal community that was not affected by fungicide application but showed clear temporal patterns in the different biobed horizons. This was most probably driven by the establishment of microaerophilic conditions upon water saturation of biobeds, as supported by the significant increase in the abundance of facultative or strict anaerobes like Chloroflexi/Anaerolinae, Acidibacter and Myxococcota. Wastewater application did not affect the dynamics of mobile genetic elements in biobeds whose abundance (intl1, IS1071, IncP-1ε) showed significant increases with time. Our findings suggest that biobeds could effectively decontaminate fungicide-contaminated effluents produced by agro-food industries and support a rather resilient microbial community.

Co-valorization of corn cobs and dairy wastewater for simultaneous saccharification and lactic acid production: Process optimization and kinetic assessment

This study optimized the co-valorization of corn cob wastes (CCW) and dairy wastewater for simultaneous saccharification and lactic acid (LA) production (sDWW-SSF). Subsequently, the kinetics of Lactobacillus plantarum growth and LA production was assessed using the optimized conditions under microaerophilic (sDWW-SSFmicroaerophilic) and anaerobic (sDWW-SSFanaerobic) conditions, and thereafter compared to De Man, Rogosa and Sharpe (MRS) medium modified with pretreated CCW (mMRS-SSFmicroaerophilic). Optimized sDWW-SSF conditions produced maximum LA concentration and conversion of 11.15 ± 0.42 g/L and 18.90 ± 0.75%, respectively. Kinetic studies revealed that although the mMRS-SSFmicroaerophilic system obtained a higher maximum specific growth rate (μmax) and maximum potential LA concentration (Pm) compared to the wastewater-based bioprocesses, the data obtained for the latter were comparable when taking the resources and costs into consideration. These findings represent the potential to eliminate the use of valuable resources in lignocellulosic bioprocesses and provide insights on innovation towards driving a sustainable economy in line with the food-energy-water nexus.

An unusual case report of hepatic actinomycosis complicating hydatid cyst

Background and Aim: Actinomyces are slow-growing, gram-positive branching bacilli that survive in anaerobic and microaerophilic conditions. Hepatic involvement in actinomycosis is uncommon, accounting for 5% of all cases of actinomycosis.