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The biological reduction of ferrous ethylenediaminetetraacetic acid (EDTA-FeII-NO and EDTA-FeIII) is an important process in the integrated electrobiofilm reduction method, and it has been regarded as a promising alternative method for removing NO x from industrial boiler flue gas. EDTA-FeII-NO and EDTA-FeIII are crucial substrates that should be biologically reduced at a high rate. However, they inhibit the reduction processes of one another when these two substrates are presented together, which might limit further promotion of the integrated method. In this study, an integrated electrobiofilm reduction system with high reduction rates of EDTA-FeII-NO and EDTA-FeIII was developed. The dynamic changes of microbial communities in the electrobiofilms were mainly investigated to analyze the changes during the reduction of these two substrates under different conditions. The results showed that compared to the conventional chemical absorption-biological reduction system, the reduction system exhibited better performance in terms of resistance to substrate shock loading and high microbial diversities. High-throughput sequencing analysis showed that Alicycliphilus, Enterobacteriaceae, and Raoultella were the dominant genera (>25% each) during the process of EDTA-FeII-NO reduction. Chryseobacterium had the ability to endure the shock loading of EDTA-FeIII, and the relative abundance of Chryseobacterium under abnormal operation conditions was up to 30.82%. Ochrobactrum was the main bacteria for reducing nitrate by electrons and the relative abundance still exhibited 16.11% under shock loading. Furthermore, higher microbial diversity and stable reactor operation were achieved when the concentrations of EDTA-FeII-NO and EDTA-FeIII approached the same value (9 mmol·L-1).

Sai Vikram Alampoondi Venkataramanan, Lovin George, Kamal Kant Sahu, George M Abraham Department of Medicine, Saint Vincent Hospital, Worcester, MA, 01608, USACorrespondence: Kamal Kant SahuDepartment of Medicine, Saint Vincent Hospital, Worcester, MA, 01608, USAEmail drkksahu85@gmail.comIntroduction: Raoultella planticola is an aerobic gram-negative rod predominantly found in soil and aquatic environments. The typical reservoirs of Raoultella spp. include the gastrointestinal tract and the upper respiratory tract. It usually causes pneumonia, biliary tract infections, and bacteremia. Urinary tract infection (UTI) secondary to R. planticola is an uncommon entity. Less than 10 cases of R. planticola-associated UTIs in adults have been published in the literature to date.Objective: This is a single institution retrospective study undertaken to identify the epidemiology, patient characteristics, clinical spectrum, predisposing risk factors and the outcome of patients with UTI caused by R. planticola.Results: A total of 37 R. planticola isolates were identified in urine samples over a 5-year study period. The mean age of the patient population was 77 years. The most common comorbidity was diabetes mellitus, which was present in 16 patients. Only 3 patients had a history of steroid use, an immunosuppressive condition, or were on chemotherapy. The most common presenting complaint was altered mental status followed by fever. Resistance to ampicillin was found in 35 isolates which seems to be an intrinsic characteristic of Raoultella spp. and 2 isolates were multidrug-resistant, but still susceptible to ciprofloxacin. The average length of stay was 3 days, and the average duration of antibiotic administration was 8 days. Ciprofloxacin was the most frequently prescribed antibiotic (9 patients). The severity of infection ranged from simple cystitis in 15 patients to urosepsis in 2 patients and septic shock in 2 patients. There were no mortalities in our cohort.Conclusion: Our study revealed that patients with R. planticola UTI had higher proportion of diabetes mellitus, renal failure compared to the general population. Our study also confirms the intrinsic resistance to ampicillin of Raoultella spp., which has been documented previously in the literature.Keywords: infection, antibiotics, Raoultella, urinary tract infection, bacteriuria

Colistin (CST) is considered the last resort for the treatment of infectious diseases due to multidrug-resistant bacteria. Since the mcr-1 gene has been reported in Enterobacteriaceae isolated from food, animals, and humans in China, the prevalence of CST-resistant bacteria has been of great concern. Here, we investigated the prevalence of CST resistance and plasmid-mediated colistin-resistance genes (mcr) in gram-negative bacteria isolated among retail meats in Japan. CST-resistant bacteria were isolated from 310 domestic retail meats (103 chicken meat, 103 pork, and 104 beef) purchased between May 2017 and July 2018 from retail shops in Japan using CST-containing media and antimicrobial susceptibility testing. The mcr gene was investigated in isolates with a CST minimum inhibitory concentration of ≥1 μg/mL. Excluding the intrinsically CST-resistant isolates, CST-resistant bacteria were isolated from 39 of the total chicken meats (37.9%), 19 of the pork samples (18.4%), and 18 of the beef samples (17.3%). A total of 459 isolates were identified, out of which 99 were CST-resistant. CST resistance (resistance breakpoints: Aeromonas, >4 μg/mL; others, >2 μg/mL) was found in Aeromonas spp. (48/206, 23.3%), Yersinia spp. (5/112, 4.5%), Escherichia coli (23/39, 59%), Citrobacter spp. (4/26, 15.4%), Klebsiella spp. (2/23, 8.7%), Raoultella spp. (2/16, 12.5%), Enterobacter spp. (7/14, 50%), Pseudomonas spp. (1/8, 12.5%), Pantoea spp. (5/7, 71.4%), Ewingella spp. (1/4, 25%), and Kluyvera spp. (1/2, 50%). The mcr gene was detected in 16 isolates: mcr-1 in 14 isolates of E. coli from 10 chicken samples (9.7%), and mcr-3 in two isolates of Aeromonas sobria from pork and chicken samples (each 1.0%). The findings of this study highlight the necessity of surveillance of CST resistance and resistance genes in bacteria that contaminate retail meats.

