Enterobacter Strains Research Articles

Comparative Analysis of the Probiotic Features of Lysinibacillus and Enterobacter Strains Isolated from Gut Tract of Triploid Cyprinid Fish.

Gut mucosal immunity of teleost is mainly governed by mucosa-associated lymphoid tissues (MALT) and indigenous microbiota on mucosal surfaces of gut tract, which can confer protection against pathogenic invasion. However, the probiotic features of bacterial isolates from gut tract of triploid cyprinid fish (TCF) were largely unclear. In this study, Lysinibacillus and Enterobacter strains were isolated for probiotic identification. Whole genome sequencing (WGS) analysis indicated that Lysinibacillus and Enterobacter isolates possessed a variety of functional genes associated with probiotic features. Biofilm-forming activity (BFA) were one of the most important probiotic features, which can enable probiotic strains to communicate with indigenous microbiota by forming sessile community and then confer protection against stressors and invading pathogens. In this study, Lysinibacillus and Enterobacter isolates displayed high levels of BFA, hydrophobicity as well as aggregating potentials. Moreover, supernatants of probiotic isolates not only decreased pathogenic BFA and growth activity, but also showed high decomposing activity to macronutrients. These results indicated that probiotic isolates from gut tract of TCFs may pose protective roles in health of farmed fish.

Advanced Large-Stokes-Shift Fluorescent Probe for the Detection of Biothiols: Facilitating Accurate Indirect Measurement of β-Lactamases.

A novel fluorescent probe, Bibc-DNBS, based on the combination of the PET (photoinduced electron transfer) and ESIPT (excited-state intramolecular proton transfer) mechanisms, was designed and synthesized. Bibc-DNBS exhibited a Stokes shift of 172 nm in the fluorescence detection field. In addition, the probe exhibited good performance in key parameters in bioassays such as sensitivity, specificity, and response time. Based on these properties, Bibc-DNBS successfully monitored the biothiol levels in live cells and zebrafish models, providing an effective analytical tool for real-time monitoring of biothiols. More importantly, Bibc-DNBS could be useful for indirectly detecting β-lactamases. Bibc-DNBS(3-(1H-benzo[d]imidazol-2-yl)-4'-cyano-[1,1'-biphenyl]-4-yl2,4-dinitrobenzenesulfonate) facilitated the screening of β-lactamase inhibitors, using tazobactam and clavulanic acid as model compounds, with respective semi-inhibitory concentration values of 31.32 μM and 2.26 μM, respectively. It might also be applied to distinguish sensitive strain Staphylococcus aureus ATCC 29213 and drug-resistant strain Enterobacter cloacae ATCC 13047, which could provide strong support for the clinical application of antibiotics and the development of new drugs.

Enterobacter-inoculation altered the C, N contents and regulated biomass allocation in Reaumuria soongorica to promote plant growth and improve salt stress tolerance.

Soil salinization poses a significant ecological and environmental challenge both in China and across the globe. Plant growth-promoting rhizobacteria (PGPR) enhance plants' resilience against biotic and abiotic stresses, thereby playing a vital role in soil improvement and vegetation restoration efforts. PGPR assist plants in thriving under salt stress by modifying plant physiology, enhancing nutrient absorption, and synthesizing plant hormones. However, the mechanisms through which PGPR regulate the contents of carbon (C) and nitrogen (N), and biomass allocation of desert plant in response to salt stress is still unclear. This study explores the impact of PGPR on biomass allocation, C, and N contents of R. soongorica seedlings through a pot experiment. Strains P6, N20, and N21, identified as Enterobacter, were isolated from the rhizosphere of R. soongorica, and they exhibited various beneficial traits such as indole-3-acetic acid (IAA) production, phosphate solubilization, nitrogen fixation, and tolerance to up to 8% NaCl stress. We found that under NaCl stress, R. soongorica seedlings exhibit significant reductions in plant height, basal diameter, and root surface area (P<0.05). However, inoculation with strains P6, N20, and N21 reverses these trends. Compared to NaCl treatment alone, co-treatment with these strains significantly increases the biomass of roots, stems, and leaves, particularly root biomass, which increases by 99.88%, 85.55%, and 141.76%, respectively (P<0.05). Moreover, N contents decrease significantly in the roots, stems and leaves, C contents increase significantly in the roots and leaves compared to NaCl treatment (P<0.05). Specifically, N contents in roots decrease by 14.50%, 12.47%, and 8.60%, while C contents in leaves increase by 4.96%, 4.45%, and 4.94%, respectively (P<0.05). Additionally, stem and leaf biomasses exhibit a significant positive correlation with C contents and a significant negative correlation with N contents in these tissues. In conclusion, inoculation of Enterobacter strains enhanced the biomass of R. soongorica seedlings, regulated the biomass distribution, and modifies C and N contents to promote plant growth and improve salt stress tolerance. This study provides a novel adaptive strategy for the integrated use of PGPR and halophytes in saline-alkali soil improvement and vegetation restoration efforts.

