Search

Introduction. Raoultella spp. representatives are Gram-negative rod-shaped bacteria of the Enterobacteriaceae family. These bacteria are commonly found in the natural environment. Aim. The aim of the study was to indicate the reliable method for Raoultella spp. strains identification, evaluate the susceptibility of Raoultella spp. strains to selected antimicrobials and to detect their resistance mechanisms to beta-lactams. Methodology. Susceptibility of the strains to chosen antimicrobials was determined using the automatic method. The presence of particular antimicrobial resistant mechanism and genes encoding ESBLs and MBLs was determined respectively with double-disc synergy test and commercially available kit – eazyplex SuperBug CRE test (Amplex Diagnostics) and standard PCR. For the selected strains, DNA sequencing was performed. Results. Amongst 105 of the examined Raoultella spp. strains, majority were sensitive to: imipenem (99.0 %), meropenem (98.1 %), gentamicin (93.3 %) and ciprofloxacin (92.4 %). Of the tested Raoultella strains, thirteen (12.4 %) produced ESBLs and one strain simultaneously ESBLs and MBLs. The DNA sequencing results were as follows: for all the reference strains the correct species identification was achieved, for the analysed strains two were identified as R. planticola and one as R. ornithinolytica . Conclusion. Although Raoultella spp. strains remain sensitive to antibiotics, there is a constant need to monitor the sensitivity of these bacteria to selected antimicrobials. Isolation of a multi-drug resistant R. ornithinolytica strain indicates that even the less frequently isolated species of Enterobacteriaceae family should be precisely identified because they might be of clinical importance and the particular strain can also produce enzymes that pose the greatest threat today.

Histamine in foods with a high histidine content may be produced by bacteria with histidine decarboxylase activity. Consumption of food enriched in histamine can produce symptoms of histamine poisoning that include flushing, headache, and urticaria. The number of histamine poisoning cases in Japan has decreased with developments in food hygiene management technology. However, approximately 10 cases are still reported each year. In addition, there have been cases where histamine was detected in the end products, prompting large product recalls. To prevent and identify causes of histamine toxicity, manufacturers must identify the bacteria causing the illness. A simple method of identification is needed, since sequence-based identification is complicated to perform and the analysis takes a long time. High-Resolution Melting Analysis (HRMA) is a method that detects differences in the base sequences of PCR products manifested as varied melting temperatures of double-stranded DNA. The present study was intended to develop a rapid identification method for major histamine-producing bacteria using HRMA. Species-specific HRMA primers were designed that specifically targeted the hdcA gene of 20 Gram-negative histamine-producing bacterial strains. The designed primers were used for HRM analysis of the 20 histamine-producing bacterial strains. The strains were divided into three groups (A, B, and C) based on differences in melting temperature values obtained by Tm Calling analysis program. Group A comprised terrestrial bacteria, such as Morganella, Enterobacter, and Raoultella, while Groups B and C comprised marine bacteria, such as those belonging to the genera Vibrio and Photobacterium. The melting profiles obtained in Group A by HRMA were used to identify the aforementioned terrestrial bacteria. The findings indicated that HRMA can easily identify the major gram-negative histamine-producing bacteria. A flow chart was created to identify histamine-producing bacterial species. This method enables the identification of histamine-producing bacterial species more quickly and easily than conventional sequence-based methods. Therefore, the method could be valuable for food companies to screen raw materials and products and track the source of contamination, which will in turn contribute to the prevention of histamine-food poisoning and investigation of its causes.

We examined how Raoultella ornithinolytica-ZK4 degraded pyrethroid pesticides within soil sediment from an abandoned pesticide plant. Lambda-cypermethrin and deltamethrin are two pyrethroid insecticides with high insecticidal activity and a wide range of applications. However, their increased use has raised concerns regarding toxicity and accumulation. We isolated a strain of ZK4 (Raoultella ornithinolytica-ZK4) from soil taken from a channel that surrounded a pesticide plant. We used enzyme localization to study degrading bacteria ZK4. The ZK4 strain underwent intracellular enzyme degradation. The degradation rates of lambda-cyhalothrin and deltamethrin were 55% and 53%, respectively. The optimum pH of the two kinds of pyrethroids in ZK4 was 6.5, and their optimum temperature was 37 °C. The intracellular degradation of the crude enzyme produced by the ZK4 strain had a pH of 6.0–8.0 and a temperature of 20–42 °C. The ZK4 strain genome contained 5310 genes with a total length of 4,864,494 bp. Sugar metabolism and exogenous chemical metabolism accounted for the largest proportion of metabolic activities. We used the clusters of orthologous groups (COG) alignment and found numbers for 4686 protein sequences, accounting for 88.25% of the total predicted protein. ZK4 degraded lambda-cyhalothrin and deltamethrin, and may serve as a reference for the preparation of future degrading microbial agents to assist with environmental restoration efforts.

Aim The aim of this study was to isolate potential molybdate-reducing bacteria to be used for bioremediation. Methods and results Two molybdate-reducing bacteria (Mo1 and MoI) were isolated from polluted soil samples from Ismailia Canal, Egypt and Sallah Elddin Governorate, Iraq respectively. The isolates exhibited dark blue colonies when grown on solid medium containing sodium molybdate which indicated the reduction of molybdate to molybdenum (Mo) blue. The absorbance values at 865 nm were 0·743 ± 0·007 and 0·453 ± 0·005 for Mo1 and MoI respectively. The Mo blue produced showed characteristic absorption spectrum peak at 865 nm and a shoulder at 700 nm. The isolates were identified by 16S rRNA genes sequencing and were submitted to GenBank as Raoultella ornithinolytica strain Mo1 and Raoultella planticola strain MoI. The optimum conditions were glucose as electron donor, initial pH of 6 and incubation temperature of 30°C. Scanning electron micrographs were taken for both isolates in the presence and absence of molybdate source. Conclusion To the best of our knowledge, this is the first recordation of molybdate reduction by Raoultella sp. isolated from Egypt and Iraq. Significance and impact of the study The isolated bacteria belonging to the Raoultella could be used in in situ bioremediation.