Background Local data from the Asella Teaching and Referral Hospital in the town of Asella, Ethiopia reveal a high prevalence of extended-spectrum β-lactamase- (ESBL) producing Gram-negative bacteria (GNB) in clinical isolates. To investigate a possible route of transmission, we determined the proportions ESBL-producing GNB in isolates from flies caught in the hospital and in the town of Asella. Methods Flies were collected in August 2019 from the neonatal intensive care unit (NICU), the orthopedic ward, the hospital’s waste disposal area, and from a butchery situated 1.5 km from the hospital. After trapping, the flies were macerated and suspended in sterile normal saline. The suspensions were inoculated on MacConkey agar and incubated overnight. Species identification and antimicrobial susceptibility testing were performed using Vitek®-MS and VITEK® 2. Results In total, 103 bacterial isolates were obtained from 85 flies (NICU: 11 isolates from 20 flies, orthopedic ward: 10 isolates from 12 flies, waste disposal area: 37 isolates from 26 flies, butchery: 45 isolates from 27 flies). The proportions of ESBL-producing bacteria among isolates obtained from flies collected in the hospital compound were significantly higher (82%, 90%, and 57% in NICU, orthopedic ward and waste disposal area, respectively) compared to flies collected outside of the hospital compound (2% (@1/45) in the butchery) (p ≤ 0.001). The proportion of ESBL was 67% (6/9) among Raoultella spp. 67% (4/6) among Kluyvera spp., 56% (5/9) among Enterobacter spp., 50% (5/10) among E. coli, and 44% (8/18) among Klebsiella spp.. Of the 40 ESBL-genes detected, 85% were CTX-M-like, 83% TEM-like, 23% SHV-like, and 2% CTX-M-2-like. ESBL-producing bacteria showed higher rates of resistance against ciprofloxacin (66% vs. 5%), gentamicin (68% vs. 3%), piperacillin-tazobactam (78% vs. 5%), and trimethoprim-sulfamethoxazole (88% vs. 16%), compared to non-ESBL-producing bacteria. Conclusion A high proportion of ESBL was identified in isolates from flies caught in the hospital compound compared with isolates of flies collected at a distance of 1.5 km from the hospital. Flies can be potential vectors for transmission of multidrug-resistant (MDR) bacteria within hospitals. Further studies are needed to determine the source of MDR colonization in flies and possible impact of MDR for nosocomial infections.

Klebsiella spp. are important opportunistic pathogens commonly defined as environmental clinical mastitis agents. Despite Klebsiella mastitis being clinically impairing in cows and costly to the industry, only a few studies describe Klebsiella isolated from mastitis cases. The aim of this work was to characterize species of Klebsiella involved in clinical mastitis cases in Canada. Klebsiella isolated from clinical mastitis cases (n = 53) were identified to the species level using a biochemical test panel and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The rpoB gene sequence was used as the gold standard method and identified Klebsiella pneumoniae (n = 40), Klebsiella oxytoca (n = 9), Raoultella ornithinolytica (n = 2), and Raoultella planticola (n = 2). Raoultella, a genus closely related to Klebsiella, was also accurately identified using mass spectrometry but not via biochemical testing. Using the disc diffusion technique, 31 (58%) isolates were found to be susceptible to all antimicrobials tested (n = 18). The remaining 22 (42%) isolates were resistant to 1 or more of the following antimicrobials: kanamycin (2%), streptomycin (38%), spectinomycin (13%), sulfisoxazole (13%), and tetracycline (19%). The following antimicrobial resistance genes were identified: tetA, tetB, sul1, strA/strB, and aadA. Random amplified polymorphic DNA revealed the majority of our isolates as unrelated and having different patterns, indicating environmental contamination as the primary source of infection. All isolates were shown to be biofilm producers. In conclusion, although antimicrobial resistance was low for both Klebsiella and Raoultella species, genetically related Klebsiella spp. isolates appeared to be more resistant.

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.

