Microbial Screening Research Articles

Molecular characterisation of virulence genes in bacterial pathogens from daycare centres in Ile-Ife, Nigeria: implications for infection control

BackgroundDaycare centres play a critical role in early childhood development but are high-risk environments for infectious disease transmission due to close physical contact, shared toys, inadequate hygiene, and poor ventilation. These risks are especially concerning in low- and middle-income countries (LMICs) like Nigeria, where resources for infection control may be limited. This study aimed to identify and characterise virulence genes in bacterial isolates from daycare centres in Ile-Ife, Nigeria, to assess infection risks.MethodsBetween November 2017 and July 2019, 233 samples were collected from 76 children, 33 daycare workers, and 124 fomites in 17 daycare centres. The bacterial isolates were analysed using conventional PCR and RAPD analysis to detect the presence of virulence genes. The frequency of crucial virulence genes and the prevalence of each bacterial species were recorded.ResultsKey virulence genes were detected, including fimH in Klebsiella species (22.73% of Gram-negative isolates), algD in Pseudomonas aeruginosa (50%), and icaA and cna in Staphylococcus aureus (16.67%). Staphylococcus aureus was the most prevalent species (35%), followed by Klebsiella (28%) and Pseudomonas aeruginosa (20%).ConclusionThis study highlights the presence of virulent bacterial pathogens in daycare environments, posing a severe infection risk to children. To mitigate these risks, it is essential to implement enhanced infection control measures, such as regular microbial screening, improved hand hygiene practices, and disinfection protocols for fomites. Training programs for daycare workers on hygiene practices and routine monitoring could also significantly reduce infection transmission. These interventions are vital for safeguarding the health of daycare children in Nigeria and similar settings globally.

Research Progress and Trend of Biochar based Microbial Fertilizer

Biochar based microbial fertilizer has loose porous structure, which can improve soil structure, improve soil fertility, promote crop growth, and provide strong support for agricultural sustainable development. In this paper, the research progress of biochar based microbial fertilizer in the preparation process, fertilizer efficiency research, application effect and other aspects was reviewed, and it was pointed out that in the future, in-depth research should be carried out in the aspects of preparation process and performance optimization, microbial strain screening and function enhancement, application effect and mechanism research, standardization and standardization system establishment, application field expansion and technology innovation.

Screening of oxytetracycline-degrading strains in the intestine of the black soldier fly larvae and their degradation characteristics

The presence of excessive antibiotic residues poses a significant threat to human health and the environment. This study was designed to identify an effective oxytetracycline (OTC)-degrading strain through the screening of the intestine of black soldier fly larvae (BSFL). A strain designated “B2” was selected using a series of traditional microbial screening methods. It could be identified as Enterococcus faecalis by Gram staining and 16S rDNA sequencing, with a similarity of 99.93%. Its ability to degrade OTC was then assessed using high-performance liquid chromatography (HPLC). The degradation of the strain was characterized using a one-way test to assess the effects of the substrate concentration, inoculum amount, and initial pH on the degrading bacteria. The results indicate that strain B2 exhibited optimal OTC-degrading performance at a substrate concentration of 50 mg/L, with an inoculum amount of 6% and a pH value of 5.0. Specifically, strain B2 achieved degradation rates of 71.11%, 56.14%, and 45.03%. These findings demonstrate the effectiveness of strain B2 in degrading OTC, indicating its potential for use in environmental remediation efforts.

In Situ Raman Hyperspectral Analysis of Microbial Colonies for Secondary Metabolites Screening.

Since the discovery of penicillin, a vast array of microbial antibiotics has been identified and applied in the medical field. Globally, the search for drug candidates via microbial screening is ongoing. Traditional screening methods, however, are time-consuming and require labor-intensive sample processing, significantly reducing throughput. This research introduces a Raman spectroscopy-based screening system tailored to the in situ analysis of microbial colonies on solid culture media. Employing multivariate curve resolution-alternating least-squares (MCR-ALS) for spectral decomposition, our approach reveals the production of secondary metabolites at the single colony level. We enhanced the microbial culture method, enabling direct, high signal-to-noise (S/N) ratio Raman spectroscopic measurements of colonies of Escherichia coli and actinomycetes species. Through semisupervised MCR analysis using the known spectra of actinorhodin and undecylprodigiosin as references, we accurately assessed the production of these compounds by Streptomyces coelicolor A3(2). Furthermore, we herein successfully detected the production of amphotericin B by Streptomyces nodosus, even in the absence of prior spectral information. This demonstrates the potential of our technique in the discovery of secondary metabolites. In addition to enabling the detection of the above-mentioned compounds, this analysis revealed the heterogeneity of the spatial distribution of their production in each colony. Our technique makes a significant contribution to the advancement of microbial screening, offering a rapid, efficient alternative to conventional methods and opening avenues for secondary metabolites discovery.