Non-nodulating Enterobacter strains with multiple Plant Growth Promoting (PGP) attributes dominantly co-exist with nodulating rhizobia as root nodule endophytes of wild perennial legumes, Tephrosia spp. of Indian Thar Desert

Non-nodulating Enterobacter strains with multiple Plant Growth Promoting (PGP) attributes dominantly co-exist with nodulating rhizobia as root nodule endophytes of wild perennial legumes, Tephrosia spp. of Indian Thar Desert

High antimony resistance strain Enterobacter sp. Z1 mediates biomineralization of antimony trioxide.

The increasing antimony (Sb) contamination prevalence poses a concern owing to its toxicity and potential carcinogenic properties. However, mechanisms underlying the microbial conversion of soluble Sb into insoluble Sb minerals remain unclear. In the present study, Enterobacter sp. Z1 strain demonstrated remarkable resistance to antimony potassium tartrate [Sb(III)] (>250mM) in R2A medium. Furthermore, Enterobacter sp. Z1 produced antimony trioxide (Sb2O3) via biomineralization during cultivation. Omics analysis revealed the upregulation of pyruvate metabolism and accumulation of DL-3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) in the presence of Sb(III).Using pyruvate as the sole carbon source in a chemically defined medium significantly enhanced Sb(III) biomineralization ratio from 20.8% to 90.4% compared with that using R2A medium. Additionally, reduced Sb(III) biomineralization and intracellular pH levels were observed following aceE gene knockout in Enterobacter sp. Z1. However, this impaired phenotype was rescued by complementing the aceE gene or introducing purified AceE into the bacterial lysates. Notably, AceE exhibited binding affinity for Sb(III). Our findings revealed the pyruvate-HMG-CoA pathway as the mechanism underlying Sb biomineralization, facilitating the release of Sb ions from tartrate and maintaining intracellular pH stability, thereby catalyzing Sb2O3 synthesis. This study provides insights into the Sb biogeochemical cycle.

Bacteria Derived from Diamondback Moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), Gut Regurgitant Negatively Regulate Glucose Oxidase-Mediated Anti-Defense Against Host Plant.

The ongoing interplay among plants, insects, and bacteria underscores the intricate balance of defense mechanisms in ecosystems. Regurgitant bacteria directly/indirectly impact plant immune responses, but the underlying mechanism is unclear. Here, we focus on the interaction between regurgitant bacteria, diamondback moth (DBM), and plant. Six culturable bacteria were isolated from DBM gut regurgitant, including three Enterobacter strains (RB1-3), Micrococcus sp. (RB4), Staphylococcus haemolyticus (RB5), and Bacillus cereus (RB6). These RB strains suppressed genes related to jasmonic acid and glucosinolate signaling pathways but had little effect on salicylic acid signaling pathway genes in Arabidopsis thaliana wounds. RB1 and RB5 inhibited DBM development on A. thaliana but not on an artificial diet. RB1 and RB5 significantly suppressed GOX genes and proteins in DBMs. However, the Pxgox2 insect mutant strain inoculated with RB1 or RB5 did not significantly affect DBM feeding on A. thaliana compared to the wild type. Six RB have been functionally identified, with RB1 and RB5 negatively regulating GOX-mediated host adaptability. The deliberate addition of RB1 and RB5 can negatively affect DBM herbivory and fitness. Our study provides a molecular basis for the further application of RB for insect pest management by modulating insect-plant interactions.

