Genus Klebsiella Research Articles

Isolation Characterization and Diversity of Indigenous Pesticide Degrading Microbes from Selected Agro Ecological Zones of Malawi

Pesticide xenobiotics have a great impact on bio argumentation, bio-magnification, and environment degradation regardless of being adopted by green revolution technologies. Bioremediation is widely accepted because it’s cheap, practical at the same time environmentally friendly. Bioremediation advocates indigenous microbes use to degrade pesticides, therefore a study has been performed to show prospects of degrading microorganisms. The study isolated microbes from different agro ecological zones to assess their capacity to utilize some pesticide as sole carbon source complimented by the presence of laccase gene. Biochemical test and genetic characterization using 16S rDNA genes were used in identification. Diversified species and strains of genus Enterobacter, Klebsiella, Pseudomonas, Pantoea and Leclercia, were found to degrade cypermethrin and acetochlor but no microbe was found to degrade dimethoate. The study adds new strain of microbes involved in degradation of cypermethrin and acetochlor and also strains that that can degrade both. The study puts proposition that pest infestation in fields is a result of abundance of xenobiotic degrading microbes due to natural selection pressure not pesticide resistance of the pest.

Specific Intratumor Bacteria Genera and TRG Recombinations Associated with Greater Survival Probability in Alimentary Tract Cancers.

There remains a lack of knowledge regarding the effects of the intratumor microbiome on the tumor immune milieu. We aimed to investigate whether intratumoral bacterial RNA sequence abundance in gastric and esophageal cancers is associated with T-cell infiltrate features. We assessed cases representing the stomach adenocarcinoma (STAD) and esophageal cancer (ESCA) databases of The Cancer Genome Atlas. RNA-seq data estimating intratumoral bacterial abundance was obtained from publicly available sources. TCR recombination reads were mined from exome files. Survival models were generated using the lifelines python package. Increasing levels of the Klebsiella genus were associated with a better OS probability (hazard ratio, 0.5), via a Cox proportional hazards model. The higher Klebsiella abundance was associated with a significantly increased overall (p = 0.0001) and disease-specific survival (p = 0.0289) probability for the STAD dataset. Cases representing the upper 50th percentile of Klebsiella abundance also represented a significantly increased recovery of TRG and TRD recombination reads (p = 0.00192). Analogous results were found for the Aquincola genus in ESCA. This is the first report of associations between low biomass bacterial samples from primary tumor samples with patient survival and with an increased gamma-delta T cell infiltrate. Results indicate that the gamma-delta T cells potentially play a role in the dynamics of the bacterial infiltration of primary tumors of the alimentary tract.

The Antibacterial Activity of Rhazya stricta Extracts against Klebsiella pneumoniae Isolated from Some Soil Invertebrates at High Altitudes.

Klebsiella is a common dangerous pathogen for humans and animals and is widely present in the digestive system. The genus Klebsiella is ubiquitous, as it is endemic to surface water, soil, and sewage. In this study, 70 samples were obtained from soil-dwelling invertebrates from September 2021 to March 2022 from Taif and Shafa in different altitudinal regions of Saudi Arabia. Fifteen of these samples were identified as Klebsiella spp. The Klebsiella isolates were genetically identified as Klebsiella pneumoniae using rDNA sequencing. The antimicrobial susceptibility of the Klebsiella isolates was determined. Amplification of virulence genes was performed using PCR. In this study, 16S rDNA sequencing showed a similarity from 98% to 100% with related K. pneumonia from the NCBI database, and the sequences were deposited in the NCBI GenBank under accession numbers ON077036 to ON077050. The growth inhibition properties of ethanolic and methanolic extracts of the medicinal plant Rhazya stricta's leaves against K. pneumoniae strains using the minimum inhibitory concentration (MIC) method and disc diffusion were evaluated. In addition, the biofilm inhibitory potential of these extracts was investigated using crystal violet. HPLC analysis identified 19 components divided into 6 flavonoids, 11 phenolic acids, stilbene (resveratrol), and quinol, and revealed variations in the number of components and their quantities between extracts. Both extracts demonstrated interesting antibacterial properties against K. pneumoniae isolates. The 2 extracts also showed strong biofilm inhibitory activities, with percentages of inhibition extending from 81.5% to 98.7% and from 35.1% to 85.8% for the ethanolic and methanolic extracts, respectively. Rhazya stricta leaf extract revealed powerful antibacterial and antibiofilm activities against K. pneumoniae isolates and could be a good candidate for the treatment or prevention of K. pneumonia-related infections.