Background and Aim: Raoultella ornithinolytica is one of the emerging gram-negative bacteria, which associated with foodborne illness. Researches affirmed that distinguish between R. ornithinolytica and Klebsiella oxytoca are difficult, as they are phylogenetic related. The evolution of multidrug resistance of Raoultella strains gained more concern for recognition of the pathogen which supports in controlling the disease and minify its threat. This study sought to find a reliable tool for the identification of Raoultella ornithinolytica, isolated from chicken product samples, and assessed the resistance profile of R. ornithinolytica using antibiogram sensitivity tests. Materials and Methods: Forty samples of chicken products were collected between January and September 2019 from different markets in Alexandria Governorate, Egypt. The products included nuggets, strips, burgers, luncheon meats, pane, frankfurters, and minced chicken meat. The samples were transferred to the Reference Laboratory. The samples were subjected to isolation, biochemical reaction testing, phenotypic system analytical profile index (API) E20, and a detection of antimicrobial susceptibility test. Phenotypic identification was confirmed through matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results: Thirty-three bacterial isolates (82.50%) out of 40 samples were isolated into pure cultures from the chicken samples. Three isolates (9.09%) were positive for R. ornithinolytica, while 30 isolates (90.91%) exhibited growth characters for different pathogens (Escherichia coli, Enterobacter aerogenes, Proteus vulgaris, R. ornithinolytica, and Klebsiella pneumoniae). The isolates of R. ornithinolytica were resistant to five types of antibiotics and sensitive to two types of antibiotics. Conclusion: This study reported the first case of R. ornithinolytica found in chicken products in Egypt. Phenotypic system API 20E and MALDI-TOF MS were found to be reliable tools for confirming the diagnosis of R. ornithinolytica. As it provides rapid identification with high sensitivity and specificity for R. ornithinolytica, which often do not require a molecular procedure for confirmation.

The spread of antibiotic resistant organisms and those producing extended spectrum -lactamases (ESBL) has become a health care problem worldwide in communities and hospitals, as it leads to more complicated infections, longer duration of treatment, and increases in patient mortality. In the present study, we analyzed 226 clinical samples in order to assess the spread of ESBL-producing Enterobacteriaceae. 196 Enterobacteriaceae were identified and classified as members of the genera Pantoea, Klebsiella, Escherichia, Enterobacter, Serratia, Proteus, Citrobacter, and Raoultella. The results of susceptibility testing of isolated strains to 19 antibiotics showed that the most part of the isolates were highly resistant (p.0.01) to the tested -lactams: penicillins and penicillin like antibiotics (amoxicillin, ticarcillin and amoxicillin-clavulanic acid), first-generation cephalosporins (cephalexin), and second generation cephalosporins (cefoxitin). 60.20% of the Enterobacteriaceae isolates were multi-drug resistant (MDR) strains. Resistant isolates to third generation cephalosporins were tested for ESBL by tree methods, concluding its presence in 29.59% of the isolates by double-disk synergy test, 27.55% by the disk approximation method and by 31.63% double-disk test. High levels of MDR strains and ESBL- producing Enterobacteriaceae in our study suggest the need for applying specific infection control measures, and rational antibiotic use to reduce the selection pressure and prevent dissemination of resistant bacteria.

A 20 year-old female at 27-week gestation was admitted for threatened preterm delivery. Following an initially unremarkable hospital course for 12 days, the patient developed fever, chills, generalized malaise, abdominal pain, and diffuse myalgias on day 13 of hospitalization. Raoultella species was isolated from blood cultures on day 16 of hospitalization. The patient’s condition improved within 24 hours of symptom onset, prior to antibiotic initiation, and a premature, viable male infant at 29 weeks and 6 days of gestation was delivered via caesarean section four days later due to breech presentation in the setting of preterm labor. Here, we present the first case of a Raoultella species infection in a gravid female reported in the literature.

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.

Raoultella genus consists of Gram-negative, aerobic, encapsulated and non-motile rods. The name of the genus derives from the name of the French bacteriologist Raoul. Currently, four species belong to the genus: R. planticola, R. ornithinolytica, R. terrigena and R. electrica. The standard biochemical test used to identify Raoultella genus should be supplemented with additional tests, because of the close relationship between the genera Raoultella and Klebsiella. In 2001 Klebsiella planticola, K. ornithinolytica and K. terrigena were re-classified to new genus Raoultella. Re-classification was based on 16S rRNA sequence and rpoB, gyrA and gyrB genes. An alternative to phenotypic identification may be mass spectrometry or genetic methods (16s rRNA). These bacteria are commonly associated with natural environments (plants, water, soil). Raoultella spp. rods are not a highly virulent pathogen. Their virulence factors include polysaccharide capsule, fimbriae, siderophores, toxins and ability to form a biofilm. It has been shown that Raoultella spp. may colonize the gastrointestinal and upper respiratory tract in humans and cause cholangitis and lung infections. The literature also includes works on the antimicrobial activity of Raoultella rods and the possibility of using them in the environment protection. This review summarizes the current knowledge of Raoultella species identification, virulence and the possibility of using them in the protection of the environment.