This paper investigated 10 carbapenemase genes and selected the hosts of these genes in the estuary of Bohai Bay. The results showed that the OXA-58 producer accounted for a large percentage of carbapenem resistant bacteria in the sampling points, whereas the VIM, KPC, NDM, IMP, GES, OXA-23, OXA-24, OXA-48 and OXA-51 producers were not detected in the study. In addition, 9 bacterial genera with 100% identical blaOXA-58 sequences, including Pseudomonas, Rheinheimera, Stenotrophomonas, Shewanella, Raoultella, Vibrio, Pseudoalteromonas, Algoriphagus, Bowmanella and Thalassospira, were isolated from seawater. It is suggested that the host of blaOXA-58 gene were varied and many kinds of them could survive in the seawater. Moreover, we preformed the quantitative RT-PCR and the result shown the abundance of blaOXA-58 fluctuated between 2.8×10-6 copies/16S and 2.46×10-4 copies/16S, which was of the same order of magnitude as some common antibiotic resistance genes in environment. Furthermore, the variation trend of blaOXA-58 gene suggested that pollution discharge and horizontal gene transfer could contribute to the increase of the gene in coastal area.

Klebsiella species occupy a wide range of environmental and animal niches, and occasionally cause opportunistic infections that are resistant to multiple antibiotics. In particular, Klebsiella pneumoniae (Kpne) has gained notoriety as a major nosocomial pathogen, due principally to the rise in non-susceptibility to carbapenems and other beta-lactam antibiotics. Whilst it has been proposed that the urban water cycle facilitates transmission of pathogens between clinical settings and the environment, the level of risk posed by resistant Klebsiella strains in hospital wastewater remains unclear. We used whole genome sequencing (WGS) to compare Klebsiella species in contemporaneous samples of wastewater from an English hospital and influent to the associated wastewater treatment plant (WWTP). As we aimed to characterize representative samples of Klebsiella communities, we did not actively select for antibiotic resistance (other than for ampicillin), nor for specific Klebsiella species. Two species, Kpne and K. ( Raoultella ) ornithinolytica (Korn), were of equal dominance in the hospital wastewater, and four other Klebsiella species were present in low abundance in this sample. In contrast, despite being the species most closely associated with healthcare settings, Kpne was the dominant species within the WWTP influent. In total, 29 % of all isolates harboured the bla OXA-48 gene on a pOXA-48-like plasmid, and these isolates were almost exclusively recovered from the hospital wastewater. This gene was far more common in Korn (68 % of isolates) than in Kpne (3.4 % of isolates). In general plasmid-borne, but not chromosomal, resistance genes were significantly enriched in the hospital wastewater sample. These data implicate hospital wastewater as an important reservoir for antibiotic-resistant Klebsiella , and point to an unsuspected role of species within the Raoultella group in the maintenance and dissemination of plasmid-borne bla OXA-48. This article contains data hosted by Microreact.

10 Páginas.-- 4 Tablas.-- 6 Figuras, This work applies metataxonomic, standard statistics, and compositional data (CoDa) techniques to study the bacterial diversity of spoiled and normal Spanish-style table olive fermentations, analysing a total of 10-tons of industrial fermentation containers from two processing yards. Forty percent were affected by butyric, sulfidic, or putrid spoilage, while 60% followed the ordinary fermentation course. The samples were obtained at 30 days of fermentation, determining their 16S rRNA gene Amplicon Sequence Variant compositions (ASVs). The butyric containers showed a bacterial profile strongly associated with the genera Enterococcus, Leuconostoc, and Atlantibacter, but also with Lactiplantibacillus and Melissococcus, and less confident to Raoultella, Enterobacter, Serratia, and Celerinatantimonas. The sulfidic fermentation was linked to Alkalibacterium and, to a lesser extent, Marinilactibacillus and the absence of Lactiplantibacillus. Putrid spoilage was mainly related to Halolactibacillus and Alkalibacterium. Sulfidic/putrid (together) differed from butyric spoilage by the presence of Alkalibacterium/Marinilactibacillus as well as by Halomonas/Halanaerobium. Lactiplantibacillus dominated normal fermentations, but Vibrio was also frequently found (0–46%), apparently not causing any alteration. These results contribute to a better microbial characterisation of non-zapatera spoiled table olive fermentations. They also suggest using several statistical techniques to discriminate normal vs spoiled fermentations adequately., This research was funded through TOBE project (RTI2018-100883-B-I00, MCIU/AEI/FEDER, UE).

Background Raoultella are Gram-negative rod-shaped aerobic bacteria which grow in water and soil. They mostly cause nosocomial infections associated with surgical procedures. This case study is the first report of a Raoultella infection in Africa. Case presentation We report a case of a surgical site infection (SSI) caused by Raoultella planticola which developed after caesarean section (CS) and surgery for secondary small bowel obstruction. The patient became febrile with neutrophilia (19,157/µL) 4 days after laparotomy and started to develop clinical signs of a SSI on the 8th day after laparotomy. The patient continued to be febrile and became critically ill despite empirical treatment with ceftriaxone and vancomycin. Raoultella species with extended antimicrobial resistance (AMR) carrying the CTX-M-9 β-lactamase was isolated from the wound discharge. Considering the antimicrobial susceptibility test, ceftriaxone was replaced by ceftazidime. The patient recovered and could be discharged on day 29 after CS. Conclusions Raoultella planticola was isolated from an infected surgical site after repeated abdominal surgery. Due to the infection the patient’s stay in the hospital was prolonged for a total of 4 weeks. It is noted that patients undergoing surgical and prolonged inpatient treatment are at risk for infections caused by Raoultella. The development of a SSI caused by Raoultella planticola with extended AMR has to be assumed to be a consequence of ineffective antibiotic utilization. The presented case advices that rare bacteria as Raoultella should be considered as potential cause of nosocomial SSI with challenging treatment due to high levels of AMR.