Three Klebsiella species as potential pathobionts generating endogenous ethanol in a clinical cohort of patients with auto-brewery syndrome: a case control study

Patients with auto-brewery syndrome (ABS) become inebriated after the ingestion of an alcohol-free, high-carbohydrate diet. Our previous work has shown that high-alcohol-producing (HiAlc) Klebsiella pneumoniae can generate excessive endogenous ethanol and cause non-alcoholic fatty liver disease (NAFLD). Therefore, it is reasonable to speculate that such bacteria might play an important role in the pathogenesis of ABS. The characteristics and metabolites of the intestinal flora from a clinical cohort of patients with ABS were analysed during different stages of disease and compared to a group of healthy controls. An invitro culture system of relevant samples was used for screening drug sensitivity and ABS-inducing factors. Rabbit intestinal and murine models were established to verify if the isolated strains could induce ABS invivo. We observed intestinal dysbiosis with decreased abundance of Firmicutes and increased of Proteobacteria in patients with ABS compared with healthy controls. The abundance of the genus Klebsiella in Enterobacteriaceae was strongly associated with fluctuations of patient's blood alcohol concentration. We isolated three species of HiAlc Klebsiella from ABS patients, which were able to induce ABS in mice. Monosaccharide content was identified as a potential food-related inducing factor for alcohol production. Treatments with antibiotics, a complex probiotic preparation and a low-carbohydrate diet not only alleviated ABS, but also erased ABS relapse during the follow-up observation of one of the patients. Excessive endogenous alcohol produced by HiAlc Klebsiella species was an underlying cause of bacterial ABS. Combined prescription of appropriate antibiotics, complex probiotic preparation and a controlled diet could be sufficient for treatment of bacteria-caused ABS. The funders are listed in the acknowledgement.

Monitoring MDR Evolution and Transmission Dynamics of MDR Klebsiella Pneumonia

A Gram-negative, non-motile, capsuled, lactose fermenting, facultatively anaerobic, rod shaped bacteria called Klebsiella pneumoniae. On MacConkey agar, it manifests as a mucoid lactose fermenter. Although it is a natural component of the flora in the mouth, skin, and intestines [1], it can harm the lungs of both humans and animals if aspirated (inhaled), notably the alveoli (in the lungs), resulting in bloody sputum. It is the most important member of the Enterobacteriaceae family’s Klebsiella genus when used in a therapeutic setting. Clinical samples from humans have also shown the presence of K. oxytoca and K. rhinoscleromatis. Klebsiella species have recently emerged as significant nosocomial infection pathogens. About 30% of the strains can fix nitrogen under anaerobic conditions, and they are found in soil where it naturally occurs [2]. As a free-living diazotroph, K. pneumoniae’s nitrogen fixation mechanism has undergone extensive research and is of agricultural importance because it has been shown to boost crop yields in agricultural settings [3]. On their cell surfaces, members of the Klebsiella genus normally express two different types of antigens. The Lipopolysaccharide (LPS), which comes in nine different types, contains the first antigen, called O antigen. The second is K antigen, an over 80 variety capsular polysaccharide [4]. Both support serogrouping and contribute to pathogenicity. It has a close relationship to K. oxytoca, which it differs from in that it is indole-negative and can grow on melezitose but not 3-hydroxybutyrate.

