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Frontiers in Microbiology 2021A cadmium (Cd)-tolerant bacterium BB12 was isolated from sewage waste collected from the municipal sewage dumping site of Bhopal, India. The bacterium showed multiple...
A cadmium (Cd)-tolerant bacterium BB12 was isolated from sewage waste collected from the municipal sewage dumping site of Bhopal, India. The bacterium showed multiple heavy metal tolerance ability and had the highest minimum inhibitory concentration of 150 mg L of Cd. Growth kinetics, biosorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy studies on BB12 in the presence of Cd suggested biosorption as primary mode of interaction. SEM and TEM studies revealed surface deposition of Cd. FTIR spectra indicated nitrogen atom in exopolysaccharides secreted by BB12 to be the main site for Cd attachment. The potential of BB12 to alleviate the impact of Cd toxicity in spinach plants ( L.) var. F1-MULAYAM grown in the soil containing Cd at 25, 50, and 75 mg kg was evaluated. Without bacterial inoculation, plants showed delayed germination, decrease in the chlorophyll content, and stunted growth at 50 and 75 mg kg Cd content. Bacterial inoculation, however, resulted in the early germination, increased chlorophyll, and increase in shoot (28.33%) and root fresh weight (72.60%) at 50 mg kg of Cd concentration after 75 days of sowing. Due to bacterial inoculation, elevated proline accumulation and lowered down superoxide dismutase (SOD) enzyme activity was observed in the Cd-stressed plants. The isolate BB12 was capable of alleviating Cd from the soil by biosorption as evident from significant reduction in the uptake/translocation and bioaccumulation of Cd in bacteria itself and in the plant parts of treated spinach. Potential PGP prospects and heavy metal bioremediation capability of BB12 can make the environmental application of the organism a promising approach to reduce Cd toxicity in the crops grown in metal-contaminated soils.
PubMed: 35140690
DOI: 10.3389/fmicb.2021.758144 -
BMC Infectious Diseases Dec 2021Ochrobactrum spp. are non-fermenting, Gram-negative bacilli that are regarded as emerging human pathogens of low virulence that can cause infections. The first...
BACKGROUND
Ochrobactrum spp. are non-fermenting, Gram-negative bacilli that are regarded as emerging human pathogens of low virulence that can cause infections. The first identified case of Ochrobactrum intermedium was reported in 1998 in a liver transplantation patient with liver abcess. There are no reports of infections in pediatric patients. Here, we report the first case of O. intermedium bacteremia in a pediatric patient.
CASE PRESENTATION
A two and a half years old male was admitted with fever, chills and nausea. He had been diagnosed as pineoblastoma and underwent surgical resection and chemotherapy. O. intermedium was isolated from his blood cultures and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), however, the Vitek II automated system failed to identify the organism. Then the pathogen was confirmed by 16S rDNA sequencing and average nucleotide identity result (ANI) confirmed the precise identification of O. intermedium at genomic level. In addition, the patient recovered well after antibiotic combined therapy.
CONCLUSIONS
This, to our knowledge, is the first case of O. intermedium bacteremia in a pediatric patient with malignant tumor. Traditional biochemical identification methods such as API 20NE or VITEK2 system cannot differentiate O. anthropi and O. intermedium. MALDI-TOF may be a promising tool for rapid identification of microorganisms such as O. intermedium.
Topics: Bacteremia; Child, Preschool; Gram-Negative Bacterial Infections; Humans; Male; Neoplasms; Ochrobactrum
PubMed: 34906070
DOI: 10.1186/s12879-021-06938-3 -
Cureus Apr 2021species are gram-negative, non-lactose fermenting, aerobic bacilli closely related to genus. () is an emergent human pathogen that is difficult to differentiate from...
species are gram-negative, non-lactose fermenting, aerobic bacilli closely related to genus. () is an emergent human pathogen that is difficult to differentiate from other species by conventional methods. It is known to infect immunocompromised hosts, has the propensity for abscess formation, and is known for its multidrug resistance. We describe the case of an 84-year-old woman with a background of primary sclerosing cholangitis who presented with fatigue, fever, and syncope. Blood cultures grew . Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were consistent with cholangitis. Cultures from the biliary duct confirmed the same microorganism. The patient was successfully treated with minocycline. Although rare, should be considered as a differential diagnosis in patients with biliary and gut pathology, particularly in immunocompromised patients.
PubMed: 34046280
DOI: 10.7759/cureus.14648 -
Frontiers in Microbiology 2020Quorum quenching (QQ) is a promising strategy for preventing and controlling quorum sensing (QS)-mediated bacterial infections. It interferes with QS by the inhibition...