Characterization of multi-trait plant growth-promoting rhizobacteria isolated from alfalfa rhizosphere and evaluation of their efficacy on tomato and watermelon growth

Plant growth-promoting rhizobacteria (PGPR) are free-existing soil-borne bacteria that can be used as bioinoculants in place of chemical fertilizers to directly or indirectly enhance plant growth. This study aimed to characterize PGPR native to the rhizosphere of alfalfa plants in Kayseri and evaluate their efficacy on the growth parameters of tomato and watermelon. A total of 56 potential PGPR isolates were isolated and 24 were selected based on their ability to produce multiple PGP traits. 16S rDNA and phylogenetic analysis characterized these isolates to be novel strains of Pseudomonas, Enterobacter, Acinetobacter, Stenotrophomonas, Staphylococcus, Lycinibacillus, and Bacillus. Sequence analysis revealed nucleotide variations and insertion/deletion mutations in their 16S rRNA genes (nucleotides 913–1408). All selected isolates demonstrated nitrogen fixation ability, whereas 54%, 83%, 71%, 54%, and 38% of isolates possessed genes for phosphate solubilization, indole-3-acetic acid (IAA) synthesis, phytase, ACC deaminase, and siderophore, respectively. Fifty-eight day old tomato and watermelon plants grown from PGPR-treated seeds showed significantly higher improvements in plant height, stem diameter, leaf area, shoot dry weight, and root fresh weight compared to non-inoculated control plants. Furthermore, treatment of watermelon seeds with these isolates significantly increased the fresh weight of shoots and the root dry weights in watermelon plants. Thus, these indigenous PGPR isolates can be used as effective seed inoculants and chemical fertilizer alternatives to enhance tomato and watermelon growth.

ANTIBIOGRAM OF PRE-PROCESSED RAW CHICKEN MEAT FROM DIFFERENT SUPERSHOPS OF DHAKA CITY, BANGLADESH

Pathogenic strains of salmonella, S. aureus, S. epidermidis, shigella, enterobacter and citrobacter are serious health threat for human being. Present investigation was conducted to assess the antibiogram of pre-processed raw chicken meat collected from different chain-shops of Dhaka city. Pre-processed chicken meat samples were collected from three different super-shops (S1, S2, and S3) in Dhaka. The Samples are serially diluted to 10-4, and after growth on MSA, MAC, and SS agars, the total counts showed The most growth S2 (360 × 10.4  18.33), (235 × 10.4), (25 × 10.14.4  3.6) followed by S3 (353.3 × 10.4  42.39), (151.67 × 10.4  22.19), 15 × 10-4  3.0) and finally S1 (3.26.67 × 10.4  29.48), (64.5 × 10.4  8.62) (14 × 10.4  5.13) respectively. Salmonella S aureus, S. epidermidis, Shigella, Enterobacter and Citrobacter were identified after a number of morphological and biochemical tests; Gram staining, MIU, KIA, oxidase and catalase tests, and citrate utilization test following aseptic techniques. Six antibiotics; Vancomycin, and five broad spectrum drugs; Streptomycin, Norfloxacin, Novobiocin, Chloramphenicol, and Cefotaxime were used to test the sensitivity or resistance of the organisms. All the pathogens were susceptible to chloramphenicol. Staphylococcusepidermidis were novobiocin-resistant. Citrobacter spp. and Enterobacter spp. were sensitive to all except novobiocin. Staphylococcusepidermidis was susceptible and intermediate to norfloxacin. Staphylococcusaureus was resistant to norfloxacin and novobiocin; intermediate to cefotaxime, and sensitive to the rest. Salmonella spp. was found to be resistant to novobiocin, vancomycin, and streptomycin; intermediate to norfloxacin, but sensitive to chloramphenicol and cefotaxime. Shigella.spp was found to be sensitive to all the antibiotics but resistant to novobiocin and vancomycin. Fecal coliform E. coli was absent showing some degree of sanitation in the chicken, and all the pathogens were found susceptible to at least two antibiotics

Mining, Identification, and Fermentation Optimization of Chitin Deacetylase from a Novel Strain Enterobacter sp. ZCDA27.