Abstract 5909: Characterization of the lung cancer microbiome using whole genome sequencing

Abstract Microbiome studies have been rapidly increasing over the last decade, providing valuable insights into the commensal bacterial contribution to human physiology and disease, including human cancer. Many studies have demonstrated the important roles of the microbiome in cancer progression, anti-tumor immunity, resistance to therapies, metastasis formation, and in some rare cases even cancer development through the production of genotoxins. However, relatively few studies have analyzed the lung cancer microbiome, and both its composition and role in cancer progression are largely unknown. To characterize the microbiome of tumor and matched normal lung tissues, we performed whole-genome sequencing (WGS) in 872 never smokers using the Kraken pipeline. At the phylum level, WGS analyses of tumor and normal samples showed predominantly Proteobacteria and Actinobacteria (58% and 32%, respectively). Notably, we found overall similar microbiome composition in tumor and normal lung tissue samples. At the genus level, Cutibacterium, Klebsiella, Pseudomonas, Sphingomonas, Staphylococcus, and Acinetobacter genera were among the most abundant bacteria in tumor and normal tissues, alike, and the genera Prevotella, Corynebacterium, and Streptococcus were more abundant in tumor samples compared to normal lung tissue. Comparison of alpha diversity at the genus level between tumors and normal samples showed no substantial difference. We are currently investigating whether the microbiome composition varies by lung tumor anatomical location, sex, histology, study subjects’ geographical location, and immune microenvironment. We will also investigate whether the tumor microbiome composition varies in relation to important genomic features, like cancer driver genes and mutational signatures. Finally, we have 16s rRNA seq data from 771 tumor and normal lung tissues from never smokers and we will compare bacterial microbiome composition and diversity based on WGS and 16s rRNA seq for the same samples. This study, based on the largest analysis of lung microbiome to date, is poised to provide important insights into the role of commensal microbiota in shaping lung tumor development and progression. Citation Format: John McElderry, Tongwu Zhang, Jianxin Shi, Maria Teresa Landi. Characterization of the lung cancer microbiome using whole genome sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5909.

Isolation, Identification, and Antibacterial Assay of Indigenous Bacterial Isolates from Apis cerana Honeycomb

Apis cerana is a honey bee species with a cavity hive known as the eastern honey bee. Honey bee hives have Indigenous bacteria that have antimicrobial potential. Indigenous bacteria are free bacteria that can synthesize nitrogen compounds, sugars, and other bioactive substances. This study aims to isolate, identify and test the antibacterial of Indigenous bacteria isolate Apis cerana against gram-positive Staphylococus aureus and gram-negative bacteria Escherichia coli. This study used a descriptive research method to obtain the data from laboratory experiments. The study consisted of isolating Indigenous bacteria, identifying and testing the antibacterial agar diffusion method. The study results obtained seven isolates of AC 1, AC 2, AC 3, AC 4, AC 5, AC 6, AC 7 Indigenous bacteria from Apis cerana nests. AC 1 isolate has similarities with the genus Streptococcus, AC 2 isolates have similarities with the Klebsiella genus, while AC 3 isolates have similarities with the Bacillus genus, and AC 4, AC 5, AC 6 and AC 7 isolates have similarities with the Citrobacter genus. Indigenous bacterial isolates with potential antibacterial potential where the most significant inhibition against Staphylococus aureus bacteria was shown by isolate AC 1 (10.79 mm). At the same time, the smallest was found in isolate AC 7 (8.52 mm). The most significant inhibition against Escherichia coli bacteria was shown by isolate AC 1 (9.0 mm) while the smallest was found in isolate AC 3 (7.4 mm). Apis cerana nests have indigenous bacteria that have the potential to produce antibacterial substances

Prevalence, antibiotic resistance patterns, and biofilm formation ability of Enterobacterales recovered from food of animal origin in Egypt.