Quorum quenching (QQ) is a promising strategy for preventing and controlling quorum sensing (QS)-mediated bacterial infections. It interferes with QS by the inhibition of signal synthesis, the detection of enzyme-catalyzed degradation, and the modification of signals. -Acyl homoserine lactones (AHLs) represent a family of widely conserved QS signals involved in the regulation of virulence factor production in many Gram-negative bacterial pathogens. In this study, AHL-degrading bacterial strains were isolated, and the most efficient one was evaluated for its potential against QS-mediated pathogens. Results showed that an AHL-degrading bacteria D-2 effectively attenuated maceration produced by the pathogen subsp. (Pcc) on radish and potato slices. Strain D-2 exhibited a superior AHL degradation activity and efficiently degraded various AHLs, including -hexanoyl-L-homoserine lactone (C6HSL), -(3-oxohexanoyl)-L-homoserine lactone (3OC6HSL), -(3-oxooctanoyl)-L-homoserine lactone (3OC8HSL), and -(3-oxododecanoyl)-L-homoserine lactone (3OC12HSL). Analysis of the degradation products of AHL by gas chromatography-mass spectrometry led to the identification of -cyclohexyl-propanamide and propanamide as the main intermediate products, suggesting that AHL was degraded by hydrolysis. Annotation and analysis of the whole genome sequence of strain D-2 revealed the presence of an AHL-lactonase, termed AidF. Moreover, the application of strain D-2 was able to substantially reduce the disease severity caused by Pcc on host plants. These results reveal the biochemical basis of a highly efficient AHL-degrading bacterial isolate and present the potential to attenuate Pcc virulence through QQ.
PubMed: 32457732
DOI: 10.3389/fmicb.2020.00898 -
Poultry Science Apr 2020This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens...
Dietary l-arginine supplementation ameliorates inflammatory response and alters gut microbiota composition in broiler chickens infected with Salmonella enterica serovar Typhimurium.
This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens subjected to Salmonella enterica serovar Typhimurium. One hundred and forty 1-day-old Arbor Acres male birds were randomly assigned to a 2 × 2 factorial arrangement including diet treatment (with or without 0.3% Arg supplementation) and immunological stress (with or without S. typhimurium challenge). Samples were obtained at 7 D after infection (day 23). Results showed that S. typhimurium challenge caused histopathological and morphological damages, but Arg addition greatly reduced these intestinal injuries. S. typhimurium challenge elevated the levels of serum inflammatory parameters, including diamine oxidase, C-reactive protein, procalcitonin, IL-1β, IL-8, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITNF) homolog. However, Arg supplementation decreased the serum procalcitonin, IL-1β, IL-8, and LITNF concentration. S. typhimurium challenge significantly increased jejunal IL-1β, IL-8, IL-10, and IL-17 mRNA expression and tended to upregulate IL-22 mRNA expression, but Arg supplementation remarkably reduced IL-8 mRNA expression, tended to downregulate IL-22 mRNA expression, and dramatically elevated IFN-γ and IL-10 mRNA expression. In addition, sequencing data of 16S rDNA indicated that the population of Proteobacteria phylum; Enterobacteriaceae family; Escherichia-Shigella, and Nitrosomonas genera; and Escherichia coli and Ochrobactrum intermedium species were more abundant, but the population of Rhodocyclaceae and Clostridiaceae_1 families and Candidatus Arthromitus genus were less abundant in the ileal digesta of birds with only S. typhimurium infection when compared with the controls. Treatment with Arg in birds subjected to S. typhimurium challenge increased the abundances of Firmicutes phylum, Clostridiaceae_1 family, Methylobacterium and Candidatus Arthromitus genera but decreased the abundance of Nitrosomonas genus and Rhizobium cellulosilyticum and Rubrobacter xylanophilus species as compared with the only S. typhimurium-challenged birds. In conclusion, Arg supplementation can alleviate intestinal mucosal impairment by ameliorating inflammatory response and modulating gut microbiota in broiler chickens challenged with S. typhimurium.
Topics: Animal Feed; Animals; Arginine; Bacterial Physiological Phenomena; Chickens; Diet; Dietary Supplements; Gastrointestinal Microbiome; Inflammation; Intestines; Male; Poultry Diseases; Random Allocation; Salmonella Infections, Animal; Salmonella typhimurium; Stress, Physiological
PubMed: 32241466
DOI: 10.1016/j.psj.2019.10.049