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Frontiers in Public Health 2021The genus was established in 2001. Species of and share many ecological, biochemical, clinical, and microbiological features. Given the shortcomings of available... (Review)
Review
The genus was established in 2001. Species of and share many ecological, biochemical, clinical, and microbiological features. Given the shortcomings of available technology for species identification in the clinical microbiology laboratory, are practically indistinguishable. Since the late 2000s there has been an increase in case reports of human infections. Therefore, several authors are postulating that spp. are rare and/or emerging pathogens. spp. are very similar to . The epidemiology and the clinical relevance of the human spp. infections is uncertain and further studies are required. The previous difficulties in the identification of spp. and the introduction of more precise identification techniques may explain the recent increase in the number of case reports. spp. might be rather underdiagnosed than rare or emerging pathogens.
Topics: Enterobacteriaceae Infections; Humans; Klebsiella
PubMed: 34409007
DOI: 10.3389/fpubh.2021.686789 -
Frontiers in Microbiology 2022Associated microbes of several herbivorous insects can improve insect fitness. However, the contribution of specific insect gut bacterium to plant toxin toxification for...
Associated microbes of several herbivorous insects can improve insect fitness. However, the contribution of specific insect gut bacterium to plant toxin toxification for its host fitness remains scarce. Here, a gut bacterium from the ghost moth larvae was identified. This bacterium grew unhindered in the presence of , which is a natural food for ghost moth larvae but showed significant growth inhibition and toxicity against . reared on artificial diets containing 5, 15 and 25% powder after 7 days coculture with were found to have shorter larval and pupal durations than on the diets containing powder but without coculture. HPLC analysis revealed that the content of quercetin in mineral medium containing 15% powder after 7 days coculture with was significantly decreased (79.48%) as compared with that in powder without coculture. fermentation further verified that could degrade 85.56% quercetin in Lucia-Bertani medium. reared on artificial diets containing 0.01, 0.05 and 0.1 mg/g quercetin after 48 h coculture with were also found to have shorter larval, prepupal and pupal durations, as well as higher average pupal weight and adult emergence rate than on the diets containing quercetin, but without coculture. In addition, was detected in the bud and root tissues of the sterilized , indicating that larvae might acquire this bacterium through feeding. These results demonstrate that the gut bacteria contribute to the degradation of plant toxic molecules to improve the development of herbivorous insects and provide fundamental knowledge for developing effective methods for beneficial insect rearing and pest control.
PubMed: 36620066
DOI: 10.3389/fmicb.2022.1079550 -
Innate Immunity Dec 2010Raoultella terrigena ATCC 33257, recently reclassified from the genus Klebsiella, is a drinking water isolate and belongs to a large group of non-typeable Klebsiella and...
Raoultella terrigena ATCC 33257, recently reclassified from the genus Klebsiella, is a drinking water isolate and belongs to a large group of non-typeable Klebsiella and Raoultella strains. Using an O-antiserum against a capsule-deficient mutant of this strain, we could show a high prevalence (10.5%) of the R. terrigena O-serotype among non-typeable, clinical Klebsiella and Raoultella isolates. We observed a strong serological cross-reaction with the K. pneumoniae O12 reference strain, indicating that a large percentage of these non-typeable strains may belong to the O12 serotype, although these are currently not detectable by the K. pneumoniae O12 reference antiserum in use. Therefore, we analyzed the O-polysaccharide (O-PS) structure and genetic organization of the wb gene cluster of R. terrigena ATCC 33257, and both confirmed a close relation of R. terrigena and K. pneumoniae O12. The two strains possess an identical O-PS, lipopolysaccharide core structure, and genetic organization of the wb gene cluster. Heterologous expression of the R. terrigena wb gene cluster in Escherichia coli K-12 resulted in the WecA-dependent synthesis of an O-PS reactive with the K. pneumoniae O12 antiserum. The serological data presented here suggest a higher prevalence of the O12-serotype among Klebsiella and Raoultella isolates than generally assumed.
Topics: Antibodies, Bacterial; Cloning, Molecular; Cross Reactions; DNA, Bacterial; Gene Knockout Techniques; Klebsiella pneumoniae; O Antigens; Serotyping; Species Specificity; Water Microbiology; Water Supply
PubMed: 20053705
DOI: 10.1177/1753425909350057 -
The American Journal of Tropical... Apr 2015Two point-of-use drinking water treatment systems designed using a carbon filter and foam material as a possible alternative to traditional biosand systems were...