Microbial Diversity and Screening for Potential Pathogens and Beneficial Bacteria of Five Jellyfish Species-Associated Microorganisms Based on 16S rRNA Sequencing.

Jellyfish, microorganisms, and the marine environment collectively shape a complex ecosystem. This study aimed to analyze the microbial communities associated with five jellyfish species, exploring their composition, diversity, and relationships. Microbial diversity among the species was assessed using 16S rRNA gene sequencing and QIIME analysis. Significant differences in bacterial composition were found, with distinct dominant taxa in each species: Mycoplasmataceae (99.21%) in Aurelia coerulea, Sphingomonadaceae (22.81%) in Cassiopea andromeda, Alphaproteobacteria_unclassified (family level) (64.09%) in Chrysaora quinquecirrha, Parcubacteria_unclassified (family level) (93.11%) in Phacellophora camtschatica, and Chlamydiaceae (35.05%) and Alphaproteobacteria_unclassified (family level) (38.73%) in Rhopilema esculentum. C. andromeda showed the highest diversity, while A. coerulea exhibited the lowest. Correlations among dominant genera varied, including a positive correlation between Parcubacteria_unclassified (genus level) and Chlamydiaceae_unclassified (genus level). Genes were enriched in metabolic pathways and ABC transporters. The most abundant potential pathogens at the phylum level were Proteobacteria, Tenericutes, Chlamydiae, and Epsilonbacteraeota. The differing microbial compositions are likely influenced by species and their habitats. Interactions between jellyfish and microorganisms, as well as among microorganisms, showed interdependency or antagonism. Most microbial gene functions focused on metabolic pathways, warranting further study on the relationship between pathogenic bacteria and these pathways.

Feasibility, efficacy, and safety of animal-assisted activities with visiting dogs in inpatient pediatric oncology.

Childhood cancer entails a heavy burden for patients and their families. Recent advances in overall survival rates have increasingly brought long-term quality of life into focus. Animal-assisted activities (AAAs) have long been hypothesized to alleviate the burden on pediatric patients and their peers in the hospital setting. However, their use in inpatient pediatric oncology has been a sensitive issue mainly due to the fear of infections, resulting in a lack of studies. This study presents data on the feasibility, safety, and efficacy of AAAs from a single German center. Between 2018 and 2022, 60 patients (median age = 10.3years) diagnosed with malignancy and undergoing treatment were visited by an intervention dog (total visits = 100). Patients were screened for infections as per hospital policy, with additional microbiological testing performed based on symptoms. The dog was screened for human pathogens and zoonoses. Microbial data and hospitalizations were analyzed from twomonths prior to the first visit until twomonths after the last visit. Acceptance of being in the hospital, both with and without planned animal-assisted interventions and pre- and post-intervention state stress, were measured using a validated visual analogue scale (0-10). Patients benefited from AAAs, showing increased acceptance of being in the hospital (median: 7.25 vs. 4.50, P < 0.001) and decreased median state stress ratings one hour after the visit compared to one hour before the visit (1.00 vs. 4.25, P < 0.001). The intervention did not result in an increased number of infections or unplanned hospitalizations, and no zoonoses were detected. All microbial screening tests of the dog were negative. AAAs with visiting dogs in inpatient pediatric oncology are feasible and safe. Although they hold promise for enhancing patients' well-being, further prospective studies are needed. Supplementary file2 (MP4 240076KB).