Two highly tellurite-resistant bacteria were isolated from wastewater. Both bacteria could perform tellurite reduction under an initial pH of 5–9, temperature of 20–37 °C, and salinity conditions lower than 5%. The maximum reduction rate of strain WYA (Vmax = 20.45 μMh−1) was much higher than that of strain WYS (Vmax = 11.49 μMh−1). Both bacteria produced tellurium nanorods that were accumulated intracellularly or extracellularly. Strain WYA is a new strain belonging to the Raoultella genus, whereas strain WYS belongs to the Escherichia genus. This study indicated that both these bacteria are potential microorganisms for green synthesis of tellurium nanorods, which have a wide application in environmental remediation and the nanotechnology industry.

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.

Coliform bacteria in foods are enumerated at food processing plants and are used as sanitary and quality indicators. To detect coliform bacteria rapidly, seven Lateral Flow Test Strips (LFTSs) that can detect the genera Aeromonas , Citrobacter , Enterobacter , Hafnia , Klebsiella/Raoultella, Pantoea and Serratia were developed. For 55 tested food isolates, the detection rate of each individual LFTS assay was only 38% to 76%, but the detection rate of the 7 combined assays was 100%. For 38 culture collection strains, including clinical isolates, each individual LFTS assay had a detection rate of only 18% to 76%, but the 7 assays in combination had a detection rate of 89%. A feasibility study conducted on 20 types of meat (beef, chicken and pork) indicated that the LFTS assays detected coliform bacteria from 3 types of meat without incubation and from all other meats after 8 h of incubation. LFTS assays showed a positive signal when the meat was spoiled by more than 4.9 log10 (cfu/g) coliform bacteria. A longer incubation time led to increased bacterial counts , more positive LFTSs (1.8 at 8 h and 4.6 at 24 h) and a greater maximal signal intensity (1, 366 at 8 h and 2, 678 at 24 h). Thus, LFTSs of coliform bacteria have great potential for the rapid determination of food freshness as well as food sanitation status.

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.

Urban wastewater treatment plants (UWTPs) are considered hot spots for the accumulation and transfer of antibiotic resistant bacteria and their genes. We investigated the prevalence, diversity, and genomic localization of β-lactamase resistance genes in wastewater from different parts of an UWTP, such as raw wastewater, wastewater from biological reactor, and treated wastewater, collected from the UWTP of Warsaw, Poland. In this study, we focused on gram-negative rods, mainly Enterobacteriaceae, and used Multiplex PCR to identify various β-lactamase resistance genes (bla). Susceptibility to a number of antibiotics and genomic localization of β-lactamase resistance genes were then determined using disc-diffusion and Southern hybridization methods, respectively. No differences in the frequency of different types of bla genes between the sampling points were discerned. Three new variants of β-lactamase genes (blaCMY-157, blaMOX-13, and blaFOX-15) were identified. Four bla genes (blaTEM-12, blaTEM-30, blaTEM-47/68, blaACT) that had never been found in UWTPs were identified in this study. Nine of the identified bla genes had been found in the same environment previously. The blaFOX-15 variant on a Kluyvera sp. plasmid and blaGES type on Raoultella spp. plasmids were observed for the first time in these genera. There was a decrease in the number of multidrug resistant strains in the effluent compared to the influent. Finally, a significantly higher number of cefotaxime and carbapenem unsusceptible strains were detected in the influent than in the effluent. The results strongly support the hypothesis of UWTPs as a hot spot for antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) accumulation and indicate that β-lactamase genes are widely disseminated among gram-negative rods isolated from this environment.

Elevated levels of arsenate can occur in the environment due to processes such as mining activities, and microbes must utilize various detoxification mechanisms to adapt to the associated pressure....

The removal of diclofenac, which is a widely used non-steroidal anti-inflammatory drug and a dangerous environmental contaminant of surface water, was studied. Its complete degradation by Raoultella sp. KDF8 to primary metabolic products was described with individual metabolites identified by mass spectrometry. The Raoultella strain KDF8 was cultivated with unlabelled and 13C6-labelled diclofenac. A total of 32 compounds were detected as intermediates in diclofenac metabolism by high resolution tandem mass spectrometry. Furthermore, proteomic analysis showed that the presence of diclofenac resulted in the upregulation of 24 enzymes associated with the benzoate, catechol, protocatechuate and ketoadipate pathways. The presence of genes encoding specific enzymes, such as catechol 1,2-dioxygenase, protocatechuate 3,4-dioxygenase and quercetin 2,3-dioxygenase, has been verified by sequence analysis of PCR products. The description of diclofenac metabolism by strain KDF8 provides a detailed view of the degradation of xenobiotic aromatic compounds by microorganisms in general.