The majority of animal-derived food safety studies have focused on foodborne zoonotic agents; however, members of the opportunistic Enterobacteriaceae (Ops) family are increasingly implicated in foodborne and public health crises due to their robust evolution of acquiring antimicrobial resistance and biofilms, consequently require thorough characterization, particularly in the Egyptian food sector. Therefore, this study aimed to determine the distribution and prevalence of Enterobacteriaceae family members in animal-derived foods, as well as their resistance to important antimicrobials and biofilm-forming potential. A total of 274 beef, rabbit meat, chicken meat, egg, butter, and milk samples were investigated for the presence of Enterobacteriaceae. All isolated strains were first recognized using traditional microbiological techniques. Following that, matrix-assisted laser desorption ionization-time of flight mass spectrometry was used to validate the Enterobacteriaceae's identity. The isolated enterobacteria strains were tested on disk diffusion and crystal violet quantitative microtiter plates to determine their antibiotic resistance and capacity to form biofilms. There have been thirty isolates of Enterobacteriaceae from seven different species and four genera. Out of the three food types, Pseudomonas aeruginosa had the highest prevalence rate (4.1%). With three species, Enterobacter genera had the second-highest prevalence (3.28%) across five different food categories. In four different food types, the Klebsiella genera had the second-highest distribution and third-highest incidence (2.55%). Almost all isolates, except three Proteus mirabilis, showed prominent levels of resistance, particularly to beta-lactam antibiotics. Except for two Enterobacter cloacae and three P. mirabilis isolates, all isolates were classified as multidrug-resistant (MDR) orextensively multidrug-resistant (XDR). The multiple antibiotic resistance index (MARI) of the majority of isolates dropped between 0.273 and 0.727. The highest MARI was conferred by Klebsiella pneumoniae, at 0.727. Overall, 83.33% of the isolates had strong biofilm capacity, while only 16.67% exhibited moderate capacity. The MDR, XDR, and strong biofilm indicators confirmed in 83.33% of the currently tested Enterobacteriaceae from animal-derived foods suggest that, if not addressed, there may be rising risks to Egypt's economy and public health.

Genomic Insights into CRISPR-Harboring Plasmids in the Klebsiella Genus: Distribution, Backbone Structures, Antibiotic Resistance, and Virulence Determinant Profiles.

CRISPR systems are often encoded by many prokaryotes as adaptive defense against mobile genetic elements (MGEs), but several MGEs also recruit CRISPR components to perform additional biological functions. Type IV-A systems are identified in Klebsiella plasmids, yet the distribution, characterization, and role of these plasmids carrying CRISPR systems in the whole Klebsiella genus remain unclear. Here, we performed large-scale comparative analysis of these plasmids using publicly available plasmid genomes. CRISPR-harboring plasmids were mainly distributed in Klebsiella pneumoniae (9.09%), covering 19.23% of sequence types, but sparse in Klebsiella species outside Klebsiella pneumoniae (3.92%). Plasmid genome comparison reiterated that these plasmids often carried the cointegrates of IncFIB and IncHI1B replicons, occasionally linked to other replicons, such as IncFIA, IncFII, IncR, IncQ, and IncU. Comparative genome analysis showed that CRISPR-carrying Klebsiella plasmids shared a conserved pNDM-MAR-like conjugation module as their backbones and served as an important vector for the accretion of antibiotic resistance genes (ARGs) and even virulence genes (VGs). Moreover, compared with CRISPR-negative IncFIB/IncHIB plasmids, CRISPR-positive IncFIB/IncHIB plasmids displayed high divergences in terms of ARGs, VGs, GC content, plasmid length, and backbone structures, suggesting their divergent evolutionary paths. The network analysis revealed that CRISPR-positive plasmids yielded fierce competitions with other plasmid types, especially conjugative plasmids, thereby affecting the dynamics of plasmid transmission. Overall, our study provides valuable insights into the role of CRISPR-positive plasmids in the spread of ARGs and VGs in Klebsiella genus.

Purine catabolism by enterobacteria.

Purines are abundant among organic nitrogen sources and have high nitrogen content. Accordingly, microorganisms have evolved different pathways to catabolize purines and their metabolic products such as allantoin. Enterobacteria from the genera Escherichia, Klebsiella and Salmonella have three such pathways. First, the HPX pathway, found in the genus Klebsiella and very close relatives, catabolizes purines during aerobic growth, extracting all four nitrogen atoms in the process. This pathway includes several known or predicted enzymes not previously observed in other purine catabolic pathways. Second, the ALL pathway, found in strains from all three species, catabolizes allantoin during anaerobic growth in a branched pathway that also includes glyoxylate assimilation. This allantoin fermentation pathway originally was characterized in a gram-positive bacterium, and therefore is widespread. Third, the XDH pathway, found in strains from Escherichia and Klebsiella spp., at present is ill-defined but likely includes enzymes to catabolize purines during anaerobic growth. Critically, this pathway may include an enzyme system for anaerobic urate catabolism, a phenomenon not previously described. Documenting such a pathway would overturn the long-held assumption that urate catabolism requires oxygen. Overall, this broad capability for purine catabolism during either aerobic or anaerobic growth suggests that purines and their metabolites contribute to enterobacterial fitness in a variety of environments.