Assessment of nematode and microbial diversity and screening of entomopathogens in revegetated post-coal-mining land in Kutai Kartanegara District, East Kalimantan, Indonesia

Abstract. Sopialena, Rosfiansyah, Suryadi A. 2024. Assessment of nematode and microbial diversity and screening of entomopathogens in revegetated post-coal-mining land in Kutai Kartanegara District, East Kalimantan, Indonesia. Biodiversitas 25: 2921-2930. Post-coal-mining management should strive toward site revegetation. The success of such revegetation efforts is largely determined by the soil's fertility status, which encompasses physical, chemical, and biological components. Biological fertility is indicated by the presence and abundance of soil microbes and nematodes. The objective of this study was to identify the diversity of nematodes and soil microbes in ex-coal-mining land revegetated with oil palm in Kutai Kartanegara District (East Kalimantan, Indonesia), to screen for entomopathogenic nematodes and microbes, and to analyze their relationships with the chemical fertility status of the land. As a control, non-mining land was also investigated. The results showed that microbial diversity and density (including fungi and bacteria) in the ex-coal-mining area were significantly lower compared to the control. Additionally, a decrease in microbial diversity and density was found in deeper soil layers of both post-mining and non-mining lands. In contrast, soil nematodes were more abundant in post-mining land, both in terms of diversity and density, and were also more plentiful in the deeper soil layers. Among the nematodes and microbes studied, only Heterorhabditis and Steinernema (nematodes), Trichoderma (fungi), and Bacillaceae (bacteria) were identified as entomopathogens, causing death in Tenebrio molitor L. larvae. Overall, soil fertility in ex-coal-mining land was observed to be lower, characterized by decreased soil pH, basic saturation, Soil Organic Carbon (SOC), and nutrient content, which contributed to a reduced microbial community compared to non-mining land.

Phyto chemical screening,formulation of cream and it’s antifungal activity of stem extract from panikoorka plant

The panikoorka plant is a noble plant which is packed with various benefits, belonging to the family Lamiaceae as it may help in lowering blood sugar levels, maintaining heart health, and helps in digestive system, the stem of panikoorka is also having the anti-cancer activity some studies also prove that the extract of panikoorka stem are effective against the acne causing bacteria (anti-microbial).We are formulating the anti-fungal cream with the extract of panikoorka stem, we have collected the different extracts of the panikoorka stem, we have formulated 2 different formulations with the stem of panikoorka (Plectranthus barbatus).The Plant extract is used to treat different types of infectious disease, hence microbial screening attempted to prove its anti-bacterial and anti-fungal activity. The demonstration of therapeutic efficacy was achieved through the use of defined settings to restrict microbial development.The paper disc diffusion method was employed in this work to assess the synthetic compounds' in vitro antifungal efficacy. One technique for figuring out the relative efficacy of the anti-fungal activity is the paper disc diffusion method. The anti-microbial drugs' toxicity and their capacity to permeate into the medium both affect the outcomes of this approach. Although it is not as effective as standard, our produced cream has antifungal action against both Aspergillus niger and Candida albicans bacteria.

Microbial screening and process optimization for efficient removal of ginkgolic acids from Ginkgo biloba leaf

This study aimed to screen microorganisms capable of removing ginkgolic acids (GAs) from Ginkgo biloba leaf. Given the presence of long alkyl side chains in GAs, the study first focused on screening microorganisms that could utilize long-chain alkanes (n-tridecane, n-pentadecane, and n-heptadecane) and further studying their GAs degradation abilities. The results showed that the degradation rates of GAs by the two bacteria strains (identified as Pantoea sp.) were about 50 %, and the degradation rates of GAs by the nine fungal strains (identified as Fusarium sp.) were about 95 %. Meanwhile, Lactiplantibacillus plantarum was also found to exhibit a robust capacity for degrading GAs. Through further optimization of the medium components and fermentation conditions, Lactiplantibacillus plantarum achieved a degradation rate of 81.581 % for total GAs after 72 hours of cultivation. Notably, this process did not significantly impact flavonoids and terpene lactones present in Ginkgo biloba extract (EGb), which are essential for its therapeutic properties. Additionally, the results demonstrated that the hydrophobicity of GAs significantly influenced the degradation efficiency of GAs by Lactiplantibacillus plantarum. This study highlights the potential industrial application value of Lactiplantibacillus plantarum in the production of ginkgo products with low GAs content, thereby enhancing the safety and efficacy of this widely used medicinal plant.