Raoultella ornithinolytica is one of the three species of Raoultella. The present case report describes a two-year-old child who had complaints of discomfort and fever, and Raoultella ornithinolytica in his urinary culture. Grade-2 hydronephrosis and a 7.5-mm urinary stone were detected in the patient’s left ureter. The stone was expelled upon consultation with pediatric urology department. The patient was treated according to culture antibiotic sensitivity report and continued to be followed-up., Raoultella ornithinolytica je jedna od vrsta bakterije Raoultella. U ovom prikazu slučaja opisuje se dvogodišnje dijete koje je imalo tegobe i groznicu te bakteriju Raoultella ornithinolytica u urinokulturi. U bolesnikovu desnom ureteru nađena je hidronefroza 2. stupnja i kamenac veličine 7,5 mm. Kamenac je izbačen u konzultaciji s pedijatrijskim urologom. Bolesnik je liječen prema antibiogramu, a njegovo stanje se i dalje prati.

The spread of antibiotic-resistant Enterobacteriaceae in the community is one of the main challenges for antibiotic treatment of community-onset infections. We evaluated the microbiological and molecular characteristics of stool samples from adults with comprehensive health examinations. Of 109 fecal samples, bacterial growth was observed in 86 samples and 61 gram-negative bacterial isolates were identified, of which 45 were Escherichia coli isolates (73.8%). Two isolates of Raoultella showed imipenem resistance, and both E. coli and Citrobacter freundii showed intermediate resistance to imipenem. Colistin resistance was identified in isolates of Klebsiella variicola and Salmonella subterranean, but no isolates carried mcr-1. As for E. coli genotypes, 35 sequence types were identified. blaTEM-1, blaTEM-30, and blaCTX-M were identified in 15, 1, and 4 E. coli isolates, respectively. In addition, all four Klebsiella pneumoniae isolates carried blaSHV. Many genotypes that have been identified in isolates causing human infections were found in isolates in this study. There is a need to control the rise and spread of antibiotic-resistant pathogens by fecal carriage.

The order Enterobacterales was divided into seven families including the family Enterobacteriaceae in 2016. The genus Klebsiella within the family Enterobacteriaceae was divided into two genera Klebsiella and Raoultella in 2001. Here, our phylogenomic analysis shows that the genus Raoultella is nested within the genus Klebsiella. Klebsiella and Raoultella together are monophyletic and share average amino acid identities (AAIs) of 86.9–89.6% above the AAI threshold (86%) for genus delimitation within the family Enterobacteriaceae. Klebsiella and Raoultella share AAIs of 79.9%–85.0% with the other genera within the subfamily “Klebsiella clade”, which are in the range of inter-genus AAIs (74–85%) within the family Enterobacteriaceae. Klebsiella and Raoultella also share six known conserved signature indels . Therefore, we propose to reunify Klebsiella and Raoultella to the single genus Klebsiella and reclassify Raoultella electrica as Klebsiella electrica comb. nov. Our genome-based taxonomic analyses also identified seven potential novel species within the unified genus Klebsiella.

Cerebral abscess is a potentially fatal neurosurgical condition, despite improvements in technology, new antimicrobial agents and modern neurosurgical instruments and techniques. I report the case of a 64-year-old woman, affected by a right frontobasal brain abscess, compressing the homolateral frontal horn of lateral ventricle, with a second mass partially occupying the right orbital cavity. She presented also with inflammatory sinusopathy involving the right maxillary, ethmoid and frontal sinuses. After 14 d of clinical observation and antimicrobial therapy, the patient received a computed tomography scan, which showed growth of the cerebral mass, with a ring of peripheral contrast enhancement and surrounding edema. She promptly underwent neurosurgical treatment and recovered well, except for the sight in her right eye, which remained compromised, as before the operation. This is believed to be the first case of cryptogenic cerebral abscess caused by Raoultella ornithinolityca isolated from the brain, with more than 1-year follow-up.

The genus Raoultella belongs to the family of Enterobacteriaceae. Raoultella spp. are Gram-negative, aerobic, non-motile rods. This genus can be distinguished from the genus Klebsiella, in that genus use histamine as the only source of carbon in the medium. Also, Raoultella grow at 4 °C and do not produce gas from lactose at 44.5 °C. Raoultella sp. is known to inhabit natural environments (water, soil, plants). The reservoir of Raoultella is the gastrointestinal tract and upper respiratory tract. Raoultella spp. are opportunistic bacteria, which usually cause infections of the biliary tract, pneumonia and bacteraemia in oncologic and with lower immunity patients. Raoultella planticola and Raoultella ornithinolytica are the most frequently encountered human pathogens among the genus Raoultella. In this review, the current knowledge on Raoultella infections is summarized.

Infections in humans by Raoultella spp. are rare and the effect that Raoultella spp. might have as a human pathogen is currently unknown. A clinical case is presented of catheter-related bacteraemia caused by Raoultella ornithinolytica, treated successfully with applied antibiotic therapy (intravenous cefepime and sealed the catheter with amikacin).

Severe cases of infections caused by Raoultella planticola are constantly being reported from all over the world with the increase in drug-resistance patterns. In this study, we retrospectively evaluated the clinical characteristics of R. planticola infections with patients’ demographics and antimicrobial susceptibilities of the R. planticola isolates. R. planticola isolates were retrospectively evaluated. VITEK 2® automated system was used for identification and antimicrobial susceptibility testing. Verification of the low-discriminated isolates was analyzed with MALDI-TOF method using VITEK MS® system. Gene-Xpert® system was used for detection of bla IMP-1-, bla KPC-, bla NDM-1-, bla OXA-48- and bla VIM-type carbapenemases. The data of the patients with R. planticola infection were collected from hospital records. During the 4-year period, 42 episodes of R. planticola infections were detected. MALDI-TOF was used for 11 of the low-discriminated isolates, and 1 of which identified as R. terrigena was excluded. Carbapenems and aminoglycosides were the most effective antimicrobial agents. Extended spectrum beta-lactamases were detected in seven of the isolates. Three carbapenem-resistant isolates were detected as bla OXA-48-type carbapenemase carrier. Nosocomial R. planticola infections constituted 80.9 % (n = 34) of the infections. Most common infections related with R. planticola were blood stream infections (n = 24) (p 0.005). Challenging infections caused by Raoultella spp., like those of multidrug resistant Klebsiella spp., will probably become a concern for clinicians as well as microbiologists . In literature, there were few cases, but we believe that the incidence of Raoultella spp. infections, which may result from misidentification, are more common than expected , and it is not unlikely that there will be a gradual increase and spread in multidrug-resistant isolates.

