Enterobacter Aerogenes Research Articles

Activity of cefepime, carbapenems and new β-lactam/β-lactamase inhibitor combinations on Enterobacter cloacae complex and Klebsiella aerogenes in Spain (SMART 2016–2022)

Abstract Objectives To analyse the susceptibility profile to cefepime, carbapenems and new β-lactam/β-lactamase inhibitor combinations in Enterobacter cloacae complex and Klebsiella aerogenes isolated from intra-abdominal, urinary, respiratory and bloodstream infections in the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study in Spain. Methods The susceptibilities of 759 isolates (473 E. cloacae complex and 286 K. aerogenes) collected in 11 Spanish hospitals from 2016 to 2022 were analysed following the EUCAST 2023 criteria. Molecular characterization looking for β-lactamase genes was performed through PCR and DNA sequencing analysis. Results E. cloacae complex showed resistance to third-generation cephalosporins in 25% of the cases, whereas K. aerogenes was resistant in 35%. Regarding cefepime, resistance in E. cloacae was higher (10%) than in K. aerogenes (2%). Carbapenems showed >85% activity in both microorganisms. Ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam had good activity against these microorganisms (>95%). In contrast, the activity of ceftolozane/tazobactam was lower (80%). A high proportion of the isolates resistant to new β-lactam/β-lactamase inhibitor combinations carried a carbapenemase, mainly OXA-48-like and VIM-1. Conclusions Ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam show high activity against both E. cloacae complex and K. aerogenes isolates recovered in the SMART-Spain study. In contrast, differences have been found in the case of cefepime, showing more activity against K. aerogenes than E. cloacae complex. These results are useful for antimicrobial stewardship programmes and for the implementation of local and national guidelines.

Isolation and Structure Determination of New Pyrones from Dictyostelium spp. Cellular Slime Molds Coincubated with Pseudomonas spp.

Cellular slime molds are excellent model organisms in the field of cell and developmental biology because of their simple developmental patterns. During our studies on the identification of bioactive molecules from secondary metabolites of cellular slime molds toward the development of novel pharmaceuticals, we revealed the structural diversity of secondary metabolites. Cellular slime molds grow by feeding on bacteria, such as Klebsiella aerogenes and Escherichia coli, without using medium components. Although changing the feeding bacteria is expected to affect dramatically the secondary metabolite production, the effect of the feeding bacteria on the production of secondary metabolites is not known. Herein, we report the isolation and structure elucidation of clavapyrone (1) from Dictyostelium clavatum, intermedipyrone (2) from D. magnum, and magnumiol (3) from D. intermedium. These compounds are not obtained from usual cultural conditions with Klebsiella aerogenes but obtained from coincubated conditions with Pseudomonas spp. The results demonstrate the diversity of the secondary metabolites of cellular slime molds and suggest that widening the range of feeding bacteria for cellular slime molds would increase their application potential in drug discovery.

Effect of crude glycerol, 2,3-butanediol, and acetoin initial concentrations on Enterobacter aerogenes ATCC 13048 growth in batch runs

The 2,3-butanediol (BD) and acetoin production from several carbon sources and microorganisms has been extensively studied, mainly due to the possibility of replacing petroleum derivatives by the diol. Crude glycerol is highlighted among the substrates that can be used to produce 2,3-BD. However, this carbon source contains impurities that can affect microbial metabolism. Furthermore, there are scarce studies about the inhibitory effect of fermentation products, such as 2,3-BD and acetoin, on the process. The aim of this study was to evaluate the effect of crude glycerol, 2,3-BD and acetoin initial concentrations on Enterobacter aerogenes growth and metabolism. For this purpose, batch runs were performed using crude glycerol concentrations varying from 20 to 80 g.L-1. To evaluate the inhibitory effect of 2,3-BD plus acetoin, batch runs were performed using product addition from 0 to 40 g.L-1. During batch runs performed using increasing crude glycerol concentrations, the values of maximum specific growth rates were decreasing, evidencing the metabolism inhibition possibly due to the osmotic pressure and substrate composition. In all batch runs, acetic and lactic acids, and ethanol were identified as co-products. In the case of fermentation products, the 2,3-BD plus acetoin initial concentration of 20 g.L-1 was found inhibitory to E. aerogenes growth by a reduction of 45% in maximum specific growth rate. The data also proved the major influence of 2,3-BD rather than acetoin on the overall rate of fermentation, since acetoin concentrations of up to 3.5 g.L-1 did not influence the E. aerogenes growth. Furthermore, the strain ability to adapt to the 2,3-BD and acetoin initial concentrations was demonstrated, opening possibilities for new processes strategies.