Efficient glycosylation and in vitro neuroprotective evaluation of abundant prenylflavonoid in hops

Structurally unique isopentenyl flavonoids are extremely low in natural plant species, and their cumbersome chemical pathways, scarcity of donors, and poor stability have severely hindered their application scenarios. Xanthohumol (XN), an isopentenyl chalcone, is a unique and abundant herbal efficacy substance in hops (Humulus upulus L.), which is an herb with a variety of clinical benefits. However, 90% of XN is left behind in the production of hop residue, resulting in a waste of natural resources. The poor water solubility and low bioavailability of XN also limit its wide application. Combined biotransformation strategies can greatly enhance the added value of resource materials and become one of the important means for the sustainable utilization of traditional Chinese medicine resources. In this study, an extreme microbial screening strategy for efficient bioconversion of phrenylflavonids is established to achieve Bacillus zanthoxyli GQ8 obtained from brewer's dregs and a non-aqueous biosynthesis system of xanthohumol glycosides (XNG, substrate concentration of 0.5 g/L, conversion rate of 73.2%) is constructed by GQ8. With HT22 cell model of H2O2-induced oxidative damage and BV2 cell model of LPS-induced neuroinflammation, XNG showed little cytotoxicity and exhibited better anti-inflammatory and antioxidant effects compared with the original compound. Our experimental results firstly provide a high-efficiency biotransformation strategy for glycosylation of XN with bacteria and provide a support that prenylflavonoid glycoside derivatives have remarkable biological activity and show better development potential.

Investigating the degradation potential of microbial consortia for perfluorooctane sulfonate through a functional "top-down" screening approach.

Perfluorooctane sulfonate (PFOS) is a prominent perfluorinated compound commonly found in the environment, known to pose various risks to human health. However, the removal of PFOS presents significant challenges, primarily due to the limited discovery of bacteria capable of effectively degrading PFOS. Moreover, single degradation bacteria often encounter obstacles in individual cultivation and the breakdown of complex pollutants. In contrast, microbial consortia have shown promise in pollutant degradation. This study employed a continuous enrichment method, combined with multiple co-metabolic substrates, to investigate a microbial consortium with the potential for PFOS degradation. By employing this methodology, we effectively identified a microbial consortium that demonstrated the capacity to reduce PFOS when exposed to an optimal concentration of methanol. The consortium predominantly comprised of Hyphomicrobium species (46.7%) along with unclassified microorganisms (53.0%). Over a duration of 20 days, the PFOS concentration exhibited a notable decrease of 56.7% in comparison to the initial level, while considering the exclusion of adsorption effects. Furthermore, by comparing the predicted metabolic pathways of the microbial consortium with the genome of a known chloromethane-degrading bacterium, Hyphomicrobium sp. MC1, using the KEGG database, we observed distinct variations in the metabolic pathways, suggesting the potential role of the unclassified microorganisms. These findings underscore the potential effectiveness of a "top-down" functional microbial screening approach in the degradation of stubborn pollutants.

Comparable bacterial growth in platelet concentrates suspended in plasma and platelet additive solution and improved detection of bacterial contamination using a new generation automated culture system.

Microbial screening of platelet concentrates (PC) with automated culture methods is widely implemented to reduce septic transfusion reactions. Herein, detection of bacterial contamination in PC was compared between units prepared in plasma and a mix of plasma and platelet additive solution (PAS) and between the BACT/ALERT 3D and next generation BACT/ALERT VIRTUO systems. Double apheresis units were split into single units, diluted in either PAS (PAS-PC) or plasma (plasma-PC), and tested for in vitro quality and sterility prior to spiking with ~30 CFU/unit of Staphylococcus epidermidis, Staphylococcus aureus, Serratia marcescens, and Klebsiella pneumoniae or ~10 CFU/mL of Cutibacterium acnes. Spiked PC were sampled for BACT/ALERT testing (36 and 48 h post-spiking) and colony counts (24, 36, and 48 h post-spiking). Times to detection (TtoD) and bacterial loads were compared between PC products and BACT/ALERT systems (N = 3). Bacterial growth was similar in plasma-PC and PAS-PC. No significant differences in TtoD were observed between plasma-PC and PAS-PC at the 36-h sampling time except for S. epidermidis which grew faster in plasma-PC and C. acnes which was detected earlier in PAS-PC (p < .05). Detection of facultative bacteria was 1.3-2.2 h sooner in VIRTUO compared with 3D (p < .05) while TtoD for C. acnes was not significantly different between the two systems. Comparable bacterial detection was observed in plasma-PC and PAS-PC with PC sampling performed at 36-h post blood collection. PC sampling at ≤36 h could result in faster detection of facultative pathogenic organisms with the VIRTUO system and improved PC safety.