Raoultella Planticola is a gram-negative, non-motile, anaerobic bacterium of the Genus Raoultella most commonly found in water, soil, and aquatic environments1 Originally classified as a member of the genus Klebsiella, it was reclassified as Raoultella spp. in 2001 based on 16S rRNA and rpoB gene sequencing.1 This bacterium is a rare source of infection in humans; current literature provides few serious cases. The first Raoultella invasive human infection was found in 1984 in a patient with sepsis.2 Most reported cases since then have been associated with bacteremia. We present a case of R. Planticola in a patient with UTI, as well as a review of prior reported cases of R. Planticola associated with cystitis. There is weak evidence for susceptibility to R. Planticola cystitis; risk factors include immunosuppression, invasive procedures, and contaminated equipment3, 4, 5, Table 2. Table 2 References.

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).

Klebsiella spp. are a major cause of both nosocomial and community acquired infections, with K. pneumoniae being responsible for most human infections. Although Klebsiella spp. are present in a variety of environments, their distribution in the sea and the associated antibiotic resistance is largely unknown. In order to examine prevalence of K. pneumoniae and related species in the marine environment, we sampled 476 batches of marine bivalve molluscs collected along the Norwegian coast. From these samples, K. pneumoniae (n = 78), K. oxytoca (n = 41), K. variicola (n = 33), K. aerogenes (n = 1), Raoultella ornithinolytica (n = 38) and R. planticola (n = 13) were isolated. The number of positive samples increased with higher levels of faecal contamination. We found low prevalence of acquired resistance in all isolates, with seven K. pneumoniae isolates showing resistance to more than one antibiotic class. The complete genome sequence of cefotaxime-resistant K. pneumoniae sensu stricto isolate 2016-1400 was obtained using Oxford Nanopore and Illumina MiSeq based sequencing. The 2016-1400 genome had two contigs, one chromosome of 5,088,943 bp and one plasmid of 191,744 bp and belonged to ST1035. The &beta, lactamase genes blaCTX-M-3 and blaTEM-1, as well as the heavy metal resistance genes pco, ars and sil were carried on a plasmid highly similar to one found in K. pneumoniae strain C17KP0055 from South-Korea recovered from a blood stream infection. The present study demonstrates that K. pneumoniae are prevalent in the coastal marine environment and that bivalve molluscs may act as a potential reservoir of extended spectrum &beta, lactamase (ESBL)-producing K. pneumoniae that may be transmitted through the food chain.

Raoultella planticola, a gram-negative bacterium, first emerged in late 1900s as Klebsiella planticola. It was later classified as Raoultella genus in 2001. This nonmotile rod is usually found in soil and aquatic environment. There are two known species of Raoultella: R. planticola and R. ornithinolytica. They are responsible for numerous yet rare infections including cystitis, pneumonia, and bacteremia. To date, only one case of joint or bone infection due to R. planticola has been reported. The infection is eradicated after arthroscopic lavage and antibiotic therapy with fluoroquinolones. We present the first case of septic arthritis due to R. planticola involving a native knee joint following synovectomy during arthroscopy.

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.

Background: Raoultella is a Gram-negative bacteria, which commonly occur in the natural environment such as water, soil and on plants. In recent years, Raoultella spp. gained more interest. There is also an increasing number of publications describing mainly clinical cases involving these bacteria. Identification of Raoultella spp. is difficult due to a phylogenetic relationship with Klebsiella spp. Purpose: Available biochemical tests do not always allow for their identification to species. Thus, the aim of this study was to evaluate selected methods of identification of Raoultella spp. and their differentiation from genus Klebsiella. Materials and Methods: In this evaluation three methods were used such as manual test ID32E (bioMérieux), automatic test VITEK2 Compact (bioMérieux) and matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) method (Bruker). Results: Good identification of the species was obtained for 81.4% of the strains in the ID32E test, 93.3% in VITEK2 Compact test, and 97.4% in MALDI-TOF MS method, respectively. Conclusion: It was established that MALDI-TOF MS method is reliable in identifying genus Raoultella.

Bacteria of the genera Klebsiella and Raoultella, which are present in foods and the natural environment, are associated with health hazards in humans. In the present study, two types of strips-based methods were developed to detect these bacteria simply and quickly. One method used lateral-flow test strips (LFTS) in combination with anti-Klebsiella antibodies labeled with palladium nanoparticles that bind to target bacteria, allowing their visualization. In the other, the antibodies were immobilized on nitrocellulose membranes, and urease activity was measured using an ion sensitive field effect transistor pH sensor. Testing of a combination of these two methods on 72 cultured strains successfully identified all 25 strains of Klebsiella pneumoniae, Klebsiella oxytoca and Raoultella ornithinolytica. This approach also accurately identified 76 of 77 (99%) strains isolated from meats and pastries. When combined with preculture, this method was accurate in identifying 19 of 26 (73%) target bacteria in food. These results suggest that the novel combination of strip-based assays may be effective for the on-site monitoring of food production plants, and thereby enhance food safety.