Two point-of-use drinking water treatment systems designed using a carbon filter and foam material as a possible alternative to traditional biosand systems were evaluated for removal of bacteria, protozoa, and viruses. Two configurations were tested: the foam material was positioned vertically around the carbon filter in the sleeve unit or horizontally in the disk unit. The filtration systems were challenged with Cryptosporidium parvum, Raoultella terrigena, and bacteriophages P22 and MS2 before and after biofilm development to determine average log reduction (ALR) for each organism and the role of the biofilm. There was no significant difference in performance between the two designs, and both designs showed significant levels of removal (at least 4 log10 reduction in viruses, 6 log10 for protozoa, and 8 log10 for bacteria). Removal levels meet or exceeded Environmental Protection Agency (EPA) standards for microbial purifiers. Exploratory test results suggested that mature biofilm formation contributed 1-2 log10 reductions. Future work is recommended to determine field viability.
Topics: Bacteria; Bacteriophages; Biofilms; Carbon; Cryptosporidium parvum; Enterobacteriaceae; Filtration; Viruses; Water Microbiology; Water Purification
PubMed: 25758649
DOI: 10.4269/ajtmh.14-0001 -
The Canadian Journal of Infectious... 2016A 63-year-old-man was admitted to our hospital with severe subungual abscess. Bacteria were isolated from pus samples, and an inconsistent identification was shown by...
A 63-year-old-man was admitted to our hospital with severe subungual abscess. Bacteria were isolated from pus samples, and an inconsistent identification was shown by VITEK 2 system and MALDI-TOF mass spectrometry as Raoultella planticola and Raoultella terrigena, respectively. Molecular identification by 16S rRNA sequencing suggested that the isolate is R. terrigena, and this was further demonstrated by sequencing three housekeeping genes (rpoB, gyrA, and parC) with phylogenetic analysis. To our knowledge, this is the first report of subungual abscess caused by R. terrigena, a rare case of human infection due to soil bacterium. Our study highlights the technique importance on this pathogen identification.
PubMed: 27379169
DOI: 10.1155/2016/3879635 -
IDCases 2019There is paucity of literature available on infection. Microbiological identification of is difficult and isolates are frequently misidentified as Klebsiella This...
BACKGROUND AND OBJECTIVES
There is paucity of literature available on infection. Microbiological identification of is difficult and isolates are frequently misidentified as Klebsiella This series of 3 cases septicemia provides a description of the pitfalls and challenges in the diagnosis and management of the highly resistant strains isolated and to the best of our knowledge, is the first report from Pakistan.
METHODS
The medical records of 3 cases reported in the hospital over two months were reviewed retrospectively to record all relevant clinical information. Organism was identified by using Analytical profile index (API) 20 E with 90-95% successful identification and the sensitivity testing was performed by disc diffusion method.
RESULTS
This organism caused fulminant sepsis in case 2 resulting in mortality and complicated urinary tract infection in the third, while in case 1 it preceded the fatal candidemia. All three patients were females who had multiple co-morbid and had a history of protracted hospital stay and antibiotic usage elsewhere before being shifted to our hospital. The isolates were resistant to all beta lactams and were even colistin resistant in two patients, creating challenges and suboptimal response for effective antibiotic therapy.
CONCLUSIONS
The purpose of this case series is to highlight the highly drug resistant profile of this organism and the fulminant infection it can cause, which if spreads in our hospitals due to breaches in infection control practices, can pose risk as a deadly and untreatable nosocomial infection.
PubMed: 31485415
DOI: 10.1016/j.idcr.2019.e00628 -
Journal of Infection in Developing... Mar 2017Gallbladder stones are a very frequently occurring condition. Despite bile bactericidal activity, many bacteria have been detected inside the gallbladder, and gallstones...
INTRODUCTION
Gallbladder stones are a very frequently occurring condition. Despite bile bactericidal activity, many bacteria have been detected inside the gallbladder, and gallstones facilitate their presence. Between 3% and 5% of the patients with Salmonella spp. infection develop the carrier stage, with the bacteria persisting inside the gallbladder, shedding bacteria in their feces without signs of infection. The aim of this study was to isolate bacteria from Colombian patients with gallstones, using standard culturing methods, and to identify Salmonella spp. carriers by molecular techniques.
METHODOLOGY
A total of 149 patients (120 female and 29 male) diagnosed with gallstones who underwent cholecystectomy and who did not have symptoms of acute inflammation were included. Gallbladder tissue and bile were cultured and used for DNA extraction and Salmonella spp. hilA gene detection.