Complete genome sequence of carbapenem-resistant pathogenic Klebsiella aerogenes strain CH7 isolated from vermicompost.

We announce the complete genome of Klebsiella aerogenes strain CH7, isolated from a vermicompost sample. A total of 9.14131 million high-quality reads comprised 96 contigs with 5,273 genes and 5,038 protein-coding genes.

Optimizing polystyrene degradation, microbial community and metabolite analysis of intestinal flora of yellow mealworms, Tenebrio molitor

This study explored a direct feeding of expanded polystyrene as the sole diet for breeding Tenebrio molitor larvae. Temperature and relative humidity were manipulated to evaluate polystyrene biodegradation efficiency, survival rate, and formation of micro-polystyrene residue. Efficient conditions were at temperature of 25 °C with a humidity of 65 ± 5 %. Comparative metabolomic and metabolic-metabolic network analyses was performed for visualizing detailed pathway. Possibility of forming 4 (p)-hydroxyphenylacetic acid from phenylacetic acid with further conversion to 4-methylphenol, 4-hydroxybenzaldehyde, and 4-hydroxybenzoate could be seen as a side chain route for further biodegrading process. Key species identified in the gut of T. molitor larvae included Citrobacter sp., Serratia marcescens, Klebsiella aerogenes, and Klebsiella oxytoca. Pseudomonas aeruginosa was detected only under an anaerobic condition whereas Acinetobacter sp. was present only under an aerobic condition. These results demonstrate the potential to decrease micro-polystyrene by optimizing breeding conditions and biodegradation process of polystyrene.

Production of Histamine by Diverse Gut Bacteria Can Activate Intestinal HRH1 and Promote Calcium Mobilization

Background: Histamine is a biogenic amine that impacts several physiological processes, including allergic reactions, neurotransmitter activity and immune regulation. Bacteria uptake L-histidine and convert it into histamine via the activity of histidine decarboxylase enzymes. Histamine can also be produced by host cells such as enterochromaffn-like cells, mast cells and neurons. We hypothesized that a diverse group of bacteria would be capable of generating histamine. We predicted that histamine producing bacteria in the gut would activate intestinal epithelial histamine receptors and promote gut health. Methods and Results: To investigate how widespread histamine production is across bacterial species, we examined 102,018 annotated genomes in the Integrated Microbiome Genome Database. We found 3,679 bacterial genomes (3.6%) possessed histidine decarboxylase. We found histidine decarboxylase in bacteria belonged to 9 phyla: Bacillota, Bacteroidota, Actinomycetota, Pseudomonadota, Lentisphaerota, Fusobacteriota, Armatimonadota, Cyanobacteriota, and Verrucomicrobiota. Although the majority of the identified bacteria were aquatic and terrestrial in origin, ~14% of the bacteria were from the human gut microbiota. We confirmed the ability of several gut bacteria to generate histamine in a chemically defined bacterial growth medium using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based targeted metabolomics. Briefly, histamine and histidine quantification is performed using authentic analytical and stable-label deuterated internal standard compounds that are used to produce calibration curves that span a linear dynamic range of 0.977-1,000 ng/mL. We found higher concentrations of histamine produced by gut-associated Klebsiella aerogenes, Fusobacterium varium, Clostridium perfringens, Limosilactobacillus reuteri and Morganella morganii. To address the question if bacterial-derived histamine could activate intestinal epithelial histamine receptors in the gut, we examined histamine receptors in publicly available single cell RNAseq datasets. We found that HRH1 was expressed in all cell types of the small and large intestine. We did not observe any expression of HRH2, HRH3 or HRH4 in the gut epithelium. We confirmed this finding in human intestinal organoids derived from duodenum, jejunum, ileum and colon. HRH1 activation in airway epithelial cells is known to signal through MAPK and promote pro-inflammatory cytokine release. Using GCaMP6S transduced organoids, we found that multiple concentrations of histamine stimulated robust calcium mobilization. However, histamine did not alter the levels of phosphorylated MAPK members p38, JNK, ERK, CREB or AKT and did not stimulate the release of any of the 18 epithelial specific cytokines we examined. Conclusions: Our work reveals that gut bacteria are capable of generating histamine, and histamine in the gut can activate epithelial HRH1 to drive calcium signaling and other downstream signals. K01 DK123195 (M Engevik) K01 DK121869 (A Engevik F32 DK130288 (K Engevik) APS Postdoctoral Fellowship (K Engevik). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Overview of Environmental Conditions and Personal Hygiene for the Presence of Pathogenic Germs in Food at Tanggo Rajo Culinary Tourism