Chitin, a natural organic compound with content slightly lower than cellulose, is also known for chitosan, a substance derived from chitin through deacetylation. In this experiment, preliminary screening was conducted using the plate discoloration circle method, leading to the selection of a high-yield CDA-producing strain from 28 candidates through rescreening. Morphological characteristics and 16S rDNA sequence analysis revealed 99.93% homology with Enterobacter sichuanensis strain N24, thus naming this strain Enterobacter strain ZCDA27. Initial fermentation of the strain yielded CDA activity of 9.29 U/mL. Single-factor optimization was then performed, followed by a PB test to screen for significant factors affecting enzyme production. The response surface method was used to further optimize the fermentation conditions. The optimal fermentation conditions for the carbon source, nitrogen source, metal ion, fermentation temperature, time, liquid volume, and initial pH were explored. Significant factors affecting enzyme production, including MgSO4, initial medium pH, and fructose levels, were identified using the PB test. Finally, the fermentation conditions of ZCDA27 were optimized using the Box-Behnken design combined with RSM, which comprised fructose at 1.020%, magnesium sulfate at 0.016%, and peptone at 1%. The fermentation conditions included a temperature of 37, initial pH of 7.1, rotation speed of 140 × g, fermentation time of 28h, inoculation amount of 2%, and liquid volume of 40%. Under these conditions, the enzyme activity of ZCDA27 reached 14.52 U/mL, a 1.6-fold increase from the pre-optimization levels. In summary, this study provides an experimental foundation for further development and application of Enterobacter spp. ZCDA27 CDA.

Exploring the Genetic, Structural, and Computational Insights of Resistance Proteins in Arsenic-Bioremediation Enterobacter Strain

Exploring the Genetic, Structural, and Computational Insights of Resistance Proteins in Arsenic-Bioremediation Enterobacter Strain

Molecular characterization of virulence genes and influence of Xanthium strumarium extract against two Enterobacter species isolated from some soil invertebrates.

The development of bacterial antibiotic resistance poses adanger to healthcare systems worldwide. To reduce the spread of disease, researchers are looking for novel measures to control bacterial infections to reduce the spread of disease. The antibacterial properties of Xanthium strumarium methanolic and ethanolic extracts were evaluated against Enterobacter cloacae and E. hormaeche isolated from some invertebrates (Porcellio laevis, Armadillidium sp. (isopods), and Archispirostreptus syriacus). All Enterobacter strains tested positive for the presence of the virulence genes csgA, csgD, AcrAB, fimH, and Hsp60. Extracts of X. strumarium had significant anti-biofilm activity against E. cloacae and E. hormaechei. The disruption of established biofilm growth by the plant samples proved to be effective against E. cloacae and E. hormaechei. Both E. cloacae and E. hormaechei showed inhibition of biofilm formation and promotion of biofilm eradication in response to X. strumarium extract. Phenolic compounds such as ferulic acid, chlorogenic acid, and trans-cinnamic acid, and flavonoids such as kaempferol were the most abundant components in the extract and might play crucial roles in the extract's antibacterial and antibiofilm action. Results suggest that ethanolic leaf extracts from X. strumarium show potential as a novel approach to prevent infections caused by E. cloacae and E. hormaechei.

Cation exchange resin coupled with bacterial pretreatment to promote waste activated sludge reduction: Performance and mechanism

Due to the rapid advancement of industrialization and urbanization, there has been a significant rise in the generation of industrial wastewater and domestic wastewater, which results in the rapid increase of waste activated sludge (WAS). However, the complex structure and slow hydrolysis of sludge limit aerobic digestion of WAS. This study evaluated the effect of lysozyme-secreting strain Proteus mirabilis sp. SJ25 and the new isolation of surfactant-secreting strain Enterobacter cloacae sp. WH11 on the promotion of sludge hydrolysis, and introduced cation exchange resin (CER) to enhance the promotion effect. The reduction efficiencies of suspended solids (SS) and volatile suspended solids (VSS) enhanced by 25.0 and 24.9 %, respectively, and the soluble chemical oxygen demand (SCOD) release was increased by 2370.27 mg/L when the inoculum of strain SJ25 and strain WH11 were 3 % and 6 %, and the dosage of CER was 2.0 g/g SS against the control. The fluorescence region integral (FRI) results showed a significant quantity of dissolved organic matter (DOM) was let out, and the biodegradability of the sludge was improved. The alterations in several physicochemical characteristics of the sludge also suggested that the extracellular polymeric substances (EPS) were disrupted and an enormous quantity of sludge cells were lysed. In addition, functional gene prediction from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database indicated that CER coupled with bacterial pretreatment enhanced microbial metabolic capacity. This work suggests a novel pathway for the development of novel pretreatment methods to promote sludge hydrolysis.