N2 -fixing bacteria belonging to the genus Raoultella of the family Enterobacteriaceae are widely associated with plants. Raoultella sp. strain L03 was isolated from surface-sterilized sugarcane roots. In this study, we inoculated the strain L03 to microbe-free micropropagated plantlets of the main sugarcane cultivar ROC22 grown in Guangxi, China and determined N2 -fixation and association between strain L03 and sugarcane plants. Inoculation of strain L03 increased plant biomass, total N, N concentration and chlorophyll, and relieved N-deficiency symptoms of plants under an N-limiting condition. An (15) N isotope dilution assay revealed (15) N isotope dilution in the inoculated sugarcane plants and incorporation of the fixed (14) N from air into chlorophyll. Moreover, a gfp-tagged and antibiotic-resistant L03 strain was reisolated from surface-sterilized sugarcane plants and was detected in plant tissues by fluorescent microscopy. This study for the first time demonstrates that a Raoultella bacterium is able to fix N2 in association with the plant host.

The genus Raoultella was excised from Klebsiella in 2001, but difficulties in its identification may have led to an underestimation of its incidence and uncertainty on its pathogenic role. Recently, clinical reports involving Raoultella have increased, probably through the introduction of mass-spectrometry in clinical microbiology laboratories and the development of accurate molecular techniques. We performed a retrospective analysis using our blood culture collection (2011-14) to identify Raoultella isolates that could have been erroneously reported as Klebsiella. PCR and gene sequencing of highly specific chromosomal class A β-lactamase genes was established as the reference method, and compared with 16S rRNA and rpoβ sequencing, as well as matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), MicroScan Walkaway system and API20E biochemical identification. MALDI-TOF and rpoβ correctly identified all Raoultella isolates, whereas 16S rRNA provided inconclusive results, and MicroScan and API20E failed to detect this genus. The analysis of the clinical characteristics of all Raoultella bacteraemia cases reported in the literature supports the role of Raoultella as an opportunistic pathogen that causes biliary tract infections in elderly patients who suffer from some kind of malignancy or have undergone an invasive procedure. Two salient conclusions are that Raoultella shows tropism for the biliary tract and so its identification could help clinicians to suspect underlying biliary tract disease when bacteraemia occurs. Concomitantly, as most phenotypic identification systems are not optimized for the identification of Raoultella, the use of MALDI-TOF or additional phenotypic tests is recommended for the reliable identification of this genus.

Pollution of the environment with chlorinated aromatic compounds is a problem of increasing importance, which has stimulated the search for efficient methods for the remediation of contaminated soil and water. Additionally, for better understanding of the significance of bioavailability to biodegradation, investigation of the cell surface properties is necessary. Hence, this study concerns the properties and possible application, in chlorotoluene removal, of three newly isolated environmental bacterial strains from the genera Pseudomonas, Raoultella and Rahnella. The results show the differences in the biochemical profiles of the isolated strains, their cellular fatty acid composition and their hemolytic properties. However, all three strains exhibit high biodegradation potential, degrading not less than 60% of each monochlorotoluene isomer in 21-day experiments. What is more, observations of changes in the cell surface properties indicate the possible adaptation mechanisms of the strains that enable efficient biodegradation of hydrophobic pollutants such as monochlorotoluenes.

Bacteria of the genus Raoultella are known to inhabit aquatic environments and can be found in medical samples. The pathogenicity of Raoultella ornithinolytica isolates in human has become increasingly important, and several cases of infections have been reported recently. However, there are no reports of isolation of bacteriophages infecting this bacterium. In this study, two novel phages (ISF3 and ISF6) of a methylotrophic Raoultella strain were isolated from sewage. To characterize the isolated phages, morphological features, protein profiles, restriction digestion patterns, and partial genome sequences were studied. Despite morphological differences, electron microscopy revealed that both phages had an icosahedral capsid connected to a contractile tail, suggesting that ISF3 and ISF6 both belong to the family Myoviridae. Partial nucleotide sequences of the ISF3 genome showed 99% to 100% identity to DNA of Klebsiella pneumonia phages KP15, KP27 and BMBT1; however, the restriction digestion profiles of ISF3 genome digested by EcoRI and EcoRV differed from those of Klebsiella phages KP15 and KP27. A partial sequence alignment showed that ISF6 can be classified as a member of a new viral genus due to its significant differences from other previously identified phages. To the best of our knowledge, this is the first report of the isolation and characterization of the specific Raoultella phages that have potential to be used as new pharmaceuticals against R. ornithinolytica.

Raoultella planticola is rarely associated with clinical infection, and a limited number of pediatric cases have been reported. Herein we report a case of bacteremia presumptively secondary to bilateral conjunctivitis in an infant caused by R. planticola which was successfully treated with piperacillin-tazobactam. It should be kept in mind that R. planticola can be a pathogen in pediatric age groups. (C) 2017 The Authors. Published by Elsevier Limited on behalf of King Saud Bin Abdulaziz University for Health Sciences. This is an open access article under the CC BY-NC-ND license

We performed a retrospective analysis of clinical and laboratory data over 5 years in a tertiary centre to assess clinical and microbiological characteristics of patients with Raoultella spp. infection. Raoultella spp. were deemed responsible for clinical infections in 57 patients (R. planticola, n = 32 and R. ornithinolytica, n = 25). The most prevalent diagnoses for R. planticola were cystitis (50%; n = 16) followed by bacteraemia and pneumonia (9.4%; n = 3); for R. ornithinolytica, cystitis (36%; n = 9) followed by pneumonia (24%; n = 6). Immunodeficiency was present in 18 patients (56.3%) with R. planticola and in 16 patients (64%) with R. ornithinolytica infection. Of these, 55.6% and 37.5% had diabetes and 27.8% and 18.% were solid organ transplant recipients, respectively. All isolates were sensitive to third-generation cephalosporins, fluoroquinolones and aminoglycosides. Mortality of infections with R. planticola (n = 5; 15.6%) was higher than for R. ornithinolytica (n = 2; 8.0%), but the difference was not statistically significant.