Foodborne disease refers to a condition when the body is affected by microbial toxins or substances that enter through the consumption of food. The World Health Organization (WHO) has reported that around 1 in 10 individuals worldwide fall ill and experience 420,000 fatalities annually due to foodborne illnesses or food poisoning. Additionally, these incidents result in a loss of 33 million years of healthy life each year. The objective of the study is to assess the ambient and personal hygiene conditions and their impact on the presence of harmful microorganisms in food during culinary excursions in Kanggano Rajo. This study was employed a quantitative research approach with a descriptive design and a cross-sectional research design. The study population consists of 101 individuals engaged in the street vendors culinary items during the Culinary Tour of Tanggo Rajo. The findings indicated that 68.5% of the respondents needed to fulfill their hygiene preferences. Additionally, study was reported unsuitable environmental sanitation conditions, 57.4% reported inadequate water condition, 77.8% reported improper waste handling, 81.5% reported inadequate waste disposal, and 100% reported insufficient vector control. The microbiological test results revealed the presence of Enterobacter Hafniae in 2 samples, enterobacter aerogenes in 16 samples, and Klebsiella Azaenae in 36 samples. Empowering and enhancing education in all critical sectors is advisable while ensuring effective monitoring and evaluation.

Molecular identification of bacteria (Klebsiella aerogenes, PP335235) isolated from street food (Fried Rice); study of its antibiotic sensitivity pattern and probiotic fortification of fruit juice (Fragaria ananassa, Passiflora ligularis and Phyllanthus e

Street food is an integral part of India's culinary culture, offering patrons a wide range of affordable options. However, concerns about the public's health risks associated with street food consumption persist due to inadequate infrastructure and the transient nature of street vendors. Contaminated street food can lead to foodborne illnesses such as gastroenteritis, typhoid fever, pneumonia, food poisoning, and hepatitis A. Probiotics, which are beneficial bacteria, are potentially effective by targeting specific infections. Probiotic-enriched fruit drinks present an innovative approach to improving population nutrition and probiotic provision. Lactobacillus gasseri is a gram-positive bacterium that has been demonstrated to be a promising strain of probiotic due to its resistance to acidity and beneficial effects on gut health. Alginate encapsulation improves the stability and release of probiotic strain. Probiotic fruit juices can be made from fruits that are rich in antioxidants and nutrients, such as Passiflora ligularis, Fragaria ananassa, and Phyllanthus emblica. The aim of this study was to use molecular methods to discover Klebsiella aerogenes (PP335235) isolated from street foods. The study also sought to determine the isolate's pattern of antibiotic sensitivity and explore the potential of fortifying fruit juice with Lactobacillus gasseri as a probiotic nutraceutical therapeutic strategy.

Chemical composition and antimicrobial activity of an apolar extract from Lactuca serriola L. leaves

Lactuca serriola L. is an annual herbaceous plant species belonging to the Asteraceae family, called Prickly lettuce, Wild lettuce, and Jagged lettuce. L. serriola grows on grassy and rocky slopes in many regions in Europe, Asia, Australia, Africa, and North, Central and South America. The plant is used as a natural pharmaceutical agent in primary health care due to its analgesic, anti-inflammatory, antibacterial, and antioxidant properties, which are attributed to the compounds it contains. However, this is the first study demonstrating the antimicrobial activity of L. serriola essential oil. In this study, L. serriola essential oil was obtained by hydrodistillation of plant leaves and analyzed by Gas Chromatography-Mass Spectrometry (GS-MS); subsequently, antimicrobial properties of the essential oil were evaluated using agar dilution and broth microdilution methods. As a result of the GS-MS analysis, hexadecanoic acid, oleic acid, myristic acid, hexahydrofarnesyl acetone, β-ionone, and n-tetradecyl butanoate were found as dominant components in the plant essential oil with the rate of 6.61%, 4.84%, 2.05, 1.55%, 1.3%, and 1.09% (v/v), respectively. The MIC value of L. serriola essential oil against Enterobacter aerogenes,Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Candida tropicalis was found to be 0.94 μLmL−1, and MIC values were determined as 1.87 μLmL−1 and 0.47 μLmL−1 against Klebsiella pneumonia and Candidaparapsilosis, respectively. These results have opened a new horizon regarding the usability of L. serriola essential oil as a pharmacological therapeutic antibacterial and antifungal agent.