In-situ chemobiocatalytic conversion of glucose into 2,5-bis(hydroxymethyl)furan by AlCl3/Enterobacter cloacae in biocompatible DMSO-water solvent

In-situ chemobiocatalytic production of 2,5-bis(hydroxymethyl)furan (BHMF) from glucose is extremely desirable but challenging owing to the incompatibility issues between two worlds of catalysts. In this study, a robust strain Enterobacter cloacae HA188, which is tolerant to 20% (v/v) DMSO, was used in the direct conversion of glucose into BHMF. The dehydration of glucose into 5-hydroxymethylfurfural (HMF) was catalyzed by AlCl3 in DMSO at 130 °C for 0.5 h, then water and E. cloacae cells were added and the bio-reduction of HMF was directly performed in 20% (v/v) DMSO at 30 °C for 6 h. Under the optimized conditions, 1000 mM glucose was transformed into HMF at 51.1% yield, which was further converted into BHMF with an overall yield of 47.2%. The BHMF yield was further improved when fructose or sucrose were utilized. This work provided a sustainable way for the production of value-added BHMF from inexpensive glucose under benign conditions.

Decoding the origins, spread, and global risks of mcr-9 gene

The global spread of the plasmid-mediated mcr (mobilized colistin resistance) gene family presents a significant threat to the efficacy of colistin, a last-line defense against numerous Gram-negative pathogens. The mcr-9 is the second most prevalent variant after mcr-1. A dataset of 698 mcr-9-positive isolates from 44 countries is compiled. The historical trajectory of the mcr-9 gene is reconstructed using Bayesian analysis. The effective reproduction number is used innovatively to study the transmission dynamics of this mobile-drug-resistant gene. Our investigation traces the origins of mcr-9 back to the 1960s, revealing a subsequent expansion from Western Europe to the America and East Asia in the late 20th century. Currently, its transmissibility remains high in Western Europe. Intriguingly, mcr-9 likely emerged from human-associated Salmonella and exhibits a unique propensity for transmission within the Enterobacter. Our research provides a new perspective that this host preference may be driven by codon usage biases in plasmids. Specifically, mcr-9-carrying plasmids prefer the nucleotide C over T compared to mcr-1-carrying plasmids among synonymous codons. The same bias is seen in Enterobacter compared to Escherichia (respectively as their most dominant genus). Furthermore, we uncovered fascinating patterns of coexistence between different mcr-9 subtypes and other resistance genes. Characterized by its low colistin resistance, mcr-9 has used this seemingly benign feature to silently circumnavigate the globe, evading conventional detection methods. However, colistin-resistant Enterobacter strains with high mcr-9 expression have emerged clinically, implying a strong risk of mcr-9 evolving into a global "true-resistance-gene". This study explores the mcr-9 gene, emphasizing its origin, adaptability, and dissemination potential. Given the high mcr-9 expression colistin-resistant strains was observed in clinically the prevalence of mcr-9 poses a significant challenge to drug resistance prevention and control within the One Health framework. This work was partially supported by the National Natural Science Foundation of China (Grant No. 32141001 and 81991533).

Isolation and Characterization of Plant-Growth-Promoting Bacteria Associated with Salvinia auriculata Aublet.

Salvinia auriculata Aublet is a floating aquatic plant, capable of absorbing the excess of nutrients and water contaminants and can be used in effluent treatment plants. The ability to survive in degraded areas may be related to the association with beneficial bacteria capable of promoting plant growth. However, little is known about the microbiota associated with this aquatic plant and its potential application to the aquatic environment. In this sense, this work aims to identify bacteria associated with S. auriculata that could be able to promote plant growth. Eighteen bacterial strains were identified by sequencing of the 16S rRNA gene, belonging to the genera Agrobacterium, Bacillus, Curtobacterium, Enterobacter, Pseudomonas, Siccibacter, and Stenotrophomonas. All isolates produced indole compounds, 12 fixed N2, and 16 solubilized phosphate. A new strain of Enterobacter (sp 3.1.3.0.X.18) was selected for inoculation into S. auriculata. For this purpose, 500 mL of nutrient solution and 1 g of the plant were used in the control and inoculated conditions. Enterobacter inoculation promoted a significant increase (p ≤ 0.05) in fresh plant biomass (17%) after 4 days of cultivation. In summary, the present study characterized 18 plant-growth-promoting bacteria isolated from S. auriculata with potential for biotechnological application, such as the production of bioinoculants or biomass resources, to protect or improve plant growth under conditions of stress.