Diversity of hexavalent chromium-reducing bacteria and physicochemical properties of the Kanpur tannery wastewater

The tannery effluent sample was collected from a tannery located in Jajmau area of Kanpur, India and subjected to physicochemical analysis. The tannery effluent was brownish in color with a foul odor. It was alkaline in nature and characterized by high biological oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS) and high amounts of chromium. Total eighteen chromium resistant bacteria were isolated from the tannery effluent sample. Based on the 16S rRNA gene sequencing and phylogenetic analysis, these eighteen bacteria belong to seven different genera including Bacillus, Pseudomonas, Kocuria, Cellulosimicrbium, Klebsiella, Microbacterium, Brucella. The members of genus Bacillus constitute 28% of total chromium transforming isolates; followed by members of genus Microbacterium (17%) Brucella (17%), Pseudomonas (11%), Cellulosimicrobium (11%), Kocuria (11%) and Klebsiella (5%). Furthermore, all eighteen bacteria were screened for their ability to reduce hexavalent chromium with increasing concentrations (600–1200 ppm) of potassium dichromate. Results showed that one bacterium, Bacillus licheniformis strain KNP exhibited hexavalent chromium reduction up to concentrations of 1000 ppm. This bacterium was selected for further study.

Видовой состав микрофлоры матки и вымени у коров при острых послеродовых эндометритах и маститах

The polyetiology of postpartum mastitis and endometritis makes it difficult to develop and use specific drugs. Therefore, there is a need for a more detailed study of the microbiological composition of the udder microflora, which will make it possible to correctly and appropriately select antimicrobial drugs. The main properties of microorganisms isolated from postpartum mastitis and endometritis in cows were studied. Of 166 samples from the exudate of the uterus and udder of cows, 32 (19,28 %) cultures of Escherichia coli (E. coli) were isolated, while in 14 cultures (43,75 %) hemolytic activity was confirmed, and 17 cultures (53,12 %) were highly pathogenic for white mice. In 35 samples (21,08 % of the total number of cultures), bacteria of the genus Klebsiella were isolated, active hemolysis was observed in 12 (34,28 %) samples, 16 (45,71 %) cultures were pathogenic for white mice. Bacteria of the genus Proteus were isolated in 24 samples (14,46 %) of the total number of cultures, hemolytic activity was detected in 11 (45,83 %) cultures, pathogenicity for laboratory animals was determined in 9 cultures (37,50 %). The analysis of isolated microorganisms from the contents of the uterus and udder from cows showed that the species composition of the microflora in postpartum mastitis and endometritis is practically the same, which gives us the opportunity to assume that pathogenic microorganisms can be transferred from the focus of inflammation in the mammary gland by lymphogenous or hematogenous way to the uterus, and back. With an increase in the number of postpartum mastitis and endometritis in cows in large livestock complexes with an intensive housing system, it is advisable to use modern PCR diagnostics. Real-time PCR has significant advantages over traditional methods, as well as higher sensitivity and specificity.

In Vitro Activity, Stability and Molecular Characterization of Eight Potent Bacteriophages Infecting Carbapenem-Resistant Klebsiella pneumoniae.