Molecular Identification and Characterization of Indigenous Rhizobacteria from Haryana and Punjab and Their Inoculation Effect on Prosopis cineraria

India grapples with escalating soil salinity, projected to afflict 16.2 million hectares by 2050. Reforestation, vital in North India's sodic wastelands, counters severe degradation. Rhizobacteria that promote plant growth (PGPR) are essential for managing forests sustainably. These microbes help rhizosphere plants form symbiotic relationships that promote hormone production, nitrogen fixation, increased phosphate availability, iron sequestration, and defense against outside threats. The study aimed to isolate halo-tolerant microbial strains from salt-affected areas and studied their effect on tree species to alleviate their overall growth in Punjab and Haryana. We isolated 880 bacterial isolates from salt-affected areas in Punjab and Haryana; they have a variety of metabolic capabilities and are resistant to both salty and alkaline environments. Pot studies with a range of tree species verify the beneficial effects of particular bacterial strains, such as Pseudomonas mosselli and Klebsiella aerogenes, on soil &plant development metrics. Validation of these results by 16S rRNA gene sequencing highlights the potential of these isolates for soil remediation in salt-affected areas. The study highlighted the importance of microbial interventions in alleviating soil deterioration and fostering sustainable land use practices, and it suggests more field studies with different varieties of trees.

PCR Detection of Extended Spectrum β-Lactamase from Some Gram Negative Bacteria of Clinical Source

Beta-lactamase-producing microorganisms present distinct challenges in health care systems around the world as a result of the extensive utilization of broad-spectrum antibiotics. The objective of this research endeavor was to ascertain the antibiotic resistance profile and presence of β-lactamase genes in Gram-negative bacteria that had been previously identified and collected from laboratory work benches at the Department of Microbiology and Parasitology, UCH, located in Ibadan, South-West Nigeria. The Kirby-Bauer disc diffusion method was used to assess antibiotic susceptibility on all the isolates, and the double disc synergy test was used to validate extended spectrum beta-lactamase (ESBL) production phenotypically. The PCR techniques were used to detect β-lactamase genes. The sample distribution of the forty clinical isolates were collected from the work benches and the distribution was: urine (17), blood (9), wound (6), sputum (4), amniotic fluid (3) and tracheal aspirate (1). Klebsiella pneumoniae was the most prevalent organism with 17 isolates ( 42.5% ). Out of the 40 isolates that were obtained, 21 were ESBL producers and the distribution was as follows: Klebsiella pneumoniae (9), Escherichia coli (6), Enterobacter cloacae (2), Enterobacter aerogenes (1), Pseudomonas aeruginosa (1), Acinetobacter baumannii (1) and Hafnia alvei (1). The majority of the clinical isolates showed considerable resistance to antibiotic classes that were tested, with amoxicillin-clavulanate showing the highest resistance rate at 65%. Out of all the ESBL producers, 35.3% had blaTEM, 29.4% had blaCTX-M, 23.5% had blaSHV, and 11.8% had blaCMY. AmpC β-lactamases, Antibiotic resistance, Disc diffusion, Gram-negative bacteria, Polymerase chain reaction.

Mitigating antimicrobial resistance, an approach to stewardship in canine urinary tract infection.