Enterobacter adelaidei sp. nov. Isolation of an extensively drug resistant strain from hospital wastewater in Australia and the global distribution of the species

BackgroundEnterobacter species are included among the normal human gut microflora and persist in a diverse range of other environmental niches. They have become important opportunistic nosocomial pathogens known to harbour plasmid-mediated multi-class antimicrobial resistance (AMR) determinants. Global AMR surveillance of Enterobacterales isolates shows the genus is second to Klebsiella in terms of frequency of carbapenem resistance. Enterobacter taxonomy is confusing and standard species identification methods are largely inaccurate or insufficient. There are currently 27 named species and a total of 46 taxa in the genus distinguishable via average nucleotide identity (ANI) calculation between pairs of genomic sequences. Here we describe an Enterobacter strain, ECC3473, isolated from the wastewater of an Australian hospital whose species could not be determined by standard methods nor by ribosomal RNA gene multi-locus typing. AimTo characterise ECC3473 in terms of phenotypic and genotypic antimicrobial resistance, biochemical characteristics and taxonomy as well as to determine the global distribution of the novel species to which it belongs. MethodsStandard broth dilution and disk diffusion were used to determine phenotypic AMR. The strain’s complete genome, including plasmids, was obtained following long- and short read sequencing and a novel long/short read hybrid assembly and polishing, and the genomic basis of AMR was determined. Phylogenomic analysis and quantitative measures of relatedness (ANI, digital DNA-DNA hybridisation, and difference in G+C content) were used to study the taxonomic relationship between ECC3473 and Enterobacter type-strains. NCBI and PubMLST databases and the literature were searched for additional members of the novel species to determine its global distribution. ResultsECC3473 is one of 21 strains isolated globally belonging to a novel Enterobacter species for which the name, Enterobacter adelaidei sp. nov. is proposed. The novel species was found to be resilient in its capacity to persist in contaminated water and adaptable in its ability to accumulate multiple transmissible AMR determinants. ConclusionE. adelaidei sp. nov. may become increasingly important to the dissemination of AMR.

Comparison of Glucose Metabolizing Properties of Enterobacterial Probiotic Strains In Vitro.

Before the absorption in the intestine, glucose encounters gut bacteria, which may serve as a barrier against hyperglycemia by metabolizing glucose. In the present study, we compared the capacity of enterobacterial strains to lower glucose levels in an in vitro model of nutrient-induced bacterial growth. Two probiotic strains, Hafnia alvei HA4597 (H. alvei) and Escherichia coli (E. coli) Nissle 1917, as well as E. coli K12, were studied. To mimic bacterial growth in the gut, a planktonic culture was supplemented twice daily by the Luria Bertani milieu with or without 0.5% glucose. Repeated nutrient provision resulted in the incremental growth of bacteria. However, in the presence of glucose, the maximal growth of both strains of E. coli but not of H. alvei was inhibited. When glucose was added to the culture medium, a continuous decrease in its concentration was observed during each feeding phase. At its highest density, H. alvei displayed more efficient glucose consumption accompanied by a more pronounced downregulation of glucose transporters' expression than E. coli K12. Thus, the study reveals that the probiotic strain H. alvei HA4597 is more resilient to maintain its growth than E. coli in the presence of 0.5% glucose accompanied by more efficient glucose consumption. This experimental approach offers a new strategy for the identification of probiotics with increased glucose metabolizing capacities potentially useful for the prevention and co-treatment of type 2 diabetes.

Survey for Enterobacteria and Vibrio spp. Associated with Irrigated Vegetables in Irrigation Areas of Northern Bauchi State, Nigeria