Background Chromosomal class A β-lactamases have been characterized in Raoultella ornithinolytica and Raoultella planticola. The purpose of this study was to characterize that of Raoultella terrigena. Materials and methods The blaTER-1 gene of R. terrigena strain ATCC33257T was cloned (pACter-1) and sequenced. It was then used to detect the bla gene of strains BM 85 01 095 and SB2796. The hypermutable Escherichia coli strain AB1157 mutS::Tn10 was transformed with pACter-1 and mutants growing on plates containing > 2 mg/L ceftazidime were studied. Notably, the impact of mutations only observed in the promoter region on β-lactam resistance was assessed by site-directed mutagenesis experiments. Results R. terrigena strains ATCC33257T and BM 85 01 095 had the same bla gene and deduced protein (TER-1) whereas there were 3 substitutions in those of strain SB2796 (TER-2). Class A β-lactamases TER showed 78%, 69.9% and 38.7% identity with PLA or ORN, TEM-1 and KOXY, respectively. Compared with TEM-1, TER-1 and TER-2 showed 2 particular substitutions, Leu75Pro and Glu240Asn demonstrated to be involved in the inherent β-lactam resistance profile of R. terrigena. TER-1 (pI of 7.6) had a high activity against penicillin G and a significantly low one against amoxicillin. Substitution G/T observed in the -35 region of the blaTER gene harbored by strains growing in the presence of ≥ 2 mg/L ceftazidime was shown to be responsible for this growth. Conclusion TER is a new class A β-lactamase belonging to functional group 2b.

Biofilm formation in a dairy waste irrigation system can reduce treatment capacity and increase maintenance and cleaning. An extreme biofilm observed in a primary treated dairy wastewater system blocked the irrigation line requiring manual cleaning. Both next-generation genomic sequencing and the culturable fraction showed the presence of predominantly Gram-negative bacteria. Isolates identified from current samples and stored samples from the extreme biofilm included Pseudomonas, Citrobacter, Klebsiella and Enterobacter, one Gram-positive spore former (Bacillus cereus) and one unique isolate from the biofilm, a member of the Raoultella genus. Raoultella spp was only cultured from the extreme biofilm; however, next-generation sequencing analysis of a wastewater sample showed this bacterium to be present in the wastewater system. The dominance of Gram negative may be due to the wastewater from the washing equipment used to handle raw milk. Six bacteria from the fresh samples were found to be strong biofilm formers along with the Raoultella spp from the extreme biofilm. Tests using multiple isolates showed Raoultella spp to be important in biofilm formation. This is the first report of the microbial composition of a dairy wastewater biofilm giving insight into the population and growth of microorganisms in the sections of a dairy wastewater irrigation system.

Autochthonous bioaugmentation for metal phytoremediation is still little explored, particularly its application to estuarine salt marshes, but results obtained so far are promising. Nevertheless, understanding the behaviour of the microbial communities in the process of bioaugmentation and their role in improving metal phytoremediation is very important to fully validate the application of this biological technology. This study aimed to characterize the bacterial community dynamic associated with the application of autochthonous bioaugmentation in an experimentation which showed that Phragmites australis rhizosphere microorganisms could increase this salt marsh plant potential to phytoremediate Cu contaminated sediments. Bacterial communities present in the autochthonous microbial consortium resistant to Cu added to the medium and in the sediment at the beginning and at the end of the experiment were characterized by ARISA. Complementarily, the consortium and the sediment used for its production were characterized by next generation sequencing using the pyrosequencing platform 454. The microbial consortium resistant to Cu obtained from non-vegetated sediment was dominated by the genus Lactococcus (46%), Raoultella (25%), Bacillus (12%) and Acinetobacter (11%), whereas the one obtained form rhizosediment was dominated by the genus Gluconacetobacter (77%), Bacillus (17%) and Dyella (3%). Results clearly showed that, after two months of experiment, Cu caused a shift in the bacterial community structure of sediments, an effect that was observed either with or without addition of the metal resistant microbial consortium. Therefore, bioaugmentation application improved the process of phytoremediation (metal translocation by the plant was increased) without inducing long term changes in the bacterial community structure of the sediments. So, phytoremediation combined with autochthonous bioaugmentation can be a suitable technology for the recovery of estuarine areas, contributing for an efficient risk management strategy of these coastal zones. © 2017 To Rayra Santiago, Tatiana Necrasov and Catarina Magalhães for their help in the experiments assembling and dismantling of the vessels and to Paula Rodrigues for helping on samples preparation and metal analysis. This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT – Foundation for Science and Technology and European Regional Development Fund (ERDF) , in the framework of the programme PT2020 and by the structured Program of R&D&I INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Resources , reference NORTE-01-0145-FEDER-000035 , namely within the Research Line ECOSERVICES (Assessing the environmental quality, vulnerability and risks for the sustainable management of the NW coast natural resources and ecosystem services in a changing world) within the R&D Institution CIIMAR (Interdisciplinary Centre of Marine and Environmental Research), supported by the Northern Regional Operational Programme ( NORTE2020 ), through the European Regional Development Fund (ERDF) .

Raoultella spp. representatives are Gram-negative capsulated, nonmotile rods. These bacteria are found in the natural environment: plants, water, soil and insects. R. ornithinolytica is one of the three species of Raoultella. R. ornithinolytica is the only species within the genus which has the ability to produce ornithine decarboxylase. Human infections related to R. ornithinolytica are exceedingly rare. The present case report describes catheter-related blood stream infection caused by R. ornithinolytica and successfully treated with antibiotic therapy.

The genus Raoultella has been separated from the genus Klebsiella in 2001. Two main species are responsible for human infections: R. ornithinolytica and R. planticola. The most frequent infections due to R. planticola include cystitis, pneumonia and bacteremia (mostly in immunocompromised hosts). To date, no joint or bone infection has been reported. We describe the first case of septic arthritis due to R. planticola following an arthroscopy with intra-articular injection of corticosteroids. Evolution was favorable after arthroscopic lavage and antibiotic therapy with quinolones. Raoultella planticola has been described rarely in human infection. It is mainly deemed responsible for cystitis, pneumonia and bacteremia (mostly in immunocompromised hosts) [1, 2, 3]. To our knowledge no case of bone or joint infection has been reported. We described here the first case of infective arthritis due to R. planticola involving a native knee joint following synovectomy and intra-articular injection of corticosteroids during arthroscopy.