In this study, nine microbial strains with oil-degrading function were isolated from oil-contaminated soil near four oil wells in the 0.6 km2 area of the Jinnan Oil Field, Huaian, Jiangsu, China (32 57' N, 119 02' E). Based on morphological observations, physiological and biochemical responses, and molecular identification, we confirmed that the nine strains belong to five genera: Pseudomonas, Raoultella, Lysinibacillus, Escherichia, and Klebsiella. The degradation capacity of the nine strains in crude oil medium ranged from 2.43% to 32.63% with an average rate of 21.64%. Further plasmid and chromosome analyses on the oil-degrading genes of the nine microbial strains were conducted. The GST gene (degradable polycyclic aromatics) was widely distributed in the chromosomes of eight strains and the plasmids of three strains. The alkB gene was detected in the chromosomes of seven strains and the plasmids of two strains. The LmPH gene (degradable phenolic substances) was only detected in the chromosome of one strain. Molecular biological analyses on the isolation, identification, and degradation characteristics of oil-degrading microbial strains provide a foundation for microbial remediation in oil-polluted environments.

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.

Raoultella electrica, a Gram-negative, non-spore-forming, rod-shaped facultative anaerobe, was identified during a regular investigation of bacterial contamination in table eggs in the winter season. A total of 165 hen's eggs were collected in the winter season from 15 different areas of the city of Jaipur, India. Gram-negative Enterobacteriales were isolated on selective and differential media by the conventional plate method and were further identified by several biochemical tests and 16S rRNA gene sequencing. Commonly prescribed antibiotics for enteric infection were used for antibiotic susceptibility testing. For isolated microorganisms, different resistance patterns were found against the different antibiotics used (p

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).

This study deals with 16S rDNA identified bacteria, Lysinibacillus sphaericus (71A), Raoultella planticola (VIP), and Streptomyces pluricolorescens (EM4) capable of precipitating CaCO3 through a nitrate reduction aerobically and anaerobically. The produced CaCO3 crystals were analyzed using XRD, EDX, and SEM. The results showed that the carbonatogenic bacteria served as nucleation sites for CaCO3 precipitation with distinct variation in polymorph and morphology; reflecting strain-specific property. Notably, the amount of precipitated CaCO3 recorded 3.27 (aerobic), 1.55 (anaerobic), 4.15 (aerobic), 3.75 (aerobic) and 1.87 (anaerobic) g/100 mL of strains 71A, EM4 and VIP, respectively, for 240 h of incubation. The study of changes in media chemistry during carbonatogenesis process revealed positive correlation between bacterial growth, nitrate reductase activity, pH, EC, amount of deposited CaCO3 and NO3− consumption. Therefore, the applications of these bacterial strains, which employed for the first time in carbonatogenesis process, are promising in the environmental, biomedical and civil engineering fields.

We report the characterization of six carbapenem-resistant Raoultella spp. (CRRS) in our hospital and a genomic analysis of 58 publicly available isolates. CRRS isolates are sporadically identified around the world, and different transposons carrying carbapenemases were the resistant mechanisms. Mobile genetic elements play an important role in acquiring antibiotic resistance genes from the hospital., We report the characterization of six carbapenem-resistant Raoultella spp. (CRRS) in our hospital and a genomic analysis of 58 publicly available isolates. CRRS isolates are sporadically identified around the world, and different transposons carrying carbapenemases were the resistant mechanisms. Mobile genetic elements play an important role in acquiring antibiotic resistance genes from the hospital. An improved understanding of these transposon and targeted control measures will be very valuable to prevent CRRS dissemination.

This paper analyzes the impact of saponins from English ivy leaves on the properties of environmental bacterial strains and hydrocarbon degradation ability. For this purpose, two bacterial strains, Raoultella ornitinolytica M03 and Acinetobacter calcoaceticus M1B, have been used in toluene, 4-chlorotoluene, and &alpha, &alpha, trifluorotoluene biodegradation supported by Hedera helix extract. Moreover, theeffects of ivy exposition on cell properties and extract toxicity were investigated. The extract was found to cause minor differences in cell surface hydrophobicity, membrane permeability, and Zeta potential, although it adhered to the cell surface. Acinetobacter calcoaceticus M1B was more affected by the ivy extract, thus, the cells were more metabolically active and degraded saponins at greater amounts. Although the extract influenced positively the cells&rsquo, viability in the presence of hydrocarbons, it could have been used by the bacteria as a carbon source, thus slowing down hydrocarbon degradation. These results show that the use of ivy saponins for hydrocarbon remediation is environmentally acceptable but should be carefully analyzed to assess the efficiency of the selected saponins-rich extract in combination with selected bacterial strains.