This study was prompted in a bid to determine the level of public health hazards associated with the presence of enterobacteria and Vibrio spp. in irrigated vegetables in irrigation areas of Northern Bauchi State, Nigeria. This was to address the question of what the recent circumstances behind the report of outbreak of gastroenteritis in the region were, thus the impetus for the current investigation. Irrigation Water and irrigated vegetable samples (72) from across the four local government areas were collected from different irrigation sites and analysed for bacteriological contamination indices. The River Zaki, River Jama’are, and River Zigau were observed to be the primary sources of irrigation water. The overall mean aerobic mesophilic count and the Most Probable Number values for coliforms observed in this study ranged from 1.6x104 to 8.x108 Cfu/mL and 14 to 33, respectively. Up to 62 isolates comprising 42 (81.82%) enterobacterial strains, eight Pseudomonas spp. and ten representing vibrio spp. were isolated from the analysis of vegetables and irrigation water samples. In descending order of dominance, the organisms isolated were E. coli 14 (22.6%), Vibrio spp. 10 (16.1%), Citrobacter spp. 9 (14.5%), Pseudomonas aeruginosa 8 (12.9), Salmonella enterica 8 (12.9%), Klebsiella oxytoca 8 (12.9%) and Klebsiella pneumoniae 5 (8.1%). All the isolates were sensitive to most of the antibiotics used except ampicillin (10 µg) and amox-clav (30 µg). No resistance was recorded against ciprofloxacin (5 µg). The findings revealed that the river water used for irrigation in this study was a possible pre-harvest source of contamination of fresh vegetables, potentially constituting a health risk to consumers.

Characterization and transmission of plasmid-mediated multidrug resistance in foodborne Vibrio parahaemolyticus.

The purpose of this study was to determine the structural features and transferability of the multidrug-resistance (MDR) plasmid, and resistance phenotypes for the tested antimicrobials in foodborne Vibrio parahaemolyticus. Plasmids were isolated from a V. parahaemolyticus strain of seafood origin, then sequenced using the Illumina NovaSeq 6000 and PacBio Sequel II sequencing platforms to obtain the complete genome data. Characterization of the MDR plasmid pVP52-1, including determination of antimicrobial resistance genes (ARGs), plasmid incompatibility groups, and transferability, was carried out. V. parahaemolyticus strain NJIFDCVp52 contained two circular chromosomes and two circular plasmids (pVP52-1 and pVP52-2). Plasmid typing indicated that pVP52-1 belonged to the incompatibility group IncA/C2 and the sequence type pST3. pVP52-1 carried 12 different ARGs, an IS110-composite transposon consisting of aac(6')-Ib-cr, qnrVC1, aac(6')-Ib, dfrA14, and the IS26-mphA-IS6100 unit flanked by inverted sequences of IS5075 and IS4321. pVP52-2 carried no ARGs. A plasmid elimination assay showed that only pVP52-1 and its ARGs were lost, the loss of resistance to several antimicrobials, causing a change from the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-trimethoprim/sulfamethoxazole resistance pattern to the ampicillin resistance pattern. In accordance, a conjugation transfer assay showed that only pVP52-1 and its ARGs were horizontally transferred, leading to increased antimicrobial resistance in Escherichia coli strain EC600, causing a change from the ampicillin-nalidixic acid resistance pattern to the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-nalidixic acid-chloramphenicol-tetracycline-trimethoprim/sulfamethoxazole-azithromycin resistance pattern. Further transferability experiments revealed that pVP52-1 could be transferred to other enterobacterial strains of E. coli and Salmonella. This study emphasizes the urgent need for continued surveillance of resistance plasmids and changes in antimicrobial resistance profiles among the V. parahaemolyticus population.

Enterobacter cloacae-mediated polymer biodegradation: in-silico analysis predicts broad spectrum degradation potential by Alkane monooxygenase.

Plastic pollution poses a significant environmental challenge. In this study, the strain Enterobacter cloacae O5-E, a bacterium displaying polyethylene-degrading capabilities was isolated. Over a span of 30days, analytical techniques including x-ray diffractometry, scanning electron microscopy, optical profilometry, hardness testing and mass spectrometric analysis were employed to examine alterations in the polymer. Results revealed an 11.48% reduction in crystallinity, a 50% decrease in hardness, and a substantial 25-fold increase in surface roughness resulting from the pits and cracks introduced in the polymer by the isolate. Additionally, the presence of degradational by-products revealed via gas chromatography ascertains the steady progression of degradation. Further, recognizing the pivotal role of alkane monooxygenase in plastic degradation, the study expanded to detect this enzyme in the isolate molecularly. Molecular docking studies were conducted to assess the enzyme's affinity with various polymers, demonstrating notable binding capability with most polymers, especially with polyurethane (-5.47kcal/mol). These findings highlight the biodegradation potential of Enterobacter cloacae O5-E and the crucial involvement of alkane monooxygenase in the initial steps of the degradation process, offering a promising avenue to address the global plastic pollution crisis.