Members of the genus Klebsiella are among the leading microbial pathogens associated with nosocomial infection. The increased incidence of antimicrobial resistance in these species has propelled the need for alternate/combination therapeutic regimens to aid clinical treatment, including bacteriophage therapy. Bacteriophages are considered very safe and effective in treating bacterial infections. In this study, we characterize eight lytic bacteriophages that were previously isolated by our team against carbapenem-resistant Klebsiella pneumoniae. The one-step-growth curves, stability and lytic ability of eight bacteriophages were characterized. Restriction fragment length polymorphism (RFLP), random amplification of polymorphic DNA (RAPD) typing analysis and protein profiling were used to characterize the microbes at the molecular level. Phylogenetic trees of four important proteins were constructed for the two selected bacteriophages. All eight bacteriophages showed high efficiency for reducing bacterial concentration with high stability under different physical and chemical conditions. We found four major protein bands out of at least ten 15-190 KDa bands that were clearly separated by SDS-PAGE, which were assumed to be the major head and tail proteins. The genomes were found to be dsDNA, with sizes of approximately 36-87 Kb. All bacteriophages reduced the optical density of the planktonic K. pneumoniae abruptly, indicating great potential to reduce K. pneumoniae infection. In this study, we have found that tail fiber protein can further distinguished closely related bacteriophages. The characterised bacteriophages showed promising potential as candidates against carbapenem-resistant Klebsiella pneumoniae via bacteriophage therapy.

Detection of Bacteria Causing Skin Infections in Mosul City and Studying its Resistance to Antibiotics

The current study was conducted to detect the bacteria that causes skin infections in Mosul city and to study its resistance pattern to different antibiotics. For this purpose, 30 swab samples were collected from different skin infections from patients referred to the dermatology consultations of Al-Salam Teaching Hospital and Mosul GeneralHospital in Mosul city. The results of isolation and diagnosis showed that (20) samples, 66.6% of the total samples were positive for bacterial culture. (56.5%) of isolated bacteria were Gram-negative and 43.5% belonged to Gram-positive bacteria. The isolation percentage for Staphylococcus aureus and Sphingomonas paucimobillis were (17.3%) each, Pantoea spp. (13%), and all three species belonging to the genus Kocuria and Klebsiella pneumonia was 8.6% each, while Acinetobacter baumannii , Brevundimonas diminuta, Enterobacter aerogenes, and Pseudomonas luteola were isolated by (4.3%) each. The results for antibiotic sensitivity showed the prevalence of multidrug resistance (MDR) phenomenon in all isolates, and the isolates showed a clear variation in their resistance to each antibiotic. The highest percentage of resistance towards antibiotics were (69.5%) and (60.8%) against the Oxacillin and Penicillin, respectively. All isolates were sensitive towards levofloxacin, which makes it a suitable treatment option for infections associated with the bacteria understudy.

Removal of bacterial pathogens and antibiotic resistance bacteria by anaerobic sludge digestion with thermal hydrolysis pre-treatment and alkaline stabilization post-treatment

Primary sludge (PS) is associated with public health and environmental risks, so regulations focus on reducing the pathogenic and heavy metal contents of the treated material (biosolids), intended for soil amendments and land reclamation. The regulations set limits for Escherichia coli (or fecal coliforms), Salmonella spp., helminth eggs and enterovirus. However, the potential risk due to antibiotic resistant bacteria (ARB) and other human potential pathogenic bacteria (HPB) are not considered.In this work, three sludge treatment processes, having in common an anaerobic digestion step, were applied to assess the removal of regulated bacteria (fecal coliforms, Salmonella spp), ARB and HPB. The treatment arrangements, fed with PS from a full-scale wastewater treatment plant were: 1) Mesophilic anaerobic digestion followed by alkaline stabilization post-treatment (MAD-CaO); 2) Thermophilic anaerobic digestion (TAD) and, 3) Pre-treatment (mild thermo-hydrolysis) followed by TAD (PT-TAD). The results address the identification, quantification (colony forming units) and taxonomic characterization of ARB resistant to β-lactams and vancomycin, as well as the taxonomic characterization of HPB by sequencing with PacBio. In addition, quantification based on culture media of fecal coliforms and Salmonella spp. is presented.The capabilities and limitations of microbiological and metataxonomomic analyses based on PacBio sequencing are discussed, emphasizing that they complement each other. Genus Aeromonas, Acinetobacter, Citrobacter, Enterobacter, Escherichia, Klebsiella, Ochrobactrum, Pseudomonas and Raoultella, among others, were found in the PS, which are of clinical or environmental importance, being either HPB, HPB-ARB, or non-pathogenic ARB with the potentiality of horizontal gene transfer. Based on the analysis of fecal coliforms and Salmonella spp., the three processes produced class A (highest) biosolids, suitable for unrestricted agriculture applications. Mild thermo-hydrolisis was effective in decreasing ARB cultivability, but it reappeared after the following TAD. O. intermedium (HPB-ARB) was enriched in MAD and TAD while Laribacter hongkongensis (HPB) did persist after the applied treatments.