Urinary tract infection (UTI) caused by antimicrobial resistant bacteria is common in dogs leading to serious health impact in pet animal as well as on human health. Understanding the prevalent uropathogens and their drug susceptibility is essential for limiting the antimicrobial resistance through implementation of stewardship policies. In view of this, present study was envisaged to determine the prevalent bacterial uropathogens and their antibiogram from clinical cases of canine UTI. Urine samples were collected from 35 dogs presented with clinical signs of UTI and a total of 27 bacterial isolates were recovered. Among that Escherichia coli was the most predominant isolate followed by Klebsiella aerogenes, Staphylococcus aureus, Proteus mirabilis, Enterococcus sp. and Citrobacter freundii. All isolates were found resistant to one or more 1st line antibiotics recommended by consensus guidelines and 70% of total isolates showed multidrug resistance. Additionally, this study evaluated the weightage of empirical therapy as per the consensus guidelines over antimicrobial susceptibility test guided treatment. Dogs with uncomplicated UTI were selected and categorized into three different groups (n = 6). Group 1 was treated with common empirical choice amoxycillin-clavulanic acid and dogs showed susceptible to ciprofloxacin were kept in Group 2 and treated with ciprofloxacin along with urinary alkalizer disodium hydrogen citrate. Nitrofurantoin susceptible cases were kept in Group 3 and treated with a combination of nitrofurantoin and urinary acidifier ammonium chloride. Therapeutic outcome was evaluated and success rate was higher in Group 2 and 3 than Group 1 suggested that selection of antibiotics with the use of local or institutional antibiogram data is more considerate than acknowledged international guidelines in the existing situation.

Comparative Study on the Bacterial Community of Cultivated and Uncultivated Rice Field Soils

A study was conducted to determine the changes in bacterial micro flora of soil in relation fallowing (abandonment) in rice fields. Soil samples from two paddy fields at Kumarakom region, southwest part of Kuttanad, Kerala, one field with paddy cultivation and the other fallowed, was subjected to the study. A total of 15 bacterial species, 8 from the cultivated field only, 6 from the fallowed field only and 1 common to both fields were isolated and identified in the study. The bacterial community in the soil of uncultivated field are entirely shifted from field where rice has been cultivated continuously. The persistent occurrence encountered in the cultivated field isolates were Bacillus megaterium, Pseudomonas aeroginosa and Klebsiella oxytoca while that in the abandoned field were of E coli followed by higher incidence of (80%) Enterobacter aerogenes and Citrobacter freundii. Under rice cultivation, soil pH, EC and bacterial density were generally higher than that in uncultivated soils while organic carbon in the soil was consistently lower than that in uncultivated soils. The study reveals the importance of bacteria in maintaining the health of a habitat and confirm that soil quality deteriorates over long-term fallowing.

Molecular Epidemiology of Carbapenem-Resistant Klebsiella aerogenes in Japan.

Information regarding Klebsiella aerogenes haboring carbapenemase in Japan is limited. A comprehensive nationwide survey was conducted from September 2014 to December 2022, and 67 non-duplicate strains of carbapenem-resistant K. aerogenes were isolated from 57 healthcare facilities in Japan. Through genetic testing and whole-genome sequencing, six strains were found to possess carbapenemases, including imipenemase (IMP)-1, IMP-6, New Delhi metallo-β-lactamase (NDM)-1, and NDM-5. The strain harboring blaNDM-5 was the novel strain ST709, which belongs to the clonal complex of the predominant ST4 in China. The novel integron containing blaIMP-1 featured the oxacillinase-101 gene, which is a previously unreported structure, with an IncN4 plasmid type. However, integrons found in the strains possessing blaIMP-6, which were the most commonly identified, matched those reported domestically in Klebsiella pneumoniae, suggesting the prevalence of identical integrons. Transposons containing blaNDM are similar or identical to the transposon structure of K. aerogenes harboring blaNDM-5 previously reported in Japan, suggesting that the same type of transposon could have been transmitted to K. aerogenes in Japan. This investigation analyzed mobile genetic elements, such as integrons and transposons, to understand the spread of carbapenemases, highlighting the growing challenge of carbapenem-resistant Enterobacterales in Japan and underscoring the critical need for ongoing surveillance to control these pathogens.