The endophytes were separated from Xinjiang carrots using gradient dilution method. There were 59 endophytes obtained by the separation and purification method, including 49 strains of endophytic bacteria, 10 strains of endophytic fungi. These endophytes incorporated 10 strains isolated from the head skin, 18 strains separated from central skin, 13 strains segregated from the tail skin, 9 strains derived from shallow meat, and 9 strains did from deep meat, which of the most number belonged to 30.5% of central skin. Gram staining experiment of endophytic bacteria authenticated 43 strains of gram-positive bacterium and 6 strains of gram-negative bacterium. Through observing the strain of morphological characteristics under a microscope, and identification of physiology and biochemistry as well as molecular biology, some strains were classified, for example 3 strains of Enterobacter cloacae strains, 5 strains of Enterobacter ludwigii strain, 1 strains of Pantoea dispersa strain, 2 strains of Pantoea, 1 strains of Enterobacter, 1 strains of Raoultella, 1 strains of Enterobacteriales bacterium, 4 strains of Enterobacter asburiae strain, 3 strains of Enterobacter aerogenes strain, 2 strains of Pantoea vagans partial, 1 strains of Pantoea agglomerans strain, 1 strains of Kluyvera cryocrescens, 1 strains of Enterobacter asburiae, 1 strains of Enterobacter cloacae subsp, 1 strains of Enterobacter mori strain. 1 strains of Aspergillus niger strain. 1 strains of Ciadosporium. 1 strains of Corynespora torulosa. Among these strains, enterobacterium was the largest, accounting for 17.9% of the total number.

This study examined the effects of pH, temperature, NaCl concentration and heat resistances of Raoultella spp. isolated from a seafood processing plant in Thailand. The ability to resist to cleaning and sanitizing agents were also investigated. The effect of growth medium (Tryptic Soy Broth) adjusted to various pHs (3, 4, 5, 6, 7, 8, 9, 10) revealed Raoultella ornithinolytica and R. terrigena were able to grow well at pH 6–9, slow growth at 4 and 10 but not at strong acidic pH 3. Growth at different temperature was done (4, 15, 20, 37, 40°C) and found optimum growth was ranged at 15–37°C. Sodium chloride concentrations test was at 1%, 1.5%, 2.5%, 3.5%, 4.5%, 5.5% and 6.5% revealed the optimal growth at 1–4.5% NaCl. D-values of both species gave similar result as 0.66–0.79 min at 57°C, with Z-value 4.2–4.5°C. When cell suspension and biofilm were exposed to cleaning agent (sodium hydroxide, lauryl dimethylamine oxide, and sodium hypochlorite), and three sanitizers, namely, sodium hypochlorite (NaClO), hydrogen peroxide (H2O2), and ozonated water. NaClO was able to eliminate single biofilm of Raoultella spp. at 50 ppm in 5 min while ozone had less efficacy to kill biofilm cells. H2O2 at 1% and 2% succeeded to eliminate biofilm. This finding properties of Raoultella spp. will be useful for designing strategies to prevent and control contamination these species regarding seafood plant sanitation.

Leachates generated by solid waste dumpsites could be a factor in the development of antibiotic resistance in environmental bacteria. In Nigeria, there is a dearth of information on the contribution of leachates from dumpsite to the ever-increasing trend of antibiotic resistance. A total of 250 cefotaxime-resistant bacteria recovered from dumpsite leachate was screened for extended spectrum β-lactamase (ESBL) production using the double disc synergy test and 41 were ESBL producers. The ESBL producers belonged to four genera and were identified as Escherichia (20), Citrobacter (13), Enterobacter (6) and Raoultella (2). Antibiotic susceptibility testing was carried out using disk diffusion method, while detection of extended spectrum and AmpC β-lactamase genes was done using Real-Time PCR. All the ESBL- producing bacteria were multidrug resistant, with 100% resistance observed to cefotaxime, cefpodoxime, tetracycline, sulfonamide, ciprofloxacin, ampicillin, ertapenem and imipenem, while 81.6% and 63.1% of the ESBL producers showed resistance to ceftazidime and amoxicillin-clavulanate respectively. blaCTX-M-1 and blaCTX-M-9 groups of CTX-M β-lactamases were detected in 33 (80.5%) of the isolates, while 26 (63.4%) harboured the blaCTX-M-2, blaCTX-M-8 and blaCTX-M-25 groups. blaTEM was detected in 31 (75.6%) of the ESBL producers, while blaSHV was detected in 13 (31.7%). One isolate (E. coli AW-32) carried blaCMY-1 gene. None of the isolates carried blaKPC, blaNDM-1 and blaampC genes, while seven isolates were devoid of any gene. There was co-occurrence of resistance genes in thirty of the isolates. This study has revealed that dumpsite leachates could be important reservoirs of multidrug resistant Enterobacteriaceae harbouring extended spectrum and AmpC β-lactamases genes.