SECONDARY COMPOUNDS RELEASED BY RHIZOSPHERIC BACTERIA EXHIBIT FUNGISTATIC EFFECTS AGAINST PHYTOPATHOGENIC FUNGUS.

The aim of conducted research was to devalute the inhibition effect of metabolites secreted by some Rhizospheric bacteria on the growth of two pathogenic fungi: Rhizoctonia solani and Fussarium solani, 330 bacteria isolates were obtained from the rhizosphere of the wheat, tomato, cowpea and Mt. Atlas mastic tree grown in the Sulaimani. Thirty-five isolates were screened for suppression of phytopathogeneic fungus. Results showed that most of these rhizospheric bacteria were have fungistatic potential in different degrees. The highest inhibition of the linear growth of fungi was noted for R. solani and F. solani, by Bacillus cereus LXJ73 (90.41%), Bacillus atropheaus SM-1 (75%) respectively. Six bacterial isolates were selected which have potential effect on the growth of the two studied fungi, five isolates belonging to the Bacillus genus and one isolate belonging to the genus Klebsiella. these isolates were molecularly confirmed by 16SrRNA, and their activity for inhibiting fungal growth were studied. The extracted metabolities analysied by Gas chromatography-Mass spectrometry (GC-MS), showing that extracts contain different volatile organic compounds as Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-, 2-Pentanone, 4-hydroxy-4-methyl-, Isosteviol methyl ester,2-methyl-, Butanoic acid, 3-methyl-, 3-Pyrrolidin-2-yl-propionic acid, 9-Octadecenamide, (Z)-, Hexadecane, Tridecane, 2,5-Piperazinedione, 3,6-bis(2-methyl propyl)-, 1,2-Benzenedicarboxylic acid, diisooctyl ester, Acetic acid, Dodecane, beta.-D-Glucopyranose, 1,6-anhydro-, Lauric acid, 2-(hexadecyloxy)-3-(octadecyloxy)propyl ester and cis-Vaccenic acid. The presence of these componuds indicate that all studied Bacillus species and Klebsiella michiganensis M1-3-11having antagonistic activity and they can be used for development of biocontrol agents to reducing the phytopathogenic problems and decreasing mycotoxine in contaminated crops.

Proteus mirabilis and Klebsiella pneumoniae as pathogens capable of causing co-infections and exhibiting similarities in their virulence factors.

The genera Klebsiella and Proteus were independently described in 1885. These Gram-negative rods colonize the human intestinal tract regarded as the main reservoir of these opportunistic pathogens. In favorable conditions they cause infections, often hospital-acquired ones. The activity of K. pneumoniae and P. mirabilis, the leading pathogens within each genus, results in infections of the urinary (UTIs) and respiratory tracts, wounds, bacteremia, affecting mainly immunocompromised patients. P. mirabilis and K. pneumoniae cause polymicrobial UTIs, which are often persistent due to the catheter biofilm formation or increasing resistance of the bacteria to antibiotics. In this situation a need arises to find the antigens with features common to both species. Among many virulence factors produced by both pathogens urease shows some structural similarities but the biggest similarities have been observed in lipids A and the core regions of lipopolysaccharides (LPSs). Both species produce capsular polysaccharides (CPSs) but only in K. pneumoniae these antigens play a crucial role in the serological classification scheme, which in Proteus spp. is based on the structural and serological diversity of LPS O-polysaccharides (OPSs). Structural and serological similarities observed for Klebsiella spp. and Proteus spp. polysaccharides are important in the search for the cross-reacting vaccine antigens.