A 58-year-old woman presented to eye emergency with a chronic conjunctivitis which was diagnosed by laboratory microbiological testing to be due to the environmental pathogen Raoultella planticola. The organism was sensitive to Chloramphenicol and the patient made a rapid recovery on these drops. This is the first report of this organism infecting the eye.

Item does not contain fulltext A case series of 14 patients with Raoultella bacteremia was compared with 28 Klebsiella oxytoca and 28 Klebsiella pneumoniae bacteremia cases. Forty-three percent of Raoultella bacteremia cases were associated with biliary tract disease, compared to 32% and 22% of patients with K. oxytoca and K. pneumoniae bacteremia, respectively.

The performance of a sulfidogenic bioreactor and the response of bacterial populations to influent alkalinity changes were investigated. The bioreactor reached 40% of sulfate removal efficiency (SRE) with 0 mg l −1 of alkalinity, and single-stranded conformation polymorphism profiles showed that some members of Bacteroides , Dysgonomonas , Sporobacter , Quinella , and Citrobacter became dominant populations. 16S rRNA gene library analysis indicated that the Actinobacteria group increased from 0% in seed to 23% in sludge. An increase in alkalinity to 1300 mg l −1 led to a rapid increase of SRE to 65% and changes in the bacterial community. Sequences representing Dysgonomonas , Raoultella , Kluyvera, and Phascolarctobacterium were now found. When alkalinity was deceased to 0 mg l −1 , SRE dropped and the bands representing Raoultella , Kluyvera, and Phascolarctobacterium disappeared, while bands representing Clostridium appeared. A second cycle of low/high alkalinity did not result in obvious changes to the bacterial community. These results indicate that the sulfidogenic bioreactor favored higher influent alkalinity and that the different functional microbial populations responded well to the alkalinity changes.

Mallard ducks have demonstrated to be a likely reservoir for zoonotic E. coli strains; thus, it is possible that these ducks could also act as a reservoir for other Enterobacteriaceae members. The present study was initiated to evaluate the species distribution of Enterobacteriaceae other than E. coli in 175 fresh faecal samples collected from a population of mallard ducks. Sixty-four samples displayed detectable colonies of Enterobacteriaceae (excluding E. coli), which resulted in 75 pulsed-field gel electrophoresis (PFGE) types. Seventy-five single representatives of each PFGE type were subjected to identification with API 32NE and MALDI TOF MS systems due to the practical difficulties in species differentiation of Enterobacteriaceae. Those isolated were found to be from nine genera: Buttiauxella (15 %), Citrobacter (5 %), Enterobacter (32 %), Hafnia (1 %), Leclercia (1 %), Pantoea (7 %), Raoultella (21 %), Rahnella (7 %) and Serratia (11 %). Evaluation of antimicrobial resistance phenotypes using the disc method and detection of resistance genes using the microarray method revealed that these microbes possess resistance to β-lactams, aminoglycosides, macrolides, quinolones, rifamycine, sulphonamides, streptogramins and diaminopyrimidines. In conclusion, mallard ducks harbour a variety of non-pathogenic and pathogenic Enterobacteriaceae species like Enterobacter cloacae and Enterobacter amnigenus in their intestine and could act as a reservoir of resistant Enterobacteriaceae.

We report a case of an elderly Caucasian female who developed bacteremia secondary to Raoultella planticola following ingestion of undercooked seafood. There have been less than 25 cases reported worldwide. Clin Infect Immun. 2016;1(2):50-51 doi: https://doi.org/10.14740/cii17w

To develop a targeted metagenomics approach for the analysis of novel multispecies microbial consortia involved in the bioconversion of lignocellulose and furanic compounds, we applied replicated sequential batch aerobic enrichment cultures with either pretreated or untreated wheat straw as the sources of carbon and energy. After each transfer, exponential growth of bacteria was detected using microscopic cell counts, indicating that the substrate was being utilized. In batch, the final bacterial abundances increased from an estimated 5 to 8.7-9.5 log 16S rRNA gene copy numbers/ml. The abundances of fungal propagules showed greater variation, i.e., between 5.4 and 8.0 log ITS1 copies/ml. Denaturing gradient gel electrophoresis analyses showed that the bacterial consortia in both treatments reached approximate structural stability after six transfers. Moreover, the structures of the fungal communities were strongly influenced by substrate treatment. A total of 124 bacterial strains were isolated from the two types of enrichment cultures. The most abundant strains were affiliated with the genera Raoultella/Klebsiella, Kluyvera, Citrobacter, Enterobacter, Pseudomonas, Acinetobacter, Flavobacterium and Arthrobacter. Totals of 43 and 11 strains obtained from the untreated and pretreated substrates, respectively, showed (hemi)cellulolytic activity (CMC-ase and xylanase), whereas 96 strains were capable of growth in 7.5 mM 5-hydroxymethylfurfural. About 50 % of the latter showed extracellular oxidoreductase activity as detected by a novel iodide oxidation method. Also, (hemi)cellulolytic fungal strains related to Coniochaeta, Plectosphaerella and Penicillium were isolated. One Trichosporon strain was isolated from pretreated wheat straw. The two novel bacterial-fungal consortia are starting points for lignocellulose degradation applications.

The wood-boring beetleAnoplophora chinensisForster, native to China, has recently spread to North America and Europe causing serious damage to ornamental and forest trees. The gut microbial community associated with these xylophagous beetles is of interest for potential biotechnological applications in lignocellulose degradation and development of pest-control measures. In this study the gut bacterial community of larvae and adults ofA. chinensis, collected from different host trees in North Italy, was investigated by both culture and culture-independent methods. Larvae and adults harboured a moderately diverse bacterial community, dominated by Proteobacteria, Actinobacteria, and Firmicutes. The gammaproteobacterial family Enterobacteriaceae (generaGibbsiella, Enterobacter, Raoultella, andKlebsiella) was the best represented. The abundance of such bacteria in the insect gut is likely due to the various metabolic abilities ofEnterobacteriaceae, including fermentation of carbohydrates derived from lignocellulose degradation and contribution to nitrogen intake by nitrogen-fixing activity. In addition, bacteria previously shown to have some lignocellulose-degrading activity were detected at a relatively low level in the gut. These bacteria possibly act synergistically with endogenous and fungal enzymes in lignocellulose breakdown. The detection of actinobacterial symbionts could be explained by a possible role in the detoxification of secondary plant metabolites and/or protection against pathogens.