Qualitative Phytochemical Screening, Fatty Acid Profile and Biological Studies of the Bark of &lt;i&gt;Mallotus nudiflorus&lt;/i&gt; (Pitali) Plant

In the present study, the Mallotus nudiflorus (L.) plant has been taken to determine the in-vitro analysis to find out the therapeutic value. The bioassays of the raw extract of methanol of bark of M. nudiflorus and by Kupchan’s extraction method collecting n-Hexane (HEX), Dichloromethane (DCM), Chloroform (CHCl3), Ethylacetate (EA) and Aqueous (AQ) fractions were scrutinized to find out its therapeutic value. The findings of phytochemical screening of the methanol extract of barks revealed the presence of several secondary metabolites. By using the GC-FID method the result showed that M. nudiflorus contained four bound fatty acids and four free fatty acids. EA fraction had the maximum phenolic content among all the fractions at (133.67±0.99) mg of GAE/g where the Folin- Ciocalteu reagent was used as an oxidizing agent. The antioxidant activity was measured in terms of its ability to scavenge free radicals (DPPH assay). Among all extractives, the greatest ability to scavenge for free radicals was shown by EA extract with an IС50 value (12.08±0.15) μg/ml. In the toxicity of brine shrimp test, the HEX fraction had the maximum toxicity with an LC50 value of (0.12±0.01) μg/ml. Cell cytotoxicity was observed for sample CHCl3 and EA on both the Vero (kidney epithelial cells taken from an African green monkey) and HeLa (a human cervical cancer cell) cell line. All the fractions were subjected to in vitro microbial screening, which revealed that DCM, CHCl3, and EA fractions showed growth inhibition, particularly against various Gram-positive and Gram-negative bacteria by disc diffusion method. The maximum zone of inhibition in the antimicrobial activity was produced by CHCl3 fraction against Staphylococcus aureus (17 mm). The results of in vitro experiments have demonstrated that the extracts from the barks of M. nudiflorus have great potential for medicinal uses and might be studied for further chemical exploration.

Gut Microbiome Integration in Drug Discovery and Development of Small Molecules.

Human microbiomes, particularly in the gut, could have a major impact on the efficacy and toxicity of drugs. However, gut microbial metabolism is often neglected in the drug discovery and development process. Medicen, a Paris-based human health innovation cluster, has gathered more than 30 international leading experts from pharma, academia, biotech, clinical research organizations, and regulatory science to develop proposals to facilitate the integration of microbiome science into drug discovery and development. Seven subteams were formed to cover the complementary expertise areas of 1) pharma experience and case studies, 2) in silico microbiome-drug interaction, 3) in vitro microbial stability screening, 4) gut fermentation models, 5) animal models, 6) microbiome integration in clinical and regulatory aspects, and 7) microbiome ecosystems and models. Each expert team produced a state-of-the-art report of their respective field highlighting existing microbiome-related tools at every stage of drug discovery and development. The most critical limitations are the growing, but still limited, drug-microbiome interaction data to produce predictive models and the lack of agreed-upon standards despite recent progress. In this paper we will report on and share proposals covering 1) how microbiome tools can support moving a compound from drug discovery to clinical proof-of-concept studies and alert early on potential undesired properties stemming from microbiome-induced drug metabolism and 2) how microbiome data can be generated and integrated in pharmacokinetic models that are predictive of the human situation. Examples of drugs metabolized by the microbiome will be discussed in detail to support recommendations from the working group. SIGNIFICANCE STATEMENT: Gut microbial metabolism is often neglected in the drug discovery and development process despite growing evidence of drugs' efficacy and safety impacted by their interaction with the microbiome. This paper will detail existing microbiome-related tools covering every stage of drug discovery and development, current progress, and limitations, as well as recommendations to integrate them into the drug discovery and development process.