Neem Leaves Extract (Azadirachta indica) and Its Bactericidal Activity against Biofilm-forming Pathogenic Bacteria

Antibiotics are used in healthcare as for prophylaxis and have therapeutic value against drug-resistant bacteria. The main aim of the study was to analyze the potential of neem leaf extract against pathogenic bacteria. The leaves were dried and phytochemicals were extracted with methanol, ethyl acetate, chloroform, and water. The methanol extract showed maximum yield. The total phenolic and flavonoid contents were found to be maximum in methanol extract. The methanol extract showed maximum activity followed by ethyl acetate, chloroform, and water. The methanol extract exhibited maximum activity against Enterobacter aerogenes (18±2 mm zone of inhibition), Salmonella typhimurium (16±1 mm zone of inhibition), Pseudomonas aeruginosa (20±2 mm zone of inhibition), Staphylococcus aureus (12±0 mm zone of inhibition), and Escherichia coli (20±0 mm) (p<0.05). The minimum inhibitory concentration values ranged from 6.25±1.25 to 300±125 µg/ml and methanol extract showed least value against bacteria (p<0.05).

Exploring the Antibacterial Properties of Carica papaya Unripe Fruit Extracts on Wound Isolates: Phytochemical Analysis and Susceptibility Testing

The rise of multidrug-resistant bacterial pathogens poses a significant challenge in wound management. In this study, we investigated the phytochemical constituents and antibacterial properties of unripe fruit extracts of Carica papaya on bacterial isolates from wounds. Phytochemical analysis revealed the presence of phenols, tannins, saponins, alkaloids, terpenoids, reducing sugars, and cardiac glycosides in both aqueous and 50% ethanolic extracts. Antimicrobial susceptibility testing demonstrated significant activity against Staphylococcus aureus, Protues vulgaris, Enterobacter aerogenes, and Escherichia coli, with aqueous extract exhibiting greater inhibition than the ethanolic counterpart. However, no activity was observed against Pseudomonas aeruginosa. These findings underscore the potential of Carica papaya extracts in combating opportunistic infections in wound management. Keywords: Carica papaya, wound, antibacterial, phytochemical, extracts, micro-organisms.

Antimicrobial and Probiotic Potential of Lactobacilli Associated with Traditional Fermented Beverages.

Fermented foods have been recognized as a source of probiotic bacteria which can have a positive effect when administered to humans and animals. Discovering new probiotics in fermented food products poses a global economic and health importance. In this study, we investigated the antimicrobial and probiotic potential of lactobacilli isolated from fermented beverages produced traditionally by ethnic groups in Northeast India. Out of thirty Lactobacilli, fifteen exhibited strong antimicrobial activity against Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter aerogenes with significant anti-biofilm and anti-quorum sensing activity. These isolates also showed characteristics associated with probiotic properties, such as tolerance to low pH and bile salts, survival in the gastric tract, auto-aggregation, and hydrophobicity without exhibiting hemolysis formation or resistance to certain antibiotics. The isolates were identified using gram staining, biochemical tests, and 16S rDNA sequencing. They exhibited probiotic potential, broad-spectrum of antibacterial activity, promising anti-biofilm, anti-quorum sensing activity, non-hemolytic, and tolerance to acidic pH and bile salts. Overall, four specific Lactobacillus isolates, Lactiplantibacillus plantarum BRD3A and Lacticaseibacillus paracasei RB10OW from fermented rice-based beverage, and Lactiplantibacillus plantarum RB30Y and Lacticaseibacillus paracasei MP11A from traditional local curd demonstrated potent antimicrobial and probiotic properties. These findings suggest that these lactobacilli isolates from fermented beverages have the potential to be used as probiotics with therapeutic benefits, highlighting the importance of traditional fermented foods for promoting gut health and infectious disease management.

Essential oil of Eugenia stictopetala Mart. ex DC. has antioxidant, antibacterial, and gastrointestinal protective effect

This work aimed to investigate the chemical composition, antioxidant capacity, antibacterial activity, and intestinal and gastric protective effects, in addition to the acute toxicity of the essential oil of E. stictopetala (EOEs). (E)-caryophyllene (18.01%), β-pinene (8.84%), and (E)-nerolidol (8.24%), were the components found in higher content in the essential oil. The EOEs showed antioxidant capacity with IC50 values ranging from 220.28 to 283.67 μg/mL, in addition to presenting antibacterial activity against Escherichia coli, Enterobacter aerogenes, Vibrio cholerae, Salmonella enterica, and Listeria monocytogenes. The essential oil showed a gastroprotective effect, with a reduction in the levels of TNF-α, IL-1β, and IL-6, having multiple pharmacological mechanisms of action. An antidiarrheal effect of EOEs was observed in the castor oil-induced diarrheal model, with reduced intestinal motility. Our findings demonstrate that essential oil can be beneficial in pharmaceutical and therapeutic applications for treating gastrointestinal diseases.