Metaprofiling of the bacterial community in sorghum silages inoculated with lactic acid bacteria.

To characterize the fermentation process and bacterial diversity of sorghum silage inoculated with Lactiplantibacillus plantarum LpAv, Pediococcus pentosaceus PpM and Lacticaseibacillus paracasei LcAv. Chopped sorghum was ensiled using the selected strains. Physicochemical parameters (Ammonia Nitrogen/Total Nitrogen, Dry Matter, Crude Protein, Acid Detergent Fibre, Neutral Detergent Fibre, Acid Detergent Lignin, Ether Extract and Ashes), bacterial counts, cell cytometry and 16sRNA sequencing were performed to characterize the ensiling process and an animal trial (BALB/c mice) was conducted in order to preliminary explore the potential of sorghum silage to promote animal gut health. After 30 days of ensiling, the genus Lactobacillus comprised 68.4 ± 2.3% and 73.5 ± 1.8% of relative abundance, in control and inoculated silages respectively. Richness (Chao1 index) in inoculated samples, but not in control silages, diminished along ensiling, suggesting the domination of fermentation by the inoculated LAB. A trend in conferring enhanced protection against Salmonella infection was observed in the mouse model used to explore the potential to promote gut health of sorghum silage. The LAB strains used in this study were able to dominate sorghum fermentation. This is the first report using metaprofiling of 16sRNA to characterize sorghum silage, showing a microbiological insight where resident and inoculated LAB strains overwhelmed the epiphytic microbiota, inhibiting potential pathogens of the genus Klebsiella.

Effect of some bacterial isolates in bioremediation of Cadmium

This study was conducted with the aim of applying Bioremediation technology in order to identify the efficiency of some bacterial isolates for improving the quality of wastewater discharging from a tank of Al-Hindiyah district sewage water treatment station in Karbala Governorate. The study included use of bacteria to remove heavy metals (Cd), as 120 bacterial isolates were isolated from wastewater before entering and after leaving the station under study, and it appeared that only 6 isolates of them were tolerant to high concentrations of heavy metals under study, up to 2,400 mg /L. These isolates were diagnosed with the Api20E technique and Vitek2 examination. Four isolates (A49, A35, A15, A1) belongs to the genus Serratia marcesens and the isolate A10 belongs to the genus Enterobacter aerogenes, while the isolate A32 refers to the genus Klebsiella pneumonia. The ability of these isolates was tested in a laboratory experiment in removing heavy metals Severally using the biomass of isolates, A35 isolation was characterized by achieving the highest removal rate for Cd, reaching 71.399% after 72 hours. Also, all isolates very high efficiency in removing (Cd) heavy metal from wastewater, with rates reaching 99.415% after 72 hours.

FastANI, Mash and Dashing equally differentiate between Klebsiella species.

Bacteria of the genus Klebsiella are among the most important multi-drug resistant human pathogens, though they have been isolated from a variety of environments. The importance and ubiquity of these organisms call for quick and accurate methods for their classification. Average Nucleotide Identity (ANI) is becoming a standard for species delimitation based on whole genome sequence comparison. However, much faster genome comparison tools have been appearing in the literature. In this study we tested the quality of different approaches for genome-based species delineation against ANI. To this end, we compared 1,189 Klebsiella genomes using measures calculated with Mash, Dashing, and DNA compositional signatures, all of which run in a fraction of the time required to obtain ANI. Receiver Operating Characteristic (ROC) curve analyses showed equal quality in species discrimination for ANI, Mash and Dashing, with Area Under the Curve (AUC) values above 0.99, followed by DNA signatures (AUC: 0.96). Accordingly, groups obtained at optimized cutoffs largely agree with species designation, with ANI, Mash and Dashing producing 15 species-level groups. DNA signatures broke the dataset into more than 30 groups. Testing Mash to map species after adding draft genomes to the dataset also showed excellent results (AUC above 0.99), producing a total of 26 Klebsiella species-level groups. The ecological niches of Klebsiella strains were found to neither be related to species delimitation, nor to protein functional content, suggesting that a single Klebsiella species can have a wide repertoire of ecological functions.