Gold Nanoparticle Coated Biocompatible Polymeric Matrix Mesh Plasticizers Embedded over Polyvinyl Chloride Plastic Porous Grid: Designed Reusable Microbial Screening Mask and Its Application

Under severe pandemic conditions, any airborne microbe, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leads to increased fatality if physical screening is compromised. Therefore, an investigation was carried out to design a reusable screening mask that could promise the highest safety and be compatible with users. After going through the analytical and clinical investigation, the design and the work quality are confined to the ground version. To initiate top quality mask screener design of high-tech gold nanoparticles (AuNPs) hydroxyethyl methacrylate (HEMA) composite mask, safety evaluation data from all masks were collected. The porous polyvinyl chloride (PVC) circular grid frame was coated with a gold metallic nano particles layer, and the flexible adhesive polymeric matrix mesh plasticizers polyethylene terephthalate (PET) was used to coat bed on each grid, as a design. In-vitro quantitative analysis process assembly of bio-contaminant and specific matter was developed, in which breathed/vacuumed air was passed via fractional screening cone adhesive edged stumbling block route for final pure contaminant free air. The vacuumed air was collected through the adhesive slide, and microbial growth and particular matter were analysed and discovered to be best compared to conventional filter masks. Gold coat film entrapment tests with colony density were performed through Fourier transform infrared spectroscopy (FTIR), and virus crystal structure analysis was done through an X-ray diffractometer. Clinical investigations of this development were done with 50 volunteers. The research demonstrates the advantages of the AuNPs HEMA composite reusable mask design comparatively best over other mask designs regarding microbiological screening and lab safety, and it may be helpful to stand against biological warfare.

Assessment of the Microbial and Chemical Safety in the Street Food – A Review

Improper personal hygiene can facilitate the transmission of pathogenic Bacteria found in the environment and on people’s hands via food. The present study is undertaken to investigate the microbiological quality and chemical residue present in the different street food samples in Karad, Maharashtra. For Microbial Screening of various street food samples, Enrichment spread plates, streak plate techniques, and Biochemical characterization will be performed. For chemical analysis, the chemical Residue present in street food will be analysed by spectroscopy. The Microbial and chemical safety of Street foods will be compared with WHO guidelines for food safety and other food regulatory Standards. FSSAI (Food Safety and Standards Authority of India) Strategies For the will be set on the Basis of collected data enhancement of Microbiological and chemical Safety of street-vended food.

Degrading characteristics of oil‐degrading bacteria and its study of petroleum hydrocarbon metabolites

AbstractExploring the community characteristics of petroleum degrading bacteria and revealing the types of petroleum metabolites produced by degrading bacteria play an important role in solving the problem of oil pollution. In this study, the bacterial suspension was extracted from the sludge of the sewage treatment plant, and the efficient dominant bacteria were enriched and cultured by microbial screening. The optimal environmental conditions and kinetic behavior of microbial degradation of petroleum hydrocarbons in groundwater were discussed, and the metabolites of microbial degradation of petroleum hydrocarbons were analyzed. The results showed that the optimum degradation conditions of the strain were as follows: bacterial suspension inoculum: 2%, pH: 7, temperature: 30°C, initial concentration of contaminated water sample: 500 mg/L. Under these conditions, the microbial petroleum hydrocarbon degradation efficiency was 84.7% and followed the first‐order kinetics; qualitative and quantitative statistical analysis of the metabolites of the microbial degradation of petroleum hydrocarbons by gas chromatography‐time‐of‐flight mass spectrometry was performed. A total of 10 significantly upregulated products and 12 significantly downregulated products were screened, which were significantly different from the metabolites of the control group. Further microbial community analysis showed that Pseudomonas was dominant in the bacterial suspension, more than 99.5%, which was significantly different from the sludge sample, providing data support for the degradation of petroleum hydrocarbons by Pseudomonas. This study has provided a scientific basis for in situ remediation of petroleum pollution in groundwater.

The Effect of the Supplementation of Humic Substances and Fermented Products in the Feed on the Content of Salinomycin Residues in Poultry Tissues.