Prevalence and Resistance Patterns of Urinary Tract Infection in Al-Madinah Al-Munawarah, Saudi Arabia: A Retrospective Study.

Urinary tract infections (UTIs) are among the most common infections and can cause numerous complications of the renal system. This study aimed to assess the prevalence of uropathogens and their antibiotic susceptibility patterns in Al-Madinah Al-Munawarah, Saudi Arabia. Data was collected from patients with UTIs presented at King Fahad General Hospital in Al-Madinah Al-Munawarah, Saudi Arabia. In this retrospective cross-sectional study, UTI microbial-causing agents and antimicrobial resistance profiles identified using automated systems, Phoenix and VITEK2, were collected between July 2022 and June 2023. In addition, minimal demographic data, including date of collection and sex and age of patients were collected and analyzed using Chi-square test. The study included 1394 patients positive for UTI, comprising 50.57% males and 49.43% females (chi-square goodness-of-fit, p > 0.999). Microbial identification and antimicrobial susceptibility tests were performed on UTI-positive cultures. Among UTIs, mono-infection, caused by a single pathogen, was the most prevalent, accounting for 88.16% of cases, whereas poly-infection (caused by multiple pathogens) presented at 11.9%. The most prevalent UTIs' pathogens were E. coli (30.59%), followed by Klebsiella pneumoniae (21.40%), Enterococcus faecalis (8.46%), Pseudomonas aeruginosa (7.81%), Streptococcus agalactiae (6.35%), Enterococcus faecium (3.01%), Proteus mirabilis (3.01%), Enterobacter cloacae (2.52%), Candida sp. (2.44%), Acinetobacter calcoaceticus-baumannii (1.95%), Staphylococcus aureus (1.79%), and Enterobacter aerogenes (1.30%). The most dominant pathogens that coexisted with other uropathogens to cause UTIs were K. pneumoniae and P. mirabilis (9.32%, chi-square 5.550, p = 0.018), K. pneumoniae and P. aeruginosa (8.07%, chi-square 6.285, p = 0.012), K. pneumoniae and E. faecalis (7.45%, chi-square 5.785, p = 0.016), Candida sp. and Enterococcus faecium (4.97%, chi-square 9.176, p = 0.002, and Candida sp. and Acinetobacter calcoaceticus-baumannii (3.11%, chi-square 4.312, p=0.038)). Among the uropathogens, gram-negative pathogens showed resistance to most of the tested antimicrobials (ampicillins, cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, aztreonam, and nitrofurantoin). High rates of resistance were identified to cephalosporins, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole. This study reported UT mono-infection and poly-infection in Al-Madinah Al-Munawarah, Saudi Arabia, with a predominant representation from gram-negative bacteria, Enterobacteriaceae. Most of the UT microbial strains showed a highly resistant profile.

Characterizing arginine, ornithine, and putrescine pathways in enteric pathobionts.

Arginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream products of its metabolism remain undefined in various gut bacteria. To bridge this knowledge gap, we employed genomic screening to pinpoint relevant metabolic targets. We also devised a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics method to measure the levels of arginine, its upstream precursors, and downstream products in cell-free conditioned media from enteric pathobionts, including Escherichia coli, Klebsiella aerogenes, K. pneumoniae, Pseudomonas fluorescens, Acinetobacter baumannii, Streptococcus agalactiae, Staphylococcus epidermidis, S. aureus, and Enterococcus faecalis. Our findings revealed that all selected bacterial strains consumed glutamine, glutamate, and arginine, and produced citrulline, ornithine, and GABA in our chemically defined medium. Additionally, E. coli, K. pneumoniae, K. aerogenes, and P. fluorescens were found to convert arginine to agmatine and produce putrescine. Interestingly, arginine supplementation promoted biofilm formation in K. pneumoniae, while ornithine supplementation enhanced biofilm formation in S. epidermidis. These findings offer a comprehensive insight into arginine-ornithine metabolism in enteric pathobionts.