Bioconversion of biodiesel-derived waste glycerol into high-value products is proposed as a solution to improve economic viability of biorefineries. Several microorganisms are able to metabolize glycerol into 2,3-butanediol (2,3-BD), a promising bulk chemical with wide applications: solvent, fuel additive, and feedstock for synthetic rubber production, among them. In the present work, a wide screening of microorganisms present both into the waste water treatment system in a biodiesel industry and in culture collections was carried out in order to evaluate their potential as new 2,3-BD producer biocatalysts. Two microorganisms for 2,3-BD production from glycerol as sole carbon source have been selected, namely Raoultella planticola CECT 843 and Raoultella terrigena CECT 4519. Raoultella strains belong to the non‐pathogenic bacteria class (biosafety level 1). This genus has not been previously described as biocatalyst for the studied process. The influence of operational temperature, organic acid addition, and yeast extract concentration on 2,3-BD yield and productivity have been studied through Taguchi design methodology as well as initial glycerol concentration. Based on these results, the feasibility of the process employing pure glycerol and different samples of raw glycerol has been demonstrated.

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.

Recently, algicidal bacteria have attracted attention as possible agents for the inhibition of algal water blooms. In this study, an aerobic denitrifying bacterium, R11, with high algicidal activity against the toxic Microcystis aeruginosa was isolated from lake sediments. Based on its physiological characteristics and 16S rRNA gene sequence, it was identified as Raoultella, indicating that the bacterium R11 has a good denitrifying ability at 30 °C and can reduce the concentration of nitrate-N completely within 36 h. Additionally, different algicidal characteristics against Microcystis aeruginosa were tested. The results showed that the initial bacterial cell density and algal cell densities strongly influence the removal rates of chlorophyll a. Algicidal activity increased with an increase in the bacterial cell density. With densities of bacterial culture at over 2.4 × 105 cell/mL, algicidal activity of up to 80% was obtained in 4 days. We have demonstrated that, with the low initial algal cell density (OD680 less than 0.220), the algicidal activity reached was higher than 90% after 6 days.

This study sought to investigate and compare bacterial contamination levels at six different sites along the Diep and Plankenburg river systems in the Western Cape, South Africa. Surface water and sediment samples were collected monthly from the six selected sampling sites along both river courses between January 2014 and December 2014 and were evaluated for bacterial contaminants. Microbial isolation, characterisation and identification were done using conventional techniques (serial dilution, Gram staining, and biochemical testing) and molecular identification techniques (polymerase chain reaction and DNA sequencing). A total of 19 bacterial isolates belonging to the genera Raoultella, Bacillus, Pseudomonas, Klebsiella, Escherichia, Enterobacter, Exiguobacterium, Acinetobacter, Serratia, Aeromonas, Staphylococcus and Citrobacter were isolated from the surface water and sediment samples at the end of the survey. Higher microbial load was obtained from sediment samples compared to surface water samples. Seasonal variation was also observed in terms of microbial counts. Higher microbial counts were obtained during summer sampling time compared to winter sampling time. The most contaminated site was located on Plankenburg River with average bacterial counts ranging between 3.1 × 105–6.9 × 108 CFU/ml and 3.9 × 106–2.88 × 109 CFU/ml from surface water and sediment, respectively, recorded at this site during winter and summer. Although lower microbial counts were recorded along the Diep River course, most of the bacterial counts recorded along both rivers exceeded the acceptable maximum limits for river water.

An incident of food-borne poisoning causing illness in 37 victims due to ingestion of fried fish sticks occurred in September 2014, in Tainan city, southern Taiwan. Leftovers of the victims' fried fish sticks and 16 other raw fish stick samples from retail stores were collected and tested to determine the occurrence of histamine and histamine-forming bacteria. Two suspected fried fish samples contained 86.6 mg/100 g and 235.0 mg/100 g histamine; levels that are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fried fish samples, this food-borne poisoning was strongly suspected to be caused by histamine intoxication. Moreover, the fish species of suspected samples was identified as milkfish ( Chanos chanos ), using polymerase chain reaction direct sequence analysis. In addition, four of the 16 commercial raw milkfish stick samples (25%) had histamine levels greater than the US Food & Drug Administration guideline of 5.0 mg/100 g for scombroid fish and/or products. Ten histamine-producing bacterial strains, capable of producing 373–1261 ppm of histamine in trypticase soy broth supplemented with 1.0% L-histidine, were identified as Enterobacter aerogenes (4 strains), Enterobacter cloacae (1 strain), Morganella morganii (2 strains), Serratia marcescens (1 strain), Hafnia alvei (1 strain), and Raoultella orithinolytica (1 strain), by 16S ribosomal DNA sequencing with polymerase chain reaction amplification.