The presence of antimicrobial residues in products of animal origin is a constant problem for consumer health. The aim of this study was to observe the effect of the addition of humic substances (H), fermented products (F) and a mixture of both (FH) to feed supplemented with the coccidiostat salinomycin, compared with a control group (C), on the content of salinomycin residues in the edible tissues of broiler chickens using two microbial inhibition screening methods, Explorer 2.0 test and the Screening Test for Antibiotic Residues (STAR), and a confirmatory competitive enzyme immunoassay analysis (Salinomycin ELISA Kit). The results of the microbial inhibition tests showed a gradual decline in the positive results in the tissue samples from the last day of salinomycin administration (30th day) tothe last day of fattening (37th day, day of slaughter) in group C and no positive results in the tissue samples from experimental groups H, F and FH slaughtered on the last day of fattening. Using the Salinomycin ELISA Kit, salinomycin was detected in the chicken muscle tissues of all the control and experimental groups. However, no sample from any group contained salinomycin at a concentration exceeding the maximum residue limits set by European law. The high level of significance (p < 0.001) confirmed the positive influence of the administration of humic substances and fermented products on the content of salinomycin residues in chicken tissues.

Microbial screening of animal skin bags used in traditional cheesemaking

Bouhezza is a traditional Algerian cheese produced and ripened in goatskin bags called Djeld. The aim of this study was to characterize the microbial ecosystem from Djeld (fresh and dried Djeld for making Bouhezza cheese) and the changes introduced by Lben microflora during its preparation and to identify its role in cheesemaking and its safety. Two replicates of fresh and dried skin bags (FS and DS) were sampled and analyzed before and after contact with Lben. The microbiological results showed no pathogens. Skins observed before the addition of Lben were less populated 2.86 and 3.20 log CFU cm−2 than skins examined after the addition of Lben (approximately 6.0 log CFU cm−2), suggesting a potential role of Lben in releasing some microorganisms into the skin during its time in the Djeld. However, an increase in mesophilic lactic acid bacteria and yeasts was observed in Lben after different periods of interaction with the skin. PCR-TTGE revealed the predominance of lactic acid bacteria (Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Staphylococcus equorum subsp. linens, Lactococcus cremoris, Streptococcus thermophilus) and a few high-GC-content bacteria (Lacticaseibacillus paracasei, Brevibacterium casei). Transfer of several microbial species was observed between the goatskin bag biofilm and Lben during the overnight interaction. Bands corresponding to Lacticaseibacillus paracasei, Brevibacterium casei, and Lactobacillus delbrueckii subsp. lactis were detected in the fresh skin profile and in Lben after contact with the fresh skin. Lacticaseibacillus paracasei was found in dried skin and Lben after contact with dry skin. Lactobacillus helveticus and Enterococcus faecalis appeared in the Lben profile and persisted in Lben and the biofilm-covered dry skin after interaction. These results demonstrate an exchange of specific microbial populations between goatskin bag biofilm and Lben during the traditional preparation method, suggesting that the diversity of goatskin biofilm contributes to the microbial diversity of Lben used in the production of Bouhezza cheese.

Ribotyping Analysis of Microbes Producing Hydrolase from Batik Liquid Waste Samples

Batik liquid waste that is disposed of into the environment still contains high levels of organic compounds as residue from the main ingredients in batik production, like dyes, wax, starch, soda ash, and others. With its high organic material content, batik liquid waste is a potential habitat for microbial growth. This research aims to isolate and genetically analyze microbes in batik liquid waste, namely by ribotyping analysis of microbes that produce hydrolase enzymes. From the results of microbial screening on selective lipase media, eight types of bacteria were obtained which have the potential to produce hydrolase enzymes. Eight types of hydrolase-producing bacteria have been genetically identified using the 16S rRNA gene. Alignment analysis using blastN from NCBI of the 16S rRNA gene nucleotide sequence of the sample suggested that the hydrolase-producing microbial isolate of the sample had the closest homology to the Serratia, Burkholderia, Stutzerimonas, and Pseudomonas groups. Four of the eight samples, RR1R, RA1R, RA2R, and ZB16R, have the highest homology &lt;97%. This suggests that the four samples are novel microbial variants, which are different from the microbial data in Genbank.