Item does not contain fulltext Ninety-nine clinical isolates previously identified as Klebsiella oxytoca were evaluated using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Eight isolates were identified as Raoultella spp., being 5 Raoultella spp. and 3 K. oxytoca, by 16S rRNA sequencing. These isolates were correctly identified by applying the 10% differential rule for the MALDI-TOF MS score values. This approach might be useful to discriminate Raoultella species from K. oxytoca. 01 april 2013

Raoultella spp. have recently been separated from the genus Klebsiella based on their molecular characteristics. It was discovered that Raoultella ornithinolytica can be misidentified as Klebsiella oxytoca by commonly used phenotypic identification systems. Therefore, this study evaluated the ability of three phenotypic systems to identify R. ornithinolytica compared with the genotypic methods sequence-specific primer PCR (SSP-PCR), 16S rRNA gene sequence analysis using the MicroSeq 500 system16S rDNA bacterial identification system or comparison with GenBank sequences using blast. The phenotypic systems examined in this study were the VITEK 2 GN ID card, the MicroScan Neg Combo 32 panel and API 20E. The SSP-PCR panel was able to distinguish the R. ornithinolytica reference strain from other Raoultella spp. and K. oxytoca. Of the 27 isolates identified as R. ornithinolytica by SSP-PCR, VITEK 2 identified all of them as R. ornithinolytica. MicroScan and API identified 25 isolates (92.6 %) and 24 isolates (88.9 %) as K. oxytoca, respectively. These isolates were ornithine decarboxylase (ODC) negative in all three phenotypic systems. MicroSeq 500 identified 24 isolates (88.9 %) as R. ornithinolytica, whereas GenBank identification was heterogeneous. Of the 68 isolates identified as K. oxytoca by SSP-PCR, 66 isolates (97.1 %) were identified as K. oxytoca by VITEK 2, MicroScan and API. MicroScan and API require additional biochemical tests to differentiate between ODC-negative R. ornithinolytica and K. oxytoca.

Fruit flies (Diptera: Tephritidae) are a highly successful, widespread group of insects that cause economic damage in agriculture. Data available so far on the composition of the bacterial community associated with their digestive tract indi- cate that members of Enterobacteriaceae are the species most often isolated. Bacteria naturally occurring in insect guts may be engineered and used to study the spatial and functional interactions of microbes within the insect system and offer one route to meet the demand for novel insect pest management strategies. With this aim we introduced by conjugation the gfp gene carried by the suicide plasmid pTn5gfpmut1 into Klebsiella oxytoca and Raoultella (formerly Klebsiella) spp. strains isolated from the oesophageal bulb of the fruit flies Ceratitis capitata (Wiedemann) and Rhagoletis completa Cresson, re- spectively. The GFP-encoding gene was stably maintained in two tested transgenic strains, both originally isolated from R. completa. In one case, GFP-labeled bacterial cells were used to feed larvae and adults of the original host. Genetically modified bacteria were able to colonize the gut of larvae and persisted through all larval instars to pupal stage. Resume : Les mouches a fruits (Dipteres : Tephritidae) forment un groupe d'insectes tres efficaces et repandus qui causent des dommages economiques a l'agriculture. Les donnees portant sur la composition de la communaute bacterienne associee a leur systeme digestif et disponibles jusqu'a maintenant indiquent que les membres des Enterobacteriaceae sont les especes le plus souvent isolees. Les bacteries naturellement presentes dans l'intestin des insectes peuvent etre modifiees par genie genetique et utilisees pour etudier les interactions spatiales et fonctionnelles des microbes a l'interieur du systeme des in- sectes, offrant une avenue pour repondre a la demande de developpement de nouvelles strategies de controle des insectes nuisibles. A cet effet, nous avons introduit par conjugaison le gene gfp contenu dans le plasmide suicide pTn5gfpmut1 dans les souches Klebsiella oxytoca et Raoultella (auparavant Klebsiella) spp., isolees du bulbe œsophagien des mouches a fruits Ceratitis capitata (Wiedemann) et Rhagoletis completa Cresson, respectivement. Le gene codant la GFP etait maintenu de facon stable dans deux souches transgeniques, toutes deux isolees a l'origine de R. completa. Dans un cas, les cellules bacte- riennes marquees a la GFP ont ete utilisees pour nourrir les larves et les adultes de l'hote original. Les bacteries modifiees genetiquement pouvaient coloniser l'intestin des larves et persistaient dans tous les instars larvaires jusqu'au stade pupal. Mots-cles : proteine fluorescente verte, conjugaison, Enterobacteriaceae, Tephritidae. (Traduit par la Redaction)

To the Editor,The report by De Jong et al. [1] of several cases of Raoultella bacteremia associated with biliary disease was interesting to us as we recently encountered a similar patient.A 66-y-ol...

Summary BACKGROUND: A completely new approach to diagnose microbial agents at least one day earlier based on mass spectrometric analysis becomes possible in the microbiology laboratory: MALDI TOF: matrix-assisted laser desorption/ionisation time-of-flight. Comparison between results of the new procedure with those obtained by conventional testing is mandatory. METHODS: 204 clinical isolates grown on agar plates were analysed both, by the MALDI TOF Bruker microflex apparatus and by conventional identification using the VITEK II and API systems, both from bioMerieux. RESULTS: Of the identified isolates, 72 were grampositive and 130 gram-negative; 2 were yeasts (candida). Concordance was seen with 61/72 (85%) of the Gram-positive bacteria and with 115/130 (88%) of the Gram-negative bacteria. In 27 samples (13.2%), a discrepancy of the species and/or genus was obvious. The discrepancy appeared with 16 gram-negative (12.2%) and with 11 grampositive germs (15.3%, n.s.). In the latter group, 6 samples showed discordance with Streptococcus pneumoniae (MALDI) and Streptococcus mitis/oralis (conventional identification) constellation. Among gram-negative samples, most differences occurred on the species level only, e.g. Enterobacter cloacae versus Enterobacter kobei. In 5 cases, discordance was major and appeared on the genus level: Enterobacter/Raoultella, Streptococcus/ Gemella, Pseumdomonas/Burkholderia, Microbacter/ Sphingomonas and Candida/Cryptococcus. The most outstanding difference was Microbacterium arborescens (MALDI TOF) and Sphingomonas paucimobilis (conventional). Molecular biological identification of two Streptococcus mitis group bacteria confirmed the erroneous diagnosis by MALDI TOF of Streptococcus pneumoniae. CONCLUSION: Good comparability between MALDI TOF analysis and conventional identification procedures (86.8%) but special caution is needed when identifying streptococcal species.