RESULTS
Of the 149 patients 28 (19%) had positive cultures. Twenty-one (75%) patients with positive cultures were from Medellin's metropolitan area. In this geographical location, the most frequent isolations were Pseudomonas spp. (38%), Klebsiella spp. (23%), and Proteus spp. (9%) in addition to unique cases of other bacteria. In Apartado, the isolates found were Enterobacter cloacae (50%), Raoultella terrigena (32%), and both Enterobacter cloacae and Raoultella terrigena were isolated in one (18%) male patient. Five (3.3%) of the 149 patients had positive polymerase chain reaction (PCR) results for the hilA gene of Salmonella spp., all of whom were female and residents of the Medellín metropolitan area.
CONCLUSIONS
The gallbladder microbiota variability found could be related to geographical, ethnic, and environmental conditions.
Topics: Adult; Aged; Bacteriological Techniques; Carrier State; Cholecystectomy; Colombia; Female; Gallbladder; Gallstones; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Male; Middle Aged; Prevalence
PubMed: 28368860
DOI: 10.3855/jidc.8258 -
Applied and Environmental Microbiology Oct 2023While the evolution of antimicrobial resistance is well studied in free-living bacteria, information on resistance development in dense and diverse biofilm communities...
While the evolution of antimicrobial resistance is well studied in free-living bacteria, information on resistance development in dense and diverse biofilm communities is largely lacking. Therefore, we explored how the social interactions in a duo-species biofilm composed of the brewery isolates and influence the adaptation to the broad-spectrum antimicrobial sulfathiazole. Previously, we showed that the competition between these brewery isolates enhances the antimicrobial tolerance of . Here, we found that this enhanced tolerance in duo-species biofilms is associated with a strongly increased antimicrobial resistance development in . Whereas was not able to evolve resistance against sulfathiazole in monospecies conditions, it rapidly evolved resistance in the majority of the duo-species communities. Although the initial presence of was thus required for to acquire resistance, the resistance mechanisms did not depend on the presence of . Whole genome sequencing of resistant clones showed no clear mutational hot spots. This indicates that the acquired resistance phenotype depends on complex interactions between low-frequency mutations in the genetic background of the strains. We hypothesize that the increased tolerance in duo-species conditions promotes resistance by enhancing the selection of partially resistant mutants and opening up novel evolutionary trajectories that enable such genetic interactions. This hypothesis is reinforced by experimentally excluding potential effects of increased initial population size, enhanced mutation rate, and horizontal gene transfer. Altogether, our observations suggest that the community mode of life and the social interactions therein strongly affect the accessible evolutionary pathways toward antimicrobial resistance.IMPORTANCEAntimicrobial resistance is one of the most studied bacterial properties due to its enormous clinical and industrial relevance; however, most research focuses on resistance development of a single species in isolation. In the present study, we showed that resistance evolution of brewery isolates can differ greatly between single- and mixed-species conditions. Specifically, we observed that the development of antimicrobial resistance in certain species can be significantly enhanced in co-culture as compared to the single-species conditions. Overall, the current study emphasizes the need of considering the within bacterial interactions in microbial communities when evaluating antimicrobial treatments and resistance evolution.
Topics: Anti-Infective Agents; Biofilms; Bacteria; Phenotype; Sulfathiazoles; Anti-Bacterial Agents
PubMed: 37819078
DOI: 10.1128/aem.01155-23 -
Marine Drugs 2011Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast,...
Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast, non-sporing and rod shaped bacterial strain (designated as gutB01) was isolated from the intestine of the puffer fish and was shown to produce tetrodotoxin (TTX). Based on the Microbial Identification (MIDI) and 16S-23S rDNA internal transcribed spacer (ITS) phylogenetic analysis, the strain was identified as Raoultella terrigena. The TTX production ability of the strain was confirmed by mouse bioassay, ELISA and mass spectrometry (MALDI-TOF). Our results reiterate that the TTX found in puffer fish was likely produced by the associated bacteria and TTX are widely produced amongst a diversity of bacterial species.
Topics: Animals; Biological Assay; Enzyme-Linked Immunosorbent Assay; Hong Kong; Intestines; Klebsiella; Mass Spectrometry; Mice; Mice, Inbred ICR; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tetraodontiformes; Tetrodotoxin
PubMed: 22163191
DOI: 10.3390/md9112384 -
Microbiology Resource Announcements Jul 2019is a bacterial species associated with soil and aquatic environments; however, sporadic cases of opportunistic disease in humans have been reported. Here, we report the...
is a bacterial species associated with soil and aquatic environments; however, sporadic cases of opportunistic disease in humans have been reported. Here, we report the first two complete genome sequences from clinical strains isolated from human sources that have been deposited in the National Collection of Type Cultures (NCTC).
PubMed: 31270187
DOI: 10.1128/MRA.00239-19