Aerobic granules lose stability during storage. The goal of this work was to highlight the main cause of stability loss for stored granules as intracellular protein hydrolysis. The quantity of extracellular proteins was noted to be significantly lower during granule storage, and protease enzyme activities were correspondingly higher in the cores of stored granules. The proteolytic bacteria, which secrete highly active protease enzymes, were for the first time isolated and characterized by analyzing 16S rDNA sequences. The proteolytic bacteria belonged to the genera Pseudomonas, Raoultella, Acinetobacter, Pandoraea, Klebsiella, Bacillus and uncultured bacterium, and were grouped into Proteobacteria, Enterobacteria and Firmicutes. The PB1 (Pseudomonas aeruginosa) strain, which exhibited very high proteolytic activity during the skim milk agar test, was located at the core regime with active protease enzymes, and was close to the obligate anaerobic strain Bacteroides sp. Hence, the extracellular proteins in stored granules were proposed to be hydrolyzed by enzymes secreted by proteolytic bacteria with the hydrolyzed products ultimately being used by nearby anaerobic strains. This process gradually digests the protein core, and eventually consumes the entire granule.

Slime formation is a serious problem nowadays in the paper industry. Some enterobacteria are associated with the formation of slime deposits in paper and board mills. Detection and characterization of slime forming bacteria, belonging to the genus Enterobacter, Raoultella, and Klebsiella have been achieved by fluorescence in situ hybridization (FISH), using one probe based on the enterobacterial repetitive intergenic consensus sequence and other two rRNA targeted oligonucleotide probes. The effects of three kinds of antimicrobiological products (biocides, dispersants, and enzymes) on these enterobacterial cells were analyzed by flow cytometry (FC). Biocides Butrol 1009 and 1072 were the most effective microbiocides against all enterobacterial cells analyzed, reaching 90% of dead bacteria after 24 h. However, the enzymatic treatment (Buzyme) was not equally efficient on enterobacteria and its microbiocide capacity varied depending on the type of microorganism. FISH and FC were effective tools to detect important slime forming enterobacteria and to select specific treatments to control microbial problems in the paper industry.

The phylogenetic relationships of the type strains of 9 Klebsiella species and 20 species from 11 genera of the family Enterobacteriaceae were investigated by performing a comparative analysis of the sequences of the 16S rRNA and rpoB genes. The sequence data were phylogenetically analysed by the neighbourjoining and parsimony methods. The phylogenetic inference of the sequence comparison confirmed that the genus Klebsiella is heterogeneous and composed of species which form three clusters that also included members of other genera, including Enterobacter aerogenes, Erwinia clusters I and II and Tatumella. Cluster I contained the type strains of Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. rhinoscleromatis and Klebsiella pneumoniae subsp. ozaenae. Cluster II contained Klebsiella ornithinolytica, Klebsiella planticola, Klebsiella trevisanii and Klebsiella terrigena, organisms characterized by growth at 10 degrees C and utilization of L-sorbose as carbon source. Cluster III contained Klebsiella oxytoca. The data from the sequence analyses along with previously reported biochemical and DNA-DNA hybridization data support the division of the genus Klebsiella into two genera and one genogroup. The name Raoultella is proposed as a genus name for species of cluster II and emended definitions of Klebsiella species are proposed.

The nameKlebsiella planticola sp. nov. is proposed for a group of organisms isolated primarily from botanical and daquatic environments. Both numerical and molecular taxonomy techniques show that the species belongs within the genusKlebsiella and that it is distinct from other described species of the genus. The new species has 3 biogroups.K. planticolla is phenotypically identical toK. pneumoniae in classical biochemical tests, but it is distinguishable fromK. pneumoniae based on its ability to grow at 10°C and its inability to produce gas from lactose at 44.5°C. Additional reactions that can be used in combination with the temperature criteria includel-sorbose fermentation and ability to utilize hydroxy-l-proline as a sole carbon source. Strain V-236 (ATCC 33531; CDC 4245-72) is the type strain of the new species.

The nameKlebsiella ornithinolytica sp. nov. is proposed for a group ofKlebsiella strains referred to previously as NIH Group 12 at the National Institute of Health, Tokyo. The members of this species are Gram-negative, encapsulated, nonmotile rods with the general characteristics of the familyEnterobacteriaceae and of the genusKlebsiella. They give positive results in tests for indole production, Voges-Proskauer, citrate utilization, lysine and ornithine decarboxylases, urease, β-galactosidase, malonate utilization, growth in KCN, and esculin hydrolysis, and they produce acid and gas fromd-glucose, and acid froml-arabinose, cellobiose, lactose, melibiose, raffinose, rhamnose, sucrose, trehalose,d-xylose, adonitol,d-arabitol, myo-inositol, sorbitol, arbutin, salicin, α-methyl-d-glucoside, and mucate. They give negative drolysis, DNase, pectinase, and acid production fromd-arabinose, melezitose, and dulcitol. They can grow at 4°C and 42°C, and do not produce any pigment. DNA relatedness of eight strains ofKlebsiella ornithinolytica to three strains including the type strain of this species averaged 88% in reaction at 75°C. DNA relatedness to the already recognizedKlebsiella species inEnterobacteriaceae was 1 to 20%. Phenotypic and DNA relatedness data also indicated that a group of organisms referred to as Enteric Group 47 orKlebsiella Group 47 at the Centers for Disease Control (Atlanta, Georgia) was identical withK. ornithinolytica. The type strain ofK. ornithinolytica is NIH 90-72 (JCM 6096).